Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/12/15
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1114 PM EST MON FEB 9 2015
.SYNOPSIS...
A BROAD AREA OF LOW PRESSURE WILL PASS OFF THE CAROLINA COAST
TONIGHT, WITH HIGH PRESSURE BUILDING OVER THE REGION FROM THE
NORTHWEST FOR TUESDAY AND WEDNESDAY. A COLD FRONT WILL CROSS THE
AREA THURSDAY, WITH A STRONG LOW PRESSURE SYSTEM EXPECTED TO DEVELOP
ALONG THIS FRONT AS IT MOVES OFF THE COAST. VERY COLD AIR AND STRONG
WINDS ARE EXPECTED FOR THE MID-ATLANTIC REGION BEHIND THIS FRONT
THURSDAY NIGHT AND FRIDAY. A CLIPPER SYSTEM MAY EFFECT THE AREA ON
SATURDAY, FOLLOWED BY YET ANOTHER BLAST OF COLD AIR ON SUNDAY AND
MONDAY AS ANOTHER CANADIAN HIGH PRESSURE SYSTEM MOVES EAST.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BASED ON RADAR FOR THE NORTH AND THE LATEST GUIDANCE FOR SOUTH,
ADVISORIES FOR THESE PARTS OF OUR CWA WERE EXTENDED FOR A FEW MORE
HOURS.
A FEW CHANGES WITH THIS UPDATE. A MAJORITY OF THE HI-RES GUIDANCE
HAS NOT BEEN HANDLING THE CURRENT PRECIPITATION ACROSS SEPA TOO
WELL, ALTHOUGH THE HRRR IS THE BETTER OF THE GUIDANCE. USED A
HEAVY BLEND OF CONTINUITY AND HRRR THROUGH TUESDAY MORNING. THE
TRANSITION LINE FROM FZRA TO SNOW IS STILL SITTING ACROSS SEPA
INTO CENTRAL NEW JERSEY BASED ON REGIONAL OBSERVATIONS. THE
FREEZING LAYER WILL CONTINUE TO SAG SOUTH-SOUTHEAST THROUGH THE
OVERNIGHT HOURS AND EVENTUALLY EVERYONE WILL CHANGE OVER TO A
SNOW/SLEET MIX...ALL SNOW NORTH OF THE DELMARVA AFTER MIDNIGHT.
DID NOT TOUCH THE CURRENT ADVISORIES AS MORE PRECIPITATION HAS
BLOSSOMED TO THE WEST OF THE REGION AND THOUGH ACROSS THE POCONOS
AND NORTHERN NEW JERSEY IT SHOULD BE MOSTLY SNOW, WHENEVER WE LOSE
THE INTENSITY OF THE PRECIPITATION THE COLUMN DRIES ENOUGH TO
INCLUDE SOME VERY PATCHY FREEZING DRIZZLE.
ACROSS THE DELMARVA TEMPERATURES HAVE DROPPED TO OR BELOW FREEZING
AND THE THERMAL PROFILE IS SHOWING THE MELTING LAYER AT 850MB
STILL ACROSS THE PHILLY METRO AREA...FREEZING RAIN WILL INCREASE
IN COVERAGE LATE THIS EVENING INTO THE EARLY TUESDAY MORNING HOURS
BEFORE A SNOW/SLEET PHASE CHANGE OCCURS.
LOW TEMPS TONIGHT WILL DROP INTO THE TEENS ACROSS THE FAR
NORTH...AND DROP INTO THE MID/UPPER 20S ELSEWHERE. WINDS WILL BE
MOSTLY N OR NE AT 10 TO 15 MPH OVERNIGHT...HIGHER ALONG THE SHORE
AREAS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
HIGH PRESSURE WELL TO THE NORTH WILL BEGIN TO BUILD TOWARDS THE
AREA. LOW PRESSURE ASSOCIATED WITH THE SYSTEM FROM THE NEAR TERM
WILL BE WELL TO THE SOUTH...BUT WILL BE STRENGTHENING WHILE MOVING
OFFSHORE. THE ONLY PCPN WE HAVE FOR TUESDAY WILL BE FOR THE MORNING
ACROSS THE DELMARVA AND SE NJ WHERE SLGT CHC OR SMALL CHC POPS WILL
BE FOUND. BY MORNING...TEMPS WILL LIKELY BE COLD ENOUGH FOR MOSTLY
LIGHT SNOW. SKY COVER TUESDAY WILL BE MOSTLY CLOUDY FOR THE MOST
PART...BUT SOME IMPROVEMENTS NORTH ARE POSSIBLE LATER TUE. WINDS
WILL BE MODERATE WITH WINDS MOSTLY NORTHERLY 10 TO 15 MPH AND GUSTS
IN THE LOW 20S MPH RANGE. HIGH TEMPS WILL MOSTLY BE IN THE 30S
ACROSS THE REGION.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE MID-LEVEL FLOW PATTERN FROM TUESDAY NIGHT THROUGH MONDAY OF NEXT
WEEK IS FORECAST TO BE PUNCTUATED BY TWO EXTREME TROUGHS...ONE
THURSDAY INTO FRIDAY...THE OTHER LATE SATURDAY THROUGH SUNDAY. SOME
OF THE COLDEST AIR OF THE SEASON...IF NOT THE COLDEST...WILL
INVADE THE NORTHEAST SECTION OF THE COUNTRY IN THEIR WAKE, WITH A
FLOW DIRECTLY FROM THE POLAR REGIONS.
TUESDAY NIGHT SHOULD BE FAIRLY TRANQUIL, WITH LIGHTER WINDS, PERHAPS
SLIGHTLY STRONGER NEAR THE COAST. NO PRECIPITATION IS EXPECTED, WITH
NORMAL TO SLIGHTLY BELOW NORMAL TEMPERATURES AS SURFACE HIGH
PRESSURE BUILDS OVER THE AREA. WEDNESDAY WILL FEATURE MAINLY CLEAR SKIES
FOR A GOOD PART OF THE DAY, BUT SOME HIGH CLOUDS ARE POSSIBLE IN
THE WEST LATE. HIGH TEMPERATURES ON WEDNESDAY WILL BE SEVERAL
DEGREES BELOW NORMAL. LIGHT SNOW IS POSSIBLE IN THE NORTHERN HALF
OF THE CWA WEDNESDAY NIGHT AS A CLIPPER SYSTEM MOVES THROUGH NEW
YORK STATE. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE
ACROSS THE AREA ON THURSDAY, USHERING IN BITTER COLD AIR FOR
THURSDAY NIGHT AND FRIDAY. THE ASSOCIATED MID-LEVEL TROUGH IS
EXPECTED TO BECOME NEGATIVELY TILTED JUST AS IT SWINGS THROUGH OUR
AREA THURSDAY NIGHT, SO RAPID DEVELOPMENT OF A SURFACE LOW IS
EXPECTED ONCE AGAIN OVER THE NEW ENGLAND MARITIMES.
UNFORTUNATELY...THE GRADIENT GENERATED BY THIS DEPARTING BUT
DEEPENING LOW PRESSURE SYSTEM WILL BRING GUSTY NORTHWEST WINDS TO
OUR AREA...DRIVING WIND CHILL TEMPERATURES DOWN TO THE NEGATIVE
TEENS (AND PERHAPS BEYOND IN THE HIGHER ELEVATIONS UP NORTH) FOR
THURSDAY NIGHT. HIGH TEMPERATURES ON FRIDAY WILL STRUGGLE TO
EMERGE OUT OF THE SINGLE DIGITS IN THE FAR NORTH, AND WON`T GET
OUT OF THE LOW TO MID 20S IN THE SOUTH...SOME TWENTY DEGREES BELOW
NORMAL FOR THIS TIME OF YEAR. ANOTHER COLD NIGHT IS ON TAP FOR
FRIDAY NIGHT, BUT WITH LESS WIND IT MIGHT NOT FEEL QUITE SO
COLD...AND THE HOUSE WILL BE A LITTLE EASIER TO HEAT.
THEN ANOTHER BLAST HEADS OUR WAY ON SATURDAY, HERALDED BY A CLIPPER
SYSTEM WITH SOME LIGHT SNOW FROM WEST TO EAST STARTING IN THE
AFTERNOON. THIS CLIPPER COULD INTENSIFY AS IT MOVES OFF THE COAST
SATURDAY NIGHT, BRINGING GUSTY WINDS BACK TO THE AREA JUST AS COLD
AIR ONCE AGAIN INVADES THE REGION BEHIND A COLD FRONT. TEMPERATURES
SATURDAY NIGHT AND SUNDAY COULD BE COLDER THAN THE MIDWEEK SYSTEM
AND PERHAPS EVEN COLDER SUNDAY NIGHT GOING INTO MONDAY, BUT BY LATE
SUNDAY WINDS SHOULD BE SUBSIDING JUST A BIT.
ALL-IN-ALL, NOT A VERY NICE WEEK AHEAD...UNLESS YOU/RE A POLAR BEAR!
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...MVFR/IFR. AREAS OF FREEZING RAIN/SNOW/SLEET ACROSS THE
REGION TONIGHT. AT THIS POINT RDG/ABE SHOULD SEE THE MOST SNOW,
THOUGH ONLY A LIGHT ACCUMULATION, WITH TIMES OF SLEET MIXING IN
THROUGH THE REMAINDER OF THE EVENING. THERE COULD BE A PERIOD LATE
TONIGHT WHERE SOME PATCHY FREEZING DRIZZLE OCCURS. ELSEWHERE
FREEZING RAIN WILL BE THE MAIN PRECIPITATION THROUGH THE EVENING
BEFORE CHANGING OVER TO A SNOW/SLEET MIX AFTER MIDNIGHT. NORTHEAST
WINDS AROUND 10 TO 15 KNOTS MAY BECOME GUSTY AT TIMES.
TUESDAY...MVFR TO POCKETS OF IFR CONDITIONS ARE EXPECTED EARLY
TUESDAY MORNING AS ANY REMAINING LIGHT SNOW WILL BE ENDING FROM WEST
TO EAST. LIGHT SNOW SHOULD TAPER OFF FIRST DURING THE EARLY MORNING
FOR THE WESTERN SITES, INCLUDING KRDG/KABE, AND THEN WITHIN A COUPLE
OF HOURS EITHER SIDE OF DAYBREAK ACROSS THE DELAWARE VALLEY AND THEN
ACROSS NJ. MVFR CONDITIONS WILL LIKELY HOLD THROUGH THE MORNING,
BEFORE TRANSITIONING TO VFR INTO THE AFTERNOON. NORTH-NORTHEAST TO
NORTHERLY WINDS ARE ANTICIPATED THROUGH THE DAYTIME, WITH GUSTS
AROUND 20 KNOTS EXPECTED.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...MAINLY VFR WITH SUBSIDING
WINDS.
THURSDAY...MAINLY VFR. HOWEVER, THERE IS A CHANCE OF LIGHT SNOW WHICH
COULD BRIEFLY REDUCE CONDITIONS INTO THE MVFR OR IFR CATEGORY.
THURSDAY NIGHT THROUGH FRIDAY NIGHT FRIDAY...MAINLY VFR.
SATURDAY...A CHANCE OF LIGHT SNOW COULD ONCE AGAIN REDUCE CONDITIONS
IN THE THE MVFR OR IFR CATEGORY.
&&
.MARINE...
HIGH PRESSURE WELL TO THE NORTH WILL MOVE TOWARDS THE AREA LATE
TONIGHT. MEANWHILE...LOW PRESSURE WILL MOVE OFFSHORE (VA/NC) THEN
DEEPEN WHILE MOVING NE. THE PRESSURE GRADIENT WILL BEGIN TO
STRENGTHEN ACROSS THE AREA WITH WINDS/SEAS BUILDING. SCA FLAGS
WILL REMAIN FOR DEL BAY. THE GALE FLAG FOR THE NRN WATERS
CONTINUES THRU 23Z TUE...WHILE THE DEL BAY AND SRN COASTAL WATERS
HAS THE FLAGS THRU 03Z WED. THESE ENDING TIMES ARE OK FOR NOW.
OUTLOOK...
TUESDAY NIGHT...A GALE WARNING IS IN EFFECT UNTIL 1000 PM ON OUR
OCEAN WATERS SOUTH OF GREAT EGG INLET, NEW JERSEY. OTHERWISE, SMALL
CRAFT ADVISORY CONDITIONS SHOULD CONTINUE IN OUR MARINE AREA.
WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED ON OUR
OCEAN WATERS.
WEDNESDAY NIGHT AND THURSDAY MORNING...WAVE HEIGHTS ON OUR OCEAN
WATERS MAY REMAIN NEAR 5 FEET. WIND SPEEDS ARE FORECAST TO STAY
BELOW THE SMALL CRAFT ADVISORY CRITERION.
THURSDAY AFTERNOON...SMALL CRAFT ADVISORY CONDITIONS ARE
ANTICIPATED TO RETURN WITH A DEVELOPING NORTHWEST WIND.
THURSDAY NIGHT AND FRIDAY...NORTHWESTERLY GALE FORCE GUSTS ARE
EXPECTED.
FRIDAY NIGHT...SMALL CRAFT ADVISORY WINDS EXPECTED.
SATURDAY...NO HEADLINES EXPECTED ATTM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR PAZ054-055-
061-062-105.
WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR PAZ060-070-
071-101>104-106.
NJ...WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR NJZ001-
007>010.
WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR NJZ012>022-
025>027.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR NJZ023-024.
DE...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR DEZ001.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR DEZ002>004.
MD...WINTER WEATHER ADVISORY UNTIL 6 AM EST TUESDAY FOR MDZ008.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ012-015-
019-020.
MARINE...GALE WARNING UNTIL 10 PM EST TUESDAY FOR ANZ452>455.
GALE WARNING UNTIL 6 PM EST TUESDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 10 PM EST TUESDAY FOR ANZ430-431.
&&
$$
SYNOPSIS...MIKETTA
NEAR TERM...HEAVENER/O`HARA
SHORT TERM...O`HARA
LONG TERM...MIKETTA
AVIATION...HEAVENER/KLINE/MIKETTA
MARINE...MIKETTA/O`HARA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1220 AM EST TUE FEB 10 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE PUSHING EAST TONIGHT BRINGING SHOWERS
TO THE AREA. FAIR WEATHER EXPECTED TUESDAY AND WEDNESDAY WITH
GENERALLY SEASONAL TEMPERATURES. A DRY COLD FRONT WILL MOVE
THROUGH THURSDAY...FOLLOWED BY MUCH COLDER CONDITIONS FRIDAY
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AN UPPER TROUGH TO OUR WEST WILL CONTINUE TO PROMOTE A CHANCE OF
SHOWERS OVERNIGHT AS IT SWINGS EAST. THE COLD FRONT IS LOCATED
ALONG THE WESTERN PART OF THE FORECAST AREA AND WILL CONTINUE TO
CROSS THE REGION TONIGHT. MAIN BAND OF RAINFALL AHEAD OF THE
FRONT HAS SHIFTED OFF THE COAST. REGIONAL RADAR IMAGERY
SHOWS SCATTERED SHOWERS IN THE UPSTATE WHICH ARE NOW MOVING INTO
THE CSRA AND WESTERN MIDLANDS. HRRR MODEL KEEPS LIGHT RAIN IN
THE NORTHERN MIDLANDS INTO TUESDAY MORNING. TEMPERATURES DROPPED
AS THE RAIN MOVED THROUGH EARLIER AND HAVE REMAINED RATHER STEADY.
LOOKING UPSTREAM...THE COLD SURGE OF AIR HAS BEEN LAGGING...SO
EXPECT OVERNIGHT LOWS TO BE MILD...IN THE 40S. WINDS WILL INCREASE
OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS AND COLD AIR ADVECTION
INCREASES. WINDS WILL INCREASE TO AROUND 10 TO 15 KNOTS WITH GUSTS
AROUND 20 TO 25 KNOTS BY 12Z. AREAS OF FOG HAVE DEVELOPED BUT
EXPECT IMPROVEMENT WITH THE NEXT BATCH OF SHOWERS AND AS WINDS
PICK UP AFTER 06Z.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
TUESDAY WILL START OFF MOSTLY CLOUDY...THEN AS DRIER AIR FINALLY
BEGINS WORKING ITS WAY INTO THE REGION BEHIND THE COLD FRONT SKIES
WILL BEGIN CLEARING BY THE AFTERNOON. WINDS WILL BECOME GUSTY
THROUGH THE DAY BEHIND THE FRONT DUE TO A RATHER STRONG PRESSURE
GRADIENT ACROSS THE REGION. WINDS GENERALLY OUT OF THE NORTH
BETWEEN 10 AND 15 MPH...WITH GUSTS AROUND 20 MPH BEING POSSIBLE.
DO NOT EXPECT LAKE WIND ADVISORY CRITERIA TO BE MET AT THIS
TIME...SO DO NOT ANTICIPATE ANY PRODUCT ISSUANCES. WINDS WILL
DIMINISH BY SUNSET. TEMPERATURES MAY BE ABLE TO CLIMB INTO THE
MIDDLE TO POSSIBLY UPPER 50S DURING THE AFTERNOON DEPENDING ON HOW
MUCH SUN THE REGION GETS.
DRY WEATHER IS EXPECTED TO CONTINUE FOR THE REMAINDER OF THE SHORT
TERM. THERE WILL BE ANOTHER FRONTAL PASSAGE ON THURSDAY...WHICH
WILL BRING INCREASING WINDS BACK TO THE REGION. WEDNESDAY AND
THURSDAY WILL STILL BE GENERALLY IN THE 50S FOR HIGHS...AND
OVERNIGHT LOWS IN THE 30S FOR TUESDAY NIGHT...THEN MODERATING INTO
THE 40S FOR WEDNESDAY NIGHT. THE COLDEST NIGHT WILL BE THURSDAY
NIGHT BEHIND THE COLD FRONT...WITH READINGS BACK DOWN INTO THE 20S
BECOMING POSSIBLE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE DRY AIR WILL CONTINUE ACROSS THE REGION THROUGH THE WEEKEND.
BELOW NORMAL TEMPERATURES WILL ALSO CONTINUE. BIGGEST QUESTION
MARK IN REGARDS TO TEMPERATURES APPEARS TO BE OVER THE WEEKEND.
LARGE STANDARD DEVIATIONS IN THE MODEL GUIDANCE FOR BOTH MAX/MIN
READINGS. THIS IS DUE TO A POSSIBLE ARCTIC INTRUSION OF AIR
SATURDAY NIGHT INTO MONDAY. THE GFS/ECMWF/CMC SHOW STRONG AREA OF
HIGH PRESSURE MOVING INTO THE REGION SUNDAY AND MONDAY...WITH A
STRONG LOW MOVING OFF THE NEW ENGLAND COAST. IN GENERAL HAVE GONE
SLIGHTLY BELOW THE MODEL AVERAGES FOR TEMPERATURES SATURDAY NIGHT
THROUGH MONDAY...BUT DID NOT GO WITH THE EXTREME VALUES. THERE IS
SOME BITTERLY COLD AIR CURRENTLY ACROSS NORTH-CENTRAL AND WESTERN
CANADA...AND EASTERN ALASKA. WOULD PREFER TO WAIT AND SEE HOW MUCH
OF THIS AIR GETS PUSHED SOUTHWARD...ALONG WITH WHAT DIRECTION IT
HEADS...WITH THE POSSIBLE SURGE NEXT WEEKEND BEFORE GOING ON THE
EXTREME SIDE OF ANY GUIDANCE.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
WIDESPREAD IFR/LIFR CIGS/VSBYS DUE TO FOG AND LOW STRATUS IN THE
CAE/CUB/OGB TERMINALS EARLY THIS MORNING...WITH VFR VSBYS/IFR CIGS
AT AGS/DNL. RADAR INDICATING SCATTERED SHOWERS IN THE UPSTATE SOUTH
CAROLINA MOVING SOUTHEAST TOWARD THE REGION. THESE SHOWERS WILL MOVE
INTO THE AREA MAINLY BETWEEN 06Z-09Z AND EXPECT SOME IMPROVEMENT TO
VISIBILITIES AND CEILINGS DURING THIS PERIOD. MAINLY MVFR FORECAST
AFTER 09Z...ALTHOUGH LOW STRATUS STILL POSSIBLE.
NORTH WINDS EXPECTED TO INCREASE AFTER 10Z WITH GUSTS TO NEAR 20
KNOTS. UPPER LEVEL TROUGH AXIS OVER THE AREA EARLY THIS MORNING AND
AND ALONG COAST LATER TODAY. MODELS INDICATE CONSIDERABLE LOW-LEVEL
MOISTURE ACROSS REGION THROUGH THIS MORNING WITH DRIER AIR ADVECTING
IN DURING THE AFTERNOON. THEREFORE...LOW CEILINGS...MVFR LIKELY TO
CONTINUE THROUGH THE MORNING WITH IMPROVEMENT TO VFR AROUND 18Z WITH
BROKEN STRATO-CU DECK. GUSTY NORTH WINDS TO CONTINUE THROUGH THE DAY
GUSTS TO ABOVE 20 KNOTS POSSIBLE.
EXTENDED AVIATION OUTLOOK...GUSTY WINDS MAY BE POSSIBLE AGAIN ON
THURSDAY BEHIND EXITING COLD FRONTS. CEILINGS AND VISIBILITIES
EXPECTED TO REMAIN VFR THROUGH THE EXTENDED PERIOD DUE TO A DRY
AIR MASS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 PM CST TUE FEB 10 2015
.UPDATE...1223 PM CST
NO BIG CHANGES/UPDATES AT THIS TIME...ONLY MAKING SOME MINOR
CHANGES TO SKY COVER AND TEMPS FOR THIS AFTERNOON. CONTINUING TO
MONITOR TRENDS FOR POSSIBLE PRECIP LATER THIS EVENING...WITH
LATEST RADAR MOSAIC SHOWING STEADILY EASTWARD MOVING AREA OF
PRECIP MOVING THROUGH IOWA. HAVE MAINTAINED SLIGHT CHANCE WORDING
FOR THE WEST/NORTHWEST CWA LATE THIS AFTERNOON WITH THIS STEADY
PUSH...AS CURRENT TIMING STILL LOOKS GOOD. MUCH DRIER AIR IN PLACE
WILL LIKELY LIMIT DURATION AND COVERAGE OF ANY LIGHT PRECIP THAT
MOVES INTO THE CWA LATER THIS EVENING...AS WELL AS PRECIP TYPE
WITH A WINTRY MIX STILL APPEARING POSSIBLE. WILL LIKELY INCREASE
POPS ACROSS THE FAR NORTHERN CWA THIS EVENING BUT WITH SOME SHORT
TERM GUIDANCE HINTING THAT THE SOUTHERN END COULD WORK ITS WAY
FURTHER EAST INTO THE CWA...WILL WAIT TO MAKE ANY FINAL DECISIONS
THIS AFTERNOON.
RODRIGUEZ
&&
.SHORT TERM...
259 AM CST
THROUGH WEDNESDAY...
SFC RIDGE HAS PUSHED OVER THE REGION...HOWEVER WITH THE LACK OF
STRONG MIXING...A NARROW CHANNEL OF LAKE EFFECT CLOUDS/STRATUS
CONTINUES TO STRETCH SOUTH/SOUTHWEST ACROSS THE LAKE INTO
NORTHEAST IL. THE SOUTHERN PORTIONS OF THE LAKE STRATUS IS
BEGINNING TO THIN...HOWEVER EXPECT THIS FEATURE TO REMAIN THRU
DAYBREAK AND SLOWLY SLIDE NORTHWEST BY MID-MORNING. CLEAR SKIES
CONTINUE FOR OUR WESTERN CWFA WHERE THE LAKE STRATUS HAS NOT
INVADED...WHICH HAS ALLOWED AN IDEAL SCENARIO OF LIGHT WINDS AND
EFFICIENT RADIATIVE PROCESSES TO TAKE PLACE. SFC OBS WILL LIKELY
DIP TO ARND ZERO TO POSSIBLY A FEW DEGREES BELOW ZERO IN THE
TRADITIONAL COLD SPOTS BEFORE DAYBREAK. ELSEWHERE TEMPS HAD
DROPPED...HOWEVER WITH THE CLOUD DECK PIVOTING WEST/NORTHWEST
TEMPS HAVE COME BACK UP A COUPLE OF DEGREES. LLVL FLOW HAS ALREADY
TURNED EASTERLY/SOUTHEASTERLY ACROSS CENTRAL IOWA INTO SOUTHERN
IL.
WITH THE ANTI-CYCLONIC FEATURE SLOWLY PUSHING EAST TODAY...LLVL FLOW
WILL INCREASE FROM THE EAST/SOUTHEAST ALLOWING A STEADY CONVEYOR OF
DRIER AIR TO PUSH ACROSS THE FORECAST AREA. THIS WILL LIKELY DELAY
SATURATION IN ADVANCE OF THE NEXT SYSTEM...WHICH IS POISED TO ARRIVE
EARLY THIS EVENING. WARM AIR ADVECTION WILL NUDGE TEMPS UP THIS AFTN
TO ARND 30-35 DEG RANGE. THE BEST FORCING FROM THE SHORTWAVE LOOKS
TO BE CONFINED TO WISC...HOWEVER SOME FORCING WILL EXTEND SOUTH INTO
THE NORTHERN PORTIONS OF THE FORECAST AREA. SOUNDINGS SUGGEST A
LINGERING THERMAL INVERSION THIS EVENING...WHICH COULD ALLOW FOR
SOME PARTIAL MELTING OF DENDRITES OR POSSIBLY A SNOW/SLEET MIX. ANY
ACCUMULATIONS WOULD BE LOCATED ALONG THE IL/WISC STATELINE. BUT A
QUICK HALF INCH IS POSSIBLE BEFORE THE VORT LIFTS NORTHEAST EARLY
WED.
THE TRAILING FRONTAL BOUNDARY IS PROGGED TO HOLD OFF UNTIL DAYBREAK
WED...WHICH COULD ALLOW TEMPS PRIOR TO DAYBREAK TO WARM A FEW
DEGREES INTO THE LOW 30S. THEN MUCH COLDER AIR WILL ADVECT SOUTHEAST
ACROSS THE CWFA...ALLOWING TEMPS TO STEADILY COOL THROUGHOUT THE
DAY. BY EARLY WED AFTN TEMPS WILL MAINLY BE IN THE MID/UPR 20S
ACROSS THE WEST/NORTH CWFA AND STILL IN THE LOW 30S FOR THE
SOUTHEAST FORECAST AREA.
A DRY WEDGE IS PROGGED TO ARRIVE WED...AND SHOULD BRING A TEMPORARY
LULL IN ANY LGT SNOW/FLURRIES FOR THE CWFA WED AFTN. THEN THE 500MB
VORT QUICKLY SLIDES SOUTH FROM CANADA INTO THE UPPER MIDWEST...AND
WILL ARRIVE OVER THE CWFA WED NGT. ROBUST THERMAL TROUGH AT 850MB
BRINGS TEMPS DOWN TO -20 TO -24 DEG C LATE WED NGT. LOWERED TEMPS
WED NGT A FEW DEGREES INTO THE SINGLE DIGITS ABOVE ZERO...HOWEVER
THIS MAY NEED TO BE LOWERED FURTHER GIVEN THE STRENGTH OF THE COLD
AIR ADVECTION.
LAKE EFFECT MACHINE WILL BE STARTING TO KICK-IN LATE WED
NGT...HOWEVER WITH A MORE NORTHWEST FLOW THIS WILL LIKELY KEEP THE
BULK OF THE ACTIVITY EAST OF PORTER COUNTY INDIANA.
BEACHLER
&&
.LONG TERM...
259 AM CST
THURSDAY THROUGH MONDAY...
STRONG ARCTIC HIGH PRESSURE ARRIVES THUR ACROSS THE UPPER
MIDWEST/MID-MISSOURI VALLEY...WITH A TIGHT PRESSURE GRADIENT
REMAINING OVER THE FORECAST AREA THUR. THIS WILL ALLOW WINDS TO TURN
MORE NORTHERLY...ALLOWING A LONG FETCH SETUP FOR LAKE EFFECT SNOW TO
PUSH WEST INTO LAKE/PORTER COUNTIES INDIANA AND POSSIBLY INTO
NEWTON/JASPER COUNTIES AS WELL. FURTHER WEST SKIES SHUD THIN...WITH
P-CLOUDY TO POSSIBLY SUNNY SKIES BY MID AFTN THUR. THE POTENT
THERMAL TROUGH WILL REMAIN OVERHEAD...WITH SFC TEMPS STRUGGLING TO
WARM BEYOND THE SINGLE DIGITS ABOVE ZERO. WHERE THE LAKE CLOUDS/SNOW
WILL BE TEMPS WILL BE IN THE LOW TEENS. SOUNDINGS SUGGEST UP TO
100J/KG OF CAPE OVER THE LAKE MAY DEVELOP THUR...SO CONDITIONS WILL
BE FAVORABLE FOR A POTENT LES BAND TO DEVELOP. ACCUMULATIONS WILL BE
POSSIBLE FOR NORTHWEST IN...BUT THE LOCATIONS WILL BE DICTATED BY
THE WIND DIRECTION.
WINDS WILL BEGIN TO RELAX AS THE SFC RIDGE SLIDES EAST OVER THE
REGION...AND YET ANOTHER CLIPPER ARRIVES FRI. TEMPS THUR NGT WILL
HINGE ON CLOUD COVER. CURRENT SOLUTIONS SUGGEST MOST OF THE AREA
WILL OBSERVE TEMPS AROUND ZERO TO A FEW DEGREES BELOW ZERO. WINDS
WILL KEEP WIND CHILLS IN THE -15 TO -20 DEG RANGE THUR EVE...BUT
SHOULD WEAKEN DURING THE OVERNIGHT HOURS.
FAST NORTHWEST FLOW WILL CONTINUE THE ACTIVE THEME...AS ANOTHER
SHORTWAVE SLIDES ACROSS THE UPPER MIDWEST FRI. THE NEXT WAVE WILL
LIKELY ARRIVE WITH THICKENING CLOUDS AND POSSIBLY LGT SNOW FRI. COOL
AIR REMAINS WITH HIGHS FRI IN THE TEENS/LOW 20S.
SATURDAY THROUGH EARLY NEXT WEEK...
THE AMPLIFIED RIDGING ACROSS WESTERN CANADA/CONUS WILL WEAKEN
MARGINALLY HEADING INTO THE WEEKEND AND NUDGE EAST. THIS SHOULD HELP
TO KICK THE POTENT THERMAL TROUGH EAST OF THE FORECAST
AREA...HOWEVER THE LONGWAVE PATTERN CONTINUES TO POINT TOWARDS A
REDEVELOPMENT TO THE HIGH AMPLITUDE RIDGE OVER EASTERN ALASKA EARLY
NEXT WEEK. WHILE A PERIOD OR TWO COULD REMAIN DRY...IT IS LIKELY
THAT A FEW CLIPPERS WILL BREAK SOUTHEAST FROM CENTRAL CANADA AND
PIVOT OVER THE GREAT LAKES...PRODUCING SOME LGT SNOW.
TEMPS WILL CONTINUE TO BE ON THE COOL SIDE WITH HIGHS IN THE TEENS
TO LOW 20S...HOWEVER HEADING INTO EARLY NEXT WEEK THE MID-LVL RIDGE
MAY BRIEFLY TRANSITION TOWARDS QUASI-ZONAL AND OFFER BREAK WITH
TEMPS APPROACHING 30 DEGREES EARLY NEXT WEEK. UNFORTUNATELY THIS
BRIEF MODERATION ONLY LOOKS TEMPORARY AS COLD AIR WILL RETURN BY THE
MIDDLE OF NEXT WEEK.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CHANCE OF LIGHT SNOW...POSSIBLY MIXING WITH SLEET...LATE THIS
EVENING.
* CHANCE OF LIGHT FREEZING DRIZZLE LATE TONIGHT WITH MVFR VIS
LIKELY.
* MVFR CIGS LATE TONIGHT INTO WEDNESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN FORECAST CONCERNS FOCUS ON WIND DIRECTION TRENDS THROUGH THE
PERIOD AS WELL AS POTENTIAL FOR A COUPLE PERIODS OF WINTRY PCPN
OVERNIGHT. THE MAIN SYSTEM RESPONSIBLE IS A WEAK CLIPPER TYPE
SYSTEM CURRENTLY TRACKING ACROSS THE UPPER MISSISSIPPI VALLEY.
SKIES HAVE IMPROVE TO VFR FOLLOWING THE EROSION OF THE ST
DECK...BUT LATEST SATELLITE TRENDS INDICATE THAT INCREASING MID
AND HIGH CLOUD SHOULD BEGIN TO OVERSPREAD THE AREA LATE THIS
AFTERNOON. AS THE CLIPPER APPROACHES THE REGION...WINDS WILL
GRADUALLY VEER FROM GENERALLY ELY TO SELY LATE THIS
AFTERNOON...BUT WITH A WEAK GRADIENT IN PLACE...WIND SPEEDS WILL
BE LIGHT AND DIRECTION SHOULD BE SOMEWHAT VARIABLE...WITH SPEEDS
AT OR UNDER 8KT. WINDS SHOULD THEN CONTINUE TO VEER THROUGH SLY
LATE THIS EVENING TO SWLY BY TOMORROW MORNING.
THE BIGGER CONCERN WILL BE THE CHANCES FOR PCPN AT THE TERMINAL.
LATEST RADAR TRENDS SHOW A NARROW BAND OF PCPN MOVING THROUGH ERN
IOWA THIS AFTERNOON...WITH THE LATEST HIGH RES MODEL GUIDANCE
SUGGESTING THAT PCPN COULD REACH THE RFD AREA BY ARND
02-03Z...WHICH IS A FEW HOURS SLOWER THAN PREVIOUS THINKING. THE
RH AND TEMPERATURE PROFILES ARE A BIT TRICKY IN DETERMINING PCPN
TYPE AS THERE IS A WEDGE OF WARMER AIR ALOFT WITH TEMPS ABOVE 0C
WITH A FREEZING LAYER ABOVE AND NEAR THE SURFACE. THIS TYPE OF
THERMAL AND MOISTURE PROFILE IS SIMILAR FROM WEST TO EAST...WITH
THE MAIN ISSUE AS THE SYSTEM CROSSES THE REGION BEING THE TRACK OF
THE STRONGEST MID LEVEL FORCING...WHICH IN TURN WOULD TRANSLATE
INTO THE GREATER CHANCES FOR PCPN REACHING THE SURFACE. THE LATEST
GUIDANCE SUGGESTS THAT THE STRONGEST FORCING WILL BE OVER THE
NORTHERN TIER COUNTIES OF IL...WITH RFD BEING THE TERMINAL WITH
THE GREATEST CHANCE TO SEE PCPN. CONSIDERING THE THERMAL PROFILE
AND FORCING...PCPN COULD BE A SNOW/SLEET MIX. AS THE SYSTEM TRACKS
EWD...THE MID LEVEL FORCING SHOULD WEAKEN AND TREND NORTH OF THE
CHICAGO AREA TERMINALS. WILL CONTINUE WITH THE PROB30 GROUP FOR
3SM -SN FOR NOW...BUT CONFIDENCE IS LOW...WITH PROBABLY EQUAL
CHANCES THAT ANY PCPN WOULD REMAIN NORTH OF THE TERMINALS...OR
THERE COULD BE A BRIEF PERIOD OF A SNOW/SLEET MIX.
AFTER MIDNIGHT...THE SNOW/SLEET POTENTIAL WILL COME TO AN END WITH
DRIER AIR OVERSPREADING THE AREA ABOVE ARND 8KFT...WITH A
SATURATED LAYER BELOW. WITH LITTLE FORCING ALOFT AND DRY
AIR...THERE WILL LITTLE OPPORTUNITY FOR ICE PRODUCTION ALOFT...SO
SOME LIGHT FREEZING DRIZZLE WILL BE POSSIBLE FOR THE EARLY MORNING
HOURS. THIS IS ALSO A LOW CONFIDENCE FORECAST DEPENDING ON HOW
QUICKLY DEEP LAYER DRY AIR MOVES OVER THE REGION...WHICH WOULD
LIMIT THE DURATION OF ANY FZDZ.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
* LOW CONFIDENCE IN EXTEND LIGHT SNOW/ICE PELLETS THIS EVENING...
AND POSSIBLE TIMING.
* LOW TO MEDIUM CONFIDENCE IN FREEZING DRIZZLE FOR LATE TONIGHT.
* MEDIUM TO HIGH CONFIDENCE IN MVFR CIGS LATE TONIGHT INTO
WEDNESDAY MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF SNOW. MVFR POSSIBLE. STRONG/GUSTY
NORTHWEST WINDS.
* THURSDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. STRONG/GUSTY
NORTHWEST WINDS.
* FRIDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST/SOUTHWEST
WINDS.
* SATURDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. VERY STRONG/GUSTY
NORTHWEST WINDS.
* SUNDAY...DRY/VFR. WEST/SOUTHWEST WINDS.
* MONDAY...MVFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
322 PM CST
MULTIPLE MARINE CONCERNS AS WE ENTER A VERY COLD AND ACTIVE PATTERN.
THIS EVENING...THERE COULD BE BRIEF WINDOW OF NEAR SMALL CRAFT
CONDITIONS ALONG THE FAR NORTHEAST ILLINOIS SHORE AS SOUTHEAST
WINDS INCREASE TO 15 TO 25 KT. WINDS WILL THEN SHIFT SOUTHERLY ON
THE ENTIRE LAKE AS A WEAK LOW OVER THE UPPER MIDWEST APPROACHES.
THERE COULD BE A FEW GUSTS TO 30 KT ON THE NORTHERN HALF OF THE
LAKE TONIGHT IN THE PEAK OF THE SOUTHERLY FLOW.
A STRONG COLD FRONT TRAILING FROM THE LOW WILL SWEEP ACROSS THE LAKE
BY MID DAY WEDNESDAY OR SO...WITH AN EXPANSIVE 1040+ MB ARCTIC HIGH
SPREADING IN FROM THE NORTHERN PLAINS BEHIND IT. VERY TIGHT PRESSURE
GRADIENT AND BITTERLY COLD AIR MASS WILL ENABLE WINDS TO QUICKLY
RAMP UP TO GALE FORCE BY EARLY WEDNESDAY EVENING FOR THE OPEN WATERS
THEN LATER IN THE EVENING FOR THE NEARSHORE. IN ADDITION...HEAVY
FREEZING SPRAY WILL DEVELOP AS AIR TEMPERATURES PLUMMET. HAVE ISSUED
A GALE WARNING AND HEAVY FREEZING SPRAY WARNING FOR THE LAKE
WEDNESDAY EVENING/NIGHT INTO THURSDAY AFTERNOON...WITH A SMALL CRAFT
LEADING UP TO THE GALE WARNING FOR THE NEAR SHORE WEDNESDAY
AFTERNOON AND EVENING. EXPECTING PEAK GUSTS UP TO 40 KT WITH THIS
EVENT...AND THERE IS SOME POTENTIAL FOR UP TO 45 KT IN/NEAR THE
LAKE EFFECT CONVERGENCE BAND EARLY THURSDAY MORNING.
THERE WILL BE ONLY A BRIEF CALMER PERIOD THURSDAY NIGHT INTO
FRIDAY...FOLLOWED BY YET ANOTHER STRONG ARCTIC FRONT SWEEPING ACROSS
THE LAKE FRIDAY EVENING/NIGHT. VERY SIMILAR SETUP TO WEDNESDAY NIGHT
INTO THURSDAY BUT AN EVEN TIGHTER PRESSURE GRADIENT DUE TO STRONGER
LOW PRESSURE TO THE EAST SHOULD RESULT IN AT LEAST GALES TO 45 KT
AND HEAVY FREEZING SPRAY. WINDS...WAVES AND FREEZING SPRAY WILL
DIMINISH LATER SATURDAY NIGHT INTO SUNDAY AS THE ARCTIC HIGH MOVES
OVER THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...NOON WEDNESDAY TO MIDNIGHT THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT
THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...MIDNIGHT THURSDAY TO 3 PM THURSDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 PM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
300 PM CST Tue Feb 10 2015
.SHORT TERM...(Tonight)
ISSUED AT 258 PM CST TUE FEB 10 2015
Stratocumulus clouds 1.5-2k ft are now west of I-55 and eroding and
will continue to decrease toward the nw over IL river valley late
this afternoon into early this evening due to influence of high
pressure ridge axis into IL. HRRR model has been handling the
clearing of low clouds well and will continue to follow its lead.
Broken to overcast mid level clouds 8-12k ft over IA and far nw IL
will spread east across central IL during this evening especially
north of I-72 where skies become mostly cloudy. These clouds ahead
of 1010 mb low pressure along the eastern ND/SD border will track
ene to the Keweenaw peninsula in upper MI by 12Z/6 am Wed with its
cold front moving toward the IL river. Meanwhile southeast IL will
likely stay in the clear most of this evening with skies becoming
partly cloudy overnight in southeast IL. Light mix of precipitation
over eastern IA and moving east into WI and far NW IL at mid
afternoon. Forecast models keep light precipitation north of I-80
tonight over northern IL. Lows tonight in the upper 20s to near 30F
with mildest readings from Springfield southwest. ESE winds less
than 10 mph to veer ssw during overnight and turn WNW nw of IL by
sunrise behind cold front.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 258 PM CST TUE FEB 10 2015
The extended will be dominated by large temperature variations,
highlighted by two surges of Arctic air into the western Great Lakes
and eastern CONUS. Precipitation will be light with any shortwaves
through Monday.
The upper ridge along the West Coast will remain a semi-permanent
feature over the 5 to 6 days, with a long wave trough east of the
Continental Divide. A brief push of warm air into the area tonight
ahead of the first cold front should help Wednesday start out with
rising temps possibly even before sunrise. The cold front could
start pushing across our western counties shortly after sunrise, but
the affects of the cold air will be delayed across the rest of the
area until afternoon when the northwest winds increase in the strong
cold air advection. A few light snow showers or flurries could
develop Wed afternoon NE of CMI to DNV where a weak shortwave helps
provide some lift in the advancing cold air. A better chance for
snow showers in our area looks to be Wed night as a strong 500mb
vort max dives south into IL. Any snow accums would be very light
and mainly confined to areas NE of BMI to MTO. Flurries could extend
as far west as Springfield and Taylorville, depending on available
moisture.
Wind chills later Wed night will drop into the -5 to -15F range,
which is just outside of our advisory levels. However, those wind
chill numbers are for the sustained winds, and gusts to 30 mph could
easily push wind chills much colder than that at times.
Thursday will be a blustery day with NW winds of 20-25 and gusts to
35 mph. Some flurries cold linger east of I-57, but the shortwave
aloft will depart east of IL early in the day to help shut down
potential for precip.
Another brief warmup is indicated for Friday, as highs climb toward
freezing in the south and into the upper 20s north.
The strongest surge of Arctic air this week is expected late Friday
night and Saturday, as a deep closed low drops straight south from
the upper latitudes into the Great Lakes region. The coldest air,
with 850 mb temperatures around -25 to -28C, will be over our area
on Saturday. Strong N winds of 25 mph gusting to 40 mph will put
wind chills into the advisory criteria between -15F and -20F
starting Saturday morning across the northern CWA. Those bitterly
cold wind chills appear likely all the way through mid-morning on
Sunday. Temperatures on Sunday will warm slightly, but still remain
well below normal in the teens to around 20. Washington`s
Birthday/Monday looks to be much warmer with highs into the low to
mid 30s as a storm system approaches southern Illinois. Some
indications are for a period of rain or snow in portions of central
IL, with a band of measurable snow possible. The track of that
system has shifted farther south in the 12z GFS, keeping light snow
confined to areas south of I-72, but the ECMWF still has the effects
of the storm reaching well into IL with rain/snow south and snow
north. Will keep chance PoPs across the entire area Monday night for
now. Beyond that, there are indications of yet another push of cold
air for late Tuesday and Tuesday night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1155 AM CST TUE FEB 10 2015
MVFR clouds with bases of 1.3-2k ft have scattered out at CMI and
DEC during the morning and will scatter out at BMI and SPI between
19Z-21Z and at PIA 21Z-23Z. Broken mid level clouds 10-12k ft over
IA will arrive at PIA around 00Z and along I-55 at 01-02Z and CMI and
DEC at 02-04Z. 1010 mb low pressure along the eastern ND/SD border
to track east to A cold front to track into western Lake Superior
by dawn Wed and then push a cold front east to the IL river early
Wed morning and through DEC/CMI by late Wed morning. MVFR clouds
to occur along and behind this front while light precipitation
stays north of central IL. ESE winds less than 10 kts to become south
tonight and then brisk WNW 10-15 kts with gusts 15-20 kts after
15Z Wed behind cold front.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Shimon
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1203 PM CST TUE FEB 10 2015
.SHORT TERM...
259 AM CST
THROUGH WEDNESDAY...
SFC RIDGE HAS PUSHED OVER THE REGION...HOWEVER WITH THE LACK OF
STRONG MIXING...A NARROW CHANNEL OF LAKE EFFECT CLOUDS/STRATUS
CONTINUES TO STRETCH SOUTH/SOUTHWEST ACROSS THE LAKE INTO
NORTHEAST IL. THE SOUTHERN PORTIONS OF THE LAKE STRATUS IS
BEGINNING TO THIN...HOWEVER EXPECT THIS FEATURE TO REMAIN THRU
DAYBREAK AND SLOWLY SLIDE NORTHWEST BY MID-MORNING. CLEAR SKIES
CONTINUE FOR OUR WESTERN CWFA WHERE THE LAKE STRATUS HAS NOT
INVADED...WHICH HAS ALLOWED AN IDEAL SCENARIO OF LIGHT WINDS AND
EFFICIENT RADIATIVE PROCESSES TO TAKE PLACE. SFC OBS WILL LIKELY
DIP TO ARND ZERO TO POSSIBLY A FEW DEGREES BELOW ZERO IN THE
TRADITIONAL COLD SPOTS BEFORE DAYBREAK. ELSEWHERE TEMPS HAD
DROPPED...HOWEVER WITH THE CLOUD DECK PIVOTING WEST/NORTHWEST
TEMPS HAVE COME BACK UP A COUPLE OF DEGREES. LLVL FLOW HAS ALREADY
TURNED EASTERLY/SOUTHEASTERLY ACROSS CENTRAL IOWA INTO SOUTHERN
IL.
WITH THE ANTI-CYCLONIC FEATURE SLOWLY PUSHING EAST TODAY...LLVL FLOW
WILL INCREASE FROM THE EAST/SOUTHEAST ALLOWING A STEADY CONVEYOR OF
DRIER AIR TO PUSH ACROSS THE FORECAST AREA. THIS WILL LIKELY DELAY
SATURATION IN ADVANCE OF THE NEXT SYSTEM...WHICH IS POISED TO ARRIVE
EARLY THIS EVENING. WARM AIR ADVECTION WILL NUDGE TEMPS UP THIS AFTN
TO ARND 30-35 DEG RANGE. THE BEST FORCING FROM THE SHORTWAVE LOOKS
TO BE CONFINED TO WISC...HOWEVER SOME FORCING WILL EXTEND SOUTH INTO
THE NORTHERN PORTIONS OF THE FORECAST AREA. SOUNDINGS SUGGEST A
LINGERING THERMAL INVERSION THIS EVENING...WHICH COULD ALLOW FOR
SOME PARTIAL MELTING OF DENDRITES OR POSSIBLY A SNOW/SLEET MIX. ANY
ACCUMULATIONS WOULD BE LOCATED ALONG THE IL/WISC STATELINE. BUT A
QUICK HALF INCH IS POSSIBLE BEFORE THE VORT LIFTS NORTHEAST EARLY
WED.
THE TRAILING FRONTAL BOUNDARY IS PROGGED TO HOLD OFF UNTIL DAYBREAK
WED...WHICH COULD ALLOW TEMPS PRIOR TO DAYBREAK TO WARM A FEW
DEGREES INTO THE LOW 30S. THEN MUCH COLDER AIR WILL ADVECT SOUTHEAST
ACROSS THE CWFA...ALLOWING TEMPS TO STEADILY COOL THROUGHOUT THE
DAY. BY EARLY WED AFTN TEMPS WILL MAINLY BE IN THE MID/UPR 20S
ACROSS THE WEST/NORTH CWFA AND STILL IN THE LOW 30S FOR THE
SOUTHEAST FORECAST AREA.
A DRY WEDGE IS PROGGED TO ARRIVE WED...AND SHOULD BRING A TEMPORARY
LULL IN ANY LGT SNOW/FLURRIES FOR THE CWFA WED AFTN. THEN THE 500MB
VORT QUICKLY SLIDES SOUTH FROM CANADA INTO THE UPPER MIDWEST...AND
WILL ARRIVE OVER THE CWFA WED NGT. ROBUST THERMAL TROUGH AT 850MB
BRINGS TEMPS DOWN TO -20 TO -24 DEG C LATE WED NGT. LOWERED TEMPS
WED NGT A FEW DEGREES INTO THE SINGLE DIGITS ABOVE ZERO...HOWEVER
THIS MAY NEED TO BE LOWERED FURTHER GIVEN THE STRENGTH OF THE COLD
AIR ADVECTION.
LAKE EFFECT MACHINE WILL BE STARTING TO KICK-IN LATE WED
NGT...HOWEVER WITH A MORE NORTHWEST FLOW THIS WILL LIKELY KEEP THE
BULK OF THE ACTIVITY EAST OF PORTER COUNTY INDIANA.
BEACHLER
&&
.LONG TERM...
259 AM CST
THURSDAY THROUGH MONDAY...
STRONG ARCTIC HIGH PRESSURE ARRIVES THUR ACROSS THE UPPER
MIDWEST/MID-MISSOURI VALLEY...WITH A TIGHT PRESSURE GRADIENT
REMAINING OVER THE FORECAST AREA THUR. THIS WILL ALLOW WINDS TO TURN
MORE NORTHERLY...ALLOWING A LONG FETCH SETUP FOR LAKE EFFECT SNOW TO
PUSH WEST INTO LAKE/PORTER COUNTIES INDIANA AND POSSIBLY INTO
NEWTON/JASPER COUNTIES AS WELL. FURTHER WEST SKIES SHUD THIN...WITH
P-CLOUDY TO POSSIBLY SUNNY SKIES BY MID AFTN THUR. THE POTENT
THERMAL TROUGH WILL REMAIN OVERHEAD...WITH SFC TEMPS STRUGGLING TO
WARM BEYOND THE SINGLE DIGITS ABOVE ZERO. WHERE THE LAKE CLOUDS/SNOW
WILL BE TEMPS WILL BE IN THE LOW TEENS. SOUNDINGS SUGGEST UP TO
100J/KG OF CAPE OVER THE LAKE MAY DEVELOP THUR...SO CONDITIONS WILL
BE FAVORABLE FOR A POTENT LES BAND TO DEVELOP. ACCUMULATIONS WILL BE
POSSIBLE FOR NORTHWEST IN...BUT THE LOCATIONS WILL BE DICTATED BY
THE WIND DIRECTION.
WINDS WILL BEGIN TO RELAX AS THE SFC RIDGE SLIDES EAST OVER THE
REGION...AND YET ANOTHER CLIPPER ARRIVES FRI. TEMPS THUR NGT WILL
HINGE ON CLOUD COVER. CURRENT SOLUTIONS SUGGEST MOST OF THE AREA
WILL OBSERVE TEMPS AROUND ZERO TO A FEW DEGREES BELOW ZERO. WINDS
WILL KEEP WIND CHILLS IN THE -15 TO -20 DEG RANGE THUR EVE...BUT
SHOULD WEAKEN DURING THE OVERNIGHT HOURS.
FAST NORTHWEST FLOW WILL CONTINUE THE ACTIVE THEME...AS ANOTHER
SHORTWAVE SLIDES ACROSS THE UPPER MIDWEST FRI. THE NEXT WAVE WILL
LIKELY ARRIVE WITH THICKENING CLOUDS AND POSSIBLY LGT SNOW FRI. COOL
AIR REMAINS WITH HIGHS FRI IN THE TEENS/LOW 20S.
SATURDAY THROUGH EARLY NEXT WEEK...
THE AMPLIFIED RIDGING ACROSS WESTERN CANADA/CONUS WILL WEAKEN
MARGINALLY HEADING INTO THE WEEKEND AND NUDGE EAST. THIS SHOULD HELP
TO KICK THE POTENT THERMAL TROUGH EAST OF THE FORECAST
AREA...HOWEVER THE LONGWAVE PATTERN CONTINUES TO POINT TOWARDS A
REDEVELOPMENT TO THE HIGH AMPLITUDE RIDGE OVER EASTERN ALASKA EARLY
NEXT WEEK. WHILE A PERIOD OR TWO COULD REMAIN DRY...IT IS LIKELY
THAT A FEW CLIPPERS WILL BREAK SOUTHEAST FROM CENTRAL CANADA AND
PIVOT OVER THE GREAT LAKES...PRODUCING SOME LGT SNOW.
TEMPS WILL CONTINUE TO BE ON THE COOL SIDE WITH HIGHS IN THE TEENS
TO LOW 20S...HOWEVER HEADING INTO EARLY NEXT WEEK THE MID-LVL RIDGE
MAY BRIEFLY TRANSITION TOWARDS QUASI-ZONAL AND OFFER BREAK WITH
TEMPS APPROACHING 30 DEGREES EARLY NEXT WEEK. UNFORTUNATELY THIS
BRIEF MODERATION ONLY LOOKS TEMPORARY AS COLD AIR WILL RETURN BY THE
MIDDLE OF NEXT WEEK.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CHANCE OF LIGHT SNOW AND...POSSIBLY...ICE PELLETS LATE THIS
EVENING.
* CHANCE OF LIGHT FREEZING DRIZZLE LATE TONIGHT.
* MVFR CIGS LATE TONIGHT INTO WEDNESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN FORECAST CONCERNS FOCUS ON WIND DIRECTION TRENDS THROUGH THE
PERIOD AS WELL AS POTENTIAL FOR A COUPLE PERIODS OF WINTRY PCPN
OVERNIGHT. THE MAIN SYSTEM RESPONSIBLE IS A WEAK CLIPPER TYPE
SYSTEM CURRENTLY TRACKING ACROSS THE UPPER MISSISSIPPI VALLEY.
SKIES HAVE IMPROVE TO VFR FOLLOWING THE EROSION OF THE ST
DECK...BUT LATEST SATELLITE TRENDS INDICATE THAT INCREASING MID
AND HIGH CLOUD SHOULD BEGIN TO OVERSPREAD THE AREA LATE THIS
AFTERNOON. AS THE CLIPPER APPROACHES THE REGION...WINDS WILL
GRADUALLY VEER FROM GENERALLY ELY TO SELY LATE THIS
AFTERNOON...BUT WITH A WEAK GRADIENT IN PLACE...WIND SPEEDS WILL
BE LIGHT AND DIRECTION SHOULD BE SOMEWHAT VARIABLE...WITH SPEEDS
AT OR UNDER 8KT. WINDS SHOULD THEN CONTINUE TO VEER THROUGH SLY
LATE THIS EVENING TO SWLY BY TOMORROW MORNING.
THE BIGGER CONCERN WILL BE THE CHANCES FOR PCPN AT THE TERMINAL.
LATEST RADAR TRENDS SHOW A NARROW BAND OF PCPN MOVING THROUGH ERN
IOWA THIS AFTERNOON...WITH THE LATEST HIGH RES MODEL GUIDANCE
SUGGESTING THAT PCPN COULD REACH THE RFD AREA BY ARND
02-03Z...WHICH IS A FEW HOURS SLOWER THAN PREVIOUS THINKING. THE
RH AND TEMPERATURE PROFILES ARE A BIT TRICKY IN DETERMINING PCPN
TYPE AS THERE IS A WEDGE OF WARMER AIR ALOFT WITH TEMPS ABOVE 0C
WITH A FREEZING LAYER ABOVE AND NEAR THE SURFACE. THIS TYPE OF
THERMAL AND MOISTURE PROFILE IS SIMILAR FROM WEST TO EAST...WITH
THE MAIN ISSUE AS THE SYSTEM CROSSES THE REGION BEING THE TRACK OF
THE STRONGEST MID LEVEL FORCING...WHICH IN TURN WOULD TRANSLATE
INTO THE GREATER CHANCES FOR PCPN REACHING THE SURFACE. THE LATEST
GUIDANCE SUGGESTS THAT THE STRONGEST FORCING WILL BE OVER THE
NORTHERN TIER COUNTIES OF IL...WITH RFD BEING THE TERMINAL WITH
THE GREATEST CHANCE TO SEE PCPN. CONSIDERING THE THERMAL PROFILE
AND FORCING...PCPN COULD BE A SNOW/SLEET MIX. AS THE SYSTEM TRACKS
EWD...THE MID LEVEL FORCING SHOULD WEAKEN AND TREND NORTH OF THE
CHICAGO AREA TERMINALS. WILL CONTINUE WITH THE PROB30 GROUP FOR
3SM -SN FOR NOW...BUT CONFIDENCE IS LOW...WITH PROBABLY EQUAL
CHANCES THAT ANY PCPN WOULD REMAIN NORTH OF THE TERMINALS...OR
THERE COULD BE A BRIEF PERIOD OF A SNOW/SLEET MIX.
AFTER MIDNIGHT...THE SNOW/SLEET POTENTIAL WILL COME TO AN END WITH
DRIER AIR OVERSPREADING THE AREA ABOVE ARND 8KFT...WITH A
SATURATED LAYER BELOW. WITH LITTLE FORCING ALOFT AND DRY
AIR...THERE WILL LITTLE OPPORTUNITY FOR ICE PRODUCTION ALOFT...SO
SOME LIGHT FREEZING DRIZZLE WILL BE POSSIBLE FOR THE EARLY MORNING
HOURS. THIS IS ALSO A LOW CONFIDENCE FORECAST DEPENDING ON HOW
QUICKLY DEEP LAYER DRY AIR MOVES OVER THE REGION...WHICH WOULD
LIMIT THE DURATION OF ANY FZDZ.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
* LOW FOR LIGHT SNOW/ICE PELLETS THIS EVENING...AND POSSIBLE
TIMING.
* LOW FOR FREEZING DRIZZLE FOR LATE TONIGHT.
* MEDIUM TO HIGH FOR MVFR CIGS LATE TONIGHT INTO WEDNESDAY
MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...CHANCE OF SNOW. MVFR POSSIBLE. STRONG/GUSTY
NORTHWEST WINDS.
* THURSDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. STRONG/GUSTY
NORTHWEST WINDS.
* FRIDAY...SLIGHT CHANCE OF SNOW. MVFR POSSIBLE. WEST/SOUTHWEST
WINDS.
* SATURDAY...CHANCE OF FLURRIES. MVFR POSSIBLE. VERY STRONG/GUSTY
NORTHWEST WINDS.
* SUNDAY...DRY/VFR. WEST/SOUTHWEST WINDS.
* MONDAY...MVFR POSSIBLE. SOUTHWEST WINDS.
&&
.MARINE...
321 AM...ACTIVE PATTERN WILL CONTINUE THROUGH THIS WEEKEND WITH A
PERIOD OF GALES AND HEAVY FREEZING SPRAY WEDNESDAY NIGHT INTO
THURSDAY AND AGAIN FRIDAY NIGHT INTO SATURDAY.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST. LOW PRESSURE OVER
THE DAKOTAS WILL MOVE EAST ACROSS THE NORTHERN LAKES WEDNESDAY
WITH A TRAILING COLD FRONT MOVING ACROSS THE LAKE BY EARLY WED
AFTERNOON. STRONG HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN
LAKES AND UPPER MIDWEST THEN SLIDE SOUTH OF THE LAKES REGION ON
THURSDAY. THE TIGHT GRADIENT COMBINED WITH VERY COLD AIR SPREADING
OVER THE REGION WILL ALLOW GALES TO DEVELOP EITHER LATE WEDNESDAY
AFTERNOON OR EARLY WEDNESDAY EVENING. HOISTED BOTH A GALE WATCH
AND HEAVY FREEZING SPRAY WATCH FOR THIS FIRST EVENT.
ANOTHER LOW WILL MOVE FROM ONTARIO FRIDAY TO THE MID ATLANTIC ON
SATURDAY AS IT DEEPENS SLIGHTLY. AT THE SAME TIME ANOTHER VERY
STRONG ARCTIC HIGH WILL BUILD ACROSS THE NORTHERN PLAINS SATURDAY
AND THEN THE WESTERN LAKES SATURDAY NIGHT. THE COMBINED TIGHT
GRADIENT AND ANOTHER BLAST OF EVEN COLDER AIR WILL LIKELY PUSH
GALES INTO THE MID 40KT RANGE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 3 PM THURSDAY.
HEAVY FREEZING SPRAY WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-
LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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
NATIONAL WEATHER SERVICE LINCOLN IL
1156 AM CST Tue Feb 10 2015
.UPDATE...
ISSUED AT 1045 AM CST TUE FEB 10 2015
Updated forecast during mid morning to address the sky cover today.
Low clouds around 1500 ft were clearing quicker over eastern IL
with clearing just east of DEC airport at 1030 am. Low clouds were
also spreading back to the nw across the IL river valley and
currently approaching Galesburg as flow was becoming se nw of IL
river with GBG having se wind 12G16 mph. HRRR model is handling
the coverage of low clouds really well this morning and used it
for afternoon cloud cover trends. HRRR model continues to show low
clouds decreasing from the east, while overspreading rest of Knox
county late this morning, with low clouds lingering through the
afternoon over IL river valley especially from PIA/IL river nw.
Highs in the mid 30s central IL and upper 30s in southeast IL
looks on track this afternoon with lower 30s nw of IL river where
low clouds linger much of the day. Winds to become ese 5-10 mph
this afternoon. 1035 mb Canadian high pressure over ne Ontario was
ridging southward into IL late this morning. Ridge axis to drift
east into the Ohio river valley this evening while a weak 1010 mb
surface low along the ND/SD border tracks east to near the WI/MN
border by midnight tonight. This system to keep the brunt of its
mixed precipitation north of I-88 this afternoon and tonight.
&&
.SHORT TERM...(Today)
ISSUED AT 251 AM CST TUE FEB 10 2015
High pressure ridge just to the northwest of the area will shift
east, through the CWA today. Low level clouds east of the ridge
continue to follow the flow around the high and based on satellite
trends is moving west and southwest early this morning. This, plus
the clear skies across most of Indiana, makes for a complicated
cloud forecast for the day. Believe clouds will hang around most of
the area east of the Illinois river, with mostly clear skies
northwest of the river. Based on timing tools, looks like the
clearing in Ind will move into eastern parts of the CWA first and
then slowly move west into the central part of the state, through
still remaining east of Decatur and Bloomington through about noon.
The clouds could diminish some as well, but this more difficult to
forecast given the strong high pressure. Believe clearing of the
rest of the CWA will occur quickly during the afternoon hours. So,
overall, looking at a partly to mostly sunny sky across the area
today. Winds will be on the light side and variable as the ridge
moves across the area. Temps should be warmer and more around
normal, in the mid to upper 30s.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 251 AM CST TUE FEB 10 2015
The main issue for the bulk of the forecast continues to be with the
temperatures. Trough axis currently across the Northwest Territories
of Canada still progged to quickly drop southeast today and sharpen
into a deep trough as a ridge axis builds along the West Coast. The
leading cold front will be passing through the forecast area
Wednesday, although highs in the 30s and 40s will be common.
However, the core of the cold air will begin to arrive during the
evening with the deep trough. 850 mb temperatures dip down to around
-20C early Thursday before the trough quickly shifts east, resulting
in high temperatures in the teens most areas, except lower 20s south
of I-70. Blustery northwest winds likely will gust to over 30 mph at
times, keeping wind chills below zero much of the day.
Stronger surge of cold air will be plunging across the Midwest late
Friday night and Saturday, as a deep closed low drops into the Great
Lakes region. The coldest air, with 850 mb temperatures around -25
to -26C, will be over our area on Saturday, with the GFS and ECMWF
both spreading this Arctic air mass over a large part of the eastern
U.S. (-20C at 850 mb as far southeast as Charleston SC by Sunday
morning). Have lowered high temperatures a couple degrees for
Saturday, with 10-15 degrees common north of I-70, although this may
be a bit conservative. With another day of northwest winds gusting
over 30 mph, persisting into Saturday evening, wind chills will be
close to advisory levels across the northern CWA. Temperatures
Sunday will be about 10 degrees warmer, but still below freezing.
Some respite on tap for Monday, although model trends in the longer
ranges suggest another surge of Arctic air arriving toward the
middle of next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1155 AM CST TUE FEB 10 2015
MVFR clouds with bases of 1.3-2k ft have scattered out at CMI and
DEC during the morning and will scatter out at BMI and SPI between
19Z-21Z and at PIA 21Z-23Z. Broken mid level clouds 10-12k ft over
IA will arrive at PIA around 00Z and along I-55 at 01-02Z and CMI and
DEC at 02-04Z. 1010 mb low pressure along the eastern ND/SD border
to track east to A cold front to track into western Lake Superior
by dawn Wed and then push a cold front east to the IL river early
Wed morning and through DEC/CMI by late Wed morning. MVFR clouds
to occur along and behind this front while light precipitation
stays north of central IL. ESE winds less than 10 kts to become south
tonight and then brisk WNW 10-15 kts with gusts 15-20 kts after
15Z Wed behind cold front.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Auten
LONG TERM...Geelhart
AVIATION...07
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
238 PM EST TUE FEB 10 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1011 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL BRING DRY WEATHER TO THE AREA TODAY AND HIGHS
NEAR NORMAL TODAY AND SLIGHT ABOVE NORMAL WEDNESDAY. HOWEVER AN
ARCTIC FRONT WILL MOVE THROUGH THE AREA WEDNESDAY AFTERNOON AND
EVENING AND BRING SOME CHANCES FOR MIXED PRECIPITATION AND THEN
SNOW WEDNESDAY NIGHT AND THURSDAY ALONG WITH MUCH COLDER AIR.
