Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/03/15
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
926 AM PST SUN MAR 1 2015
.SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS
OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK
WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED
SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND
ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE
NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY
THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO
MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH
SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND
SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY
THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS
IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE
ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN
ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF
THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER
THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST
HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND
LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE
GENERAL T-STORM OUTLOOK TODAY AS WELL.
SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A
FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY
AIRMASS OVER THE REGION.
NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS
ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING
OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD
AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE
SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS
ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS
OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT
MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER
TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW.
ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE
BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING
TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR
UNTIL MIDDLE OF THE MONTH.
&&
.AVIATION...AS OF 9:25 AM PST SUNDAY...VFR CONDITIONS AT ALL
TERMINALS THIS MORNING AND THIS WILL BE THE CASE FOR MUCH OF THE
DAY. SOME OF THE MODEL GUIDANCE SUGGESTS A LOW LEVEL CLOUD DECK
TONIGHT...BUT NOT TOTALLY BUYING THIS AS ANOTHER LOW APPROACHES
FROM THE NORTH.
VICINITY OF KSFO...FORECASTING VFR THROUGH THE PERIOD. HIGH CIGS
TOMORROW AS ANOTHER LOW SLIDES THROUGH. WILL NOT INTRODUCE ANY
PRECIP AS IT WILL BE SCT AND BEST CHC SOUTH OF SFO/OAK.
CONFIDENCE IS HIGH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH THE PERIOD. SCT CU DECK
POSS THIS AFTERNOON.
CONFIDENCE IS HIGH.
&&
.MARINE...AS OF 09:22 AM PST SUNDAY...LIGHT TO MODERATE WINDS WILL
PREVAIL OVER THE BAY AREA WATERS TODAY AS A STORM SYSTEM EXITS TO
THE SOUTH. ANOTHER STORM SYSTEM WILL MOVER OVER THE REGION ON
MONDAY WITH ANOTHER CHANCE FOR SHOWERS...THUNDERSTORMS AND GUSTY
WINDS. WINDS WILL BE STRONGEST NORTH OF PIGEON POINT OVER THE
OUTER WATERS. LIGHT WINDS AND GENTLE SEAS DEVELOP ON TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: MM
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
845 AM PST SUN MAR 1 2015
.SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS
OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK
WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED
SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND
ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE
NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY
THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO
MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH
SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND
SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY
THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS
IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE
ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN
ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF
THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER
THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST
HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND
LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE
GENERAL T-STORM OUTLOOK TODAY AS WELL.
SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A
FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY
AIRMASS OVER THE REGION.
NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS
ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING
OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD
AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE
SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS
ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS
OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT
MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER
TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW.
ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE
BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING
TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR
UNTIL MIDDLE OF THE MONTH.
&&
.AVIATION...AS OF 4:04 AM PST SUNDAY...THE CURRENT IR SATELLITE
IMAGE IS SHOWING YESTERDAYS STORM SYSTEM NOW CENTERED JUST OFF OF
POINT ARGUELLO. THIS IS PLACING THE SAN FRANCISCO AND MONTEREY BAY
AREA IN A ZONE OF OFFSHORE FLOW. THIS OFFSHORE FLOW WILL PREVENT
STRATUS FROM FORMING TODAY. HOWEVER...RESIDUAL MOISTURE FROM
YESTERDAYS STORM SYSTEM WILL PROMOTE THE FORMATION OF CUMULUS
CLOUDS THIS AFTERNOON.
VICINITY OF KSFO...VFR IS ANTICIPATED TO PREVAIL TODAY WITH MVFR
CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED TO
GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON.
CONFIDENCE IS HIGH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS ANTICIPATED TO PREVAIL TODAY WITH
MVFR CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED
TO GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON.
CONFIDENCE IS HIGH.
&&
.MARINE...AS OF 2:42 AM PST SUNDAY...A WEAK SURFACE PRESSURE
GRADIENT WILL PROMOTE GENERALLY LIGHT WINDS ACROSS A MAJORITY OF
THE COASTAL WATERS TODAY. A STORM SYSTEM WILL SLIDE OVER THE
COASTAL WATERS ON MONDAY BRINGING ANOTHER ROUND OF SHOWERS AND
POTENTIAL THUNDERSTORMS TO THE AREA. THIS FAST MOVING SYSTEM WILL
BE OUT OF THE AREA TUESDAY LEAVING BEHIND LIGHT WINDS AND GENTLE
SEAS FOR THE REMAINDER OF THE WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: LARRY
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
1058 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM MST SUN MAR 1 2015
RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS
MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS.
THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS
VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT
THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME
FLURRIES.
AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR
LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO
MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND
TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE
CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL
INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL
STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING
BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED
TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE
STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO
VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS.
THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN
PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN
THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST
OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL
POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS
AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25
CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS
HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN
SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR
THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS
MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS
AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR
EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES
AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE
FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING...
BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN
OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE
LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP
SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE
A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING
COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR
A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES...
THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN
IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE
SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT
FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM MST SUN MAR 1 2015
...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND
WARMER WEATHER THEREAFTER...
MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS
THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A
STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS
SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER
PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS
ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL
OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY
MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON
AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING
MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS.
CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH
THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY
MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL
EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE
SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST
TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW
ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL
BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY
CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND
KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S.
TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS
THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY
AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES
AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT
ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN
COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED
BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME
SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT
TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT
AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS
ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES
WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS
AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST
FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON
AND EVENING.
THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL
RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN.
LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN
THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF
STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT
SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT
CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1048 AM MST SUN MAR 1 2015
KCOS...VFR TO INTERMITTENT MVFR DUE TO PATCHY LIGHT GROUND FOG
THROUGH 20-21Z...THEN TRENDING TOWARDS IFR AS SNOW MOVES BACK INTO
THE AREA. SHOULD REMAIN IFR THROUGH 12-14Z DUE TO SNOW...FOG AND
LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A FEW
MORE HOURS MONDAY MORNING.
KPUB...VFR UNTIL 21-23Z THEN IFR-MVFR CONDITIONS EXPECTED AS SNOW
MOVES IN. SHOULD REMAIN MVFR-IFR THROUGH 12-14Z DUE TO SNOW...FOG
AND LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A
FEW MORE HOURS MONDAY MORNING.
KALS...INTERMITTENT SNOW HAS MOVED BACK INTO THE AREA THIS
AFTN...AND WITH PATCHY FOG AND LOW CLOUDS WILL CONTINUE MVFR TO
IFR CONDITIONS OVER THE NEXT 24 HRS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061-
066-067-073-075.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065-
074.
BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1010 AM MST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1003 AM MST SUN MAR 1 2015
MINOR ADJUSTMENTS TO THE GRIDS THIS MORNING..I SLOWED THE TIMING
OF THE HIGHER POPS A BIT THIS AFTERNOON. OVERRUNNING MOISTURE WILL
PRODUCE JUST SOME LIGHT SNOW TODAY...OVERALL SLGT CHC IN THE URBAN
CORRIDOR...WITH CHC POPS NEAR THE FOOTHILLS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 346 AM MST SUN MAR 1 2015
THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT
AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE
CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE
WY BORDER WHERE OROGRAPHIC SNOWS HAVE BEEN OCCURRING OVER THE
HIGHER TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS
ACTIVITY HAS SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY
AND NWRN WELD COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END
AROUND 12Z EXCEPT IN THE MTNS.
BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS
THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE
EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE
MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS
THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW
ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE
GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN
FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER
DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST
POPS OVER SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR
HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE
FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S.
OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE
MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER
SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID
LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER
NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH
STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE
PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY
BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC
OF LIGHT SNOW OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM MST SUN MAR 1 2015
VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE
CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO
160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES
MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO
COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON
WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL
VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY
AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES
ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY
TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH-
SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN
MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME
AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY
WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE
IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE
MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY
NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE
PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON
AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY
THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY
EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO
MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY
NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS
MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS
ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS
BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING
HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD
GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER
DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH
GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW
IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN
FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED
THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY
DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL
FOUR DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1003 AM MST SUN MAR 1 2015
TREND OF IMPROVING CONDITIONS AT KDEN THE REMAINDER OF THE
MORNING...IFR NO LONGER EXPECTED BUT MAINLY MVFR CIG/VSBY
RESTRICTIONS AT TIMES THROUGH THE AFTN. BEST CHC OF SNOW LATE
THIS AFTN AND EVENING WILL STAY TO THE WEST AND SOUTH OF DIA NEAR
KAPA AND KBJC WITH ONLY LIGHT ACCUMULATIONS EXPECTED. WINDS WILL
BE LIGHT AND VARIABLE THIS MORNING AND THE MORE ELY BY THIS AFTN.
BY THIS EVENING WINDS WILL BECOME MORE SELY AND THEN SLY AFTER
MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...COOPER
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
414 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM MST SUN MAR 1 2015
RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS
MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS.
THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS
VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT
THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME
FLURRIES.
AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR
LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO
MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND
TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE
CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL
INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL
STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING
BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED
TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE
STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO
VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS.
THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN
PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN
THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST
OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL
POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS
AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25
CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS
HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN
SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR
THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS
MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS
AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR
EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES
AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE
FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING...
BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN
OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE
LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP
SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE
A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING
COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR
A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES...
THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN
IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE
SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT
FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM MST SUN MAR 1 2015
...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND
WARMER WEATHER THEREAFTER...
MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS
THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A
STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS
SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER
PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS
ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL
OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY
MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON
AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING
MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS.
CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH
THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY
MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL
EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE
SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST
TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW
ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL
BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY
CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND
KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S.
TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS
THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY
AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES
AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT
ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN
COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED
BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME
SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT
TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT
AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS
ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES
WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS
AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST
FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON
AND EVENING.
THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL
RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN.
LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN
THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF
STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT
SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT
CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 414 AM MST SUN MAR 1 2015
KCOS WL HAVE IFR OR MVFR CONDITIONS THRU ABOUT 16Z WITH LOW CLOUDS
AND FOG REMAINING IN THE AREA. VFR CONDITIONS ARE THEN EXPECTED
THRU ABOUT MID AFTERNOON. IN THE LATE AFTERNOON HOURS...SNOW IS
EXPECTED TO MOVE INTO THE AREA WHICH WL CONTINUE THRU 12Z MON AND
CONDITIONS WL AGAIN BECOME MVFR OR IFR. KPUB SHOULD SEE VFR
CONDITIONS THRU THE EARLY EVENING AND THEN SNOW IS EXPECTED TO
REDUCE VSBYS AND CIGS INTO THE MVFR OR IFR CATEGORY THRU THE NIGHT.
KALS WL GENERALLY HAVE VFR CONDITIONS...HOWEVER SOME FOG IN THE AREA
THIS MORNING WL BRING IFR CONDITIONS THRU ABOUT 16Z AND THERE WL BE
THE POSSIBILITY OF SNOW SHOWERS IN THE VCNTY TODAY AND TONIGHT WHICH
COULD CAUSE PERIODS OF MVFR OR IFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061-
066-067-073-075.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065-
074.
BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
356 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 346 AM MST SUN MAR 1 2015
THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT
AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE
CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE
WY BORDER WHERE OROGRPAHIC SNOWS HAVE BEEN OCCURRING OVER THE HIGHER
TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS ACTIVITY HAS
SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY AND NWRN WELD
COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END AROUND 12Z EXCEPT IN
THE MTNS.
BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS
THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE
EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE
MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS
THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW
ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE
GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN
FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER
DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST
POPS OVE SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR
HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE
FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S.
OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE
MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER
SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID
LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER
NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH
STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE
PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY
BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC
OF LIGHT SNOW OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM MST SUN MAR 1 2015
VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE
CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO
160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES
MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO
COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON
WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL
VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY
AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES
ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY
TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH-
SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN
MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME
AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY
WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE
IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE
MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY
NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE
PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON
AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY
THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY
EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO
MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY
NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS
MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS
ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS
BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING
HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD
GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER
DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH
GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW
IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN
FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED
THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY
DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL
FOUR DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 346 AM MST SUN MAR 1 2015
SATELLITE SHOWS STRATUS AND SOME FOG DEVELOPING TO THE WEST AND
NORTH OF DIA EARLY THIS MORNING AS A WK DENVER CYCLONE HAS
DEVELOPED. IF SFC WINDS AT DIA BECOME LIGHT NNW THEN FOG AND
STRATUS COULD DVLP IN THE NEXT FEW HOURS AND LINGER THRU AT LEAST
16Z. BY LATE MORNING EXPECT IFR CONDITIONS WHICH MAY LINGER THRU
THE AFTN HOURS. AS FOR SNOW APPEARS BEST CHC LATE THIS AFTN AND
EVENING WILL STAY TO THE WEST AND SOUTH OF DIA WITH ONLY LIGHT
ACCUMULATIONS EXPECTED. WINDS WILL BE LIGHT AND VARIABLE THIS
MORNING AND THE MORE ELY BY MIDDAY. BY THIS EVENING WINDS WILL
BECOME MORE SELY AND THEN SLY AFTER MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
426 PM EST SUN MAR 1 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL APPROACH FROM THE WEST...THEN PASS THROUGH
TONIGHT AS WEAK LOW PRESSURE DEVELOPS SOUTH OF LONG ISLAND.
HIGH PRESSURE WILL BRIEFLY BUILD IN MONDAY INTO MONDAY NIGHT...
THEN PASS TO THE EAST ON TUESDAY. LOW PRESSURE WILL TRACK WELL
NORTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY...WITH A WARM FRONT
LIFTING INTO THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT
WEDNESDAY AND A REINFORCING COLD FRONT WEDNESDAY NIGHT.
HIGH PRESSURE WILL THEN BUILD IN FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
BAND OF FRONTOGENETICALLY FORCED MODERATE TO HEAVY SNOW ACROSS
LONG ISLAND AND NYC METRO ATTM...WITH SNOWFALL RATES UP TO AN
INCH PER HOUR. PER HRRR THIS BAND SHOULD SHIFT MORE INTO LONG
ISLAND AND COASTAL CT OVER THE NEXT COUPLE OF HOURS...AND PERSIST
THERE INTO AT LEAST THE FIRST PART OF THIS EVENING. HAVE BUMPED UP
SNOWFALL TOTALS ESPECIALLY ACROSS SUFFOLK COUNTY AND AND COASTAL
SE CT. GIVEN THIS PLUS A SPOTTER REPORT OF 2 INCHES ON THE GROUND
IN WEST ISLIP...WILL ISSUE WINTER STORM WARNINGS FOR THOSE
AREAS...WHERE 5-7 INCHES OF ACCUMULATION IS EXPECTED.
ELSEWHERE EXPECT A SOLID ADVY EVENT...WITH 4-6 INCHES OF SNOW.
A SPOTTER FROM BROOKLYN REPORTED SLEET MIXING IN WITH THE
SNOW...WHICH CORRELATES WELL WITH RADAR DUAL-POL CC.
THIS TRANSITION SHOULD BE BRIEF...AND EXPECT PRECIP TO TRANSITION
BACK MORE TOWARD SNOW BEFORE A MORE DEFINITE TRANSITION LINE NOW
EXTENDING FROM TTN-WRI-ACY MOVES IN. THIS SHOULD MAKE IT TO NYC
METRO BY 00Z...THEN TO NEAR TEB-ISP BY LATE EVENING. AREAS SOUTH
OF THAT LINE SHOULD SEE A GLAZE TO A TENTH OF AN INCH OF ICE THIS
EVENING BEFORE PRECIP WINDS DOWN AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE APPROACHES FROM THE WEST ON MONDAY...THEN BUILDS
OVERHEAD ON TUESDAY. HIGHS ON MON WILL BE IN THE MID AND UPPER
30S...WITH A BRISK NW WINDS GUSTING TO 25-35 MPH. MUCH COLDER AIR
WILL FOLLOW FOR MON NIGHT...AND UNDERCUT MOS GUIDANCE BY 2-3 DEG
GIVEN DIMINISHING WINDS LATE AT NIGHT AND FRESH SNOW COVER...WITH
LOWS IN THE TEENS FOR NYC METRO AND LONG ISLAND...AND SINGLE
DIGITS FARTHER NORTH/WEST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS ARE IN DECENT AGREEMENT AT H5 THROUGH THE WEEK...ALTHOUGH
SLIGHT DIFFERENCES IN HEIGHTS BEGIN TO TAKE SHAPE DURING THE LATTER
HALF FROM A DIGGING TROF IN THE MIDDLE OF THE COUNTRY.
RIDGING AT THE SFC AND ALOFT TRACKS MOVES OFFSHORE ON TUE. PCPN WILL
OVERSPREAD THE AREA LATE TUE AFTN AS SNOW...BUT WITH INCREASING S-SW
WINDS AND STRONG WAA TEMPS WILL WARM TUE EVE/NIGHT WITH SNOW
CHANGING TO MIXED PCPN THEN RAIN FROM S TO N. WARM FRONT LIFTS
TOWARDS THE AREA TUE NIGHT...BUT THERE IS SOME UNCERTAINTY IF THE
LLJ WILL BE STRONG ENOUGH TO PUSH IT THROUGH AT THE SFC. CLIMATOLOGY
SAYS NO WITH THE LOW SO FAR TO THE NW AND VERY COLD WATERS/ICE...SO
HAVE GONE BELOW GUIDANCE WITH HIGHS WED...GENERALLY LOWER 40S WITH
MID 40S POSSIBLE IN NYC METRO.
THE COMBINATION OF THESE TEMPS AND RAINFALL WILL RESULT IN MELTING
SNOWPACK WHICH COULD LEAD TO MINOR FLOODING ACROSS THE AREA ON WED.
COLD FRONT MOVES ACROSS WED FOLLOWED BY A REINFORCING COLD FRONT WED
NIGHT. THE NORTHERN EDGE OF THE PCPN SHIELD OF A SOUTHERN STREAM
SYSTEM RIDING ALONG THIS SECONDARY BOUNDARY COULD KEEP PCPN
LINGERING WED NIGHT INTO THU. MODELS REMAIN SPLIT ON THIS...GFS IS
FURTHER SUPPRESSED THAN EC SO HAVE KEPT CHC POPS.
COLD AIR FILTERS IN BEHIND THE INITIAL COLD FRONT ON WED. THERMAL
PROFILES SUPPORT A CHANGE BACK OVER TO SNOW WED NIGHT AND THU WITH
ANY PCPN ASSOCIATED WITH THE SOUTHERN STREAM SYSTEM. ANOTHER SHOT OF
ARCTIC AIR INFILTRATES THE AREA THU INTO FRI.
STRONG CANADIAN HIGH PRES THEN BUILDS TOWARDS THE AREA INTO THE
WEEKEND WITH DRY WEATHER. TEMPS WILL REBOUND AROUND 5 DEGREES BELOW
NORMAL NEXT WEEKEND WITH WAA DEVELOPING.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE WILL TRACK TO THE SOUTH THEN EAST OF LONG ISLAND
TONIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST ON MONDAY.
MAINLY LIFR TO VLIFR ACROSS THE AREA...WITH POCKETS OF IFR IN MAINLY
MODERATE TO OCCASIONALLY HEAVY SNOW. SHOULD REMAIN ALL SNOW
KSWF/KHPN/KBDR/KGON/KTEB.
SNOW WILL CHANGE TO ZR AT KJFK AROUND 1Z AND CHANGE TO ZR AT KISP
AROUND 2Z. FOR NOW HAVE KEPT CHANGE OVER AT KEWR AND KLGA TO ZR AT
3Z...BUT BEGINNING TO HAVE SOME DOUBTS THIS WILL OCCUR.
PRECIPITATION WILL COME TO AN END A COUPLE OF HOURS ON EITHER SIDE
OF MIDNIGHT FROM W TO E.
MOST LIKELY TOTAL RUNWAY ACCUMULATIONS BY 06Z MON: KGON/KISP...4-7
INCHES. KSWF/KHPN/KBDR/KTEB/KLGA/KJFK/KEWR...4-6 INCHES.
AFTER THE PRECIPITATION ENDS...CONDITIONS TRANSITION TO VFR BY
AROUND 12Z.
WINDS IN THE PROCESS OF BECOMING LIGHT AND VARIABLE THROUGHOUT. AS
THE PRECIPITATION ENDS WINDS GO SW THEN W AT UNDER 10 KT EARLY
MONDAY MORNING. WINDS THEN BECOME NW AND INCREASE TO 13-18G22-27KT
BY AROUND MID MONDAY MORNING.
.OUTLOOK FOR 18Z MONDAY THROUGH WEDNESDAY...
.MONDAY AFTERNOON-TUESDAY MORNING...VFR. NW WINDS G25-30 KT
LIKELY INTO EARLY MONDAY EVENING.
.TUESDAY AFTERNOON...CHANCE MVFR OR LOWER IN SNOW.
.TUESDAY NIGHT...IFR OR LOWER LIKELY. SNOW...CHANGING TO A WINTRY
MIX AFTER MIDNIGHT...AND THEN RAIN LATE AT ALL TERMINALS EXCEPT KSWF
AND POSSIBLY CT TERMINALS. LLWS LIKELY.
.WEDNESDAY...IFR OR LOWER POSSIBLE IN ANY RAIN - WITH A BRIEF PERIOD
OF ZR POSSIBLE IN THE MORNING AT KSWF. LLWS POSSIBLE IN THE MORNING.
.WEDNESDAY NIGHT-THURSDAY...MVFR OR LOWER POSSIBLE IN ANY
PRECIPITATION...OTHERWISE VFR. IF THERE IS PRECIPITATION...SHOULD
CHANGE TO ALL SNOW WEDNESDAY NIGHT AND POSSIBLY CONTINUE INTO
THURSDAY. NW WINDS G15-20KT POSSIBLE.
.THURSDAY NIGHT-FRIDAY...VFR. NW WINDS G15-20KT POSSIBLE THURSDAY
NIGHT.
&&
.MARINE...
TRANQUIL TODAY WITH DEPARTING HI PRES...THEN WINDS INCREASE TO SCA
LEVELS MON AND GRADUALLY DIMINISH MON NIGHT. EXPECT SUB-ADVY CONDS
ON TUE AS HIGH PRES BUILDS ACROSS. SCA CONDS POSSIBLE ON THE OCEAN
TUE NIGHT INTO THU BEHIND THE PASSAGE OF TWO COLD FRONTS...WITH A
TIGHT PRES GRADIENT. SUB-ADVY CONDS THEN EXPECTED THEREAFTER AS
THE PRES GRADIENT WEAKENS WITH ANOTHER BUILDING HIGH.
&&
.HYDROLOGY...
LIQUID EQUIVALENT QPF OF 4-6 TENTHS OF AN INCH EXPECTED TONIGHT.
WITH ALL OF THIS EXPECTED TO BE EITHER FROZEN OR FREEZING
PRECIPITATION...NO IMMEDIATE HYDROLOGIC IMPACT EXPECTED.
BETWEEN 1/2 TO 1 INCH OF LIQUID EQUIVALENT PCPN IS POSSIBLE LATE
TUE THROUGH WED. SOME OF THIS WILL FALL AS RAIN...THEREFORE THE
COMBINATION OF THIS AND MELTING SNOW PACK COULD CAUSE MINOR
FLOODING ISSUES.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPERATURES REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ005>012.
NY...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NYZ067>075-
078>081-176>179.
NJ...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NJZ002-004-
006-103>108.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO MIDNIGHT EST MONDAY
NIGHT FOR ANZ330-335-338-340-345.
SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EST TUESDAY FOR
ANZ350-353-355.
&&
$$
SYNOPSIS...GOODMAN/24
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...24
AVIATION...MALOIT
MARINE...GOODMAN/24
HYDROLOGY...GOODMAN/24
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
315 AM EST SUN MAR 01 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS CONVERGENT UPPER LEVEL
FLOW ACROSS THE MID-SECTION OF THE COUNTY AS ONE BRANCH OF THE
NORTHER STREAM DIPS INTO THE UPPER MIDWEST/NORTHERN PLAINS...AND A
SECOND BRANCH DROPS DOWN THE PACIFIC COAST AROUND A LARGE CUTOFF LOW
OVER CALIFORNIA...AND EJECTS OUT OF THE SOUTHWESTERN STATES INTO THE
CENTRAL PLAINS. HIGH LEVEL SOUTHERN STREAM MOISTURE CAN BE SEEN VERY
WELL ON WV IMAGERY MOVING ACROSS CENTRAL MEXICO...THE GULF OF MEXICO
AND OVER THE FL PENINSULA. SOUTH OF THIS SOUTHERN STREAM WE FIND A
LARGE WEST-EAST ORIENTED UPPER RIDGE IN PLACE FROM THE BAY OF
CAMPECHE ACROSS TO THE WESTERN CARIBBEAN. OVER THE NEXT 36-48
HOURS...AS THE WESTERN TROUGH/CUTOFF LOW DIGS FURTHER SOUTH...AND
HEIGHTS FALL ACROSS THE SOUTHWESTERN STATES...THIS WILL FORCE THE
DOWNSTREAM RIDGE TO AMPLIFY NORTHWARD OVER THE GULF OF MEXICO AND
FLORIDA PENINSULA. ALL THIS TRANSLATES INTO A WARM AND SPRING-LIKE
FORECAST FOR OUR REGION DURING THE EARLY AND MIDDLE PORTION OF THE
WEEK.
AT THE SURFACE...STRONG HIGH PRESSURE CONTINUES TO RIDGE DOWN THE
ATLANTIC SEABOARD INTO THE SOUTHEAST CONUS AND WAS THE SET UP FOR
THE OVERRUNNING/UPGLIDE PATTERN THAT BROUGHT ALL THE RAIN TO PARTS
OF THE REGION ON SATURDAY. THE INFLUENCE OF THIS RIDGE IS JUST NOW
BEGINNING TO SLACKEN AS IT WEAKENS AND MOVES OFF INTO THE WESTERN
ATLANTIC. THIS ACTION WILL CONTINUE TO WEAKEN THE THE DEPTH OF
UPGLIDE REGIME AND SLOWLY SHUT DOWN THE SHOWER PRODUCTION THROUGH
THE REMAINDER OF THE EARLY MORNING HOURS. LINGERING UPGLIDE IN THE
LOWEST LEVELS ALONG THE 295-300K SURFACES WILL KEEP THE POTENTIAL
FOR LOWER STRATUS...AND RESULT IN A DIFFICULT AVIATION FORECAST
THROUGH THE MORNING HOURS. HOWEVER...AT LEAST THINGS WILL START TO
DRY OUT...TEMPORARILY.
&&
.SHORT TERM (TODAY THROUGH MONDAY)...
TODAY...
SUNDAY WILL BE A TRANSITION DAY IN THE WEATHER PATTERN FROM ONE
DOMINATED BY THE SURFACE HIGH RIDGING DOWN THE ATLANTIC SEABOARD
INTO OUR REGION...TO ONE COMING UNDER THE INFLUENCE MORE AND MORE
FROM A BUILDING UPPER LEVEL RIDGE OUT OF THE CARIBBEAN. AS MENTIONED
IN THE SYNOPSIS...THE DEEP LAYER UPGLIDE IS SHOWN BY MOST NUMERICAL
GUIDANCE TO HAVE SHIFTED OFF TO THE NORTHEAST BY SUNRISE...HOWEVER A
LOWER LEVEL LAYER OF UPGLIDE WILL STILL BE IN PLACE AND BE HELPING
TO SUPPORT AREAS OF LOWER STRATUS INTO THE MORNING HOURS. THIS WILL
ESPECIALLY BE TRUE ACROSS THE CENTRAL AND NORTHERN PORTIONS OF THE
PENINSULA. FURTHER SOUTH...ON THE OTHER SIDE OF A WEAK BOUNDARY
ACROSS THE STATE...EARLY MORNING SATELLITE IMAGERY IS ALREADY
SHOWING IMPROVING CONDITIONS (IN TERMS OF CLOUD COVER)...AND THIS
SHOULD EXPAND UP INTO OUR SOUTHERN ZONES DURING THE MORNING.
OVER TIME WILL SEE MORE AND MORE SUNNY BREAKS FURTHER NORTH AS
WELL...AND WILL HAVE EVERYONE GOING PARTLY CLOUDY FOR THE AFTERNOON
HOURS. WITH THE SUNNY BREAKS...WE WILL BE SEEING STRONG TERRESTRIAL
HEATING...WITH TEMPS CLIMBING WELL UP INTO THE 70S TO THE NORTH OF
THE I-4 CORRIDOR...AND INTO THE UPPER 70S/LOWER 80S FURTHER SOUTH.
THE LOCAL GRADIENT WILL BE RELAXING OVER TIME AS WELL AS THE SURFACE
RIDGE WEAKENS AND EXITS INTO THE WESTERN ATLANTIC. THIS WEAKENING OF
THE GRADIENT WILL ALLOW A DECENT SEA-BREEZE CIRCULATION TO DEVELOP
AFTER 18Z...AND IN FACT ALL THE HIRES GUIDANCE SHOW THIS TURNING OF
THE WINDS ONSHORE NEAR THE COAST.
WHILE WE EXPECT THE MORNING TO BE MOSTLY DRY ACROSS THE REGION...WE
CAN NOT KEEP THE FORECAST RAIN FREE COMPLETELY FOR THE AFTERNOON AND
EVENING HOURS. A COUPLE OF THINGS COME INTO PLAY HERE. THE FIRST IS
THE STRONG HEATING OVER LAND WILL ALLOW FOR AT LEAST A FEW HUNDRED
J/KG OF BL CAPE THIS AFTERNOON. THE DIFFERENTIAL HEATING ALONG WITH
HELPING TO FORCE THE SEA-BREEZE...IS ALSO SHOWING BY THE GUIDANCE
SUITE TO STRENGTHEN AN INVERTED SURFACE TROUGH ACROSS THE
CENTRAL/WESTERN PORTIONS OF THE PENINSULA FOR THE SECOND HALF OF THE
DAY. THIS TROUGH IS PARTICULARLY PRONOUNCED IN THE NAM/SREF AND
HIRES MEMBERS. THE TROUGH WILL HELP TO FOCUS LOW LEVEL CONVERGENCE
BY MID/LATE AFTERNOON GENERALLY ALONG THE I-75 CORRIDOR. WHEN ONE
ADDS THE EVENTUAL ADDITIONAL FOCUS/CONVERGENCE FROM THE
SEA-BREEZE...IT BECOMES CLEAR THAT UPDRAFTS SUPPORTING LIMITED
CONVECTION CAN NOT BE RULED OUT. IN FACT...THE LAST 4 RUNS OF THE
LOCAL WRFARW...ALONG WITH THE LATEST NCEP HIRES RUNS ARE REMARKABLY
SIMILAR IN THE PATTERN OF ALLOWED CONVECTION DEVELOPING AFTER 19-20Z
ALONG THIS I-75 CORRIDOR. WITH ALL THIS IN MIND HAVE GONE WITH A 30%
POP FOR SCT SHOWERS/ISOLATED THUNDERSTORMS FOR THE LATER AFTERNOON
THROUGH MIDDLE EVENING HOURS. IF THE HIRES RUNS ARE CORRECT...THEN
THE GREATEST THREAT FOR AN AFTERNOON SHOWER WOULD EXIST WITHIN ABOUT
30 MILES EITHER SIDE OF I-75...HOWEVER...HAVE GONE A BIT MORE BROAD
THAN THAT WITH THE FORECAST FOR NOW...AND WILL ALLOW THE DAY SHIFT
TO EVALUATE THE PATTERN EVOLUTION...AND ADD A BIT MORE TEMPORAL
AND/OR SPATIAL DETAIL. THE CONVECTION IS NOT GOING TO BE VERY
ROBUST...AND CERTAINLY NOT EXPECTING ANY STRONG STORMS AT THIS
TIME...HOWEVER A BRIEF DOWNPOUR...AND A FEW LIGHTNING STRIKES SHOULD
BE PLANNED FOR IF OUTDOORS LATER TODAY.
TONIGHT...
WIDELY SCATTERED CONVECTIVE CELLS WILL LINGER INTO THE MIDDLE
EVENING HOURS...MAINLY TO THE NORTH OF THE I-4 CORRIDOR...AND THEN
BEGIN TO DISSIPATE WITH THE LOSS OF DIURNAL HEATING AND RESULTING
LOSS OF SURFACE FOCUS. WILL END ALL SHOWERS BY 03-04Z...WITH A DRY
OVERNIGHT PERIOD THEREAFTER. FOCUS INTO THE LATER OVERNIGHT HOURS
WILL SHIFT TO THE POTENTIAL FOR AREAS OF DENSE FOG DEVELOPMENT. A
MOIST BOUNDARY LAYER WILL STILL BE IN PLACE...AND AS WE START TO SEE
THE UPPER RIDGE BUILD...AND INCREASED LARGE SCALE SUBSIDENCE...THE
SETUP FOR FOG IS FAIRLY GOOD. IN FACT...THE LATEST SREF
PROBABILITIES OF VISIBILITY LESS THAN 1 MILE DURING THE LATE NIGHT
HOURS TONIGHT IS GREATER THAN 80% ACROSS MUCH OF THE REGION. IT HAS
BEEN MY EXPERIENCE TO BEGIN TAKING THE SREF FOG POTENTIAL SERIOUSLY
WHEN PROBABILITIES BEGIN TO EXCEED 70% OR SO. HAVE ADDED AREAS OF
FOG INTO THE GRIDS...AND AGAIN WILL LET THE DAY SHIFT REEVALUATE
BEFORE ADDING DENSE FOG WORDING TO THE FORECAST. FOR NOW...JUST BE
AWARE THAT SOME LOCATIONS MAY HAVE A MORE DIFFICULT MONDAY MORNING
COMMUTE RESULTING FROM VISIBILITY REDUCTIONS. LOW TEMPERATURES EARLY
MONDAY MORNING WILL RANGE FROM THE UPPER 50S OVER LEVY COUNTY...TO
THE LOWER/MIDDLE 60S ELSEWHERE.
MONDAY...
UPPER RIDGE WILL TAKE FIRM CONTROL OVER OUR WEATHER DURING THE DAY.
WILL BE EXPECTING A FAIR AMOUNT OF SUN...AFTER ANY MORNING FOG BURNS
OFF (WHICH MAY TAKE SEVERAL HOURS). FORECASTING ABOVE AVERAGE
TEMPERATURES ACROSS THE REGION AS BOUNDARY LAYER SHOULD BE ABLE TO
EASILY MIX OUT TO THE UPPER 70S ACROSS THE FAR NORTH (LEVY/CITRUS
COUNTIES)...AND LOWER TO MIDDLE 80S FOR MOST OTHER AREAS. THE STRONG
HEATING FORCES ANOTHER SEA-BREEZE TO DEVELOP...AND THIS WILL LIKELY
KEEP TEMPERATURES DOWN A BIT (MID/UPPER 70S) ALONG THE IMMEDIATE
COAST...AS THE FLOW DEVELOPS OFF THE COOLER SHELF WATERS.
HOWEVER...IT WILL NOT TAKE MUCH DISTANCE INLAND TO FIND THE LOWER
80S AGAIN.
THE POTENTIAL FOR A BRIEF AFTERNOON SHOWER ALONG THE SEA-BREEZE IS
NOT ZERO...HOWEVER WITH THE RIDGE BUILDING OVERHEAD...CONDITIONS ARE
NOT AS FAVORABLE AS WE MIGHT SEE THIS AFTERNOON...AND GIVEN THE TIME
OF YEAR...IF THINGS DO NOT LINE UP JUST RIGHT...THEN CONVECTION IS
REALLY NOT THAT LIKELY. FOR NOW WILL KEEP THE FORECAST GENERALLY DRY
MONDAY AFTERNOON. CAN TAKE ANOTHER LOOK AT THIS TONIGHT.
&&
.LONG TERM (TUESDAY THROUGH NEXT SATURDAY)...
THROUGH WED; THE AREA WILL BE DOMINATED BY DEEP LAYER RIDGING THAT
GRADUALLY SLIDES EAST. INITIALLY THE PATTERN ALOFT BEGINS WITH A
LONG WAVE TROUGH FROM CENTRAL CANADA TO THE GREAT BASIN...RIDGING
CENTERED OVER THE YUCATAN THAT REACHED ACROSS THE UPPER GREAT
LAKES...AND ANOTHER TROUGH FROM QUEBEC SOUTH OVER NEW ENGLAND AND
THE CANADIAN MARITIMES TO ATLANTIC WATERS. SURFACE HIGH PRESSURE
CENTERED IN THE OHIO VALLEY...AND SPRAWLING DOWN ACROSS THE GULF
REGION SHIFTS OUT OVER THE OPEN ATLANTIC WHILE RIDGING BACK ACROSS
FL TO THE GULF. THE UPPER RIDGE KEEPS THE ATMOSPHERE STABLE WARM AND
GENERALLY DRY. THE TRACK OF THE SURFACE HIGH WILL VEER WINDS FROM
NORTHEAST AND EAST TO SOUTHEAST AND SOUTHERLY. THE SOUTHERLY WINDS
WILL BRING IN SOME WARM AND MORE HUMID AIR WHICH COULD RESULT IN
SEA FOG AS IT MOVES ACROSS THE COOLER GULF WATERS.
THU-FRI; THE WESTERN LONG WAVE TROUGH...WITH AN ACCOMPANYING COLD
FRONT...BY NOW STRETCHES FROM THE FOUR CORNERS REGION TO THE UPPER
GREAT LAKES. THE TROUGH THEN BEGINS TO SHEAR OUT WITH THE EASTERN
PORTION DE-AMPLIFYING AS IT SHIFTS OFF THE NORTHEAST U.S. COAST
WHILE THE WESTERN END MEANDERS NEAR NORTHERN BAJA CALIFORNIA. THE
GULF UPPER RIDGE FLATTENS AND HANGS ON FROM THE YUCATAN ACROSS CUBA
TO THE ATLANTIC EAST OF THE BAHAMAS. AS A RESULT NEARLY ZONAL FLOW
SETS UP ACROSS THE SOUTHEAST CONUS AND GULF REGION...WITH THE FRONT
GETTING STRUNG OUT FROM WEST TO EAST ON OR NEAR THE GULF COAST. HIGH
PRESSURE BUILDS IN NORTH OF THE FRONT AND TRACKS EAST...WITH NORTH
THEN NORTHEAST WINDS EVENTUALLY BRIDGING THE FRONT AND FILLING IN
ACROSS THE AREA. INCREASING MOISTURE ALONG WITH THE FRONT
APPROACHING FROM THE NORTH WILL SUPPORT SOME SLIGHT CHANCE SHOWERS
AND THUNDERSTORM...INITIALLY ACROSS THE NORTH BUT THAT SPREAD
SOUTHWARD WITH TIME. TEMPERATURES THU RUN ABOVE NORMAL BUT COOL ON
FRI...TO NEAR NORMAL CENTRAL AND SOUTH BUT NEAR TO A BIT BELOW
NORMAL IN THE NORTH WHERE THERE WILL BE MORE RAINFALL AND CLOUDS.
SAT; THE BAJA TROUGH BEGINS WORKING EAST...ALONG THE SOUTHWEST CONUS
OR NORTHWEST MEXICO BORDER REGIONS...WITH FLOW ALOFT STARTING TO
BACK TO WEST-SOUTHWEST. THE FRONT RESIDES ALONG THE GULF COAST IN
THE ECMWF SOLUTION WITH SOMEWHAT DRIER CONDITIONS IN FL OR OVER THE
NORTHERN GULF WATERS AND NORTH FL WITH THE GFS SOLUTION...KEEPING
SLIGHTLY MORE RAINFALL OVER OR NEAR THE AREA. IN EITHER CASE THERE
WILL BE SLIGHT CHANCE TO LOW END CHANCE SHOWERS OR STORMS.
TEMPERATURES CONTINUE NEAR NORMAL CENTRAL AND SOUTH AND JUST UNDER
IN THE NORTH.
&&
.AVIATION...
SO FAR...THE CONDITIONS HAVE NOT BE AS PESSIMISTIC AS THE
STATISTICAL GUIDANCE PREDICTED AT MOST TERMINALS. WILL CONTINUE THIS
TREND FOR THE REMAINDER OF THE OVERNIGHT. ALTHOUGH A FEW PERIODS OF
IFR CIGS ARE CERTAINLY POSSIBLE...THE MAJORITY OF THE TIME SHOULD BE
MVFR AND WILL CHOOSE TO STAY IN THE RANGE OVER THE NEXT SEVERAL
HOURS. PERIODS OF MVFR CIGS SHOULD SLOWLY IMPROVE AFTER SUNRISE AND
BRING ALL TERMINALS BACK TO VFR FOR THE MIDDAY/AFTERNOON/EVENING
HOURS. THERE IS THE POTENTIAL FOR WIDELY SCT SHOWERS AND ISOLATED
STORMS AFTER 19-20Z...LINGERING THROUGH 00-02Z. ANY SHOWERS WILL BE
BRIEF AND HAVE USED VCSH TO HIGHLIGHT THIS POTENTIAL. ANY SHOWERS
DISSIPATED BY LATE EVENING AND FOCUS SHIFTS TO FOG POTENTIAL AFTER
MIDNIGHT. BOTH STATISTICAL AND ENSEMBLE GUIDANCE ARE BEGINNING TO
SUGGEST THE POTENTIAL FOR AREAS OF IFR FOG AFTER 06Z.
&&
.MARINE...
HIGH PRESSURE TO OUR NORTH WILL WEAKEN TODAY ALLOWING THE GRADIENT
TO RELAX AND WIND FIELDS TO WEAKEN. THE GRADIENT WILL RELAX ENOUGH
BY THIS AFTERNOON TO ALLOW SEA BREEZE FORMATION WITH WINDS BECOMING
LIGHT ONSHORE THROUGH THE EARLY EVENING. THE GENERALLY SYNOPTIC
EASTERLY FLOW WILL SHIFT SOUTHEAST ON TUESDAY AND THEN SOUTH BY
WEDNESDAY. EXPECT NEARSHORE WINDS TO BECOME ONSHORE EACH AFTERNOON
AND EARLY EVENING. THERE IS THE POTENTIAL WITH THE MOIST SOUTHERLY
FLOW FOR AREAS OF SEA FOG TO REDUCE VISIBILITY BY LATER TUESDAY OR
WEDNESDAY...AND THIS POTENTIAL WILL NEED TO BE MONITORED CLOSELY. A
COLD FRONT IS SCHEDULED TO ARRIVE LATER THURSDAY OR THURSDAY NIGHT
WHICH WOULD END THE THREAT FOR SEA FOG FOR THE END OF THE WEEK...AND
SHIFT WINDS BACK FROM THE NORTH AND NORTHEAST.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS OUTSIDE OF FOG POTENTIAL ARE
ANTICIPATED OVER THE NEXT SEVERAL DAYS AS RELATIVE HUMIDITY REMAINS
WELL ABOVE CRITICAL LEVELS AND ERC VALUES ARE LOW ACROSS THE REGION.
TEMPERATURES WILL HOWEVER BE ABOVE AVERAGE FOR MUCH OF THE EARLY AND
MIDDLE PORTION OF THE WEEK.
FOG POTENTIAL...
AREAS OF FOG ARE EXPECTED TO DEVELOP TONIGHT INTO EARLY MONDAY
MORNING ACROSS MUCH OF WEST-CENTRAL AND SOUTHWEST FLORIDA. THE FOG
HAS THE POTENTIAL TO BECOME LOCALLY DENSE AT TIME. AREAS OF FOG ARE
ALSO FORECAST FOR LATER MONDAY NIGHT INTO TUESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 65 79 64 / 30 10 10 0
FMY 82 65 83 64 / 30 10 10 0
GIF 80 65 81 63 / 30 20 10 10
SRQ 78 63 79 62 / 20 10 10 0
BKV 80 60 80 59 / 30 20 10 0
SPG 78 65 78 65 / 20 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1040 PM EST MON MAR 2 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CURRENT SURFACE ANALYSIS REVEALS THAT THE FRONTAL BOUNDARY HAS
DROPPED SOUTH OF THE FORECAST AREA WITH SURFACE WINDS BECOMING
NORTHEASTERLY IN THE WAKE OF THE FRONT. THE BOUNDARY WILL STALL
TO OUR SOUTH AND WEST TONIGHT. DEWPOINTS REMAIN IN THE 50S AT MOST
LOCATIONS ACROSS THE FORECAST AREA BUT A STRONG GRADIENT IN
DEWPOINTS EXISTS TO OUR NORTH AND WEST. REGIONAL RADAR COMPOSITE
SHOWS A FEW LIGHT SHOWERS FINALLY REACHING THE CSRA AND WESTERN
MIDLANDS DUE TO ISENTROPIC LIFT AHEAD OF SOME UPPER ENERGY. EXPECT
PRECIPITATION COVERAGE TO INCREASE TOWARD DAYBREAK TUESDAY WHICH
IS CONSISTENT WITH LATEST HRRR AND LAMP POP TRENDS. OVERNIGHT LOWS
RANGING FROM AROUND 40 NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
ISENTROPIC LIFT WITH A MOISTURE INCREASE WILL OCCUR BEHIND THE
COLD FRONT. CONDITIONS WILL DETERIORATE INTO THE MVFR AND IFR
CATEGORIES. THE GFS AND NAM MOS INDICATE MAINLY MVFR CEILINGS
DEVELOPING TONIGHT AND IFR TUESDAY. THE HRRR AND SPC WRF DISPLAY
SCATTERED AREAS OF RAIN LATE TONIGHT. THE SPC WRF SHOWS COVERAGE
OVER MUCH OF THE AREA TUESDAY. THERE WILL BE LOW-LEVEL WIND SHEAR
BEHIND THE FRONT WITH SURFACE NORTHEAST WINDS VEERING TO SOUTHEAST
AND SOUTHWEST TONIGHT AND TUESDAY. THE NAM INDICATES 2000 FOOT
SOUTHERLY WINDS ABOVE THE SURFACE NORTHEAST WINDS INCREASING TO 25
TO 30 KNOTS. THEREFORE...WE INCLUDED LLWS IN THE TAFS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND
ALSO ON THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1007 PM EST MON MAR 2 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CURRENT SURFACE ANALYSIS REVEALS THAT THE FRONTAL BOUNDARY HAS
DROPPED SOUTH OF THE CENTRAL MIDLANDS EARLY THIS EVENING WITH
SURFACE WINDS BECOMING NORTHEASTERLY IN THE WAKE OF THE FRONT.
THE BOUNDARY WILL CONTINUE CROSSING THE AREA BEFORE STALLING TO
OUR SOUTH AND WEST TONIGHT. REGIONAL RADAR COMPOSITE SHOWS ONLY A
FEW SHOWERS ACROSS EAST CENTRAL ALABAMA AND CENTRAL GEORGIA SO
HAVE LOWERED POPS A BIT. ISENTROPIC LIFT AHEAD OF SOME UPPER
ENERGY WILL LEAD TO PRECIPITATION DEVELOPING FROM THE CSRA AND
MOVING EASTWARD TONIGHT. OVERNIGHT LOWS RANGING FROM AROUND 40
NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
ISENTROPIC LIFT WITH A MOISTURE INCREASE WILL OCCUR BEHIND THE
COLD FRONT. CONDITIONS WILL DETERIORATE INTO THE MVFR AND IFR
CATEGORIES. THE GFS AND NAM MOS INDICATE MAINLY MVFR CEILINGS
DEVELOPING TONIGHT AND IFR TUESDAY. THE HRRR AND SPC WRF DISPLAY
SCATTERED AREAS OF RAIN LATE TONIGHT. THE SPC WRF SHOWS COVERAGE
OVER MUCH OF THE AREA TUESDAY. THERE WILL BE LOW-LEVEL WIND SHEAR
BEHIND THE FRONT WITH SURFACE NORTHEAST WINDS VEERING TO SOUTHEAST
AND SOUTHWEST TONIGHT AND TUESDAY. THE NAM INDICATES 2000 FOOT
SOUTHERLY WINDS ABOVE THE SURFACE NORTHEAST WINDS INCREASING TO 25
TO 30 KNOTS. THEREFORE...WE INCLUDED LLWS IN THE TAFS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND
ALSO ON THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
643 PM EST MON MAR 2 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CURRENT SURFACE ANALYSIS REVEALS THAT THE FRONTAL BOUNDARY HAS
DROPPED SOUTH OF THE CENTRAL MIDLANDS EARLY THIS EVENING WITH
SURFACE WINDS BECOMING NORTHEASTERLY IN THE WAKE OF THE FRONT.
THE BOUNDARY WILL CONTINUE CROSSING THE AREA BEFORE STALLING TO
OUR SOUTH AND WEST TONIGHT. REGIONAL RADAR COMPOSITE SHOWS ONLY A
FEW SHOWERS ACROSS EAST CENTRAL ALABAMA AND CENTRAL GEORGIA SO
HAVE LOWERED POPS A BIT. ISENTROPIC LIFT AHEAD OF SOME UPPER
ENERGY WILL LEAD TO PRECIPITATION DEVELOPING FROM THE CSRA AND
MOVING EASTWARD TONIGHT. OVERNIGHT LOWS RANGING FROM AROUND 40
NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
ISENTROPIC LIFT WITH A MOISTURE INCREASE WILL OCCUR BEHIND THE
COLD FRONT. CONDITIONS WILL DETERIORATE INTO THE MVFR AND IFR
CATEGORIES. THE GFS AND NAM MOS INDICATE MAINLY MVFR CEILINGS
DEVELOPING TONIGHT AND IFR TUESDAY. THE HRRR AND SPC WRF DISPLAYS
SCATTERED AREAS OF RAIN LATE TONIGHT. THE SPC WRF SHOWS COVERAGE
OVER MUCH OF THE AREA TUESDAY. THERE WILL BE LOW-LEVEL WIND SHEAR
BEHIND THE FRONT WITH SURFACE NORTHEAST WINDS VEERING TO SOUTHEAST
AND SOUTHWEST TONIGHT AND TUESDAY. THE NAM INDICATES 2000 FOOT
SOUTHERLY WINDS ABOVE THE SURFACE NORTHEAST WINDS INCREASING TO 25
TO 30 KNOTS. THEREFORE...WE INCLUDED LLWS IN THE TAFS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND
ALSO ON THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
631 PM EST MON MAR 2 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE FRONTAL BOUNDARY WILL CROSS THE AREA BY THIS EVENING BEFORE
STALLING TO OUR SOUTH AND WEST. REGIONAL RADAR COMPOSITE SHOWS
ONLY A FEW SHOWERS ACROSS EAST CENTRAL ALABAMA AND CENTRAL GEORGIA
SO HAVE LOWERED POPS A BIT. ISENTROPIC LIFT AHEAD OF SOME UPPER
ENERGY WILL LEAD TO PRECIPITATION DEVELOPING FROM THE CSRA AND
MOVING EASTWARD TONIGHT. OVERNIGHT LOWS RANGING FROM AROUND 40
NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
ISENTROPIC LIFT WITH A MOISTURE INCREASE WILL OCCUR BEHIND THE
COLD FRONT. CONDITIONS WILL DETERIORATE INTO THE MVFR AND IFR
CATEGORIES. THE GFS AND NAM MOS INDICATE MAINLY MVFR CEILINGS
DEVELOPING TONIGHT AND IFR TUESDAY. THE HRRR AND SPC WRF DISPLAYS
SCATTERED AREAS OF RAIN LATE TONIGHT. THE SPC WRF SHOWS COVERAGE
OVER MUCH OF THE AREA TUESDAY. THERE WILL BE LOW-LEVEL WIND SHEAR
BEHIND THE FRONT WITH SURFACE NORTHEAST WINDS VEERING TO SOUTHEAST
AND SOUTHWEST TONIGHT AND TUESDAY. THE NAM INDICATES 2000 FOOT
SOUTHERLY WINDS ABOVE THE SURFACE NORTHEAST WINDS INCREASING TO 25
TO 30 KNOTS. THEREFORE...WE INCLUDED LLWS IN THE TAFS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND
ALSO ON THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
626 PM EST MON MAR 2 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE FRONTAL BOUNDARY WILL CROSS THE AREA BY THIS EVENING BEFORE
STALLING TO OUR SOUTH AND WEST. REGIONAL RADAR COMPOSITE SHOWS
ONLY A FEW SHOWERS ACROSS EAST CENTRAL ALABAMA AND CENTRAL GEORGIA
SO HAVE LOWERED POPS A BIT. ISENTROPIC LIFT AHEAD OF SOME UPPER
ENERGY WILL LEAD TO PRECIPITATION DEVELOPING FROM THE CSRA AND
MOVING EASTWARD TONIGHT. OVERNIGHT LOWS RANGING FROM AROUND 40
NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
ISENTROPIC LIFT WITH A MOISTURE INCREASE WILL OCCUR BEHIND THE
COLD FRONT. CONDITIONS WILL DETERIORATE INTO THE MVFR AND IFR
CATEGORIES. THE GFS AND NAM MOS INDICATE MAINLY MVFR CEILINGS
DEVELOPING TONIGHT AND IFR TUESDAY. THE HRRR AND SPC WRF DISPLAYS
SCATTERED AREAS OF RAIN LATE TONIGHT. THE SPC WRF SHOWS COVERAGE
OVER MUCH OF THE AREA TUESDAY. THERE WILL BE LOW-LEVEL WIND SHEAR
BEHIND THE FRONT WITH SURFACE NORTHEAST WINDS VEERING TO SOUTHEAST
AND SOUTHWEST TONIGHT AND TUESDAY. THE NAM INDICATES 2000 FOOT
SOUTHERLY WINDS ABOVE THE SURFACE NORTHEAST WINDS INCREASING TO 25
TO 30 KNOTS. THEREFORE...WE INCLUDED LLWS IN THE TAFS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
116 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE
SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY
ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH
POSITIONED NEAR THE MID-ATLANTIC COAST.
ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC
ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OF RAIN ACROSS
SOUTHEAST SOUTH CAROLINA EARLY THIS AFTERNOON. THE HRRR AND OTHER
HIGH RESOLUTION MESOSCALE MODELS APPEAR TO BE HANDLING
LOCATION/COVERAGE OF THE PRECIPITATION FAIRLY WELL...AND GENERALLY
SHOW THE RAIN SHIELD CONTINUING TO LIFT NORTHWARD THROUGH THE
AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS LOWERING RAIN
CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE DAY...BUT
PROBABILITIES PEAKING AT 70-90 PERCENT IN SOUTHEAST SOUTH
CAROLINA THROUGH MID-AFTERNOON BEFORE RAIN CHANCES LOWER AS WELL
LATE IN THE DAY.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL
TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE
SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR
IN THE BOUNDARY LAYER ADVECTING JUST INLAND ALONG THE COAST. WITH
THE MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ACROSS THE
BOARD 1-3 DEGREES TO ACCOUNT FOR THE LATEST TRENDS. HIGHS ARE NOW
FORECAST TO RANGE FROM THE LOWER/MID 40S INLAND TO THE MID 50S
NEAR THE COAST.
TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING
INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A
CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING
ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW
CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY
FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY
DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES
AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT
READINGS MANY BE STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
IFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE AFTERNOON
WITH LIGHT RAIN/DRIZZLE PERSISTING. CEILINGS SHOULD DETERIORATE
FURTHER AFTER 23Z...LOWERING TO LIFR LEVELS AT BOTH TERMINALS.
VISIBILITIES WILL LOWER LATE TONIGHT AS WELL...DUE TO STRATUS
BUILD DOWN AND/OR FOG FORMATION. AT THIS TIME...GUIDANCE APPEARS
TO SHOW HIGHER PROBABILITIES OF DENSE FOG AT KSAV...SO HAVE
INCLUDED A TEMPO GROUP FROM 08-12Z AT THAT TERMINAL WITH FURTHER
REDUCED VISIBILITIES/CEILINGS. GRADUAL IMPROVEMENT IS GENERALLY
EXPECTED AFTER ABOUT 15Z MONDAY AS SOMEWHAT DRIER AIR FILTERS IN
ON A WEST-NORTHWEST FLOW...BUT CONDITIONS WILL LIKELY REMAIN
BELOW VFR THROUGH THE END OF THE FORECAST PERIOD AT 18Z.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY
AFTERNOON. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT
RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS
AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON
WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS
WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE
AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH
LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO
TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE
CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER
TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER
GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS
UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO
1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA
INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL
BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...JAQ
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...JAQ/DPB
MARINE...JAQ/DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1101 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE
SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY
ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH
POSITIONED NEAR THE MID-ATLANTIC COAST.
ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC
ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OR RAIN ACROSS MAINLY
CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA LATE THIS
MORNING. THE HRRR AND OTHER HIGH RESOLUTION MESOSCALE MODELS
APPEAR TO BE HANDLING LOCATION/COVERAGE OF THE PRECIPITATION
FAIRLY WELL...AND GENERALLY SHOW THE RAIN SHIELD LIFTING NORTHWARD
THROUGH THE AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS
LOWERING RAIN CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE
DAY...BUT PROBABILITIES PEAKING AT 60-80 PERCENT IN SOUTHEAST
SOUTH CAROLINA EARLY THIS AFTERNOON BEFORE RAIN CHANCES LOWER AS
WELL LATE IN THE DAY.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL
TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE
SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR
IN THE BOUNDARY ADVECTING JUST INLAND ALONG THE COAST. WITH THE
MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ALONG THE COAST
JUST A BIT TO ACCOUNT FOR THE LATEST MODEL TRENDS...BUT TIGHTENED
THE GRADIENT FURTHER BY LOWERING TEMPERATURES WELL INLAND NEAR THE
CORE OF THE WEDGE. HIGH ARE NOW FORECAST TO RANGE FROM THE MID 40S
WELL INLAND TO THE MID 50S NEAR THE COAST.
TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING
INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A
CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING
ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW
CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY
FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY
DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES
AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT
READINGS MANY BE STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT
RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL
CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER
THROUGH 12Z MONDAY.
BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY
WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS.
DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS
NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER
TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE
IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION
THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A
CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD
LIFR THROUGH THE COASTAL CORRIDOR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH
LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO
TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE
CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER
TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER
GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS
UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO
1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA
INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL
BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
NEAR TERM...JAQ
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
709 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN
WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST
QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH
HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH
UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS.
EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A
FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING
OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND
SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL
EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS
VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF
NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND
NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO
LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT THAT
SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED JUST
TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH PLENTY
OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE. RAINFALL
AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER INCH FOR
THE MOST PART.
WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT
WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR
DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE
INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS
JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF
FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE
REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC
OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE
STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT
RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL
CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER
THROUGH 12Z MONDAY.
BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY
WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS.
DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS
NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER
TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE
IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION
THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A
CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD
LIFR THROUGH THE COASTAL CORRIDOR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE
MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT.
IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT
GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW
TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT
OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN
ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS
COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE
LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS
LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
455 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PRE-DAWN...HIGH PRES WEDGED INTO GEORGIA AND THE CAROLINAS EARLY THIS
MORNING WITH A COASTAL TROUGH ALONG THE WEST WALL OF THE GULF STREAM.
AREAS OF LIGHT RAINS HAVE BEEN QUITE TRANSIENT OVERNIGHT AND MAINLY
NORTH OF I-16 BUT A STEADY STREAM OF ISENTROPIC ASCENT SHOULD ENSURE
PERIODIC WET WEATHER FOR MUCH OF THE FORECAST AREA AS ISENTROPIC
ASCENT IS MAINTAINED ACROSS A DEEP THERMAL SURFACE. AT THE GROUND
LEVEL...SURFACE PRESSURES WERE FALLING ACROSS THE AREA...A SIGN
THAT THE STRENGTH OF THE WEDGE HAS PEAKED. CLOUDS WERE LOWERING AS
WARM AIR ADVECTION INCREASES ATOP THE BOUNDARY LAYER. TEMPS WERE
CHILLY ONCE AGAIN WITH READINGS IN THE UPPER 30S INLAND TO LOWER
40S ALONG THE COAST.
WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN
WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST
QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH
HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH
UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS.
EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A
FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING
OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND
SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL
EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS
VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF
NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND
NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO
LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT
THAT SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED
JUST TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH
PLENTY OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE.
RAINFALL AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER
INCH FOR THE MOST PART.
WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT
WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR
DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE
INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS
JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF
FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE
REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC
OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE
STEADY OR RISING LATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
BOTH AIRFIELDS HAD MVFR CEILINGS AT 09Z...WHICH WILL GRADUALLY
LOWER INTO THE IFR RANGE IN A FEW HOURS...THEN PERSIST THROUGH
THE REMAINDER OF THE VALID CYCLE. THIS IS THE RESULT OF ABUNDANT
MOISTURE TRAPPED BENEATH THE WEDGE INVERSION...AIDED BY ISENTROPIC
LIFT AT VARIOUS LEVELS. PERIODIC LIGHT RAINS OR EVEN DRIZZLE AT
TIMES LIKELY TODAY WITH FOG POTENTIALLY AN ISSUE TONIGHT AS THE
LOW CLOUDS BUILD DOWN WITH STRONG WARM AIR ADVECTION ABOVE THE
COOLER SURFACE TEMPS WITH A DRYING TREND IN THE 3-5 KFT LAYER.
THEE 00Z-06Z MONDAY PORTION OF THE TAFS...CONFIDENCE IS VERY GOOD
THAT LIFR CIGS AND PERHAPS IFR VSBYS WILL PREVAIL GIVEN LATEST
MODEL DATA.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE
MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT.
IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT
GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW
TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT
OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN
ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS
COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE
LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS
LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS POCATELLO ID
903 PM MST MON MAR 2 2015
.UPDATE...UPPER TROUGH SLIDING SOUTH ACROSS EAST IDAHO THIS
EVENING. SOUTHERN SHORTWAVE EJECTING NORTHEAST THROUGH UT INTO
WY/CO. MAIN SHORTWAVE DROPPING THROUGH PANHANDLE TOWARD CENTRAL
MTNS. COLD CLOUD TOPS FILLING IN OVER CENTRAL MTNS WITH
OBSERVATIONS INDICATING SNOW UPSTREAM OF FCST AREA. TREND OF FCST
STILL CONTINUES WITH MODELS PUSHING SNOW OUT OF THE SOUTHEAST
CORNER AS WRAP AROUND FROM SOUTHERN SHORTWAVE CONTINUES EAST.
LIGHT SNOW STILL PROGGED TO SAG SOUTH ACROSS THE CENTRAL MTNS
THROUGH ROUGHLY 09Z. HEAVIEST BAND OF SNOW DEVELOPS ALONG/BEHIND
COLD FRONT/CONVERGENT LINE AS IT SAGS SOUTH THROUGH SNAKE PLAIN
BETWEEN 09Z-15Z. LATEST HRRR RUNS SHIFT THIS LINE QUICKLY
SOUTH/SOUTHWEST INTO EASTERN MAGIC VALLEY/SOUTH CENTRAL HIGHLANDS LEAVING
WEAK UPSLOPE CONDITIONS ALONG I-15/I86 CORRIDOR. HAVE MADE SOME
MINOR MODIFICATIONS TO FCST FOR TONIGHT TO TREND WITH CURRENT
RADAR/SATELLITE. WINTER WX ADVISORIES IN GOOD SHAPE SO NO CHANGES
TO HEADLINES AT THIS TIME. DMH
&&
.PREV DISCUSSION... /ISSUED 134 PM MST MON MAR 2 2015/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
MAIN FOCUS IS ON POWERFUL FAST MOVING COLD FRONT THAT WILL ARRIVE
TONIGHT AND EXIT THE REGION BY TUESDAY AFTERNOON. EXPECT THIS SYSTEM
TO BRING SOME LIGHT SNOW INTO THE CENTRAL MOUNTAINS THIS EVENING.
MEANWHILE A LOW PRESSURE SYSTEM PASSING SOUTH OF THE REGION WILL
BRING SOME LIGHT SNOW TO EXTREME SOUTHEAST IDAHO...AROUND THE SODA
SPRINGS AREA THIS EVENING. THE COLD FRONT WILL ARRIVE IN THE UPPER
SNAKE PLAIN AND UPPER SNAKE HIGHLANDS AFTER MIDNIGHT TO AROUND THE
POCATELLO AREA AROUND SUNRISE. THIS FRONT WILL EXIT THE AREA BY
NOON. VERY QUICK HITTING ROUND OF SNOW WITH THIS SYSTEM. THE SNOW
AMOUNTS HAVE BEEN FLUCTUATING QUITE A BIT. LATEST MODELS DID COME
DOWN A LITTLE ON THE AMOUNTS...BUT STILL LOOKING AT 1 TO 3 INCHES OF
SNOW ACROSS THE EASTERN SNAKE PLAIN AND EASTERN HIGHLANDS. WIND
GUSTS OF 20 TO 25 MPH ARE POSSIBLE WITH THE FRONT AS WELL WHICH
COULD CREATE SOME BLOWING AND DRIFTING ISSUES. WILL CONTINUE THE
ADVISORY BECAUSE IT MAY CREATE PROBLEMS FOR THE TUESDAY MORNING
COMMUTE...ESPECIALLY SINCE THERE HASNT BEEN MUCH SNOW IN A WHILE.
SEEM TO HAVE A REALLY GOOD HANDLE ON THE TIMING SO WILL TRIM THE
ADVISORY TO START AT 03Z AND END AROUND 21Z.
VALLE
LONG TERM...WEDNESDAY THROUGH MONDAY NIGHT. EXPECT DRY CONDITIONS
AND SLIGHTLY COOLER THAN NORMAL TEMPERATURES WEDNESDAY BEHIND AN
EXITING COLD FRONT. THURSDAY THROUGH THE END OF PERIOD EXPECT DRY
CONDITIONS AND GRADUAL WARMING TEMPERATURES. EXPECT WELL ABOVE
AVERAGE TEMPERATURES BY THE WEEKEND INTO MONDAY. THE GFS MODEL HAS
DROPPED THE POSSIBILITY OF A WEAK SYSTEM FRIDAY INTO SATURDAY.
HOWEVER...THE ECMWF MODELS CONTINUES TO SHOW A SLIGHT CHANCE OF
PRECIPITATION LATE FRIDAY INTO SATURDAY. WYATT
AVIATION...LOOK FOR VFR CONDITIONS THIS AFTERNOON THROUGH THIS
EARLY EVENING. HOWEVER...A SYSTEM WILL BRING SNOW ACROSS THE AREA
LATE TONIGHT INTO TOMORROW. EXPECT IFR/MVFR CONDITIONS BY LATE
EVENING THROUGH EARLY TOMORROW AFTERNOON FOR MAINLY KIDA AND KPIH
AND TO AN LESSER EXTENT FOR KBYI AND KSUN. ALSO...LOOK FOR BREEZY
WINDS ACROSS THE AREA TOMORROW. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 PM MST TUESDAY IDZ020-021.
WINTER WEATHER ADVISORY UNTIL 2 PM MST TUESDAY IDZ019-023.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
917 PM CST MON MAR 2 2015
.UPDATE...
758 PM CST
THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO
THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL
REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A
STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD
ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY
MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY
TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT
AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER
ADVISORY AS IS.
JEE
&&
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SOUTHEAST WINDS ARND 9KT THRU THIS EVENING...TURNING SOUTHWEST
ARND DAYBREAK AND INCREASING TO 12-15KT WITH GUSTS APPROACHING
20-25KT SHORTLY AFT DAYBREAK TUE.
* SNOW OVERSPREADING THE AIRFIELDS ARND 10-11Z...WITH POSSIBLY A
BURST OF MODERATE SNOW SHORTLY AFTER ONSET. SNOW BECOMES MIXED
WITH FREEZING RAIN/SLEET THEN POSSIBLY ALL RAIN BY MIDDAY.
* VFR CONDS RAPIDLY DETERIORATE TO IFR/LIFR AROUND DAYBREAK...AND
IFR OR LIFR CIGS COULD LINGER THRU TUE AFTN.
BEACHLER
//DISCUSSION...UPDATED 00Z...
QUIET THIS EVENING WITH VFR CONDS. CIRRUS DECK WILL CONTINUE TO
THICKEN THIS EVENING WITH ADDITIONAL MOISTURE LIFTING NORTH ACROSS
THE OZARKS TOWARDS NORTHERN IL/NORTHWEST IN AIRFIELDS...WHICH WILL
RAPIDLY LOWER CIGS TOWARDS IFR CONDS SHORTLY BEFORE DAYBREAK.
WINDS WILL TURN FROM SOUTHEAST TO SOUTHWEST AND INCREASE. GUSTS
DEVELOP AROUND DAYBREAK TO 25KT AND THEN RELAX SLIGHTLY TO 18KT
LATE TUE AFTN.
PRECIP TIMING AND TRANSITION REMAINS THE MAIN FOCUS FOR THE
OVERNIGHT HOURS THRU TUE MIDDAY. SNOW DEVELOPS PRIOR TO
DAYBREAK...AND WILL BEGIN MIXING WITH SLEET/FREEZING RAIN AROUND
13-15Z. PRIOR TO A MIXTURE OF PRECIP...A BURST OF MODERATE SNOW
MAY OCCUR AND COULD BRING VSBYS DOWN TO ARND 1/2SM OR LESS FOR A
BRIEF PERIOD. IFR VSBY IN SNOW AND LOWERING CIGS ARE LIKELY...AND
WILL LIKELY PERSIST THROUGH THE AFTN. FURTHER REDUCTIONS COULD
OCCUR TOWARDS LIFR CATEGORIES DURING THE LATE MORNING HOURS AS
WARMER AIR ALOFT BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME
FREEZING RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING
TREND DURING THE MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING
BY MIDDAY...SO ANY LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO
LONGER PRODUCE A FREEZING THREAT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM/HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* MEDIUM/HIGH IN PRECIP TYPE.
* HIGH ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
813 PM CST MON MAR 2 2015
.UPDATE...
758 PM CST
THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO
THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL
REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A
STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD
ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY
MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY
TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT
AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER
ADVISORY AS IS.
JEE
&&
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...417 PM CST
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SOUTHEAST WINDS ARND 9KT THRU THIS EVENING...TURNING SOUTHWEST
ARND DAYBREAK AND INCREASING TO 12-15KT WITH GUSTS APPROACHING
20-25KT SHORTLY AFT DAYBREAK TUE.
* SNOW OVERSPREADING THE AIRFIELDS ARND 10-11Z...WITH POSSIBLY A
BURST OF MODERATE SNOW SHORTLY AFTER ONSET. SNOW BECOMES MIXED
WITH FREEZING RAIN/SLEET THEN POSSIBLY ALL RAIN BY MIDDAY.
* VFR CONDS RAPIDLY DETERIORATE TO IFR/LIFR AROUND DAYBREAK...AND
IFR OR LIFR CIGS COULD LINGER THRU TUE AFTN.
BEACHLER
//DISCUSSION...UPDATED 00Z...
QUIET THIS EVENING WITH VFR CONDS. CIRRUS DECK WILL CONTINUE TO
THICKEN THIS EVENING WITH ADDITIONAL MOISTURE LIFTING NORTH ACROSS
THE OZARKS TOWARDS NORTHERN IL/NORTHWEST IN AIRFIELDS...WHICH WILL
RAPIDLY LOWER CIGS TOWARDS IFR CONDS SHORTLY BEFORE DAYBREAK.
WINDS WILL TURN FROM SOUTHEAST TO SOUTHWEST AND INCREASE. GUSTS
DEVELOP AROUND DAYBREAK TO 25KT AND THEN RELAX SLIGHTLY TO 18KT
LATE TUE AFTN.
PRECIP TIMING AND TRANSITION REMAINS THE MAIN FOCUS FOR THE
OVERNIGHT HOURS THRU TUE MIDDAY. SNOW DEVELOPS PRIOR TO
DAYBREAK...AND WILL BEGIN MIXING WITH SLEET/FREEZING RAIN AROUND
13-15Z. PRIOR TO A MIXTURE OF PRECIP...A BURST OF MODERATE SNOW
MAY OCCUR AND COULD BRING VSBYS DOWN TO ARND 1/2SM OR LESS FOR A
BRIEF PERIOD. IFR VSBY IN SNOW AND LOWERING CIGS ARE LIKELY...AND
WILL LIKELY PERSIST THROUGH THE AFTN. FURTHER REDUCTIONS COULD
OCCUR TOWARDS LIFR CATEGORIES DURING THE LATE MORNING HOURS AS
WARMER AIR ALOFT BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME
FREEZING RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING
TREND DURING THE MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING
BY MIDDAY...SO ANY LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO
LONGER PRODUCE A FREEZING THREAT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* MEDIUM/HIGH IN PRECIP TYPE.
* HIGH ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
552 PM CST MON MAR 2 2015
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEWPOINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
417 PM CST
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SOUTHEAST WINDS ARND 9KT THRU THIS EVENING...TURNING SOUTHWEST
ARND DAYBREAK AND INCREASING TO 12-15KT WITH GUSTS APPROACHING
20-25KT SHORTLY AFT DAYBREAK TUE.
* SNOW OVERSPREADING THE AIRFIELDS ARND 10-11Z...WITH POSSIBLY A
BURST OF MODERATE SNOW SHORTLY AFTER ONSET. SNOW BECOMES MIXED
WITH FREEZING RAIN/SLEET THEN POSSIBLY ALL RAIN BY MIDDAY.
* VFR CONDS RAPIDLY DETERIORATE TO IFR/LIFR AROUND DAYBREAK...AND
IFR OR LIFR CIGS COULD LINGER THRU TUE AFTN.
BEACHLER
//DISCUSSION...UPDATED 00Z...
QUIET THIS EVENING WITH VFR CONDS. CIRRUS DECK WILL CONTINUE TO
THICKEN THIS EVENING WITH ADDITIONAL MOISTURE LIFTING NORTH ACROSS
THE OZARKS TOWARDS NORTHERN IL/NORTHWEST IN AIRFIELDS...WHICH WILL
RAPIDLY LOWER CIGS TOWARDS IFR CONDS SHORTLY BEFORE DAYBREAK.
WINDS WILL TURN FROM SOUTHEAST TO SOUTHWEST AND INCREASE. GUSTS
DEVELOP AROUND DAYBREAK TO 25KT AND THEN RELAX SLIGHTLY TO 18KT
LATE TUE AFTN.
PRECIP TIMING AND TRANSITION REMAINS THE MAIN FOCUS FOR THE
OVERNIGHT HOURS THRU TUE MIDDAY. SNOW DEVELOPS PRIOR TO
DAYBREAK...AND WILL BEGIN MIXING WITH SLEET/FREEZING RAIN AROUND
13-15Z. PRIOR TO A MIXTURE OF PRECIP...A BURST OF MODERATE SNOW
MAY OCCUR AND COULD BRING VSBYS DOWN TO ARND 1/2SM OR LESS FOR A
BRIEF PERIOD. IFR VSBY IN SNOW AND LOWERING CIGS ARE LIKELY...AND
WILL LIKELY PERSIST THROUGH THE AFTN. FURTHER REDUCTIONS COULD
OCCUR TOWARDS LIFR CATEGORIES DURING THE LATE MORNING HOURS AS
WARMER AIR ALOFT BEGINS TO CHANGE THE SNOW AND SLEET OVER TO SOME
FREEZING RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON A WARMING
TREND DURING THE MORNING...AND ARE EXPECTED TO WARM ABOVE FREEZING
BY MIDDAY...SO ANY LINGERING PRECIP AFTER THIS TIME WILL LIKELY NO
LONGER PRODUCE A FREEZING THREAT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH IN PRECIP TIMING/TREND EARLY TUESDAY. MEDIUM IN
CIG/VIS IMPACTS.
* MEDIUM/HIGH IN PRECIP TYPE.
* HIGH ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1113 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 637 AM CST SUN MAR 1 2015
OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR
RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH
TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE
BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME
PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE
LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF
THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK.
&&
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM CST SUN MAR 1 2015
VFR CONDITIONS FOR AT LEAST THE NEXT 24 HOURS. ANOTHER ARCTIC HIGH
PRESSURE SYSTEM WILL MOVE IN FROM THE NORTHERN PLAINS. SKIES WILL
CONTINUE TO CLEAR THIS AFTERNOON WITH LIGHT SOUTHWEST WINDS SHIFTING
TO THE NORTHWEST AT 5 TO 10 KTS BY DUSK...CONTINUING THEN INTO MID
DAY MONDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...NICHOLS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
644 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 637 AM CST SUN MAR 1 2015
OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR
RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH
TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE
BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME
PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE
LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF
THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK.
&&
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 535 AM CST SUN MAR 1 2015
TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID
MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO
CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED
ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW
MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG
WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST
MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS
AFTERNOON AND OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
542 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 535 AM CST SUN MAR 1 2015
TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID
MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO
CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED
ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW
MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG
WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST
MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS
AFTERNOON AND OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
257 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CST SAT FEB 28 2015
CONDITIONS EXPECTED TO DETERIORATE TO MVFR AND IFR OVERNIGHT INTO
SUNDAY AM IN LOW CLOUDS AND/OR FOG. PATCHY LIFR/VLIFR CONDITIONS IN
FOG WILL BE POSSIBLE. LIGHT SNOW LOOKS TO STAY JUST SOUTH OF BRL
TAF SITE THROUGH SUNDAY AM AND THUS LEFT OUT MENTION THOUGH A FEW
FLURRIES ALSO POSSIBLE AT TIMES AT ALL SITES. ANTICIPATE CIGS LIFTING
TO HIGH MVFR AND EVENTUALLY VFR SUNDAY PM WITH DEVELOPING SOUTHWEST
WINDS AROUND 10 KTS. WINDS WILL SHIFT TO WEST/NORTHWEST LATE PM
INTO EARLY EVE WITH VFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
602 PM MST MON MAR 2 2015
.UPDATE...
ISSUED AT 551 PM MST MON MAR 2 2015
JUST COMPLETED AN UPDATE. MODELS ARE NOT CATCHING THE FULL EXTENT
OF THE FOG. FOG HAS ALREADY DEVELOPED/ADVECTED INTO MOST LOCATIONS
IN THE WESTERN HALF OF THE FORECAST AREA. THIS IS FASTER AND
FURTHER EAST THAN THE MODEL DEPICTION. THE NAM LOOKS TO BE
CAPTURING THIS THE BEST. SO USED A BLEND OF REALITY AND THE LATEST
NAM TO INCREASE THE EXTENT OF THE FOG.
DAY SHIFT HAD SOME CONCERN ABOUT THE FOG BECOMING DENSE BUT WAS
THINKING THE WIND/MIXING WOULD PREVENT THAT. CURRENTLY THE NAM...
HRRR AND RAP ARE INDICATING DENSE FOG POSSIBLE FOR LOCATIONS ALONG
THE COLORADO BORDER. WHAT COMPLICATES THE EXTENT OF THE FOG AND
HOW LONG IT COULD STAY DENSE IS THE MODEL DIFFERENCE IN THE SPEED
THEY SWITCH THE WINDS TO A WESTERLY DIRECTION AS THEY BRING IN
DRIER AIR. BASED ON THE STRENGTH OF THE SURFACE TROUGH IT IS
POSSIBLE THE SLOWEST SOLUTIONS COULD BE RIGHT. THIS WOULD ALLOW A
LONGER PERIOD OF DENSE FOG. WILL KEEP MONITOR AND WAIT FOR THE
LATEST MODEL DATA TO SEE IF A DENSE FOG ADVISORY MAY BE NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 200 PM MST MON MAR 2 2015
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE REGION ARE
MOSTLY CLOUDY TO OVERCAST. WINDS ARE SOUTH AT 15 TO 25 MPH...GUSTING
35 MPH. TEMPERATURES RANGED FROM THE LOW 30S WHERE STRATUS PERSISTS
TO THE UPPER 30S WHERE CLOUD BREAKS ARE NOTED. AT THE SURFACE...LOW
PRESSURE IS LOCATED ALONG THE FRONT RANGE. ALOFT...A WEAK SHORTWAVE
AND MOISTURE ADVECTION IS MOVING IN FROM THE SOUTHWEST. THIS
DISTURBANCE IS EJECTING AHEAD OF A DEEP UPPER LOW OVER CALIFORNIA.
FOR THIS AFTERNOON/TONIGHT...MANY FORECAST COMPLICATIONS HAVE LEAD
TO LOWER CONFIDENCE THAN NORMAL. SEVERAL FACTORS ARE WORKING FOR
PRECIPITATION/FOG WHILE THERE ARE ALSO COMPETING FACTORS THAT COULD
NEGATE ANY POTENTIAL PRECIP/FOG THREAT. FIRST...BEGINNING WITH
PRECIPITATION CHANCES...A STRONG LOW LEVEL JET DEVELOPS THIS
EVENING. THIS RESULTS IN FURTHER WARM/MOIST AIR ADVECTION. IN
ADDITION...SLIGHT LIFT APPLIED BY PASSING SHORTWAVE MAY ALLOW FOR
SOME DRIZZLE/FREEZING DRIZZLE TO DEVELOP...MAINLY EAST OF HIGHWAY
25. HOWEVER...CONDENSATION PRESSURE DEFICITS INDICATE THAT MOST
DRIZZLE/FREEZING DRIZZLE AND ANY HEAVIER PRECIPITATION REMAINS
SOUTHEAST. IN ADDITION...ONLY A SHALLOW LAYER OF MOISTURE IS PRESENT
IN THE ATMOSPHERIC COLUMN SO NOT SURE IF THERE IS EVEN ENOUGH
MOISTURE TO PRECIPITATE. MOST LIKELY...PERSISTENT STRATUS CONTINUES
THROUGH THE NIGHT WITH A FEW SPORADIC OBSERVATIONS OF
DRIZZLE/FREEZING DRIZZLE. ANY PRECIPITATION EXITS TO THE EAST BY
SUNRISE. WITH COLD GROUND/ROAD TEMPERATURES...IT IS POSSIBLE THAT
DRIZZLE FREEZES ON CONTACT SO CAN NOT COMPLETELY RULE OUT A PATCHY
GLAZE. A COMPLICATING FACTOR TO THIS IS THE STRONG WARM AIR
ADVECTION. TEMPERATURES MAY REMAIN ABOVE FREEZING THROUGHOUT THE
NIGHT. THIS WOULD LIKELY ELIMINATE ANY THREAT OF ICE.
AS FOR THE FOG THREAT...SEVERAL HIGH RESOLUTION MODELS CONTINUE TO
INDICATE FOG DEVELOPMENT OVER EAST COLORADO SHORTLY AFTER SUNSET
WITH FOG ADVECTING EAST DURING THE EVENING. GUIDANCE INDICATES THAT
FOG MAY BE DENSE GIVEN THE AMOUNT OF MOISTURE ADVECTION INITIALLY.
HOWEVER...GUSTY SOUTH WINDS PERSIST THROUGH THE NIGHT. THIS
RESTRICTS HOW LOW VISIBILITIES DROP AND WOULD LEAD TO MORE STRATUS
AND LIGHT FOG OBSERVATIONS THAN DENSE FOG. HAVE NOT MENTIONED DENSE
FOG BUT DID MENTION PATCHY/AREAS OF FOG WHERE OCCURRENCE IS MOST
LIKELY. FOG DIMINISHES IN DENSITY/COVERAGE AFTER MIDNIGHT AS DRIER
AIR ADVECTS IN FROM THE SOUTHWEST. IT IS SOMEWHAT UNUSUAL THAT
VISIBILITIES IMPROVE BEFORE SUNRISE BUT THIS SHOULD BE ONE OF THOSE
CASES WHERE IT OCCURS.
DURING THE DAY TOMORROW...THE NEXT DISTURBANCE BEGINS TO PUSH IN
FROM THE WEST. IN ADDITION...A STRONG COLD FRONT WILL PUSH THROUGH
DURING THE MORNING. BEHIND THE COLD FRONT...GUSTY NORTHWEST WINDS
ARE LIKELY WITH GUIDANCE INDICATING PRESSURE RISES ON THE ORDER OF
10-15 MBS IN 6 HOURS. PRECIPITATION CHANCES LOOK MEAGER UNTIL BETTER
FORCING ARRIVES LATER IN THE AFTERNOON BUT CAN`T RULE OUT A FEW
FLURRIES ALONG AND JUST BEHIND THE FRONT. HIGH TEMPERATURES SHOULD
BE REACHED DURING THE MORNING WITH FALLING TEMPS THROUGH REMAINDER
OF THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 200 PM MST MON MAR 2 2015
THE MAIN FORECAST CONCERNS THROUGH THIS PERIOD ARE THE POSSIBILITY
OF SNOW TUESDAY NIGHT INTO WEDNESDAY MORNING AND THE CONTINUED
COLD TEMPERATURES.
THE THROUGH ALOFT OVER THE WESTERN UNITED STATES FINALLY SWEEPS
EAST OF THE ROCKIES AND ACROSS THE CENTRAL HIGH PLAINS REGION WITH
A COLD FRONT PUSHING SOUTH ACROSS THE FORECAST AREA TUESDAY NIGHT.
EXPECT SNOW TO DEVELOP ALONG THE FRONT AS IT MOVES SOUTH WITH SNOW
DIMINISHING FROM NORTH TO SOUTH WEDNESDAY MORNING. EXPECT 1-2
INCHES AT MOST OVER EASTERN COLORADO WITH AMOUNTS TAPERING OFF TO
LESS THAN ONE INCH FURTHER EAST.
IN ADDITION TO THE SNOW...10-15 MPH NORTH WINDS BEHIND THE FRONT
ON WEDNESDAY MORNING ALONG WITH LOW TEMPERATURES IN THE SINGLE
DIGITS ABOVE ZERO WILL PRODUCE WIND CHILLS IN THE -10 TO -15
DEGREE RANGE ACROSS THE FAR WESTERN PORTIONS OF THE FORECAST
AREA.
NO HIGHLIGHTS ARE CURRENTLY WARRANTED FOR EITHER THE SNOW OR THE
COLD WIND CHILLS AT THIS POINT...BUT MAY END UP MENTIONING THEM
IN THE HWO TO MAINTAIN SOME CONSISTENCY.
SIGNIFICANT WARMING TAKES PLACE OVER THE REMAINDER OF THE FORECAST
PERIOD AS TEMPERATURES COME UP TO NEAR NORMAL ON THURSDAY AND
REMAIN ABOVE NORMAL FOR FRIDAY THROUGH MONDAY. BOTH THE ECMWF AND
GFS AMPLIFY THE RIDGE OVER THE WESTERN U.S. THROUGH FRIDAY WITH
MAINLY NORTHWEST FLOW BEING MAINTAINED ACROSS THE FORECAST AREA.
THE GFS AND ECMWF BEGIN TO DIVERGE OVER THE WEEKEND WITH THE GFS
PLACING THE RIDGE OVER THE ROCKIES WHILE THE ECMWF RETROGRADES THE
RIDGE OVER THE WEST COAST. THE PATTERN FLATTENS AND BECOMES MORE
OUT OF PHASE BETWEEN MODELS BY TUESDAY...BUT THE END RESULT IS
THE CENTRAL HIGH PLAINS REGION REMAINS WARMER THAN AVERAGE AND DRY
INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 429 PM MST MON MAR 2 2015
FOR KGLD...WIDE RANGE OF CONDITIONS THIS EVENING. MVFR VISIBILITIES
WITH OCCASIONAL IFR/LIFR WILL OCCUR DURING THIS TIME. AT THE SAME
IFR CEILINGS ARE EXPECTED. LATE IN THE EVENING CONDITIONS WILL
BEGIN TO IMPROVE AS DOWNSLOPE WINDS AND DRIER STARTS MOVING IN.
MVFR TO OCCASIONAL IFR CONDITIONS WILL BECOME VFR AROUND 10Z.
HOWEVER THAT WILL BE SHORT LIVED AS A FRONT BEGINS TO MOVE THROUGH
WITH MVFR CEILINGS MOVING IN BEHIND IT. AROUND 19Z VFR CONDITIONS
WILL RETURN TO THE AREA. THROUGH THE NIGHT THE WINDS WILL REMAIN
GUSTY AS THEY START FROM A SOUTH DIRECTION AND THEN SHIFT TO THE
WEST TO NORTHWEST LATE IN THE NIGHT. AROUND 16Z THE WINDS WILL
SHIFT TO THE NORTH AND CONTINUE THROUGH THE REST OF THE DAY.
FOR KMCK...MVFR CEILINGS AT THE BEGINNING OF THE PERIOD WILL
BECOME IFR BY LATE EVENING. BY 09Z CONDITIONS WILL BRIEFLY BECOME
VFR. AS WITH KGLD...WHEN A FRONT BEGINS TO MOVE THROUGH...MVFR
CEILING MOVE IN BEHIND THE FRONT AND CONTINUE UNTIL MID AFTERNOON
VFR CONDITIONS RETURN.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...RRH
LONG TERM...LOCKHART
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
341 PM CST SUN MAR 1 2015
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 340 PM CST SUN MAR 1 2015
SOUTHWEST KANSAS FOUND ITSELF DOWNSTREAM OF WEAK SHORTWAVE RIDGING
AS A BIG UPPER LOW REMAINED ANCHORED OFF THE COAST OF SOUTHERN
CALIFORNIA. REMNANT COLD CANADIAN AIR REMAINED LOCKED IN PLACE WITH
ALMOST NO ADVECTION OCCURRING THANKS TO VERY LIGHT WINDS. THERE IS
SOME LIGHT NORTH-NORTHEAST WINDS AROUND 850MB, WHICH WILL CONTINUE
TO PUSH SOME LOWER RH AIR TOWARD SOUTHWEST KANSAS...AIDING IN THE
EVENTUAL SCOURING OUT OF STRATUS. WE WILL STILL SEE SOME MID AND
HIGH LEVEL CLOUD AROUND THROUGH THE EVENING AND OVERNIGHT, THOUGH,
AS WE REMAIN IN THE MOIST SOUTHWEST FLOW REGIME IN THE MID LEVELS.
TEMPERATURES WILL FALL IN TO THE LOWER 20S BY 09-12Z MONDAY MORNING,
AND WITH THE VERY LIGHT WINDS NEAR THE SURFACE RIDGE AXIS, WE WILL
LIKELY SEE SOME LIGHT FOG DEVELOPMENT, SO WE HAVE INCLUDED SOME
PATCHY FREEZING FOG ACROSS THE SOUTHERN COUNTIES (MAINLY SOUTH OF
THE ARKANSAS RIVER). DENSE FOG DEVELOPMENT, HOWEVER, APPEARS
UNLIKELY.
DURING THE DAY MONDAY, WE WILL SEE THE SOUTHERN CALIFORNIA UPPER LOW
MOVE SLOWLY EAST, AND THIS WILL LEAD TO LOW LEVEL DEVELOPMENT OF A
LEE TROUGH, BUT RIGHT UP AGAINST THE MOUNTAINS. THE CHANGE IN
PRESSURE GRADIENT WILL LEAD TO AN INCREASE IN SOUTH WINDS BY MIDDAY,
BUT THE WINDS WILL STILL BE COLD, WITH THE TRAJECTORIES COMING FROM
AROUND THE REMNANT SURFACE HIGH. AS A RESULT, WE HAVE BACKED OFF ON
TEMPERATURES A FEW DEGREES, ONLY EXPECTING HIGHS IN THE 35 TO 37F
RANGE AS A GENERAL RULE (COOLEST IN CENTRAL/SOUTH CENTRAL KANSAS).
ELKHART SHOULD TOUCH LOWER 40S BY LATE IN THE AFTERNOON CLOSER TO
THE LEE TROUGH AND SLIGHTLY WARMER LOWER TROPOSPHERE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CST SUN MAR 1 2015
STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY
NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS
NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT
EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING
INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO
THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE
AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG
NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES
FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF
THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY
LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW
ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE
MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS
THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO
DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE
AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST
KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE
MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT
AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR
TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID
30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE
AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS
TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS
TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED
WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS
AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS
THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN
THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS
LOOK TO DIP INTO THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 36 34 43 / 10 10 10 10
GCK 22 37 33 39 / 10 10 10 10
EHA 21 41 36 43 / 10 10 10 10
LBL 22 40 35 45 / 10 10 10 10
HYS 19 34 33 38 / 0 10 10 10
P28 19 35 33 47 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
243 PM CST SUN MAR 1 2015
...UPDATED LONG TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CST SUN MAR 1 2015
STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY
NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS
NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT
EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING
INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO
THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE
AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG
NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES
FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF
THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY
LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW
ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE
MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS
THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO
DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE
AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST
KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE
MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT
AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR
TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID
30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE
AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS
TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS
TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED
WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS
AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS
THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN
THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS
LOOK TO DIP INTO THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 36 34 43 / 10 10 10 10
GCK 18 37 33 39 / 10 10 10 10
EHA 20 41 36 43 / 20 10 10 10
LBL 23 40 35 45 / 10 10 10 10
HYS 17 34 33 38 / 10 20 10 10
P28 20 35 33 47 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1146 AM CST SUN MAR 1 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 10 20 10 10
LBL 34 23 43 37 / 10 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1137 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1136 AM CST SUN MAR 1 2015
For the 18z TAFs, scattered to broken MVFR cigs will persist
through the day as the storm system exits east of the area. As
surface high pressure moves over the area tonight into Monday,
northwesterly winds will veer toward the northeast and eventually
to the southeast by the end of the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1134 AM CST SUN MAR 1 2015
For the 12z TAFs, scattered to broken MVFR cigs will persist through
the day as the storm system exits east of the area. As surface high
pressure moves over the area tonight into Monday, northwesterly winds will
veer toward the northeast and eventually to the southeast by the end
of the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS WICHITA KS
1027 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1027 AM CST SUN MAR 1 2015
UPDATED PRECIPITATION CHANCES THROUGH THE EARLY PART OF THE
AFTERNOON. WHILE GUIDANCE IS NOT INDICATING MUCH...THE EARLIER
RUNS OF THE HRRR SEEMED TO DO THE BEST FOR CURRENT RADAR
INDICATIONS AND HAVE TRIED TO FOLLOW THAT FOR THE BEST TRENDS.
THINK THAT THE UPPER JET DYNAMICS WILL KEEP SOME LIFT AROUND INTO
THE EARLY AFTERNOON HOURS...AT LEAST OVER SOUTHERN AND
SOUTHEASTERN KANSAS. THIS WILL PRODUCE A WINTRY MIX OF FREEZING
RAIN/SLEET AND SNOW. THIS WILL CAUSE TRAVEL IMPACTS AND THUS HAVE
EXTENDED THE WINTER WEATHER ADVISORY UNTIL 20Z FOR MUCH OF THE
AREA...CLEARING OUT CENTRAL KANSAS COUNTIES WHERE THE
PRECIPITATION HAS ENDED. WILL PLAN TO CLEAR THE ADVISORY FROM WEST
TO EAST AS THE PRECIPITATION ENDS AND/OR EXTEND IF NEEDED IF THE
WINTRY WEATHER PERSISTS LONGER THAN 20Z. AT THIS TIME FEEL THAT
THE BEST CHANCE FOR THAT OCCURRING WOULD BE OVER SOUTHEAST
KANSAS...EXPECT CHANCES TO DIMINISH OVER SOUTH CENTRAL KANSAS
TOWARDS THE EARLY AFTERNOON HOURS. INCREASED ICE MENTION WITH THE
FREEZING RAIN...BUT ONLY A FEW HUNDREDTHS EXPECTED...ICING HAD
ALREADY OCCURRED AT THE WICHITA FORECAST OFFICE. SLICK ROADWAYS
ARE EXPECTED AS THIS PERSISTS.
BILLINGS WRIGHT
UPDATE ISSUED AT 735 AM CST SUN MAR 1 2015
HAVE MADE UPDATES TO POPS AND WEATHER OVER THE LAST HOUR.
INCREASED PRECIP CHANCES THIS MORNING OVER SOUTH CENTRAL AND SE KS
AS RADAR TRENDS CONTINUE TO SHOW RETURNS BUILDING BACK TO THE
SOUTHWEST. ALSO TOOK OUT MENTION OF FREEZING DRIZZLE AND ADDED
SLEET BASED ON REPORTS AND CURRENT OBS. NOT EXPECTING MUCH IN THE
WAY OF ACCUMULATIONS BUT MAYBE JUST ENOUGH TO KEEP ROADWAYS SLICK.
SO WILL MAINTAIN THE WINTER WEATHER ADVISORY.
LAWSON
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM CST SUN MAR 1 2015
THERE IS A CHANCE FOR A WEAK MID-LEVEL BAND OF SNOW TO DEVELOP OVER
CENTRAL KANSAS INTO EASTERN KANSAS EARLY THIS MORNING...WITH SOME
LIGHT SNOW AND LITTLE ACCUMULATION POSSIBLE...MAINLY NEAR THE
HIGHWAY 50 CORRIDOR. THE MAIN HAZARD FOR THIS MORNING WILL BE
AREAS OF DENSE FREEZING FOG AND PATCHY FREEZING DRIZZLE OVER SOUTH
CENTRAL AND SOUTHEAST KANSAS...WHICH COULD CREATE A LIGHT GLAZE ON
ELEVATED SURFACES AND UNTREATED ROADWAYS ALONG WITH REDUCED
VISIBILITIES TO AROUND ONE QUARTER OF A MILE.
DRY WEATHER IS EXPECTED FOR TONIGHT INTO EARLY MONDAY WITH A
CHANCE OF OF DRIZZLE POSSIBLY DEVELOPING MONDAY AFTERNOON...AS LOW
LEVEL MOISTURE RETURNS NORTHWARD. DAYTIME HIGHS ON MONDAY SHOULD
RISE SOME COMPARED TO SUNDAY`S HIGHS BUT VALUES WILL STILL BE
WELL BELOW NORMAL FOR EARLY MARCH...ESPECIALLY FOR THE SNOW
COVERED AREAS. CHANCES OF RAIN LOOK TO INCREASE FOR EASTERN KANSAS
ON MONDAY NIGHT INTO TUESDAY...WITH A FEW WEAK ELEVATED
THUNDERSTORMS POSSIBLE OVER FAR SOUTHEAST KANSAS. THE ARCTIC COLD
FRONT WILL SURGE SOUTHWARD ACROSS KANSAS DURING THE DAY ON
TUESDAY...WITH FALLING TEMPERATURES IN THE AFTERNOON ACCOMPANIED
BY STRONG GUSTY NORTH WINDS. THE COLDER AIR WOULD CHANGE THE
PRECIPITATION OVER TO A RAIN SNOW MIXTURE FOR CENTRAL KANSAS
TUESDAY AFTERNOON...WITH CHANCES OF LIGHT SNOW FOR TUESDAY NIGHT.
AT THIS JUNCTURE SNOW ACCUMULATIONS ARE LOOKING RATHER LOW FOR
TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 322 AM CST SUN MAR 1 2015
OTHER THAN SOME POSSIBLE LINGERING LIGHT SNOW FOR SOUTHEAST KANSAS
WEDNESDAY MORNING THE BETTER CHANCES SHOULD BE FOR LOCATIONS
SOUTHEAST OF THE AREA. DAYTIME HIGHS ON WEDNESDAY WILL BE WELL BELOW
NORMAL ESPECIALLY FOR SNOW COVER AREAS ACROSS SOUTHERN KANSAS.
OTHERWISE...A DRY WEATHER PATTERN WILL BE IN STORE FOR THURSDAY-
SATURDAY WITH A GRADUAL WARMING TREND FOR FRIDAY INTO THE WEEKEND.
JAKUB
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 530 AM CST SUN MAR 1 2015
MAIN AVIATION CONCERNS WILL BE FOG AND LOW CEILINGS THIS MORNING.
LOCALLY DENSE FOG DEVELOPED OVERNIGHT OVER MAINLY SOUTH CENTRAL
KS. KICT WAS THE MOST AFFECTED WITH LIFR VISIBILITIES AND
CEILINGS. CONDITIONS HAVE STARTED TO SLOWLY IMPROVE OVER THE LAST
HALF HOUR AND WOULD EXPECT THIS TO CONTINUE. HOWEVER...STILL
EXPECTING AT LEAST IFR CONDITIONS THIS MORNING AT KICT-KHUT. SOME
LIGHT SNOW/SLEET IS QUICKLY MAKING ITS WAY ACROSS SOUTH CENTRAL
AND SE KS AND WILL BE OUT OF THE FORECAST AREA IN THE NEXT HOUR.
NOT EXPECTING ANY ACCUMULATION WITH THIS. HIGH PRESSURE IS
EXPECTED TO SETTLE OVER THE AREA LATE THIS AFTERNOON THROUGH THE
OVERNIGHT HOURS WHICH WILL ALLOW VFR CONDITIONS TO MOVE BACK IN.
LAWSON
&&
.FIRE WEATHER...
ISSUED AT 322 AM CST SUN MAR 1 2015
FIRE WEATHER CONCERNS WILL REMAIN VERY LOW FOR THE NEXT SEVERAL DAYS
DUE TO SNOW COVER BLANKETING MUCH OF THE AREA...ALONG WITH RAIN
CHANCES FOR MONDAY NIGHT INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 31 20 35 34 / 50 10 20 30
HUTCHINSON 32 20 34 33 / 30 10 20 30
NEWTON 30 19 34 34 / 70 10 20 30
ELDORADO 30 20 35 34 / 50 10 20 40
WINFIELD-KWLD 31 21 36 35 / 50 10 20 40
RUSSELL 33 18 37 34 / 10 10 20 20
GREAT BEND 33 19 37 34 / 10 10 20 20
SALINA 34 20 36 33 / 20 10 20 30
MCPHERSON 32 19 35 33 / 30 10 20 30
COFFEYVILLE 33 22 37 36 / 40 10 20 60
CHANUTE 31 21 36 35 / 40 10 20 60
IOLA 31 20 36 35 / 50 10 20 60
PARSONS-KPPF 32 22 36 35 / 40 10 20 60
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR KSZ053-
067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
539 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Monday Morning)
Issued at 527 AM CST SUN MAR 1 2015
VFR prevails at KTOP/KFOE/KMHK as scattered light snow bands
develop south of KTOP/KFOE. Will occasionally see MVFR conditions
within the snow bands before coming to an end by 16Z. Currently
not confident enough for IFR cigs to reach KTOP/KFOE as there is some
uncertainty in guidance on where heavier snow band develops. MVFR
stratus develops after 16Z before incoming dry air with the high
pressure scatters out lower stratus to VFR this evening.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
529 AM CST SUN MAR 1 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 528 AM CST SUN MAR 1 2015
A LOW STRATUS CLOUD DECK WILL BLANKET SOUTHWEST KANSAS THROUGH THE
DAY WITH SOME IMPROVEMENT. LIFR CIGS ALONG WITH IFR VSBYS AT
GARDEN CITY AND DODGE CITY SHOULD IMPROVE INTO THE IFR AND VFR
CATEGORIES, RESPECTIVELY, AFTER 15Z. BY THIS AFTERNOON MVFR CIGS
SHOULD PREVAIL AT GARDEN CITY AND DODGE CITY WITH VFR CIGS AT
HAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
423 AM CST SUN MAR 1 2015
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INDICATE A NARROW BAND OF
WHAT WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID
MORNING. BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE
MORE OF AN ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN
MVFR STRATUS AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
350 AM CST SUN MAR 1 2015
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT
WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING.
BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN
ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS
AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 20 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...HOVORKA_42
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
257 AM CST Sun Mar 1 2015
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1125 PM CST SAT FEB 28 2015
WILL SCATTER OUT THE 2 KFT DECK AT THIS TIME AS PREVAILING CIGS
HEIGHT IS GENERALLY BETWEEN 3-4 KFT. WILL KEEP PREVAILING SNOW FOR
LIGHT BAND MOVING OVER TAF SITES BUT HAVE IMPROVED VSBY TO 4SM.
STILL HOLD LOWER CLOUDS TILL AROUND THE NOON HOUR BEFORE STARTING
TO LIFT AND CLEAR OUT LATER IN THE PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...67
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
112 AM CST SUN MAR 1 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CST SAT FEB 28 2015
AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE
WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS
ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR
LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE
LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE
SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS
WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A
CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z
RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN
THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT
PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY
THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS
THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A
FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN
THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE
SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT
THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET
AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE
ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION
TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE
INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER
WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE
MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY
AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT
WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING.
BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN
ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS
AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 20 38 35 / 60 20 20 20
GCK 31 19 40 34 / 30 20 20 10
EHA 33 21 45 38 / 20 30 20 10
LBL 34 22 43 37 / 30 20 10 10
HYS 35 21 39 33 / 30 20 20 20
P28 32 22 39 35 / 60 10 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ046-064>066-
076>081-086>090.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
104 PM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1253 PM EST SUN MAR 1 2015
ENDED UP EXTENDING THE WSW AND SPS FOR FREEZING RAIN POTENTIAL TO
11AM THIS MORNING BASED ON THE CURRENT /AT THE TIME/ TEMPERATURES
ACROSS THE CWA...AND REPORTS OF CONTINUED SLICK SPOTS ON AREA
ROADWAYS. TEMPERATURES IN MOST AREAS WITHIN THE WSW OR SPS
CONTINUED TO RISE THROUGHOUT THE MORNING...AND WERE SEVERAL
DEGREES ABOVE FREEZING BY THE EXPIRATION OF THE HEADLINES...SO HAD
NO NEED TO CONTINUE THE WSW OR SPS ANY LONGER. DURING THE INITIAL
EXTENSION OF THE PRODUCTS...ALSO WENT IN AND UPDATED THE WEATHER
IN THE FORECAST TO REFLECT THE POSSIBILITY OF FREEZING RAIN IN
VALLEY LOCATIONS WITHIN THE WSW AREA. THIS HAS SINCE FALLEN OUT OF
THE FORECAST AS WELL.
CURRENTLY...A DECENT BAND OF PRECIPITATION IS CONTINUING ACROSS
THE NORTHERN CWA...AND MOVING INTO THE SOUTHWESTERN CWA. THIS
MATCHES UP WELL WITH THE UPDATED FORECAST FROM A FEW HOURS AGO.
WITH TEMPERATURES WELL ABOVE FREEZING AT THIS POINT...EXPECT ALL
OF THIS PRECIPITATION TO CONTINUE IN THE FORM OF LIGHT RAIN. WILL
BE LOADING IN THE LATEST OBSERVATIONAL DATA AT THE TOP OF THE HOUR
FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THAT THE NEAR
TERM FORECAST IS ON TRACK WITH THE ONGOING CONDITIONS.
UPDATE ISSUED AT 647 AM EST SUN MAR 1 2015
CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME
SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL
JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS
MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME
SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE
RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN
FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST
WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE
BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE
SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT
DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS
MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD
ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY
AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW
HIGHLIGHTED.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 104 PM EST SUN MAR 1 2015
LIGHT RAIN SHOWERS CONTINUE ACROSS CENTRAL AND NORTHEAST KY AT
THIS TIME...WITH ALMOST EVERY TAF SITE BEING IMPACTED. SO
FAR THE RAIN REMAINS FAIRLY LIGHT...WITH ONLY MVFR RESTRICTIONS
TO VIS. THE HEAVIEST RAIN WILL CONTINUE TO BE ACROSS THE NORTHERN
FORECAST AREA...WITH KSYM POSSIBLY SEEING SOME TEMPORARILY DROPS
DOWN TO IFR VIS CONDITIONS IN SOME OF THE HEAVIER BURSTS.
OVERALL...MOST OF CENTRAL AND EASTERN KY CONTINUES TO SEE MVFR
SKIES...AND EXPECT THIS TO CONTINUE THROUGH AT LEAST THIS EVENING.
WOULDN/T BE SURPRISED IF WE DROPPED TO IFR LATER ON TONIGHT AS WE
SEE SOME OF OUR BEST SATURATION. THERE IS STILL THE POTENTIAL THAT
SOME SNOW COULD MIX IN WITH THE RAIN ON THE BACK SIDE OF THIS
SYSTEM...JUST BEFORE TAPERING OFF SOON AFTER. TRIED TO TIME THIS
OUT IN THE FORECAST...WITH MOST OF THE SNOW EXPECTED TO BE AFTER
AROUND 6-7Z. PRECIP WILL BE ENDING SOMETIME TOMORROW
MORNING...WITH SKIES SLOWLY BREAKING UP DURING THE DAY. WINDS WILL
SHIFT BACK TO A MORE NW TO NRLY DIRECTION...BUT SHOULD GENERALLY
REMAIN BELOW 10KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
648 AM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 647 AM EST SUN MAR 1 2015
CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME
SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL
JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS
MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME
SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE
RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN
FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST
WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE
BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE
SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT
DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS
MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD
ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY
AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW
HIGHLIGHTED.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 647 AM EST SUN MAR 1 2015
EXPECT FIELD MIN CIGS TO DEVELOP AT JUST ABOUT EVERY TAF SITE AS
A GOOD AREA OF RAIN ARRIVES INTO THE AREA THIS MORNING AND INTO
THE DAY TODAY. EXPECT SOME IFR VISIBILITY AS WELL. THESE
CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD
AND PAST 00Z TONIGHT. AFTER 06Z TONIGHT...RAIN WILL CHANGE TO SNOW
WITH SOME LOCATIONS SEEING SIGNIFICANT REDUCTION IN VIS. WINDS
WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE
THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR KYZ088-
106>115-117>120.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
343 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
212 AM EST SUN MAR 1 2015
.MESOSCALE DISCUSSION...
ISSUED AT 212 AM EST SUN MAR 1 2015
THE MAIN SURGE OF MOISTURE CONTINUES TO STAY TO THE NORTH AS OF
07Z WITH ONLY LIGHT RETURNS...LIKELY VIRGA...OVER THE BLUEGRASS
REGION. MESONETS IN CENTRAL KY WELL NORTH OF I-64 ARE THE ONLY
LOCATIONS INDICATING MEASURABLE PRECIP. THOUGH AIR TEMPS ACROSS
THE AREA ARE REACHING FREEZING IN THE BLUEGRASS AREAS BUT
ALSO...AS CONCERNING AS THIS IS...IN SOME OF THE DEEPER VALLEYS IN
THE FAR EAST OF EASTERN KENTUCKY...SUCH AS THE PAINTSVILLE MESONET
WHERE A CHILLY 30 DEGREES IS DISPLAYED. AS WELL...MOST DEW POINT
DEPRESSIONS ARE STILL A GOOD 10 DEGREES PLUS IN MANY AREAS. IN
ADDITION...HI RES MODELS SUCH AS THE HRRR SHOW PRECIP HOLDING OFF
UNTIL 10Z AND AFTER. THE GENERAL CONSENSUS HERE IS THAT THE BULK
OF THE MOISTURE WILL STAY NORTH WHILE WHAT RESIDUAL MOISTURE
ADVECTING IN FROM THE SOUTHWEST WILL NOT BE ABLE TO SATURATING THE
LAYER FOR PRECIP TO REACH THE SURFACE. ONCE THIS DOES OCCUR...THE
CURRENT ROAD TEMPS...NOW IN THE MID TO UPPER 30S...WOULD SUGGEST A
SUBSTANTIAL COOL DOWN NEEDED FOR ICE ON ROADWAYS TO DEVELOP. THESE
TEMPS SHOULD HOLD OFF UNTIL AFTER DAWN WHEN TEMPS WARM AGAIN. DUE
TO THE THREAT AND THE FACT THAT 0.01 OF FZRA COULD OCCUR...THIS
STILL NEEDS TO BE A SLIGHT REMINDER SO HAVE REISSUED THE SPS
THROUGH DAWN.
&&
.UPDATE...
ISSUED AT 958 PM EST SAT FEB 28 2015
MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE
ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS.
DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE
SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE
QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO
PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE
A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS
BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT
THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER
WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING
RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND
TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER
TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE
FORECAST AS IS.
UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015
OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING
RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE
HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z
TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY
ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING
RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY
ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS
THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND
DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE
EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A
TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD
AIR GETS SCOURED OUT IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SAT FEB 28 2015
WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING
HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL
BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL
THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL
KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP
INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE
CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT
ICE AND SNOW POTENTIAL.
LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR
GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS...
CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE
ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS
SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3
HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING
BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY
A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL
JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN
A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST
SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM
ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO
15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY
INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE
AFTERNOON...GENERALLY IN THE 40S.
FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE
CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY
NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL
THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER
DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY
MORNING AS HIGH PRESSURE MOVES IN OVERHEAD.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 451 PM EST SAT FEB 28 2015
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A
POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST
FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW
FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND
TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH
WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE
FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING
PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD
AND DRY.
DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER
CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE
STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS
SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY
FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT
RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH
THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS
WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC
OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY
TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS
WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD
THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON
TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL
FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE
HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING
HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK
INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR
THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S
FOR SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE...SHALLENBERGER
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1234 AM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 958 PM EST SAT FEB 28 2015
MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE
ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS.
DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE
SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE
QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO
PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE
A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS
BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT
THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER
WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING
RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND
TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER
TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE
FORECAST AS IS.
UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015
OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING
RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE
HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z
TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY
ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING
RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY
ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS
THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND
DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE
EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A
TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD
AIR GETS SCOURED OUT IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SAT FEB 28 2015
WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING
HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL
BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL
THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL
KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP
INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE
CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT
ICE AND SNOW POTENTIAL.
LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR
GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS...
CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE
ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS
SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3
HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING
BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY
A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL
JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN
A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST
SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM
ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO
15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY
INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE
AFTERNOON...GENERALLY IN THE 40S.
FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE
CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY
NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL
THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER
DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY
MORNING AS HIGH PRESSURE MOVES IN OVERHEAD.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 451 PM EST SAT FEB 28 2015
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A
POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST
FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW
FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND
TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH
WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE
FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING
PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD
AND DRY.
DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER
CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE
STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS
SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY
FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT
RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH
THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS
WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC
OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY
TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS
WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD
THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON
TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL
FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE
HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING
HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK
INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR
THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S
FOR SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
923 PM EST MON MAR 2 2015
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS EVENING. HIGH
PRESSURE WILL RIDGE ACROSS THE AREA ON TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
921 PM UPDATE...COLD AIR WILL CONTINUE TO POUR INTO THE CWA
OVERNIGHT ON A GUSTY NW WIND. THE WIND WILL CONTINUE TO PRODUCE
QUITE A BIT OF BLOWING AND DRIFTING SNOW OVERNIGHT IN OPEN
AREAS...ESPECIALLY ALONG THE ROUTES 1...161 AND 11 CORRIDORS. DID
AN UPDATE EARLIER TO ADD BLOWING SNOW TO THE FORECAST. HAVE ISSUED
SPECIAL WEATHER STATEMENTS ALONG AND AHEAD OF A SNOW SQUALL THAT
IS NOW WEAKENING AS IT MOVES INTO NORTHERN WASHINGTON COUNTY. WILL
ISSUE ANOTHER SPS FOR THE OVERNIGHT HOURS TO HIGHLIGHT THE
BLOWING AND DRIFTING SNOW. ELECTED TO NOT COMPLICATE THE ISSUE BY
REPLACING THE WIND CHILL ADVISORIES WITH WINTER WEATHER
ADVISORIES AS THE BLOWING AND DRIFTING SNOW WILL BEGIN TO DIMINISH
TOWARD MORNING.
PREVIOUS DISCUSSION...
SNOW SHOWERS/SQUALLS THIS EVENING AND THEN MUCH COLDER. WIND
CHILLS WILL BE THE MAIN CONCERN OVERNIGHT INTO TUESDAY MORNING.
20Z SURFACE ANALYSIS SHOWED THE ARCTIC FRONT MAKING ITS WAY SE
ACROSS THE REGION. THE FIRST BATCH OF SNOW SHOWERS/SQUALLS OUT
AHEAD OF THE BOUNDARY THIS AFTERNOON PER THE RADAR. ANOTHER ROUND
SETTING UP AND WILL DIVE SE W/THE UPPER LEVEL SUPPORT EARLY THIS
EVENING. THE LATEST RUN OF THE HRRR 3KM AND RAP MODEL DOING WELL
W/THE PLACEMENT OF THE SNOW MATCHING UP W/THE RADAR TRENDS. LAPSE
RATES ARE STEEPENING ATTM ESPECIALLY FROM 850-700MBS(7.0 C/KM).
THIS COMBINED W/DECENT SHEAR AT 0-3KM OF 35 KTS AND FORECAST CAPE
80+ JOULES WILL BE ENOUGH TO GET SOME MORE SQUALLS GOING. 12Z
UPPER AIR ANALYSIS SUPPORTED THE MODEL SOUNDINGS W/DEEP MOISTURE
THROUGH 700MBS. THE HEAVIEST ACTIVITY WILL RESIDE FROM THE ST.
JOHN VALLEY DOWN THROUGH CARIBOU-PRESQUE ISLE DOWN INTO HOULTON.
ANOTHER AREA OF HEAVY SNOW SHOWERS/SQUALLS IS FORECAST TO DROP
ACROSS PORTIONS OF CENTRAL MAINE INCLUDING THE MILLINOCKET-PATTEN
AREA ALONG ROUTE 11 AND PORTIONS OF I-95. BRIEF HEAVY SNOW BURSTS
W/WIND GUSTS TO 35 MPH WILL LEAD TO BRIEF WHITEOUTS AND VSBY 1/4
OF A MILE OR LESS. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
EVENING AS SKIES BEGIN TO CLEAR AND THE FRONT PUSHES TO THE COAST.
WINDS WILL REMAIN UP AT 15 TO 25 MPH SUSTAINED THROUGH THE
OVERNIGHT PERIOD W/GUSTS AT LEAST 30 MPH. THESE WINDS COMBINED
W/THE ARCTIC AIRMASS MOVING IN WILL LEAD TO SOME DANGEROUS WIND
CHILLS ACROSS THE NORTHERN 1/2 OF THE CWA. WIND CHILL ADVISORIES
REMAIN UP FOR NORTHERN AREAS THROUGH TUESDAY MORNING. ATTM, IT
LOOKS LIKE THE CENTRAL HIGHLANDS AND DOWNEAST WILL SEE WIND CHILLS
STAY ABOVE ADVISORY CRITERIA OF -20F.
FOR TUESDAY, HIGH PRES IS FORECAST TO RIDGE ACROSS THE REGION
W/DAYTIME TEMPERATURES BELOW NORMAL FOR EARLY MARCH. CLOUDS WILL
BE ON THE INCREASE LATER IN THE AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM TO AFFECT OUR REGION. THIS IS EXPLAINED MORE IN THE SHORT
TERM SECTION BELOW.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LOOKING FOR ANOTHER SNOW EVENT TUESDAY NIGHT JUST AHEAD OF A WARM FRONT
MOVING FROM WEST TO EAST THROUGH THE AREA SOUTH OF THE PARENT LOW
PASSING WELL TO OUR NORTH. TEMPERATURES WILL BE RISING THROUGH THE
NIGHT TUESDAY NIGHT, BUT THINK THAT FOR THE VAST MAJORITY OF
AREAS, THIS WILL BE AN ALL SNOW EVENT, PERHAPS ENDING AS JUST A BIT
OF LIGHT RAIN NEAR THE COAST. LOOKING FOR ABOUT 3 TO 5 INCHES OF
SNOW.
AFTER THE WARM FRONT PASSES LATE TUESDAY NIGHT, WE ARE LOOKING FOR
A WARM DAY WEDNESDAY WITH HIGHS ABOVE FREEZING FOR PRETTY MUCH
EVERYWHERE, AND EVEN IN THE LOW 40S DOWNEAST. THE WARMTH IS
SHORT LIVED, HOWEVER, AS THE COLD FRONT MOVES THROUGH LATE
WEDNESDAY. THURSDAY WILL BE MUCH COOLER WITH TEMPERATURES NEAR
STEADY IN THE TEENS TO LOW 20S. THERE MAY BE A FEW SNOW SHOWERS
WITH AND BEHIND THE FRONT LATE WEDNESDAY INTO THURSDAY, BUT
NOTHING MAJOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LOOK FOR BELOW AVERAGE TEMPERATURES TO PERSIST FRIDAY THROUGH
EARLY NEXT WEEK. WE DO NOT FORESEE ANY MAJOR STORMS, BUT THERE
COULD BE A FEW WEAK ONES BEYOND FRIDAY AFTER WEAK HIGH PRESSURE
OVER THE AREA WEAKENS. TOO MUCH MODEL DISAGREEMENT TO TIME THE
WEAK SYSTEMS THIS FAR OUT.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR FOR THE MOST PART FOR ALL TERMINALS INTO TUE.
BRIEF IFR IN ISOLATED SNOW SHOWERS AND AREAS OF BLOWING SNOW
TONIGHT AS A NW SFC WIND GUSTS TO 35 KNOTS. THE WIND WILL DIMINISH
TUE MORNING.
SHORT TERM: IFR OR WORSE AREAWIDE TUESDAY NIGHT WITH SNOW.
PRECIPITATION TAPERING OFF WEDNESDAY THROUGH THURSDAY WITH
GENERALLY VFR, THOUGH MVFR COULD LINGER IN THE NORTH ESPECIALLY
WEDNESDAY.
&&
.MARINE...
NEAR TERM: GALES ARE OCCURRING NOW AS THE COLD AIR POURS OUT OVER
THE WATERS. WINDS ARE EXPECTED TO DROP BACK TO SCA LEVELS BY
EARLY TUESDAY MORNING. THE SCA LOOKS TO BE SHORT LIVED AS HIGH
PRES RIDGES IN FROM THE SOUTH. SEAS OF 5 TO 8 FT OVERNIGHT WILL
SUBSIDE TUE. FREEZING SPRAY WILL BE DEVELOPING OVERNIGHT INTO
EARLY TUE MORNING.
SHORT TERM: EXPECT PROLONGED SMALL CRAFT CONDITIONS TUESDAY NIGHT
THROUGH THURSDAY NIGHT. WINDS WILL SHIFT FROM SOUTH TO NORTHWEST
AS A SYSTEM MOVES THROUGH. SEAS WILL PEAK AROUND 9 FEET ON
WEDNESDAY.
&&
.CLIMATE...
THE METEOROLOGICAL WINTER WHICH IS THE 3 MONTH PERIOD
OF DECEMBER THROUGH FEBRUARY HAD AN AVERAGE TEMPERATURE OF 16.8
DEGREES AT BANGOR. IT WAS THE COLDEST SINCE THE WINTER OF
2002-03.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 2 AM TO 7 AM EST TUESDAY FOR
MEZ001>004.
MARINE...FREEZING SPRAY ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR
ANZ050>052.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...FOISY
LONG TERM...FOISY
AVIATION...CB/HEWITT/FOISY
MARINE...CB/HEWITT/FOISY
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
617 PM EST MON MAR 2 2015
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS EVENING. HIGH
PRESSURE WILL RIDGE ACROSS THE AREA ON TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
617 PM...A COLD FRONT IS CROSSING THE REGION THIS EVENING. A LINE
OF SNOW SHOWERS EXTENDS FROM NEAR MASARDIS TO MONTICELLO IN
AROOSTOOK COUNTY. THE LINE IS MOVING SOUTHEAST AT AROUND 30 MPH
AND WILL WEAKEN AS IT MOVES TOWARD NORTHERN WASHINGTON COUNTY OVER
THE NEXT COUPLE OF HOURS. A QUICK INCH OF SNOW...WIND GUSTS TO 35
MPH...AND LOCAL WHITEOUTS WILL ACCOMPANY THIS LINE OF SNOW
SHOWERS. ELSEWHERE JUST ISOLATED SNOW SHOWERS THAT WILL DISSIPATE
WITHIN THE NEXT HOUR OR TWO. MUCH COLDER AIR WILL FILTER INTO THE
AREA TONIGHT WITH WIND CHILLS TO DROP TO AROUND 25 BELOW ACROSS
FAR NORTHERN MAINE AFTER MIDNIGHT. THE MAIN UPDATE WAS TO ADJUST
THE POPS TO BETTER REFLECT THE LATEST RADAR TRENDS.
PREVIOUS DISCUSSION...
SNOW SHOWERS/SQUALLS THIS EVENING AND THEN MUCH COLDER. WIND
CHILLS WILL BE THE MAIN CONCERN OVERNIGHT INTO TUESDAY MORNING.
20Z SURFACE ANALYSIS SHOWED THE ARCTIC FRONT MAKING ITS WAY SE
ACROSS THE REGION. THE FIRST BATCH OF SNOW SHOWERS/SQUALLS OUT
AHEAD OF THE BOUNDARY THIS AFTERNOON PER THE RADAR. ANOTHER ROUND
SETTING UP AND WILL DIVE SE W/THE UPPER LEVEL SUPPORT EARLY THIS
EVENING. THE LATEST RUN OF THE HRRR 3KM AND RAP MODEL DOING WELL
W/THE PLACEMENT OF THE SNOW MATCHING UP W/THE RADAR TRENDS. LAPSE
RATES ARE STEEPENING ATTM ESPECIALLY FROM 850-700MBS(7.0 C/KM).
THIS COMBINED W/DECENT SHEAR AT 0-3KM OF 35 KTS AND FORECAST CAPE
80+ JOULES WILL BE ENOUGH TO GET SOME MORE SQUALLS GOING. 12Z
UPPER AIR ANALYSIS SUPPORTED THE MODEL SOUNDINGS W/DEEP MOISTURE
THROUGH 700MBS. THE HEAVIEST ACTIVITY WILL RESIDE FROM THE ST.
JOHN VALLEY DOWN THROUGH CARIBOU-PRESQUE ISLE DOWN INTO HOULTON.
ANOTHER AREA OF HEAVY SNOW SHOWERS/SQUALLS IS FORECAST TO DROP
ACROSS PORTIONS OF CENTRAL MAINE INCLUDING THE MILLINOCKET-PATTEN
AREA ALONG ROUTE 11 AND PORTIONS OF I-95. BRIEF HEAVY SNOW BURSTS
W/WIND GUSTS TO 35 MPH WILL LEAD TO BRIEF WHITEOUTS AND VSBY 1/4
OF A MILE OR LESS. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
EVENING AS SKIES BEGIN TO CLEAR AND THE FRONT PUSHES TO THE COAST.
WINDS WILL REMAIN UP AT 15 TO 25 MPH SUSTAINED THROUGH THE
OVERNIGHT PERIOD W/GUSTS AT LEAST 30 MPH. THESE WINDS COMBINED
W/THE ARCTIC AIRMASS MOVING IN WILL LEAD TO SOME DANGEROUS WIND
CHILLS ACROSS THE NORTHERN 1/2 OF THE CWA. WIND CHILL ADVISORIES
REMAIN UP FOR NORTHERN AREAS THROUGH TUESDAY MORNING. ATTM, IT
LOOKS LIKE THE CENTRAL HIGHLANDS AND DOWNEAST WILL SEE WIND CHILLS
STAY ABOVE ADVISORY CRITERIA OF -20F.
FOR TUESDAY, HIGH PRES IS FORECAST TO RIDGE ACROSS THE REGION
W/DAYTIME TEMPERATURES BELOW NORMAL FOR EARLY MARCH. CLOUDS WILL
BE ON THE INCREASE LATER IN THE AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM TO AFFECT OUR REGION. THIS IS EXPLAINED MORE IN THE SHORT
TERM SECTION BELOW.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LOOKING FOR ANOTHER SNOW EVENT TUESDAY NIGHT JUST AHEAD OF A WARM FRONT
MOVING FROM WEST TO EAST THROUGH THE AREA SOUTH OF THE PARENT LOW
PASSING WELL TO OUR NORTH. TEMPERATURES WILL BE RISING THROUGH THE
NIGHT TUESDAY NIGHT, BUT THINK THAT FOR THE VAST MAJORITY OF
AREAS, THIS WILL BE AN ALL SNOW EVENT, PERHAPS ENDING AS JUST A BIT
OF LIGHT RAIN NEAR THE COAST. LOOKING FOR ABOUT 3 TO 5 INCHES OF
SNOW.
AFTER THE WARM FRONT PASSES LATE TUESDAY NIGHT, WE ARE LOOKING FOR
A WARM DAY WEDNESDAY WITH HIGHS ABOVE FREEZING FOR PRETTY MUCH
EVERYWHERE, AND EVEN IN THE LOW 40S DOWNEAST. THE WARMTH IS
SHORT LIVED, HOWEVER, AS THE COLD FRONT MOVES THROUGH LATE
WEDNESDAY. THURSDAY WILL BE MUCH COOLER WITH TEMPERATURES NEAR
STEADY IN THE TEENS TO LOW 20S. THERE MAY BE A FEW SNOW SHOWERS
WITH AND BEHIND THE FRONT LATE WEDNESDAY INTO THURSDAY, BUT
NOTHING MAJOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LOOK FOR BELOW AVERAGE TEMPERATURES TO PERSIST FRIDAY THROUGH
EARLY NEXT WEEK. WE DO NOT FORESEE ANY MAJOR STORMS, BUT THERE
COULD BE A FEW WEAK ONES BEYOND FRIDAY AFTER WEAK HIGH PRESSURE
OVER THE AREA WEAKENS. TOO MUCH MODEL DISAGREEMENT TO TIME THE
WEAK SYSTEMS THIS FAR OUT.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
NEAR TERM: VFR FOR THE MOST PART FOR ALL TERMINALS INTO TUESDAY.
THE EXCEPTION WILL BE THIS EVENING AS SOME SNOW SQUALLS COULD
BRING CONDITIONS DOWN BRIEFLY TO MVFR/IFR MAINLY FOR THE NORTHERN
TERMINALS.
SHORT TERM: IFR OR WORSE AREAWIDE TUESDAY NIGHT WITH SNOW.
PRECIPITATION TAPERING OFF WEDNESDAY THROUGH THURSDAY WITH
GENERALLY VFR, THOUGH MVFR COULD LINGER IN THE NORTH ESPECIALLY
WEDNESDAY.
&&
.MARINE...
NEAR TERM: GALES ARE STILL EXPECTED THIS EVENING AND OVERNIGHT AS
CAA HITS THE WATERS AND THE PRES GRADIENT TIGHTENS. GUST POTENTIAL
IS POSSIBLE FOR GUSTS TO 40 KTS. WINDS ARE EXPECTED TO DROP BACK
TO SCA LEVELS BY EARLY TUESDAY MORNING. THE SCA LOOKS TO BE SHORT
LIVED AS HIGH PRES RIDGES IN FROM THE SOUTH. SEAS ARE COMING UP
BUT AT LEAST A FOOT UNDER WHAT WAS PREVIOUSLY FORECAST. STAYED
CLOSE TO MIDNIGHT CREW`S ASSESSMENT OF THOSE WAVE HEIGHTS
BUILDING W/A RANGE OF 5 TO 8 FT OVERNIGHT AND THEN COMING DOWN ON
TUESDAY. FREEZING SPRAY WILL BE DEVELOPING LATER THIS EVENING
RIGHT INTO EARLY TUESDAY MORNING W/SOME MODERATE ICE ACCRETION.
SHORT TERM: EXPECT PROLONGED SMALL CRAFT CONDITIONS TUESDAY NIGHT
THROUGH THURSDAY NIGHT. WINDS WILL SHIFT FROM SOUTH TO NORTHWEST
AS A SYSTEM MOVES THROUGH. SEAS WILL PEAK AROUND 9 FEET ON
WEDNESDAY.
&&
.CLIMATE...THE METEOROLOGICAL WINTER WHICH IS THE 3 MONTH PERIOD
OF DECEMBER THROUGH FEBRUARY HAD AN AVERAGE TEMPERATURE OF 16.8
DEGREES AT BANGOR. IT WAS THE COLDEST SINCE THE WINTER OF
2002-03.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 2 AM TO 7 AM EST TUESDAY FOR
MEZ001>004.
MARINE...FREEZING SPRAY ADVISORY FROM 1 AM TO 10 AM EST TUESDAY FOR
ANZ050>052.
GALE WARNING UNTIL 6 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...FOISY
LONG TERM...FOISY
AVIATION...CB/HEWITT/FOISY
MARINE...CB/HEWITT/FOISY
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
337 PM EST SUN MAR 1 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS
EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY.
THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH
PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM
THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW
SQUALL POTENTIAL ON MONDAY.
18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING
ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE
LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF
TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN
AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN
AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE
CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS
LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS
COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS
THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE
SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE
RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS
SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY
EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW
PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE
TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF
SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS
THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF
MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES
OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST
AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER
WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N
AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER
W/A GENERAL 1-3 INCHES AT BEST.
FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND
DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF
AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM
OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE
SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS
SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT
850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN
ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE
REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2
AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS
AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP
OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF
SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30
MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A
WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE
FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING
SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO
WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT
LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS
TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY
AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN
A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL
OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY
AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE
EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK
SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY
COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: VFR DROPPING TO MVFR LATER THIS EVENING AND THEN IFR
OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST TO IMPROVE TO
VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN TERMINALS
GOING FROM IFR TO MVFR.
SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA
TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE
AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY
AFTERNOON.
&&
.MARINE...
NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING
FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT
MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO
HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST
POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS
HANDLED WELL AND STAYED CLOSE TO IT.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEED FOR OUR
COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS
CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
MONDAY FOR MEZ029-030.
MARINE...GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...BERDES
LONG TERM...BERDES
AVIATION...HEWITT/BERDES
MARINE...HEWITT/BERDES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
127 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON. LOW
PRESSURE WILL CROSS THE REGION TONIGHT INTO MONDAY. HIGH PRESSURE
WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...FIRST BATCH OF CLOUDS PULLING EASTWARD PER THE
LATEST SATELLITE LOOP W/SOME PARTIAL CLEARING. THIS WILL ALLOW FOR
SOME WARMING INTO LATE AFTERNOON. ANOTHER AREA OF CLOUDS
ASSOCIATED W/THE STORM SYSTEM MOVING INTO THE OHIO VALLEY SET TO
ADVANCE INTO THE REGION. THEREFORE ADJUSTED MAX TEMPS UP A FEW
DEGREES W/SOME NORTHERN AREAS HITTING THE UPPER 20S AND DOWNEAST
TOPPING 30F.
REGIONAL RADAR LOOP SNOW SOME PRECIP(LIGHT) MOVING ACROSS SOUTHERN
NEW ENGLAND TOWARD SOUTHERN MAINE. THE MORE SIGNIFICANT PRECIP
WAS MOVING ACROSS LONG ISLAND. THE RAP AND HRRR 3KM MODELS WERE
DOING WELL W/THIS SETUP W/DRY CONDITIONS INTO EARLY EVENING. SNOW
EXPECTED TO DEVELOP LATER IN THE EVENING ACROSS THE SW AND
DOWNEAST AND SPREAD NE OVERNIGHT INTO MONDAY. MORE ON THIS LATER.
A LOW PRESSURE SYSTEM WILL DEEPEN SIGNIFICANTLY AS IT CROSSES THE
GULF OF MAINE OVERNIGHT ENROUTE TO HALIFAX. THE FORECAST AREA WILL
RECEIVE A GLANCING BLOW FROM THE STORM WITH THE BEST QPF ALONG THE
WASHINGTON COUNTY COAST WHERE THREE- TENTHS OF AN INCH IS
EXPECTED. WITH SNOW-WATER RATIOS GENERALLY AROUND 15 TO 1 OR
HIGHER...THIS TRANSLATES TO A NARROW SWATH OF 4-6 INCHES POSSIBLE
FOR HARD-HIT MACHIAS AND EASTPORT AS WELL AS MDI. AMOUNTS WILL
TAPER TO THE NORTH SUCH JUST AN INCH IS FORECAST FOR FORT KENT AND
MADAWASKA. WITH ADVISORY CRITERIA AT 4 INCHES...WILL HOLD OFF ON
ANY WINTER WEATHER HEADLINES UNTIL LATER TODAY.
&&
.SHORT TERM /MONDAY/...
LOW PRESSURE IN THE GULF OF MAINE MONDAY MORNING WILL MOVE AWAY TO
THE NORTHEAST. STRONG HIGH PRESSURE WILL THEN BUILD IN FROM THE
WEST MONDAY NIGHT AND CREST OVER THE STATE TUESDAY. EXPECT SNOW TO
END LATE MONDAY AS LOW PRESSURE MOVES AWAY. WILL USE A MODEL
CONSENSUS APPROACH AND BLEND THE NAM... GFS AND ECMWF FOR POP...
SKY AND QPF. HAVE USE THE OFFICE SNOW FROM THICKNESS TOOL FOR SNOW
ACCUMULATIONS. WILL USE THE NAM12 FOR WINDS. FOR TEMPERATURE AND
DEW POINT HAVE USED THE SUPER BLEND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL MOVE TO THE EAST TUESDAY NIGHT AS LOW PRESSURE
APPROACHES FROM THE WEST. THIS SYSTEM IS EXPECTED TO PASS TO THE
NORTHWEST OF THE STATE WEDNESDAY MORNING. THE TRACK OF THE LOW
WILL RESULT IN SNOW CHANGING TO RAIN ACROSS SOUTHERN AND CENTRAL
AREAS AS WARM AIR ADVECTION TAKES PLACE AHEAD OF THE LOW. COLD AIR
WILL RETURN AS THE LOW PASSES TO THE NORTH LATE WEDNESDAY AND
WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST
THURSDAY. WILL USE THE SUPER BLEND TO POPULATE GRIDS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: VFR TODAY AND INTO EARLY SUNDAY EVENING. IFR TONIGHT
IN SNOW FOR ALL SITES. LIFR POSSIBLE FOR SEVERAL HOURS AT
BGR AND BHB.
SHORT TERM:
EXPECT IFR/MVFR CONDITIONS TO TRANSITION TO VFR MONDAY. VFR
CONDITIONS EXPECTED MONDAY NIGHT AND TUESDAY. IFR CONDITIONS
EXPECTED TUESDAY NIGHT AND WEDNESDAY. EXPECT VFR CONDITIONS
THURSDAY.
&&
.MARINE...
NEAR TERM: WINDS WILL INCREASE TO SCA LEVELS THIS EVENING IN THE
OUTER WATERS THEN DECREASE AGAIN AFTER MIDNIGHT. WITH THE GALE
WATCH OUT...HAVE ELECTED NOT TO CREATE A SECOND HEADLINE.
SHORT TERM: FOR SUSTAINED WINDS WILL USE THE NAM12. FOR WAVES:
EXPECT OFF-SHORE WIND WAVE TO DOMINATE MONDAY WITH WAVE HEIGHTS
DEPENDENT ON FETCH DISTANCE OFF-SHORE. SOUTHERLY WIND WAVE WILL
BUILD TUESDAY NIGHT INTO WEDNESDAY AS LOW PRESSURE PASS TO THE
NORTHWEST OF THE REGION. WILL USE THE NEAR SHORE WAVE MODEL FOR
WAVE GRIDS THROUGH TUESDAY THEN TRANSITION TO THE WW III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
639 PM EST MON MAR 2 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 451 PM EST MON MAR 2 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA.
FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM
SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF
OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE
CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD
SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE
ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC
HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION.
SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN
TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST
CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING
850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE
LAKE/ICE BREEZE HAS DEVELOPED.
LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES
REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL
ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT
WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT
APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER
PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS
SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET
STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET
TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT
JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET
ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND
BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE
LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO
WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS
THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL
BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH
MAY OCCUR ALONG THE WI BORDER BY 12Z.
ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING
COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE
SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC
ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN
INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY
SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING
RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3
INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER
FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS
EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE
WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW
USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP
LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO
SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS
DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE
ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE
ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE
QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY
SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E
DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY
OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY
UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY
CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE
FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EST MON MAR 2 2015
AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE
SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN
THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER
THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE
TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR
SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY
NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST
TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY
TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE
INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR
THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER
AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND
SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED
IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE
INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS.
THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN
RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN
WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY
NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND
AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT
SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE
ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE
EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL
BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION.
THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A
SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN
LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON
WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS
IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND
OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG
WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY
OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN
COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO
VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS
LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO
WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE
FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS
POPULATED AREAS.
HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY
NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING
INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE
SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR
A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY
AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR
THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS.
SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE
FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE
MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER
30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO
DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON
SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES
SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH
ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE
WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND.
EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH
MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL
ONLY MENTION SLIGHT CHANCES.
A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT
INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A
WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED
WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN
THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE
A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE
850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO
MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER
HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR.
BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE
SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS
AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS
AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES
WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE
SNOWPACK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 634 PM EST MON MAR 2 2015
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THIS EVENING UNDER DRY
AIR MASS ASSOCIATED WITH HIGH PRES MOVING FROM THE OHIO VALLEY TO
THE MID ATLANTIC STATES. LATE TONIGHT...SW FLOW BTWN THE HIGH AND AN
APPROACHING LOW PRES TROF WILL BRING A RAPID INCREASE IN MOISTURE
WHICH WILL LEAD TO SNOW DEVELOPMENT. AS THE SNOW SPREADS NE...MVFR
CONDITIONS SHOULD DEVELOP AT KIWD AROUND 09Z AND AT KCMX/KSAW AROUND
12Z. BY MID TO LATE MORNING...ALL TERMINALS SHOULD SEE IFR
CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT ALL TERMINALS LATE
AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER CONDITIONS AND DEVELOPING
W WINDS IN WAKE OF LOW PRES TROF/COLD FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EST MON MAR 2 2015
GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S
AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING
LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING
PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH
PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF
NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER
WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE
WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND
94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE
COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6
PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EST SUN MAR 1 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 422 PM EST SUN MAR 1 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF
INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME
-SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL
UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING
UPPER MI.
TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN
GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS
SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED
BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A
ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE
CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF
THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W
WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN
THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE
PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS
SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED
FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N
OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH
HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN
WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW
DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD
TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE
DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL
DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS...
WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER
1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE
PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL
DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN
TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F.
ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER
WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN
850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME
STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE
DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR
MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM
AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO
DEPARTING THERMAL TROF.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1245 PM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1156 AM EST SUN MAR 1 2015
.AVIATION...
THE WIDESPREAD LIGHT SNOW WILL REMAIN SOUTH OF PTK THROUGH THE
DURATION OF THE AFTERNOON. SOME ENHANCED SUBSIDENCE AND DAYTIME
MIXING HAS ACTUALLY CLEARED THE LOW CLOUDS FROM PTK NORTHWARD. THERE
ARE HOWEVER A FEW AREAS OF MVFR STRATO CU NEAR LAKE MI AND ACROSS
PORTIONS OF WISCONSIN. A SFC TROUGH AXIS NOW OVER WISCONSIN WILL BE
DRIVEN ACROSS SE MI OVERNIGHT IN RESPONSE TO THE PASSAGE OF AN
UPPER LEVEL SHORT WAVE. THIS SHOULD ALLOW THESE LOWER CLOUDS
UPSTREAM TO FILTER BACK INTO SE MI THIS EVENING. SOME LOW LEVEL COLD
AIR ADVECTION TONIGHT ALONG THE SFC TROUGH WILL STEEPEN LOW LEVEL
LAPSE RATES AND WILL SUPPORT SOME GUSTINESS /AROUND 20 KNOTS/ WITH
THE WESTERLY WINDS OVERNIGHT.
FOR DTW...THE NORTHERN EDGE TO THE LIGHT SNOW HAS LIFTED BACK ACROSS
METRO LATE THIS MORNING. TRENDS IN RADAR...SFC OBS AND LATEST MODEL
DATA SUGGEST THE SNOW WILL PERSIST THROUGH ROUGHLY 22Z BEFORE
ENDING. AFTERNOON ACCUMULATIONS OF A HALF INCH TO AN INCH OF DRY
POWDERY SNOW SEEM POSSIBLE.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 907 AM EST SUN MAR 1 2015
UPDATE...
THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW
EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE
LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND
REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS
SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP
THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE
EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF
ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS.
SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN
ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI
THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS
BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES
REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO
ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT
SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/.
THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL
MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL
MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE
ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY
TODAY.
PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015
SHORT TERM...TODAY AND TONIGHT
SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A
POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT
ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW
ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO
LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING
WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS
THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD
AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON
AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL
STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL
SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE
HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS
SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE
DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A
STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW
ACCUMULATIONS THIS MORNING.
WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION
VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK
ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON
WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO
GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A
DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR
ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN
LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE
AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER
LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR
SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO
OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN
ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS
AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL
ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT
SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS.
THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP
TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z.
SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO
STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE
PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC
VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF
OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION
OF FLURRIES AT THIS TIME.
LONG TERM...
MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE
00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE
BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER
TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN
STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD
THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE
OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER
SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN
THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS
ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS
EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE
GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR
WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A
FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW.
EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR
NORTHERN CWA.
THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER
TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON
AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL
ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT
A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE
FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN
LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE
FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING
WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH
AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO
RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND
BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL
PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT
TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY
SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL
THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM.
AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE
PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH
AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA
WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR
WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART
OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST
THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN
THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS
INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES
EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS
EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK
INTO THE 30S.
MARINE...
A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS
BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE
NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST
BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY
UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY
NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN
ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1140 AM EST SUN MAR 1 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1125 AM EST SUN MAR 1 2015
FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR
CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT
KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS
TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC
TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE
TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY
WITH WNW WINDS AOB 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 1140 AM EST SUN MAR 1 2015
THE FORECAST GETS A LITTLE TRICKY IN THE UPCOMING WEEK WITH THE
APPROACHING SYSTEM GOING INTO TUESDAY. TEMPERATURES COULD VARY
QUITE A BIT RIGHT ALONG WITH EXPECTED PRECIPITATION TOTALS AND
PRECIPITATION TYPE. THE CURRENT GUIDANCE SUGGESTS WE COULD GET A
BIT FURTHER INTO MILDER AIR (NEAR NORMAL) AND ADD MORE LIQUID
PRECIPITATION AS OPPOSED TO SNOW. OVERALL....IT IS NOT A DRASTIC
WARM UP AND AMOUNTS MAY REMAIN AROUND OR BELOW HALF AN INCH. THIS
COULD MOSTLY BE SOAKED UP BY CURRENT SNOW PACK. WITH LOW RIVER
LEVELS AND GIVEN SITUATION...THIS SHOULD NOT RAISE ANY IMMEDIATE
CONCERN BUT WILL BE ADDED LIQUID TO BE CONSIDERED IN FORECASTS
DOWN THE ROAD.
THE GOOD NEWS IS THAT THE SYSTEM LAST NIGHT INTO TODAY WAS QUITE
LACKLUSTER IN REGARDS TO TOTALS. THEREFORE...WHAT WE MISSED LAST
NIGHT WILL JUST SUBTRACT FROM THE OVERALL WEEKLY AMOUNTS WE WERE
LOOKING AT YESTERDAY. THOUGH IT WAS NOT ANYTHING TOO HEAVY TO
BEGIN WITH IT JUST RAISES CONFIDENCE THAT ANY UPWARD TRENDS IN
TEMPERATURES WILL NOT HAVE AS MUCH OF A NEGATIVE IMPACT.
CONDITIONS ARE EXPECTED TO REMAIN STABLE FOR NOW AND IN THE NEAR
TERM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1125 AM EST SUN MAR 1 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1125 AM EST SUN MAR 1 2015
FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR
CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT
KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS
TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC
TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE
TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY
WITH WNW WINDS AOB 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 1132 AM EST SAT FEB 28 2015
CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS
EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT
COUPLE OF DAYS.
THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO
THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME
COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP
ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL
MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO
THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE
MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE
OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A
HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING
IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT
SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
933 AM EST SUN MAR 1 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM EST SUN MAR 1 2015
LATEST RUC/NAM GUIDANCE SHOWS LOW LEVEL MOISTURE BECOMING
WIDESPREAD BY NOON SO WILL FCST MVFR/FUEL ALTERNATE CIGS AROUND
1500 FT AT ALL THE TERMINALS FOR THIS AFTERNOON INTO THE EVENING.
SOME IFR CIGS BELOW 1000 FT CANNOT BE RULED OUT EITHER WITH THE
ARRIVAL OF A MILDER AIR MASS AND RISING SFC DEW POINTS OVER THE
SNOW PACK.
IMPROVEMENT IS EXPECTED LATE TONIGHT AS WINDS SHIFT TO THE
WEST/NORTHWEST BEHIND A WEAK SFC TROUGH. DRIER AIR BEHIND THIS
FEATURE SHOULD GRADUALLY LIFT CIGS TO VFR LEVELS ABOVE 3000 FT
FROM WEST TO EAST AFTER 06Z.
&&
.HYDROLOGY...
ISSUED AT 1132 AM EST SAT FEB 28 2015
CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS
EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT
COUPLE OF DAYS.
THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO
THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME
COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP
ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL
MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO
THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE
MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE
OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A
HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING
IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT
SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
907 AM EST SUN MAR 1 2015
.UPDATE...
THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW
EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE
LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND
REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS
SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP
THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE
EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF
ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS.
SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN
ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI
THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS
BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES
REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO
ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT
SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/.
THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL
MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL
MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE
ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY
TODAY.
&&
.AVIATION...ISSUED 554 AM EST SUN MAR 1 2015
THE WIDESPREAD SHIELD OF LIGHT SNOW HAS STRIPPED OUT OF SOUTHEASTERN
MICHIGAN THIS MORNING AS FAVORABLE UPPER LEVEL JET FORCING LIFTS OFF
TO THE NORTHEAST. BACKED OFF A FAIR AMOUNT ON THE MENTION FOR
ADDITIONAL SNOWFALL IN THE TAFS. THERE IS A HIGH AMOUNT OF
UNCERTAINTY AS WHETHER OR NOT PRECIPITATION THIS MORNING WILL BE
ABLE TO CLIP DTW. DID LEAVE A PERIOD OF IFR LIGHT SNOW THIS
AFTERNOON AS ANOTHER BOUT OF FORCING IS FORECASTED TO SLIDE OVER
SOUTHEASTERN MICHIGAN.
FOR DTW...LIGHT SNOW IS EXPECTED TO REFOCUS SOUTH OF THE DTW
TERMINAL THIS MORNING. IT IS TOUGH CALL ON WHETHER OR NOT A LONG
DURATION OF SNOW WILL IMPACT THE TERMINAL. EXPECTATIONS ARE THAT
LIGHT SNOW WILL FILL BACK IN FOR THE 19-23Z TIMEFRAME. SNOWFALL
ACCUMULATIONS WILL REMAIN RELATIVELY LIGHT...WITH PERHAPS AN INCH
FALLING DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THROUGH SUNDAY.
* HIGH IN PTYPE AS SNOW TONIGHT AND SUNDAY.
&&
.PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015
SHORT TERM...TODAY AND TONIGHT
SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A
POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT
ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW
ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO
LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING
WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS
THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD
AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON
AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL
STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL
SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE
HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS
SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE
DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A
STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW
ACCUMULATIONS THIS MORNING.
WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION
VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK
ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON
WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO
GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A
DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR
ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN
LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE
AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER
LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR
SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO
OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN
ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS
AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL
ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT
SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS.
THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP
TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z.
SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO
STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE
PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC
VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF
OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION
OF FLURRIES AT THIS TIME.
LONG TERM...
MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE
00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE
BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER
TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN
STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD
THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE
OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER
SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN
THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS
ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS
EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE
GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR
WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A
FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW.
EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR
NORTHERN CWA.
THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER
TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON
AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL
ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT
A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE
FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN
LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE
FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING
WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH
AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO
RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND
BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL
PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT
TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY
SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL
THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM.
AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE
PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH
AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA
WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR
WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART
OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST
THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN
THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS
INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES
EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS
EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK
INTO THE 30S.
MARINE...
A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS
BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE
NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST
BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY
UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY
NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN
ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....CB
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 644 AM EST SUN MAR 1 2015
A SW FLOW IN ADVANCE OF AN APRCHG LO PRES TROF THAT IS TAPPING A BIT
MORE LLVL MSTR WL BRING A PERIOD OF MVFR CIGS THIS MRNG INTO THE
AFTN BEFORE THE ARRIVAL OF DRIER AIR IN THE WAKE OF THE TROF PASSAGE
RETURNS CONDITIONS TO VFR IN THE AFTN. AS COLDER AIR RETURNS TNGT
BEHIND A REINFORCING COLD FROPA...MVFR CIGS AND PERHAPS SOME -SHSN
WL RETURN TO THE CMX AND IWD LOCATIONS THAT EXPERIENCE UPSLOPE
MOISTENING WITH THE EXPECTED GUSTY WNW FLOW. DOWNSLOPE NATURE OF
THIS FLOW INTO SAW SHOULD MAINTAIN VFR CONDITIONS THERE. ENUF DRY
AIR AHEAD OF A HI PRES RDG WL LIKELY BRING CLRG/VFR WX TO IWD LATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN
MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS
SHOULD DIE DOWN SUN EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 259 PM EST SAT FEB 28 2015
GOOD AGREEMENT FM THE MODELS ON OVERALL LOOK OF LARGE SCALE PATTERN
THROUGH THE EXTENDED. TROUGH AND COLD AIR THAT HAS DOMINATED FOR
FEBRUARY EASES FIRST PART OF THE WEEK. JUST BEFORE THAT OCCURS THERE
COULD BE SOME LIGHT LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT FOR AREAS
FAVORED BY WNW WINDS. SOUNDINGS INDICATE INVERSIONS UP TO 5KFT WITH
A LOT OF THE MOIST LAYER IN THE DGZ. LACK OF OPEN WATER WILL HAMPER
THE LES...BUT WILL CARRY SCATTERED POPS FOR SNOW BELTS EAST OF MQT
AND P53. LES COULD LINGER AS FLURRIES ON MONDAY MORNING...BUT WILL
OPT FOR DRY FORECAST AS HIGH PRESSURE RIDGE SHOULD BE PUTTING AN END
TO THE LES. WITH A NW LOW-LEVEL FLOW...MODELS HANG ON TO LOW CLOUDS
PROBABLY ENHANCED DUE TO DAYTIME HEATING. MODELS MAY BE OVERDOING
LOW-LEVEL RH THOUGH...SO WILL JUST GO PARTLY CLOUDY FOR DAYTIME ON
MONDAY. HIGHS BOUNCE UP INTO THE 20S...THOUGH WILL REMAIN ONLY TO
AROUND 20 OVER EAST WITH LINGERING NW WINDS OFF ICE OF LK SUPERIOR
MOST OF THE DAY.
CLOUDS THICKEN ON MONDAY NIGHT AHEAD OF DOUBLE BARRELLED LOW
PRESSURE SYSTEM THAT MOVES OVER THE REGION ON TUESDAY. TEMPS MAY
FALL QUICKLY OVER THE EAST CWA ON MONDAY NIGHT...BUT WILL BE IN THE
TEENS ELSEWHERE. ON TUESDAY...NORTHERN STREAM LOW IS THE ONE
AFFECTING ALASKA THIS AFTN AND THE SOUTHERN STREAM LOW IS FORECAST
TO EMERGE OUT OF GENERAL TROUGHING CURRENTLY OVER THE SOUTHWEST
CONUS. H85-H7/H7-H5 Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION
AHEAD OF SFC-H85 TROUGHS WITH H7 MIXING RATIOS 2-3 G/KG SUPPORT
POTENTIAL FOR MODERATE SNOWFALL OVER EAST HALF OF UPR MICHIGAN.
BLEND OF QPF ALONG WITH EXPECTED SLR/S IN THE 13-18:1 RANGE POINT TO
SNOWFALL RANGING FM 2-4 INCHES/3-5 INCHES. KIND OF SEEMS THAT THERE
MAY BE TWO MAIN TIMES OF SNOW WITH THE SYSTEM...LATE MONDAY NIGHT
INTO TUESDAY MORNING...THEN AGAIN TUESDAY AFTN INTO EARLY TUESDAY
EVENING. MODELS ARE LOCKED IN THAT THE TUESDAY AFTN AND TUESDAY
EVENING TIME FRAME WILL FEATURE THE HEAVIEST SNOW...POSSIBLY WITH
SNOWFALL RATES AROUND 1 INCH PER HOUR. IMPACT COULD BE ON THE HIGHER
SIDE TOO AS THE HEAVIEST SNOW COULD FALL DURING THE AFTN AND EVENING
COMMUTE. WILL CONTINUE TO MENTION IN THE HWO AND EHWO GRAPHICS.
REPRIEVE IN THE COLD AIR IS BRIEF AS MORE COLD AIR...CURRENTLY
UPSTREAM OF THE LOW PRESSURE SYSTEM OVER ALASKA...CHARGES IN LATE
TUESDAY NIGHT INTO WEDNESDAY AND LINGERS THROUGH LATE WEEK. RETURN
OF THE COLD WITH H85 TEMPS BLO -20C WILL LEAD TO LAKE EFFECT FOR NW
FLOW AREAS. SOUNDINGS SHOW INVERSIONS START OUT AT 5KFT ON TUESDAY
NIGHT OVER EASTERN LK SUPERIOR BUT RISE UP TO 8KFT ON WEDNESDAY.
EXTENT OF OVER-WATER INSTABILITY AND DEPTH OF THE CONVECTIVE LAYER
SUGGESTS LOCALLY MODERATE SNOW SHOWERS WILL BE POSSIBLE FOR MAINLY
WNW-NW FLOW AREAS. OVERALL THE LOW VSBY WITH SMALLER SNOWFLAKES WILL
BE THE LARGER IMPACT. WINDS 25-30 KTS SO MAY ALSO HAVE BLSN ALONG
THE SHORE...ESPECIALLY IN THE SNOW BELTS EAST OF MQT. WITH ENOUGH
MOISTURE INLAND ON WEDNESDAY...MAY ALSO SEE DIURNALLY ENHANCED SNOW
SHOWERS WITH PERIODS OF GUSTY WINDS/LOWER VSBY. WINDS BACK W-WSW ON
WEDNESDAY NIGHT WHICH WILL END THE LES ALONG MOST OF LK SUPERIOR.
TEMPS INLAND WILL FALL OFF WELL BLO ZERO. WINDS WILL BE ON THE
DECLINE BUT MAY STILL BE STRONG ENOUGH TO PRODUCE NEAR ADVISORY WIND
CHILLS THURSDAY MORNING OVER PARTS OF THE CWA.
HIGH PRESSURE BUILDING OVER THE NORTHERN PLAINS BY THURSDAY SLIDES
TO THE OHIO VALLEY INTO FRIDAY AS LOW PRESSURE SYSTEM CROSSING
NORTHERN ONTARIO PUSHES A WARM FRONT ACROSS THE UPPER GREAT LAKES.
MID-LEVEL MOISTURE H85-H7 AND WEAK LIFT MAY TRIGGER A FEW SNOW
SHOWERS OR FLURRIES THURSDAY NIGHT INTO FRIDAY MORNING. GFS AND
ECMWF BOTH SHOW MAIN FORCING STAYING OVER LK SUPERIOR AND TO THE
NORTH. ANOTHER COLD FRONT WORKS THROUGH ON FRIDAY NIGHT WITH MORE
COLD AIR SETTLING OVER THE AREA BY NEXT SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN
MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS
SHOULD DIE DOWN SUN EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
913 PM CST MON MAR 2 2015
.UPDATE...AREAS OF FOG ARE BECOMING MORE WIDESPREAD AND CEILINGS ARE
LOWERING. DECIDED TO EXPAND THE DENSE FOG ADVISORY OVER THE REST OF
THE CWA AS CONDITIONS FOR DENSE FOG LOOK PRETTY UNIVERSAL ACROSS THE
AREA. UPDATED MINS AND HOURLY TEMPS/DEWPOINTS AS TEMPS LOOKS TO HOLD
STEADY AND MAYBE RISE A FEW DEGREES PRIOR TO DAWN...SIMILAR TO THE
LATEST HRRR OUTPUT. ALSO...LOWERED POPS TO SLIGHT AS PRECIP HAS ABOUT
ALL MOVED OUT AND HRRR IS NOT SHOWING MUCH OVERNIGHT./26/
&&
.AVIATION...LIFR CIGS/VSBYS WILL BE THE RULE THROUGH 03/15Z WITH SOME
SLOW IMPROVEMENT TOWARD LOW MVFR VSBYS BY 03/18Z. CIGS WILL RISE AS
WELL...APPROACHING MVFR BY 04/00Z./26/
&&
.PREV DISCUSSION... /ISSUED 402 PM CST MON MAR 2 2015/
DISCUSSION......A COMPLICATED WEATHER SCENARIO IS SETTING UP FOR
THE NEXT FEW DAYS. FOR TONIGHT THE MAIN CONCERN WILL BE DENSE FOG AS
THE WARM SECTOR SPREADS NORTH OVER THE AREA. A DENSE FOG ADVISORY
WILL BE ISSUED FOR MUCH OF THE AREA UNTIL MID MORNING ON TUESDAY. BY
TUESDAY THE ENTIRE AREA WILL BE WELL INTO THE WARM SECTOR WITH A
CONTINUED CHANCE FOR SHOWERS AND VERY WARM TEMPERATURES INTO THE
LOW/MID 70S. LITTLE WILL CHANGE TUESDAY NIGHT INTO WEDNESDAY WITH A
CONTINUATION OF THE VERY WARM TEMPERATURES AND CHANCES FOR SHOWERS.
BY WEDNESDAY MORNING A STRONG COLD FRONT WILL EXTEND FROM OKLAHOMA
ACROSS ARKANSAS INTO THE TENNESSEE VALLEY. THIS BOUNDARY WILL SLOWLY
DRIFT SOUTH THROUGH THE DAY WITH THE SHALLOW COLD AIR MOVING INTO
THE DELTA BY THE LATE AFTERNOON HOURS. THE COLD FRONT WILL CONTINUE
TO MOVE SOUTH ACROSS THE AREA THROUGH THE EVENING AND INTO THE
OVERNIGHT. THE TEMPERATURE DIFFERENCE ACROSS THE BOUNDARY WILL BE
DRASTIC WITH A 30-40 DEGREE DROP WITH FROPA. AS MENTIONED IN
PREVIOUS DISCUSSIONS THE MAIN UPPER JET WILL REMAIN WELL TO THE
NORTH PROMOTING LIFT ACROSS THE AREA AND WITH PWATS AROUND 1.6-1.7
THERE WILL BE A BOUNTIFUL AMOUNT OF MOISTURE.
ALTHOUGH MOST OF THE PRECIPITATION WILL BE ANA-FRONTAL THERE WILL BE
ENOUGH MOISTURE AND INSTABILITY FOR AT LEAST A CHANCE OF
THUNDERSTORMS ALONG AND JUST OUT AHEAD OF THE BOUNDARY DURING THE
LATE MORNING INTO THE AFTERNOON HOURS ON WEDNESDAY.
THE PRECIPITATION WILL QUICKLY CHANGE TO FREEZING RAIN AND SLEET BY
EARLY EVENING IN THE NORTH WITH THE COLD AIR SPREADING SOUTH THROUGH
THE LATE EVENING INTO THE OVERNIGHT HOURS. A MIX OF SLEET/FREEZING
RAIN LOOK LIKELY IN THE DELTA DURING THE EARLY EVENING WITH THIS
AREA SPREADING SOUTH WITH THE COLD AIR. CURRENTLY THE TIMING LOOKS
LIKE AREAS ALONG THE NATCHEZ TRACE CORRIDOR WILL SEE A CHANGE-OVER
FROM RAIN TO FREEZING RAIN/SLEET AFTER MIDNIGHT. THE PRECIPITATION
MAY CHANGE OVER TO SNOW WITH SOME ACCUMULATIONS IN THE DELTA BEFORE
ENDING EARLY THURSDAY MORNING. THE PRECIP WILL END FROM NORTHWEST TO
SOUTHEAST THROUGH THE MORNING HOURS AS A MIX OF LIGHT SNOW...FREEZING
RAIN AND SLEET. CURRENTLY IT LOOKS LIKE THE PRECIPITATION WILL REMAIN
LIQUID IN THE FAR SOUTHEAST THROUGH THE EVENT...BUT IF THE
PRECIPITATION LINGERS LONG ENOUGH THROUGH THE MORNING...THERE MAY BE
A BRIEF CHANGEOVER. A WINTER STORM WATCH HAS BEEN ISSUED WITH THE
AFTERNOON PACKAGE FOR AREAS GENERALLY ALONG THE HIGHWAY 82 CORRIDOR.
AS WE GO OUT INTO THE EXTENDED FORECAST COLD HIGH PRESSURE WILL
PREVAIL INTO THE WEEKEND...BUT THE GFS/ECMWF DIVERGING IN THERE
SOLUTIONS ON SUNDAY. THE ECMWF BRINGING ANOTHER WAVE ACROSS THE AREA
ON SUNDAY WITH INCREASED CHANCES FOR RAIN WHILE THE GFS IS MAINLY DRY
ALL THE WAY THROUGH THE EXTENDED PERIOD. WILL COMPROMISE WITH LEAVING
CHANCES FOR LIGHT RAIN SUNDAY THROUGH MONDAY./15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 53 74 63 74 / 15 39 54 68
MERIDIAN 53 74 60 75 / 15 24 52 59
VICKSBURG 44 74 64 71 / 15 39 37 80
HATTIESBURG 59 73 61 78 / 15 23 26 47
NATCHEZ 46 73 64 74 / 15 39 23 66
GREENVILLE 40 67 62 63 / 15 40 61 99
GREENWOOD 44 71 63 65 / 15 41 76 94
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...DENSE FOG ADVISORY UNTIL 9 AM CST TUESDAY FOR MSZ018-019-025>066-
072>074.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR MSZ018-019-025>030-034.
LA...DENSE FOG ADVISORY UNTIL 9 AM CST TUESDAY FOR LAZ007>009-015-016-
023>026.
AR...DENSE FOG ADVISORY UNTIL 9 AM CST TUESDAY FOR ARZ074-075.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR ARZ074-075.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1135 PM CST Sat Feb 28 2015
...AVIATION UPDATE...
.UPDATE...
FREEZING RAIN AND LIGHT SNOW WILL CONTINUE TO IMPACT SOUTH CENTRAL
MISSOURI AFTER MIDNIGHT. ALL OTHER LOCATIONS WILL BE DEALING
MAINLY WITH FREEZING DRIZZLE DEVELOPING AS WE HEAD INTO THE MONDAY
MORNING HOURS.
DUE TO THE FREEZING DRIZZLE CAUSING TRAVEL IMPACTS...THE HEADLINES
WILL REMAIN IN EFFECT FOR NOW.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 307 PM CST SAT FEB 28 2015
A large area of snow has blanketed all of the Missouri Ozarks and
extreme southeastern Kansas as of mid afternoon. Visibilities were
pretty much below one mile over all areas...with occasional
observations indicating quarter mile visibilities with heavy snow.
Snowfall accumulations up through 3 PM have been in the 1-3"
range. We suspect that some locations across extreme southeastern
Kansas and west-central Missouri may be in that 3-4" range.
As we head into late this afternoon and this evening, short term
models are beginning to change their tune a bit. Both the RAP
and the HRRR have somewhat backed off on a secondary band of snow
developing along the I-44 corridor this evening. Even the 18Z NAM
has trended this way. Instead, models gradually take the large
area of moderate to occasionally heavy snow to the east and
northeast with the back edge of the heavier snow moving east
across the Ozarks this evening. This would tend to make sense as
low level isentropic upglide and a weak upper level jet coupling
structure shift towards the Mid Mississippi Valley. We will still
have to watch for some banding of snow as models do indicate some
slugs of increased 700 mb frontogenesis...especially along and
north of the I-44 corridor.
As we head into later tonight, the main area of snow will have
shifted east of the area. Pockets of light snow and flurries
will be left in its wake. While snow intensity will be on the
downward trend this evening (again from west to east), it will
tend to accumulate more efficiently given that the sun will have
set. Models are also indicating perhaps some loss of cloud ice
later tonight. Additionally, models still bring a warm nose into
southern Missouri by late tonight. Thus, we are continuing a
mention of either light freezing rain or freezing drizzle.
This trend will then continue into Sunday morning with pockets of
light snow and drizzle/freezing drizzle. We have slowed the
progress of the surface freezing line to the north by a few
hours...which does keep the door open a bit longer for minor ice
accumulation. One thing we will have to watch very closely is what
will be a good setup for a banded snow event from late tonight
into Sunday morning up towards I-70. Models continue to indicate
strong 700 mb frontogenesis and available negative EPV becoming
juxtaposed with a favorable upper level jet streak. If this
materializes, it could put down a narrow swath of additional
heavier snowfall. While this could glance our central Missouri
counties, confidence is higher that it will remain just north of
the area. Once we get into Sunday afternoon and especially Sunday
night, the primary precipitation will be shifting east and
southeast of the region.
As for storm total ice and snow amounts, we have not changed much.
Any ice accumulations are still expected to remain at or below
five-hundredths of an inch. 1-3" of snow is expected across
south-central Missouri. Accumulations near and north of the I-44
corridor will be in the 3-6" range. We still think a few isolated
reports of around 7" will be possible. Given that any 6-7" amounts
are expected to be isolated (if they occur at all), the current
Winter Weather Advisory will be left intact.
.LONG TERM...(Monday through Saturday)
Issued at 307 PM CST SAT FEB 28 2015
By Monday morning, precipitation should push south of the region,
at least temporarily, as high pressure noses south from the
Dakotas. Highs on Monday look to reach the upper 30s in most
locations.
Precipitation will then return to the area Monday night into
Tuesday, though at this point it appears that temperatures
should be above freezing by the time rain begins to fall Monday
night. Rain will continue through much of the day Tuesday, as low
pressure at the surface deepens and lifts north across Kansas and
northern Missouri. Breezy southwest winds during the day Tuesday
will help temperatures warm into the low to mid 50s. Will continue
to include a mention of thunder in the forecast for Tuesday, with
guidance suggesting a couple hundred J/KG of CAPE making its way
into the CWA.
A strong cold front will then sweep across the area Tuesday
afternoon and evening, with colder air quickly advecting into
the area Tuesday night. We will need to carefully watch the
potential for post frontal snow Tuesday night and Wednesday, as
lift from a secondary trough axis may be enough to result in areas
of snow on Wednesday. As it stands right now, the highest snow
potential for Wednesday looks to be south of I-44, though this
will be highly dependent on the eventual location of the front.
The upper level flow will then flatten out a bit, with
southwesterly flow developing at the surface for the end of the
week into next weekend. This is suggestive of warmer temperatures
for the end of the week, with highs perhaps (finally) approaching
climatological averages by this time next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
BE DEALING WITH IFR CEILINGS AND AT LEAST MVFR VISIBILITIES
THROUGH TONIGHT AND MOST OF SUNDAY MORNING.
MOST OF THE HEAVIER SNOW AND FREEZING RAIN HAS SHIFTED INTO SOUTH
CENTRAL MISSOURI. ALL OTHER LOCATIONS WILL BE DEALING WITH
FREEZING DRIZZLE HEADING INTO SUNDAY MORNING.
LOOK FOR WINDS TO BE LIGHT AND VARIABLE.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055-056-066-
067-077-078-088-089-093>098-101>106.
WINTER STORM WARNING until Noon CST Sunday FOR MOZ057-058-
068>071-079>083-090>092.
KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101.
&&
$$
UPDATE...Schaumann/Cramer
SHORT TERM...Schaumann
LONG TERM...Boxell
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1129 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1129 AM CST SUN MAR 1 2015
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH TONIGHT. MID LEVEL CLOUDS WILL BEGIN TO MOVE INTO
THE AREA FROM THE SOUTH MONDAY MORNING. LIGHT SNOW IS POSSIBLE AT
KLBF AFTER 02/10Z...WHICH MAY TEMPORARILY CREATE MVFR CEILINGS
AND/OR VISBY. WIND WILL LIKELY BE THE HIGHER CONCERN FOR KLBF AND
KVTN AS GUSTS ABOVE 20 KNOTS ARE EXPECTED BY LATE MORNING MONDAY.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...DS
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
617 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 615 AM CST SUN MAR 1 2015
VFR CONDITIONS ARE FORECAST FOR THE KLBF AND KVTN TERMINALS TODAY
AND TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...ROBERG
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
347 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1110 PM CST SAT FEB 28 2015
A FEW LIGHT SNOW SHOWERS...CURRENTLY OVER NORTHEAST COLORADO...
WILL MAKE THEIR WAY ACROSS SOUTHWEST NEBRASKA. AS THEY COME
ACROSS...CEILINGS OF 2000-3000 FEET AGL AND VISIBILITY AT OR
ABOVE 5SM ARE LIKELY...THOUGH VERY LOCALIZED.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...SPRINGER
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1138 PM CST SAT FEB 28 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS
AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE
DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE
CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW
THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN
NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN
COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS
TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN
BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW
PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE.
TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM
TEMPS RUNNING THE WHOLE RANGE OF 20S.
WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON
AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE
EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z
TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER
SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER
LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL
PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND
SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS
LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST
INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO
THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN
ADDITION FEW TENTHS OF A INCH OF ACCUMULATION.
HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH
DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS
EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH.
WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY
TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST
ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW
DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN
THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY
AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID
30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE
SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE
MONDAY NIGHT INTO TUESDAY MORNING.
NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP
TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE
FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST
FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS
LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT
UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS
WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS
AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS.
GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF
OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES.
CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH
PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE
NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT
SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC
LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF
SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A
SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE
ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF
AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL
PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND
STICK WITH SNOW.
ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH
SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT
30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES
OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY.
WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO
MENTION IN THE HWO.
ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY
DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR
OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1138 PM CST SAT FEB 28 2015
VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24 HOURS...ALTHOUGH
CONDITIONS WILL NEED TO BE MONITORED FOR A PERIODIC MVFR CEILING.
HIGH-LEVEL CLOUDS NEAR 15000FT AGL WILL REMAIN POSSIBLE THROUGH
MUCH OF THE TAF PERIOD. OCCASIONAL STRATUS NEAR 2000FT AGL WILL
ALSO BE POSSIBLE THROUGH THE FIRST HALF OF THE TAF PERIOD...BUT
THE PROBABILITY OF THIS STRATUS MATERIALIZING IS TOO LOW FOR
INCLUSION IN THE TAFS AT THIS TIME. THE SURFACE WIND WILL REMAIN
LIGHT AND VARIABLE TONIGHT BEFORE BECOMING MORE ESTABLISHED FROM
THE NORTHWEST DURING THE DAY SUNDAY. VISIBILITY RESTRICTION IS NOT
EXPECTED AT EITHER TAF SITE THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1008 PM PST SAT FEB 28 2015
.SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA
RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS
THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT
WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT
THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE
ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS
POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND
WARMING TREND TAKES PLACE.
&&
.UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL
RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL
MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK
POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT
PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES
NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL
MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE
COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS.
FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A
BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND
EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TOO
AGGRESSIVE SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE
IMAGERY BUT BY THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD
MAKE PROGRESS INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO
ISSUES IN MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS
WELL AS THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY
WHERE SNOW LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000
FEET. AREAS NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH
AS PANACA SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME
MAKING FOR TRICKY TRAVEL.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE
EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS
INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY
ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING
THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS
BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN
OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY
AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A
KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR
ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA
7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY,
EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES
LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER
21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW
LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED
NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED
TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY
PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 230 PM PST SAT FEB 28 2015
.SHORT TERM...THROUGH MONDAY NIGHT.
OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH
OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER
LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF
SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE
AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE
HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL
NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING.
THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE
NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A
BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN
MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND
THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND
CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS
THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND
5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY
MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS
SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3
INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY
WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS
EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD
DECREASE OVERNIGHT.
AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A
PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER
SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY
SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT
VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE
IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO
LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE
A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH
WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY
FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND
HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING
SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A
WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN
MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET
ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT.
WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE
HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY
MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY
HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD
RANGE BETWEEN 4500-5500 FEET.
DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL
FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS
MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR
FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES.
WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE
COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR
EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON
THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING
BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT.
SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION.
ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN.
NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY
NONETHELESS.
AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S
FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO
GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST
METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE!
TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION
WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY.
A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW
PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING
TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY
SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW
THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE
SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC
TROUGH APPROACHES FROM THE WEST.
SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION
AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE
TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER
DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR
CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS
MOVES INTO THE AREA SATURDAY.
NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE
AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND
FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS
REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND
THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO
BE RIGHT AROUND NORMAL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT
ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES
TODAY THROUGH TUESDAY NIGHT.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...PADDOCK/SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
932 PM PST SAT FEB 28 2015
.SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA
RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS
THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT
WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT
THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE
ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS
POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND
WARMING TREND TAKES PLACE.
&&
.UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL
RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL
MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK
POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT
PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES
NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL
MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE
COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS.
FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A
BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND
EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TO AGGRESSIVE
SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE IMAGERY BUT BY
THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD MAKE PROGRESS
INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO ISSUES IN
MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS
THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY WHERE SNOW
LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000 FEET. AREAS
NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH AS PANACA
SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME MAKING
FOR TRICKY TRAVEL.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE
EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS
INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY
ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING
THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS
BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN
OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY
AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A
KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR
ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA
7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY,
EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES
LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER
21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW
LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED
NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED
TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY
PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 230 PM PST SAT FEB 28 2015
.SHORT TERM...THROUGH MONDAY NIGHT.
OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH
OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER
LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF
SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE
AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE
HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL
NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING.
THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE
NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A
BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN
MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND
THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND
CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS
THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND
5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY
MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS
SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3
INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY
WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS
EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD
DECREASE OVERNIGHT.
AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A
PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER
SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY
SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT
VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE
IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO
LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE
A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH
WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY
FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND
HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING
SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A
WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN
MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET
ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT.
WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE
HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY
MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY
HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD
RANGE BETWEEN 4500-5500 FEET.
DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL
FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS
MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR
FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES.
WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE
COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR
EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON
THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING
BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT.
SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION.
ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN.
NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY
NONETHELESS.
AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S
FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO
GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST
METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE!
TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION
WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY.
A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW
PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING
TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY
SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW
THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE
SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC
TROUGH APPROACHES FROM THE WEST.
SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION
AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE
TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER
DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR
CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS
MOVES INTO THE AREA SATURDAY.
NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE
AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND
FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS
REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND
THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO
BE RIGHT AROUND NORMAL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT
ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES
TODAY THROUGH TUESDAY NIGHT.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...PADDOCK/SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 PM EST MON MAR 2 2015
.SYNOPSIS...HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH
TONIGHT AND WILL SHIFT OFFSHORE DURING THE DAY TUESDAY AS A LOW
PRESSURE SYSTEM TRACKS NORTHEAST FROM THE CENTRAL PLAINS INTO THE
GREAT LAKES.
&&
.NEAR TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 1000 PM MONDAY...
AFTER A PLEASANTLY WARM DAY...COOLER AND DRIER AIR IS WORKING ITS
WAY INTO THE AREA FROM THE NORTH-NORTHEAST AS A 1034MB SURFACE HIGH
TRANSLATES EAST ACROSS THE MID-ATLANTIC STATES. THE PRIMARY COLD
FRONT IS TO OUR SOUTH...BUT THERE APPEARS TO BE A SECONDARY
BOUNDARY...WITH NOTICEABLY HIGH DEWPOINTS POOLING ALONG IT...MOVING
FROM THE COASTAL PLAIN TOWARD THE PIEDMONT. THIS COMPLICATES THE
OVERNIGHT FORECAST AS THE DRIER...SUB-20F DEWPOINT AIR OVER THE THE
NORTHWEST PIEDMONT TRIES TO PUSH SOUTH BUT MAY ULTIMATELY BE HALTED
OR SHUNTED OFF TO THE WEST. MOST MODEL ARENT HANDLING THIS VERY
WELL...EVIDENT IN PART BY THE MUCH DRIER THAN FORECAST BOUNDARY
LAYER ON THE 00Z KGSO RAOB...SO WILL LEAN ON THE RAP/HRRR WHICH HAS
DEWPOINTS MOSTLY IN THE 20S TO LOWER 30S TUESDAY MORNING. TEMPS
WILL CONTINUE TO FALL INTO THE 30S OVERNIGHT...BUT AS SOME 290K
ISENTROPIC LIFT AND HIGHER BASED STRATUS SPREAD NORTH AND
EAST ACROSS THE AREA...TEMPS SHOULD STABILIZE MOSTLY ABOVE FREEZING.
THE BIGGEST FORECAST ISSUES TONIGHT WILL STILL BE 1) WHETHER OR NOT
ANY LIGHT RAIN/DRIZZLE SPREADS FAR ENOUGH NORTH AND EAST INTO THE
SUB-FREEZING AIRMASS BEFORE A WEAK DIURNAL RECOVERY IN TEMPS BEGINS
ON TUESDAY MORNING...OR 2) PRECIP IS EVEN HEAVY ENOUGH WETBULB TEMPS
BELOW FREEZING IN AREAS WHERE THEY ARE INITIALLY ABOVE FREEZING.
18Z AND 00Z GUIDANCE CONTINUES TO ONLY SHOW A COUPLE HUNDREDTHS AT
BEST AND MOSTLY COMING AFTER 12Z. THE RAP AND HRRR ARE COMPLETELY
DRY THROUGH 12Z. WILL LOWER POPS A LITTLE AND JUST MAINTAIN A
MENTION JUST FREEZING DRIZZLE IN THE SMALL AREA WHERE TEMPS AT AT
OR BELOW 32...WHICH IS CONFINED TO JUST THE NORTH PIEDMONT PRIOR TO
15Z. NO ADVISORY FOR FREEZING RAIN IS NEEDED AT THIS TIME. TEMPS ON
TUESDAY WILL MOVE LITTLE OFF MORNING LOWS...MID 30S TO LOWER 40S.
A WARM FRONT IS EXPECTED TO LIFT NORTHWARD TOWARD CENTRAL NC TUE
NIGHT...WITH TEMPERATURES RISING OVERNIGHT ACROSS MUCH OF THE
AREA...ALTHOUGH THEY COULD REMAIN NEAR STEADY IN THE N/NW PIEDMONT.
LIGHT RAIN/DRIZZLE COULD TAPER AS THE WARM FRONT LIFTS WITH
EXPANDING FOG CONDITIONS POSSIBLE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 PM MONDAY...
THE FORECAST PROBLEM FOR THIS PART OF THE FORECAST CONTINUES TO BE
THE UNCERTAINTY IN TEMPERATURES DUE TO THE POTENTIALLY LINGERING
WEDGE AND THE TIMING AND EXTENT TO WHICH THE WARM FRONT RETREATS
NORTHWARD. GIVEN THAT THE MODELS HAVE A TENDENCY TO ERODE THE WEDGE
TOO QUICKLY...ESPECIALLY IF THERE IS PRECIPITATION FALLING INTO
IT...CURRENTLY FORECAST THE WEDGE STICKING AROUND INTO WEDNESDAY
AFTERNOON IN THE FAR NW PIEDMONT...WITH A LARGE SPREAD IN TEMPS FROM
NW TO SE ACROSS THE AREA. CONFIDENCE REMAINS SOMEWHAT LOW WITH
RESPECT TO TEMPS...AS ANY CHANGES TO THE TIMING AND POSITION OF THE
WEDGE/WARM FRONT AS THEY ERODE/RETREAT NORTHWARD WILL HIGHLY IMPACT
TEMPERATURES. THEY WILL HOWEVER INCREASE GRADUALLY THROUGH AROUND
MIDNIGHT THURSDAY BEFORE THE COLD FRONT BEGINS MOVING INTO THE NW.
KEEPING IN MIND THE POTENTIAL MARGIN FOR ERRORS...FORECAST HIGH
TEMPS IN THE MID 60S NW TO MID 70S SE ON WEDNESDAY. A NORMAL DIURNAL
TEMPERATURE CURVE SHOULD RETURN WEDNESDAY NIGHT...ALTHOUGH THE
TEMPERATURE GRADIENT WILL BE QUITE LARGE AND WILL DEPEND ON THE
TIMING AND POSITION OF THE COLD FRONT...EXPECT LOWS IN THE UPPER 30S
NORTH TO LOW 50S SOUTH WEDNESDAY NIGHT AND HIGHS IN THE LOW 40S
NORTH TO MID 50S SOUTH ON THURSDAY AND DECREASING BEHIND THE FRONT.