UPPER TROUGHING WILL KEEP COLDER THAN NORMAL TEMPERATURES IN PLACE
THROUGH AT LEAST THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1011 AM EST TUE FEB 10 2015
WESTERN HALF OF THE FORECAST AREA ENJOYING MOSTLY SUNNY SKIES THIS
MORNING WHILE EASTERN COUNTIES REMAIN UNDER STRATUS. CHILLY START
WITH TEMPS RANGING FROM THE HIGH TEENS INTO THE 20S AT 15Z.
FEW CHANGES NECESSARY FOR MORNING UPDATE FOCUSED ON CLOUD COVER
AND IMPACTS TO AFTERNOON HIGHS. STRATUS DECK HAS EXPANDED WESTWARD
ACROSS EASTERN COUNTIES SO FAR THIS MORNING. RAP SHOWING LOW LEVEL
FLOW WILL REMAIN EASTERLY AT LEAST FOR THE NEXT FEW HOURS BEFORE
GRADUALLY VEERING TO THE SOUTHEAST BY AFTERNOON. THE EASTERLY FLOW
SHOULD ENABLE SOME ADDITIONAL WESTWARD EXPANSION TO THE
DECK...POSSIBLY INTO THE INDY METRO BEFORE THE DECK BEGINS TO MIX
OUT AND SHIFT NORTH. HAVE BUMPED UP CLOUD COVER EXTENSIVELY OVER
THE EASTERN COUNTIES INTO THE AFTERNOON...WITH POTENTIAL FOR SKIES
TO REMAIN CLOUDY FOR MUCH OF THE DAY OVER DELAWARE AND RANDOLPH
COUNTIES.
HAVE PULLED HIGHS DOWN AS MUCH AS 5 DEGREES IN THE NORTHEAST WITH
THE EXPECTED CLOUDS...ANTICIPATE PORTIONS OF DELAWARE AND RANDOLPH
COUNTIES MAY NOT GET MUCH WARMER THAN 26 OR 27. REST UNCHANGED...
PREVIOUS DISCUSSION FOLLOWS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 343 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL SHIFT EAST DURING THE NIGHT TONIGHT AND ALLOW FOR
INCREASING CLOUD COVER AND WARM ADVECTION. A FRONTAL SYSTEM WILL
BEGIN TO APPROACH FROM THE WEST BUT THE FORCING FROM THIS SHOULD
REMAIN UPSTREAM OF THE AREA UNTIL DAYTIME ON WEDNESDAY SO SHOULD
REMAIN DRY THROUGH TONIGHT. WEDNESDAY MORNING FRONTOGENESIS REMAINS
WELL WEST OR NORTHWEST OF THE AREA...HOWEVER THERE IS SOME
INDICATION OF ISENTROPIC LIFT AND SATURATION SHOWING UP ACROSS THE
EASTERN COUNTIES IN BOTH THE NAM AND THE ECMWF. THIS COULD BE AN
INDICATION OF JUST ENOUGH LIFT TO PRODUCE SOME LIGHT SHOWERS THERE
SO WILL ADD A SLIGHT CHANCE AT THIS TIME. TEMPERATURE PROFILES
INDICATE THE WARMING ALOFT WILL OUTPACE THAT AT THE SURFACE SO COULD
SEE A FEW HOURS OF SLEET OR SNOW BEFORE THE COLUMN WARMS ENOUGH FOR
RAIN. A COLD FRONT SHOULD MOVE INTO THE AREA DURING THE
AFTERNOON/EVENING AND THUS MUCH OF THE AREA WILL HAVE A SLIGHT
CHANCE FOR SOME PRECIP...WITH WARM ENOUGH TEMPERATURES TO START AS
RAIN IN THE AFTERNOON AND CHANGE TO A MIX OR ALL SNOW IN THE
EVENING.
WEDNESDAY NIGHT HAS THE BEST FORCING OF THE SHORT
TERM...WITH UPPER FORCING COMBINING WITH THE FRONT STILL IN THE
AREA. THERE IS LITTLE MOISTURE TO WORK WITH SO DON/T EXPECT MUCH IN
THE WAY OF ACCUMULATION BUT THINK THE FORCING LOOKS STRONG ENOUGH TO
PRODUCE A COUPLE TENTHS OF AN INCH AND RAISED POPS FROM CONSENSUS
DURING THIS TIME.
THURSDAY HIGH PRESSURE BEGINS TO BUILD BACK IN AND THE FLOW DURING
THIS TIME COULD BE CONDUCIVE FOR SOME LAKE EFFECT. CONTINUED TO
CARRY LOW CHANCES FOR SNOW ACROSS ALL BUT THE WESTERN COUNTIES
THROUGH THE DAY. THURSDAY NIGHT CONTINUED WITH A CHANCE FOR FLURRIES
IN THE NORTHEAST FOR A FEW HOURS WITH THE LAKE FETCH STILL CONDUCIVE
TO PRODUCING A FEW FLAKES IN THAT AREA.
FOR TEMPERATURES GENERALLY STUCK NEAR A CONSENSUS THROUGH WEDNESDAY.
WENT CLOSER TO THE COLDER END OF THE SOLUTION ENVELOPE FOR WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WITH STRONG COLD ADVECTION BEHIND THE
ARCTIC FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 223 PM EST TUE FEB 10 2015
A STRONG COLD FRONT IS SET TO MOVE INTO THE GREAT LAKES AND OHIO
VALLEY ON FRIDAY NIGHT INTO SATURDAY AS THE GFS AND ECMWF BOTH
SUGGEST A DEEP UPPER LOW SINKING OUT OF NORTHERN CANADA BEFORE
DIPPING INTO THE OHIO VALLEY. STRONG DYNAMICS AND VERY COLD AIR IS
EXPECTED IN THE WAKE OF THIS SYSTEM. AHEAD OF THE SYSTEM
PERSISTENT DRY AIR AMID THE NW FLOW IS EXPECTED TO LIMIT
PRECIPITATION CHANCES. ECMWF 850MB TEMPS FALL TO -22C BY SUNDAY
MORNING...BRINGING SOME OF THE COLDEST AIR OF THE SEASON TO
CENTRAL INDIANA.
FORTUNATELY IT APPEARS THE COLD AIR WILL DEPART QUICKLY TO THE EAST
AS THE STRONG LOW PULLS EAST OFF THE COAST AND RIDGING ASSOCIATED
WITH THE ARCTIC HIGH BUILDS ACROSS THE REGION...PROVIDING DRY
WEATHER SUNDAY AND INTO MONDAY. A WARM FRONT WILL THEN APPROACH
THE AREA ON MONDAY NIGHT AND INTO TUESDAY. THUS WILL INCLUDE
CHANCES FOR A PRECIP AT THAT TIME.
&&
.AVIATION /DISCUSSION FOR THE 101800Z TAFS/...
ISSUED AT 1200 PM EST TUE FEB 10 2015
VFR CONDITIONS AREA EXPECTED TO CONTINUE THIS TAF PERIOD AS A
RIDGE OF HIGH PRESSURE IN PLACE OVER INDIANA AND ILLINOIS WILL
SLOWLY PROGRESS EASTWARD.
A WARM FRONT IS EXPECTED TO PUSH ACROSS THE STATE OVERNIGHT AND
TIME HEIGHTS AND FORECAST SOUNDINGS INDICATE SOME UPPER LEVEL
SATURATION. THUS WILL EXPECT SOME ALTOCU CIGS TO PASS OVERNIGHT
WITH THIS FEATURE.
CIGS WILL TREND TO MVFR AFTER 18Z WEDNESDAY AS A QUICK MOVING COLD
FRONT PASSES ACROSS THE AREA FROM THE NORTHWEST AND COLD AIR
ADVECTION RESUMES WITH TRAPPED STRATOCU.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP/RYAN
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1208 PM EST TUE FEB 10 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1011 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL BRING DRY WEATHER TO THE AREA TODAY AND HIGHS
NEAR NORMAL TODAY AND SLIGHT ABOVE NORMAL WEDNESDAY. HOWEVER AN
ARCTIC FRONT WILL MOVE THROUGH THE AREA WEDNESDAY AFTERNOON AND
EVENING AND BRING SOME CHANCES FOR MIXED PRECIPITATION AND THEN
SNOW WEDNESDAY NIGHT AND THURSDAY ALONG WITH MUCH COLDER AIR.
UPPER TROUGHING WILL KEEP COLDER THAN NORMAL TEMPERATURES IN PLACE
THROUGH AT LEAST THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1011 AM EST TUE FEB 10 2015
WESTERN HALF OF THE FORECAST AREA ENJOYING MOSTLY SUNNY SKIES THIS
MORNING WHILE EASTERN COUNTIES REMAIN UNDER STRATUS. CHILLY START
WITH TEMPS RANGING FROM THE HIGH TEENS INTO THE 20S AT 15Z.
FEW CHANGES NECESSARY FOR MORNING UPDATE FOCUSED ON CLOUD COVER
AND IMPACTS TO AFTERNOON HIGHS. STRATUS DECK HAS EXPANDED WESTWARD
ACROSS EASTERN COUNTIES SO FAR THIS MORNING. RAP SHOWING LOW LEVEL
FLOW WILL REMAIN EASTERLY AT LEAST FOR THE NEXT FEW HOURS BEFORE
GRADUALLY VEERING TO THE SOUTHEAST BY AFTERNOON. THE EASTERLY FLOW
SHOULD ENABLE SOME ADDITIONAL WESTWARD EXPANSION TO THE
DECK...POSSIBLY INTO THE INDY METRO BEFORE THE DECK BEGINS TO MIX
OUT AND SHIFT NORTH. HAVE BUMPED UP CLOUD COVER EXTENSIVELY OVER
THE EASTERN COUNTIES INTO THE AFTERNOON...WITH POTENTIAL FOR SKIES
TO REMAIN CLOUDY FOR MUCH OF THE DAY OVER DELAWARE AND RANDOLPH
COUNTIES.
HAVE PULLED HIGHS DOWN AS MUCH AS 5 DEGREES IN THE NORTHEAST WITH
THE EXPECTED CLOUDS...ANTICIPATE PORTIONS OF DELAWARE AND RANDOLPH
COUNTIES MAY NOT GET MUCH WARMER THAN 26 OR 27. REST UNCHANGED...
PREVIOUS DISCUSSION FOLLOWS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 343 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL SHIFT EAST DURING THE NIGHT TONIGHT AND ALLOW FOR
INCREASING CLOUD COVER AND WARM ADVECTION. A FRONTAL SYSTEM WILL
BEGIN TO APPROACH FROM THE WEST BUT THE FORCING FROM THIS SHOULD
REMAIN UPSTREAM OF THE AREA UNTIL DAYTIME ON WEDNESDAY SO SHOULD
REMAIN DRY THROUGH TONIGHT. WEDNESDAY MORNING FRONTOGENESIS REMAINS
WELL WEST OR NORTHWEST OF THE AREA...HOWEVER THERE IS SOME
INDICATION OF ISENTROPIC LIFT AND SATURATION SHOWING UP ACROSS THE
EASTERN COUNTIES IN BOTH THE NAM AND THE ECMWF. THIS COULD BE AN
INDICATION OF JUST ENOUGH LIFT TO PRODUCE SOME LIGHT SHOWERS THERE
SO WILL ADD A SLIGHT CHANCE AT THIS TIME. TEMPERATURE PROFILES
INDICATE THE WARMING ALOFT WILL OUTPACE THAT AT THE SURFACE SO COULD
SEE A FEW HOURS OF SLEET OR SNOW BEFORE THE COLUMN WARMS ENOUGH FOR
RAIN. A COLD FRONT SHOULD MOVE INTO THE AREA DURING THE
AFTERNOON/EVENING AND THUS MUCH OF THE AREA WILL HAVE A SLIGHT
CHANCE FOR SOME PRECIP...WITH WARM ENOUGH TEMPERATURES TO START AS
RAIN IN THE AFTERNOON AND CHANGE TO A MIX OR ALL SNOW IN THE
EVENING.
WEDNESDAY NIGHT HAS THE BEST FORCING OF THE SHORT
TERM...WITH UPPER FORCING COMBINING WITH THE FRONT STILL IN THE
AREA. THERE IS LITTLE MOISTURE TO WORK WITH SO DON/T EXPECT MUCH IN
THE WAY OF ACCUMULATION BUT THINK THE FORCING LOOKS STRONG ENOUGH TO
PRODUCE A COUPLE TENTHS OF AN INCH AND RAISED POPS FROM CONSENSUS
DURING THIS TIME.
THURSDAY HIGH PRESSURE BEGINS TO BUILD BACK IN AND THE FLOW DURING
THIS TIME COULD BE CONDUCIVE FOR SOME LAKE EFFECT. CONTINUED TO
CARRY LOW CHANCES FOR SNOW ACROSS ALL BUT THE WESTERN COUNTIES
THROUGH THE DAY. THURSDAY NIGHT CONTINUED WITH A CHANCE FOR FLURRIES
IN THE NORTHEAST FOR A FEW HOURS WITH THE LAKE FETCH STILL CONDUCIVE
TO PRODUCING A FEW FLAKES IN THAT AREA.
FOR TEMPERATURES GENERALLY STUCK NEAR A CONSENSUS THROUGH WEDNESDAY.
WENT CLOSER TO THE COLDER END OF THE SOLUTION ENVELOPE FOR WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WITH STRONG COLD ADVECTION BEHIND THE
ARCTIC FRONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY NIGHT/...
ISSUED AT 343 AM EST TUE FEB 10 2015
ENSEMBLES ARE STILL VERY CONSISTENT WITH DEPICTING COLD FLOW ACROSS
THE GREAT LAKES AND OHIO VALLEY THROUGH THE MAJORITY OF THIS
PERIOD. ARCTIC AIR ASSOCIATED WITH THIS FLOW WILL CONTINUE TO
PROVIDE WELL BELOW NORMAL TEMPERATURES THROUGH AT LEAST EARLY NEXT
WEEK ALONG WITH VERY DRY AIR. A SHORT WAVE WILL PASS THROUGH THE
AREA FRIDAY THROUGH SATURDAY. THE PERSISTENT DRY AND COLD NORTHERLY
FLOW WILL NOT ALLOW MUCH MOISTURE TO BE IN THE AREA AND PRECIP IS
NOT EXPECTED AT THIS TIME AS THIS SYSTEM PASSES. HOWEVER...LAKE
EFFECT FLURRIES OR SNOW SHOWERS WILL BE POSSIBLE ACROSS THE
NORTHEAST PARTS OF THE FORECAST AREA DURING THE DAY SATURDAY.
THEN LATE IN THE PERIOD...MONDAY NIGHT INTO NEXT TUESDAY A SOUTHERN
STREAM SYSTEM APPEARS TO DEVELOP AND ORGANIZE OVER THE TN VALLEY AND
ALONG WITH SLIGHTLY WARMER FLOW TEMPERATURES WILL MODERATE BACK
TOWARD NORMAL FOR THIS TIME OF YEAR. ALSO CHANCES FOR PRECIP LOOK
MORE PROMISING WITH EITHER SNOW...OR POSSIBLY A MIX OF RAIN/SNOW
BEFORE THIS SYSTEM EXITS THE REGION BY TUESDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 101800Z TAFS/...
ISSUED AT 1200 PM EST TUE FEB 10 2015
VFR CONDITIONS AREA EXPECTED TO CONTINUE THIS TAF PERIOD AS A
RIDGE OF HIGH PRESSURE IN PLACE OVER INDIANA AND ILLINOIS WILL
SLOWLY PROGRESS EASTWARD.
A WARM FRONT IS EXPECTED TO PUSH ACROSS THE STATE OVERNIGHT AND
TIME HEIGHTS AND FORECAST SOUNDINGS INDICATE SOME UPPER LEVEL
SATURATION. THUS WILL EXPECT SOME ALTOCU CIGS TO PASS OVERNIGHT
WITH THIS FEATURE.
CIGS WILL TREND TO MVFR AFTER 18Z WEDNESDAY AS A QUICK MOVING COLD
FRONT PASSES ACROSS THE AREA FROM THE NORTHWEST AND COLD AIR
ADVECTION RESUMES WITH TRAPPED STRATOCU.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP/RYAN
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....SMF
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1011 AM EST TUE FEB 10 2015
.UPDATE...
THE SYNOPSIS AND NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1011 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL BRING DRY WEATHER TO THE AREA TODAY AND HIGHS
NEAR NORMAL TODAY AND SLIGHT ABOVE NORMAL WEDNESDAY. HOWEVER AN
ARCTIC FRONT WILL MOVE THROUGH THE AREA WEDNESDAY AFTERNOON AND
EVENING AND BRING SOME CHANCES FOR MIXED PRECIPITATION AND THEN
SNOW WEDNESDAY NIGHT AND THURSDAY ALONG WITH MUCH COLDER AIR.
UPPER TROUGHING WILL KEEP COLDER THAN NORMAL TEMPERATURES IN PLACE
THROUGH AT LEAST THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1011 AM EST TUE FEB 10 2015
WESTERN HALF OF THE FORECAST AREA ENJOYING MOSTLY SUNNY SKIES THIS
MORNING WHILE EASTERN COUNTIES REMAIN UNDER STRATUS. CHILLY START
WITH TEMPS RANGING FROM THE HIGH TEENS INTO THE 20S AT 15Z.
FEW CHANGES NECESSARY FOR MORNING UPDATE FOCUSED ON CLOUD COVER
AND IMPACTS TO AFTERNOON HIGHS. STRATUS DECK HAS EXPANDED WESTWARD
ACROSS EASTERN COUNTIES SO FAR THIS MORNING. RAP SHOWING LOW LEVEL
FLOW WILL REMAIN EASTERLY AT LEAST FOR THE NEXT FEW HOURS BEFORE
GRADUALLY VEERING TO THE SOUTHEAST BY AFTERNOON. THE EASTERLY FLOW
SHOULD ENABLE SOME ADDITIONAL WESTWARD EXPANSION TO THE
DECK...POSSIBLY INTO THE INDY METRO BEFORE THE DECK BEGINS TO MIX
OUT AND SHIFT NORTH. HAVE BUMPED UP CLOUD COVER EXTENSIVELY OVER
THE EASTERN COUNTIES INTO THE AFTERNOON...WITH POTENTIAL FOR SKIES
TO REMAIN CLOUDY FOR MUCH OF THE DAY OVER DELAWARE AND RANDOLPH
COUNTIES.
HAVE PULLED HIGHS DOWN AS MUCH AS 5 DEGREES IN THE NORTHEAST WITH
THE EXPECTED CLOUDS...ANTICIPATE PORTIONS OF DELAWARE AND RANDOLPH
COUNTIES MAY NOT GET MUCH WARMER THAN 26 OR 27. REST UNCHANGED...
PREVIOUS DISCUSSION FOLLOWS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 343 AM EST TUE FEB 10 2015
HIGH PRESSURE WILL SHIFT EAST DURING THE NIGHT TONIGHT AND ALLOW FOR
INCREASING CLOUD COVER AND WARM ADVECTION. A FRONTAL SYSTEM WILL
BEGIN TO APPROACH FROM THE WEST BUT THE FORCING FROM THIS SHOULD
REMAIN UPSTREAM OF THE AREA UNTIL DAYTIME ON WEDNESDAY SO SHOULD
REMAIN DRY THROUGH TONIGHT. WEDNESDAY MORNING FRONTOGENESIS REMAINS
WELL WEST OR NORTHWEST OF THE AREA...HOWEVER THERE IS SOME
INDICATION OF ISENTROPIC LIFT AND SATURATION SHOWING UP ACROSS THE
EASTERN COUNTIES IN BOTH THE NAM AND THE ECMWF. THIS COULD BE AN
INDICATION OF JUST ENOUGH LIFT TO PRODUCE SOME LIGHT SHOWERS THERE
SO WILL ADD A SLIGHT CHANCE AT THIS TIME. TEMPERATURE PROFILES
INDICATE THE WARMING ALOFT WILL OUTPACE THAT AT THE SURFACE SO COULD
SEE A FEW HOURS OF SLEET OR SNOW BEFORE THE COLUMN WARMS ENOUGH FOR
RAIN. A COLD FRONT SHOULD MOVE INTO THE AREA DURING THE
AFTERNOON/EVENING AND THUS MUCH OF THE AREA WILL HAVE A SLIGHT
CHANCE FOR SOME PRECIP...WITH WARM ENOUGH TEMPERATURES TO START AS
RAIN IN THE AFTERNOON AND CHANGE TO A MIX OR ALL SNOW IN THE
EVENING.
WEDNESDAY NIGHT HAS THE BEST FORCING OF THE SHORT
TERM...WITH UPPER FORCING COMBINING WITH THE FRONT STILL IN THE
AREA. THERE IS LITTLE MOISTURE TO WORK WITH SO DON/T EXPECT MUCH IN
THE WAY OF ACCUMULATION BUT THINK THE FORCING LOOKS STRONG ENOUGH TO
PRODUCE A COUPLE TENTHS OF AN INCH AND RAISED POPS FROM CONSENSUS
DURING THIS TIME.
THURSDAY HIGH PRESSURE BEGINS TO BUILD BACK IN AND THE FLOW DURING
THIS TIME COULD BE CONDUCIVE FOR SOME LAKE EFFECT. CONTINUED TO
CARRY LOW CHANCES FOR SNOW ACROSS ALL BUT THE WESTERN COUNTIES
THROUGH THE DAY. THURSDAY NIGHT CONTINUED WITH A CHANCE FOR FLURRIES
IN THE NORTHEAST FOR A FEW HOURS WITH THE LAKE FETCH STILL CONDUCIVE
TO PRODUCING A FEW FLAKES IN THAT AREA.
FOR TEMPERATURES GENERALLY STUCK NEAR A CONSENSUS THROUGH WEDNESDAY.
WENT CLOSER TO THE COLDER END OF THE SOLUTION ENVELOPE FOR WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WITH STRONG COLD ADVECTION BEHIND THE
ARCTIC FRONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY NIGHT/...
ISSUED AT 343 AM EST TUE FEB 10 2015
ENSEMBLES ARE STILL VERY CONSISTENT WITH DEPICTING COLD FLOW ACROSS
THE GREAT LAKES AND OHIO VALLEY THROUGH THE MAJORITY OF THIS
PERIOD. ARCTIC AIR ASSOCIATED WITH THIS FLOW WILL CONTINUE TO
PROVIDE WELL BELOW NORMAL TEMPERATURES THROUGH AT LEAST EARLY NEXT
WEEK ALONG WITH VERY DRY AIR. A SHORT WAVE WILL PASS THROUGH THE
AREA FRIDAY THROUGH SATURDAY. THE PERSISTENT DRY AND COLD NORTHERLY
FLOW WILL NOT ALLOW MUCH MOISTURE TO BE IN THE AREA AND PRECIP IS
NOT EXPECTED AT THIS TIME AS THIS SYSTEM PASSES. HOWEVER...LAKE
EFFECT FLURRIES OR SNOW SHOWERS WILL BE POSSIBLE ACROSS THE
NORTHEAST PARTS OF THE FORECAST AREA DURING THE DAY SATURDAY.
THEN LATE IN THE PERIOD...MONDAY NIGHT INTO NEXT TUESDAY A SOUTHERN
STREAM SYSTEM APPEARS TO DEVELOP AND ORGANIZE OVER THE TN VALLEY AND
ALONG WITH SLIGHTLY WARMER FLOW TEMPERATURES WILL MODERATE BACK
TOWARD NORMAL FOR THIS TIME OF YEAR. ALSO CHANCES FOR PRECIP LOOK
MORE PROMISING WITH EITHER SNOW...OR POSSIBLY A MIX OF RAIN/SNOW
BEFORE THIS SYSTEM EXITS THE REGION BY TUESDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 101500Z IND TAF UPDATE/...
VFR CONDITIONS ARE EXPECTED TO CONTINUE. HIGH PRESSURE OVER THE
GREAT LAKES AND RIDGING ALOFT ARE EXPECTED TO CONTINUE TO PROVIDE
SUBSIDENCE...RESULTING IN UNLIMITED CIGS. WILL WATCH IFR CLOUDS
NEAR MUNCIE CLOSELY. THESE CLOUDS MAY ADVECT FROM THE NORTHEAST
AND CLIP THE IND TAF SITE. PROGRESSION IS RATHER SLOW.
/DISCUSSION FOR THE 101200Z TAF ISSUANCE/...
ISSUED AT 604 AM EST TUE FEB 10 2015
LOW LEVEL CLOUDS HAVE SINCE SCATTERED OUT AND VFR CONDITIONS WITH
CLEAR TO MOSTLY CLEAR SKIES ARE THE PREVAILING FLIGHT CATEGORY
THIS MORNING AND WILL CONTINUE TO BE INTO EARLY THIS AFTERNOON.
WINDS WILL BE NORTHEAST/EASTERLY WITH SUSTAINED SPEEDS OF 5 TO 10
KTS. HOWEVER CLOUDS WILL BE ON THE INCREASE TONIGHT AS AN ARCTIC
FRONT IS EXPECTED TO MOVE THROUGH THE AREA WEDNESDAY AFTERNOON AND
EVENING. WINDS WILL BECOME SOUTHERLY WED MORNING AND SW/W AROUND
10-12 KT LATE WED AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP/RYAN
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1151 PM CST MON FEB 9 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
ISSUED AT 328 PM CST MON FEB 9 2015
MAIN CONCERNS ARE CLOUD COVER AND APPROACHING WAVE FROM THE WEST.
LOW STRATUS ERODING OVER THE NORTH MOMENTARILY BUT SHOULD BEGIN TO
FILL BACK IN AFTER SUNSET. THE HRRR SHOWS THE CURRENT SETUP QUITE
WELL WITH SOME THINNING OF THE CLOUD DECK OVER THE NORTH FOLLOWED
BY CLOUDS FILLING IN ONCE AGAIN. THE UPSTREAM SHORT WAVE OVER MT
WILL MOVE SOUTHEAST OVERNIGHT AND SHOULD BEGIN TO IMPACT THE
NORTHWEST WITH PRECIPITATION CHANCES BETWEEN 09-12Z. BUFR
SOUNDINGS OVER THE NORTHWEST SHOW LOWER LAYERS THICKENING TOWARD
MORNING WITH SOME LIFT INCREASING TOWARD 12Z. WILL MAINTAIN LIGHT
FREEZING DRIZZLE ACROSS THE NORTHWEST TRANSITIONING TO A CHANCE
FOR LIGHT FREEZING DRIZZLE OR LIGHT FREEZING RAIN/ICE PELLET MIX
BY 12Z. INITIALLY THERE IS NOT MUCH IN THE WAY OF ICE INTRODUCTION
WHICH WOULD FAVOR SOME LIGHT FREEZING DRIZZLE. TEMPERATURES
TONIGHT ARE CHALLENGING AS WELL. GUIDANCE DROPS VALUES INTO THE
TEENS NORTH TO LOWER TO MID 20S MOST AREAS. LAST NIGHT MOIST
BOUNDARY LAYER AND CLOUD COVER KEPT MINS IN THE LOWER 30S. THOUGH
NOT EXPECTING IT TO BE THAT WARM TONIGHT THERE SHOULD BE A DECENT
GRADIENT FROM EAST TO SOUTHWEST WITH UPPER TEENS EAST TO THE MID
TO UPPER 20S OVER THE SOUTHWEST WHERE CLOUDS WILL HOLD.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 328 PM CST MON FEB 9 2015
LITTLE HAS CHANGED IN OVERALL FORECAST THINKING FROM PREVIOUS
SHIFTS. A LOW PRESSURE SYSTEM WILL SPREAD PRECIPITATION ACROSS
MOST OF MINNESOTA ON TUESDAY...WITH LIGHT PRECIPITATION AFFECTING
NORTHERN IOWA...THEN PUSH A PRETTY STRONG COLD FRONT ACROSS IOWA
ON TUESDAY NIGHT AND WEDNESDAY MORNING. THE PRECIPITATION ACROSS
NORTHERN IOWA STILL LOOKS SPOTTY AND VERY LIGHT...WITH FORECAST
SOUNDINGS SHOWING CLOUD DEPTHS WAVERING BETWEEN ABOUT 3000 AND
8000 FEET AND MAINLY LOCATED BENEATH BOTH THE ICE INTRODUCTION
LAYER AND THE LIMITED FORCING ASSOCIATED WITH THE LOW PASSING BY
TO THE NORTH. THIS SUPPORTS MOSTLY A DRIZZLE/LIGHT RAIN SCENARIO
WITH TEMPERATURES NEAR OR A LITTLE BELOW FREEZING...LIKELY LEADING
TO SOME LIGHT ICE ACCUMULATIONS OF PERHAPS A FEW HUNDREDTHS OF AN
INCH. GIVEN THE RELATIVELY LOW CONFIDENCE IN ACCUMULATING
PRECIPITATION OCCURRING IN OUR AREA...WITH ONLY 40 TO 50 POPS IN
THE NORTH AND VERY LIGHT EXPECTED AMOUNTS...HAVE NOT ISSUED AN
ADVISORY AT THIS TIME. HOWEVER...THIS WILL BE CLOSELY MONITORED
TONIGHT AND TOMORROW AND ONE MAY YET BECOME WARRANTED IF THERE IS
A MORE CONSISTENT SIGNAL FOR MEANINGFUL ICE ACCUMULATION/IMPACTS.
THE LIGHT PRECIPITATION ACROSS THE NORTH WILL END ON TUESDAY
NIGHT...THEN THE AFOREMENTIONED COLD FRONT WILL SWEEP RAPIDLY
SOUTHEASTWARD ACROSS THE AREA. WINDS WILL SURGE SIGNIFICANTLY ON
WEDNESDAY MORNING...THEN AGAIN ON WEDNESDAY EVENING AS ONE LAST
500 MB IMPULSE ROUNDS THE TROUGH AND IS REFLECTED BY A TIGHTENING
SURFACE PRESSURE GRADIENT. FORECAST SOUNDINGS INDICATE WINDS AT
THE TOP OF THE MIXED LAYER APPROACHING 40 KNOTS AT TIMES AND THERE
IS AN INCREASING POSSIBILITY...ESPECIALLY GIVEN THE COLD AIR
ADVECTION AND EFFICIENT MIXING EXPECTED...THAT A WIND ADVISORY MAY
BECOME NECESSARY AT SOME POINT FOR WEDNESDAY INTO WEDNESDAY NIGHT.
TEMPERATURES WILL LIKELY REMAIN STEADY OR FALL DURING THE DAY
WEDNESDAY...THEN PLUMMET FURTHER WEDNESDAY NIGHT WITH WIND CHILLS
OF AROUND 20 TO 25 BELOW FORECAST ACROSS NORTHERN IOWA BY THURSDAY
MORNING.
AS A SURFACE HIGH PRESSURE AREA CROSSES IOWA ON THURSDAY WINDS
WILL LIGHTEN SUBSTANTIALLY BUT IT WILL REMAIN COLD...THEN WE WILL
CONTINUE THIS SERIES OF ALTERNATING HIGHS AND LOW PRESSURE TROUGHS
THROUGH THE WEEKEND. THIS WILL RESULT IN A MODEST WARM UP ON
FRIDAY...ANOTHER FRONTAL PASSAGE LATE FRIDAY...MORE STRONG WINDS
AROUND FRIDAY NIGHT INTO SATURDAY...MORE COLD ON SATURDAY AND
SATURDAY NIGHT...ETC. IN A REPEAT OF THE PATTERN WE HAVE SEEN FOR
THE LAST SEVERAL DAYS ALREADY. THERE IS SOME INDICATION IN THE
PAST SEVERAL RUNS OF THE ECMWF AND GFS THAT THIS PATTERN COULD
SHIFT A BIT FURTHER SOUTHWARD AROUND MONDAY OR TUESDAY OF NEXT
WEEK AS A BROAD 500 MB TROUGH DIGS A BIT FURTHER DOWN INTO THE
CENTRAL U.S. IF THIS VERIFIES THEN IT WOULD SPREAD THE BULK OF THE
PRECIPITATION FROM THE ASSOCIATED SURFACE SYSTEM MORE ACROSS IOWA
RATHER THAN FURTHER NORTH AS WE HAVE SEEN THUS FAR...HOWEVER AT
THIS RANGE IT IS WAY TOO EARLY TO GET MUCH DETAIL OUT OF WHAT THIS
WOULD MEAN FOR SENSIBLE WEATHER AND PRECIPITATION AMOUNTS ACROSS
CENTRAL IOWA.
&&
.AVIATION...10/06Z
ISSUED AT 1150 PM CST MON FEB 9 2015
HIGHER CONFIDENCE WITH FOD/MCW RECEIVING SOME LIGHT FZRA/FZDZ BY
SUNRISE TUESDAY MORNING AND SHOULD NOT LAST PAST 18Z. THE LATEST
HRRR HAS A GOOD HANDLE ON CURRENT RADAR TRENDS AND HAS THE LIGHT
PRECIP MOVING ACROSS NORTHERN IOWA B/T 12-17Z. THE MVFR STRATUS
DECK LOOKS TO PERSIST OVER MCW/FOD/DSM THROUGH TOMORROW NIGHT AND
EVEN INTO WEDNESDAY MORNING. FOR ALO/OTM...CLEARING HAS ALLOWED
FOR SOME PATCHY FOG TO DEVELOP AND SATELLITE TRENDS SHOW THE
STRATUS DECK ERODING JUST SLIGHTLY BACK WESTWARD.
HOWEVER...EXPECTING THE STRATUS TO FILL BACK IN FURTHER EAST WITH
THE SHORTWAVE COMING ACROSS THE STATE BY 09Z. BUT BEFORE
THEN...HAVE MVFR FOG AT OTM AND ALO MENTIONED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...LEE
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS WICHITA KS
739 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 739 AM CST TUE FEB 10 2015
CONTINUED TO MONITOR TRENDS AND AREAS OF DENSE FOG IS OVER THE
FLINT HILLS AND MOVING EASTWARD ALONG THE TURNPIKE AND INTO THE
METRO OF WICHITA. CONFIDENCE OVER CENTRAL KANSAS IS LOWER...BUT
COULD SEE EXTENSION TO THOSE AREAS IF TRENDS PERSIST FROM NORTH
CENTRAL KANSAS. WITH CURRENT OBSERVATIONS AND TRENDS...CONFIDENCE
WAS NOT HIGH ENOUGH TO INCLUDE THEM AT THIS TIME...SALINA AND
NORTH AND EAST OF THEM HAS REMAINED WITH VISIBILITIES OF 4 TO 5SM
AND HIGHER.
BILLINGS WRIGHT
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 333 AM CST TUE FEB 10 2015
TODAY-TONIGHT:
EXPECT FOG TO THICKEN OVER THE NEXT COUPLE OF HOURS...ESPECIALLY
IN THE FLINT HILLS...WHERE SATELLITE LOOP SHOWS LOW CLOUDS MOVING
WEST. DO NOT BELIEVE FOG WILL BE AS WIDESPREAD AS YESTERDAY.
TEMPERATURES WILL MAKE SOME RECOVERY TODAY AS WEAK RETURN FLOW
DEVELOPS. COLD FRONT STILL ANTICIPATED TO MOVE THROUGH AREA LATE
TONIGHT/EARLY WED. TEMPERATURES WILL FALL BACK BELOW NORMAL ON
WED. RELATIVELY DRY AIR SHOULD PRECLUDE ANY PRECIPITATION WITH
FRONT.
WED NIGHT-THU:
CHILLY PERIOD WITH COLD AIR ADVECTION PERSISTING WED NIGHT AND
INTO THU WITH LIMITED MIXING. LOWS THU NIGHT WILL BE TRICKY AS
INCREASING RETURN FLOW DEVELOPS IN THE WEST...SO MINIMUMS COULD
OCCUR EARLY THERE. -HOWERTON
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 333 AM CST TUE FEB 10 2015
GFS/ECMWF REMAIN IN SURPRISINGLY GOOD AGREEMENT WITH RIDGE
BUILDING IN THE WESTERN US AND TROUGHING IN THE EAST. BOTH
CONTINUE TO SHOW A LARGE SURFACE HIGH OVERSPREADING THE CENTRAL
US...SENDING MUCH COOLER AIR INTO THE AREA ON SAT...WHICH WILL
PERSIST INTO SUN. THERE WAS SUFFICIENT AGREEMENT BETWEEN MODELS
AND SURROUNDING OFFICES TO HEDGE COOLER THAN GUIDANCE FOR
NOW...ESPECIALLY ON SAT MAXES AND LOWS SUN NIGHT. RETURN FLOW
DEVELOPING SUN NIGHT/MON WILL START ANOTHER WARMING TREND. SMALL
CHANCE OF RAIN ON MON IN SE KS AS LOW LEVEL MOISTURE RETURN NORTH.
-HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 537 AM CST TUE FEB 10 2015
SIMILAR CONCERN THIS MORNING LIKE YESTERDAY MORNING...LOW CEILINGS
AND FOG...DIFFICULT AVIATION FORECAST. LOW CLOUDS HAVE DEVELOPED
OVER SOUTHEAST KANSAS AND ARE STARTING TO SHOW ACROSS CENTRAL AND
SOUTH CENTRAL KANSAS. EXPECT THIS TREND TO CONTINUE THROUGH THE
EARLY MORNING HOURS. THE RR DOES NOT HAVE THE TREND QUITE AS WELL
AS IT DID YESTERDAY...BUT THINK THE TREND WILL BE
SIMILAR...DEVELOPMENT THIS MORNING BETWEEN 12 TO 14Z WITH WORST
CONDITIONS BETWEEN 13 AND 15-16Z AND THEN IMPROVING INTO THE
AFTERNOON HOURS. CEILINGS THAT ARE DEVELOPING OVER SOUTHEAST
KANSAS ARE LIFR AND HAVE NO REASON TO BELIEVE THEY WILL NOT BE
SIMILAR OVER CENTRAL AND SOUTH CENTRAL KANSAS TAF SITES...HAVE
LIFR CEILINGS FOR THIS MORNING IF NOT LIFR...LOW END IFR. HAVE
TRIED TO TIME IT THE BEST I CAN WITH GUIDANCE AND SATELLITE
TRENDS...AND STAYED ON THE PESSIMISTIC SIDE. HAVE TEMPO GROUPS FOR
THE 1/2SM AND FOG...BUT THE LIFR CEILINGS ALREADY TAKE IT INTO THE
LOWEST CATEGORY. NOT AS CONFIDENT IN WIDESPREAD DENSE FOG SO
HOLDING ON THAT FOR NOW.
WINDS WILL SHIFT THIS AFTERNOON AND EVENING AS A FRONT MOVES
THROUGH THE AREA. LOW-MID CLOUDS COULD AGAIN DEVELOP BEHIND THE
FRONT TOWARDS MORNING...ONLY HINTED AT THEM WITH A SCATTERED DECK.
CONFIDENCE IS NOT AS HIGH.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 38 42 21 / 0 0 0 0
HUTCHINSON 57 38 41 19 / 0 0 10 0
NEWTON 56 37 40 17 / 0 0 0 0
ELDORADO 58 37 41 19 / 0 0 0 0
WINFIELD-KWLD 60 38 44 21 / 0 0 10 0
RUSSELL 58 38 42 18 / 0 0 0 0
GREAT BEND 59 39 42 18 / 0 0 0 0
SALINA 56 37 40 17 / 0 0 0 0
MCPHERSON 56 37 40 18 / 0 0 0 0
COFFEYVILLE 59 38 44 22 / 0 0 0 0
CHANUTE 56 36 40 19 / 0 0 0 0
IOLA 55 35 39 18 / 0 0 0 0
PARSONS-KPPF 57 37 42 20 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ051>053-
067>069-083-094.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
537 AM CST TUE FEB 10 2015
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 333 AM CST TUE FEB 10 2015
TODAY-TONIGHT:
EXPECT FOG TO THICKEN OVER THE NEXT COUPLE OF HOURS...ESPECIALLY
IN THE FLINT HILLS...WHERE SATELLITE LOOP SHOWS LOW CLOUDS MOVING
WEST. DO NOT BELIEVE FOG WILL BE AS WIDESPREAD AS YESTERDAY.
TEMPERATURES WILL MAKE SOME RECOVERY TODAY AS WEAK RETURN FLOW
DEVELOPS. COLD FRONT STILL ANTICIPATED TO MOVE THROUGH AREA LATE
TONIGHT/EARLY WED. TEMPERATURES WILL FALL BACK BELOW NORMAL ON
WED. RELATIVELY DRY AIR SHOULD PRECLUDE ANY PRECIPITATION WITH
FRONT.
WED NIGHT-THU:
CHILLY PERIOD WITH COLD AIR ADVECTION PERSISTING WED NIGHT AND
INTO THU WITH LIMITED MIXING. LOWS THU NIGHT WILL BE TRICKY AS
INCREASING RETURN FLOW DEVELOPS IN THE WEST...SO MINIMUMS COULD
OCCUR EARLY THERE. -HOWERTON
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 333 AM CST TUE FEB 10 2015
GFS/ECMWF REMAIN IN SURPRISINGLY GOOD AGREEMENT WITH RIDGE
BUILDING IN THE WESTERN US AND TROUGHING IN THE EAST. BOTH
CONTINUE TO SHOW A LARGE SURFACE HIGH OVERSPREADING THE CENTRAL
US...SENDING MUCH COOLER AIR INTO THE AREA ON SAT...WHICH WILL
PERSIST INTO SUN. THERE WAS SUFFICIENT AGREEMENT BETWEEN MODELS
AND SURROUNDING OFFICES TO HEDGE COOLER THAN GUIDANCE FOR
NOW...ESPECIALLY ON SAT MAXES AND LOWS SUN NIGHT. RETURN FLOW
DEVELOPING SUN NIGHT/MON WILL START ANOTHER WARMING TREND. SMALL
CHANCE OF RAIN ON MON IN SE KS AS LOW LEVEL MOISTURE RETURN NORTH.
-HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 537 AM CST TUE FEB 10 2015
SIMILAR CONCERN THIS MORNING LIKE YESTERDAY MORNING...LOW CEILINGS
AND FOG...DIFFICULT AVIATION FORECAST. LOW CLOUDS HAVE DEVELOPED
OVER SOUTHEAST KANSAS AND ARE STARTING TO SHOW ACROSS CENTRAL AND
SOUTH CENTRAL KANSAS. EXPECT THIS TREND TO CONTINUE THROUGH THE
EARLY MORNING HOURS. THE RR DOES NOT HAVE THE TREND QUITE AS WELL
AS IT DID YESTERDAY...BUT THINK THE TREND WILL BE
SIMILAR...DEVELOPMENT THIS MORNING BETWEEN 12 TO 14Z WITH WORST
CONDITIONS BETWEEN 13 AND 15-16Z AND THEN IMPROVING INTO THE
AFTERNOON HOURS. CEILINGS THAT ARE DEVELOPING OVER SOUTHEAST
KANSAS ARE LIFR AND HAVE NO REASON TO BELIEVE THEY WILL NOT BE
SIMILAR OVER CENTRAL AND SOUTH CENTRAL KANSAS TAF SITES...HAVE
LIFR CEILINGS FOR THIS MORNING IF NOT LIFR...LOW END IFR. HAVE
TRIED TO TIME IT THE BEST I CAN WITH GUIDANCE AND SATELLITE
TRENDS...AND STAYED ON THE PESSIMISTIC SIDE. HAVE TEMPO GROUPS FOR
THE 1/2SM AND FOG...BUT THE LIFR CEILINGS ALREADY TAKE IT INTO THE
LOWEST CATEGORY. NOT AS CONFIDENT IN WIDESPREAD DENSE FOG SO
HOLDING ON THAT FOR NOW.
WINDS WILL SHIFT THIS AFTERNOON AND EVENING AS A FRONT MOVES
THROUGH THE AREA. LOW-MID CLOUDS COULD AGAIN DEVELOP BEHIND THE
FRONT TOWARDS MORNING...ONLY HINTED AT THEM WITH A SCATTERED DECK.
CONFIDENCE IS NOT AS HIGH.
BILLINGS WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 57 38 42 21 / 0 0 0 0
HUTCHINSON 57 38 41 19 / 0 0 10 0
NEWTON 56 37 40 17 / 0 0 0 0
ELDORADO 58 37 41 19 / 0 0 0 0
WINFIELD-KWLD 60 38 44 21 / 0 0 10 0
RUSSELL 58 38 42 18 / 0 0 0 0
GREAT BEND 59 39 42 18 / 0 0 0 0
SALINA 56 37 40 17 / 0 0 0 0
MCPHERSON 56 37 40 18 / 0 0 0 0
COFFEYVILLE 59 38 44 22 / 0 0 0 0
CHANUTE 56 36 40 19 / 0 0 0 0
IOLA 55 35 39 18 / 0 0 0 0
PARSONS-KPPF 57 37 42 20 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1142 PM CST Mon Feb 9 2015
...Update to aviation forecast discussion and fog forecast...
.UPDATE...
Issued at 825 PM CST MON FEB 9 2015
Surge of dry air has managed to make it into the Cloud/Republic
county areas, so will cancel the dense fog advisory at this time.
There is a small chance for redevelopment of fog within the clear
sky area, but confidence in redevelopment is very low at this
time.
&&
.SHORT TERM...(This Evening through Tuesday)
Issued at 343 PM CST MON FEB 9 2015
Surface high pressure ridge extends southeast across eastern Kansas
from Minnesota. Cool east to northeast flow along with stratus which
has held on most of the day, has kept temperatures from rising much
from morning lows especially across north central Kansas.
Latest visible satellite loop shows the stratus breaking up from
central Missouri into east central Kansas. HRRR, NAM and RAP show
some semblance of this trend for partial clearing from Emporia to
Topeka along with some further clearing this evening into northeast
Kansas. Areas of north central Kansas look to stay in the stratus
tonight. The low clouds may reform later tonight across the east.
Areas of fog are likely for much of the area overnight. Lows tonight
will vary due to breaks in the clouds. Expecting lows in the upper
20s to low to mid 30s.
Thermal axis noses into northeast Kansas on Tuesday ahead of the
next shortwave and surface frontal boundary. Forecast soundings show
mixing to 925mb to 900mb in the afternoon. Stratus looks to break up
in the late morning and early afternoon hours. Highs will range from
the 50s to around 60.
.LONG TERM...(Tuesday Night through Monday)
Issued at 343 PM CST MON FEB 9 2015
Next cold front still on track to move through the county warning
area (cwa) Tuesday night as a weak shortwave trough extending from
the Great Lakes into the southwest CONUS moves through and shears
with time. The initial push of cooler air will lower highs into the
upper 30s and lower 40s for Wednesdays and should move through the
area dry as well.
As the stronger secondary d cold front moves through late
Wednesday/Wednesday night...a much colder push of air will
overspread the area. The GFS is deeper with the eastern trough and
colder than the EC. Following lows in the teens and lower 20s
Thursday morning...highs will struggle to reach the 20s and lower
30s most areas. Again...with only weak forcing and limited
moisture...will maintain a dry fcst.
The upper ridging along the west coast will amplify and edge
eastward by Friday with warmer air temporarily advecting into the
cwa with highs into the 40s east and the low to mid 50s west. Models
are in agreement with the next strong northwest flow wave into the
eastern CONUS trough which will drive another push colder air back
into the cwa with highs mainly in the 30s Saturday...then the low to
mid 40s Sunday.
Even warmer air will then overspread the area on Monday with highs
mainly in the low to middle 50s as another longer wave trough
approaches the central plains. There will be a chance for rain
across the southeast cwa during the day...then a chance for rain or
snow that night as the cold front moves through.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1134 PM CST MON FEB 9 2015
Difficult period of aviation forecast continues. Now seeing
westward progression of the stratus deck toward TAF sites with
expected arrival at TOP/FOE 08-09Z. Cigs would likely be 1100 to
1500 feet, but with some potential to be IFR. Greater uncertainty
in this stratus reaching MHK, but believe it will around roughly
11Z and also with potential for lower cigs than forecast, and have
a good chance of MVFR vis for several hours at MHK. Question then
becomes when clouds scatter, and this seems likely by mid morning
as stratus will be quite thin.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY until 9 AM CST Tuesday FOR KSZ008-020.
&&
$$
UPDATE...Barjenbruch
SHORT TERM...53
LONG TERM...63
AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1251 AM EST Tue Feb 10 2015
...Forecast Update...
Issued at 1250 AM EST Tue Feb 10 2015
Light precip continues over our east and south, as the top of the
cloud layer is just at the right temperature to allow a few snow
crystals/grains to form. RUC and NAM time height sections indicate
some thinning of these clouds from the top as subsidence dries the
air from aloft. Thus expect the flurries to end over the next few
hours from north to south. Have updated the forecast for this
adjustment.
Issued at 804 PM EST Mon Feb 9 2015
Have updated the forecast this evening to put in some light drizzle
and/or flurries for the next few hours. Despite drier near-surface
air working in, there has been enough lingering low-level moisture
to squeeze out some light drizzle and/or flurries this evening.
Latest IR-satellite imagery pegs cloud tops at -9 to -11C over most
of the area, so think as surface temperatures fall below freezing,
we should see more flurries than freezing drizzle given ice nuclei
likely to be present in the clouds. Either way, should not cause
many issues and shouldn`t last too long given the drier air working
in. Updated products out shortly.
.SHORT TERM (Now through Tuesday Night)...
Issued at 300 PM EST Mon Feb 9 2015
A 500mb trough will move east of Kentucky this afternoon. In its
wake northerly flow will ensure continued coolish temperatures
through tomorrow.
Extensive low strato-cu currently extends north all the way to
southern Michigan. Forecast soundings and low level relative
humidity progs show low cloudiness continuing all the way through
much of the morning hours Tuesday. North winds of 12 to 15 kts this
afternoon will slowly diminish this evening and remain from the
north at 5 to 10 mph through the morning hours. Winds will become
light and variable Tuesday night as a surface ridge axis passes over
the Commonwealth.
Temperatures tonight will fall into the mid 20s, with highs Tuesday
rising into the upper 30s to the lower 40s. Skies will clear
tomorrow afternoon and stay clear to partly cloudy through Wednesday
morning. Lows will fall into the lower to mid 20s early Wednesday.
.LONG TERM (Wednesday through Monday)...
Issued at 233 PM EST Mon Feb 9 2015
Low pressure crossing the Great Lakes will drag a cold front through
southern Indiana/central Kentucky Wednesday. The front itself will
likely be dry, however it will usher in very cold air with high
pressure that will have had its beginnings over the Yukon. Though
moisture will be shallow behind the front, it shouldn`t be too
difficult to squeeze some snowflakes out in the cold air Wednesday
night and Thursday, especially given the strong upper trof digging
in. Anything that does fall will be very light. The best chances
will be in the Blue Grass, including the Lexington metro, where Lake
Michigan influence will be greatest.
Temperatures Wednesday will be highly dependent on when exactly the
front passes through the region. For now will stay consistent with
recent forecasts and shoot for low to mid 50s. Wednesday night
we`ll drop into the 20s...maybe upper teens in southern Indiana west
of I-65. Thursday will see highs only in the 20s, with brisk
northwest winds gusting to around 20mph, and wind chills of 5 to 15
degrees.
The next cold front will approach Friday and pass through the area
Friday night. The great majority of the precipitation associated
with this system will remain to our north as the front`s parent low
crosses the Great Lakes.
It will then be deja vu all over again as the cold front ushers in
another high from northern Canada. Post-frontal flurries or light
snow showers will be possible Saturday and Saturday night,
especially in the Blue Grass. The real story, however, will be the
cold. After mid-day highs in the 20s on Saturday, temperatures will
begin to fall in the afternoon. Brisk west breezes in the morning
will become frigid northwest winds in the afternoon with gusts to
25, maybe 30, miles per hour. Wind chills will be in the single
digits during the day. Then Saturday night the mercury will drop
into the single digits with wind chills from five below to ten below
zero. Sunday will see highs in the 20s, and then on Monday we may
be able to rebound to around 40 as we get into some return flow.
&&
.AVIATION (06Z TAF Update)...
Issued at 1225 AM EST Tue Feb 10 2015
Light snow continues to affect the LEX terminal this hour. Latest
RUC and NAM time height sections indicate the cloud tops should
start to warm, effectively shutting off the crystals for the light
snow. As cloud tops warm, cigs should stay in the low-end MVFR
range, likely through daybreak. We should start to see some erosion
of those clouds by late morning, with all of the sites likely
becoming VFR by afternoon. Winds will stay northerly the rest of the
morning hours, but will shift to northeasterly during the day as
high pressure moves by to our north.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Updates........KD/RJS
Short Term.....JSD
Long Term......13
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
912 AM EST TUE FEB 10 2015
.SYNOPSIS...
A STRENGTHENING LOW PRESSURE SYSTEM WILL REMAIN LARGELY TO THE
SOUTH OF OUR AREA TODAY...AS IT MOVES OFF THE SOUTHERN ATLANTIC
COAST THIS EVENING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
THROUGH EARLY THURSDAY. AN ARCTIC FRONT IS EXPECTED TO MOVE OVER
THE REGION BY MIDDAY THURSDAY...WITH GUSTY WINDS AND COLD
CANADIAN AIR RESIDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH 6 PM/...
PCPN DIMINISHING ACRS CWFA...ALTHO A FEW ECHOES LINGERING ACRS THE
TIP OF SRN MD. HRRR CLEARS THAT OUT BTWN 15-16Z. HV XTNDD CALVERT
AND ST MARYS CNTYS TO ACCT FOR THAT. ELSW...HV ALLOWED ADVYS TO
EXPIRE...AS NO NEW PCPN OCCURRING OR XPCTD.
CLOUDS WILL BE LOCKED IN FOR THE REST OF THE DAY WITH THE LOW NEARBY
AND UPPER TROUGH AXIS OVERHEAD...THUS LIMITING TEMP RISE. ON THE
WHOLE VSBYS HAVE BEEN BETTER THAN PREVIOUSLY INDICATED BY GUIDANCE
WITH STEADY WINDS...BUT SOME PATCHY LIGHT FOG REMAINS POSSIBLE.
&&
.SHORT TERM /TONIGHT AND WEDNESDAY/...
A NARROW RIDGE OF HIGH PRESSURE WILL EXTEND SOUTH FROM CANADA
BETWEEN THE DEPARTING COASTAL LOW AND THE NEXT LOW PRESSURE SYSTEM
IN THE UPPER GREAT LAKES TONIGHT INTO WEDNESDAY. THE NORTHERLY
BREEZE WILL LIGHTEN AND CLOUDS WILL DECREASE FOR A BRIEF PERIOD.
SEASONABLE TEMPERATURES ARE EXPECTED...ALTHOUGH GUIDANCE SUGGESTS
LOWER HIGHS FOR WEDNESDAY BY A FEW DEGREES OVER PREVIOUS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE MAIN STORY OF THE LONG TERM CONTINUES TO BE THE ONE-TWO SHOTS
OF ARCTIC AIR TO CLOSE OUT THE WEEK AND TO START NEXT WEEK. AN
INTERESTING UPPER-LEVEL INTERACTION WILL CAUSE THE FIRST WAVE...AS
A WEAK CLIPPER MOVING EAST - JUST N OF THE CANADIAN/US BORDER IS
UNDERCUT BY A POTENT VORT SLIDING DOWN FROM THE NORTH. THIS
FEATURE WILL COMBINE W/ THE FORMER AND MAKE FOR A MORE INTENSE
SYSTEM THAT DIVES DOWN ACROSS THE GREAT LAKES FROM LATE WED INTO
THU.
THE INITIAL WAVES OF PRECIP AND THICKER CLOUD DECKS WILL SLIDE
INTO THE APLCNS EARLY ON THU...WHILE BRIEF SURGE OF WARMER AIR
TAKES TEMPS UP INTO THE L40S BEFORE NOONTIME. THE FRONT WILL THEN
MAKE A SWIFT PASSAGE DURING THE MIDDAY HRS...USHERING-IN GUSTY
WINDS AND QUICKLY DROPPING TEMPS BEHIND IT. POSSIBLY ACCUMULATING
SNOWS IN THE HIGHER TERRAIN OF THE APLCNS THU INTO FRI...BUT
ALSO...SCATTERED PRECIP BANDS WILL ALSO BE POSSIBLE E OF THE MTNS.
THE WEAKLY UNSTABLE SITUATION CREATED BY THE RELATIVELY WARMER
AIR OUT AHEAD OF THE FRONT AND THE DYNAMIC COOLING BEHIND...THE
INCOMING COLD UPPER TROUGH WILL BE MORE THAN CAPABLE FOR
DEVELOPING ISOLATED SNOW BANDS THAT STREAK ACROSS THE AREA BUT TOO
FAR OUT IN THE FORECAST TO PREDICT MUCH MORE THAN THE POTENTIAL
FOR THEM.
NOT MUCH RELIEF/RECOVERY OVER THE NEXT COUPLE OF DAYS BEFORE AN
EVEN LARGER/COLDER SYSTEM MOVES ACROSS THE AREA THIS WEEKEND.
HIGHS ON FRI AND SAT WILL BARELY APPROACH THE FREEZING MARK ACROSS
MUCH OF THE REGION W/ BREEZY CONDS PERSISTING AND WIND CHILLS
BECOMING THE MAIN CONCERN NOT ONLY THU NIGHT BEHIND THE ARCTIC
FRONT - BUT EACH NIGHT INTO EARLY NEXT WEEK W/ AMBIENT TEMPS
DROPPING WELL INTO THE TEENS AND 20S. SUB-ZERO WIND CHILLS ARE
EXPECTED ACROSS AT LEAST THE WRN HALF OF THE CWA EACH NIGHT INTO
THE WEEKEND.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
PCPN HAS ENDED ACRS CWFA. MVFR CIGS REMAIN IN PLACE. LTLCHG XPCTD
THRU THE DAY. CIGS MAY NOT COMPLETELY SCATTER OUT UNTIL THIS
EVENING. VSBYS TRENDING HIGHER WITH A STEADY N WIND...BUT SOME
MVFR POSSIBLE THROUGH AT LEAST THE MORNING.
VFR CONDITIONS WITH LIGHT WINDS EXPECTED TONIGHT/WED.
THE LONGER RANGE FORECAST HAS TWO ARCTIC FRONT PASSAGES - ONE
MIDDAY THU AND ANOTHER THIS COMING WEEKEND. THE THU PASSAGE WILL
QUICKLY DROP TEMPS IN THE AFTN/EVE W/ A SEVERAL-HR PERIOD OF
GUSTY...IF NOT WINDY NW GUSTS IN THE 20-30KT RANGE. SUB-FREEZING
TEMPS WILL BE COMMON WELL INTO THE WEEKEND - W/ SUB-ZERO WIND
CHILLS AT TIMES.
&&
.MARINE...
WNDS LGT NLY ATTM...AS THERES LTL MIXING UNDER LOW CLDS/LGT FZRA.
HWVR WITH LOW PRESSURE OFFSHORE...STEADY N WINDS IN SCA LEVELS
SHOULD DEVELOP TODAY.
INDS WILL BEGIN TO DIMINISH ON THE UPPER TIDAL POTOMAC AND
NORTHERN BAY THIS EVENING...BUT 20 KT GUSTS REMAIN POSSIBLE UNTIL
WEDNESDAY MORNING ON THE CENTRAL/LOWER MD BAY...WHERE THE SCA HAS
BEEN EXTENDED.
A STRONG COLD FRONT WILL SWING THRU THE AREA THU AFTN...USHERING
IN ANOTHER MULTI-DAY PERIOD OF GUSTY WINDS - ESPEC THU NIGHT INTO
FRI. A SIMILAR SCENARIO FROM LATE SAT INTO SUN...W/ GALE POSSIBLE
FOR MUCH OF THESE PERIODS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MDZ017-018.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR
ANZ530>532-539-540.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536-538.
SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR ANZ533-534-
537-541>543.
&&
$$
SYNOPSIS...
NEAR TERM...HTS/ADS
SHORT TERM...ADS
LONG TERM...GMS
AVIATION...HTS/ADS/GMS
MARINE...HTS/ADS/GMS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
714 PM EST WED FEB 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EST WED FEB 11 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEPENING UPR
TROF OVER CENTRAL NAMERICA DOWNSTREAM OF A RDG OVER THE W. SEVERAL
SHRTWVS ARE EMBEDDED WITHIN THIS TROF...AND THEIR PRESENCE IS
RESPONSIBLE FOR 00Z-12Z H3 HGT FALLS IN EXCESS OF 200M AT YPL. THE
FIRST DISTURBANCE THAT BROUGHT THE LIGHT SN LAST NGT IS NOW MOVING E
INTO WRN QUEBEC. A SECOND SHRTWV THAT BROUGHT ANOTHER ROUND OF MORE
WDSPRD LIGHT SN THIS MRNG IS NOW MOVING TO THE E OF THE AREA...WITH
SUBSIDENCE IN ITS WAKE...WHICH LOWERED THE INVRN BASE TO H9 AT INL
AT 12Z...NOW RESTRICTING SN SHOWERS MAINLY TO AREAS NEAR LK SUP
IMPACTED BY THE COLD NW FLOW IN ITS WAKE. NW SFC WINDS HAVE BEEN
GUSTING AS HI AS 35 MPH...RESULTING IN SOME BLSN/REDUCED VSBYS.
LOOKING TO THE NW... AN EVEN STRONGER SHRTWV IS DIGGING SEWD THRU
MANITOBA AND TOWARD NW MN. 12Z H85-7 TEMPS WERE AS LO AS -30C/-28C
AT THE PAS MANITOBA WITHIN THE COLD SURGE ACCOMPANYING THIS SHRTWV.
THE 12Z RAOB AT THAT SITE ALSO SHOWED A FAIRLY MOIST LYR UP TO JUST
ABOVE H7.
MAIN FCST CONCERNS THRU THU ARE NUMEROUS AND RELATED TO GOING
HEADLINES/LES COVERAGE/AMOUNTS/WINDS AND BLSN AS WELL AS WIND CHILLS
THAT WL ACCOMPANY THIS INCOMING ARCTIC SURGE ASSOCIATED WITH
MANITOBA SHRTWV.
LATE TODAY/TNGT...SHRTWV NOW DIGGING THRU SRN MANITBOA IS FCST TO
DIVE TO NEAR THE MN ARROWHEAD BY 00Z AND INTO THE LOWER LKS BY 12Z
THU. THE ARRIVAL OF THE STRONGER DYNAMIC FORCING/DEEPER MSTR/CYC NW
VEERING N FLOW THIS EVNG ASSOCIATED WITH THIS DISTURBANCE WL BRING A
PERIOD OF LK ENHANCED SN IN AREAS FAVORED BY THESE WINDS AS THE
ACCOMPANYING CAA CAUSES H85 TEMPS TO BOTTOM OUT AS LO AS -25C TO
-27C BY 12Z THU. MIXING OF THE H925 WINDS AS HI AS 35-40 KTS WITH
THE VIGOROUS CAA WL CAUSE VERY GUSTY WINDS AND BLSN AS WELL...
ESPECIALLY IN OPEN AREAS NEAR LK SUP. STEADILY SHIFTING WINDS AND
THE ARRIVAL OF THE VERY COLD AIR THAT WL NEARLY ELIMINATE THE DGZ
AND GUSTY WINDS THAT WL FRAGMENT THE SN FLAKES AND FURTHER LOWER SN/
WATER RATIOS WL LIMIT LES AMOUNTS. THE HIER RES MODELS INDICATE THE
HEAVIEST SN WL FALL IN WRN ALGER COUNTY...WITH MORE PERSISTENT LLVL
CNVGC THERE ENHANCED BY THE PRESENCE OF A LARGE AMOUNT OF ICE BTWN
THE KEWEENAW AND MARQUETTE THAT WL ENHANCE A BIT OF A WNW LAND
BREEZE COMPONENT OFF THE W HALF OF UPR MI. THE STRONG LLVL WINDS WL
BLOW THESE SN SHOWERS FARTHER INLAND AND INTO DELTA COUNTY. THE ICE
COVER OVER FAR ERN LK SUP AND VEERING FLOW TO THE N THAT LIMITS
OVERWATER TRAJECTORY INTO LUCE COUNTY WL HAMPER SN ACCUMS OVER THE
FAR ERN CWA. THE COMBINATION OF THE STRONG WINDS/LO TEMPS FALLING
BLO ZERO WL CAUSE WIND CHILLS TO DIP AS LO AS -25F TO PERHAPS -30F.
LATE TNGT...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC/STEADILY RISING H5
HGTS...FCST UP TO 100M BTWN 06Z-12Z OVER THE FAR W AT IWD...IN THE
WAKE OF THE DIGGING SHRTWV ARE FCST TO SHARPLY LOWER THE SUBSIDENCE
INVRN BASE TOWARD 2K FT AT IWD WL BRING A DIMINISHING TREND TO THE
LES. WEAKENING PRES GRADIENT/DIMINISHING LLVL WINDS FOLLOWING SHIFT
OF PRES CENTER TO THE E OF UPR MI WL CAUSE THE BLSN TO SUBSIDE A BIT
AS WELL.