PRECIPITATION: THERE WILL BE A SLIGHT CHANCE OF PRECIP...MAINLY
ACROSS THE WESTERN PORTIONS OF THE AREA WEDNESDAY...EVEN THOUGH THE
MAIN PRE-FRONTAL CONVECTIVE RAINFALL REMAINS LARGELY ALONG OR WEST
OF THE APPALACHIANS UNTIL WEDNESDAY AFT/EVE. SOUTHWESTERLY WINDS
WILL BE QUITE STRONG ON WEDNESDAY AFT/EVE AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT. LATE WEDNESDAY AFTERNOON IS STARTING TO SHAPE UP
AS A HIGH SHEAR/LOW CAPE EVENT. FORECAST SOUNDINGS INDICATE 200-300
JOULES OF CAPE AND 0-3 KM SHEAR VALUES AROUND 35 KTS...MAINLY ALONG
AND EAST OF I-95 AT THIS TIME. WITH SURFACE TEMPS EXPECTED IN THE
MID 70S AND DEWPOINTS AROUND 60 DEGREES...THUNDERSTORMS WILL BE
POSSIBLE WEDNESDAY AFTERNOON...THUS WILL INTRODUCE A SLIGHT CHANCE
ACROSS THE EAST WITH THIS AFTERNOON`S FORECAST. THE LATEST 12Z ECMWF
AND GFS MODEL RUNS ARE IN BETTER AGREEMENT WITH THE TIMING OF THE
FROPA AND THE ASSOCIATED RAINFALL AS IT MOVES THROUGH THE AREA. THE
LATEST RUNS SUGGEST THAT RAIN WILL BE LIKELY WEDNESDAY NIGHT...
PROGRESSING NW TO SE THROUGH CENTRAL NC THROUGH MIDNIGHT FRIDAY.
THIS REMAINS CASE OF THE COLD AIR CHASING THE PRECIP...BUT FOR NOW
STILL EXPECT ALL PRECIP TO FALL AS RAIN...HOWEVER THERE IS A SMALL
CHANCE THAT A FEW SNOWFLAKES COULD MIX IN ON THE TAIL END OF THE
EVENT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 300 PM MONDAY...
FRIDAY THROUGH SATURDAY: HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT THURSDAY NIGHT...REMAINING OVER THE REGION INTO THE WEEKEND.
EXPECT A DRY FORECAST FRIDAY THROUGH SATURDAY...WITH HIGHS IN THE
UPPER 30S TO LOW 40S FRIDAY...INCREASING THROUGH THE WEEKEND AND
INTO THE UPPER 50S TO LOW 60S BY MONDAY. LOWS WILL SEE A SIMILAR
TREND...INCREASING FROM MAINLY LOW 20S LOW 20S THU AND FRI NIGHTS TO
THE LOW TO MID 30S BY SAT AND SUN NIGHTS. THERE IS SOME MODEL
DISAGREEMENT TOWARD THE END OF THE PERIOD WITH REGARD TO PRECIP
CHANCES...AS THE ECMWF BRINGS PRECIP IN FROM THE SOUTHWEST SUNDAY
NIGHT AND THE GFS IS COMPLETELY DRY. WILL FORECAST A SLIGHT CHANCE
FOR RAIN SUN NIGHT/MONDAY...ALTHOUGH CONFIDENCE IS LOW AT THIS TIME.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 745 PM MONDAY...
STRONG (1032 MB) BUT TRANSIENT MODIFIED ARCTIC HIGH PRESSURE WILL
RIDGE SOUTH INTO NC TONIGHT...THEN BUILD QUICKLY OFFSHORE ON TUE.
INITIALLY VFR CONDITIONS THIS EVENING WILL BE THREATENED WITH FIRST
A NARROW BAND OF LOW MVFR CLOUDS THAT NEAR TERM GUIDANCE WILL
DEVELOP IN THE VICINITY OF KRWI IN THE NEXT COUPLE OF HOURS...THEN
SWEEP...IN NORTHEASTERLY FLOW...TO THE SOUTHWEST ACROSS THE
REMAINDER OF CENTRAL NC BETWEEN 02-07Z...LASTING AT ANY ONE LOCATION
FOR JUST 2-3 HOURS BEFORE DEPARTING.
MEANWHILE...AN AREA OF 4-5 THOUSAND FT CEILINGS OVER SC WILL EXPAND
NORTH AS THE FLOW IN THAT LAYER STRENGTHENS AND CAUSES AIR TO GENTLY
RISE ATOP THE AFOREMENTIONED RIDGE OF SURFACE HIGH PRESSURE AND
ASSOCIATED NORTHEASTERLY FLOW BENEATH. CONFIDENCE IS RELATIVELY HIGH
THAT CEILINGS WITHIN THIS AREA OF CLOUDS WILL THEN GRADUALLY LOWER
TO INTO MVFR RANGE FROM WSW TO ENE ON TUE - FIRST AT KINT/KGSO AND
LAST AT KRWI. THERE IS A LESSER...MEDIUM CHANCE (AROUND 50
PERCENT)... THAT CONDITIONS WILL LOWER TO IFR...WITH ACCOMPANYING
PERIODS OF LIGHT RAIN/DRIZZLE MAINLY AT KGSO/KINT...AND PERHAPS AS
FAR EAST AS KRDU...TUE MORNING. IF PRECIPITATION WERE TO INDEED
OCCUR... TEMPERATURES WILL BE CLOSE TO FREEZING AT KINT/KGSO...WHERE
AN ASSOCIATED PERIOD OF FREEZING PRECIPITATION WOULD BE POSSIBLE.
OUTLOOK: TUE NIGHT: SUB-VFR CONDITIONS WILL CONTINUE TO DEVELOP
NORTHEAST AND LOWER ACROSS CENTRAL NC THROUGH TUE NIGHT...SUCH THAT
LIFR CONDITIONS WITH RESPECT TO CEILINGS AND POSSIBLY VISIBILITIES
IN DENSE FOG...ARE EXPECTED TO PREVAIL LATE TUE NIGHT-WED
MORNING...IN ASSOCIATION WITH THE SLOW RETREAT/APPROACH OF A WARM
FRONT FROM THE SOUTHEAST.
WED-THU: A RETURN TO VFR WILL BE PROBABLE WITH THE PASSAGE OF THE
WARM FRONT LATER WED AT KFAY/KRWI/KRDU...BUT THIS IMPROVEMENT WILL
BE DELAYED...OR MAY NOT OCCUR AT ALL AT KINT/KGSO...BEFORE A COLD
FRONT AND AREA OF RAIN ARRIVE FROM THE NORTHWEST WED NIGHT...AND
PERSIST THROUGH MUCH OF THU.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...CBL/BLS
SHORT TERM...KC
LONG TERM...KC
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 PM EST SUN MAR 1 2015
.SYNOPSIS...
A WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN THROUGH MONDAY
MORNING. A COLD FRONT WILL MOVE THROUGH MONDAY AFTERNOON FOLLOWED BY
ANOTHER WEDGE OF COOL HIGH PRESSURE FOR TUESDAY. TEMPERATURES ARE
EXPECTED TO BE WELL ABOVE NORMAL ON WEDNESDAY AHEAD OF A STRONG COLD
FRONT THAT WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW
PRESSURE MAY DEVELOP ALONG THE FRONT...KEEPING THE WEATHER UNSETTLED
THROUGH THURSDAY. CHILLY HIGH PRESSURE WILL BUILD ACROSS THE AREA
FRIDAY AND PERSIST THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 200 PM SUNDAY...ISENTROPIC LIFT OVER THE AREA THIS AFTERNOON
WILL GRADUALLY WEAKEN AS HIGH WEDGING DOWN THE COAST IS SHIFTED EAST
BY WESTERLY FLOW ALOFT. ALTHOUGH THE WEDGE WILL BE IN THE PROCESS OF
BREAKING DOWN OVERNIGHT...LIGHT WESTERLY FLOW BECOMES PREVALENT BY
DAYBREAK...LOW LEVEL CLOUDS AND MOISTURE WILL LINGER THROUGH THE END
OF THE PERIOD. FORECAST SOUNDINGS CONTINUE TO SHOW THE COLUMN UNDER
1500 FT ALMOST FULLY SATURATED. WHILE THERE IS NO REAL SOURCE OF
LIFT...AND EVEN SOME WEAK SUBSIDENCE ...THE PRESENCE OF ABUNDANT LOW
LEVEL MOISTURE TRAPPED UNDER THE LOW LEVEL INVERSION WILL NOT ONLY
RESULT IN STRATUS HANGING AROUND ALL NIGHT BUT COULD LEAD TO PATCHES
OF MIST OR DRIZZLE. THE PREVIOUSLY MENTIONED LACK OF FORCING SHOULD
PREVENT ANY MEASURABLE PRECIP SO BY MIDNIGHT HAVE MOST AREAS UNDER
MENTIONABLE POP THRESHOLDS. FORECAST SOUNDINGS AND MODEL LAYER DATA
KEEP BOUNDARY LAYER WINDS JUST HIGH ENOUGH TO PREVENT DEVELOPMENT OF
WIDESPREAD FOG...THOUGH PATCHES OF 4-5SM ARE CERTAINLY POSSIBLE.
TEMPERATURES WILL BE NEAR CLIMO OVERNIGHT WITH WESTERLY FLOW AND
CLOUDS KEEPING LOWS IN THE UPPER 30S TO LOWER 40S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PROGRESSIVE REGIME THROUGH THE PERIOD. ONE
WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN MON MORNING
AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE ACROSS THE EASTERN
CAROLINAS MON AFTERNOON. THERE COULD BE SOME VERY LIGHT
PRECIPITATION AROUND ON MON...DIFFICULT TO SAY WHETHER ISOLATED
SPOTS WILL RECEIVE MEASURABLE RAINFALL. WILL CONFINE POPS TO NEAR 20
PERCENT OR JUST BELOW ON MON. A VERY PRONOUNCED NEAR SURFACE
INVERSION WILL KEEP LOW CLOUDS/FOG AROUND FOR THE FIRST PART OF THE
MORNING. THIS STRONG INVERSION DOES FINALLY BREAK DOWN AND SO WE
MAY AT LEAST SEE SOME GLIMPSES OF SUNSHINE DURING MON.
ONCE THE COLD FRONT MOVES THROUGH...ANOTHER WEDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE CAROLINAS MON NIGHT INTO TUE AS HIGH PRESSURE
MOVES OUT OF THE MID-WEST AND ACROSS THE MID-ATLANTIC STATES. THIS
WILL LOCK IN LOW-LEVEL MOISTURE...WITH WIDESPREAD LOW CLOUDS
EXPECTED TO REDEVELOP LATER MON NIGHT AND THEN PERSIST INTO TUE AS
COLD AIR ADVECTION REDEVELOPS ON LOW-LEVEL NE FLOW. ISENTROPIC
UPGLIDE IS EXPECTED TO DEVELOP MON NIGHT AS MOIST S TO SW OR WSW
WINDS ABOVE 2 KFT TOP THE COOL DOME OF AIR NEAR THE SURFACE.
ALSO...A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE MON NIGHT AND
TUE. THIS TROUGH WILL LIFT ATLANTIC MOISTURE OVER THE TOP OF THE
LOW-LEVEL INVERSION AND NOT ONLY KEEP SKIES CLOUDY...BUT BRING MORE
WET WEATHER. THERE IS NO RISK OF ANY FREEZING OR FROZEN
PRECIPITATION. QPF AMOUNTS WILL BE LIGHT.
THE HIGH DOES MOVE OFF THE COAST LATE TUE AND TUE NIGHT AND THE
MODELS ARE IN A HURRY TO BREAK DOWN THE WEDGE. ALTHOUGH IT MAY
EVOLVE SLOWER THAN CURRENTLY PORTRAYED...IT DOES LOOK LIKE THE NEXT
COLD FRONT WILL BE STRONGER AND ITS PROXIMITY SHOULD ALLOW A WARMER
RETURN FLOW TO DEVELOP OVERNIGHT AT ALL LEVELS. WILL SHOW TEMPS
TRENDING HIGHER THROUGH THE NIGHT AS INCREASINGLY SOUTHERLY WINDS
DEVELOP.
TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD WITH MON LIKELY
CONSIDERABLY WARMER THAN TUE. HIGHS MON WILL BE IN THE UPPER 50S AND
LOWER 60S WITH SOME MID 60S POSSIBLE ALONG THE SOUTH SANTEE RIVER
AREA. WE WILL HAVE TO SUBTRACT A GOOD 10 DEGREES FROM THOSE VALUES
ON TUE. LOWS WILL BE MAINLY IN THE UPPER 30S AND LOWER 40S MON
NIGHT. LOWS TUE EVE WILL BE VERY NEAR THE HIGHS OF THE DAY AND
THEN MOVE UPWARDS FROM THERE DURING THE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...VERY WARM START TO THE EXTENDED PERIOD WITH
WEDNESDAY BEING THE WARMEST DAY IN QUITE A WHILE. UPPER RIDGE WILL
HOLD ON UP THROUGH THE SOUTHEAST AS DEEP TROUGH DIGS DOWN THROUGH
THE MID WEST. THIS WILL AID IN KEEPING A DRIER AND WARMER DAY OVER
THE COASTAL CAROLINAS. ALTHOUGH OVERALL MOISTURE THROUGH THE COLUMN
IS GENERALLY HIGH WITH UP TO 1.3 INCHES OF PCP WATER WED
MORNING...THE SOUNDINGS AND MOISTURE PROFILES KEEP IT CONFINED TO
VERY LOW LEVELS AND VERY HIGH WITH A DECENT DRY LAYER THROUGH THE
MID LEVELS. THIS MAY ALLOW SOME BREAKS IN THE CLOUDS TO HELP PUSH
TEMPS WELL INTO THE 70S. THE COAST WILL NOT BE AS FORTUNATE AS
SOUTHERLY FLOW WILL BRING THE COOLER OCEAN AIR OVER THE BEACHES
ADVECTING INLAND A BIT. ALSO THE POTENTIAL FOR SEA FOG WILL EXIST AS
THE WARMER AIR RUSHES OVER THE COOLER WATERS. BY LATE WED SHWRS WILL
INCREASE AS COLD FRONT DRAWS CLOSER. WILL KEEP LOW END POPS OVER
PORTIONS OF AREA...MAINLY INLAND ON WED BUT EXPECT BEST CHC OF PCP
TO COME WED EVE INTO THURS. A STRONG COLD FRONT WILL CROSS THE AREA
WED NIGHT WITH PLENTY OF CAA TO FOLLOW. SEEMS LIKE MODELS ARE
COMING BACK TO AN EARLIER FROPA FOR WED NIGHT INSTEAD OF THURS. MAY
SEE MAX TEMPS FOR THURS AT MIDNIGHT WED NIGHT BEFORE DROPPING BEHIND
FRONT...ESPECIALLY ALONG COASTAL LOCATIONS WHERE FRONT WILL PASS
THROUGH AFTER MIDNIGHT. THE SHALLOW COOL AIR WILL COME RUSHING IN
BUT MID TO UPPER TROUGH HANGS BACK TO THE WEST. THIS WILL LEAD TO
SHORTWAVE ENERGY RIDING UP ALONG THE EAST SIDE OF THE TROUGH THROUGH
THE SOUTHEAST PRODUCING WAVES OF LOW PRESSURE DEVELOPING ALONG FRONT
WHICH SHOULD REMAINED ALIGNED SW TO NE JUST TO OUR SOUTH. THEREFORE
CLOUDS AND PCP SHOULD LINGER THROUGH THURS AND POSSIBLY LONGER.
ALTHOUGH COLD AIR WILL BE LOCKED IN AT THE SFC...WARMER AIR ALOFT
SHOULD KEEP ALL PCP AS A COLD RAIN BEHIND FRONT AT THIS POINT. THE
GFS DOES SHOW MAIN SHORTWAVE SWINGING OFF THE COAST BY FRI MORNING
AS SFC HIGH BUILDS OVER THE CAROLINAS....BUT A BROAD TROUGH REMAINS
OVER THE EAST WITH MORE OF A ZONAL FLOW ALOFT BUT THERE WILL BE
POTENTIAL FOR OTHER SHORTWAVES TO MOVE THROUGH. FOR NOW WILL REMAIN
MORE OPTIMISTIC FOR FRI INTO THE WEEKEND WITH A DRIER ALTHOUGH
COOLER FORECAST.
TEMPS WILL TAKE A DIVE ONCE COLD FRONT SHIFTS SOUTH WED NIGHT WITH
850 TEMPS UP AROUND 12C WED AFTN DROPPING DOWN JUST BELOW 0C BY FRI
MORNING. THIS STRONG CAA AND POSSIBLY LINGERING CLOUDS AND PCP WILL
KEEP VERY COOL TEMPS FOR THURS AND FRI. THE LATEST GUIDANCE SHOWS
MAX TEMPS ONLY REACHING INTO THE 40S ON THURS AND NOT EVEN REACHING
40 ON FRI IN MANY PLACES. FOR NOW...WILL TREND COOLER BUT NOT GET
THAT EXTREME JUST YET AS MODELS HAVE NOT REMAINED VERY CONSISTENT
WITH THIS SYSTEM FOR LATE WEEK. HESITANT ESPECIALLY ON FRI AS
SUNSHINE WILL MAKE ITS WAY OUT AND THIS TIME OF YEAR THE SUN IS
PLAYING A BIGGER ROLE IN WARMING.
&&
.AVIATION /00Z MONDAY THROUGH SATURDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE WITH THE NEXT SET OF TAFS AS FRONT
PRETTY MUCH LAYS OVER TOP OF US THROUGH THE FORECAST PERIOD.
CEILINGS WILL LIKELY BOUNCE FROM IFR TO MVFR BEFORE REMAINING
PREDOMINATELY IFR OVERNIGHT. LIGHT PRECIP ALONG THE COAST WILL MOVE
OUT OF THE REGION IN A FEW HOURS...AND THE HRRR MODEL SEEMS TO HAVE
A REASONABLE HANDLE ON IT. A WEAK TROUGH OF LOW PRESSURE WILL GIVE
US MAINLY WESTERLY WINDS OVERNIGHT...QUITE LIGHT. IFR CONDITIONS
WILL CONTINUE THROUGH THE MORNING HOURS ON MONDAY BEFORE LIFTING TO
MVFR OR BETTER. FRONT DROPS SOUTH OF THE REGION MONDAY
AFTERNOON...WITH WINDS SHIFTING TO THE NORTHEAST.
EXTENDED OUTLOOK...BECOMING VFR LATE MON. PERIODS OF MVFR/SHOWERS
TUE/WED. RAIN/IFR THUR. VFR DEVELOPING FRI.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM SUNDAY...GRADIENT CONTINUES TO WEAKEN WITH THE WEAKENING
COASTAL TROUGH NOW CLOSE TO THE COAST. WINDS AT 41013 HAVE GONE
SOUTH-SOUTHEAST BUT REMAIN AROUND 10 KT. NORTHEAST 10 TO 15 KT OVER
THE NEARSHORE WATERS WILL CONTINUE FOR THE REMAINDER OF THE
AFTERNOON WITH WINDS BECOMING LIGHT AND VARIABLE OVERNIGHT. CLOSER
TO DAYBREAK LIGHT OFFSHORE FLOW WILL DEVELOP AS WEAK HIGH CENTERED
OVER GA/SC BECOMES MORE DOMINANT. GRADIENT REMAINS WEAK AND WESTERLY
FLOW LATE IN THE PERIOD WILL CONTINUE TO RUN 10 KT OR LESS. SEAS 3
TO 5 FT THIS AFTERNOON AND EVENING WILL CONTINUE THE DOWNWARD TREND
OVERNIGHT...FALLING TO 2 TO 4 FT BY THE END OF THE PERIOD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...MARINERS SHOULD EXPECT CHANGEABLE WIND
DIRECTIONS THIS PERIOD. WINDS MON MORNING WILL BE WESTERLY...BUT
WITH THE PASSAGE OF A COLD FRONT WILL SHIFT TO N DURING THE
AFTERNOON. NE WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS MON
NIGHT AS A SURGE DEVELOPS IN RESPONSE TO A BUILDING WEDGE OF HIGH
PRESSURE. THE WIND DIRECTION WILL VEER TO EASTERLY DURING TUE AND
THEN SE AND S BY TUE EVE AS HIGH PRESSURE TO OUR NORTH MOVES FURTHER
OFFSHORE. WINDS OVERNIGHT TUE WILL VEER TO SW AHEAD OF A STRONG COLD
FRONT. THE STRONGEST WINDS ARE EXPECTED MON NIGHT...UP TO 20 TO 25
KT. SEAS WILL BE HIGHEST MON NIGHT INTO TUE...UP TO 4 TO 7 FT. SEAS
MAY APPROACH 6 FT TUE NIGHT...MAINLY ACROSS THE NORTHERN OFFSHORE
WATERS.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH WED UP
TO 15 TO 20 KTS KEEPING SEAS GENERALLY IN THE 4 TO 6 FT RANGE BUT
WILL INCREASE WED NIGHT INTO THURS AS COLD FRONT MOVES THROUGH. THE
TIGHTENED GRADIENT FLOW WILL PRODUCE WINDS UP NEAR 20 KTS AS THEY
SHIFT MORE ABRUPTLY AROUND FROM SW TO N BEHIND FRONT OVERNIGHT WED.
STRONG CAA AND TIGHTENED GRADIENT WILL KEEP SEAS UP TO 4 TO 7 FT
THURS. THE FRONT WILL LINGER TO THE SOUTH AS HIGH PRESSURE BUILDS
DOWN INTO THE WATERS FROM THE NW. THIS MAY KEEP A PROLONGED PERIOD
OF SCA CONDITIONS IN STRONG NORTHERLY WINDS THROUGH THURS INTO FRI.
WINDS WILL LIGHTEN THROUGH LATE FRI AND BECOME MORE VARIABLE INTO
THE WEEKEND AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...III
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1018 PM EST MON MAR 2 2015
.SYNOPSIS...
MOISTURE BEING LIFTED UP AND OVER RETREATING COLD AIR WILL BRING
AREAS OF FREEZING RAIN...POSSIBLY MIXED WITH SLEET...ACROSS MOST
OF THE AREA TUESDAY MORNING BEFORE CHANGING TO RAIN BY TUESDAY
AFTERNOON AS TEMPERATURES WARM. LATER TUESDAY AFTERNOON...MODERATE
RAIN WILL DEVELOP AND SPREAD ACROSS MUCH OF THE AREA...BUT
ESPECIALLY NORTHERN KENTUCKY AND SOUTHERN OHIO WHERE LOCALLY HEAVY
RAIN WILL BE POSSIBLE. THE COMBINATION OF RAIN AND MELTING SNOW
MAY CAUSE FLOODING. AS COLDER AIR MOVES INTO THE AREA WEDNESDAY
AFTERNOON...RAIN WILL CHANGE TO SNOW AND A PERIOD OF HEAVY SNOW IS
POSSIBLE FOR NORTHERN KENTUCKY AND SOUTHERN OHIO. THE ENTIRE
SYSTEM SHIFTS EAST OF THE AREA BY THURSDAY AFTERNOON WITH DRYING
CONDITIONS FOR THE END OF THE WEEK AND INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
ONLY SOME TWEAKS TO THE FORECAST FOR TONIGHT. THE BIGGEST CHANGE IS
THAT TEMPERATURES OVER PORTIONS OF THE NORTHERN COUNTIES HAVE
FALLEN RAPIDLY UNDER THE MOSTLY CLEAR SKIES. SO ADJUSTED THEIR
LOWS DOWN...BUT THE TEMPERATURES SHOULD BEGIN TO RISE ACROSS THE
ENTIRE FA AFTER MIDNIGHT.
THE SECOND AND MORE MINOR CHANGE HAS TO DO WITH POPS. LATEST NAM
IS SLOWER IN BRINGING IN PCPN TUESDAY MORNING. THE RAP AND THE
HRRR LIFT A LIGHT BAND ACROSS PORTIONS OF THE FA BETWEEN 12Z-15Z
THEN PRETTY MUCH LEAVE THE REST OF THE FA DRY THRU 15Z. BACKED OFF
ON THE BEGINNING OF THE POPS BY AN HOUR OR TWO...BUT DIDNT GO AS
DRASTIC AS THE RAP/HRRR WITH THIS UPDATE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
NOT TOO MANY TIMES DO WE ISSUE BACK TO BACK TO BACK ADVISORY/WATCH
PRODUCTS BUT THE PATTERN NECESSITATES IT TO RAISE AWARENESS FOR
MULTIPLE THREATS BEGINNING TUES A.M. AND CONTINUING INTO EARLY THURSDAY.
FIRST OFF...THE TUESDAY MORNING FREEZING RAIN/SLEET POTENTIAL.
THIS IS NOT AS CLEAR CUT AS ORIGINALLY THOUGHT. VERY CLEAR PER
02.12Z GUIDANCE THAT VERY STRONG MOISTURE FLUX/TRANSPORT WILL GET
GOING AFTER MIDNIGHT TONIGHT TO OUR SOUTHWEST...WITH SREF 850MB
TRANSPORT MAGNITUDES OF 5+ SIGMA ABOVE CLIMO AS LOW LEVEL JET
RAMPS UP DOWNSTREAM OF APPROACHING NRN STREAM TROUGH SLIPPING THRU
THE UPPER MS VALLEY. HOWEVER...AMBIENT AIRMASS /ESP BELOW 500 MB/
IS EXTREMELY DRY PER 02.12Z KILN SOUNDING AND FORECAST SOUNDINGS
THROUGH MON NIGHT. MODEL QPFS HAVE BEEN TRENDING LIGHTER/DRIER IN
THE TUESDAY MORNING TIME FRAME WHICH IS WORRISOME...BUT HAVE ALSO
SEEN TIME AND TIME AGAIN WHERE STRONG WAA/MOISTURE
TRANSPORT/ISENTROPIC LIFT SIGNALS USE MOISTURE EFFICIENTLY TO
WRING OUT LIGHT QPF OVER RETREATING ARCTIC DOMES. THUS...AM
RUNNING WITH HIGHER PRECIP CHANCES THAN MDLS ON TUES MORNING IN
THIS SCENARIO GIVEN THE VERY STRONG TRANSPORT SIGNAL AND
RETREATING ARCTIC DOME. NOT ONLY IS THERE THAT ASPECT...BUT
BOUNDARY LAYER WARMING WILL BE RACING NORTH ON DEVELOPING SSELY
FLOW. CURRENT FORECAST IS BEST CURRENT ESTIMATION OF OVERLAP
BETWEEN ADVANCING AREAS OF LIGHT RAIN...INCREASING BOUNDARY LAYER
WARMING...AND TIMING OF THE TWO...WHICH SPELLS A TWO TO FIVE HOUR
PERIOD /LEAST IN THE SOUTH AND MORE IN THE NORTH/ OF LIGHT
FREEZING RAIN POTENTIAL. GIVEN VIRTUALLY NO IMPACT OR CHANCE TO
MIX WITH SLEET ACROSS SERN IND/SWRN OH/CNTL OH...HAVE OPTED FOR
FREEZING RAIN ADVISORY HERE FOR LIGHT ICE AMOUNTS THAT MAY CAUSE
TRAVEL ISSUES. FURTHER NORTH...DEPTH OF COLD AIR AND PERHAPS A
LITTLE LONGER DURATION MAY ALLOW FOR MORE FZRA/SLEET COMBO SO
WINTER WX ADVISORY THERE. TOO MUCH RISK TO LET THIS SITUATION GO
WITHOUT AN ADVISORY AS MAGNITUDE OF WARMING/MOISTENING ALOFT MAY
ALLOW FOR A MORE RAPID DEVELOPMENT AND BETTER COVERAGE THAN MODELS
ARE SHOWING. THE DIFFERENCE BETWEEN 02.12Z NAM/ECMWF /MEAGER ON
QPF AND COVERAGE/ TO 02.12Z SREF /HIGH PROBABILITIES OF NOT ONLY
MEASURABLE FZRA BUT SOME HINTS OF UP TO 0.10"/ SPURRED THE
DECISION TO MOVE TO ADVISORY ON THIS ISSUANCE.
NEXT UP...MODERATE TO HEAVY RAIN AND POTENTIAL FLOODING. THIS
SIGNAL HAS BEEN VERY LONG ADVERTISED PER ANALOGS AND
ANOMALIES...AND NOW IT/S TIME TO SWITCH HIGHER RES DETERMINISTIC
GUIDANCE FOR DETAILS. THE PATTERN SUPPORTS A CONTINUED LONG FEED
OF MOISTURE TRANSPORT ALONG AND AHEAD OF A SLOWLY MOVING FRONTAL
ZONE TUESDAY AFTERNOON INTO WEDNESDAY MORNING. BIG PUSH OF VERY
ANOMALOUS/DEEP MOISTURE...WITH PWAT RUNNING 300% NORMAL AND 3
SIGMA ABOVE CLIMO ON TUESDAY NIGHT. 70+KT LOW LEVEL JET AROUND
BACKSIDE OF SERN CONUS RIDGING SHOULD FOCUS/FUNNEL MOISTURE INTO
THE OHIO VALLEY AND IT SEEMS POTENTIAL FOR EXCESSIVE RAIN IS
SHIFTING A TAD SOUTH W/TIME OVER THE LAST 24 HOURS. CURRENTLY
EXPECT THE HEAVIEST RAINFALL FOOTPRINT /VIA LONG DURATION TRAIN OF
MODERATE/SOMETIMES HEAVY RAIN/ TO BE ALONG AND SOUTH/EAST OF I-71
WHICH IS WHERE FLOOD WATCH HAS BEEN PLACED. PLENTY OF SNOW/FROZEN
SOILS TO CONTEND WITH SO STRAIGHTFORWARD TO GET FLOOD WATCH OUT
TODAY. AMTS FROM 1-2" - AND WHILE CONVECTION ISN/T GOING TO PLAY A
HUGE ROLE - CONVECTIVE ELEMENTS VIA MODEST DESTABILIZATION ABOVE
THE STABLE BOUNDARY LAYER WILL CERTAINLY CAUSE
CONCERN...ESPECIALLY SOUTH/SOUTHEAST CWA IN NORTHERN KY/SCNTL OH.
COULD SEE BRUSH CREEK BASIN...LOWER SCIOTO...AND KENTUCKY/LICKING
RIVERS IN KY REALLY RESPOND TO THIS...AS 0.5" TO 1.00" SNOW WATER
EQUIVALENT TIED UP IN THE SNOW PACK IS RELEASED RATHER QUICKLY
WITH TEMPS APPROACHING 50F IN THE SOUTH. AM A LITTLE MORE THAN
CONCERNED FOR NRN KY/FAR SCNTL OHIO SO HOPING FOR A SLOW RELEASE
FROM THE SNOW PACK AND RAIN AMOUNTS ON THE LIGHTER END OF THE SPECTRUM.
FINALLY...POTENTIAL WINTER STORM. LOW CONFIDENCE HERE BUT A SIGNAL
I COULD NOT IGNORE. 02.12Z MODELS CONTINUE TO STABILIZE SOMEWHAT
ON COLD AIR OOZING INTO THE FRONTOGENETICALLY FORCED PCPN REGION
THAT WILL BE ONGOING ACROSS NRN KY/SRN OH. 02.12Z GFS AND ITS
PRIOR RUNS SEEMED WAY TOO COLD IN THE BOUNDARY LAYER AND THROWN
OUT. MUCH MORE CONSISTENCY FROM NAM/ECMWF AND THAT IS WHERE
FORECAST IS BASED. A LONG DURATION RIGHT ENTRANCE REGION OF THE
JET/FGEN FORCED BAND OF PRECIPITATION WILL CONTINUE WED AFTN/NIGHT
INTO THURSDAY MORNING AS THE COLD AIR OVERTAKES IT. THERE/S A
SCENARIO /ONE OF SEVERAL/ WHERE 12-18 HOURS OF MODERATE SNOW
OCCURS FROM NRN KY INTO SRN OHIO...AND SOME SOLUTIONS ARE EXTREME
IN SNOWFALL AMOUNTS. ANECDOTALLY...HAVE TO ACKNOWLEDGE THAT THE
PATTERN AND FORCING SUPPORTS A POTENTIAL HIGHER-END SNOW
ACCUMULATION. BUT USING CLIMO AND WHAT WILL LIKELY BE A SLOWER
TRANSITION TO SNOW...AND MARCH INSOLATION /EVEN THRU CLOUDS/ THAT
WILL KEEP ANYTHING BUT HEAVY SNOW RATES FROM ACCUMULATING TOO
MUCH. IT/S WEDNESDAY NIGHT THAT HAS MY ATTENTION AS A POSSIBILITY
OF REALLY ACCUMULATING SNOW UNDER CLOAK OF DARKNESS WITH CONTINUED
BANDING/FGEN FORCING IN THE RIGHT ENTRANCE REGION OF THE JET THAT
MOVES ONLY VERY SLOWLY SOUTHEAST FROM WED AFTN INTO THURS MORNING.
WILL HAVE TO WATCH AREAS BACK FROM CVG TO ILN TO SOUTH OF CMH FOR
POSSIBLE EXPANSION OF WATCH IF SOME OF THE MORE DIRE /QUICKER
CHANGEOVER/ SITUATIONS GET MORE SUPPORT IN THE ENSEMBLES. HAVE
TAKEN A VERY CONSERVATIVE APPROACH TO SNOWFALL FORECAST IN OUR
SOUTHERN AREAS AND CURRENTLY INDICATING 4-7" WHICH NECESSITATES A
WATCH CENTERED ON WED NIGHT...AGAIN...WITH NEED TO WATCH THAT THIS
MAY GET EXPANDED IN TIME.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ANOTHER ROUND OF COLD ARCTIC AIR IS ON TAP FOR THURSDAY AS ARCTIC
HIGH PRESSURE BUILDS EAST INTO THE REGION. TEMPERATURES WILL
STRUGGLE TO WARM INTO THE MID TEENS NORTH TO THE MID 20S SOUTH.
THESE TEMPERATURES ARE SOME 25 TO 30 DEGREES BELOW NORMAL FOR EARLY
MARCH. NEEDLESS TO SAY...SOME RECORD LOW MAX TEMPERATURES MAY BE IN
JEOPARDY. THEY ARE 24...22...AND 20 AT CVG...DAY...AND CMH
RESPECTIVELY. WE ARE CURRENTLY FORECASTING 21...17...AND 19 AT
CVG...DAY...AND CMH RESPECTIVELY. WHO HAS FRESH SNOW COVER...AND THE
AMOUNT OF CLOUDS...WILL ULTIMATELY PLAY A ROLE ON HOW WARM IT GETS
DESPITE AN INCREASING SUN ANGLE FOR EARLY MARCH.
FOR THURSDAY NIGHT...THE ARCTIC HIGH WILL MOVE EAST ACROSS THE OHIO
VALLEY. AT THIS TIME...THE BEST CHANCE FOR WINDS TO BECOME LIGHT OR
CALM WILL BE ALONG AND SOUTH OF THE OHIO RIVER. WITH CLEAR SKIES
EXPECTED...TEMPERATURES WILL LIKELY DROP BELOW ZERO IN MOST SPOTS.
AGAIN...KNOWING HOW COLD IT WILL GET ATTM IS DIFFICULT WHICH WILL
DEPEND ON SNOW COVER AND HOW DEEP THAT SNOW COVER IS FOR MAXIMUM
RADIATIONAL COOLING EFFECTS. HAVE GONE CONSERVATIVE ATTM...BUT
GETTING LOWER THAN WHAT IS FORECAST IS CERTAINLY POSSIBLE. WILL
FORECAST LOWS GENERALLY IN THE ZERO TO 5 BELOW RANGE. RECORD LOWS OF
2...0 AND 2 AT CVG...DAY AND CMH WILL ALSO BE IN JEOPARDY.
FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST
WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY
SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY
RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON
FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING
SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE
HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY
NIGHT WILL GENERALLY BE IN THE TEENS.
FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR
THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH
OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED
SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS.
TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL
STILL AVERAGE BELOW NORMAL FOR EARLY MARCH.
HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY
ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE
FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S
READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE
BIT BELOW NORMAL FOR EARLY MARCH.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
FIRST HALF OF THE FORECAST PERIOD WILL BE QUIET. CIGS WILL SLOWLY
LOWER OVERNIGHT BUT WILL REMAIN VFR.
SWLY FLOW ON THE BACKSIDE OF THE RETREATING HIGH WILL PULL
MOISTURE INTO THE REGION. WARM AIR SCREAMING IN ALOFT WILL ALLOW
FOR THE PTYPE TO BE RAIN ALOFT...BUT WITH SURFACE TEMPS BY 12Z IN
THE 20S...A PERIOD OF FREEZING RAIN WILL AFFECT THE TAFS DURING
THE MORNING.
TEMPERATURES WILL WARM ABOVE FREEZING FROM S TO N...WITH CVG
CHANGING OVER TO RAIN AROUND 14Z...BUT DAY/CMH/LCK WILL PROBABLY
STAY AT OR BELOW FREEZING UNTIL ABOUT 18Z. CIGS AND VSBYS WILL
DROP TO IFR QUICKLY DURING THE MORNING AS THE ATMOSPHERE BECOMES
SATURATED.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY NIGHT..
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
OHZ053>055-060>065-070>072-074-077.
WINTER WEATHER ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
OHZ026-034-035-042>046-051-052-056.
FLOOD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON
FOR OHZ063>065-071>074-077>082-088.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR OHZ081-088.
KY...FLOOD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON
FOR KYZ089>100.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR KYZ089-090-094>100.
IN...FREEZING RAIN ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
INZ058-059-066-073-074.
WINTER WEATHER ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
INZ050.
FLOOD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON
FOR INZ075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...SITES
SHORT TERM...BINAU
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
307 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A PROLONGED WET SYSTEM APPROACHES THE FORECAST AREA ON TUESDAY AND
ULTIMATELY DECIDES TO TAKE ITS TIME MOVING THROUGH THE WILD AND
WONDERFUL STATE. THE GFS IS THE MOST PROGRESSIVE OF THE BUNCH
WHILE THE EURO AND NAM ARE SIMILAR KEEPING A FIRE HOSE POINTED AT
US FOR AT LEAST 24 HOURS. THIS FORECAST MORE CLOSELY FOLLOWS THE
WETTER/SLOWER MODELS. ITS WORTH MENTIONING THAT THERE IS SOME
UNCERTAINTY IN THE LOCATION IN WHICH THE HEAVIEST RAIN FALLS...SO
THE QPF IS LIKELY BLENDED OVER A LARGER PORTION OF THE AREA THAN
WHAT WILL ACTUALLY HAPPEN.
THE MOISTURE TAP FOR THIS SYSTEM EXTENDS ALL THE WAY BACK TO THE
BAJA PENINSULA...SO REGARDLESS THIS WILL BE A RATHER JUICY SYSTEM
WITH ATMOSPHERIC RIVER POTENTIAL. A 70+ KT SWLY LLJ DEVELOPS
ENHANCING LOW LEVEL MOISTURE ADVECTION. ALL SAID AND DONE 2 INCHES
OF QPF SOUNDS REASONABLE FOR MOST PLACES...THIS COUPLED WITH
SNOWPACK MELTING IN THE WARMER TEMPERATURES THAT WE WILL
EXPERIENCE WILL CAUSE A SCENARIO WHERE FLOODING IS A LARGE
CONCERN.
ALSO OF CONCERN IS THE STRONGER WINDS IN THE MOUNTAINS...DEPENDING
ON HOW MUCH SNOW MELT OCCURS AND HOW THAWED AND SATURATED THE GROUNDS
ARE THIS COULD BE ANOTHER POTENTIAL HAZARD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH
COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING
PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS
EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR
CONTINUED COOL...BUT DRY CONDITIONS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H L L L L L L L L L L
HTS CONSISTENCY M M L L L L L L L L L L
BKW CONSISTENCY H H L L L L L L L L M M
EKN CONSISTENCY M M L L L L L L L L L L
PKB CONSISTENCY L L L L L L L L L L M H
CKB CONSISTENCY L L L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...JW
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM
SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE
SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO
LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO
SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT
TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF
MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY.
TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF
AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR
70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO
BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN
CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED
ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON
IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE
ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS
THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS
CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS
PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM
COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE
SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH
RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF
AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING
AS IS.
AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH
THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG
THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT
STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM
WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX
ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM.
ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN
THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY
TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM
TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF
YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY
NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND
THE FRONT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH
COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING
PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS
EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR
CONTINUED COOL...BUT DRY CONDITIONS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H L L L L L L L L
HTS CONSISTENCY H H M M L L L L L L L L
BKW CONSISTENCY H H H M L L L L L L L L
EKN CONSISTENCY H H H H L L L L L L L L
PKB CONSISTENCY H H L L L L L L L L L L
CKB CONSISTENCY H H L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...30
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
135 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFETRNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERRADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM
SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE
SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO
LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO
SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT
TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF
MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY.
TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF
AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR
70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO
BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN
CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED
ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON
IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE
ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS
THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS
CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS
PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM
COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE
SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH
RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF
AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING
AS IS.
AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH
THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG
THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT
STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM
WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX
ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM.
ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN
THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY
TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM
TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF
YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY
NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND
THE FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM STARTS OUT RATHER SOAKING WET. COLD FRONT WILL SLOWLY BE
PROGRESSING EASTWARD ACROSS THE CWA AT THE BEGINNING OF THE
PERIOD...WITH A WAVE OF LOW PRESSURE RIDING ALONG THE FRONT FROM
SOUTHWEST TO NORTHEAST...ENHANCING PRECIPITATION AS IT DOES SO.
STILL LOOKING LIKE HEAVY RAIN ON WEDNESDAY...IN THE MOIST
ATMOSPHERE...ALONG WITH SOME RATHER GUSTY WINDS EXPECTED TUESDAY
NIGHT INTO EARLY WEDNESDAY...WITH THE STRONG SOUTHWESTERLY FLOW AND
TIGHT PRESSURE GRADIENT. RAISED WIND GUSTS AND ADDED HEAVY RAIN
WORDING IN THE TUESDAY NIGHT THROUGH WEDNESDAY PERIOD.
FRONT WILL BEGIN TO PUSH EAST THURSDAY OR THURSDAY NIGHT...WITH
COLDER AIR RUSHING IN...AND A CHANGE OVER TO SNOW AREA WIDE. ITS
POSSIBLE THERE COULD BE SOME LIGHT ACCUMULATIONS...BUT WITH THE
WET...WARM GROUND...AT THIS POINT NOT SURE HOW MUCH WILL ACTUALLY BE
ABLE TO ACCUMULATE.
COLD HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING FRONT FOR FRIDAY
INTO THE REMAINDER OF THE EXTENDED. WITH TEMPERATURES DIPPING BELOW
NORMAL ONCE AGAIN.
WILL CONTINUE TO HIGHLIGHT WATER ISSUES FOR NEXT WEEK IN THE HWO.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MOERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H L L L L L L L L
HTS CONSISTENCY H H M M L L L L L L L L
BKW CONSISTENCY H H H M L L L L L L L L
EKN CONSISTENCY H H H H L L L L L L L L
PKB CONSISTENCY H H L L L L L L L L L L
CKB CONSISTENCY H H L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...30
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS TULSA OK
1139 PM CST SAT FEB 28 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
WIDESPREAD IFR TO LIFR CONDITIONS ARE EXPECTED THROUGH SUNDAY
MORNING ALONG WITH AREAS OF FREEZING DRIZZLE OR LIGHT FREEZING
RAIN. SOME SLOW IMPROVEMENT WILL OCCUR SUNDAY AFTERNOON AND
EVENING WITH ALL SITES BECOMING MVFR BY SUNDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 846 PM CST SAT FEB 28 2015/
DISCUSSION...
IT NOW LOOKS LIKE THE SNOW IS CONFINED TO EXTREME NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS AT THIS HOUR. FREEZING RAIN IS BECOMING MORE
OF AN ISSUE WITH AREAS OF FREEZING RAIN AND SLEET ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS. A SOUTHWESTERLY LOW LEVEL JET OF
AROUND 60 MPH CONTINUES TO CREATE ISENTROPIC LIFT ACROSS THE REGION
THIS EVENING PRODUCING THE AREAS OF FREEZING RAIN AND SLEET. THIS IS
EXPECTED TO PERSIST FOR A GOOD DEAL OF THE NIGHT. HAVE INCREASED ICE
AMOUNTS SOME ACROSS EAST-CENTRAL OKLAHOMA INTO WESTERN ARKANSAS. STILL
BELOW WARNING CRITERIA. THE HRRR SHOWS THE PRECIP TAPERING OFF AROUND 3 AM.
WILL SEE MAINLY FREEZING DRIZZLE ACROSS THE REMAINDER OF NORTHEAST OKLAHOMA.
THE TEMPERATURE HAS RISEN TO FREEZING OR JUST ABOVE ACROSS FAR SOUTHEAST
OKLAHOMA. WILL CONTINUE ADVISORY AS IS FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR OKZ049-OKZ053-
OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS PENDLETON OR
537 PM PST MON MAR 2 2015
.SHORT TERM...ISSUED AN EARLY FORECAST UPDATE THIS EVENING TO PLACE
THE ENTIRE FORECAST AREA UNDER AT LEAST A SLIGHT CHANCE OF SHOWERS
THROUGH THE EVENING. RADAR AND SATELLITE ARE SHOWING ISOLATED TO
SCATTERED SHOWERS ACROSS THE FORECAST AREA UNDER THIS NORTHERLY
FLOW. NORTHEAST OREGON CONTINUES TO HAVE THE BEST CHANCE OF SHOWERS
ESPECIALLY OVER THE HIGHER TERRAIN AND WALLOWA COUNTY. THESE AREAS
COULD SEE 1 TO 3 INCHES OF SNOW OVERNIGHT. REST OF THE FORECAST AREA
WILL SEE LITTLE TO NO ACCUMULATIONS. SHOWERS WILL BE ON THE DECREASE
AFTER MIDNIGHT.
&&
.PREV DISC... /ISSUED 230 PM PST MON MAR 2 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR
COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST
OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK
RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW
THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A
TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY
SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED
OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA
MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6
INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA
VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY
RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO
AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND
EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE
SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE
TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL
BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND
CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR
TUESDAY NIGHT.
A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A
WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS.
AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON
THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER
LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE
WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH
PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS.
AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO
THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND.
AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A
DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO
THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT.
DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR
CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE
FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND
KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 23 43 19 50 / 20 0 0 0
ALW 27 44 24 53 / 20 0 0 0
PSC 23 48 18 52 / 20 0 0 0
YKM 25 46 21 51 / 20 0 0 0
HRI 22 47 18 53 / 20 0 0 0
ELN 23 48 19 51 / 20 0 0 0
RDM 16 45 12 52 / 20 0 0 0
LGD 22 40 13 47 / 20 10 0 0
GCD 20 41 15 50 / 20 10 0 0
DLS 28 52 24 57 / 20 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 PM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA THIS EVENING. THIS PAIR OF WEATHER FEATURES WILL
BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED
PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY INTO
THIS EVENING. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS
TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY...BRINGING MAINLY RAIN TO THE AREA. COLDER TEMPERATURES
WILL FOLLOW FOR THE LATER PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
DID ADJUST THE AREA OF FREEZING RAIN SOME...TO FIT IN WITH THE
CURRENT OBS.
EARLIER DISCUSSION BELOW.
BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE
WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH
CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW
O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW
FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER
ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF
INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL
CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15"
OF ICE ON TOP IN THOSE AREAS.
OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF
VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR
EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE
ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER
CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON
AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH
HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES
FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED
TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD
AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF
NEARS.
12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG
THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT
HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY
LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN
THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP
OF THE 2-4" OF SNOW ACCUM.
ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES
CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF
THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322
CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN
TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT
APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE
AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE
COULD SEE SOME SPOT AMOUNTS COME IN HIGHER.
TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE
UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID
30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH MONDAY NIGHT/...
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
DID NOT MAKE ANY LARGE CHANGES TO MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
MAIN CHANGE WAS TO ADJUST POPS SOME TUE INTO TUE NIGHT.
THINK MAIN TYPE OF PCPN WILL BE RAIN TUE NIGHT INTO WED. DID
PUT SMALL AMTS OF .01 ICE ACROSS THE AREA...GIVEN THAT OBJECT
TEMPS WILL STILL LIKELY BE COLD. TEMPERATURES TUE NIGHT MAY
DROP A LITTLE...BEFORE COMING BACK UP LATE.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
FOR WED...TOOK SNOW SHOWERS OUT OF THE NW. TIGHT THICKNESS PATTERN
ACROSS THE AREA...SUPPORT A LARGE TEMPERATURE GRADIENT FROM NW PA
TO SE PA. THERE COULD BE A FEW SHOW SHOWERS ACROSS THE FAR
NW...BUT IT LOOKS LIKE MAINLY NW OF OUR AREA. LEFT POPS UP...THINK
FRONT WILL BE SLOW TO MOVE OUT.
A TREND TOWARD COLDER WEATHER AGAIN LATER IN THE WEEK...GIVEN
SPLIT FLOW.
PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW
NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO
BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE
LEAVE THE RECORD COLD OF FEBRUARY BEHIND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA
THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX
TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ
WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW
PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL
HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA
COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM
HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI...MAINLY VFR.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT/MARTIN
NEAR TERM...DEVOIR/LAMBERT/MARTIN
SHORT TERM...DEVOIR/LAMBERT/MARTIN
LONG TERM...LA CORTE/LAMBERT/MARTIN
AVIATION...DEVOIR/LAMBERT/MARTIN
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
129 PM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE
WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH
CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW
O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW
FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER
ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF
INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL
CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15" OF
ICE ON TOP IN THOSE AREAS.
OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF
VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR
EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE
ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER
CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON
AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH
HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES
FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED
TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD
AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF
NEARS.
12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG
THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT
HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY
LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN
THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP
OF THE 2-4" OF SNOW ACCUM.
ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES
CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF
THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322
CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN
TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT
APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE
AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE
COULD SEE SOME SPOT AMOUNTS COME IN HIGHER.
TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE
UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID
30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS
RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST
PLACES THROUGH TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA
THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX
TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ
WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW
PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL
HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA
COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM
HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...DEVOIR/LAMBERT
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN
THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT.
VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE
WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT
STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH
THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN
925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH
OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE
NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS.
WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF
BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T
EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL
SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD
BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY
REGION...BUT VALUES WILL STILL RESIDE WELL WITHIN THE ADVISORY
CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW
MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY
REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF
AMOUNTS.
12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN
MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF.
06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE
LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH
FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME.
GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES
WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT
WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL
PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F
THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S
ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS
THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF
SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR
FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS
/BETWEEN 19Z-00Z/.
VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE
IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE
MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN
THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS
THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO
MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES.
THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE
WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY
AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST
WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT
PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING
THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER
CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA.
GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE
IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL
MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM
NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB
21ST.
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
STRONGEST RADAR RETURNS ASSOCIATED WITH 0.5-1.5SM SNOW BLANKET THE
REGION MAINLY TO THE SOUTH OF INTERSTATE 80 AT 1530Z. EXPECT THIS
AREAL DISTRIBUTION OF THE SNOWFALL INTENSITY TO CONTINUE THIS
AFTERNOON AS WEAK LOW PRESSURE FROM THE OHIO VALLEY TRACKS
EASTWARD INTO THE LAUREL HIGHLANDS AND SECONDARY WEAK LOW PRES
FORMS NEAR THE DELMARVA COAST. ACROSS THE NRN MTNS OF PA VSBYS
SHOULD AVERAGE NEARLY 1SM HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...LAMBERT/RXR
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
954 AM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN
THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT.
VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE
WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT
STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH
THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN
925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH
OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE
NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS.
WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF
BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T
EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL
SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD
BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY
REGION...BUT VALUES WILL STILL RESIDE WEEL WITHIN THE ADVISORY
CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW
MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY
REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF
AMOUNTS.
12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN
MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF.
06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE
LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH
FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME.
GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES
WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT
WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL
PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F
THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S
ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS
THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF
SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR
FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS
/BETWEEN 19Z-00Z/.
VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE
IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE
MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN
THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS
THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO
MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES.
THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE
WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY
AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST
WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT
PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING
THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER
CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA.
GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE
IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL
MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM
NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB
21ST.
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THIS MID MORNING..THE LEADING EDGE OF THE LARGE SHIELD OF LIGHT
SNOW HAS OVERSPREAD CENTRAL PA...REDUCING VSBYS TO 2 MILES OR LESS
/IFR CONDITIONS/ ACROSS A WIDESPREAD AREA.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED ALL DAY AND INTO
THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 13Z...BUT WILL ALSO
DROP AS DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR
THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...RXR
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1026 AM EST SUN MAR 1 2015
.DISCUSSION...
MOISTURE ADVECTION AND DOWNSLOPE WINDS ARE DUELING FOR TERRITORY
ACROSS NE TN AND THE FOOTHILLS THIS MORNING. THE MOISTURE ADVECTION
APPEARS TO HAVE THE UPPER HAND AS CLOUDS ARE SLOWLY ADVANCING
EASTWARD...AND THE RAP SHOWS 925 MB WINDS THAT ARE ONLY 15 KTS.
HOWEVER...IT IS ENOUGH TO PROVIDE PLENTY OF SUNSHINE IN THE LEE OF
THE MOUNTAINS...ALLOW TEMPS TO REACH THE LOWER 50S ALREADY. WILL
UPDATE TO ADJUST TEMPERATUERS IN THIS AREA. UPSTREAM RADAR SHOWS
QUITE A BIT OF RAIN OVER MIDDLE TN...AND WHILE IT APPEARS THAT MUCH
OF IT IS NOT REACHING THE GROUND AT THE MOMENT...IT SHOULD MOVE
INTO OUR PLATEAU COUNTIES THIS AFTERNOON TO PRODUCE SOME LIGHT QPF.
WILL UPDATE POPS TO RAISE POPS IN THIS AREA FOR THE AFTERNOON...AND
LOWER POPS IN EASTERN SECTIONS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
731 PM CST MON MAR 2 2015
.UPDATE...
ISSUED A DENSE FOG ADVISORY FOR THE REGION. SEA FOG AT THE COAST
ALREADY MOVING ONSHORE AND VISBY THERE FALLING. OVER THE NORTHERN
COUNTIES 1/2 TO 2 MILES IS COMMON WHILE IN BETWEEN 5-9 MILES IS
MORE COMMON. AS WE COOL DOWN AND WINDS BECOME MORE EAST AND SOUTHEAST
AM EXPECTING VISBY TO DROP AND DENSE TO BECOME WIDESPREAD.
WARM FRONT MOVES INLAND TOMORROW MORNING AND SOME IMPROVEMENT IN
VISBY SHOULD OCCUR...COASTAL AREAS WILL BE TRICKY DEPENDING ON
TRAJECTORIES AND DURATION OVER THE COOLER SHELF WATERS. FOR NOW
THE ADVISORY RUN THROUGH 10 AM.
ALSO MADE SOME CHANGES TO THE GRIDS IN THE SHORT TERM TO LOWER
TEMPERATURES UP NORTH AND INCREASE SKY COVER.
45
&&
.DISCUSSION...
&&
.PREV DISCUSSION... /ISSUED 523 PM CST MON MAR 2 2015/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
AVIATION...
POOR AVIATION CONDITIONS ARE EXPECTED AGAIN OVERNIGHT INTO TUESDAY
MORNING. FCST SOUNDINGS AND HRRR VSBY PROGS SHOW STRONG POTENTIAL
FOR DENSE FOG OVERNIGHT WITH VISIBILITIES DROPPING TO 1/4 MILE
OVER ALL TAF SITES. CIGS WILL ALSO LOWER TO BELOW 200 FEET AT ALL
TAF SITES AS WELL. SLOW IMPROVEMENT IS EXPECTED TUESDAY MORNING
AFTER 16Z WITH MVFR CONDS EXPECTED TO OCCUR BRIEFLY ON TUESDAY
AFTN. WINDS WILL REMAIN LIGHT OVERNIGHT AND GRADUALLY VEER TO THE
E-SE BY MORNING. S-SE WINDS EXPECTED ON TUESDAY AFTN AND SPEEDS
WILL PROBABLY GET A BIT GUSTY OVER THE WESTERN TAF SITES DURING
THE AFTN. 43
PREV DISCUSSION... /ISSUED 337 PM CST MON MAR 2 2015/
DISCUSSION...
FRONTAL BOUNDARY HAS REMAINED IN THE GULF OF MEXICO TODAY
ALLOWING FOR COOL DAMP CONDITIONS MOST OF THE DAY. TEMPS HAVE NOT
RISEN MUCH BUT WITH THIN ENOUGH CLOUD COVER A FEW AREAS HAVE
REACHED THE UPPER 50S TO LOW 60S ALONG THE COAST. AREAS FROM KCLL
TO KUTS REMAIN IN THE 40S. KCLL HAS NOT REACHED THE 50S SINCE
HAVING A HIGH OF 50F ON FEB 25. BEFORE THAT IT WAS FEB 22. WATER
VAPOR IMAGERY DOES SHOW STRONG SHORT WAVE TROUGH OVER THE DESERT
SW WHICH SHOULD PUSH INTO THE C PLAINS BY 12Z TUE. THIS SHOULD
ALLOW FOR SFC CYCLOGENESIS IN THE HIGH PLAINS AND FOR SOUTHERLY
WINDS TO DEVELOP. FRONTAL BOUNDARY SHOULD MOVE NORTH AS A WARM
FRONT BRINGING BACK TEMPS IN THE 70S AND DEWPOINTS IN THE 60S.
FORECAST WILL KEEP A CHANCE OF SHOWERS AND MAYBE AN ISO
THUNDERSTORM. FORECAST SOUNDING STILL SHOW A DECENT CAP AND
LIMITED INSTABILITY SO AN ISO STORM MAYBE A STRETCH.
THE MAIN FORECAST CHALLENGE WILL BE THE CHANGES IN THE WEATHER
WED INTO THUR. FORECAST MODELS ARE IN DECENT AGREEMENT WITH STRONG
TROUGH PULLING THROUGH THE PLAINS WEDNESDAY WITH AN UPPER LOW OVER
CALIFORNIA MOVING EAST ACROSS MEXICO AND S ROCKIES PHASING WITH
THIS SYSTEM. A STRONG COLD FRONT IS EXPECTED TO PUSH INTO THE AREA
WED BUT THE NAM/GFS/ECMWF ALL HAVE DIFFERENT TIMING. FORECAST
LEANED MORE ON THE FASTER GFS AND EVEN ABOUT 3 HRS FASTER THAN
THAT. THERE IS GOOD SUPPORT FOR A FASTER FRONTAL MOVEMENT GIVEN
THE DEEP TROUGH OVER THE PLAINS. THE ONLY PROBLEM IS THAT THE
PHASING TROUGH MAY KEEP JET STREAM FLOW SW AND HELP STALL THE
FRONT. THAT SAID...JUST LOOKS LIKE THERE WILL BE A COLD ENOUGH
AIRMASS TO KEEP IT PUSHING THROUGH.
THE RACE IS THEN ON BETWEEN FREEZING TEMPS AND PRECIP FALLING FOR
WED NIGHT INTO THUR. SYNOPTICALLY JET STREAM BECOMES FAVORABLE
WITH LIFT DUE TO RIGHT ENTRANCE REGION POSITIONED OVER MUCH OF C
AND E TX. FRONTOGENETIC LIFT INCREASES IN 850-700MB OVER THE AREA.
MODEL SOUNDINGS AT KCLL/KUTS SHOW A NICE MIX OF PRECIP FROM
RA/FRZRA TO SLEET. IF THE COLD AIR DEEPENS ENOUGH AND
SATURATES...COULD GET MORE SLEET TO FALL. MAIN AREAS OF CONCERN
WILL BE FOR COLLEGE STATION TO LIVINGSTON NORTHWARD. THIS ALSO
HINGES ON TIMING OF FREEZING TEMPS AND IF PRECIP WILL BE FALLING
THROUGH THAT AIR. PRECIP IS EXPECTED TO DECREASE THROUGH THE
MORNING AS LIFT EXITS THE REGION AND SUBSIDENCE BEGINS TO TAKE
OVER. ICE/SLEET AMOUNTS WILL BE DIFFICULT TO DETERMINE SINCE THERE
WILL BE TIMING ISSUES WITH THE COLD SUB FREEZING AIR AND PRECIP
FALLING INTO IT. ISSUED A SPECIAL WEATHER STATEMENT TO HIGHLIGHT
MAIN THINKING ON WHAT WHEN AND WHERE WITH IMPACTS.
EXTENDED FORECAST IS STILL QUITE UNCERTAIN FOR THE WEEKEND AND
INTO EARLY NEXT WEEK. GFS/ECMWF BOTH BRING ANOTHER UPPER LOW
TOWARDS TEXAS SATURDAY INTO SUNDAY. FORECAST WILL KEEP SOME RAIN
CHANCES GOING TO ACCOUNT FOR THIS WAVE BUT STILL LOTS OF TIMING
ISSUES. BOTH MODELS HAVE RUN TO RUN CONSISTENCY BUT NOT WITH EACH
OTHER.
39
MARINE...
THIS BREAK IN THE SEA FOG EXPECTED TO BE BRIEF WITH THE RETURN OF
ONSHORE SFC WINDS THIS EVENING/OVERNIGHT. THE LIMITED/LOWERED
VISIBILITIES WITH THE FOG SHOULD LINGER FOR MOST OF TOMORROW AND
WEDS...EVEN WITH THE ONSHORE WINDS STRENGTHENING/DEEPENING OUT
AHEAD OF THE NEXT COLD FRONT. MODELS STILL BRINGING THIS FRONT
INTO THE BAYS LATE WEDS AFTN AND INTO THE COASTAL WATERS WEDS
EVENING. TIGHT GRADIENT IN THE WAKE OF THE FRONT WILL PRODUCE VERY
STRONG/GUSTY N/NE WINDS FOR WEDS NIGHT ON THROUGH MOST OF THURS.
WIND GUSTS MAY EXCEED GALE FORCE BUT THE PROGGED SUSTAINED FLOW
WILL LIKELY KEEP US IN THE SMALL CRAFT ADVISORY CATEGORY FOR THAT
TIME FRAME. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 72 61 63 30 / 20 30 30 70 70
HOUSTON (IAH) 55 76 64 70 34 / 20 20 20 50 70
GALVESTON (GLS) 56 72 61 66 37 / 20 20 20 30 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
523 PM CST MON MAR 2 2015
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
POOR AVIATION CONDITIONS ARE EXPECTED AGAIN OVERNIGHT INTO TUESDAY
MORNING. FCST SOUNDINGS AND HRRR VSBY PROGS SHOW STRONG POTENTIAL
FOR DENSE FOG OVERNIGHT WITH VISIBILITIES DROPPING TO 1/4 MILE
OVER ALL TAF SITES. CIGS WILL ALSO LOWER TO BELOW 200 FEET AT ALL
TAF SITES AS WELL. SLOW IMPROVEMENT IS EXPECTED TUESDAY MORNING
AFTER 16Z WITH MVFR CONDS EXPECTED TO OCCUR BRIEFLY ON TUESDAY
AFTN. WINDS WILL REMAIN LIGHT OVERNIGHT AND GRADUALLY VEER TO THE
E-SE BY MORNING. S-SE WINDS EXPECTED ON TUESDAY AFTN AND SPEEDS
WILL PROBABLY GET A BIT GUSTY OVER THE WESTERN TAF SITES DURING
THE AFTN. 43
&&
.PREV DISCUSSION... /ISSUED 337 PM CST MON MAR 2 2015/
DISCUSSION...
FRONTAL BOUNDARY HAS REMAINED IN THE GULF OF MEXICO TODAY
ALLOWING FOR COOL DAMP CONDITIONS MOST OF THE DAY. TEMPS HAVE NOT
RISEN MUCH BUT WITH THIN ENOUGH CLOUD COVER A FEW AREAS HAVE
REACHED THE UPPER 50S TO LOW 60S ALONG THE COAST. AREAS FROM KCLL
TO KUTS REMAIN IN THE 40S. KCLL HAS NOT REACHED THE 50S SINCE
HAVING A HIGH OF 50F ON FEB 25. BEFORE THAT IT WAS FEB 22. WATER
VAPOR IMAGERY DOES SHOW STRONG SHORT WAVE TROUGH OVER THE DESERT
SW WHICH SHOULD PUSH INTO THE C PLAINS BY 12Z TUE. THIS SHOULD
ALLOW FOR SFC CYCLOGENESIS IN THE HIGH PLAINS AND FOR SOUTHERLY
WINDS TO DEVELOP. FRONTAL BOUNDARY SHOULD MOVE NORTH AS A WARM
FRONT BRINGING BACK TEMPS IN THE 70S AND DEWPOINTS IN THE 60S.
FORECAST WILL KEEP A CHANCE OF SHOWERS AND MAYBE AN ISO
THUNDERSTORM. FORECAST SOUNDING STILL SHOW A DECENT CAP AND
LIMITED INSTABILITY SO AN ISO STORM MAYBE A STRETCH.
THE MAIN FORECAST CHALLENGE WILL BE THE CHANGES IN THE WEATHER
WED INTO THUR. FORECAST MODELS ARE IN DECENT AGREEMENT WITH STRONG
TROUGH PULLING THROUGH THE PLAINS WEDNESDAY WITH AN UPPER LOW OVER
CALIFORNIA MOVING EAST ACROSS MEXICO AND S ROCKIES PHASING WITH
THIS SYSTEM. A STRONG COLD FRONT IS EXPECTED TO PUSH INTO THE AREA
WED BUT THE NAM/GFS/ECMWF ALL HAVE DIFFERENT TIMING. FORECAST
LEANED MORE ON THE FASTER GFS AND EVEN ABOUT 3 HRS FASTER THAN
THAT. THERE IS GOOD SUPPORT FOR A FASTER FRONTAL MOVEMENT GIVEN
THE DEEP TROUGH OVER THE PLAINS. THE ONLY PROBLEM IS THAT THE
PHASING TROUGH MAY KEEP JET STREAM FLOW SW AND HELP STALL THE
FRONT. THAT SAID...JUST LOOKS LIKE THERE WILL BE A COLD ENOUGH
AIRMASS TO KEEP IT PUSHING THROUGH.
THE RACE IS THEN ON BETWEEN FREEZING TEMPS AND PRECIP FALLING FOR
WED NIGHT INTO THUR. SYNOPTICALLY JET STREAM BECOMES FAVORABLE
WITH LIFT DUE TO RIGHT ENTRANCE REGION POSITIONED OVER MUCH OF C
AND E TX. FRONTOGENETIC LIFT INCREASES IN 850-700MB OVER THE AREA.
MODEL SOUNDINGS AT KCLL/KUTS SHOW A NICE MIX OF PRECIP FROM
RA/FRZRA TO SLEET. IF THE COLD AIR DEEPENS ENOUGH AND
SATURATES...COULD GET MORE SLEET TO FALL. MAIN AREAS OF CONCERN
WILL BE FOR COLLEGE STATION TO LIVINGSTON NORTHWARD. THIS ALSO
HINGES ON TIMING OF FREEZING TEMPS AND IF PRECIP WILL BE FALLING
THROUGH THAT AIR. PRECIP IS EXPECTED TO DECREASE THROUGH THE
MORNING AS LIFT EXITS THE REGION AND SUBSIDENCE BEGINS TO TAKE
OVER. ICE/SLEET AMOUNTS WILL BE DIFFICULT TO DETERMINE SINCE THERE
WILL BE TIMING ISSUES WITH THE COLD SUB FREEZING AIR AND PRECIP
FALLING INTO IT. ISSUED A SPECIAL WEATHER STATEMENT TO HIGHLIGHT
MAIN THINKING ON WHAT WHEN AND WHERE WITH IMPACTS.
EXTENDED FORECAST IS STILL QUITE UNCERTAIN FOR THE WEEKEND AND
INTO EARLY NEXT WEEK. GFS/ECMWF BOTH BRING ANOTHER UPPER LOW
TOWARDS TEXAS SATURDAY INTO SUNDAY. FORECAST WILL KEEP SOME RAIN
CHANCES GOING TO ACCOUNT FOR THIS WAVE BUT STILL LOTS OF TIMING
ISSUES. BOTH MODELS HAVE RUN TO RUN CONSISTENCY BUT NOT WITH EACH
OTHER.
39
MARINE...
THIS BREAK IN THE SEA FOG EXPECTED TO BE BRIEF WITH THE RETURN OF
ONSHORE SFC WINDS THIS EVENING/OVERNIGHT. THE LIMITED/LOWERED
VISIBILITIES WITH THE FOG SHOULD LINGER FOR MOST OF TOMORROW AND
WEDS...EVEN WITH THE ONSHORE WINDS STRENGTHENING/DEEPENING OUT
AHEAD OF THE NEXT COLD FRONT. MODELS STILL BRINGING THIS FRONT
INTO THE BAYS LATE WEDS AFTN AND INTO THE COASTAL WATERS WEDS
EVENING. TIGHT GRADIENT IN THE WAKE OF THE FRONT WILL PRODUCE VERY
STRONG/GUSTY N/NE WINDS FOR WEDS NIGHT ON THROUGH MOST OF THURS.
WIND GUSTS MAY EXCEED GALE FORCE BUT THE PROGGED SUSTAINED FLOW
WILL LIKELY KEEP US IN THE SMALL CRAFT ADVISORY CATEGORY FOR THAT
TIME FRAME. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 50 72 61 63 30 / 30 30 30 70 70
HOUSTON (IAH) 56 76 64 70 34 / 20 20 20 50 70
GALVESTON (GLS) 57 72 61 66 37 / 20 20 20 30 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 10 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1008 PM EST MON MAR 2 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST INTO THE MID ATLANTIC REGION TONIGHT.
MEANWHILE...A WARM FRONT WILL PUSH NORTH THROUGH THE AREA LATE
TONIGHT INTO TUESDAY...THEN FOLLOWED BY A COLD FRONT TUESDAY NIGHT
INTO WEDNESDAY. COLD HIGH PRESSURE WILL RETURN FOR THURSDAY INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1000 PM EST MONDAY...
1033 MB SURFACE HIGH WAS CENTERED OVER OHIO. THIS HIGH WILL
CONTINUE TO DRIFT EAST OVERNIGHT PROVIDING MAINLY DRY CONDITIONS.
A STATIONARY FRONT WAS OVER THE DEEP SOUTH...EXTENDING FROM
CENTRAL SOUTH CAROLINA SOUTHWEST TO JACKSON MS. THIS STATIONARY
FROM IS EXPECTED TO BEGIN MOVING NORTH OVERNIGHT AS A WARM
FRONT RESULTING IN THE RETURN OF LOW LEVEL MOISTURE TO THE AREA BY
DAYBREAK TUESDAY. QUESTION TO BE ANSWERED IS WHETHER THERE WILL BE
ENOUGH MOISTURE FOR PRECIPITATION. THE CLOSEST THING ON RADAR AT
THE MOMENT IS OVER THE SOUTHERN APPALACHIANS BETWEEN ASHVILLE NC
AND ATLANTA GA.
THE SURFACE HIGH WILL CERTAINLY BE IN A POSITION TO PROVIDE ENOUGH
COLD AIR FOR A WINTRY FORM OF PRECIPITATION TUESDAY MORNING. THE
QUESTION IS WHETHER THERE WILL BE ENOUGH DEPTH TO THE MOISTURE TO
PRODUCE PRECIPITATION. BOTH THE HRRR AND RNKWRF SUGGEST ONLY TRACE
AMOUNTS TO OCCUR BETWEEN NOW AND NOON TUESDAY WITH THE LARGER
SCALE MODELS PRODUCING A FEW HUNDREDTHS OF AN INCH. TRACE ICE IS
CERTAINLY ENOUGH TO BE A NUSCIANCE...BUT THIS IS NOT GOING TO BE
A WIDESPREAD EVENT.
THE MAIN PROBLEM WITH PRECIP PRODUCTION FOR TUESDAY IS THE LACK OF
UPPER LEVEL MOISTURE WITHIN THE M8-M12 DEG C DENDRITIC GROWTH ZONE.
FORECAST MODEL SOUNDINGS ARE DRY WITHIN THIS LAYER...ALL OF THE
SATURATION TAKING PLACE IN A LOWER LAYER BETWEEN +3 DEG C AND -3
DEG C. UNLESS THERE IS SOME SEEDER FEEDER PROCESS THAT DEVELOPS
INOF THE WARM FRONT...THE MODEL SOUNDINGS SUGGESTS THE PYTYPE WILL
BE EITHER DRIZZLE OR FREEZING DRIZZLE PENDING SURFACE TEMEPRATURE
AT THE TIME. THE CRITICAL WINDOW FOR THE FREEZING PRECIPITATION
WILL BE DURING THE MORNING...SO STILL SEE THE NEED FOR WINTER
WEATHER ADVISORIES TO ACCOUNT FOR THE POTENTIALLY LIGHT ICING THAT
MAY OCCUR...KEEPING IN MIND THAT EVEN A VERY LIGHT COATING OF ICE
ON AN UNTREATED SURFACE CAN POSE A TRAVEL/WALKING HAZARD.
LOW TEMPERATURES OVERNIGHT WILL RANGE FROM THE MID 20S IN THE
COLDEST VALLEYS TO THE LOWER 30S IN THE PIEDMONT. WARM AIR WILL
MOVE IN FROM THE SOUTHWEST TUESDAY CHANGING PRECIPITATION OVER TO
ALL LIQUID TUESDAY AFTERNOON. AREAS ACROSS THE NORTH AND
NORTHEAST WILL BE THE SLOWEST TO TRANSITION. HIGH TEMPERATURES
TUESDAY WILL RANGE FROM THE MID 30S IN THE NORTHEAST TO THE LOWER
50S IN THE SOUTHWEST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 330 PM EST MONDAY...
COMPLICATED SHORT TERM FORECAST WITH MULTIPLE CONCERNS. TO BEGIN
TUESDAY NIGHT...ANY REMNANTS OF EARLIER WEDGE WILL BE LONG GONE TO
THE NORTHEAST WITH THE AREA SOLIDLY IN THE WARM SECTOR.
TEMPERATURES WILL BE WELL ABOVE FREEZING AND CONTINUING TO RISE
DURING THE OVERNIGHT HOURS ON THE HEELS OF A STRONG SOUTHWESTERLY
LLJ. CONSEQUENTLY...ANY ASSOCIATED WARM FRONTAL PRECIPITATION
WILL ALSO HAVE LIFTED WELL NORTHEAST OF THE REGION. NOW...THE
ATTENTION SHIFTS TO THE ARCTIC FRONT APPROACHING FROM THE WEST. A
BROAD UPPER RIDGE ACROSS THE CENTRAL/EASTERN GULF...590+ DM AT
THAT...WILL AMPLIFY INTO THE SOUTHEAST WHILE A DEEP UPPER TROUGH
DIGS INTO THE SOUTHERN PLAINS. A SIGNIFICANT SURGE OF ARCTIC AIR
WILL PLUNGE INITIALLY SOUTH INTO THE CENTRAL/SOUTH CENTRAL U.S. AS
THE ASSOCIATED ARCTIC FRONT SLOWS ITS PUSH INTO THE MID-
ATLANTIC/SOUTHEAST STATES THANKS TO THE AFOREMENTIONED UPPER RIDGE
AND THE APPALACHIAN MOUNTAINS. THIS HOLDS THE HEAVIEST RAINFALL
WEST OF OUR CWA THROUGH WEDNESDAY MUCH OF THE DAY
WEDNESDAY...MAINLY ACROSS THE OH/TN VALLEYS. FINALLY...WEDNESDAY
AFTERNOON/EVENING...THE FRONT WILL BEGIN A BETTER SOUTHEASTWARD
PUSH AS SHORT WAVE ENERGY KICKS OUT OF THE CENTRAL PLAINS. WOULD
EXPECT HEAVIER RAIN TO MOVE INTO THE WESTERN PARTS OF THE CWA BY
00Z WED...THEN BEGIN TO SPREAD EASTWARD OVERNIGHT.
MEANWHILE...PART OF THE UPPER TROUGH LAGS BEHIND AND SURFACE LOW
PRESSURE DEVELOPS ACROSS THE SOUTHEAST STATES IN RESPONSE. THIS
WILL FURTHER DELAY THE PUSH OF THE PRECIPITATION INTO/THROUGH THE
CWA...BUT PERHAPS NOT THE SHALLOW COLD ARCTIC AIR ONCE IT MANGES
TO CROSS THE APPALACHIANS. QUITE A VARIETY OF SOLUTIONS PRESENTED
BY THE MODELS AND WPC AS TO THE WINTER WEATHER THREAT THURSDAY
GIVEN THAT THIS IS FAR FROM A NORMAL SYNOPTIC SITUATION FOR A SNOW
EVENT IN THIS REGION. THE BIG QUESTION IS NOT WHETHER OR NOT THERE
WILL BE PRECIPITATION...BUT HOW QUICKLY WILL THE COLD AIR SPREAD
INTO THE REGION BEHIND THE FRONT...BEFORE THE HEAVIER
PRECIPITATION MOVES OUT...AND HOW QUICKLY WILL THE COLD AIR BECOME
DEEP ENOUGH TO CHANGE THE PRECIPITATION TO SNOW. AM INCLINED AT
THIS POINT TO THROW OUT RAIN TO FREEZING RAIN SCENARIOS...NOT ONLY
BECAUSE IT IS NOT CLIMATOLOGICALLY OR SYNOPTICALLY FAVORABLE IN
THIS SITUATION...BUT THINKING IS THAT COLD AIR WILL BECOME DEEP
ENOUGH QUICKLY ENOUGH TO CHANGE RAIN OVER TO SNOW...OTHER THAN A
BRIEF PERIOD OF SLEET ALONG THE LEADING EDGE OF THE CHANGEOVER.
FURTHERMORE...GROUND TEMPS WILL NOT SUPPORT FZRA AT THE CHANGEOVER
TIME AS THE SOUNDING COLUMN COOLS ISOTHERMALLY. FINALLY...THIS IS
YET AGAIN A SIGNIFICANT ARCTIC AIR MASS...SO ONCE IT ENTERS THE
REGION...COOLING WILL BE QUICK...ESPECIALLY WEST OF I-81. FOR SNOW
AMOUNTS...A PRELIMINARY ESTIMATE...FAIRLY CONSISTENT WITH WPC
WWD...IS 4-5 INCHES NORTH...2-4 INCHES CENTRAL/WESTERN AREAS...1-2
INCHES VA PIEDMONT...LITTLE TO NONE NC PIEDMONT.
SEE THE HYDROLOGY SECTION BELOW FOR FURTHER DETAILS ON THE FLOOD
THREAT ASSOCIATED WITH COMBINED RAINFALL AND SNOW MELT. DID
ADVERTISE A PERIOD OF MODERATE RAIN WEDNESDAY EVENING FROM WEST TO
EAST...BUT HAVE REDUCED THE TIME PERIOD OF SUCH COMPARED TO
PREVIOUS FORECAST PACKAGES.
TEMPERATURE WISE...A LOT OF NON-DIURNAL TEMPERATURE TRENDS THROUGH
THIS FORECAST PERIOD. TEMPERATURES CONTINUING TO RISE TUESDAY
NIGHT/WEDNESDAY MORNING AND REMAINING MILD/ABOVE FREEZING UNTIL
THE ARCTIC FRONT ARRIVES IN THE WEST WEDNESDAY NIGHT. THE PIEDMONT
WILL LIKELY REMAIN ABOVE FREEZING FROM TUESDAY AFTERNOON UNTIL
THURSDAY MORNING. LIKEWISE...A NON-DIURNAL COOLING TREND EXPECTED
THROUGHOUT THE DAY THURSDAY AS ARCTIC AIR SPREADS INTO THE REGION.
THE GFS IN PARTICULAR SHOW SFC TEMPS BELOW ZERO IN OUR WESTERN
COUNTIES BY FRIDAY MORNING. GIVEN THAT IT IS EARLY MARCH AND THE
850MB TEMPS ARE ONLY AROUND -16C...AS COMPARED TO -26C A COUPLE OF
WEEKS AGO...I FIND THIS SOMEWHAT EXTREME. NONETHELESS...IT IS A
VERY COLD AIR MASS AND WELL BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BUILD OVER THE REGION ON FRIDAY...AND BE IN
CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE
HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS
WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD
MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES
GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS
TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AS OF 630 PM EST MONDAY...
VFR CONDITIONS WILL CONTINUE ACROSS THE ENTIRE REGION THROUGH
ROUGHLY 04Z/11PM. AFTER THIS TIME...MVFR CIGS WILL START
PROGRESSES NORTHEAST ACROSS THE REGION IN CONJUCTION WITH A WARM
FRONT HEADING TOWARD THE AREA. ALONG WITH THE FRONT WILL COME
LIGHT WINTRY PRECIPITATION IN THE FORM OF PATCHY LIGHT FREEZING
RAIN AND SLEET. BY DAYBREAK TUESDAY...MANY AREAS WILL HAVE LOWERED
TO LIFR/IFR CIGS AND MVFR VSBYS DUE TO THE PRECIPITATION AND
MIST. THE BULK OF THE WINTRY PRECIPITATION WILL BE CONFINED TO
NORTH A LINE FROM KBLF-KROA-KLYH DURING THE LATE MORNING. BY THE
AFTERNOON...SURFACE TEMPERATURES SHOULD BE MILD ENOUGH FOR A
WIDESPREAD AREA OF PLAIN RAIN. LIFR/IFR CIGS AND IFR/MVFR VSBYS
WILL BE THE NORM DURING THE DAY TUESDAY.
WINDS WILL REMAIN LIGHT THROUGH THE NIGHT AND GRADUALLY VEER NORTH
TO SOUTHEAST. ON TUESDAY...WINDS WILL INCREASE DURING THE DAY FROM
THE SOUTHWEST...AND WINDS AT 850 MB WILL INCREASE TO AROUND 45 TO
50 KTS. LOW LEVEL WIND SHEAR WILL BE POSSIBLE DURING THE
AFTERNOON...ESPECIALLY AT TERMINALS AT HIGHER ELEVATION.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
PERIOD.
EXTENDED FORECAST...
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO NEW ENGLAND TUESDAY NIGHT
INTO WEDNESDAY. THIS WILL RESULT IN SUB-VFR CONDITIONS WEDNESDAY
AND THURSDAY WITH WIDESPREAD RAIN AHEAD OF THE FRONT ON WEDNESDAY
AND WINTER PRECIPITATION BEHIND THE FRONT WEDNESDAY NIGHT AND
THURSDAY.
FRIDAY SHOULD SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO. THE OTHER ELEMENT OF COURSE IS THE
QPF. 12Z MODELS (INCLUDING LATEST EC) HAVE NUDGED THE HEAVIEST
QPF A LITTLE MORE TO THE WEST...REDUCING AMOUNTS IN THE JAMES AND
GREENBRIER SOME. IT STILL APPEARS AS IF 1 TO 2 INCHES COULD FALL
ACROSS THE WESTERN BASINS BY 12Z THURSDAY AND COMBINED WITH
SNOWMELT THIS COULD PRODUCE AT LEAST MINOR RIVER FLOODING ALONG
THE GREENBRIER AND POSSIBLY THE UPPER JAMES. GUIDANCE RECEIVED
FROM OHRFC THIS MORNING SUGGESTED MINOR FLOOD STAGE AT ALDERSON WV
ON THE GREENBRIER LIKELY BY EARLY THURSDAY WITH THE COMBINED
SNOWMELT AND QPF. HOWEVER...GIVEN THE CONTINUED UNCERTAINTIES WILL
HOLD OFF ON A FLOOD WATCH AT THIS POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
VAZ018>020-022>024-034-035-045>047.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ007-009-
010-012-015-016.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST TUESDAY FOR
VAZ011-013-014-017-032-033-043.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR NCZ001-002-
018.
WV...WINTER WEATHER ADVISORY FROM 7 AM TO 1 PM EST TUESDAY FOR
WVZ507-508.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR WVZ042.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST TUESDAY FOR
WVZ043-044.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...KK/PM
SHORT TERM...RAB
LONG TERM...DS
AVIATION...DS/KK
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1054 AM MST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1055 AM MST SUN MAR 1 2015
NO CHANGES TO THE FORECAST TODAY. MAIN FOCUS REMAINS ON THE STORM
SYSTEM WHICH WILL MOVE ACROSS THE AREA TOMORROW AND TOMORROW
NIGHT. MODELS NOT IN GREAT AGREEMENT WITH WHERE THE HEAVIEST SNOW
WILL FALL...BUT THERE IS GENERAL CONSENSUS POINTS TO SOUTH
CENTRAL WYOMING. CURRENT WATER VAPOR AND RADAR OVER THE SOUTHWEST
CONUS SHOWING MOISTURE STREAMING NORTHEASTWARD FROM ARIZONA. SEEMS
REASONABLE THERE WILL BE WIDESPREAD SNOW ACROSS THE ENTIRE AREA BY
MONDAY NIGHT AS AN UPPER LEVEL DISTURBANCE MOVES FROM THE CENTRAL
ROCKIES INTO THE NORTHERN PLAINS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH MONDAY MORNING)
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY
MVFR CONDITIONS PREVAILING ALONG I80...AND VFR FURTHER NORTH
ACROSS WESTERN NEBRASKA. A WARM FRONT WILL SLOWLY MOVE NORTHWARD
ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW TO AREAS
ALONG I80. LOW MVFR TO IFR CIGS/VSBYS ARE LIKELY AFTER 06Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD BUT WILL
INCREASE OUT OF THE SOUTH LATE TONIGHT AND INTO EARLY MONDAY
MORNING.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...TJT
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION...AMENDED AVIATION SECTION.
NWS CHEYENNE WY
524 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 515 AM MST SUN MAR 1 2015
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY
VFR CONDITIONS PREVAILING. SPORADIC MVFR CIGS ARE POSSIBLE THROUGH
THE MORNING BENEATH A STRATUS DECK AROUND 5K FEET AGL. A COLD FRONT
WILL SWEEP ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW
TO AREAS ALONG AND SOUTH OF I80. MVFR TO IFR CIGS/VSBYS ARE LIKELY
AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
430 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 425 AM MST SUN MAR 1 2015
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH VFR
CONDITIONS PREVAILING. A COLD FRONT WILL SWEEP ACROSS THE AREA
THIS EVENING AND OVERNIGHT...BRINGING ANOTHER ROUND OF SNOW TO
AREAS ALONG AND SOUTH OF INTERSTATE 80. MVFR TO IFR CIGS/VSBYS
ARE LIKELY AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH
THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
406 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 952 PM MST SAT FEB 28 2015
TOUGH FORECAST FOR OUR SOUTHEAST WYOMING AIRPORTS. RADAR SHOWING
AREA OF SNOW FILLING IN FROM KCYS TO KLAR...BUT IT IS NOT TOO HEAVY
AND BARELY RESTRICTING VISIBILITIES. GOING TO HOLD OFF LOWERING
CONDITIONS UNTIL AFTER 12Z AND CONFINE LOWER CONDITIONS TO KLAR.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
315 AM EST TUE MAR 3 2015
.SHORT TERM /TODAY THROUGH WEDNESDAY/...
WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA
THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT
GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE
LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF
THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS
TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT
THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW
CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK
FRONT.
RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A
MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND
CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS
WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING
NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY
NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE
NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH
LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE
LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE
BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR
SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES
REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF
PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT
APPROACHES FROM THE NW.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS
SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS
NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD
BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION
OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD
CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE.
WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE
FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE
METRO AREA.
NLISTEMAA
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS
MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF
COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS
LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS
LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV
AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO
BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE
TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH
ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I
HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE
FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN
WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT
THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE
COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH
SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND
RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION
GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH
WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY
WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT
WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP
A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES.
LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT
TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL
UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF
THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR
POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS
NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION
CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW.
20
&&
AVIATION...
06Z UPDATE...
OLD FRONTAL BOUNDARY SITUATED ACROSS CENTRAL GA THIS MORNING. THE
BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. NORTH OF THE
BOUNDARY...WEDGING TRIES TO BUILD IN...SO LOW CLOUDS AND PATCHY
DRIZZLE WILL BE THE RULE FOR THE NORTHERN TAFS TODAY. THE LATEST
RUN OF THE HRRR DOES BRING A PATCH OF PRECIP ACROSS ATL BETWEEN
11Z AND 16Z...SO TRIED TO TIME THIS WITH A TEMPO GROUP. CIGS MAY
TRY AND LIFT TO MVFR LATE THIS AFTERNOON...BUT ARE EXPECTED TO GO
IFR AFTER DARK AGAIN. MORE ORGANIZED PRECIP ANTICIPATED ON
WEDNESDAY WITH A FROPA.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 51 49 72 54 / 60 50 40 70
ATLANTA 59 55 70 45 / 60 40 50 70
BLAIRSVILLE 49 47 62 42 / 70 70 70 70
CARTERSVILLE 54 52 69 40 / 60 50 60 70
COLUMBUS 74 60 75 54 / 30 20 30 60
GAINESVILLE 49 47 67 47 / 60 50 50 70
MACON 66 58 77 59 / 30 20 20 50
ROME 57 53 68 37 / 60 60 70 70
PEACHTREE CITY 62 56 71 48 / 50 30 40 70
VIDALIA 68 62 79 62 / 30 20 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....20
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1259 AM EST TUE MAR 3 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL JUST TO OUR SOUTH AND WEST TONIGHT
THROUGH TUESDAY. THE FRONT WILL SHIFT BACK THROUGH LATE TUESDAY
NIGHT OR EARLY WEDNESDAY AS A WARM FRONT. A COLD FRONT WILL COME
THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE INTO THE REGION
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CURRENT SURFACE ANALYSIS REVEALS THAT THE FRONTAL BOUNDARY HAS
DROPPED SOUTH OF THE FORECAST AREA WITH SURFACE WINDS BECOMING
NORTHEASTERLY IN THE WAKE OF THE FRONT. THE BOUNDARY WILL STALL
TO OUR SOUTH AND WEST TONIGHT. DEWPOINTS REMAIN IN THE 50S AT MOST
LOCATIONS ACROSS THE FORECAST AREA BUT A STRONG GRADIENT IN
DEWPOINTS EXISTS TO OUR NORTH AND WEST. REGIONAL RADAR COMPOSITE
SHOWS A FEW LIGHT SHOWERS FINALLY REACHING THE CSRA AND WESTERN
MIDLANDS DUE TO ISENTROPIC LIFT AHEAD OF SOME UPPER ENERGY. EXPECT
PRECIPITATION COVERAGE TO INCREASE TOWARD DAYBREAK TUESDAY WHICH
IS CONSISTENT WITH LATEST HRRR AND LAMP POP TRENDS. OVERNIGHT LOWS
RANGING FROM AROUND 40 NORTH TO THE LOWER 50S EXTREME SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL BE SITUATED JUST TO THE SOUTH OF THE CWA TUESDAY
MORNING...BUT WILL BEGIN TO SLOWLY LIFT NORTHWARD LATE IN THE DAY
AND INTO TUESDAY NIGHT. MODELS SUGGESTING THE BEST CHANCE FOR RAIN
WITH ISENTROPIC LIFT MAY BE DURING THE MORNING HOURS ACROSS THE
MAJORITY OF THE CWA...THEN THE BEST CHANCES FOR RAINFALL MOVE
NORTH AND WEST DURING THE AFTERNOON HOURS ON TUESDAY. WITH THE
SLOW NORTHWARD PROGRESSION OF THE WARM FRONT...TEMPERATURES
THROUGH THE DAY TUESDAY WILL BE BACK BELOW NORMAL. TEMPERATURES
ARE EXPECTED TO BE ON THE INCREASE TUESDAY NIGHT AS THE WARM FRONT
MOVES THROUGH THE AREA...WITH A WARM DAY...HIGHS BACK IN THE
70S...LOOKING ON TAP FOR WEDNESDAY. BEST CHANCE FOR RAIN SHOULD
STILL REMAIN OFF TO THE NORTH AND WEST THROUGH THE DAY WEDNESDAY.
BETTER RAIN CHANCES WILL INCREASE WEDNESDAY NIGHT AHEAD OF THE
NEXT APPROACHING COLD FRONT...ESPECIALLY ACROSS THE WESTERN
COUNTIES LATE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT POISED TO MOVE THROUGH THE CWA DURING THE DAY THURSDAY.
MAY SEE HIGH TEMPERATURES EARLY IN THE DAY...WITH READINGS THEN
BECOMING STEADY OR FALLING INTO THE AFTERNOON. BEST CHANCE FOR
RAINFALL WILL BE EARLY IN THE DAY THURSDAY AHEAD OF THE
FRONT...AND SHOULD SEE SOME SHOWER OR AN ISOLATED THUNDERSTORMS.
ANOTHER AREA OF COOL HIGH PRESSURE WILL BUILD OVER THE AREA BEHIND
THE FRONT THURSDAY NIGHT AND FRIDAY. AT THIS POINT IT LOOKS AS IF
THE FRONT WILL STALL OUT FAR ENOUGH SOUTH OF THE CWA SO THAT DRY
CONDITIONS WOULD OCCUR THURSDAY NIGHT THROUGH SATURDAY MORNING.
AFTER THAT...MOISTURE WILL BEGIN INCREASING FROM THE
SOUTH...ALTHOUGH DO NOT EXPECT MORE THAN SLIGHT CHANCE FOR
RAINFALL ACROSS SOUTHERN COUNTIES. LATER ON IN THE LONGER
TERM...CONFIDENCE IS LOW DUE TO DISAGREEMENTS BETWEEN THE GFS AND
THE ECMWF.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE HAS BEGUN RIDGING INTO THE AREA FROM THE
NORTH WITH LIGHT EAST-NORTHEASTERLY FLOW. INCREASING SOUTHWESTERLY
FLOW ALOFT ATOP THE NORTHEASTERLY SURFACE FLOW IS GOING TO RESULT
IN THE DEVELOPMENT OF ANOTHER WEDGE WITH LOWERING CEILINGS AND
LIGHT RAIN DEVELOPING.
VFR CEILINGS TO START THE PERIOD ARE EXPECTED TO DROP TO MVFR BY
08Z AND EVENTUALLY TO IFR BY AROUND 12Z AND REMAIN RESTRICTED
THROUGH MUCH OF THE REMAINDER OF THE FORECAST PERIOD. LIGHT RAIN
AND LOWERING VISIBILITIES TO IFR ARE EXPECTED BY 15Z ALL
TERMINALS...THOUGH LOWER CONFIDENCE AT AGS/DNL/OGB AS IT COULD
OCCUR A LITTLE LATER THERE. CONDITIONS WILL REMAIN DETERIORATED
THIS AFTERNOON AND TONIGHT AS THE STALL FRONT TO THE SOUTH BEGINS
TO LIFT NORTHWARD AS A WARM FRONT AND CEILINGS AND VISIBILITIES
DROP FURTHER TO LIFR WITH SOME DENSE FOG POSSIBLE BY THE END OF
THE FORECAST PERIOD. STRENGTHENING FLOW ABOVE THE SURFACE LIKELY
WILL RESULT IN LOW LEVEL WIND SHEAR AND WILL INCLUDE IN THE
FORECAST.
EXTENDED AVIATION OUTLOOK...WIDESPREAD IFR OR MVFR CONDITIONS ARE
EXPECTED DURING THE REST OF TUESDAY NIGHT AND EARLY WEDNESDAY AND
ALSO ON THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1245 AM EST TUE MAR 3 2015
.PREV DISCUSSION... /ISSUED 1048 PM EST MON MAR 2 2015/
EVENING UPDATE...
CURRENT FORECAST LOOKS ON TRACK... SO NO SIGNIFICANT CHANGES ARE
NEEDED AT THIS TIME. /39
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
/ISSUED AT 259 PM EST MON MAR 2 2015/
SHORT TERM BEGINS WITH WEAK ZONAL FLOW ALOFT GIVING WAY TO WEAK
RIDGING AS AN AREA OF SURFACE HIGH PRESSURE CROSSES THE APPALACHIANS
AND RIDGES DOWN THE EASTERN SEABOARD IN A HYBRID DAMMING EVENT.
MOISTURE CONTINUES TO OVERSPREAD THE AREA BRINGING A CHANCE OF RAIN
TO MAINLY NORTH GEORGIA...BUT HAVE CONTINUED TREND OF AT LEAST
SLIGHT CHANCE POPS ACROSS THE AREA. ZERO SBCAPE TO SPEAK OF TOMORROW
BUT SOME LOW-LEVEL MUCAPE /LESS THAN 100 J/KG/ SHOWS UP IN PORTIONS
OR NORTH GEORGIA ESPECIALLY ON THE NAM...WHICH OF COURSE TENDS TO BE
ON THE HIGH SIDE ANYWAY. SPC DAY2 OUTLOOK DOES NOT HAVE EVEN GENERAL
THUNDER NOSING INTO GEORGIA SO WHILE AN ISOLATED RUMBLE CANNOT BE
TOTALLY RULED OUT...JUST NOT ENOUGH CONFIDENCE TO KEEP THUNDER
CHANCES IN AT THIS TIME.
TEMPERATURES TODAY HAVE RISEN QUITE A BIT HIGHER THAN ANTICIPATED
WITH CLEARING SKIES WHICH MAY VERY WELL HAVE IMPLICATIONS ON LOWS
TONIGHT AS MOISTURE FILLS BACK IN AND CLOUD COVER INCREASES...AND
THUS TRENDED A TAD LOWER WITH OVERNIGHT LOWS. HIGHS TOMORROW NEAR
SEASONAL FOR THE SOUTHWEST HALF OF THE AREA BUT WITH THE DAMMING
BUILDING IN THERE SHOULD NOT BE MUCH OF A DIURNAL CURVE ACROSS
ESPECIALLY NORTHEAST GEORGIA...AND AS IT IS CURRENT FORECAST HIGHS
MAY BE A LITTLE TOO WARM IN THOSE AREAS. FOLLOWING THAT...LOWS
TOMORROW NIGHT WILL HAVE TO BE REEVALUATED DEPENDING ON THE STRENGTH
OF THE DAMMING AND HOW MUCH PRECIPITATION HAS INFLUENCED THE COLD
DOME. HIGH CHANCE TO LIKELY POPS REMAIN ACROSS NORTH GEORGIA THROUGH
THE END OF THE PERIOD THOUGH BY WEDNESDAY MORNING EXPECT VERY LITTLE
IF ANY RAIN ACROSS THE REST OF THE AREA.
TDP
LONG TERM /WEDNESDAY THROUGH MONDAY/...
/ISSUED AT 259 PM EST MON MAR 2 2015/
HAVE LEFT THE LONG TERM ESSENTIALLY AS IS. POTENTIAL WINTER
WEATHER EVENT FOR WEDNESDAY NIGHT THURSDAY MORNING DEPENDS ON
SEVERAL FACTORS...HOW FAR SOUTH THE COLD AIR GETS SEEMS TO BE THE
MAIN UNCERTAINTY. UPPER FLOW REMAINS SOUTHWEST AND IT MAY BE HARD
FOR THE FREEZING TEMPERATURES TO GET TOO FAR SOUTH INTO THE
STATE. THICKNESS PROFILES SHOW A POSSIBILITY OF RAIN...FREEZING
RAIN AND SLEET WITH SOME SNOW INTO THURSDAY MORNING. THIS WILL BE
MONITORED IN UPCOMING MODEL RUNS. REMAINDER OF FORECAST LOOKS OKAY
BUT THERE IS MORE UNCERTAINTY TOWARD THE END OF THE PERIOD WITH
GFS AND ECMWF SHOWING DIFFERING UPPER AIR PATTERNS. HAVE ONLY
TWEAKED THE LAST COUPLE OF PERIODS. PREVIOUS DISCUSSION IS
INCLUDED BELOW.
41
PREVIOUS LONG TERM.../ISSUED AT 344 AM EST MON MAR 2 2015/
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS REMAIN CONSISTENT AND IN RELATIVELY GOOD
AGREEMENT THROUGH THE MAJORITY OF THE EXTENDED FORECAST PERIOD.
STILL SHOWING THE WORK WEEK DOMINATED BY SOUTHWESTERLY UPPER FLOW
AHEAD OF THE DEEP WESTERN U.S. TROUGH. THIS KEEPS THE REGION IN A
FAIRLY WARM PATTERN UNTIL THURSDAY BEHIND THE SHARP SURFACE FRONT
THE SWEEPS THROUGH WEDNESDAY/WEDNESDAY NIGHT. STILL SEEING ENOUGH
INSTABILITY FOR CHANCE COVERAGE OF THUNDERSTORMS WEDNESDAY. STRONG
LOW/MID-LEVEL WINDS ALSO STILL HAVE ME A BIT CONCERNED ABOUT AT
LEAST ISOLATED SEVERE THUNDERSTORM POTENTIAL. GOOD LOW-LEVEL FORCING
AHEAD OF THE FRONT BUT UPPER SUPPORT IS LACKING WITH THE MAIN UPPER
TROUGH/SHORT WAVE LAGGING FAR BEHIND THE FRONT. GFS AND ECMWF ALSO
STILL INSIST ON BRINGING IN MUCH COLDER AIR AS EARLY AS LATE
WEDNESDAY NIGHT WITH RESIDUAL MOISTURE AND THE INFLUENCE OF THE
UPPER SYSTEM SQUEEZING OUT SOME LOW QPF PRECIPITATION. UPPER FLOW
REMAINS SOUTHWESTERLY THROUGH THURSDAY AND LOWEST THICKNESSES REMAIN
WELL NORTH OF THE STATE. WILL NEED TO WATCH TRENDS FOR THE
POSSIBILITY OF SOME WINTRY MIX ACROSS THE NORTH. GFS AND ECMWF BOTH
SHOW A GOOD TEMPERATURE RECOVERY INTO THE WEEKEND AFTER A THE SHOT
OF COOL AIR THURSDAY THROUGH FRIDAY MORNING AS THE UPPER FLOW
REMAINS GENERALLY ZONAL OVER THE SOUTHEASTERN U.S. AND THE HEART OF
THE COLDEST AIR REMAINS WELL NORTH OF THE STATE. MAINLY DRY AS
WELL...HOWEVER BOTH MODELS SHOW SOME PRECIPITATION POSSIBLY SURGING
NORTH INTO CENTRAL GEORGIA SATURDAY AS SURFACE LOW PRESSURE SPINS UP
OFF THE GEORGIA/CAROLINA COAST. NOT REAL CONFIDENT WE WILL SEE
ANYTHING SIGNIFICANT WITH THIS BUT SLIGHT CHANCE OR LOW CHANCE POPS
MAY BE APPROPRIATE.
20
&&
.AVIATION...
06Z UPDATE...
OLD FRONTAL BOUNDARY SITUATED ACROSS CENTRAL GA THIS MORNING. THE
BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. NORTH OF THE
BOUNDARY...WEDGING TRIES TO BUILD IN...SO LOW CLOUDS AND PATCHY
DRIZZLE WILL BE THE RULE FOR THE NORTHERN TAFS TODAY. THE LATEST
RUN OF THE HRRR DOES BRING A PATCH OF PRECIP ACROSS ATL BETWEEN
11Z AND 16Z...SO TRIED TO TIME THIS WITH A TEMPO GROUP. CIGS MAY
TRY AND LIFT TO MVFR LATE THIS AFTERNOON...BUT ARE EXPECTED TO GO
IFR AFTER DARK AGAIN. MORE ORGANIZED PRECIP ANTICIPATED ON
WEDNESDAY WITH A FROPA.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 49 48 71 46 / 60 50 70 80
ATLANTA 58 54 69 39 / 60 40 70 80
BLAIRSVILLE 51 48 61 35 / 70 70 80 80
CARTERSVILLE 56 53 67 35 / 60 50 80 80
COLUMBUS 72 58 74 52 / 30 20 70 80
GAINESVILLE 49 46 66 40 / 60 50 80 80
MACON 67 56 76 53 / 30 20 60 80
ROME 58 54 64 33 / 60 60 80 80
PEACHTREE CITY 63 55 71 42 / 50 30 70 80
VIDALIA 67 59 81 61 / 30 20 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CST TUE MAR 3 2015
.SHORT TERM...
300 AM CST
THROUGH WEDNESDAY...
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE
ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING.
SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS
EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID
MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM
ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO
INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN
SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM
MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS
MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST
CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND
NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH
WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID
MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING
SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA
BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR
AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS
INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME
MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO
LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT
LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES
PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH
OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z
AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE
LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE
THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH
IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE
BEFORE ENDING ALTOGETHER THIS EVENING.
HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT
WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE
TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME
INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS
EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW
CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION
WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST
CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL
NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER
DEUBELBEISS
&&
.LONG TERM...
300 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH
PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO
DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH
MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY
NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN
COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO
RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD
COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH
PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND
WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY
NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO
DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD
FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING.
FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT
DOESNT COME THROUGH DRY.
DEUBELBEISS
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB/BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY
TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING
THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP
CHANGING TO RAIN/DRIZZLE.
* CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO
IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN
CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR
CIGS LIKELY LINGERING TONIGHT.
* SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND
BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE
THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS
AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING
GUSTY.
RATZER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT...
WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST
AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF.
REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE
MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT
DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO
DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY
10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY
MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT.
SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR
MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR
DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS
NORTH OF THE AREA.
WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN
A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW
HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM
FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND
THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA.
SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING
AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY
ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY
AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST
SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND
CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST
THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS
WELL AS CIG/VIS IMPACTS.
* HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS
EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
214 AM CST
MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR
TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN
AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN
LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE
LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS
EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE
NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO
SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF
THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND
BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE
AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST
AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS
ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS
A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS
TO RELAX A BIT AND SHIFT TO THE WEST.
SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA
NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS.
RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS
A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN
ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS
WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME
GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR
TO HAVE A FAIR AMOUNT OF OPEN WATER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
247 AM CST Tue Mar 3 2015
.SHORT TERM...(Today)
ISSUED AT 244 AM CST TUE MAR 3 2015
Freezing rain and sleet developed over western Illinois around
midnight and quickly tracked east over all but extreme southeast
Illinois by 08z/2am. Already seeing the back edge of our second
band of wintry precip entering west central Illinois, so it appears
we will have a brief lull in the freezing rain and sleet. However,
the latest HRRR suggests another band of rain, freezing rain and
sleet will move northeast across our area at or just after dawn.
Rainfall rates have not been much with these quick moving bands
of freezing rain/sleet with most areas seeing less than 0.05" per
hour, but certainly enough for some light icing to occur on bridge
decks and overpasses and on lesser traveled roads.
RAP forecast soundings continue to suggest temperatures will rise
above the freezing mark over southeast Illinois by dawn...central
sections of the forecast area by 900 am...and between 10 am and Noon
roughly along and north of the Interstate 74 corridor. By late
morning into the afternoon hours the stronger lift associated with
the low level warm advection/ isentropic ascent shifts off to our
east and southeast with a gradual lowering of POPs warranted from
northwest to southeast. Best 850-700 forcing edges into southeast IL
by mid to late afternoon where our highest POPs will be located.
Guidance temperatures look reasonable for this afternoon with highs
ranging from the upper 30s far north to the upper 40s far southeast.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 244 AM CST TUE MAR 3 2015
Current system will not fully clear our area until Thursday, as the
trailing end of the cold front becomes parallel to the upper flow
over the Ohio Valley. Most of the evening models keep the threat for
precipitation from about I-70 southward, although the NAM has a
secondary surge on Wednesday afternoon all the way up to about I-72.
Leaning more toward the ECMWF/GFS blend for PoP`s tonight and
Wednesday. Lingering precip north of I-70 should end this evening,
but kept higher PoP`s all night into Wednesday. This evening, most
areas will see the precipitation switch briefly to snow before
ending, with little accumulation. While the transition to snow south
of I-70 occurs late tonight, temperatures will be supportive of all
snow through Wednesday. Greatest snow amounts expected near the Ohio
Valley, but currently think that 1 to 3 inches in southeast Illinois
is likely. Light snow will linger into Wednesday night before ending
late.
The other feature of note is what hopefully will be the last Arctic
blast of the winter. Digging upper trough currently coming into
Manitoba will spread a chunk of unseasonably cold air over much of
the Midwest Wednesday and Thursday, with 850 mb temperatures down
into the -18C range by Thursday morning. Highs both days will
struggle to get out of the teens in some areas -- normal highs are
well into the 40s by now -- and lows Thursday morning should be a
few degrees either side of zero. Current indications are that a wind
chill advisory would be needed across the northern CWA Wednesday
night and early Thursday, as the system to our south keeps the winds
up and slows the arrival of high pressure.
Heading into the weekend and early next week, 40s should become more
widespread, and the latest 8-14 day outlook introduces a foreign
concept called "above normal temperatures".
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1147 PM CST MON MAR 2 2015
Freezing rain and sleet is still expected to move into the area
and effect all the TAFs in the next 1 to 3 hours, starting in SPI
and PIA and then move east. The pcpn will start as a mix of FZRA
and PL given how dry the lower layers are. Then in a few hours, it
will change over to all FZRA and then last until morning, when the
temp rises to above freezing. Expecting the FZRA to last around
4hrs at each site. Cigs and vis will be VFR to start but then drop
into the IFR category later overnight. The rain will end at the
sites late afternoon or early evening as the front moves through.
Winds will be southeast and then become south during the morning,
then become westerly when the front moves through. Could be some
gusts to around 22kts in the morning and afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 10 AM CST this morning FOR
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
215 AM CST TUE MAR 3 2015
.UPDATE...
758 PM CST
THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO
THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL
REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A
STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD
ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY
MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY
TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT
AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER
ADVISORY AS IS.
JEE
&&
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY
TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING
THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP
CHANGING TO RAIN/DRIZZLE.
* CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO
IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN
CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR
CIGS LIKELY LINGERING TONIGHT.
* SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND
BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE
THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS
AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING
GUSTY.
RATZER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT...
WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST
AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF.
REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE
MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT
DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO
DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY
10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY
MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT.
SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR
MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR
DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS
NORTH OF THE AREA.
WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN
A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW
HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM
FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND
THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA.
SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING
AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY
ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY
AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST
SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND
CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST
THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS
WELL AS CIG/VIS IMPACTS.
* HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS
EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
214 AM CST
MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR
TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN
AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN
LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE
LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS
EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE
NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO
SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF
THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND
BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE
AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST
AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS
ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS
A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS
TO RELAX A BIT AND SHIFT TO THE WEST.
SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA
NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS.
RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS
A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN
ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS
WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME
GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR
TO HAVE A FAIR AMOUNT OF OPEN WATER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1200 AM CST TUE MAR 3 2015
.UPDATE...
758 PM CST
THE FORECAST REMAINS ON TRACK WITH THE NEXT SYSTEM OVER COLORADO
THIS EVENING. GUIDANCE CONTINUES TO SUGGEST THAT THE LOW WILL
REACH SOUTHERN WISCONSIN MID-DAY TUESDAY AND MERGE WITH A
STRONGER LOW PUSHING EAST ACROSS ONTARIO. PRECIP WILL SPREAD
ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST EARLY TUESDAY
MORNING. PRECIP SHOULD INITIALLY FALL AS SNOW...BUT WILL QUICKLY
TURN OVER TO A WINTRY MIX AS TEMPERATURES WARM TO ABOVE ZERO ALOFT
AND WE LOSE SATURATION IN THE DGZ. WILL KEEP THE WINTER WEATHER
ADVISORY AS IS.
JEE
&&
.SHORT TERM...
317 PM CST
THROUGH WEDNESDAY...
.SHORT TERM...THROUGH WEDNESDAY
AS MENTIONED IN THE EARLIER UPDATE... A WINTER WEATHER ADVISORY
WAS ISSUED FOR THE ENTIRE AREA EARLIER IN THE SHIFT FOR LATE
TONIGHT THROUGH TUESDAY MORNING. MODELS ARE STILL SHOWING
PRECIPITATION BEGINNING AS SNOW NORTH OF INTERSTATE 80...AND SOME
FORM OF SNOW...SLEET OR FREEZING RAIN IN THE FAR SOUTH. IT COULD
BE A PRETTY GOOD BURST OF WET SNOW INITIALLY BEFORE THE TRANSITION
BEGINS.
A WARM FRONT WILL LIFT THROUGH THE AREA DURING THE MORNING HOURS.
THIS IS THE PERIOD WHERE MODELS A SHOWING A MORE SIGNIFICANT PUSH
OF PRECIPITATION. WE ARE COMING OUT OF A PRETTY COLD AIR
MASS..AND DEW POINTS ARE STILL VERY LOW ACROSS THE AREA...WITH
DEWPOINTS ABOVE FREEZING NOT VERY CLOSE. TEMPERATURES LOOK TO
REMAIN BELOW FREEZING THROUGH AT LEAST MID MORNING AREA WIDE.
MODEST PRECIPITABLE WATER VALUES IN EXCESS OF 0.75 INCHES COUPLED
WITH A 35-40 KT LOW LEVEL JET FEEDING INTO THE LOW LEVEL FRONTAL
ZONE WOULD SUGGEST MODEST PRECIPITATION RATES DURING THIS TIME WHEN
THE LOW LEVEL (925-850 MB) TEMPERATURES ARE HEADING ABOVE
FREEZING. SOME OF THE RECENT NAM/GFS WAS SLIGHTLY COOLER IN THE
THERMAL PROFILE FOR THIS PERIOD SUGGESTING THAT SNOW/SLEET MAY
DOMINATE...ESPECIALLY FOR THE NORTHERN METRO AREA AND POINTS NORTH
TOWARD WISCONSIN... AND IF PRECIPITATION RATES CONTINUE A BIT
HEAVIER THIS MAY SLOW THE LOW LEVEL WARMING. BUT THE SIGNAL IS
STILL THERE FOR A SNOW-SLEET-FZRA TRANSITION AND ICE ACCUMULATION
POTENTIAL.
WHERE THE UNCERTAINTIES REMAIN IS IN REGARDS TO HOW MUCH ICE
ACCUMULATION WILL OCCUR AND HOW FAR NORTH THE IMPACTS ARE FELT. ICE IS
EXPECTED TO BE THE LEAST NORTH TOWARDS WISCONSIN AND IN THE
ROCKFORD AREA WHERE IT MAY JUST BE AN ALL SNOW/SLEET SITUATION
WHERE ADVISORY CRITERIA MAY NOT BE TECHNICALLY SATISFIED. GIVEN
THE UNCERTAINTY AND THE RUSH-HOUR TIME...FEEL IT IS THE SAFER CALL
WITH SOME SNOW/SLEET AS WELL. AND IN NW INDIANA...THE BETTER
MOISTURE ADVECTION IS FOCUSED HERE WHERE THERE IS HIGHER POTENTIAL
FOR ICE ACCUMULATION...BUT IT WILL BE A RACE AGAINST SURFACE TEMPS
AS WELL WHICH LOOK TO WARM THROUGH THE MORNING. AS MENTIONED
EARLIER...MEANWHILE...THE ECMWF/GEM ARE MORE SUPPORTIVE OF A
SNOW/SLEET SOLUTION IN MANY AREAS...ESPECIALLY NORTH OF INTERSTATE
80. IT LOOKS LIKE THE TRANSITION TIME FOR MIXED PRECIPITATION
SOUTH OF I-80 WILL OCCUR BEFORE DAYBREAK BASED ON THE NAM AND
EARLY LOOKS AT THE RAP CLOSE TO THAT TIME FRAME. IT WOULD LIKELY
BE AFTER 6-7 AM WHEN THAT TRANSITION OCCURS IN THE METRO
AREA...BUT CONFIDENCE ON THAT TIMING IS NOT SUPER HIGH.
WHILE WE ARE LOSING THE DEEPER MOISTURE IN THE AFTERNOON...WE ARE
GETTING SOME DECENT MID LEVEL FRONTOGENESIS WHICH SHOULD STILL ALLOW
US TO WRING OUT SOME PRECIPITATION IN THE AFTERNOON WHICH COULD BE A
SNOW-RAIN MIX IN THE NW...LIKELY RAIN IN THE SE...WITH EVEN SOME
-SN/DZ/FZDZ POSSIBLE ACROSS THE CHICAGO METRO AREA LATE IN THE
AFTERNOON AND EVENING.
THE UPPER TROUGH AXIS WILL GRADUALLY MOVE THROUGH THE AREA WHILE
SURFACE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. EXPECT COLDER
CONDITIONS WITH SOME HIGH CLOUDS MOVING THROUGH. HIGHS WILL BE IN
THE TEENS WEDNESDAY AND THURSDAY...WITH LOWS EARLY THURSDAY MORNING
BOTTOMING OUT AT OR BELOW ZERO. WITH THE HIGH STILL TO THE
EAST...WIND CHILLS...YES WE ARE STILL DISCUSSING WIND CHILLS IN
EARLY MARCH...GET DOWN TO -10 TO -20 BELOW. A CLIMATE SECTION TO
THE AFD WILL BE FORTHCOMING.
KMD
&&
.LONG TERM...
317 PM CST
THURSDAY THROUGH MONDAY...
THE EXTENDED PERIOD WILL START OUT VERY COLD AS A 1040 MB ARCTIC
HIGH SHIFTS ACROSS THE REGION. WITH 925 AND 850 MB TEMPERATURES
PROGGED TO BE AROUND -18 CELSIUS...THIS SHOULD ONLY ALLOW FOR HIGHS
IN THE MIDDLE TO UPPER TEENS...FOLLOWING A BITTERLY COLD AND
POTENTIALLY RECORD COLD MORNING. THE GOOD NEWS IS THAT THIS WILL BE
A PROGRESSIVE HIT OF ARCTIC AIR. IN FACT...TEMPERATURES SHOULD
QUICKLY RECOVER BY FRIDAY AS A GUSTY SOUTH-SOUTHWESTERLY FLOW SETS
UP ALONG THE NORTHWESTERN PERIPHERY OF THE EXITING SURFACE RIDGE OF
HIGH PRESSURE. THIS SHOULD SUPPORT HIGHS INTO THE LOW 30S
FRIDAY...AND POSSIBLY WELL INTO THE 30S FOR THE WEEKEND. A WEAK COLD
FRONT MAY DROP ACROSS THE AREA OVER THE WEEKEND...BUT IT APPEARS THE
DEEPER COLD WILL BE AIMED TO OUR NORTHEAST. PRECIPITATION CHANCES
ALSO APPEAR TO BE MINIMAL DURING MUCH OF THE EXTENDED PERIOD.
KJB
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED ORBROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SNOW EXPECTED TO DEVELOP DURING PREDAWN HOURS...QUICKLY
TRANSITIONING TO A SNOW/SLEET MIX AND THEN FREEZING RAIN DURING
THE MORNING. TEMPS RISE TO/ABOVE FREEZING BY MIDDAY WITH PRECIP
CHANGING TO RAIN/DRIZZLE.
* CIG/VIS EXPECTED TO DETERIORATE FAIRLY QUICKLY FROM VFR TO
IFR/LIFR WITH PRECIPITATION THIS MORNING. SLOW IMPROVEMENT IN
CONDITIONS EXPECTED LATER THIS AFTERNOON/EVENING...WITH MVFR
CIGS LIKELY LINGERING TONIGHT.
* SOUTH-SOUTHEAST WINDS INCREASING 10-15 KT EARLY THIS MORNING AND
BECOMING GUSTY AROUND 20 KTS AT TIMES WHILE BACKING SOUTH LATE
THIS MORNING. SOUTHWEST WINDS GUSTING AROUND 20 KTS THIS
AFTERNOON BECOME WEST-NORTHWEST BY EARLY EVENING AND REMAINING
GUSTY.
RATZER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE WAS DEVELOPING OVER EASTERN COLORADO AROUND MIDNIGHT...
WITH SOUTH-SOUTHEAST WINDS INCREASING ACROSS THE PLAINS AND MIDWEST
AND STARTING TO PULL MOISTURE NORTHWARD FROM THE WESTERN GULF.
REGIONAL RADAR MOSAIC SHOWS PRECIPITATION BLOSSOMING ACROSS THE
MID-MISSISSIPPI VALLEY AND LIFTING NORTHEAST AHEAD OF WARM FRONT
DEVELOPING ACROSS MISSOURI AND KANSAS. FORECAST MODELS CONTINUE TO
DEPICT PRECIPITATION SPREADING ACROSS THE LOCAL TERMINALS ROUGHLY
10-12Z...WITH THERMAL PROFILES SUPPORTING INITIALLY SNOW...QUICKLY
MIXING WITH SLEET AND FREEZING RAIN AS TEMPERATURES WARM ALOFT.
SURFACE TEMPS LOOK TO CLIMB TO/ABOVE FREEZING BY LATE MORNING OR
MIDDAY WITH ANY LINGERING PRECIPITATION IN THE FORM OF RAIN OR
DRIZZLE AS THE BETTER FORCING WITH THE ELEVATED WARM FRONT LIFTS
NORTH OF THE AREA.
WITH DEVELOPMENT OF PRECIPITATION...GUIDANCE REMAINS STEADFAST IN
A RAPID DETERIORATION OF VFR CONDITIONS TO IFR/LIFR WITHIN A FEW
HOURS OF ONSET. CIGS SHOULD LIFT ABOVE LIFR THIS AFTERNOON AS WARM
FRONT MOVES NORTH...AND EVENTUALLY TO MVFR LATE THIS AFTERNOON AND
THIS EVENING AS A COLD FRONT PUSHES EAST ACROSS THE AREA.
SOUTH-SOUTHEAST WINDS WILL BACK MORE SOUTHEAST EARLY THIS MORNING
AND INCREASE INTO THE 10-15 KT RANGE AS THE LOW MOVES QUICKLY
ACROSS THE PLAINS. WINDS WILL BACK SOUTH BY LATE MORNING/EARLY
AFTERNOON AS THE LOW PASSES NORTH ACROSS WISCONSIN. FORECAST
SOUNDINGS SUPPORT GUSTS AROUND 20 KTS BY LATE MORNING...AND
CONTINUE TO INDICATE GUSTY CONDITIONS AS WINDS SHIFT SOUTHWEST
THIS AFTERNOON AND WEST-NORTHWEST THIS EVENING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN TIMING PRECIP DEVELOPMENT AND TRANSITION OF P-TYPES AS
WELL AS CIG/VIS IMPACTS.
* HIGH IN WINDS...AND DRY WEATHER WITH LINGERING MVFR CIGS THIS
EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z TUESDAY...UPDATED 00Z...
WEDNESDAY...MVFR CIGS.
THURSDAY AND FRIDAY...VFR.
SATURDAY AND SUNDAY...MVFR CIGS POSSIBLE.
BEACHLER
&&
.MARINE...
224 PM...HIGH PRESSURE OVER THE SOUTHERN LAKES AND OHIO VALLEY
WILL MOVE EAST TO THE MID ATLANTIC AND NEW ENGLAND TUESDAY MORNING
AS LOW PRESSURE FORMS OVER THE CENTRAL PLAINS TONIGHT. THIS LOW
WILL QUICKLY MOVE NORTHEAST TUESDAY AND BE ABSORBED BY STRONGER
LOW PRESSURE OVER NORTHERN ONTARIO...AS A COLD FRONT MOVES ACROSS
LAKE MICHIGAN. THE GRADIENT WILL SLOWLY INCREASE AHEAD OF THIS LOW
TONIGHT INTO TUESDAY MORNING WITH 30 KTS EXPECTED BY TUESDAY
MORNING AND THERE COULD BE SOME LOW END GALE GUSTS BUT CONFIDENCE
REGARDING FREQUENCY IS LOW. WINDS WILL SHIFT TO THE SOUTHWEST IN
THE AFTERNOON AND THEN TO THE NORTHWEST TUESDAY NIGHT. SPEEDS WILL
LIKELY REMAIN IN THE 30 KT RANGE...ESPECIALLY ACROSS THE SOUTHERN
TWO THIRDS...AS HIGH PRESSURE BUILDS ACROSS THE PLAINS WEDNESDAY
AND COLD AIR OVERSPREADS THE REGION. THIS HIGH WILL EXTEND FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY THURSDAY AS WINDS TURN MORE
WESTERLY AND BEGIN TO SLOWLY DIMINISH. BUT AS THE HIGH DEPARTS
THURSDAY NIGHT...THE GRADIENT WILL TIGHTEN AS LOW PRESSURE MOVES
ACROSS NORTHERN ONTARIO WITH A PERIOD OF SOUTHWEST WINDS TO 30 KTS
ON FRIDAY...WITH SOME LOW END GALES POSSIBLE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM TUESDAY TO NOON
TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...3
AM TUESDAY TO NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM TUESDAY TO 6 PM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
443 AM EST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 440 AM EST MON MAR 2 2015
A WINTRY MIX OF PRECIPITATION WILL SPREAD ACROSS THE AREA THIS
MORNING. LIGHT SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO
JUST FREEZING RAIN. AS TEMPERATURES RISE ABOVE FREEZING LATE THIS
MORNING AND EARLY THIS AFTERNOON...PRECIPITATION WILL THEN BE IN
THE FORM OF JUST RAIN. LIGHT ACCUMULATIONS OF SNOW...SLEET AND ICE
ARE POSSIBLE WHICH WILL MAKE CONDITIONS SLICK THIS MORNING.
HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 30S NORTH TO
LOWER AND MIDDLE 40S SOUTH. A COLD FRONT WILL MOVE THROUGH THE
REGION TONIGHT. LOWS WILL DROP BACK INTO THE TEENS AND 20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST TUE MAR 3 2015
RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST
UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH
MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA
AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE
INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS
MORNING WHERE SFC TEMPS IN THE MID 20S.
PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND
HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY
REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z.
ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS
MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED
DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY
RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING
PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3
TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING.
THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE
MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING.
POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING
RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN
EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE
SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE
FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING
WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM
SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS
FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO
LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON.
CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS
RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN
THIS MORNING.
SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY
EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z.
HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY
LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE
BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN
FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS
COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE
AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK
TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS
DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2
INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING
ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL
WITHIN GOING ADVISORY WHICH WILL CONTINUE.
MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE
EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON
WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE
WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO
OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR
SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT
CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW
END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY
PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL
CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND
DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY
SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EST TUE MAR 3 2015
STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO
KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN
HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE
LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS
SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW
SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM
WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW
TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT
SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO
LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS
SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL
GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE
FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD
AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE
ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH
TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC
AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE
COLDEST HIGH AT FT WAYNE FOR THE DATE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1232 AM EST TUE MAR 3 2015
PRIOR TAF FORECASTS ON TRACK AND CONTINUED TREND WITH THIS
PACKAGE. SLIGHT ADJUSTMENTS MADE TO PCPN TIMING BASED ON LATEST
00Z MODELS AND 03Z HIRES MODELS WHICH CONTINUE TO SLOW ONSET OF
PCPN. THIS IN LARGE PART DUE TO VERY DRY WEDGE IN THE LOWER LEVELS
WHICH WILL AID IN EVAPORATION OF FALLING PCPN UNTIL DEEPER
MOISTURE SURGE ARRIVES AROUND 12-15Z. THIS DRY WEDGE ALSO UNDER
DEEP LAYER OF SUPERCOOLED WATER. THIS SUGGEST EVAP COOLING
PROCESSES MAY ALSO ALLOW SOME OF THIS WATER TO FREEZE AND FALL AS
SLEET ALONG WITH SNOW AT ONSET. MOVED UP TIMING OF SLEET GIVEN
THIS POSSIBLE SCENARIO. PCPN BECOMES FZRA FOR A FEW HOURS MID
MORNING WITH WARM AIR ALOFT. THIS DEEPENS TO NEAR SFC AROUND
18-19Z WITH SFC TEMPS JUST BARELY ABOVE FREEZING FOR JUST RAIN IN
AFTERNOON. CHANGE BACK TO LIGHT SNOW WITH COLD FRONT PASSAGE EARLY
EVENING. A SLIGHT CHANCE FOR FZDZ THIS EVENING WITH DRYING ALOFT
BUT FEW MODELS SHOW SOME CLOUD SEEDING SO WILL NOT INTRODUCE ANY
MENTION INTO TAFS AT THIS TIME GIVEN SMALL PROBABILITY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>009-012>018-020-022>027-032>034.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ077>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 AM CST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 252 AM CST TUE MAR 3 2015
STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK
JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY
HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST
ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW
FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR
INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING
IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH
TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CST TUE MAR 3 2015
THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND
HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A
SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE
ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON
RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH
15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN
THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND
2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND
ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD
CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH
THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN
FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER
SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS
HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED.
HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED
THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS
THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE
SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH
THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY
FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND
BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY
KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER
SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT
THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE
BATTLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 252 AM CST TUE MAR 3 2015
MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR
MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO
GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND
CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS
THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST!
AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF
THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS
WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES.
GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON
THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH
PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND
CHILLS THAT WILL REACH WIND CHILL CRITERIA.
NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY.
MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF
THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL
US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND
INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS
FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE
AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF
THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE
CONFIDENCE ON A WARM UP NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1147 PM CST MON MAR 2 2015
LOW LEVEL WIND SHEAR IS STILL POSSIBLE OVERNIGHT INTO EARLY
TUESDAY AM WITH STRENGTHENING LOW LEVEL JET. MODELS THOUGH VARY ON
STRENGTH OF WINDS 1500-2000 FT AGL (30-40 KTS) AND WITH EXPECTED
INCREASE IN SURFACE WINDS WITH SOME GUSTS HAVE CONTINUED TO LEAVE
OUT MENTION ATTIM BUT CONTINUE TO MONITOR. OTHERWISE... OVERNIGHT
AND TUESDAY AM EXPECT CONDITIONS TO DETERIORATE INTO MVFR TO
POSSIBLY AREAS OF IFR WITH A SHOWERY WINTRY MIX OF PCPN ACROSS THE
AREA. PCPN WILL BE MAINLY LIGHT WITH TYPES FAVORING MAINLY SLEET/
SNOW NORTH OF I-80 WITH FREEZING RAIN/SLEET TRANSITION TO RAIN
SOUTH WHERE MINOR GLAZING OF ICE ACCUM POSSIBLE. PCPN TO DIMINISH
IN COVERAGE BY LATE AM THROUGH MIDDAY WITH MVFR TO POSSIBLY AREAS
OF IFR CONDITIONS CONTINUING THROUGH AFTN AHEAD OF A COLD FRONT
WHICH WILL PASS THROUGH THE TERMINALS 19-23Z AND MAY BE
ACCOMPANIED BY FLURRIES OR BRIEF PERIOD OF LIGHT SNOW ESPECIALLY
NORTHEAST IA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES-
KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DES
MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL-
HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-
WHITESIDE.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR HANCOCK-
HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...GIBBS
AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1042 PM MST MON MAR 2 2015
.UPDATE...
ISSUED AT 551 PM MST MON MAR 2 2015
JUST COMPLETED AN UPDATE. MODELS ARE NOT CATCHING THE FULL EXTENT
OF THE FOG. FOG HAS ALREADY DEVELOPED/ADVECTED INTO MOST LOCATIONS
IN THE WESTERN HALF OF THE FORECAST AREA. THIS IS FASTER AND
FURTHER EAST THAN THE MODEL DEPICTION. THE NAM LOOKS TO BE
CAPTURING THIS THE BEST. SO USED A BLEND OF REALITY AND THE LATEST
NAM TO INCREASE THE EXTENT OF THE FOG.
DAY SHIFT HAD SOME CONCERN ABOUT THE FOG BECOMING DENSE BUT WAS
THINKING THE WIND/MIXING WOULD PREVENT THAT. CURRENTLY THE NAM...
HRRR AND RAP ARE INDICATING DENSE FOG POSSIBLE FOR LOCATIONS ALONG
THE COLORADO BORDER. WHAT COMPLICATES THE EXTENT OF THE FOG AND
HOW LONG IT COULD STAY DENSE IS THE MODEL DIFFERENCE IN THE SPEED
THEY SWITCH THE WINDS TO A WESTERLY DIRECTION AS THEY BRING IN
DRIER AIR. BASED ON THE STRENGTH OF THE SURFACE TROUGH IT IS
POSSIBLE THE SLOWEST SOLUTIONS COULD BE RIGHT. THIS WOULD ALLOW A
LONGER PERIOD OF DENSE FOG. WILL KEEP MONITOR AND WAIT FOR THE
LATEST MODEL DATA TO SEE IF A DENSE FOG ADVISORY MAY BE NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 200 PM MST MON MAR 2 2015
AS OF 3 PM CST...2 PM MST...SKIES ACROSS THE TRI-STATE REGION ARE
MOSTLY CLOUDY TO OVERCAST. WINDS ARE SOUTH AT 15 TO 25 MPH...GUSTING
35 MPH. TEMPERATURES RANGED FROM THE LOW 30S WHERE STRATUS PERSISTS
TO THE UPPER 30S WHERE CLOUD BREAKS ARE NOTED. AT THE SURFACE...LOW
PRESSURE IS LOCATED ALONG THE FRONT RANGE. ALOFT...A WEAK SHORTWAVE
AND MOISTURE ADVECTION IS MOVING IN FROM THE SOUTHWEST. THIS
DISTURBANCE IS EJECTING AHEAD OF A DEEP UPPER LOW OVER CALIFORNIA.
FOR THIS AFTERNOON/TONIGHT...MANY FORECAST COMPLICATIONS HAVE LEAD
TO LOWER CONFIDENCE THAN NORMAL. SEVERAL FACTORS ARE WORKING FOR
PRECIPITATION/FOG WHILE THERE ARE ALSO COMPETING FACTORS THAT COULD
NEGATE ANY POTENTIAL PRECIP/FOG THREAT. FIRST...BEGINNING WITH
PRECIPITATION CHANCES...A STRONG LOW LEVEL JET DEVELOPS THIS
EVENING. THIS RESULTS IN FURTHER WARM/MOIST AIR ADVECTION. IN
ADDITION...SLIGHT LIFT APPLIED BY PASSING SHORTWAVE MAY ALLOW FOR
SOME DRIZZLE/FREEZING DRIZZLE TO DEVELOP...MAINLY EAST OF HIGHWAY
25. HOWEVER...CONDENSATION PRESSURE DEFICITS INDICATE THAT MOST
DRIZZLE/FREEZING DRIZZLE AND ANY HEAVIER PRECIPITATION REMAINS
SOUTHEAST. IN ADDITION...ONLY A SHALLOW LAYER OF MOISTURE IS PRESENT
IN THE ATMOSPHERIC COLUMN SO NOT SURE IF THERE IS EVEN ENOUGH
MOISTURE TO PRECIPITATE. MOST LIKELY...PERSISTENT STRATUS CONTINUES
THROUGH THE NIGHT WITH A FEW SPORADIC OBSERVATIONS OF
DRIZZLE/FREEZING DRIZZLE. ANY PRECIPITATION EXITS TO THE EAST BY
SUNRISE. WITH COLD GROUND/ROAD TEMPERATURES...IT IS POSSIBLE THAT
DRIZZLE FREEZES ON CONTACT SO CAN NOT COMPLETELY RULE OUT A PATCHY
GLAZE. A COMPLICATING FACTOR TO THIS IS THE STRONG WARM AIR
ADVECTION. TEMPERATURES MAY REMAIN ABOVE FREEZING THROUGHOUT THE
NIGHT. THIS WOULD LIKELY ELIMINATE ANY THREAT OF ICE.
AS FOR THE FOG THREAT...SEVERAL HIGH RESOLUTION MODELS CONTINUE TO
INDICATE FOG DEVELOPMENT OVER EAST COLORADO SHORTLY AFTER SUNSET
WITH FOG ADVECTING EAST DURING THE EVENING. GUIDANCE INDICATES THAT
FOG MAY BE DENSE GIVEN THE AMOUNT OF MOISTURE ADVECTION INITIALLY.
HOWEVER...GUSTY SOUTH WINDS PERSIST THROUGH THE NIGHT. THIS
RESTRICTS HOW LOW VISIBILITIES DROP AND WOULD LEAD TO MORE STRATUS
AND LIGHT FOG OBSERVATIONS THAN DENSE FOG. HAVE NOT MENTIONED DENSE
FOG BUT DID MENTION PATCHY/AREAS OF FOG WHERE OCCURRENCE IS MOST
LIKELY. FOG DIMINISHES IN DENSITY/COVERAGE AFTER MIDNIGHT AS DRIER
AIR ADVECTS IN FROM THE SOUTHWEST. IT IS SOMEWHAT UNUSUAL THAT
VISIBILITIES IMPROVE BEFORE SUNRISE BUT THIS SHOULD BE ONE OF THOSE
CASES WHERE IT OCCURS.
DURING THE DAY TOMORROW...THE NEXT DISTURBANCE BEGINS TO PUSH IN
FROM THE WEST. IN ADDITION...A STRONG COLD FRONT WILL PUSH THROUGH
DURING THE MORNING. BEHIND THE COLD FRONT...GUSTY NORTHWEST WINDS
ARE LIKELY WITH GUIDANCE INDICATING PRESSURE RISES ON THE ORDER OF
10-15 MBS IN 6 HOURS. PRECIPITATION CHANCES LOOK MEAGER UNTIL BETTER
FORCING ARRIVES LATER IN THE AFTERNOON BUT CAN`T RULE OUT A FEW
FLURRIES ALONG AND JUST BEHIND THE FRONT. HIGH TEMPERATURES SHOULD
BE REACHED DURING THE MORNING WITH FALLING TEMPS THROUGH REMAINDER
OF THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 200 PM MST MON MAR 2 2015
THE MAIN FORECAST CONCERNS THROUGH THIS PERIOD ARE THE POSSIBILITY
OF SNOW TUESDAY NIGHT INTO WEDNESDAY MORNING AND THE CONTINUED
COLD TEMPERATURES.
THE THROUGH ALOFT OVER THE WESTERN UNITED STATES FINALLY SWEEPS
EAST OF THE ROCKIES AND ACROSS THE CENTRAL HIGH PLAINS REGION WITH
A COLD FRONT PUSHING SOUTH ACROSS THE FORECAST AREA TUESDAY NIGHT.
EXPECT SNOW TO DEVELOP ALONG THE FRONT AS IT MOVES SOUTH WITH SNOW
DIMINISHING FROM NORTH TO SOUTH WEDNESDAY MORNING. EXPECT 1-2
INCHES AT MOST OVER EASTERN COLORADO WITH AMOUNTS TAPERING OFF TO
LESS THAN ONE INCH FURTHER EAST.
IN ADDITION TO THE SNOW...10-15 MPH NORTH WINDS BEHIND THE FRONT
ON WEDNESDAY MORNING ALONG WITH LOW TEMPERATURES IN THE SINGLE
DIGITS ABOVE ZERO WILL PRODUCE WIND CHILLS IN THE -10 TO -15
DEGREE RANGE ACROSS THE FAR WESTERN PORTIONS OF THE FORECAST
AREA.
NO HIGHLIGHTS ARE CURRENTLY WARRANTED FOR EITHER THE SNOW OR THE
COLD WIND CHILLS AT THIS POINT...BUT MAY END UP MENTIONING THEM
IN THE HWO TO MAINTAIN SOME CONSISTENCY.
SIGNIFICANT WARMING TAKES PLACE OVER THE REMAINDER OF THE FORECAST
PERIOD AS TEMPERATURES COME UP TO NEAR NORMAL ON THURSDAY AND
REMAIN ABOVE NORMAL FOR FRIDAY THROUGH MONDAY. BOTH THE ECMWF AND
GFS AMPLIFY THE RIDGE OVER THE WESTERN U.S. THROUGH FRIDAY WITH
MAINLY NORTHWEST FLOW BEING MAINTAINED ACROSS THE FORECAST AREA.
THE GFS AND ECMWF BEGIN TO DIVERGE OVER THE WEEKEND WITH THE GFS
PLACING THE RIDGE OVER THE ROCKIES WHILE THE ECMWF RETROGRADES THE
RIDGE OVER THE WEST COAST. THE PATTERN FLATTENS AND BECOMES MORE
OUT OF PHASE BETWEEN MODELS BY TUESDAY...BUT THE END RESULT IS
THE CENTRAL HIGH PLAINS REGION REMAINS WARMER THAN AVERAGE AND DRY
INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1035 PM MST MON MAR 2 2015
MODELS ARE NOW REVERSING COURSE ON NOT ONLY FOG BUT STRATUS.
MODELS HAVE BEEN HAVING A VERY HARD TIME THE LAST FEW DAYS IN
RESOLVING THE LOW LEVEL MOISTURE. CONFIDENCE IS LOW RIGHT NOW.
CONDITIONS HAVE BECOME VFR AT KGLD. PER SATELLITE AND LATEST
RAP/HRRR THAT MATCHES UP PRETTY WELL. SO UNTIL THE PASSAGE OF THE
FRONT NEAR 14Z...CONDITIONS WILL BE VFR.
AS THE FRONT MOVES THROUGH KGLD...MVFR CONDITIONS ARE EXPECTED TO
BECOME MVFR FOR ABOUT 4 TO 5 HOURS BEFORE BECOME VFR AGAIN. TOWARD
THE END OF THE PERIOD...SNOW IS EXPECTED TO START MOVING NEAR
KGLD. SO AT THIS TIME JUST PUT VCSH WITH MVFR CEILINGS. GUSTY
NORTHERLY WINDS ARE EXPECTED FOR THE MAJORITY OF THE DAY.
FOR KMCK...MVFR CONDITIONS ARE EXPECTED UNTIL NEAR 12Z WHEN THEY
BRIEFLY BECOME VFR RIGHT BEFORE THE FRONT COMES THROUGH. JUST LIKE
KGLD MVFR CONDITIONS ARE EXPECTED FOR ABOUT 4 TO 5 HOURS AFTER THE
FRONT COMES THROUGH. AROUND 19Z VFR CONDITIONS ARE EXPECTED UNTIL
TOWARD THE END OF THE PERIOD. AT THAT TIME...MVFR CONDITIONS ARE
EXPECTED AS LIGHT SNOW...DEPICTED BY VCSH...MOVES INTO THE AREA.
GUSTY NORTHERLY WINDS WILL PREVAIL DURING THE DAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...RRH
LONG TERM...LOCKHART
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1240 AM EST TUE MAR 3 2015
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL CROSS THE AREA THIS EVENING. HIGH
PRESSURE WILL RIDGE ACROSS THE AREA ON TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE 0010 EST: HAVE ADJUSTED POP GRIDS TO EXTEND SNOW SHOWERS A
FEW MORE HOURS. ALSO UPDATED WINDS... TEMPERATURE AND DEW POINT
BASED ON LATEST OBSERVATIONS.
PREVIOUS DISCUSSION...
SNOW SHOWERS/SQUALLS THIS EVENING AND THEN MUCH COLDER. WIND
CHILLS WILL BE THE MAIN CONCERN OVERNIGHT INTO TUESDAY MORNING.
20Z SURFACE ANALYSIS SHOWED THE ARCTIC FRONT MAKING ITS WAY SE
ACROSS THE REGION. THE FIRST BATCH OF SNOW SHOWERS/SQUALLS OUT
AHEAD OF THE BOUNDARY THIS AFTERNOON PER THE RADAR. ANOTHER ROUND
SETTING UP AND WILL DIVE SE W/THE UPPER LEVEL SUPPORT EARLY THIS
EVENING. THE LATEST RUN OF THE HRRR 3KM AND RAP MODEL DOING WELL
W/THE PLACEMENT OF THE SNOW MATCHING UP W/THE RADAR TRENDS. LAPSE
RATES ARE STEEPENING ATTM ESPECIALLY FROM 850-700MBS(7.0 C/KM).
THIS COMBINED W/DECENT SHEAR AT 0-3KM OF 35 KTS AND FORECAST CAPE
80+ JOULES WILL BE ENOUGH TO GET SOME MORE SQUALLS GOING. 12Z
UPPER AIR ANALYSIS SUPPORTED THE MODEL SOUNDINGS W/DEEP MOISTURE
THROUGH 700MBS. THE HEAVIEST ACTIVITY WILL RESIDE FROM THE ST.
JOHN VALLEY DOWN THROUGH CARIBOU-PRESQUE ISLE DOWN INTO HOULTON.
ANOTHER AREA OF HEAVY SNOW SHOWERS/SQUALLS IS FORECAST TO DROP
ACROSS PORTIONS OF CENTRAL MAINE INCLUDING THE MILLINOCKET-PATTEN
AREA ALONG ROUTE 11 AND PORTIONS OF I-95. BRIEF HEAVY SNOW BURSTS
W/WIND GUSTS TO 35 MPH WILL LEAD TO BRIEF WHITEOUTS AND VSBY 1/4
OF A MILE OR LESS. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
EVENING AS SKIES BEGIN TO CLEAR AND THE FRONT PUSHES TO THE COAST.
WINDS WILL REMAIN UP AT 15 TO 25 MPH SUSTAINED THROUGH THE
OVERNIGHT PERIOD W/GUSTS AT LEAST 30 MPH. THESE WINDS COMBINED
W/THE ARCTIC AIRMASS MOVING IN WILL LEAD TO SOME DANGEROUS WIND
CHILLS ACROSS THE NORTHERN 1/2 OF THE CWA. WIND CHILL ADVISORIES
REMAIN UP FOR NORTHERN AREAS THROUGH TUESDAY MORNING. ATTM, IT
LOOKS LIKE THE CENTRAL HIGHLANDS AND DOWNEAST WILL SEE WIND CHILLS
STAY ABOVE ADVISORY CRITERIA OF -20F.
FOR TUESDAY, HIGH PRES IS FORECAST TO RIDGE ACROSS THE REGION
W/DAYTIME TEMPERATURES BELOW NORMAL FOR EARLY MARCH. CLOUDS WILL
BE ON THE INCREASE LATER IN THE AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM TO AFFECT OUR REGION. THIS IS EXPLAINED MORE IN THE SHORT
TERM SECTION BELOW.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
LOOKING FOR ANOTHER SNOW EVENT TUESDAY NIGHT JUST AHEAD OF A WARM FRONT
MOVING FROM WEST TO EAST THROUGH THE AREA SOUTH OF THE PARENT LOW
PASSING WELL TO OUR NORTH. TEMPERATURES WILL BE RISING THROUGH THE
NIGHT TUESDAY NIGHT, BUT THINK THAT FOR THE VAST MAJORITY OF
AREAS, THIS WILL BE AN ALL SNOW EVENT, PERHAPS ENDING AS JUST A BIT
OF LIGHT RAIN NEAR THE COAST. LOOKING FOR ABOUT 3 TO 5 INCHES OF
SNOW.
AFTER THE WARM FRONT PASSES LATE TUESDAY NIGHT, WE ARE LOOKING FOR
A WARM DAY WEDNESDAY WITH HIGHS ABOVE FREEZING FOR PRETTY MUCH
EVERYWHERE, AND EVEN IN THE LOW 40S DOWNEAST. THE WARMTH IS
SHORT LIVED, HOWEVER, AS THE COLD FRONT MOVES THROUGH LATE
WEDNESDAY. THURSDAY WILL BE MUCH COOLER WITH TEMPERATURES NEAR
STEADY IN THE TEENS TO LOW 20S. THERE MAY BE A FEW SNOW SHOWERS
WITH AND BEHIND THE FRONT LATE WEDNESDAY INTO THURSDAY, BUT
NOTHING MAJOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LOOK FOR BELOW AVERAGE TEMPERATURES TO PERSIST FRIDAY THROUGH
EARLY NEXT WEEK. WE DO NOT FORESEE ANY MAJOR STORMS, BUT THERE
COULD BE A FEW WEAK ONES BEYOND FRIDAY AFTER WEAK HIGH PRESSURE
OVER THE AREA WEAKENS. TOO MUCH MODEL DISAGREEMENT TO TIME THE
WEAK SYSTEMS THIS FAR OUT.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR FOR THE MOST PART FOR ALL TERMINALS INTO TUE.
BRIEF IFR IN ISOLATED SNOW SHOWERS AND AREAS OF BLOWING SNOW
TONIGHT AS A NW SFC WIND GUSTS TO 35 KNOTS. THE WIND WILL DIMINISH
TUE MORNING.
SHORT TERM: IFR OR WORSE AREAWIDE TUESDAY NIGHT WITH SNOW.
PRECIPITATION TAPERING OFF WEDNESDAY THROUGH THURSDAY WITH
GENERALLY VFR, THOUGH MVFR COULD LINGER IN THE NORTH ESPECIALLY
WEDNESDAY.
&&
.MARINE...
NEAR TERM: GALES ARE OCCURRING NOW AS THE COLD AIR POURS OUT OVER
THE WATERS. WINDS ARE EXPECTED TO DROP BACK TO SCA LEVELS BY
EARLY TUESDAY MORNING. THE SCA LOOKS TO BE SHORT LIVED AS HIGH
PRES RIDGES IN FROM THE SOUTH. SEAS OF 5 TO 8 FT OVERNIGHT WILL
SUBSIDE TUE. FREEZING SPRAY WILL BE DEVELOPING OVERNIGHT INTO
EARLY TUE MORNING.
SHORT TERM: EXPECT PROLONGED SMALL CRAFT CONDITIONS TUESDAY NIGHT
THROUGH THURSDAY NIGHT. WINDS WILL SHIFT FROM SOUTH TO NORTHWEST
AS A SYSTEM MOVES THROUGH. SEAS WILL PEAK AROUND 9 FEET ON
WEDNESDAY.
&&
.CLIMATE...
THE METEOROLOGICAL WINTER WHICH IS THE 3 MONTH PERIOD
OF DECEMBER THROUGH FEBRUARY HAD AN AVERAGE TEMPERATURE OF 16.8
DEGREES AT BANGOR. IT WAS THE COLDEST SINCE THE WINTER OF
2002-03.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY UNTIL 7 AM EST THIS MORNING FOR MEZ001>004.
MARINE...FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR
ANZ050>052.
GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ050>052.
&&
$$
NEAR TERM...CB/MIGNONE
AREA FORECAST DISCUSSION...CORRECTED
NWS MARQUETTE MI
413 AM EST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EST TUE MAR 3 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW
REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG
OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY
AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33
PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO
SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH
STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE
WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC
LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST
TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW
KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF
SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A
STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS
APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT
HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO
EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME...
A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF
FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT
AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING
LIGHT SN.
MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS
ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE
DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED
TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR
FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND
BRINGS A RETURN OF SOME LES.
TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND
ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS
THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT
ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY.
ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT
EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN
THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF
PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND
IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC
ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO
IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF
LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW
AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE...
EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN
THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6-
9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS
QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS
DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E
BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR
TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER
RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN
TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN
GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE
DROPPED A FEW HRS EARLY OVER THE W.
TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN
THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN
THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS
TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN
AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF
THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA
IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER...
AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE
INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE
NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL
BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE
THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER.
GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND
DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK
SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY
APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH
MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR
THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EST TUE MAR 3 2015
A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED
EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE
OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW
BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS
GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO
BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE
KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND
DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND
EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED
LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES
WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W
WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON
WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU.
FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE
REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH
ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION
FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE
SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE
IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO
MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN
FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E
INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING
ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1149 PM EST MON MAR 2 2015
VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD
(AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW
FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT
ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER
CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD
FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME
BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO
SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EST TUE MAR 3 2015
S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING
COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT
LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR
ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS
WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND
ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS.
AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF
THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE
SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK
THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE
SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR
LSZ266.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 AM EST TUE MAR 3 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 451 PM EST MON MAR 2 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA.
FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM
SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF
OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE
CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD
SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE
ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC
HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION.
SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN
TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST
CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING
850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE
LAKE/ICE BREEZE HAS DEVELOPED.
LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES
REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL
ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT
WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT
APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER
PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS
SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET
STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET
TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT
JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET
ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND
BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE
LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO
WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS
THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL
BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH
MAY OCCUR ALONG THE WI BORDER BY 12Z.
ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING
COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE
SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC
ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN
INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY
SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING
RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3
INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER
FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS
EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE
WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW
USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP
LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO
SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS
DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE
ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE
ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE
QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY
SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E
DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY
OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY
UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY
CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE
FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EST TUE MAR 3 2015
A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED
EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE
OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW
BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS
GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO
BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE
KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND
DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND
EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED
LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES
WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W
WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON
WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU.
FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE
REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH
ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION
FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE
SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE
IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO
MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN
FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E
INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING
ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1149 PM EST MON MAR 2 2015
VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD
(AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW
FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT
ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER
CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD
FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME
BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO
SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EST MON MAR 2 2015
GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S
AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING
LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING
PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH
PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF
NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER
WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE
WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND
94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE
COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ THIS MORNING TO
7 PM EST /6 PM CST/ THIS EVENING FOR MIZ001>007-009>014-084-
085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR
LSZ266.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST MON MAR 2 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 451 PM EST MON MAR 2 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW OVER N AMERICA.
FEATURES OF INTEREST FOR THE SHORT TERM FCST ARE A NRN STREAM
SHORTWAVE DROPPING THRU ALBERTA/SASKATCHEWAN AND THE SRN STREAM TROF
OVER CA/NV...IN PARTICULAR THE SHORTWAVE OVER SRN CA/SRN NV WHERE
CONVECTION IS NOTED. THESE TWO WAVES WILL BRING A WIDESPREAD
SYNOPTIC SNOW TO THE AREA TUE. ABUNDANT SUNSHINE HAS BEEN THE RULE
ACROSS THE AREA THIS AFTN UNDER DRY AIR MASS ASSOCIATED WITH SFC
HIGH OVER THE MID MISSISSIPPI VALLEY AND WRN GREAT LAKES REGION.
SUNSHINE WORKING ON THE FORESTED TERRAIN OF UPPER MI HAS RESULTED IN
TEMPS RISING WELL INTO THE 20S OVER MOST OF THE AREA. COOLEST
CONDITIONS (AROUND 20F) ARE OVER THE FAR E...CLOSER TO THE DEPARTING
850MB THERMAL TROF...AND AT MANY LOCATIONS ALONG LAKE SUPERIOR WHERE
LAKE/ICE BREEZE HAS DEVELOPED.
LATEST MODEL RUNS CONTINUE TO SHOW THE 2 AFOREMENTIONED SHORTWAVES
REMAINING UNPHASED AS THEY AFFECT THE AREA TUE. THE SRN WAVE WILL
ACCELERATE OUT OF THE SW INTO THE DOWNSTREAM CONFLUENT FLOW...AND IT
WILL BE THE DRIVER OF THE SNOW THAT SPREADS INTO THE UPPER LAKES. IT
APPEARS 1 MAIN STREAK OF PCPN OR AT LEAST MORE ORGANIZED/HEAVIER
PCPN WILL DEVELOP TONIGHT TO THE SW. THIS PCPN WILL STREAK NE ACROSS
SD INTO CNTRL MN IN ASSOCIATION WITH A COUPLED UPPER JET
STRUCTURE/ENHANCED UPPER DIVERGENCE FROM LEFT EXIT OF 150KT JET
TRANSLATING OUT OF THE SRN ROCKIES AND THE RIGHT ENTRANCE OF 125KT
JET STREAK OVER ND INTO NRN ONTARIO. MORE PCPN WILL BEGIN TO GET
ORGANIZED FARTHER E LATE IN THE NIGHT AS MID LEVEL FRONTOGENESIS AND
BROADER WAA/ISENTROPIC ASCENT BEGIN TO SATURATE DRIER AIR AT THE
LOWER LEVELS. MODELS ARE NEARLY IDENTICAL IN TIMING THE PCPN INTO
WRN AND SRN UPPER MI IN THE 08-12Z TIME FRAME...AND STARTING ACROSS
THE N AND E AROUND OR SHORTLY AFTER 12Z. SO...LITTLE ADJUSTMENT WILL
BE REQUIRED WITH ONSET TIMING. ACCUMULATIONS AROUND ONE HALF INCH
MAY OCCUR ALONG THE WI BORDER BY 12Z.
ON TUE...THE BEST UPPER DIVERGENCE ASSOCIATED WITH A WEAKENING
COUPLED UPPER JET STRUCTURE QUICKLY SHIFTS NE ACROSS NE MN/WRN LAKE
SUPERIOR INTO NRN ONTARIO. MEANWHILE...WAA/ISENTROPIC
ASCENT/FRONTOGENETICALLY FORCED PCPN WILL QUICKLY EXPAND/INCREASE IN
INTENSITY AS AIR MASS SATURATES AND DEEP LAYER FORCING PROVIDED BY
SHORTWAVE ARRIVES. ON THE 285K SFC (ROUGHLY 700-750MB)...MIXING
RATIOS AROUND 2.5G/KG ARE AVBL...SUGGESTING SOMETHING AROUND 3
INCHES OF SNOW FOR 6-9HRS OF ASCENT. HOWEVER...GIVEN THE OTHER
FACTORS AT PLAY...A WIDESPREAD FAIRLY UNIFORM 3-5 INCH SNOW IS
EXPECTED ACROSS THE ENTIRE FCST AREA TUE...WHICH FALLS NICELY INLINE
WITH THE CONSENSUS QPF NUMBERS FROM THE MODELS CONVERTED TO SNOW
USING A 15 TO 1 OR SO SNOW RATIO. WITH SOUTHERLY LOW-LEVEL FLOW UP
LAKE MICHIGAN FOR SEVERAL HRS AND AIR MASS JUST COLD ENOUGH TO
SUPPORT ENHANCEMENT...THERE SHOULD BE SOME BOOST TO SNOW TOTALS
DOWNWIND OF LAKE MICHIGAN THOUGH ICE COVER WILL LIMIT THE
ENHANCEMENT OVER WHAT IT COULD BE. THAT AREA IS MORE LIKELY TO SEE
ACCUMULATIONS CLOSER TO 5 INCHES THAN 3...AND NOT OUT OF THE
QUESTION THAT SOME 6 INCH AMOUNTS COULD OCCUR. FORCING QUICKLY
SHIFTS E TUE AFTN...RESULTING IN SNOW RAPIDLY DIMINISHING W TO E
DURING THE MID AND LATE AFTN HRS. IN FACT...IT MAY END COMPLETELY
OVER PORTIONS OF THE WEST LATE IN THE AFTN. WITH SNOW RATIO LIKELY
UNDER 20 TO 1...THIS SYSTEM WILL ACHIEVE THE WETTER SNOW TYPE ADVY
CRITERIA OF AN AVG SNOWFALL OF AT LEAST 3IN/12HR OVER THE ENTIRE
FCST AREA. SO...ADVY WILL BE HOISTED ACROSS THE BOARD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EST MON MAR 2 2015
AT THE START OF THE LONG TERM PERIOD...UPPER MICHIGAN WILL SEE THE
SYNOPTIC PRECIPITATION QUICKLY COMING TO AN END OVER THE EASTERN
THIRD OF THE CWA. THIS IS DUE TO THE DRY MID LEVEL AIR MOVING OVER
THE AREA BEHIND THE COLD FRONT AND AHEAD OF THE MAIN SHORTWAVE
TROUGH THAT WILL MOVE THROUGH ON TUESDAY. THEN...AS COLDER AIR
SURGES INTO THE AREA...GENERALLY AFTER MIDNIGHT TUESDAY
NIGHT...SHOULD SEE THE POTENTIAL FOR LAKE EFFECT INCREASE FROM WEST
TO EAST. 850MB TEMPS WILL FALL FROM AROUND -11C AT 00Z WEDNESDAY
TO -26C AT 18Z WEDNESDAY...PROVIDING PLENTY OF OVER LAKE
INSTABILITY WHERE THERE IS OPEN WATER. THAT IS THE BIG QUESTION FOR
THE LAKE EFFECT FORECAST. VISIBLE SATELLITE SHOWS SEVERAL LARGER
AREAS OF OPEN WATER AND SLUSH OVER WESTERN...NORTH CENTRAL...AND
SOUTH CENTRAL LAKE SUPERIOR. THOSE AREAS HAVE NOT BEEN REPRESENTED
IN THE MODELS AT THIS POINT...SO I DON/T FEEL THE MODELS ARE
INDICATING THE LAKE EFFECT POTENTIAL IN THE QPF FIELDS.
THUS...HAVE PERFORMED SIGNIFICANT HAND EDITS TO THE GRIDS...BOTH IN
RAISING POPS AND HIGHLIGHTING AREAS DOWNWIND OF THE CURRENT OPEN
WATER AREAS. WITH THE STRONG WEST TO WEST-NORTHWEST WINDS TUESDAY
NIGHT INTO WEDNESDAY...THOSE AREAS OF OPEN WATER WILL LIKELY EXPAND
AND MOVE...SO THAT DOES INCREASE THE UNCERTAINTY OF THE LAKE EFFECT
SOME...BUT EVEN WITH THE COLD AIR...THINK THE WINDS WILL LIMIT THE
ICE COVER EXPANDING AT LEAST THROUGH WEDNESDAY. WHILE THE LAKE
EFFECT WON/T BE TOO STRONG INITIALLY TUESDAY NIGHT...THE CLOUD WILL
BE WITHIN THE DGZ AND LEAD TO A FLUFFY INCH OR SO OF ACCUMULATION.
THEN ON WEDNESDAY...INVERSION HEIGHTS WILL RISE TO 7-9KFT AS A
SHORTWAVE MOVES THROUGH AND SUPPORT MODERATE TO POTENTIALLY EVEN
LOCALLY HEAVY SNOWFALL. WITH THE COLD AIR BEING IN PLACE ON
WEDNESDAY...SNOWFLAKE SIZE SHOULD BE SMALL AND KEEP ACCUMULATIONS
IN THE COUPLE INCH RANGE FOR THE WEST-NORTHWEST WIND AREAS DOWNWIND
OF THE OPEN WATER. IN ADDITION...RECENT SNOWFALL AND THE STRONG
WINDS WILL LIKELY LEAD TO PATCHY/AREAS OF BLOWING SNOW...ESPECIALLY
OVER THE KEWEENAW AND NEAR LAKE SUPERIOR EAST OF MARQUETTE. WHEN
COMBINED WITH THE FINE FLAKED LAKE EFFECT SNOW...THIS WILL LEAD TO
VISIBILITIES BEING REDUCED BELOW 1 MILE AND IN THE STRONGER BANDS
LIKELY BELOW 1/2MI. FORTUNATELY...WITH WINDS MORE OUT OF THE WEST TO
WEST-NORTHWEST...THE IMPACT FOR AREAS EAST OF MARQUETTE WILL BE
FOCUSED MORE IN THE AREAS TO THE EAST OF MUNISING AND GENERALLY LESS
POPULATED AREAS.
HIGH PRESSURE RIDGE WILL BEGIN TO MOVE INTO THE AREA WEDNESDAY
NIGHT...DECREASING WINDS AND INCREASING SUBSIDENCE (LOWERING
INVERSION HEIGHTS). A WEAK SURFACE TROUGH MOVING OVER EASTERN LAKE
SUPERIOR AROUND MIDNIGHT WILL SHIFT WINDS MORE TO THE NORTHWEST FOR
A BRIEF PERIOD OF TIME BEFORE BACKING BACK TO THE WEST BY THURSDAY
AFTERNOON. WILL SHOW A GRADUALLY DECREASING TREND TO THE POPS FOR
THAT TIME PERIOD WHILE FOLLOWING THE WIND DIRECTIONS.
SHOULD SEE TEMPERATURES MODERATING BOTH ALOFT AND AT THE SURFACE
FRIDAY THROUGH THE WEEKEND AS 500MB FLOW BEGINS TO TURN A LITTLE
MORE WEST-NORTHWESTERLY. THIS SHOULD LEAD TO TEMPERATURES WARMING
TOWARDS MORE NORMAL VALUES FOR THIS TIME OF YEAR (INTO THE LOWER
30S). BUT THE CONFIDENCE ON PRECIPITATION OCCURRENCE IS LOW DUE TO
DIFFERENCES IN THE WAY THE MODELS HANDLE A COUPLE WAVES COMING ON
SHORE IN NORTHERN BRITISH COLUMBIA. THE 12Z GFS/GEM SLIDE THE WAVES
SOUTHEAST THROUGH THE AREA LATE FRIDAY NIGHT INTO SATURDAY...WITH
ANOTHER ONE ARRIVING ON SUNDAY. MEANWHILE...THE 12Z ECMWF SHOWS THE
WAVES BECOMING SEPARATED AND SPLITTING THE CWA THROUGH THE WEEKEND.
EITHER WAY WITH THE LIMITED DEEP MOISTURE...WOULDN/T EXPECT MUCH
MORE THAN LIGHT PRECIP ACCUMULATION THROUGH THE WEEKEND AND WILL
ONLY MENTION SLIGHT CHANCES.
A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH THE AREA SUNDAY NIGHT
INTO MONDAY...LIKELY PULLING IN THE LAST SURGE OF COLD AIR FOR A
WHILE THROUGH THE AREA. EXPECT THERE TO BE SOME PRECIP ASSOCIATED
WITH THE SHORTWAVE...BUT THEN WITH WINDS TURNING NORTHERLY BETWEEN
THE DEPARTING SURFACE TROUGH AND A HIGH IN THE DAKOTAS...SHOULD SEE
A PERIOD OF LAKE EFFECT IN THE NORMAL SNOW BELTS. WITH THE FAVORABLE
850MB TEMPS (AROUND -14 TO -18C MONDAY)...WILL TREND POPS UP TO
MID/HIGH END CHANCES FOR NOW UNTIL WE ARE ABLE TO GET A BETTER
HANDLE ON THE ICE SITUATION ON LAKE SUPERIOR.
BEHIND THIS WAVE...GFS/ECMWF DETERMINISTIC AND ENSEMBLE MEMBERS ARE
SHOWING THE RIDGE THAT HAS BEEN PERSISTENT OVER THE WESTERN CONUS
AND ALASKA FOR THE LAST MONTH TO SHIFT EAST INTO THE CENTRAL CONUS
AROUND THE MIDDLE OF NEXT WEEK. THIS WILL LEAD TO TEMPERATURES
WARMING TO ABOVE NORMAL VALUES AND START MELTING SOME OF THE
SNOWPACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1149 PM EST MON MAR 2 2015
VFR CONDITIONS WILL GIVE WAY TO MVFR CONDITIONS LATE TONIGHT AT KIWD
(AROUND 10Z) AND AT KCMX/KSAW AROUND 12Z AS INCREASING MOISTURE IN A SW
FLOW WILL LEAD TO SNOW DEVELOPMENT. BY MID TO LATE MORNING...ALL
TERMINALS SHOULD SEE IFR CONDITIONS. EXPECT IMPROVEMENT TO MVFR AT
ALL TERMINALS LATE AFTERNOON/EVENING (BTWN 20-22Z) WITH DRIER
CONDITIONS AND DEVELOPING W WINDS IN WAKE OF LOW PRES TROF/COLD
FROPA. W WINDS GUSTING AS HIGH AS 30 MPH AT KCMX COULD LEAD TO SOME
BLSN AND POSSIBLY BRIEF IFR CONDITIONS TUE EVENING. EXPECT KSAW TO
SEE VFR CONDITIONS DEVELOPING TUE EVENING IN DOWNSLOPE WNW FLOW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 451 PM EST MON MAR 2 2015
GENERALLY LIGHT WINDS CURRENTLY ACROSS LAKE SUPERIOR WILL BECOME S
AND RAMP UP TONIGHT AND TUE TO 15-25KT IN ADVANCE OF AN APPROACHING
LO PRES TROF. ONCE THE TROF PASSES TO THE E TUE NIGHT...TIGHTENING
PRES GRADIENT AND STRONG COLD AIR ADVECTION AHEAD OF ARCTIC HIGH
PRES MOVING INTO THE NORTHERN PLAINS WILL LIKELY BRING A PERIOD OF
NW GALES INTO WED...MAINLY ACROSS CNTRL AND ERN LAKE SUPERIOR. AFTER
WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF THE
WEEK. LATEST OFFICIAL ICE CONCENTRATION ON LAKE SUPERIOR IS AROUND
94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK...THE HIGHER ICE
COVERAGE SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6
PM CST/ TUESDAY FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
335 AM CST TUE MAR 3 2015
.SHORT TERM...(TODAY THROUGH LATE TONIGHT)
ISSUED AT 332 AM CST TUE MAR 3 2015
INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE
PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE
VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT.
SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE
LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY
TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW
LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF
700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF
STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA
OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS
MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD
LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO
PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS
EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO
THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2
INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL
BE THIS MORNING FROM AROUND 5 AM TO 11 AM.
THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE
ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT
FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY
WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND
GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE
COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW
LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT
TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE
WINTER WEATHER ADVISORIES.
THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS
TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT
POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28
DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC
TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW
ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND
CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL
ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE MAR 3 2015
WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW
MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST
FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA
DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS
DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT
SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL
POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL
FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH
GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS.
WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE
AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND
FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY
BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND...
BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS
LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY
LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY
NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING.
FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET
CLOSER IN.
THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS
SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE
QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY.
ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY.
FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED
TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE
30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY.
HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW
30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND
SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE.
THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING
DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE
BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH
THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR
DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF
STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID
30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION...
BUT WE WILL NEED TO WATCH THIS CAREFULLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1137 PM CST MON MAR 2 2015
VFR CONDITIONS THROUGH 09Z...THEN LOWERING CEILINGS AS SNOW
SPREADS NORTH AND EAST ACROSS THE FORECAST AREA THROUGH DAYBREAK.
A 4-6 HOUR WINDOW OF HEAVY SNOW AND LIFR/VLIFR CONDITIONS WILL BE
FOUND AT KBRD/KDLH/KHYR WITH THE SNOW INTENSITY AND AMOUNTS
DECREASING NORTHWARD FOR THE KHIB AND KINL AREAS. THE MAIN PERIOD
OF ACCUMULATING SNOW WILL END IN THE AFTERNOON...FOLLOWED BY STRONG
NORTHWEST WINDS GUSTING AROUND 30 KT THROUGH THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 -9 4 -11 / 100 10 10 0
INL 19 -15 3 -19 / 60 10 10 0
BRD 22 -11 5 -14 / 100 10 10 0
HYR 27 -8 6 -15 / 100 10 20 10
ASX 28 -4 7 -8 / 100 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR MNZ011-012-018-019-021-025-026.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020-
033>038.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>004-006>009.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...LE
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
306 AM CST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CST TUE MAR 3 2015
TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND
ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT
SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT
UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW
ABOVE 850 MB.
THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE
MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A
WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT
MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR
LIKELY.
THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS
GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL
WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER
ADVISORY APPEARS TO BE RIGHT ON TRACK.
WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW
PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING
FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING
DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE
HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE
FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING
ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR
SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS
MORNING AHEAD OF THE ARCTIC FRONT.
ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING
THREAT SHOULD END.
LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE
WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND
LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE
NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES
WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND
CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE
FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM CST TUE MAR 3 2015
TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE
EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY
DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE
TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT
THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES.
WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE
REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH
APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS.
MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL
NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING
GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN
CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE
WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT
SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER
RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS
AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE
DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN
OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD
EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST
TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE
DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND
THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND
FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH
50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE
OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A
GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO
COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN
COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES
NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY
AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST
HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES
WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE
RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND
SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR
ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST
TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY
WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM CST MON MAR 2 2015
A FRONT ACROSS WESTERN SOUTH DAKOTA AND NORTHWEST NEBRASKA IS
EXPECTED TO MOVE ACROSS THE STATE TONIGHT. RADAR-INDICATED
PRECIPITATION IN WESTERN NEBRASKA AND SOUTHEAST WYOMING WILL
SPREAD ACROSS NORTHERN NEBRASKA AS THE FRONT MAKEST ITS WAY
SOUTHEASTWARD THROUGH WESTERN AND THEN CENTRAL NEBRASKA. FORECAST
SOUNDINGS INDICATE THAT THE VERTICAL TEMPERATURE PROFILES WOULD
FAVOR SNOW MOST AREAS. IT IS POSSIBLE THAT...IN SOUTHWEST
NEBRASKA...THERE COULD BE SOME FREEZING DRIZZLE OR LIGHT FREEZING
RAIN.
WIND WILL BE 180-210 AT 15-20G23-29KT UNTIL SOMETIME AFTER 06Z.
WIND WILL SHIFT TO 330-360 AT 15-25G30-36KT BEGINNING IN THE
NORTH AROUND 10Z AND THE REST OF WESTERN NEBRASKA BEGINNING 14Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ004>007-094.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
400 AM EST TUE MAR 3 2015
.SYNOPSIS...HIGH PRESSURE WILL WILL SHIFT OFFSHORE DURING THE DAY
AS A LOW PRESSURE SYSTEM TRACKS NORTHEAST FROM THE CENTRAL PLAINS
INTO THE GREAT LAKES LATER TODAY AND TONIGHT. A WARM FRONT WILL MOVE
NORTH THROUGH THE REGION WEDNESDAY.
&&
.NEAR TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 1000 PM MONDAY...
AFTER A PLEASANTLY WARM DAY...COOLER AND DRIER AIR IS WORKING ITS
WAY INTO THE AREA FROM THE NORTH-NORTHEAST AS A 1034MB SURFACE HIGH
TRANSLATES EAST ACROSS THE MID-ATLANTIC STATES. THE PRIMARY COLD
FRONT IS TO OUR SOUTH...BUT THERE APPEARS TO BE A SECONDARY
BOUNDARY...WITH NOTICEABLY HIGH DEWPOINTS POOLING ALONG IT...MOVING
FROM THE COASTAL PLAIN TOWARD THE PIEDMONT. THIS COMPLICATES THE
OVERNIGHT FORECAST AS THE DRIER...SUB-20F DEWPOINT AIR OVER THE THE
NORTHWEST PIEDMONT TRIES TO PUSH SOUTH BUT MAY ULTIMATELY BE HALTED
OR SHUNTED OFF TO THE WEST. MOST MODEL ARENT HANDLING THIS VERY
WELL...EVIDENT IN PART BY THE MUCH DRIER THAN FORECAST BOUNDARY
LAYER ON THE 00Z KGSO RAOB...SO WILL LEAN ON THE RAP/HRRR WHICH HAS
DEWPOINTS MOSTLY IN THE 20S TO LOWER 30S TUESDAY MORNING. TEMPS
WILL CONTINUE TO FALL INTO THE 30S OVERNIGHT...BUT AS SOME 290K
ISENTROPIC LIFT AND HIGHER BASED STRATUS SPREAD NORTH AND
EAST ACROSS THE AREA...TEMPS SHOULD STABILIZE MOSTLY ABOVE FREEZING.
THE BIGGEST FORECAST ISSUES TONIGHT WILL STILL BE 1) WHETHER OR NOT
ANY LIGHT RAIN/DRIZZLE SPREADS FAR ENOUGH NORTH AND EAST INTO THE
SUB-FREEZING AIRMASS BEFORE A WEAK DIURNAL RECOVERY IN TEMPS BEGINS
ON TUESDAY MORNING...OR 2) PRECIP IS EVEN HEAVY ENOUGH WETBULB TEMPS
BELOW FREEZING IN AREAS WHERE THEY ARE INITIALLY ABOVE FREEZING.
18Z AND 00Z GUIDANCE CONTINUES TO ONLY SHOW A COUPLE HUNDREDTHS AT
BEST AND MOSTLY COMING AFTER 12Z. THE RAP AND HRRR ARE COMPLETELY
DRY THROUGH 12Z. WILL LOWER POPS A LITTLE AND JUST MAINTAIN A
MENTION JUST FREEZING DRIZZLE IN THE SMALL AREA WHERE TEMPS AT AT
OR BELOW 32...WHICH IS CONFINED TO JUST THE NORTH PIEDMONT PRIOR TO
15Z. NO ADVISORY FOR FREEZING RAIN IS NEEDED AT THIS TIME. TEMPS ON
TUESDAY WILL MOVE LITTLE OFF MORNING LOWS...MID 30S TO LOWER 40S.
A WARM FRONT IS EXPECTED TO LIFT NORTHWARD TOWARD CENTRAL NC TUE
NIGHT...WITH TEMPERATURES RISING OVERNIGHT ACROSS MUCH OF THE
AREA...ALTHOUGH THEY COULD REMAIN NEAR STEADY IN THE N/NW PIEDMONT.
LIGHT RAIN/DRIZZLE COULD TAPER AS THE WARM FRONT LIFTS WITH
EXPANDING FOG CONDITIONS POSSIBLE.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
THE FORECAST PROBLEM FOR THIS PART OF THE FORECAST CONTINUES TO BE
THE UNCERTAINTY IN TEMPERATURES DUE TO THE POTENTIALLY LINGERING
WEDGE AND THE TIMING AND EXTENT TO WHICH THE WARM FRONT RETREATS
NORTHWARD. GIVEN THAT THE MODELS HAVE A TENDENCY TO ERODE THE WEDGE
TOO QUICKLY...ESPECIALLY IF THERE IS PRECIPITATION FALLING INTO
IT...CURRENTLY FORECAST THE WEDGE STICKING AROUND INTO WEDNESDAY
AFTERNOON IN THE FAR NW PIEDMONT...WITH A LARGE SPREAD IN TEMPS FROM
NW TO SE ACROSS THE AREA. CONFIDENCE REMAINS SOMEWHAT LOW WITH
RESPECT TO TEMPS...AS ANY CHANGES TO THE TIMING AND POSITION OF THE
WEDGE/WARM FRONT AS THEY ERODE/RETREAT NORTHWARD WILL HIGHLY IMPACT
TEMPERATURES. THEY WILL HOWEVER INCREASE GRADUALLY THROUGH AROUND
MIDNIGHT THURSDAY BEFORE THE COLD FRONT BEGINS MOVING INTO THE NW.
KEEPING IN MIND THE POTENTIAL MARGIN FOR ERRORS...FORECAST HIGH
TEMPS IN THE MID 60S NW TO MID 70S SE ON WEDNESDAY. A NORMAL DIURNAL
TEMPERATURE CURVE SHOULD RETURN WEDNESDAY NIGHT...ALTHOUGH THE
TEMPERATURE GRADIENT WILL BE QUITE LARGE AND WILL DEPEND ON THE
TIMING AND POSITION OF THE COLD FRONT...EXPECT LOWS IN THE UPPER 30S
NORTH TO LOW 50S SOUTH WEDNESDAY NIGHT AND HIGHS IN THE LOW 40S
NORTH TO MID 50S SOUTH ON THURSDAY AND DECREASING BEHIND THE FRONT.
PRECIPITATION: THERE WILL BE A SLIGHT CHANCE OF PRECIP...MAINLY
ACROSS THE WESTERN PORTIONS OF THE AREA WEDNESDAY...EVEN THOUGH THE
MAIN PRE-FRONTAL CONVECTIVE RAINFALL REMAINS LARGELY ALONG OR WEST
OF THE APPALACHIANS UNTIL WEDNESDAY AFT/EVE. SOUTHWESTERLY WINDS
WILL BE QUITE STRONG ON WEDNESDAY AFT/EVE AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT. LATE WEDNESDAY AFTERNOON IS STARTING TO SHAPE UP
AS A HIGH SHEAR/LOW CAPE EVENT. FORECAST SOUNDINGS INDICATE 200-300
JOULES OF CAPE AND 0-3 KM SHEAR VALUES AROUND 35 KTS...MAINLY ALONG
AND EAST OF I-95 AT THIS TIME. WITH SURFACE TEMPS EXPECTED IN THE
MID 70S AND DEWPOINTS AROUND 60 DEGREES...THUNDERSTORMS WILL BE
POSSIBLE WEDNESDAY AFTERNOON...THUS WILL INTRODUCE A SLIGHT CHANCE
ACROSS THE EAST WITH THIS AFTERNOON`S FORECAST. THE LATEST 12Z ECMWF
AND GFS MODEL RUNS ARE IN BETTER AGREEMENT WITH THE TIMING OF THE
FROPA AND THE ASSOCIATED RAINFALL AS IT MOVES THROUGH THE AREA. THE
LATEST RUNS SUGGEST THAT RAIN WILL BE LIKELY WEDNESDAY NIGHT...
PROGRESSING NW TO SE THROUGH CENTRAL NC THROUGH MIDDAY THURSDAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 400 AM TUESDAY...
THE LATEST MODELS ARE IN GOOD AGREEMENT IN BRING THE COLD FRONT
SOUTH THROUGH CENTRAL NORTH CAROLINA THURSDAY MORNING. A WAVE IS
EXPECTED TO FORM ALONG THE FRONT OVER UPSTATE SC... WHICH IN TURN
HELPS TO HOLD UP THE COLD FRONT FOR SEVERAL HOURS FROM REACHING THE
SOUTHERN ZONES. THE STRONGEST CAA SHOULD ALSO LAG THE FRONTAL
PASSAGE BY SEVERAL HOURS IT APPEARS. THIS SUPPORTS THE CONTINUATION
OF OUR CURRENT PREDOMINATELY RAIN FORECAST FOR THURSDAY WITH LIMITED
POTENTIAL FOR WINTERY MIX NEAR THE END OF THE EVENT BETWEEN 18Z AND
23Z OR SO THURSDAY AFTERNOON FOR THE NORTHERN PIEDMONT AND NORTHERN
COASTAL PLAIN.
P-TYPE NOMOGRAMS SUPPORT SOME MIX WITH OR CHANGE TO FREEZING RAIN
THEN EVEN A BRIEF PERIOD OF LIGHT SNOW/SLEET AT THE VERY VERY END OF
THE EVENT... ACROSS THE FAR NORTHERN PIEDMONT DURING THE MID TO LATE
AFTERNOON. FORECAST WET BULB TEMPERATURES DEPENDING ON THE MODEL OF
CHOICE WITH SOME MODEL VARIABILITY ALSO TARGET THE NORTHERN ZONES
FOR THIS POTENTIAL CHANGEOVER (ESPECIALLY NORTH OF A LINE EXTENDING
FROM DAVIDSON TO RANDOLPH TO WAKE TO WARREN COUNTIES. PRECIPITATION
SHOULD END QUICKLY BETWEEN 21Z-00Z... LIMITING THE WINDOW OF
OPPORTUNITY FOR ICE TO BECOME A SIGNIFICANT WEATHER HAZARD. TO THE
SOUTH... ALL RAIN IS EXPECTED WITH THE SLOWER TO COOL TEMPERATURES
THERE.
ALL IN ALL... A SIGNIFICANT WINTER WEATHER EVENT IS NOT EXPECTED AT
THIS TIME WITH THE PREDOMINATE P-TYPE EXPECTED TO BE RAIN. THE
CHANGEOVER WOULD OCCUR DURING THE AFTERNOON IN THE NORTH (IF AT
ALL)... AND THE WARM GROUND TEMPERATURES AND TIME OF DAY WOULD LIMIT
THE POTENTIAL TO MOSTLY ELEVATED SURFACES.
THURSDAY NIGHT... BREEZY AND COLDER CONDITIONS COULD LEAD TO A QUICK
FREEZE OF RESIDUAL WATER LEFT BEHIND WHICH MAY BECOME A WEATHER
HAZARD. OTHERWISE... SIMPLY CLEARING AND COLD WITH LOWS IN THE 20-25
RANGE.
FRIDAY IS EXPECTED TO BE MOSTLY SUNNY AND COLD WITH THE HEART OF THE
ARCTIC COLD EXPECTED OVER THE OHIO VALLEY AND NORTHERN MID ATLANTIC
STATES. WE WILL STILL BE A GOOD 20 DEGREES BELOW NORMAL WITH HIGHS
EXPECTED IN THE UPPER 30S TO LOWER 40S.
MODERATION WILL OCCUR IN THE TEMPERATURES OVER THE WEEKEND AS THE
HIGH SLIPS SOUTH AND A WESTERLY FLOW DEVELOPS. HIGHS SHOULD RAPIDLY
WARM INTO THE MID 40S TO LOWER 50S SATURDAY AND MID 50S TO LOWER 60S
SUNDAY. A DRIER PATTERN IS ALSO ANTICIPATED THROUGH THE WEEKEND.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 745 PM MONDAY...
STRONG (1032 MB) BUT TRANSIENT MODIFIED ARCTIC HIGH PRESSURE WILL
RIDGE SOUTH INTO NC TONIGHT...THEN BUILD QUICKLY OFFSHORE ON TUE.
INITIALLY VFR CONDITIONS THIS EVENING WILL BE THREATENED WITH FIRST
A NARROW BAND OF LOW MVFR CLOUDS THAT NEAR TERM GUIDANCE WILL
DEVELOP IN THE VICINITY OF KRWI IN THE NEXT COUPLE OF HOURS...THEN
SWEEP...IN NORTHEASTERLY FLOW...TO THE SOUTHWEST ACROSS THE
REMAINDER OF CENTRAL NC BETWEEN 02-07Z...LASTING AT ANY ONE LOCATION
FOR JUST 2-3 HOURS BEFORE DEPARTING.