THU...STEADILY RISING HGTS UNDER THE DNVA/LARGE SCALE QVECTOR DVGC
IN THE WAKE OF DEPARTING SHRTWV TOWARD THE MID ATLANTIC STATES AND
AHEAD OF SHRTWV RDG AXIS MOVING TOWARD THE UPR LKS THAT CAUSE A
CONTINUED LOWERING OF THE INVRN BASE TOWARD 2-3K FT EVEN OVER THE E
HALF LATE IN THE DAY WL BRING ABOUT A DIMINISHING TREND OF THE
LES...LATER OVER THE E. DIMINISHING/BACKING WINDS TOWARD THE NW WITH
APRCH OF SFC HI PRES RDG UNVER THE SUBSIDENCE WL CAUSE THE HEAVIER
LES OVER WRN ALGER COUNTY TO SHIFT TO THE E.
AS FOR THE HEADLINES...ALTHOUGH A GOOD DEAL OF ICE COVER IN THE LK
SUP NEARSHORE AREAS WL LIMIT SN TOTALS A BIT COMPARED TO WHAT WOULD
HAVE HAPPENED EARLY IN THE SEASON...GUSTY WINDS/BLSN EXACERBATED BY
THE NEARSHORE SN COVERED ICE WL BE SUFFICIENT TO WARRANT CONTINUED
HEADLINES. WILL CONTINUE THE WARNING FOR ALGER COUNTY GIVEN SUPPORT
FM THE HI RES MODELS FOR THE HEAVIEST QPF IN THE WESTERN PART OF
THAT COUNTY. ADDED WIND CHILL ADVYS FOR LUCE AND DICKINSON/IRON
COUNTIES WITH WIND CHILLS FALLING AS LO AS -28F IN THE PRESENCE OF
SUSTAINED N WIND NEAR 10 MPH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 500 PM EST WED FEB 11 2015
THE REGION IS NOW AMIDST AN ACTIVE PATTERN THAT WILL CONTINUE
THROUGH THE PERIOD. THIS PATTERN IS SOMEWHAT REMINISCENT TO LAST
WINTER AS A BROAD TROUGH BUILDS ACROSS EASTERN NORTH AMERICA.
CONCERNS CONTINUE TO GROW FOR POOR CONDITIONS FRIDAY NIGHT AND
SATURDAY WITH THE ARRIVAL OF SOME OF THE COLDEST AIR OF THE SEASON.
STRONG WINDS WILL LEAD TO VERY LOW VISIBILITIES ALONG LAKE
SUPERIOR...WITH BLIZZARD CONDITIONS QUITE POSSIBLE ALONG LAKE
SUPERIOR TO START THE WEEKEND.
THURSDAY NIGHT...A BROAD TROUGH CENTERED NEAR EASTERN HUDSON BAY
WILL SLOWLY SHIFT NORTHEASTWARD AS AN ASSOCIATED SFC TROUGH TRACKS
ACROSS THE LOWER GREAT LAKES. A SUBTLE RIDGE WILL SHIFT ACROSS THE
CWA THURSDAY NIGHT. HOWEVER...WITH COLD AIR LINGERING AROUND AND
INVERSION HEIGHTS REMAINING AROUND 3KFT...SOME LES WILL CONTINUE
ACROSS THE EAST BEFORE WINDS BACK TO THE SW BY DAYBREAK FRIDAY.
FRIDAY THROUGH SATURDAY...A STRENGTHENING UPPER JET COMBINED WITH A
POTENT SHORTWAVE TROUGH DIGGING SE INTO NW ONTARIO WILL INDUCE A SFC
LOW NORTH OF LAKE SUPERIOR FRIDAY MORNING. WEAK ISENTROPIC LIFT
AHEAD OF THIS LOW WILL SPREAD LIGHT SNOW ACROSS MUCH OF THE CWA
DURING THE DAY FRIDAY...WITH ACCUMULATIONS GENERALLY AROUND AN INCH.
BY EARLY-AFTERNOON...THE COLD FRONT ASSOCIATED WITH THE SFC LOW WILL
BE NEARING THE WESTERN CWA. H8 TEMPS FALLING FROM -15 TO -30C OVER
12-18 HOURS WILL ALLOW FOR A RAPID ONSET OF LAKE EFFECT SNOW FOR THE
NW-WIND SNOW BELTS ACROSS THE WEST BY LATE FRIDAY AFTERNOON. THE
WIND WILL QUICKLY BECOME NORTHERLY FOR ALL OF UPPER MI SATURDAY
EVENING AS THE SFC LOW TRACKS INTO NW LAKE HURON/GEORGIAN BAY.
TEMPERATURES WILL FALL QUICKLY...WITH HIGHS FAILING TO RISE ABOVE
ZERO FOR MOST OF THE AREA ON SATURDAY. WITH BLUSTERLY
CONDITIONS...WIND CHILLS WILL BE -20 TO -30F LATE FRIDAY NIGHT
THROUGH SATURDAY NIGHT.
THERE IS LITTLE DOUBT THAT WINDS WILL BE QUITE STRONG /GUSTING OVER
40MPH ALONG LAKE SUPERIOR/ BEHIND THIS FRONT AS AN ARCTIC HIGH OF
APPROX 1050MB BUILDS SE OUT OF SASKATCHEWAN AND THE 1005MB LOW MOVES
TOWARD THE LOWER GREAT LAKES. HOWEVER...THE STRENGTH OF THE PRESSURE
GRADIENT WILL DEPEND HEAVILY ON HOW THE UPPER JET AND MID-LEVEL
TROUGH INTERACT AS THE LOW MOVES AWAY FROM THE AREA. THE BEST
FORCING ON THE LEFT-EXIT OF THE JET LOOKS TO BE SOMEWHAT REMOVED TO
THE SOUTH OF THE MAIN SHORTWAVE ENERGY. IF THESE FEATURES CAN COME
INTO BETTER ALIGNMENT TO PRODUCE A STRONGER LOW...BLIZZARD
CONDITIONS WOULD BE LIKELY ALONG MUCH OF LAKE SUPERIOR FRIDAY NIGHT
THROUGH SATURDAY. THE AFOREMENTIONED ISSUES ALSO PRODUCE A STRONG
ISALLOBARIC WIND COMPONENT THAT IS MORE PERPENDICULAR THAN PARALLEL
TO THE GRADIENT WIND...THUS PROVIDING ONLY MARGINAL ENHANCEMENT TO
THE OVERALL WINDS.
WITH THE VERY COLD...AND RATHER DRY...ARCTIC AIR...SNOWFLAKE
PRODUCTION WILL BE DIFFICULT. THE EXPECTATIONS IS FOR VERY SMALL LOW-
RATIO SNOWFLAKES BY LATE FRIDAY NIGHT. FOR THIS REASON...SNOW
AMOUNTS ARE NOT OF UTMOST CONCERN WITH THIS SYSTEM. THE COMBINATION
OF THE STRONG WINDS AND SMALL SNOWFLAKE SIZE WILL GREATLY REDUCE
VISIBILITY. WHITE-OUT CONDITIONS ARE EXPECTED AT TIMES ALONG LAKE
SUPERIOR...ESPECIALLY SATURDAY MORNING. THE ONE MAJOR WILD CARD WILL
BE THE EVOLUTION OF THE ICE PACK ON LAKE SUPERIOR. ICE MODEL
FORECASTS INDICATE THAT TONIGHTS WINDS WILL GREATLY COMPACT THE ICE
ALONG THE SOUTHERN SHORE OF LAKE SUPERIOR. THIS WOULD PROVIDE MORE
OPEN WATER FOR LES PRODUCTION FOR THE WEEKEND. ADDITIONALLY...THE
ICE SHELF OFF SHORE WILL BE YET ANOTHER SOURCE OF SNOW FOR THE WINDS
TO BLOW AROUND NEAR THE SHORELINES.
WHILE BLIZZARD CONDITIONS ARE APPEARING MORE LIKELY FOR MUCH OF THE
KEWEENAW AND AREAS FROM BIG BAY TO GRAND MARAIS ALONG LAKE SUPERIOR
FRIDAY NIGHT THROUGH SATURDAY...HAVE DECIDED TO HOLD OFF ON ANY
HEADLINES AT THIS TIME FOR TWO REASONS. FIRST...THE MESSAGE
PERTAINING TO ONGOING ADVISORIES AND HEADLINES HIGHLIGHTING TONIGHTS
WEATHER MAY GET MIXED WITH ANY WATCHES FOR FRI NIGHT AND SAT.
SECOND...FORECASTER CONCENSUS IS TO SEE WHAT HAPPENS TONIGHT IN
ORDER TO GET A SAMPLE OF WHAT FRIDAY NIGHT AND SAT MAY HOLD. IF
CONDITIONS TONIGHT BECOME QUITE POOR...CONFIDENCE WILL SIGNIFICANTLY
INCREASE FOR BLIZZARD CONDITIONS EARLY THIS WEEKEND. ANY HEADLINES
MAY NOT BE ISSUED UNTIL THURSDAY...AND COULD SKIP ANY WATCHES AND GO
STRAIGHT TO A WARNING IF NEED BE.
SATURDAY NIGHT AND SUNDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE
FOR THE NORTH WIND SNOW BELTS AS A WEAK SECONDARY TROUGH TRACKS
ACROSS THE AREA IN THE EVENING. A MID-LEVEL/SFC RIDGE BUILDING IN
FROM THE NORTHERN PLAINS LATE SATURDAY NIGHT WILL INCREASE
CONVERGENCE ACROSS THE EASTERN LAKE. THIS MAY LEAD TO A CONTINUED
DOMINATE LES BAND BETWEEN MARQUETTE AND MUNISING AS INVERSION
HEIGHTS REMAIN AROUND 5KFT. THIS LES WILL QUICKLY SHIFT OFF SHORE
DURING THE DAY SUNDAY AS THE RIDGE WORKS ACROSS LAKE SUPERIOR.
MONDAY THROUGH WEDNESDAY...A BROAD TROUGH MOVING IN FROM SOUTH-
CENTRAL CANADA WILL BRING SMALL CHANCES OF SNOW FOR MONDAY. THIS
TROUGH WILL AMPLIFY MONDAY NIGHT AND CROSS UPPER MI TUESDAY INTO
TUESDAY NIGHT. THIS WILL BRING ANOTHER ROUND OF BREEZY CONDITIONS
AND INCREASED LES FOR THE NW-WIND SNOW BELTS. HOWEVER...CONDITIONS
ARE NET EXPECTED TO BE AS BAD AS EARLY THIS WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 713 PM EST WED FEB 11 2015
AS ANOTHER STRONGER DISTURBANCE/DYNAMIC FORCING AND DEEPER MOISTURE
ARRIVES TONIGHT WITH STRONG NNW WINDS THAT WILL CAUSE CONSIDERABLE
BLSN...IFR TO LIFR CONDITIONS ARE EXPECTED AT ALL 3 TAF SITES. WITH
STRONG SUBSIDENCE/DIMINISHING WINDS AND BLSN FOLLOWING THE PASSAGE
OF THIS DISTURBANCE...CONDITIONS WILL SLOWLY IMPROVE TO MVFR LATE
TONIGHT THROUGH THU MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST WED FEB 11 2015
ONGOING GALES/HEAVY FREEZING SPRAY WILL DIMINISH W-E LATE TONIGHT
AND THU WITH THE APPROACH OF A HI PRES RIDGE/WEAKER PRES GRADIENT
AND DIMINISHING WINDS/WAVES. ANOTHER ROUND OF GALES/HEAVY FREEZING
SPRAY ASSOCIATED WITH ANOTHER ARCTIC AIR INVASION WILL DEVELOP FRI
NIGHT AND PERSIST THRU SAT. NOT OUT OF THE QUESTION THERE COULD BE
SOME STORM FORCE GUSTS ON SAT...ESPECIALLY OVER THE E HALF.
LOW PRESSURE NEAR GEORGIAN BAY WILL SLIDE ACROSS NEW ENGLAND THROUGH
THURSDAY AND DEEPEN. HIGH PRESSURE OVER SASKATCHEWAN WILL THEN
SETTLE OVER THE MID MISSISSIPPI RIVER VALLEY BY THURSDAY AFTERNOON
WITH A RIDGE EXTENDING NORTHWARD ACROSS THE UPPER GREAT LAKES.
EXPECT THE RIDGE TO REACH THE LOWER GREAT LAKES ON FRIDAY AS LOW
PRESSURE MOVES FROM NORTHERN ONTARIO TO LAKE SUPERIOR. THE LOW WILL
DEEPEN AS IT REACHES THE LOWER GREAT LAKES ON SATURDAY AND JUST OFF
THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE BUILDING FROM CENTRAL
CANADA INTO THE NORTHERN PLAINS ON SATURDAY WILL CROSS THE GREAT
LAKES THROUGH MONDAY AS A LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ THURSDAY FOR
MIZ001>004-009-084.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THURSDAY FOR MIZ013-085.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR MIZ010-011.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THURSDAY FOR MIZ005.
WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THURSDAY FOR LSZ264-
267.
GALE WARNING UNTIL 1 PM EST THURSDAY FOR LSZ265-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THURSDAY FOR LSZ266.
GALE WARNING UNTIL 4 PM EST THURSDAY FOR LSZ266.
GALE WARNING UNTIL 10 AM EST THURSDAY FOR LSZ264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TK
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EST TUE FEB 10 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A POLAR BRANCH WNW
FLOW ALOFT OVER THE UPPER GREAT LKS BTWN AN ARCTIC BRANCH FARTHER N
IN CANADA AND A SUBTROPICAL BRANCH OVER THE SRN CONUS. SHRTWV
EMBEDDED IN THIS POLAR BRANCH FLOW IS MOVING ESE TOWARD WRN MN...
CAUSING 12HR H3 HGT FALLS UP TO 120M. ACCOMPANYING AREA OF PCPN IS
OVER MN UNDER AREA OF DEEPER MSTR ENHANCED BY UPR DVGC AHEAD OF THIS
FEATURE AS WELL AS WAA/ISENTROPIC ASCENT BEST SHOWN ON THE 290-300K
SFCS /ABOUT H6-75/ AND SPREADING TO THE NE TOWARD THE WRN CWA.
AHEAD OF THIS PCPN...SKIES OVER UPR MI ARE MAINLY CLDY WITH MOIST
LLVL AIRMASS TRAPPED UNDER SHARP INVRN BASE ARND H9. THERE HAS BEEN
SOME PATCHY LIGHT FREEZING DZ IN AREAS OVER THE KEWEENAW/NCENTRAL
WHERE LLVL ESE FLOW UPSLOPES.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON SN AMOUNTS
ASSOCIATED WITH INCOMING SHRTWV AND GOING HEADLINES.
LATE TODAY/TNGT...AS AREA OF ISENTROPIC ASCENT/UPR DVGC/DEEP LYR
QVECTOR CNVGC IN ADVANCE OF SHRTWV MOVING THRU MN PUSHES INTO THE
CWA...EXPECT SN TO OVERSPREAD THE AREA W-E. MODELS ARE INDICATING
A 9-12 HR PERIOD OF FORCING BEFORE THE ARRIVAL OF SOME DEEP LYR
QVECTOR DVGC/DNVA OVER THE W LATE IN THE WAKE OF THE SHRTWV/SFC LO
MOVING OVER CENTRAL UPR MI/NRN LK SUP BY 12Z WED. BUT SOME LINGERING
DRY AIR JUST ABOVE THE INVRN BASE WL HINDER THE DEVELOPMENT OF
STEADIER PCPN...ESPECIALLY IN AREAS THAT EXPERIENCE A DOWNSLOPE
WIND COMPONENT WITH ONGOING S FLOW...SO THE ACTUAL WINDOW FOR
STEADIER SN WL ACTUALLY BE 6-9 HRS. MODELS INDICATE ABOUT 2.5 G/KG
SPECIFIC HUMIDITY WL BE PRESENT ON THE 290K SFC ARND H7...WHICH
WOULD SUPPORT GOING FCST UP 3 TO 4 INCHES OF SNOW DURING THE 6-9 HR
WINDOW OF STEADY PCPN. ABSENCE OF ANY PHASING WITH THE ARCTIC/
SUBTROPICAL BRANCES AND SHARPER UPR DVGC ASSOCIATED WITH THE JET
CORES IN THOSE BRANCHES AS WELL AS FCST HI THIN DGZ THAT WL LIMIT
SN/WATER RATIOS WL LIMIT SN TOTALS. LATE TNGT...EXPECT THE PCPN OVER
THE W TO DIMINISH FOR AT LEAST A TIME FOLLOWING THE EXIT OF THE DEEP
UPR FORCING AND PASSAGE OF LO PRES TROF ACCOMPANYING SFC LO MOVING
THRU NRN LK SUP. THE INCOMING AIRMASS WL BE INITIALLY TOO WARM TO
SUPPORT LES. GOING HEADLINES APPEAR TO BE IN GOOD SHAPE. DID ADD
LUCE COUNTY TO THE HEADLINE MIX WITH ARND 3 INCHES EXPECTED THERE
BEFORE THE SN DIMINISHES LATER ON WED MRNG.
WED...LINGERING STEADY SN OVER THE ERN CWA SHOULD END IN THE MRNG
WITH THE PASSAGE OF SHRTWV/ACCOMPANYING SFC LO PRES TROF AND EXIT OF
DEEP LYR QVECTOR CNVGC. GUIDANCE THEN SHOWS AN ARCTIC BRANCH SHRTWV
DIGGING SHARPLY TO NEAR WRN LK SUP BY 00Z THU...WITH H85 TEMPS
FALLING TOWARD -21C OVER THE NW CWA BY 00Z THU FOLLOWING ATTENDANT
COLD FROPA. NNW H925 WINDS INCRSG UP TO 30-35KTS IN THE SHARP CYC
FLOW LEFT IN THE WAKE OF THIS DISTURBANCE AND DEEPENING LO PRES
EXITING TO THE E IN THE STRONG CAA WL RESULT IN VERY GUSTY SFC WINDS
THAT WL AT LEAST APRCH ADVY LEVELS AS WELL AS CONSIDERABLE BLSN IN
ADDITION TO THE LES IN EXPOSED AREAS NEAR LK SUP. THE COMBINATION OF
THE SHARP CYC FLOW AS WELL AS SOME DPVA/DEEP LYR QVECTOR CNVGC/
DEEPENING MSTR WITH THE STRONG CAD MAY BRING A PERIOD OF SOME LK
ENHANCED SN LATE IN THE DAY OVER THE W. LATER SHIFTS WL
NEED TO INCLUDE ADDITIONAL HEADLINES FOR AT LEAST AREAS NEAR LK SUP
FOR LATER WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 348 PM EST TUE FEB 10 2015
STEADY N TO NNE WINDS WILL ALREADY BE SET UP AT 00Z THURSDAY...WITH
THE SFC LOW OVER NE LAKE HURON. MUCH OF WEDNESDAY NIGHT WILL BE
MARKED BY STRONG WINDS WITH GUSTS ON THE ORDER OF 30-40KTS. THERE IS
A POCKET OF 35-40KT WINDS BETWEEN 925 AND 800MB FROM 00Z-12Z
THURSDAY. THERE WILL DEFINETLY BE A NON-DIURNAL TREND TO THE WINDS.
WINDS WILL REMAIN OUT OF THE N THROUGH 12Z SUNDAY...ALTHOUGH WEAKEN
SIGNIFICANTLY LATE SATURDAY NIGHT/EARLY SUNDAY MONRING. IT WILL BE
AN EXTENDED PERIOD OF LAKE EFFECT SNOW SHOWERS...THAT WHEN
ACCOMPANIED WITH THE WIND AND THE SNOW ALREADY ON THE GROUND...WILL
RESULT IN SHARPLY REDUCED VISIBILITIES. HEADLINES WILL EVENTUALLY BE
POSTED FOR THIS PERIOD TO NOT ONLY HIGHLIGHT THE 2-4IN OF SNOW FROM
WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...BUT THE BLOWING SNOW
SHARPLY REDUCING VIS. WILL CONTINUE TO HIGHLIGHT THIS PERIOD IN THE
HWO...WITH THE MAIN FOCUS OF THE SNOW AND BLOWING SNOW BEING ALONG
LAKE SUPERIOR...AND MAINLY FROM THE HURON MOUNTAINS THROUGH MUNISING
AND GRAND MARIAS.
BY DAYBREAK THURSDAY THE SFC WILL HAVE SHIFTED TO NY AND THE STRONG
1048-1052MB/30.9IN HIGH WILL HAVE SLIPPED INTO THE DAKOTAS. THE
PRESSURE GRADIENT WILL WEAKEN DURING THE AFTERNOON HOURS AS THE HIGH
WEAKENS SLIGHTLY ACROSS IA.
EXPECT THE SFC RIDGE TO EXTEND DIRECTLY OVER THE CWA 00-06Z
FRIDAY...BRINGING THE LIGHTEST WINDS OF THE PERIOD AND SHIFTING
LINGERING LES OVER E ALGER AND SCHOOLCRAFT/W LUCE COUNTIES FROM LATE
AFTERNOON THROUGH THE EVENING HOURS. OFFSHORE WINDS WILL TAKE HOLD
ACROSS ALL OF N UPPER MI BY 12Z FRIDAY.
QUICK ON THE HEALS OF THIS PAST SYSTEM...THE NEXT SFC LOW OVER THE W
HALF OF ONTARIO AT 12Z FRIDAY SHOULD CROSS N/CENTRAL LAKE SUPERIOR
BY MID DAY...AND DEEPEN OVER E LAKE SUPERIOR/UPPER MI BY 00Z
SATURDAY. A LIMITED PERIOD OF WAA WILL MEAN THAT 850MB TEMPS WILL
ONLY RISE TO AROUND -18C FRIDAY MORNING-EARLY AFTERNOON. AFTER THE
PASSAGE OF THE LOW LOOK FOR THE -20 TO -25C 850MB AIR TO FILTER BACK
IN. UNLIKE THE PAST COUPLE OF EVENTS...FREEZING DRIZZLE ON THE ONSET
WILL NOT BE A CONCERN.
NW WINDS WILL BE PICKING UP ACROSS THE W HALF OF UPPER MY BY AROUND
21Z...AND INCREASE ACROSS THE ENTIRE CWA OVERNIGHT TURNING FROM OUT
OF THE NW TO N AS THE SFC LOW EXITS ACROSS LAKE HURON AND THE COLD
AIR SETTLES IN WITH THE 500MB LOW OVER CENTRAL ONTARIO AT 06Z
SATURDAY SINKING OVER CENTRAL/E UPPER MI AROUND 12Z. -25 TO -35C AIR
WILL BE OVER THE W HALF BY 12Z SATURDAY /COLDEST OFF THE 10/12Z RUN
OF THE GFS/. EXPECT COLD AND BLUSTERY CONDITIONS LATE FRIDAY NIGHT
THROUGH SATURDAY!
AS PREVIOUSLY STATED...THE FIRST WAVE OF LAKE EFFECT AND STRONG
WINDS WEDNESDAY NIGHT AND THURSDAY WILL GIVE A GOOD FEEL TO WHAT
WILL HAPPEN FRIDAY NIGHT INTO SATURDAY. AT THIS POINT EXPECT
CONDITIONS TO BE WORSE THAN THE FIRST WAVE AND THERE WILL LIKELY BE
A PERIOD OF BLIZZARD CONDITIONS FOR THE FAVORED MARQUETTE-MUNISING
STRETCH AND PERSONS WILL LIKELY NEED TO PLAN FOR THE POSSIBILITY OF
M-28 BEING CLOSED.
WIND CHILL READINGS SATURDAY MORNING WILL FALL TO -15 TO -25F
SATURDAY MORNING AS THE STRONG WINDS COMBINE WITH LOWS AROUND 0F.
LOOK FOR SOME MODERATION TO THE VERY COLD AIR ALOFT SUNDAY...BUT
STILL AROUND -20 TO -25C THROUGH THE DAY SUNDAY. THERE IS SOME
DISCREPANCIES IN THE LOCAL WIND SHIFTS ACROSS LAKE SUPERIOR
SUNDAY...BUT THE TREND WILL BE IMPROVING CONDITIONS EITHER WAY AS
THE SFC HIGH SHIFTS OVERHEAD SUNDAY AND EXITS E SUNDAY
AFTERNOON/EVENING. THE NEXT GOOD CHANCE OF SNOW FOR LATE MONDAY
NIGHT/TUESDAY DOESN/T LOOK TOO IMPRESSIVE OFF THE ECMWF...BUT MORE
DYNAMIC OFF THE GFS. A BLENDED MODEL SOLUTION SEEMS REASONABLE AT
THIS POINT...AS THE MAIN CONCERS AND FOCUS FOR THIS FCST PERIOD ARE
RIGHT AT THE BEGINING AND THEN FRIDAY NIGHT THROUGH SATURDAY
MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1229 PM EST TUE FEB 10 2015
IWD...AS AN AREA OF SN MOVES IN BY ABOUT 21Z...EXPECT VFR CONDITIONS
TO DETERIORATE TO IFR DESPITE PREVAILING DOWNSLOPE SSE FLOW. BUT
ONCE THE MAIN AREA OF FORCING SHIFTS TO THE E BY LATE EVNG...MVFR
CONDITIONS SHOULD RETURN WITH THE DOWNSLOPE S WIND COMPONENT. WINDS
WL SHIFT TO THE W FOLLOWING THE PASSAGE OF A LO PRES TROF EARLY ON
WED MRNG. A STRONGER COLD FROPA TOWARD 15Z WL BRING STRONGER NW
WINDS/SOME LES AND A RETURN OF IFR CONDITIONS.
CMX...EXPECT IFR/LIFR CONDITIONS TO PREVAIL THIS AFTN WITH AN
UPSLOPE ESE FLOW AND PERHAPS A BIT OF -FZDZ. LIFR WX CONTINUE THRU
THIS EVNG WITH THE ARRIVAL OF AREA OF STEADIER SN FM THE SW. THERE
IS LIKELY TO BE A BIT OF A LULL LATER TNGT AND SOME MVFR
CONDITIONS...BUT WSHFT TO AN UPSLOPE W DIRECTION ARND 12Z FOLLOWING
A LO PRES TROF PASSAGE SHOULD BRING A RETURN OF IFR CIGS. GUSTY NW
WINDS AND SOME LES/IFR CONDITIONS WL FOLLOW A STRONGER COLD FROPA BY
LATE MRNG.
SAW...EXPECT IFR CONDITIONS TO PERSIST MOST OF THE TIME THRU TNGT.
BEFORE THE MAIN AREA OF SN ARRIVES THIS EVNG...UPSLOPE SE WINDS WL
BRING SOME FOG AND -FZDZ. CONDIIONS ARE LIKELY TO FALL TO LIFR FOR
AT LEAST A TIME DURING THE NGT UNDER THE BAND OF STEADY SN. ONCE
THIS AREA OF PCPN EXITS BY 12Z...CONDITIONS SHOULD RETURN TO MVFR
WITH STRENGTHENING DOWNSLOPE W VEERING NW WIND FOLLOWING LO PRES
TROF PASSAGE/COLD FROPA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST TUE FEB 10 2015
THE GALE WATCH FOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING WILL
BE UPGRADED TO A GALE WARNING. HEAVY FREEZING SPRAY WARNING WILL BE
NEEDED.
A RIDGE STRETCHING FROM JAMES BAY TO THE LOWER GREAT LAKES WILL
SHIFT E ACROSS QUEBEC TONIGHT. MEANWHILE...A TROUGH ACROSS THE UPPER
MS VALLEY WILL MOVE ACROSS LAKE SUPERIOR LATE TONIGHT AND WEDNESDAY
MORNING. THE LOW WILL CONTINUE E ACROSS THE LOWER GREAT LAKES
THROUGH WEDNESDAY NIGHT AS A TROUGH REMAINS ACROSS LOWER MI. A HIGH
ACROSS S CENTRAL CANADA WEDNESDAY WILL MOVE TO THE MID MS VALLEY ON
THURSDAY AND BUILD A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. IN BETWEEN THE EXITING LOW AND NEARING HIGH...N
GALES OF 35 TO 45 KNOTS ACROSS CENTRAL AND EASTERN LAKE SUPERIOR
LATE WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS LAKE
SUPERIOR FRIDAY AFTERNOON AND EVENING...AND THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE A LARGE HIGH NEARS FROM SOUTH CENTRAL
CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT ANOTHER ROUND
OF N GALES OF 35 TO 45 KNOTS AND HEAVY FREEZING SPRAY IS POSSIBLE
FRIDAY NIGHT THROUGH SATURDAY...MAINLY OVER CENTRAL AND EASTERN LAKE
SUPERIOR. EXPECT THE HIGH TO DRIFT ACROSS THE UPPER GREAT LAKES ON
SUNDAY...WITH MUCH LIGHTER WINDS TAKING HOLD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 AM EST /6 AM CST/ WEDNESDAY FOR MIZ001-003>005-010-011-
084.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ006-013-014-085.
WINTER WEATHER ADVISORY UNTIL 4 AM EST /3 AM CST/ WEDNESDAY FOR
MIZ002-009.
WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR
MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ267.
GALE WARNING FROM 4 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 PM EST
THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 4 PM EST THURSDAY FOR LSZ266.
GALE WARNING FROM 1 PM WEDNESDAY TO 1 PM EST THURSDAY FOR LSZ265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR LSZ264.
GALE WARNING FROM 1 PM WEDNESDAY TO 10 AM EST THURSDAY FOR
LSZ264.
HEAVY FREEZING SPRAY WARNING FROM 1 PM WEDNESDAY TO 7 AM EST
THURSDAY FOR LSZ263.
GALE WARNING FROM 1 PM WEDNESDAY TO 7 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
357 AM EST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 348 PM EST MON FEB 9 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE GREAT LKS BTWN AN UPR RDG OVER THE WRN PLAINS AND A TROF
ACROSS THE ERN CONUS. A SHRTWV EMBEDDED IN THIS NW FLOW AND
ACCOMPANYING AREA OF SOMEWHAT DEEPER MSTR/DYNAMIC FORCING THAT
LIFTED INVRN BASE UP TO ARND 4K FT AGL BROUGHT AN UPTICK THIS MRNG
TO THE LES IN THE PRESENCE OF INVRN BASE TEMPS ARND -12C OVER MAINLY
THE NCNTRL WHERE OBSVD N WINDS UPSLOPE. BUT DNVA/SUBSIDENCE IN THE
WAKE OF THE SHRTWV PASSAGE AND IN ADVANCE OF APRCHG SHRTWV RDG HAVE
CAUSED THE LES TO DIMINISH THIS AFTN...AND EVEN FOR THE LO CLDS TO
BREAK UP TO A CERTAIN EXTENT. SINCE THE 12Z INL/YPL ROABS TO THE NW
SHOW MSTR EXTENDING UP THRU ABOUT H7...PLENTY OF CLD COVER AND SOME
FLURRIES LINGER UPSTREAM IN NRN MN AND NW ONTARIO. LOOKING FARTHER
UPSTREAM...A FAIRLY VIGOROUS SHRTWV IS MOVING INTO THE PAC NW AND
OVER THE WRN RDG.
LATE TODAY/TNGT...ALTHOUGH THE LLVLS WL REMAIN COLD ENUF FOR LES...
LARGE SCALE SUBSIDENCE IN ADVANCE OF APRCHG SHRTWV RDG THAT DEPRESS
INVRN BASE TOWARD 2-3K FT WL LIMIT LES INTENSITY AND COVERAGE.
INITIALLY...LLVL LIGHT WINDS ARE FCST TO BACK TOWARD THE NW INTO
THIS EVNG AHEAD OF THE INCOMING SFC RDG. SO MOST OF THE LINGERING
LES/LK CLDS SHOULD BE TO THE E OF MQT AND OVER THE KEWEENAW THIS
EVNG. LIGHT WINDS ASSOCIATED WITH THE PASSING SFC RDG AXIS MAY ALLOW
FOR A MESOLO PRES TO DVLP. HOWEVER...PRESENCE OF A GOOD DEAL OF ICE
NEAR LK SUP E OF MARQUETTE WL LIMIT THE POTENTIAL IMPACT OF THIS
FEATURE IN THESE AREAS. AS THE WINDS TEND TO SHIFT BACK TO THE NE
LATER FOLLOWING THE PASSAGE OF THE RDG AXIS TO THE E...SOME LES
MIGHT SHIFT BACK TOWARD MARQUETTE. ANOTHER WEAK SHRTWV/AREA OF DEEP
LYR QVECTOR CNVGC IS FCST TO MOVE BY LATE TNGT. BUT SINCE SFC RDG
AXIS WL BE PASSING THRU AT THAT TIME...THE IMPACT SHOULD BE MINIMAL.
EXPECT THE LOWEST MIN TEMPS OVER THE E AND SCNTRL WHERE LIGHT E
WINDS WL DRAIN OFF SOME VERY COLD OVER ONTARIO AND MSTR/CLDS TO THE
NW WL HAVE A HARDER TIME REACHING.
TUE...LARGE SCALE WAA/DEEP LYR QVECTOR CNVGC/UPR DVGC IN INCRSG SSE
FLOW BTWN DEPARTING SFC HI PRES RDG TO THE E AND IN ADVANCE OF
SHRTWV NOW OVER THE PAC NW THAT WL BE MOVING THRU THE NRN PLAINS IS
FCST TO ARRIVE IN THE AFTN. THE ARRIVAL OF THIS FORCING AND
ACCOMPANYING UVV WL ALLOW FOR THICKENING CLDS AND SOME SN TO PUSH
INTO THE WRN COUNTIES DURING THE AFTN. H7 SPECIFIC HUMIDITY FCST UP
TO 3 G/KG UNDER THE AXIS OF WAA INDICATES A FEW INCHES OF SN MAY
ACCUMULATE OVER THE FAR W BY 00Z DESPITE A RATHER HI...NARROW DGZ.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 357 AM EST TUE FEB 10 2015
MUCH OF THE FOCUS OF THE LONG TERM PERIOD WILL BE TIED TO THE COLD
AIR MOVING SOUTHEAST ACROSS THE REGION ON WEDNESDAY...LEADING TO
MODERATE LAKE EFFECT SNOW UNDER GUSTY NORTHERLY WINDS WEDNESDAY
NIGHT INTO THURSDAY. HIGH PRESSURE WILL QUICKLY DROP SOUTHEAST
ACROSS THE UPPER GREAT LAKES REGION THURSDAY NIGHT...BEFORE ANOTHER
CLIPPER AND STRONG SHORTWAVE DIVES SOUTHEAST ACROSS THE AREA FRIDAY
AND FRIDAY EVENING. THIS WILL USHER IN EVEN COLDER AIR OVER THE
REGION...PRODUCING ANOTHER PERIOD OF LAKE EFFECT AND GUSTY
NORTHERLY WINDS. THE SHRINKING SNOWFLAKE SIZE WILL BE EFFECTIVE AT
REDUCING VISIBILITIES WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
FRIDAY NIGHT INTO SATURDAY...LEADING TO VERY LOW VISIBILITIES IN
THE LAKE EFFECT SNOW SHOWERS. WITH THE GUSTY NORTHERLY
WINDS AIDING BLOWING SNOW...EXPECT SOME AREAS TO SEE VISIBILITIES
FREQUENTLY BELOW A QUARTER MILE.
NOW FOR THE DETAILS...THE 1011MB SURFACE LOW WILL BE LOCATED OVER
EASTERN LAKE SUPERIOR AND CENTRAL UPPER MICHIGAN AT THE START OF THE
LONG TERM PERIOD AND BE QUICKLY SHIFTING EAST-SOUTHEAST THROUGH THE
DAY. MEANWHILE...A STRONG SHORTWAVE (LOCATED IN NORTHWEST ONTARIO
AND MANITOBA AT THE START OF THE PERIOD) WILL BE DIVING SOUTHEAST
ACROSS THE AREA WEDNESDAY AFTERNOON. THE COMBINATION OF THESE TWO
FEATURES WILL LEAD TO A SIGNIFICANT TRANSITION IN THE WEATHER
CONDITIONS THROUGH THE DAY ON WEDNESDAY. STILL EXPECT THERE TO BE
SOME LIGHT SNOW ONGOING OVER THE EASTERN HALF OF THE CWA AT THE
START OF THE PERIOD AND THEN SHIFTING OFF TO THE EAST. MEANWHILE
OVER THE WEST...WINDS WILL BE TURNING TO THE NORTHWEST AND EXPECT
LAKE EFFECT SNOW TO DEVELOP FAIRLY QUICKLY DURING THE MORNING HOURS.
AS THE COLD AIR SURGES INTO THE AREA...EXPECT THAT LAKE EFFECT
INTENSITY/COVERAGE TO INCREASE OVER THE WESTERN U.P. WITH 1-4
INCHES OF ACCUMULATION EXPECTED. WINDS WILL BE LIGHTER INITIALLY
WITH MUCH OF THE CLOUD WITHIN THE DGZ...SO EXPECT THE SNOW RATIOS TO
BE IN THE 20-25 TO 1 RANGE DURING THE DAY WEDNESDAY OVER THE WEST.
OVER THE EAST BEHIND THE LOW...THE NORTHWEST WINDS SHOULD LEAD TO
LAKE EFFECT DEVELOPMENT BY EARLY AFTERNOON IN THE FAVORED NORTHWEST
WIND AREAS...ALTHOUGH THE ICE OVER THE SOUTH CENTRAL LAKE WILL
LIKELY LIMIT THE INTENSITY OF THE SNOW OVER PORTIONS OF WESTERN
ALGER COUNTY.
WINDS WILL BECOME GUSTY DURING THE AFTERNOON (20-30KTS) SO HAVE
BLOWING SNOW POTENTIAL INCREASING DURING THAT TIME...BUT EXPECT THE
GUSTINESS TO REALLY KICK IN WEDNESDAY EVENING. THIS IS DUE TO A
TRAILING SURFACE TROUGH DROPPING SOUTH ACROSS THE AREA AND SHIFTING
WINDS TO THE NORTH. THUS...WILL SEE LAKE EFFECT TRANSITIONING TO
THAT FAVORED WIND DIRECTION DURING THE EVENING AND CONTINUING INTO
THURSDAY MORNING. SNOWRATIOS WILL BE LOWERING DUE TO THE INCREASING
COLD AIR AND WINDS...BUT STILL HAVE THE NORTHERLY WIND AREAS SEEING
2 TO 5 INCHES OF SNOW. WITH STEEP LOW LEVEL LAPSE RATES AND
950-925MB WINDS AT LEAST 35KTS...EXPECT GUSTS TO AROUND THAT FROM
THE KEWEENAW PENINSULA AND EASTWARD. THE STRONGEST WINDS ARE
EXPECTED TO OCCUR OVER SOUTH CENTRAL LAKE SUPERIOR AND NORTH CENTRAL
UPPER MICHIGAN...WHERE THE TIGHTEST PRESSURE GRADIENT IS EXPECTED
AND AIDED BY THE LONGER FETCH OVER ICE FREE WATERS OF
CENTRAL/EASTERN LAKE SUPERIOR. GUSTS IN THAT AREA WILL LIKELY BE
INTO THE LOW 40KTS RANGE AT TIMES WEDNESDAY NIGHT. THE COMBINATION
OF THE SNOW WITH THE BLOWING SNOW WILL FREQUENTLY REDUCE
VISIBILITIES BELOW 1/2 MILE FOR AREAS NEAR LAKE SUPERIOR. WITH THE
SEVERAL MILES OF ICE OFFSHORE FROM MARQUETTE TO MUNISING...WOULD
EXPECT THAT TO AID THE BLOWING SNOW AND WITH THE STRONGEST WINDS
EXPECTED IN THAT AREA...THINK THERE WILL BE PERIODS OF VISIBILITIES
BELOW 1/4MI (ESPECIALLY ALONG M-28). WILL CONTINUE THE HEIGHTENED
WORDING IN HWO AND WILL DEFINITELY NEED HEADLINES FOR THAT AREA
WEDNESDAY NIGHT INTO THURSDAY.
EXPECT THE SNOW INTENSITY TO DIMINISH FROM WEST TO EAST ON
THURSDAY...AS AN APPROACHING HIGH PRESSURE RIDGE FROM CENTRAL CANADA
LOWERS INVERSION HEIGHTS AND BRINGS DRIER AIR INTO THE AREA. WITH
WINDS GRADUALLY WEAKENING AND BACKING THROUGH THE DAY...SHOULD SEE
CONDITIONS IMPROVE BY THE AFTERNOON OVER THE WEST AND EVENING OVER
THE EAST. HIGHS ON THURSDAY WILL BE IN THE SINGLE DIGITS ABOVE ZERO
AND CLOSE TO THE NORMAL LOWS FOR THIS TIME OF YEAR. MODELS SEEM TO
HAVE SPEED UP THE HIGH CLOUDS FROM THE NEXT SHORTWAVE/CLIPPER TO
AFFECT THE AREA ON FRIDAY...SO THAT LEAVES LOWS ON THURSDAY NIGHT A
LITTLE UNCERTAIN UNDER THE HIGH PRESSURE MOVING THROUGH. WITH SOME
CLEARING EXPECTED IN THE EVENING OVER THE INTERIOR
WEST/CENTRAL...WILL CONTINUE TO SHOW A QUICK FALL AFTER SUNSET AND
THEN STEADY OR SLOWLY RISING TEMPERATURES OVERNIGHT.
THE AREA OF HIGH PRESSURE WILL SLIDE SOUTHEAST OF THE AREA LATE
THURSDAY NIGHT...AS ANOTHER SHORTWAVE DIVES SOUTHEAST ACROSS THE
AREA ON FRIDAY. EXPECT ANY SNOWFALL AMOUNTS TO BE LIGHT (DUSTING TO
AN INCH)...BUT IT WILL USHER IN ANOTHER PERIOD OF LAKE EFFECT SNOW
FOR LATER FRIDAY NIGHT AND SATURDAY. 850MB TEMPERATURES WILL FALL TO
AROUND -30C ON SATURDAY...WHICH WILL LIKELY HAVE HIGHS STRUGGLING TO
GET MUCH ABOVE ZERO. THAT AMOUNT OF COLD AIR WILL LEAD TO VERY FINE
FLAKE LAKE EFFECT (ALTHOUGH STRONGER BANDS WITH INVERSION HEIGHTS
TO 10-12KFT) AND WITH NORTHERLY WINDS ONCE AGAIN GUSTING TO 30-40KTS
(POSSIBLE EVEN 45KTS FOR THE MARQUETTE-MUNISING STRETCH) LATE FRIDAY
NIGHT THROUGH SATURDAY...EXPECT VERY POOR VISIBILITIES (LIKELY NEAR
ZERO AT TIMES BETWEEN MARQUETTE/MUNISING ALONG THE LAKE SUPERIOR
SHORELINE). THAT FIRST WAVE OF LAKE EFFECT AND STRONG WINDS
WEDNESDAY NIGHT AND THURSDAY WILL GIVE A GOOD FEEL TO WHAT WILL
HAPPEN FRIDAY NIGHT INTO SATURDAY. AT THIS POINT EXPECT CONDITIONS
TO BE WORSE THAN THE FIRST WAVE AND THERE WILL LIKELY BE A
PERIOD OF BLIZZARD CONDITIONS FOR THE FAVORED MARQUETTE-MUNISING
STRETCH AND PERSONS WILL LIKELY NEED TO PLAN FOR THE POSSIBILITY OF
M-28 BEING CLOSED.
A HIGH PRESSURE RIDGE WILL BUILD OVER THE AREA SATURDAY
NIGHT...LOWERING INVERSION HEIGHTS...WEAKENING WINDS...AND
GRADUALLY DIMINISHING THE LAKE EFFECT FROM WEST TO EAST. DID OPT TO
TREND POPS UP OVER THE NORTH CENTRAL FOR MUCH OF SATURDAY NIGHT DUE
TO THE LINGERING FAVORABLE FETCH OVER THE MOST ICE FREE WATERS.
ONCE THE RIDGE SHIFTS SOUTHEAST ON SUNDAY...EXPECT THE LAKE EFFECT
TO COME TO AN END AND LEAD TO A QUIETER DAY. THAT WILL LIKELY BE
SHORT LIVED AS ANOTHER (ALTHOUGH WEAKER) SHORTWAVE AND SURFACE
TROUGH MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY. SNOWFALL
AMOUNTS LOOK TO BE LIGHT WITH THIS FEATURE AND UNDER AN INCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1159 PM EST MON FEB 9 2015
VFR CONDITIONS WILL LIKELY PREVAIL AT KIWD THRU MID AFTN AS
LIGHT/CALM WIND BECOMES A DOWNSLOPE SE WIND. AT KCMX...MVFR CIGS
SHOULD GENERALLY BE THE RULE INTO THE AFTN WITH LIGHT WINDS OFF LAKE
SUPERIOR. AT KSAW...VFR CONDITIONS SHOULD GIVE WAY TO MVFR CIGS IN
THE NEXT FEW HRS AS LIGHT NE WINDS DEVELOP OFF LAKE SUPERIOR.
CONTINUED UPSLOPE FLOW AS WINDS VEER SE WILL HELP TO MAINTAIN MVFR
CIGS AT KSAW INTO THE AFTN. LATE IN THE AFTN AND THIS EVENING...
DISTURBANCE APPROACHING FROM THE W WILL BRING -SN/IFR CONDITIONS TO
ALL TERMINALS. NOT OUT OF THE QUESTION THAT THERE COULD BE BRIEF
LIFR THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST MON FEB 9 2015
A COUPLE ROUNDS AND HEAVY FREEZING SPRAY ARE EXPECTED THIS PERIOD. A
RIDGE ACROSS LAKE SUPERIOR WILL SLOWLY ERODE TUESDAY...AS A LOW
NEARS FROM THE N PLAINS. EXPECT THE LOW TO CROSS THE UPPER GREAT
LAKE TUESDAY NIGHT AND WEDNESDAY...THE LOWER GREAT LAKES WEDNESDAY
NIGHT...AND EVENTUALLY END UP DEEPENING SIGNIFICANTLY OFF THE NEW
ENGLAND COAST THURSDAY NIGHT. THIS WILL BE WHILE A HIGH ACROSS S
CENTRAL CANADA WEDNESDAY MOVES TO THE MID MS VALLEY THURSDAY NIGHT
...AND BUILDS A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. A GALE WATCH HAS BEEN ISSUED FOR MUCH OF CENTRAL TO
E LAKE SUPERIOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS
MAINLY N WINDS INCREASE W/30-40KT GUSTS.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS THE
UPPER GREAT LAKES FRIDAY...AND INTO THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE LARGE HIGH PRESSURE NEARS FROM THE S
CENTRAL CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT
ANOTHER PERIOD OF MAINLY N GALES OF 35-40KTS OVER MUCH OF LAKE
SUPERIOR FRIDAY EVENING THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 AM EST /6 AM CST/ WEDNESDAY FOR MIZ001-003>006-010-011-
013-014-084-085.
WINTER WEATHER ADVISORY FROM 2 PM EST /1 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON
FOR LSZ266-267.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ265.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ264.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1200 AM EST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 348 PM EST MON FEB 9 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE GREAT LKS BTWN AN UPR RDG OVER THE WRN PLAINS AND A TROF
ACROSS THE ERN CONUS. A SHRTWV EMBEDDED IN THIS NW FLOW AND
ACCOMPANYING AREA OF SOMEWHAT DEEPER MSTR/DYNAMIC FORCING THAT
LIFTED INVRN BASE UP TO ARND 4K FT AGL BROUGHT AN UPTICK THIS MRNG
TO THE LES IN THE PRESENCE OF INVRN BASE TEMPS ARND -12C OVER MAINLY
THE NCNTRL WHERE OBSVD N WINDS UPSLOPE. BUT DNVA/SUBSIDENCE IN THE
WAKE OF THE SHRTWV PASSAGE AND IN ADVANCE OF APRCHG SHRTWV RDG HAVE
CAUSED THE LES TO DIMINISH THIS AFTN...AND EVEN FOR THE LO CLDS TO
BREAK UP TO A CERTAIN EXTENT. SINCE THE 12Z INL/YPL ROABS TO THE NW
SHOW MSTR EXTENDING UP THRU ABOUT H7...PLENTY OF CLD COVER AND SOME
FLURRIES LINGER UPSTREAM IN NRN MN AND NW ONTARIO. LOOKING FARTHER
UPSTREAM...A FAIRLY VIGOROUS SHRTWV IS MOVING INTO THE PAC NW AND
OVER THE WRN RDG.
LATE TODAY/TNGT...ALTHOUGH THE LLVLS WL REMAIN COLD ENUF FOR LES...
LARGE SCALE SUBSIDENCE IN ADVANCE OF APRCHG SHRTWV RDG THAT DEPRESS
INVRN BASE TOWARD 2-3K FT WL LIMIT LES INTENSITY AND COVERAGE.
INITIALLY...LLVL LIGHT WINDS ARE FCST TO BACK TOWARD THE NW INTO
THIS EVNG AHEAD OF THE INCOMING SFC RDG. SO MOST OF THE LINGERING
LES/LK CLDS SHOULD BE TO THE E OF MQT AND OVER THE KEWEENAW THIS
EVNG. LIGHT WINDS ASSOCIATED WITH THE PASSING SFC RDG AXIS MAY ALLOW
FOR A MESOLO PRES TO DVLP. HOWEVER...PRESENCE OF A GOOD DEAL OF ICE
NEAR LK SUP E OF MARQUETTE WL LIMIT THE POTENTIAL IMPACT OF THIS
FEATURE IN THESE AREAS. AS THE WINDS TEND TO SHIFT BACK TO THE NE
LATER FOLLOWING THE PASSAGE OF THE RDG AXIS TO THE E...SOME LES
MIGHT SHIFT BACK TOWARD MARQUETTE. ANOTHER WEAK SHRTWV/AREA OF DEEP
LYR QVECTOR CNVGC IS FCST TO MOVE BY LATE TNGT. BUT SINCE SFC RDG
AXIS WL BE PASSING THRU AT THAT TIME...THE IMPACT SHOULD BE MINIMAL.
EXPECT THE LOWEST MIN TEMPS OVER THE E AND SCNTRL WHERE LIGHT E
WINDS WL DRAIN OFF SOME VERY COLD OVER ONTARIO AND MSTR/CLDS TO THE
NW WL HAVE A HARDER TIME REACHING.
TUE...LARGE SCALE WAA/DEEP LYR QVECTOR CNVGC/UPR DVGC IN INCRSG SSE
FLOW BTWN DEPARTING SFC HI PRES RDG TO THE E AND IN ADVANCE OF
SHRTWV NOW OVER THE PAC NW THAT WL BE MOVING THRU THE NRN PLAINS IS
FCST TO ARRIVE IN THE AFTN. THE ARRIVAL OF THIS FORCING AND
ACCOMPANYING UVV WL ALLOW FOR THICKENING CLDS AND SOME SN TO PUSH
INTO THE WRN COUNTIES DURING THE AFTN. H7 SPECIFIC HUMIDITY FCST UP
TO 3 G/KG UNDER THE AXIS OF WAA INDICATES A FEW INCHES OF SN MAY
ACCUMULATE OVER THE FAR W BY 00Z DESPITE A RATHER HI...NARROW DGZ.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 510 PM EST MON FEB 9 2015
BOUTS OF COLD AND SNOW WILL BE THE THEME FOR THE LONG TERM PERIOD.
SNOW WILL BE EXPANDING W TO E ACROSS THE CWA TUESDAY NIGHT AS THE
MAIN SFC LOW OVER S AND CENTRAL MN CROSSES FAR W BY 06Z...AND SPLITS
THE AREA IN HALF BY 12Z WEDNESDAY. 850MB TEMPS WILL FALL TO AROUND -
12C BEHIND THE LOW...WITH -20C AIR WEDNESDAY EVENING ON FAVORABLE
UPSLOPE FLOW.
CONTINUED TO MENTION THE POTENTIAL FOR WIDESPREAD SNOW TUESDAY
AFTERNOON THROUGH TUESDAY NIGHT WITH A FEW INCHES OF SNOW
ACCUMULATION POSSIBLE...THEN LAKE EFFECT SNOW WEDNESDAY INTO
THURSDAY. GUSTY NW TO N WINDS WILL HELP PRODUCE BLOWING SNOW AND
REDUCED VIS WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING. MAY NEED
TO ISSUE WINTER WX ADVISORY FOR THE 2-4.5IN OF SNOW TUESDAY THROUGH
DAYBREAK WEDNESDAY...AND DEPENDING ON THE FOCUS OF MODERATE LES FOR
SNOW AND BLOWING SNOW FOR THE LONGER DURATION LES FOR THE N WIND
FAVORED AREAS OF GOGEBIC/ONTONAGON AND BARAGA/MARQUETTE E ALONG LAKE
SUPERIOR AS 850MB TEMPS FALL TO AROUND -25C.
WITH ALL THIS COLD AIR...WIND CHILL VALUES ARE EXPECTED TO FALL
BETWEEN 15 BELOW AND 25 BELOW ZERO THURSDAY MORNING INLAND FROM THE
GREAT LAKES.
THE N WINDS WILL ALSO BE A CONCERN FOR LATE FRIDAY EVENING THROUGH
ALL OF SATURDAY...WITH THE BEST CHANCE OF LES N CENTRAL. DID BUMP UP
THE WINDS/GUSTS APPROX 5KTS SATURDAY MORNING. LOOKING AT IT FROM A
DIFFERENT PERSPECTIVE...THIS WIND SATURDAY WILL PROBABLY RESULT IN A
RESTRICTION OR ROAD CLOSURE OF M-28 EAST OF HARVEY THROUGH MUNISING
LATE FRIDAY NIGHT THROUGH SATURDAY MORNING...ESPECIALLY CONSIDERING
THE AMOUNT OF SNOW THAT WILL BE ABLE TO ACCUMULATE ON THE SNOW JUST
OFFSHORE. AS THIS IS STILL 4-5 DAYS OUT...LOOK FOR ADJUSTMENTS TO
THE ONGOING FCST. IMPROVING CONDITIONS WILL COME IN SATURDAY NIGHT
AS THE SFC LOW SINING ACROSS THE UPPER GREAT LAKES FRIDAY
AFTERNOON/EVENING PUSHES TO THE CENTRAL APPALACHIANS BY SATURDAY
AFTERNOON. VERY STRONG HIGH PRESSURE ACROSS S CANADA AND THE CENTRAL
PLAINS WILL THEN SLOWLY MOVE IN. THE SFC RIDGE WILL BE
DIRECTLY OVERHEAD SUNDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1159 PM EST MON FEB 9 2015
VFR CONDITIONS WILL LIKELY PREVAIL AT KIWD THRU MID AFTN AS
LIGHT/CALM WIND BECOMES A DOWNSLOPE SE WIND. AT KCMX...MVFR CIGS
SHOULD GENERALLY BE THE RULE INTO THE AFTN WITH LIGHT WINDS OFF LAKE
SUPERIOR. AT KSAW...VFR CONDITIONS SHOULD GIVE WAY TO MVFR CIGS IN
THE NEXT FEW HRS AS LIGHT NE WINDS DEVELOP OFF LAKE SUPERIOR.
CONTINUED UPSLOPE FLOW AS WINDS VEER SE WILL HELP TO MAINTAIN MVFR
CIGS AT KSAW INTO THE AFTN. LATE IN THE AFTN AND THIS EVENING...
DISTURBANCE APPROACHING FROM THE W WILL BRING -SN/IFR CONDITIONS TO
ALL TERMINALS. NOT OUT OF THE QUESTION THAT THERE COULD BE BRIEF
LIFR THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 PM EST MON FEB 9 2015
A COUPLE ROUNDS AND HEAVY FREEZING SPRAY ARE EXPECTED THIS PERIOD. A
RIDGE ACROSS LAKE SUPERIOR WILL SLOWLY ERODE TUESDAY...AS A LOW
NEARS FROM THE N PLAINS. EXPECT THE LOW TO CROSS THE UPPER GREAT
LAKE TUESDAY NIGHT AND WEDNESDAY...THE LOWER GREAT LAKES WEDNESDAY
NIGHT...AND EVENTUALLY END UP DEEPENING SIGNIFICANTLY OFF THE NEW
ENGLAND COAST THURSDAY NIGHT. THIS WILL BE WHILE A HIGH ACROSS S
CENTRAL CANADA WEDNESDAY MOVES TO THE MID MS VALLEY THURSDAY NIGHT
...AND BUILDS A RIDGE ACROSS LAKE SUPERIOR LATE THURSDAY INTO
THURSDAY NIGHT. A GALE WATCH HAS BEEN ISSUED FOR MUCH OF CENTRAL TO
E LAKE SUPERIOR WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING AS
MAINLY N WINDS INCREASE W/30-40KT GUSTS.
LOOK FOR A LOW ACROSS MANITOBA THURSDAY NIGHT TO SINK ACROSS THE
UPPER GREAT LAKES FRIDAY...AND INTO THE CENTRAL APPALACHIANS
SATURDAY AFTERNOON...WHILE LARGE HIGH PRESSURE NEARS FROM THE S
CENTRAL CANADA AND THE NORTHERN PLAINS. THIS WILL BRING ABOUT
ANOTHER PERIOD OF MAINLY N GALES OF 35-40KTS OVER MUCH OF LAKE
SUPERIOR FRIDAY EVENING THROUGH SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON
FOR LSZ266-267.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ265.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ264.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1220 PM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 917 AM CST TUE FEB 10 2015
BRIEF UPDATE TO ADJUST FOR TEMPERATURE TRENDS. NO MAJOR CHANGE TO
WX ELEMENT GRIDS OR POPS...FORECAST STILL ON TRACK. HAVE RECEIVED
REPORTS OF PRECIP BEGINNING AS SLEET THEN CHANGING TO SNOW...BUT
SINCE THIS WAS ONLY OBSERVED FOR A BRIEF PERIOD HAVE OMITTED FROM
THE FORECAST FOR NOW. HAVE SOME CONCERN ABOUT LACK OF ICE IN
COLUMN...ESPECIALLY IN SOUTHERN PINE COUNTY WHERE IT LOOKS LIKE
PRECIP COULD FALL AS FREEZING RAIN FOR A TIME THIS AFTERNOON PER
THE RAP MODEL. LATER TODAY /LATE AFTERNOON/ THERE WILL BE A PERIOD
OF DRYING ALOFT IN THE SOUTHWEST PART OF THE CWA /BRAINERD LAKES
REGION/ WHICH MEANS ANY PRECIP THAT FALLS COULD FALL AS FREEZING
RAIN/DRIZZLE. ON THIS UPDATE ADDED A MIX OF FREEZING RAIN AND
SNOW INTO THIS AREA...AND WILL TAKE A BETTER LOOK LATER THIS
MORNING AS THE GUIDANCE ROLLS IN AS TO WHETHER OR NOT THIS COULD
BE CHANGED TO JUST FREEZING DRIZZLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST TUE FEB 10 2015
THE FOCUS REMAINS ON THE APPROACHING LOW PRESSURE SYSTEM FROM THE
WEST...CURRENTLY IN THE NORTHERN HIGH PLAINS EARLY THIS
MORNING...WHICH IS EXPECTED TO BRING WIDESPREAD LIGHT TO MODERATE
SNOWFALL TO THE NORTHLAND TODAY AND TONIGHT. THE LATEST MODELS
RUNS DID NOT SIGNIFICANTLY CHANGE...SO THE FORECAST IS STILL FOR
WIDESPREAD SNOWFALL OF 3 TO 5 INCHES. THERE IS INCREASING
CONFIDENCE THAT THE FAR EASTERN COUNTIES IN NW WISCONSIN WILL
REACH AROUND 3 TO 4 INCHES...SO WAS ABLE TO ISSUE WINTER WEATHER
ADVISORIES FOR THOSE COUNTIES. THE WHOLE FORECAST AREA IS NOW
UNDER A WINTER WEATHER ADVISORY.
TODAY AND TONIGHT...A LOW PRESSURE SYSTEM IN THE NORTHERN HIGH
PLAINS WILL MOVE EAST THROUGH THE DAKOTAS TODAY...THEN CUT ACROSS
MINNESOTA AND WISCONSIN TONIGHT. THIS STORM SYSTEM IS EXPECTED TO
BRING A WIDESPREAD 3 TO 5 INCHES OF SNOW TO THE NORTHLAND LATE
THIS MORNING THROUGH TONIGHT AS IT MOVES THROUGH THE REGION. THERE
COULD BE LOCALLY HIGHER AMOUNTS OF UP TO AROUND 6 INCHES ALONG THE
MINNESOTA ARROWHEAD NORTH SHORE DUE TO LAKE AND TERRAIN
ENHANCEMENT FROM THE SE TO SOUTH WINDS. THE SNOW WILL GRADUALLY
TAPER OFF TONIGHT...GENERALLY FROM WEST TO EAST. A STRONG
SHORTWAVE AND COLD FRONT WILL SWEEP ACROSS THE NORTHLAND TONIGHT
IN THE WAKE OF THE PASSING SYSTEM. GUSTY NORTHWEST WINDS WILL
DEVELOP IN THE WAKE OF THE FRONT. MODEL SOUNDINGS INDICATE THE
POTENTIAL FOR WIND GUSTS UP TO AROUND 25 MPH LATE TONIGHT.
THERE IS A VERY LOW THREAT OF FREEZING DRIZZLE AT TIMES DURING THE
PASSAGE OF THIS SYSTEM...BUT OVERALL THE THERMAL PROFILE IN MODEL
SOUNDINGS SUGGESTS SNOW IS THE MOST LIKELY PCPN TYPE. THINK THE
MAIN CONCERN FOR FREEZING DRIZZLE IS FOR THE INITIAL ONSET OF THE
PCPN THIS MORNING BEFORE THERE IS MORE RAPID AND WIDESPREAD
SATURATION ALOFT BY THIS AFTERNOON. THE RAP13 AND NAM12 MODEL
SOUNDINGS OVER THE WESTERN FORECAST AREA ARE INDICATING A LOW
LEVEL SATURATED LAYER WITH TEMPERATURES AS COLD AS -6 TO -8
DEGREES CELSIUS...WITH BORDERLINE CONFIDENCE IN SUFFICIENT ICE
CRYSTAL DEPOSITION FROM ALOFT...BEFORE CLEARLY SUPPORTING ALL SNOW
BY LATE THIS MORNING. AT THIS TIME...KEPT THE FORECAST ALL SNOW
THROUGH TONIGHT...BUT WILL NEED TO KEEP A CLOSE EYE ON THE
FREEZING DRIZZLE THREAT.
IT HAS BEEN A RELATIVELY QUIET WINTER FOR A WHILE AND MANY WEEKS
SINCE THE MAJORITY OF THE FORECAST AREA HAS SEEN A SIGNIFICANT
SNOW SYSTEM SUCH AS EXPECTED FOR TODAY. MOTORISTS MAY BE A LITTLE
UNPREPARED AND RUSTY FOR THIS KIND OF WEATHER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CST TUE FEB 10 2015
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR THE SNOW WILL BE LOCATED
DIRECTLY OVER LAKE SUPERIOR BY 12Z WEDNESDAY. SCATTERED SNOW
SHOWERS WILL LINGER IN THE WAKE OF THE LOW PASSAGE...AS INTENSE
COLD ADVECTION ACCOMPANIES A COLD FRONT THAT WILL MOVE THROUGH THE
REGION. SOME DIURNALLY DRIVEN SNOW SHOWERS OR FLURRIES WILL BE
POSSIBLE FOR MOST AREAS ON WEDNESDAY...WITH SNOW SHOWERS BECOMING
LIKELY ALONG THE GOGEBIC RANGE OF IRON COUNTY BY LATE WEDNESDAY.
WINDS BECOME ALMOST DIRECTLY NORTH ACROSS LAKE SUPERIOR BY 00Z
THURSDAY. LIMITING FACTOR INITIALLY WILL BE FAIRLY LOW INVERSION
HEIGHTS BUT THE INVERSION HEIGHTS DO RISE SOMEWHAT BY WEDNESDAY
NIGHT AND WE SHOULD SEE SOME ACCUMULATION ACROSS THE SOUTH SHORE
AS A RESULT. STILL A LOT OF OPEN WATER ACROSS LAKE SUPERIOR. VERY
COLD AIR WILL SETTLE IN ACROSS THE REGION FOR THE LAST HALF OF THE
WORK WEEK AND INTO THE WEEKEND AS ARCTIC HIGH PRESSURE BUILDS INTO
THE NORTHLAND. BY WEDNESDAY NIGHT...H85 TEMPS WILL BE AS LOW AS
-25C WITH SURFACE TEMPS WELL INTO THE TEENS AND 20S BELOW ZERO.
ANOTHER WEAK SYSTEM WILL BRING THE CHANCE FOR LIGHT SNOW ON
THURSDAY NIGHT AND FRIDAY...FOLLOWED BY ANOTHER COLD FRONT FRIDAY
NIGHT. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE THROUGH THURSDAY
NIGHT INTO FRIDAY...WITH MORE LIGHT SNOW. OVERALL IT LOOKS LIKE A
COLD EXTENDED TIME PERIOD...WITH A COUPLE OPPORTUNITIES FOR SOME
LIGHTER SNOWFALL AMOUNTS. NO MAJOR STORMS ARE EXPECTED DURING THIS
TIME FRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1210 PM CST TUE FEB 10 2015
SNOW WITH IFR/LIFR CEILINGS AND VSBYS WILL PREVAIL ACROSS THE
FORECAST AREA THROUGH THE AFTERNOON. CONDITIONS WILL BEGIN TO
GRADUALLY IMPROVE TO MVFR AFTER 00Z FOR KINL/KBRD/KHIB...AND
AFTER 03Z FOR KHYR AS THE SFC LOW EXITS TO THE EAST OVER LAKE
SUPERIOR AND UPPER MICHIGAN. A BATCH OF ARCTIC AIR WILL SURGE INTO
THE REGION LATE TONIGHT THROUGH WEDNESDAY...RESULTING IN NW WINDS
GUSTING TO 30KT...AND LINGERING CLOUDS/FLURRIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 16 16 -13 6 / 90 20 10 0
INL 5 9 -25 3 / 100 20 10 0
BRD 11 13 -11 8 / 60 10 10 0
HYR 20 22 -10 7 / 90 20 30 10
ASX 19 23 -5 6 / 100 40 70 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ011-
012-019>021-037-038.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ010-
018-025-026-033>036.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-
002-006>008.