MEANWHILE...AN AREA OF 4-5 THOUSAND FT CEILINGS OVER SC WILL EXPAND
NORTH AS THE FLOW IN THAT LAYER STRENGTHENS AND CAUSES AIR TO GENTLY
RISE ATOP THE AFOREMENTIONED RIDGE OF SURFACE HIGH PRESSURE AND
ASSOCIATED NORTHEASTERLY FLOW BENEATH. CONFIDENCE IS RELATIVELY HIGH
THAT CEILINGS WITHIN THIS AREA OF CLOUDS WILL THEN GRADUALLY LOWER
TO INTO MVFR RANGE FROM WSW TO ENE ON TUE - FIRST AT KINT/KGSO AND
LAST AT KRWI. THERE IS A LESSER...MEDIUM CHANCE (AROUND 50
PERCENT)... THAT CONDITIONS WILL LOWER TO IFR...WITH ACCOMPANYING
PERIODS OF LIGHT RAIN/DRIZZLE MAINLY AT KGSO/KINT...AND PERHAPS AS
FAR EAST AS KRDU...TUE MORNING. IF PRECIPITATION WERE TO INDEED
OCCUR... TEMPERATURES WILL BE CLOSE TO FREEZING AT KINT/KGSO...WHERE
AN ASSOCIATED PERIOD OF FREEZING PRECIPITATION WOULD BE POSSIBLE.
OUTLOOK: TUE NIGHT: SUB-VFR CONDITIONS WILL CONTINUE TO DEVELOP
NORTHEAST AND LOWER ACROSS CENTRAL NC THROUGH TUE NIGHT...SUCH THAT
LIFR CONDITIONS WITH RESPECT TO CEILINGS AND POSSIBLY VISIBILITIES
IN DENSE FOG...ARE EXPECTED TO PREVAIL LATE TUE NIGHT-WED
MORNING...IN ASSOCIATION WITH THE SLOW RETREAT/APPROACH OF A WARM
FRONT FROM THE SOUTHEAST.
WED-THU: A RETURN TO VFR WILL BE PROBABLE WITH THE PASSAGE OF THE
WARM FRONT LATER WED AT KFAY/KRWI/KRDU...BUT THIS IMPROVEMENT WILL
BE DELAYED...OR MAY NOT OCCUR AT ALL AT KINT/KGSO...BEFORE A COLD
FRONT AND AREA OF RAIN ARRIVE FROM THE NORTHWEST WED NIGHT...AND
PERSIST THROUGH MUCH OF THU.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...CBL/BLS
SHORT TERM...KC
LONG TERM...BADGETT
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
328 AM CST TUE MAR 3 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG
COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED
WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS.
MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN
CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS
WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING
DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM
TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH
WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH.
SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL
MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR
NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR
TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR
SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION
INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN
FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH
CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN
ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K
SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS
MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING.
SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH.
SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS
THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW.
BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING
WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW
MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED
NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO
SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH
BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD
CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER
MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL
REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST
CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR.
WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD.
N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING
BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT
HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD
TO MINIMAL TEMPERATURE RECOVERY.
TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT
TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES
WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD
POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP
TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND
CHILL HEADLINES.
WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER
MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM
ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY
PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY.
MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD
TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL
COLD START.
GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH
PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES
WILL BE MUCH CLOSER TO AVERAGE.
FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR
THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY
MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO
COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK
WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO
REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS
DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN
SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS
SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW
CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN
STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE
THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST
DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD
BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY
MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER
CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE
ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1138 PM CST MON MAR 2 2015
FOG LOOP/SURFACE OBS INDICATED MID LEVEL CLOUDS AROUND 7 THOUSAND FT
WAS EAST OF A LINE FROM ROX TO WYNDMERE ND. HIGH LEVEL CLOUDS WERE
LOCATED OVER NORTHEAST ND. POST FRONTAL MVFR CIGS WERE OVER WESTERN
ND. LOW CLOUDS WERE BEING MASKED BY A HIGHER LEVEL CLOUD DECK. CIGS
EXPECTED TO LOWER AS COLD FRONT MOVES INTO THE AREA OVER THE NEXT
FEW HOURS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024-
026-028-038.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ039-
049-052-053.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003-
024-027>032-040.
&&
$$
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
425 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS
TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY
NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING
OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF
PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR
FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND
HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO
EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV
ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED
END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT
ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER
THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR
NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN
THE WAY OF SLEET INITIALLY VS FZRA.
ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD
BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT
ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE
WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND
CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS.
THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW
LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE
COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT
CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE
NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL
BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND
INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE
FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL
SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE
MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z.
STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER
SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON
THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD.
FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH
TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE
50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA.
DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME
OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR
FLOODING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR
WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE
TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE
MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING
OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY
CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD
INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT
AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV
MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE
SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A
WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF
WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS
AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL
CAUSING FLOODING CONCERNS.
SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR
MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE
REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS
FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF
THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES
THROUGHOUT.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH
VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL
IFR CEILINGS AND VSBY IN RAIN AND FOG. THERE MAY BE A PERIOD OF
FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL
RAIN...ESPECIALLY AT HTS/BKW/PKB...BUT DURATION OF THIS PCPN WILL
BE SHORT.
THERE MAY BE A BREAK IN THE RAIN THIS AFTERNOON NIGHT...MAINLY SE
PORTION...LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH
AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS
CRW/EKN/CKB. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED
THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND
NIGHT.
THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY
09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG
THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR.
SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT
GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE
TOPS THIS MORNING...INCLUDING KBKW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL
VARY WITH ONSET OF THE RAIN TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 03/03/15
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H M M M H H
HTS CONSISTENCY H H H H H H H M H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H M M H H
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS
THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ007>009-017.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR WVZ005>011-013>020-026-029.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
EVENING FOR WVZ027-028-030>032-035>040-046-047.
FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR WVZ046-047.
OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ083>087.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ066-067-075-076.
KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
KYZ101>103-105.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...JS/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...JS
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
310 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT.
FRONT STALLS TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT
WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP BREAKING
OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH EXTENT OF
PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A CONCERN FOR
FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE VALLEYS AND
HOLLOWS. AFTER COORDINATING WITH SURROUNDING OFFICES...ELECTED TO
EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH AND PORTIONS OF W WV
ALONG OH RIVER. LOOKING AT ONLY A FEW HUNDREDTHS AT BEST. ADJUSTED
END TIMES TO REFLECT EXPECTED WARMING OF TEMPS. LEFT NE KY OUT
ATTM AS CONFIDENCE NOT AS HIGH THAT PRECIP WILL BREAK OUT OVER
THAT AREA BEFORE TEMPS CAN RECOVER. WILL HANDLE WITH AN SPS FOR
NOW AND MONITOR TRENDS. ACROSS THE N MOUNTAINS...THERE MAY MORE IN
THE WAY OF SLEET INITIALLY VS FZRA.
ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD
BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT
ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE
WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND
CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS.
THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW
LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE
COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT
CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE
NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL
BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND
INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE
FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL
SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE
MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z.
STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER
SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON
THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD.
FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH
TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE
50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA.
DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME
OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR
FLOODING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A SIGNIFICANT SYSTEM WILL IMPACT THE AREA WEDNESDAY AND THURSDAY. A FRONTAL
BOUNDARY STALLS OVER THE FORECAST AREA ON WEDNESDAY AND WILL BRING COPIOUS
AMOUNTS OF PRECIPITATION...ON THE ORDER OF 2 TO 3 INCHES IN MOST PLACES. THIS
FORECAST IS STILL LIKELY UNDERESTIMATING THE TOTAL ACCUMULATION SPIT OUT BY THE
MODELS OF 3 TO 4 INCHES. THE LARGE AMOUNTS OF RAIN...WARM TEMPERATURES...HIGH
DEW POINTS AND STRONG 850 MB WINDS WILL PROVIDE IDEAL CONDITIONS FOR MELTING THE
CURRENT SNOWPACK ADDING ADDITIONAL MOISTURE AVAILABLE FOR RUNOFF HENCE WE RAISED
A FLOOD WATCH FOR OUR ENTIRE FORECAST AREA.
TO ADD FUEL TO THE FIRE...A SHARP COLD AIR MASS WILL INFILTRATE THE REGION ON
THURSDAY TURNING THE RAIN TO SNOW. DEPENDING ON HOW FAST THIS COLD AIR
PROPAGATES TO THE SOUTH WILL DICTATE HOW MUCH SNOW WE GET. RIGHT NOW...THE
FORECAST IS FOR ABOUT 5-7 INCHES OVER MUCH OF OUR AREA...AND THIS MAY BE A
CONSERVATIVE AMOUNT AS WELL. WHEN THE PRECIPITATION FINALLY DOES SHUT OFF...SOME
OF OUR MODELS ARE CALLING FOR SURFACE TEMPERATURES OF -20 F YET AGAIN. WE ARE IN
FOR A WILD RIDE OF WEATHER FOR THE NEXT SEVERAL DAYS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE
REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS
FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF
THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES
THROUGHOUT.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH
VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL
IFR CEILINGS AND VSBY IN RAIN AND FOG. THERE MAY BE A PERIOD OF
FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL
RAIN...ESPECIALLY AT HTS/BKW/PKB...BUT DURATION OF THIS PCPN WILL
BE SHORT.
THERE MAY BE A BREAK IN THE RAIN THIS AFTERNOON NIGHT...MAINLY SE
PORTION...LOOK FOR GENERAL MVFR CONDITIONS TO PREVAIL ACROSS SE OH
AND POSSIBLY JUST VFR CONDITIONS IN THE WARM SECTOR ACROSS
CRW/EKN/CKB. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED
THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND
NIGHT.
THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY
09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG
THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR.
SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT
GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE
TOPS THIS MORNING...INCLUDING KBKW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL
VARY WITH ONSET OF THE RAIN TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 03/03/15
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H M M M H H
HTS CONSISTENCY H H H H H H H M H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H M M H H
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN OR SNOW
WEDNESDAY/WEDNESDAY NIGHT. IFR IN SNOW SHOWERS THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR
WVZ007>009-017.
FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR WVZ046-047.
OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR
OHZ083>087.
FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR OHZ066-067-075-076.
KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...JS/RPY/30
NEAR TERM...30
SHORT TERM...JW
LONG TERM...JS
AVIATION...30
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
100 AM EST TUE MAR 3 2015
.SYNOPSIS...
MOISTURE BEING LIFTED UP AND OVER RETREATING COLD AIR WILL BRING
AREAS OF FREEZING RAIN...POSSIBLY MIXED WITH SLEET...ACROSS MOST
OF THE AREA TUESDAY MORNING BEFORE CHANGING TO RAIN BY TUESDAY
AFTERNOON AS TEMPERATURES WARM. LATER TUESDAY AFTERNOON...MODERATE
RAIN WILL DEVELOP AND SPREAD ACROSS MUCH OF THE AREA...BUT
ESPECIALLY NORTHERN KENTUCKY AND SOUTHERN OHIO WHERE LOCALLY HEAVY
RAIN WILL BE POSSIBLE. THE COMBINATION OF RAIN AND MELTING SNOW
MAY CAUSE FLOODING. AS COLDER AIR MOVES INTO THE AREA WEDNESDAY
AFTERNOON...RAIN WILL CHANGE TO SNOW AND A PERIOD OF HEAVY SNOW IS
POSSIBLE FOR NORTHERN KENTUCKY AND SOUTHERN OHIO. THE ENTIRE
SYSTEM SHIFTS EAST OF THE AREA BY THURSDAY AFTERNOON WITH DRYING
CONDITIONS FOR THE END OF THE WEEK AND INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ONLY SOME TWEAKS TO THE FORECAST FOR TONIGHT. THE BIGGEST CHANGE IS
THAT TEMPERATURES OVER PORTIONS OF THE NORTHERN COUNTIES HAVE
FALLEN RAPIDLY UNDER THE MOSTLY CLEAR SKIES. SO ADJUSTED THEIR
LOWS DOWN...BUT THE TEMPERATURES SHOULD BEGIN TO RISE ACROSS THE
ENTIRE FA AFTER MIDNIGHT.
THE SECOND AND MORE MINOR CHANGE HAS TO DO WITH POPS. LATEST NAM
IS SLOWER IN BRINGING IN PCPN TUESDAY MORNING. THE RAP AND THE
HRRR LIFT A LIGHT BAND ACROSS PORTIONS OF THE FA BETWEEN 12Z-15Z
THEN PRETTY MUCH LEAVE THE REST OF THE FA DRY THRU 15Z. BACKED OFF
ON THE BEGINNING OF THE POPS BY AN HOUR OR TWO...BUT DIDNT GO AS
DRASTIC AS THE RAP/HRRR WITH THIS UPDATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
NOT TOO MANY TIMES DO WE ISSUE BACK TO BACK TO BACK ADVISORY/WATCH
PRODUCTS BUT THE PATTERN NECESSITATES IT TO RAISE AWARENESS FOR
MULTIPLE THREATS BEGINNING TUES A.M. AND CONTINUING INTO EARLY THURSDAY.
FIRST OFF...THE TUESDAY MORNING FREEZING RAIN/SLEET POTENTIAL.
THIS IS NOT AS CLEAR CUT AS ORIGINALLY THOUGHT. VERY CLEAR PER
02.12Z GUIDANCE THAT VERY STRONG MOISTURE FLUX/TRANSPORT WILL GET
GOING AFTER MIDNIGHT TONIGHT TO OUR SOUTHWEST...WITH SREF 850MB
TRANSPORT MAGNITUDES OF 5+ SIGMA ABOVE CLIMO AS LOW LEVEL JET
RAMPS UP DOWNSTREAM OF APPROACHING NRN STREAM TROUGH SLIPPING THRU
THE UPPER MS VALLEY. HOWEVER...AMBIENT AIRMASS /ESP BELOW 500 MB/
IS EXTREMELY DRY PER 02.12Z KILN SOUNDING AND FORECAST SOUNDINGS
THROUGH MON NIGHT. MODEL QPFS HAVE BEEN TRENDING LIGHTER/DRIER IN
THE TUESDAY MORNING TIME FRAME WHICH IS WORRISOME...BUT HAVE ALSO
SEEN TIME AND TIME AGAIN WHERE STRONG WAA/MOISTURE
TRANSPORT/ISENTROPIC LIFT SIGNALS USE MOISTURE EFFICIENTLY TO
WRING OUT LIGHT QPF OVER RETREATING ARCTIC DOMES. THUS...AM
RUNNING WITH HIGHER PRECIP CHANCES THAN MDLS ON TUES MORNING IN
THIS SCENARIO GIVEN THE VERY STRONG TRANSPORT SIGNAL AND
RETREATING ARCTIC DOME. NOT ONLY IS THERE THAT ASPECT...BUT
BOUNDARY LAYER WARMING WILL BE RACING NORTH ON DEVELOPING SSELY
FLOW. CURRENT FORECAST IS BEST CURRENT ESTIMATION OF OVERLAP
BETWEEN ADVANCING AREAS OF LIGHT RAIN...INCREASING BOUNDARY LAYER
WARMING...AND TIMING OF THE TWO...WHICH SPELLS A TWO TO FIVE HOUR
PERIOD /LEAST IN THE SOUTH AND MORE IN THE NORTH/ OF LIGHT
FREEZING RAIN POTENTIAL. GIVEN VIRTUALLY NO IMPACT OR CHANCE TO
MIX WITH SLEET ACROSS SERN IND/SWRN OH/CNTL OH...HAVE OPTED FOR
FREEZING RAIN ADVISORY HERE FOR LIGHT ICE AMOUNTS THAT MAY CAUSE
TRAVEL ISSUES. FURTHER NORTH...DEPTH OF COLD AIR AND PERHAPS A
LITTLE LONGER DURATION MAY ALLOW FOR MORE FZRA/SLEET COMBO SO
WINTER WX ADVISORY THERE. TOO MUCH RISK TO LET THIS SITUATION GO
WITHOUT AN ADVISORY AS MAGNITUDE OF WARMING/MOISTENING ALOFT MAY
ALLOW FOR A MORE RAPID DEVELOPMENT AND BETTER COVERAGE THAN MODELS
ARE SHOWING. THE DIFFERENCE BETWEEN 02.12Z NAM/ECMWF /MEAGER ON
QPF AND COVERAGE/ TO 02.12Z SREF /HIGH PROBABILITIES OF NOT ONLY
MEASURABLE FZRA BUT SOME HINTS OF UP TO 0.10"/ SPURRED THE
DECISION TO MOVE TO ADVISORY ON THIS ISSUANCE.
NEXT UP...MODERATE TO HEAVY RAIN AND POTENTIAL FLOODING. THIS
SIGNAL HAS BEEN VERY LONG ADVERTISED PER ANALOGS AND
ANOMALIES...AND NOW IT/S TIME TO SWITCH HIGHER RES DETERMINISTIC
GUIDANCE FOR DETAILS. THE PATTERN SUPPORTS A CONTINUED LONG FEED
OF MOISTURE TRANSPORT ALONG AND AHEAD OF A SLOWLY MOVING FRONTAL
ZONE TUESDAY AFTERNOON INTO WEDNESDAY MORNING. BIG PUSH OF VERY
ANOMALOUS/DEEP MOISTURE...WITH PWAT RUNNING 300% NORMAL AND 3
SIGMA ABOVE CLIMO ON TUESDAY NIGHT. 70+KT LOW LEVEL JET AROUND
BACKSIDE OF SERN CONUS RIDGING SHOULD FOCUS/FUNNEL MOISTURE INTO
THE OHIO VALLEY AND IT SEEMS POTENTIAL FOR EXCESSIVE RAIN IS
SHIFTING A TAD SOUTH W/TIME OVER THE LAST 24 HOURS. CURRENTLY
EXPECT THE HEAVIEST RAINFALL FOOTPRINT /VIA LONG DURATION TRAIN OF
MODERATE/SOMETIMES HEAVY RAIN/ TO BE ALONG AND SOUTH/EAST OF I-71
WHICH IS WHERE FLOOD WATCH HAS BEEN PLACED. PLENTY OF SNOW/FROZEN
SOILS TO CONTEND WITH SO STRAIGHTFORWARD TO GET FLOOD WATCH OUT
TODAY. AMTS FROM 1-2" - AND WHILE CONVECTION ISN/T GOING TO PLAY A
HUGE ROLE - CONVECTIVE ELEMENTS VIA MODEST DESTABILIZATION ABOVE
THE STABLE BOUNDARY LAYER WILL CERTAINLY CAUSE
CONCERN...ESPECIALLY SOUTH/SOUTHEAST CWA IN NORTHERN KY/SCNTL OH.
COULD SEE BRUSH CREEK BASIN...LOWER SCIOTO...AND KENTUCKY/LICKING
RIVERS IN KY REALLY RESPOND TO THIS...AS 0.5" TO 1.00" SNOW WATER
EQUIVALENT TIED UP IN THE SNOW PACK IS RELEASED RATHER QUICKLY
WITH TEMPS APPROACHING 50F IN THE SOUTH. AM A LITTLE MORE THAN
CONCERNED FOR NRN KY/FAR SCNTL OHIO SO HOPING FOR A SLOW RELEASE
FROM THE SNOW PACK AND RAIN AMOUNTS ON THE LIGHTER END OF THE SPECTRUM.
FINALLY...POTENTIAL WINTER STORM. LOW CONFIDENCE HERE BUT A SIGNAL
I COULD NOT IGNORE. 02.12Z MODELS CONTINUE TO STABILIZE SOMEWHAT
ON COLD AIR OOZING INTO THE FRONTOGENETICALLY FORCED PCPN REGION
THAT WILL BE ONGOING ACROSS NRN KY/SRN OH. 02.12Z GFS AND ITS
PRIOR RUNS SEEMED WAY TOO COLD IN THE BOUNDARY LAYER AND THROWN
OUT. MUCH MORE CONSISTENCY FROM NAM/ECMWF AND THAT IS WHERE
FORECAST IS BASED. A LONG DURATION RIGHT ENTRANCE REGION OF THE
JET/FGEN FORCED BAND OF PRECIPITATION WILL CONTINUE WED AFTN/NIGHT
INTO THURSDAY MORNING AS THE COLD AIR OVERTAKES IT. THERE/S A
SCENARIO /ONE OF SEVERAL/ WHERE 12-18 HOURS OF MODERATE SNOW
OCCURS FROM NRN KY INTO SRN OHIO...AND SOME SOLUTIONS ARE EXTREME
IN SNOWFALL AMOUNTS. ANECDOTALLY...HAVE TO ACKNOWLEDGE THAT THE
PATTERN AND FORCING SUPPORTS A POTENTIAL HIGHER-END SNOW
ACCUMULATION. BUT USING CLIMO AND WHAT WILL LIKELY BE A SLOWER
TRANSITION TO SNOW...AND MARCH INSOLATION /EVEN THRU CLOUDS/ THAT
WILL KEEP ANYTHING BUT HEAVY SNOW RATES FROM ACCUMULATING TOO
MUCH. IT/S WEDNESDAY NIGHT THAT HAS MY ATTENTION AS A POSSIBILITY
OF REALLY ACCUMULATING SNOW UNDER CLOAK OF DARKNESS WITH CONTINUED
BANDING/FGEN FORCING IN THE RIGHT ENTRANCE REGION OF THE JET THAT
MOVES ONLY VERY SLOWLY SOUTHEAST FROM WED AFTN INTO THURS MORNING.
WILL HAVE TO WATCH AREAS BACK FROM CVG TO ILN TO SOUTH OF CMH FOR
POSSIBLE EXPANSION OF WATCH IF SOME OF THE MORE DIRE /QUICKER
CHANGEOVER/ SITUATIONS GET MORE SUPPORT IN THE ENSEMBLES. HAVE
TAKEN A VERY CONSERVATIVE APPROACH TO SNOWFALL FORECAST IN OUR
SOUTHERN AREAS AND CURRENTLY INDICATING 4-7" WHICH NECESSITATES A
WATCH CENTERED ON WED NIGHT...AGAIN...WITH NEED TO WATCH THAT THIS
MAY GET EXPANDED IN TIME.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ANOTHER ROUND OF COLD ARCTIC AIR IS ON TAP FOR THURSDAY AS ARCTIC
HIGH PRESSURE BUILDS EAST INTO THE REGION. TEMPERATURES WILL
STRUGGLE TO WARM INTO THE MID TEENS NORTH TO THE MID 20S SOUTH.
THESE TEMPERATURES ARE SOME 25 TO 30 DEGREES BELOW NORMAL FOR EARLY
MARCH. NEEDLESS TO SAY...SOME RECORD LOW MAX TEMPERATURES MAY BE IN
JEOPARDY. THEY ARE 24...22...AND 20 AT CVG...DAY...AND CMH
RESPECTIVELY. WE ARE CURRENTLY FORECASTING 21...17...AND 19 AT
CVG...DAY...AND CMH RESPECTIVELY. WHO HAS FRESH SNOW COVER...AND THE
AMOUNT OF CLOUDS...WILL ULTIMATELY PLAY A ROLE ON HOW WARM IT GETS
DESPITE AN INCREASING SUN ANGLE FOR EARLY MARCH.
FOR THURSDAY NIGHT...THE ARCTIC HIGH WILL MOVE EAST ACROSS THE OHIO
VALLEY. AT THIS TIME...THE BEST CHANCE FOR WINDS TO BECOME LIGHT OR
CALM WILL BE ALONG AND SOUTH OF THE OHIO RIVER. WITH CLEAR SKIES
EXPECTED...TEMPERATURES WILL LIKELY DROP BELOW ZERO IN MOST SPOTS.
AGAIN...KNOWING HOW COLD IT WILL GET ATTM IS DIFFICULT WHICH WILL
DEPEND ON SNOW COVER AND HOW DEEP THAT SNOW COVER IS FOR MAXIMUM
RADIATIONAL COOLING EFFECTS. HAVE GONE CONSERVATIVE ATTM...BUT
GETTING LOWER THAN WHAT IS FORECAST IS CERTAINLY POSSIBLE. WILL
FORECAST LOWS GENERALLY IN THE ZERO TO 5 BELOW RANGE. RECORD LOWS OF
2...0 AND 2 AT CVG...DAY AND CMH WILL ALSO BE IN JEOPARDY.
FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES EAST
WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES. MOSTLY
SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING SOUTHERLY
RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL GET ON
FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT LINGERING
SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY. WILL RANGE
HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH. LOWS FRIDAY
NIGHT WILL GENERALLY BE IN THE TEENS.
FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR
THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH
OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED
SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS.
TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL
STILL AVERAGE BELOW NORMAL FOR EARLY MARCH.
HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY
ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE
FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S
READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE
BIT BELOW NORMAL FOR EARLY MARCH.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS ARE EXPECTED FOR THE EARLY PART OF THE TAF PERIOD.
HOWEVER A BAND LIGHT PRECIPITATION WILL SPREAD ACROSS THE
TERMINALS AFTER 09Z. EXPECT THIS TO BE FREEZING RAIN WITH LIGHT
ICE ACCUMULATIONS. AT THIS POINT EXPECT THE BAND TO MOVE THROUGH
ANY ONE SPOT WITHIN THREE HOURS. APPEARS THAT THERE WILL BE A LULL
IN PRECIPITATION WITH TEMPERATURES WARMING ABOVE FREEZING BEFORE
ANY THING ELSE DEVELOPS. HOWEVER CEILINGS WILL BE DROPPING TO MVFR
AS THE INITIAL PRECIPITATION PULLS OUT. WINDS WILL BE VEERING TO
THE SOUTH AND SLOWLY STRENGTHENING. SHOWERS WILL DEVELOP
AROUND/AFTER 18Z. CONDITIONS SHOULD REMAIN MVFR BUT THERE COULD BE
SOME BRIEF DROPS TO IFR PARTICULARLY IN ANY HEAVIER SHOWERS.
EVOLUTION OF PRECIPITATION BECOMES MORE UNCERTAIN FURTHER OUT IN
TIME. PRECIPITATION MAY BECOME MORE WIDESPREAD AS A COLD FRONT
SAGS INTO THE AREA...ESPECIALLY FOR THE CINCINNATI SITES AS WELL
AS KILN. WHERE THIS OCCURS IFR CONDITIONS WILL BECOME MORE
PREVALENT.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH
WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL
POTENTIALLY LINGER THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR OHZ053>055-060>065-070>072-074-077.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST
THIS AFTERNOON FOR OHZ026-034-035-042>046-051-052-056.
FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR
OHZ063>065-071>074-077>082-088.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR OHZ081-088.
KY...FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR
KYZ089>100.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
MORNING FOR KYZ089-090-094>100.
IN...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR INZ058-059-066-073-074.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST
THIS AFTERNOON FOR INZ050.
FLOOD WATCH FROM THIS EVENING THROUGH WEDNESDAY AFTERNOON FOR
INZ075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...SITES
SHORT TERM...BINAU
LONG TERM...HICKMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS PENDLETON OR
523 PM PST MON MAR 2 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...ISSUED AN EARLY FORECAST UPDATE THIS EVENING TO PLACE
THE ENTIRE FORECAST AREA UNDER AT LEAST A SLIGHT CHANCE OF SHOWERS
THROUGH THE EVENING. RADAR AND SATELLITE ARE SHOWING ISOLATED TO
SCATTERED SHOWERS ACROSS THE FORECAST AREA UNDER THIS NORTHERLY
FLOW. NORTHEAST OREGON CONTINUES TO HAVE THE BEST CHANCE OF SHOWERS
ESPECIALLY OVER THE HIGHER TERRAIN AND WALLOWA COUNTY. THESE AREAS
COULD SEE 1 TO 3 INCHES OF SNOW OVERNIGHT. REST OF THE FORECAST AREA
WILL SEE LITTLE TO NO ACCUMULATIONS. SHOWERS WILL BE ON THE DECREASE
AFTER MIDNIGHT.
.AVIATION...VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS.
THERE WILL BE SOME SCT-BKN CLOUDS 060-080 MAINLY IMPACTING KRDM AND
KBDN OTHERWISE CLEARING SKIES FOR OTHER SITES. THERE WILL BE SOME
NORTH WINDS 10-20 KNOTS AT KPSC OVERNIGHT DECREASING LATE OTHERWISE
EXPECTING MAINLY LESS THAN 10 KNOTS.
&&
.PREV DISC... /ISSUED 230 PM PST MON MAR 2 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR
COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST
OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK
RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW
THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A
TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY
SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED
OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA
MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6
INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA
VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY
RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO
AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND
EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE
SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE
TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL
BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND
CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR
TUESDAY NIGHT.
A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A
WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS.
AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON
THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER
LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE
WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH
PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS.
AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO
THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND.
AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A
DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO
THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT.
DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR
CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE
FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND
KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 23 43 19 50 / 20 0 0 0
ALW 27 44 24 53 / 20 0 0 0
PSC 23 48 18 52 / 20 0 0 0
YKM 25 46 21 51 / 20 0 0 0
HRI 22 47 18 53 / 20 0 0 0
ELN 23 48 19 51 / 20 0 0 0
RDM 16 45 12 52 / 20 0 0 0
LGD 22 40 13 47 / 20 10 0 0
GCD 20 41 15 50 / 20 10 0 0
DLS 28 52 24 57 / 20 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION
NWS PENDLETON OR
924 PM PST MON MAR 2 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...ISSUED AN EARLY FORECAST UPDATE THIS EVENING TO PLACE
THE ENTIRE FORECAST AREA UNDER AT LEAST A SLIGHT CHANCE OF SHOWERS
THROUGH THE EVENING. RADAR AND SATELLITE ARE SHOWING ISOLATED TO
SCATTERED SHOWERS ACROSS THE FORECAST AREA UNDER THIS NORTHERLY
FLOW. NORTHEAST OREGON CONTINUES TO HAVE THE BEST CHANCE OF SHOWERS
ESPECIALLY OVER THE HIGHER TERRAIN AND WALLOWA COUNTY. THESE AREAS
COULD SEE 1 TO 3 INCHES OF SNOW OVERNIGHT. REST OF THE FORECAST AREA
WILL SEE LITTLE TO NO ACCUMULATIONS. SHOWERS WILL BE ON THE DECREASE
AFTER MIDNIGHT.
.AVIATION...VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS.
THERE WILL BE SOME SCT-BKN CLOUDS 060-080 MAINLY IMPACTING KRDM AND
KBDN OTHERWISE CLEARING SKIES FOR OTHER SITES. THERE WILL BE SOME
NORTH WINDS 10-20 KNOTS AT KPSC OVERNIGHT DECREASING LATE OTHERWISE
EXPECTING MAINLY LESS THAN 10 KNOTS.
&&
.PREV DISC... /ISSUED 230 PM PST MON MAR 2 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY. THE TAIL END OF A BACKDOOR
COLD FRONT IS MAKING ITS WAY ACROSS EASTERN WASHINGTON AND NORTHEAST
OREGON. DOPPLER RADAR AT SPOKANE IS SHOWING A WIDE SWATH OF WEAK
RETURNS (LESS THAN 20 DBZ). LATEST HRRR KEEP REFLECTIVITIES THIS LOW
THROUGH EARLY TUESDAY MORNING WITH 12-HOUR QPF AMOUNTS LESS THAN A
TENTH OVER MOST OF THE AREA. THIS INCREASES CONFIDENCE THAT ANY
SNOWFALL TONIGHT WILL BE LIGHT AND MAINLY ISOLATED TO SCATTERED
OROGRAPHIC SHOWERS. THE ONE EXCEPTION WILL BE OVER THE WALLOWA
MOUNTAINS WHERE A NORTHERLY FLOW ALOFT AND MOISTURE WILL BRING 3-6
INCHES OF SNOW IN THE HIGHER TERRAIN. THE WALLOWA VALLEY...IMNAHA
VALLEY...AND THE NORTHERN PLATEAU OF WALLOWA COUNTY WILL LIKELY
RECEIVE 1-3 INCHES OVERNIGHT DUE TO THE 20:1 SNOW-TO-LIQUID RATIO
AND LOW LEVEL UPSLOPE. PRECIPITATION WILL TAPER OFF TONIGHT AND
EARLY TUESDAY MORNING. A DRY NORTHERLY FLOW ALOFT FOLLOWING THE
SYSTEM WILL CAUSE OVERNIGHT TEMPERATURES TONIGHT TO FALL INTO THE
TEENS AND 20S...AND SINGLE DIGITS AND TEENS TUESDAY NIGHT. IT WILL
BE BREEZY TONIGHT IN THE LOWER COLUMBIA BASIN RESULTING IN WIND
CHILLS IN THE TEENS. A FEW LOCATIONS MAY BEAT THEIR RECORD LOWS FOR
TUESDAY NIGHT.
A DRY FORECAST IS IN STORE TUESDAY AFTERNOON THROUGH THURSDAY. A
WARMING TREND BEGINS WEDNESDAY AS HIGH PRESSURE ALOFT BUILDS.
AFTERNOON TEMPERATURES WILL CLIMB INTO THE 50S ACROSS THE REGION ON
THURSDAY--ABOUT 5 DEGREES ABOVE SEASONAL AVERAGE. WISTER
LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TOWARD THE END OF THE
WEEK A DISTURBANCE WILL PASS TO THE NORTH OF THE AREA AS STRONG HIGH
PRESSURE DOMINATES OUR WEATHER INTO THE WEEKEND WITH DRY CONDITIONS.
AFTERNOON TEMPERATURES ARE FORECAST TO CLIMB ABOVE NORMAL AND INTO
THE 60S ACROSS SOME LOCATIONS BY THE WEEKEND.
AVIATION...LCL MVFR CEILINGS WILL PERSIST INTO THIS EVENING AS A
DISTURBANCE MOVES THROUGH THE REGION. WNW SFC WINDS WILL SHIFT TO
THE NORTH THAT WILL USHER SOME COLDER AIR INTO THE REGION TONIGHT.
DECREASING CLOUDS WILL ACCOMPANY THE COLDER AIR AND A RETURN TO VFR
CONDITIONS ARE EXPECTED AFTER 02Z EXCEPT AFTER 06Z ALONG THE
FOOTHILLS OF THE BLUE MOUNTAINS THAT INCLUDES TAF SITES KPDT AND
KALW. THE VFR CONDITIONS WILL CONTINUE INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 23 43 19 50 / 20 0 0 0
ALW 27 44 24 53 / 20 0 0 0
PSC 23 48 18 52 / 20 0 0 0
YKM 25 46 21 51 / 20 0 0 0
HRI 22 47 18 53 / 20 0 0 0
ELN 23 48 19 51 / 20 0 0 0
RDM 16 45 12 52 / 20 0 0 0
LGD 22 40 13 47 / 20 10 0 0
GCD 20 41 15 50 / 20 10 0 0
DLS 28 52 24 57 / 20 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1112 PM CST MON MAR 2 2015
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
POOR AVIATION CONDITIONS ARE EXPECTED AGAIN OVERNIGHT INTO TUESDAY
MORNING. FCST SOUNDINGS AND HRRR VSBY PROGS SHOW STRONG POTENTIAL
FOR DENSE FOG OVERNIGHT WITH VISIBILITIES DROPPING TO 1/4 MILE
OVER ALL TAF SITES. CIGS WILL ALSO LOWER TO BELOW 200 FEET AT ALL
TAF SITES AS WELL. SLOW IMPROVEMENT IS EXPECTED TUESDAY MORNING
AFTER 16Z WITH MVFR CONDS EXPECTED TO OCCUR BRIEFLY ON TUESDAY
AFTN. WINDS WILL REMAIN LIGHT OVERNIGHT AND GRADUALLY VEER TO THE
E-SE BY MORNING. S-SE WINDS EXPECTED ON TUESDAY AFTN AND SPEEDS
WILL PROBABLY GET A BIT GUSTY OVER THE WESTERN TAF SITES DURING
THE AFTN. 43
&&
.PREV DISCUSSION... /ISSUED 731 PM CST MON MAR 2 2015/
UPDATE...
ISSUED A DENSE FOG ADVISORY FOR THE REGION. SEA FOG AT THE COAST
ALREADY MOVING ONSHORE AND VISBY THERE FALLING. OVER THE NORTHERN
COUNTIES 1/2 TO 2 MILES IS COMMON WHILE IN BETWEEN 5-9 MILES IS
MORE COMMON. AS WE COOL DOWN AND WINDS BECOME MORE EAST AND SOUTHEAST
AM EXPECTING VISBY TO DROP AND DENSE TO BECOME WIDESPREAD.
WARM FRONT MOVES INLAND TOMORROW MORNING AND SOME IMPROVEMENT IN
VISBY SHOULD OCCUR...COASTAL AREAS WILL BE TRICKY DEPENDING ON
TRAJECTORIES AND DURATION OVER THE COOLER SHELF WATERS. FOR NOW
THE ADVISORY RUN THROUGH 10 AM.
ALSO MADE SOME CHANGES TO THE GRIDS IN THE SHORT TERM TO LOWER
TEMPERATURES UP NORTH AND INCREASE SKY COVER. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 72 61 63 30 / 20 30 30 70 70
HOUSTON (IAH) 55 76 64 70 34 / 20 20 20 50 70
GALVESTON (GLS) 56 72 61 66 37 / 20 20 20 30 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1252 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST INTO THE MID ATLANTIC REGION TONIGHT.
MEANWHILE...A WARM FRONT WILL PUSH NORTH THROUGH THE AREA LATE
TONIGHT INTO TUESDAY...THEN FOLLOWED BY A COLD FRONT TUESDAY NIGHT
INTO WEDNESDAY. COLD HIGH PRESSURE WILL RETURN FOR THURSDAY INTO THE
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1000 PM EST MONDAY...
1033 MB SURFACE HIGH WAS CENTERED OVER OHIO. THIS HIGH WILL
CONTINUE TO DRIFT EAST OVERNIGHT PROVIDING MAINLY DRY CONDITIONS.
A STATIONARY FRONT WAS OVER THE DEEP SOUTH...EXTENDING FROM
CENTRAL SOUTH CAROLINA SOUTHWEST TO JACKSON MS. THIS STATIONARY
FROM IS EXPECTED TO BEGIN MOVING NORTH OVERNIGHT AS A WARM
FRONT RESULTING IN THE RETURN OF LOW LEVEL MOISTURE TO THE AREA BY
DAYBREAK TUESDAY. QUESTION TO BE ANSWERED IS WHETHER THERE WILL BE
ENOUGH MOISTURE FOR PRECIPITATION. THE CLOSEST THING ON RADAR AT
THE MOMENT IS OVER THE SOUTHERN APPALACHIANS BETWEEN ASHEVILLE NC
AND ATLANTA GA.
THE SURFACE HIGH WILL CERTAINLY BE IN A POSITION TO PROVIDE ENOUGH
COLD AIR FOR A WINTRY FORM OF PRECIPITATION TUESDAY MORNING. THE
QUESTION IS WHETHER THERE WILL BE ENOUGH DEPTH TO THE MOISTURE TO
PRODUCE PRECIPITATION. BOTH THE HRRR AND RNKWRF SUGGEST ONLY TRACE
AMOUNTS TO OCCUR BETWEEN NOW AND NOON TUESDAY WITH THE LARGER
SCALE MODELS PRODUCING A FEW HUNDREDTHS OF AN INCH. TRACE ICE IS
CERTAINLY ENOUGH TO BE A NUISANCE...BUT THIS IS NOT GOING TO BE A
WIDESPREAD EVENT.
THE MAIN PROBLEM WITH PRECIP PRODUCTION FOR TUESDAY IS THE LACK OF
UPPER LEVEL MOISTURE WITHIN THE M8-M12 DEG C DENDRITIC GROWTH ZONE.
FORECAST MODEL SOUNDINGS ARE DRY WITHIN THIS LAYER...ALL OF THE
SATURATION TAKING PLACE IN A LOWER LAYER BETWEEN +3 DEG C AND -3
DEG C. UNLESS THERE IS SOME SEEDER FEEDER PROCESS THAT DEVELOPS
INOF THE WARM FRONT...THE MODEL SOUNDINGS SUGGESTS THE PTYPE WILL
BE EITHER DRIZZLE OR FREEZING DRIZZLE PENDING SURFACE TEMPERATURE
AT THE TIME. THE CRITICAL WINDOW FOR THE FREEZING PRECIPITATION
WILL BE DURING THE MORNING...SO STILL SEE THE NEED FOR WINTER
WEATHER ADVISORIES TO ACCOUNT FOR THE POTENTIALLY LIGHT ICING THAT
MAY OCCUR...KEEPING IN MIND THAT EVEN A VERY LIGHT COATING OF ICE
ON AN UNTREATED SURFACE CAN POSE A TRAVEL/WALKING HAZARD.
LOW TEMPERATURES OVERNIGHT WILL RANGE FROM THE MID 20S IN THE
COLDEST VALLEYS TO THE LOWER 30S IN THE PIEDMONT. WARM AIR WILL
MOVE IN FROM THE SOUTHWEST TUESDAY CHANGING PRECIPITATION OVER TO
ALL LIQUID TUESDAY AFTERNOON. AREAS ACROSS THE NORTH AND
NORTHEAST WILL BE THE SLOWEST TO TRANSITION. HIGH TEMPERATURES
TUESDAY WILL RANGE FROM THE MID 30S IN THE NORTHEAST TO THE LOWER
50S IN THE SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 330 PM EST MONDAY...
COMPLICATED SHORT TERM FORECAST WITH MULTIPLE CONCERNS. TO BEGIN
TUESDAY NIGHT...ANY REMNANTS OF EARLIER WEDGE WILL BE LONG GONE TO
THE NORTHEAST WITH THE AREA SOLIDLY IN THE WARM SECTOR.
TEMPERATURES WILL BE WELL ABOVE FREEZING AND CONTINUING TO RISE
DURING THE OVERNIGHT HOURS ON THE HEELS OF A STRONG SOUTHWESTERLY
LLJ. CONSEQUENTLY...ANY ASSOCIATED WARM FRONTAL PRECIPITATION
WILL ALSO HAVE LIFTED WELL NORTHEAST OF THE REGION. NOW...THE
ATTENTION SHIFTS TO THE ARCTIC FRONT APPROACHING FROM THE WEST. A
BROAD UPPER RIDGE ACROSS THE CENTRAL/EASTERN GULF...590+ DM AT
THAT...WILL AMPLIFY INTO THE SOUTHEAST WHILE A DEEP UPPER TROUGH
DIGS INTO THE SOUTHERN PLAINS. A SIGNIFICANT SURGE OF ARCTIC AIR
WILL PLUNGE INITIALLY SOUTH INTO THE CENTRAL/SOUTH CENTRAL U.S. AS
THE ASSOCIATED ARCTIC FRONT SLOWS ITS PUSH INTO THE MID-
ATLANTIC/SOUTHEAST STATES THANKS TO THE AFOREMENTIONED UPPER RIDGE
AND THE APPALACHIAN MOUNTAINS. THIS HOLDS THE HEAVIEST RAINFALL
WEST OF OUR CWA THROUGH WEDNESDAY MUCH OF THE DAY
WEDNESDAY...MAINLY ACROSS THE OH/TN VALLEYS. FINALLY...WEDNESDAY
AFTERNOON/EVENING...THE FRONT WILL BEGIN A BETTER SOUTHEASTWARD
PUSH AS SHORT WAVE ENERGY KICKS OUT OF THE CENTRAL PLAINS. WOULD
EXPECT HEAVIER RAIN TO MOVE INTO THE WESTERN PARTS OF THE CWA BY
00Z WED...THEN BEGIN TO SPREAD EASTWARD OVERNIGHT.
MEANWHILE...PART OF THE UPPER TROUGH LAGS BEHIND AND SURFACE LOW
PRESSURE DEVELOPS ACROSS THE SOUTHEAST STATES IN RESPONSE. THIS
WILL FURTHER DELAY THE PUSH OF THE PRECIPITATION INTO/THROUGH THE
CWA...BUT PERHAPS NOT THE SHALLOW COLD ARCTIC AIR ONCE IT MANGES
TO CROSS THE APPALACHIANS. QUITE A VARIETY OF SOLUTIONS PRESENTED
BY THE MODELS AND WPC AS TO THE WINTER WEATHER THREAT THURSDAY
GIVEN THAT THIS IS FAR FROM A NORMAL SYNOPTIC SITUATION FOR A SNOW
EVENT IN THIS REGION. THE BIG QUESTION IS NOT WHETHER OR NOT THERE
WILL BE PRECIPITATION...BUT HOW QUICKLY WILL THE COLD AIR SPREAD
INTO THE REGION BEHIND THE FRONT...BEFORE THE HEAVIER
PRECIPITATION MOVES OUT...AND HOW QUICKLY WILL THE COLD AIR BECOME
DEEP ENOUGH TO CHANGE THE PRECIPITATION TO SNOW. AM INCLINED AT
THIS POINT TO THROW OUT RAIN TO FREEZING RAIN SCENARIOS...NOT ONLY
BECAUSE IT IS NOT CLIMATOLOGICALLY OR SYNOPTICALLY FAVORABLE IN
THIS SITUATION...BUT THINKING IS THAT COLD AIR WILL BECOME DEEP
ENOUGH QUICKLY ENOUGH TO CHANGE RAIN OVER TO SNOW...OTHER THAN A
BRIEF PERIOD OF SLEET ALONG THE LEADING EDGE OF THE CHANGEOVER.
FURTHERMORE...GROUND TEMPS WILL NOT SUPPORT FZRA AT THE CHANGEOVER
TIME AS THE SOUNDING COLUMN COOLS ISOTHERMALLY. FINALLY...THIS IS
YET AGAIN A SIGNIFICANT ARCTIC AIR MASS...SO ONCE IT ENTERS THE
REGION...COOLING WILL BE QUICK...ESPECIALLY WEST OF I-81. FOR SNOW
AMOUNTS...A PRELIMINARY ESTIMATE...FAIRLY CONSISTENT WITH WPC
WWD...IS 4-5 INCHES NORTH...2-4 INCHES CENTRAL/WESTERN AREAS...1-2
INCHES VA PIEDMONT...LITTLE TO NONE NC PIEDMONT.
SEE THE HYDROLOGY SECTION BELOW FOR FURTHER DETAILS ON THE FLOOD
THREAT ASSOCIATED WITH COMBINED RAINFALL AND SNOW MELT. DID
ADVERTISE A PERIOD OF MODERATE RAIN WEDNESDAY EVENING FROM WEST TO
EAST...BUT HAVE REDUCED THE TIME PERIOD OF SUCH COMPARED TO
PREVIOUS FORECAST PACKAGES.
TEMPERATURE WISE...A LOT OF NON-DIURNAL TEMPERATURE TRENDS THROUGH
THIS FORECAST PERIOD. TEMPERATURES CONTINUING TO RISE TUESDAY
NIGHT/WEDNESDAY MORNING AND REMAINING MILD/ABOVE FREEZING UNTIL
THE ARCTIC FRONT ARRIVES IN THE WEST WEDNESDAY NIGHT. THE PIEDMONT
WILL LIKELY REMAIN ABOVE FREEZING FROM TUESDAY AFTERNOON UNTIL
THURSDAY MORNING. LIKEWISE...A NON-DIURNAL COOLING TREND EXPECTED
THROUGHOUT THE DAY THURSDAY AS ARCTIC AIR SPREADS INTO THE REGION.
THE GFS IN PARTICULAR SHOW SFC TEMPS BELOW ZERO IN OUR WESTERN
COUNTIES BY FRIDAY MORNING. GIVEN THAT IT IS EARLY MARCH AND THE
850MB TEMPS ARE ONLY AROUND -16C...AS COMPARED TO -26C A COUPLE OF
WEEKS AGO...I FIND THIS SOMEWHAT EXTREME. NONETHELESS...IT IS A
VERY COLD AIR MASS AND WELL BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BUILD OVER THE REGION ON FRIDAY...AND BE IN
CONTROL OF OUR WEATHER PATTERN THROUGH AT LEAST SATURDAY NIGHT. THE
HIGH WILL GRADUALLY BUILD INTO THE AREA FROM THE WEST...AND MAKE ITS
WAY TO THE COAST BY SATURDAY. THIS WILL ALLOW FOR A TREND TOWARD
MILDER CONDITIONS AS THE LOW LEVEL FLOW ACROSS THE AREA BECOMES
GRADUALLY MORE SW-W...WHILE A SHORTWAVE RIDGE AND RISING 850 TEMPS
TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM EST TUESDAY...
MVFR CIGS WILL START PROGRESSES NORTHEAST ACROSS THE REGION IN
CONJUNCTION WITH A WARM FRONT HEADING TOWARD THE AREA. ALONG WITH
THE FRONT WILL COME LIGHT WINTRY PRECIPITATION IN THE FORM OF
PATCHY LIGHT FREEZING RAIN AND SLEET. BY DAYBREAK TUESDAY...MANY
AREAS WILL HAVE LOWERED TO LIFR/IFR CIGS AND MVFR VSBYS DUE TO THE
PRECIPITATION AND MIST. THE BULK OF THE WINTRY PRECIPITATION WILL
BE CONFINED TO NORTH A LINE FROM KBLF-KROA-KLYH DURING THE LATE
MORNING. BY THE AFTERNOON...SURFACE TEMPERATURES SHOULD BE MILD
ENOUGH FOR A WIDESPREAD AREA OF RAIN.
WINDS WILL REMAIN LIGHT THROUGH THE NIGHT AND GRADUALLY VEER TO
THE SOUTHEAST. ON TUESDAY...WINDS WILL INCREASE DURING THE DAY
FROM THE SOUTHWEST...AND WINDS AT 850 MB WILL INCREASE TO AROUND
45 TO 50 KTS. LOW LEVEL WIND SHEAR WILL BE POSSIBLE DURING THE
AFTERNOON...ESPECIALLY AT TERMINALS AT HIGHER ELEVATION.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
PERIOD.
EXTENDED FORECAST...
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO NEW ENGLAND TUESDAY NIGHT
INTO WEDNESDAY. THIS WILL RESULT IN SUB-VFR CONDITIONS WEDNESDAY
AND THURSDAY WITH WIDESPREAD RAIN AHEAD OF THE FRONT ON WEDNESDAY
AND WINTER PRECIPITATION BEHIND THE FRONT WEDNESDAY NIGHT AND
THURSDAY.
FRIDAY SHOULD SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO.
THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING
LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE
WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL
APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS
BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT
LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE
UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED
MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY
THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE
CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS
POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST
THIS AFTERNOON FOR VAZ018>020-022>024-034-035-045>047.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009-
010-012-015-016.
WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM
EST THIS AFTERNOON FOR VAZ011-013-014-017-032-033-043.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ001-002-
018.
WV...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST
THIS AFTERNOON FOR WVZ507-508.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ042.
WINTER WEATHER ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM
EST THIS AFTERNOON FOR WVZ043-044.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...KK/PM
SHORT TERM...RAB
LONG TERM...DS
AVIATION...AMS/DS/KK
HYDROLOGY...PC
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1037 AM EST TUE MAR 3 2015
.UPDATE...
VERY FEW CHANGES THIS MORNING...MAINLY SOME TWEAKS TO ACCOUNT FOR
CURRENT TRENDS AND DESPITE THE WIDESPREAD CLOUDS...TEMPS ARE
RISING A LITTLE MORE QUICKLY THAN ANTICIPATED SO HAVE ADJUSTED
HIGHS AND WILL UPDATE PRODUCTS SHORTLY. OTHERWISE...CONTINUED
CLOUDS AND SPOTTY RAIN/DRIZZLE.
TDP
&&
.PREV DISCUSSION... /ISSUED 623 AM EST TUE MAR 3 2015/
PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA
THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT
GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE
LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF
THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS
TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT
THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW
CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK
FRONT.
RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A
MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND
CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS
WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING
NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY
NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE
NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH
LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE
LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE
BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR
SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES
REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF
PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT
APPROACHES FROM THE NW.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS
SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS
NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD
BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION
OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD
CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE.
WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE
FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE
METRO AREA.
NLISTEMAA
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS
MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF
COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS
LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS
LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV
AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO
BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE
TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH
ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I
HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE
FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN
WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT
THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE
COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH
SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND
RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION
GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH
WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY
WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT
WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP
A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES.
LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT
TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL
UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF
THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR
POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS
NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION
CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW.
20
AVIATION...
12Z UPDATE...
OLD FRONTAL BOUNDARY SITUATED ACROSS SOUTH GA THIS MORNING. THE
BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. WEDGING HAS STARTED
TO BUILD IN ACROSS THE NE PORTION OF THE STATE AS THE EASTERLY
WINDS HAVE BECOME ESTABLISHED. REGIONAL RADAR SHOWS SOME PATCHY
LIGHT RAIN/HEAVY DRIZZLE MAKING ITS WAY ACROSS THE NORTHERN
TERMINAL SITES...IN ASSOCIATION WITH A PASSING SHORTWAVE. LOW CIGS
SHOULD CONTINUE FOR MUCH OF THE DAY...HOWEVER A BRIEF PERIOD OF
MVFR IS POSSIBLE DURING THE LATE AFTERNOON. IFR EXPECTED AGAIN
OVERNIGHT. EAST WINDS WILL ALSO BEGIN TO SHIFT TO THE S/SW
OVERNIGHT AS A COLD FRONT APPROACHES FROM THE NW.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 55 49 72 54 / 60 50 40 70
ATLANTA 60 55 70 45 / 60 40 50 70
BLAIRSVILLE 54 47 62 42 / 70 70 70 70
CARTERSVILLE 55 52 69 40 / 60 50 60 70
COLUMBUS 75 60 75 54 / 30 20 30 60
GAINESVILLE 51 47 67 47 / 60 50 50 70
MACON 67 58 77 59 / 30 20 20 50
ROME 58 53 68 37 / 60 60 70 70
PEACHTREE CITY 63 56 71 48 / 50 30 40 70
VIDALIA 69 62 79 62 / 30 20 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
623 AM EST TUE MAR 3 2015
.PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA
THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT
GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE
LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF
THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS
TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT
THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW
CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK
FRONT.
RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A
MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND
CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS
WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING
NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY
NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE
NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH
LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE
LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE
BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR
SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES
REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF
PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT
APPROACHES FROM THE NW.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS
SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS
NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD
BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION
OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD
CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE.
WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE
FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE
METRO AREA.
NLISTEMAA
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS
MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF
COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS
LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS
LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV
AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO
BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE
TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH
ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I
HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE
FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN
WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT
THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE
COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH
SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND
RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION
GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH
WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY
WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT
WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP
A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES.
LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT
TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL
UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF
THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR
POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS
NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION
CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW.
20
&&
.AVIATION...
12Z UPDATE...
OLD FRONTAL BOUNDARY SITUATED ACROSS SOUTH GA THIS MORNING. THE
BOUNDARY WILL EVENTUALLY WASH OUT OVERNIGHT. WEDGING HAS STARTED
TO BUILD IN ACROSS THE NE PORTION OF THE STATE AS THE EASTERLY
WINDS HAVE BECOME ESTABLISHED. REGIONAL RADAR SHOWS SOME PATCHY
LIGHT RAIN/HEAVY DRIZZLE MAKING ITS WAY ACROSS THE NORTHERN
TERMINAL SITES...IN ASSOCIATION WITH A PASSING SHORTWAVE. LOW CIGS
SHOULD CONTINUE FOR MUCH OF THE DAY...HOWEVER A BRIEF PERIOD OF
MVFR IS POSSIBLE DURING THE LATE AFTERNOON. IFR EXPECTED AGAIN
OVERNIGHT. EAST WINDS WILL ALSO BEGIN TO SHIFT TO THE S/SW
OVERNIGHT AS A COLD FRONT APPROACHES FROM THE NW.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 51 49 72 54 / 60 50 40 70
ATLANTA 59 55 70 45 / 60 40 50 70
BLAIRSVILLE 49 47 62 42 / 70 70 70 70
CARTERSVILLE 54 52 69 40 / 60 50 60 70
COLUMBUS 74 60 75 54 / 30 20 30 60
GAINESVILLE 49 47 67 47 / 60 50 50 70
MACON 66 58 77 59 / 30 20 20 50
ROME 57 53 68 37 / 60 60 70 70
PEACHTREE CITY 62 56 71 48 / 50 30 40 70
VIDALIA 68 62 79 62 / 30 20 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 AM CST TUE MAR 3 2015
.SHORT TERM...
300 AM CST
THROUGH WEDNESDAY...
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE
ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING.
SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS
EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID
MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM
ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO
INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN
SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM
MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS
MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST
CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND
NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH
WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID
MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING
SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA
BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR
AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS
INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME
MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO
LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT
LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES
PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH
OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z
AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE
LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE
THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH
IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE
BEFORE ENDING ALTOGETHER THIS EVENING.
HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT
WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE
TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME
INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS
EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW
CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION
WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST
CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL
NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER
DEUBELBEISS
&&
.LONG TERM...
300 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH
PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO
DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH
MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY
NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN
COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO
RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD
COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH
PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND
WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY
NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO
DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD
FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING.
FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT
DOESNT COME THROUGH DRY.
DEUBELBEISS
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB/BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SNOW...SLEET AND FREEZING RAIN THIS MORNING EVENTUALLY TURNING
TO RAIN/DRIZZLE AS TEMPS RISE ABOVE FREEZING LATE
MORNING/MIDDAY. GENERALLY IFR/LIFR CONDITIONS THIS MORNING WITH
CONDITIONS IMPROVING TO MVFR CIGS AND HIGHER VSBYS LATE AFTN AND
EVENING.
* SOUTHEAST WINDS BECOMING GUSTY AROUND 20 KT FROM THE SOUTH BY
LATE MORNING AND SOUTHWEST THIS AFTERNOON. WEST-NORTHWEST WINDS
TONIGHT REMAIN GUSTY.
RATZER
//DISCUSSION...UPDATED 12Z...
AREA OF PRECIPITATION HAS OVERSPREAD THE TERMINALS EARLY THIS
MORNING...WITH SOME MODERATE SNOW AT TIMES FROM ORD
NORTH/NORTHWEST. NORTHERN TERMINALS...RFD...DPA...ORD WILL LIKELY
CONTINUE TO BE THE FOCUS FOR HEAVIER SNOW/SLEET THIS MORNING WITH
OCCASIONALLY LOWER VIS/CIG CONDITIONS RESULTING. FARTHER SOUTH
SOME DRYING IN THE MID-LEVELS IS RESULTING IN LIGHTER PRECIP WHICH
WILL AFFECT MDW/GYY...AND MAY RESULT IN MORE OF A FZRA/FZDZ TREND
RATHER THAN SNOW FOR MUCH OF THE MORNING AT THOSE LOCATIONS.
IN ANY CASE...WARMING ALOFT WILL EVENTUALLY TURN PRECIP FROM SNOW
TO SLEET/FREEZING RAIN OR DRIZZLE OVER THE NEXT FEW HOURS...AND
EVENTUALLY TO RAIN/DRIZZLE AS SURFACE TEMPS RISE ABOVE FREEZING
LATER THIS MORNING. PRECIP IS EXPECTED TO END LATER THIS AFTERNOON
AS WINDS SHIFT WEST AND DRIER AIR FILTERS IN.
SPEAKING OF WINDS...WINDS ARE CURRENTLY SOUTHEAST AROUND 10 KT BUT
WILL INCREASE 10-15 KT WITH GUSTS AROUND 20 KT BY LATE MORNING...
BACKING TO THE SOUTH AND SOUTHWEST INTO THIS AFTERNOON AS LOW
PRESSURE MOVES ACROSS WISCONSIN. TRAILING COLD FRONT WILL SHIFT
WINDS WEST THIS EVENING...WITH GUSTS 20-25 KT LINGERING INTO
TONIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM IN TIMING OF PRECIP TYPE CHANGES AND CIG/VIS IMPACTS.
* HIGH IN WIND TRENDS...AND IN MVFR OR BETTER CONDITIONS BY THIS
EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH FRIDAY...VFR.
SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
214 AM CST
MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR
TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN
AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN
LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE
LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS
EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE
NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO
SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF
THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND
BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE
AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST
AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS
ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS
A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS
TO RELAX A BIT AND SHIFT TO THE WEST.
SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA
NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS.
RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS
A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN
ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS
WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME
GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR
TO HAVE A FAIR AMOUNT OF OPEN WATER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
507 AM CST Tue Mar 3 2015
.SHORT TERM...(Today)
ISSUED AT 244 AM CST TUE MAR 3 2015
Freezing rain and sleet developed over western Illinois around
midnight and quickly tracked east over all but extreme southeast
Illinois by 08z/2am. Already seeing the back edge of our second
band of wintry precip entering west central Illinois, so it appears
we will have a brief lull in the freezing rain and sleet. However,
the latest HRRR suggests another band of rain, freezing rain and
sleet will move northeast across our area at or just after dawn.
Rainfall rates have not been much with these quick moving bands
of freezing rain/sleet with most areas seeing less than 0.05" per
hour, but certainly enough for some light icing to occur on bridge
decks and overpasses and on lesser traveled roads.
RAP forecast soundings continue to suggest temperatures will rise
above the freezing mark over southeast Illinois by dawn...central
sections of the forecast area by 900 am...and between 10 am and Noon
roughly along and north of the Interstate 74 corridor. By late
morning into the afternoon hours the stronger lift associated with
the low level warm advection/ isentropic ascent shifts off to our
east and southeast with a gradual lowering of POPs warranted from
northwest to southeast. Best 850-700 forcing edges into southeast IL
by mid to late afternoon where our highest POPs will be located.
Guidance temperatures look reasonable for this afternoon with highs
ranging from the upper 30s far north to the upper 40s far southeast.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 244 AM CST TUE MAR 3 2015
Current system will not fully clear our area until Thursday, as the
trailing end of the cold front becomes parallel to the upper flow
over the Ohio Valley. Most of the evening models keep the threat for
precipitation from about I-70 southward, although the NAM has a
secondary surge on Wednesday afternoon all the way up to about I-72.
Leaning more toward the ECMWF/GFS blend for PoP`s tonight and
Wednesday. Lingering precip north of I-70 should end this evening,
but kept higher PoP`s all night into Wednesday. This evening, most
areas will see the precipitation switch briefly to snow before
ending, with little accumulation. While the transition to snow south
of I-70 occurs late tonight, temperatures will be supportive of all
snow through Wednesday. Greatest snow amounts expected near the Ohio
Valley, but currently think that 1 to 3 inches in southeast Illinois
is likely. Light snow will linger into Wednesday night before ending
late.
The other feature of note is what hopefully will be the last Arctic
blast of the winter. Digging upper trough currently coming into
Manitoba will spread a chunk of unseasonably cold air over much of
the Midwest Wednesday and Thursday, with 850 mb temperatures down
into the -18C range by Thursday morning. Highs both days will
struggle to get out of the teens in some areas -- normal highs are
well into the 40s by now -- and lows Thursday morning should be a
few degrees either side of zero. Current indications are that a wind
chill advisory would be needed across the northern CWA Wednesday
night and early Thursday, as the system to our south keeps the winds
up and slows the arrival of high pressure.
Heading into the weekend and early next week, 40s should become more
widespread, and the latest 8-14 day outlook introduces a foreign
concept called "above normal temperatures".
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 500 AM CST TUE MAR 3 2015
MVFR cigs expected to deteriorate to IFR/LIFR this morning as the
freezing rain/drizzle continues. We expect a change over to light
rain at SPI between 14z-16z, CMI between 15z-17z and BMI and PIA
between 17z-18z. IFR to LIFR cigs will continue this afternoon
along with some light rain at times with short term models
suggesting a slight improvement to MVFR cigs after 21z as drier
air works east into the region. However, will continue with MVFR
cigs thru at least 02z this evening. Surface winds at all sites
will become south and increase to between 12 and 17 kts by 16z
with gusts in the 20-23kt range into the afternoon hours. We will
see the direction begin to veer more into the southwest and west
as a cold front approaches the area this afternoon and then into
the northwest at 10 to 15 kts just after 00z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 10 AM CST this morning FOR
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1039 AM EST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 1038 AM EST TUE MAR 3 2015
AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND
DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT.
LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED
ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE
THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER
30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER
TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST TUE MAR 3 2015
RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST
UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH
MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA
AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE
INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS
MORNING WHERE SFC TEMPS IN THE MID 20S.
PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND
HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY
REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z.
ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS
MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED
DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY
RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING
PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3
TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING.
THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE
MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING.
POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING
RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN
EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE
SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE
FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING
WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM
SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS
FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO
LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON.
CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS
RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN
THIS MORNING.
SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY
EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z.
HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY
LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE
BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN
FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS
COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE
AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK
TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS
DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2
INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING
ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL
WITHIN GOING ADVISORY WHICH WILL CONTINUE.
MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE
EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON
WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE
WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO
OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR
SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT
CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW
END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY
PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL
CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND
DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY
SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EST TUE MAR 3 2015
STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO
KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN
HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE
LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS
SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW
SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM
WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW
TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT
SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO
LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS
SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL
GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE
FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD
AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE
ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH
TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC
AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE
COLDEST HIGH AT FT WAYNE FOR THE DATE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 639 AM EST TUE MAR 3 2015
FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL
POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND.
HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND
EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING
UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING
STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS
THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A
FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL
EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT
SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A
CHANCE TO MENTION AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>009-012>018-020-022>027-032>034.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ077>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...STEINWEDEL
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
644 AM EST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 440 AM EST MON MAR 2 2015
A WINTRY MIX OF PRECIPITATION WILL SPREAD ACROSS THE AREA THIS
MORNING. LIGHT SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO
JUST FREEZING RAIN. AS TEMPERATURES RISE ABOVE FREEZING LATE THIS
MORNING AND EARLY THIS AFTERNOON...PRECIPITATION WILL THEN BE IN
THE FORM OF JUST RAIN. LIGHT ACCUMULATIONS OF SNOW...SLEET AND ICE
ARE POSSIBLE WHICH WILL MAKE CONDITIONS SLICK THIS MORNING.
HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 30S NORTH TO
LOWER AND MIDDLE 40S SOUTH. A COLD FRONT WILL MOVE THROUGH THE
REGION TONIGHT. LOWS WILL DROP BACK INTO THE TEENS AND 20S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST TUE MAR 3 2015
RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST
UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH
MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA
AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE
INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS
MORNING WHERE SFC TEMPS IN THE MID 20S.
PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND
HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY
REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z.
ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS
MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED
DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY
RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING
PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3
TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING.
THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE
MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING.
POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING
RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN
EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE
SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE
FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING
WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM
SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS
FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO
LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON.
CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS
RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN
THIS MORNING.
SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY
EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z.
HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY
LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE
BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN
FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS
COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE
AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK
TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS
DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2
INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING
ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL
WITHIN GOING ADVISORY WHICH WILL CONTINUE.
MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE
EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON
WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE
WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO
OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR
SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT
CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW
END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY
PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL
CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND
DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY
SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EST TUE MAR 3 2015
STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO
KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN
HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE
LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS
SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW
SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM
WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW
TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT
SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO
LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS
SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL
GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE
FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD
AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE
ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH
TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC
AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE
COLDEST HIGH AT FT WAYNE FOR THE DATE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 639 AM EST TUE MAR 3 2015
FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL
POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND.
HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND
EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING
UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING
STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS
THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A
FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL
EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT
SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A
CHANCE TO MENTION AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>009-012>018-020-022>027-032>034.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ077>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ001-
002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
532 AM CST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 252 AM CST TUE MAR 3 2015
STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK
JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY
HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST
ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW
FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR
INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING
IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH
TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CST TUE MAR 3 2015
THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND
HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A
SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE
ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON
RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH
15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN
THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND
2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND
ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD
CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH
THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN
FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER
SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS
HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED.
HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED
THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS
THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE
SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH
THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY
FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND
BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY
KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER
SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT
THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE
BATTLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 252 AM CST TUE MAR 3 2015
MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR
MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO
GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND
CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS
THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST!
AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF
THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS
WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES.
GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON
THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH
PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND
CHILLS THAT WILL REACH WIND CHILL CRITERIA.
NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY.
MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF
THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL
US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND
INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS
FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE
AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF
THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE
CONFIDENCE ON A WARM UP NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 524 AM CST TUE MAR 3 2015
FREEZING RAIN AND SNOW WILL FALL AT ALL LOCATIONS THROUGH AROUND
15Z...AT WHICH TIME THE PRECIPITATION SHOULD END. AS THE FREEZING
RAIN AND SNOW END...TEMPERATURES WILL QUICKLY RISE TO THE MID TO
UPPER 30S...ENDING THE FREEZING THREAT...AND HELPING TO IMPROVE
REMAINING ICING CONDITIONS. SOUTH WINDS BRINGING IN THE MILD AIR
WILL BLOW AROUND 15 TO 20 KTS THROUGH THE MORNING...BEFORE
SWITCHING TO SOUTHWEST AT 15 KTS...THEN AS A COLD FRONT
ARRIVES...NORTHWEST AT 18 TO 26 KTS THIS EVENING. IFR TO MVFR CIGS
WILL CONTINUE THROUGH THE MORNING...BUT SHOULD IMPROVE ONCE
SOUTHWESTERLY WINDS ESTABLISH THEMSELVES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES-
KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR DES
MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL-
HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-
WHITESIDE.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR HANCOCK-
HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...GIBBS
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1027 AM EST TUE MAR 3 2015
.UPDATE...
ISSUED AT 1026 AM EST TUE MAR 3 2015
LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG
NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO
EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND
NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER
TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS
SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE
HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES
ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES
THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN
SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A
LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE
LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON
TRACK WITH THE CURRENT CONDITIONS.
UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015
QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR
TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT
WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE
FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE
ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE
ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM EST TUE MAR 3 2015
A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY
THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE
THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS
MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE
THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF
SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN
HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR
NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES
RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED
CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES
DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH
IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL
BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT
THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST
PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS
RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT
TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT
EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY
RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF
THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION
AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT
2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY.
DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY
SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN
TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT
APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST
SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE
KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT
RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE
NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID
50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY
EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR
TODAY.
THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS
MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED
COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO
THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST.
WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE
THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE
EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM
RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE
I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS
FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE
DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE
PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY
AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY
OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS
PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE
ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12
BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE
MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS
SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH
SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE
MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO
SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT
AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS
CURRENTLY PREDICTING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 557 AM EST TUE MAR 3 2015
APPEARS INCREASINGLY LIKELY THAT WE WILL BE DIVING HEADLONG INTO
A TRANSITION FROM A HEAVY RAIN INTO A SIGNIFICANT WINTER WEATHER
EVENT BY THE BEGINNING OF THE EXTENDED. GFS...ECMWF SOLUTIONS
CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH THIS SCENARIO.
HOWEVER...THE NAM CONTINUES TO TREND FURTHER TO THE NORTHWEST
WITH THE MOST SIGNIFICANT FEATURES IN OUR SENSIBLE WEATHER. WITH
THE NAM OUTSIDE ITS WINDOW OF BEST PERFORMANCE...GENERAL PREFERRED
TO REMAINED CLOSER TO THE OFFICIAL FORECAST AND A CONSENSUS OF THE
GFS AND ECMWF. ENOUGH UNCERTAINTY REMAINS IN THE MODEL SOLUTIONS
TO WARRANT STAYING WITH THE CURRENT SUITE OF WATCH PRODUCTS
THROUGH THE FIRST PORTIONS OF THE EXTENDED.
A VERY TIGHT BAROCLINIC ZONE STRETCHING WSW TO ENE ACROSS THE
OHIO VALLEY WILL GRADUALLY SHIFT SOUTHEAST INTO TENNESSEE VALLEY
THROUGH THURSDAY. WEATHER ALONG THE BAROCLINIC ZONE WILL REMAIN
OF ACTIVE AS SEVERAL WAVES OF LOW PRESSURE TRACK THROUGH THE TN
VALLEY REGION. COLDER ARCTIC AIR FILTERING INTO OUR AREA ON THE
NORTHERN SIDE OF THIS ZONE WILL CHANGE RAIN OVER TO SNOW WEDNESDAY
NIGHT. THERMAL PROFILES SUGGEST THAT THERE WILL BE A PERIOD OF
MIXED PRECIPITATION DURING THE CHANGOVER...GENERALLY SLEET IN THE
NORTH BUT SLEET OR POSSIBLY EVEN SOME FREEZING RAIN IN THE SOUTH.
OVERALL MODEL TRENDS SEEM TO BE SLIGHTLY SLOWER WITH THE
ONSLAUGHT OF COLD ARCTIC AIR INTO OUR FORECAST AREA LATE WEDNESDAY
INTO WEDNESDAY NIGHT. BUT SIGNIFICANT SNOW/SLEET ACCUMULATIONS
STILL APPEAR POSSIBLE...WITH THE HIGHEST AMOUNTS LIKELY NEAR THE
I-64 CORRIDOR AND LESSER AMOUNTS ACROSS OUR SOUTHEAST.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT BEGINNING LATE THURSDAY
NIGHT AND REMAIN OVER THE AREA THROUGH LATE SUNDAY. TEMPS FRIDAY
MORNING WILL LIKELY DIP INTO THE SINGLE DIGITS...WITH A FEW SPOTS
IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...WELL BELOW
NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO
BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK
TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL
GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE
POSSIBLE EARLY NEXT WEEK AS A WEAK FRONTAL BOUNDARY DROPS
SOUTHWARD OUT OF CANADA AND THE GREAT LAKES. BUT WEATHER WITH
THIS FEATURE HAS BEEN TRENDING DRIER WITH TIME. FOR NOW MAINTAINED
A SLIGHT POP SUNDAY NIGHT INTO MONDAY BUT FEEL THIS MAY BE
OVERDONE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 358 AM EST TUE MAR 3 2015
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH AROUND 10Z.
CLOUD BASES WILL CONTINUE TO GRADUALLY LOWER THROUGH THE REMAINDER
OF THE OVERNIGHT AND PREDAWN HOURS AS A WARM FRONT APPROACHES
FROM THE SOUTHWEST. CIGS AT 10 OR 11Z AT JKL...LOZ...AND SME
SHOULD RANGE BETWEEN 2.5 AND 3K AS MULTIPLE LAYERS OF LOW LEVEL
CLOUDS MOVE IN. CIGS WILL STEADILY LOWER THROUGHOUT THE
MORNING...AND WE WILL LIKELY SEE IFR CIGS AT THE TAF SITES BY 14
TO 16Z THIS MORNING. PRECIPITATION IN THE FORM OF DRIZZLE OR LIGHT
WILL BEGIN AFFECTING THE TAF SITES BY AROUND 9Z THIS MORNING.
THERE IS A SMALL CHANCE FOR SOME FREEZING RAIN OR FREEZING DRIZZLE
AT SJS AND SYM BETWEEN 9 AND 13Z AS PRECIP OVERRIDES A LAYER OF
NEAR FREEZING AIR NORTH OF THE MOUNTAIN PARKWAY. THE PRECIP SHOULD
CHANGE OVER TO ALL RAIN BY 14Z. CONDITIONS WILL WORSEN DURING THE
TRANSITION...WITH IFR TO LIFR CONDITIONS THROUGH THE REMAINDER OF
THE TAF PERIOD. THERE IS ALSO A CHANCE OF THUNDER THIS AFTERNOON
AND EVENING...AS A STRONG COLD MOVING ACROSS THE AREA INTERACTS
WITH WARM MOIST AIR OFF THE GULF OF MEXICO.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY EVENING
FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-
106>120.
&&
$$
UPDATE...JMW
SHORT TERM...AR
LONG TERM...RAY
AVIATION...AR
AREA FORECAST DISCUSSION
NWS CARIBOU ME
931 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE SOUTH OF THE AREA TODAY. A FAST MOVING
TROUGH OF LOW PRESSURE WILL CROSS THE REGION TONIGHT. HIGH PRESSURE
WILL BUILD TOWARD THE EAST COAST WEDNESDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE: ADJUSTED THE SKY CONDITIONS TO ALLOW FOR MORE
SUNSHINE AS THE NAM12 AND RAP KEEP THE THICKEST CLOUD SHIELD
FURTHER S THROUGH THE AFTERNOON AS RIDGE AXIS IS OVERHEAD. ALSO
NEEDED TO PUSH BACK TIMING OF THE ARRIVAL OF SNOW AND LOWERED THE
POPS THIS AFTERNOON. HRLY TEMPS WERE ADJUSTED TO ACCOUNT FOR THE
LATEST CONDITIONS.
STRONG HIGH PRESSURE WILL MOVE ACROSS THE REGION TODAY THEN MOVE
TO THE EAST THIS EVENING. OVER-RUNNING SNOW WILL SPREAD ACROSS THE
REGION THIS EVENING AS LOW PRESSURE APPROACHES FROM THE WEST. SNOW
COULD MIX WITH OR CHANGE TO RAIN IN COASTAL AREA LATE TONIGHT BUT
EXPECT MOST OF THE PRECIPITATION WILL BE IN THE FORM OF SNOW. WILL
USE PRECIPITATION TYPE FROM THICKNESS TOOL RUN ON 50/50 BLEND OF
THE NAM AND GFS. WILL ALSO USE SNOW ACCUMULATION FROM THICKNESS
FOR SNOW AMOUNTS. FOR QPF... POPS AND SKY CONDITIONS WILL BLEND
THE NAM... GFS AND ECMWF. HAVE USED THE GMOS FOR WINDS. HAVE
MANUALLY ADJUSTED THE TEMPERATURE AND DEW POINTS. WILL ISSUE
ADVISORY FOR SNOW.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
LOW PRESSURE NORTH OF THE AREA COMBINED WITH HIGH PRESSURE BEGINNING
TO BUILD IN FROM THE WEST WILL BRING A WARM AND WINDY DAY ON
WEDNESDAY. TEMPERATURES WILL GET ABOVE FREEZING ACROSS THE AREA
RANGING FROM THE 30S ACROSS THE NORTH TO THE 40S DOWNEAST. WEST
WINDS WILL BE VERY GUSTY, ESPECIALLY IN THE AFTERNOON, AS COOLER
AIR BEGINS WORKING IN FORM THE WEST AND STRONG WINDS ALOFT BEGIN
TO MIX DOWN. WEDNESDAY NIGHT WILL BE BREEZY AND COOLER. HIGH
PRESSURE WILL THEN BRING A SUNNY TO PARTLY CLOUDY AND COLD DAY ON
THURSDAY WITH TEMPS ABOUT 20 DEGREES COLDER THAN THEY WILL BE ON
WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
DRY WEATHER WILL CONTINUE FRIDAY AS HIGH PRESSURE SLIDES TOWARD THE
EAST COAST. A WEAK TROUGH OF LOW PRESSURE FRIDAY NIGHT THROUGH
SATURDAY WILL BRING A CHANCE FOR SOME SNOW SHOWERS. DRY WEATHER WILL
RETURN FOR SUNDAY. A SMALL CLIPPER LOW MAY THEN BRING ANOTHER CHANCE
FOR SNOW SHOWERS ON MONDAY BEFORE HIGH PRESSURE BRINGS A RETURN OF
DRY WEATHER ON TUESDAY. IN GENERAL, NO MAJOR STORMS ARE IN SIGHT
WELL INTO NEXT WEEK AS A BROAD TROUGH REMAINS OVER THE EAST AND
WEAK, FAST MOVING LOWS FOLLOWED BY LARGE HIGHS DOMINATE THE
PATTERN.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: EXPECT VFR CONDITIONS TODAY THEN IFR CONDITIONS EARLY
THIS EVENING AS SNOW SPREADS ACROSS THE AREA.
SHORT TERM: CONDITIONS WILL BECOME VFR WEDNESDAY. VERY GUSTY
WINDS MAY RESULT IN TURBULANCE, ESPECIALLY IN THE AFTERNOON
WEDNESDAY. MAINLY VFR CONDITIONS SHOULD PERSIST THROUGH FRIDAY.
CONDITIONS MAY LOWER TO MVFR ACROSS THE NORTH FRIDAY NIGHT THEN
MVFR OR IFR ON SATURDAY IN LOWER CLOUDS.
&&
.MARINE...
UPDATE 0545 EST: HAVE LOWERED GALE TO SCA.
NEAR TERM: HAVE USED THE NAM12 FOR SUSTAINED WINDS. FOR WAVES:
PRIMARY WAVE SYSTEM EARLY TODAY WILL BE OFF-SHORE WIND WAVE WITH
HEIGHTS A FUNCTION OF FETCH DISTANCE FROM SHORE. WIND WAVE WILL
SUBSIDE WITH WINDS LATER TODAY. A NEW SOUTHERLY FETCH WILL DEVELOP
TONIGHT ACROSS THE GULF OF MAINE WITH WIND WAVE BUILDING TO 6 TO
10 FEET/8 SECONDS BY MORNING.
SHORT TERM: A STRONG SCA OR A GALE WILL LIKELY BE NEEDED
WEDNESDAY INTO WEDNESDAY NIGHT FOR GUSTY WEST WINDS. AN SCA MAY BE
NEEDED THURSDAY. WINDS MAY DIMINISH FRIDAY AS HIGH PRESSURE BUILDS
OVER. AN SCA MAY BE NEEDED ON SATURDAY. WINDS SHOULD THEN BE
LIGHTER SUNDAY WITH ANOTHER HIGH BUILDING OVER THE WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
WEDNESDAY FOR MEZ002>006-010-011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
ANZ050>052.
FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT/MIGNONE
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...HEWITT/MIGNONE/BLOOMER
MARINE...HEWITT/MIGNONE/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
643 AM EST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EST TUE MAR 3 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW
REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG
OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY
AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33
PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO
SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH
STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE
WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC
LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST
TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW
KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF
SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A
STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS
APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT
HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO
EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME...
A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF
FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT
AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING
LIGHT SN.
MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS
ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE
DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED
TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR
FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND
BRINGS A RETURN OF SOME LES.
TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND
ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS
THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT
ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY.
ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT
EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN
THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF
PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND
IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC
ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO
IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF
LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW
AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE...
EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN
THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6-
9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS
QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS
DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E
BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR
TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER
RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN
TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN
GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE
DROPPED A FEW HRS EARLY OVER THE W.
TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN
THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN
THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS
TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN
AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF
THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA
IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER...
AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE
INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE
NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL
BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE
THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER.
GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND
DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK
SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY
APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH
MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR
THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EST TUE MAR 3 2015
A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED
EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE
OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW
BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS
GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO
BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE
KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND
DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND
EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED
LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES
WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W
WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON
WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU.
FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE
REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH
ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION
FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE
SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE
IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO
MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN
FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E
INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING
ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 643 AM EST TUE MAR 3 2015
A BAND OF SOME -SN FALLING INTO LLVL DRY AIR MAY RESULT IN MVFR
CONDITIONS AT TIMES INTO MID MRNG...BUT THE ARRIVAL OF STRONGER
DYNAMIC FORCING IN ADVANCE OF A LO PRES MOVING NE FM THE CENTRAL
PLAINS WL RESULT IN STEADY SN BY MID MRNG AND CAUSE PREDOMINANT IFR
VSBYS INTO MID AFTN. AS THIS FORCING EXITS W-E THIS AFTN...
CONDITIONS WL IMPROVE TO MVFR. A STRONG COLD FNT WL THEN PASS LATE
THIS AFTN OVER THE W AND DURING THE EVNG AT SAW. GUSTY WNW WINDS WL
DVLP IN ITS WAKE. EXPECT THE STRONGEST WINDS AT THE MORE EXPOSED IWD
AND ESPECIALLY THE CMX LOCATIONS. DESPITE EXTENSIVE ICE COVER ON LK
SUP...MVFR CONDITIONS ARE LIKELY TO PREDOMINANT AT THESE LOCATIONS
WITH AN UPSLOPE WIND COMPONENT. DOWNSLOPE FLOW INTO SAW WL CAUSE VFR
CONDITIONS THERE TNGT FOLLOWING THE COLD FROPA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EST TUE MAR 3 2015
S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING
COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT
LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR
ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS
WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND
ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS.
AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF
THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE
SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK
THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE
SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR
LSZ266.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
556 AM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 555 AM CST TUE MAR 3 2015
UPDATED AVIATION SECTION BELOW.
&&
.SHORT TERM...(TODAY THROUGH LATE TONIGHT)
ISSUED AT 332 AM CST TUE MAR 3 2015
INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE
PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE
VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT.
SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE
LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY
TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW
LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF
700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF
STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA
OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS
MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD
LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO
PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS
EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO
THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2
INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL
BE THIS MORNING FROM AROUND 5 AM TO 11 AM.
THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE
ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT
FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY
WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND
GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE
COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW
LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT
TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE
WINTER WEATHER ADVISORIES.
THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS
TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT
POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28
DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC
TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW
ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND
CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL
ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE MAR 3 2015
WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW
MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST
FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA
DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS
DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT
SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL
POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL
FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH
GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS.
WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE
AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND
FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY
BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND...
BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS
LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY
LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY
NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING.
FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET
CLOSER IN.
THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS
SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE
QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY.
ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY.
FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED
TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE
30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY.
HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW
30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND
SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE.
THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING
DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE
BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH
THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR
DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF
STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID
30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION...
BUT WE WILL NEED TO WATCH THIS CAREFULLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 555 AM CST TUE MAR 3 2015
BAND OF SNOW WITH IFR TO LIFR CEILINGS AND VISIBILITIES TO
CONTINUE TO AFFECT KBRD...KDLH...KHIB AND KHYR UNTIL 18Z-21Z. KINL
TO ONLY GET IFR VISIBILITIES AND MVFR CEILINGS WITH THIS BAND.
NORTHWEST WINDS TO INCREASE TO 15-20KTS WITH GUSTS TO 25KTS AFTER
18Z...AND THOUGH SNOW EXPECTED TO END...BLOWING SNOW WILL KEEP
VISIBILITIES MVFR. CONDITIONS TO SLOWLY IMPROVE TO VFR AROUND
21Z OR SHORTLY AFTER. WINDS TO DIMINISH AGAIN BETWEEN 04Z AND 08Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 -9 4 -11 / 100 10 10 0
INL 19 -15 3 -19 / 60 10 10 0
BRD 22 -11 5 -14 / 100 10 10 0
HYR 27 -8 6 -15 / 100 10 20 10
ASX 28 -4 7 -8 / 100 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR MNZ011-012-018-019-021-025-026.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020-
033>038.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>004-006>009.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...BJT
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
523 AM CST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CST TUE MAR 3 2015
TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND
ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT
SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT
UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW
ABOVE 850 MB.
THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE
MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A
WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT
MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR
LIKELY.
THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS
GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL
WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER
ADVISORY APPEARS TO BE RIGHT ON TRACK.
WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW
PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING
FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING
DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE
HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE
FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING
ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR
SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS
MORNING AHEAD OF THE ARCTIC FRONT.
ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING
THREAT SHOULD END.
LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE
WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND
LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE
NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES
WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND
CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE
FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM CST TUE MAR 3 2015
TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE
EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY
DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE
TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT
THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES.
WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE
REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH
APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS.
MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL
NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING
GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN
CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE
WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT
SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER
RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS
AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE
DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN
OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD
EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST
TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE
DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND
THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND
FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH
50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE
OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A
GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO
COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN
COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES
NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY
AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST
HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES
WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE
RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND
SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR
ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST
TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY
WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 523 AM CST TUE MAR 3 2015
IFR/LOCAL LIFR IN SNOW...BLOWING SNOW AND FOG CONTINUE UNTIL
AROUND 15Z THIS MORNING AND THEN IMPROVE TO MVFR 15Z-18Z.
VFR/MVFR IN LOW CLOUDS ARE EXPECTED FROM 18Z ONWARD.
NORTH WINDS INCREASE TO 34025G40KT THIS MORNING AND DECREASE
DURING THE AFTN.
MVFR/IFR IN SNOW AND LOW CIGS MAY DEVELOP TONIGHT ALONG AND SOUTH
OF INTERSTATE 80. LOWEST FLIGHT CONDITIONS ARE EXPECTED SOUTH
TOWARD THE KANSAS BORDER WHERE SNOW IS MORE LIKELY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ004>007-094.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
916 AM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 910 AM CST TUE MAR 3 2015
WE WILL BE CANCELING CASS/CLAY/SARGENT AND RANSOM COUNTIES FROM
THE WINTER WEATHER ADVISORY...WITH LITTLE SNOW HERE AND NO BLOWING
SNOW ISSUES. WE WILL ISSUE A WIND ADVISORY FOR RANSOM/SARGENT.
OTHERWISE...NO OTHER CHANGES PLANNED BUT WE WILL MONITOR POTENTIAL
FOR A WIND ADVISORY INTO THE WESTERN EDGE OF THE RED RIVER VALLEY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG
COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED
WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS.
MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN
CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS
WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING
DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM
TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH
WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH.
SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL
MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR
NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR
TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR
SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION
INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN
FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH
CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN
ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K
SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS
MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING.
SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH.
SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS
THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW.
BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING
WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW
MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED
NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO
SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH
BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD
CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER
MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL
REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST
CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR.
WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD.
N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING
BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT
HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD
TO MINIMAL TEMPERATURE RECOVERY.
TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT
TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES
WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD
POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP
TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND
CHILL HEADLINES.
WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER
MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM
ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY
PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY.
MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD
TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL
COLD START.
GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH
PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES
WILL BE MUCH CLOSER TO AVERAGE.
FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR
THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY
MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO
COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK
WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO
REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS
DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN
SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS
SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW
CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN
STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE
THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST
DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD
BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY
MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER
CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE
ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 633 AM CST TUE MAR 3 2015
LOWER CIGS MASKED BY CI HOWEVER APPEARS TO BE QUITE A BIT OF MVFR
CIGS OVER ALL BUT DVL BASIN WERE CLEARING TAKING PLACE. SOUNDINGS
SUPPORTIVE OF SOME SC DEVELOPMENT DURING THE DAY HOWEVER KEPT MVFR
CIGS LIMITED TO THE AM. STRONG NW WINDS SPREADING ACROSS THE FA.
LOWER VSBY IN SN/BLSN SHOULD REMAIN SOUTH OF TAF SITES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024-
026-028-038-049-052.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ053.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ024-
027>032-040.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
647 AM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 633 AM CST TUE MAR 3 2015
VIA KABR WSR-88D RADAR RETURNS SHRINKING AND DIMINISHING IN
INTENSITY AND VSBY FROM METARS RISING. HAVE SERIOUS DOUBTS THAT
NORTHERN COUNTIES WILL REACH ADVISORY CRITERIA/CONDITIONS HOWEVER WILL
MAINTAIN THOSE HEADLINES AS -SN CONTINUES AND MORNING COMMUTE SOON
TO START. JUST SOUTH AND EAST OF THE FA SNOW REPORTS RANGING FROM
2-3 INCHES SO THIS AREA OK. IF CURRENT TRENDS CONTINUE DAY SHIFT CAN
START TRIMMING ADVISORY AREA AT MID MORNING UPDATE. WINDS ALSO YET
TO REV UP OVER WESTERN ADVISORY AREA HOWEVER SHOULD INCREASE ONCE
MIX LAYER DEEPENS. NO CHANGES PLANNED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG
COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED
WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS.
MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN
CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS
WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING
DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM
TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH
WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH.
SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL
MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR
NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR
TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR
SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION
INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN
FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH
CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN
ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K
SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS
MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING.
SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH.
SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS
THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW.
BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING
WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW
MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED
NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO
SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH
BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD
CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER
MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL
REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST
CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR.
WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD.
N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING
BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT
HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD
TO MINIMAL TEMPERATURE RECOVERY.
TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT
TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES
WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD
POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP
TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND
CHILL HEADLINES.
WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER
MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM
ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY
PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY.
MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD
TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL
COLD START.
GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH
PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES
WILL BE MUCH CLOSER TO AVERAGE.
FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR
THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY
MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO
COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK
WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO
REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS
DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN
SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS
SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW
CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN
STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE
THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST
DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD
BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY
MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER
CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE
ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 633 AM CST TUE MAR 3 2015
LOWER CIGS MASKED BY CI HOWEVER APPEARS TO BE QUITE A BIT OF MVFR
CIGS OVER ALL BUT DVL BASIN WERE CLEARING TAKING PLACE. SOUNDINGS
SUPPORTIVE OF SOME SC DEVELOPMENT DURING THE DAY HOWEVER KEPT MVFR
CIGS LIMITED TO THE AM. STRONG NW WINDS SPREADING ACROSS THE FA.
LOWER VSBY IN SN/BLSN SHOULD REMAIN SOUTH OF TAF SITES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006-014-015-024-
026-028-038.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ039-
049-052-053.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003-
024-027>032-040.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1022 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS
TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY
NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...NO SIGNIFICANT CHANGES. LETTING MUCH OF THE FREEZING
RAIN ADVISORY EXPIRE AT 10 AM.
645 AM UPDATE...
PRECIP GRADUALLY TRYING TO FILL IN UPSTREAM...BUT STILL FALLING OUT
OF A MID DECK. HRRR INSISTS ON THIS EXPANDING AND REACHING THE
GROUND INTO SE OH IN THE 13 TO 15Z TIME FRAME. WILL CONT HEADLINE AS
IS FOR NOW.
PREVIOUS DISCUSSION BELOW...
A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP
BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH
EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A
CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE
VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING
OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH
AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW
HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING
OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT
PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER.
WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N
MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA.
ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD
BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT
ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE
WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND
CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS.
THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW
LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE
COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT
CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE
NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL
BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND
INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE
FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL
SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE
MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z.
STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER
SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON
THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD.
FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH
TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE
50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA.
DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME
OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR
FLOODING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR
WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE
TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE
MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING
OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY
CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD
INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT
AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV
MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE
SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A
WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF
WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS
AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL
CAUSING FLOODING CONCERNS.
SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR
MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE
REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS
FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF
THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES
THROUGHOUT.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
15Z TUESDAY THRU 12Z WEDNESDAY...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS AFTERNOON...WITH VFR
CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL IFR
CEILINGS AND VSBY IN RAIN AND FOG ON E SLOPES. ANY VERY LIGHT
FREEZING RAIN NORTH WILL END BY 18Z AS TEMPERATURES RISE ABOVE
FREEZING.
THERE WILL BE A BREAK IN THE RAIN THIS AFTERNOON. LOOK FOR GENERAL
MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR
CONDITIONS IN THE WARM SECTOR ACROSS EKN AMID DOWNSLOPE WINDS. IFR
CONDITIONS LOOK TO DEVELOP ON E SLOPES INCLUDING KBKW THIS
AFTERNOON. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED
THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT.
THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY
09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG
THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR OR WORSE.
SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT
GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE
TOPS THIS MORNING...INCLUDING KBKW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL
VARY WITH ONSET OF THE RAIN TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H M M H H H H H H H H
HTS CONSISTENCY M H M H H H H H M M M M
BKW CONSISTENCY H H H H M M M M M H M M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H M M H H H H H M M M
CKB CONSISTENCY H H H H M M M M M M H H
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS
THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY
MORNING FOR WVZ005>011-013>020-024>040-046-047.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR WVZ005>011-013>020-026-029.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
EVENING FOR WVZ027-028-030>032-035>040-046-047.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ046-047.
OH...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY
MORNING FOR OHZ066-067-075-076-083>087.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ066-067-075-076.
KY...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY
MORNING FOR KYZ101>103-105.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ101>103-105.
VA...FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY
MORNING FOR VAZ003-004.
&&
$$
SYNOPSIS...JS/RPY/30
NEAR TERM...JMV/30
SHORT TERM...RPY
LONG TERM...JS
AVIATION...JMV/30
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1001 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO
TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO
WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ACTIVE WEATHER PATTERN WITH INITIAL FOCUS ON THE FREEZING RAIN
POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT
AND HEAVY SNOW WED/THU.
ISENTROPIC LIFT LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S
NORTHERN COUNTIES EARLY THIS MORNING. THIS PRECIPITATION AXIS HAS
PIVOTED NORTH AND EAST OF ILN/S FA.
ILN/S 12Z MORNING SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C
AROUND 78O MB BUT RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO
RETURNS...THIS HAS LIMITED ANY FREEZING RAIN IN THE SOUTH THIS
MORNING.
BETTER LIFT COMING INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL
CONVERGENCE DEVELOPS ASSOCIATED WITH 60-65 KT LLJ. SEEING THIS
BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS
INDIANA. CURRENTLY IN LULL BUT HAVE SHOWN THIS TREND WITH AN
INCREASE IN POPS FROM THE WEST LATER THIS MORNING.
HAVE ALLOWED THE SRN TIER OF THE FREEZING RAIN ADVISORY TO EXPIRE
WITH TEMPERATURES WARMING ABOVE FREEZING. SOME SFC ROAD/WALKWAY TEMPS
WILL LAG. THEREFORE...HAVE AN SPS THRU NOON ACRS THE FAR SOUTH.
HAVE KEPT NRN FREEZING RAIN ADVISORY THRU 1 PM WITH TEMPERATURES EXPECTED
TO WARM ABOVE FREEZING THIS AFTN AS LOW LEVEL WINDS VEER FROM THE
EAST TO THE SOUTH.
PREVIOUS DISCUSSION...
FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE
HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH
ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A
COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE
THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS
NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR
THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE
TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION
OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD
AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS
FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING
CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A
FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS
EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER
ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET
MIXING IN.
TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES
NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN.
THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT
GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES
HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE
THE END TIME OF THE WINTER WEATHER ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS
EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS
PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD
WATCH.
A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT
OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE
THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE
REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE
IN THE OVERNIGHT HOURS.
TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS
THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION
PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE
ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL.
PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND
EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF
PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY
AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW
HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF
NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS.
PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING.
SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES
ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT
OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER
STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY
OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON
THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE
COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH
WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6
TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT.
THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL
TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME
UNCERTAINTY IN FORECAST SNOW AMOUNTS.
SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND
INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE
REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME
RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND
MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE
NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES
EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES.
MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING
SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL
GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT
LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY.
WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH.
LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS.
FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR
THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH
OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED
SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS.
TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL
STILL AVERAGE BELOW NORMAL FOR EARLY MARCH.
HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY
ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE
FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S
READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE
BIT BELOW NORMAL FOR EARLY MARCH.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM
WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT
LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH
TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT
THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT
QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP
SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON
TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR
CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE
HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA
LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES
THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW
PRECIP TO AGAIN TRANSITION BACK TO SNOW.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH
WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL
POTENTIALLY LINGER THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ042-051>055-060>065-070>074-077.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ026-034-035-043>046-056.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ089>100.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR KYZ089>100.
IN...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ050-058-059-066-073-074.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR INZ073>075-080.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR INZ075-080.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...AR
SHORT TERM...NOVAK
LONG TERM...HICKMAN
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
904 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO
TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO
WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ACTIVE WEATHER PATTERN WITH INTIAL FOCUS ON THE FREEZING RAIN
POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT
AND HEAVY SNOW WED/THU.
ISENTROPIC LIFT HAS LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S
NORTHERN COUNTIES EARLY THIS MORNING. REPORTS AND RADAR INDICATED
A MIX WITH SLEET AT TIME ACRS CENTRAL OHIO. THIS BAND IS SHIFTING
N WITH BEST COVERAGE OF PCPN EXITING ILN/S FA.
12Z ILN SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C AROUND 78O MB BUT
RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO RETURNS...THIS HAS
LIMITED ANY FREEZING RAIN IN THE SOUTH THIS MORNING.
BETTER LIFT COMES INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL
CONVERGENCE DEVELOPS ASSOICATED WITH 60-65 KT LLJ. SEEING THIS
BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS
CENTRAL INDIANA AND WESTERN INDIANA. HAVE SHOWN THIS TREND OF
DIMINISHING POPS WITH AN INCREASE FROM THE WEST LATER THIS
MORNING.
HAVE KEPT CURRENT FREEZING RAIN HEADLINES IN PLACE WITH SFC
TEMPERATURES RUNNING FROM THE MID/UPR 20S NORTH TO THE LOWER 30S
FAR SOUTH. MAY HAVE TO EXTEND FREEZING RAIN ADVISORY ACRS THE NE
WITH EASTERLY FLOW RESULTING IN A SLOW TEMPERATURE RISE. WILL
CONTINUE TO MONITOR TEMP TRENDS REGARDING.
PREVIOUS DISCUSSION...
FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE
HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH
ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A
COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE
THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS
NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR
THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE
TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION
OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD
AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS
FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING
CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A
FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS
EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER
ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET
MIXING IN.
TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES
NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN.
THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT
GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES
HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE
THE END TIME OF THE WINTER WEATHER ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS
EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS
PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD
WATCH.
A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT
OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE
THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE
REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE
IN THE OVERNIGHT HOURS.
TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS
THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION
PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE
ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL.
PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND
EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF
PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY
AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW
HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF
NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS.
PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING.
SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES
ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT
OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER
STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY
OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON
THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE
COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH
WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6
TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT.
THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL
TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME
UNCERTAINTY IN FORECAST SNOW AMOUNTS.
SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND
INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE
REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME
RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND
MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE
NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES
EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES.
MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING
SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL
GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT
LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY.
WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH.
LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS.
FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR
THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH
OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED
SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS.
TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL
STILL AVERAGE BELOW NORMAL FOR EARLY MARCH.
HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY
ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE
FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S
READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE
BIT BELOW NORMAL FOR EARLY MARCH.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM
WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT
LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH
TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT
THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT
QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP
SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON
TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR
CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE
HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA
LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES
THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW
PRECIP TO AGAIN TRANSITION BACK TO SNOW.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH
WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL
POTENTIALLY LINGER THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ042-051>055-060>065-070>074-077.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ026-034-035-043>046-056.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ078>082-088.
KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ089>100.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR KYZ089>100.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
KYZ091>093.
IN...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ050-058-059-066-073-074.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR INZ073>075-080.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR INZ075-080.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ075.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...AR
SHORT TERM...NOVAK
LONG TERM...HICKMAN
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
553 AM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT TODAY...FOLLOWED BY A COLD FRONT TONIGHT. FRONT STALLS
TO THE SOUTH WITH LOW PRESSURE MOVING ALONG THE FRONT WEDNESDAY
NIGHT. SNOW SHOWERS LINGER ON THURSDAY. HIGH PRESSURE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
645 AM UPDATE...
PRECIP GRADUALLY TRYING TO FILL IN UPSTREAM...BUT STILL FALLING
OUT OF A MID DECK. HRRR INSISTS ON THIS EXPANDING AND REACHING THE
GROUND INTO SE OH IN THE 13 TO 15Z TIME FRAME. WILL CONT HEADLINE
AS IS FOR NOW.
PREVIOUS DISCUSSION BELOW...
A WARM FRONT WILL CROSS THE AREA THIS MORNING WITH PRECIP
BREAKING OUT ALONG IT. THE HRRR AND RUC ARE MORE ROBUST WITH
EXTENT OF PRECIP THIS MORNING VS OTHER MODELS. THIS PRESENTS A
CONCERN FOR FZRA GIVEN EXPECTED SFC TEMPS...ESPECIALLY IN THE
VALLEYS AND HOLLOWS. AFTER COORDINATING WITH SURROUNDING
OFFICES...ELECTED TO EXPAND THE FZRA ADV TO INCLUDE ALL OF SE OH
AND PORTIONS OF W WV ALONG OH RIVER. LOOKING AT ONLY A FEW
HUNDREDTHS AT BEST. ADJUSTED END TIMES TO REFLECT EXPECTED WARMING
OF TEMPS. LEFT NE KY OUT ATTM AS CONFIDENCE NOT AS HIGH THAT
PRECIP WILL BREAK OUT OVER THAT AREA BEFORE TEMPS CAN RECOVER.
WILL HANDLE WITH AN SPS FOR NOW AND MONITOR TRENDS. ACROSS THE N
MOUNTAINS...THERE MAY MORE IN THE WAY OF SLEET INITIALLY VS FZRA.
ONCE THE WARM FRONT MOVES N OUT OF THE AREA...MOST PLACES SHOULD
BE LOOKING AT MORE IN THE WAY OF SCT SHRA VS STEADY RAIN...EXCEPT
ACROSS SE OH. AS SUCH...HAVE TWEAKED POPS TO REFLECT LESS IN THE
WAY OF COVERAGE ACROSS SW VA AND S HALF OF WV. THIS TREND
CONTINUES THIS EVENING AS DOWNSLOPING LOW LEVEL FLOW STRENGTHENS.
THE COLD FRONT WILL BE SAGGING INTO SE OH BY MIDNIGHT WITH THE LOW
LEVEL FLOW VEERING AROUND TO SW AND INCREASING TO AROUND 60 KTS. THE
COLD AIR ABOVE THE SFC WILL LAG WELL BEHIND THE SFC FRONT AS IT
CROSSES SE OH...SO STILL HAVE LIQUID AS PRECIP TYPE THRU THE
NIGHT. KEPT HEAVY RAIN WORDING ON EITHER SIDE OF THE FRONTAL
BOUNDARY. FRONT WILL CONTINUE TO SAG SE...INTO C WV BY 09Z AND
INTO THE MOUNTAINS BY 12Z...THOUGH MOST OF THE PRECIP WILL BE
FALLING BEHIND THE BAROCLINIC ZONE. AS SUCH...THE HEAVY RAIN WILL
SHIFT INTO AREAS ALONG OH RIVER AND THE WV LOWLANDS. THINK THE
MOUNTAINS WILL ONLY HAVE LIGHT QPF THRU 12Z.
STILL LOOKING AT POSSIBLE CREEK AND STREAM ISSUES DEVELOPING OVER
SE OH TONIGHT AND PERHAPS NE KY AND W WV BY DAWN. ANY ISSUES ON
THE MAIN STEM RIVERS WILL HOLD OFF BEYOND THE NEAR TERM PERIOD.
FOR TEMPS...LOOKING AT A SURGE OF WARMTH BY THIS EVENING WITH HIGH
TEMPS PROBABLY OCCURRING AT MIDNIGHT AS MANY AREAS GET INTO THE
50S. TEMPS WILL START TO FALL DURING THE PREDAWN FOLLOWING FROPA.
DEWPOINTS WILL ALSO RESPOND...WITH A JUICY AIRMASS FOR THIS TIME
OF YEAR OVER RESIDUAL SNOWPACK...ADDING FURTHER CONCERN FOR
FLOODING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS ARE STILL IN DISAGREEMENT WITH HOW FAR SOUTH THE COLDER AIR
WILL PUSH INTO THE REGION ON WEDNESDAY. THIS IS CRITICAL FOR THE
TYPE OF PRECIPITATION THAT WILL OCCUR WEDNESDAY NIGHT WITH A WAVE
MOVING ALONG THE FRONT. ALSO DUE TO THE DIFFERENCES IN THE HANDLING
OF THE COLD AIR...PLACEMENT OF HIGHER PRECIPITATION AMOUNTS VARY
CONSIDERABLY. THIS LEADS TO A LOW CONFIDENCE FORECAST. NAM/SREF WOULD
INDICATE SNOW IN CENTRAL OHIO...WITH A LARGE BAND OF SIGNIFICANT
AMOUNTS OF SLEET FROM NE KY/S OH INTO CENTRAL WV AND THE WV
MOUNTAINS. GFS AND ECMWF ARE MUCH COLDER AND WOULD PRODUCE
SIGNIFICANTLY MORE SNOW INSTEAD OF SLEET. IN ANY CASE...FEEL THAT A
WINTER STORM WATCH IS WARRANTED AT THIS POINT...ALTHOUGH THE TYPE OF
WEATHER IS UNCERTAIN. WILL NOT ISSUE FOR THE SOUTHERN COAL FIELDS
AND VA HOWEVER...AS ODDS OF BEING RAIN ARE MUCH LARGER THERE...STILL
CAUSING FLOODING CONCERNS.
SOME UPSLOPE SNOW LOOKS TO BE A GOOD BET FOR THURSDAY AS COLD AIR
MOVES IN BEHIND THE SYSTEM. WILL INCREASE POPS SOME.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE ALONG WITH A GENERAL WARM UP WILL BUILD IN ACROSS THE
REGION AND WILL BE IN CONTROL THROUGH SATURDAY. A WEAK SYSTEM IS
FORECAST TO TRACK TO OUR NORTH AND AFFECT THE NORTHERN PORTION OF
THE CWA. GENERALLY WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES
THROUGHOUT.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
12Z TUESDAY THRU 12Z WEDNESDAY...
A WARM FRONT WILL LIFT NORTHWARD ACROSS THE AREA THIS MORNING...WITH
VFR CONDITIONS BECOMING MVFR FROM SOUTH TO NORTH AND OCCASIONAL
IFR CEILINGS AND VSBY IN RAIN AND FOG ON E SLOPES. THERE MAY BE A PERIOD
OF FREEZING RAIN IN THE MORNING BEFORE CHANGING TO ALL
RAIN...AT HTS/PKB...BUT DURATION OF THIS PCPN WILL BE SHORT.
THERE WILL BE A BREAK IN THE RAIN THIS AFTERNOON. LOOK FOR GENERAL
MVFR CONDITIONS TO PREVAIL ACROSS SE OH AND POSSIBLY JUST VFR
CONDITIONS IN THE WARM SECTOR ACROSS EKN AMID DOWNSLOPE WINDS. IFR
CONDITIONS LOOK TO DEVELOP ON E SLOPES INCLUDING KBKW THIS
AFTERNOON. THERE WILL BE ONLY A SLIGHT CHANCE OF AN EMBEDDED
THUNDERSTORM SOUTHEAST PORTIONS OF AREA THIS AFTERNOON AND NIGHT.
THE FRONT SAGS SE TONIGHT...CLEARING SE OH BY 06Z...C WV BY
09Z...AND INTO THE MOUNTAINS BY 12Z. HEAVY RAIN WILL FALL ALONG
THE BAROCLINIC ZONE...SENDING AVIATION CONDITIONS INTO IFR OR WORSE.
SOUTHERLY WINDS WILL GENERALLY BE LIGHT IN THE LOWLANDS...BUT
GUSTS WILL BE INCREASING TO AROUND 25 KNOTS ON MOUNTAIN RIDGE
TOPS THIS MORNING...INCLUDING KBKW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: LOWERING OF FLIGHT CATEGORIES TO MVFR/IFR WILL
VARY WITH ONSET OF THE RAIN TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H M H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H M H H H M H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H M H H H H M
CKB CONSISTENCY H H H H H H M M M M H H
AFTER 12Z WEDNESDAY...
IFR POSSIBLE IN RAIN WEDNESDAY...AND RAIN/SLEET OR SNOW
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. IFR IN SNOW SHOWERS
THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
WVZ005>011-013>020-024>040-046-047.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ007>009-017.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR WVZ005>011-013>020-026-029.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
EVENING FOR WVZ027-028-030>032-035>040-046-047.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ046-047.
OH...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ083>087.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ066-067-075-076-083>087.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ066-067-075-076.
KY...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
KYZ101>103-105.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ101>103-105.
VA...FLOOD WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR
VAZ003-004.
&&
$$
SYNOPSIS...JS/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...JS
AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1057 AM EST TUE MAR 3 2015
.SYNOPSIS...
AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE
QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF
DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR
IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF
SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY
TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS
SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW
FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN
WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES
ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR
SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE
FIRST PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AFTER SEVERAL HOURS OF VIRGA...FIRST BANDS OF PRECIP (SNOW) HAVE
ARRIVED ACROSS NORTHWEST/WEST CENTRAL/CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS LATE THIS MORNING. SOME QUICK MODERATE RATES HAVE BEEN
NOTED AROUND ERIE AND BAND IS INTENSIFYING AS IT PUSHES EASTWARD.
A QUICK 1 TO LOCALLY 2 INCHES WILL ACCUMULATE IN SPOTS BEFORE THE
INITIAL INTENSE SNOW BAND MOVES EAST OF THE LAUREL HIGHLANDS AND
SOUT CENTRAL MOUNTAINS. THE SOUTHERN THIRD OF CENTRAL PA WILL
LIKELY THEN SEE A SEVERAL HOUR LULL IN PRECIP LATER THIS
AFTERNOON...WHILE THE NORTH TRANSITIONS TO SLEET AND THEN
FREEZING RAIN.
NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE...BUT CONCERNED THAT
WE`LL EXCEED ADVISORY CRITERIA FOR ICE LATER TONIGHT NORTH OF
INTERSATE 80. SREF THREATS PAGE INDICATE 70-80% CONFIDENCE IN
.20-.30" OR MORE OF ICE AND SUCCESSIVE HRRR RUNS CONTINUE TO DELAY
WARMING AT THE END OF ITS 15-HOUR WINDOW...MEANING THAT MUCH OF
NORTH CENTRAL PA WILL LIKELY NEVER RISE ABOVE FREEZING. CRITICAL
TIMEFRAME WILL BE BETWEEN 21Z AND 04Z...AND MAY BE A WHITES OF
THEIR EYES DECISION BASED ON RADAR EVOLUTION AND ADJUSTMENTS OF
HRW-ARW AND HRRR CONSENSUS LATE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
PROLONGED ICE ACCRETION IS THE MAIN THREAT TONIGHT THROUGHOUT THE
CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS
THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH
OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP
TO 3 INCHES NORTH).
THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY
BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST
THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD
BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF
PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE
80.
WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET
ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY
THROUGH THE EARLY MORNING HOURS ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH
MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR
FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT
LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE
IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO
MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING
TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS.
MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS
ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY
TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND
ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN.
SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE
ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE
COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE
ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS
TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL
BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF
AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS
THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF
TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT
PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO
SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE
OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS
FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA.
HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL
WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO
COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY
3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE
PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF
THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT
IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS
THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH
MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN
PORTIONS OF THE CWA.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND
THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY
MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW
SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD
FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
CONDITIONS WILL QUICKLY DETERIORATE FROM WEST TO EAST AS MODERATE
SNOW BANDS CROSS THROUGH THE CENTRAL AND NORTH CENTRAL MOUNTAINS
THROUGH MIDDAY AND EARLY AFTERNOON HOURS. WARMER AIR SURGING IN
ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY
MIX/FREEZING RAIN EVENT BY MID TO LATE AFTERNOON INTO THE EARLY
EVENING...BEFORE CHANGING TO RAIN /FZRA NORTH/ LATE TONIGHT INTO
EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD
SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM
AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS
MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB
WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR PAZ006-011-012-018-037-041-042.
WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR PAZ004-
005-010-017-024>026-033>035.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
736 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE THE POCONO MOUNTAINS EARLY TODAY
WILL DRIFT EAST TO THE SOUTHERN NEW ENGLAND COAST BY THIS
AFTERNOON. AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES
WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A
SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE
COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF
SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY
TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS
SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW
FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN
WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES
ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR
SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE
FIRST PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL NOON TODAY/...
SFC HIGH PRESSURE /1030 MB/ WAS CENTERED OVER NORTHEASTERN
PENNSYLVANIA AND WILL BE DRIFTING EAST ACROSS THE LOWER HUDSON
RIVER VALLEY DURING THE LATE MORNING HOURS. CIRRUS SHIELD HAS
OVERSPREAD ALL OF THE CWA AND THICKENED-UP SUBSTANTIALLY OVER THE
PAST FEW HOURS.
REGIONAL 88D MOSAIC LOOP SHOWS PLENTY OF 10-20 DBZ RETURNS MOVING
QUICKLY EAST INTO THE WESTERN PORTIONS OF OUR CWA.HOWEVER...SFC
OBS CONFIRM NOTHING MORE THAN A FEW FLURRIES OR LIGHT SLEET
PELLETS REACHING THE GROUND ALL THE WAY BACK THROUGH OHIO AND WVA.
EXPECT CONDITIONS TO CHANGE RATHER QUICKLY LATE THIS MORNING AND
EARLY THIS AFTERNOON /PER LATEST RAP AND HRRR/ AS AN ANOMALOUSLY
STRONG 50-60 KT 850 JET /SREF/ TRANSPORTS A PLUME OF DEEP
MOISTURE UP AND OVER THIS DOME OF LLVL COLD AIR.
ONLY SOME MINOR CHANGES /UPWARD ADJUSTMENTS/ WERE MADE TO THE
POPS FOR TODAY WITH LITTLE OR NO CHANGE IN THE ONSET OF THE
PRECIP.
EARLY MORNING LOWS WITH WINDS LIGHT AND VARIABLE WERE IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE NRN MTNS...IN THE
LOWER TO MID TEENS THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION
OF THE STATE...AND UPPER TEENS TO AROUND 20F IN THE SOUTHEAST.
STILL EXPECT PRECIP ONSET FROM THE SOUTHWEST TO HOLD OFF UNTIL
AFTER 15Z/10AM.
&&
.SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/...
CONDITIONS WILL GO DOWNHILL FAIRLY QUICKLY TODAY WITH AN
ANTICYCLONIC ARC OF DEEP MOISTURE FROM BAJA MONSOONAL FLOW
ADVECTING THROUGH THE OHIO VALLEY AND ARRIVING INTO/BLOSSOMING
OVER THE ALLEGHENIES BY LATE THIS MORNING IN THE FORM OF SNOW
INITIALLY...SPREADING EASTWARD ACROSS MY CWA THROUGH THE MIDDAY
AND EARLY AFTERNOON HOURS.
VERY MILD UPPER BOUNDARY LAYER FLOW WILL BRING A QUICK MIX AND
EVENTUAL CHANGEOVER TO FREEZING RAIN FOR ALL AS THE DAY
PROGRESSES. THERE MAY BE A COMPLETE CHANGEOVER TO RAIN ACROSS THE
FAR SOUTH AND SOUTHEAST. CONSENSUS BLEND OF 00Z-06Z OPERATIONAL
MODELS AND ENS GUIDANCE IS STILL CONSISTENT WITH PREVIOUS
SOLUTIONS FOR AN INITIAL FEW TO SEVERAL HOUR PERIOD OF SNOW/SLEET
THIS AFTERNOON...FOLLOWED BY A SIGNIFICANT BOUT OF MIXED
PRECIP/FREEZING RAIN LATER THIS AFTERNOON THROUGH EARLY TONIGHT.
OVERALL IT APPEARS THAT PROLONGED ICE ACCRETION IS THE MAIN
THREAT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A
LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY
THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW
IN MOST AREAS (WITH UP TO 3 INCHES NORTH).
THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY
BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST
THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD
BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF
PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE
80.
WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET
ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY
THROUGH THE EARLY MORNING HOURS ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH
MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR
FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT
LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE
IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO
MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING
TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS.
MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS
ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY
TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND
ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN.
SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE
ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE
COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE
ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS
TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL
BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF
AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS
THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF
TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT
PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO
SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE
OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS
FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA.
HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL
WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO
COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY
3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE
PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF
THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT
IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS
THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH
MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN
PORTIONS OF THE CWA.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND
THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY
MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW
SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD
FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
ONGOING VFR CONDITIONS AT 12Z WILL PERSIST INTO THE MID/LATE
MORNING HOURS AS HIGH PRESSURE QUICKLY CEDES TO AN APPROACHING
WINTER STORM SYSTEM. WINDS THROUGH MID MORNING WILL BE LESS THAN
5 MPH.
A FAST MOVING STORM SYSTEM WILL LIFT ACROSS THE GREAT LAKES...AND
QUICKLY SPREAD SNOW/SLEET INTO WESTERN SECTIONS BY NOON AND ACROSS
ALL OF CENTRAL PA BY MID AFTERNOON. WARMER AIR SURGING IN ON
INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY
MIX/FREEZING RAIN EVENT BY LATE AFTERNOON INTO THE EARLY
EVENING...BEFORE CHANGING TO RAIN /FZRA EAST/ LATE TONIGHT INTO
EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD
SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM
AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS
MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB
WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR PAZ006-011-012-018-037-041-042.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ004-005-010-017-024>026-033>035.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
608 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE THE POCONO MOUNTAINS EARLY TODAY
WILL DRIFT EAST TO THE SOUTHERN NEW ENGLAND COAST BY THIS
AFTERNOON. AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES
WILL MOVE QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A
SURGE OF DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE
COLD AIR IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF
SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY
TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS
SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW
FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN
WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES
ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR
SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE
FIRST PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL NOON TODAY/...
SFC HIGH PRESSURE /1030 MB/ WAS CENTERED OVER NORTHEASTERN
PENNSYLVANIA AND WILL BE DRIFTING EAST ACROSS THE LOWER HUDSON
RIVER VALLEY DURING THE LATE MORNING HOURS. CIRRUS SHIELD HAS
OVERSPREAD ALL OF THE CWA AND THICKENED-UP SUBSTANTIALLY OVER THE
PAST FEW HOURS.
REGIONAL 88D MOSAIC LOOP SHOWS PLENTY OF 10-20 DBZ RETURNS MOVING
QUICKLY EAST INTO THE WESTERN PORTIONS OF OUR CWA.HOWEVER...SFC
OBS CONFIRM NOTHING MORE THAN A FEW FLURRIES OR LIGHT SLEET
PELLETS REACHING THE GROUND ALL THE WAY BACK THROUGH OHIO AND WVA.
EXPECT CONDITIONS TO CHANGE RATHER QUICKLY LATE THIS MORNING AND
EARLY THIS AFTERNOON /PER LATEST RAP AND HRRR/ AS AN ANOMALOUSLY
STRONG 50-60 KT 850 JET /SREF/ TRANSPORTS A PLUME OF DEEP
MOISTURE UP AND OVER THIS DOME OF LLVL COLD AIR.
ONLY SOME MINOR CHANGES /UPWARD ADJUSTMENTS/ WERE MADE TO THE
POPS FOR TODAY WITH LITTLE OR NO CHANGE IN THE ONSET OF THE
PRECIP.
EARLY MORNING LOWS WITH WINDS LIGHT AND VARIABLE WERE IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO ACROSS THE NRN MTNS...IN THE
LOWER TO MID TEENS THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION
OF THE STATE...AND UPPER TEENS TO AROUND 20F IN THE SOUTHEAST.
STILL EXPECT PRECIP ONSET FROM THE SOUTHWEST TO HOLD OFF UNTIL
AFTER 15Z/10AM.
&&
.SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/...
CONDITIONS WILL GO DOWNHILL FAIRLY QUICKLY TODAY WITH AN
ANTICYCLONIC ARC OF DEEP MOISTURE FROM BAJA MONSOONAL FLOW
ADVECTING THROUGH THE OHIO VALLEY AND ARRIVING INTO/BLOSSOMING
OVER THE ALLEGHENIES BY LATE THIS MORNING IN THE FORM OF SNOW
INITIALLY...SPREADING EASTWARD ACROSS MY CWA THROUGH THE MIDDAY
AND EARLY AFTERNOON HOURS.
VERY MILD UPPER BOUNDARY LAYER FLOW WILL BRING A QUICK MIX AND
EVENTUAL CHANGEOVER TO FREEZING RAIN FOR ALL AS THE DAY
PROGRESSES. THERE MAY BE A COMPLETE CHANGEOVER TO RAIN ACROSS THE
FAR SOUTH AND SOUTHEAST. CONSENSUS BLEND OF 00Z-06Z OPERATIONAL
MODELS AND ENS GUIDANCE IS STILL CONSISTENT WITH PREVIOUS
SOLUTIONS FOR AN INITIAL FEW TO SEVERAL HOUR PERIOD OF SNOW/SLEET
THIS AFTERNOON...FOLLOWED BY A SIGNIFICANT BOUT OF MIXED
PRECIP/FREEZING RAIN LATER THIS AFTERNOON THROUGH EARLY TONIGHT.
OVERALL IT APPEARS THAT PROLONGED ICE ACCRETION IS THE MAIN
THREAT THROUGHOUT THE CENTRAL AND NRN MTNS OF THE STATE /AND TO A
LESSER DEGREE ACROSS THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY
THE COATING TO 1 INCH OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW
IN MOST AREAS (WITH UP TO 3 INCHES NORTH).
THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY
BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST
THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD
BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF
PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE
80.
WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET
ACCUM...FOLLOWED BY FREEZING RAIN...GENERALLY FROM MIDDAY TODAY
THROUGH THE EARLY MORNING HOURS ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH
MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR
FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT
LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE
IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO
MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING
TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS.
MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS
ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY
TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND
ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN.
SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE
ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE
COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE
ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS
TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL
BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF
AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS
THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF
TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT
PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO
SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE
OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS
FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA.
HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL
WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO
COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY
3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE
PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF
THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT
IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS
THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH
MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN
PORTIONS OF THE CWA.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND
THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY
MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW
SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD
FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PERSIST INTO THE MID/LATE MORNING HOURS AS
HIGH PRESSURE QUICKLY CEDES TO AN APPROACHING WINTER STORM
SYSTEM. WINDS THROUGH MID MORNING WILL BE LESS THAN 5 MPH.
A FAST MOVING SYSTEM MOVING ACROSS THE GREAT LAKES WILL QUICKLY
SPREAD SNOW/SLEET INTO WESTERN SECTIONS BY NOON AND ACROSS ALL OF
CENTRAL PA BY MID AFTERNOON. WARMER AIR SURGING IN ON INCREASING
SW FLOW WILL BRING A TRANSITION TO A WINTRY MIX/FREEZING RAIN
EVENT BY LATE AFTERNOON INTO THE EARLY EVENING...BEFORE CHANGING
TO RAIN /FZRA EAST/ LATE TONIGHT INTO EARLY WED. WIDESPREAD
SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM
AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS
MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB
WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR PAZ006-011-012-018-037-041-042.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ004-005-010-017-024>026-033>035.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1010 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A
WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW
PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA
AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER
AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM EST TUESDAY...
CANCELLED THE WINTER WEATHER ADVISORY MAINLY WEST OF I77 WHERE
TEMPERATURES WERE ABOVE FREEZING MARK AND EXPECTED TO REMAIN AS
SUCH...AND RADAR COVERAGE IS LIGHT. STILL CONCERN OVER DIABATIC
COOLING OF TEMPERATURES WITH LIGHT PRECIPITATION...THUS WILL HOLD
WITH REST OF WINTER WEATHER ADVISORY AT THIS TIME. MODIFIED POPS
WITH LATEST RADAR TRENDS. SHAPED MORNING TEMPERATURES WITH SFC OBS
AND LATEST MODEL TRENDS. MORE CHANGES LATER THIS MORNING IN THE
ACTIVE WEATHER PATTERN .
AS OF 415 AM EST TUESDAY...
LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS
MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION
BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF
THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS
TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS
OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN
8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION
ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED
FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL.
WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT
SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE
WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL
THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING
FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE
ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN
TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST
COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE
COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START
OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH
LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING.
TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW
POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD
FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE
NORTHWEST COUNTY WARNING AREA INCREASES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 430 AM EST TUESDAY...
EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE
ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE
FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET
WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE
WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY
ABOVE NORMAL FOR EARLY MARCH.
DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE
RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO
BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST
VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER
EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT
AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING
PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND
DOWNSLOPE.
DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL
SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A
STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST
ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA
DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE
DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE
RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN.
AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL
ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD
AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA.
THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO
CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE
MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON.
BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN
PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY.
RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND
SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND
ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO
GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT
HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS.
PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER
OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL
MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY
ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH
PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE
SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE
APPALACHIANS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH
AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE
AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY.
THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW
LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A
SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AS OF 700 AM EST TUESDAY...
CEILINGS WERE LOWERING ACROSS THE REGION...DOWN TO MVFR THIS
MORNING AND IFR THIS AFTERNOON. STRONG SOUTH TO SOUTHWEST WINDS
ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION TODAY. EXPECT
SCATTERED LIGHT RAIN AND FREEZING RAIN THROUGH NOON. TEMPERATURES
WILL BE NEARLY STEADY TODAY THEN RISE TONIGHT. MEDIUM CONFIDENCE
AS TO WHEN THE THREAT OF FREEZING RAIN ENDS...ESPECIALLY AT KLYH
TODAY. BUFKIT AND MET TEMPERATURE GUIDANCE SUGGESTED THE THREAT OF
FREEZING RAIN OR FREEZING DRIZZLE MAY CONTINUE AT KLYH UNTIL
21Z/4PM. MAINTAINED LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT.
CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE
AREA.
EXTENDED FORECAST...
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY.
THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY
AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH
THE AREA ON WEDNESDAY. WINTER PRECIPITATION IS LIKELY BEHIND THE
FRONT WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME THE MOST LIKELY
PRECIPITATION TYPES ARE SNOW AND SLEET.
FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR
WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO.
THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING
LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE
WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL
APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS
BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT
LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE
UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED
MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY
THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE
CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS
POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
VAZ011-013-014-017>019-022-023-032>034-043-045.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
VAZ020-024-035-046-047.
NC...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
WVZ043-044-507-508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...NF
LONG TERM...DS
AVIATION...AMS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
704 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A
WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW
PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA
AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER
AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EST TUESDAY...
LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS
MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION
BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF
THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS
TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS
OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN
8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION
ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED
FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL.
WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT
SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE
WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL
THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING
FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE
ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN
TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST
COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE
COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START
OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH
LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING.
TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW
POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD
FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE
NORTHWEST COUNTY WARNING AREA INCREASES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 430 AM EST TUESDAY...
EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE
ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE
FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET
WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE
WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY
ABOVE NORMAL FOR EARLY MARCH.
DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE
RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO
BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST
VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER
EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT
AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING
PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND
DOWNSLOPE.
DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL
SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A
STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST
ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA
DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE
DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE
RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN.
AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL
ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD
AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA.
THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO
CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE
MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON.
BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN
PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY.
RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND
SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND
ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO
GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT
HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS.
PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER
OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL
MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY
ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH
PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE
SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE
APPALACHIANS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH
AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE
AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY.
THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW
LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A
SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 700 AM EST TUESDAY...
CEILINGS WERE LOWERING ACROSS THE REGION...DOWN TO MVFR THIS
MORNING AND IFR THIS AFTERNOON. STRONG SOUTH TO SOUTHWEST WINDS
ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION TODAY. EXPECT
SCATTERED LIGHT RAIN AND FREEZING RAIN THROUGH NOON. TEMPERATURES
WILL BE NEARLY STEADY TODAY THEN RISE TONIGHT. MEDIUM CONFIDENCE
AS TO WHEN THE THREAT OF FREEZING RAIN ENDS...ESPECIALLY AT KLYH
TODAY. BUFKIT AND MET TEMPERATURE GUIDANCE SUGGESTED THE THREAT OF
FREEZING RAIN OR FREEZING DRIZZLE MAY CONTINUE AT KLYH UNTIL
21Z/4PM. MAINTAINED LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT.
CEILINGS AND VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE
AREA.
EXTENDED FORECAST...
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY.
THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY
AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH
THE AREA ON WEDNESDAY. WINTER PRECIPITATION IS LIKELY BEHIND THE
FRONT WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME THE MOST LIKELY
PRECIPITATION TYPES ARE SNOW AND SLEET.
FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR
WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO.
THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING
LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE
WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL
APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS
BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT
LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE
UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED
MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY
THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE
CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS
POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
VAZ011-013-014-017>019-022-023-032>034-043-045.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
VAZ007-009-010-012-015-016.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST
THIS AFTERNOON FOR VAZ020-024-035-046-047.
NC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NCZ001-002-018.
WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
WVZ043-044-507-508.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ042.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...DS
AVIATION...AMS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
531 AM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A
WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW
PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA
AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER
AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EST TUESDAY...
LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS
MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION
BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF
THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS
TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS
OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN
8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION
ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED
FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL.
WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT
SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE
WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL
THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING
FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE
ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN
TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST
COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE
COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START
OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH
LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING.
TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW
POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD
FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE
NORTHWEST COUNTY WARNING AREA INCREASES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 430 AM EST TUESDAY...
EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE
ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE
FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET
WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE
WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY
ABOVE NORMAL FOR EARLY MARCH.
DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE
RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO
BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST
VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER
EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT
AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING
PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND
DOWNSLOPE.
DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL
SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A
STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST
ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA
DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE
DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE
RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN.
AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL
ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD
AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA.
THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO
CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE
MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON.
BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN
PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY.
RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND
SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND
ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO
GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT
HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS.
PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER
OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL
MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY
ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH
PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE
SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE
APPALACHIANS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH
AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE
AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY.
THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW
LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A
SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM EST TUESDAY...
MVFR CIGS WILL START PROGRESSES NORTHEAST ACROSS THE REGION IN
CONJUNCTION WITH A WARM FRONT HEADING TOWARD THE AREA. ALONG WITH
THE FRONT WILL COME LIGHT WINTRY PRECIPITATION IN THE FORM OF
PATCHY LIGHT FREEZING RAIN AND SLEET. BY DAYBREAK TUESDAY...MANY
AREAS WILL HAVE LOWERED TO LIFR/IFR CIGS AND MVFR VSBYS DUE TO THE
PRECIPITATION AND MIST. THE BULK OF THE WINTRY PRECIPITATION WILL
BE CONFINED TO NORTH A LINE FROM KBLF-KROA-KLYH DURING THE LATE
MORNING. BY THE AFTERNOON...SURFACE TEMPERATURES SHOULD BE MILD
ENOUGH FOR A WIDESPREAD AREA OF RAIN.
WINDS WILL REMAIN LIGHT THROUGH THE NIGHT AND GRADUALLY VEER TO
THE SOUTHEAST. ON TUESDAY...WINDS WILL INCREASE DURING THE DAY
FROM THE SOUTHWEST...AND WINDS AT 850 MB WILL INCREASE TO AROUND
45 TO 50 KTS. LOW LEVEL WIND SHEAR WILL BE POSSIBLE DURING THE
AFTERNOON...ESPECIALLY AT TERMINALS AT HIGHER ELEVATION.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
PERIOD.
EXTENDED FORECAST...
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO NEW ENGLAND TUESDAY NIGHT
INTO WEDNESDAY. THIS WILL RESULT IN SUB-VFR CONDITIONS WEDNESDAY
AND THURSDAY WITH WIDESPREAD RAIN AHEAD OF THE FRONT ON WEDNESDAY
AND WINTER PRECIPITATION BEHIND THE FRONT WEDNESDAY NIGHT AND
THURSDAY.
FRIDAY SHOULD SEE A RETURN TO HIGH PRESSURE AND VFR WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO.
THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING
LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE
WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL
APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS
BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT
LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE
UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED
MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY
THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE
CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS
POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
VAZ011-013-014-017>019-022-023-032>034-043-045.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
VAZ007-009-010-012-015-016.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST
THIS AFTERNOON FOR VAZ020-024-035-046-047.
NC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NCZ001-002-018.
WV...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
WVZ043-044-507-508.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ042.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...DS
AVIATION...AMS/DS/KK
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
521 AM MST TUE MAR 3 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
HIGH-IMPACT WINTER STORM CONTINUES THIS MORNING FOR A LARGE PART
OF THE CWA. AS EXPECTED...MODERATE TO HEAVY SNOW HAS BECOME QUITE
WIDESPREAD THIS MORNING WITH AN ARCTIC COLD FRONT BLASTING SOUTH
INTO NORTHERN CO. STRONG NORTHERLY WINDS ARE OCCURRING POST FROPA
WITH EXCELLENT MIXING VIA INTENSE COLD ADVECTION ALOFT. PEAK WIND
AT KCYS WAS 42 KTS JUST BEFORE 10Z...AND REMAINS STEADY AT 20 TO
30 MPH AT THIS HOUR WITH VERY LOW VISIBILITY OCCURRING IN FALLING
AND BLOWING SNOW. DO NOT EXPECT MUCH FOR AMOUNTS AS LLVL FORCING
WILL DISAPPEAR QUICKLY...BUT WILL NEED TO MONITOR FOR A POSSIBLE
SHORT FUSED ADVISORY IF HEAVY BANDING PERSISTS INTO THE MORNING
COMMUTE. A WARM DAY YESTERDAY AHEAD OF THE ARCTIC FRONT SET US UP
FOR A FLASH FREEZE...SO ROADWAYS ARE ALREADY QUITE SLICK IN TOWN
HERE THIS MORNING. SUSPECT THIS IS THE CASE AREAWIDE BASED ON THE
ROAD CLOSURES WE HAVE SEEN ALREADY WITH LARGE SECTIONS OF I25 AND
I80 AFFECTED WEST OF LARAMIE AND NORTH OF CHEYENNE.
LATEST WATER VAPOR LOOP SHOWS LARGE SCALE TROUGHING ENCOMPASSING
MUCH OF THE WESTERN CONUS WITH THE LEAD SHORTWAVE NOW EXITING
INTO THE CENTRAL PLAINS. WITH THAT...WE SHOULD CONTINUE TO LOSE
DYNAMIC SUPPORT ASSOCIATED WITH THE 150+ KT H25 JET OVER CENTRAL
NEBRASKA AND WILL HAVE TO RELY ENTIRELY ON LLVL CONVERGENCE AND
FRONTOGENESIS FOR ENHANCED SNOWFALL RATES. SFC COLD FRONT ALREADY
ANALYZED ALONG THE CO/WY BORDER WILL CONTINUE TO MOVE SOUTH ALONG
THE FRONT RANGE...SO EXPECT SNOW TO LIGHTEN UP BEFORE LONG. EVEN
SO...WE SAW SOME HEFTY SNOW RATES OVER PLATTE/NIOBRARA COUNTIES
OVERNIGHT WITH THE INITIAL FRONTAL SURGE. INITIAL CALLS TO AREA
DISPATCHERS INDICATE GENERALLY 3 TO 5 INCHES WITH WINDS CREATING
PROBLEMS. NUMEROUS POWER OUTAGES WERE REPORTED IN NIOBRARA COUNTY
AND INTERSTATE 25 WAS CLOSED IN PLATTE. ADDITIONAL LIGHT ACCUMS
ARE POSSIBLE THROUGH THE MORNING. NAM/GFS SUGGEST WINDS BECOMING
NORTHEASTERLY ALONG THE CENTRAL LARAMIE RANGE BY MID AFTN AS SFC
PRESSURE RISES SPREAD INTO SOUTH CENTRAL NE. DEFINITELY CONCERNED
WITH POTENTIAL UPSLOPE ENHANCEMENT CAUSING SNOW TO REDEVELOP IN
THE AFTN/EVE WITH THE ARRIVAL OF A SECONDARY SHORTWAVE. HRRR IS
HITTING THIS AREA HARD BEYOND 21Z. EVEN THOUGH WINDS WILL MOST
LIKELY BE A NON FACTOR LATER ON...OPTED TO UPGRADE TO A WINTER
STORM WARNING GIVEN OBSERVED IMPACTS AND POTENTIAL FOR AT LEAST
ANOTHER COUPLE INCHES OF SNOW THROUGH TONIGHT.
ALL AREAS SHOULD SEE THE WORST CONDITIONS RIGHT AWAY IN THE AM
WITH THE STRONGEST WINDS OCCURRING THEN. THE MODELS SHOW FLOW
ALOFT WEAKENING CONSIDERABLY AFTER 15Z...SO BLOWING SNOW SHOULD
BECOME LESS OF A PROBLEM WITH TIME. PRECIPITATION COVERAGE WILL
TRANSITION TO SNOW SHOWERS FOR A TIME...BUT ANOTHER SHOT OF PCPN
IS EXPECTED LATE THIS AFTN AND EVE WITH A SECONDARY SHORTWAVE AND
ASSOCIATED MID LEVEL MOISTURE PLUME UPSTREAM OVER EASTERN IDAHO AS
OF 12Z PER MORNING SATELLITE IMAGERY. MIDLVL DRY SLOT HAS PROVEN
TO BE A MAJOR INHIBITOR FOR SNOW SO FAR ALONG THE I80 CORRIDOR
BETWEEN CHEYENNE AND SIDNEY...SO EXPECT THE BEST CHANCES FOR SNOW
LOCALLY TO COME TONIGHT. AMOUNTS WILL PROBABLY BE ON THE LOW SIDE
SO DECIDED AGAINST AN ADVISORY FOR NOW...BUT THE DAY SHIFT WILL
NEED TO REVISIT. KEPT ALL OTHER HEADLINES THE SAME...EXCEPT FOR
EXTENDING THEM THROUGH 07Z WED AS THE NEXT DISTURBANCE WILL KEEP
SNOW POTENTIAL GOING A LITTLE LONGER THAN EARLIER EXPECTED. AS
SNOW ENDS LATE TONIGHT...WINTER HAZARDS WILL TRANSITION TO WIND
CHILLS WITH WIDESPREAD -20F TO -30F READINGS LIKELY. FULLY EXPECT
SOME SORT OF WIND CHILL HEADLINES WILL BE NECESSARY ON THE HEELS
OF THE CURRENT WINTER PRECIPITATION PRODUCTS.
WARMEST TEMPERATURES FOR TODAY OCCURRED OVERNIGHT WITH VERY STRONG
H7 COLD AIR ADVECTION EXPECTED TO DRIVE TEMPERATURES DOWNWARD INTO
THE AFTERNOON. TEMPERATURES WILL FALL BELOW ZERO ACROSS MUCH OF
THE AREA TONIGHT DESPITE WIDESPREAD ABUNDANT MOISTURE ALOFT
LEADING TO THICK CLOUDS AND SNOW GIVEN UNSEASONABLY COLD THERMAL
PROFILES IN THE LLVLS. HIGHS WEDNESDAY SHOULD BE WELL BELOW ANY
CONSENSUS GUIDANCE WITH FRESH SNOWPACK AND 700 MILLIBAR TEMPS
REMAINING VERY COLD / -20C PER THE NAM. SHOULD FINALLY SEE SOME
IMPROVEMENT ON THURSDAY AS WESTERLY DOWNSLOPE WINDS RETURN FOR
AREAS EAST OF THE LARAMIE RANGE...ALLOWING HIGHS TO CLIMB BACK
ABOVE FREEZING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
PROGRESSIVE NORTHWEST FLOW THRU THE WEEKEND WILL GIVE WAY TO A
BUILDING RIDGE OF HIGH PRESSURE AND A RETURN TO ABOVE AVERAGE
TEMPERATURES FOR EARLY NEXT WEEK. BOTH THE 00Z GFS AND ECMWF
ADVERTISE TWO CLIPPER SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
TRAVERSE SOMEWHERE THRU THE NRN ROCKIES FRIDAY AND SATURDAY. AS IS
TYPICAL IN PROGRESSIVE NORTHWEST FLOW...TIMING AND STRENGTH
DIFFERENCES EXIST IN JUST HOW THESE DISTURBANCES PUSH THRU. EITHER
SCENARIO CARRIES LITTLE IF ANY IMPACTS FROM THESE SYSTEM.
ALTHOUGH...THE DID HAD SOME MOUNTAIN SNOW SHOWER CHANCES ON SUNDAY
WITH THE GFS STEERING ONE OF THE CLIPPERS DIRECTLY OVR THE REGION.
THE NORTHWEST FLOW WILL CONTINUE SUNDAY AND MONDAY...WITH THE RIDGE
AXIS ARRIVING ON TUESDAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL
LEVELS FRIDAY THROUGH SUNDAY WITH HIGHS GENERALLY REACHING THE 30S
WEST AND 40S OVR THE ERN PLAINS. THE APPROACHING UPPER-RIDGE AND
ASSOCIATED WAA WILL LIFT HIGH TEMPERATURES ABOVE AVERAGE FOR THE
FIRST TIME SINCE THE THIRD WEEK OF FEBRUARY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 520 AM MST TUE MAR 3 2015
AVIATION CONDITIONS WILL CONTINUE TO
BE POOR TODAY WITH WIDESPREAD IFR CONDITIONS PREVAILING AS A
SERIES OF STORMS SYSTEMS AND FRONT PUSH THROUGH AREA AIRFIELDS.
ALL SITES WILL SEE A PERIOD OF -SN/SN ESPECIALLY THROUGH 16Z AND
AGAIN BETWEEN 22-06Z. NORTH/NORTHEAST WINDS WILL PREVAIL TODAY AND
TONIGHT AT SPEEDS OF BETWEEN 15 AND 25 KNOTS. THESE BREEZY
CONDITIONS WILL PRODUCE SOME AREAS OF BLOWING SNOW. LOW CIGS ALONG
WITH THE ACTIVE UPSLOPE PATTERN WILL OBSCURE MOUNTAINS TODAY AND
TONIGHT. SHOULD BEGIN TO SEE IMPROVEMENT TO CONDITIONS AFTER 04Z
OR SO...WITH VFR RETURNING TO MANY SPOTS AFTER 06Z.
&&
.FIRE WEATHER...
ISSUED AT 520 AM MST TUE MAR 3 2015
A WINTER STORM WILL CONTINUE TO IMPACT MUCH OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE THROUGH TONIGHT. SIGNIFICANT
SNOWFALL ACCUMULATIONS ARE LIKELY ALONG WITH STRONG NORTHERLY
WINDS RESULTING IN EXTREMELY DANGEROUS TRAVEL CONDITIONS. VERY
COLD TEMPERATURES ARE EXPECTED TODAY AND TONIGHT WITH WIDESPREAD
DANGEROUS WIND CHILLS POSSIBLE ON EARLY WEDNESDAY MORNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR WYZ108-
115>117.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ101>107-
109>114.
NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR NEZ002-
003-095-096.
&&
$$
SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
958 AM MST TUE MAR 3 2015
.UPDATE...
ISSUED AT 958 AM MST TUE MAR 3 2015
COLD FRONT HAS PUSHED THROUGH EASTERN COLORADO ALREADY THIS
MORNING. TEMPERATURES ARE EXPECTED TO SLOWLY FALL THROUGH THE
DAY. UPDATED TEMPERATURE GRIDS TO REFLECT THE COLDER START TO THE
MORNING.
LIGHT SNOW HAS FORMED OVER THE DENVER AREA DUE TO UPSLOPE BEHIND
THE FRONT. EXPECT LIGHT SNOW TO LINGER THROUGH THE DAY WITH SNOW
ACCUMULATION AROUND AN INCH WITH SLIGHTLY MORE POSSIBLE NEAR THE
FOOTHILLS AND UNDER SNOW BANDS. THE HRRR AND OTHER SHORT TERM
MODELS STILL HAVE NOT CAUGHT ON TO THE LIGHT SNOW THIS
MORNING...SO EXPECT SNOW AMOUNTS TO BE A LITTLE HIGHER THAN IN
THE MODELS THROUGH THIS AFTERNOON.
A BAND OF SLIGHTLY HEAVIER SNOW IS OVER BOULDER...LARIMER AND
WELD COUNTIES. MORNING SOUNDING AT KDNR SHOWED STEEP LAPSE RATES
UP TO ABOUT 550 MB. SO ADDITIONAL SNOW SHOWERS WILL REMAIN
POSSIBLE THROUGH THE DAY WHICH WILL PRODUCE HEAVIER SNOW FOR A
SHORT TIME.
HEAVIEST SNOW AND BEST COVERAGE IS STILL EXPECTED LATE THIS
AFTERNOON AND TONIGHT AS AN UPPER LEVEL TROUGH PROVIDES ADDITIONAL
LIFT. IN ADDITION TO THIS...A SECONDARY PUSH FROM THE NORTH MAY
PRODUCE A LINE OF HEAVIER SNOW THAT WILL MOVE SOUTH ACROSS THE
AREA. WILL KEEP WINTER WEATHER HIGHLIGHTS AS IS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 446 AM MST TUE MAR 3 2015
MODELS CONTINUE A TREND OF SLIGHTLY SLOWING THE INCOMING SYSTEM.
THIS LOOKS CORRECT SO THE MAIN ADJUSTMENT HAS BEEN TO SLOW THINGS
DOWN BY 3-6 HOURS. COLD FRONT COMING ACROSS THE BORDER AND SHOULD
BE THROUGH DENVER BY ABOUT 7 AM. ONE GOOD SHOWER BAND HAS FORMED
AROUND CHEYENNE BUT IS TIED TO THE UPPER FEATURES...NOT THE COLD
FRONT. AIRMASS IS ACTUALLY DRYING FROM THE WEST OVERALL AT THIS
TIME...THOUGH THERE ARE STILL SOME SHALLOW SHOWER BANDS AND ENOUGH
MOISTURE FOR OROGRAPHIC SNOW TO CONTINUE ON THE RIDGES. SO FOR
THIS MORNING THE LOW LEVELS WILL BECOME MORE SUPPORTIVE OF
SHOWERS...BUT THERE WILL BE LESS UPPER LEVEL SUPPORT. I REDUCED
THE COVERAGE OF SHOWERS ON THE PLAINS THIS MORNING BUT THERE WILL
LIKELY STILL BE SOME. THIS AFTERNOON THE LOW LEVEL COLD AIR
DEEPENS WHILE UPSLOPE CONVERGENCE DEVELOPS ON THE EAST SIDE OF THE
FRONT RANGE. THERE IS COOLING ALOFT WITH DESTABILIZATION AND THE
NEXT AREA OF LIFT MOVES INTO THE MOUNTAINS AND NORTHERN
AREAS...AND ACROSS THE REST OF OUR AREA BY EARLY EVENING. PRETTY
GOOD CONSENSUS ON WIDESPREAD 2-3 INCHES OF SNOW AS THIS FEATURE
PASSES IN THE LATE AFTERNOON AND OVERNIGHT...PLUS THE OROGRAPHIC
INFLUENCES. ENVIRONMENT WILL BE FAVORABLE FOR A GOOD RESPONSE TO
THE LOW LEVEL CONVERGENCE THIS EVENING...NOT SUPER UNSTABLE BUT A
DEEP LAYER OF WEAK STABILITY. FOR THIS REASON PLANNING ON DECENT
ENHANCEMENT IN AND NEAR THE FOOTHILLS...AND ALSO A PERIOD OF
PRETTY GOOD OROGRAPHIC SNOW IN THE HIGHER MOUNTAINS IN THE LATE
AFTERNOON/EARLY EVENING WHILE THERE IS BOTH INSTABILITY AND WIND.
EXTENDED THE MOUNTAIN WARNING THROUGH TONIGHT...AND ISSUED AN
ADVISORY FOR THE FOOTHILLS...DENVER/BOULDER AND DOUGLAS AND ELBERT
COUNTIES WHERE THIS ENHANCEMENT WILL LIKELY CREATE SEVERAL HOURS OF
MODERATE TO HEAVY SNOW. HOPING THE HEAVIEST TIME FOR DENVER WILL
BE AFTER RUSH HOUR...BUT AT A MINIMUM THINGS WILL LIKELY BE GOING
DOWNHILL WITH SOME SNOWFALL AND COOLING TEMPERATURES. AREAS JUST
EAST OF THE ADVISORY MAY WIND UP NEEDING ONE...ESPECIALLY IF THE
WIND ON THE PLAINS LASTS LONGER THAN EXPECTED. THE CURRENT
EXPECTATION IS THAT THE STRONGEST WINDS WILL OCCUR BEFORE THERE IS
MUCH SNOW ON THE GROUND.
SNOW WILL BE DECREASING FROM NORTH TO SOUTH LATE TONIGHT THOUGH
THERE WILL LIKELY STILL BE LIGHT SNOW IN DENVER ALL NIGHT. BUMPED
TEMPERATURES UP SLIGHTLY THIS MORNING FOR THE FRONT TIMING...BUT
THEY WILL BE COLDER THIS AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM MST TUE MAR 3 2015
MAIN AXIS OF UPPER LEVEL TROUGH WILL BE MOVING ACROSS ERN CO WED
MORNING AND THEN BE EAST OF AREA BY 18Z. CROSS-SECTIONS STILL SHOW
WEAK UPSLOPE COMPONENT THRU MID MORNING WITH QUITE A BIT OF MOISTURE
SO THERE WILL LIKELY BE SOME LIGHT SNOW FM DENVER SOUTH ACROSS THE
PALMER DIVIDE INTO THE FOOTHILLS. EXPECT MOST OF THIS ACTIVITY WILL
GRADUALLY END BY MID TO LATE MORNING. OTHERWISE DRIER AIR WILL
SPREAD ACROSS THE RGN BY AFTN WITH DECREASING CLOUDS AND ONLY A A
SLIGHT CHC OF -SN IN THE MTNS. AFTN HIGHS WILL BE WELL BLO NORMAL
AS READINGS OVER NERN CO RANGE FROM THE UPPER TEENS TO LOWER 20S.
ON THU A WK DISTURBANCE WILL MOVE ACROSS THE AREA IN NW FLOW ALOFT
HOWEVER THIS FEATURE HAS NO MOISTURE WITH IT SO WILL KEEP FCST DRY.
AS FOR HIGHS 850-700 MB TEMPS RISE AROUND 10-11 DEGREES C BY LATE
AFTN SO SHOULD SEE READINGS WRM INTO THE 35 TO 40 DEGREE RANGE OVER
NERN CO WITH LOWER TO MID 40S OVER THE FAR NERN CORNER. FOR FRI DRY
NWLY FLOW ALOFT WILL CONTINUE WITH 850-700 MB TEMPS RISING ANOTHER 3-
DEGREES C WHICH SHOULD ALLOW FOR HIGHS TO REACH THE 45 TO 50 DEGREE
RANGE OVER NERN CO.
OVER THE WEEKEND NWLY FLOW ALOFT WILL REMAIN OVER THE AREA WITH SOME
MOISTURE EMBEDDED IN THE FLOW. THUS MAY SEE A CHC OF LIGHT SNOW IN
THE MTNS ESPECIALLY SAT AFTN AND EVENING AS A WK DISTURBANCE MOVES
ACROSS. OVER NERN CO A COOL FNT WILL MOVE ACROSS LATE FRI NIGHT INTO
SAT. CROSS-SECTIONS DO NOT SHOW MUCH MOISTURE WITH THIS FNT SO WILL
KEEP FCST DRY FOR NOW. HIGHS WILL BE IN THE LOWER TO MID 40S OVER
THE PLAINS ON SAT AND THEN SLIGHTLY WARMER ON SUN WITH READINGS IN
THE 45 TO 50 DEGREE RANGE.
FOR EARLY NEXT WEEK THE FLOW ALOFT WILL CONTINUE NWLY WITH NOT MUCH
MOISTURE SHOWN SO WILL NOT MENTION ANY PCPN. TEMPS WILL CONTINUE TO
MODERATE WITH READINGS IN THE LOWER TO MID 50S ACROSS NERN CO ON MON.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 958 AM MST TUE MAR 3 2015
LIGHT SNOW WILL SLOWLY INCREASE OVER THE DENVER AREA AFTER 21Z.
VISIBILITY IS EXPECTED TO REMAIN 2-5 MILES THROUGH 21Z AND THEN
LOWER. CEILINGS ARE EXPECTED TO STAY BELOW 2000 TODAY AND BE LOWER
TONIGHT. POCKETS OF HEAVIER SNOW MAY REDUCE VISIBILITY TO A HALF
MILE FOR A SHORT TIME.
NORTH TO NORTHEAST WINDS UP TO 20 KNOTS WILL SLOWLY DECREASE
THROUGH THE NEXT 24 HOURS. WINDS MAY SHIFT EASTERLY FOR A SHORT
TIME BUT WILL BOUNCE BACK TO THE NORTH-NORTHEAST WITH A SECOND
PUSH FROM THE NORTH AROUND 03Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 5 AM MST
WEDNESDAY FOR COZ035-036-039>041.
WINTER STORM WARNING UNTIL 5 AM MST WEDNESDAY FOR COZ031-033.
&&
$$
UPDATE...MEIER
SHORT TERM...GIMMESTAD
LONG TERM...RPK
AVIATION...MEIER
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1235 PM EST TUE MAR 3 2015
.PREV DISCUSSION... /ISSUED 1037 AM EST TUE MAR 3 2015/
UPDATE...
VERY FEW CHANGES THIS MORNING...MAINLY SOME TWEAKS TO ACCOUNT FOR
CURRENT TRENDS AND DESPITE THE WIDESPREAD CLOUDS...TEMPS ARE
RISING A LITTLE MORE QUICKLY THAN ANTICIPATED SO HAVE ADJUSTED
HIGHS AND WILL UPDATE PRODUCTS SHORTLY. OTHERWISE...CONTINUED
CLOUDS AND SPOTTY RAIN/DRIZZLE.
TDP
PREV DISCUSSION... /ISSUED 623 AM EST TUE MAR 3 2015/
PREV DISCUSSION... /ISSUED 315 AM EST TUE MAR 3 2015/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
WEAK FRONTAL BOUNDARY LOOKS TO BE SITUATED ACROSS THE SOUTHERN CWFA
THIS MORNING AND CAN MOSTLY BE FOUND BY THE DECENT DEWPOINT
GRADIENT. SOME PATCHY FOG IS NOTED SOUTH OF THE BOUNDARY...BUT THE
LOWER CIGS AND VSBYS REMAIN JUST SOUTH OF THE CWFA. DO THINK SOME OF
THE FOG WILL ADVECT NORTHWARD...MAINLY ALONG AND SOUTH OF A COLUMBUS
TO MACON LINE. FURTHER NORTH...A LIGHT NORTHERLY WIND HAS KEPT
THINGS A LITTLE MORE MIXED WITH LARGER TEMP/DEWPOINT SPREADS. LOW
CLOUDS/FOG/DRIZZLE MAY BE A LITTLE HARDER TO GET NORTH OF THE WEAK
FRONT.
RECENT RUNS OF THE HRRR HAVE BEEN PRETTY CONSISTENT WITH BRINGING A
MORE ORGANIZED AREA OF LIGHT TO MODERATE RAINFALL ACROSS NORTH AND
CENTRAL GA TOWARDS SUNRISE. THIS SOLUTION SEEMS REASONABLE...AS
WATER VAPOR AND RAP40 500MB ANALYSIS SHOWS A SHORTWAVE APPROACHING
NORTHERN GA. LOW LEVEL WINDS ARE EXPECTED TO TURN MORE EASTERLY
NORTH OF THE WEAK FRONT TODAY AS A WEDGE TRIES TO BUILD IN FROM THE
NORTHEAST. SO...POPS SHOULD BE THE HIGHEST ACROSS THE FAR NORTH WITH
LIGHT RAIN AND/OR A PROLONGED PERIOD OF DRIZZLE IS LIKELY FOR THE
LATE MORNING AND AFTERNOON. ALONG AND SOUTH OF THE
BOUNDARY/WEDGE...PRECIP SHOULD BE MORE HIT AND MISS AND CHANCE OR
SLIGHT CHANCE POPS SHOULD BE SUFFICIENT. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OR THUNDER OR TWO LATER THIS AFTERNOON...BUT CHANCES
REMAIN TOO SMALL TO MENTION AT THIS TIME. A MORE ORGANIZED AREA OF
PRECIPITATION IS EXPECTED BY WEDNESDAY MORNING AS A COLD FRONT
APPROACHES FROM THE NW.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY AGAIN TODAY. AREAS
SOUTH OF THE WEAK BOUNDARY WILL REMAIN IN WARM SOUTHERLY FLOW. AREAS
NORTH WILL REMAIN N/NE. IF THE BOUNDARY MOVES A LITTLE NORTHWARD
BEFORE WASHING OUT OVERNIGHT...THEN TEMPS ACROSS THE CENTRAL PORTION
OF THE FORECAST AREA HAVE THE POTENTIAL TO BUST...AGAIN. MILD
CONDITIONS EXPECTED OVERNIGHT AS MODELS CONTINUE TO ERODE THE WEDGE.
WARMER THAN NORMAL TEMPS LIKELY ON WEDNESDAY AHEAD OF THE
FRONT...EVEN NEAR 80 IN THE FAR SOUTH CWFA WITH LOWER 70S IN THE
METRO AREA.
NLISTEMAA
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
EXTENDED FORECAST PERIOD STARTS OUT WITH A LOT OF UNCERTAINTY AS
MEDIUM RANGE MODELS CONTINUE TO TREND A BIT SLOWER WITH THE PUSH OF
COLD AIR INTO NORTHWEST GEORGIA...AND A BIT WARMER AS WELL. MAV MOS
LOWS THURSDAY MORNING REMAIN AT OR ABOVE FREEZING NOW AND MET MOS
LOWS REMAIN ALL ABOVE. EVEN SO...IF WE ARE CLOSER TO THE COOLER MAV
AT THE MOS SITES WE SHOULD SEE SOME AREAS AT OR A DEGREE OR TWO
BELOW FREEZING BEFORE SUNUP THURSDAY IN THE FAR NORTH. THIS FITS THE
TRENDS IN THE ICE ACCUMULATION FORECASTS FROM THE WWD AS WELL WHICH
ARE PULLING LIGHT ACCUMULATIONS BACK FURTHER TO THE NORTHWEST. I
HAVE ADJUSTED GRIDDED WEATHER TO SHOW LIKELY RAIN WITH CHANCE
FREEZING RAIN AND SLEET AT THE COOLER GRID POINTS AND LIKELY RAIN
WITH CHANCE SLEET AT THE MORE BORDERLINE GRID POINTS FROM MIDNIGHT
THROUGH SUNUP...WITH LINGERING CHANCE/SLIGHT CHANCE FOR A MIX AT THE
COOLER POINTS IN THE FAR NORTH THROUGH THE DAY AS BETTER POPS PUSH
SOUTH AND EAST OF THAT AREA. WITH THE QPF VALUES FORECAST AND
RELATIVELY WARM ANTECEDENT CONDITIONS MY TOTAL ICE ACCUMULATION
GRIDS ARE GENERALLY .10 INCH OR LESS WHICH ALSO LINES UP WELL WITH
WWD FORECAST VALUES. WITH THE TREND TOWARD AT LEAST A SLIGHTLY
WARMER SCENARIO I AM NOT NEAR THE CONFIDENCE LEVEL NEEDED TO GO OUT
WITH A WINTER WEATHER WATCH AT THIS POINT...BUT WE WILL NEED TO KEEP
A CLOSE EYE ON TRENDS THROUGH THE NEXT COUPLE OF FORECAST CYCLES.
LOOKS COOL BUT GENERALLY DRY FOR THURSDAY NIGHT/FRIDAY BUT
TEMPERATURES REBOUND NICELY INTO THE WEEKEND AS GENERALLY ZONAL
UPPER-LEVEL FLOW PATTERN KEEPS THE BETTER COLD AIR NORTH AND WEST OF
THE FORECAST AREA. HARD TO GO ABOVE SLIGHT CHANCE/LOW CHANCE FOR
POPS THROUGH ANY OF THE REMAINDER OF THE EXTENDED FORECAST PERIOD AS
NO SIGNIFICANT FOCUS FOR BETTER...MORE ORGANIZED...PRECIPITATION
CHANCES ARE EVIDENT IN THE PERSISTENT ZONAL FLOW.
20
&&
.AVIATION...
18Z UPDATE...
WIDESPREAD IFR TO LIFR CONDITIONS FOR NORTHERN TAFS...MVFR
CREEPING UP TO MCN/CSG. MCN/CSG WILL CONTINUE TO IMPROVE AND
LIKELY SEE VFR LATER THIS EVENING...BUT NORTHERN TAFS WILL REMAIN
IFR TO AT BEST BRIEFLY LOW MVFR THROUGH THE EVENING. EXPECT LIFR
AGAIN OVERNIGHT ESPECIALLY NORTHERN TAFS AND CANNOT RULE OUT CIGS
AS LOW AS 002...WITH GRADUAL LIFTING LATE MORNING WEDNESDAY. WILL
PROBABLY SEE AT LEAST SOME MVFR BY THE END OF THE PERIOD. ESE
WINDS ALL BUT MCN/CSG TO START...WITH SHIFT TO SW EXPECTED
OVERNIGHT...CURRENT TIMING AROUND 08Z. COULD SEE LOW-END GUSTS ATL
WEDNESDAY AFTERNOON.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON LIFTING POTENTIAL THIS AFTERNOON/EVENING.
HIGH ON OVERNIGHT CIG TRENDS...MEDIUM ON ACTUAL CIGS.
HIGH ON WINDS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 55 49 72 54 / 60 30 10 70
ATLANTA 60 55 70 45 / 60 20 20 70
BLAIRSVILLE 54 47 62 42 / 70 70 50 70
CARTERSVILLE 55 52 69 40 / 60 40 40 70
COLUMBUS 75 60 75 54 / 30 10 10 60
GAINESVILLE 51 47 67 47 / 60 50 30 70
MACON 67 58 77 59 / 20 20 5 50
ROME 58 53 68 37 / 60 50 50 70
PEACHTREE CITY 63 56 71 48 / 50 20 20 70
VIDALIA 69 62 79 62 / 20 10 5 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
355 PM CST TUE MAR 3 2015
.SHORT TERM...
247 PM CST
THROUGH THURSDAY...
SOMEWHAT BAGGY COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING
AND USHER IN PROGRESSIVELY COLDER AIR MASS THROUGH THE NIGHT. AHEAD
OF THE INTO THE EARLY-MID EVENING ANTICIPATE LOW STRATUS HANGING
AROUND AND LIKELY RESULTING IN NEARLY STEADY TEMPS AND HAVE GONE A
BIT ABOVE HOURLY GUIDANCE TEMPS HANGING ONTO 30S INTO THE EARLY
EVENING OVER MOST OF THE CWA BEFORE BOTTOM DROPS OUT LATE TONIGHT.
SOME PARTIAL CLEARING IS EXPECTED OVERNIGHT BUT SOME MID-HIGH CLOUDS
WILL MOVE IN AS WELL...SO NOT CURRENTLY EXPECTING SKIES TO GO CLEAR.
A COUPLE DAYS OF UNSEASONABLY COLD WEATHER LOOK TO BE ON TAP
WEDNESDAY AND THURSDAY. WEDNESDAY NIGHT HAS POTENTIAL TO GIVE
CHICAGO`S RECORD LOW A RUN FOR ITS MONEY...THOUGH GUIDANCE SUGGESTS
MID-HIGH LEVEL CLOUDINESS COULD BE RATHER EXTENSIVE FOR MUCH OF THE
NIGHT AND WINDS STAYING UP A BIT. BOTH OF THESE FACTORS COULD KEEP
TEMPS FROM REALIZING THEIR FULL FRIGID POTENTIAL...THOUGH ANY LATE
NIGHT CLEARING COULD ALLOW FOR LAST MINUTE DROPS IN TEMPS. ARCTIC
HIGH WILL BE NEAR BY THURSDAY WITH HEART OF THE ARCTIC AIR MASS
OVERHEAD TO START THE DAY...SUGGESTING THAT HIGHS COULD THREATEN
RECORD LOW MAX TEMPS. FULL SUNSHINE THURSDAY WITH LOWER ALBEDO IN
CHICAGO AND RFD METRO AREAS SHOULD ALLOW TEMPS TO MODERATE A BIT
ABOVE GUIDANCE AND HAVE TRENDED HIGHS EVER SO SLIGHTLY UPWARD.
IZZI
&&
.LONG TERM...
247 PM CST
THURSDAY NIGHT THROUGH TUESDAY...
THURSDAY NIGHT COULD BE ONE OF THOSE NIGHTS THAT SEE TEMPERATURES
CRASH DURING THE EVENING HOURS GIVEN CLEAR SKIES AND PROXIMITY OF
THE HIGH. HIGH DOES SCOOT OFF TO THE EAST OVERNIGHT AND SOUTHERLY
WINDS LOOK TO DEVELOP AFTER MIDNIGHT WHICH SHOULD ALLOW TEMPS TO
LEVEL OFF AND THEN BEGIN TO SLOWLY RISE PRIOR TO SUNRISE AND DID
REFLECT THIS TREND IN THE HOURLY TEMP GRIDS.
FRIDAY INTO NEXT WEEK LOOK TO BE FAIRLY QUIET PERIOD WITH A TREND TO
NORMAL AND THEN POTENTIALLY EVEN ABOVE NORMAL TEMPS BY EARLY NEXT
WEEK. STRONG MARCH SUN AND TEMPS WARMING ABOVE FREEZING THIS WEEKEND
DURING THE DAYTIME SHOULD BEGIN THE PROCESS OF CHIPPING AWAY AT THE
DEEP SNOW PACK/GLACIER THAT HAS BLANKETED THE REGION SINCE THE EARLY
FEBRUARY BLIZZARD. MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN
EXTENDED PERIOD OF ABOVE AVERAGE TEMPERATURES HEADING INTO THE
MIDDLE OF THE MONTH...THE QUICKER THE SNOW PACK MELTS THE WARMER
TEMPS COULD POTENTIALLY GET AS A MEAN RIDGE IS PROGGED TO DEVELOP OF
THE NATION`S MID SECTION.
IZZI
&&
.CLIMATE...
WE COULD COME CLOSE TO A COUPLE RECORDS WITH THIS NEXT COLD SPELL.
THE ONES WITH STARS (*) ARE MOST VULNERABLE.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890) 12 (1901)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MVFR CIGS EXPECTED THROUGH THE NIGHT BCMG VFR WEDNESDAY MORNING.
* WEST WINDS GUSTING TO 22 KT THIS AFTN.
* NW WINDS GUSTING TO 25 KT WEDNESDAY.
JEE
//DISCUSSION...UPDATED 18Z...
WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF
A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA.
CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS
TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEW POINTS RISE
INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY
SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC
TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW
FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT
SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED
OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG
THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY
MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET
GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO
END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT
LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK
EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD
GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS
COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE
FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP
DRIVE NWLY GUSTS TO 25KT TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH CONFIDENCE IN WHEN CIGS IMPROVE TO VFR.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH FRIDAY...VFR.
SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
230 PM...LOW PRESSURE OVER THE NORTHERN LAKES WILL MERGE WITH
DEEPER LOW PRESSURE OVER NORTHERN ONTARIO TONIGHT AND THEN MOVE
INTO QUEBEC WEDNESDAY MORNING. WINDS WILL BE SHIFTING WESTERLY
OVER THE NEXT FEW HOURS AND THEN MORE NORTHWEST ACROSS THE
SOUTHERN PART OF THE LAKE OVERNIGHT. THE GRADIENT WILL REMAIN
TIGHT AS HIGH PRESSURE BUILDS ACROSS THE NORTHERN AND CENTRAL
PLAINS WEDNESDAY AND WEDNESDAY NIGHT AND COMBINED WITH RETURNING
COLD AIR...WINDS TO 30KT LOOKS REASONABLE. AS THE HIGH MOVES EAST
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES WITH
SOUTHWEST WINDS INCREASING BACK TO 30KT WITH SOME POTENTIAL FOR
LOW END GALES. THESE WINDS WILL GRADUALLY DIMINISH FRIDAY NIGHT AS
THE GRADIENT BEGINS TO WEAKEN. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
331 PM CST Tue Mar 3 2015
.SHORT TERM...(Tonight)
ISSUED AT 330 PM CST TUE MAR 3 2015
Freezing rain and sleet developed over western Illinois around
midnight and quickly tracked east over all but extreme southeast
Illinois by 08z/2am. Already seeing the backedge of our second
band of wintry precip entering west central Illinois, so it appears
we will have a brief lull in the freezing rain and sleet. However,
the latest HRRR suggests another band of rain, freezing rain and
sleet will move northeast across our area at or just after dawn
Rainfall rates have not been much with these quick moving bands
of freezing rain/sleet with most areas seeing less than 0.05" per
hour, but certainly enough for some light icing to occur on bridge
decks and overpasses and on lesser traveled roads.
RAP forecast soundings continue to suggest temperatures will rise
above the freezing mark over southeast Illinois by dawn...central
sections of the forecast area by 900 am...and between 10 am and Noon
roughly along and north of the Interstate 74 corridor. By late
morning into the afternoon hours the stronger lift associated with
the low level warm advection/ isentropic ascent shifts off to our
east and southeast with a gradual lowering of POPs warranted from
northwest to southeast. Best 850-700 forcing edges into southeast IL
by mid to late afternoon where our highest POPs will be located.
Guidance temperatures look reasonable for this afternoon with highs
ranging from the upper 30s far north to the upper 40s far southeast.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 330 PM CST TUE MAR 3 2015
The cold front currently passing through the forecast area will
stall out south of the Ohio River Valley early Wednesday as it
becomes parallel to the upper-level flow. A 180+ kt jet streak will
be in our vicinity on the cool side of this front/low level
baroclinic zone for much of the day Wednesday. A very small portion
of our forecast area south of I-70 will be at least nicked by the
good frontogenetical forcing/jet dynamics in this flow regime. With
this in mind it is looking like 2-4 inches of snow will fall late
tonight through Wednesday evening across at least Clay, Richland,
and Lawrence counties. There is some model disagreement on where the
axis of heavier snow will set up, and the snow totals may need to
be boosted a little and pushed further north or decreased and pulled
further south depending on future model runs.
The snow threat in southeast IL diminishes later Wednesday night, as
the current system finally pulls away, and another Arctic high
(hopefully the last of the winter) builds into the entire forecast
area. This high will be accompanied by a couple nights of mainly
single digit lows Wednesday night and Thursday night, and highs
mainly in the teens for Thursday.
Temperatures are still expected to gradually moderate beginning
Friday and continuing into next week. High temperatures may actually
be above normal for a change by early next week, with highs in the
50s possible by next Tuesday. The models do not suggest the passage
of any significant system from Thursday-Tuesday, so predominantly
dry weather looks to be the rule through the period.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1157 AM CST TUE MAR 3 2015
Mainly LIFR cigs/IFR vsbys in fog and -dz/-ra across central IL
late this morning. Conditions expected to remain steady for a few
more hours before gradual lifting of ceilings during afternoon as
a cold front and drier air approach from the NW. Gradual
improvement to continue from 20Z through 06Z before MVFR ceilings
dissipate to scattered cloud cover. Winds S-SW 15-20 kts with
higher gusts through early afternoon, gradually shifting to NW
through evening and decreasing to 10-15 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 6 AM to 6 PM CST Wednesday FOR
ILZ071>073.
&&
$$
SHORT TERM...Onton
LONG TERM...Bak
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
151 PM CST TUE MAR 3 2015
.UPDATE...
1022 AM CST
THE MORE SIGNIFICANT PRECIP IS MOVING OFF TO THE EAST AND SHOULD SEE
PRECIP TAPER TO DRIZZLE/FREEZING DRIZZLE WITH JUST SOME INTERMITTENT
LIGHT RAIN OR FREEZING RAIN INTO THE EARLY AFTERNOON. TEMPERATURES
SHOULD CONTINUE TO INCH UPWARD AND CLIMB ABOVE FREEZING ACROSS THE
AREA IN THE NEXT COUPLE HOURS. IT IS POSSIBLE THAT WINTER WX
ADVISORY COULD NEED TO BE EXTENDED A COUPLE OF HOURS OVER NORTHERN
PORTIONS OF THE CWA...WILL CONTINUE TO MONITOR TEMP TRENDS AND MAKE
A LAST MINUTE DECISION ON THAT.
IZZI
&&
.SHORT TERM...
300 AM CST
THROUGH WEDNESDAY...
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE
ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING.
SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS
EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID
MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM
ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO
INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN
SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM
MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS
MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST
CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND
NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH
WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID
MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING
SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA
BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR
AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS
INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME
MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO
LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT
LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES
PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH
OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z
AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE
LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE
THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH
IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE
BEFORE ENDING ALTOGETHER THIS EVENING.
HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT
WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE
TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME
INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS
EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW
CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION
WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST
CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL
NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER
DEUBELBEISS
&&
.LONG TERM...
300 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH
PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO
DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH
MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY
NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN
COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO
RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD
COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH
PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND
WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY
NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO
DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD
FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING.
FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT
DOESNT COME THROUGH DRY.
DEUBELBEISS
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB/BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WSWLY WINDS GUSTING TO 20-25KT UNTIL FROPA EARLY THIS
EVENING...THEN WIND SHIFTING TO WNWLY OVERNIGHT AND NWLY
TOMORROW GUSTING TO 20KT.
* IFR VIS IN -DZ/BR FOR A COUPLE MORE HOURS...IMPROVING TO MVFR IN
BR UNTIL FROPA.
* IFR CIGS UNTIL FROPA...THEN IMPROVING TO MVFR OVERNIGHT INTO
EARLY TOMORROW MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF
A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA.
CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS
TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEWPOINTS RISE
INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY
SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC
TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW
FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT
SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED
OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG
THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY
MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET
GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO
END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT
LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK
EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD
GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS
COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE
FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP
DRIVE NWLY GUSTS TO 25KT TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TIMING PCPN ENDING.
* LOW CONFIDENCE IN TIMING OF CIGS/VIS IMPROVING TO MVFR AND VFR.
* HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH FRIDAY...VFR.
SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
214 AM CST
MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR
TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN
AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN
LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE
LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS
EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE
NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO
SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF
THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND
BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE
AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST
AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS
ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS
A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS
TO RELAX A BIT AND SHIFT TO THE WEST.
SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA
NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS.
RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS
A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN
ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS
WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME
GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR
TO HAVE A FAIR AMOUNT OF OPEN WATER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1157 AM CST Tue Mar 3 2015
.UPDATE...
ISSUED AT 1044 AM CST TUE MAR 3 2015
Temperatures have risen above 32 degrees at all sites with an
immediate threat for precipitation this morning, with all sites
expected above freezing in the next hour, therefore the winter
weather advisory has been allowed to expire. Temperatures expected
to continue to rise to the upper 30s to mid 40s this afternoon as
central Illinois remains in the warm sector of the current system.
Winds breezy S-SW 10-20 mph with dewpoints well into the 30s will
help melt the light ice accumulations off. Scattered light showers
continue to stream into the area from the southwest and this will
continue until after a cold front moves in from the northwest
later this afternoon and evening.
&&
.SHORT TERM...(Today)
ISSUED AT 244 AM CST TUE MAR 3 2015
Freezing rain and sleet developed over western Illinois around
midnight and quickly tracked east over all but extreme southeast
Illinois by 08z/2am. Already seeing the back edge of our second
band of wintry precip entering west central Illinois, so it appears
we will have a brief lull in the freezing rain and sleet. However,
the latest HRRR suggests another band of rain, freezing rain and
sleet will move northeast across our area at or just after dawn.
Rainfall rates have not been much with these quick moving bands
of freezing rain/sleet with most areas seeing less than 0.05" per
hour, but certainly enough for some light icing to occur on bridge
decks and overpasses and on lesser traveled roads.
RAP forecast soundings continue to suggest temperatures will rise
above the freezing mark over southeast Illinois by dawn...central
sections of the forecast area by 900 am...and between 10 am and Noon
roughly along and north of the Interstate 74 corridor. By late
morning into the afternoon hours the stronger lift associated with
the low level warm advection/ isentropic ascent shifts off to our
east and southeast with a gradual lowering of POPs warranted from
northwest to southeast. Best 850-700 forcing edges into southeast IL
by mid to late afternoon where our highest POPs will be located.
Guidance temperatures look reasonable for this afternoon with highs
ranging from the upper 30s far north to the upper 40s far southeast.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 244 AM CST TUE MAR 3 2015
Current system will not fully clear our area until Thursday, as the
trailing end of the cold front becomes parallel to the upper flow
over the Ohio Valley. Most of the evening models keep the threat for
precipitation from about I-70 southward, although the NAM has a
secondary surge on Wednesday afternoon all the way up to about I-72.
Leaning more toward the ECMWF/GFS blend for PoP`s tonight and
Wednesday. Lingering precip north of I-70 should end this evening,
but kept higher PoP`s all night into Wednesday. This evening, most
areas will see the precipitation switch briefly to snow before
ending, with little accumulation. While the transition to snow south
of I-70 occurs late tonight, temperatures will be supportive of all
snow through Wednesday. Greatest snow amounts expected near the Ohio
Valley, but currently think that 1 to 3 inches in southeast Illinois
is likely. Light snow will linger into Wednesday night before ending
late.
The other feature of note is what hopefully will be the last Arctic
blast of the winter. Digging upper trough currently coming into
Manitoba will spread a chunk of unseasonably cold air over much of
the Midwest Wednesday and Thursday, with 850 mb temperatures down
into the -18C range by Thursday morning. Highs both days will
struggle to get out of the teens in some areas -- normal highs are
well into the 40s by now -- and lows Thursday morning should be a
few degrees either side of zero. Current indications are that a wind
chill advisory would be needed across the northern CWA Wednesday
night and early Thursday, as the system to our south keeps the winds
up and slows the arrival of high pressure.
Heading into the weekend and early next week, 40s should become more
widespread, and the latest 8-14 day outlook introduces a foreign
concept called "above normal temperatures".
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1157 AM CST TUE MAR 3 2015
Mainly LIFR cigs/IFR vsbys in fog and -dz/-ra across central IL
late this morning. Conditions expected to remain steady for a few
more hours before gradual lifting of ceilings during afternoon as
a cold front and drier air approach from the NW. Gradual
improvement to continue from 20Z through 06Z before MVFR ceilings
dissipate to scattered cloud cover. Winds S-SW 15-20 kts with
higher gusts through early afternoon, gradually shifting to NW
through evening and decreasing to 10-15 kts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Onton
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1153 AM CST TUE MAR 3 2015
.UPDATE...
1022 AM CST
THE MORE SIGNIFICANT PRECIP IS MOVING OFF TO THE EAST AND SHOULD SEE
PRECIP TAPER TO DRIZZLE/FREEZING DRIZZLE WITH JUST SOME INTERMITTENT
LIGHT RAIN OR FREEZING RAIN INTO THE EARLY AFTERNOON. TEMPERATURES
SHOULD CONTINUE TO INCH UPWARD AND CLIMB ABOVE FREEZING ACROSS THE
AREA IN THE NEXT COUPLE HOURS. IT IS POSSIBLE THAT WINTER WX
ADVISORY COULD NEED TO BE EXTENDED A COUPLE OF HOURS OVER NORTHERN
PORTIONS OF THE CWA...WILL CONTINUE TO MONITOR TEMP TRENDS AND MAKE
A LAST MINUTE DECISION ON THAT.
IZZI
&&
.SHORT TERM...
300 AM CST
THROUGH WEDNESDAY...
MAIN FORECAST CONCERNS THIS MORNING WILL BE DEALING WITH PRECIP TYPE
ISSUES WITH WARM FRONT LIFTING ACROSS THE REGION EARLY THIS MORNING.
SURFACE LOW IS IN PLACE ACROSS EASTERN COLORADO AND WESTERN KANSAS
EARLY WITH AXIS OF STRONGEST PRESSURE FALLS SPRAWLED ACROSS THE MID
MISSOURI VALLEY INTO SOUTHEASTERN MINNESOTA. MID LEVEL WARM
ADVECTION IS RAMPING UP ACROSS THE MIDWEST AND WILL CONTINUE TO
INCREASE ACROSS NORTHERN ILLINOIS OVER THE NEXT FEW HOURS...THEN
SHOULD START TO SPREAD NORTH AND NORTHEAST OF THE FORECAST AREA FROM
MID MORNING ON. WIDESPREAD PRECIPITATION NOTED ON RADAR ALREADY THIS
MORNING WITH REPORTS OF FREEZING RAIN AND SLEET UPSTREAM. BEST
CHANCE FOR ANY SNOW ACCUMULATIONS WITH THIS SYSTEM WILL BE ALONG AND
NORTH OF I-80...BUT PARTICULARLY CLOSER TO THE WI STATE LINE WHICH
WILL REMAIN MARGINALLY COLD ENOUGH ALOFT FOR SNOW THROUGH MID
MORNING. H9-H8 LAYER MAX WET BULB TEMPS WILL RISE ABOVE FREEZING
SOUTH OF THE I-80 CORRIDOR BY AROUND 12Z...AND ACROSS THE ENTIRE CWA
BY 15Z AT WHICH POINT SLEET OR FREEZING RAIN CAN BE EXPECTED FOR
AREAS WITH SURFACE TEMPS STILL BELOW FREEZING. GUIDANCE IS
INITIALIZING TOO COLD WITH SURFACE TEMPS THIS MORNING...AND SOME
MODELS SUCH AS THE NAM SEEM TO HOLD ON TO FREEZING TEMPS TOO
LONG...SO FEEL THE THREAT FOR FREEZING RAIN MAY BE SOMEWHAT
LIMITED...THOUGH ANY ICE ACCUMULATIONS WILL CAUSE ISSUES
PARTICULARLY WITH THE TIMING DURING THE MORNING COMMUTE. AREAS SOUTH
OF I-80 SHOULD SEE SURFACE TEMPS RISE ABOVE THE FREEZING MARK 13-15Z
AND THROUGH 15-17Z THE FREEZING LINE SHOULD LIFT UP TO THE STATE
LINE MARKING THE END OF THE FREEZING RAIN THREAT. MEANWHILE...LATE
THIS MORNING INTO THE EARLY AFTERNOON MID LEVEL DRY SLOT WILL PUNCH
IN FROM THE WEST WITH PRECIP TAPERING TO A LIGHT RAIN OR DRIZZLE
BEFORE ENDING ALTOGETHER THIS EVENING.
HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE NORTHERN PLAINS TONIGHT
WITH A MODERATE NORTHWEST GRADIENT AND COLD/DRY ADVECTION IN PLACE
TONIGHT. STEEP LOW LEVEL LAPSE RATES DEVELOP AND THERE IS SOME
INDICATION THERE MAY BE A FEW LIGHT FLURRIES THAT DEVELOP THIS
EVENING AND EARLY OVERNIGHT BEFORE DRIER AIR MOVES IN...BUT FOR NOW
CHANCES SEEM TOO LOW TO INCLUDE MENTION IN FORECAST. COLD ADVECTION
WILL DRIVE TEMPERATURES INTO THE SINGLE DIGITS IN THE NORTHWEST
CWA...AND UPPER TEENS TO LOW 20S IN THE SOUTHEAST. TEMPERATURES WILL
NOT REBOUND MUCH ON WEDNESDAY WITH HIGHS IN THE HIGH TEENS TO LOWER
DEUBELBEISS
&&
.LONG TERM...
300 AM CST
WEDNESDAY NIGHT THROUGH MONDAY...
FAIRLY QUIET WEATHER EXPECTED FROM MIDWEEK THROUGH THE WEEKEND. HIGH
PRESSURE WILL BUILD FROM THE NORTHERN PLAINS WEDNESDAY NIGHT TO
DOWNSTATE ILLINOIS THURSDAY. COLDER AIR WILL ACCOMPANY THE HIGH WITH
MODELS CONTINUING TO ADVERTISE H85 TEMPS AROUND -20C WEDNESDAY
NIGHT. HIGH PRESSURE CENTERED TO OUR WEST WILL ALLOW WESTERN
COUNTIES TO BEGIN TO CLEAR AND WINDS TO DECOUPLE ALLOWING TEMPS TO
RADIATE BELOW ZERO...THOUGH A MODEST GRADIENT AND LINGERING CLOUD
COVER IN EASTERN COUNTIES MAY PROP UP TEMPS ABOVE ZERO. HIGH
PRESSURE SHIFTS TO OUR EAST LATER ON THURSDAY AND RETURN FLOW AND
WARM ADVECTION WILL RESULT IN TEMPS LEVELING OFF OR RISING THURSDAY
NIGHT. THIS IS IN ADVANCE OF LOW PRESSURE OVER NORTHERN ONTARIO
DRAGGING A COLD FRONT ACROSS THE UPPER MIDWEST. TEMPERATURES SHOULD
BE ABLE TO RISE ABOVE FREEZING FRIDAY AND SATURDAY BEFORE THE COLD
FRONT PASSES THROUGH NORTHERN ILLINOIS SATURDAY AFTERNOON/EVENING.
FRONT IS PRETTY MOISTURE STARVED SO MAYBE A FEW FLURRIES IF IT
DOESNT COME THROUGH DRY.
DEUBELBEISS
&&
.CLIMATE...
A FEW RECORD LOW AND AND RECORD LOW MAXIMUM TEMPERATURES ARE IN
JEOPARDY ON WEDNESDAY AND THURSDAY.
HERE ARE THE CURRENT RECORDS FOR ROCKFORD AND CHICAGO. THE ONES THAT
STAND THE BEST CHANCE TO BE REACHED OR BROKEN HAVE A STAR (*) NEXT TO
THEM.
WED 3/4 THU 3/5
ROCKFORD
RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*
CHICAGO
RECORD LOW-12 (1873) 0 (1978)*
RECORD LOW MAX 17 (1890)* 12 (1901)
KMD/KJB/BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* FREEZING DRIZZLE CHANGING OVER TO DRIZZLE OR OCNL LIGHT RAIN AS
TEMPS RISE ABOVE FREEZING.
* IFR CIGS UNTIL FROPA LATE AFTERNOON/EARLY EVENING...THEN
IMPROVING TO MVFR OVERNIGHT INTO EARLY TOMORROW MORNING.
* SSWLY WINDS GUSTING TO 25KT...VEERING TO WLY BY EARLY EVENING...
THEN VEERING NWLY AND GUSTING TO 25KT TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF
A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA.
CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS
TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEWPOINTS RISE
INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY
SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC
TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW
FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT
SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED
OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG
THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY
MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET
GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO
END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT
LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK
EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD
GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS
COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE
FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP
DRIVE NWLY GUSTS TO 25KT TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TIMING PCPN ENDING.
* LOW CONFIDENCE IN TIMING OF CIGS/VIS IMPROVING TO MVFR AND VFR.
* HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT THROUGH FRIDAY...VFR.
SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE.
RATZER
&&
.MARINE...
214 AM CST
MAIN FOCUS FOR THE LAKE MICHIGAN FORECAST REMAINS IN THE NEAR
TERM...AS SOUTH WINDS INCREASE QUICKLY THIS MORNING IN ADVANCE OF AN
AREA OF LOW PRESSURE MOVING QUICKLY FROM THE PLAINS TO THE WESTERN
LAKES BY THIS EVENING. SOUTH WINDS TO 30 KT...WITH A FEW GALE FORCE
GUSTS TO 35 KT...ARE EXPECTED ON MAINLY THE SOUTHERN PORTION OF THE
LAKE. THE LOW WILL TRAIL A COLD FRONT ACROSS THE LAKE EARLY THIS
EVENING WHICH WILL SHIFT WINDS TO THE WEST INITIALLY AND MORE
NORTHWEST OVERNIGHT AND WEDNESDAY...AS THE GRADIENT CONTINUES TO
SUPPORT 25-30 KT WINDS AS HIGH PRESSURE SLOWLY BUILDS FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY. THE HIGH WILL PASS SOUTHWEST OF
THE LAKES THURSDAY AND THURSDAY NIGHT ALLOWING WINDS TO EASE AND
BACK SOUTHWEST BY EARLY FRIDAY. THE GRADIENT WILL TIGHTEN UP ONCE
AGAIN FRIDAY HOWEVER...BETWEEN THE HIGH RETREATING TO THE SOUTHEAST
AND AN AREA OF LOW PRESSURE MOVING NORTH OF THE LAKES ACROSS
ONTARIO. 30 KT SOUTHWESTERLIES LIKELY FRIDAY...BEFORE THE LOW TRAILS
A COLD FRONTAL TROUGH INTO THE AREA EARLY SATURDAY AND ALLOWS WINDS
TO RELAX A BIT AND SHIFT TO THE WEST.
SMALL CRAFT HEADLINES REMAIN UP FOR THE ILLINOIS AND INDIANA
NEARSHORE TODAY THROUGH WEDNESDAY EVENING FOR THE 25-30 KT WINDS.
RECENT POLAR-ORBITING SATELLITE IMAGERY FROM MONDAY AFTERNOON SHOWS
A GOOD PORTION OF THE ILLINOIS SHORE TO BE MAINLY OPEN WATER OR THIN
ICE FLOES...THUS HAVE INCLUDED WAVE FORECAST FOR ILLINOIS WATERS
WHILE INDIANA SHORE APPEARS TO REMAIN LARGELY ICE-COVERED. THE SAME
GOES FOR WESTERN PORTIONS OF NORTHERN LAKE MICHIGAN...WHICH APPEAR
TO HAVE A FAIR AMOUNT OF OPEN WATER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL NOON TUESDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1044 AM CST Tue Mar 3 2015
.UPDATE...
ISSUED AT 1044 AM CST TUE MAR 3 2015
Temperatures have risen above 32 degrees at all sites with an
immediate threat for precipitation this morning, with all sites
expected above freezing in the next hour, therefore the winter
weather advisory has been allowed to expire. Temperatures expected
to continue to rise to the upper 30s to mid 40s this afternoon as
central Illinois remains in the warm sector of the current system.
Winds breezy S-SW 10-20 mph with dewpoints well into the 30s will
help melt the light ice accumulations off. Scattered light showers
continue to stream into the area from the southwest and this will
continue until after a cold front moves in from the northwest
later this afternoon and evening.
&&
.SHORT TERM...(Today)
ISSUED AT 244 AM CST TUE MAR 3 2015
Freezing rain and sleet developed over western Illinois around
midnight and quickly tracked east over all but extreme southeast
Illinois by 08z/2am. Already seeing the back edge of our second
band of wintry precip entering west central Illinois, so it appears
we will have a brief lull in the freezing rain and sleet. However,
the latest HRRR suggests another band of rain, freezing rain and
sleet will move northeast across our area at or just after dawn.
Rainfall rates have not been much with these quick moving bands
of freezing rain/sleet with most areas seeing less than 0.05" per
hour, but certainly enough for some light icing to occur on bridge
decks and overpasses and on lesser traveled roads.
RAP forecast soundings continue to suggest temperatures will rise
above the freezing mark over southeast Illinois by dawn...central
sections of the forecast area by 900 am...and between 10 am and Noon
roughly along and north of the Interstate 74 corridor. By late
morning into the afternoon hours the stronger lift associated with
the low level warm advection/ isentropic ascent shifts off to our
east and southeast with a gradual lowering of POPs warranted from
northwest to southeast. Best 850-700 forcing edges into southeast IL
by mid to late afternoon where our highest POPs will be located.
Guidance temperatures look reasonable for this afternoon with highs
ranging from the upper 30s far north to the upper 40s far southeast.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 244 AM CST TUE MAR 3 2015
Current system will not fully clear our area until Thursday, as the
trailing end of the cold front becomes parallel to the upper flow
over the Ohio Valley. Most of the evening models keep the threat for
precipitation from about I-70 southward, although the NAM has a
secondary surge on Wednesday afternoon all the way up to about I-72.
Leaning more toward the ECMWF/GFS blend for PoP`s tonight and
Wednesday. Lingering precip north of I-70 should end this evening,
but kept higher PoP`s all night into Wednesday. This evening, most
areas will see the precipitation switch briefly to snow before
ending, with little accumulation. While the transition to snow south
of I-70 occurs late tonight, temperatures will be supportive of all
snow through Wednesday. Greatest snow amounts expected near the Ohio
Valley, but currently think that 1 to 3 inches in southeast Illinois
is likely. Light snow will linger into Wednesday night before ending
late.
The other feature of note is what hopefully will be the last Arctic
blast of the winter. Digging upper trough currently coming into
Manitoba will spread a chunk of unseasonably cold air over much of
the Midwest Wednesday and Thursday, with 850 mb temperatures down
into the -18C range by Thursday morning. Highs both days will
struggle to get out of the teens in some areas -- normal highs are
well into the 40s by now -- and lows Thursday morning should be a
few degrees either side of zero. Current indications are that a wind
chill advisory would be needed across the northern CWA Wednesday
night and early Thursday, as the system to our south keeps the winds
up and slows the arrival of high pressure.
Heading into the weekend and early next week, 40s should become more
widespread, and the latest 8-14 day outlook introduces a foreign
concept called "above normal temperatures".
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 500 AM CST TUE MAR 3 2015
MVFR cigs expected to deteriorate to IFR/LIFR this morning as the
freezing rain/drizzle continues. We expect a change over to light
rain at SPI between 14z-16z, CMI between 15z-17z and BMI and PIA
between 17z-18z. IFR to LIFR cigs will continue this afternoon
along with some light rain at times with short term models
suggesting a slight improvement to MVFR cigs after 21z as drier
air works east into the region. However, will continue with MVFR
cigs thru at least 02z this evening. Surface winds at all sites
will become south and increase to between 12 and 17 kts by 16z
with gusts in the 20-23kt range into the afternoon hours. We will
see the direction begin to veer more into the southwest and west
as a cold front approaches the area this afternoon and then into
the northwest at 10 to 15 kts just after 00z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Onton
SHORT TERM...Smith
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
110 PM EST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 1038 AM EST TUE MAR 3 2015
AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND
DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT.
LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED
ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE
THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER
30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER
TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT.
&&
.UPDATE...
ISSUED AT 1120 AM EST TUE MAR 3 2015
3 HR EXTENSION OF ADVISORY PRIMARILY FOR FREEZING RAIN PERSISTING
ACRS FAR NORTHERN/NORTHEAST CWA. SHALLOW INVERSION AFFORDING
SLOWER RECESSION ACRS DEEPER SNOWPACK/MORE DEEPLY ROOTED
ANTECEDENT ARCTIC AIRMASS. HOWEVER...WITH EARLY MARCH SUN PEAKING
HIR ALTITUDES...EXPECT EVENTUAL MIXOUT ACRS ENTIRE CWA TO AOA FZG.
MAR 3 PEAK SOLAR ALTITUDE AT KASW FOR EXAMPLE IS 42 DEGREES WHICH
SHOULD ALSO AFFORD RAPID IMPROVEMENT OF EVEN UNTREATED SFCS IN ALL
BUT INSOLATION SHELTERED LOCALES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST TUE MAR 3 2015
RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST
UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH
MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA
AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE
INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS
MORNING WHERE SFC TEMPS IN THE MID 20S.
PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND
HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY
REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z.
ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS
MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED
DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY
RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING
PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3
TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING.
THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE
MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING.
POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING
RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN
EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE
SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE
FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING
WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM
SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS
FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO
LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON.
CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS
RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN
THIS MORNING.
SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY
EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z.
HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY
LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE
BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN
FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS
COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE
AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK
TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS
DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2
INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING
ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL
WITHIN GOING ADVISORY WHICH WILL CONTINUE.
MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE
EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON
WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE
WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO
OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR
SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT
CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW
END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY
PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL
CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND
DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY
SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EST TUE MAR 3 2015
STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO
KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN
HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE
LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS
SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW
SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM
WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW
TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT
SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO
LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS
SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL
GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE
FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD
AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE
ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH
TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC
AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE
COLDEST HIGH AT FT WAYNE FOR THE DATE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 109 PM EST TUE MAR 3 2015
AMPLE AFTN SUN ANGLE AND WARM AIR ADVECTION SHOULD ALLOW PTYPE TO
CHANGE TO ALL LIQUID BY 19 UTC AT KFWA. CONTD MOISTURE FLUX FROM
SLOW MELTING SNOWPACK AND TOP/DOWN SATURATION TO LIKELY LEND LONG
DURATION IFR CIGS ACRS NRN INDIANA THROUGH AT LEAST MID.LATE
EAVENING. FRONTAL BOUNDARY CRTNLY ACRS WI INTO FAR ERN IA TO PUSH
EWD THROUGH REGION IN 01-03 UTC TIMEFRAME AND SHOULD LEAD TO
MIXOUT INVERSION TRAPPED MOISTURE FOR IMPROVED VSBYS/CIGS THROUGH
REMAINDER OF FCST PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005-008-009-012>018-020-022>027-032>034.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR INZ006-
007.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ078>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ004-
005-015-016-024-025.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...NONE.
&&
$$
UPDATE...MURPHY
SYNOPSIS...STEINWEDEL
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1123 AM EST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 1038 AM EST TUE MAR 3 2015
AREAS OF FREEZING RAIN AND SLEET WILL CHANGEOVER TO LIGHT RAIN AND
DRIZZLE THIS AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT.
LIGHT ICE ACCUMULATIONS WILL CREATE SLICK SPOTS ON UNTREATED
ROADS AND SIDEWALKS INTO THE EARLY AFTERNOON. TEMPERATURES BY LATE
THIS AFTERNOON AND EVENING SHOULD RECOVER INTO THE MID TO UPPER
30S BEFORE FALLING BACK INTO THE UPPER TEENS AND 20S LATER
TONIGHT INTO WEDNESDAY BEHIND A COLD FRONT.
&&
.UPDATE...
ISSUED AT 1120 AM EST TUE MAR 3 2015
3 HR EXTENSION OF ADVISORY PRIMARILY FOR FREEZING RAIN PERSISTING
ACRS FAR NORTHERN/NORTHEAST CWA. SHALLOW INVERSION AFFORDING
SLOWER RECESSION ACRS DEEPER SNOWPACK/MORE DEEPLY ROOTED
ANTECEDENT ARCTIC AIRMASS. HOWEVER...WITH EARLY MARCH SUN PEAKING
HIR ALTITUDES...EXPECT EVENTUAL MIXOUT ACRS ENTIRE CWA TO AOA FZG.
MAR 3 PEAK SOLAR ALTITUDE AT KASW FOR EXAMPLE IS 42 DEGREES WHICH
SHOULD ALSO AFFORD RAPID IMPROVEMENT OF EVEN UNTREATED SFCS IN ALL
BUT INSOLATION SHELTERED LOCALES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EST TUE MAR 3 2015
RADAR MOSAIC EARLY THIS MORNING SHOWING INCREASING RETURNS JUST
UPSTREAM AND SFC OBS INDICATE LOWER LEVELS SLOWLY SATURATING WITH
MIXED PCPN TYPES BEING REPORTED AT OBSERVING SITES ACROSS IL AND IA
AS EXPECTED. FORECAST REMAINS ON TRACK THOUGH DID REMOVE THE
INEXPLICABLE ANOMALOUS RAIN SHOWERS FROM GRIDS AND FORECAST THIS
MORNING WHERE SFC TEMPS IN THE MID 20S.
PREFERENCE THIS MORNING FOR THERMAL PROFILES LIES WITH NAM12 AND
HIRES RUC GUIDANCE WHICH ARE BOTH SIMILAR THROUGH THE MORNING. ONLY
REAL ISSUE IS WITH SFC TEMPS AT INITIALIZATION THROUGH ABOUT 14Z.
ALL HIRES GUIDANCE HAS BEEN TOO COLD WITH FALLING TEMPS EARLY THIS
MORNING...SEEMINGLY TRYING TO FOLLOW SOME TYPE OF CLIMO BASED
DIURNAL CURVE. SFC OBS ACROSS THE REGION SHOW STEADY OR SLOWLY
RISING TEMPS WITH WARM AIR ADVECTION OFFSETTING EVAP COOLING
PROCESSES. WHILE TEMPS MY DROP A DEGREE OR TWO...NOT EXPECTING A 3
TO 5 DEGREE DROP BEFORE RISING AS MOST GUIDANCE HAS BEEN SHOWING.
THUS HAD TO MANUALLY EDIT HOURLY TEMP GRIDS THROUGH 13Z BEFORE
MODEL TRENDS SEEM TO LATCH ONTO ACTUAL WARMING.
POWT PROCESS ONCE AGAIN USED FOR WEATHER GRID OUTPUT TODAY USING
RUC13 AND NAM12 AS BASE GRIDS. RESULTS GENERALLY AS WE HAVE BEEN
EXPECTING WITH A MIX OF FREEZING RAIN...SNOW AND SLEET EARLY IN THE
SOUTH AND WEST AND LIGHT SNOW INITIALLY NORTH AND EAST WITH A CHANCE
FOR SLEET. AS MENTIONED...DID REMOVE RAIN SHOWERS FOR THIS MORNING
WHERE TEMPS WERE BELOW 32F. TRANSITION ZONE WILL SLOWLY MOVE FROM
SOUTH TO NORTH THIS MORNING AS PCPN BECOMES FREEZING RAIN ALL AREAS
FOR A FEW HOURS. HIRES GUIDANCE DOES SHOW A BREAK IN PCPN MID TO
LATE MORNING BEFORE SECONDARY BATCH MOVES IN THIS AFTERNOON.
CONFIDENCE LOW IN TRYING TO TIME THIS OUT BUT IS WORTH NOTING AS
RADAR MOSAIC SHOWS A WEAK DRY SLOT BUT THIS COULD EASILY FILL IN
THIS MORNING.
SFC TEMPS PROGGED TO WARM NEAR OR JUST ABOVE FREEZING ALL AREAS BY
EARLY AFTERNOON SO RAIN SHOULD BE PREDOMINANT AFTER 18Z TO 19Z.
HOWEVER...WE CONTINUE TO WORRY ABOUT ACTUAL SFC TEMPS POSSIBLY
LAGGING 2M MEASURED AIR TEMPS BY A FEW HOURS DUE TO HOW COLD WE HAVE
BEEN AND FROZEN GROUND DOWN TO AROUND 10 INCHES. THIS IS AN UNKNOWN
FACTOR AND ONE THAT IS NEARLY IMPOSSIBLE TO FORECAST. THUS THIS
COULD KEEP SOME SECONDARY AND LESS TRAVELED ROADS ICY WELL INTO THE
AFTERNOON...ESPECIALLY NORTH AND EAST. ICE ACCUMULATIONS STILL LOOK
TO BE AROUND A TENTH OF AN INCH AND NO MORE THAN 0.15. SNOW ACCUMS
DOWN A BIT IN THE NORTH WITH AN INCH STILL POSSIBLE AND ISOLATED 2
INCHES NOT OUT OF QUESTION. THESE AMOUNTS CAN STILL VARY DEPENDING
ON EXACT TIMING OF CHANGEOVER AT DIFFERENT LOCATIONS. STILL WELL
WITHIN GOING ADVISORY WHICH WILL CONTINUE.
MODELS HAVE CONTINUED TO BACK OFF ON QPF TOTALS WITH THIS ENTIRE
EVENT OVER OUR AREA. IMPRESSIVE SUB TROPICAL MOISTURE PLUME SEEN ON
WATER VAPOR WILL BE TAKEN SOUTH AND BE RESPONSIBLE FOR IMPRESSIVE
WINTER STORM OVER THE LOWER OH VALLEY REGION. DRY SLOT MAY WORK INTO
OUR AREA QUICKER LATE THIS AFTERNOON AND EVENING AS SYSTEM TO OUR
SOUTH GETS GOING AND STEALS NORTHWARD MOISTURE TRANSPORT. LEFT
CHANCE POPS IN ACROSS CENTRAL AND NORTHWEST THIS EVENING WITH LOW
END LIKELY FAR SOUTHEAST. SHOULD BE LIGHT RAIN INITIALLY WITH ANY
PCPN CHANGING TO LIGHT SNOW AS COLDER AIR WORKS IN. THERE IS A SMALL
CHANCE FOR FREEZING DRIZZLE TONIGHT WITH DRYING ALOFT AND
DIMINISHING ICE. HOWEVER...CHANCES LOOK SMALL AND WILL DEFER TO DAY
SHIFT TO EVALUATE PCPN TRENDS GOING INTO THE EVENING.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EST TUE MAR 3 2015
STRONG COLD AIR ADVECTION WILL BE UNDERWAY WEDNESDAY...HELPING TO
KEEP TEMPERATURES CLOSE TO 20 DEGREES BELOW NORMAL. LAKE MICHIGAN
HAS OPENED UP SOME...WITH MOST OF THE ICE ON THE EAST SIDE OF THE
LAKE PER VISIBLE SATELLITE FROM YESTERDAY. ALTHOUGH DELTA T VALUES
WILL BE FAVORABLE FOR LAKE EFFECT SNOW...LOW INVERSION HEIGHTS
SHOULD KEEP SNOW AMOUNTS LIGHT. KEPT A CHANCE FOR LAKE EFFECT SNOW
SHOWERS OVER FAR SW LOWER MICHIGAN INTO NORTHERN INDIANA FROM
WEDNESDAY THROUGH THURSDAY BEFORE INVERSION HEIGHTS BECOME TOO LOW
TO SUPPORT SNOW SHOWERS. THE NEXT SYSTEM COULD SPREAD SOME LIGHT
SNOW ON THE SOUTHEAST FRINGE OF THE FORECAST AREA FROM MARION TO
LIMA. BOTH THE NAM AND THE GFS HAVE TRENDED NORTHWEST WITH THIS
SYSTEM. SUFFICIENT ISENTROPIC LIFT FOR SNOW STILL APPEARS MARGINAL
GIVEN QUESTIONABLE SATURATION IN THE MID LEVELS. INTRODUCED A CHANCE
FOR SNOW THURSDAY NIGHT. OTHERWISE...ANOTHER ROUND OF BITTERLY COLD
AIR TO INVADE THE AREA YET AGAIN. WENT ABOVE THE GFS/MEX 13F AND THE
ECMWF 14F HIGHS THURSDAY. MODELS HAVE BEEN TOO COLD WITH HIGH
TEMPERATURES WITH CLEAR TO PARTLY CLOUDY SKIES RECENTLY IN ARCTIC
AIRMASSES. SO KEPT HIGHS AROUND 16F THURSDAY...WHICH WOULD BE THE
COLDEST HIGH AT FT WAYNE FOR THE DATE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 639 AM EST TUE MAR 3 2015
FIRST BATCH OF MIXED PCPN COMING THROUGH THIS MORNING. BRIEF LULL
POSSIBLE AS RADAR RETURNS WEAKEN IMMEDIATELY BEHIND.
HOWEVER...UPSTREAM RADARS SHOWING LIGHT RETURNS DEVELOPING AND
EXPECT THESE TO MOVE BACK IN SHORTLY. CIGS AND VIS LOWERING
UPSTREAM AS WELL SO EXPECT THIS TREND LATER TODAY. LIGHT ICING
STILL EXPECTED THROUGH THE MORNING THOUGH PCPN AMOUNTS MAY BE LESS
THAN PREVIOUSLY ANTICIPATED. HOWEVER...LIGHT GLAZE OF AT LEAST A
FEW HUNDREDTHS EXPECTED WHICH WILL CAUSE PROBLEMS. TEMPS STILL
EXPECTED ABOVE FREEZING BY AFTERNOON WITH RAIN. CHANCE OF LIGHT
SNOW TONIGHT AND STILL POSSIBILITY OF LIGHT FZDZ BUT TOO LOW OF A
CHANCE TO MENTION AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005-008-009-012>018-020-022>027-032>034.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR INZ006-
007.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ078>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ004-
005-015-016-024-025.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...NONE.
&&
$$
UPDATE...MURPHY
SYNOPSIS...STEINWEDEL
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
135 PM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 133 PM CST TUE MAR 3 2015
COLD FRONT ARRIVING FASTER THAN FORECAST. AS SUCH HIGH
TEMPERATURES WILL PEAK BETWEEN NOW AND 3 PM AND THEN START
FALLING. AN UPDATE FOR LOWER HIGH TEMPERATURES WILL BE OUT SHORTLY.
&&
.SYNOPSIS...
ISSUED AT 252 AM CST TUE MAR 3 2015
STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK
JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY
HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST
ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW
FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR
INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING
IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH
TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CST TUE MAR 3 2015
THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND
HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A
SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE
ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON
RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH
15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN
THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND
2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND
ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD
CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH
THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN
FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER
SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS
HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED.
HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED
THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS
THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE
SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH
THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY
FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND
BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY
KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER
SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT
THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE
BATTLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 252 AM CST TUE MAR 3 2015
MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR
MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO
GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND
CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS
THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST!
AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF
THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS
WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES.
GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON
THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH
PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND
CHILLS THAT WILL REACH WIND CHILL CRITERIA.
NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY.
MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF
THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL
US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND
INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS
FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE
AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF
THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE
CONFIDENCE ON A WARM UP NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1123 AM CST TUE MAR 3 2015
IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH 00Z/04 WITH AREAS OF
DRIZZLE AS TEMPERATURES CLIMB ABOVE FREEZING. AFT 00Z/04
CONDITIONS WILL SLOWLY IMPROVE TO MVFR FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT. AFT 09Z/04 CONDITIONS WILL SLOWLY IMPROVE TO VFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...GIBBS
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1126 AM CST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 252 AM CST TUE MAR 3 2015
STRONG WARM ADVECTION PAIRED WITH LIFT FROM A 120 KT JET STREAK
JUST NORTH OF OUR CWA IS PROVIDING A BAND OF MODERATE TO LOCALLY
HEAVY PRECIPITATION FROM SOUTHWEST IOWA THROUGH NORTHWEST
ILLINOIS. THIS BAND BISECT OUR CWA...AND HAS HEAVY DENDRITIC SNOW
FOUND NORTH OF INTERSTATE 80...WITH SNOW AND SLEET MIX NEAR
INTERSTATE 80...AND FREEZING RAIN FARTHER SOUTH. THIS WILD SWING
IN PCPN TYPES WAS EXPECTED...YET IS PERSONALLY AMAZING TO WATCH
TAKE PLACE OUT THE WINDOW OF AN OFFICE AT NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CST TUE MAR 3 2015
THE MAIN AXIS OF PCPN APPEARS BEST HANDLED BY THE RAP AND
HRRR...WHICH ARE BOTH FARTHER NORTH THAN THE GFS. IF THERE IS A
SYNOPTIC SCALE MODEL HANDLING THIS WELL...THE GEM SEEMS ACCURATE
ENOUGH. SO...WITH FRONTOGENETICAL FORCING SHOWING ITS HAND ON
RADAR...WE WILL SEE A BAND OF MODERATE AMOUNTS TAKE PLACE THROUGH
15Z...POSSIBLY 16Z...BEFORE ENDING AND SHIFTING NORTHEAST. WITHIN
THIS EVENT...LOCATIONS JUST NORTH OF INTERSTATE 80 MAY SEE AROUND
2 INCHES OF SNOW...BEFORE MIXING WITH SLEET OR FREEZING RAIN AND
ENDING THIS MORNING. ALONG INTERSTATE 80...INCLUDING THE QUAD
CITIES...AND IOWA CITY...WE WILL LIKELY WAFFLE BACK AND FORTH
THROUGH 6 AM BETWEEN LARGE FLAKES AND SLEET...WITH ANY LIGHT PCPN
FALLING AND FREEZING RAIN. A SLIPPERY MIX NO DOUBT. FARTHER
SOUTH...IT APPEARS MOST OF THE MORE INTENSE BAND OF FREEZING RAINS
HAVE SHIFTED NORTH AS THE MESOSCALE BAND SOLIDIFIED.
HOWEVER...SOME SHOWERS OF FREEZING RAIN CAN STILL BE EXPECTED
THROUGH 8 AM...AS TEMPERATURES RISE ABOVE FREEZING. ELSEWHERE...AS
THE MIX ENDS...TEMPERATURES SHOULD RESPOND MORE QUICKLY IN THE
SOUTH WINDS AND MIXING OF DAYTIME HOURS. HIGHS SHOULD STILL REACH
THE MID TO UPPER 30S IN MOST SPOTS. BY NOON...ONLY PATCHY
FLURRIES...SPRINKLES OR DRIZZLE IS EXPECTED. THUS...A DRY AND
BREEZY AFTERNOON SHOULD BE WIDESPREAD...WITH COLD ADVECTION REALLY
KICKING IN BY EVENING. TEMPERATURES TONIGHT WILL FALL TO THE LOWER
SINGLE DIGIT NORTHWEST TO AROUND 10 SOUTHEAST. THERE IS NO DOUBT
THAT SPRING AIR CAME CLOSE TO OUR CWA TODAY...BUT IT LOST THE
BATTLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 252 AM CST TUE MAR 3 2015
MAIN FORECAST CONCERN FOR THE EXTENDED ARE THE WIND CHILLS FOR
MIDWEEK. COLD AIR SURGING IN BEHIND THE SYSTEM ON TUESDAY LOOKS TO
GIVE US ANOTHER SHOT OF VERY COLD AIR. THIS WILL LEAD TO WIND
CHILLS BETWEEN 20 AND 30 BELOW ZERO. AFTER THIS IT APPEARS AS
THOUGH WARMER TEMPERATURES ARE FINALLY IN THE FORECAST!
AN ARCTIC HIGH PRESSURE WILL SLIDE INTO THE AREA AT THE BEGINNING OF
THE PERIOD. ON THURSDAY MORNING IT WILL BE DIRECTLY OVER US. THIS
WILL LEAD TO CLEAR SKIES AND VERY UNSEASONABLE LOW TEMPERATURES.
GUIDANCE IS IN REMARKABLY GOOD AGREEMENT WITH COLD TEMPERATURES ON
THURSDAY AM. EVEN THOUGH WINDS WILL BE LIGHT...DUE TO THE HIGH
PRESSURE...ANY WIND WITH THOSE LOW TEMPERATURES WILL LEAD TO WIND
CHILLS THAT WILL REACH WIND CHILL CRITERIA.
NOW TO THE MORE HAPPY NEWS...A PATTERN SHIFT LOOKS MORE LIKELY.
MODELS SHOW THAT THE FLOW BECOMES MORE ZONAL AND THE TRAJECTORIES OF
THE AIR MOVING INTO OUR AREA LOOKS TO BE MORE OFF OF THE CONTINENTAL
US. THIS MEANS WARMER...MORE AVERAGE TEMPERATURES THIS WEEKEND AND
INTO NEXT WEEK. THE EURO IS ESPECIALLY WARM FOR JUST OUT OF THIS
FORECAST PERIOD. THE EVEN BETTER NEWS IS THAT THE ENSEMBLE
AVERAGE...GFS AND ECMWF H5 FLOW IS CLOSE TO EACH OTHER AT THE END OF
THE FORECAST PERIOD. THIS LEADS ME TO HAVE HIGHER THAN AVERAGE
CONFIDENCE ON A WARM UP NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1123 AM CST TUE MAR 3 2015
IFR TO LIFR CONDITIONS WILL CONTINUE THROUGH 00Z/04 WITH AREAS OF
DRIZZLE AS TEMPERATURES CLIMB ABOVE FREEZING. AFT 00Z/04
CONDITIONS WILL SLOWLY IMPROVE TO MVFR FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT. AFT 09Z/04 CONDITIONS WILL SLOWLY IMPROVE TO VFR.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JOHNSON-JONES-
KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-WASHINGTON.
IL...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BUREAU-CARROLL-
HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-
WHITESIDE.
MO...NONE.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...GIBBS
AVIATION...08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 PM CST TUE MAR 3 2015
...UPDATE TO SHORT TERM...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 245 PM CST TUE MAR 3 2015
MOST OF THE ACTION IS AFTER MIDNIGHT. IN THE MEANTIME, COLDER AIR WILL
CONTINUE TO ADVECT IN FROM THE NORTHWEST AND NORTH. BY MIDNIGHT, THE
THERMO PROFILE SHOULD BE COLD ENOUGH FOR SNOW. A FORECAST SOUNDING DID
SHOW 0.5C WARM TONGUE FOR MEDICINE LODGE BETWEEN 00-06Z, BUT FOR RIGHT
NOW, WILL KEEP PRECIPITATION TYPE ALL SNOW THROUGH THE SHORT TERM DOMAIN.
SPEAKING OF, HAVE RELIED ON THE MESOSCALE MODELS LIKE THE WRF AND NAM,
WHICH SHOWS A MESOSCALE SNOW BAND MOVING ACROSS THE REGION. FROM THE
METEOROLOGICAL COOKBOOK... 290-300K ISENTROPIC LIFT, 700-HPA OMEGA AND
BAROCLINIC BAND, 800-600-HPA FRONTOGENESIS DO GIVE SUPPORT TO THE PHYSICAL
REASONING AS WHY THE MODELS ARE BEHAVING AS SUCH. IT SHOULD BE NOTED
THAT THE WRF-NMM ACTUALLY SHOWS A STRONGER BAND AND HIGHER SNOW AMOUNTS.
WILL GO IN THE MIDDLE OF THE ROAD FOR NOW. HAVE A 2-4" BAND OF SNOW
ROUGHLY ALONG THE HIGHWAY 56 CORRIDOR AS WELL AS A 50 MILE BUFFER ZONE
SURROUNDING IT. HAVE THE LOWEST CONFIDENCE FARTHER NORTH TOWARDS HAYS.
THE RAP SHOWS THE FRONTO BAND STRONGER IN THIS AREA AND HAS HIGH SNOW
AMOUNTS. WILL LET THE MID SHIFT ALONG WITH 00Z GUIDANCE SPLIT THAT DETAIL.
HAVE ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF THE FORECAST AREA
EXCEPT THE NORTHWEST AND NORTHERN ZONES. THE 18Z NAM HAS SHIFTED THE
HEAVIEST SNOW BAND ABOUT 20 MILES NORTH FROM WHAT I HAVE IT NOW. AGAIN,
WITH INCREASED POPS/SNOWFALL AMOUNTS, FEEL THE POSITIVE TREND COVERS
THE SITUATION FOR NOW. THAT BEING SAID, DON`T BE SURPRISED IF THERE
ARE TWEAKS BETWEEN NOW AND THE STORM EVENT AS CONFIDENCE ON MESOSCALE
EVOLUTION INCREASES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 209 PM CST TUE MAR 3 2015
FOR WEDNESDAY NIGHT...ANY LINGERING LIGHT PRECIPITATION NEAR THE
OKLAHOMA BORDER WILL END DURING THE EVENING AS AN UPPER LEVEL
TROUGH CROSSES WESTERN KANSAS. SUBSIDENCE DEVELOPING BEHIND THIS
UPPER TROUGH SHOULD BRING SOME CLEARING SKIES DURING THE OVERNIGHT
HOURS. WINDS WILL BE LIGHT BASED ON WHERE THE SURFACE RIDGE AXIS
WILL BE LOCATED EARLY THURSDAY MORNING ALSO. GIVEN CLEAR SKIES,
LIGHT WINDS AND EXPECTED SNOW COVER WILL BE STAY SEVERAL DEGREES
BELOW THE COOLER GUIDANCE FOR LOWS, ESPECIALLY EAST OF DODGE CITY.
AN UPPER LEVEL RIDGE AXIS WILL BECOME ESTABLISHED OVER THE WEST
COAST LATE WEEK AND A NORTHWEST FLOW IS EXPECTED ACROSS THE
CENTRAL HIGH PLAINS THROUGH THE WEEKEND PERIOD. THE WARMING TREND
CURRENTLY ADVERTISED IN THE PREVIOUS FORECAST STILL LOOKS ON TRACK
GIVEN THIS NORTHWEST DOWNSLOPE FLOW. TOWARDS SUNDAY AN UPPER LEVEL
DISTURBANCE EMBEDDED IN THIS NORTHWEST WILL CROSS THE NORTHERN
PLAINS WHICH WILL BRING ANOTHER COLD FRONT INTO WESTERN KANSAS. AT
THIS TIME NOT MUCH IN THE WAY OF COLDER AIR IS EXPECTED TO RETURN
TO WESTERN KANSAS BEHIND THIS FRONT. PRECIPITATION CHANCES APPEAR
SMALL LATE WEEK INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1108 AM CST TUE MAR 3 2015
GUSTY NORTH/NORTHEAST WINDS WILL GRADUALLY SUBSIDE TO 10 TO 15
KNOTS BY 00Z WEDNESDAY AS A SURFACE RIDGE AXIS BUILDS INTO WESTERN
KANSAS. A BRIEF PERIOD OF LOW MVFR CEILINGS WILL BE POSSIBLE AT
GCK AND DDC BETWEEN 18Z AND 21Z BASED ON LATEST HRRR. TONIGHT VFR
CEILINGS WILL GRADUALLY LOWER THIS EVENING AS MOISTURE AND FORCING
IMPROVES IN THE 800MB TO 600MB LEVEL. LOW VFR CONDITIONS WILL THEN
GIVE WAY TO MVFR AND IFR CEILINGS BETWEEN 06Z AND 12Z WEDNESDAY AS
THE LOWER LEVELS SATURATE AND LIGHT SNOW DEVELOPS, ESPECIALLY AT
GCK AND DDC. NORTHEASTERLY WINDS WILL ALSO BE INCREASING AFTER
MIDNIGHT INTO THE 15 TO 20 KNOT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 16 24 7 38 / 80 80 10 0
GCK 15 24 6 38 / 60 60 10 0
EHA 16 23 10 39 / 70 70 10 0
LBL 17 24 9 38 / 80 80 10 0
HYS 15 28 6 40 / 50 50 0 0
P28 19 25 9 39 / 80 80 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST
WEDNESDAY FOR KSZ045-046-062>066-074>081-084>090.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS JACKSON KY
405 PM EST TUE MAR 3 2015
.UPDATE...
ISSUED AT 120 PM EST TUE MAR 3 2015
ISOLATED TO SCATTERED SHOWERS CONTINUED ACROSS A GOOD PORTION OF
KY...MAINLY ACROSS OUR NORTHERN CWA. STILL HAVE MENTION OF CHANCE
POPS...INCLUDING THUNDER...FOR THE REST OF THE AFTERNOON. MAY END
UP TRENDING BACK ON THIS A BIT GIVEN THE ONGOING RADAR TRENDS.
HOWEVER...CONDITIONS ARE RIPE FOR ANY SHOWERS TO BEGIN DEVELOPING
AT ANY TIME...SO MAY END UP KEEPING WITH THE ONGOING CHANCES TO BE
SAFE. UPDATED THE FORECAST /ZFP AND SAF/ TO TAKE OUT ANY MORNING
WORDING FOR ISOLATED SHOWERS.
UPDATE ISSUED AT 1026 AM EST TUE MAR 3 2015
LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG
NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO
EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND
NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER
TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS
SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE
HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES
ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES
THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN
SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A
LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE
LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON
TRACK WITH THE CURRENT CONDITIONS.
UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015
QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR
TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT
WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE
FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE
ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE
ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM EST TUE MAR 3 2015
A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY
THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE
THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS
MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE
THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF
SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN
HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR
NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES
RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED
CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES
DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH
IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL
BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT
THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST
PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS
RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT
TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT
EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY
RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF
THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION
AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT
2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY.
DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY
SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN
TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT
APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST
SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE
KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT
RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE
NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID
50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY
EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR
TODAY.
THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS
MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED
COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO
THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST.
WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE
THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE
EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM
RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE
I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS
FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE
DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE
PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY
AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY
OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS
PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE
ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12
BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE
MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS
SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH
SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE
MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO
SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT
AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS
CURRENTLY PREDICTING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 405 PM EST TUE MAR 3 2015
HIGH PRESSURE (AND QUIET WEATHER) WILL BE THE DOMINANT FEATURE
BEGINNING LATE THURSDAY THROUGH THE REMAINDER OF THE EXTENDED
PERIOD. TEMPS FRIDAY MORNING WILL DIP INTO THE SINGLE DIGITS...
WITH A FEW SPOTS IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...
WHICH IS WELL BELOW NORMAL FOR MARCH AND NEAR RECORD LOWS. THE
COLD SNAP APPEARS TO BE FAIRLY SHORT LIVED AS TEMPERATURES START
MODERATING BACK TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH
THEY WILL GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION
WILL BE POSSIBLE EARLY NEXT WEEK... LATE SUNDAY INTO MONDAY AND
AGAIN EARLY TUESDAY MORNING. BUT WITH SIGNIFICANT MODEL
DIFFERENCES ASSOCIATED WITH THE LATTER PART OF THE FORECAST HAVE
MAINTAINED SLIGHT POPS DURING THOSE PERIODS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EST TUE MAR 3 2015
SCT SHOWERS CONTINUE TO MOVE ACROSS NORTH CENTRAL KY...GENERALLY
PUSHING JUST NORTH OF EASTERN KY...MISSING MOST OF THE TAF SITES.
AS SUCH...TOOK OUT MENTION OF SHRA OR TSRA DIRECTLY IMPACTING THE
TAF SITES THROUGH ABOUT 00Z...THOUGH SOME VCSH OR VCTS ARE STILL
POSSIBLE. AFTER 0Z...EXPECTING PRECIP TO BEGIN INCREASING IN
COVERAGE AND INTENSITY ACROSS KY. WITH INSTABILITY STILL IN
PLACE /DUE TO A STRONG PUSH OF COLDER NORTHERLY AIR INTERACTING
WITH MOIST SRLY FLOW OFF THE GULF OF MEXICO/...COULD SEE SOME
LINGERING POTENTIAL FOR THUNDER THROUGH THE EVENING AS WELL. BY
OVERNIGHT...WE WILL LOSE OUR INSTABILITY...BUT RAIN WILL REALLY
TAKE HOLD. ALL MODELS ARE SHOWING TAF SITES GOING BELOW AIRPORT
MINS THROUGH THE REMAINDER OF THE FORECAST PERIOD...WITH PERIODS
OF VIS AND CIGS LIFR AND BELOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THURSDAY EVENING FOR KYZ044-050>052-058>060-
068-069-079-080-083>088-104-106>120.
WINTER STORM WARNING FROM 1 PM TO 10 PM EST WEDNESDAY FOR KYZ044-
050>052.
WINTER STORM WARNING FROM 4 PM TO 10 PM EST WEDNESDAY FOR
KYZ058>060-104-106-108-111.
WINTER STORM WARNING FROM 7 PM TO 10 PM EST WEDNESDAY FOR KYZ068-
069-079-080-083>086-107-109-110-112>117-119-120.
WINTER STORM WARNING FROM 10 PM WEDNESDAY TO 1 PM EST THURSDAY
FOR KYZ087-088-118.
&&
$$
UPDATE...JMW
SHORT TERM...AR
LONG TERM...JVM
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
138 PM EST TUE MAR 3 2015
.UPDATE...
ISSUED AT 120 PM EST TUE MAR 3 2015
ISOLATED TO SCATTERED SHOWERS CONTINUED ACROSS A GOOD PORTION OF
KY...MAINLY ACROSS OUR NORTHERN CWA. STILL HAVE MENTION OF CHANCE
POPS...INCLUDING THUNDER...FOR THE REST OF THE AFTERNOON. MAY END
UP TRENDING BACK ON THIS A BIT GIVEN THE ONGOING RADAR TRENDS.
HOWEVER...CONDITIONS ARE RIPE FOR ANY SHOWERS TO BEGIN DEVELOPING
AT ANY TIME...SO MAY END UP KEEPING WITH THE ONGOING CHANCES TO BE
SAFE. UPDATED THE FORECAST /ZFP AND SAF/ TO TAKE OUT ANY MORNING
WORDING FOR ISOLATED SHOWERS.
UPDATE ISSUED AT 1026 AM EST TUE MAR 3 2015
LATEST RADAR TRENDS CONTINUE TO MOVE THE HEAVIEST SHOWERS ALONG
NORTH CENTRAL KY AND THEN NORTH OF THE CWA. EXPECT THINGS TO
EVENTUALLY START SHIFTING SOUTHWARD...BUT THE LATEST HRRR AND
NAM12 ARE NOT SHOWING THIS TRANSITION UNTIL THIS EVENING /CLOSER
TO 3Z/...A LITTLE LATER THAN ORIGINALLY FORECASTED/ANTICIPATED. AS
SUCH...GIVEN THE LATEST RADAR TRENDS AND GOOD INITIATION OF THESE
HI RES MODELS...WENT AHEAD AND DROPPED TO ONLY SLIGHT CHANCES
ACROSS THE SE CWA THROUGH THE MORNING...INCREASING TO CHANCES
THROUGH THE REST OF THE DAY. BY THIS EVENING...HEAVIEST RAIN
SHOULD BE MAKING IT INTO MUCH OF THE CWA...SO KEPT WITH A
LIKELY/DEFINITE POP FROM THIS POINT ON. ALSO...LOADED IN THE
LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE THE NEAR-TERM FORECAST FOR THESE PARAMETERS WAS WELL ON
TRACK WITH THE CURRENT CONDITIONS.
UPDATE ISSUED AT 850 AM EST TUE MAR 3 2015
QUICK UPDATE TO BRING GRIDS IN LINE WITH HOURLY OBS AND RADAR
TRENDS. HAD SOME SPRINKLES THIS MORNING BUT NOTHING SIGNIFICANT
WITH RESPECT TO LIGHT FREEZING DZ...RA. TEMPS ARE RISING ABOVE
FREEZING NOW. WILL LET CURRENT SPS FOR PATCHY FREEZING DRIZZLE
ACROSS PORTIONS OF THE AREA EXPIRE AT 9 AM. ALSO FRESHENED UP THE
ZONES. OTHERWISE...NO OTHER CHANGES TO THE FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 358 AM EST TUE MAR 3 2015
A COMPLICATED WEATHER PATTERN SHAPING UP FOR EASTERN KENTUCKY
THROUGH THE MIDDLE OF THE WEEK. THE FIRST FORECAST CONCERN WILL BE
THE POTENTIAL FOR FREEZING DRIZZLE OR FREEZING RAIN EARLY THIS
MORNING NORTH OF THE MOUNTAIN PARKWAY. THERE IS A SMALL CHANCE
THAT SOME LIGHT PRECIPITATION WILL FALL INTO A LAYER OF
SUBFREEZING AIR THAT IS CURRENTLY IN PLACE ACROSS THE NORTHERN
HALF OF THE FORECAST AREA. THE ISSUE WITH THIS WILL BE WHETHER OR
NOT THE PRECIP IS ABLE TO REACH THE GROUND BEFORE TEMPERATURES
RISE ABOVE FREEZING. THIS SITUATION WILL CONTINUE TO BE MONITORED
CLOSELY OVER THE NEXT SEVERAL HOURS. IF SOME FREEZING PRECIP DOES
DEVELOP...AN SPECIAL WEATHER STATEMENT WILL BE ISSUED TO DEAL WITH
IT. THE SECOND CONCERN IN THE FIRST 36 HOURS OF THE FORECAST WILL
BE HEAVY RAIN AND THE POTENTIAL FOR FLOODING ACROSS THE AREA. AT
THIS TIME...THE FORECAST MODELS HAVE MOVED THE AXIS OF HEAVIEST
PRECIPITATION TODAY SLIGHTLY NORTH OF WHERE IT WAS IN PREVIOUS
RUNS. THE POP AND QPF FORECAST FOR TODAY WAS MODIFIED AS A RESULT
TO ACCOUNT FOR THIS CHANGE. IT STILL APPEARS HIGHLY LIKELY THAT
EASTERN KENTUCKY WILL EXPERIENCE A PERIOD OF MODERATE TO HEAVY
RAIN BEGINNING LATE THIS AFTERNOON AND LASTING THROUGH THE END OF
THE DAY ON WEDNESDAY. THERE MAY EVEN BE ENOUGH VERTICAL MOTION
AND WIND ENERGY ALOFT TO FIRE OFF A FEW THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING. AT THIS TIME...IT STILL APPEARS THAT
2 TO 3 INCHES OF RAIN WILL FALL ACROSS ALL OF EASTERN KENTUCKY.
DUE TO RECENTLY MELTED SNOW...THE GROUND IS ALREADY COMPLETELY
SATURATED ACROSS THE ENTIRE AREA...SO IT WILL NOT TAKE MUCH RAIN
TO BEGIN CAUSING PROBLEMS. BASED ON CURRENT HYDRO FORECASTS...IT
APPEARS THAT THE CUMBERLAND RIVER BASIN MAY EXPERIENCE THE MOST
SIGNIFICANT FLOODING ISSUES. THERE WILL ALSO BE POINTS ALONG THE
KENTUCKY BASIN THAT MAY SEE SIGNIFICANT FLOODING...SUCH AS AT
RAVENNA. THE TEMPERATURES TODAY ARE STILL EXPECTED TO RISE ABOVE
NORMAL ACROSS THE AREA...WITH HIGHS TOPPING OUT IN THE LOW TO MID
50S FOR THE ENTIRE AREA. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY
EVEN APPROACH 60 IN THE STRONG SOUTHERLY FLOW THAT IS ON TAP FOR
TODAY.
THE END OF THE SHORT TERM PERIOD IS WHERE OUR SECOND AND PERHAPS
MORE SERIOUS FORECAST CONCERN LIES. ONCE THE PREVIOUSLY MENTIONED
COLD FRONT MOVES THROUGH THE AREA...VERY COLD AIR WILL FILTER INTO
THE AREA BEHIND IT...AS WINDS SHIFT TO THE NORTH AND NORTHWEST.
WITH A STRONG FEED OF GULF MOISTURE STILL ON TRACK TO OVERRIDE
THE SLUGGISH COLD FRONT...SIGNIFICANT AMOUNTS OF PRECIPITATION ARE
EXPECTED TO OCCUR. PRECIPITATION WILL GRADUALLY TRANSITION FROM
RAIN TO A MIX OF RAIN...SLEET...AND SNOW ALONG AND NORTH OF THE
I634 CORRIDOR WEDNESDAY AFTERNOON. THIS MIX OF PRECIPITATION IS
FORECAST TO MOVE STEADILY EASTWARD ACROSS THE AREA BEHIND THE
DEPARTING FRONT. AS MORE AND MORE COLD AIR MOVES IN...THE
PRECIP WILL CHANGE OVER FROM A MESSY WINTRY MIX TO ALL SNOW BY
AROUND 0Z THURSDAY. SOME LIGHT SNOW AND SLEET ACCUMULATIONS MAY
OCCUR LATE WEDNESDAY IN OUR FAR NORTHWEST. THE CHALLENGE WITH THIS
PART OF THE FORECAST WILL BE DETERMINING HOW STRONG THE WARM NOSE
ALOFT WILL BE AT THE START OF THE EVENT. AT THIS TIME...THE NAM12
BY FAR HAS THE MOST WELL DEFINED LAYER OF WARM AIR AMONGST THE
MODELS...WHICH WOULD LEAD TO MORE SLEET IN OUR NORTHER AND LESS
SNOW. THE GFS AND ECMWF MODELS...ON THE OTHER HAND...ARE BOTH
SHOWING A MUCH LESS WELL DEFINED WARM NOSE ALOFT AND THEREFORE
MORE SNOW. FOR NOW HAVE DECIDED TO USE A BLEND OF THE TWO
SOLUTIONS...GOING WITH A MIX OF SNOW AND SLEET TO START THE EVENT
AND LEANING MORE TOWARD THE SNOWFALL AMOUNTS THE WWD FORECAST IS
CURRENTLY PREDICTING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 557 AM EST TUE MAR 3 2015
APPEARS INCREASINGLY LIKELY THAT WE WILL BE DIVING HEADLONG INTO
A TRANSITION FROM A HEAVY RAIN INTO A SIGNIFICANT WINTER WEATHER
EVENT BY THE BEGINNING OF THE EXTENDED. GFS...ECMWF SOLUTIONS
CONTINUE TO SHOW FAIRLY GOOD AGREEMENT WITH THIS SCENARIO.
HOWEVER...THE NAM CONTINUES TO TREND FURTHER TO THE NORTHWEST
WITH THE MOST SIGNIFICANT FEATURES IN OUR SENSIBLE WEATHER. WITH
THE NAM OUTSIDE ITS WINDOW OF BEST PERFORMANCE...GENERAL PREFERRED
TO REMAINED CLOSER TO THE OFFICIAL FORECAST AND A CONSENSUS OF THE
GFS AND ECMWF. ENOUGH UNCERTAINTY REMAINS IN THE MODEL SOLUTIONS
TO WARRANT STAYING WITH THE CURRENT SUITE OF WATCH PRODUCTS
THROUGH THE FIRST PORTIONS OF THE EXTENDED.
A VERY TIGHT BAROCLINIC ZONE STRETCHING WSW TO ENE ACROSS THE
OHIO VALLEY WILL GRADUALLY SHIFT SOUTHEAST INTO TENNESSEE VALLEY
THROUGH THURSDAY. WEATHER ALONG THE BAROCLINIC ZONE WILL REMAIN
OF ACTIVE AS SEVERAL WAVES OF LOW PRESSURE TRACK THROUGH THE TN
VALLEY REGION. COLDER ARCTIC AIR FILTERING INTO OUR AREA ON THE
NORTHERN SIDE OF THIS ZONE WILL CHANGE RAIN OVER TO SNOW WEDNESDAY
NIGHT. THERMAL PROFILES SUGGEST THAT THERE WILL BE A PERIOD OF
MIXED PRECIPITATION DURING THE CHANGOVER...GENERALLY SLEET IN THE
NORTH BUT SLEET OR POSSIBLY EVEN SOME FREEZING RAIN IN THE SOUTH.
OVERALL MODEL TRENDS SEEM TO BE SLIGHTLY SLOWER WITH THE
ONSLAUGHT OF COLD ARCTIC AIR INTO OUR FORECAST AREA LATE WEDNESDAY
INTO WEDNESDAY NIGHT. BUT SIGNIFICANT SNOW/SLEET ACCUMULATIONS
STILL APPEAR POSSIBLE...WITH THE HIGHEST AMOUNTS LIKELY NEAR THE
I-64 CORRIDOR AND LESSER AMOUNTS ACROSS OUR SOUTHEAST.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT BEGINNING LATE THURSDAY
NIGHT AND REMAIN OVER THE AREA THROUGH LATE SUNDAY. TEMPS FRIDAY
MORNING WILL LIKELY DIP INTO THE SINGLE DIGITS...WITH A FEW SPOTS
IN OUR NORTH POSSIBLY DROPPING BELOW 0 DEGREES...WELL BELOW
NORMAL FOR MARCH AND NEAR RECORD LOWS. THE COLD SNAP APPEARS TO
BE FAIRLY SHORT LIVED AS TEMPERATURES START MODERATING BACK
TOWARDS SEASONABLE LEVELS BY THE WEEKEND...THOUGH THEY WILL
GENERALLY REMAIN BELOW NORMAL. SOME LIGHT PRECIPITATION WILL BE
POSSIBLE EARLY NEXT WEEK AS A WEAK FRONTAL BOUNDARY DROPS
SOUTHWARD OUT OF CANADA AND THE GREAT LAKES. BUT WEATHER WITH
THIS FEATURE HAS BEEN TRENDING DRIER WITH TIME. FOR NOW MAINTAINED
A SLIGHT POP SUNDAY NIGHT INTO MONDAY BUT FEEL THIS MAY BE
OVERDONE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 137 PM EST TUE MAR 3 2015
SCT SHOWERS CONTINUE TO MOVE ACROSS NORTH CENTRAL KY...GENERALLY
PUSHING JUST NORTH OF EASTERN KY...MISSING MOST OF THE TAF SITES.
AS SUCH...TOOK OUT MENTION OF SHRA OR TSRA DIRECTLY IMPACTING THE
TAF SITES THROUGH ABOUT 00Z...THOUGH SOME VCSH OR VCTS ARE STILL
POSSIBLE. AFTER 0Z...EXPECTING PRECIP TO BEGIN INCREASING IN
COVERAGE AND INTENSITY ACROSS KY. WITH INSTABILITY STILL IN
PLACE /DUE TO A STRONG PUSH OF COLDER NORTHERLY AIR INTERACTING
WITH MOIST SRLY FLOW OFF THE GULF OF MEXICO/...COULD SEE SOME
LINGERING POTENTIAL FOR THUNDER THROUGH THE EVENING AS WELL. BY
OVERNIGHT...WE WILL LOSE OUR INSTABILITY...BUT RAIN WILL REALLY
TAKE HOLD. ALL MODELS ARE SHOWING TAF SITES GOING BELOW AIRPORT
MINS THROUGH THE REMAINDER OF THE FORECAST PERIOD...WITH PERIODS
OF VIS AND CIGS LIFR AND BELOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY EVENING
FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-
106>120.
&&
$$
UPDATE...JMW
SHORT TERM...AR
LONG TERM...RAY
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 PM EST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EST TUE MAR 3 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW
REGIME ACRS NAMERICA WITH ARCTIC AND POLAR/SUBTROPICAL BRANCH RDG
OVER THE GREAT LKS EARLY THIS MRNG. LOCAL 00Z ROABS SHOW A VERY DRY
AIRMASS WITH PWATS UNDER 0.10 INCH AT INL/GRB/APX...ON AVERAGE 33
PCT OF NORMAL...AND H7 DEWPT DEPRESSIONS UP TO 40-45C. THERE ARE TWO
SHRTWVS THAT WL HAVE A SGNFT IMPACT ON UPR MI WX...ONE IN EACH
STREAM. THE POLAR/SUBTROPICAL BRANCH SHRTWV IS LIFTING NEWD INTO THE
WRN PLAINS EARLY THIS MRNG AND SUPPORTING A WELL DEFINED BAROCLINIC
LEAF CLD...WITH SOME VERY COLD CLD TOPS OVER NEBRASKA AND IOWA JUST
TO THE N OF H85 WARM FNT ATTENDANT TO DVLPG SFC LO PRES IN FAR NW
KANSAS AND WHERE THERE IS ENHANCED UPR DVGC IN EXIT REGION OF
SUPPORTING 140KT H3 JET MAX. IN THE ARCTIC BRANCH...THERE IS A
STRONG SHRTWV DIGGING SEWD INTO MANITOBA...WITH 12HR H5 HGT FALLS
APRCHG 150M IN THE VIGOROUS DPVA AHEAD OF THIS FEATURE. SFC COLD FNT
HANGING S OF THE ACCOMPANYING SFC LO MOVING INTO FAR NW ONTARIO
EXTENDS S INTO THE NRN PLAINS AND IS APRCHG NW MN. CLOSER TO HOME...
A BAND OF COLDER CLD TOPS IS NOTED NEAR THE WI BORDER ALONG AXIS OF
FGEN SHOWN BEST BTWN ABOUT H7-5. HOWEVER...DRYNESS OF ANTECEDENT
AIRMASS HAS SO FAR LIMITED THE COVERAGE/INTENSITY OF ACCOMPANYING
LIGHT SN.
MAIN FCST CONCERNS THIS FCST PERIOD WL BE ON POPS/SN TOTALS
ASSOCIATED WITH THE TWO SHRTWVS NOTED ABOVE. SINCE THESE
DISTURBANCES WL REMAIN OUT OF PHASE...OVERALL SN TOTALS EXPECTED
TODAY OVER UPR MI WL NOT BE EXCESSIVE BEFORE MUCH COLDER AIR
FOLLOWING THE ARCTIC BRANCH FROPA SURGES INTO THE AREA TNGT AND
BRINGS A RETURN OF SOME LES.
TODAY...SRN BRANCH DISTURBANCE IS FCST TO ACCELERATE TO THE NE AND
ACROSS THE UPPER MIDWEST IN FAST WSW FLOW BTWN THE TWO BRANCHES AS
THE NRN BRANCH SHRTWV PUSHES INTO NW ONTARIO...WITH COLD FNT
ATTENDANT TO ACCOMPANY SFC LO REACHING THE WRN CWA LATE IN THE DAY.
ARRIVAL OF SOME VIGOROUS DEEP LYR QVECTOR CNVGC/UPR DVGC IN LEFT
EXIT OF SUPPORTING H3 JET MAX AS WELL AS DEEP ISENTROPIC ASCENT IN
THE SSW FLOW ALF IN ADVANCE OF THESE DISTURBANCES WL CAUSE BAND OF
PATCHY SN NEAR THE WI BORDER EARLY RELATED TO MID LVL FGEN TO EXPAND
IN COVERAGE DURING THE MRNG HRS. SINCE THE SHARPEST ISENTROPIC
ASCENT AS WELL AS FGEN THAT IS MAXIMIZED IN THE H7-6 LYR IS FCST TO
IMPACT MAINLY THE SE HALF OF THE CWA...WHERE SOME LK ENHANCEMENT OFF
LK MI LIMITED SOMEHWAT BY ICE COVERAGE IS PSBL IN THE LLVL SLY FLOW
AHEAD OF THE SFC LO ASSOCIATED WITH THE SRN BRANCH DISTURBANCE...
EXPECT THE GREATER SN TOTALS IN THIS AREA. WITH SPECIFIC HUMIDITY IN
THE H7-75 LYR UP TO 3G/KG...3-6 INCHES OF SN SEEMS A GOOD BET FOR 6-
9 HR PERIOD OF STEADY PCPN EXPECTED BEFORE ARRIVAL OF DNVA/VIGOROUS
QVECTOR DVGC DURING THE MID TO LATE AFTN IN THE WAKE OF THIS
DISTURANCE WL BRING AN END TO THE STEADIER SN W-E AND OVER THE FAR E
BY 00Z WED. ALTHOUGH THE SHARPER ISENTROPIC ASCENT/FGEN/MSTR
TRANSPORT WL TEND TO MISS THE WRN CWA...EXPECTED HIER SN/WATER
RATIOS IN THAT AREA DUE TO A DEEPER FCST DGZ MAY HELP RAISE SN
TOTALS AT LEAST TO THE 3 INCH THRESHOLD IN THAT AREA. WL MAINTAIN
GOING ADVY FOR THE ENTIRE CWA AS IS EVEN THOUGH THE HEADLINE MAY BE
DROPPED A FEW HRS EARLY OVER THE W.
TNGT...UPR MI WL BE DOMINATED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE IN
THE WAKE OF THE DEPARTING DISTURBANCES. BUT ARRIVAL OF COLDER AIR IN
THE WAKE OF ARCTIC BRANCH COLD FROPA THAT IS FCST TO DROP H85 TEMPS
TO AS LO AS -26C OVER THE W BY 12Z WED WL RESULT IN LES...MAINLY IN
AERAS THAT ARE DOWNSTREAM OF HOLES IN THE ICE COVER OBSVED JUST E OF
THE MN ARROWHEAD...THE BAYFIELD PENINSULA AND THE KEWEENAW PENINSULA
IN THE FCST WNW H925 FLOW. BUT STILL RATHER EXTENSIVE ICE COVER...
AS WELL AS DISAPPEARING DGZ OVER THE W RELATED TO THE CHILL OF THE
INCOMING AIRMASS...WL HOLD DOWN SN TOTALS. THE BEST CHANCE FOR MORE
NMRS SN SHOWERS APPEARS TO BE E OF MUNISING IN ALGER COUNTY THAT WL
BE DOWNWIND OF THE AREA OF OPEN WATER E OF THE KEWEENAW AND WHERE
THE ONSHORE 290 FLOW WL BE MORE PARALLEL TO THAT AREA OF OPEN WATER.
GUSTY WINDS RELATED TO FCST H925 WINDS UP TO 35-40KTS/STRONG CAA AND
DESTABILIZATION WL CAUSE SOME GUSTY WINDS...ESPECIALLY NEAR THE LK
SUP SHORE. GUSTS IN THE MORE EXPOSED LOCATIONS E OF MUNISING MAY
APRCH ADVY CRITERIA. OVER THE SCENTRAL...EXPECT SOME CLEARING...WITH
MIN TEMPS FALLING BLO ZERO OVER THE INTERIOR W HALF...ESPECIALLY NEAR
THE WI BORDER WHERE LK MODERATION WL BE MINIMAL OR ABSENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM EST TUE MAR 3 2015
A SHORTWAVE AND SFC TROUGH WILL SHIFT ACROSS THE CWA ON WED/WED
EVENING WITH 850MB TEMPS AS COLD AS -27C. LOW LEVEL WINDS WILL BE
OUT OF THE WNW THROUGH THE AFTERNOON BUT WILL VEER AROUND TO THE NW
BEHIND THE TROUGH WED EVENING. MORNING AND EARLY AFTERNOON WINDS
GUSTING TO 30-40MPH ALONG THE LAKE SUPERIOR SHORE WILL LEAD TO
BLOWING SNOW AND SIGNIFICANTLY REDUCED VISIBILITIES OVER THE
KEWEENAW AND EAST OF MUNISING DUE TO THE MORE WNW WIND
DIRECTIONS...BUT WINDS WILL DECREASE IN THE LATE AFTERNOON AND
EVENING. OF COURSE...LES WILL RESULT EVEN WITH A MOSTLY ICE COVERED
LAKE SUPERIOR...ESPECIALLY WITH THE SHORTWAVE COMING THROUGH. LES
WILL DIMINISH WED NIGHT INTO THU AS A SFC RIDGE MOVES IN FROM THE W
WHILE WINDS BACK. GENERALLY HAVE 1-2 INCHES IN WNW WIND SNOWBELTS ON
WED...WITH AROUND ANOTHER INCH WED NIGHT INTO THU.
FOR FRI THROUGH NEXT MON...SEVERAL SHORTWAVES MAY MOVE THROUGH THE
REGION DURING THIS TIME. A STRONGER SHORTWAVE LOOKS TO MOVE THROUGH
ON SUN/SUN NIGHT...BUT THE OTHER WILL BE PRETTY WEAK. PRECIPITATION
FORECAST CONFIDENCE IS QUITE LOW GIVEN UNCERTAINTIES WITH THE
SHORTWAVES. THAT BEING SAID...ISOLATED TO SCATTERED LES IS POSSIBLE
IN W-NW WINDS SO WILL INCLUDE THAT IN THE FORECAST. TEMPS DO LOOK TO
MODERATE...AND SHOULD REACH NORMAL VALUES THIS WEEKEND. LOOKING EVEN
FARTHER AHEAD...MODELS CONTINUE TO SHOW THE W COAST RIDGE SHIFTING E
INTO THE CENTRAL CONUS MID TO LATE NEXT WEEK...WHICH WOULD BRING
ABOVE NORMAL TEMPS AND START MELTING THE SNOWPACK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1220 PM EST TUE MAR 3 2015
ARRIVAL OF STRONGER DYNAMIC FORCING WL RESULT IN STEADY SN AND CAUSE
PREDOMINANT IFR VSBYS INTO MID AFTN. AS THIS FORCING EXITS W-E THIS
AFTN... CONDITIONS WL IMPROVE TO MVFR. A STRONG COLD FNT WL THEN
PASS LATE THIS AFTN OVER THE W AND DURING THE EVNG AT SAW. GUSTY WNW
WINDS WL DVLP IN ITS WAKE. EXPECT THE STRONGEST WINDS AT THE MORE
EXPOSED IWD AND ESPECIALLY THE CMX LOCATIONS. DESPITE EXTENSIVE ICE
COVER ON LK SUP...MVFR CONDITIONS ARE LIKELY TO PREDOMINANT AT THESE
LOCATIONS WITH AN UPSLOPE WIND COMPONENT. DOWNSLOPE FLOW INTO SAW WL
CAUSE VFR CONDITIONS THERE TNGT FOLLOWING THE COLD FROPA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EST TUE MAR 3 2015
S WINDS UP TO 25 KTS TODAY IN ADVANCE OF AN APPROACHING
COLD FRONT WILL SHIFT TO THE WNW FOLLOWING THE PASSAGE OF THIS FRONT
LATE TODAY/TONIGHT. TIGHTENING PRES GRADIENT AND STRONG COLD AIR
ADVECTION AHEAD OF ARCTIC HI PRES MOVING INTO THE NORTHERN PLAINS
WILL BRING A PERIOD OF WNW GALES INTO WED...MAINLY ACROSS CNTRL AND
ERN LAKE SUPERIOR. UPGRADED GALE WATCH TO A WARNING FOR THESE AREAS.
AFTER WED...NO GALE FORCE WINDS ARE EXPECTED THRU THE REMAINDER OF
THE FORECAST PERIOD. LATEST OFFICIAL ICE CONCENTRATION ON LAKE
SUPERIOR IS AROUND 94 PCT. EVEN WITH STRONG WINDS AT TIMES THIS WEEK
THAT WILL OPEN SOME HOLES IN THE ICE...THE SIGNIFICANT ICE COVERAGE
SHOULD PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ001>007-009>014-084-085.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 7 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 10 PM THIS EVENING TO 7 PM EST WEDNESDAY FOR
LSZ266.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1201 PM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 555 AM CST TUE MAR 3 2015
UPDATED AVIATION SECTION BELOW.
&&
.SHORT TERM...(TODAY THROUGH LATE TONIGHT)
ISSUED AT 332 AM CST TUE MAR 3 2015
INCOMING WINTER STORM WITH SNOW AND BLOWING SNOW TODAY IS THE
PRIMARY CONCERN IN THE SHORT TERM...WITH A SECONDARY FOCUS ON THE
VERY COLD AIR EXPECTED TO PUSH IN LATE TONIGHT.
SNOW HAS STARTED TO MOVE IN FROM THE SOUTH THIS MORNING WITH THE
LATEST RADAR LOOP SHOWING THE RETURNS INCREASING SOUTH OF HIGHWAY
TWO AND THE COLUMN QUICKLY BECOMING SATURATED AS THE AREA OF SNOW
LIFTS TO THE NORTH. THE LATEST RAP MESO ANALYSIS SHOWS A BAND OF
700MB F-GEN ALONG THE NRN EDGE OF STRONG WAA...AND THE CORRIDOR OF
STRONGEST SNOWFALL DIRECTLY IN LINE WITH THIS FORCING. THIS AREA
OF F-GEN WILL DEFINE WHERE THE HEAVIEST SNOW WILL OCCUR THIS
MORNING...AND IS STILL EXPECTED FROM AROUND THE BRAINERD
LAKES/LAKE MILLE LACS AREA NEWD TO THE TWIN PORTS AND INTO
PORTIONS OF NW WISCONSIN. A BROAD AREA OF 3 TO 5 INCHES IS
EXPECTED IN THIS ZONE. OTHER AREAS TO THE NORTH/NW...AND EVEN TO
THE SE...SOUTH OF STATE HIGHWAY 70 IN WI WILL SEE AROUND 1 TO 2
INCHES. THE MOST FAVORABLE TIME FOR ACCUMULATING SNOW WILL STILL
BE THIS MORNING FROM AROUND 5 AM TO 11 AM.
THE SFC COLD FRONT...CURRENTLY MOVING INTO FAR NW MN WILL MOVE
ACROSS THE NORTHLAND THIS AFTERNOON AND ALLOW THE WINDS TO SHIFT
FROM SW TO NW. THIS FRONT WILL ALSO BRING WITH IT VERY GUSTY
WINDS. STILL EXPECTING SUSTAINED WINDS AROUND 10 TO 20 MPH AND
GUSTS AROUND 30 MPH LATE THIS AFTERNOON THROUGH THE EVENING. THE
COMBINATION OF THE INITIAL SNOW THIS MORNING...AND BLOWING SNOW
LATER TODAY WILL KEEP CONDITIONS HAZARDOUS THROUGH MIDNIGHT
TONIGHT. NO CHANGES...SPATIAL OR TIMING...HAVE BEEN MADE TO THE
WINTER WEATHER ADVISORIES.
THE SNOW WILL TAPER OFF DURING THE EVENING AND OVERNIGHT HOURS
TONIGHT FROM WEST TO EAST WITH THE COLD AIR BEHIND THE FRONT
POURING IN ACROSS THE UPPER MIDWEST. 850MB TEMPS FROM -25 TO -28
DEG C ARE EXPECTED WITH THIS AIR MASS. THIS WILL ALLOW SFC
TEMPERATURES WILL FALL INTO THE SINGLE DIGITS AND TEENS BELOW
ZERO...AND THE COMBINATION OF GUSTY NW WINDS WILL PRODUCE WIND
CHILLS IN THE -25 TO -35 F RANGE. WILL LIKELY NEED A WIND CHILL
ADVISORY OVER MUCH OF THE FORECAST AREA TONIGHT/WED MORNING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE MAR 3 2015
WEDNESDAY TO BE A COLD AND BLUSTERY DAY WITH THE STRONG SURFACE LOW
MOVING NORTHEAST ACROSS QUEBEC. AN INVERTED TROUGH WILL EXTEND WEST
FROM THIS LOW...AND SLOWLY SAG SOUTHEAST ACROSS THE FORECAST AREA
DURING THE DAY. A STRONG SURFACE HIGH WILL BUILD DOWN THE PLAINS
DURING THE DAY AS WELL. EXPECT THAT WE WILL SEE FLURRIES OR LIGHT
SNOW IN THE VICINITY OF THE TROUGH AXIS...AND AM CARRYING SOME SMALL
POPS FOR THIS ALONG WITH CLOUDY SKIES. WITH THE PRESSURE GRADIENT STILL
FAIRLY STEEP SURFACE WINDS WILL REMAIN IN THE 10-15MPH RANGE WITH
GUSTS IN THE 20-25MPH RANGE...ESPECIALLY IN EXPOSED AREAS.
WEDNESDAY NIGHT THE SURFACE RIDGE BUILDS INTO THE AREA A LITTLE MORE
AND ALLOWS THE PRESSURE GRADIENT TO WEAKEN...AND THE CLOUDS AND
FLURRIES ARE PULLED OFF TO THE EAST WITH THE SURFACE LOW. THERE MAY
BE SOME LAKE EFFECT SNOW AFFECTING THE SOUTH SHORE EAST OF ASHLAND...
BUT WIND TRAJECTORY IS NOT THE MOST FAVORABLE AND HAVE KEPT POPS
LOW. TEMPERATURES TO BOTTOM OUT IN THE NEGATIVE TEENS FOR MANY
LOCATIONS...AND WITH THE LIGHT NORTHWEST WINDS IT LOOKS LIKE WE MAY
NEED A WIND CHILL ADVISORY FOR WEDNESDAY NIGHT AND THURSDAY MORNING.
FOR NOW WILL DISCUSS IN HWO...AND WILL HAVE TO RE-EVALUATE AS WE GET
CLOSER IN.
THURSDAY SOME STRONG WARM AIR ADVECTION SETS IN ALOFT AND HIGHS
SHOULD RISE INTO THE 10-15 DEGREE RANGE...IF NOT WARMER. OTHERWISE
QUIET WEATHER IS EXPECTED WITH THE SURFACE RIDGE IN THE VICINITY.
ANOTHER SHORTWAVE IS DUE TO MOVE THROUGH THURSDAY NIGHT AND FRIDAY.
FOR NOW AM NOT CARRYING ANY SNOW CHANCES BUT WOULD NOT BE SURPRISED
TO SEE FLURRIES. CURRENTLY HAVE HIGHS FRIDAY UP IN LOWER TO MIDDLE
30S. INITIALLY THIS WARMING SEEMS OVERDONE COMPARED TO THURSDAY.
HOWEVER...PURE MIXING TECHNIQUES WOULD INDICATE MID 20S TO LOW
30S...AND THEN YOU ADD IN SOME SUNSHINE AND OUR DARK TREES AND
SUDDENLY THOSE LOW TO MIDDLE 30S SEEM MORE REASONABLE.
THE WEEKEND LOOKS QUESTIONABLE WITH A SERIES OF SHORTWAVES DROPPING
DOWN ACROSS THE AREA IN UPPER LEVEL NORTHWEST FLOW. MODELS ARE
BRINGING SOME WARM 850MB TEMPERATURES INTO THE AREA ALOFT...BUT WITH
THE INCREASED CLOUD COVER ASSOCIATED WITH THE CLIPPERS...AND OUR
DECENT SNOWPACK...AM WONDERING IF WE MIGHT NOT GET A BUNCH OF
STRATUS AND FOG AND COOLER TEMPERATURES INSTEAD OF SUNSHINE AND MID
30S. HAVE LEFT CONSENSUS ALONE IN THIS LOW CONFIDENCE SITUATION...
BUT WE WILL NEED TO WATCH THIS CAREFULLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1158 AM CST TUE MAR 3 2015
THE STORM SYSTEM THAT BROUGHT THE ACCUMULATING SNOW TO THE
NORTHLAND WILL CONTINUE TO PULL OFF THROUGHOUT THE DAY AND INTO
TONIGHT. STRONG CAA AND GUSTY WINDS WILL BE FOUND IN THE WAKE OF
THE DEPARTING SYSTEM. VLIFR TO IFR CONDITIONS WILL QUICKLY
TRANSITION TO MVFR AND EVEN SOME VFR AS THE DAY WEARS ON. WITH THE
PASSAGE OF A SYSTEM SUCH AS THIS...THERE ARE OFTEN SOME LINGERING
CLOUD STREETS AND SPOTTY FLURRIES OR SNOW SHOWERS. THIS COULD MEAN
SOME LOCAL MVFR CIGS/VSBYS TONIGHT OR EVEN ON WEDNESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 25 -9 4 -11 / 100 10 10 0
INL 24 -15 3 -19 / 60 10 10 0
BRD 22 -11 5 -14 / 100 10 10 0
HYR 27 -8 6 -15 / 100 10 20 10
ASX 28 -4 7 -8 / 100 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ011-
012-018-019-021-025-026.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ020-
033>038.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>004-006>009.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...BJT
LONG TERM...LE
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS BILLINGS MT
251 PM MST TUE MAR 3 2015
.SHORT TERM...VALID FOR WED AND THU...
WEATHER SYSTEM LAST NIGHT CARVED OUT A NICE CYCLONIC FLOW OVER
OUR REGION. THERE IS STILL SOME WEAK ENERGY ALOFT IN THE FLOW
WHICH WILL DROP THROUGH OUR FORECAST AREA TONIGHT...BUT THERE IS
LITTLE IF ANY LOW LEVEL RESPONSE. SO I ANTICIPATE SOME LIGHT SNOW
OF PERHAPS FLURRIES IN THE EASTERN BORDER COUNTIES. FURTHER
WEST...THE HRRR IS PAINTING SOME VERY LIGHT QPF OVER THE HIGHER
TERRAIN. THIS IS SUPPORTED SOMEWHAT BY THE GFS. SO I DID ADD SOME
SPOTTY LOW POPS OVER THE BEARTOOTHS AND NEARBY ADJACENT AREAS
OVERNIGHT. THE BRISK WIND OVER THE COLD AIR MASS DOES DRIVE DOWN
THE WIND CHILLS OUT EAST. AS SUCH I WILL ISSUE A WIND CHILL
ADVISORY FOR FALLON AND CARTER COUNTIES FROM 11 PM TO 11 AM
WEDNESDAY.
TOMORROW...WE BEGIN TO TRANSITION TO A MORE CYCLONIC FLOW ALOFT
AND SURFACE FLOW WILL SWITCH TO A WESTERLY DOWNSLOPE LATE. THIS
WILL LEAD TO SOME WARMING OVER TODAYS HIGHS. I AM GOING LOWER THAN
GUIDANCE THROUGH WEDNESDAY IN THE FOOTHILLS DUE TO THE DEEP NEW
SNOW THERE. ELSEWHERE...WE MAY BE ABLE TO MELT OFF MOST OF THE
SNOW NOW THAT WE ARE IN TO EARLY MARCH.
EVEN BETTER WARM UP FOR THURSDAY AS WESTERLY SURFACE FLOW
STRENGTHENS AND FLOW ALOFT TURNS ANTI-CYCLONIC OVER THE ENTIRE
FORECAST AREA. LOOK FOR BRISK WINDS IN THE GAP LOCATIONS THURSDAY
...BUT DOES NOT LOOK QUITE STRONG ENOUGH FOR ADVISORY HIGHLIGHTS.
BT
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
EXTENDED FORECAST LOOKS TO BE IN GOOD SHAPE SO ONLY MADE A FEW
MINOR TWEAKS WITH THIS ISSUANCE. A NORTHWEST TO WEST FLOW ALOFT
WILL BE OVER THE FORECAST AREA THROUGH THE PERIOD. MODELS BRING A
WEAK DISTURBANCE ACROSS EASTERN MONTANA AND THE DAKOTAS FRIDAY
NIGHT. THIS IS INCONSISTENT WITH WHAT THEY WERE SHOWING YESTERDAY
WITH THE DISTURBANCE BEING FURTHER WEST. IN ANY CASE...REMOVED
POPS FROM THE WEST FRIDAY AND ADDED A SLIGHT CHANCE FOR A SNOW
SHOWER TO THE EAST FRIDAY NIGHT. OTHER THAN THIS SYSTEM...DRY
WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES LOOK TO BE IN STORE
FOR THE WEEKEND INTO NEXT WEEK. AFTERNOON TEMPERATURES WILL BE IN
THE LOWER 50S FOR THE WEEKEND WARMING INTO THE UPPER 50S EARLY
NEXT WEEK. HOOLEY
&&
.AVIATION...
SKIES WILL BE MOSTLY CLEAR TO PARTLY CLOUDY WITH VFR CONDITIONS
PREVAILING THIS EVENING AND THROUGH THE OVERNIGHT HOURS. THE
EXCEPTION WILL BE FROM KMLS TO KBHK WHERE AN ISOLATED SNOW SHOWER
AND MVFR CONDITION WILL BE POSSIBLE. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 004/029 016/046 029/050 029/050 030/054 033/058 033/058
00/B 00/N 01/B 21/B 10/B 00/U 00/U
LVM 001/031 022/044 029/048 028/049 030/052 031/055 033/056
10/B 00/N 01/B 21/B 00/B 00/U 00/U
HDN 002/028 012/047 025/051 026/051 028/055 030/059 030/059
00/U 00/B 01/B 21/B 10/B 00/U 00/U
MLS 901/019 006/046 025/048 027/048 028/051 029/055 032/057
20/U 00/B 01/B 21/B 10/B 00/U 00/U
4BQ 902/018 003/042 020/047 024/047 026/051 027/056 029/057
10/B 00/B 00/B 21/B 10/B 00/U 00/U
BHK 903/012 000/041 021/046 024/045 025/047 026/051 029/053
20/B 00/B 01/B 21/B 11/B 00/U 00/U
SHR 907/018 005/041 021/045 022/044 024/050 027/055 029/056
00/U 00/U 01/B 21/B 00/B 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND CHILL ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 11
AM MST WEDNESDAY FOR ZONES 33-37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
327 PM CST TUE MAR 3 2015
.SYNOPSIS...
ISSUED AT 330 PM CST TUE MAR 3 2015
AT H5 CLOSED LOW OVER WINNIPEG WITH TROUGH EXTENDING SOUTHWEST
INTO SOUTHERN CALIFORNIA. HIGH OVER THE GULF OF MEXICO AD RIDGE
OVER THE EASTERN PACIFIC.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CST TUE MAR 3 2015
WATER VAPOR IMAGERY SHOWS A THE NEXT SHORTWAVE ACROSS SOUTHWEST
WYOMING/NORTHWEST COLORADO LATE THIS AFTERNOON. THIS WAVE WILL
TRANSLATE EAST ACROSS THE AREA TONIGHT...WITH CHANCES FOR SNOW
INCREASING THIS EVENING AND OVERNIGHT ACROSS WEST CENTRAL THROUGH
SOUTHWEST NEBRASKA. IT SHOULD REMAIN DRY ACROSS NORTHERN NEBRASKA.
MODELS AGREE THAT A NARROW BAND OF LIGHT TO PERHAPS MODERATE SNOW
WILL DEVELOP FROM NORTHEAST COLORADO...EASTWARD ACROSS FAR SOUTHWEST
NEBRASKA AND INTO FAR SOUTH CENTRAL NEBRASKA LATE THIS EVENING. THE
BAND WILL NOT LAST LONG...AROUND 3 OR 4 HOURS. COULD SEE AN INCH OR
TWO WITHIN THIS BAND. INITIALLY CROSS SECTIONS INDICATE DRY AIR IN
THE LOWER LEVELS OF THE ATMOSPHERE...AND THIS IS CURRENTLY SUPPORTED
BY 20 DEGREE PLUS TEMPERATURE/DEW POINT SPREADS. AS THE SYSTEM MOVES
EAST INTO THE AREA BY LATE EVENING...DEEP LIFT WILL
INCREASE...MAXIMIZED ACROSS FAR SOUTHWEST NEBRASKA BY AROUND 06Z OR
SO. LIFT WILL BE WEAKER TO THE NORTH TOWARD INTERSTATE 80. SHOULD
SEE A FAIRLY QUICK TOP DOWN SATURATION LATE THIS
EVENING...ESPECIALLY ACROSS FAR SOUTHWEST NEBRASKA WHERE THE
STRONGER LIFT WILL BE LOCATED. THE LATEST RAP MODEL INDICATES A
LITTLE BETTER LIFT WITHIN THE DGZ /EARLIER MODEL RUNS WERE JUST
ABOVE THE DGZ/ SO THAT GAVE A BOOST OF CONFIDENCE...AND WILL TAKE
LOW END LIKELY POPS ALL THE WAY NORTH INTO THE INTERSTATE 80
CORRIDOR REGION...WHICH IS SUPPORTED BY THE NEW 18Z NAM MODEL
RUN.
CLOUDS WILL GRADUALLY DECREASE WEDNESDAY...AS DRIER AIR ALOFT
ADVECTS INTO THE AREA THROUGH THE DAY. WINDS WILL ALSO BE ON THE
DECREASE. STILL PRETTY COLD WEDNESDAY...WITH H850MB NOT WARMING MUCH
THROUGH THE DAY...AND STAYING WELL BELOW ZERO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CST TUE MAR 3 2015
MODELS IN GOOD AGREEMENT IN THE MID AND LONG TERM SOLUTIONS AND
HAVE GOOD CONFIDENCE IN THE FORECAST. CAN SEE SOME SNOW ON THE
GROUND OVER NORTHERN SHERIDAN COUNTY THROUGH CENTRAL CHERRY COUNTY
BUT OVER THE REMAINDER OF THE FORECAST AREA GROUND LOOKS PRETTY
BARE. WEDNESDAY NIGHT HAVE LOWS IN THE SINGLE DIGITS WITH BELOW
ZERO TEMPERATURES OVER NORTHERN SHERIDAN COUNTY. 850MB
TEMPERATURES RISING THROUGH THE DAY ON THURSDAY AS UPPER TROUGH
MOVES EAST AND WARMER DRIER AIR MOVES EAST INTO THE FORECAST AREA.
QUASI BLOCK ALONG THE WEST COAST WILL SLOW PROGRESSION OF UPPER
PATTERN LEAVING NORTHERN PLAINS IN FAST NORTHWEST FLOW. WEAK WAVE
WILL MOVE THROUGH NORTHWEST PATTERN SATURDAY WITH MAINLY JUST A
WIND SHIFT. TEMPERATURES RISING INTO THE 50S. ANOTHER WEAK WAVE
MOVING THROUGH SUNDAY NIGHT WILL PULL ANOTHER WEAK COOL FRONT
THROUGH THE FORECAST MONDAY DRY. TEMPERATURES WILL CONTINUE SLOW
CLIMB THROUGH THE COMING WEEK AND DRY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1144 AM CST TUE MAR 3 2015
AN UPPER LEVEL DISTURBANCE CURRENTLY LOCATED NEAR KSLC...WILL MOVE
EAST ACROSS SOUTHERN WY AND NORTHERN CO THIS AFTERNOON. THE
DISTURBANCE WILL ARRIVE IN SOUTHWEST NEBRASKA THIS EVENING...AND
EXPECT A PERIOD...AROUND 4 HOURS OR SO...OF MVFR AND SNOW AS THE
SYSTEM PASSES. EXPECT IMPROVING CONDITIONS AFTER ABOUT 07Z
WEDNESDAY.
WINDS ARE CURRENTLY GUSTING TO NEAR 35 KTS FROM THE NORTH...AND
THESE WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON...WITH SPEEDS
GENERALLY 10 KTS OR LESS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...TAYLOR
LONG TERM...POWER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 AM CST TUE MAR 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CST TUE MAR 3 2015
TODAY AND TONIGHT...THE RAP AND OTHER MODELS INDICATE THE SNOW BAND
ACROSS NRN NEB WILL EXIT THIS FORECAST AREA THIS MORNING. SOME LIGHT
SNOW WOULD LIKELY PERSIST INTO THE AFTN AS THE ARCTIC FRONT
UNDERCUTS DEEP MOISTURE IN PLACE LEAVING A GROWTH ZONE FOR SNOW
ABOVE 850 MB.
THERE IS NO REAL CHANGE IN THE SNOWFALL FORECAST EXCEPT TO SAY THE
MODELS CAME IN A BIT DRIER ACROSS THE NORTH BUT THIS MAY JUST BE A
WOBBLE IN THE MODEL CONSENSUS. GIVEN THE ROBUST MOISTURE AND DECENT
MID AND LOW LEVEL FRONTOGENESIS...1 TO 4 INCHES OF SNOW WOULD APPEAR
LIKELY.
THE MODEL CONSENSUS OF THE HRRR...RAP...MOSGUIDE AND NAMDNG SUGGESTS
GUSTS TO 45 MPH BEHIND THE ARCTIC FRONT. THE BULK OF THE SNOWFALL
WILL BE OCCURRING AHEAD OF THESE GUSTS. SO THE WINTER WEATHER
ADVISORY APPEARS TO BE RIGHT ON TRACK.