WINTER WEATHER ADVISORY UNTIL 3 AM CST WEDNESDAY FOR WIZ003-004-
009.
LS...NONE.
&&
$$
UPDATE...JJM
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
917 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 917 AM CST TUE FEB 10 2015
BRIEF UPDATE TO ADJUST FOR TEMPERATURE TRENDS. NO MAJOR CHANGE TO
WX ELEMENT GRIDS OR POPS...FORECAST STILL ON TRACK. HAVE RECIEVED
REPORTS OF PRECIP BEGINNING AS SLEET THEN CHANGING TO SNOW...BUT
SINCE THIS WAS ONLY OBSERVED FOR A BRIEF PERIOD HAVE OMITTED FROM
THE FORECAST FOR NOW. HAVE SOME CONCERN ABOUT LACK OF ICE IN
COLUMN...ESPECIALLY IN SOUTHERN PINE COUNTY WHERE IT LOOKS LIKE
PRECIP COULD FALL AS FREEZING RAIN FOR A TIME THIS AFTERNOON PER
THE RAP MODEL. LATER TODAY /LATE AFTERNOON/ THERE WILL BE A PERIOD
OF DRYING ALOFT IN THE SOUTHWEST PART OF THE CWA /BRAINERD LAKES
REGION/ WHICH MEANS ANY PRECIP THAT FALLS COULD FALL AS FREEZING
RAIN/DRIZZLE. ON THIS UPDATE ADDED A MIX OF FREEZING RAIN AND
SNOW INTO THIS AREA...AND WILL TAKE A BETTER LOOK LATER THIS
MORNING AS THE GUIDANCE ROLLS IN AS TO WHETHER OR NOT THIS COULD
BE CHANGED TO JUST FREEZING DRIZZLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST TUE FEB 10 2015
THE FOCUS REMAINS ON THE APPROACHING LOW PRESSURE SYSTEM FROM THE
WEST...CURRENTLY IN THE NORTHERN HIGH PLAINS EARLY THIS
MORNING...WHICH IS EXPECTED TO BRING WIDESPREAD LIGHT TO MODERATE
SNOWFALL TO THE NORTHLAND TODAY AND TONIGHT. THE LATEST MODELS
RUNS DID NOT SIGNIFICANTLY CHANGE...SO THE FORECAST IS STILL FOR
WIDESPREAD SNOWFALL OF 3 TO 5 INCHES. THERE IS INCREASING
CONFIDENCE THAT THE FAR EASTERN COUNTIES IN NW WISCONSIN WILL
REACH AROUND 3 TO 4 INCHES...SO WAS ABLE TO ISSUE WINTER WEATHER
ADVISORIES FOR THOSE COUNTIES. THE WHOLE FORECAST AREA IS NOW
UNDER A WINTER WEATHER ADVISORY.
TODAY AND TONIGHT...A LOW PRESSURE SYSTEM IN THE NORTHERN HIGH
PLAINS WILL MOVE EAST THROUGH THE DAKOTAS TODAY...THEN CUT ACROSS
MINNESOTA AND WISCONSIN TONIGHT. THIS STORM SYSTEM IS EXPECTED TO
BRING A WIDESPREAD 3 TO 5 INCHES OF SNOW TO THE NORTHLAND LATE
THIS MORNING THROUGH TONIGHT AS IT MOVES THROUGH THE REGION. THERE
COULD BE LOCALLY HIGHER AMOUNTS OF UP TO AROUND 6 INCHES ALONG THE
MINNESOTA ARROWHEAD NORTH SHORE DUE TO LAKE AND TERRAIN
ENHANCEMENT FROM THE SE TO SOUTH WINDS. THE SNOW WILL GRADUALLY
TAPER OFF TONIGHT...GENERALLY FROM WEST TO EAST. A STRONG
SHORTWAVE AND COLD FRONT WILL SWEEP ACROSS THE NORTHLAND TONIGHT
IN THE WAKE OF THE PASSING SYSTEM. GUSTY NORTHWEST WINDS WILL
DEVELOP IN THE WAKE OF THE FRONT. MODEL SOUNDINGS INDICATE THE
POTENTIAL FOR WIND GUSTS UP TO AROUND 25 MPH LATE TONIGHT.
THERE IS A VERY LOW THREAT OF FREEZING DRIZZLE AT TIMES DURING THE
PASSAGE OF THIS SYSTEM...BUT OVERALL THE THERMAL PROFILE IN MODEL
SOUNDINGS SUGGESTS SNOW IS THE MOST LIKELY PCPN TYPE. THINK THE
MAIN CONCERN FOR FREEZING DRIZZLE IS FOR THE INITIAL ONSET OF THE
PCPN THIS MORNING BEFORE THERE IS MORE RAPID AND WIDESPREAD
SATURATION ALOFT BY THIS AFTERNOON. THE RAP13 AND NAM12 MODEL
SOUNDINGS OVER THE WESTERN FORECAST AREA ARE INDICATING A LOW
LEVEL SATURATED LAYER WITH TEMPERATURES AS COLD AS -6 TO -8
DEGREES CELSIUS...WITH BORDERLINE CONFIDENCE IN SUFFICIENT ICE
CRYSTAL DEPOSITION FROM ALOFT...BEFORE CLEARLY SUPPORTING ALL SNOW
BY LATE THIS MORNING. AT THIS TIME...KEPT THE FORECAST ALL SNOW
THROUGH TONIGHT...BUT WILL NEED TO KEEP A CLOSE EYE ON THE
FREEZING DRIZZLE THREAT.
IT HAS BEEN A RELATIVELY QUIET WINTER FOR A WHILE AND MANY WEEKS
SINCE THE MAJORITY OF THE FORECAST AREA HAS SEEN A SIGNIFICANT
SNOW SYSTEM SUCH AS EXPECTED FOR TODAY. MOTORISTS MAY BE A LITTLE
UNPREPARED AND RUSTY FOR THIS KIND OF WEATHER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CST TUE FEB 10 2015
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR THE SNOW WILL BE LOCATED
DIRECTLY OVER LAKE SUPERIOR BY 12Z WEDNESDAY. SCATTERED SNOW
SHOWERS WILL LINGER IN THE WAKE OF THE LOW PASSAGE...AS INTENSE
COLD ADVECTION ACCOMPANIES A COLD FRONT THAT WILL MOVE THROUGH THE
REGION. SOME DIURNALLY DRIVEN SNOW SHOWERS OR FLURRIES WILL BE
POSSIBLE FOR MOST AREAS ON WEDNESDAY...WITH SNOW SHOWERS BECOMING
LIKELY ALONG THE GOGEBIC RANGE OF IRON COUNTY BY LATE WEDNESDAY.
WINDS BECOME ALMOST DIRECTLY NORTH ACROSS LAKE SUPERIOR BY 00Z
THURSDAY. LIMITING FACTOR INITIALLY WILL BE FAIRLY LOW INVERSION
HEIGHTS BUT THE INVERSION HEIGHTS DO RISE SOMEWHAT BY WEDNESDAY
NIGHT AND WE SHOULD SEE SOME ACCUMULATION ACROSS THE SOUTH SHORE
AS A RESULT. STILL A LOT OF OPEN WATER ACROSS LAKE SUPERIOR. VERY
COLD AIR WILL SETTLE IN ACROSS THE REGION FOR THE LAST HALF OF THE
WORK WEEK AND INTO THE WEEKEND AS ARCTIC HIGH PRESSURE BUILDS INTO
THE NORTHLAND. BY WEDNESDAY NIGHT...H85 TEMPS WILL BE AS LOW AS
-25C WITH SURFACE TEMPS WELL INTO THE TEENS AND 20S BELOW ZERO.
ANOTHER WEAK SYSTEM WILL BRING THE CHANCE FOR LIGHT SNOW ON
THURSDAY NIGHT AND FRIDAY...FOLLOWED BY ANOTHER COLD FRONT FRIDAY
NIGHT. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE THROUGH THURSDAY
NIGHT INTO FRIDAY...WITH MORE LIGHT SNOW. OVERALL IT LOOKS LIKE A
COLD EXTENDED TIME PERIOD...WITH A COUPLE OPPORTUNITIES FOR SOME
LIGHTER SNOWFALL AMOUNTS. NO MAJOR STORMS ARE EXPECTED DURING THIS
TIME FRAME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 549 AM CST TUE FEB 10 2015
A DRAMATIC CHANGE IN WEATHER CONDITIONS WILL HAPPEN AS THE MORNING
WEARS ON...AS WE SEE MVFR TO VFR CIGS GRADUALLY GIVE WAY TO
IFR/LIFR CIGS/VSBYS DUE TO FALLING SNOW. THE SNOW SHOULD COME IN
VERY QUICKLY...RESULTING IN A DRAMATIC REDUCTION IN VISIBILITY AND
LOWERING CIGS. THE SNOW SHOULD BE PERSISTENT THROUGH THE
AFTERNOON...BEFORE DIMINISHING FROM THE WEST. GUSTY NORTHWEST
WINDS WILL DEVELOP BEHIND A COLD FRONT THAT WILL MOVE THROUGH THE
NORTHLAND OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 16 16 -13 / 100 90 20 10
INL 26 5 9 -25 / 100 100 20 10
BRD 28 11 13 -11 / 100 60 10 10
HYR 25 20 22 -10 / 100 90 20 30
ASX 29 19 23 -5 / 100 100 40 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ011-
012-019>021-037-038.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ010-
018-025-026-033>036.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-
002-006>008.
WINTER WEATHER ADVISORY UNTIL 3 AM CST WEDNESDAY FOR WIZ003-004-
009.
LS...NONE.
&&
$$
UPDATE...JJM
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
401 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 959 PM CST MON FEB 9 2015
AFTER WATCHING SEVERAL RUNS OF THE RAP...HRRR...AND HOPWRF DECIDED
TO EXPAND THE ADVISORY SLIGHTLY SOUTH AND EAST TO ENCOMPASS THE
ENTIRE TWIN CITIES METRO AND THE REST OF WEST CENTRAL WISCONSIN.
NOT MUCH ON RADAR OUT TO THE WEST LATE THIS EVENING...BUT
STRENGTHENING WAA OVERNIGHT WILL ALLOW PRECIP TO BLOSSOM ACROSS
THE EASTERN DAKOTAS AFTER 06-08Z. THIS WAA WILL MAXIMIZE AROUND
12Z ACROSS WRN MN...15Z ACROSS ERN MN...AND 18Z OVER WRN WI. A
DEEP MOIST LAYER AND HIGH DGZ CENTERED AROUND 550 MB ALLOWS FOR
NOT ONLY A HIGH MOISTURE CONTENT ATMOSPHERE WITH PW VALUES ABOVE
0.6 INCHES /NEARING 3 STANDARD DEVIATIONS ABOVE AVERAGE/...BUT
ALSO SOME CAPE FROM THE DGZ UPWARD AND THUS CONVECTIVE POTENTIAL.
THE STRONG FORCING WITH THIS BAND COUPLED WITH THE MOISTURE
CONTENT AND WEAK INSTABILITY ALOFT SHOULD ALLOW THE INITIAL BAND
OF PRECIP TO BECOME PRETTY INTENSE FOR A TIME. RAPIDLY DETERIORATING
CONDITIONS ARE THUS EXPECTED SHORTLY AFTER THE ONSET. FOR SEVERAL
RUNS...THE RAP HAS HINTED AT 1-2 INCH PER HOUR RATES AS THE BAND
PUSHES INTO ERN MN AND WRN WI AND THIS SEEMS REASONABLE.
IF THIS WERE TO PERSIST FOR MORE THAN A COUPLE HOURS...COULD
PROBABLY JUSTIFY A WARNING. HOWEVER...THERE ARE SOME
SIGNS...PARTICULARLY ACROSS WRN AND SRN MN...THAT ONCE THIS BAND
GOES THROUGH THAT MAY BE IT FOR STEADY PRECIP AS DRY SLOTTING
COMES IN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM CST MON FEB 9 2015
TURNED OUT TO BE A BEAUTIFUL DAY OUTSIDE OF WESTERN AND FAR SOUTHERN
MN...AS A WEDGE OF DRY AIR EMANATING FROM HIGH PRESSURE MOVING INTO
WRN ONTARIO HELPED CLEAR SKIES OUT. HOWEVER...TROUBLE IS ALREADY
BREWING TO OUR WEST AS WATER VAPOR IMAGERY SHOWS A POWERFUL WAVE
MOVING ACROSS THE NW CONUS. THIS WAVE WILL QUICKLY WORK ACROSS THE
DAKOTAS TONIGHT AND MN TUESDAY...PROVIDING US WITH THE POTPOURRI OF
WINTRY PRECIPITATION ON TUESDAY THAT WE HAVE BEEN ADVERTISING FOR
THE LAST SEVERAL DAYS.
WE DID NOT SEE MUCH CHANGE IN THE GUIDANCE TODAY WITH WHAT WAS SEEN
LAST NIGHT...SO THIS FORECAST DID NOT CHANGE A WHOLE LOT
EITHER...WITH ABOUT THE ONLY CHANGE OF SIGNIFICANCE BEING TO SLOW
DOWN HOW QUICKLY PRECIP MOVES INTO AND THEN ACROSS THE MPX CWA.
THIS FORECAST FAVORED THE GFS FOR BOTH P-TYPE AND QPF. FOR P-
TYPE...THE NAM...ALONG WITH THE RAP WERE CONSIDERABLY WARMER WITH
THE WARM NOSE ALOFT THAN THE GFS/ECMWF. HAD WE GONE THE NAM
ROUTE...A MIX WOULD HAVE BEEN MENTIONED FARTHER NORTH THAN IT IS
TUESDAY AFTERNOON...AND SAID MIX WOULD BE MORE OF A FZRA/SLEET/SNOW
MIX /MOST LIKELY TO LEAST LIKELY/ AS OPPOSED TO THE CURRENT
SLEET/SNOW/FZRA MIX THAT WE HAVE.
FOR QPF...THE NAM IS A CONSIDERABLE SRN OUTLIER. THE POTENTIAL
PROBLEM WITH IT STARTS TONIGHT...WHEN THE NAM SHOWS NEARLY A QUARTER
INCH OF QPF FALLING BY 12Z TUESDAY IN NE SODAK...IN ADDITION TO
ANOTHER QPF BULLSEYE FROM CENTRAL NODAK INTO SE NODAK. THE RAP AND
HOPWRF HAVE THE NODAK BULLSEYE...BUT SHOW CONSIDERABLY LESS QPF INTO
SODAK. THE LATENT HEAT DIFFERENCES THIS CREATES THEN CASCADES INTO
TUESDAY...WHEN THE NAM SHOWS QPF IN EXCESS OF 0.3" ALL THE WAY DOWN
TO MANKATO. THE GFS ON THE OTHER HAND HAS THE NODAK QPF...BUT MUCH
LOWER QPF DOWN INTO SODAK...SIMILAR TO WHAT THE RAP/HOPWRF
HAVE...HENCE FAVORING THE QPF THAT DIRECTION. WE THEN TEMPERED THE
GFS QPF A BIT WITH THE ECMWF/SREF AND ENDED UP WITH 0.3" QPF DOWN
ABOUT AS FAR SOUTH AS THE TWIN CITIES DOWN TO MENOMONIE.
CONVERTING THIS QPF OVER TO SNOW WITH RATIOS IN THE 10-12:1 RANGE
AND WE ENDED UP WITH SNOWFALL AMOUNTS BETWEEN 2 AND 5 INCHES NORTH
OF A MORRIS/MINNEAPOLIS/EAU CLAIRE LINE WITH THE LARGEST AMOUNTS
UP AROUND MILLE LACS LAKE TO POINTS EAST.
THE HEAVIEST SNOW IS EXPECTED IN CENTRAL MN AS THEY WILL GET THE
COMBINATION OF WAA AND DEFORMATION SNOW. FARTHER SOUTH...THE
MAJORITY OF THE PRECIP WILL FALL IN THE WAA BAND. THIS WILL RESULT
IN A 2-4 HOUR WINDOW WHERE SNOWFALL RATES ARE LIKELY NEAR OR IN
EXCESS OF AN INCH PER HOUR...SO THIS SNOW WILL FALL IN A SHORT
AMOUNT OF TIME. TIMING WISE...THINGS DO NOT LOOK TO BE TO DISSIMILAR
FROM WHAT WE SAW LAST TUESDAY WHEN ABOUT 2 INCHES OF SNOW SEVERAL
IMPACTED THE EVENING COMMUTE IN THE TWIN CITIES. WITH A SIMILAR
SCENARIO EXPECTED TO TO PLAY OUT TOMORROW...PULLED THE ADVISORY DOWN
TO COVER ALL BUT THE SRN TWIN CITIES METRO. DECIDED AGAINST PUTTING
HEADLINES ANY FARTHER SOUTH THAN WHAT WE HAVE NOW SINCE THERE ARE
MORE QUESTIONS AS TO HOW MUCH PRECIP LOCATIONS FARTHER SOUTH WILL
ACTUALLY SEE. IN ADDITION...WITH CURRENT PRIMARY P-TYPE EXPECTED TO
BE SLEET AS OPPOSED TO FREEZING RAIN...THAT WILL LIMIT THE TRAVEL
IMPACT FROM THIS PRECIP AS WELL. HOWEVER...THIS WILL BE AN AREA THAT
WILL NEED TO BE CLOSELY MONITORED THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 AM CST TUE FEB 10 2015
IN THE LONG TERM PERIOD...MAIN ITEMS OF NOTE ARE THE BELOW NORMAL
TEMPERATURES EXPECTED WITH A COUPLE COLD FRONTS MOVING THROUGH
DURING THE PERIOD AND OVERALL NORTHWEST FLOW...AND THE LIMITED
PRECIPITATION AMOUNTS EXPECTED.
WEDNESDAY THROUGH THURSDAY...THE SYSTEM THAT WILL BRING SNOW AND A
WINTRY MIX THROUGH THE AREA TODAY WILL BE DEPARTING BY WEDNESDAY
MORNING. CYCLONIC FLOW WILL CONTINUE IN TO THURSDAY BEFORE BECOMING
ANTI-CYCLONIC IN CONJUNCTION WITH AN INCOMING SURFACE HIGH FOR
THURSDAY. MODEL SOUNDINGS INDICATE LOW LEVEL SATURATION AND WEAK
LIFT LINGERING IN EASTERN MN AND ESPECIALLY WESTERN WI...SO KEPT LOW
POPS IN THE FORECAST FOR LIGHT SNOW/FLURRIES THERE FOR WEDNESDAY
MORNING. FOR THE AFTERNOON AND NIGHT...LOW LEVEL LAPSE RATES STEEPEN
IN THE EAST SO THE POTENTIAL FOR SNOW SHOWER DEVELOPMENT IS DECENT.
WESTERN WI COULD SEE A QUICK DUSTING TO A FEW TENTHS OF AN INCH FROM
THESE SNOW SHOWERS. AS FAR AS TEMPERATURES ARE
CONCERNED...TEMPERATURES WILL ONLY FALL THROUGH THE DAY ON WEDNESDAY
THANKS TO STRONG COLD AIR ADVECTION. THE SURFACE PRESSURE GRADIENT
LOOKS FAIRLY TIGHT ACROSS THE STATE...WITH ABOUT A 10MB DIFFERENCE
ACROSS THE STATE THROUGH THE DAY...SO IT WILL BE VERY
WINDY...ESPECIALLY ACROSS WESTERN MN. NOT A PLEASANT DAY AT ALL FOR
OUTDOOR ACTIVITIES WITH WIND CHILLS NEAR OR BELOW ZERO DURING THE
DAYLIGHT HOURS. WITH THE ARCTIC SURGE CONTINUING...EXPECTING LOW
TEMPERATURES TO FALL BELOW ZERO ACROSS ESSENTIALLY ALL OF THE
FORECAST AREA. WINDS WILL EASILY STAY UP IN THE 10-20MPH RANGE
OVERNIGHT SO WIND CHILL VALUES BY EARLY THURSDAY MORNING WILL RANGE
FROM -20F T0 -30F. CLOUDS SHOULD CLEAR THURSDAY AS THE SURFACE HIGH
PUSHES IN BY MID DAY...AND WINDS WILL WEAKEN THROUGH THE DAY
THURSDAY AS THE GRADIENT WEAKENS. WITH THE ARCTIC AIR MASS IN
PLACE...EXPECTING HIGH TEMPERATURES 15-20 DEGREES BELOW AVERAGE ON
THURSDAY.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...A CLIPPER SYSTEM WILL COME
RACING SOUTHEAST THROUGH CANADA AND WE`LL BE SOUTH OF THE HIGHEST
PRECIP AMOUNTS...BUT STILL LOOKS LIKE A DECENT SHOT OF VERY LIGHT
SNOW/FLURRIES WITH THIS WAVE. AS IT MOVES EAST OF US BY
FRIDAY...ANOTHER ARCTIC SURGE WILL ADVANCE INTO THE UPPER MIDWEST
THROUGH SATURDAY. THE CORE OF THE COLD AIR THIS TIME LOOKS TO DIVE
THROUGH WESTERN WI/EASTERN MN. ANOTHER BELOW ZERO NIGHT LIKELY
FRIDAY NIGHT...WITH HIGH TEMPERATURES SATURDAY NOT ESCAPING THE
SINGLE DIGITS IN STRONG NORTHWEST FLOW...SO AGAIN NOT A PLEASANT DAY
FOR OUTDOOR ACTIVITIES.
SUNDAY THROUGH TUESDAY...REALLY A VERY SIMILAR STORY FOR THIS
PERIOD. ANOTHER NORTHERN WAVE WILL MOVE SOUTHEAST ACROSS CANADA AND
PROVIDE US WITH THE POTENTIAL TO SEE LIGHT SNOW ON SUNDAY AND SUNDAY
NIGHT...WHICH WILL BE FOLLOWED BY YET ANOTHER ARCTIC SURGE INTO
EARLY NEXT WEEK. AT THIS POINT...TUESDAY WILL BE VERY SIMILAR TO
SATURDAY IN TERMS OF COLD TEMPS AND STRONG NORTHWEST WINDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1218 AM CST TUE FEB 10 2015
VFR CONDITIONS EVERYWHERE EXCEPT SOUTHWEST AND FAR WRN MN AT TAF
ISSUANCE TIME...BUT PRECIPITATION IS NOW DEVELOPING ACROSS SOUTH
DAKOTA WHICH WILL PUSH EAST INTO WRN MN LATE TONIGHT...ERN MN BY
MID MORNING...AND WRN WI LATE MORNING. THIS IS EXPECTED TO BRING A
PERIOD OF MODERATE TO HEAVY PRECIP ACROSS MOST OF THE AREA FOR A
3-4 HOUR WINDOW BEFORE LIGHTER SNOW FOLLOWS FOR SEVERAL MORE
HOURS. SEVERAL MODELS ARE INDICATING POTENTIAL FOR 1-2 INCH PER
HOUR RATES WITH THE HEAVY ROUND AND A FEW THUNDERSTORMS MAY ALSO
ACCOMPANY IT...PARTICULARLY ACROSS SRN MN. ALSO OF NOTE...A THIN
BAND OF SN/PL APPEARS TO BE IN THE EARLY STAGES OF DEVELOPING
AHEAD OF THE MAIN AREA OF PRECIP...FROM MADISON TO MARHSALL. THIS
WILL PUSH ACROSS OVERNIGHT AND SHOULD NOT AMOUNT TO MUCH OTHER
THAN A BRIEF PERIOD OF PRECIP. DID ACCOUNT FOR THIS AS A TEMPO
BEFORE THE MAIN ROUND...BUT CONFIDENCE IS LOW.
KMSP...SIGNIFICANT IMPACTS POSSIBLE FROM MID MORNING TO EARLY
AFTERNOON AS A ROUND OF HEAVY SNOW IS LOOKING MORE LIKELY TO
IMPACT THE AREA. MANY MODELS HAVE SHOWN THIS WITH GOOD CONSISTENCY
FOR THE LAST SEVERAL HOURS...SO FELT CONFIDENT ENOUGH TO INCLUDE
IN THIS TAF ISSUANCE. SNOW RATES OF 1-2 INCHES PER HOUR ARE LIKELY
IF THIS DOES UNFOLD WITH LIFR CONDITIONS PERSISTING 3-4 HOURS.
/OUTLOOK FOR KMSP/
WED...MVFR WITH FLURRIES POSSIBLE. WINDS NW 15G30KT.
THU...BCMG VFR. WINDS BCMG LGT/VAR.
FRI...CHC MVFR CIGS. WINDS SW 5-10 KTS BCMG NW 15-20G25 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR
MNZ043>045-050>053-059>063-068>070-076-077-084-085-093.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ041-
042-047>049-054>058-064>067-073>075-082-083-091-092.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ078.
WI...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ014>016-023>028.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...MPG
LONG TERM...SPD
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1218 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 959 PM CST MON FEB 9 2015
AFTER WATCHING SEVERAL RUNS OF THE RAP...HRRR...AND HOPWRF DECIDED
TO EXPAND THE ADVISORY SLIGHTLY SOUTH AND EAST TO ENCOMPASS THE
ENTIRE TWIN CITIES METRO AND THE REST OF WEST CENTRAL WISCONSIN.
NOT MUCH ON RADAR OUT TO THE WEST LATE THIS EVENING...BUT
STRENGTHENING WAA OVERNIGHT WILL ALLOW PRECIP TO BLOSSOM ACROSS
THE EASTERN DAKOTAS AFTER 06-08Z. THIS WAA WILL MAXIMIZE AROUND
12Z ACROSS WRN MN...15Z ACROSS ERN MN...AND 18Z OVER WRN WI. A
DEEP MOIST LAYER AND HIGH DGZ CENTERED AROUND 550 MB ALLOWS FOR
NOT ONLY A HIGH MOISTURE CONTENT ATMOSPHERE WITH PW VALUES ABOVE
0.6 INCHES /NEARING 3 STANDARD DEVIATIONS ABOVE AVERAGE/...BUT
ALSO SOME CAPE FROM THE DGZ UPWARD AND THUS CONVECTIVE POTENTIAL.
THE STRONG FORCING WITH THIS BAND COUPLED WITH THE MOISTURE
CONTENT AND WEAK INSTABILITY ALOFT SHOULD ALLOW THE INITIAL BAND
OF PRECIP TO BECOME PRETTY INTENSE FOR A TIME. RAPIDLY DETERIORATING
CONDITIONS ARE THUS EXPECTED SHORTLY AFTER THE ONSET. FOR SEVERAL
RUNS...THE RAP HAS HINTED AT 1-2 INCH PER HOUR RATES AS THE BAND
PUSHES INTO ERN MN AND WRN WI AND THIS SEEMS REASONABLE.
IF THIS WERE TO PERSIST FOR MORE THAN A COUPLE HOURS...COULD
PROBABLY JUSTIFY A WARNING. HOWEVER...THERE ARE SOME
SIGNS...PARTICULARLY ACROSS WRN AND SRN MN...THAT ONCE THIS BAND
GOES THROUGH THAT MAY BE IT FOR STEADY PRECIP AS DRY SLOTTING
COMES IN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM CST MON FEB 9 2015
TURNED OUT TO BE A BEAUTIFUL DAY OUTSIDE OF WESTERN AND FAR SOUTHERN
MN...AS A WEDGE OF DRY AIR EMANATING FROM HIGH PRESSURE MOVING INTO
WRN ONTARIO HELPED CLEAR SKIES OUT. HOWEVER...TROUBLE IS ALREADY
BREWING TO OUR WEST AS WATER VAPOR IMAGERY SHOWS A POWERFUL WAVE
MOVING ACROSS THE NW CONUS. THIS WAVE WILL QUICKLY WORK ACROSS THE
DAKOTAS TONIGHT AND MN TUESDAY...PROVIDING US WITH THE POTPOURRI OF
WINTRY PRECIPITATION ON TUESDAY THAT WE HAVE BEEN ADVERTISING FOR
THE LAST SEVERAL DAYS.
WE DID NOT SEE MUCH CHANGE IN THE GUIDANCE TODAY WITH WHAT WAS SEEN
LAST NIGHT...SO THIS FORECAST DID NOT CHANGE A WHOLE LOT
EITHER...WITH ABOUT THE ONLY CHANGE OF SIGNIFICANCE BEING TO SLOW
DOWN HOW QUICKLY PRECIP MOVES INTO AND THEN ACROSS THE MPX CWA.
THIS FORECAST FAVORED THE GFS FOR BOTH P-TYPE AND QPF. FOR P-
TYPE...THE NAM...ALONG WITH THE RAP WERE CONSIDERABLY WARMER WITH
THE WARM NOSE ALOFT THAN THE GFS/ECMWF. HAD WE GONE THE NAM
ROUTE...A MIX WOULD HAVE BEEN MENTIONED FARTHER NORTH THAN IT IS
TUESDAY AFTERNOON...AND SAID MIX WOULD BE MORE OF A FZRA/SLEET/SNOW
MIX /MOST LIKELY TO LEAST LIKELY/ AS OPPOSED TO THE CURRENT
SLEET/SNOW/FZRA MIX THAT WE HAVE.
FOR QPF...THE NAM IS A CONSIDERABLE SRN OUTLIER. THE POTENTIAL
PROBLEM WITH IT STARTS TONIGHT...WHEN THE NAM SHOWS NEARLY A QUARTER
INCH OF QPF FALLING BY 12Z TUESDAY IN NE SODAK...IN ADDITION TO
ANOTHER QPF BULLSEYE FROM CENTRAL NODAK INTO SE NODAK. THE RAP AND
HOPWRF HAVE THE NODAK BULLSEYE...BUT SHOW CONSIDERABLY LESS QPF INTO
SODAK. THE LATENT HEAT DIFFERENCES THIS CREATES THEN CASCADES INTO
TUESDAY...WHEN THE NAM SHOWS QPF IN EXCESS OF 0.3" ALL THE WAY DOWN
TO MANKATO. THE GFS ON THE OTHER HAND HAS THE NODAK QPF...BUT MUCH
LOWER QPF DOWN INTO SODAK...SIMILAR TO WHAT THE RAP/HOPWRF
HAVE...HENCE FAVORING THE QPF THAT DIRECTION. WE THEN TEMPERED THE
GFS QPF A BIT WITH THE ECMWF/SREF AND ENDED UP WITH 0.3" QPF DOWN
ABOUT AS FAR SOUTH AS THE TWIN CITIES DOWN TO MENOMONIE.
CONVERTING THIS QPF OVER TO SNOW WITH RATIOS IN THE 10-12:1 RANGE
AND WE ENDED UP WITH SNOWFALL AMOUNTS BETWEEN 2 AND 5 INCHES NORTH
OF A MORRIS/MINNEAPOLIS/EAU CLAIRE LINE WITH THE LARGEST AMOUNTS
UP AROUND MILLE LACS LAKE TO POINTS EAST.
THE HEAVIEST SNOW IS EXPECTED IN CENTRAL MN AS THEY WILL GET THE
COMBINATION OF WAA AND DEFORMATION SNOW. FARTHER SOUTH...THE
MAJORITY OF THE PRECIP WILL FALL IN THE WAA BAND. THIS WILL RESULT
IN A 2-4 HOUR WINDOW WHERE SNOWFALL RATES ARE LIKELY NEAR OR IN
EXCESS OF AN INCH PER HOUR...SO THIS SNOW WILL FALL IN A SHORT
AMOUNT OF TIME. TIMING WISE...THINGS DO NOT LOOK TO BE TO DISSIMILAR
FROM WHAT WE SAW LAST TUESDAY WHEN ABOUT 2 INCHES OF SNOW SEVERAL
IMPACTED THE EVENING COMMUTE IN THE TWIN CITIES. WITH A SIMILAR
SCENARIO EXPECTED TO TO PLAY OUT TOMORROW...PULLED THE ADVISORY DOWN
TO COVER ALL BUT THE SRN TWIN CITIES METRO. DECIDED AGAINST PUTTING
HEADLINES ANY FARTHER SOUTH THAN WHAT WE HAVE NOW SINCE THERE ARE
MORE QUESTIONS AS TO HOW MUCH PRECIP LOCATIONS FARTHER SOUTH WILL
ACTUALLY SEE. IN ADDITION...WITH CURRENT PRIMARY P-TYPE EXPECTED TO
BE SLEET AS OPPOSED TO FREEZING RAIN...THAT WILL LIMIT THE TRAVEL
IMPACT FROM THIS PRECIP AS WELL. HOWEVER...THIS WILL BE AN AREA THAT
WILL NEED TO BE CLOSELY MONITORED THROUGH THE NIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM CST MON FEB 9 2015
THE EXTENDED PERIOD CAN BE CHARACTERIZED AS BLW NORMAL IN TERMS OF
TEMPERATURES AS THE MEAN PATTERN SHIFTS TO A MORE NW
DIRECTION...LEADING TO COLDER CANADIAN AIR FILTERING SOUTHWARD.
A BRIEF PERIOD TUESDAY EVENING OF MIXED PRECIPITATION ALONG THE MN
RIVER VALLEY WILL QUICKLY CHG TO ALL SNOW AS A MUCH COLDER AIR MASS
REPLACES THE CURRENT ONE. BASED ON THE STRENGTH OF A SECONDARY
SHRTWV MOVING SE ACROSS THE UPPER MIDWEST TUESDAY NIGHT/WEDNESDAY
AND THE STRENGTH OF THE CAA BEHIND IT...BREEZY/WINDY CONDS WILL
DEVELOP...ESPECIALLY IN THE TYPICAL AREAS OF WC/SC MN WHERE GUSTS UP
TO 45 MPH WILL BE COMMON. WAS CONSIDERING A BLOWING SNOW PROBLEM IN
THESE AREAS...BUT DO TO A LACK OF SNOW COVER AND NO ADDITIONAL NEW
SNOW EXPECTED...DO NOT ANTICIPATE ANY CONCERNS.
VERY LITTLE CHC/S OF PRECIPITATION IS EXPECTED PAST TUESDAY
EVENING...WITH THE EXCEPTION BY NEXT MONDAY AS THE MEAN PATTERN WILL
REMAIN DRY AND UNEVENTFUL. TWO STRONG COLD FRONTS WILL MOVE ACROSS
OUR REGION...ONE WILL OCCUR TUESDAY AFTN/EVENING...AND ANOTHER
FRIDAY AFTN/SATURDAY MORNING. THESE FRONTS WILL CAUSE A FEW SNOW
SHOWERS TO DEVELOP...BUT AGAIN NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATIONS.
OVER THE PAST TWO MONTHS...THE MEAN AREA OF ARCTIC AIR HAS REMAINED
ACROSS NE NORTH AMERICA...AFFECTING MAINLY THE NE CONUS...AND
EASTERN CANADA. ONCE IN A WHILE A BRIEF COLD SPELL MOVES ACROSS THE
UPPER MIDWEST/GREAT LAKES AS THE PATTERN BUCKLES. THE LATEST
PROBABILISTIC FORECASTS ON NCEP GEFS REFORECASTS CFS/V2...HAS 50H
ANOMALIES SHIFTING ACROSS THE ALASKA REGION...WITH A SECONDARY 50H
ANOMALY FOCUSING ACROSS THE DEEP SOUTH/SW. THIS BASICALLY SHIFTS THE
COLDER AIR ACROSS NORTHEAST CANADA FURTHER TO THE SW ACROSS THE
GREAT LAKES...AND THE EASTERN 1/3 OF NORTH AMERICA. THIS ALSO
SUGGESTS A STRONGER CORRELATION OF ABV NORMAL ANOMALIES FOCUSING
ACROSS THE GREAT BASIN AND THE FAR WEST COAST. THE TIME FRAME FOR
THIS PERIOD IS FEB 15 TO FEB 24. THE 45 DAY CFS PLUMES FOR THE PAST
4 RUNS DOES SUPPORT THE COLDER PATTERN DEVELOPING IN OUR REGION FOR
THE SECOND AND THIRD WEEK OF FEB 24. IN ADDITION...IT SEEMS IT MAYBE
A WETTER PATTERN AS THE STRONGER JET WORKS ACROSS THE CENTRAL
CONUS...LEADING TO A BETTER CHC OF A THERMAL BOUNDARY AND WIDESPREAD
PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1218 AM CST TUE FEB 10 2015
VFR CONDITIONS EVERYWHERE EXCEPT SOUTHWEST AND FAR WRN MN AT TAF
ISSUANCE TIME...BUT PRECIPITATION IS NOW DEVELOPING ACROSS SOUTH
DAKOTA WHICH WILL PUSH EAST INTO WRN MN LATE TONIGHT...ERN MN BY
MID MORNING...AND WRN WI LATE MORNING. THIS IS EXPECTED TO BRING A
PERIOD OF MODERATE TO HEAVY PRECIP ACROSS MOST OF THE AREA FOR A
3-4 HOUR WINDOW BEFORE LIGHTER SNOW FOLLOWS FOR SEVERAL MORE
HOURS. SEVERAL MODELS ARE INDICATING POTENTIAL FOR 1-2 INCH PER
HOUR RATES WITH THE HEAVY ROUND AND A FEW THUNDERSTORMS MAY ALSO
ACCOMPANY IT...PARTICULARLY ACROSS SRN MN. ALSO OF NOTE...A THIN
BAND OF SN/PL APPEARS TO BE IN THE EARLY STAGES OF DEVELOPING
AHEAD OF THE MAIN AREA OF PRECIP...FROM MADISON TO MARHSALL. THIS
WILL PUSH ACROSS OVERNIGHT AND SHOULD NOT AMOUNT TO MUCH OTHER
THAN A BRIEF PERIOD OF PRECIP. DID ACCOUNT FOR THIS AS A TEMPO
BEFORE THE MAIN ROUND...BUT CONFIDENCE IS LOW.
KMSP...SIGNIFICANT IMPACTS POSSIBLE FROM MID MORNING TO EARLY
AFTERNOON AS A ROUND OF HEAVY SNOW IS LOOKING MORE LIKELY TO
IMPACT THE AREA. MANY MODELS HAVE SHOWN THIS WITH GOOD CONSISTENCY
FOR THE LAST SEVERAL HOURS...SO FELT CONFIDENT ENOUGH TO INCLUDE
IN THIS TAF ISSUANCE. SNOW RATES OF 1-2 INCHES PER HOUR ARE LIKELY
IF THIS DOES UNFOLD WITH LIFR CONDITIONS PERSISTING 3-4 HOURS.
/OUTLOOK FOR KMSP/
WED...MVFR WITH FLURRIES POSSIBLE. WINDS NW 15G30KT.
THU...BCMG VFR. WINDS BCMG LGT/VAR.
FRI...CHC MVFR CIGS. WINDS SW 5-10 KTS BCMG NW 15-20G25 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR MNZ041-042-047>049-054>058-064>067.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ043>045-050>053-059>063-068>070.
WI...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ014-023-024.
WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR WIZ015-016-025>028.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...MPG
LONG TERM...JLT
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CST TUE FEB 10 2015
LOW PRESSURE ACROSS SCNTL SD IS EXPECTED TO CLEAR THE FCST AREA
OF LOW CLOUDS AND FOG BY 15Z THIS AM. FOG PRODUCTION IN THE DENSE
FOG ADVISORY AREA HAS BE BEEN LIMITED BY MIXING FROM STRONG SFC
WINDS AND POOR RADIATION FROM A BATCH OF MID LEVEL CLOUDS ALOFT.
THE RAP...ETAL MODELS INDICATES FAIRLY STRONG WEST WINDS WILL
DEVELOP BY 12Z SCOURING THE AREA OF MOISTURE AND SHUNTING THE FOG
EAST. THUS THE PROBABILITY OF DENSE FOG APPEARS LOW IN ALL SOLNS.
THE RAP WAS THE WARMEST MODEL AND WAS USED FOR THE TEMPERATURE
FORECAST TODAY FOR HIGHS IN THE UPPER 50S TO MID 60S. NORTHWEST
WINDS WILL BE INCREASING TO 15 TO 25 MPH IN THE WAKE OF THE SFC LOW
ACROSS SD. A TANDEM LOW ACROSS ERN MT WILL MOVE INTO CNTL ND THIS
AFTN AND SEND A COLD FRONT TOWARD NRN NEB. THE MODELS SHOW WEAK
CONVERGENCE AROUND THE LEE SIDE OF THE BLACK HILLS AS THE FRONT
APPROACHES AND THIS MIGHT BE ENOUGH FOR SPRINKLES ACROSS NRN
SHERIDAN COUNTY AND WRN CHERRY COUNTY. THE HRRR...GEM REGIONAL AND
RAP SUPPORT THIS RAIN CHANCE ALBEIT NON-MEASURABLE.
NORTHWEST WINDS SHOULD REMAIN STRONG TONIGHT AS AN ARCTIC COLD FRONT
MOVES THROUGH THE FCST AREA. THE MODELS SHOW WIND SPEEDS INCREASING
FROM 06Z ONWARD ACROSS THE NORTH AND H850MB TEMPERATURES FALLING TO
AROUND -7C BY MORNING WHICH MIGHT SUPPORT LOWS IN THE LOWER 20S
NORTH AND WARMER READINGS IN THE MID AND UPPER 20S TO NEAR 30 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CST TUE FEB 10 2015
PRIMARY FORECAST CONCERNS FOR THIS PORTION OF THE FORECAST PERIOD
DEAL WITH TEMPERATURES THROUGHOUT...THEN WITH CHANCES FOR SNOW FOR
EARLY NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT FOR MUCH OF THE FORECAST PERIOD WITH
ONLY MINOR DETAILS SEEN TO IMPACT THE FORECAST. THAT BEING
SAID...EVEN SOME MINOR DIFFERENCES COULD HAVE AN IMPACT ON THE
SENSIBLE WEATHER...MAINLY THE CLOUD COVER AND WINDS...WHICH IN TURN
CAN IMPACT THE TEMPERATURE FORECAST.
THE PERIOD BEGINS ON WEDNESDAY...WITH THE UPPER LEVEL SHORTWAVE
TROUGH WHICH IS NOW OVER THE NORTHWEST TERRITORIES DIGGING SOUTH
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. THIS WILL PUSH A
GOOD COLD FRONT THROUGH THE REGION BY 12Z WEDNESDAY. THE TRACK OF
THE MAIN PV ANOMALY EMBEDDED IN THE SHORTWAVE STAYS WELL NORTH AND
EAST OF THE LOCAL AREA BUT THIS WILL LIKELY STILL ENHANCE THE
DOWNWARD MOTION/SUBSIDENCE...DRYING AND COLD AIR ADVECTION DURING
THE DAY TO AT LEAST HELP THE LOW LEVEL MIXING AND BRING ABOUT BREEZY
NORTHWEST WINDS. WITH THE COLD AIR ADVECTION BEHIND THE
FRONT...WEDNESDAY WILL BE QUITE A BIT COOLER THAN WHAT HAS BEEN
EXPERIENCED OVER THE PAST FEW DAYS...WITH HIGHS NEAR NORMAL MOST
PLACES. THE MODELS ARE SHOWING SOME WARMING ALOFT BY THE END OF THE
DAY WEDNESDAY WHICH COULD LEAD TO SLIGHTLY WARMER TEMPERATURES OVER
SOUTHWEST NEBRASKA. THE FORECAST WILL KEEP MID 40S FOR THESE AREAS
WITH LOW 30S OVER NORTH CENTRAL NEBRASKA ON WEDNESDAY.
THE SURFACE HIGH BEHIND THE SYSTEM BUILDS SOUTH INTO THE NORTHERN
PLAINS WEDNESDAY NIGHT...THEN INTO THE MISSISSIPPI RIVER VALLEY ON
THURSDAY. WITH THE COLD AIR ASSOCIATED WITH THE SURFACE
HIGH...TEMPERATURES WILL BE FAIRLY COLD WEDNESDAY NIGHT. THE COLDEST
AIR ALOFT WILL REMAIN ACROSS EASTERN NEBRASKA AND AS THOSE LOCATIONS
WILL BE CLOSER TO THE CENTER OF THE HIGH...WINDS WILL BE LIGHTER
WHICH SHOULD PROMOTE BETTER RADIATIONAL COOLING. FURTHER
WEST...RETURN FLOW SOUTHERLY WINDS SET UP AND ALTHOUGH WILL BE
LIGHT...ARE NOT EXPECTED TO COMPLETELY DROP OFF. THESE CONDITIONS
WILL CREATE A DECENT TEMPERATURE GRADIENT ACROSS THE FORECAST
AREA...FROM THE LOW SINGLE DIGITS TO AROUND 20 DEGREES.
FOR THURSDAY...THE NAM IS A BIT QUICKER THAN THE REMAINDER OF THE
MODEL SOLUTIONS WITH A WARM FRONT MOVING INTO NEBRASKA ON THURSDAY.
TIMING OF THIS FRONT WILL MAKE A DIFFERENCE IN TEMPERATURES DURING
THE AFTERNOON AS 850MB TEMPERATURES INCREASE TO AROUND 10C...WHILE
WEST-NORTHWEST FLOW AT THE SURFACE WILL HELP TO ENHANCE THE MIXING
POTENTIAL AND HELP WARM THINGS UP. HOWEVER...IF THE FRONT IS
SLOWER...COOLER TEMPERATURES WILL BE MAINTAINED THROUGH THE DAY. FOR
THE FORECAST...DID INCREASE HIGHS OVER THE WESTERN PART OF THE
FORECAST AREA AS CONFIDENCE IS HIGHER ON A BIT FASTER MOVEMENT AND
WITH A WARM BIAS THAT HAS BEEN SEEN LATELY IN OBSERVATIONS.
BY THIS POINT IN TIME...THE UPPER LEVEL FLOW ACROSS THE CONUS WILL
BE QUITE AMPLIFIED WITH A DEEP TROUGH OVER THE EAST COAST AND A
STRONG RIDGE OVER THE WESTERN CONUS. THIS PUTS THE LOCAL AREA WITHIN
NORTHWEST FLOW WHICH WILL BRING MULTIPLE SHORTWAVE TROUGHS ACROSS
THE AREA THROUGH THE REMAINDER OF THE FORECAST PERIOD. WHILE
MOISTURE WITH THE MAJORITY OF THESE SYSTEMS STAYS WELL NORTH OF THE
AREA TO KEEP THE FORECAST DRY...DESPITE PERIODS OF STRONGER LIFT.
WHAT WILL OCCUR IS LIKELY A BACK AND FORTH TREND FOR TEMPERATURES.
FRIDAY AND SUNDAY LOOK LIKE WARMER DAYS...WHILE SATURDAY AND MONDAY
WILL BE COOLER AS THE AREA WILL SIT IN THE WAKE OF WEAK SYSTEMS WITH
COLD AIR ADVECTION TO WORK WITH.
THE NEXT CHANCES FOR MEASURABLE PRECIPITATION WILL COME ON MONDAY.
THE UPPER LEVEL PATTERN DAMPENS OUT WITH MORE BROAD WEST TO
NORTHWEST FLOW IN PLACE. THE MODELS CONTINUE TO BE IN DECENT
AGREEMENT THIS FAR OUT BRINGING A WEAK SHORTWAVE TROUGH ACROSS
NEBRASKA AND SOUTH DAKOTA. THE MODELS ARE SHOWING A NEARLY COUPLED
RIGHT OVER-TOP OF THE FORECAST AREA WHICH SHOULD LEAD TO STRONGER
LIFT OVER THE AREA. IN ADDITION...DEEP LAYER MOISTURE INCREASES SO
AT THIS TIME WILL CONTINUE WITH MENTION OF PRECIPITATION FOR EARLY
IN THE WEEK. WITH COLD AIR ADVECTION THROUGH THE DAY
MONDAY...SOUNDINGS AND TEMPERATURE PROFILES WOULD INDICATE THE
PRECIPITATION WILL FALL AS SNOW SO ONLY HAVE THAT MENTION IN THE
FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1153 CST TUE FEB 10 2015
SCATTERED HIGH CLOUDS WILL MOVE IN FROM THE NORTHWEST INTO NORTH
CENTRAL AND SOUTHWEST NEBRASKA. A COLD FRONT WILL PUSH THROUGH
NORTHERN NEBRASKA TONIGHT. STRATUS WILL DEVELOP OVERNIGHT ACROSS
NORTHERN NEBRASKA...INCLUDING KVTN...CREATING MVFR CONDITIONS. WINDS
WILL CONTINUE TO BE OUT OF THE NORTHWEST ACROSS THE REGION AND WILL
BECOME STRONG LATE AFTERNOON INTO THE OVERNIGHT ACROSS NORTH CENTRAL
NEBRASKA WITH GUST REACHING UP TO 30KTS. ACROSS SOUTHWEST NEBRASKA
EXPECT LIGHTER WINDS AND VFR CONDITIONS TO PREVAIL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...GOMEZ/MASEK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1149 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 1038 AM CST TUE FEB 10 2015
THE FOG HAS BEEN GRADUALLY LIFTING AND THIS TREND WILL CONTINUE.
THEREFORE...WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 11 AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM CST TUE FEB 10 2015
BEFORE STATING ANOTHER WORD...WANT TO SAY THAT THE ONGOING DENSE
FOG ADVISORY FOR MOST OF THE NEBRASKA CWA IS STANDING ON
INCREASINGLY-SHAKY GROUND BASED ON IMPROVING TRENDS THE NEXT FEW
HOURS...AND AN EARLY CANCELLATION BEFORE 5AM NEWS TIME IS
PROBABLY A GOOD BET...AS ALTHOUGH LOCALIZED POCKETS OF DENSE FOG
MIGHT STILL EXIST...THEY ARE CERTAINLY NOT LOOKING WIDESPREAD
ENOUGH TO SUPPORT A FORMAL HEADLINE.
ALTHOUGH ANOTHER SOMEWHAT TRICKY SKY COVER/TEMPERATURE FORECAST IS
IN STORE TODAY...THE ONE GLARING DIFFERENCE BETWEEN NOW AND 24
HOURS AGO IS THAT THE LOW STRATUS/FOG SITUATION IS ON A
DIMINISHING/IMPROVING TREND INSTEAD OF A WORSENING ONE...AND THE
ENTIRE AREA IS EXPECTED TO WARM INTO THE 50S/60S TODAY INSTEAD OF
JUST WESTERN COUNTIES. RUNNING WITH THE ASSUMPTION THAT SKIES
OVER THE CWA SHOULD EXHIBIT A FAIRLY EFFICIENT WEST-TO-EAST AND
IN SOME AREAS A NORTH-TO-SOUTH CLEARING TREND THROUGH MID-
DAY...WE SHOULD NOT BE FACING THE PESKY EXTREMELY SHARP INTERFACE
BETWEEN CLOUDY/SUNNY AREAS THAT LINGERED ALL DAY YESTERDAY. THAT
BEING SAID...WITH EASTERN COUNTIES NEAREST HIGHWAY 81 EXPECTED TO
BE LAST TO SEE APPRECIABLE CLEARING...THESE AREAS SHOULD IN THEORY
REMAIN A BIT COOLER...AND ALSO STAND THE BEST POTENTIAL FOR A
MODEST TEMPERATURE BUST OF 5+ DEGREES.
PRECIPITATION-WISE...OTHER THAN ANY LINGERING LIGHT PATCHY DRIZZLE
OUT THERE THIS MORNING...THE VAST MAJORITY OF THE CWA IS EXPECTED
TO REMAIN DRY THROUGH THESE NEXT 24 HOURS AND THE OFFICIAL
FORECAST REMAINS AS SUCH. THAT BEING SAID...AT LEAST ONE RUN OF
THE NCEP 4KM WRF-NMM SUGGESTS THAT SOME ROGUE SPRINKLES/SPITS OF
DRIZZLE AND MAYBE EVEN A FEW FLURRIES CANNOT BE RULED OUT FROM
LATE THIS AFTERNOON INTO TONIGHT...BUT LACK OF CONFIDENCE IN
OCCURRENCE AND DOUBTS ABOUT HOW MUCH OF THIS LIGHT PRECIP WILL
ACTUALLY REACH THE GROUND HAS PRECLUDED ANY FORMAL FORECAST
MENTION AT THIS TIME. THIS WILL BE SOMETHING FOR THE NEXT FEW
SHIFTS TO KEEP AN EYE ON THOUGH.
ALTHOUGH IT IS EXPECTED TO ESSENTIALLY BE A DRY PASSAGE...THE COLD
FRONT PASSING THROUGH TONIGHT IS DECENTLY-STRONG AND WILL FEATURE
A NOTICEABLE INCREASE IN LATE-NIGHT NORTH WIND...AND SET THE STAGE
FOR A ROUGHLY A 20-DEGREE COOL DOWN FOR WEDNESDAY AS DESCRIBED IN
THE LONG TERM BELOW.
AS FOR THE HERE AND NOW AS OF 1030Z/430AM...ALTHOUGH THE VAST
MAJORITY OF THE CWA REMAINS SOCKED UNDER A VERY LOW STRATUS
DECK...SOME MODEST POCKETS OF CLEARING HAVE BEEN NOTED MAINLY IN
PARTS OF KS ZONES AND ALSO THE THAYER COUNTY AREA. MORE
IMPORTANTLY...INCREASING BOUNDARY-LAYER FLOW THAT IS STARTING TO
TURN MORE SOUTHWESTERLY HAS RESULTED IN IMPROVING VISIBILITY
OVERNIGHT. AS OF THIS WRITING...NEARLY ALL AUTOMATED AIRPORT SITES
IN THE CWA ARE REPORTING VISIBILITY OF NOW-WORSE-THAN ONE-HALF
MILE. ACTUAL SURFACE WIND IS AVERAGING SUSTAINED 10-15 MPH IN MOST
AREAS WITH SOME HIGHER GUSTS MAINLY IN NEB ZONES. EARLIER IN THE
NIGHT AN AREA OF MAINLY ELEVATED RADAR RETURNS BRUSHED ACROSS FAR
NORTHERN ZONES BUT IS CURRENTLY FOCUSED OUTSIDE THE AREA FROM
NORTHEAST NEB NORTHWARD. WOULD NOT BE SHOCKED IF A FEW SLEET
PELLETS/SNOW GRAINS FELL FROM THOSE RADAR ECHOES BUT ITS A NON-
ISSUE NOW. LOW TEMPERATURES THIS MORNING ARE ON TRACK TO BOTTOM
OUT BETWEEN 29-35 IN MOST AREAS. IN THE MID-UPPER LEVELS...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM A LOW-AMPLITUDE
SHORTWAVE TRACKING EITHER SIDE OF THE NEB/SD BORDER...PROMOTING
THE LIGHT PRECIP TO THE NORTH. THE ASSOCIATED SURFACE LOW WITH
THAT SYSTEM IS AIDING THE TRANSITION TO MORE SOUTH-SOUTHWESTERLY
SURFACE FLOW THAN THE SOUTHEASTERLY THAT PREVAILED 6-12 HOURS AGO.
MEANWHILE FARTHER NORTH...A SOMEWHAT STRONGER MID LEVEL WAVE IS
SLIPPING EAST-SOUTHEAST OUT OF CANADA INTO ND...AND WILL BE THE
DRIVING FORCE BEHIND THE COLD FRONTAL PASSAGE TONIGHT.
LOOKING FORWARD-FORECAST-WISE IN MORE DETAIL AND STARTING WITH
THE DAYTIME HOURS...ALREADY TOUCHED ON IT ABOVE...BUT THE NUMBER 1
CHALLENGE IS TRYING TO PIN DOWN THE DISSIPATION OF LINGERING
MAINLY LIGHT FOG AND ESPECIALLY THE STILL-EXPANSIVE STRATUS DECK.
ALTHOUGH PRONE TO PLENTY OF SITE-SPECIFIC ERROR...HAVE INDICATED A
FAIRLY- STEADY MAINLY WEST-TO-EAST CLEARING TREND THROUGH MID-
DAY...WITH AT LEAST THE WESTERN 2/3 OF THE CWA LIKELY SEEING
PLENTY OF SUN BY NOON OR SO. THE LATEST HRRR LOW CLOUD PRODUCT
WOULD SUGGEST CLEARING COULD BE EVEN MORE RAPID BUT AM A TOUCH
SKEPTICAL OF THAT. COUNTIES NEAR/ALONG THE HIGHWAY 81 CORRIDOR ARE
MOST PRONE TO SEE AT LEAST HALFWAY-DECENT COVERAGE OF LOW CLOUDS
LINGER INTO EARLY AFTERNOON...BUT WHEN ALL IS SAID AND DONE WOULD
BE SURPRISED IF THE ENTIRE CWA DOES NOT CATCH AT LEAST A FEW HOURS
OF SUN TODAY AS LOW LEVEL FLOW CONTINUES TURNING
WESTERLY/NORTHWESTERLY AND HELPS TO ERODE THE LOW CLOUD MASS. AS A
WEAK TROUGH PASSES THROUGH THE AREA...A GRADUAL TRANSITION FROM
SOUTHERLY TO MORE WESTERLY AND EVENTUALLY NORTHWEST BREEZES WILL
OCCUR TODAY. WHILE SUSTAINED SPEEDS THROUGH MOST OF THE DAY SHOULD
ONLY AVERAGE NO MORE THAN 10-15 MPH WITH SLIGHTLY HIGHER GUSTS.
TEMP-WISE...GENERALLY FOLLOWED A BLEND OF SOME OF THE MOST
OPTIMISTIC MODELS TO YIELD UPPER 50S- MID 60S ACROSS THE MAJORITY
OF THE CWA...BUT HEDGED A BIT COOLER IN FAR EASTERN ZONES WITH
MAINLY MID-50S. OF COURSE...IF LOW STRATUS UNEXPECTEDLY HANGS
AROUND LONGER IN THIS AREA...THIS COULD BE A BIT OPTIMISTIC.
OVERALL THOUGH...UPPED HIGHS ONLY 1-2 DEGREES FROM PREVIOUS
FORECAST. AS EARLIER-STATED...ALTHOUGH NOT IN THE OFFICIAL
FORECAST...SUPPOSE A FEW LATE-DAY SPRINKLES CANNOT BE RULED OUT
MAINLY NORTH OF I-80.
TURNING TO THIS EVENING TONIGHT...THE AFOREMENTIONED DAKOTAS
DISTURBANCE WILL TRACK INTO THE GREAT LAKES REGION...AND BE
REINFORCED BY ANOTHER LOBE OF ENERGY DROPPING SOUTHWARD TOWARD
MN/ND OUT OF CANADA. AGAIN...ALTHOUGH SOME VERY LIGHT/SPOTTY
PRECIP CANNOT BE RULED OUT TONIGHT LOCALLY...BY FAR THE MAIN STORY
WILL BE THE PASSAGE OF A FAIRLY HEALTHY COLD FRONT...WITH 850
MILLIBAR TEMPS BY SUNRISE WEDNESDAY PROGGED TO GENERALLY DROP INTO
THE -3 TO -8 C RANGE OVER MOST OF THE CWA. ALTHOUGH NOT OVERLY-
WINDY...THE ARRIVAL OF THIS FRONT WILL BE MARKED BY SEVERAL HOURS
OF SUSTAINED 15-25 MPH NORTH WIND WITH GUSTS UP TO AROUND 30 MPH.
EXCEPT GENERALLY NORTH OF I-80...THE BRUNT OF THESE STRONGER WINDS
WILL NOT KICK IN UNTIL NEAR/AFTER MIDNIGHT. ALTHOUGH NOT
NECESSARILY EXPECTING ANOTHER TOTALLY-SOLID LOW STRATUS DECK
MOVING IN BEHIND THE FRONT...MODELS SUGGEST A COMBINATION OF
PARTLY- MOSTLY CLOUDY SKIES OVERNIGHT BEHIND THE BOUNDARY...WITH
ANY LOWER STRATUS THAT IS PRESENT POSSIBLY EVEN TRYING TO THROW
OUT A FEW SPITS OF DRIZZLE. AGAIN THOUGH...CONFIDENCE JUST TOO LOW
TO "RUIN" THE CURRENTLY DRY FORECAST. TEMP-WISE...LOWS WILL BE A
LITTLE TRICKY AS WELL...AS FAIRLY PRONOUNCED LOW LEVEL COLD AIR
ADVECTION WILL USHER IN COLDER AIR...BUT ITS FULL POTENTIAL MAY BE
MITIGATED A BIT BY THE INFLUENCE OF LOW LEVEL MIXING FROM THE
STEADY WIND AND ALSO CLOUD COVER. BLENDED A FEW MODELS TOGETHER TO
ESSENTIALLY DROP LOWS A FEW DEGREES IN THE NORTH AND BRING THEM UP
VERY SLIGHTLY SOUTH...AIMING FOR A RANGE FROM MID-20S NORTH OF
I-80 TO MID-30S IN KS ZONES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM CST TUE FEB 10 2015
FLUCTUATING TEMPERATURES AND MOSTLY DRY CONDITIONS WILL CONTINUE
THROUGH THE EXTENDED PERIODS...WITH ONLY A SMALL CHANCE OF SOME
LIGHT SNOW RETURNING NEXT MONDAY OR TUESDAY.
OVERALL...EXPECT NORTHWESTERLY FLOW ALOFT TO BE DOMINANT THROUGH THE
EXTENDED PERIODS AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST
COAST AND MULTIPLE LOW PRESSURE SYSTEMS SWING THROUGH THE OHIO RIVER
VALLEY AND UP THE EAST COAST. THIS GENERAL PATTERN IS FORECAST TO
HOLD THROUGH MOST OF THE EXTENDED...WITH AN UPPER LEVEL DISTURBANCE
PUSHING ACROSS BRITISH COLUMBIA ON SUNDAY FORECAST TO DROP INTO THE
PLAINS EARLY NEXT WEEK. WHILE NOT OVERLY MOIST...THIS SYSTEM WILL
BRING THE BEST CHANCE FOR SOME LIGHT SNOWFALL TO THE LOCAL AREA IN
OVER A WEEK.
STARTING OFF WEDNESDAY...EXPECT BREEZY NORTHERLY WINDS TO BE
ADVECTING COOLER AIR FROM THE NORTH THROUGH THE DAY BEHIND AN EARLY
MORNING COLD FRONT. WHILE NOT BITTERLY COLD...THIS AIRMASS WILL BE
IN STARK CONTRAST TO THIS AFTERNOONS ABOVE NORMAL TEMPERATURES....
LIKELY DROPPING AFTERNOON READINGS VERY CLOSE TO CLIMATOLOGY FOR MID
FEBRUARY. WITH THE ASSOCIATED SURFACE HIGH SLIDING SOUTHEAST ACROSS
THE MISSOURI RIVER VALLEY TO START THE DAY ON THURSDAY...EXPECT A
RETURN TO BELOW NORMAL TEMPERATURES TO START THE DAY...WITH SINGLE
DIGITS FORECAST FOR AT LEAST THE NORTHEASTERN HALF OF THE LOCAL AREA
WHERE THE WINDS WILL BE THE LIGHTEST. WHILE THESE COOL MORNING TEMPS
APPEAR TO BE A SURE THING...AFTERNOON TEMPS ARE A BIT TRICKIER AS
THERE COULD BE A SHARP GRADIENT ACROSS THE LOCAL AREA AS WINDS MAY
BEGIN TO SHIFT LATE IN THE DAY IN RESPONSE TO A SURFACE TROUGH
TRACKING EASTWARD FROM COLORADO. THAT SAID...MODEL CONSENSUS KEEPS
THE WINDS GENERALLY SOUTHERLY BEHIND THE DEPARTING HIGH THROUGH THE
PERIOD OF MAXIMUM HEATING...SO KEPT TEMPS ON THE COOLER SIDE ACROSS
OUR LOCAL AREA THURSDAY AFTERNOON.
THEN AS THE SURFACE TROUGH MOVES ACROSS THE HEART OF THE LOCAL AREA
ON FRIDAY...TEMPERATURES SHOULD SHOOT BACK UP WELL ABOVE NORMAL TO
END THE WEEK...ONLY TO BE BROUGHT BACK DOWN OVER THE UPCOMING
WEEKEND AS A BACKDOOR COLD FRONT WORKS ITS WAY WEST...ASSOCIATED
WITH A VIGOROUS LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION.
WHILE THERE IS SOME DISCREPANCY WITH JUST HOW COLD THIS AIRMASS WILL
BE...TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY...WITH BELOW NORMAL
TEMPERATURES FORECAST FOR SATURDAY...AND ONLY A MODEST WARM UP TO
END THE WEEKEND.
STARTING NEXT WEEK...THE FOCUS WILL SHIFT TO A WEST COAST SYSTEM
THAT WILL BRING ANOTHER COLD FRONT ACROSS THE LOCAL AREA LATE MONDAY
OR TUESDAY...BRINGING ENOUGH MOISTURE TO JUSTIFY THE MENTION FOR A
SMALL CHANCE FOR SOME LIGHT SNOWFALL FOR THE TIME BEING.
OVERALL...THIS DOES NOT APPEAR TO BE A VERY MOIST SYSTEM...BUT WITH
VERY COLD TEMPERATURES...WE COULD SEE SOME LIGHT ACCUMULATIONS AS A
RESULT OF HIGH SNOWFALL RATIOS IF MODEL TRENDS HOLD.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM CST TUE FEB 10 2015
THE FOG HAS LIFTED BUT WILL NEED TO WATCH OUT FOR POSSIBLY MORE
FOG THIS EVENING BASED ON EARLY INDICATIONS FROM A FEW MODELS.