WIDESPREAD FOG HAS DEVELOPED AHEAD OF THE ARCTIC FRONT. SFC LOW
PRESSURE IS CAUSING THE WINDS TO BACK WITH DRY AIR ALOFT PROMOTING
FOG DEVELOPMENT. LIGHT FREEZING RAIN...FREEZING FOG AND FREEZING
DRIZZLE SHOULD CONTINUE AHEAD OF THE ARCTIC FRONT. A CHECK ON THE
HIGHWAY CAMS INDICATES THE ROAD SURFACES HAVE NOT YET CROSSED THE
FREEZING MARK AND ONLY THE CHAPPELL CAMERA APPEARED TO BE COLLECTING
ICE ON THE LENS. WEATHER CONDITIONS WILL BE MONITORED CLOSELY FOR
SIGNS OF ICING WHICH WOULD WARRANT A FREEZING RAIN ADVISORY THIS
MORNING AHEAD OF THE ARCTIC FRONT.
ONCE THE ARCTIC FRONT CROSSES THE FCST AREA AROUND 15Z THE ICING
THREAT SHOULD END.
LOWS TONIGHT FALL INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO. THE
WARMER READINGS ACROSS THE SOUTH ARE THE RESULT OF CLOUD COVER AND
LINGERING SNOW ACROSS THE FAR SOUTH. SKIES SHOULD CLEAR ACROSS THE
NORTH AND WIND CHILL READING ACROSS SHERIDAN AND CHERRY COUNTIES
WILL BE APPROACHING OR EXCEEDING THE MINUS 20 THRESHOLD FOR A WIND
CHILL ADVISORY. LATER FORECASTS CAN REFINE THIS ELEMENT OF THE
FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM CST TUE MAR 3 2015
TEMPERATURES ARE THE MAIN FORECAST CHALLENGE GOING IN THE
EXTENDED PERIODS...AS ARCTIC HIGH PRESSURE WILL BE REPLACED BY
DOWNSLOPING WARMING WESTERLY WIND ON THURSDAY. THUS...BELOW AVERAGE
TEMPERATURES ARE FORECAST FOR WEDNESDAY...BUT
THEREAFTER...CONDITIONS FAVOR NEAR OR ABOVE NORMAL TEMPERATURES.
WEDNESDAY...ANOTHER COLD DAY ANTICIPATED AS ARCTIC HIGH PRESSURE
REIGNS SUPREME. HIGHS IN THE TEENS AND 20S ARE FORECAST WITH
APPARENT TEMPERATURES DANGEROUSLY COLD DURING THE MORNING HOURS.
MOST LOCATIONS SHOULD SEE WIND CHILLS OF MINUS TEN OR COLDER UNTIL
NOON. THEREAFTER...THE MEDIUM AND LONG RANGE MODELS ARE SHOWING
GOOD AGREEMENT IN THAT A SHARP TROUGH...WHICH EXTENDS FROM EASTERN
CANADA SOUTHWEST TO BAJA WILL SPLIT AND PROGRESS EAST THROUGH LATE
WEEK. THIS WILL LEAVE A CUT OFF LOW SOUTH OF THE DESERT
SOUTHWEST...BUT ALLOW THE EASTWARD EXPANSION OF AN AMPLIFIED UPPER
RIDGE ACROSS THE WESTERN CONUS. AS THE UPPER LEVELS BECOME LESS
AMPLIFIED OVER THE PLAINS...THE PATTERN WOULD THEN FAVOR A MORE
DIRECT PATH FROM THE PACIFIC...RATHER THAN THE ARCTIC WHICH HAS BEEN
OBSERVED LATELY. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD
EAST WITH THE ADVANCING TROUGH...LEAVING BEHIND A GREATER SOUTHWEST
TO WESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND. THE
DOWNSLOPING TRAJECTORY WILL WORK IN CONCERT WITH RISING HEIGHTS AND
THE ASSOCIATED WAA TO PROMOTE RISING TEMPERATURES THURSDAY AND
FRIDAY. MOST LOCATIONS WILL SEE HIGHS IN THE 40S BY THURSDAY...WITH
50S ANTICIPATED FOR FRIDAY. THE MODELS ARE HIGHLIGHTING THE PASSAGE
OF A WEAK SHORTWAVE AND COLD FRONT ON SATURDAY. THIS AIRMASS HAS A
GREATER PACIFIC INFLUENCE...THUS TEMPERATURES ONLY ARE FORECAST TO
COOL SLIGHTLY. IT SHOULD BE NOTED HOWEVER THAT THE GFS HAS CAME IN
COOLER THAN PREVIOUS FORECASTS...WITH COOLER H85 TEMPERATURES
NEARING MINUS 5 ACROSS MUCH OF THE FORECAST AREA EARLY SATURDAY
AFTERNOON. WE MAY BE A BIT OPTIMISTIC ON THE CURRENT FORECAST
HIGHS...WILL SEE IN THE COMING DAYS. OTHERWISE THE WAVE ARRIVES
WILL LITTLE FANFARE...MOISTURE PROFILES IN THE TROPOSPHERE ARE
RATHER LACKING...SO WILL CONTINUE THE DRY FORECAST. BEYOND
SATURDAY...A DOWNSLOPING REGIME REIGNS ONCE AGAIN ALLOWING FOR
ANOTHER WARMUP. THE MODELS ADVERTISE THE RIDGE AXIS BUILDING EAST
TOWARD THE HIGH PLAINS EARLY NEXT WEEK...HIGHS SHOULD RESPOND BY
WARMING INTO THE UPPER 50S...POSSIBLY LOWER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1144 AM CST TUE MAR 3 2015
AN UPPER LEVEL DISTURBANCE CURRENTLY LOCATED NEAR KSLC...WILL MOVE
EAST ACROSS SOUTHERN WY AND NORTHERN CO THIS AFTERNOON. THE
DISTURBANCE WILL ARRIVE IN SOUTHWEST NEBRASKA THIS EVENING...AND
EXPECT A PERIOD...AROUND 4 HOURS OR SO...OF MVFR AND SNOW AS THE
SYSTEM PASSES. EXPECT IMPROVING CONDITIONS AFTER ABOUT 07Z
WEDNESDAY.
WINDS ARE CURRENTLY GUSTING TO NEAR 35 KTS FROM THE NORTH...AND
THESE WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON...WITH SPEEDS
GENERALLY 10 KTS OR LESS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ004>007-094.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1222 PM CST TUE MAR 3 2015
.UPDATE...
ISSUED AT 1220 PM CST TUE MAR 3 2015
WE WILL ISSUE A WIND ADVISORY THROUGH 00Z IN THE VALLEY...GETTING
WINDS INTO CRITERIA NOW. OTHERWISE...THE FORECAST REMAINS
UNCHANGED FROM PREVIOUS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
NUMEROUS FORECAST CHALLENGES WITH MOST REVOLVING AROUND STRONG
COLD FRONT AND SNOW BAND ACROSS THE FAR SOUTH-EAST ASSOCIATED
WITH COUPLED JET STRUCTURE MAINLY DURING THE MORNING HOURS.
MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. OF MAIN
CONCERN WILL BE SNOW POTENTIAL AND BASED ON CURRENT RADAR TRENDS
WILL FOLLOW RUC/HRRR WHICH ARE PRETTY CLOSE IN DEPICTING
DEVELOPING SNOW BAND. REASON IS MESOSCALE MODELS IN THE SHORT TERM
TEND TO OUT PERFORM LARGER SCALE MODELS IN SNOW COVERAGE WHICH
WILL BE KEY TO POTENTIAL BLIZZARD CONDITIONS ACROSS THE FAR SOUTH.
SNOW BAND JUST STARTING TO GET ORGANIZED FROM SW-NE SD INTO CENTRAL
MN. EARLY GOING LOOKS LIKE OPERATIONAL MODELS MAY BE A BIT TOO FAR
NORTH WITH SNOW BAND. SO FAR BASED ON CURRENT UPSTREAM RADAR
TRENDS AND MESOSCALE MODEL SOLUTIONS PRIMARY CONCERN FOR
SIGNIFICANT BLSN/SNOWFALL WILL BE IN THE MN/ND/SD BORDER REGION
INTO ADJACENT WEST CENTRAL MN. RUC PUTS THIS AREA ON NORTHERN
FRINGE OF MAIN SNOW BAND WHILE THE HRRR A BIT FARTHER SOUTH
CLIPPING POSSIBLY GRANT COUNTY. WITH THE FARTHER NORTH RUC MAIN
ISENTROPIC LIFT AND LOWER CONDENSATION PRESSURE DEFICITS FROM 285K
SURFACE FARTHER SOUTH SUPPORTING HRRR SOLUTION. RUC THEN SHIFTS
MAIN SNOW BAND EAST OF TARGET AREA MID-LATE MORNING.
SEVERAL THINGS TO CONSIDER FOR POTENTIAL BLIZZARD ACROSS THE FAR SOUTH.
SNOW COVER FROM FROM COOPS AND VISIBLE IMAGERY SLIM TO NONE ACROSS
THE FAR SOUTH SO WILL BE RELYING ON FALLING/ACCUMULATING SNOW.
BASED ON TIMING OF COLD FRONT STRONGER WINDS WILL BE DEVELOPING
WHEN SNOW SHOULD BE WINDING DOWN. OUTPUT FROM LOCAL BLOWING SNOW
MODEL MARGINAL FOR BLIZZARD CONDITIONS WITH OVER 30KTS SUSTAINED
NECESSARY FOR BLIZZARD WITH FALLING SNOW AND NEARLY 40KTS WITH NO
SNOW. WOULD LIKE TO SEE MORE CONVINCING DATA BEFORE GOING WITH
BLIZZARD WARNING. OF COURSE ITS POSSIBLE FOR BRIEF BLIZZARD
CONDITIONS BUT THIS LOOKS TO BE A BRIEF PERIOD AND SHOULD BE AFTER
MORNING COMMUTE AND START OF SCHOOL. WITH THIS REASONING WILL
REPLACE BLIZZARD WATCH WITH ADVISORY. FARTHER NORTH AND WEST
CONFIDENCE LOWERING THAT MUCH IF ANY MEASURABLE SNOW WILL OCCUR.
WILL MAINTAIN CURRENT ADVISORY BUT MONITOR AT NEXT UPDATE PERIOD.
N AND W OF THIS AREA ISOLD SHSN ABOUT THE ONLY THING HAPPENING
BEHIND COLD FRONT AND WITH NO BLOWABLE SNOW WILL HOLD WITH CURRENT
HEADLINES. ONCE FRONT GOES THROUGH STRONG COLD ADVECTION WILL LEAD
TO MINIMAL TEMPERATURE RECOVERY.
TONIGHT WIND CHILLS WILL BE THE MAIN ISSUE. SINCE WIND CHILLS NOT
TO REACH ADVISORY CRITERIA UNTIL EVENING HELD OFF ON HEADLINES
WITH OTHER MORE IMPORTANT HEADLINES ONGOING DURING THE DAY. COLD
POOL SETTLES OVER FA LATE TONIGHT. WILL BE ENOUGH MIXING TO KEEP
TEMPERATURES FROM REALLY DROPPING BUT WILL BE SUFFICIENT FOR WIND
CHILL HEADLINES.
WEDNESDAY WILL BE COLD WITH DIMINISHING WIND DURING THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 AM CST TUE MAR 3 2015
SURFACE HIGH DROPS THROUGH THE FA WEDNESDAY NIGHT AND AFTER
MIDNIGHT WILL BE SEEING SOME W-SW SURFACE WIND ALONG WITH WARM
ADVECTION. EXPECT MINIMUM TEMPERATURES ALONG AND WEST OF VALLEY
PRIOR TO MIDNIGHT AND COLDEST READINGS MAINLY EAST OF THE VALLEY.
MIXING AND RESPECTABLE WARM ADVECTION WILL ALLOW FOR GOOD
TEMPERATURE RECOVERY THURSDAY BUT STILL BLO AVERAGE WITH INITIAL
COLD START.
GFS SOLE MODEL PAINTING QPF ACROSS THE NORTH WITH WEAK TROUGH
PASSAGE THURSDAY NIGHT AND KEPT FORECAST DRY. MINIMUM TEMPERATURES
WILL BE MUCH CLOSER TO AVERAGE.
FOR FRIDAY THROUGH MONDAY...WILL KEEP THE NORTHWEST FLOW ALOFT FOR
THE DURATION. HOWEVER THE FLOW DOES START TO TURN MORE WEST-NW BY
MONDAY WITH THE MODELS SHOWING THE PROMISE OF EVEN BETTER THINGS TO
COME BY MID NEXT WEEK. FIRST THINGS FIRST...MODELS STILL SHOW A WEAK
WAVE ON FRIDAY NIGHT. HOWEVER SINCE THE MAIN SFC REFLECTION LOOKS TO
REMAIN IN CANADA WILL KEEP THE DRY FORECAST. NEXT WEAK WAVE DROPS
DOWN THE NORTHWEST FLOW SAT NIGHT/SUN MORNING. ONCE AGAIN THE MAIN
SFC REFLECTION STAYS IN SOUTHERN CANADA BUT THIS TIME THE MODELS
SHOW SOME LIGHT PCPN ACROSS THE NORTH/NE FA. WILL KEEP SOME LOW
CHANCES IN THESE AREAS FOR NOW AND SEE WHAT LATER RUNS HAVE IN
STORE. 00Z GFS SHOWS ANOTHER WEAK SYSTEM SUN NIGHT/MON MORNING WHILE
THE ECMWF IS MUCH WEAKER AND FURTHER EAST. WILL KEEP THE FORECAST
DRY FOR THIS ONE. KEPT TEMPS ABOVE NORMAL THROUGH THE ENTIRE PERIOD
BUT STILL HAVE SOME UNCERTAINTY FOR FRI-SUN AS THE PREVIOUSLY
MENTIONED WAVES MOVE THROUGH. ACTUALLY HAVE A LITTLE BETTER
CONFIDENCE BY MONDAY AS THE FLOW STARTS TO TURN WEST-NW AND THE
ECMWF ESPECIALLY INDICATES WARMER 850MB TEMPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1220 PM CST TUE MAR 3 2015
WINDS WILL GUST NEAR OR OVER 30KTS AT TIMES THROUGH THE
AFTERNOON...BEFORE GRADUALLY SUBSIDING BY THIS EVENING. A MIX OF
MVFR TO LOW VFR CEILINGS ARE EXPECTED THROUGH THE AFTERNOON...WITH
SOME CLEARING BY THIS EVENING. SOME REDUCED VISIBILITIES ARE
EXPECTED AT TIMES THIS AFTERNOON ESPECIALLY AT KTVF/KBJI...OR WITHIN
ANY BRIEF SNOW SHOWERS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ053.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ006>008-014>016-
024-026>030-038-039-049-052-054.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ024-
027>032-040.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ001>004-007.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1204 PM EST TUE MAR 3 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHWARD TODAY ALLOWING FREEZING RAIN TO
TRANSITION TO RAIN. A COLD FRONT WILL MOVE THROUGH TONIGHT INTO
WEDNESDAY MORNING. ANOTHER WAVE WILL ALLOW FOR ACCUMULATING SNOW
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...WITH SLOW TEMPERATURE RISE...HAVE EXTENDED FREEZING RAIN
ADVISORY ACRS THE NORTH TO 3 PM.
PREVIOUS...
ACTIVE WEATHER PATTERN WITH INITIAL FOCUS ON THE FREEZING RAIN
POTENTIAL THIS MORNING AND THEN SWITCHING TO HEAVY RAIN TONIGHT
AND HEAVY SNOW WED/THU.
ISENTROPIC LIFT LEAD TO AN AXIS OF FREEZING RAIN ACRS ILN/S
NORTHERN COUNTIES EARLY THIS MORNING. THIS PRECIPITATION AXIS HAS
PIVOTED NORTH AND EAST OF ILN/S FA.
ILN/S 12Z MORNING SOUNDING SHOWS WARM BULGE ALOFT OF 6 DEG C
AROUND 78O MB BUT RATHER DRY AIR BELOW THIS. WITH LIGHT ECHO
RETURNS...THIS HAS LIMITED ANY FREEZING RAIN IN THE SOUTH THIS
MORNING.
BETTER LIFT COMING INTO PLAY BY LATE MORNING AS FAVORABLE LOW LEVEL
CONVERGENCE DEVELOPS ASSOCIATED WITH 60-65 KT LLJ. SEEING THIS
BETTER FORCING LEADING TO AN INCREASE IN RADAR RETURNS ACRS
INDIANA. CURRENTLY IN LULL BUT HAVE SHOWN THIS TREND WITH AN
INCREASE IN POPS FROM THE WEST LATER THIS MORNING.
HAVE ALLOWED THE SRN TIER OF THE FREEZING RAIN ADVISORY TO EXPIRE
WITH TEMPERATURES WARMING ABOVE FREEZING. SOME SFC ROAD/WALKWAY TEMPS
WILL LAG. THEREFORE...HAVE AN SPS THRU NOON ACRS THE FAR SOUTH.
HAVE KEPT NRN FREEZING RAIN ADVISORY THRU 1 PM WITH TEMPERATURES EXPECTED
TO WARM ABOVE FREEZING THIS AFTN AS LOW LEVEL WINDS VEER FROM THE
EAST TO THE SOUTH.
PREVIOUS DISCUSSION...
FREEZING RAIN AND SLEET ARE MOVING INTO NW PORTIONS OF THE FA. THE
HIGHEST ICE ACCUMULATIONS OF AROUND FIVE HUNDREDTHS OF AN INCH
ARE EXPECTED IN THIS AREA. ELSEWHERE ACROSS THE AREA AROUND A
COUPLE HUNDREDTHS OF AN INCH OF ICE ACCUMULATION WILL BE POSSIBLE
THIS MORNING. THE LOWEST ICE ACCUMULATIONS ARE EXPECTED ACROSS
NORTHERN KENTUCKY WHERE TEMPERATURES WILL BE BELOW FREEZING FOR
THE SHORTEST AMOUNT OF TIME AND PRECIPITATION WILL BE LIGHTER. DUE
TO THIS REASON HELD OFF ON A FREEZING RAIN ADVISORY FOR A PORTION
OF NORTHERN KENTUCKY AND EXTREME SOUTHERN INDIANA. DID GO AHEAD
AND EXPAND THE FREEZING RAIN ADVISORY SOUTHWARD FROM PREVIOUS
FORECAST SINCE EVEN LIGHT ICE AMOUNTS CAN CREATE HAZARDOUS DRIVING
CONDITIONS. CHANGED A TIER OF THE WINTER WEATHER ADVISORY TO A
FREEZING RAIN ADVISORY SINCE THE MAIN PRECIPITATION TYPE IS
EXPECTED TO BE FREEZING RAIN. KEPT A TIER OF WINTER WEATHER
ADVISORY ACROSS THE NORTH DUE TO THE POSSIBILITY OF SOME SLEET
MIXING IN.
TEMPERATURES WILL RISE THROUGH THE DAY AS A WARM FRONT PUSHES
NORTHWARD AND FREEZING RAIN WILL GRADUALLY TRANSITION TO RAIN.
THERE IS SOME CONCERN THAT NORTHERN PORTIONS OF THE FA WILL NOT
GET ABOVE FREEZING BY THE TIME THE WINTER WEATHER ADVISORY EXPIRES
HOWEVER BELIEVE THAT IT WILL BE CLOSE AND THEREFORE DID NOT CHANGE
THE END TIME OF THE WINTER WEATHER ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
RAIN WILL PICK UP IN INTENSITY ACROSS SE PORTIONS OF THE FA THIS
EVENING INTO TONIGHT. OVER AN INCH OF RAIN WILL BE POSSIBLE ACROSS
PORTIONS OF THE AREA AND DUE TO THIS HAVE CONTINUED THE FLOOD
WATCH.
A COLD FRONT WILL WORK INTO THE AREA TONIGHT. THERE IS NOT A LOT
OF INSTABILITY WITH THIS SYSTEM AND THEREFORE DECIDED TO LEAVE
THUNDER OUT OF THE FORECAST. AS COLDER AIR BEGINS TO WORK INTO THE
REGION A MIX OF PRECIPITATION PRIMARILY NW OF DAYTON WILL BE POSSIBLE LATE
IN THE OVERNIGHT HOURS.
TEMPERATURES ARE EXPECTED TO FALL DURING THE DAY ON WEDNESDAY. AS
THEY DO RAIN WILL TRANSITION OVER TO SNOW. DURING THIS TRANSITION
PERIOD...SLEET AND FREEZING RAIN WILL BE POSSIBLE. ANY ICE
ACCUMULATION FROM FREEZING RAIN IS EXPECTED TO BE MINIMAL.
PRECIPITATION WILL BRIEFLY TAPER DOWN DURING THE LATE MORNING AND
EARLY AFTERNOON HOURS ON WEDNESDAY HOWEVER ANOTHER WAVE OF
PRECIPITATION WILL BEGIN TO WORK INTO THE REGION WEDNESDAY
AFTERNOON. THIS PRECIPITATION IS EXPECTED TO BE PRIMARILY SNOW
HOWEVER A WINTRY MIX WILL STILL BE POSSIBLE ACROSS PORTIONS OF
NORTHERN KENTUCKY AND SE OHIO THROUGH THE AFTERNOON HOURS.
PRECIPITATION WILL CHANGE OVER TO ALL SNOW WEDNESDAY EVENING.
SNOW WILL CONTINUE ACROSS THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING BEFORE BEGINNING TO TAPER OFF. SNOW WILL BE HEAVY AT TIMES
ESPECIALLY ACROSS THE SE HALF OF THE FA. THERE WILL BE A SHARP CUT
OFF IN AMOUNTS FURTHER NW OF INTERSTATE 71. EXPANDED THE WINTER
STORM WATCH TO COVER ALL BUT FRANKLIN INDIANA AND BUTLER COUNTY
OHIO OF THE 4 INCH SNOW CRITERIA. THERE IS SOME UNCERTAINTY ON
THE NW EDGE OF THE SNOW AND THEREFORE DECIDED TO LEAVE THOSE
COUNTIES OUT AT THIS TIME. HAVE THE NORTHERN TIER OF THE WATCH
WITH 4 TO 6 INCHES OF SNOW AND THE REST OF THE WATCH WITH AROUND 6
TO 9 INCHES OF SNOW. ISOLATED HIGHER AMOUNTS CANNOT BE RULED OUT.
THERE IS STILL SOME UNCERTAINTY ON HOW QUICKLY THE RAIN WILL
TRANSITION TO SNOW ON WEDNESDAY AND THUS THERE IS STILL SOME
UNCERTAINTY IN FORECAST SNOW AMOUNTS.
SNOW WILL MOVE OUT OF THE FA DURING THE LATE MORNING HOURS AND
INTO THE AFTERNOON ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE
REGION THURSDAY NIGHT AND CLOUD COVER WILL DECREASE. ALTHOUGH SOME
RETURN SOUTHERLY FLOW WILL DEVELOP...WITH FRESH SNOW COVER AND
MOSTLY CLEAR SKIES EXPECT TEMPERATURES TO DROP DOWN TO THE
NEGATIVE SINGLE DIGITS ACROSS MANY LOCATIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FOR THE PERIOD FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE MOVES
EAST WHILE A WEAK COLD FRONT DROPS SOUTHEAST INTO THE GREAT LAKES.
MOSTLY SUNNY SKIES ARE EXPECTED ON FRIDAY WITH AN INCREASING
SOUTHERLY RETURN FLOW. AGAIN...DIFFICULT TO KNOW HOW WARM IT WILL
GET ON FRIDAY AS SHALLOW ARCTIC AIR WILL LIKELY GET MIXED OUT BUT
LINGERING SNOW COVER AND A STRONG MARCH SUN ANGLE WILL BE IN PLAY.
WILL RANGE HIGHS FROM THE MID 20S NORTH TO THE LOWER 30S SOUTH.
LOWS FRIDAY NIGHT WILL GENERALLY BE IN THE TEENS.
FOR SATURDAY INTO SATURDAY NIGHT...HAVE LEANED TOWARD THE ECMWF FOR
THE MOVEMENT OF SYNOPTIC SCALE SYSTEMS. A WEAK FRONT DROPS THROUGH
OUR AREA ON SATURDAY/SATURDAY NIGHT. FRONT APPEARS MOISTURE STARVED
SO HAVE KEPT THE FORECAST DRY WITH ONLY SOME INCREASE IN CLOUDS.
TEMPERATURES WILL WARM INTO THE 30S AND 40S ON SATURDAY...BUT WILL
STILL AVERAGE BELOW NORMAL FOR EARLY MARCH.
HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA FOR SUNDAY...FOLLOWED BY
ANOTHER WEAK FRONT ON MONDAY. FRONT ON MONDAY MAY BRING A LOW CHANCE
FOR RAIN AND/OR SNOW. TEMPERATURES WILL BE SIMILAR TO SATURDAY/S
READINGS...30S AND 40S...BUT FOR THE MOST PART AVERAGING A LITTLE
BIT BELOW NORMAL FOR EARLY MARCH.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
FREEZING RAIN AND DRIZZLE IS CURRENTLY MOVING INTO THE AREA FROM
WEST TO EAST THIS MORNING WITH KDAY ALREADY REPORTING FZDZ. EXPECT
LIGHT FREEZING RAIN AND DRIZZLE TO CONTINUE THIS MORNING WITH
TEMPERATURES SLOWLY WARMING. LATEST HRRR MODEL RUN SHOWS THAT
THERE MIGHT BE A BRIEF BREAK IN THE PRECIP THIS MORNING BUT
QUICKLY REDEVELOPS PRECIP ACROSS THE AREA. GFS/ NAM AND RAP
SOUNDINGS ALL SHOW TEMPERATURES RISING ABOVE FREEZING BY NOON
TODAY. FORECAST SOUNDINGS ALSO SHOW CIGS FALLING INTO IFR
CONDITIONS THIS AFTERNOON. LOOKING AT UPSTREAM OBS AM A LITTLE
HESITANT WITH THIS. A COLD FRONT WILL THEN MOVE THROUGH THE AREA
LATE TONIGHT INTO EARLY WEDNESDAY MORNING. AS THE FRONT MOVES
THROUGH THE AREA MUCH COLDER AIR WILL FILTER IN. THIS WILL ALLOW
PRECIP TO AGAIN TRANSITION BACK TO SNOW.
OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH
WEDNESDAY NIGHT WITH ACCUMULATING SNOW. MVFR CEILINGS WILL
POTENTIALLY LINGER THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
OHZ026-034-035-042>046-051>056-060>062.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ063>065-070>074-077.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR OHZ063>065-071>074-077>082-088.
KY...WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR KYZ089>100.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR KYZ089>100.
IN...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
INZ050-058-059.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
INZ066-073-074.
WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
AFTERNOON FOR INZ073>075-080.
FLOOD WATCH FROM 7 PM EST THIS EVENING THROUGH WEDNESDAY
AFTERNOON FOR INZ075-080.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...AR
SHORT TERM...NOVAK
LONG TERM...HICKMAN
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
444 PM EST TUE MAR 3 2015
.SYNOPSIS...
MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING
RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL
LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS
EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER
PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING
INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY
STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH
PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH
INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ
RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY
FREEZING RAIN BY EARLY EVENING. HRRR HAS VACILLATED CONSIDERABLY
FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND
THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO SHORT-
TERM CHANGES ON SHORT RANGE ENSEMBLES AND IN PARTICULAR SREF
THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER
CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON
THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY. WILL
UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME SNOW/SLEET
BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE NORTH CENTRAL
MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS EXPECTED. FARTHER
WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER WARREN AND ELK
COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN BORDERS OF THOSE
COUNTIES. THE WARNING AREA MAY NEED TO BE EXPANDED FARTHER SOUTH
INTO THE CENTRAL MOUNTAINS IN TIME...BUT CONFIDENCE IN DOING SO
SOUTH OF INTERSTATE 80 WAS LOW GIVEN CONFLICTING HRRR LLVL
TEMPERATURE READINGS AND QPF DISTRIBUTION THROUGH LATE TONIGHT.
THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL
HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT
WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS
FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH
A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN.
NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT
TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO
WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE
STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND
CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY
MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT
AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS
ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF
AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING
UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE
SOUTH OF INTERSTATE 80.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
AN ACTIVE LATE-WINTER PRECIPITATION PATTERN WILL IMPACT CENTRAL
PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF
ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD
DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH
PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL AND ENSEMBLE
CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE
EAST THROUGH THE WEEKEND WITH SOME SIGNS OF A PATTERN SHIFT BY THE
MIDDLE OF NEXT WEEK WITH TROUGHING FCST TO DEVELOP ALONG THE WEST
COAST. BELOW NORMAL TEMPS SHOULD MODERATE CLOSER TO NORMAL EARLY
NEXT WEEK WITH SOME HINTS AT EVEN WARMER TEMPS LATER NEXT WEEK.
MODELS CONTINUE TO SHOW AN AMPLIFIED AND MOIST SW FLOW ALOFT AND
JET ENTRANCE REGION DYNAMICS SUPPORTING A BROAD STRIPE OF PCPN
ALONG A WELL DEFINED BAROCLINIC ZONE AHEAD OF PHASING UPPER LEVEL
ENERGY OVER THE DSW/ROCKIES ON WED AND MOVING EWD THROUGH THE OH
VLY AND MID ATLC ON THURSDAY. SEVERAL WAVES OF LOW PRESSURE ARE
FCST TO DEVELOP AND MOVE ENEWD ALONG A SW-NE ORIENTED COLD FRONT
WHICH SHOULD PROGRESS AND SETTLE SEWD THROUGH THE MID ATLC REGION
BY EARLY THURS...AS ARCTIC HIGH PRESSURE BUILDS INTO THE UPPER
PLAINS. AMPLE MOISTURE IS FCST BY THE MODELS TO MOVE INTO A
DEEPENING COLD SECTOR ALONG/NORTH OF THE SEWD-ADVANCING COLD
FRONTAL BOUNDARY WHICH COULD RESULT IN A LATE SEASON HEAVY SNOW
EVENT FOR SOUTH CENTRAL PA WED NGT INTO THURS. THERE ARE MODEL
DIFFERENCES WITH THE TIMING OF THE FRONT WHICH IS LKLY TIED TO THE
CONSOLIDATION OF SHORTWAVE ENERGY UPSTREAM. THAT SAID...THE
CONSENSUS FCST AXIS OF MAX QPF /0.50 INCH OR GREATER/ HAS BEEN
FAIRLY CONSISTENT PAINTED OVER THE SRN 1/3 OF THE CWA. SIMILAR TO
YESTERDAY...USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION
FACTOR TO DERIVE GRIDDED QPF AMTS WHICH GENERALLY RANGE FROM 0.25
TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE
IN A STATE OF TRANSITION AND COOLING DOWN FROM NW TO SE WED-WED
NGT AS THE COLD FRONT PUSHES SOUTHEAST ACROSS THE AREA. THIS
SHOULD SUPPORT A TRANSITION FROM RAIN TO SNOW. A PERIOD OF SLEET
MAY IMPACT FCST SNOW ACCUMULATIONS WITH THE DURATION A KEY FACTOR
IN THIS FCST. WITH INCREASING CONFIDENCE AND GREATEST RISK IN THE
POTENTIAL FOR HEAVY SNOW/6+ INCHES...WHICH IS SUPPORTED BY ROBUST
WPC ENSEMBLE AS WELL AS THE GEFS MEAN...HAVE ISSUED A WINTER STORM
WATCH FOR THE SOUTH-CENTRAL COUNTIES FROM WEDNESDAY EVENING
THROUGH THURSDAY EVENING.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR THIS SEASON SHOULD
ARRIVE BEHIND THE COLD FRONT. FRIDAY MORNING LOWS ARE LKLY TO BE
20-30F BELOW NORMAL WITH SINGLE DIGIT LOWS +/- ZERO DEGREES. SUCH
READINGS MAY BREAK DAILY RECORDS.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
A LARGE AREA OF SLEET AND FREEZING RAIN OVER THE AREA AS OF LATE
AFT.
MINOR ADJUSTMENTS MADE TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED
WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY
WEDNESDAY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL
CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN
ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER
SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR
WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING
FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING.
AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS
WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD
FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE
PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
SUN...MVFR WITH CHC -SHSN MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004-
010-017-019-024>028-033>036-042-045-046-049>053-056>059-
063>066.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
EVENING FOR PAZ024>028-033>036-056>059-063>066.
WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006-
011-012-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...STEINBUGL
AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
407 PM EST TUE MAR 3 2015
.SYNOPSIS...
MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING
RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL
LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS
EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER
PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING
INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY
STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH
PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH
INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ
RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY
FREEZING RAIN BY EARLY EVENING. HRRR HAS VACILLATED CONSIDERABLY
FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND
THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO SHORT-
TERM CHANGES ON SHORT RANGE ENSEMBLES AND IN PARTICULAR SREF
THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER
CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON
THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY. WILL
UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME SNOW/SLEET
BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE NORTH CENTRAL
MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS EXPECTED. FARTHER
WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER WARREN AND ELK
COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN BORDERS OF THOSE
COUNTIES. THE WARNING AREA MAY NEED TO BE EXPANDED FARTHER SOUTH
INTO THE CENTRAL MOUNTAINS IN TIME...BUT CONFIDENCE IN DOING SO
SOUTH OF INTERSTATE 80 WAS LOW GIVEN CONFLICTING HRRR LLVL
TEMPERATURE READINGS AND QPF DISTRIBUTION THROUGH LATE TONIGHT.
THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL
HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT
WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS
FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH
A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN.
NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT
TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO
WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE
STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND
CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY
MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT
AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS
ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF
AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING
UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE
SOUTH OF INTERSTATE 80.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PRECIPITATION PATTERN WILL IMPACT CENTRAL
PA THROUGH MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF
ARCTIC AIR FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD
DRY OUT LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH
PRESSURE IN CONTROL MOST OF THE TIME. THE GENERAL MODEL AND ENSEMBLE
CONSENSUS IS TO MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE
EAST THROUGH THE WEEKEND WITH SOME SIGNS OF A PATTERN SHIFT BY THE
MIDDLE OF NEXT WEEK WITH TROUGHING FCST TO DEVELOP ALONG THE WEST
COAST. BELOW NORMAL TEMPS SHOULD MODERATE CLOSER TO NORMAL EARLY
NEXT WEEK WITH SOME HINTS AT EVEN WARMER TEMPS LATER NEXT WEEK.
MODELS CONTINUE TO SHOW AN AMPLIFIED AND MOIST SW FLOW ALOFT AND
JET ENTRANCE REGION DYNAMICS SUPPORTING A BROAD STRIPE OF PCPN
ALONG A WELL DEFINED BAROCLINIC ZONE AHEAD OF PHASING UPPER LEVEL
ENERGY OVER THE DSW/ROCKIES ON WED AND MOVING EWD THROUGH THE OH
VLY AND MID ATLC ON THURSDAY. SEVERAL WAVES OF LOW PRESSURE ARE
FCST TO DEVELOP AND MOVE ENEWD ALONG A SW-NE ORIENTED COLD FRONT
WHICH SHOULD PROGRESS AND SETTLE SEWD THROUGH THE MID ATLC REGION
BY EARLY THURS...AS ARCTIC HIGH PRESSURE BUILDS INTO THE UPPER
PLAINS. AMPLE MOISTURE IS FCST BY THE MODELS TO MOVE INTO A
DEEPENING COLD SECTOR ALONG/NORTH OF THE SEWD-ADVANCING COLD
FRONTAL BOUNDARY WHICH COULD RESULT IN A LATE SEASON HEAVY SNOW
EVENT FOR SOUTH CENTRAL PA WED NGT INTO THURS. THERE ARE MODEL
DIFFERENCES WITH THE TIMING OF THE FRONT WHICH IS LKLY TIED TO THE
CONSOLIDATION OF SHORTWAVE ENERGY UPSTREAM. THAT SAID...THE
CONSENSUS FCST AXIS OF MAX QPF /0.50 INCH OR GREATER/ HAS BEEN
FAIRLY CONSISTENT PAINTED OVER THE SRN 1/3 OF THE CWA. SIMILAR TO
YESTERDAY...USED A MULTI MODEL BLEND WITH PSEUDO BIAS CORRECTION
FACTOR TO DERIVE GRIDDED QPF AMTS WHICH GENERALLY RANGE FROM 0.25
TO 0.75 INCHES ACROSS THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE
IN A STATE OF TRANSITION AND COOLING DOWN FROM NW TO SE WED-WED
NGT AS THE COLD FRONT PUSHES SOUTHEAST ACROSS THE AREA. THIS
SHOULD SUPPORT A TRANSITION FROM RAIN TO SNOW. A PERIOD OF SLEET
MAY IMPACT FCST SNOW ACCUMULATIONS WITH THE DURATION A KEY FACTOR
IN THIS FCST. WITH INCREASING CONFIDENCE AND GREATEST RISK IN THE
POTENTIAL FOR HEAVY SNOW/6+ INCHES...WHICH IS SUPPORTED BY ROBUST
WPC ENSEMBLE AS WELL AS THE GEFS MEAN...HAVE ISSUED A WINTER STORM
WATCH FOR THE SOUTH-CENTRAL COUNTIES FROM WEDNESDAY EVENING
THROUGH THURSDAY EVENING.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR THIS SEASON SHOULD
ARRIVE BEHIND THE COLD FRONT. FRIDAY MORNING LOWS ARE LKLY TO BE
20-30F BELOW NORMAL WITH SINGLE DIGIT LOWS +/- ZERO DEGREES. SUCH
READINGS MAY BREAK DAILY RECORDS.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED
WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY
WEDNESDAY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL
CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN
ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER
SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR
WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING
FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING.
AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS
WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD
FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE
PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
SUN...MVFR WITH CHC -SHSN MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004-
010-017-019-024>028-033>036-042-045-046-049>053-056>059-
063>066.
WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
EVENING FOR PAZ024>028-033>036-056>059-063>066.
WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006-
011-012-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...STEINBUGL
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
225 PM EST TUE MAR 3 2015
.SYNOPSIS...
MIXED PRECIPITATION WILL CHANGE TO AN EXTENDED PERIOD OF FREEZING
RAIN THIS EVENING THROUGH LATE TONIGHT. THE PRECIPITATION WILL
LIKELY TURN TO RAIN ACROSS SOUTHERN AND FAR WESTERN SECTIONS
EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW FOR THE LATTER
PART OF THE WEEK...AND STEADY SNOW WILL RETURN WEDNESDAY EVENING
INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES ALONG A NEARLY
STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR SOUTH. HIGH
PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AT MID AFTERNOON...PRECIPITATION TRANSITION IS WELL UNDERWAY WITH
INITIAL BURST OF SNOW HAVING PUSHED INTO THE MIDDLE TO LOWER SUSQ
RIVER VALLEY. SNOW AND SLEET WILL HAVE CHANGED OVER TO PRIMARILY
FREEZING RAIN BY EARLY EVENING. HRRR HAS VASCILLATED CONSIDERABLY
FROM HOUR TO HOUR...BOTH WITH QPF AND OVERNIGHT TEMPERATURES...AND
THUS AM BASING THE ICE FORECAST AND ITS ASSOCIATED NEAR- TO
SHORT- TERM CHANGES ON SHORT RANGE ENSEMBES AND IN PARTICULAR SREF
THREATS WHICH CONSECUTIVELY HAVE INDICATED 80% OR GREATER
CONFIDENCE IN .25"+ OF ICE ACCRETION FROM LATE THIS AFTERNOON
THROUGH THE EARLY MORNING HOURS (PAST MIDNIGHT) OF WEDNESDAY.
WILL UPGRADE TO WINTER STORM WARNINGS (THERE IS STILL SOME
SNOW/SLEET BEFORE THE COMPLETE CHANGEOVER) FOR ICE ACROSS THE
NORTH CENTRAL MOUNTAINS...WHERE GREATER THAN 0.25" OF ICE IS
EXPECTED. FARTHER WEST...A CHANGEOVER TO RAIN IS EXPECTED OVER
WARREN AND ELK COUNTIES...HOLDING DOWN AMOUNTS ALONG THE WESTERN
BORDERS OF THOSE COUNTIES. THE WARNING AREA MAY NEED TO BE
EXPANDED FARTHER SOUTH INTO THE CENTRAL MOUNTAINS IN TIME...BUT
CONFIDENCE IN DOING SO SOUTH OF INTERSTATE 80 WAS LOW GIVEN
CONFLICTING HRRR LLVL TEMPERATURE READINGS AND QPF DISTRIBUTION
THROUGH LATE TONIGHT.
THE REST OF THE SOUTHERN THIRD OF CENTRAL PA IS SEEING A SEVERAL
HOUR LULL IN PRECIP AT MID AFTERNOON AS A RESULT OF A DRY SLOT
WHICH FOLLOWED THE INITIAL WAA BURST. PRECIP FILLING IN BEHIND IS
FZRA OVER THE LAURELS AND HEADING INTO THE CENTRAL MOUNTAINS WITH
A FEW REPORTS STILL OF SOME SLEET PELLETS MIXED IN.
NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE. EVE SHIFT WILL CONT
TO MONITOR EVOLUTION OF QPF AND ADJUST ICE AMOUNTS AS NECESSARY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
PROLONGED ICE ACCRETION IS THE MAIN THREAT LATE TONIGHT INTO
WEDNESDAY MORNING THROUGHOUT THE CENTRAL AND NRN MTNS OF THE
STATE. BY LATE TONIGHT...WARM AIR WILL BE FLOODING THE SOUTH AND
CHANGING FZRA OVER TO PLAIN RAIN. THE NORTH MAY NOT COMPLETELY
MIX OUT THE SHALLOW AND INITIALLY QUITE COLD AIR...SO EXPECT
AREAS OF FREEZING RAIN TO PERSIST THERE THROUGH THE PRE DAWN HOURS
ON WEDNESDAY. ICE ACCUMS SHOULD BE ON THE ORDER OF 0.20-0.30 OF
AN INCH ACROSS THE NCENT MTNS OF PA WHERE ADVISORIES ARE BEING
UPGRADED TO WARNINGS...WITH LESSER AMOUNTS IN MOST PLACES TO THE
SOUTH OF INTERSTATE 80.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH
MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR
FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT
LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE
IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO
MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING
TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS.
MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS
ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY
TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND
ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN.
SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE
ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE
COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE
ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS
TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL
BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF
AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS
THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF
TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT
PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO
SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE
OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS
FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA.
HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL
WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO
COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY
3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE
PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF
THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT
IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS
THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH
MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN
PORTIONS OF THE CWA.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND
THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY
MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW
SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD
FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
WARMER AIR SURGING IN ON INCREASING SW FLOW WILL BRING A PROLONGED
WINTRY MIX/FREEZING RAIN EVENT THIS AFTERNOON THROUGH EARLY
WEDNESADY MORNING ACROSS MUCH OF CENTRAL PA. SNOW/SLEET WILL
CHANGE TO FREEZING RAIN SOUTH THIS AFTERNOON...AND EVEN PLAIN RAIN
ACROSS THE LAUREL HIGHLANDS AND SOUTH CENTRAL MOUNTAINS AND LOWER
SUSQUEHANNA RIVER VALLEY BY THIS EVENING. FARTHER NORTH...COLD AIR
WILL REMAIN LOCKED OVER THE NORTH CENTRAL MOUNTAINS MAINTAINING
FREEZING RAIN THROUGH EARLY WEDNESDAY MORNING.
AS A RESULT...WIDESPREAD SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS
WILL ACCOMPANY THIS STORM AT ALL TERMINALS FOR AN EXTENDED PERIOD
FROM THIS AFTERNOON THROUGH LATE TONIGHT. LLWS WILL ALSO BE
PREVALENT AS 850MB WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
SUN...MVFR WITH CHC -SHSN MAINLY NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR PAZ004-
010-017-019-024>028-033>036-042-045-046-049>053-056>059-
063>066.
WINTER STORM WARNING UNTIL 7 AM EST WEDNESDAY FOR PAZ005-006-
011-012-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1148 AM EST TUE MAR 3 2015
.SYNOPSIS...
AN AREA OF LOW PRESSURE OVER THE CENTRAL PLAINS STATES WILL MOVE
QUICKLY NORTHEAST TO THE UPPER GREAT LAKES BY TONIGHT. A SURGE OF
DEEP MOISTURE AHEAD OF THIS LOW WILL RIDE UP AN OVER THE COLD AIR
IN PLACE ACROSS PENNSYLVANIA AND LEAD TO ANOTHER ROUND OF
SIGNIFICANT WINTRY/MIXED PRECIPITATION THIS AFTERNOON INTO EARLY
TONIGHT. THE PRECIPITATION WILL LIKELY TURN TO RAIN ACROSS
SOUTHERN SECTIONS EARLY WEDNESDAY. COLDER TEMPERATURES WILL FOLLOW
FOR THE LATTER PART OF THE WEEK...AND STEADY SNOW WILL RETURN
WEDNESDAY EVENING INTO THURSDAY AS A WAVE OF LOW PRESSURE RIPPLES
ALONG A NEARLY STATIONARY FRONT THAT WILL BE DRAPED JUST TO OUR
SOUTH. HIGH PRESSURE AND COLD AIR WILL RETURN FOR FRIDAY INTO THE
FIRST PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT MIDDAY...PRIMARY BURST OF WARM ADVECTION IS
MAINTAINING/PROPOGATING A MODERATE BAND OF SNOW EXTENDING FROM THE
NORTHWEST MOUNTAINS TO THE LOWER SUSQ RIVER VALLEY...WITH A LARGE
DRY SLOT OVER SOUTHEAST OHIO AND SOUTHWEST PA FILLING IN WITH MORE
SHOWERY ELEMENTS. TEMPERATURES OVER SOMERSET COUNTY RANG FROM THE
LOWER 20S NORTH TO THE UPPER 20S SOUTH WITHIN THIS DRY SLOT.
SUBSEQUENT PRECIP SHOULD BE MIX TO FZRA THIS AFTERNOON.
THE REST OF THE SOUTHERN THIRD OF CENTRAL PA WILL SEE A SEVERAL
HOUR LULL IN PRECIP EARLY TO MID AFTERNOON AS A RESULT OF THIS DRY
SLOT...AFTER THE INITIAL WAA BAND CROSSES. ACROSS THE NORTHERN
HALF OF CENTRAL PA...TRANSITIONS TO SLEET AND THEN FREEZING RAIN
WILL TAKE PLACE MID TO LATE AFTERNOON.
NEAR TERM DETAILS APPEAR TO BE IN GOOD SHAPE...BUT STILL CONCERNED
THAT WE`LL EXCEED ADVISORY CRITERIA FOR ICE LATER TONIGHT NORTH OF
INTERSATE 80. ADJUSTED ICE AMOUNTS UPWARD BY SEVERAL HUNDRETHS
ALONG AND NORTH OF I80 WHICH KEEPS AMOUNTS WITHIN ADVISORY
CRITERIA. 06Z SREF THREATS BACKED OFF ON EARLIER ROBUST AMOUNTS
AND PERCENTAGES...BUT PREVIOUS THREATS HAD INDICATED 70-80%
CONFIDENCE IN .20-.30" OR MORE OF ICE. SUCCESSIVE HRRR RUNS
CONTINUE TO DELAY WARMING AT THE END OF ITS 15-HOUR
WINDOW...MEANING THAT MUCH OF NORTH CENTRAL PA WILL LIKELY NEVER
RISE ABOVE FREEZING. CRITICAL TIMEFRAME WILL BE BETWEEN 21Z AND
04Z...AND THINK IT WILL BE A WHITES OF THEIR EYES DECISION FOR THE
EVENING SHFIT BASED ON RADAR EVOLUTION AND ADJUSTMENTS OF HRW-ARW
AND HRRR CONSENSUS LATE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
PROLONGED ICE ACCRETION IS THE MAIN THREAT TONIGHT THROUGHOUT THE
CENTRAL AND NRN MTNS OF THE STATE /AND TO A LESSER DEGREE ACROSS
THE MID AND LOWER SUSQ VALLEY/...PRECEDED BY THE COATING TO 1 INCH
OF SNOW FAR SOUTH AND 1 TO 2 INCHES OF SNOW IN MOST AREAS (WITH UP
TO 3 INCHES NORTH).
THE NORTH MAY NOT COMPLETELY MIX OUT THE SHALLOW AND INITIALLY
BITTERLY COLD AIR...SO EXPECT AREAS OF FREEZING RAIN TO PERSIST
THERE THROUGH THE PRE DAWN HOURS ON WEDNESDAY. ICE ACCUMS SHOULD
BE ON THE ORDER OF 0.10-0.20 OF AN INCH ACROSS THE NCENT MTNS OF
PA...WITH LESSER AMOUNTS IN MOST PLACES TO THE SOUTH OF INTERSTATE
80.
WINTER WEATHER ADVISORIES CONTINUE FOR A PERIOD OF SNOW/SLEET
ACCUM...FOLLOWED BY FREEZING RAIN...THIS AFTERNOON THROUGH THE
EARLY MORNING HOURS ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ACTIVE LATE-WINTER PATTERN WILL AFFECT CENTRAL PA THROUGH
MIDWEEK FOLLOWED BY WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR
FOR THE SEASON THURSDAY INTO FRIDAY. THE PATTERN SHOULD DRY OUT
LATE IN THE WEEK THROUGH THE UPCOMING WEEKEND WITH HIGH PRESSURE
IN CONTROL MOST OF THE TIME. THE GENERAL MODEL CONSENSUS IS TO
MAINTAIN A RIDGE IN THE WEST AND TROUGH IN THE EAST...LIMITING
TEMPERATURE MODERATIONS TO NO BETTER THAN CLIMATE NORMALS.
MODELS SHOW AN ACTIVE PCPN ZONE EXTENDING FROM THE SRN PLAINS
ENEWD INTO THE NRN MID ATLANTIC STATES...IN BTWN A POSITIVELY
TILTED TROUGH PUSHING THROUGH THE PLAINS/MIDWEST/GREAT LAKES AND
ABOVE NORMAL RIDGING FROM THE GOMEX INTO THE WRN ATLANTIC OCEAN.
SEVERAL WAVES OF LOW PRESSURE ARE FCST TO MOVE ALONG A SW-NE
ORIENTED COLD FRONT WHICH SHOULD SLOWLY PROGRESS EWD TOWARD THE
COAST WED-THUR AS NRN STREAM ENERGY CROSSES THE GREAT LAKES. THERE
ARE SOME DIFFERENCES WITH MODEL QPF BUT THE CONSENSUS POINTS
TOWARD THE SRN PA FOR THE HIGHEST PCPN AMTS. USED A MULTI MODEL
BLEND WITH PSEUDO BIAS CORRECTION FACTOR TO DERIVE GRIDDED QPF
AMTS WHICH CONSERVATIVELY RANGE FROM 0.25 TO 0.75 INCHES ACROSS
THE SRN 1/2 OF THE CWA. THE COLUMN WILL BE IN A STATE OF
TRANSITION AND COOLING FROM NW TO SE WED-WED NGT AS THE COLD FRONT
PUSHES EAST. THIS SHOULD SUPPORT A GENERAL TRANSITION FROM RAIN TO
SNOW ACROSS THE CWA. WITH A DECENT AMOUNT OF MSTR AVAILABLE/STRIPE
OF ABOVE NORMAL PW LOCATED JUST SOUTH OF PA...THE POTENTIAL EXISTS
FOR MODERATE TO HEAVY SNOW OVER THE SRN PORTIONS OF THE AREA.
HOWEVER GIVEN THE UNCERTAINTY AT DAY 3-4 RANGE IN THE FRONTAL
WAVES AND THERMAL PROFILES IN A STATE OF FLUX GOING FROM WARM TO
COLD...CONFIDENCE IN BIG AMOUNTS IS QUESTIONABLE. FOR NOW THE DAY
3+4 NUMBERS RANGE FROM 0-2" NORTH OF I-80...2-4" FROM I80 TO THE
PA TURNPIKE/I-81 AND AMOUNTS IN EXCESS OF 4" POSSIBLE ALONG/S OF
THE TURNPIKE/I-81. THIS IS SUBJECT TO CHANGE AS ANY SLIGHT SHIFT
IN THE QPF AXIS IS PLAUSIBLE AT THIS POINT. THE TAKEAWAY HERE IS
THAT WINTER WX WILL LKLY CONTINUE TO IMPACT THE AREA THROUGH
MIDWEEK WITH THE GREATEST RISK FOR HEAVY SNOW OVER THE SRN
PORTIONS OF THE CWA.
WHAT IS HOPEFULLY THE LAST SHOT OF ARCTIC AIR SHOULD ARRIVE BEHIND
THE COLD FRONT THURSDAY WITH SINGLE DIGIT LOWS +/- OF FRIDAY
MORNING. MAY BE THE COLDEST MORNING UNTIL NEXT WINTER. SOME SNOW
SHOWERS ARE POSSIBLE OVER THE WEEKEND WITH A REINFORCING COLD
FRONT. TEMPS WILL REMAIN AT OR BELOW AVG THROUGH THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CONDITIONS WILL QUICKLY DETERIORATE FROM WEST TO EAST AS MODERATE
SNOW BANDS CROSS THROUGH THE CENTRAL AND NORTH CENTRAL MOUNTAINS
THROUGH MIDDAY AND EARLY AFTERNOON HOURS. WARMER AIR SURGING IN
ON INCREASING SW FLOW WILL BRING A TRANSITION TO A WINTRY
MIX/FREEZING RAIN EVENT BY MID TO LATE AFTERNOON INTO THE EARLY
EVENING...BEFORE CHANGING TO RAIN /FZRA NORTH/ LATE TONIGHT INTO
EARLY WED AS HEAVIER PRECIP GRADUALLY TAPERS OFF. WIDESPREAD
SIGNIFICANT RESTRICTIONS TO CIGS/VSBYS WILL ACCOMPANY THIS STORM
AT ALL TERMINALS FOR AN EXTENDED PERIOD STARTING LATE THIS
MORNING/EARLY THIS AFTERNOON. LLWS WILL ALSO DEVELOP AS 850MB
WINDS INCREASE TO AROUND 50 KTS.
LATE WED/EARLY THURS AS COLDER AIR WORKS BACK TO THE SOUTH...LOW
PRESSURE MOVING NE ALONG THE FRONT WILL LIKELY RESULT IN A NASTY
MIXTURE OF PRECIPITATION. POTENTIAL IS THERE FOR HEAVY WET SNOW
AND SIGNIFICANT FREEZING RAIN AS WELL.
OUTLOOK...
WED...SOME IMPROVEMENT TO CONDITIONS BUT SOME REDUCTIONS WILL
CONTINUE /ESP SOUTH/ IN RAIN TRANSITIONING BACK TO SNOW LATER IN
THE DAY.
WED NIGHT...SIG REDUCTIONS IN SNOW DEVELOPING MAINLY ACROSS THE
SOUTH.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI-SAT...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST
WEDNESDAY FOR PAZ006-011-012-018-037-041-042.
WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR PAZ004-
005-010-017-024>026-033>035.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 4 AM EST
WEDNESDAY FOR PAZ019-027-028-036-045-046-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...DEVOIR/RXR
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
139 PM EST TUE MAR 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST TODAY...THEN A
WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS EVENING. LOW
PRESSURE OVER THE CENTRAL PLAINS WILL TRACK INTO SOUTHEAST CANADA
AND WILL PUSH A COLD FRONT INTO THE REGION ON WEDNESDAY. COLDER
AIR BEHIND THE FRONT WILL ALLOW FOR A TRANSITION FROM RAIN TO SNOW
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 138 PM EST TUESDAY...
WITH TEMPERATURES RISING THIS AFTERNOON INTO THIS EVENING. THE
THREAT FOR WIDESPREAD ICING PROBLEMS HAS ENDED...THUS THE WINTER
WEATHER ADVISORY IS CANCELLED. SOME LIGHT RAIN AND PATCHES OF
DRIZZLE ARE EXPECTED FOR THE THIS AFTERNOON. ISOLATED POCKETS OF
ICE MAY BE POSSIBLE ON THE COLDEST SURFACES. DRIVER SHOULD WATCH
FOR SLICK ICY SPOTS ON ROADWAYS.
AS OF 1000 AM EST TUESDAY...
CANCELLED THE WINTER WEATHER ADVISORY MAINLY WEST OF I77 WHERE
TEMPERATURES WERE ABOVE FREEZING MARK AND EXPECTED TO REMAIN AS
SUCH...AND RADAR COVERAGE IS LIGHT. STILL CONCERN OVER DIABATIC
COOLING OF TEMPERATURES WITH LIGHT PRECIPITATION...THUS WILL HOLD
WITH REST OF WINTER WEATHER ADVISORY AT THIS TIME. MODIFIED POPS
WITH LATEST RADAR TRENDS. SHAPED MORNING TEMPERATURES WITH SFC OBS
AND LATEST MODEL TRENDS. MORE CHANGES LATER THIS MORNING IN THE
ACTIVE WEATHER PATTERN .
AS OF 415 AM EST TUESDAY...
LOWER CLOUDS WERE JUST FILLING IN ACROSS THE FORECAST AREA THIS
MORNING. HAVE MADE ADJUSTMENTS TO THE TIMING OF THE PRECIPITATION
BASED ON RADAR TRENDS AND THE TIMING SHOWN ON THE LAST FEW RUNS OF
THE HRRR AND THE LATEST WRF GUIDANCE. HAVE THEREFORE MADE ADJUSTMENTS
TO THE VALID TIME OF THE ADVISORIES. APPEARS A MORE ORGANIZED AREAS
OF PRECIPITATION WILL CROSS THE NORTHERN COUNTY WARNING AREA BETWEEN
8AM AND NOON. STILL EXPECTING A BETTER PROBABILITY OF PRECIPITATION
ON THE EASTERN SLOPES OF THE BLUE RIDGE. OTHERWISE...NO WELL DEFINED
FEATURES THAT WILL DEFINE WHERE AND WHEN PRECIPITATION WILL FALL.
WHEREVER THE PRECIPITATION IS...IT WILL BE LIGHT. BUFKIT NOT
SHOWING GOOD DENDRITIC GROWTH AND BY 15Z/10AM...WARM NOSE WILL BE
WELL STRONG ENOUGH TO RESULT IN LIQUID AS THE HYDROMETEORS FALL
THROUGH THAT LAYER. SO SURFACE TEMPERATURES WILL BE THE DECIDING
FACTOR IN PRECIPITATION TYPE. NEW RIVER VALLEY THROUGH THE
ALLEGHANY HIGHLANDS WERE BELOW FREEZING. ONLY A SLOW RISE IN
TEMPERATURES EXPECTED TODAY. GUIDANCE KEPT THE NORTHEAST
COUNTIES...MAINLY FROM LYNCHBURG INTO AMHERST AND ROCKBRIDGE
COUNTY BELOW FREEZING FOR MUCH OF THE DAY. HAVE DELAYED THE START
OF THE WINTER WEATHER ADVISORY AND EXTENDED THE ADVISORY THROUGH
LATER IN THE DAY WHERE THE TEMPERATURE REMAINS BELOW FREEZING.
TONIGHT...A STRONG LOW LEVEL JET PUSHES UP TEMPERATURES AND DEW
POINTS. LOWS WILL OCCUR IN THE EVENING. AFTER MIDNIGHT...THE COLD
FRONT APPROACHES AND THE PROBABILITY OF MODERATE RAIN IN THE
NORTHWEST COUNTY WARNING AREA INCREASES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 430 AM EST TUESDAY...
EXPECT TO START WEDNESDAY WITH A COLD FRONT SITUATED FROM THE
ALLEGHANY HIGHLANDS THROUGH THE MOUNTAIN EMPIRE. STRONG MOISTURE
FLOW INTO THE AREA ON A 50KT TO 60KT SOUTHWESTERLY LOW LEVEL JET
WILL PUSH PRECIPITABLE WATER VALUES TO 1.0-1.1 INCHES IN THE
WEST...AND AS HIGH AS 1.4 INCHES FURTHER EAST...ALL SIGNIFICANTLY
ABOVE NORMAL FOR EARLY MARCH.
DURING THE MORNING...RAIN WILL BE WIDESPREAD WEST OF THE BLUE
RIDGE...ALTHOUGH THE STRONGEST LIFT/HEAVIEST RAINFALL IS EXPECTED TO
BE WEST OF THE CONTINENTAL DIVIDE...JUST SKIRTING OUR SOUTHEAST WEST
VIRGINIA COUNTIES...PARTICULARLY THE WEST FACING SLOPES. FURTHER
EAST...WILL LIKELY SEE A BAND OF HEAVY RAIN JUST AHEAD OF THE FRONT
AS IT SLOWLY DRIFTS EAST THROUGH THE DAY...WITH SOME DRYING TAKING
PLACE BEHIND THE BOUNDARY AS WINDS SHIFT NORTHWESTERLY AND
DOWNSLOPE.
DURING WEDNESDAY AFTERNOON AND EVENING...THE COLD FRONT WILL
SLOW/STALL ACROSS THE SOUTHSIDE AND NORTH CAROLINA PIEDMONT AS A
STRONG WAVE DEVELOPS OVER NORTHERN GEORGIA AND PUSHES NORTHEAST
ALONG THE BOUNDARY. THE WAVE WILL PASS JUST SOUTHEAST OF OUR AREA
DURING THE EARLY MORNING HOURS OF THURSDAY...WITH STRONG CONVERGENCE
DEVELOPING FROM THE ALLEGHANY HIGHLANDS SOUTHWARD ALONG THE BLUE
RIDGE...SUPPORTING AN ADDITIONAL ROUND OF POTENTIALLY HEAVY RAIN.
AS THE WAVE PASSES OUR AREA DURING LATE THURSDAY MORNING...IT WILL
ENHANCE THE NORTHWESTERLY FLOW ACROSS THE MOUNTAINS...DRAWING COLD
AIR ASSOCIATED WITH ARCTIC HIGH PRESSURE FURTHER ACROSS OUR AREA.
THE SURGE OF COLDER AIR HUGGING THE SURFACE WILL CAUSE RAIN TO
CHANGE TO SLEET AND/OR FREEZING RAIN FOR A FEW HOURS ACROSS THE
MOUNTAINS...BEFORE FINALLY CHANGING TO SNOW BY THURSDAY AFTERNOON.
BECAUSE WE ARE EXPECTING MORE SLEET AND FREEZING RAIN THAN
PREVIOUSLY FORECAST...WENT WITH LOWER SNOWFALL TOTALS FOR THURSDAY.
RIGHT NOW...LOOKING AT THE POSSIBILITY OF WINTER STORM SNOW AND
SLEET AMOUNTS FOR WESTERN GREENBRIER...AND PERHAPS BATH AND
ROCKBRIDGE COUNTIES IN SPOTS...BUT DO NOT HAVE ENOUGH CONFIDENCE TO
GO WITH A WINTER STORM WATCH AT THIS POINT. WILL LET THE DAY SHIFT
HAVE ANOTHER LOOK AT THE COMING 03/12Z MODEL RUNS.
PRECIPITATION WILL WIND DOWN THURSDAY AFTERNOON AND EVENING AS HIGH
PRESSURE BUILDS IN FROM THE WEST...SETTLING ACROSS THE MID AND UPPER
OHIO RIVER VALLEY BY FRIDAY MORNING. STRONG RADIATIONAL COOLING WILL
MEAN ONE MORE SHOT OF SINGLE DIGIT TEMPERATURES TO START THE DAY
ACROSS THE MOUNTAINS...WITH TEENS EXPECTED ACROSS THE PIEDMONT. HIGH
PRESSURE WILL SHIFT TO NEW ENGLAND...WHERE IT WILL THEN WEDGE
SOUTHWARD FRIDAY NIGHT...HUGGING THE EASTERN FACE OF THE
APPALACHIANS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 145 PM EST MONDAY...
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER PATTERN THROUGH
AT LEAST SATURDAY NIGHT. THE HIGH WILL GRADUALLY BUILD INTO THE
AREA FROM THE WEST...AND MAKE ITS WAY TO THE COAST BY SATURDAY.
THIS WILL ALLOW FOR A TREND TOWARD MILDER CONDITIONS AS THE LOW
LEVEL FLOW ACROSS THE AREA BECOMES GRADUALLY MORE SW-W...WHILE A
SHORTWAVE RIDGE AND RISING 850 TEMPS TAKE PLACE.
SUNDAY INTO MONDAY A GENEROUS AMOUNT OF VARIATIONS IN THE MODELS
TAKE PLACE. WHILE BOTH THE GFS AND THE NAM EVENTUALLY COME INTO
AGREEMENT OF A LONG WAVE TROUGH OVER THE EASTERN THIRD OF CONUS BY
MONDAY OR TUESDAY OR NEXT WEEK...HOW THE SOLUTIONS COME TO BE THAT
WAY HAVE NOTABLE DIFFERENCES. THE GFS IS MORE PROGRESSIVE IN
ESTABLISHING THE TROUGH IN THE EAST BY SUNDAY...AND ANY SOUTHERN
STREAM SYSTEMS EASILY BYPASS OUR REGION EXITING THE U.S. NEAR THE
GA/FL BORDER. THE ECWMF IS NOT A QUICK TO ESTABLISH AN EAST COAST
TROUGH...AND A SUCH...SOUTHERN STREAM SYSTEMS HAVE A BETTER
OPPORTUNITY TO PROGRESS NORTHEAST THROUGH OUR REGION ON THE EAST
SIDE OF AN APPROACHING SHORTWAVE TROUGH.
OUR FORECAST FOR SUNDAY INTO MONDAY WILL BE A CONSENSUS OF THESE
TWO...WITH IT RESEMBLING A WATERED DOWN VERSION OF THE ECWMF IN
TERMS OF PRECIPITATION POTENTIAL ON SUNDAY AND SUNDAY NIGHT...AND
ALSO STAYING ON MORE OF THE MILD SIDE THAN COLD IN REGARDS TO
MONDAY.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 1230 PM EST TUESDAY...
MVFR CONDITIONS WITH POCKETS OF IFR IN PRECIPITATION...CLOUDS AND
FOG THIS AFTERNOON INTO TONIGHT. STRONG SOUTH TO SOUTHWEST WINDS
ALOFT WILL BRING ABUNDANT MOISTURE INTO THE REGION THIS AFTERNOON
INTO TONIGHT. TEMPERATURES WILL SLOWLY RISE THIS AFTERNOON INTO
TONIGHT. THIS WILL END THE THREAT FOR FREEZING RAIN/FREEZING
DRIZZLE ACROSS OUR AREA. TRIMMED BACK AND NARROWED THE WINDOW FOR
LOW LEVEL WIND SHEAR IN THE TAFS FOR TONIGHT. CEILINGS AND
VISIBILITIES WILL BE IFR TO LIFR FOR MUCH OF THE AREA IN LOW
CLOUDS AND FOG THIS EVENING INTO WEDNESDAY MORNING.
ANOTHER LOW PRESSURE SYSTEM THAT WILL IMPACT ALL OF THE REGION
WILL TRACK FROM THE CENTRAL PLAINS INTO SOUTHEAST CANADA BY WEDNESDAY.
THIS WILL RESULT IN WIDESPREAD SUB-VFR CONDITIONS ACROSS THE AREA WEDNESDAY
AND THURSDAY WITH ABUNDANT RAIN. A COLD FRONT WILL CROSS THROUGH
THE AREA ON WEDNESDAY.
MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED FORECAST...
WINTER PRECIPITATION IS LIKELY BEHIND THE FRONT WEDNESDAY NIGHT
AND THURSDAY. AT THIS TIME THE MOST LIKELY PRECIPITATION TYPES ARE
SNOW AND SLEET.
FRIDAY AND SATURDAY WILL SEE A RETURN TO HIGH PRESSURE AND VFR
WEATHER.
&&
.HYDROLOGY...
AS OF 300 PM EST MONDAY
LIKELY TO SEE SOME SUBSTANTIAL RISES ON AREA RIVERS AND STREAMS IN
RESPONSE TO UPCOMING RAIN EVENT AND SNOWMELT IN THE
MOUNTAINS...QUESTIONS REMAIN ABOUT HOW SUBSTANTIAL. SIGNIFICANT SNOW
AMOUNTS ARE NOW CONFINED TO PARTS OF THE UPPER JAMES AND
GREENBRIER RIVER BASINS WHERE THE LATEST AVAILABLE ESTIMATES FROM
THE NATIONAL OPERATIONAL REMOTE SENSING CENTER SHOW ROUGHLY 1 TO 3
INCHES OF SNOW WATER EQUIVALENT WITH ISOLATED 4 INCHES IN THE
HIGHEST ELEVATIONS OF THE GREENBRIER. IN THE OTHER MAJOR RIVER
BASINS...NEW...ROANOKE/DAN AND TENNESSEE... MELTING OVER THE
WEEKEND AND TODAY HAS REDUCED THE SNOW TO LESS THAN 1 INCH OF SNOW
WATER AND IN MOST PLACES ZERO.
THE OTHER ELEMENT OF COURSE IS THE QPF. 12Z MODELS (INCLUDING
LATEST EC) HAVE NUDGED THE HEAVIEST QPF A LITTLE MORE TO THE
WEST...REDUCING AMOUNTS IN THE JAMES AND GREENBRIER SOME. IT STILL
APPEARS AS IF 1 TO 2 INCHES COULD FALL ACROSS THE WESTERN BASINS
BY 12Z THURSDAY AND COMBINED WITH SNOWMELT THIS COULD PRODUCE AT
LEAST MINOR RIVER FLOODING ALONG THE GREENBRIER AND POSSIBLY THE
UPPER JAMES. GUIDANCE RECEIVED FROM OHRFC THIS MORNING SUGGESTED
MINOR FLOOD STAGE AT ALDERSON WV ON THE GREENBRIER LIKELY BY EARLY
THURSDAY WITH THE COMBINED SNOWMELT AND QPF. HOWEVER...GIVEN THE
CONTINUED UNCERTAINTIES WILL HOLD OFF ON A FLOOD WATCH AT THIS
POINT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...NF
LONG TERM...DS
AVIATION...AMS/KK
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1108 AM MST TUE MAR 3 2015
.UPDATE...
ISSUED AT 1052 AM MST TUE MAR 3 2015
UPDATED WINTER WEATHER HEADLINES TO CONVERT THE WINTER STORM
WARNING TO AN ADVISORY. SOME POCKETS OF BLOWING SNOW CONTINUE
ALONG WITH SOME LIGHT SNOW SHOWER ACTIVITY THIS MORNING. THE
NORTHERN STREAM DISTURBANCE WHICH IS CURRENTLY OVER WESTERN
WYOMING WILL MOVE EASTWARD TODAY AND TONIGHT BRINING ANOTHER SHOT
OF LIGHT SNOW TO THE FORECAST AREA THIS AFTERNOON AND EVENING.
MOST SNOW ACCUMLUATIONS WILL BE ALONG THE SOUTHERN TIER OF THE
FORECAST AREA WITH 1 TO 2 INCHES OF ACCUMLUATION OUTSIDE OF THE
MOUNTAINS. MOST OF THE FORECAST AREA WILL PICK UP LESS THAN ONE
INCH. WINDS WILL REMAIN ON THE BREEZY SIDE AND WILL PRODUCE SOME
BLOWING AND DRIFTING THIS AFTERNOON AND EVENING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
HIGH-IMPACT WINTER STORM CONTINUES THIS MORNING FOR A LARGE PART
OF THE CWA. AS EXPECTED...MODERATE TO HEAVY SNOW HAS BECOME QUITE
WIDESPREAD THIS MORNING WITH AN ARCTIC COLD FRONT BLASTING SOUTH
INTO NORTHERN CO. STRONG NORTHERLY WINDS ARE OCCURRING POST FROPA
WITH EXCELLENT MIXING VIA INTENSE COLD ADVECTION ALOFT. PEAK WIND
AT KCYS WAS 42 KTS JUST BEFORE 10Z...AND REMAINS STEADY AT 20 TO
30 MPH AT THIS HOUR WITH VERY LOW VISIBILITY OCCURRING IN FALLING
AND BLOWING SNOW. DO NOT EXPECT MUCH FOR AMOUNTS AS LLVL FORCING
WILL DISAPPEAR QUICKLY...BUT WILL NEED TO MONITOR FOR A POSSIBLE
SHORT FUSED ADVISORY IF HEAVY BANDING PERSISTS INTO THE MORNING
COMMUTE. A WARM DAY YESTERDAY AHEAD OF THE ARCTIC FRONT SET US UP
FOR A FLASH FREEZE...SO ROADWAYS ARE ALREADY QUITE SLICK IN TOWN
HERE THIS MORNING. SUSPECT THIS IS THE CASE AREAWIDE BASED ON THE
ROAD CLOSURES WE HAVE SEEN ALREADY WITH LARGE SECTIONS OF I25 AND
I80 AFFECTED WEST OF LARAMIE AND NORTH OF CHEYENNE.
LATEST WATER VAPOR LOOP SHOWS LARGE SCALE TROUGHING ENCOMPASSING
MUCH OF THE WESTERN CONUS WITH THE LEAD SHORTWAVE NOW EXITING
INTO THE CENTRAL PLAINS. WITH THAT...WE SHOULD CONTINUE TO LOSE
DYNAMIC SUPPORT ASSOCIATED WITH THE 150+ KT H25 JET OVER CENTRAL
NEBRASKA AND WILL HAVE TO RELY ENTIRELY ON LLVL CONVERGENCE AND
FRONTOGENESIS FOR ENHANCED SNOWFALL RATES. SFC COLD FRONT ALREADY
ANALYZED ALONG THE CO/WY BORDER WILL CONTINUE TO MOVE SOUTH ALONG
THE FRONT RANGE...SO EXPECT SNOW TO LIGHTEN UP BEFORE LONG. EVEN
SO...WE SAW SOME HEFTY SNOW RATES OVER PLATTE/NIOBRARA COUNTIES
OVERNIGHT WITH THE INITIAL FRONTAL SURGE. INITIAL CALLS TO AREA
DISPATCHERS INDICATE GENERALLY 3 TO 5 INCHES WITH WINDS CREATING
PROBLEMS. NUMEROUS POWER OUTAGES WERE REPORTED IN NIOBRARA COUNTY
AND INTERSTATE 25 WAS CLOSED IN PLATTE. ADDITIONAL LIGHT ACCUMS
ARE POSSIBLE THROUGH THE MORNING. NAM/GFS SUGGEST WINDS BECOMING
NORTHEASTERLY ALONG THE CENTRAL LARAMIE RANGE BY MID AFTN AS SFC
PRESSURE RISES SPREAD INTO SOUTH CENTRAL NE. DEFINITELY CONCERNED
WITH POTENTIAL UPSLOPE ENHANCEMENT CAUSING SNOW TO REDEVELOP IN
THE AFTN/EVE WITH THE ARRIVAL OF A SECONDARY SHORTWAVE. HRRR IS
HITTING THIS AREA HARD BEYOND 21Z. EVEN THOUGH WINDS WILL MOST
LIKELY BE A NON FACTOR LATER ON...OPTED TO UPGRADE TO A WINTER
STORM WARNING GIVEN OBSERVED IMPACTS AND POTENTIAL FOR AT LEAST
ANOTHER COUPLE INCHES OF SNOW THROUGH TONIGHT.
ALL AREAS SHOULD SEE THE WORST CONDITIONS RIGHT AWAY IN THE AM
WITH THE STRONGEST WINDS OCCURRING THEN. THE MODELS SHOW FLOW
ALOFT WEAKENING CONSIDERABLY AFTER 15Z...SO BLOWING SNOW SHOULD
BECOME LESS OF A PROBLEM WITH TIME. PRECIPITATION COVERAGE WILL
TRANSITION TO SNOW SHOWERS FOR A TIME...BUT ANOTHER SHOT OF PCPN
IS EXPECTED LATE THIS AFTN AND EVE WITH A SECONDARY SHORTWAVE AND
ASSOCIATED MID LEVEL MOISTURE PLUME UPSTREAM OVER EASTERN IDAHO AS
OF 12Z PER MORNING SATELLITE IMAGERY. MIDLVL DRY SLOT HAS PROVEN
TO BE A MAJOR INHIBITOR FOR SNOW SO FAR ALONG THE I80 CORRIDOR
BETWEEN CHEYENNE AND SIDNEY...SO EXPECT THE BEST CHANCES FOR SNOW
LOCALLY TO COME TONIGHT. AMOUNTS WILL PROBABLY BE ON THE LOW SIDE
SO DECIDED AGAINST AN ADVISORY FOR NOW...BUT THE DAY SHIFT WILL
NEED TO REVISIT. KEPT ALL OTHER HEADLINES THE SAME...EXCEPT FOR
EXTENDING THEM THROUGH 07Z WED AS THE NEXT DISTURBANCE WILL KEEP
SNOW POTENTIAL GOING A LITTLE LONGER THAN EARLIER EXPECTED. AS
SNOW ENDS LATE TONIGHT...WINTER HAZARDS WILL TRANSITION TO WIND
CHILLS WITH WIDESPREAD -20F TO -30F READINGS LIKELY. FULLY EXPECT
SOME SORT OF WIND CHILL HEADLINES WILL BE NECESSARY ON THE HEELS
OF THE CURRENT WINTER PRECIPITATION PRODUCTS.
WARMEST TEMPERATURES FOR TODAY OCCURRED OVERNIGHT WITH VERY STRONG
H7 COLD AIR ADVECTION EXPECTED TO DRIVE TEMPERATURES DOWNWARD INTO
THE AFTERNOON. TEMPERATURES WILL FALL BELOW ZERO ACROSS MUCH OF
THE AREA TONIGHT DESPITE WIDESPREAD ABUNDANT MOISTURE ALOFT
LEADING TO THICK CLOUDS AND SNOW GIVEN UNSEASONABLY COLD THERMAL
PROFILES IN THE LLVLS. HIGHS WEDNESDAY SHOULD BE WELL BELOW ANY
CONSENSUS GUIDANCE WITH FRESH SNOWPACK AND 700 MILLIBAR TEMPS
REMAINING VERY COLD / -20C PER THE NAM. SHOULD FINALLY SEE SOME
IMPROVEMENT ON THURSDAY AS WESTERLY DOWNSLOPE WINDS RETURN FOR
AREAS EAST OF THE LARAMIE RANGE...ALLOWING HIGHS TO CLIMB BACK
ABOVE FREEZING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
PROGRESSIVE NORTHWEST FLOW THRU THE WEEKEND WILL GIVE WAY TO A
BUILDING RIDGE OF HIGH PRESSURE AND A RETURN TO ABOVE AVERAGE
TEMPERATURES FOR EARLY NEXT WEEK. BOTH THE 00Z GFS AND ECMWF
ADVERTISE TWO CLIPPER SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
TRAVERSE SOMEWHERE THRU THE NRN ROCKIES FRIDAY AND SATURDAY. AS IS
TYPICAL IN PROGRESSIVE NORTHWEST FLOW...TIMING AND STRENGTH
DIFFERENCES EXIST IN JUST HOW THESE DISTURBANCES PUSH THRU. EITHER
SCENARIO CARRIES LITTLE IF ANY IMPACTS FROM THESE SYSTEM.
ALTHOUGH...THE DID HAD SOME MOUNTAIN SNOW SHOWER CHANCES ON SUNDAY
WITH THE GFS STEERING ONE OF THE CLIPPERS DIRECTLY OVR THE REGION.
THE NORTHWEST FLOW WILL CONTINUE SUNDAY AND MONDAY...WITH THE RIDGE
AXIS ARRIVING ON TUESDAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL
LEVELS FRIDAY THROUGH SUNDAY WITH HIGHS GENERALLY REACHING THE 30S
WEST AND 40S OVR THE ERN PLAINS. THE APPROACHING UPPER-RIDGE AND
ASSOCIATED WAA WILL LIFT HIGH TEMPERATURES ABOVE AVERAGE FOR THE
FIRST TIME SINCE THE THIRD WEEK OF FEBRUARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1108 AM MST TUE MAR 3 2015
FAIRLY WIDESPREAD MVFR CONDITIONS WILL PERSIST OVER THE TERMINALS
THROUGH THIS EVENING WITH SCTD IFR CIGS AND VSBYS IN SNOW.
CONDITIONS SHOULD IMPROVE LATER THIS EVENING AND OVERNIGHT.
&&
.FIRE WEATHER...
ISSUED AT 520 AM MST TUE MAR 3 2015
A WINTER STORM WILL CONTINUE TO IMPACT MUCH OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE THROUGH TONIGHT. SIGNIFICANT
SNOWFALL ACCUMULATIONS ARE LIKELY ALONG WITH STRONG NORTHERLY
WINDS RESULTING IN EXTREMELY DANGEROUS TRAVEL CONDITIONS. VERY
COLD TEMPERATURES ARE EXPECTED TODAY AND TONIGHT WITH WIDESPREAD
DANGEROUS WIND CHILLS POSSIBLE ON EARLY WEDNESDAY MORNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR
WYZ101>111-113-115>117.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ112-114.
NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR NEZ002-
003-095-096.
&&
$$
UPDATE...SML
SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...RE
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1058 AM MST TUE MAR 3 2015
.UPDATE...
ISSUED AT 1052 AM MST TUE MAR 3 2015
UPDATED WINTER WEATHER HEADLINES TO CONVERT THE WINTER STORM
WARNING TO AN ADVISORY. SOME POCKETS OF BLOWING SNOW CONTINUE
ALONG WITH SOME LIGHT SNOW SHOWER ACTIVITY THIS MORNING. THE
NORTHERN STREAM DISTURBANCE WHICH IS CURRENTLY OVER WESTERN
WYOMING WILL MOVE EASTWARD TODAY AND TONIGHT BRINING ANOTHER SHOT
OF LIGHT SNOW TO THE FORECAST AREA THIS AFTERNOON AND EVENING.
MOST SNOW ACCUMLUATIONS WILL BE ALONG THE SOUTHERN TIER OF THE
FORECAST AREA WITH 1 TO 2 INCHES OF ACCUMLUATION OUTSIDE OF THE
MOUNTAINS. MOST OF THE FORECAST AREA WILL PICK UP LESS THAN ONE
INCH. WINDS WILL REMAIN ON THE BREEZY SIDE AND WILL PRODUCE SOME
BLOWING AND DRIFTING THIS AFTERNOON AND EVENING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
HIGH-IMPACT WINTER STORM CONTINUES THIS MORNING FOR A LARGE PART
OF THE CWA. AS EXPECTED...MODERATE TO HEAVY SNOW HAS BECOME QUITE
WIDESPREAD THIS MORNING WITH AN ARCTIC COLD FRONT BLASTING SOUTH
INTO NORTHERN CO. STRONG NORTHERLY WINDS ARE OCCURRING POST FROPA
WITH EXCELLENT MIXING VIA INTENSE COLD ADVECTION ALOFT. PEAK WIND
AT KCYS WAS 42 KTS JUST BEFORE 10Z...AND REMAINS STEADY AT 20 TO
30 MPH AT THIS HOUR WITH VERY LOW VISIBILITY OCCURRING IN FALLING
AND BLOWING SNOW. DO NOT EXPECT MUCH FOR AMOUNTS AS LLVL FORCING
WILL DISAPPEAR QUICKLY...BUT WILL NEED TO MONITOR FOR A POSSIBLE
SHORT FUSED ADVISORY IF HEAVY BANDING PERSISTS INTO THE MORNING
COMMUTE. A WARM DAY YESTERDAY AHEAD OF THE ARCTIC FRONT SET US UP
FOR A FLASH FREEZE...SO ROADWAYS ARE ALREADY QUITE SLICK IN TOWN
HERE THIS MORNING. SUSPECT THIS IS THE CASE AREAWIDE BASED ON THE
ROAD CLOSURES WE HAVE SEEN ALREADY WITH LARGE SECTIONS OF I25 AND
I80 AFFECTED WEST OF LARAMIE AND NORTH OF CHEYENNE.
LATEST WATER VAPOR LOOP SHOWS LARGE SCALE TROUGHING ENCOMPASSING
MUCH OF THE WESTERN CONUS WITH THE LEAD SHORTWAVE NOW EXITING
INTO THE CENTRAL PLAINS. WITH THAT...WE SHOULD CONTINUE TO LOSE
DYNAMIC SUPPORT ASSOCIATED WITH THE 150+ KT H25 JET OVER CENTRAL
NEBRASKA AND WILL HAVE TO RELY ENTIRELY ON LLVL CONVERGENCE AND
FRONTOGENESIS FOR ENHANCED SNOWFALL RATES. SFC COLD FRONT ALREADY
ANALYZED ALONG THE CO/WY BORDER WILL CONTINUE TO MOVE SOUTH ALONG
THE FRONT RANGE...SO EXPECT SNOW TO LIGHTEN UP BEFORE LONG. EVEN
SO...WE SAW SOME HEFTY SNOW RATES OVER PLATTE/NIOBRARA COUNTIES
OVERNIGHT WITH THE INITIAL FRONTAL SURGE. INITIAL CALLS TO AREA
DISPATCHERS INDICATE GENERALLY 3 TO 5 INCHES WITH WINDS CREATING
PROBLEMS. NUMEROUS POWER OUTAGES WERE REPORTED IN NIOBRARA COUNTY
AND INTERSTATE 25 WAS CLOSED IN PLATTE. ADDITIONAL LIGHT ACCUMS
ARE POSSIBLE THROUGH THE MORNING. NAM/GFS SUGGEST WINDS BECOMING
NORTHEASTERLY ALONG THE CENTRAL LARAMIE RANGE BY MID AFTN AS SFC
PRESSURE RISES SPREAD INTO SOUTH CENTRAL NE. DEFINITELY CONCERNED
WITH POTENTIAL UPSLOPE ENHANCEMENT CAUSING SNOW TO REDEVELOP IN
THE AFTN/EVE WITH THE ARRIVAL OF A SECONDARY SHORTWAVE. HRRR IS
HITTING THIS AREA HARD BEYOND 21Z. EVEN THOUGH WINDS WILL MOST
LIKELY BE A NON FACTOR LATER ON...OPTED TO UPGRADE TO A WINTER
STORM WARNING GIVEN OBSERVED IMPACTS AND POTENTIAL FOR AT LEAST
ANOTHER COUPLE INCHES OF SNOW THROUGH TONIGHT.
ALL AREAS SHOULD SEE THE WORST CONDITIONS RIGHT AWAY IN THE AM
WITH THE STRONGEST WINDS OCCURRING THEN. THE MODELS SHOW FLOW
ALOFT WEAKENING CONSIDERABLY AFTER 15Z...SO BLOWING SNOW SHOULD
BECOME LESS OF A PROBLEM WITH TIME. PRECIPITATION COVERAGE WILL
TRANSITION TO SNOW SHOWERS FOR A TIME...BUT ANOTHER SHOT OF PCPN
IS EXPECTED LATE THIS AFTN AND EVE WITH A SECONDARY SHORTWAVE AND
ASSOCIATED MID LEVEL MOISTURE PLUME UPSTREAM OVER EASTERN IDAHO AS
OF 12Z PER MORNING SATELLITE IMAGERY. MIDLVL DRY SLOT HAS PROVEN
TO BE A MAJOR INHIBITOR FOR SNOW SO FAR ALONG THE I80 CORRIDOR
BETWEEN CHEYENNE AND SIDNEY...SO EXPECT THE BEST CHANCES FOR SNOW
LOCALLY TO COME TONIGHT. AMOUNTS WILL PROBABLY BE ON THE LOW SIDE
SO DECIDED AGAINST AN ADVISORY FOR NOW...BUT THE DAY SHIFT WILL
NEED TO REVISIT. KEPT ALL OTHER HEADLINES THE SAME...EXCEPT FOR
EXTENDING THEM THROUGH 07Z WED AS THE NEXT DISTURBANCE WILL KEEP
SNOW POTENTIAL GOING A LITTLE LONGER THAN EARLIER EXPECTED. AS
SNOW ENDS LATE TONIGHT...WINTER HAZARDS WILL TRANSITION TO WIND
CHILLS WITH WIDESPREAD -20F TO -30F READINGS LIKELY. FULLY EXPECT
SOME SORT OF WIND CHILL HEADLINES WILL BE NECESSARY ON THE HEELS
OF THE CURRENT WINTER PRECIPITATION PRODUCTS.
WARMEST TEMPERATURES FOR TODAY OCCURRED OVERNIGHT WITH VERY STRONG
H7 COLD AIR ADVECTION EXPECTED TO DRIVE TEMPERATURES DOWNWARD INTO
THE AFTERNOON. TEMPERATURES WILL FALL BELOW ZERO ACROSS MUCH OF
THE AREA TONIGHT DESPITE WIDESPREAD ABUNDANT MOISTURE ALOFT
LEADING TO THICK CLOUDS AND SNOW GIVEN UNSEASONABLY COLD THERMAL
PROFILES IN THE LLVLS. HIGHS WEDNESDAY SHOULD BE WELL BELOW ANY
CONSENSUS GUIDANCE WITH FRESH SNOWPACK AND 700 MILLIBAR TEMPS
REMAINING VERY COLD / -20C PER THE NAM. SHOULD FINALLY SEE SOME
IMPROVEMENT ON THURSDAY AS WESTERLY DOWNSLOPE WINDS RETURN FOR
AREAS EAST OF THE LARAMIE RANGE...ALLOWING HIGHS TO CLIMB BACK
ABOVE FREEZING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 520 AM MST TUE MAR 3 2015
PROGRESSIVE NORTHWEST FLOW THRU THE WEEKEND WILL GIVE WAY TO A
BUILDING RIDGE OF HIGH PRESSURE AND A RETURN TO ABOVE AVERAGE
TEMPERATURES FOR EARLY NEXT WEEK. BOTH THE 00Z GFS AND ECMWF
ADVERTISE TWO CLIPPER SHORTWAVES EMBEDDED WITHIN THE FLOW WILL
TRAVERSE SOMEWHERE THRU THE NRN ROCKIES FRIDAY AND SATURDAY. AS IS
TYPICAL IN PROGRESSIVE NORTHWEST FLOW...TIMING AND STRENGTH
DIFFERENCES EXIST IN JUST HOW THESE DISTURBANCES PUSH THRU. EITHER
SCENARIO CARRIES LITTLE IF ANY IMPACTS FROM THESE SYSTEM.
ALTHOUGH...THE DID HAD SOME MOUNTAIN SNOW SHOWER CHANCES ON SUNDAY
WITH THE GFS STEERING ONE OF THE CLIPPERS DIRECTLY OVR THE REGION.
THE NORTHWEST FLOW WILL CONTINUE SUNDAY AND MONDAY...WITH THE RIDGE
AXIS ARRIVING ON TUESDAY. TEMPERATURES WILL HOLD CLOSE TO SEASONAL
LEVELS FRIDAY THROUGH SUNDAY WITH HIGHS GENERALLY REACHING THE 30S
WEST AND 40S OVR THE ERN PLAINS. THE APPROACHING UPPER-RIDGE AND
ASSOCIATED WAA WILL LIFT HIGH TEMPERATURES ABOVE AVERAGE FOR THE
FIRST TIME SINCE THE THIRD WEEK OF FEBRUARY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 520 AM MST TUE MAR 3 2015
AVIATION CONDITIONS WILL CONTINUE TO
BE POOR TODAY WITH WIDESPREAD IFR CONDITIONS PREVAILING AS A
SERIES OF STORMS SYSTEMS AND FRONT PUSH THROUGH AREA AIRFIELDS.
ALL SITES WILL SEE A PERIOD OF -SN/SN ESPECIALLY THROUGH 16Z AND
AGAIN BETWEEN 22-06Z. NORTH/NORTHEAST WINDS WILL PREVAIL TODAY AND
TONIGHT AT SPEEDS OF BETWEEN 15 AND 25 KNOTS. THESE BREEZY
CONDITIONS WILL PRODUCE SOME AREAS OF BLOWING SNOW. LOW CIGS ALONG
WITH THE ACTIVE UPSLOPE PATTERN WILL OBSCURE MOUNTAINS TODAY AND
TONIGHT. SHOULD BEGIN TO SEE IMPROVEMENT TO CONDITIONS AFTER 04Z
OR SO...WITH VFR RETURNING TO MANY SPOTS AFTER 06Z.
&&
.FIRE WEATHER...
ISSUED AT 520 AM MST TUE MAR 3 2015
A WINTER STORM WILL CONTINUE TO IMPACT MUCH OF SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE THROUGH TONIGHT. SIGNIFICANT
SNOWFALL ACCUMULATIONS ARE LIKELY ALONG WITH STRONG NORTHERLY
WINDS RESULTING IN EXTREMELY DANGEROUS TRAVEL CONDITIONS. VERY
COLD TEMPERATURES ARE EXPECTED TODAY AND TONIGHT WITH WIDESPREAD
DANGEROUS WIND CHILLS POSSIBLE ON EARLY WEDNESDAY MORNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR
WYZ101>111-113-115>117.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ112-114.
NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR NEZ002-
003-095-096.
&&
$$
UPDATE...SML
SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...HAMMER