HOWEVER...THE BETTER CHANCE OF FOG THIS EVENING WILL BE EAST OF
KGRI AND KEAR. IN ADDITION...FOG IS TOO UNCERTAIN TO INCLUDE IN
THE TAF AT THIS POINT IN TIME. IF THERE IS FOG THIS
EVENING/TONIGHT IT WOULD BE MOST LIKELY SOMETIME BETWEEN 7 PM AND
1 AM. OVERALL...EXPECT IMPROVING AVIATION CONDITIONS TODAY WITH
THE CLOUDS BREAKING UP AT KEAR FIRST AND THEN SHORTLY THEREAFTER
AT KGRI. BOTH SHOULD SEE PLENTY OF SUN BY EARLY AFTERNOON IN
KEARNEY...AND BY MID AFTERNOON IN GRAND ISLAND. A FRONT WILL BE
TRACKING SOUTH ACROSS THE AREA TODAY TURNING THE WINDS TO
NORTHERLY THIS AFTERNOON. A STRONGER REINFORCING SHOT OF COLDER
AIR WILL COME THROUGH TONIGHT AND WE WILL NOTICE AN INCREASING
NORTH WIND BEGINNING AROUND MIDNIGHT TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...WESELY
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1044 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 1038 AM CST TUE FEB 10 2015
THE FOG HAS BEEN GRADUALLY LIFTING AND THIS TREND WILL CONTINUE.
THEREFORE...WILL ALLOW THE DENSE FOG ADVISORY TO EXPIRE AT 11 AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM CST TUE FEB 10 2015
BEFORE STATING ANOTHER WORD...WANT TO SAY THAT THE ONGOING DENSE
FOG ADVISORY FOR MOST OF THE NEBRASKA CWA IS STANDING ON
INCREASINGLY-SHAKY GROUND BASED ON IMPROVING TRENDS THE NEXT FEW
HOURS...AND AN EARLY CANCELLATION BEFORE 5AM NEWS TIME IS
PROBABLY A GOOD BET...AS ALTHOUGH LOCALIZED POCKETS OF DENSE FOG
MIGHT STILL EXIST...THEY ARE CERTAINLY NOT LOOKING WIDESPREAD
ENOUGH TO SUPPORT A FORMAL HEADLINE.
ALTHOUGH ANOTHER SOMEWHAT TRICKY SKY COVER/TEMPERATURE FORECAST IS
IN STORE TODAY...THE ONE GLARING DIFFERENCE BETWEEN NOW AND 24
HOURS AGO IS THAT THE LOW STRATUS/FOG SITUATION IS ON A
DIMINISHING/IMPROVING TREND INSTEAD OF A WORSENING ONE...AND THE
ENTIRE AREA IS EXPECTED TO WARM INTO THE 50S/60S TODAY INSTEAD OF
JUST WESTERN COUNTIES. RUNNING WITH THE ASSUMPTION THAT SKIES
OVER THE CWA SHOULD EXHIBIT A FAIRLY EFFICIENT WEST-TO-EAST AND
IN SOME AREAS A NORTH-TO-SOUTH CLEARING TREND THROUGH MID-
DAY...WE SHOULD NOT BE FACING THE PESKY EXTREMELY SHARP INTERFACE
BETWEEN CLOUDY/SUNNY AREAS THAT LINGERED ALL DAY YESTERDAY. THAT
BEING SAID...WITH EASTERN COUNTIES NEAREST HIGHWAY 81 EXPECTED TO
BE LAST TO SEE APPRECIABLE CLEARING...THESE AREAS SHOULD IN THEORY
REMAIN A BIT COOLER...AND ALSO STAND THE BEST POTENTIAL FOR A
MODEST TEMPERATURE BUST OF 5+ DEGREES.
PRECIPITATION-WISE...OTHER THAN ANY LINGERING LIGHT PATCHY DRIZZLE
OUT THERE THIS MORNING...THE VAST MAJORITY OF THE CWA IS EXPECTED
TO REMAIN DRY THROUGH THESE NEXT 24 HOURS AND THE OFFICIAL
FORECAST REMAINS AS SUCH. THAT BEING SAID...AT LEAST ONE RUN OF
THE NCEP 4KM WRF-NMM SUGGESTS THAT SOME ROGUE SPRINKLES/SPITS OF
DRIZZLE AND MAYBE EVEN A FEW FLURRIES CANNOT BE RULED OUT FROM
LATE THIS AFTERNOON INTO TONIGHT...BUT LACK OF CONFIDENCE IN
OCCURRENCE AND DOUBTS ABOUT HOW MUCH OF THIS LIGHT PRECIP WILL
ACTUALLY REACH THE GROUND HAS PRECLUDED ANY FORMAL FORECAST
MENTION AT THIS TIME. THIS WILL BE SOMETHING FOR THE NEXT FEW
SHIFTS TO KEEP AN EYE ON THOUGH.
ALTHOUGH IT IS EXPECTED TO ESSENTIALLY BE A DRY PASSAGE...THE COLD
FRONT PASSING THROUGH TONIGHT IS DECENTLY-STRONG AND WILL FEATURE
A NOTICEABLE INCREASE IN LATE-NIGHT NORTH WIND...AND SET THE STAGE
FOR A ROUGHLY A 20-DEGREE COOL DOWN FOR WEDNESDAY AS DESCRIBED IN
THE LONG TERM BELOW.
AS FOR THE HERE AND NOW AS OF 1030Z/430AM...ALTHOUGH THE VAST
MAJORITY OF THE CWA REMAINS SOCKED UNDER A VERY LOW STRATUS
DECK...SOME MODEST POCKETS OF CLEARING HAVE BEEN NOTED MAINLY IN
PARTS OF KS ZONES AND ALSO THE THAYER COUNTY AREA. MORE
IMPORTANTLY...INCREASING BOUNDARY-LAYER FLOW THAT IS STARTING TO
TURN MORE SOUTHWESTERLY HAS RESULTED IN IMPROVING VISIBILITY
OVERNIGHT. AS OF THIS WRITING...NEARLY ALL AUTOMATED AIRPORT SITES
IN THE CWA ARE REPORTING VISIBILITY OF NOW-WORSE-THAN ONE-HALF
MILE. ACTUAL SURFACE WIND IS AVERAGING SUSTAINED 10-15 MPH IN MOST
AREAS WITH SOME HIGHER GUSTS MAINLY IN NEB ZONES. EARLIER IN THE
NIGHT AN AREA OF MAINLY ELEVATED RADAR RETURNS BRUSHED ACROSS FAR
NORTHERN ZONES BUT IS CURRENTLY FOCUSED OUTSIDE THE AREA FROM
NORTHEAST NEB NORTHWARD. WOULD NOT BE SHOCKED IF A FEW SLEET
PELLETS/SNOW GRAINS FELL FROM THOSE RADAR ECHOES BUT ITS A NON-
ISSUE NOW. LOW TEMPERATURES THIS MORNING ARE ON TRACK TO BOTTOM
OUT BETWEEN 29-35 IN MOST AREAS. IN THE MID-UPPER LEVELS...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM A LOW-AMPLITUDE
SHORTWAVE TRACKING EITHER SIDE OF THE NEB/SD BORDER...PROMOTING
THE LIGHT PRECIP TO THE NORTH. THE ASSOCIATED SURFACE LOW WITH
THAT SYSTEM IS AIDING THE TRANSITION TO MORE SOUTH-SOUTHWESTERLY
SURFACE FLOW THAN THE SOUTHEASTERLY THAT PREVAILED 6-12 HOURS AGO.
MEANWHILE FARTHER NORTH...A SOMEWHAT STRONGER MID LEVEL WAVE IS
SLIPPING EAST-SOUTHEAST OUT OF CANADA INTO ND...AND WILL BE THE
DRIVING FORCE BEHIND THE COLD FRONTAL PASSAGE TONIGHT.
LOOKING FORWARD-FORECAST-WISE IN MORE DETAIL AND STARTING WITH
THE DAYTIME HOURS...ALREADY TOUCHED ON IT ABOVE...BUT THE NUMBER 1
CHALLENGE IS TRYING TO PIN DOWN THE DISSIPATION OF LINGERING
MAINLY LIGHT FOG AND ESPECIALLY THE STILL-EXPANSIVE STRATUS DECK.
ALTHOUGH PRONE TO PLENTY OF SITE-SPECIFIC ERROR...HAVE INDICATED A
FAIRLY- STEADY MAINLY WEST-TO-EAST CLEARING TREND THROUGH MID-
DAY...WITH AT LEAST THE WESTERN 2/3 OF THE CWA LIKELY SEEING
PLENTY OF SUN BY NOON OR SO. THE LATEST HRRR LOW CLOUD PRODUCT
WOULD SUGGEST CLEARING COULD BE EVEN MORE RAPID BUT AM A TOUCH
SKEPTICAL OF THAT. COUNTIES NEAR/ALONG THE HIGHWAY 81 CORRIDOR ARE
MOST PRONE TO SEE AT LEAST HALFWAY-DECENT COVERAGE OF LOW CLOUDS
LINGER INTO EARLY AFTERNOON...BUT WHEN ALL IS SAID AND DONE WOULD
BE SURPRISED IF THE ENTIRE CWA DOES NOT CATCH AT LEAST A FEW HOURS
OF SUN TODAY AS LOW LEVEL FLOW CONTINUES TURNING
WESTERLY/NORTHWESTERLY AND HELPS TO ERODE THE LOW CLOUD MASS. AS A
WEAK TROUGH PASSES THROUGH THE AREA...A GRADUAL TRANSITION FROM
SOUTHERLY TO MORE WESTERLY AND EVENTUALLY NORTHWEST BREEZES WILL
OCCUR TODAY. WHILE SUSTAINED SPEEDS THROUGH MOST OF THE DAY SHOULD
ONLY AVERAGE NO MORE THAN 10-15 MPH WITH SLIGHTLY HIGHER GUSTS.
TEMP-WISE...GENERALLY FOLLOWED A BLEND OF SOME OF THE MOST
OPTIMISTIC MODELS TO YIELD UPPER 50S- MID 60S ACROSS THE MAJORITY
OF THE CWA...BUT HEDGED A BIT COOLER IN FAR EASTERN ZONES WITH
MAINLY MID-50S. OF COURSE...IF LOW STRATUS UNEXPECTEDLY HANGS
AROUND LONGER IN THIS AREA...THIS COULD BE A BIT OPTIMISTIC.
OVERALL THOUGH...UPPED HIGHS ONLY 1-2 DEGREES FROM PREVIOUS
FORECAST. AS EARLIER-STATED...ALTHOUGH NOT IN THE OFFICIAL
FORECAST...SUPPOSE A FEW LATE-DAY SPRINKLES CANNOT BE RULED OUT
MAINLY NORTH OF I-80.
TURNING TO THIS EVENING TONIGHT...THE AFOREMENTIONED DAKOTAS
DISTURBANCE WILL TRACK INTO THE GREAT LAKES REGION...AND BE
REINFORCED BY ANOTHER LOBE OF ENERGY DROPPING SOUTHWARD TOWARD
MN/ND OUT OF CANADA. AGAIN...ALTHOUGH SOME VERY LIGHT/SPOTTY
PRECIP CANNOT BE RULED OUT TONIGHT LOCALLY...BY FAR THE MAIN STORY
WILL BE THE PASSAGE OF A FAIRLY HEALTHY COLD FRONT...WITH 850
MILLIBAR TEMPS BY SUNRISE WEDNESDAY PROGGED TO GENERALLY DROP INTO
THE -3 TO -8 C RANGE OVER MOST OF THE CWA. ALTHOUGH NOT OVERLY-
WINDY...THE ARRIVAL OF THIS FRONT WILL BE MARKED BY SEVERAL HOURS
OF SUSTAINED 15-25 MPH NORTH WIND WITH GUSTS UP TO AROUND 30 MPH.
EXCEPT GENERALLY NORTH OF I-80...THE BRUNT OF THESE STRONGER WINDS
WILL NOT KICK IN UNTIL NEAR/AFTER MIDNIGHT. ALTHOUGH NOT
NECESSARILY EXPECTING ANOTHER TOTALLY-SOLID LOW STRATUS DECK
MOVING IN BEHIND THE FRONT...MODELS SUGGEST A COMBINATION OF
PARTLY- MOSTLY CLOUDY SKIES OVERNIGHT BEHIND THE BOUNDARY...WITH
ANY LOWER STRATUS THAT IS PRESENT POSSIBLY EVEN TRYING TO THROW
OUT A FEW SPITS OF DRIZZLE. AGAIN THOUGH...CONFIDENCE JUST TOO LOW
TO "RUIN" THE CURRENTLY DRY FORECAST. TEMP-WISE...LOWS WILL BE A
LITTLE TRICKY AS WELL...AS FAIRLY PRONOUNCED LOW LEVEL COLD AIR
ADVECTION WILL USHER IN COLDER AIR...BUT ITS FULL POTENTIAL MAY BE
MITIGATED A BIT BY THE INFLUENCE OF LOW LEVEL MIXING FROM THE
STEADY WIND AND ALSO CLOUD COVER. BLENDED A FEW MODELS TOGETHER TO
ESSENTIALLY DROP LOWS A FEW DEGREES IN THE NORTH AND BRING THEM UP
VERY SLIGHTLY SOUTH...AIMING FOR A RANGE FROM MID-20S NORTH OF
I-80 TO MID-30S IN KS ZONES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM CST TUE FEB 10 2015
FLUCTUATING TEMPERATURES AND MOSTLY DRY CONDITIONS WILL CONTINUE
THROUGH THE EXTENDED PERIODS...WITH ONLY A SMALL CHANCE OF SOME
LIGHT SNOW RETURNING NEXT MONDAY OR TUESDAY.
OVERALL...EXPECT NORTHWESTERLY FLOW ALOFT TO BE DOMINANT THROUGH THE
EXTENDED PERIODS AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST
COAST AND MULTIPLE LOW PRESSURE SYSTEMS SWING THROUGH THE OHIO RIVER
VALLEY AND UP THE EAST COAST. THIS GENERAL PATTERN IS FORECAST TO
HOLD THROUGH MOST OF THE EXTENDED...WITH AN UPPER LEVEL DISTURBANCE
PUSHING ACROSS BRITISH COLUMBIA ON SUNDAY FORECAST TO DROP INTO THE
PLAINS EARLY NEXT WEEK. WHILE NOT OVERLY MOIST...THIS SYSTEM WILL
BRING THE BEST CHANCE FOR SOME LIGHT SNOWFALL TO THE LOCAL AREA IN
OVER A WEEK.
STARTING OFF WEDNESDAY...EXPECT BREEZY NORTHERLY WINDS TO BE
ADVECTING COOLER AIR FROM THE NORTH THROUGH THE DAY BEHIND AN EARLY
MORNING COLD FRONT. WHILE NOT BITTERLY COLD...THIS AIRMASS WILL BE
IN STARK CONTRAST TO THIS AFTERNOONS ABOVE NORMAL TEMPERATURES....
LIKELY DROPPING AFTERNOON READINGS VERY CLOSE TO CLIMATOLOGY FOR MID
FEBRUARY. WITH THE ASSOCIATED SURFACE HIGH SLIDING SOUTHEAST ACROSS
THE MISSOURI RIVER VALLEY TO START THE DAY ON THURSDAY...EXPECT A
RETURN TO BELOW NORMAL TEMPERATURES TO START THE DAY...WITH SINGLE
DIGITS FORECAST FOR AT LEAST THE NORTHEASTERN HALF OF THE LOCAL AREA
WHERE THE WINDS WILL BE THE LIGHTEST. WHILE THESE COOL MORNING TEMPS
APPEAR TO BE A SURE THING...AFTERNOON TEMPS ARE A BIT TRICKIER AS
THERE COULD BE A SHARP GRADIENT ACROSS THE LOCAL AREA AS WINDS MAY
BEGIN TO SHIFT LATE IN THE DAY IN RESPONSE TO A SURFACE TROUGH
TRACKING EASTWARD FROM COLORADO. THAT SAID...MODEL CONSENSUS KEEPS
THE WINDS GENERALLY SOUTHERLY BEHIND THE DEPARTING HIGH THROUGH THE
PERIOD OF MAXIMUM HEATING...SO KEPT TEMPS ON THE COOLER SIDE ACROSS
OUR LOCAL AREA THURSDAY AFTERNOON.
THEN AS THE SURFACE TROUGH MOVES ACROSS THE HEART OF THE LOCAL AREA
ON FRIDAY...TEMPERATURES SHOULD SHOOT BACK UP WELL ABOVE NORMAL TO
END THE WEEK...ONLY TO BE BROUGHT BACK DOWN OVER THE UPCOMING
WEEKEND AS A BACKDOOR COLD FRONT WORKS ITS WAY WEST...ASSOCIATED
WITH A VIGOROUS LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION.
WHILE THERE IS SOME DISCREPANCY WITH JUST HOW COLD THIS AIRMASS WILL
BE...TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY...WITH BELOW NORMAL
TEMPERATURES FORECAST FOR SATURDAY...AND ONLY A MODEST WARM UP TO
END THE WEEKEND.
STARTING NEXT WEEK...THE FOCUS WILL SHIFT TO A WEST COAST SYSTEM
THAT WILL BRING ANOTHER COLD FRONT ACROSS THE LOCAL AREA LATE MONDAY
OR TUESDAY...BRINGING ENOUGH MOISTURE TO JUSTIFY THE MENTION FOR A
SMALL CHANCE FOR SOME LIGHT SNOWFALL FOR THE TIME BEING.
OVERALL...THIS DOES NOT APPEAR TO BE A VERY MOIST SYSTEM...BUT WITH
VERY COLD TEMPERATURES...WE COULD SEE SOME LIGHT ACCUMULATIONS AS A
RESULT OF HIGH SNOWFALL RATIOS IF MODEL TRENDS HOLD.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 651 AM CST TUE FEB 10 2015
ALTHOUGH AT LEAST A FEW MORE HOURS OF VERY POOR (MAINLY LIFR/IFR)
CEILING/VISIBILITY CONDITIONS ARE EXPECTED AT BOTH TERMINALS
THIS MORNING IN PERSISTENT FOG/STRATUS...A MARKED IMPROVEMENT IS
EXPECTED BY EARLY AFTERNOON AS A RETURN TO WESTERLY LOW-LEVEL
FLOW SCOURS OUT THE FOG AND STRATUS. CONFIDENCE IN THE TIMING
DETAILS IS ADMITTEDLY A BIT SHAKY...AS IT COULD BE A VERY GRADUAL
IMPROVEMENT OVER TIME OR IT COULD BE A VERY ABRUPT
IMPROVEMENT...SO STAY TUNED FOR AMENDMENTS. AT ANY RATE...HAVE
KEAR RETURNING TO VFR BY 18Z AND KGRI 19Z AS A BEST STAB FOR NOW.
AS FOR WIND...SURFACE BREEZES THIS MORNING WILL REMAIN QUITE
STEADY FROM THE SOUTH-SOUTHWEST...WITH GUST POTENTIAL TO AROUND
20KT. AS A TROUGH AXIS/WEAK COLD FRONT PASSES THROUGH DURING THE
DAY...BREEZES WILL DIMINISH A BIT AND TURN MORE WEST-
NORTHWESTERLY. LATE IN THE PERIOD TONIGHT..STRONGER NORTH-
NORTHWEST WIND WILL ARRIVE BEHIND A COLD FRONT WITH GUST POTENTIAL
TO AROUND 25KT. DURING THE FINAL 6 HOURS...ANOTHER ROUND OF
POTENTIAL MVFR OR EVEN IFR CEILING COULD OVERSPREAD THE AREA FROM
THE NORTH...BUT CONFIDENCE IS LOW AND WENT WITH A LOW-END VFR
CEILING AT THIS TIME. LASTLY...WILL CONTINUE A SOMEWHAT MARGINAL
MENTION OF LOW LEVEL WIND SHEAR (LLWS) FOR A FEW MORE HOURS AT
KGRI THIS MORNING TO ACCOUNT FOR A GENERALLY 30KT BULK SHEAR
DIFFERENCE BETWEEN THE SURFACE AND ROUGHLY 1500 FT AGL...THANKS TO
SOUTHWESTERLY WIND TOPPING OUT AROUND 40KT AT THIS LEVEL. HAVE
OMITTED THIS LLWS MENTION FROM KEAR GIVEN THAT BULK SHEAR
DIFFERENCE SHOULD BE LESS LIKELY TO EXCEED 30KT BUT IT WILL STILL
BE CLOSE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...WESELY
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
651 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 651 AM CST TUE FEB 10 2015
ALTHOUGH STILL FEELING PRETTY CONFIDENT THAN WE WILL GET AWAY
WITHOUT NEEDING ANOTHER DENSE FOG ADVISORY...THE LAST 90 MINUTES
OR SO HAVE BROUGHT ANOTHER UPTICK IN SITES REPORTING VISIBILITY
DOWN TO 1/2 MILE...WITH LOCALIZED SENSORS MAINLY NEAR
PHILLIPSBURG/STOCKTON KS BOUNCING DOWN TO 1/4. ALTHOUGH ONCOMING
DAY SHIFT WILL OBVIOUSLY KEEP AN EYE ON THINGS...FOR NOW WILL JUST
CONTINUE CARRYING LESS-THAN-1-MILE WORDING IN THE PUBLIC FORECAST
AND MENTION 1/2-MILE AND LOCALLY LESS IN THE HAZARDOUS WEATHER
OUTLOOK. IT WILL LIKELY BE A SLOW PROCESS TODAY...BUT STILL
EXPECTING STRATUS AND FOG TO GRADUALLY VACATE MUCH OF THE CWA FROM
WEST-TO-EAST BY EARLY-MID AFTERNOON.
UPDATE ISSUED AT 509 AM CST TUE FEB 10 2015
AS SUGGESTED BELOW LESS THAN 1 HOUR AGO...HAVE OPTED TO CANCEL
THE REMAINDER OF THE DENSE FOG ADVISORY EARLY BASED ON A CONTINUED
OVERALL-IMPROVING TREND SINCE EARLIER IN THE NIGHT. AS OF THIS
WRITING...ONLY 1 OF THE 13 PRIMARY AUTOMATED AIRPORT SENSORS
WITHIN THE CWA (HOLDREGE) IS REPORTING VISIBILITY AS LOW AS 1/2
MILE AND AN ASSORTMENT OF WEB CAMS SUPPORT THE MARKED-IMPROVEMENT
AS WELL. CERTAINLY CANNOT COMPLETELY RULE OUT SOME VERY SMALL
AREAS OF DENSE FOG YET THIS MORNING...ESPECIALLY NEAR THE EDGES OF
THE EXPANSIVE LOW STRATUS DECK STILL SQUARELY PLANTED OVER THE
MAJORITY OF THE CWA...BUT EVEN SO THIS WOULD NOT BE ENOUGH TO
JUSTIFY CONTINUING THE FORMAL HEADLINE.
ON A SEPARATE MINOR NOTE...FORGOT TO MENTION IN THE MAIN
DISCUSSION BELOW THAT FORECASTED AFTERNOON RELATIVE HUMIDITY
VALUES DROP DOWN TO AROUND 25 PERCENT FOR A SHORT TIME IN THE
EXTREME SOUTHWEST CORNER OF THE CWA (FURNAS/PHILLIPS/ROOKS
COUNTIES). IF WEST-NORTHWEST WIND GUSTS THIS AFTERNOON HAPPEN TO
BREACH 20 MPH THIS COULD TECHNICALLY PROMOTE A PERIOD OF NEAR-
CRITICAL FIRE DANGER. HOWEVER...GIVEN THAT IT IS SUCH A SMALL
SPATIAL COVERAGE WITH ONLY MARGINAL-AT-BEST NEAR-CRITICAL
POTENTIAL...WILL FOREGO ANY FORMAL MENTION IN THE HAZARDOUS
WEATHER OUTLOOK PRODUCT (HWOGID).
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM CST TUE FEB 10 2015
BEFORE STATING ANOTHER WORD...WANT TO SAY THAT THE ONGOING DENSE
FOG ADVISORY FOR MOST OF THE NEBRASKA CWA IS STANDING ON
INCREASINGLY-SHAKY GROUND BASED ON IMPROVING TRENDS THE NEXT FEW
HOURS...AND AN EARLY CANCELLATION BEFORE 5AM NEWS TIME IS
PROBABLY A GOOD BET...AS ALTHOUGH LOCALIZED POCKETS OF DENSE FOG
MIGHT STILL EXIST...THEY ARE CERTAINLY NOT LOOKING WIDESPREAD
ENOUGH TO SUPPORT A FORMAL HEADLINE.
ALTHOUGH ANOTHER SOMEWHAT TRICKY SKY COVER/TEMPERATURE FORECAST IS
IN STORE TODAY...THE ONE GLARING DIFFERENCE BETWEEN NOW AND 24
HOURS AGO IS THAT THE LOW STRATUS/FOG SITUATION IS ON A
DIMINISHING/IMPROVING TREND INSTEAD OF A WORSENING ONE...AND THE
ENTIRE AREA IS EXPECTED TO WARM INTO THE 50S/60S TODAY INSTEAD OF
JUST WESTERN COUNTIES. RUNNING WITH THE ASSUMPTION THAT SKIES
OVER THE CWA SHOULD EXHIBIT A FAIRLY EFFICIENT WEST-TO-EAST AND
IN SOME AREAS A NORTH-TO-SOUTH CLEARING TREND THROUGH MID-
DAY...WE SHOULD NOT BE FACING THE PESKY EXTREMELY SHARP INTERFACE
BETWEEN CLOUDY/SUNNY AREAS THAT LINGERED ALL DAY YESTERDAY. THAT
BEING SAID...WITH EASTERN COUNTIES NEAREST HIGHWAY 81 EXPECTED TO
BE LAST TO SEE APPRECIABLE CLEARING...THESE AREAS SHOULD IN THEORY
REMAIN A BIT COOLER...AND ALSO STAND THE BEST POTENTIAL FOR A
MODEST TEMPERATURE BUST OF 5+ DEGREES.
PRECIPITATION-WISE...OTHER THAN ANY LINGERING LIGHT PATCHY DRIZZLE
OUT THERE THIS MORNING...THE VAST MAJORITY OF THE CWA IS EXPECTED
TO REMAIN DRY THROUGH THESE NEXT 24 HOURS AND THE OFFICIAL
FORECAST REMAINS AS SUCH. THAT BEING SAID...AT LEAST ONE RUN OF
THE NCEP 4KM WRF-NMM SUGGESTS THAT SOME ROGUE SPRINKLES/SPITS OF
DRIZZLE AND MAYBE EVEN A FEW FLURRIES CANNOT BE RULED OUT FROM
LATE THIS AFTERNOON INTO TONIGHT...BUT LACK OF CONFIDENCE IN
OCCURRENCE AND DOUBTS ABOUT HOW MUCH OF THIS LIGHT PRECIP WILL
ACTUALLY REACH THE GROUND HAS PRECLUDED ANY FORMAL FORECAST
MENTION AT THIS TIME. THIS WILL BE SOMETHING FOR THE NEXT FEW
SHIFTS TO KEEP AN EYE ON THOUGH.
ALTHOUGH IT IS EXPECTED TO ESSENTIALLY BE A DRY PASSAGE...THE COLD
FRONT PASSING THROUGH TONIGHT IS DECENTLY-STRONG AND WILL FEATURE
A NOTICEABLE INCREASE IN LATE-NIGHT NORTH WIND...AND SET THE STAGE
FOR A ROUGHLY A 20-DEGREE COOL DOWN FOR WEDNESDAY AS DESCRIBED IN
THE LONG TERM BELOW.
AS FOR THE HERE AND NOW AS OF 1030Z/430AM...ALTHOUGH THE VAST
MAJORITY OF THE CWA REMAINS SOCKED UNDER A VERY LOW STRATUS
DECK...SOME MODEST POCKETS OF CLEARING HAVE BEEN NOTED MAINLY IN
PARTS OF KS ZONES AND ALSO THE THAYER COUNTY AREA. MORE
IMPORTANTLY...INCREASING BOUNDARY-LAYER FLOW THAT IS STARTING TO
TURN MORE SOUTHWESTERLY HAS RESULTED IN IMPROVING VISIBILITY
OVERNIGHT. AS OF THIS WRITING...NEARLY ALL AUTOMATED AIRPORT SITES
IN THE CWA ARE REPORTING VISIBILITY OF NOW-WORSE-THAN ONE-HALF
MILE. ACTUAL SURFACE WIND IS AVERAGING SUSTAINED 10-15 MPH IN MOST
AREAS WITH SOME HIGHER GUSTS MAINLY IN NEB ZONES. EARLIER IN THE
NIGHT AN AREA OF MAINLY ELEVATED RADAR RETURNS BRUSHED ACROSS FAR
NORTHERN ZONES BUT IS CURRENTLY FOCUSED OUTSIDE THE AREA FROM
NORTHEAST NEB NORTHWARD. WOULD NOT BE SHOCKED IF A FEW SLEET
PELLETS/SNOW GRAINS FELL FROM THOSE RADAR ECHOES BUT ITS A NON-
ISSUE NOW. LOW TEMPERATURES THIS MORNING ARE ON TRACK TO BOTTOM
OUT BETWEEN 29-35 IN MOST AREAS. IN THE MID-UPPER LEVELS...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM A LOW-AMPLITUDE
SHORTWAVE TRACKING EITHER SIDE OF THE NEB/SD BORDER...PROMOTING
THE LIGHT PRECIP TO THE NORTH. THE ASSOCIATED SURFACE LOW WITH
THAT SYSTEM IS AIDING THE TRANSITION TO MORE SOUTH-SOUTHWESTERLY
SURFACE FLOW THAN THE SOUTHEASTERLY THAT PREVAILED 6-12 HOURS AGO.
MEANWHILE FARTHER NORTH...A SOMEWHAT STRONGER MID LEVEL WAVE IS
SLIPPING EAST-SOUTHEAST OUT OF CANADA INTO ND...AND WILL BE THE
DRIVING FORCE BEHIND THE COLD FRONTAL PASSAGE TONIGHT.
LOOKING FORWARD-FORECAST-WISE IN MORE DETAIL AND STARTING WITH
THE DAYTIME HOURS...ALREADY TOUCHED ON IT ABOVE...BUT THE NUMBER 1
CHALLENGE IS TRYING TO PIN DOWN THE DISSIPATION OF LINGERING
MAINLY LIGHT FOG AND ESPECIALLY THE STILL-EXPANSIVE STRATUS DECK.
ALTHOUGH PRONE TO PLENTY OF SITE-SPECIFIC ERROR...HAVE INDICATED A
FAIRLY- STEADY MAINLY WEST-TO-EAST CLEARING TREND THROUGH MID-
DAY...WITH AT LEAST THE WESTERN 2/3 OF THE CWA LIKELY SEEING
PLENTY OF SUN BY NOON OR SO. THE LATEST HRRR LOW CLOUD PRODUCT
WOULD SUGGEST CLEARING COULD BE EVEN MORE RAPID BUT AM A TOUCH
SKEPTICAL OF THAT. COUNTIES NEAR/ALONG THE HIGHWAY 81 CORRIDOR ARE
MOST PRONE TO SEE AT LEAST HALFWAY-DECENT COVERAGE OF LOW CLOUDS
LINGER INTO EARLY AFTERNOON...BUT WHEN ALL IS SAID AND DONE WOULD
BE SURPRISED IF THE ENTIRE CWA DOES NOT CATCH AT LEAST A FEW HOURS
OF SUN TODAY AS LOW LEVEL FLOW CONTINUES TURNING
WESTERLY/NORTHWESTERLY AND HELPS TO ERODE THE LOW CLOUD MASS. AS A
WEAK TROUGH PASSES THROUGH THE AREA...A GRADUAL TRANSITION FROM
SOUTHERLY TO MORE WESTERLY AND EVENTUALLY NORTHWEST BREEZES WILL
OCCUR TODAY. WHILE SUSTAINED SPEEDS THROUGH MOST OF THE DAY SHOULD
ONLY AVERAGE NO MORE THAN 10-15 MPH WITH SLIGHTLY HIGHER GUSTS.
TEMP-WISE...GENERALLY FOLLOWED A BLEND OF SOME OF THE MOST
OPTIMISTIC MODELS TO YIELD UPPER 50S- MID 60S ACROSS THE MAJORITY
OF THE CWA...BUT HEDGED A BIT COOLER IN FAR EASTERN ZONES WITH
MAINLY MID-50S. OF COURSE...IF LOW STRATUS UNEXPECTEDLY HANGS
AROUND LONGER IN THIS AREA...THIS COULD BE A BIT OPTIMISTIC.
OVERALL THOUGH...UPPED HIGHS ONLY 1-2 DEGREES FROM PREVIOUS
FORECAST. AS EARLIER-STATED...ALTHOUGH NOT IN THE OFFICIAL
FORECAST...SUPPOSE A FEW LATE-DAY SPRINKLES CANNOT BE RULED OUT
MAINLY NORTH OF I-80.
TURNING TO THIS EVENING TONIGHT...THE AFOREMENTIONED DAKOTAS
DISTURBANCE WILL TRACK INTO THE GREAT LAKES REGION...AND BE
REINFORCED BY ANOTHER LOBE OF ENERGY DROPPING SOUTHWARD TOWARD
MN/ND OUT OF CANADA. AGAIN...ALTHOUGH SOME VERY LIGHT/SPOTTY
PRECIP CANNOT BE RULED OUT TONIGHT LOCALLY...BY FAR THE MAIN STORY
WILL BE THE PASSAGE OF A FAIRLY HEALTHY COLD FRONT...WITH 850
MILLIBAR TEMPS BY SUNRISE WEDNESDAY PROGGED TO GENERALLY DROP INTO
THE -3 TO -8 C RANGE OVER MOST OF THE CWA. ALTHOUGH NOT OVERLY-
WINDY...THE ARRIVAL OF THIS FRONT WILL BE MARKED BY SEVERAL HOURS
OF SUSTAINED 15-25 MPH NORTH WIND WITH GUSTS UP TO AROUND 30 MPH.
EXCEPT GENERALLY NORTH OF I-80...THE BRUNT OF THESE STRONGER WINDS
WILL NOT KICK IN UNTIL NEAR/AFTER MIDNIGHT. ALTHOUGH NOT
NECESSARILY EXPECTING ANOTHER TOTALLY-SOLID LOW STRATUS DECK
MOVING IN BEHIND THE FRONT...MODELS SUGGEST A COMBINATION OF
PARTLY- MOSTLY CLOUDY SKIES OVERNIGHT BEHIND THE BOUNDARY...WITH
ANY LOWER STRATUS THAT IS PRESENT POSSIBLY EVEN TRYING TO THROW
OUT A FEW SPITS OF DRIZZLE. AGAIN THOUGH...CONFIDENCE JUST TOO LOW
TO "RUIN" THE CURRENTLY DRY FORECAST. TEMP-WISE...LOWS WILL BE A
LITTLE TRICKY AS WELL...AS FAIRLY PRONOUNCED LOW LEVEL COLD AIR
ADVECTION WILL USHER IN COLDER AIR...BUT ITS FULL POTENTIAL MAY BE
MITIGATED A BIT BY THE INFLUENCE OF LOW LEVEL MIXING FROM THE
STEADY WIND AND ALSO CLOUD COVER. BLENDED A FEW MODELS TOGETHER TO
ESSENTIALLY DROP LOWS A FEW DEGREES IN THE NORTH AND BRING THEM UP
VERY SLIGHTLY SOUTH...AIMING FOR A RANGE FROM MID-20S NORTH OF
I-80 TO MID-30S IN KS ZONES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM CST TUE FEB 10 2015
FLUCTUATING TEMPERATURES AND MOSTLY DRY CONDITIONS WILL CONTINUE
THROUGH THE EXTENDED PERIODS...WITH ONLY A SMALL CHANCE OF SOME
LIGHT SNOW RETURNING NEXT MONDAY OR TUESDAY.
OVERALL...EXPECT NORTHWESTERLY FLOW ALOFT TO BE DOMINANT THROUGH THE
EXTENDED PERIODS AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST
COAST AND MULTIPLE LOW PRESSURE SYSTEMS SWING THROUGH THE OHIO RIVER
VALLEY AND UP THE EAST COAST. THIS GENERAL PATTERN IS FORECAST TO
HOLD THROUGH MOST OF THE EXTENDED...WITH AN UPPER LEVEL DISTURBANCE
PUSHING ACROSS BRITISH COLUMBIA ON SUNDAY FORECAST TO DROP INTO THE
PLAINS EARLY NEXT WEEK. WHILE NOT OVERLY MOIST...THIS SYSTEM WILL
BRING THE BEST CHANCE FOR SOME LIGHT SNOWFALL TO THE LOCAL AREA IN
OVER A WEEK.
STARTING OFF WEDNESDAY...EXPECT BREEZY NORTHERLY WINDS TO BE
ADVECTING COOLER AIR FROM THE NORTH THROUGH THE DAY BEHIND AN EARLY
MORNING COLD FRONT. WHILE NOT BITTERLY COLD...THIS AIRMASS WILL BE
IN STARK CONTRAST TO THIS AFTERNOONS ABOVE NORMAL TEMPERATURES....
LIKELY DROPPING AFTERNOON READINGS VERY CLOSE TO CLIMATOLOGY FOR MID
FEBRUARY. WITH THE ASSOCIATED SURFACE HIGH SLIDING SOUTHEAST ACROSS
THE MISSOURI RIVER VALLEY TO START THE DAY ON THURSDAY...EXPECT A
RETURN TO BELOW NORMAL TEMPERATURES TO START THE DAY...WITH SINGLE
DIGITS FORECAST FOR AT LEAST THE NORTHEASTERN HALF OF THE LOCAL AREA
WHERE THE WINDS WILL BE THE LIGHTEST. WHILE THESE COOL MORNING TEMPS
APPEAR TO BE A SURE THING...AFTERNOON TEMPS ARE A BIT TRICKIER AS
THERE COULD BE A SHARP GRADIENT ACROSS THE LOCAL AREA AS WINDS MAY
BEGIN TO SHIFT LATE IN THE DAY IN RESPONSE TO A SURFACE TROUGH
TRACKING EASTWARD FROM COLORADO. THAT SAID...MODEL CONSENSUS KEEPS
THE WINDS GENERALLY SOUTHERLY BEHIND THE DEPARTING HIGH THROUGH THE
PERIOD OF MAXIMUM HEATING...SO KEPT TEMPS ON THE COOLER SIDE ACROSS
OUR LOCAL AREA THURSDAY AFTERNOON.
THEN AS THE SURFACE TROUGH MOVES ACROSS THE HEART OF THE LOCAL AREA
ON FRIDAY...TEMPERATURES SHOULD SHOOT BACK UP WELL ABOVE NORMAL TO
END THE WEEK...ONLY TO BE BROUGHT BACK DOWN OVER THE UPCOMING
WEEKEND AS A BACKDOOR COLD FRONT WORKS ITS WAY WEST...ASSOCIATED
WITH A VIGOROUS LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION.
WHILE THERE IS SOME DISCREPANCY WITH JUST HOW COLD THIS AIRMASS WILL
BE...TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY...WITH BELOW NORMAL
TEMPERATURES FORECAST FOR SATURDAY...AND ONLY A MODEST WARM UP TO
END THE WEEKEND.
STARTING NEXT WEEK...THE FOCUS WILL SHIFT TO A WEST COAST SYSTEM
THAT WILL BRING ANOTHER COLD FRONT ACROSS THE LOCAL AREA LATE MONDAY
OR TUESDAY...BRINGING ENOUGH MOISTURE TO JUSTIFY THE MENTION FOR A
SMALL CHANCE FOR SOME LIGHT SNOWFALL FOR THE TIME BEING.
OVERALL...THIS DOES NOT APPEAR TO BE A VERY MOIST SYSTEM...BUT WITH
VERY COLD TEMPERATURES...WE COULD SEE SOME LIGHT ACCUMULATIONS AS A
RESULT OF HIGH SNOWFALL RATIOS IF MODEL TRENDS HOLD.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 651 AM CST TUE FEB 10 2015
ALTHOUGH AT LEAST A FEW MORE HOURS OF VERY POOR (MAINLY LIFR/IFR)
CEILING/VISIBILITY CONDITIONS ARE EXPECTED AT BOTH TERMINALS
THIS MORNING IN PERSISTENT FOG/STRATUS...A MARKED IMPROVEMENT IS
EXPECTED BY EARLY AFTERNOON AS A RETURN TO WESTERLY LOW-LEVEL
FLOW SCOURS OUT THE FOG AND STRATUS. CONFIDENCE IN THE TIMING
DETAILS IS ADMITTEDLY A BIT SHAKY...AS IT COULD BE A VERY GRADUAL
IMPROVEMENT OVER TIME OR IT COULD BE A VERY ABRUPT
IMPROVEMENT...SO STAY TUNED FOR AMENDMENTS. AT ANY RATE...HAVE
KEAR RETURNING TO VFR BY 18Z AND KGRI 19Z AS A BEST STAB FOR NOW.
AS FOR WIND...SURFACE BREEZES THIS MORNING WILL REMAIN QUITE
STEADY FROM THE SOUTH-SOUTHWEST...WITH GUST POTENTIAL TO AROUND
20KT. AS A TROUGH AXIS/WEAK COLD FRONT PASSES THROUGH DURING THE
DAY...BREEZES WILL DIMINISH A BIT AND TURN MORE WEST-
NORTHWESTERLY. LATE IN THE PERIOD TONIGHT..STRONGER NORTH-
NORTHWEST WIND WILL ARRIVE BEHIND A COLD FRONT WITH GUST POTENTIAL
TO AROUND 25KT. DURING THE FINAL 6 HOURS...ANOTHER ROUND OF
POTENTIAL MVFR OR EVEN IFR CEILING COULD OVERSPREAD THE AREA FROM
THE NORTH...BUT CONFIDENCE IS LOW AND WENT WITH A LOW-END VFR
CEILING AT THIS TIME. LASTLY...WILL CONTINUE A SOMEWHAT MARGINAL
MENTION OF LOW LEVEL WIND SHEAR (LLWS) FOR A FEW MORE HOURS AT
KGRI THIS MORNING TO ACCOUNT FOR A GENERALLY 30KT BULK SHEAR
DIFFERENCE BETWEEN THE SURFACE AND ROUGHLY 1500 FT AGL...THANKS TO
SOUTHWESTERLY WIND TOPPING OUT AROUND 40KT AT THIS LEVEL. HAVE
OMITTED THIS LLWS MENTION FROM KEAR GIVEN THAT BULK SHEAR
DIFFERENCE SHOULD BE LESS LIKELY TO EXCEED 30KT BUT IT WILL STILL
BE CLOSE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
520 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CST TUE FEB 10 2015
LOW PRESSURE ACROSS SCNTL SD IS EXPECTED TO CLEAR THE FCST AREA
OF LOW CLOUDS AND FOG BY 15Z THIS AM. FOG PRODUCTION IN THE DENSE
FOG ADVISORY AREA HAS BE BEEN LIMITED BY MIXING FROM STRONG SFC
WINDS AND POOR RADIATION FROM A BATCH OF MID LEVEL CLOUDS ALOFT.
THE RAP...ETAL MODELS INDICATES FAIRLY STRONG WEST WINDS WILL
DEVELOP BY 12Z SCOURING THE AREA OF MOISTURE AND SHUNTING THE FOG
EAST. THUS THE PROBABILITY OF DENSE FOG APPEARS LOW IN ALL SOLNS.
THE RAP WAS THE WARMEST MODEL AND WAS USED FOR THE TEMPERATURE
FORECAST TODAY FOR HIGHS IN THE UPPER 50S TO MID 60S. NORTHWEST
WINDS WILL BE INCREASING TO 15 TO 25 MPH IN THE WAKE OF THE SFC LOW
ACROSS SD. A TANDEM LOW ACROSS ERN MT WILL MOVE INTO CNTL ND THIS
AFTN AND SEND A COLD FRONT TOWARD NRN NEB. THE MODELS SHOW WEAK
CONVERGENCE AROUND THE LEE SIDE OF THE BLACK HILLS AS THE FRONT
APPROACHES AND THIS MIGHT BE ENOUGH FOR SPRINKLES ACROSS NRN
SHERIDAN COUNTY AND WRN CHERRY COUNTY. THE HRRR...GEM REGIONAL AND
RAP SUPPORT THIS RAIN CHANCE ALBEIT NON-MEASURABLE.
NORTHWEST WINDS SHOULD REMAIN STRONG TONIGHT AS AN ARCTIC COLD FRONT
MOVES THROUGH THE FCST AREA. THE MODELS SHOW WIND SPEEDS INCREASING
FROM 06Z ONWARD ACROSS THE NORTH AND H850MB TEMPERATURES FALLING TO
AROUND -7C BY MORNING WHICH MIGHT SUPPORT LOWS IN THE LOWER 20S
NORTH AND WARMER READINGS IN THE MID AND UPPER 20S TO NEAR 30 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CST TUE FEB 10 2015
PRIMARY FORECAST CONCERNS FOR THIS PORTION OF THE FORECAST PERIOD
DEAL WITH TEMPERATURES THROUGHOUT...THEN WITH CHANCES FOR SNOW FOR
EARLY NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT FOR MUCH OF THE FORECAST PERIOD WITH
ONLY MINOR DETAILS SEEN TO IMPACT THE FORECAST. THAT BEING
SAID...EVEN SOME MINOR DIFFERENCES COULD HAVE AN IMPACT ON THE
SENSIBLE WEATHER...MAINLY THE CLOUD COVER AND WINDS...WHICH IN TURN
CAN IMPACT THE TEMPERATURE FORECAST.
THE PERIOD BEGINS ON WEDNESDAY...WITH THE UPPER LEVEL SHORTWAVE
TROUGH WHICH IS NOW OVER THE NORTHWEST TERRITORIES DIGGING SOUTH
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. THIS WILL PUSH A
GOOD COLD FRONT THROUGH THE REGION BY 12Z WEDNESDAY. THE TRACK OF
THE MAIN PV ANOMALY EMBEDDED IN THE SHORTWAVE STAYS WELL NORTH AND
EAST OF THE LOCAL AREA BUT THIS WILL LIKELY STILL ENHANCE THE
DOWNWARD MOTION/SUBSIDENCE...DRYING AND COLD AIR ADVECTION DURING
THE DAY TO AT LEAST HELP THE LOW LEVEL MIXING AND BRING ABOUT BREEZY
NORTHWEST WINDS. WITH THE COLD AIR ADVECTION BEHIND THE
FRONT...WEDNESDAY WILL BE QUITE A BIT COOLER THAN WHAT HAS BEEN
EXPERIENCED OVER THE PAST FEW DAYS...WITH HIGHS NEAR NORMAL MOST
PLACES. THE MODELS ARE SHOWING SOME WARMING ALOFT BY THE END OF THE
DAY WEDNESDAY WHICH COULD LEAD TO SLIGHTLY WARMER TEMPERATURES OVER
SOUTHWEST NEBRASKA. THE FORECAST WILL KEEP MID 40S FOR THESE AREAS
WITH LOW 30S OVER NORTH CENTRAL NEBRASKA ON WEDNESDAY.
THE SURFACE HIGH BEHIND THE SYSTEM BUILDS SOUTH INTO THE NORTHERN
PLAINS WEDNESDAY NIGHT...THEN INTO THE MISSISSIPPI RIVER VALLEY ON
THURSDAY. WITH THE COLD AIR ASSOCIATED WITH THE SURFACE
HIGH...TEMPERATURES WILL BE FAIRLY COLD WEDNESDAY NIGHT. THE COLDEST
AIR ALOFT WILL REMAIN ACROSS EASTERN NEBRASKA AND AS THOSE LOCATIONS
WILL BE CLOSER TO THE CENTER OF THE HIGH...WINDS WILL BE LIGHTER
WHICH SHOULD PROMOTE BETTER RADIATIONAL COOLING. FURTHER
WEST...RETURN FLOW SOUTHERLY WINDS SET UP AND ALTHOUGH WILL BE
LIGHT...ARE NOT EXPECTED TO COMPLETELY DROP OFF. THESE CONDITIONS
WILL CREATE A DECENT TEMPERATURE GRADIENT ACROSS THE FORECAST
AREA...FROM THE LOW SINGLE DIGITS TO AROUND 20 DEGREES.
FOR THURSDAY...THE NAM IS A BIT QUICKER THAN THE REMAINDER OF THE
MODEL SOLUTIONS WITH A WARM FRONT MOVING INTO NEBRASKA ON THURSDAY.
TIMING OF THIS FRONT WILL MAKE A DIFFERENCE IN TEMPERATURES DURING
THE AFTERNOON AS 850MB TEMPERATURES INCREASE TO AROUND 10C...WHILE
WEST-NORTHWEST FLOW AT THE SURFACE WILL HELP TO ENHANCE THE MIXING
POTENTIAL AND HELP WARM THINGS UP. HOWEVER...IF THE FRONT IS
SLOWER...COOLER TEMPERATURES WILL BE MAINTAINED THROUGH THE DAY. FOR
THE FORECAST...DID INCREASE HIGHS OVER THE WESTERN PART OF THE
FORECAST AREA AS CONFIDENCE IS HIGHER ON A BIT FASTER MOVEMENT AND
WITH A WARM BIAS THAT HAS BEEN SEEN LATELY IN OBSERVATIONS.
BY THIS POINT IN TIME...THE UPPER LEVEL FLOW ACROSS THE CONUS WILL
BE QUITE AMPLIFIED WITH A DEEP TROUGH OVER THE EAST COAST AND A
STRONG RIDGE OVER THE WESTERN CONUS. THIS PUTS THE LOCAL AREA WITHIN
NORTHWEST FLOW WHICH WILL BRING MULTIPLE SHORTWAVE TROUGHS ACROSS
THE AREA THROUGH THE REMAINDER OF THE FORECAST PERIOD. WHILE
MOISTURE WITH THE MAJORITY OF THESE SYSTEMS STAYS WELL NORTH OF THE
AREA TO KEEP THE FORECAST DRY...DESPITE PERIODS OF STRONGER LIFT.
WHAT WILL OCCUR IS LIKELY A BACK AND FORTH TREND FOR TEMPERATURES.
FRIDAY AND SUNDAY LOOK LIKE WARMER DAYS...WHILE SATURDAY AND MONDAY
WILL BE COOLER AS THE AREA WILL SIT IN THE WAKE OF WEAK SYSTEMS WITH
COLD AIR ADVECTION TO WORK WITH.
THE NEXT CHANCES FOR MEASURABLE PRECIPITATION WILL COME ON MONDAY.
THE UPPER LEVEL PATTERN DAMPENS OUT WITH MORE BROAD WEST TO
NORTHWEST FLOW IN PLACE. THE MODELS CONTINUE TO BE IN DECENT
AGREEMENT THIS FAR OUT BRINGING A WEAK SHORTWAVE TROUGH ACROSS
NEBRASKA AND SOUTH DAKOTA. THE MODELS ARE SHOWING A NEARLY COUPLED
RIGHT OVER-TOP OF THE FORECAST AREA WHICH SHOULD LEAD TO STRONGER
LIFT OVER THE AREA. IN ADDITION...DEEP LAYER MOISTURE INCREASES SO
AT THIS TIME WILL CONTINUE WITH MENTION OF PRECIPITATION FOR EARLY
IN THE WEEK. WITH COLD AIR ADVECTION THROUGH THE DAY
MONDAY...SOUNDINGS AND TEMPERATURE PROFILES WOULD INDICATE THE
PRECIPITATION WILL FALL AS SNOW SO ONLY HAVE THAT MENTION IN THE
FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 520 AM CST TUE FEB 10 2015
THE BANK OF LIFR/IFR CIGS FROM STOCKVILLE TO ONEILL SHOULD EXIT
THE FCST AREA BY 15Z. THEREAFTER VFR IS EXPECTED ALL AREAS THROUGH
06Z TONIGHT. THEREAFTER...THE SREF SUGGESTS MVFR CIGS MAY DEVELOP
FROM KVTN-KONL ASSOCIATED WITH AN ARCTIC HIGH BUILDING INTO NRN
NEB. VFR IS EXPECTED ELSEWHERE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
509 AM CST TUE FEB 10 2015
.UPDATE...
ISSUED AT 509 AM CST TUE FEB 10 2015
AS SUGGESTED BELOW LESS THAN 1 HOUR AGO...HAVE OPTED TO CANCEL
THE REMAINDER OF THE DENSE FOG ADVISORY EARLY BASED ON A CONTINUED
OVERALL-IMPROVING TREND SINCE EARLIER IN THE NIGHT. AS OF THIS
WRITING...ONLY 1 OF THE 13 PRIMARY AUTOMATED AIRPORT SENSORS
WITHIN THE CWA (HOLDREGE) IS REPORTING VISIBILITY AS LOW AS 1/2
MILE AND AN ASSORTMENT OF WEB CAMS SUPPORT THE MARKED-IMPROVEMENT
AS WELL. CERTAINLY CANNOT COMPLETELY RULE OUT SOME VERY SMALL
AREAS OF DENSE FOG YET THIS MORNING...ESPECIALLY NEAR THE EDGES OF
THE EXPANSIVE LOW STRATUS DECK STILL SQUARELY PLANTED OVER THE
MAJORITY OF THE CWA...BUT EVEN SO THIS WOULD NOT BE ENOUGH TO
JUSTIFY CONTINUING THE FORMAL HEADLINE.
ON A SEPARATE MINOR NOTE...FORGOT TO MENTION IN THE MAIN
DISCUSSION BELOW THAT FORECASTED AFTERNOON RELATIVE HUMIDITY
VALUES DROP DOWN TO AROUND 25 PERCENT FOR A SHORT TIME IN THE
EXTREME SOUTHWEST CORNER OF THE CWA (FURNAS/PHILLIPS/ROOKS
COUNTIES). IF WEST-NORTHWEST WIND GUSTS THIS AFTERNOON HAPPEN TO
BREACH 20 MPH THIS COULD TECHNICALLY PROMOTE A PERIOD OF NEAR-
CRITICAL FIRE DANGER. HOWEVER...GIVEN THAT IT IS SUCH A SMALL
SPATIAL COVERAGE WITH ONLY MARGINAL-AT-BEST NEAR-CRITICAL
POTENTIAL...WILL FOREGO ANY FORMAL MENTION IN THE HAZARDOUS
WEATHER OUTLOOK PRODUCT (HWOGID).
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM CST TUE FEB 10 2015
BEFORE STATING ANOTHER WORD...WANT TO SAY THAT THE ONGOING DENSE
FOG ADVISORY FOR MOST OF THE NEBRASKA CWA IS STANDING ON
INCREASINGLY-SHAKY GROUND BASED ON IMPROVING TRENDS THE NEXT FEW
HOURS...AND AN EARLY CANCELLATION BEFORE 5AM NEWS TIME IS
PROBABLY A GOOD BET...AS ALTHOUGH LOCALIZED POCKETS OF DENSE FOG
MIGHT STILL EXIST...THEY ARE CERTAINLY NOT LOOKING WIDESPREAD
ENOUGH TO SUPPORT A FORMAL HEADLINE.
ALTHOUGH ANOTHER SOMEWHAT TRICKY SKY COVER/TEMPERATURE FORECAST IS
IN STORE TODAY...THE ONE GLARING DIFFERENCE BETWEEN NOW AND 24
HOURS AGO IS THAT THE LOW STRATUS/FOG SITUATION IS ON A
DIMINISHING/IMPROVING TREND INSTEAD OF A WORSENING ONE...AND THE
ENTIRE AREA IS EXPECTED TO WARM INTO THE 50S/60S TODAY INSTEAD OF
JUST WESTERN COUNTIES. RUNNING WITH THE ASSUMPTION THAT SKIES
OVER THE CWA SHOULD EXHIBIT A FAIRLY EFFICIENT WEST-TO-EAST AND
IN SOME AREAS A NORTH-TO-SOUTH CLEARING TREND THROUGH MID-
DAY...WE SHOULD NOT BE FACING THE PESKY EXTREMELY SHARP INTERFACE
BETWEEN CLOUDY/SUNNY AREAS THAT LINGERED ALL DAY YESTERDAY. THAT
BEING SAID...WITH EASTERN COUNTIES NEAREST HIGHWAY 81 EXPECTED TO
BE LAST TO SEE APPRECIABLE CLEARING...THESE AREAS SHOULD IN THEORY
REMAIN A BIT COOLER...AND ALSO STAND THE BEST POTENTIAL FOR A
MODEST TEMPERATURE BUST OF 5+ DEGREES.
PRECIPITATION-WISE...OTHER THAN ANY LINGERING LIGHT PATCHY DRIZZLE
OUT THERE THIS MORNING...THE VAST MAJORITY OF THE CWA IS EXPECTED
TO REMAIN DRY THROUGH THESE NEXT 24 HOURS AND THE OFFICIAL
FORECAST REMAINS AS SUCH. THAT BEING SAID...AT LEAST ONE RUN OF
THE NCEP 4KM WRF-NMM SUGGESTS THAT SOME ROGUE SPRINKLES/SPITS OF
DRIZZLE AND MAYBE EVEN A FEW FLURRIES CANNOT BE RULED OUT FROM
LATE THIS AFTERNOON INTO TONIGHT...BUT LACK OF CONFIDENCE IN
OCCURRENCE AND DOUBTS ABOUT HOW MUCH OF THIS LIGHT PRECIP WILL
ACTUALLY REACH THE GROUND HAS PRECLUDED ANY FORMAL FORECAST
MENTION AT THIS TIME. THIS WILL BE SOMETHING FOR THE NEXT FEW
SHIFTS TO KEEP AN EYE ON THOUGH.
ALTHOUGH IT IS EXPECTED TO ESSENTIALLY BE A DRY PASSAGE...THE COLD
FRONT PASSING THROUGH TONIGHT IS DECENTLY-STRONG AND WILL FEATURE
A NOTICEABLE INCREASE IN LATE-NIGHT NORTH WIND...AND SET THE STAGE
FOR A ROUGHLY A 20-DEGREE COOL DOWN FOR WEDNESDAY AS DESCRIBED IN
THE LONG TERM BELOW.
AS FOR THE HERE AND NOW AS OF 1030Z/430AM...ALTHOUGH THE VAST
MAJORITY OF THE CWA REMAINS SOCKED UNDER A VERY LOW STRATUS
DECK...SOME MODEST POCKETS OF CLEARING HAVE BEEN NOTED MAINLY IN
PARTS OF KS ZONES AND ALSO THE THAYER COUNTY AREA. MORE
IMPORTANTLY...INCREASING BOUNDARY-LAYER FLOW THAT IS STARTING TO
TURN MORE SOUTHWESTERLY HAS RESULTED IN IMPROVING VISIBILITY
OVERNIGHT. AS OF THIS WRITING...NEARLY ALL AUTOMATED AIRPORT SITES
IN THE CWA ARE REPORTING VISIBILITY OF NOW-WORSE-THAN ONE-HALF
MILE. ACTUAL SURFACE WIND IS AVERAGING SUSTAINED 10-15 MPH IN MOST
AREAS WITH SOME HIGHER GUSTS MAINLY IN NEB ZONES. EARLIER IN THE
NIGHT AN AREA OF MAINLY ELEVATED RADAR RETURNS BRUSHED ACROSS FAR
NORTHERN ZONES BUT IS CURRENTLY FOCUSED OUTSIDE THE AREA FROM
NORTHEAST NEB NORTHWARD. WOULD NOT BE SHOCKED IF A FEW SLEET
PELLETS/SNOW GRAINS FELL FROM THOSE RADAR ECHOES BUT ITS A NON-
ISSUE NOW. LOW TEMPERATURES THIS MORNING ARE ON TRACK TO BOTTOM
OUT BETWEEN 29-35 IN MOST AREAS. IN THE MID-UPPER LEVELS...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM A LOW-AMPLITUDE
SHORTWAVE TRACKING EITHER SIDE OF THE NEB/SD BORDER...PROMOTING
THE LIGHT PRECIP TO THE NORTH. THE ASSOCIATED SURFACE LOW WITH
THAT SYSTEM IS AIDING THE TRANSITION TO MORE SOUTH-SOUTHWESTERLY
SURFACE FLOW THAN THE SOUTHEASTERLY THAT PREVAILED 6-12 HOURS AGO.
MEANWHILE FARTHER NORTH...A SOMEWHAT STRONGER MID LEVEL WAVE IS
SLIPPING EAST-SOUTHEAST OUT OF CANADA INTO ND...AND WILL BE THE
DRIVING FORCE BEHIND THE COLD FRONTAL PASSAGE TONIGHT.
LOOKING FORWARD-FORECAST-WISE IN MORE DETAIL AND STARTING WITH
THE DAYTIME HOURS...ALREADY TOUCHED ON IT ABOVE...BUT THE NUMBER 1
CHALLENGE IS TRYING TO PIN DOWN THE DISSIPATION OF LINGERING
MAINLY LIGHT FOG AND ESPECIALLY THE STILL-EXPANSIVE STRATUS DECK.
ALTHOUGH PRONE TO PLENTY OF SITE-SPECIFIC ERROR...HAVE INDICATED A
FAIRLY- STEADY MAINLY WEST-TO-EAST CLEARING TREND THROUGH MID-
DAY...WITH AT LEAST THE WESTERN 2/3 OF THE CWA LIKELY SEEING
PLENTY OF SUN BY NOON OR SO. THE LATEST HRRR LOW CLOUD PRODUCT
WOULD SUGGEST CLEARING COULD BE EVEN MORE RAPID BUT AM A TOUCH
SKEPTICAL OF THAT. COUNTIES NEAR/ALONG THE HIGHWAY 81 CORRIDOR ARE
MOST PRONE TO SEE AT LEAST HALFWAY-DECENT COVERAGE OF LOW CLOUDS
LINGER INTO EARLY AFTERNOON...BUT WHEN ALL IS SAID AND DONE WOULD
BE SURPRISED IF THE ENTIRE CWA DOES NOT CATCH AT LEAST A FEW HOURS
OF SUN TODAY AS LOW LEVEL FLOW CONTINUES TURNING
WESTERLY/NORTHWESTERLY AND HELPS TO ERODE THE LOW CLOUD MASS. AS A
WEAK TROUGH PASSES THROUGH THE AREA...A GRADUAL TRANSITION FROM
SOUTHERLY TO MORE WESTERLY AND EVENTUALLY NORTHWEST BREEZES WILL
OCCUR TODAY. WHILE SUSTAINED SPEEDS THROUGH MOST OF THE DAY SHOULD
ONLY AVERAGE NO MORE THAN 10-15 MPH WITH SLIGHTLY HIGHER GUSTS.
TEMP-WISE...GENERALLY FOLLOWED A BLEND OF SOME OF THE MOST
OPTIMISTIC MODELS TO YIELD UPPER 50S- MID 60S ACROSS THE MAJORITY
OF THE CWA...BUT HEDGED A BIT COOLER IN FAR EASTERN ZONES WITH
MAINLY MID-50S. OF COURSE...IF LOW STRATUS UNEXPECTEDLY HANGS
AROUND LONGER IN THIS AREA...THIS COULD BE A BIT OPTIMISTIC.
OVERALL THOUGH...UPPED HIGHS ONLY 1-2 DEGREES FROM PREVIOUS
FORECAST. AS EARLIER-STATED...ALTHOUGH NOT IN THE OFFICIAL
FORECAST...SUPPOSE A FEW LATE-DAY SPRINKLES CANNOT BE RULED OUT
MAINLY NORTH OF I-80.
TURNING TO THIS EVENING TONIGHT...THE AFOREMENTIONED DAKOTAS
DISTURBANCE WILL TRACK INTO THE GREAT LAKES REGION...AND BE
REINFORCED BY ANOTHER LOBE OF ENERGY DROPPING SOUTHWARD TOWARD
MN/ND OUT OF CANADA. AGAIN...ALTHOUGH SOME VERY LIGHT/SPOTTY
PRECIP CANNOT BE RULED OUT TONIGHT LOCALLY...BY FAR THE MAIN STORY
WILL BE THE PASSAGE OF A FAIRLY HEALTHY COLD FRONT...WITH 850
MILLIBAR TEMPS BY SUNRISE WEDNESDAY PROGGED TO GENERALLY DROP INTO
THE -3 TO -8 C RANGE OVER MOST OF THE CWA. ALTHOUGH NOT OVERLY-
WINDY...THE ARRIVAL OF THIS FRONT WILL BE MARKED BY SEVERAL HOURS
OF SUSTAINED 15-25 MPH NORTH WIND WITH GUSTS UP TO AROUND 30 MPH.
EXCEPT GENERALLY NORTH OF I-80...THE BRUNT OF THESE STRONGER WINDS
WILL NOT KICK IN UNTIL NEAR/AFTER MIDNIGHT. ALTHOUGH NOT
NECESSARILY EXPECTING ANOTHER TOTALLY-SOLID LOW STRATUS DECK
MOVING IN BEHIND THE FRONT...MODELS SUGGEST A COMBINATION OF
PARTLY- MOSTLY CLOUDY SKIES OVERNIGHT BEHIND THE BOUNDARY...WITH
ANY LOWER STRATUS THAT IS PRESENT POSSIBLY EVEN TRYING TO THROW
OUT A FEW SPITS OF DRIZZLE. AGAIN THOUGH...CONFIDENCE JUST TOO LOW
TO "RUIN" THE CURRENTLY DRY FORECAST. TEMP-WISE...LOWS WILL BE A
LITTLE TRICKY AS WELL...AS FAIRLY PRONOUNCED LOW LEVEL COLD AIR
ADVECTION WILL USHER IN COLDER AIR...BUT ITS FULL POTENTIAL MAY BE
MITIGATED A BIT BY THE INFLUENCE OF LOW LEVEL MIXING FROM THE
STEADY WIND AND ALSO CLOUD COVER. BLENDED A FEW MODELS TOGETHER TO
ESSENTIALLY DROP LOWS A FEW DEGREES IN THE NORTH AND BRING THEM UP
VERY SLIGHTLY SOUTH...AIMING FOR A RANGE FROM MID-20S NORTH OF
I-80 TO MID-30S IN KS ZONES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM CST TUE FEB 10 2015
FLUCTUATING TEMPERATURES AND MOSTLY DRY CONDITIONS WILL CONTINUE
THROUGH THE EXTENDED PERIODS...WITH ONLY A SMALL CHANCE OF SOME
LIGHT SNOW RETURNING NEXT MONDAY OR TUESDAY.
OVERALL...EXPECT NORTHWESTERLY FLOW ALOFT TO BE DOMINANT THROUGH THE
EXTENDED PERIODS AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST
COAST AND MULTIPLE LOW PRESSURE SYSTEMS SWING THROUGH THE OHIO RIVER
VALLEY AND UP THE EAST COAST. THIS GENERAL PATTERN IS FORECAST TO
HOLD THROUGH MOST OF THE EXTENDED...WITH AN UPPER LEVEL DISTURBANCE
PUSHING ACROSS BRITISH COLUMBIA ON SUNDAY FORECAST TO DROP INTO THE
PLAINS EARLY NEXT WEEK. WHILE NOT OVERLY MOIST...THIS SYSTEM WILL
BRING THE BEST CHANCE FOR SOME LIGHT SNOWFALL TO THE LOCAL AREA IN
OVER A WEEK.
STARTING OFF WEDNESDAY...EXPECT BREEZY NORTHERLY WINDS TO BE
ADVECTING COOLER AIR FROM THE NORTH THROUGH THE DAY BEHIND AN EARLY
MORNING COLD FRONT. WHILE NOT BITTERLY COLD...THIS AIRMASS WILL BE
IN STARK CONTRAST TO THIS AFTERNOONS ABOVE NORMAL TEMPERATURES....
LIKELY DROPPING AFTERNOON READINGS VERY CLOSE TO CLIMATOLOGY FOR MID
FEBRUARY. WITH THE ASSOCIATED SURFACE HIGH SLIDING SOUTHEAST ACROSS
THE MISSOURI RIVER VALLEY TO START THE DAY ON THURSDAY...EXPECT A
RETURN TO BELOW NORMAL TEMPERATURES TO START THE DAY...WITH SINGLE
DIGITS FORECAST FOR AT LEAST THE NORTHEASTERN HALF OF THE LOCAL AREA
WHERE THE WINDS WILL BE THE LIGHTEST. WHILE THESE COOL MORNING TEMPS
APPEAR TO BE A SURE THING...AFTERNOON TEMPS ARE A BIT TRICKIER AS
THERE COULD BE A SHARP GRADIENT ACROSS THE LOCAL AREA AS WINDS MAY
BEGIN TO SHIFT LATE IN THE DAY IN RESPONSE TO A SURFACE TROUGH
TRACKING EASTWARD FROM COLORADO. THAT SAID...MODEL CONSENSUS KEEPS
THE WINDS GENERALLY SOUTHERLY BEHIND THE DEPARTING HIGH THROUGH THE
PERIOD OF MAXIMUM HEATING...SO KEPT TEMPS ON THE COOLER SIDE ACROSS
OUR LOCAL AREA THURSDAY AFTERNOON.
THEN AS THE SURFACE TROUGH MOVES ACROSS THE HEART OF THE LOCAL AREA
ON FRIDAY...TEMPERATURES SHOULD SHOOT BACK UP WELL ABOVE NORMAL TO
END THE WEEK...ONLY TO BE BROUGHT BACK DOWN OVER THE UPCOMING
WEEKEND AS A BACKDOOR COLD FRONT WORKS ITS WAY WEST...ASSOCIATED
WITH A VIGOROUS LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION.
WHILE THERE IS SOME DISCREPANCY WITH JUST HOW COLD THIS AIRMASS WILL
BE...TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY...WITH BELOW NORMAL
TEMPERATURES FORECAST FOR SATURDAY...AND ONLY A MODEST WARM UP TO
END THE WEEKEND.
STARTING NEXT WEEK...THE FOCUS WILL SHIFT TO A WEST COAST SYSTEM
THAT WILL BRING ANOTHER COLD FRONT ACROSS THE LOCAL AREA LATE MONDAY
OR TUESDAY...BRINGING ENOUGH MOISTURE TO JUSTIFY THE MENTION FOR A
SMALL CHANCE FOR SOME LIGHT SNOWFALL FOR THE TIME BEING.
OVERALL...THIS DOES NOT APPEAR TO BE A VERY MOIST SYSTEM...BUT WITH
VERY COLD TEMPERATURES...WE COULD SEE SOME LIGHT ACCUMULATIONS AS A
RESULT OF HIGH SNOWFALL RATIOS IF MODEL TRENDS HOLD.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1214 AM CST TUE FEB 10 2015
ALTHOUGH SEVERAL MORE HOURS OF VERY POOR (MAINLY LIFR)
CEILING/VISIBILITY CONDITIONS ARE EXPECTED AT BOTH TERMINALS
THROUGH THESE FIRST SEVERAL HOURS THIS MORNING IN PERSISTENT
FOG/STRATUS/LIGHT DRIZZLE...A MARKED IMPROVEMENT IS EXPECTED FOR
BY THE LATTER HALF OF THE PERIOD AS A RETURN TO WESTERLY LOW-LEVEL
FLOW SCOURS OUT THE FOG AND STRATUS. CONFIDENCE IS FAIRLY HIGH
THAT VISIBILITY WILL START TO IMPROVE BEFORE CEILING DOES...BUT
NEARLY ALL MODELS/GUIDANCE STRONGLY SUGGEST A RETURN TO OUTRIGHT-
VFR CONDITIONS EVEN CEILING-WISE BY EARLY AFTERNOON. CONFIDENCE IN
THE TIMING DETAILS IS ADMITTEDLY A BIT SHAKY...AS IT COULD BE A
VERY GRADUAL IMPROVEMENT OVER TIME OR IT COULD BE A VERY ABRUPT
IMPROVEMENT...SO STAY TUNED FOR AMENDMENTS. AS FOR WIND...SURFACE
BREEZES THIS MORNING WILL REMAIN QUITE STEADY FROM THE SOUTH AND
EVENTUALLY TURN MORE SOUTHWESTERLY...WITH GUST POTENTIAL TO AROUND
20KT. AS A TROUGH AXIS/WEAK COLD FRONT PASSES THROUGH DURING THE
DAY...BREEZES WILL DIMINISH A BIT AND TURN MORE WEST-
NORTHWESTERLY. VERY LATE IN THE PERIOD...STEADIER/GUSTIER NORTH-
NORTHWEST WIND WILL ARRIVE BEHIND A STRONGER COLD FRONT. TOWARD
THE VERY END OF THE PERIOD ANOTHER ROUND OF MVFR/POSSIBLY IFR
CEILING COULD BE ON THE DOORSTEP FROM THE NORTH...BUT WILL ADDRESS
THIS IN NEXT ISSUANCE. OTHERWISE...THE ONLY OTHER ITEM OF
NOTE INVOLVES A 4-HOUR PERIOD OF LOW LEVEL WIND SHEAR (LLWS) THAT
HAS BEEN INTRODUCED FROM 11-15Z THIS MORNING AT KGRI TO ACCOUNT
FOR A GENERALLY 30-35KT BULK SHEAR DIFFERENCE BETWEEN THE SURFACE
AND ROUGHLY 1500 FT AGL...THANKS TO SOUTHWESTERLY WIND TOPPING OUT
AROUND 45KT AT THIS LEVEL. HAVE OMITTED THIS LLWS MENTION FROM
KEAR GIVEN THAT BULK SHEAR DIFFERENCE SHOULD BE LESS LIKELY TO
EXCEED 30KT FOR SEVERAL HOURS...BUT IT WILL STILL BE CLOSE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
417 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM CST TUE FEB 10 2015
BEFORE STATING ANOTHER WORD...WANT TO SAY THAT THE ONGOING DENSE
FOG ADVISORY FOR MOST OF THE NEBRASKA CWA IS STANDING ON
INCREASINGLY-SHAKY GROUND BASED ON IMPROVING TRENDS THE NEXT FEW
HOURS...AND AN EARLY CANCELLATION BEFORE 5AM NEWS TIME IS
PROBABLY A GOOD BET...AS ALTHOUGH LOCALIZED POCKETS OF DENSE FOG
MIGHT STILL EXIST...THEY ARE CERTAINLY NOT LOOKING WIDESPREAD
ENOUGH TO SUPPORT A FORMAL HEADLINE.
ALTHOUGH ANOTHER SOMEWHAT TRICKY SKY COVER/TEMPERATURE FORECAST IS
IN STORE TODAY...THE ONE GLARING DIFFERENCE BETWEEN NOW AND 24
HOURS AGO IS THAT THE LOW STRATUS/FOG SITUATION IS ON A
DIMINISHING/IMPROVING TREND INSTEAD OF A WORSENING ONE...AND THE
ENTIRE AREA IS EXPECTED TO WARM INTO THE 50S/60S TODAY INSTEAD OF
JUST WESTERN COUNTIES. RUNNING WITH THE ASSUMPTION THAT SKIES
OVER THE CWA SHOULD EXHIBIT A FAIRLY EFFICIENT WEST-TO-EAST AND
IN SOME AREAS A NORTH-TO-SOUTH CLEARING TREND THROUGH MID-
DAY...WE SHOULD NOT BE FACING THE PESKY EXTREMELY SHARP INTERFACE
BETWEEN CLOUDY/SUNNY AREAS THAT LINGERED ALL DAY YESTERDAY. THAT
BEING SAID...WITH EASTERN COUNTIES NEAREST HIGHWAY 81 EXPECTED TO
BE LAST TO SEE APPRECIABLE CLEARING...THESE AREAS SHOULD IN THEORY
REMAIN A BIT COOLER...AND ALSO STAND THE BEST POTENTIAL FOR A
MODEST TEMPERATURE BUST OF 5+ DEGREES.
PRECIPITATION-WISE...OTHER THAN ANY LINGERING LIGHT PATCHY DRIZZLE
OUT THERE THIS MORNING...THE VAST MAJORITY OF THE CWA IS EXPECTED
TO REMAIN DRY THROUGH THESE NEXT 24 HOURS AND THE OFFICIAL
FORECAST REMAINS AS SUCH. THAT BEING SAID...AT LEAST ONE RUN OF
THE NCEP 4KM WRF-NMM SUGGESTS THAT SOME ROGUE SPRINKLES/SPITS OF
DRIZZLE AND MAYBE EVEN A FEW FLURRIES CANNOT BE RULED OUT FROM
LATE THIS AFTERNOON INTO TONIGHT...BUT LACK OF CONFIDENCE IN
OCCURRENCE AND DOUBTS ABOUT HOW MUCH OF THIS LIGHT PRECIP WILL
ACTUALLY REACH THE GROUND HAS PRECLUDED ANY FORMAL FORECAST
MENTION AT THIS TIME. THIS WILL BE SOMETHING FOR THE NEXT FEW
SHIFTS TO KEEP AN EYE ON THOUGH.
ALTHOUGH IT IS EXPECTED TO ESSENTIALLY BE A DRY PASSAGE...THE COLD
FRONT PASSING THROUGH TONIGHT IS DECENTLY-STRONG AND WILL FEATURE
A NOTICEABLE INCREASE IN LATE-NIGHT NORTH WIND...AND SET THE STAGE
FOR A ROUGHLY A 20-DEGREE COOL DOWN FOR WEDNESDAY AS DESCRIBED IN
THE LONG TERM BELOW.
AS FOR THE HERE AND NOW AS OF 1030Z/430AM...ALTHOUGH THE VAST
MAJORITY OF THE CWA REMAINS SOCKED UNDER A VERY LOW STRATUS
DECK...SOME MODEST POCKETS OF CLEARING HAVE BEEN NOTED MAINLY IN
PARTS OF KS ZONES AND ALSO THE THAYER COUNTY AREA. MORE
IMPORTANTLY...INCREASING BOUNDARY-LAYER FLOW THAT IS STARTING TO
TURN MORE SOUTHWESTERLY HAS RESULTED IN IMPROVING VISIBILITY
OVERNIGHT. AS OF THIS WRITING...NEARLY ALL AUTOMATED AIRPORT SITES
IN THE CWA ARE REPORTING VISIBILITY OF NOW-WORSE-THAN ONE-HALF
MILE. ACTUAL SURFACE WIND IS AVERAGING SUSTAINED 10-15 MPH IN MOST
AREAS WITH SOME HIGHER GUSTS MAINLY IN NEB ZONES. EARLIER IN THE
NIGHT AN AREA OF MAINLY ELEVATED RADAR RETURNS BRUSHED ACROSS FAR
NORTHERN ZONES BUT IS CURRENTLY FOCUSED OUTSIDE THE AREA FROM
NORTHEAST NEB NORTHWARD. WOULD NOT BE SHOCKED IF A FEW SLEET
PELLETS/SNOW GRAINS FELL FROM THOSE RADAR ECHOES BUT ITS A NON-
ISSUE NOW. LOW TEMPERATURES THIS MORNING ARE ON TRACK TO BOTTOM
OUT BETWEEN 29-35 IN MOST AREAS. IN THE MID-UPPER LEVELS...WATER
VAPOR SATELLITE AND SHORT TERM MODEL DATA CONFIRM A LOW-AMPLITUDE
SHORTWAVE TRACKING EITHER SIDE OF THE NEB/SD BORDER...PROMOTING
THE LIGHT PRECIP TO THE NORTH. THE ASSOCIATED SURFACE LOW WITH
THAT SYSTEM IS AIDING THE TRANSITION TO MORE SOUTH-SOUTHWESTERLY
SURFACE FLOW THAN THE SOUTHEASTERLY THAT PREVAILED 6-12 HOURS AGO.
MEANWHILE FARTHER NORTH...A SOMEWHAT STRONGER MID LEVEL WAVE IS
SLIPPING EAST-SOUTHEAST OUT OF CANADA INTO ND...AND WILL BE THE
DRIVING FORCE BEHIND THE COLD FRONTAL PASSAGE TONIGHT.
LOOKING FORWARD-FORECAST-WISE IN MORE DETAIL AND STARTING WITH
THE DAYTIME HOURS...ALREADY TOUCHED ON IT ABOVE...BUT THE NUMBER 1
CHALLENGE IS TRYING TO PIN DOWN THE DISSIPATION OF LINGERING
MAINLY LIGHT FOG AND ESPECIALLY THE STILL-EXPANSIVE STRATUS DECK.
ALTHOUGH PRONE TO PLENTY OF SITE-SPECIFIC ERROR...HAVE INDICATED A
FAIRLY- STEADY MAINLY WEST-TO-EAST CLEARING TREND THROUGH MID-
DAY...WITH AT LEAST THE WESTERN 2/3 OF THE CWA LIKELY SEEING
PLENTY OF SUN BY NOON OR SO. THE LATEST HRRR LOW CLOUD PRODUCT
WOULD SUGGEST CLEARING COULD BE EVEN MORE RAPID BUT AM A TOUCH
SKEPTICAL OF THAT. COUNTIES NEAR/ALONG THE HIGHWAY 81 CORRIDOR ARE
MOST PRONE TO SEE AT LEAST HALFWAY-DECENT COVERAGE OF LOW CLOUDS
LINGER INTO EARLY AFTERNOON...BUT WHEN ALL IS SAID AND DONE WOULD
BE SURPRISED IF THE ENTIRE CWA DOES NOT CATCH AT LEAST A FEW HOURS
OF SUN TODAY AS LOW LEVEL FLOW CONTINUES TURNING
WESTERLY/NORTHWESTERLY AND HELPS TO ERODE THE LOW CLOUD MASS. AS A
WEAK TROUGH PASSES THROUGH THE AREA...A GRADUAL TRANSITION FROM
SOUTHERLY TO MORE WESTERLY AND EVENTUALLY NORTHWEST BREEZES WILL
OCCUR TODAY. WHILE SUSTAINED SPEEDS THROUGH MOST OF THE DAY SHOULD
ONLY AVERAGE NO MORE THAN 10-15 MPH WITH SLIGHTLY HIGHER GUSTS.
TEMP-WISE...GENERALLY FOLLOWED A BLEND OF SOME OF THE MOST
OPTIMISTIC MODELS TO YIELD UPPER 50S- MID 60S ACROSS THE MAJORITY
OF THE CWA...BUT HEDGED A BIT COOLER IN FAR EASTERN ZONES WITH
MAINLY MID-50S. OF COURSE...IF LOW STRATUS UNEXPECTEDLY HANGS
AROUND LONGER IN THIS AREA...THIS COULD BE A BIT OPTIMISTIC.
OVERALL THOUGH...UPPED HIGHS ONLY 1-2 DEGREES FROM PREVIOUS
FORECAST. AS EARLIER-STATED...ALTHOUGH NOT IN THE OFFICIAL
FORECAST...SUPPOSE A FEW LATE-DAY SPRINKLES CANNOT BE RULED OUT
MAINLY NORTH OF I-80.
TURNING TO THIS EVENING TONIGHT...THE AFOREMENTIONED DAKOTAS
DISTURBANCE WILL TRACK INTO THE GREAT LAKES REGION...AND BE
REINFORCED BY ANOTHER LOBE OF ENERGY DROPPING SOUTHWARD TOWARD
MN/ND OUT OF CANADA. AGAIN...ALTHOUGH SOME VERY LIGHT/SPOTTY
PRECIP CANNOT BE RULED OUT TONIGHT LOCALLY...BY FAR THE MAIN STORY
WILL BE THE PASSAGE OF A FAIRLY HEALTHY COLD FRONT...WITH 850
MILLIBAR TEMPS BY SUNRISE WEDNESDAY PROGGED TO GENERALLY DROP INTO
THE -3 TO -8 C RANGE OVER MOST OF THE CWA. ALTHOUGH NOT OVERLY-
WINDY...THE ARRIVAL OF THIS FRONT WILL BE MARKED BY SEVERAL HOURS
OF SUSTAINED 15-25 MPH NORTH WIND WITH GUSTS UP TO AROUND 30 MPH.
EXCEPT GENERALLY NORTH OF I-80...THE BRUNT OF THESE STRONGER WINDS
WILL NOT KICK IN UNTIL NEAR/AFTER MIDNIGHT. ALTHOUGH NOT
NECESSARILY EXPECTING ANOTHER TOTALLY-SOLID LOW STRATUS DECK
MOVING IN BEHIND THE FRONT...MODELS SUGGEST A COMBINATION OF
PARTLY- MOSTLY CLOUDY SKIES OVERNIGHT BEHIND THE BOUNDARY...WITH
ANY LOWER STRATUS THAT IS PRESENT POSSIBLY EVEN TRYING TO THROW
OUT A FEW SPITS OF DRIZZLE. AGAIN THOUGH...CONFIDENCE JUST TOO LOW
TO "RUIN" THE CURRENTLY DRY FORECAST. TEMP-WISE...LOWS WILL BE A
LITTLE TRICKY AS WELL...AS FAIRLY PRONOUNCED LOW LEVEL COLD AIR
ADVECTION WILL USHER IN COLDER AIR...BUT ITS FULL POTENTIAL MAY BE
MITIGATED A BIT BY THE INFLUENCE OF LOW LEVEL MIXING FROM THE
STEADY WIND AND ALSO CLOUD COVER. BLENDED A FEW MODELS TOGETHER TO
ESSENTIALLY DROP LOWS A FEW DEGREES IN THE NORTH AND BRING THEM UP
VERY SLIGHTLY SOUTH...AIMING FOR A RANGE FROM MID-20S NORTH OF
I-80 TO MID-30S IN KS ZONES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM CST TUE FEB 10 2015
FLUCTUATING TEMPERATURES AND MOSTLY DRY CONDITIONS WILL CONTINUE
THROUGH THE EXTENDED PERIODS...WITH ONLY A SMALL CHANCE OF SOME
LIGHT SNOW RETURNING NEXT MONDAY OR TUESDAY.
OVERALL...EXPECT NORTHWESTERLY FLOW ALOFT TO BE DOMINANT THROUGH THE
EXTENDED PERIODS AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE WEST
COAST AND MULTIPLE LOW PRESSURE SYSTEMS SWING THROUGH THE OHIO RIVER
VALLEY AND UP THE EAST COAST. THIS GENERAL PATTERN IS FORECAST TO
HOLD THROUGH MOST OF THE EXTENDED...WITH AN UPPER LEVEL DISTURBANCE
PUSHING ACROSS BRITISH COLUMBIA ON SUNDAY FORECAST TO DROP INTO THE
PLAINS EARLY NEXT WEEK. WHILE NOT OVERLY MOIST...THIS SYSTEM WILL
BRING THE BEST CHANCE FOR SOME LIGHT SNOWFALL TO THE LOCAL AREA IN
OVER A WEEK.
STARTING OFF WEDNESDAY...EXPECT BREEZY NORTHERLY WINDS TO BE
ADVECTING COOLER AIR FROM THE NORTH THROUGH THE DAY BEHIND AN EARLY
MORNING COLD FRONT. WHILE NOT BITTERLY COLD...THIS AIRMASS WILL BE
IN STARK CONTRAST TO THIS AFTERNOONS ABOVE NORMAL TEMPERATURES....
LIKELY DROPPING AFTERNOON READINGS VERY CLOSE TO CLIMATOLOGY FOR MID
FEBRUARY. WITH THE ASSOCIATED SURFACE HIGH SLIDING SOUTHEAST ACROSS
THE MISSOURI RIVER VALLEY TO START THE DAY ON THURSDAY...EXPECT A
RETURN TO BELOW NORMAL TEMPERATURES TO START THE DAY...WITH SINGLE
DIGITS FORECAST FOR AT LEAST THE NORTHEASTERN HALF OF THE LOCAL AREA
WHERE THE WINDS WILL BE THE LIGHTEST. WHILE THESE COOL MORNING TEMPS
APPEAR TO BE A SURE THING...AFTERNOON TEMPS ARE A BIT TRICKIER AS
THERE COULD BE A SHARP GRADIENT ACROSS THE LOCAL AREA AS WINDS MAY
BEGIN TO SHIFT LATE IN THE DAY IN RESPONSE TO A SURFACE TROUGH
TRACKING EASTWARD FROM COLORADO. THAT SAID...MODEL CONSENSUS KEEPS
THE WINDS GENERALLY SOUTHERLY BEHIND THE DEPARTING HIGH THROUGH THE
PERIOD OF MAXIMUM HEATING...SO KEPT TEMPS ON THE COOLER SIDE ACROSS
OUR LOCAL AREA THURSDAY AFTERNOON.
THEN AS THE SURFACE TROUGH MOVES ACROSS THE HEART OF THE LOCAL AREA
ON FRIDAY...TEMPERATURES SHOULD SHOOT BACK UP WELL ABOVE NORMAL TO
END THE WEEK...ONLY TO BE BROUGHT BACK DOWN OVER THE UPCOMING
WEEKEND AS A BACKDOOR COLD FRONT WORKS ITS WAY WEST...ASSOCIATED
WITH A VIGOROUS LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION.
WHILE THERE IS SOME DISCREPANCY WITH JUST HOW COLD THIS AIRMASS WILL
BE...TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY...WITH BELOW NORMAL
TEMPERATURES FORECAST FOR SATURDAY...AND ONLY A MODEST WARM UP TO
END THE WEEKEND.
STARTING NEXT WEEK...THE FOCUS WILL SHIFT TO A WEST COAST SYSTEM
THAT WILL BRING ANOTHER COLD FRONT ACROSS THE LOCAL AREA LATE MONDAY
OR TUESDAY...BRINGING ENOUGH MOISTURE TO JUSTIFY THE MENTION FOR A
SMALL CHANCE FOR SOME LIGHT SNOWFALL FOR THE TIME BEING.
OVERALL...THIS DOES NOT APPEAR TO BE A VERY MOIST SYSTEM...BUT WITH
VERY COLD TEMPERATURES...WE COULD SEE SOME LIGHT ACCUMULATIONS AS A
RESULT OF HIGH SNOWFALL RATIOS IF MODEL TRENDS HOLD.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1214 AM CST TUE FEB 10 2015
ALTHOUGH SEVERAL MORE HOURS OF VERY POOR (MAINLY LIFR)
CEILING/VISIBILITY CONDITIONS ARE EXPECTED AT BOTH TERMINALS
THROUGH THESE FIRST SEVERAL HOURS THIS MORNING IN PERSISTENT
FOG/STRATUS/LIGHT DRIZZLE...A MARKED IMPROVEMENT IS EXPECTED FOR
BY THE LATTER HALF OF THE PERIOD AS A RETURN TO WESTERLY LOW-LEVEL
FLOW SCOURS OUT THE FOG AND STRATUS. CONFIDENCE IS FAIRLY HIGH
THAT VISIBILITY WILL START TO IMPROVE BEFORE CEILING DOES...BUT
NEARLY ALL MODELS/GUIDANCE STRONGLY SUGGEST A RETURN TO OUTRIGHT-
VFR CONDITIONS EVEN CEILING-WISE BY EARLY AFTERNOON. CONFIDENCE IN
THE TIMING DETAILS IS ADMITTEDLY A BIT SHAKY...AS IT COULD BE A
VERY GRADUAL IMPROVEMENT OVER TIME OR IT COULD BE A VERY ABRUPT
IMPROVEMENT...SO STAY TUNED FOR AMENDMENTS. AS FOR WIND...SURFACE
BREEZES THIS MORNING WILL REMAIN QUITE STEADY FROM THE SOUTH AND
EVENTUALLY TURN MORE SOUTHWESTERLY...WITH GUST POTENTIAL TO AROUND
20KT. AS A TROUGH AXIS/WEAK COLD FRONT PASSES THROUGH DURING THE
DAY...BREEZES WILL DIMINISH A BIT AND TURN MORE WEST-
NORTHWESTERLY. VERY LATE IN THE PERIOD...STEADIER/GUSTIER NORTH-
NORTHWEST WIND WILL ARRIVE BEHIND A STRONGER COLD FRONT. TOWARD
THE VERY END OF THE PERIOD ANOTHER ROUND OF MVFR/POSSIBLY IFR
CEILING COULD BE ON THE DOORSTEP FROM THE NORTH...BUT WILL ADDRESS
THIS IN NEXT ISSUANCE. OTHERWISE...THE ONLY OTHER ITEM OF
NOTE INVOLVES A 4-HOUR PERIOD OF LOW LEVEL WIND SHEAR (LLWS) THAT
HAS BEEN INTRODUCED FROM 11-15Z THIS MORNING AT KGRI TO ACCOUNT
FOR A GENERALLY 30-35KT BULK SHEAR DIFFERENCE BETWEEN THE SURFACE
AND ROUGHLY 1500 FT AGL...THANKS TO SOUTHWESTERLY WIND TOPPING OUT
AROUND 45KT AT THIS LEVEL. HAVE OMITTED THIS LLWS MENTION FROM
KEAR GIVEN THAT BULK SHEAR DIFFERENCE SHOULD BE LESS LIKELY TO
EXCEED 30KT FOR SEVERAL HOURS...BUT IT WILL STILL BE CLOSE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ039>041-
046>049-061>064-073>077-083>087.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
323 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CST TUE FEB 10 2015
LOW PRESSURE ACROSS SCNTL SD IS EXPECTED TO CLEAR THE FCST AREA
OF LOW CLOUDS AND FOG BY 15Z THIS AM. FOG PRODUCTION IN THE DENSE
FOG ADVISORY AREA HAS BE BEEN LIMITED BY MIXING FROM STRONG SFC
WINDS AND POOR RADIATION FROM A BATCH OF MID LEVEL CLOUDS ALOFT.
THE RAP...ETAL MODELS INDICATES FAIRLY STRONG WEST WINDS WILL
DEVELOP BY 12Z SCOURING THE AREA OF MOISTURE AND SHUNTING THE FOG
EAST. THUS THE PROBABILITY OF DENSE FOG APPEARS LOW IN ALL SOLNS.
THE RAP WAS THE WARMEST MODEL AND WAS USED FOR THE TEMPERATURE
FORECAST TODAY FOR HIGHS IN THE UPPER 50S TO MID 60S. NORTHWEST
WINDS WILL BE INCREASING TO 15 TO 25 MPH IN THE WAKE OF THE SFC LOW
ACROSS SD. A TANDEM LOW ACROSS ERN MT WILL MOVE INTO CNTL ND THIS
AFTN AND SEND A COLD FRONT TOWARD NRN NEB. THE MODELS SHOW WEAK
CONVERGENCE AROUND THE LEE SIDE OF THE BLACK HILLS AS THE FRONT
APPROACHES AND THIS MIGHT BE ENOUGH FOR SPRINKLES ACROSS NRN
SHERIDAN COUNTY AND WRN CHERRY COUNTY. THE HRRR...GEM REGIONAL AND
RAP SUPPORT THIS RAIN CHANCE ALBEIT NON-MEASURABLE.
NORTHWEST WINDS SHOULD REMAIN STRONG TONIGHT AS AN ARCTIC COLD FRONT
MOVES THROUGH THE FCST AREA. THE MODELS SHOW WIND SPEEDS INCREASING
FROM 06Z ONWARD ACROSS THE NORTH AND H850MB TEMPERATURES FALLING TO
AROUND -7C BY MORNING WHICH MIGHT SUPPORT LOWS IN THE LOWER 20S
NORTH AND WARMER READINGS IN THE MID AND UPPER 20S TO NEAR 30 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 322 AM CST TUE FEB 10 2015
PRIMARY FORECAST CONCERNS FOR THIS PORTION OF THE FORECAST PERIOD
DEAL WITH TEMPERATURES THROUGHOUT...THEN WITH CHANCES FOR SNOW FOR
EARLY NEXT WEEK.
MODELS ARE IN GOOD AGREEMENT FOR MUCH OF THE FORECAST PERIOD WITH
ONLY MINOR DETAILS SEEN TO IMPACT THE FORECAST. THAT BEING
SAID...EVEN SOME MINOR DIFFERENCES COULD HAVE AN IMPACT ON THE
SENSIBLE WEATHER...MAINLY THE CLOUD COVER AND WINDS...WHICH IN TURN
CAN IMPACT THE TEMPERATURE FORECAST.
THE PERIOD BEGINS ON WEDNESDAY...WITH THE UPPER LEVEL SHORTWAVE
TROUGH WHICH IS NOW OVER THE NORTHWEST TERRITORIES DIGGING SOUTH
INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. THIS WILL PUSH A
GOOD COLD FRONT THROUGH THE REGION BY 12Z WEDNESDAY. THE TRACK OF
THE MAIN PV ANOMALY EMBEDDED IN THE SHORTWAVE STAYS WELL NORTH AND
EAST OF THE LOCAL AREA BUT THIS WILL LIKELY STILL ENHANCE THE
DOWNWARD MOTION/SUBSIDENCE...DRYING AND COLD AIR ADVECTION DURING
THE DAY TO AT LEAST HELP THE LOW LEVEL MIXING AND BRING ABOUT BREEZY
NORTHWEST WINDS. WITH THE COLD AIR ADVECTION BEHIND THE
FRONT...WEDNESDAY WILL BE QUITE A BIT COOLER THAN WHAT HAS BEEN
EXPERIENCED OVER THE PAST FEW DAYS...WITH HIGHS NEAR NORMAL MOST
PLACES. THE MODELS ARE SHOWING SOME WARMING ALOFT BY THE END OF THE
DAY WEDNESDAY WHICH COULD LEAD TO SLIGHTLY WARMER TEMPERATURES OVER
SOUTHWEST NEBRASKA. THE FORECAST WILL KEEP MID 40S FOR THESE AREAS
WITH LOW 30S OVER NORTH CENTRAL NEBRASKA ON WEDNESDAY.
THE SURFACE HIGH BEHIND THE SYSTEM BUILDS SOUTH INTO THE NORTHERN
PLAINS WEDNESDAY NIGHT...THEN INTO THE MISSISSIPPI RIVER VALLEY ON
THURSDAY. WITH THE COLD AIR ASSOCIATED WITH THE SURFACE
HIGH...TEMPERATURES WILL BE FAIRLY COLD WEDNESDAY NIGHT. THE COLDEST
AIR ALOFT WILL REMAIN ACROSS EASTERN NEBRASKA AND AS THOSE LOCATIONS
WILL BE CLOSER TO THE CENTER OF THE HIGH...WINDS WILL BE LIGHTER
WHICH SHOULD PROMOTE BETTER RADIATIONAL COOLING. FURTHER
WEST...RETURN FLOW SOUTHERLY WINDS SET UP AND ALTHOUGH WILL BE
LIGHT...ARE NOT EXPECTED TO COMPLETELY DROP OFF. THESE CONDITIONS
WILL CREATE A DECENT TEMPERATURE GRADIENT ACROSS THE FORECAST
AREA...FROM THE LOW SINGLE DIGITS TO AROUND 20 DEGREES.
FOR THURSDAY...THE NAM IS A BIT QUICKER THAN THE REMAINDER OF THE
MODEL SOLUTIONS WITH A WARM FRONT MOVING INTO NEBRASKA ON THURSDAY.
TIMING OF THIS FRONT WILL MAKE A DIFFERENCE IN TEMPERATURES DURING
THE AFTERNOON AS 850MB TEMPERATURES INCREASE TO AROUND 10C...WHILE
WEST-NORTHWEST FLOW AT THE SURFACE WILL HELP TO ENHANCE THE MIXING
POTENTIAL AND HELP WARM THINGS UP. HOWEVER...IF THE FRONT IS
SLOWER...COOLER TEMPERATURES WILL BE MAINTAINED THROUGH THE DAY. FOR
THE FORECAST...DID INCREASE HIGHS OVER THE WESTERN PART OF THE
FORECAST AREA AS CONFIDENCE IS HIGHER ON A BIT FASTER MOVEMENT AND
WITH A WARM BIAS THAT HAS BEEN SEEN LATELY IN OBSERVATIONS.
BY THIS POINT IN TIME...THE UPPER LEVEL FLOW ACROSS THE CONUS WILL
BE QUITE AMPLIFIED WITH A DEEP TROUGH OVER THE EAST COAST AND A
STRONG RIDGE OVER THE WESTERN CONUS. THIS PUTS THE LOCAL AREA WITHIN
NORTHWEST FLOW WHICH WILL BRING MULTIPLE SHORTWAVE TROUGHS ACROSS
THE AREA THROUGH THE REMAINDER OF THE FORECAST PERIOD. WHILE
MOISTURE WITH THE MAJORITY OF THESE SYSTEMS STAYS WELL NORTH OF THE
AREA TO KEEP THE FORECAST DRY...DESPITE PERIODS OF STRONGER LIFT.
WHAT WILL OCCUR IS LIKELY A BACK AND FORTH TREND FOR TEMPERATURES.
FRIDAY AND SUNDAY LOOK LIKE WARMER DAYS...WHILE SATURDAY AND MONDAY
WILL BE COOLER AS THE AREA WILL SIT IN THE WAKE OF WEAK SYSTEMS WITH
COLD AIR ADVECTION TO WORK WITH.
THE NEXT CHANCES FOR MEASURABLE PRECIPITATION WILL COME ON MONDAY.
THE UPPER LEVEL PATTERN DAMPENS OUT WITH MORE BROAD WEST TO
NORTHWEST FLOW IN PLACE. THE MODELS CONTINUE TO BE IN DECENT
AGREEMENT THIS FAR OUT BRINGING A WEAK SHORTWAVE TROUGH ACROSS
NEBRASKA AND SOUTH DAKOTA. THE MODELS ARE SHOWING A NEARLY COUPLED
RIGHT OVER-TOP OF THE FORECAST AREA WHICH SHOULD LEAD TO STRONGER
LIFT OVER THE AREA. IN ADDITION...DEEP LAYER MOISTURE INCREASES SO
AT THIS TIME WILL CONTINUE WITH MENTION OF PRECIPITATION FOR EARLY
IN THE WEEK. WITH COLD AIR ADVECTION THROUGH THE DAY
MONDAY...SOUNDINGS AND TEMPERATURE PROFILES WOULD INDICATE THE
PRECIPITATION WILL FALL AS SNOW SO ONLY HAVE THAT MENTION IN THE
FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1141 PM CST MON FEB 9 2015
FOR THE KLBF TERMINAL...EXPECT MOSTLY CLEAR SKIES OVER THE NEXT 24
HOURS. SOME LOW CLOUDS MAY IMPACT THE VICINITY OF THE KLBF
TERMINAL...MAINLY TO THE EAST OF THE FIELD WITH CIGS UNDER 1000 FT
AND VISBYS BLO 1SM. FOR NOW WILL LEAVE OUT THE MENTION OF LOW
CLOUDS AS THEY SEEM TO BE REMAINING STATIONARY JUST EAST OF THE
FIELD. FOR THE KVTN TERMINAL...CLEAR TO PARTLY CLOUDY SKIES ARE
EXPECTED THROUGH TUESDAY AFTERNOON WITH CIGS AROUND 25000 FT AGL.
CIGS WILL LOWER TO 10000 FT AGL AND THEN 5000 FT AGL TUESDAY
EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
257 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 255 AM CST TUE FEB 10 2015
LATEST MODELS IN AGREEMENT GOING FCST CONSISTING OF DRY CONDITIONS
LOOKS ON TRACK HEADING INTO THIS WEEKEND...THUS LEAVING TEMPS THE
MAIN ISSUE.
MODELS PROG NEAR ZONAL FLOW WILL EVOLVE OVER THE NEXT SEVERAL DAYS
TO A MORE AMPLIFIED PATTERN...LEADING TO A NOTICEABLE TEMP CHANGE
AS A SIGNIFICANT COLD AIR INTRUSION SWEEPS INTO THE CNTRL/ERN
CONUS. GFS/ECM/CMC METEOGRAMS IN GOOD AGREEMENT SHOWING THE
LEADING EDGE OF THE FRONT MAKING ITS WAY INTO THE OMAHA METRO
SOMETIME AROUND MIDNIGHT TONIGHT FOLLOWED BY A RE-ENFORCING SHOT
OF CAA COMING WED NIGHT.
FOR TODAY...HIGHS IN MID 40S EAST/MID 50S WEST STILL LOOK
REASONABLE FOLLOWED BY LOW/MID 30S WED...AND LOW/MID 20S THURS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 255 AM CST TUE FEB 10 2015
EXT PDS START OFF WITH REBOUNDING TEMPS ON FRIDAY FOLLOWED BY A
ROLLER COASTER RIDE OF TEMPS THRU EARLY NEXT WEEK. THE COLD FRONT
MOVING EARLY NEXT WEEK WILL ALLOW FOR POSSIBLE PCPN OVER THE CWA
MON/MON NIGHT. PCPN TYPE FCST LOOKS A BIT TRICKY AS IT APPEARS THAT
ENOUGH CAA TO MAKE CHANGE OVER FROM LIQUID TO FROZEN WILL NOT COME
UNTIL LATE IN THE DAY. THIS FAR OUT THOUGH...SEE NO NEED TO GET INTO
DETAILS SO WILL JUST GO WITH RA/SN MIX NORTH AND RA SOUTH...THEN
SLGT SN CHC MON NIGHT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1120 PM CST MON FEB 9 2015
LOW CLOUDS SHOULD PREVAILS OVERNIGHT. EXPECT A GENERAL DOWNWARD
TREND OF VBSYS THROUGH ABOUT 14Z...WITH WINDS INCREASING SLIGHTLY.
RECENT RAP MODEL RUNS SUGGEST THE LOW CLOUDS WILL BREAK UP LATE
MORNING OR EARLY AFTN AT KOFK AND KLNK...THEN BY MID AFTN AT
KOMA. WINDS WILL SHIFT TO THE NORTHWEST AT KOFK BY 00Z WED AT
KOFK...AND 02Z TO 04Z AT KOMA AND KLNK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1141 PM CST MON FEB 9 2015
.SYNOPSIS...
ISSUED AT 254 PM CST MON FEB 9 2015
AT H5 TROUGH FROM GREAT LAKES INTO FLORIDA PANHANDLE WITH
ASSOCIATED PRECIPITATION ALL ALONG THE EASTERN SEABOARD. RIDGE
INTO THE NORTHERN PLAINS WITH FAIRLY STRONG WAVE MOVING ACROSS THE
PACIFIC NORTHWEST.
&&
.UPDATE...
ISSUED AT 857 PM CST MON FEB 9 2015
RELEASED A SECOND UPDATE TO BETTER DEPICT HOW FAR WEST THE FOG
WILL MAKE IT INTO THE OVERNIGHT. BASED ON THE LATEST HRRR AND
NAM12...00Z VERSION...HAVE THE FOG GOING AS FAR WEST AS A LINE
FROM CURTIS...TO ARNOLD...TO NEAR VALENTINE. BASED ON OBS AT ONEILL
AND ORD...DECIDED TO HOIST A DENSE FOG ADVISORY FOR PORTIONS OF
THE EASTERN SANDHILLS AND PORTIONS OF NORTH CENTRAL NEBRASKA. THIS
WILL BE IN EFFECT UNTIL 9 AM CST TUESDAY MORNING. FOR LOCATIONS
ALONG THE WESTERN PERIPHERY OF THE FOG...THIS SHOULD BEGIN TO MOVE
SLOWLY EAST OVERNIGHT AS SURFACE WINDS SHIFT AROUND TO THE
SOUTHWEST AND WEST AS LOW PRESSURE ENTERS SOUTH DAKOTA.
UPDATE ISSUED AT 752 PM CST MON FEB 9 2015
JUST RELEASED AN UPDATED FORECAST TO ADDRESS THE FOG AND STRATUS
ACROSS EASTERN PORTIONS OF THE FORECAST AREA. LOOKING AT THE
HRRR...LATEST NAM12 SOLN AND SREF DATA...DECIDED TO PUSH FOG
FURTHER WEST UP TO THE HIGHWAY 83 CORRIDOR THIS EVENING. THE
MODELS DO SHIFT THIS EAST OVERNIGHT AS THE LOW LEVEL WINDS SHIFT
TO THE WEST...SO FOG WILL PEAK AROUND MIDNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 254 PM CST MON FEB 9 2015
MAIN FORECAST CONCERN FOR THE OVERNIGHT REVOLVES AROUND THE WESTWARD
RETURN OF STRATUS AND/OR FOG. THE NAM MODEL IS ONCE AGAIN THE MOST
BULLISH WITH REDUCED VISIBILITY...BRINGING DENSE FOG AS FAR WEST AS
THE HIGHWAY 83 CORRIDOR. THE HRRR SEEMS TO BE A GOOD COMPROMISE FOR
NOW...WHICH INDICATES FOG IN THE SAME GENERAL AREA AS SEEN EARLIER
TODAY. SURFACE LOW PRESSURE IS SHOWN TO MOVE EAST ACROSS SOUTHERN
SOUTH DAKOTA OVERNIGHT...DRAGGING A TROUGH THROUGH THE
SANDHILLS...SO AM EXPECTING A GREATER WESTWARD...OR
SOUTHWEST...TRAJECTORY OF THE LOWER TROPOSPHERIC WIND...WHICH WILL
DRAW DRY LOW LEVEL AIR BACK INTO THE REGION. THIS BOUNDARY IS SHOWN
TO BE ALONG OR NEAR HIGHWAY 281 BY 12Z TOMORROW. FOR THIS...WOULD
EXPECT SOME IMPROVEMENT IN VISIBILITY AND SKY COVER FROM WEST TO
EAST THROUGH THE OVERNIGHT HOURS AND THE STRATUS SHOULD ONLY BE
CONFINED TO OUR FAR EAST.
A WEAK UPPER LEVEL DISTURBANCE/PV ANOMALY WILL CROSS THE
CENTRAL/NORTHERN PLAINS OVERNIGHT PROVIDING FOR A LEAST A SLIGHT
CHANCE OF PRECIPITATION ACROSS OUR FAR NORTHEAST. THE MODELS ARE
KEYING ON THE GREATEST FORCING WELL NORTH OF THE FORECAST AREA...AND
WITH SATURATION CONFINED TO THE LOWER TROPOSPHERE...RAIN WILL BE
DIFFICULT. AM LEANING TOWARD A DRIZZLE POTENTIAL...OR VERY LIGHT
RAIN...IF PRECIPITATION WERE TO BE REALIZED. ANY LIFT IS QUICKLY
EAST OF THE FORECAST AREA BY 12Z TUESDAY...BEYOND THAT...THE REST OF
THE DAY APPEARS DRY.
TEMPERATURES OVERNIGHT WILL BE MILD AS WAA SPREADS EAST AHEAD OF THE
PASSING SURFACE TROUGH. FORECAST LOWS RANGE FROM THE UPPER 20S IN
THE RIVER VALLEYS...TO THE MID 30S ACROSS THE HEART OF THE SANDHILLS
WHERE GREATER MIXING IS ANTICIPATED. FOR TUESDAY...THE DISTURBANCE
WILL DRAW SLIGHTLY COOLER AIR ACROSS WEST CENTRAL NEBRASKA. HIGHS
WERE TRENDED ACCORDINGLY...WITH MOST LOCATIONS SEEING A DROP OF 5-7F
FROM WHAT WAS OBSERVED TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 254 PM CST MON FEB 9 2015
MODELS IN FAIR AGREEMENT IN MID TERM AND THEN HAVING SOME
VARIABILITY IN LONG TERM SOLUTIONS. TUESDAY NIGHT COOLER AIR
FILTERS IN ACROSS THE NORTHERN PLAINS INTO WESTERN NEBRASKA. WITH
THE UPPER RIDGE IN PLACE THE HIGH PRESSURE WILL BE MOVED FURTHER
EAST WITH A STATIONARY BOUNDARY FROM THE NORTHERN NEBRASKA
PANHANDLE INTO BROKEN BOW. WARMER 40S TO THE SOUTHWEST AND 30S TO
THE NORTHEAST. LOWS WEDNESDAY NIGHT QUITE COLD WITH MOSTLY CLEAR
SKIES AND LIGHT WINDS. SINGLE DIGITS ONEILL AND LOW 20S OVER
SOUTHWEST NEBRASKA. SOUTHERLY WINDS THURSDAY WILL MODERATE
TEMPERATURES SOME WHAT ON THE BACKSIDE OF THE SURFACE HIGH. MILD
NIGHT THURSDAY NIGHT WITH RETURN FLOW. FRIDAY TEMPERATURES REBOUND
INTO THE 40S NORTH AND 50S SOUTH. A DRY BACKDOOR COLD FRONT WILL
MOVE ACROSS THE FORECAST AREA FRIDAY NIGHT INTO SATURDAY WITH
HIGHS ON SATURDAY RANGING FROM THE 20S ONEILL TO MID 40S IMPERIAL.
TEMPERATURES REBOUND SUNDAY WITH 40S NORTH AND 50S SOUTH IN RETURN
FLOW. INCREASING MOISTURE ACROSS THE SOUTHERN PLAINS SUNDAY AND AN
ARCTIC COLD FRONT MOVING SOUTH ACROSS THE NORTHERN PLAINS WILL SEE
A RETURN TO SNOW IN THE FORECAST SUNDAY NIGHT INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1141 PM CST MON FEB 9 2015
FOR THE KLBF TERMINAL...EXPECT MOSTLY CLEAR SKIES OVER THE NEXT 24
HOURS. SOME LOW CLOUDS MAY IMPACT THE VICINITY OF THE KLBF
TERMINAL...MAINLY TO THE EAST OF THE FIELD WITH CIGS UNDER 1000 FT
AND VISBYS BLO 1SM. FOR NOW WILL LEAVE OUT THE MENTION OF LOW
CLOUDS AS THEY SEEM TO BE REMAINING STATIONARY JUST EAST OF THE
FIELD. FOR THE KVTN TERMINAL...CLEAR TO PARTLY CLOUDY SKIES ARE
EXPECTED THROUGH TUESDAY AFTERNOON WITH CIGS AROUND 25000 FT AGL.
CIGS WILL LOWER TO 10000 FT AGL AND THEN 5000 FT AGL TUESDAY
EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST TUESDAY FOR NEZ006-007-009-010-
028-029.
&&
$$
UPDATE...CLB
SYNOPSIS...POWER
SHORT TERM...JACOBS
LONG TERM...POWER
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1121 PM CST MON FEB 9 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 146 PM CST MON FEB 9 2015
LOW CLOUDS AND PATCHY FOG CONTINUES TO BLANKET THE REGION THIS
AFTERNOON AS AN AREA OF SFC HIGH PRESSURE REMAINS OVERHEAD. THIS
HAS KEPT TEMPERATURES FAIRLY COOL TODAY IN ADDITION TO LIGHT
SOUTHEASTERLY SFC WINDS. AN UPPER LEVEL RIDGE AXIS WAS OVER THE
HIGH PLAINS REGION THIS AFTERNOON WITH A TROUGH OVER THE WEST
COAST. A WEAK SHORTWAVE WAS MOVING OVER THE FRONT SIDE OF THE
RIDGE ACROSS SOUTHEASTERN WYOMING WHERE A FEW LIGHTNING STRIKES
HAVE SHOWN UP. THIS WAVE WILL CONTINUE TO SLIDE EAST TOWARD THE
REGION OVERNIGHT AS SFC LOW PRESSURE MOVES ACROSS THE NORTHERN
PLAINS. BEST FORCING ASSOCIATED WITH THE SHORTWAVE WILL BE TO OUR
NORTH BUT WILL CONTINUE TO MAINTAIN A VERY SMALL POP OVERNIGHT
NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AHEAD OF APPROACHING SFC
FRONT. WILL CONTINUE THE MENTION OF PATCHY FOG THROUGH THE
EVENING...WITH AREAS OF FOG MENTIONED FOR OUR WESTERN AREAS. HRRR
VISIBILITY PLOTS CONTINUE TO SHOW EXTENSIVE FOG ACROSS OUR WESTERN
COUNTIES. DO NOT SEE VISIBILITIES IMPROVING MUCH UNTIL SFC WINDS
COME AROUND TO THE SOUTH/SOUTHWEST LATE TONIGHT.
SFC COLD FRONT WILL SWING THROUGH THE FORECAST AREA LATE TUESDAY
BRINGING A MUCH COLDER AIRMASS INTO THE AREA. 850MB WINDS BEHIND
THE FRONT BY WED 06Z ARE ON THE ORDER OF 40-50KTS ACROSS OUR
NORTHERN COUNTIES. SHOULD SEE STRONG MOMENTUM TRANSFER TO THE
SURFACE SO DID BUMP UP WINDS TUE NIGHT/WED MORNING. BREEZY
CONDITIONS SHOULD CONTINUE INTO THE DAY WEDNESDAY AS ANOTHER
REINFORCING SHOT OF ARCTIC AIR SLIDES INTO THE AREA. THIS WILL
BRING WIND CHILLS DOWN TO THE -10 TO -15 RANGE...ESPECIALLY IN OUR
EASTERN COUNTIES. A 1040 MB HIGH WILL MOVE OVERHEAD ON THURSDAY
WHICH SHOULD KEEP HIGH TEMPS FAIRLY CHILLY IN THE 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 146 PM CST MON FEB 9 2015
AS SOON AS RETURN FLOW BEGINS THURSDAY NIGHT IT IS ENDED BY YET
ANOTHER COLD FRONT DROPPING OUT OF THE PLAINS FOR THE WEEKEND.
THIS WILL BRING A BITTERLY COLD AIRMASS TO PORTIONS OF THE UPPER
MIDWEST. WE LOOK TO BE ON THE WESTERN EDGE OF THE VERY COLD AIR
AS A 1045 MB HIGH MOVES SOUTHEAST FROM THE DAKOTAS INTO CENTRAL
IOWA SATURDAY. WE WILL CONTINUE WITH A DRY FORECAST UNTIL WE GET
LATE INTO DAY 7. THE ECMWF AND GFS CONTINUE TO DROP PCPN INTO THE
NORTHERN AND CENTRAL PLAINS EARLY NEXT WEEK.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1120 PM CST MON FEB 9 2015
LOW CLOUDS SHOULD PREVAILS OVERNIGHT. EXPECT A GENERAL DOWNWARD
TREND OF VBSYS THROUGH ABOUT 14Z...WITH WINDS INCREASING SLIGHTLY.
RECENT RAP MODEL RUNS SUGGEST THE LOW CLOUDS WILL BREAK UP LATE
MORNING OR EARLY AFTN AT KOFK AND KLNK...THEN BY MID AFTN AT
KOMA. WINDS WILL SHIFT TO THE NORTHWEST AT KOFK BY 00Z WED AT
KOFK...AND 02Z TO 04Z AT KOMA AND KLNK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1234 PM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDING EASTWARD FROM THE GREAT LAKES AND NORTHERN
ONTARIO WILL PROVIDE DRY AND SEASONABLY COLD WEATHER WEATHER
CONDITIONS ACROSS THE NORTH COUNTRY TODAY THROUGH WEDNESDAY.
PREVAILING LOW CLOUDS WILL GRADUALLY DIMINISH PROVIDING PARTLY
CLOUDY CONDITIONS THIS AFTERNOON THROUGH MUCH OF WEDNESDAY. AN
ALBERTA CLIPPER WILL MOVE EAST SOUTHEASTWARD INTO OUR REGION
DURING THE PRE-DAWN HOURS THURSDAY...WITH PERIODS OF LIGHT SNOW
CONTINUING THROUGHOUT THE DAYLIGHT HOURS THURSDAY INTO EARLY
THURSDAY NIGHT. SOME MINOR TRAVEL IMPACTS ARE POSSIBLE WITH
WIDESPREAD LIGHT SNOW ACCUMULATIONS EXPECTED. NO SIGNIFICANT
PRECIPITATION SYSTEMS ARE EXPECTED THEREAFTER...BUT BITTERLY COLD
AIR WILL BECOME ESTABLISHED ACROSS THE REGION FRIDAY AND
CONTINUING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1136 AM EST TUESDAY...ONLY REAL CHANGE WITH THIS UPDATE WAS
TO DELAY THE CLEARING BY AN HOUR OR TWO. WIDESPREAD DECK OF
STRATUS REMAINS TRAPPED UNDER THE DEVELOPING SUBSIDENCE INVERSION.
CONTINUING TO SEE SOME REPORTS OF FLURRIES ACROSS NORTHERN NEW
YORK AND VERMONT. BACK EDGE OF CLOUDS HAS NOW CLEARED OTTAWA AND
MOVING SLOWLY BUT SURELY FROM NORTHWEST TO SOUTHEAST AS DRIER AIR
OVER SOUTHERN CANADA GRADUALLY PUSHES SOUTHWARD. RAP LOW LEVEL
MOISTURE FIELDS APPEAR TO HANDLING IT THE BEST AND LARGELY USED
ITS DEPICTION FOR CLOUD TRENDS. THUS EXPECTING CLOUD SHIELD TO
GRADUALLY ERODE AND PUSH SOUTH AND EAST AS WE HEAD INTO THE
AFTERNOON HOURS. THINKING CLEARING SKIES REACH THE SAINT LAWRENCE
VALLEY AND NORTHERN CHAMPLAIN VALLEY AROUND 2 PM...BURLINGTON AREA
AROUND 3 PM...CENTRAL VERMONT 4 PM...AND FINALLY SOUTHERN VERMONT
BY 5 PM. HIGH TEMPERATURES SHOULD STILL REACH THE 20S FOR THE
MOST...EXCEPT SOME UPPER TEENS ACROSS PARTS OF NORTHERN NEW YORK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 321 AM EST TUESDAY...SURFACE RIDGE AXIS BUILDS ACROSS
QUEBEC AND NORTHERN NEW ENGLAND OVERNIGHT TONIGHT. PROVIDED SKIES
BECOME MOSTLY CLEAR AS EXPECTED...SHOULD SET UP A GOOD RADIATIVE
COOLING SETUP WITH LIGHT WINDS AND FRESH SNOW COVER. LOOKING AT
LOWS GENERALLY -8 TO +2F (WARMEST IN THE CHAMPLAIN VALLEY AND FAR
SERN VT)...BUT COULD SEE SOME READINGS IN THE TEENS BELOW ZERO
AROUND KSLK AND THE COLDER HOLLOWS IN VERMONT/S NORTHEAST KINGDOM.
POPS NIL.
SURFACE RIDGE AXIS SHOULD HOLD IN PLACE THROUGHOUT THE DAY
WEDNESDAY FROM MAINE SWWD THROUGH VT/NH AND INTO SERN NY.
MEANWHILE...ALBERTA CLIPPER LOW AND ASSOCIATED MID- LEVEL TROUGH
WILL BE SHIFTING ESEWD ACROSS THE GREAT LAKES REGION BY WEDNESDAY
AFTERNOON. DEVELOPING MID- LEVEL SWLY FLOW IN ADVANCE OF THE
TROUGH AXIS SHOULD YIELD AN INCREASE IN MID TO UPPER CLOUDINESS
FROM W-E ACROSS THE NORTH COUNTRY AS THE DAY PROGRESSES. SFC WINDS
SHOULD REMAIN LIGHT AND NOT EXPECTING ANY PRECIPITATION WITH VERY
DRY PBL CONDITIONS PREVAILING. HIGH TEMPERATURES SHOULD REACH THE
15-20F RANGE IN MOST LOCATIONS.
IT APPEARS THAT AREAS OF LIGHT SNOW WILL DEVELOP EASTWARD ACROSS
THE NORTH COUNTRY IN ASSOCIATED WITH THE CLIPPER SYSTEM DURING
WEDNESDAY NIGHT. SHOULD SEE SNOW BEGIN AROUND MIDNIGHT IN NRN NY
AND DURING THE PRE-DAWN HOURS FOR VERMONT. PRIMARY LOW SHIFTS
SLOWLY EASTWARD ACROSS THE REGION LATE THURSDAY MORNING INTO
THURSDAY AFTERNOON...WITH CONTINUED OVERCAST SKIES AND PERIODS OF
LIGHT SNOW. PRESENT INDICATES FROM 00Z GFS/NAM SUGGEST QPF VALUES
OF 0.15 TO 0.3". GIVEN POTENTIAL FOR GOOD DENDRITE GROWTH PER
MODEL SOUNDINGS...SLR/S AROUND 15:1 WOULD YIELD 2-5" WITH THIS
SYSTEM OF GENERALLY LOW DENSITY SNOWFALL. MAIN IMPACT WOULD BE TO
TRAVEL...WITH MINOR SLOWDOWNS EXPECTED FOR BOTH THE EARLY MORNING
AND EVENING COMMUTES ON THURSDAY.
LOW TEMPS WEDNESDAY NIGHT WILL NOT DROP VERY FAR WITH OVERCAST
CONDITIONS IN PLACE (GENERALLY LOW TO MID TEENS). LIKEWISE...HIGHS
THURSDAY WILL ONLY CLIMB INTO THE LOW 20S FOR MOST
SECTIONS...WHICH WILL PROBABLY BE OUR "WARMEST" DAY FOR A WHILE AS
ARCTIC AIR RETURNS IN THE WAKE OF THE CLIPPER SYSTEM BEGINNING
FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 320 AM EST MONDAY...DAYS 4 THRU 7 WILL FEATURE DEEP FULL
LATITUDE TROF ACROSS THE EASTERN CONUS WITH SEVERAL COMPACTED
VORTICITIES MOVING ACROSS THE GREAT LAKE AND NE CONUS. THIS LARGE
SCALE SYNOPTIC SETUP WILL FEATURE TEMPS 10 TO 20 DEGREES BLW FOR
THE WEEKEND...AND MOSTLY A DRY FCST. MODEL TRENDS CONT TO SHOW THE
GFS SOLUTION AND ASSOCIATED ENSEMBLE MEMBERS AS THE MOST
AGGRESSIVE WITH S/W ENERGY AND DEVELOPMENT OF STRONG SFC LOW PRES
OFF THE SNE COAST ON FRIDAY...WITH SOME MOISTURE BEING ADVECTED
BACK INTO OUR CWA. HOWEVER...ECMWF IS FURTHER EAST WITH CYCLONE
DEVELOPMENT AND PLACES MUCH LESS DYNAMICS AND MOISTURE ACRS OUR
CWA. WL MENTION CHC POPS ACROSS THE SAINT LAWRENCE VALLEY TO
LIKELY FOR CHAMPLAIN VALLEY AND POINTS EASTWARD ON THURS NIGHT
INTO FRIDAY MORNING. HOWEVER...WITH PWS DROPPING BLW
0.25"...EXPECTING ONLY LIGHT SNOW ACCUMULATIONS...AN ADDITIONAL
DUSTING TO 2 INCHES. PROGGED 85H TEMPS DROP BTWN -22C AND -25C BY
12Z SATURDAY...WITH 925MB TEMPS BTWN -20C TO -24C...SUPPORTING
HIGHS MAINLY 0 TO 10F FOR BOTH FRIDAY AND SATURDAY WITH LOWS -5F
TO -15F. A WIND CHILL ADVISORY WILL BE LIKELY DURING THIS
PERIOD...GIVEN THE EXPECTED PRES GRADIENT ACROSS OUR
CWA...ASSOCIATED WITH DEVELOPING LOW PRESS OFF THE SNE COAST ON
FRIDAY.
NEXT TIGHTLY COMPACTED VORTEX DROPS FROM THE HUDSON BAY REGION ON
SAT INTO SUNDAY AND QUICKLY BECOMES CLOSED OFF AT 7H/5H WITH RAPID
SFC LOW PRES DEVELOPMENT OFF THE SNE COAST. THIS LOOKS TO DEVELOP
TOO FAR EAST TO HAVE SIGNIFICANT PRECIP IMPACTS ACRS OUR CWA...BUT
GUSTY NORTH TO NORTHWEST WINDS WILL RESULT IN STRONG LLVL CAA.
ONCE AGAIN GFS IS MORE AGGRESSIVE WITH ADVECTING LOW LEVEL COLD
AIR ACROSS OUR CWA WITH BOTH 925MB AND 850MB TEMPS NEAR -30C BY
12Z SUNDAY. MEANWHILE...LATEST 00Z EWCMF IS SLIGHTLY WARMER WITH
925MB TO 850MB TEMPS BTWN -24C AND -28C DURING THIS TIME PERIOD.
HAVE NOTED GFS ENSEMBLE 850MB TEMPS ARE 2 TO 3 STD BLW NORMAL
DURING THIS TIME PERIOD...WITH PW VALUES BTWN 1 AND 2 STD BLW
NORMAL...SUPPORTING A COLD AND MAINLY DRY FCST. GIVEN LOW LEVEL
THERMAL PROFILES HIGHS WILL STRUGGLE IN THE -5F TO +5F RANGE FOR
SUNDAY...WITH LOWS SUNDAY NIGHT/MONDAY MORNING BTWN -10F AND -20F.
ALSO...THE COMBINATION OF DEEPENING SFC LOW PRES OVER THE NORTH
ATLANTIC AND BUILDING HIGH PRES WILL CREATE A TIGHT PRES GRADIENT
OVER OUR CWA...WITH GUSTY NORTHWEST WINDS AT 15 TO 25 MPH EXPECTED
WITH THESE COLD TEMPS...CREATING BITTERLY COLD WIND CHILLS. WIND
CHILL ADVISORIES AND WARNINGS WILL BE LIKELY SAT NIGHT THRU
MONDAY. THE ONLY THINK FROM KEEPING TEMPS FROM DROPPING BTWN -20F
AND -30F BY MONDAY MORNING WITH BE THE BRISK WINDS AND SOME MID
LEVEL CLOUDS. THE COLDEST CORE OF AIR SLOWLY MODIFIES BY
MONDAY...WITH WEAK LOW LEVEL WARM ADVECTION DEVELOPING. PROGGED
85H TEMPS WARM TO -20C BY 18Z MONDAY...WITH SFC RIDGE OVERHEAD.
THIS WILL SUPPORT HIGHS BTWN ZERO AND +10F MOST LOCATIONS...WITH
ANOTHER VERY COLD NIGHT EXPECTED ON TUESDAY MORNING. ONCE
AGAIN...GFS AND ECMWF BOTH SHOW CLOUDS INCREASING FROM LOW LEVEL
WARM ADVECTION OVERNIGHT...WILL MAY PREVENT TEMPS FROM COMPLETELY
BOTTOMING OUT. WILL KEEP LOWS MAINLY -5F TO -15F...BUT IF MORE
CLEARING DEVELOPS THAN FORECAST LOWS WILL BE -10F TO -20F WITH
ISOLATED VALUES NEAR -30F...NEK AND SLK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...LOW CLOUDS STILL HANGING TOUGH THIS
AFTERNOON ACROSS ALL OUR TAF SITES WITH GENERAL MVFR CONDITIONS.
WEAK FLOW AND LIMITED MIXING NOT HELPING US OUT VERY MUCH.
TRACKING CLEARING LINE CURRENTLY MOVING VERY SLOWLY TOWARDS MSS.
ALL SITES SHOULD HAVE VFR CONDITIONS BY 21Z THIS EVENING. IN
ADDITION...LOOK FOR A LIGHT NORTH TO NORTHWEST WIND AT 4 TO 8
KNOTS...TO BECOME LIGHT AND TERRAIN DRIVEN THIS EVENING.
OUTLOOK 18Z WEDNESDAY THROUGH SUNDAY... VFR CONDITIONS WITH
SURFACE HIGH PRESSURE THROUGH 00Z THURS. WEAK CLIPPER SYSTEM WILL
PRODUCE IFR CONDITIONS BETWEEN 03Z THURSDAY TO 18Z THURSDAY WITH
SURFACE VIS VALUES OF 1 TO 3SM AND MVFR CIGS. A BRIEF PERIOD OF
LIFR CONDITIONS WILL BE LIKELY ASSOCIATED WITH THE ACTUAL SFC COLD
FRONT. OTHERWISE...LINGERING SNOW SHOWERS WILL PERSIST INTO FRIDAY
WITH MAINLY MVFR VIS/CIGS IN THE MTNS AND TRENDING VFR ELSEWHERE.
ANOTHER CLIPPER BRINGS MORE MVFR VIS/CIGS ON SATURDAY...SUNDAY
WILL BE VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...MUCCILLI
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...NEILES/TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1138 AM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDING EASTWARD FROM THE GREAT LAKES AND NORTHERN
ONTARIO WILL PROVIDE DRY AND SEASONABLY COLD WEATHER WEATHER
CONDITIONS ACROSS THE NORTH COUNTRY TODAY THROUGH WEDNESDAY.
PREVAILING LOW CLOUDS WILL GRADUALLY DIMINISH PROVIDING PARTLY
CLOUDY CONDITIONS THIS AFTERNOON THROUGH MUCH OF WEDNESDAY. AN
ALBERTA CLIPPER WILL MOVE EAST SOUTHEASTWARD INTO OUR REGION DURING
THE PRE-DAWN HOURS THURSDAY...WITH PERIODS OF LIGHT SNOW CONTINUING
THROUGHOUT THE DAYLIGHT HOURS THURSDAY INTO EARLY THURSDAY NIGHT.
SOME MINOR TRAVEL IMPACTS ARE POSSIBLE WITH WIDESPREAD LIGHT SNOW
ACCUMULATIONS EXPECTED. NO SIGNIFICANT PRECIPITATION SYSTEMS ARE
EXPECTED THEREAFTER...BUT BITTERLY COLD AIR WILL BECOME ESTABLISHED
ACROSS THE REGION FRIDAY AND CONTINUING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1136 AM EST TUESDAY...ONLY REAL CHANGE WITH THIS UPDATE WAS
TO DELAY THE CLEARING BY AN HOUR OR TWO. WIDESPREAD DECK OF
STRATUS REMAINS TRAPPED UNDER THE DEVELOPING SUBSIDENCE INVERSION.
CONTINUING TO SEE SOME REPORTS OF FLURRIES ACROSS NORTHERN NEW
YORK AND VERMONT. BACK EDGE OF CLOUDS HAS NOW CLEARED OTTAWA AND
MOVING SLOWLY BUT SURELY FROM NORTHWEST TO SOUTHEAST AS DRIER AIR
OVER SOUTHERN CANADA GRADUALLY PUSHES SOUTHWARD. RAP LOW LEVEL
MOISTURE FIELDS APPEAR TO HANDLING IT THE BEST AND LARGELY USED
ITS DEPICTION FOR CLOUD TRENDS. THUS EXPECTING CLOUD SHIELD TO
GRADUALLY ERODE AND PUSH SOUTH AND EAST AS WE HEAD INTO THE
AFTERNOON HOURS. THINKING CLEARING SKIES REACH THE SAINT LAWRENCE
VALLEY AND NORTHERN CHAMPLAIN VALLEY AROUND 2 PM...BURLINGTON
AREA AROUND 3 PM...CENTRAL VERMONT 4 PM...AND FINALLY SOUTHERN
VERMONT BY 5 PM. HIGH TEMPERATURES SHOULD STILL REACH THE 20S FOR
THE MOST...EXCEPT SOME UPPER TEENS ACROSS PARTS OF NORTHERN NEW
YORK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 321 AM EST TUESDAY...SURFACE RIDGE AXIS BUILDS ACROSS
QUEBEC AND NORTHERN NEW ENGLAND OVERNIGHT TONIGHT. PROVIDED SKIES
BECOME MOSTLY CLEAR AS EXPECTED...SHOULD SET UP A GOOD RADIATIVE
COOLING SETUP WITH LIGHT WINDS AND FRESH SNOW COVER. LOOKING AT
LOWS GENERALLY -8 TO +2F (WARMEST IN THE CHAMPLAIN VALLEY AND FAR
SERN VT)...BUT COULD SEE SOME READINGS IN THE TEENS BELOW ZERO
AROUND KSLK AND THE COLDER HOLLOWS IN VERMONT/S NORTHEAST KINGDOM.
POPS NIL.
SURFACE RIDGE AXIS SHOULD HOLD IN PLACE THROUGHOUT THE DAY
WEDNESDAY FROM MAINE SWWD THROUGH VT/NH AND INTO SERN NY.
MEANWHILE...ALBERTA CLIPPER LOW AND ASSOCIATED MID- LEVEL TROUGH
WILL BE SHIFTING ESEWD ACROSS THE GREAT LAKES REGION BY WEDNESDAY
AFTERNOON. DEVELOPING MID- LEVEL SWLY FLOW IN ADVANCE OF THE
TROUGH AXIS SHOULD YIELD AN INCREASE IN MID TO UPPER CLOUDINESS
FROM W-E ACROSS THE NORTH COUNTRY AS THE DAY PROGRESSES. SFC WINDS
SHOULD REMAIN LIGHT AND NOT EXPECTING ANY PRECIPITATION WITH VERY
DRY PBL CONDITIONS PREVAILING. HIGH TEMPERATURES SHOULD REACH THE
15-20F RANGE IN MOST LOCATIONS.
IT APPEARS THAT AREAS OF LIGHT SNOW WILL DEVELOP EASTWARD ACROSS THE
NORTH COUNTRY IN ASSOCIATED WITH THE CLIPPER SYSTEM DURING WEDNESDAY
NIGHT. SHOULD SEE SNOW BEGIN AROUND MIDNIGHT IN NRN NY AND DURING
THE PRE-DAWN HOURS FOR VERMONT. PRIMARY LOW SHIFTS SLOWLY EASTWARD
ACROSS THE REGION LATE THURSDAY MORNING INTO THURSDAY
AFTERNOON...WITH CONTINUED OVERCAST SKIES AND PERIODS OF LIGHT SNOW.
PRESENT INDICATES FROM 00Z GFS/NAM SUGGEST QPF VALUES OF 0.15 TO
0.3". GIVEN POTENTIAL FOR GOOD DENDRITE GROWTH PER MODEL
SOUNDINGS...SLR/S AROUND 15:1 WOULD YIELD 2-5" WITH THIS SYSTEM OF
GENERALLY LOW DENSITY SNOWFALL. MAIN IMPACT WOULD BE TO
TRAVEL...WITH MINOR SLOWDOWNS EXPECTED FOR BOTH THE EARLY MORNING
AND EVENING COMMUTES ON THURSDAY.
LOW TEMPS WEDNESDAY NIGHT WILL NOT DROP VERY FAR WITH OVERCAST
CONDITIONS IN PLACE (GENERALLY LOW TO MID TEENS). LIKEWISE...HIGHS
THURSDAY WILL ONLY CLIMB INTO THE LOW 20S FOR MOST SECTIONS...WHICH
WILL PROBABLY BE OUR "WARMEST" DAY FOR A WHILE AS ARCTIC AIR RETURNS
IN THE WAKE OF THE CLIPPER SYSTEM BEGINNING FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 320 AM EST MONDAY...DAYS 4 THRU 7 WILL FEATURE DEEP FULL
LATITUDE TROF ACROSS THE EASTERN CONUS WITH SEVERAL COMPACTED
VORTICITIES MOVING ACROSS THE GREAT LAKE AND NE CONUS. THIS LARGE
SCALE SYNOPTIC SETUP WILL FEATURE TEMPS 10 TO 20 DEGREES BLW FOR
THE WEEKEND...AND MOSTLY A DRY FCST. MODEL TRENDS CONT TO SHOW THE
GFS SOLUTION AND ASSOCIATED ENSEMBLE MEMBERS AS THE MOST
AGGRESSIVE WITH S/W ENERGY AND DEVELOPMENT OF STRONG SFC LOW PRES
OFF THE SNE COAST ON FRIDAY...WITH SOME MOISTURE BEING ADVECTED
BACK INTO OUR CWA. HOWEVER...ECMWF IS FURTHER EAST WITH CYCLONE
DEVELOPMENT AND PLACES MUCH LESS DYNAMICS AND MOISTURE ACRS OUR
CWA. WL MENTION CHC POPS ACROSS THE SAINT LAWRENCE VALLEY TO
LIKELY FOR CHAMPLAIN VALLEY AND POINTS EASTWARD ON THURS NIGHT
INTO FRIDAY MORNING. HOWEVER...WITH PWS DROPPING BLW
0.25"...EXPECTING ONLY LIGHT SNOW ACCUMULATIONS...AN ADDITIONAL
DUSTING TO 2 INCHES. PROGGED 85H TEMPS DROP BTWN -22C AND -25C BY
12Z SATURDAY...WITH 925MB TEMPS BTWN -20C TO -24C...SUPPORTING
HIGHS MAINLY 0 TO 10F FOR BOTH FRIDAY AND SATURDAY WITH LOWS -5F
TO -15F. A WIND CHILL ADVISORY WILL BE LIKELY DURING THIS
PERIOD...GIVEN THE EXPECTED PRES GRADIENT ACROSS OUR
CWA...ASSOCIATED WITH DEVELOPING LOW PRESS OFF THE SNE COAST ON
FRIDAY.
NEXT TIGHTLY COMPACTED VORTEX DROPS FROM THE HUDSON BAY REGION ON
SAT INTO SUNDAY AND QUICKLY BECOMES CLOSED OFF AT 7H/5H WITH RAPID
SFC LOW PRES DEVELOPMENT OFF THE SNE COAST. THIS LOOKS TO DEVELOP
TOO FAR EAST TO HAVE SIGNIFICANT PRECIP IMPACTS ACRS OUR CWA...BUT
GUSTY NORTH TO NORTHWEST WINDS WILL RESULT IN STRONG LLVL CAA.
ONCE AGAIN GFS IS MORE AGGRESSIVE WITH ADVECTING LOW LEVEL COLD
AIR ACROSS OUR CWA WITH BOTH 925MB AND 850MB TEMPS NEAR -30C BY
12Z SUNDAY. MEANWHILE...LATEST 00Z EWCMF IS SLIGHTLY WARMER WITH
925MB TO 850MB TEMPS BTWN -24C AND -28C DURING THIS TIME PERIOD.
HAVE NOTED GFS ENSEMBLE 850MB TEMPS ARE 2 TO 3 STD BLW NORMAL
DURING THIS TIME PERIOD...WITH PW VALUES BTWN 1 AND 2 STD BLW
NORMAL...SUPPORTING A COLD AND MAINLY DRY FCST. GIVEN LOW LEVEL
THERMAL PROFILES HIGHS WILL STRUGGLE IN THE -5F TO +5F RANGE FOR
SUNDAY...WITH LOWS SUNDAY NIGHT/MONDAY MORNING BTWN -10F AND -20F.
ALSO...THE COMBINATION OF DEEPENING SFC LOW PRES OVER THE NORTH
ATLANTIC AND BUILDING HIGH PRES WILL CREATE A TIGHT PRES GRADIENT
OVER OUR CWA...WITH GUSTY NORTHWEST WINDS AT 15 TO 25 MPH EXPECTED
WITH THESE COLD TEMPS...CREATING BITTERLY COLD WIND CHILLS. WIND
CHILL ADVISORIES AND WARNINGS WILL BE LIKELY SAT NIGHT THRU
MONDAY. THE ONLY THINK FROM KEEPING TEMPS FROM DROPPING BTWN -20F
AND -30F BY MONDAY MORNING WITH BE THE BRISK WINDS AND SOME MID
LEVEL CLOUDS. THE COLDEST CORE OF AIR SLOWLY MODIFIES BY
MONDAY...WITH WEAK LOW LEVEL WARM ADVECTION DEVELOPING. PROGGED
85H TEMPS WARM TO -20C BY 18Z MONDAY...WITH SFC RIDGE OVERHEAD.
THIS WILL SUPPORT HIGHS BTWN ZERO AND +10F MOST LOCATIONS...WITH
ANOTHER VERY COLD NIGHT EXPECTED ON TUESDAY MORNING. ONCE
AGAIN...GFS AND ECMWF BOTH SHOW CLOUDS INCREASING FROM LOW LEVEL
WARM ADVECTION OVERNIGHT...WILL MAY PREVENT TEMPS FROM COMPLETELY
BOTTOMING OUT. WILL KEEP LOWS MAINLY -5F TO -15F...BUT IF MORE
CLEARING DEVELOPS THAN FORECAST LOWS WILL BE -10F TO -20F WITH
ISOLATED VALUES NEAR -30F...NEK AND SLK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THROUGH 12Z WEDNESDAY...LOW CLOUDS STILL HANGING TOUGH THIS
MORNING ACROSS ALL OUR TAF SITES WITH GENERAL VFR TO MVFR
CONDITIONS. HAVE NOTED IFR CIGS AT SLK. SOUNDINGS ARE TRICKY TODAY
WITH PLENTY OF LOW LEVEL MOISTURE BELOW TEMP INVERSION...ALONG
WITH WEAK FLOW AND LIMITED MIXING. THESE FACTORS COMBINED WITH
WEAK UPSLOPE FLOW...WILL RESULT IN IFR CIGS AT SLK THRU 16Z.
ELSEWHERE...EXPECTING MVFR CIGS TO SLOWLY BECOME VFR BTWN 15Z-17Z
TODAY...AND ALL SITES SHOULD HAVE VFR CONDITIONS BY 21Z THIS
EVENING. IN ADDITION...LOOK FOR A LIGHT NORTH TO NORTHWEST WIND AT
4 TO 8 KNOTS...TO BECOME LIGHT AND TRRN DRIVEN THIS EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH FRIDAY... VFR CONDITIONS WITH
SURFACE HIGH PRESSURE THROUGH 00Z THURS. WEAK CLIPPER SYSTEM WILL
PRODUCE IFR CONDITIONS BETWEEN 03Z THURSDAY TO 18Z THURSDAY WITH
SURFACE VIS VALUES OF 1 TO 3SM AND MVFR CIGS. A BRIEF PERIOD OF
LIFR CONDITIONS WILL BE LIKELY ASSOCIATED WITH THE ACTUAL SFC COLD
FRONT. OTHERWISE...LINGERING SNOW SHOWERS WILL PERSIST INTO FRIDAY
WITH MAINLY MVFR VIS/CIGS IN THE MTNS AND TRENDING VFR ELSEWHERE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...MUCCILLI
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
932 AM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDING EASTWARD FROM THE GREAT LAKES AND NORTHERN
ONTARIO WILL PROVIDE DRY AND SEASONABLY COLD WEATHER WEATHER
CONDITIONS ACROSS THE NORTH COUNTRY TODAY THROUGH WEDNESDAY.
PREVAILING LOW CLOUDS WILL GRADUALLY DIMINISH PROVIDING PARTLY
CLOUDY CONDITIONS THIS AFTERNOON THROUGH MUCH OF WEDNESDAY. AN
ALBERTA CLIPPER WILL MOVE EAST SOUTHEASTWARD INTO OUR REGION DURING
THE PRE-DAWN HOURS THURSDAY...WITH PERIODS OF LIGHT SNOW CONTINUING
THROUGHOUT THE DAYLIGHT HOURS THURSDAY INTO EARLY THURSDAY NIGHT.
SOME MINOR TRAVEL IMPACTS ARE POSSIBLE WITH WIDESPREAD LIGHT SNOW
ACCUMULATIONS EXPECTED. NO SIGNIFICANT PRECIPITATION SYSTEMS ARE
EXPECTED THEREAFTER...BUT BITTERLY COLD AIR WILL BECOME ESTABLISHED
ACROSS THE REGION FRIDAY AND CONTINUING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 924 AM EST TUESDAY...WIDESPREAD DECK OF STRATUS REMAINS
TRAPPED UNDER THE DEVELOPING SUBSIDENCE INVERSION. EVEN SEEING
SOME REPORTS OF FLURRIES ACROSS NORTHERN NEW YORK AND VERMONT.
BACK EDGE OF CLOUDS IS NOW NEAR OTTAWA AND MOVING SLOWLY BUT
SURELY FROM NORTHWEST TO SOUTHEAST AS DRIER AIR OVER SOUTHERN
CANADA GRADUALLY PUSHES SOUTHWARD. RAP LOW LEVEL MOISTURE FIELDS
APPEAR TO HANDLING IT THE BEST AND LARGELY USED ITS DEPICTION FOR
CLOUD TRENDS. THUS EXPECTING CLOUD SHIELD TO GRADUALLY ERODE AND
PUSH SOUTH AND EAST AS WE HEAD INTO THE AFTERNOON HOURS. THINKING
CLEARING SKIES REACH THE SAINT LAWRENCE VALLEY AND NORTHERN
CHAMPLAIN VALLEY AROUND 1 PM...BURLINGTON AREA AROUND 2
PM...CENTRAL VERMONT 3 PM...AND FINALLY SOUTHERN VERMONT BY 4 PM.
HIGH TEMPERATURES SHOULD STILL REACH THE 20S FOR THE MOST...EXCEPT
SOME UPPER TEENS ACROSS PARTS OF NORTHERN NEW YORK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 321 AM EST TUESDAY...SURFACE RIDGE AXIS BUILDS ACROSS
QUEBEC AND NORTHERN NEW ENGLAND OVERNIGHT TONIGHT. PROVIDED SKIES
BECOME MOSTLY CLEAR AS EXPECTED...SHOULD SET UP A GOOD RADIATIVE
COOLING SETUP WITH LIGHT WINDS AND FRESH SNOW COVER. LOOKING AT
LOWS GENERALLY -8 TO +2F (WARMEST IN THE CHAMPLAIN VALLEY AND FAR
SERN VT)...BUT COULD SEE SOME READINGS IN THE TEENS BELOW ZERO
AROUND KSLK AND THE COLDER HOLLOWS IN VERMONT/S NORTHEAST KINGDOM.
POPS NIL.
SURFACE RIDGE AXIS SHOULD HOLD IN PLACE THROUGHOUT THE DAY
WEDNESDAY FROM MAINE SWWD THROUGH VT/NH AND INTO SERN NY.
MEANWHILE...ALBERTA CLIPPER LOW AND ASSOCIATED MID- LEVEL TROUGH
WILL BE SHIFTING ESEWD ACROSS THE GREAT LAKES REGION BY WEDNESDAY
AFTERNOON. DEVELOPING MID- LEVEL SWLY FLOW IN ADVANCE OF THE
TROUGH AXIS SHOULD YIELD AN INCREASE IN MID TO UPPER CLOUDINESS
FROM W-E ACROSS THE NORTH COUNTRY AS THE DAY PROGRESSES. SFC WINDS
SHOULD REMAIN LIGHT AND NOT EXPECTING ANY PRECIPITATION WITH VERY
DRY PBL CONDITIONS PREVAILING. HIGH TEMPERATURES SHOULD REACH THE
15-20F RANGE IN MOST LOCATIONS.
IT APPEARS THAT AREAS OF LIGHT SNOW WILL DEVELOP EASTWARD ACROSS THE
NORTH COUNTRY IN ASSOCIATED WITH THE CLIPPER SYSTEM DURING WEDNESDAY
NIGHT. SHOULD SEE SNOW BEGIN AROUND MIDNIGHT IN NRN NY AND DURING
THE PRE-DAWN HOURS FOR VERMONT. PRIMARY LOW SHIFTS SLOWLY EASTWARD
ACROSS THE REGION LATE THURSDAY MORNING INTO THURSDAY
AFTERNOON...WITH CONTINUED OVERCAST SKIES AND PERIODS OF LIGHT SNOW.
PRESENT INDICATES FROM 00Z GFS/NAM SUGGEST QPF VALUES OF 0.15 TO
0.3". GIVEN POTENTIAL FOR GOOD DENDRITE GROWTH PER MODEL
SOUNDINGS...SLR/S AROUND 15:1 WOULD YIELD 2-5" WITH THIS SYSTEM OF
GENERALLY LOW DENSITY SNOWFALL. MAIN IMPACT WOULD BE TO
TRAVEL...WITH MINOR SLOWDOWNS EXPECTED FOR BOTH THE EARLY MORNING
AND EVENING COMMUTES ON THURSDAY.
LOW TEMPS WEDNESDAY NIGHT WILL NOT DROP VERY FAR WITH OVERCAST
CONDITIONS IN PLACE (GENERALLY LOW TO MID TEENS). LIKEWISE...HIGHS
THURSDAY WILL ONLY CLIMB INTO THE LOW 20S FOR MOST SECTIONS...WHICH
WILL PROBABLY BE OUR "WARMEST" DAY FOR A WHILE AS ARCTIC AIR RETURNS
IN THE WAKE OF THE CLIPPER SYSTEM BEGINNING FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 320 AM EST MONDAY...DAYS 4 THRU 7 WILL FEATURE DEEP FULL
LATITUDE TROF ACROSS THE EASTERN CONUS WITH SEVERAL COMPACTED
VORTICITIES MOVING ACROSS THE GREAT LAKE AND NE CONUS. THIS LARGE
SCALE SYNOPTIC SETUP WILL FEATURE TEMPS 10 TO 20 DEGREES BLW FOR
THE WEEKEND...AND MOSTLY A DRY FCST. MODEL TRENDS CONT TO SHOW THE
GFS SOLUTION AND ASSOCIATED ENSEMBLE MEMBERS AS THE MOST
AGGRESSIVE WITH S/W ENERGY AND DEVELOPMENT OF STRONG SFC LOW PRES
OFF THE SNE COAST ON FRIDAY...WITH SOME MOISTURE BEING ADVECTED
BACK INTO OUR CWA. HOWEVER...ECMWF IS FURTHER EAST WITH CYCLONE
DEVELOPMENT AND PLACES MUCH LESS DYNAMICS AND MOISTURE ACRS OUR
CWA. WL MENTION CHC POPS ACROSS THE SAINT LAWRENCE VALLEY TO
LIKELY FOR CHAMPLAIN VALLEY AND POINTS EASTWARD ON THURS NIGHT
INTO FRIDAY MORNING. HOWEVER...WITH PWS DROPPING BLW
0.25"...EXPECTING ONLY LIGHT SNOW ACCUMULATIONS...AN ADDITIONAL
DUSTING TO 2 INCHES. PROGGED 85H TEMPS DROP BTWN -22C AND -25C BY
12Z SATURDAY...WITH 925MB TEMPS BTWN -20C TO -24C...SUPPORTING
HIGHS MAINLY 0 TO 10F FOR BOTH FRIDAY AND SATURDAY WITH LOWS -5F
TO -15F. A WIND CHILL ADVISORY WILL BE LIKELY DURING THIS
PERIOD...GIVEN THE EXPECTED PRES GRADIENT ACROSS OUR
CWA...ASSOCIATED WITH DEVELOPING LOW PRESS OFF THE SNE COAST ON
FRIDAY.
NEXT TIGHTLY COMPACTED VORTEX DROPS FROM THE HUDSON BAY REGION ON
SAT INTO SUNDAY AND QUICKLY BECOMES CLOSED OFF AT 7H/5H WITH RAPID
SFC LOW PRES DEVELOPMENT OFF THE SNE COAST. THIS LOOKS TO DEVELOP
TOO FAR EAST TO HAVE SIGNIFICANT PRECIP IMPACTS ACRS OUR CWA...BUT
GUSTY NORTH TO NORTHWEST WINDS WILL RESULT IN STRONG LLVL CAA.
ONCE AGAIN GFS IS MORE AGGRESSIVE WITH ADVECTING LOW LEVEL COLD
AIR ACROSS OUR CWA WITH BOTH 925MB AND 850MB TEMPS NEAR -30C BY
12Z SUNDAY. MEANWHILE...LATEST 00Z EWCMF IS SLIGHTLY WARMER WITH
925MB TO 850MB TEMPS BTWN -24C AND -28C DURING THIS TIME PERIOD.
HAVE NOTED GFS ENSEMBLE 850MB TEMPS ARE 2 TO 3 STD BLW NORMAL
DURING THIS TIME PERIOD...WITH PW VALUES BTWN 1 AND 2 STD BLW
NORMAL...SUPPORTING A COLD AND MAINLY DRY FCST. GIVEN LOW LEVEL
THERMAL PROFILES HIGHS WILL STRUGGLE IN THE -5F TO +5F RANGE FOR
SUNDAY...WITH LOWS SUNDAY NIGHT/MONDAY MORNING BTWN -10F AND -20F.
ALSO...THE COMBINATION OF DEEPENING SFC LOW PRES OVER THE NORTH
ATLANTIC AND BUILDING HIGH PRES WILL CREATE A TIGHT PRES GRADIENT
OVER OUR CWA...WITH GUSTY NORTHWEST WINDS AT 15 TO 25 MPH EXPECTED
WITH THESE COLD TEMPS...CREATING BITTERLY COLD WIND CHILLS. WIND
CHILL ADVISORIES AND WARNINGS WILL BE LIKELY SAT NIGHT THRU
MONDAY. THE ONLY THINK FROM KEEPING TEMPS FROM DROPPING BTWN -20F
AND -30F BY MONDAY MORNING WITH BE THE BRISK WINDS AND SOME MID
LEVEL CLOUDS. THE COLDEST CORE OF AIR SLOWLY MODIFIES BY
MONDAY...WITH WEAK LOW LEVEL WARM ADVECTION DEVELOPING. PROGGED
85H TEMPS WARM TO -20C BY 18Z MONDAY...WITH SFC RIDGE OVERHEAD.
THIS WILL SUPPORT HIGHS BTWN ZERO AND +10F MOST LOCATIONS...WITH
ANOTHER VERY COLD NIGHT EXPECTED ON TUESDAY MORNING. ONCE
AGAIN...GFS AND ECMWF BOTH SHOW CLOUDS INCREASING FROM LOW LEVEL
WARM ADVECTION OVERNIGHT...WILL MAY PREVENT TEMPS FROM COMPLETELY
BOTTOMING OUT. WILL KEEP LOWS MAINLY -5F TO -15F...BUT IF MORE
CLEARING DEVELOPS THAN FORECAST LOWS WILL BE -10F TO -20F WITH
ISOLATED VALUES NEAR -30F...NEK AND SLK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...LOW CLOUDS STILL HANGING TOUGH THIS
MORNING ACROSS ALL OUR TAF SITES WITH GENERAL VFR TO MVFR
CONDITIONS. HAVE NOTED IFR CIGS AT SLK. SOUNDINGS ARE TRICKY TODAY
WITH PLENTY OF LOW LEVEL MOISTURE BELOW TEMP INVERSION...ALONG
WITH WEAK FLOW AND LIMITED MIXING. THESE FACTORS COMBINED WITH
WEAK UPSLOPE FLOW...WILL RESULT IN IFR CIGS AT SLK THRU 16Z.
ELSEWHERE...EXPECTING MVFR CIGS TO SLOWLY BECOME VFR BTWN 15Z-17Z
TODAY...AND ALL SITES SHOULD HAVE VFR CONDITIONS BY 21Z THIS
EVENING. IN ADDITION...LOOK FOR A LIGHT NORTH TO NORTHWEST WIND AT
4 TO 8 KNOTS...TO BECOME LIGHT AND TRRN DRIVEN THIS EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH FRIDAY... VFR CONDITIONS WITH
SURFACE HIGH PRESSURE THROUGH 00Z THURS. WEAK CLIPPER SYSTEM WILL
PRODUCE IFR CONDITIONS BETWEEN 03Z THURSDAY TO 18Z THURSDAY WITH
SURFACE VIS VALUES OF 1 TO 3SM AND MVFR CIGS. A BRIEF PERIOD OF
LIFR CONDITIONS WILL BE LIKELY ASSOCIATED WITH THE ACTUAL SFC COLD
FRONT. OTHERWISE...LINGERING SNOW SHOWERS WILL PERSIST INTO FRIDAY
WITH MAINLY MVFR VIS/CIGS IN THE MTNS AND TRENDING VFR ELSEWHERE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...MUCCILLI
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
736 AM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDING EASTWARD FROM THE GREAT LAKES AND NORTHERN
ONTARIO WILL PROVIDE DRY AND SEASONABLY COLD WEATHER WEATHER
CONDITIONS ACROSS THE NORTH COUNTRY TODAY THROUGH WEDNESDAY.
PREVAILING LOW CLOUDS WILL GRADUALLY DIMINISH PROVIDING PARTLY
CLOUDY CONDITIONS THIS AFTERNOON THROUGH MUCH OF WEDNESDAY. AN
ALBERTA CLIPPER WILL MOVE EAST SOUTHEASTWARD INTO OUR REGION DURING
THE PRE-DAWN HOURS THURSDAY...WITH PERIODS OF LIGHT SNOW CONTINUING
THROUGHOUT THE DAYLIGHT HOURS THURSDAY INTO EARLY THURSDAY NIGHT.
SOME MINOR TRAVEL IMPACTS ARE POSSIBLE WITH WIDESPREAD LIGHT SNOW
ACCUMULATIONS EXPECTED. NO SIGNIFICANT PRECIPITATION SYSTEMS ARE
EXPECTED THEREAFTER...BUT BITTERLY COLD AIR WILL BECOME ESTABLISHED
ACROSS THE REGION FRIDAY AND CONTINUING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 723 AM EST TUESDAY...WEAK WIND FIELDS FROM THE SURFACE
THROUGH 10 KFT AND MOIST, ISOTHERMAL VERTICAL PROFILES HAVE LEFT
A PREVAILING STRATUS LAYER ACROSS THE NORTH COUNTRY EARLY THIS
MORNING, EVEN AS LOW PRESSURE DEPARTS WELL EAST OF CAPE COD. IT
APPEARS THAT AS THE SURFACE ANTICYCLONE BUILDS EASTWARD FROM NRN
ONTARIO THAT A MODEST INCREASE IN LOW-LEVEL NORTHERLY FLOW AND
INCREASED MID-LEVEL SUBSIDENCE WILL GRADUALLY ALLOW STRATUS LAYER
TO BREAK UP DURING THE DAYLIGHT HOURS TODAY. THE RAP AND NAM
SUGGEST THIS WILL OCCUR AROUND/AFTER 16Z. THE NORTH WINDS AND
LIMITED VERTICAL MIXING WILL KEEP TEMPERATURES BELOW NORMAL THIS
AFTERNOON...WITH HIGHS GENERALLY EXPECTED IN THE LOWER TO MID 20S.
MAY SEE A FEW LINGERING FLURRIES EARLY THIS MORNING...MAINLY
ACROSS THE MOUNTAINS...BUT OTHERWISE LOOKING AT DRY CONDITIONS
TODAY AND TONIGHT.
SURFACE RIDGE AXIS BUILDS ACROSS QUEBEC AND NORTHERN NEW ENGLAND
OVERNIGHT TONIGHT. PROVIDED SKIES BECOME MOSTLY CLEAR AS
EXPECTED...SHOULD SET UP A GOOD RADIATIVE COOLING SETUP WITH LIGHT
WINDS AND FRESH SNOW COVER. LOOKING AT LOWS GENERALLY -8 TO +2F
(WARMEST IN THE CHAMPLAIN VALLEY AND FAR SERN VT)...BUT COULD SEE
SOME READINGS IN THE TEENS BELOW ZERO AROUND KSLK AND THE COLDER
HOLLOWS IN VERMONT/S NORTHEAST KINGDOM. POPS NIL.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 321 AM EST TUESDAY...SURFACE RIDGE AXIS SHOULD HOLD IN PLACE
THROUGHOUT THE DAY WEDNESDAY FROM MAINE SWWD THROUGH VT/NH AND
INTO SERN NY. MEANWHILE...ALBERTA CLIPPER LOW AND ASSOCIATED MID-
LEVEL TROUGH WILL BE SHIFTING ESEWD ACROSS THE GREAT LAKES REGION
BY WEDNESDAY AFTERNOON. DEVELOPING MID- LEVEL SWLY FLOW IN ADVANCE
OF THE TROUGH AXIS SHOULD YIELD AN INCREASE IN MID TO UPPER
CLOUDINESS FROM W-E ACROSS THE NORTH COUNTRY AS THE DAY
PROGRESSES. SFC WINDS SHOULD REMAIN LIGHT AND NOT EXPECTING ANY
PRECIPITATION WITH VERY DRY PBL CONDITIONS PREVAILING. HIGH
TEMPERATURES SHOULD REACH THE 15-20F RANGE IN MOST LOCATIONS.
IT APPEARS THAT AREAS OF LIGHT SNOW WILL DEVELOP EASTWARD ACROSS THE
NORTH COUNTRY IN ASSOCIATED WITH THE CLIPPER SYSTEM DURING WEDNESDAY
NIGHT. SHOULD SEE SNOW BEGIN AROUND MIDNIGHT IN NRN NY AND DURING
THE PRE-DAWN HOURS FOR VERMONT. PRIMARY LOW SHIFTS SLOWLY EASTWARD
ACROSS THE REGION LATE THURSDAY MORNING INTO THURSDAY
AFTERNOON...WITH CONTINUED OVERCAST SKIES AND PERIODS OF LIGHT SNOW.
PRESENT INDICATES FROM 00Z GFS/NAM SUGGEST QPF VALUES OF 0.15 TO
0.3". GIVEN POTENTIAL FOR GOOD DENDRITE GROWTH PER MODEL
SOUNDINGS...SLR/S AROUND 15:1 WOULD YIELD 2-5" WITH THIS SYSTEM OF
GENERALLY LOW DENSITY SNOWFALL. MAIN IMPACT WOULD BE TO
TRAVEL...WITH MINOR SLOWDOWNS EXPECTED FOR BOTH THE EARLY MORNING
AND EVENING COMMUTES ON THURSDAY.
LOW TEMPS WEDNESDAY NIGHT WILL NOT DROP VERY FAR WITH OVERCAST
CONDITIONS IN PLACE (GENERALLY LOW TO MID TEENS). LIKEWISE...HIGHS
THURSDAY WILL ONLY CLIMB INTO THE LOW 20S FOR MOST SECTIONS...WHICH
WILL PROBABLY BE OUR "WARMEST" DAY FOR A WHILE AS ARCTIC AIR RETURNS
IN THE WAKE OF THE CLIPPER SYSTEM BEGINNING FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 320 AM EST MONDAY...DAYS 4 THRU 7 WILL FEATURE DEEP FULL
LATITUDE TROF ACROSS THE EASTERN CONUS WITH SEVERAL COMPACTED
VORTICITIES MOVING ACROSS THE GREAT LAKE AND NE CONUS. THIS LARGE
SCALE SYNOPTIC SETUP WILL FEATURE TEMPS 10 TO 20 DEGREES BLW FOR
THE WEEKEND...AND MOSTLY A DRY FCST. MODEL TRENDS CONT TO SHOW THE
GFS SOLUTION AND ASSOCIATED ENSEMBLE MEMBERS AS THE MOST
AGGRESSIVE WITH S/W ENERGY AND DEVELOPMENT OF STRONG SFC LOW PRES
OFF THE SNE COAST ON FRIDAY...WITH SOME MOISTURE BEING ADVECTED
BACK INTO OUR CWA. HOWEVER...ECMWF IS FURTHER EAST WITH CYCLONE
DEVELOPMENT AND PLACES MUCH LESS DYNAMICS AND MOISTURE ACRS OUR
CWA. WL MENTION CHC POPS ACROSS THE SAINT LAWRENCE VALLEY TO
LIKELY FOR CHAMPLAIN VALLEY AND POINTS EASTWARD ON THURS NIGHT
INTO FRIDAY MORNING. HOWEVER...WITH PWS DROPPING BLW
0.25"...EXPECTING ONLY LIGHT SNOW ACCUMULATIONS...AN ADDITIONAL
DUSTING TO 2 INCHES. PROGGED 85H TEMPS DROP BTWN -22C AND -25C BY
12Z SATURDAY...WITH 925MB TEMPS BTWN -20C TO -24C...SUPPORTING
HIGHS MAINLY 0 TO 10F FOR BOTH FRIDAY AND SATURDAY WITH LOWS -5F
TO -15F. A WIND CHILL ADVISORY WILL BE LIKELY DURING THIS
PERIOD...GIVEN THE EXPECTED PRES GRADIENT ACROSS OUR
CWA...ASSOCIATED WITH DEVELOPING LOW PRESS OFF THE SNE COAST ON
FRIDAY.
NEXT TIGHTLY COMPACTED VORTEX DROPS FROM THE HUDSON BAY REGION ON
SAT INTO SUNDAY AND QUICKLY BECOMES CLOSED OFF AT 7H/5H WITH RAPID
SFC LOW PRES DEVELOPMENT OFF THE SNE COAST. THIS LOOKS TO DEVELOP
TOO FAR EAST TO HAVE SIGNIFICANT PRECIP IMPACTS ACRS OUR CWA...BUT
GUSTY NORTH TO NORTHWEST WINDS WILL RESULT IN STRONG LLVL CAA.
ONCE AGAIN GFS IS MORE AGGRESSIVE WITH ADVECTING LOW LEVEL COLD
AIR ACROSS OUR CWA WITH BOTH 925MB AND 850MB TEMPS NEAR -30C BY
12Z SUNDAY. MEANWHILE...LATEST 00Z EWCMF IS SLIGHTLY WARMER WITH
925MB TO 850MB TEMPS BTWN -24C AND -28C DURING THIS TIME PERIOD.
HAVE NOTED GFS ENSEMBLE 850MB TEMPS ARE 2 TO 3 STD BLW NORMAL
DURING THIS TIME PERIOD...WITH PW VALUES BTWN 1 AND 2 STD BLW
NORMAL...SUPPORTING A COLD AND MAINLY DRY FCST. GIVEN LOW LEVEL
THERMAL PROFILES HIGHS WILL STRUGGLE IN THE -5F TO +5F RANGE FOR
SUNDAY...WITH LOWS SUNDAY NIGHT/MONDAY MORNING BTWN -10F AND -20F.
ALSO...THE COMBINATION OF DEEPENING SFC LOW PRES OVER THE NORTH
ATLANTIC AND BUILDING HIGH PRES WILL CREATE A TIGHT PRES GRADIENT
OVER OUR CWA...WITH GUSTY NORTHWEST WINDS AT 15 TO 25 MPH EXPECTED
WITH THESE COLD TEMPS...CREATING BITTERLY COLD WIND CHILLS. WIND
CHILL ADVISORIES AND WARNINGS WILL BE LIKELY SAT NIGHT THRU
MONDAY. THE ONLY THINK FROM KEEPING TEMPS FROM DROPPING BTWN -20F
AND -30F BY MONDAY MORNING WITH BE THE BRISK WINDS AND SOME MID
LEVEL CLOUDS. THE COLDEST CORE OF AIR SLOWLY MODIFIES BY
MONDAY...WITH WEAK LOW LEVEL WARM ADVECTION DEVELOPING. PROGGED
85H TEMPS WARM TO -20C BY 18Z MONDAY...WITH SFC RIDGE OVERHEAD.
THIS WILL SUPPORT HIGHS BTWN ZERO AND +10F MOST LOCATIONS...WITH
ANOTHER VERY COLD NIGHT EXPECTED ON TUESDAY MORNING. ONCE
AGAIN...GFS AND ECMWF BOTH SHOW CLOUDS INCREASING FROM LOW LEVEL
WARM ADVECTION OVERNIGHT...WILL MAY PREVENT TEMPS FROM COMPLETELY
BOTTOMING OUT. WILL KEEP LOWS MAINLY -5F TO -15F...BUT IF MORE
CLEARING DEVELOPS THAN FORECAST LOWS WILL BE -10F TO -20F WITH
ISOLATED VALUES NEAR -30F...NEK AND SLK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...LOW CLOUDS STILL HANGING TOUGH THIS
MORNING ACROSS ALL OUR TAF SITES WITH GENERAL VFR TO MVFR
CONDITIONS. HAVE NOTED IFR CIGS AT SLK. SOUNDINGS ARE TRICKY TODAY
WITH PLENTY OF LOW LEVEL MOISTURE BELOW TEMP INVERSION...ALONG
WITH WEAK FLOW AND LIMITED MIXING. THESE FACTORS COMBINED WITH
WEAK UPSLOPE FLOW...WILL RESULT IN IFR CIGS AT SLK THRU 16Z.
ELSEWHERE...EXPECTING MVFR CIGS TO SLOWLY BECOME VFR BTWN 15Z-17Z
TODAY...AND ALL SITES SHOULD HAVE VFR CONDITIONS BY 21Z THIS
EVENING. IN ADDITION...LOOK FOR A LIGHT NORTH TO NORTHWEST WIND AT
4 TO 8 KNOTS...TO BECOME LIGHT AND TRRN DRIVEN THIS EVENING.
OUTLOOK 12Z WEDNESDAY THROUGH FRIDAY... VFR CONDITIONS WITH
SURFACE HIGH PRESSURE THROUGH 00Z THURS. WEAK CLIPPER SYSTEM WILL
PRODUCE IFR CONDITIONS BETWEEN 03Z THURSDAY TO 18Z THURSDAY WITH
SURFACE VIS VALUES OF 1 TO 3SM AND MVFR CIGS. A BRIEF PERIOD OF
LIFR CONDITIONS WILL BE LIKELY ASSOCIATED WITH THE ACTUAL SFC COLD
FRONT. OTHERWISE...LINGERING SNOW SHOWERS WILL PERSIST INTO FRIDAY
WITH MAINLY MVFR VIS/CIGS IN THE MTNS AND TRENDING VFR ELSEWHERE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
320 PM CST TUE FEB 10 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
STRONG WINDS AND FALLING TEMPERATURES HIGHLIGHT THE SHORT TERM FORECAST.
AS A OF 20 UTC...A 5MB/3HR PRESSURE RISE BUBBLE WAS ANALYZED OVER
LAKE SAKAKAWEA. THIS FEATURE WILL CONTINUE TO PROPAGATE SOUTHEAST
THROUGH THE LATE AFTERNOON AND EARLY EVENING. WITH 35 TO 40 KTS TO
MIX PER 19 UTC RAP SOUNDINGS...AND ISALLOBARIC FORCING FROM THE
PRESSURE RISES...LOW END WIND ADVISORY CRITERIA GUSTS ARE EXPECTED
INTO THE EARLY EVENING SOUTHWEST AND SOUTH CENTRAL. DID MAINTAIN
A SLIGHT CHANCE FOR SNOW THROUGH THE EVENING AS WELL FOR MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA WITH LIGHT SNOW BEING OBSERVED AT
MULTIPLE SITES ACROSS NORTH DAKOTA INTO SOUTHERN CANADA.
FOR WEDNESDAY...COLD SURFACE HIGH PRESSURE WILL BUILD ACROSS NORTH
DAKOTA. THIS WILL YIELD LITTLE TEMPERATURE RECOVERY FROM MORNING
LOWS WITH CONTINUED COLD AIR ADVECTION THROUGH THE DAY. ADVISORY
LEVEL WIND CHILLS MAY BE POSSIBLE ACROSS THE TURTLE MOUNTAINS BY
LATE AFTERNOON. HOWEVER...WILL FORGO ANY ADVISORY FOR NOW. GIVEN
GOOD AGREEMENT THROUGH THE PERIOD...A BLEND OF THE 12 UTC SUITE
WAS USED FOR MOST FIELDS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CST TUE FEB 10 2015
THE LONG TERM WILL BE CHARACTERIZED BY SEVERAL COLD BLASTS AND
OCCASIONAL SNOW CHANCES.
WEDNESDAY NIGHT INTO THURSDAY IS WHEN THE FIRST SUCH COLD BLAST
ENTERS THE REGION. ARCTIC HIGH PRESSURE WILL SETTLE OVER NORTH
DAKOTA THURSDAY MORNING. WITH CLEAR SKIES AND THE MAJORITY OF THE
REGION UNDER AT LEAST A LIGHT BLANKET OF SNOW...TEMPERATURES
SHOULD PLUMMET THURSDAY MORNING INTO THE TEENS AND POSSIBLY 20S
BELOW ZERO EAST OF THE MISSOURI RIVER. SCATTERED LIGHT SNOW MAY
FOLLOW THE HIGH PRESSURE AS AN UPPER LEVEL JET SHOULD BE IN A
FAVORABLE POSITION FOR BROAD SCALE LIFT.
THE NEXT BLAST ARRIVES SATURDAY...WHERE ONCE AGAIN TEMPERATURES
SHOULD ONCE AGAIN FALL INTO THE TEENS BELOW ZERO. AND ONCE AGAIN
SNOW WILL BE POSSIBLE FOLLOWING THE HIGH PRESSURE. HOWEVER...THE
12 UTC GFS AND ECMWF ARE MORE BULLISH WITH THIS EVENT AS A SURFACE
LOW IS FORECAST TO DEVELOP ACROSS EASTERN MONTANA AND SLIDE
SOUTHEAST THROUGH THE DAY SUNDAY. THERE IS THE POTENTIAL FOR MORE
SIGNIFICANT ACCUMULATION WITH THIS EVENT AS THERE APPEARS TO BE
FOCUSED LOW LEVEL ASCENT ALONG WITH THE UPPER LEVEL JET DYNAMICS.
OTHERWISE...THE LONG TERM LOOKS DRY...WITH COLD TEMPERATURES EAST
OF THE MISSOURI AND TEMPERATURES WEST OF THE MISSOURI RIVER
LOOKING RATHER MILD...WITH READINGS IN THE 30S MOST DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 320 PM CST TUE FEB 10 2015
MVFR STRATUS WILL CONTINUE INTO TONIGHT. ISOLATED TO SCATTERED
LIGHT SNOW SHOWERS MAY YIELD BRIEF IFR CONDITIONS THIS AFTERNOON
AND EARLY EVENING. NORTHWEST WINDS WITH GUSTS OF 30 TO 40KTS WILL
INCREASE ACROSS THE AREA THROUGH THE AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CST /8 PM MST/ THIS EVENING FOR
NDZ019>022-033>035-040>046.
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ023-025-036-037-
047-048-050-051.
&&
$$
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1150 PM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 1150 PM CST MON FEB 9 2015
CURRENT HEADLINES IN GOOD SHAPE. THE LATEST WATER VAPOR IMAGERY
LOOP PLACES A WELL DEFINED SHORTWAVE TROUGH OVER SOUTHEAST ALBERTA
INTO SOUTH CENTRAL MONTANA. SURFACE ANALYSIS SHOWS LOW PRESSURE
NORTH OF BILLINGS MONTANA...IN LINE WITH THE 00Z NAM/GFS. SURFACE
LOW SLIDES TO NEAR KILLDEER/DICKINSON AREA BY 12Z TUESDAY AND
PASSING THROUGH THE JAMES RIVER VALLEY TUESDAY AFTERNOON. CURRENT
LOCAL/REGIONAL RADAR SHOWS PRECIPITATION ON TRACK ACROSS WESTERN
AND CENTRAL NORTH DAKOTA AND NO CHANGES TO THE PREVIOUS FORECAST.
WILL MONITOR ICE ACCUMULATIONS CLOSELY OVERNIGHT.
LOOKING AHEAD...A STRONG PRESSURE GRADIENT AND COLD AIR ADVECTION
DEVELOP TUESDAY AFTERNOON AND EVENING...BEHIND THE SURFACE LOW. EARLY
INDICATIONS PER BUFKIT SHOWS MOST LOCATIONS MAY TAP INTO 30KT TO
40KT WINDS AT THE VERY TOP OF THE MIXED LAYER. A WIND ADVISORY MAY
BE WARRANTED...BUT WITH CURRENT WINTER WEATHER ADVISORIES IN
PLACE...WILL LOOK MORE AT THIS AT THE NEXT UPDATE.
UPDATE ISSUED AT 952 PM CST MON FEB 9 2015
NO SIGNIFICANT CHANGES FOR THE LATE EVENING UPDATE. REFLECTIVITIES
CONTINUE TO INCREASE ACROSS WESTERN AND INTO CENTRAL NORTH DAKOTA.
REPORTS OF FREEZING RAIN IN WESTERN NORTH DAKOTA. ALSO NOTICED
SOME VERY LIGHT FREEZING RAIN AND ICE PELLETS AT WFO BISMARCK THIS
PAST HOUR. DID CANCEL THE DENSE FOG ADVISORY AS EXCEPT FOR
HETTINGER...VISIBILITIES HAVE IMPROVED TO AROUND A MILE OR GREATER
IN MOST AREAS IN THE ADVISORY. NO CHANGES TO CURRENT WINTER
WEATHER HEADLINES. WILL FRESHEN UP TEXT PRODUCTS SHORTLY.
UPDATE ISSUED AT 600 PM CST MON FEB 9 2015
NO CHANGES TO CURRENT WINTER WEATHER OR FREEZING RAIN ADVISORIES.
DID EXTEND THE DENSE FOG ADVISORY THROUGH 10 PM THIS EVENING.
STILL SURFACE REPORTS AND WEATHER CAMERAS SHOWING DENSE FOG. THINK
WITH THE SYSTEM MOVING IN THROUGH THE EVENING VISIBILITIES WILL
BEGIN TO IMPROVE. NO ADDITIONAL CHANGES AT THIS TIME. WILL TAKE A
CLOSER LOOK AT TEMPERATURES AND PRECIPITATION WITH NEXT UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM CST MON FEB 9 2015
THE UPCOMING MIXED PRECIPITATION EVENT HIGHLIGHTS THE SHORT TERM
FORECAST.
IN REGARDS TO HEADLINES...WILL LET THE DENSE FOG ADVISORY ACROSS
MUCH OF THE WEST AND CENTRAL CONTINUE THROUGH 00 UTC WITH
CONTINUED UPSLOPE SOUTHEASTERLY FLOW. OTHER THAN ADDING
SIOUX...GRANT...STARK AND HETTINGER COUNTIES TO THE FREEZING RAIN
ADVISORY...ALL OTHER WINTER HEADLINES REMAIN UNCHANGED.
IN GENERAL...OVERALL EXPECTATIONS FOR THE EVENT VARY LITTLE WITH
THIS FORECAST PACKAGE THAT UTILIZED THE 12 AND INCOMING 18 UTC
DETERMINISTIC AND ENSEMBLE SUITES COMPARED TO THE 06 AND 00 UTC
GUIDANCE. THE 18 THROUGH 20 UTC HRRR ITERATIONS LINE UP WELL WITH
RADAR ACROSS EASTERN MONTANA AND WILL WEIGH HEAVILY ON THESE
SOLUTIONS IN THE NEAR TERM...BLENDED TO THE GLOBAL 12 AND 18 UTC
SUITES THROUGH THE NIGHT. THIS SUPPORTS AN EXPANDED THREAT FOR
FREEZING RAIN INTO SOUTHWEST NORTH DAKOTA GIVEN SURFACE
TEMPERATURES THAT HAVE REMAINED BELOW FREEZING UNDER THE STRATUS.
FOLLOWED CLOSELY TO THE 19-20 UTC RAP AND 18 UTC NAM BUFR
SOUNDINGS FOR THE STRENGTH OF THE WARM LAYER ALOFT. AS ALWAYS IN
MIXED PRECIPITATION TYPES EVENTS...THIS VARIABLE IS THE MOST
UNCERTAIN. EXPECT THE WARM LAYER ALOFT TO SUPPORT LIQUID TO THE
SURFACE FROM NORTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA THROUGH
10-12 UTC...BEFORE A TRANSITION TO A SLEET AND SNOW MIX AND AN
EVENTUAL END TO PRECIPITATION WITH A DRY SLOT OVERTAKING THE AREA.
FOR LOCATIONS ALONG AND NORTH OF HIGHWAYS 2 AND
52....PRECIPITATION IS EXPECTED TO BE ALL SNOW...WITH A SLIGHT
CHANCE FOR FREEZING DRIZZLE GIVEN LOW LEVEL SATURATION WARMER
THAN -10 C UNTIL THE FULL COLUMN CAN SATURATE AND SUPPORT ICE
CRYSTALS TO THE GROUND. THE 18 UTC GFS/NAM HAVE BOTH COME IN WITH
HIGHER QPF...ESPECIALLY ACROSS THE JAMES RIVER VALLEY INTO THE
TURTLE MOUNTAINS IN THE 06-12 UTC TIME FRAME. THIS TREND WILL HAVE
TO BE MONITORED IN THE 00 UTC RUNS...AS THIS WOULD LEAD TO HIGHER
SNOWFALL...AND POSSIBLE GREATER ICE ACCUMULATIONS IN THE SOUTHERN
JAMES RIVER VALLEY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 410 PM CST MON FEB 9 2015
...THE MAIN IMPACT IN THE LONG TERM IS COLD...
TUESDAY`S SYSTEM WILL DEPART THE REGION BY LATE TUESDAY NIGHT.
SCATTERED LIGHT SNOW WILL DIMINISH THROUGH THE EVENING HOURS WITH
LITTLE TO NO ADDITIONAL ACCUMULATION EXPECTED.
THE REST OF THE LONG TERM FORECAST LOOKS RATHER COLD ACROSS THE
EAST AND MILD ACROSS THE SOUTHWEST. A COLD AND DRY ARCTIC AIRMASS
WILL ENTER WEDNESDAY INTO THURSDAY. A STRONG SURFACE HIGH WILL
SETTLE ACROSS THE AREA THURSDAY MORNING...WHICH COULD LEAD TO VERY
COLD TEMPERATURES...AROUND 20 BELOW...ACROSS NORTH CENTRAL NORTH
DAKOTA.
A WARM FRONT IS THEN EXPECTED TO ENTER WESTERN NORTH DAKOTA
THURSDAY AFTERNOON AND EVENING WHICH SHOULD BRING MUCH WARMER
TEMPERATURES WESTERN NORTH DAKOTA. OVERALL THE LONG TERM LOOKS
RATHER DRY...WITH A FEW FLURRIES POSSIBLE THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CST MON FEB 9 2015
LIFR TO VLIFR CIGS AND IFR/LIFR VSBYS WILL DOMINATE THE TERMINALS
THROUGH TUESDAY MORNING. A WINTRY MIX OF LIGHT FREEZING RAIN AND
SNOW WILL ALSO IMPACT THE TERMINALS MONDAY NIGHT AND TAPER OFF FROM
WEST TO EAST THROUGH 18Z TUESDAY. GUSTY NORTHWEST WINDS TO 30KT WILL
TAKE CONTROL TUESDAY AFTERNOON THROUGH TUESDAY EVENING. CIGS WILL
LIFT TO MVFR BY MID TO LATE TUESDAY AFTERNOON AND REMAIN THERE
THROUGH THE END OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON CST /11 AM MST/ TUESDAY FOR
NDZ019>022-034>036-042-045>047-050.
FREEZING RAIN ADVISORY UNTIL 6 AM CST /5 AM MST/ TUESDAY FOR
NDZ001-009-010-017-018-033-041.
WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR NDZ002-003-
011.
WINTER WEATHER ADVISORY UNTIL 6 PM CST TUESDAY FOR NDZ004-005-
012-013-023-025-037-048-051.
&&
$$
UPDATE...KS
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1144 PM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 1143 PM CST MON FEB 9 2015
UPDATED POPS FOR SLOWER PRECIP MOVEMENT INTO THE AREA FOR THE REST
OF THE NIGHT. SOME FREEZING DRIZZLE HAS DEVELOPED AHEAD OF MAIN
SYSTEM. WILL INTRODUCE FREEZING DRIZZLE MAINLY OVER THE SOUTH AND
EAST OVERNIGHT.
UPDATE ISSUED AT 1004 PM CST MON FEB 9 2015
TEMPS CONTINUE TO RISE SLOWLY THIS EVENING. BIS AND ABR OBSERVED
SOUNDINGS INDICATED A SHALLOW MOIST LAYER BELOW 875 HPA WITH A SHARP
INVERSION AT 875 HPA. ALSO A DRY LAYER FROM 875 UP TO 500/550 HPA.
COMPARING OBSERVED SOUNDING WITH THE RUC, THE RUC APPEARED TO CATCH
THE WARM AIR ALOFT BEST THIS EVENING. SOME FREEZING PRECIP WILL BE
POSSIBLE OVER THE FAR SOUTHWEST ZONES LATER TONIGHT. NO OTHER
CHANGES MADE.
UPDATE ISSUED AT 700 PM CST MON FEB 9 2015
WILL TWEAK WINDS A BIT FOR TONIGHT. OTHERWISE LITTLE CHANGE TO THE
CURRENT FORECAST AT THIS UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 345 PM CST MON FEB 9 2015
WATER VAPOR IMAGERY DEPICTS A COUPLE STRONG UPPER WAVES THAT WILL
AFFECT THE REGION. MODELS ALL AGREE THAT A BAND OF MODERATE TO
HEAVY PRECIPITATION WILL MOVE THROUGH THE REGION LATER TONIGHT INTO
TUESDAY. HOWEVER...EACH SOLUTION HAS ITS OWN IDEA WITH REGARDS TO
P-TYPE...AND QPF AMOUNTS. GIVEN THE FACT THAT THERE WILL BE TWO
WAVES...AND THE INTERACTION AND EXACT TIMING OF THESE WAVES WILL
AFFECT THE DETAILS...THE UNCERTAINTY AMONG THE MODELS MAKES
SENSE. WITH THAT SAID...ATTEMPTING TO DECIDE THE FORECAST
DETAILS...HEADLINES...AND THE OVERALL MESSAGE IS DIFFICULT.
SNOW AMOUNTS...THIS SYSTEM WILL BE MOSTLY A QUICK MOVING WARM AIR
ADVECTION EVENT. PWATS WILL BE HIGH (ABOVE 0.5 INCH)...AND THERE
WILL BE POCKETS OF STRONGER FORCING JUST AHEAD OF EACH UPPER WAVE.
SNOW RATIOS WILL BE LOWER...AND GIVEN THE AVERAGE QPF AMONG THE
MODELS MOST AREAS WILL LIKELY RECEIVE 0.20 TO 0.30 INCHES PRECIP.
WHERE ALL SNOW OCCURS...THIS WOULD LEAD TO 2-4 INCHES...WHICH
WOULD OCCUR IN A SHORT PERIOD OF TIME GIVEN THE EXPECTED
INTENSITY. WITH THAT SAID...IN THOSE POCKETS OF STRONGER FORCING
SLIGHTLY HIGHER SNOWFALL AMOUNT UP TO 5 INCHES SHOULD BE
POSSIBLE.
FREEZING RAIN/SLEET POTENTIAL...MOST GUIDANCE INDICATE A STRONGER
SIGNAL FOR FREEZING RAIN ACROSS A PORTION OF SOUTHEAST NORTH
DAKOTA. THE MAIN QUESTION IS...GIVEN THE STRENGTH OF THE UPPER
WAVE...WILL THE ABOVE FREEZING WARM LAYER ALOFT ADVECT FURTHER
NORTH/EAST THAN EXPECTED? THE ANSWER IS MOST LIKELY YES...BUT HOW
FAR? DID ADJUST FREEZING RAIN/SLEET CHANCES TO ACCOUNT FOR THIS
POSSIBILITY (JUST SOUTH OF DEVILS LAKE AND INTO THE SOUTHERN RED
RIVER VALLEY)...AND ATTEMPTED TO MESSAGE THESE CHANCES
APPROPRIATELY. SNOW AMOUNTS IN THESE AREAS WILL DEPEND ON WHEN/IF
A SWITCH OVER TO SNOW OCCURS...AND ICE/SNOW AMOUNTS WILL NEED TO
BE REFINED ONCE MORE CONFIDENCE IS OBTAINED.
GIVEN THE ABOVE EXPECTED CONDITIONS...ISSUED A WINTER WEATHER
ADVISORY FOR THE ENTIRE AREA. SEGMENTED THE WSW BASED ON EXPECTED
IMPACTS AND TIMING. EVEN WITH LOW CONFIDENCE IN THE DETAILS...MOST
AREAS WILL RECEIVE 2-4 INCHES OF SNOW IN A BRIEF PERIOD OF
TIME...WHICH WILL INCREASE IMPACTS (NOT TO MENTION THE FREEZING
RAIN ACROSS A PORTION OF THE REGION).
A QUICK BURST OF STRONG LOW LEVEL COLD AIR ADVECTION WILL CAUSE A
PERIOD OF STRONGER NORTH WINDS TUESDAY EVENING...AND HUNG ONTO THE
ADVISORY FOR AREAS ALONG AND WEST OF THE VALLEY TO ACCOUNT FOR
BLOWING SNOW AND REDUCED VSBY.
WEAK WARM AIR ADVECTION THIS EVENING MAY LEAD TO FLURRIES/FZDZ.
MENTIONED THIS POSSIBLY IN THE GRIDS...AND IF IT DOES MATERIALIZE
THE START TIME OF THE ADVISORY MAY NEED TO BE MOVED UP. MOST
LIKELY LOCATION FOR FREEZING DRIZZLE WILL BE THE SOUTHERN VALLEY
WHERE THE AVERAGE TEMPERATURE OF THE LOW LEVEL SATURATED LAYER
WILL BE WARMER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 PM CST MON FEB 9 2015
WEDNESDAY-THURSDAY...ANOTHER SURGE OF CAA WED AFTERNOON COULD LEAD
TO GUSTY WINDS AND BLOWING SNOW. OTHERWISE...ANTICIPATE SFC HIGH
PRESSURE AND BELOW NORMAL TEMPERATURES. WIND CHILL ADVISORY
CRITERIA POSSIBLE WED NIGHT.
THURSDAY NIGHT-MONDAY...PRETTY MUCH REMAIN IN NORTHWEST FLOW
ALOFT SO NO DIFFERENCES FROM PREVIOUS FEW DISCUSSIONS. MAIN
QUESTIONS REMAIN TIMING OR RESOLVING THE INDIVIDUAL WAVES AND
TEMPS. MODELS INDICATE WARM ADVECTION THU NIGHT WHICH COULD RESULT
IN SOME VERY LIGHT SNOW ACROSS THE EAST/NE. COULD BE A LITTLE
GUSTY ON FRI BEFORE THE SFC HIGH BUILDS IN FRI NIGHT. ANOTHER WAVE
BRINGS A SHOT AT SOME LIGHT PCPN SAT NIGHT OR SUNDAY FOLLOWED BY
ANOTHER SHOT MAINLY SOUTH OF THE FA ON MONDAY. QUITE A ROLLER
COASTER RIDE FOR TEMPS DEPENDENT ON THE TIMING OF THESE
SYSTEMS...WITH WARMER TEMPS AHEAD AND COOLER TEMPS BEHIND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1143 PM CST MON FEB 9 2015
IFR CONDITIONS ARE MOSTLY OVER THE ND SIDE OF THE RED RIVER. MVFR
ARE OVER THE MN SIDE. VFR CONDITIONS ARE OVER THE SOUTHEAST ZONES.
EXPECT CLEARING TO CONTINUE OVER THE SOUTHEAST ZONES. MVFR
CONDITIONS ON THE MN SIDE SHOULD MOVE SLOWLY NORTH. IFR CONDITIONS
OVER ND SIDE WILL SHIFT EAST OVERNIGHT AND TUE OVER MOST OF THE
AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY FROM 3 AM TUESDAY TO 4 AM CST WEDNESDAY
FOR NDZ006-007-014-015-024-026-028>030-038-039-049-052>054.
WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO 4 AM CST WEDNESDAY
FOR NDZ008-016-027.
MN...WINTER WEATHER ADVISORY FROM 3 AM TUESDAY TO 4 AM CST WEDNESDAY
FOR MNZ002-003-029.
WINTER WEATHER ADVISORY FROM 9 AM TO 9 PM CST TUESDAY FOR MNZ005-
006-008-009-013>017-022>024-027-028-030>032-040.
WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO 4 AM CST WEDNESDAY
FOR MNZ001-004-007.
&&
$$
UPDATE...HOPPES
SHORT TERM...TG
LONG TERM...GODON/TG
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
314 PM EST TUE FEB 10 2015
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT. ARCTIC FRONTS CROSSES WEDNESDAY
NIGHT AND AGAIN ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM THE
MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR NW
COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER AIR
FROM THE WEST. THE RAP HAS THE BEST HANDLE ON THIS...BUT THATS NOT
SAYING MUCH. MOST GUIDANCE HAS BEEN TERRIBLE WITH RESPECT TO THE
CLEARING OF THE LOW CLOUDS. MOISTURE IS EXPECTED TO HOLD LONGER IN
THE MNTS...WHERE LOW CEILINGS WILL PERSIST UNTIL WED MORNING.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLGHT CHC POPS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
ACTIVE AND COLD WEATHER PATTERN REMAINS IN THE SHORT TERM AS A
BARRAGE OF UPPER LEVEL WAVES WILL REINFORCE THE MEAN TROF IN THE
EAST. ANOTHER WEAK WAVE WILL PASS JUST NORTH OF THE FORECAST AREA
WEDS NIGHT AND AGAIN WILL DEAMPLIFY AS ON APPROACH. THIS
DEAMPLIFICATION IS DUE TO THE THIRD AND BY FAR MOST VIGOROUS WAVE
DROPPING IN QUICKLY BEHIND IT. EXPECT LIGHT RAIN CHANGING OVER TO
LIGHT SNOW FOR MAINLY NRN PORTIONS OF THE CWA THROUGH THE PRE-DAWN
HOURS THURS.
AROUND DAWN THURS...CONDITIONS WILL DETERIORATE VERY QUICKLY. AS
AN AMPLIFYING TROF DROPS THROUGH THE WRN GREAT LAKES AND TRIES TO
CLOSE OFF AT 500MB. THIS WILL SEND A A VIGOROUS WAVE THROUGH THE
FORECAST AREA...USHERING IN A COLD FRONT WITH A VASTLY DIFFERENT
AIR MASS BEHIND IT. TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE
WITH THURS HIGHS MORE THAN LIKELY REALIZED NEAR SUNRISE.
ORIENTED ALONG THE COLD FRONT...SNOW SHOWERS WILL OVERTAKE THE
REGION FROM W TO E QUICKLY DURING THE DAYLIGHT HOURS THURS. BEHIND
THE COLD FRONT...850MB TEMPS WILL DROP SHARPLY INTO THE -10 TO
-15C RANGE ALLOWING CRYSTAL GROWTH TO BE MAXIMIZED. WITH LAPSE
RATES STEEPENING...CONVECTIVE SNOW SQUALLS WILL PERSIST THROUGH THURS
EVENING. THE BTV SNOW SQUALL PARAMETER DRIVEN BY THE 12Z NAM DATA
SHOWS A BULLSEYE OF GREATER THAN 4 FOR MUCH OF THE AFTERNOON
THURS...FURTHER DIAGNOSING A PRIME SET UP FOR SNOW SQUALLS TO
EXIST.
MOISTURE IS DRIVEN INTO THE MOUNTAINS THROUGH THURS NIGHT...AND
SNOW SHOWERS SHOULD PERSIST THERE THROUGH MIDNIGHT THURS.
ELSEWHERE...THE MOISTURE QUICKLY DRIES UP...BUT THE AIRMASS IS
COLD ENOUGH THAT LIGHT SNOW SHOWERS OR FLURRIES COULD PERSIST
THROUGH LATE THURS EVENING.
EXPECT MOUNTAINOUS LOCATIONS TO BE IN THE SINGLE DIGITS TO BELOW
ZERO...AS WELL AS SINGLE DIGITS IN SOUTHEAST OHIO FRIDAY MORNING.
ADDING TO THIS IS THE STRONG...GUSTY WINDS THAT WILL DRIVE WIND
CHILLS TO NEAR 0 ACROSS THE LOWLANDS AND WELL BELOW 0 IN THE
MOUNTAINS. STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE MET
ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN WV.
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEAN TROF PERSISTS ACROSS THE ERN CONUS THROUGH THE EXTENDED
PERIOD KEEPING A PROLONGED COLD AND DISTURBED WEATHER PATTERN.
BRIEF SFC HIGH FRI WILL BE FOLLOWED QUICKLY BY YET ANOTHER VERY
STRONG CLOSED UPPER LOW THIS WEEKEND. THIS WILL ONCE AGAIN
REINFORCE THE COLD AIR...BRINGING THE COLDEST TEMPERATURES OF THE
WEEK TO OUR AREA. MORE LIGHT SNOW IS EXPECTED THROUGH THE
WEEKEND...BUT THE MAIN STORYLINE WILL BE THE COLD TEMPERATURES.
NEXT WEEK BEGINS WITH A VERY BRIEF SPELL OF ZONAL FLOW ALOFT AND
TEMPERATURE MODERATION BEFORE YET ANOTHER INTRUSION OF ARCTIC AIR.
MAINLY FOLLOW WPC FOR WEATHER VARIABLES IN THE EXTENDED...WITH
CONSIDERABLE MODEL AGREEMENT BETWEEN THE GFS/ECMWF.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
IFR CEILINGS CONTINUE AT MOUNTAIN SITES WITH LITTLE OR NO
IMPROVEMENT EXPECTED THIS AFTERNOON. CONDITIONS WILL DETERIORATE
AGAIN AT BOTH SITES OVERNIGHT. REMAINING TERMINALS HAVE IMPROVED TO
MVFR/MOSTLY VFR CEILINGS AS DRY AIR INTRUDES LOW LEVELS. LOW LAND
SITES ARE EXPECTED TO DROP BACK TO MOSTLY MVFR CONDITIONS AT TIMES
AS TEMPERATURES DECREASE OVERNIGHT. ALL TERMINAL SITES WILL SEE
GRADUAL IMPROVEMENT AS FLOW BECOMES SW WITH SURFACE HIGH PRESSURE IN
PLACE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: TIMING OF IMPROVEMENT MAY VARY. MVFR CIGS MAY
NOT MATERIALIZE TONIGHT. IFR FOG IN THE MOUNTAINS OVERNIGHT
TONIGHT MAY NOT HAPPEN EITHER.
AFTER 18Z WEDNESDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY AND
AGAIN SATURDAY AFTERNOON...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TAX
NEAR TERM...TAX
SHORT TERM...TAX
LONG TERM...TAX
AVIATION...RG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
132 PM EST TUE FEB 10 2015
.SYNOPSIS...
DRIER AIR GRADUALLY PUSHES SOUTH TODAY...AHEAD OF HIGH PRESSURE
BUILDING IN TONIGHT. ARCTIC FRONTS CROSS WEDNESDAY NIGHT AND AGAIN
ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM THE
MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR NW
COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER AIR
FROM THE WEST. THE RAP HAS A PRETTY GOOD HANDLE ON THIS AND WILL
BE FOLLOWED FOR THIS TREND THROUGH THE EVENING. MOISTURE WILL HOLD
LONGER IN THE MNTS WHERE EARLIER DRIZZLE AND FOG WERE OBSERVED.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLGHT CHC POPS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
ACTIVE AND COLD WEATHER PATTERN REMAINS IN THE SHORT TERM AS A
BARRAGE OF UPPER LEVEL WAVES WILL REINFORCE THE MEAN TROF IN THE
EAST. ANOTHER WEAK WAVE WILL PASS JUST NORTH OF THE FORECAST AREA
WEDS NIGHT AND AGAIN WILL DEAMPLIFY AS ON APPROACH. THIS
DEAMPLIFICATION IS DUE TO THE THIRD AND BY FAR MOST VIGOROUS WAVE
DROPPING IN QUICKLY BEHIND IT. EXPECT LIGHT RAIN CHANGING OVER TO
LIGHT SNOW FOR MAINLY NRN PORTIONS OF THE CWA THROUGH THE PRE-DAWN
HOURS THURS.
AROUND DAWN THURS...CONDITIONS WILL DETERIORATE VERY QUICKLY. AS
AN AMPLIFYING TROF DROPS THROUGH THE WRN GREAT LAKES AND TRIES TO
CLOSE OFF AT 500MB. THIS WILL SEND A A VIGOROUS WAVE THROUGH THE
FORECAST AREA...USHERING IN A COLD FRONT WITH A VASTLY DIFFERENT
AIR MASS BEHIND IT. TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE
WITH THURS HIGHS MORE THAN LIKELY REALIZED NEAR SUNRISE.
ORIENTED ALONG THE COLD FRONT...SNOW SHOWERS WILL OVERTAKE THE
REGION FROM W TO E QUICKLY DURING THE DAYLIGHT HOURS THURS. BEHIND
THE COLD FRONT...850MB TEMPS WILL DROP SHARPLY INTO THE -10 TO
-15C RANGE ALLOWING CRYSTAL GROWTH TO BE MAXIMIZED. WITH LAPSE
RATES STEEPENING...CONVECTIVE SNOW SQUALLS WILL PERSIST THROUGH THURS
EVENING. THE BTV SNOW SQUALL PARAMETER DRIVEN BY THE 12Z NAM DATA
SHOWS A BULLSEYE OF GREATER THAN 4 FOR MUCH OF THE AFTERNOON
THURS...FURTHER DIAGNOSING A PRIME SET UP FOR SNOW SQUALLS TO
EXIST.
MOISTURE IS DRIVEN INTO THE MOUNTAINS THROUGH THURS NIGHT...AND
SNOW SHOWERS SHOULD PERSIST THERE THROUGH MIDNIGHT THURS.
ELSEWHERE...THE MOISTURE QUICKLY DRIES UP...BUT THE AIRMASS IS
COLD ENOUGH THAT LIGHT SNOW SHOWERS OR FLURRIES COULD PERSIST
THROUGH LATE THURS EVENING.
EXPECT MOUNTAINOUS LOCATIONS TO BE IN THE SINGLE DIGITS TO BELOW
ZERO...AS WELL AS SINGLE DIGITS IN SOUTHEAST OHIO FRIDAY MORNING.
ADDING TO THIS IS THE STRONG...GUSTY WINDS THAT WILL DRIVE WIND
CHILLS TO NEAR 0 ACROSS THE LOWLANDS AND WELL BELOW 0 IN THE
MOUNTAINS. STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE MET
ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN WV.
WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS SHOW STRONG UPPER TROUGH MOVING EAST OF THE APPALACHIANS BY
00Z FRIDAY. MUCH FRIGID AIR RUSHES IN UNDER NORTHWEST FLOW
BRINGING H850 TEMPERATURES INTO THE MINUS 20C. LINGERING MOISTURE
MAY STILL PRODUCE LIGHT FLUFFY SNOW OR FLURRIES ALONG THE EASTERN
MOUNTAINS ENDING TOWARDS FRIDAY MORNING. STRONG GUSTY WINDS AND
SFC TEMPERATURES FROM THE TEENS TO THE SINGLE DIGITS LOWLANDS AND
EVEN SINGLE DIGITS BELOW WILL PRODUCE DANGEROUS WIND CHILL VALUES
THURSDAY NIGHT INTO FRIDAY MORNING OVER THE NORTHEAST MOUNTAINS.
THERE COULD BE A SLIGHT WARM UP POSSIBLE MAINLY ACROSS THE
LOWLANDS SATURDAY NIGHT. ANOTHER BUT EVEN COLDER ARCTIC BLAST
EXPECTED AS AN UPPER LEVEL LOW PRESSURE CROSSES JUST NORTH OF THE
AREA SATURDAY NIGHT INTO SUNDAY...WITH EVEN COLDER AIR AT H850
REACHING THE MINUS 28C MARK. WIND CHILL ADVISORIES MAY BE NEEDED
FOR THESE TWO EVENTS ACROSS THE NORTHEAST MOUNTAINS AND HAVE BEEN
MENTIONED IN THE HWO.
A WEAK CLIPPER CROSSES THROUGH THE WEEKEND WITH LOW CHANCES OF
PCPN.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
IFR CEILINGS CONTINUE AT MOUNTAIN SITES WITH LITTLE OR NO
IMPROVEMENT EXPECTED THIS AFTERNOON. CONDITIONS WILL DETERIORATE
AGAIN AT BOTH SITES OVERNIGHT. REMAINING TERMINALS HAVE IMPROVED TO
MVFR/MOSTLY VFR CEILINGS AS DRY AIR INTRUDES LOW LEVELS. LOW LAND
SITES ARE EXPECTED TO DROP BACK TO MOSTLY MVFR CONDITIONS AT TIMES
AS TEMPERATURES DECREASE OVERNIGHT. ALL TERMINAL SITES WILL SEE
GRADUAL IMPROVEMENT AS FLOW BECOMES SW WITH SURFACE HIGH PRESSURE IN
PLACE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: TIMING OF IMPROVEMENT MAY VARY. MVFR CIGS MAY
NOT MATERIALIZE TONIGHT. IFR FOG IN THE MOUNTAINS OVERNIGHT
TONIGHT MAY NOT HAPPEN EITHER.
AFTER 18Z WEDNESDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY AND
AGAIN SATURDAY AFTERNOON...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL/TAX
NEAR TERM...TAX
SHORT TERM...TAX
LONG TERM...ARJ
AVIATION...RG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1124 AM EST TUE FEB 10 2015
.SYNOPSIS...
DRIER AIR GRADUALLY PUSHES SOUTH TODAY...AHEAD OF HIGH PRESSURE
BUILDING IN TONIGHT. ARCTIC FRONTS CROSS WEDNESDAY NIGHT AND AGAIN
ON SATURDAY....AND MAYBE EVEN AGAIN NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
CURRENT SATELLITE IMAGERY SHOWS THE AREA BLANKETED BY LLVL STRATUS
AIDED BY RESIDUAL MOISTURE FROM THE SFC LOW NOW PULLING AWAY FROM THE
MID-ATLANTIC COAST. SOME CLEARING IS BEING OBSERVED IN THE FAR NW
COUNTIES OF OUR CWA AS THE MOISTURE IS SLOWLY ERODED BY DRIER AIR
FROM THE WEST. THE RAP HAS A PRETTY GOOD HANDLE ON THIS AND WILL
BE FOLLOWED FOR THIS TREND THROUGH THE EVENING. MOISTURE WILL HOLD
LONGER IN THE MNTS WHERE EARLIER DRIZZLE AND FOG WERE OBSERVED.
RELATIVELY QUIET NIGHT ON TAP WITH CLOUD COVER CONTINUING TO ERODE
AS THE UPPER RIDGE SETTLES IN. TEMPERATURES WILL REMAIN ON THE
COOL SIDE TONIGHT AS WE DECOUPLE...BUT WAA BEGINS TO KICK FOR
DAYBREAK AND MIXING WILL BRING WEDS TEMPS BACK UP INTO THE 40S FOR
MOST LOCATIONS.
FOR AS LONG AS IT TOOK THE SW RIDGE TO BUILD IN AND DRY THINGS
OUT...IT UNFORTUNATELY WONT STAY LONG. THE FIRST IN A SERIES OF
UPPER LEVEL WAVES WILL ARRIVE EARLY WEDS AFTERNOON...BRINGING
MAINLY CLOUDS BACK TO THE AREA. AS THE UPPER LEVEL WAVE
ARRIVES...IT DEAMPLIFIES AND THE FLOW ALOFT BECOMES MORE ZONAL.
STILL...SOME WEAK MID-LEVEL CONVERGENCE EXISTS AHEAD OF THE FIRST
WAVE AND MODELS HAVE CONSISTENTLY INCLUDED QPF WITH LIGHT SHOWERS
WEDS EVENING. NOT SOLD ON THE IDEA...BUT WITH THIS FEATURE EVEN
RESOLVED IN THE COARSER SUITE OF MODELS...THOUGHT IS WAS PRUDENT
TO INTRODUCE SLGHT CHC POPS.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
ACTIVE AND COLD WEATHER PATTERN IN THE SHORT TERM PERIOD AS A COLD
FRONT AND UPPER TROUGH DIG SOUTH ACROSS THE REGION THURSDAY INTO
FRIDAY. EXPECT A SHARP DROP IN TEMPERATURES THROUGHOUT THE DAY ON
THURSDAY...AND A GRADUAL CHANGE OVER TO SNOW...WITH LIGHT
ACCUMULATIONS POSSIBLE. IN ADDITION...GUSTY WINDS WILL MAKE FOR A
RATHER BLUSTERY DAY AND NIGHT...WITH -21C AIR AT 850MB PROGGED TO
MOVE INTO THE AREA THURSDAY NIGHT...EXPECT MOUNTAINOUS LOCATIONS TO
BE IN THE SINGLE DIGITS TO BELOW ZERO...AS WELL AS SINGLE DIGITS IN
SOUTHEAST OHIO FRIDAY MORNING. THIS...COMBINED WITH THE CONTINUED
GUSTY WINDS...AM STILL EXPECTING WIND CHILL ADVISORY CRITERIA TO BE
MET ACROSS MUCH OF THE MOUNTAINOUS COUNTIES AND PARTS OF NORTHERN
WV. WILL CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS SHOW STRONG UPPER TROUGH MOVING EAST OF THE APPALACHIANS BY
00Z FRIDAY. MUCH FRIGID AIR RUSHES IN UNDER NORTHWEST FLOW
BRINGING H850 TEMPERATURES INTO THE MINUS 20C. LINGERING MOISTURE
MAY STILL PRODUCE LIGHT FLUFFY SNOW OR FLURRIES ALONG THE EASTERN
MOUNTAINS ENDING TOWARDS FRIDAY MORNING. STRONG GUSTY WINDS AND
SFC TEMPERATURES FROM THE TEENS TO THE SINGLE DIGITS LOWLANDS AND
EVEN SINGLE DIGITS BELOW WILL PRODUCE DANGEROUS WIND CHILL VALUES
THURSDAY NIGHT INTO FRIDAY MORNING OVER THE NORTHEAST MOUNTAINS.
THERE COULD BE A SLIGHT WARM UP POSSIBLE MAINLY ACROSS THE
LOWLANDS SATURDAY NIGHT. ANOTHER BUT EVEN COLDER ARCTIC BLAST
EXPECTED AS AN UPPER LEVEL LOW PRESSURE CROSSES JUST NORTH OF THE
AREA SATURDAY NIGHT INTO SUNDAY...WITH EVEN COLDER AIR AT H850
REACHING THE MINUS 28C MARK. WIND CHILL ADVISORIES MAY BE NEEDED
FOR THESE TWO EVENTS ACROSS THE NORTHEAST MOUNTAINS AND HAVE BEEN
MENTIONED IN THE HWO.
A WEAK CLIPPER CROSSES THROUGH THE WEEKEND WITH LOW CHANCES OF
PCPN.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
DENSE FOG IN NRLY FLOW AND SATURATED LOW LEVELS AT BKW WILL LIFT
DURING THE MORNING HOURS AND CIGS WILL IMPROVE TO MVFR. FARTHER N
UP THE MOUNTAINS...IFR CIGS AND MVFR VSBY AT EKN WILL IMPROVE THIS
MORNING...WITH MVFR CIGS AND VFR VSBY THIS AFTERNOON. CONDITIONS
WILL DETERIORATE IN THE MOUNTAINS /BOTH OF THESE SITES/ LATE
TONIGHT WITH IFR FOG BRIEFLY POSSIBLE BEFORE DAWN. THE CLOUDS MAY
START TO BREAK RIGHT AT THE END OF THE PERIOD AT BKW.
OUT ACROSS THE LOWLANDS...MVFR CIGS THIS MORNING WILL IMPROVE TO VFR
FOR THIS AFTERNOON. THEY WILL DROP BACK TO MVFR TONIGHT BUT THEN
CLEARING WILL BE TAKING PLACE W TO E LATE TODAY AND TONIGHT.
N SFC FLOW THROUGH TODAY WILL BECOME LIGHT AND VARIABLE TONIGHT.
LIGHT N FLOW ALOFT WILL VEER TO LIGHT NE THIS AFTERNOON AND THEN TO
LIGHT E TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIO: TIMING OF IMPROVEMENT THIS MORNING MAY VARY.
MVFR CIGS MAY NOT MATERIALIZE TONIGHT. IFR FOG IN THE MOUNTAINS
OVERNIGHT TONIGHT MAY NOT HAPPEN EITHER.
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.
AFTER 18Z WEDNESDAY...
IFR IN THE MOUNTAINOUS COUNTIES IN SNOW SHOWERS ON THURSDAY AND
AGAIN SATURDAY AFTERNOON...EACH IN THE WAKE OF ARCTIC FRONTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TAX/TRM/SL
NEAR TERM...TAX
SHORT TERM... SL
LONG TERM... ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS TULSA OK
1117 PM CST MON FEB 9 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
DECK OF LOW CLOUDS CONTINUES TO VERY SLOWLY SPREAD TOWARD THE WEST
BUT IT REMAINS UNCERTAIN JUST HOW FAR WEST IT WILL EXPAND TONIGHT.
INCREASING S COMPONENT TO CLOUD-LEVEL WINDS WILL ULTIMATELY HALT
ITS PROGRESS BUT NOT BEFORE AT LEAST A FEW HOURS OF MVFR CEILINGS
AT KROG/KXNA...LESS CERTAIN FOR KFYV. WILL ALSO SEE SOME REDUCED
VIS AT SOME SITES OVERNIGHT. OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL.
&&
.PREV DISCUSSION... /ISSUED 853 PM CST MON FEB 9 2015/
DISCUSSION...
ANOTHER QUIET EVENING ACROSS THE FORECAST AREA. DECK OF LOW CLOUDS
THAT BACK-DOORED INTO OUR AREA THIS MORNING HAD RETREATED DURING
THE DAYTIME HOURS...BUT HAS SINCE SAGGED BACK TO THE SOUTHWEST
AGAIN. THE LATEST HRRR SHOWS SOME PENETRATION INTO FAR NE OK AND
NW AR...BUT ONLY TEMPORARILY. WE SHALL SEE. IT IS OFTEN DIFFICULT
FOR A CLOUD DECK TO BREAK UP AT NIGHT. I ALSO ADDED SOME FOG/CLOUD
COVER WESTWARD ALONG THE KS BORDER BASED ON PERSISTENT HRRR
FORECAST. SKY GRIDS MAY NEED CONTINUAL TWEAKING BASED ON WHAT THE
EXTENSIVE LOW CLOUD DECK TO OUR NORTHEAST DOES.
LACY
PREV DISCUSSION... /ISSUED 530 PM CST MON FEB 9 2015/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE MOST PART VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD. POSSIBLE EXCEPTIONS WILL BE THAT PARTS OF NW ARKANSAS AND
FAR NORTHERN OK COULD SEE PATCHY FOG LATER TONIGHT....AND AREA OF
LOW CLOUDS MAY SPREAD BACK WEST NEAR KS/MO BORDERS OVERNIGHT AS
LOW LEVEL WINDS SWITCH AROUND TO THE EAST THEN SOUTHEAST. BOTH
SCENARIOS BRING RISK OF MVFR CONDITIONS BETWEEN APPROX 06-15Z.
PREV DISCUSSION... /ISSUED 328 PM CST MON FEB 9 2015/
DISCUSSION...
SFC RIDGE AXIS OVERHEAD TODAY WITH GOOD EAST/WEST GRADIENT IN
AFTERNOON TEMPS. RIDGE TO SHIFT EASTWARD ON TUESDAY ALLOWING
WARMER TEMPS AND RETURN TO SOUTHERLY WINDS. PATCHY FOG MAY DEVELOP
TONIGHT BEFORE WINDS PICK UP OTHERWISE CLEAR SKIES WILL PREVAIL.
COLD FRONT TO PUSH THROUGH THE AREA ON WEDNESDAY WITH A SLIGHT
CHANCE OF SHOWERS FOR SE OK / WESTERN AR...WITH NOTICEABLY COOLER
TEMPS EXPECTED ON THURSDAY. A BRIEF WARM UP IS LIKELY ON FRIDAY
BEFORE AN EVEN STRONGER COLD FRONT SWEEPS THROUGH THE AREA PUSHING
TEMPS BELOW NORMAL FOR THE WEEKEND.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...14
AREA FORECAST DISCUSSION
NWS NORMAN OK
1048 PM CST MON FEB 9 2015
.AVIATION...
06Z TAFS...AS TEMPERATURES CONTINUE TO FALL AND MOISTURE
INCREASES SLIGHTLY...EXPECT PATCHY FOG TO PERSIST AND POSSIBLY
EXPAND FROM NORTH CENTRAL THROUGH CENTRAL AND NORTHWESTERN
OKLAHOMA. BRIEF MVFR/IFR CIGS MAY OCCUR IN THESE
AREAS...ESPECIALLY FROM NOW THROUGH 13Z TUES. BKN CIGS MAY ALSO
DEVELOP AT KPNC...BUT SHOULD GENERALLY REMAIN NORTHEAST OF
REMAINING TERMINALS. VFR CONDITIONS SHOULD RETURN BY 15Z TUES...WITH
LIGHT EAST WINDS SHIFTING TO THE SOUTH AND BECOMING BREEZY BY 16Z
TO 18Z. A WEAK FRONT/WIND SHIFT WILL BRING A NORTHERLY WIND SHIFT
TO KGAG/KWWR BY 19Z. THIS WIND SHIFT WILL THEN SPREAD SOUTHWARD
THROUGH TOMORROW EVENING.
&&
.PREV DISCUSSION... /ISSUED 944 PM CST MON FEB 9 2015/
DISCUSSION...
ONLY MINOR UPDATES TO THE PACKAGE THIS EVENING. AN AREA OF
RESTRICTED VISIBILITY HAS DEVELOPED IN NORTHERN OKLAHOMA AND
PORTIONS OF KANSAS INCLUDING KPNC. ALTHOUGH RAP AND HRRR SUGGEST
THAT ANY AREAS OF SIGNIFICANT FOG WILL REMAIN NORTH OF OKLAHOMA...
HAVE ADDED THE MENTION OF PATCHY FOG IN NORTH CENTRAL OKLAHOMA
GIVEN THE CURRENT REDUCTION OF VISIBILITY. HAVE ALSO REDUCED THE
FORECAST CLOUD COVER IN NORTHWEST OKLAHOMA LATER TONIGHT.
PREV DISCUSSION... /ISSUED 539 PM CST MON FEB 9 2015/
AVIATION...
00Z TAFS...VFR CONDITIONS WILL PERSIST THROUGH AROUND 09Z.
THEREAFTER...SOME PATCHY FOG MAY REDUCE VSBYS TO 2 TO 5 SM FROM
CENTRAL THROUGH NORTHERN AND WESTERN OKLAHOMA. IFR CIGS MAY ALSO
OCCUR BRIEFLY AT KCSM/KGAG EARLY TUESDAY. WINDS WILL GRADUALLY
SHIFT FROM EAST TO SOUTHEAST THROUGH THE NIGHT...BECOMING GUSTY
EARLY TUESDAY. A WEAK FRONT WILL RESULT IN AT NORTHERLY WIND SHIFT
BY 18Z AT KGAG AND KWWR. VFR CONDITIONS SHOULD RETURN EARLY
THURSDAY TO ANY TERMINALS THAT SEE PATCHY FOG.
PREV DISCUSSION... /ISSUED 344 PM CST MON FEB 9 2015/
DISCUSSION...
VERY MILD WEATHER WILL CONTINUE ONE MORE DAY...BEFORE A STRONG
COLD FRONT SENDS TEMPERATURES TUMBLING BACK DOWN TOWARD THE
SEASONAL AVERAGE. MOISTURE WILL BE MEAGER WITH THE FRONT...SO RAIN
CHANCES WILL BE LOW.
THE TEMPERATURE ROLLER COASTER WILL CONTINUE WITH A WARMING TREND
THURSDAY AND FRIDAY...FOLLOWED BY ANOTHER STRONG COLD FRONT ON
SATURDAY. THEN...ANOTHER WARMING TREND...AND ANOTHER COLD FRONT
EARLY NEXT WEEK...JUST BEYOND THE REACH OF THIS FORECAST. EACH
COLD FRONT WILL BRING A COLDER AIRMASS THAN THE ONE BEFORE. NONE
OF THEM ARE LIKELY TO INVOLVE ENOUGH MOISTURE FOR SIGNIFICANT
PRECIPITATION.
WINDS BEHIND EACH COLD FRONT WILL BE FAIRLY STRONG AND GUSTY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 41 69 43 55 / 0 0 0 10
HOBART OK 44 72 43 57 / 0 0 0 0
WICHITA FALLS TX 45 76 46 62 / 0 0 0 0
GAGE OK 41 68 37 53 / 0 0 0 10
PONCA CITY OK 35 63 39 50 / 0 0 0 10
DURANT OK 42 67 45 63 / 0 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/84
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
442 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA TODAY AND
WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOC CLIPPERS WILL
CARVE OUT A DEEP UPPER LVL TROUGH OVER THE NORTHEAST CONUS LATE
THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING COLD
BITTER AIR BACK INTO CENTRAL PENNSYLVANIA THROUGH THE SECOND HALF
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF THIS
TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
SOME CLEARING TO THE EAST AND SE. NOT IN A BIG RUSH TO BRING
MUCH CLEARING TO THE WEST...GIVEN WEATHER PATTERN AND TIME OF
DAY.
MINOR ADJUSTMENTS MADE TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
SUB VFR CONDS WILL CONTINUE AS LOW LEVEL MOISTURE REMAINS
ENTRENCHED BEHIND MONDAYS STORM SYSTEM. NO ACTIVE PCPN IS
AFFECTING THE AIRSPACE...AND NONE IS EXPECTED THROUGH TOMORROW
AFTERNOON. LOWEST CONDS...IFR OR LOWER CIGS...ARE AT BFD AND JST.
JST IS DUE TO FOG/MIST/HAZE DUE TO RESIDUAL MOISTURE FROM MELTING
SNOW...AND THICK LOW CLOUDS. EXPECT SLOW IMPROVING TREND FROM
NORTH TO SOUTH THIS AFTERNOON INTO TONIGHT WITH VFR RETURNING TO
MOST AREAS BY TUESDAY OVERNIGHT...AS HIGH PRESSURE BUILDS INTO THE
REGION.
JST AND BFD SHOULD IMPROVE 00Z TO 06Z...BUT CONDS MAY VERY WELL
GO LOW AGAIN TONIGHT ESPECIALLY AT KBFD AND KJST AS WINDS GO CALM
AND POSSIBLE MVFR TO A BRIEF PERIOD OF IFR REDEVELOPS TOWARDS
WEDNESDAY MORNING.
AROUND 12 TO 15Z CONDITIONS SHOULD IMPROVE WITH VFR DOMINATING
THE PATTERN TOMORROW. CONDITIONS WILL DETERIORATE AS ANOTHER
TROUGH DROPS THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA
WEDNESDAY NIGHT INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/CERU
NEAR TERM...FITZGERALD/CERU/MARTIN
SHORT TERM...LAMBERT
LONG TERM...FITZGERALD/LAMBERT
AVIATION...CERU/GARTNER/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
403 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA TODAY AND
WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOC CLIPPERS WILL
CARVE OUT A DEEP UPPER LVL TROUGH OVER THE NORTHEAST CONUS LATE
THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING COLD
BITTER AIR BACK INTO CENTRAL PENNSYLVANIA THROUGH THE SECOND HALF
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF
THIS TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE WAVE TRAIN OF ALBERTA CLIPPERS BEGINS WEDNESDAY NIGHT AND
THURSDAY. NOT MANY SIGNIFICANT CHANGES HAVE OCCURRED IN THE MODEL
CONSENSUS TRACK AND INTENSITY OF THESE FEATURES OVER THE PAST 24
HOURS...SO MINOR MODIFICATIONS TO POPS...TEMPS..AND WIND/WIND
CHILLS HAVE BEEN MADE WITH THIS ROUND OF GRIDDED DATA.
AFTER A BRIEF...SEVERAL-HOUR PERIOD OF WARM ADVECTION CLOUDS AND
A FEW AREAS OF LIGHT SNOW/SNOW SHOWERS ACROSS NRN AND WRN PENN
LATE WED/WED NIGHT...THE FIRST CLIPPER IS STILL TIMED TO PUSH THE
LEADING EDGE OF AN ARCTIC AIRMASS INTO THE COMMONWEALTH LATE WED
NIGHT AND THURSDAY MORNING.
TEMPS STARTING OUT IN THE 20S THURSDAY MORNING WILL BE FOLLOWED
BY GRADUALLY FALLING TEMPS ALL DAY /AT LEAST ACROSS CENTRAL AND
NWRN PENN/ WITH NUMEROUS SNOW SHOWERS FLYING ACROSS THE
ALLEGHENIES...AND FLURRIES/SCATTERED SNOW SHOWERS OCCURRING
THROUGHOUT THE CENTRAL RIDGE AND VALLEY REGION.
AN ACCUMULATION OF 1-3 INCHES APPEARS POSSIBLE ACROSS THE LAURELS
AND NW MTNS...WHILE JUST A COATING TO ONE HALF OF AN INCH IS
EXPECTED ELSEWHERE.
AS THE LEADING EDGE OF THE VERY COLD MID LEVEL AIR PUSHES SE
ACROSS THE STATE DURING PRIME HEATING OF THE LATE MORNING AND
AFTERNOON HOURS...850-500 MB LAPSE RATES WILL STEEPEN TO AROUND
6.5C/KM WHICH WILL SUPPORT SOME BRIEF...HEAVY SNOW SHOWERS/SQUALLS.
SHOULD THIS SCENARIO BECOME MORE EVIDENT...POPS ACROSS THE SE HALF
OF THE CWA WILL NEED TO BE INCREASED FOR ANTICIPATED LIGHT ACCUMS
OF SNOW.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
WIDESPREAD WIND CHILL ADVISORY VALUES LOOK PROBABLY THROUGHOUT THE
RIDGE AND VALLEY REGION LATE THURSDAY NIGHT/EARLY FRIDAY...WITH
WARNING CRITERIA /LESS THAN -25C/ POSSIBLE ACROSS PORTIONS OF THE
NORTH AND WEST. THE SUSQ VALLEY MAY ESCAPE THE BRUTALLY COLD WIND
CHILLS WITH APPARENT TEMPS OF -10 TO -14F.
LATER SHIFTS - OVERNIGHT TONIGHT OR WEDNESDAY WILL LIKELY BE
POSTING WIND CHILL WATCH/OR ADVISORY FOR THE AFOREMENTIONED
LOCATIONS.
THE ALLEGHENY PLATEAU. A BITING WIND WILL LIKELY ACCOMPANY THE
SUB- ZERO TEMPS...DUE TO TIGHT PRES GRADIENT WEST OF RAPIDLY
DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS STILL FCST TO
PLUMMET TO ARND -20C OVER THE AREA. HIGH TEMPS FRIDAY PROJECTED
TO VARY VARY FROM JUST THE SINGLE DIGITS ACROSS THE NORTHERN
MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS EAST ACROSS THE FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND
PARTLY TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE
NW MTNS MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU
THOUGH...SO HEDGED TOWARD MSTLY CLOUDY ACROSS THE NRN AND WRN MTNS
/BUT WITH LITTLE MORE THAN SOME FLURRIES/.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE NEXT CAR IN THE CLIPPER TRAIN RIDES ACROSS THE CWA LATE
FRIDAY NIGHT AND SATURDAY...ACCOMPANIED BY NUMEROUS SNOW
SHOWERS...OR EVEN A FEW PERIODS OF STEADY SNOW INTO SATURDAY
EVENING AS SOME MODEL GUIDANCE INDICATES A CLOSED MID/UPPER LOW
CENTER FORMING OVER CENTRAL/ERN PENN BEFORE SCOOTING QUICKLY EAST
OFF THE MID ATLANTIC COAST. AIR BEHIND THIS SYSTEM WILL BE EVEN A
FEW-SVRL DEG F COLDER THAN THE INITIAL LATE WEEK CLIPPER. TEMPS
SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW NORMAL VALUES/
SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS EMBEDDED IN THE
LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GRADUAL CLEARING FOR SUNDAY NIGHT/MONDAY AS A LARGE AREA OF HIGH
PRESSURE SETTLES SE ACROSS THE STATE. SHOULD THE WIND DIMINISH AND
SKIES CLEAR OUT QUICK ENOUGH...WIDESPREAD SUB-ZERO TEMPS ARE WOULD
BECOME LIKELY...WITH EVEN SOME RECORD MINS FOR THE DATE POSSIBLE.
FOR A QUICK EXAMPLE...WILLIAMSPORT`S LOW FOR FEB 16TH IS -5F SET
OVER A CENTURY AGO IN 1905...AND OUR FCST LOW THERE NEXT TUESDAY
MORNING IS IS -3F. GEFS MIN TEMP RANGE FOR KITP ON FEB 16TH IS
BETWEEN -3F AND -14F...SO I/M BEING OPTIMISTICALLY WARM- HEARTED
WITH THAT FCST LOW RIGHT AFTER V-DAY.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN U.S. A LITTLE FURTHER TO THE
WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING FOR
SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT HEADS
EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND AT
THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE CENTRAL
AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING ON
WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN AND
SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY REBOUND
BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SUB VFR CONDS WILL CONTINUE AS LOW LEVEL MOISTURE REMAINS
ENTRENCHED BEHIND MONDAYS STORM SYSTEM. NO ACTIVE PCPN IS
AFFECTING THE AIRSPACE...AND NONE IS EXPECTED THROUGH TOMORROW
AFTERNOON. LOWEST CONDS...IFR OR LOWER CIGS...ARE AT BFD AND JST.
JST IS DUE TO FOG/MIST/HAZE DUE TO RESIDUAL MOISTURE FROM MELTING
SNOW...AND THICK LOW CLOUDS. EXPECT SLOW IMPROVING TREND FROM
NORTH TO SOUTH THIS AFTERNOON INTO TONIGHT WITH VFR RETURNING TO
MOST AREAS BY TUESDAY OVERNIGHT...AS HIGH PRESSURE BUILDS INTO THE
REGION.
JST AND BFD SHOULD IMPROVE 00Z TO 06Z...BUT CONDS MAY VERY WELL
GO LOW AGAIN TONIGHT ESPECIALLY AT KBFD AND KJST AS WINDS GO CALM
AND POSSIBLE MVFR TO A BRIEF PERIOD OF IFR REDEVELOPS TOWARDS
WEDNESDAY MORNING.
AROUND 12 TO 15Z CONDITIONS SHOULD IMPROVE WITH VFR DOMINATING
THE PATTERN TOMORROW. CONDITIONS WILL DETERIORATE AS ANOTHER
TROUGH DROPS THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA
WEDNESDAY NIGHT INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/CERU
NEAR TERM...FITZGERALD/CERU
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
245 PM EST TUE FEB 10 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO PENNSYLVANIA TODAY AND
WEDNESDAY. A PAIR OF POTENT SHORTWAVES AND ASSOC CLIPPERS WILL
CARVE OUT A DEEP UPPER LVL TROUGH OVER THE NORTHEAST CONUS LATE
THIS WEEK THROUGH EARLY NEXT WEEK. THESE SYSTEMS WILL BRING COLD
BITTER AIR BACK INTO CENTRAL PENNSYLVANIA THROUGH THE SECOND HALF
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS A RIDGE OF HIGH PRESSURE REMAINS OVER THE REGION...LARGE SCALE
SUBSIDENCE DOMINATES THE FORECAST THROUGH TOMORROW. THE MAIN
CONCERN WILL BE HOW MUCH CLEARING IS OBSERVED. CURRENT HRRR AND
MODEL SOUNDINGS SUGGEST STRATOCU WILL CONTINUE THROUGH THE REST OF
THE AFTERNOON AND INTO THE EVENING. THE WINDS ARE COMING FROM THE
NORTH TO NORTHEAST...AND AS THEY SHIFT TO THE EAST...THERE WILL BE
SOME DRY AIR ADVECTION. THE THICKEST CLOUDS CONTINUE TO BE OVER
THE CENTRAL AND NW MTNS...ESPECIALLY THE LAURELS...WHERE LOW
STRATOCU...UPSLOPE FLOW...AND LOW LEVEL MOISTURE FROM YESTERDAYS
PRECIPITATION AND CORRESPONDING MELTED SNOWPACK HAVE ALLOWED FOR
REDUCED VISIBILITIES AS WELL. THESE CONDITIONS WILL SLOWLY WEAKEN
AS THE NIGHT CONTINUES AS THE RIDGE FLATTENS...AND MORE ZONAL
UPPER LEVEL FLOW MOVES OVER THE REGION FOR TOMORROW.
FAIR WX EXPECTED TONIGHT AS THE DRY AIR MOVES INTO THE
REGION...CLOUDS WILL SLOWLY BREAK UP AND DISSIPATE. IF THE SFC
DECOUPLES OVERNIGHT...THERE IS A CHANCE FOR SOME LOW CLOUDS TO
REDEVELOP...MAINLY OVER THE CENTRAL AND NORTHWEST MOUNTAINS.
LIGHT WINDS...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO
FALL SEVERAL DEG BLW SEASONAL NORMS WITH TEMPERATURES RANGING FROM
THE LOW SINGLE DIGITS IN THE NORTHEAST...TO THE MID TO UPPER TEENS
ELSEWHERE.
OVERALL FAIR WEATHER WILL CONTINUE THROUGH TOMORROW AS A POTENT
SHORTWAVE WILL BE DIVING SOUTHEASTWARD INTO THE GREAT LAKES REGION
LATE WEDNESDAY. THE WINDS SHIFT TO THE NORTHWEST OUT AHEAD OF
THIS TROUGH. THIS SYSTEM WILL BRING AN INCREASE CHANCE FOR
PRECIPITATION THROUGH THE NW MTNS LATE WEDNESDAY.
PARTIAL SUNSHINE AND A BRIEF SHOT OF WAA IN ADVANCE OF CLIPPER
SHOULD HELP TEMPS RECOVER TO NEAR NORMAL WED AFTN WITH MAXES
MOSTLY IN THE LOW TO MID 30S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
BIG CHANGES OCCUR FOR LATE IN THE WEEK BEHIND AN INITIAL ARCTIC
FRONT THAT WILL PLOW SE ACROSS THE STATE LATER WEDNESDAY NIGHT
/NW/ AND THURSDAY MORNING /SERN ZONES/. PAINTED LIKELY POPS FOR
SNOW SHOWERS ACROSS THE NRN AND WESTERN MTNS AS LIMITED LAKE
MOISTURE IS FED INTO THE VERY COLD AIR AND LIFTED ACROSS THE
ALLEGHENIES. POPS MAY EASILY BE UNDERDONE...BUT ACCUMS SHOULD
REMAIN LIGHT DUE TO MOSTLY FROZEN LKS ERIE/HURON AND ALSO DRYNESS
OF ARCTIC AIR MASS.
EXPECT STEADILY FALLING TEMPS ALL DAY THURSDAY WITH NORTHWEST
WINDS GUSTING UP TO 30 KTS AT TIMES. THIS WILL LEAD TO WIND CHILLS
FALLING WELL INTO THE SINGLE DIGITS BY LATE AFTERNOON...THEN WELL
BELOW ZERO AND LIKELY INTO AT LEAST THE WIND CHILL ADVISORY RANGE
THU NIGHT ACROSS THE NRN AND WRN MTNS. LATER SHIFTS MAY NEED TO
CONSIDER A WIND CHILL WATCH FOR THE ALLEGHENY PLATEAU. A BITING
WIND WILL LIKELY ACCOMPANY THE SUB-ZERO TEMPS...DUE TO TIGHT PRES
GRADIENT WEST OF RAPIDLY DEVELOPING COASTAL STORM EAST OF NEW ENG.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY GEFS MEAN 850 MB TEMPS OF ARND -20C OVER
THE AREA. HIGH TEMPS WILL VARY FROM JUST THE SINGLE DIGITS ACROSS
THE NORTHERN MTNS...TO THE MID AND UPPER TEENS ACROSS THE SOUTHERN
VALLEYS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
ANOTHER POTENT SHORTWAVE AND ASSOC CLIPPER IS PROGGED BY ALL MED
RANGE GUIDANCE TO DIVE SE ACROSS PA ON SATURDAY. BASED ON THIS
TRACK AND LACK OF MDL SPREAD...HAVE RAMPED UP THE POPS SATURDAY
FOR THE POSSIBILITY OF A WIDESPREAD LIGHT SNOWFALL. EVEN COLDER
AIR IS POISED TO BLAST INTO CENTRAL PA BEHIND SATURDAY/S CLIPPER.
IT/S A LONG WAY OFF...BUT BASED ON ECENS AND GEFS MEAN 8H TEMPS
ARND -24C...SUNDAY COULD BE THE COLDEST DAY WE/LL SEE UNTIL AT
LEAST NEXT WINTER. OUR CURRENT... GRIDDED FCST MAX TEMPS RANGE
FROM THE LOW SINGLE DIGITS NORTH...TO THE MID TEENS SOUTH. THIS
FRIGID AIRMASS IS LIKELY TO BE ACCOMPANIED BY GUSTY NW WINDS ON
WESTERN PERIPHERY OF YET ANOTHER RAPIDLY DEVELOPING COASTAL LOW
EAST OF NEW ENG. SCT LAKE-ENHANCED SNOW SHOWERS ARE LKLY SUN/MON.
HOWEVER...FROZEN LAKES AND DRY AIR MASS SHOULD RESULT IN ONLY LGT
ACCUMS ACROSS THE W MTNS.
MODERATING...BUT STILL COLD...CONDS APPEAR LIKELY EARLY NEXT
WEEK...AS TEMPS REBOUND IN ADVANCE OF NEXT CLIPPER.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
SUB VFR CONDS WILL CONTINUE AS LOW LEVEL MOISTURE REMAINS
ENTRENCHED BEHIND MONDAYS STORM SYSTEM. NO ACTIVE PCPN IS
AFFECTING THE AIRSPACE...AND NONE IS EXPECTED THROUGH TOMORROW
AFTERNOON. LOWEST CONDS...IFR OR LOWER CIGS...ARE AT BFD AND JST.
JST IS DUE TO FOG/MIST/HAZE DUE TO RESIDUAL MOISTURE FROM MELTING
SNOW...AND THICK LOW CLOUDS. EXPECT SLOW IMPROVING TREND FROM
NORTH TO SOUTH THIS AFTERNOON INTO TONIGHT WITH VFR RETURNING TO
MOST AREAS BY TUESDAY OVERNIGHT...AS HIGH PRESSURE BUILDS INTO THE
REGION.
JST AND BFD SHOULD IMPROVE 00Z TO 06Z...BUT CONDS MAY VERY WELL
GO LOW AGAIN TONIGHT ESPECIALLY AT KBFD AND KJST AS WINDS GO CALM
AND POSSIBLE MVFR TO A BRIEF PERIOD OF IFR REDEVELOPS TOWARDS
WEDNESDAY MORNING.
AROUND 12 TO 15Z CONDITIONS SHOULD IMPROVE WITH VFR DOMINATING
THE PATTERN TOMORROW. CONDITIONS WILL DETERIORATE AS ANOTHER
TROUGH DROPS THROUGH THE GREAT LAKES AND THROUGH PENNSYLVANIA
WEDNESDAY NIGHT INTO THURSDAY.
OUTLOOK...
WED NGT-THU...MVFR/IFR IN -SN. GUSTY NW WINDS THU NIGHT INTO
EARLY FRI BEHIND FROPA.
FRI...MVFR/IFR WITH -SHSN WEST.
SAT...MVFR/IFR WITH -SN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/CERU
NEAR TERM...FITZGERALD/CERU
SHORT TERM...FITZGERALD/CERU
LONG TERM...FITZGERALD/LAMBERT
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
127 AM EST TUE FEB 10 2015
.SYNOPSIS...
IN THE WAKE OF A COLD FRONT...DRY HIGH PRESSURE WILL BUILD INTO THE
REGION ON TUESDAY AND LINGER THROUGH WEDNESDAY. AN ARCTIC COLD FRONT
WILL REACH THE MOUNTAINS ON THURSDAY WITH A COLD AIR MASS FILTERING
INTO THE REGION FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
120 AM EST TUESDAY UPDATE...POPS WERE RAISED INTO THE LIKELY TO
CATEGORICAL RANGE OVER THE WESTERN NC PIEDMONT INCLUDING THE
CHARLOTTE METRO AREA WHERE WIDESPREAD SHOWERS WERE OCCURRING AS A
CONSEQUENCE OF THE UPPER LVL LOW PRESSURE SLOWLY DRIFTING EASTWARD.
EXPECT THE PRECIP TO TAPER OFF BY AROUND DAYBREAK AS THE PRECIP
SHIELD ASSOCIATED WITH THE UPPER LOW PUSHES OFF TO THE EAST.
AS OF 825 PM...HAVE UPDATED THE FCST TO REMOVE MENTION OF THUNDER
AND INCREASE POPS ACRS THE ERN HALF OF THE CWFA TO LIKELY BASED ON
RADAR TRENDS. THE AXIS OF THE MID LVL SHORTWAVE TROF IS IN LINE WITH
THE BACK EDGE OF PRECIP. SO EXPECT POPS TO TAPER OFF FROM WEST TO
EAST THIS EVENING. THE EXCEPTION IS ALONG THE TN LINE...WHERE POPS
LINGER THRU THE OVERNIGHT. THE LATEST RAP 850 MB INITIALIZES THE 0C
LINE STILL BACK TO THE WEST. AND TEMPS IN THE MTNS ARE STILL IN THE
UPR 30S TO MID 40S. SO CHANGEOVER TO SNOW SHWRS HAS BEEN DELAYED.
LITTLE IF ANY ACCUMS ARE EXPECTED OVERNIGHT BEFORE SHWRS TAPER OFF
AROUND DAYBREAK TUESDAY.
AS OF 655 PM...NO SIGNIFICANT CHANGES TO THE PUBLIC FCST WITH THIS
UPDATE. TWEAKED TEMPS/DWPTS AGAIN WITH LATEST OBS. SKY/WIND/POP/WX
WERE ADJUSTED WITH LATEST GUIDANCE FOR THE 00Z TAFS. BASED ON RADAR
TRENDS...IT LOOKS LIKE THE THUNDER THREAT IS PRETTY MUCH OVER IN THE
UPPER SAVANNAH VALLEY.
AS OF 430 PM...THE POP TRENDS STILL LOOK ON TRACK. THERE ARE FEW
BREAKS IN THE CLOUDS ACRS GA AND WRN UPSTATE ON VIS SAT. CONVECTION
IS DEVELOPING WHERE THERE IS SOME INSOLATION...AND STILL MAY SEE AN
ISOLD TSTM OR TWO ACRS THE UPPER SAVANNAH VALLEY AND SRN UPSTATE
OVER THE NEXT COUPLE HOURS (LAPS CAPE IS UP TO 250 TO 600+ J/KG).
CANNOT RULE OUT SMALL HAIL/GRAUPEL WITH THE HEAVIEST
CONVECTION...GIVEN THE LOW FREEZING LEVELS...AND A FEW REPORTS IN
GA. I UPDATED THE TEMPS/DWPTS WITH THE LATEST OBS. TEMPS ARE RUNNING
COOLER THAN EXPECTED...GIVEN STUBBORN RAIN AND CLOUDS.
AS OF 210 PM EST...WATER VAPOR IMAGERY SHOWS A DIGGING UPPER LEVEL
SHORTWAVE OVER THE BASE OF THE SRN APPALACHIANS THIS
AFTERNOON...GRADUALLY ACQUIRING A MORE NEUTRAL TILT AS IT MOVES
EAST. DEEP LAYER DPVA AHEAD OF THIS WAVE IS CROSSING THE ERN HALF OF
THE FORECAST AREA THIS AFTN...WHILE ADDITIONAL SCT ACTIVITY DEVELOPS
BACK TO THE WEST UNDER THE COLD TROUGH ALOFT AND AHEAD OF THE
ASSOCIATED SFC COLD FRONT. A VERY FEW CLOUD TO CLOUD LIGHTNING
STRIKES WERE INDICATED EARLIER THIS AFTN...BUT THE CLOUD COVER HAS
KEPT LAPS SFC BASED CAPE VALUES LESS THAN 100 J/KG FOR ALL AREAS
EXCEPT THE EXTREME SRN PIEDMONT. WILL CONFINE ANY ISOLD THUNDER
MENTION GOING FORWARD TO SRN AND ERN SECTIONS THROUGH LATE AFTN.
SHEAR PROFILES REMAIN TOO WEAK FOR ANY SEVERE CONVECTION.
ANTICIPATE FROPA ACROSS THE MTNS THIS EVENING...BUT THEN THE
BOUNDARY WILL WASH OUT OVER THE PIEDMONT OR POSSIBLY GET HUNG UP
NEAR THE HIGHER TERRAIN OF THE SRN MTNS AND GRADUALLY DISSIPATE. THE
PASSING UPPER TROUGH WILL DEEPEN FURTHER TONIGHT...AND POSSIBLY CUT
OFF JUST EAST OF OUR FORECAST AREA...WITH STRONGER SFC WAVE
FORMATION LIKELY OUT OVER THE COASTAL PLAIN OVERNIGHT. THIS WILL
SLOW THE DEEP LAYER DRYING FROM THE WEST...AND LEAD TO A MORE
GRADUAL WEST TO EAST DROPOFF IN POPS. IN ADDITION...SUBFREEZING 850
MB TEMPS WILL ARRIVE ALONG THE SPINE OF THE SRN APPALACHIANS TOWARD
06Z. SCATTERED WESTERN MTNS SNOW SHOWERS OVERNIGHT COULD LEAD TO
VERY LIGHT ACCUMS IN THE TN BORDER COUNTIES...HOWEVER...THE LOW
LEVEL UPSLOPE FLOW WILL BE MORE NRLY THAN DESIRED FOR DECENT UPSLOPE
PRECIPITATION. CANNOT RULE OUT SOME LIGHT ICING GIVEN THE SHALLOW
MOISTURE PROFILES AND POSSIBLE LINGERING WARM NOSE...BUT RAIN/SNOW
IS PREFERRED BY THE CONSENSUS PROFILES.
FINALLY...WEAK DEFORMATION ZONE FORCING W OF THE COASTAL LOW...ALONG
WITH LINGERING 850 MB MOISTURE IN THE NRLY FLOW...WILL LIKELY ALLOW
CLOUDS TO PERSIST OVER THE WRN CAROLINAS THROUGH MUCH OF TUESDAY.
HOWEVER...NO FURTHER SHOWERS ARE EXPECTED THIS FAR W. TEMPERATURES
WILL BE NEAR CLIMATOLOGY...EXCEPT COOLER THAN CLIMO IN WRN NC.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
AS OF 145 PM MONDAY...TUESDAY NIGHT AND WED SHOULD BE QUIET ACROSS
THE WESTERN CAROLINAS AND NE GA AS SHORT WAVE RIDGING DEVLOPS ACROSS
THE AREA. HOWEVER...THE FLOW WILL QUICKLY AMPLIFY ON THURSDAY AS A
SHARP UPPER TROUGH QUICKLY DIGS SE OUT OF CANADA WITH A LONG WAVE
TROUGH DEVELOPING OVER THE EASTERN U.S. ON THURSDAY. THE DIGGING
UPPER TROUGH WILL SPAWN A CLIPPER LOW WHICH IS FORECAST TO MOVE WELL
NORTH OF THE AREA...BUT IS ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE FORECAST AREA ON THURSDAY. THE FRONT WILL BE MOISTURE STARVED SO
DESPITE THE RATHER IMPRESSIVE UPPER AIR DYNAMICS...LITTLE IN THE WAY
OF PRECIP WILL ACCOMPANY THE FRONT OUTSIDE THE MOUNTAINS EXCEPT
PERHAPS SOME SPRINKLES/FLURRIES WITH THE PASSAGE OF THE UPPER TROUGH
THU AFTERNOON. HOWEVER...THE DEVELOPING NW FLOW WILL SQEEZE OUT SOME
MAINLY UPSLOPE INDUCED SNOW SHOWERS IN THE MOUTNAINS ON THU...BUT
RIGHT NOW ACCUMULATIONS LOOK TO BE ON THE LIGHT SIDE EVEN THOUGH
FORECAST SOUNDINGS LOOK SOMEWHAT CONVECTIVE. THEREFORE...WOULD NOT
BE SURPRISED IF ADVISORY LEVEL SNOW ACCUMS RESULT BY LATE THU
ESPECIALLY IN THE NORTHERN MOUNTAINS. THE BIG STORY WILL BE THE
PLUNGING TEMPS. MAX TEMPS IN THE MOUNTAINS ON THURSDAY WILL OCCUR IN
THE EARLY MORNING THEN FALLING THROUGHOUT THE DAY AS 850 TEMPS FALL
WELL INTO THE NEGATIVE TEENS. OUTSIDE THE MOUNTAINS AS
USUAL...DOWNSLOPE FLOW WILL MITIGATE COLD ADVECTION INITIALLY BUT
WILL EVENTUALLY BE OVERWHELMED BY CAA IN THE AFTERNOON. MAX TEMPS
OUTSIDE THE MOUNTAINS LOOK TO OCCUR IN THE EARLY AFTEERNOON AND THEN
FALL OFF AS 850 TEMPS FALL INTO THE NEGATIVE LOWER TEENS BY 00Z FRI.
WINDS WILL ALSO INCREASE AND BECOME GUSTY ON THURSDAY BUT LOOK TO
REMAIN BELOW ADVISORY LEVELS AT THIS POINT. MAX TEMPS SHOULD BE NEAR
CLIMO ON WED AND THEN WELL BELOW CLIMO IN THE MOUNTAINS THU AND
ABOUT A CATEGORY BELOW EAST OF THE MOUNTAINS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 210 PM MONDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON FRIDAY
WITH A HIGHLY AMPLIFIED UPPER TROF AXIS RIGHT OVER THE CAROLINAS AND
STEEP UPPER RIDGING OVER THE WESTERN CONUS. OVER THE NEXT 24
HRS...THE TROF AXIS LIFTS TO THE NE HOWEVER WE WILL LIKELY REMAIN
UNDER BROAD UPPER TROFFING THRU MOST OF THE PERIOD. ON SAT...THE
TROF AMPLIFIES AGAIN AND BRINGS ANOTHER ROUND OF IMPRESSIVE PVA AND
COLD AIR OVER THE REGION. BY EARLY MON...THIS ENERGY LIFTS NE AND
HEIGHTS RISE AS THE UPPER PATTERN FLATTENS OUT. IT SHOULD BE NOTED
THAT THE OVERALL MODEL AGREEMENT FOR THE PERIOD LOOKS ESPECIALLY
GOOD.
AT THE SFC...SIGNIFICANT CAA WILL BE UNDERWAY BY LATE THURS/EARLY
FRI AS COLD CANADIAN HIGH PRESSURE PUSHES INTO THE REGION FROM THE
NW. OVER THE NEXT 24 HRS...A LOW IS EXPECTED TO DEVELOP OVER THE
GREAT LAKES AND DRIFT SE...YET ITS LOOKING LIKE MOST OF THE DEEPER
MOISTURE ASSOCIATED WITH THAT SYSTEM WILL REMAIN TO OUR NORTH. AS
THE LOW TRACKS EASTWARD...ANOTHER STRONG CANADIAN HIGH MOVES INTO
THE REGION ON SUNDAY BRINGING SOME OF THE COLDEST/DRIEST AIR OF THE
SEASON. THE HIGH IS EXPECTED TO REMAIN OVER THE AREA THRU NEW DAY 7
WHICH IS NEXT MONDAY. THE ONLY POPS I CARRY FOR THE PERIOD ARE SMALL
AREAS OF SLIGHT CHANCE OVER THE NORTHERN MTS LATE THURS/EARLY FRI
AND SAT. OTHERWISE...IT WILL BE DRY. MORE NOTEWORTHY WILL BE WELL
BELOW NORMAL TEMPS ON FRI AND SUN WITH EQUALLY DRY DEWPTS. THESE
TEMPS COUPLED WITH GUSTY WINDS COULD CAUSE SOME FIRE DANGER ISSUES
AND WIND CHILL CONCERNS EARLY FRIDAY AND SUNDAY...ESPECIALLY OVER
THE HIGHER ELEVATIONS.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
AT KCLT...LIFR CIGS IN LIGHT SHOWERS WILL CONTINUE OVER THE NEXT
SEVERAL HOURS BEFORE THE PRECIP DRYING OUT BY AROUND 8Z WITH CIGS
LIFTING TO ABOUT 800FT RANGE. AN UPPER LOW WILL CONTINUE TO SLOWLY
MOVE EASTWARD THROUGH THE DAYBREAK...YIELDING N/NNELY FLOW AND IFR
CLOUDS. EXPECT GUSTY NNE WINDS OF 15-22KTS TO DEVELOP AND CIGS
SHOULD LIFT INTO THE MVFR LVL BY THIS MORNING AS SURFACE PRESSURE
GRADIENT TIGHTENS UP BEHIND THE DEPARTING LOW. AS DRY HIGH PRESSURE
FURTHER BUILDS IN...CIGS SHOULD RISE TO VFR LVL BY MIDDAY. GUSTY
WINDS SHOULD SUBSIDE BEYOND 22Z...BUT WILL REMAIN AROUND 7-10KT
RANGE.
ELSEWHERE...AREAS OF LIGHT SHOWERS OVER THE NC PIEDMONT AND PORTIONS
OF THE EASTERN UPSTATE SC SHOULD TAPER OFF OVER THE NEXT FEW HOURS
AS THE UPPER LOW ASSOCIATED WITH PRECIP SHIELD FURTHER MOVES OFF TO
THE EAST. AN INTRUSION OF DRY SLOT BEHIND THE DEPARTING LOW WILL
YIELD VFR CIGS ACROSS MUCH OF THE REGION OVERNIGHT EXCEPT KAVL WHERE
IFR/MVFR CLOUDS SHOULD LINGER AT LEAST THRU DAYBREAK. WINDS SHOULD
INCREASE THRU THE OVERNIGHT...BECOMING GUSTY AT TIMES BY EARLY THIS
MORNING AS PRESSURE GRADIENT TIGHTENS UP BETWEEN THE DEPARTING LOW
AND HIGH PRESSURE TO THE NW. EXPECT VFR CONDITIONS TO PREVAIL TODAY
UNDER THE INFLUENCE OF BUILDING HIGH PRESSURE. GUSTY WINDS OF
10-20KTS SHOULD DECREASE TO AROUND 5-10KT BY THE AFTERNOON.
OUTLOOK...DRYING CONDITIONS ARE EXPECTED LATE TUE THROUGH WED. A
COLD FRONT WILL CROSS THE REGION FROM THE NW ON THU...BUT WITH
LIMITED MOISTURE. BREEZY TO WINDY CONDITIONS ARE EXPECTED BEHIND THE
FRONT THU THROUGH FRI...WITH COLDER TEMPERATURES.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 80% MED 79% HIGH 97% HIGH 100%
KGSP MED 65% HIGH 92% HIGH 100% HIGH 100%
KAVL LOW 57% MED 73% HIGH 100% HIGH 100%
KHKY LOW 25% MED 65% HIGH 100% HIGH 100%
KGMU MED 63% HIGH 85% HIGH 100% HIGH 100%
KAND LOW 58% MED 74% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...ARK/HG/JOH
SHORT TERM...LG
LONG TERM...JPT
AVIATION...JOH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
109 AM EST TUE FEB 10 2015
.SYNOPSIS...
IN THE WAKE OF A COLD FRONT...DRY HIGH PRESSURE WILL BUILD INTO THE
REGION ON TUESDAY AND LINGER THROUGH WEDNESDAY. AN ARCTIC COLD FRONT
WILL REACH THE MOUNTAINS ON THURSDAY WITH A COLD AIR MASS FILTERING
INTO THE REGION FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 825 PM...HAVE UPDATED THE FCST TO REMOVE MENTION OF THUNDER
AND INCREASE POPS ACRS THE ERN HALF OF THE CWFA TO LIKELY BASED ON
RADAR TRENDS. THE AXIS OF THE MID LVL SHORTWAVE TROF IS IN LINE WITH
THE BACK EDGE OF PRECIP. SO EXPECT POPS TO TAPER OFF FROM WEST TO
EAST THIS EVENING. THE EXCEPTION IS ALONG THE TN LINE...WHERE POPS
LINGER THRU THE OVERNIGHT. THE LATEST RAP 850 MB INITIALIZES THE 0C
LINE STILL BACK TO THE WEST. AND TEMPS IN THE MTNS ARE STILL IN THE
UPR 30S TO MID 40S. SO CHANGEOVER TO SNOW SHWRS HAS BEEN DELAYED.
LITTLE IF ANY ACCUMS ARE EXPECTED OVERNIGHT BEFORE SHWRS TAPER OFF
AROUND DAYBREAK TUESDAY.
AS OF 655 PM...NO SIGNIFICANT CHANGES TO THE PUBLIC FCST WITH THIS
UPDATE. TWEAKED TEMPS/DWPTS AGAIN WITH LATEST OBS. SKY/WIND/POP/WX
WERE ADJUSTED WITH LATEST GUIDANCE FOR THE 00Z TAFS. BASED ON RADAR
TRENDS...IT LOOKS LIKE THE THUNDER THREAT IS PRETTY MUCH OVER IN THE
UPPER SAVANNAH VALLEY.
AS OF 430 PM...THE POP TRENDS STILL LOOK ON TRACK. THERE ARE FEW
BREAKS IN THE CLOUDS ACRS GA AND WRN UPSTATE ON VIS SAT. CONVECTION
IS DEVELOPING WHERE THERE IS SOME INSOLATION...AND STILL MAY SEE AN
ISOLD TSTM OR TWO ACRS THE UPPER SAVANNAH VALLEY AND SRN UPSTATE
OVER THE NEXT COUPLE HOURS (LAPS CAPE IS UP TO 250 TO 600+ J/KG).
CANNOT RULE OUT SMALL HAIL/GRAUPEL WITH THE HEAVIEST
CONVECTION...GIVEN THE LOW FREEZING LEVELS...AND A FEW REPORTS IN
GA. I UPDATED THE TEMPS/DWPTS WITH THE LATEST OBS. TEMPS ARE RUNNING
COOLER THAN EXPECTED...GIVEN STUBBORN RAIN AND CLOUDS.
AS OF 210 PM EST...WATER VAPOR IMAGERY SHOWS A DIGGING UPPER LEVEL
SHORTWAVE OVER THE BASE OF THE SRN APPALACHIANS THIS
AFTERNOON...GRADUALLY ACQUIRING A MORE NEUTRAL TILT AS IT MOVES
EAST. DEEP LAYER DPVA AHEAD OF THIS WAVE IS CROSSING THE ERN HALF OF
THE FORECAST AREA THIS AFTN...WHILE ADDITIONAL SCT ACTIVITY DEVELOPS
BACK TO THE WEST UNDER THE COLD TROUGH ALOFT AND AHEAD OF THE
ASSOCIATED SFC COLD FRONT. A VERY FEW CLOUD TO CLOUD LIGHTNING
STRIKES WERE INDICATED EARLIER THIS AFTN...BUT THE CLOUD COVER HAS
KEPT LAPS SFC BASED CAPE VALUES LESS THAN 100 J/KG FOR ALL AREAS
EXCEPT THE EXTREME SRN PIEDMONT. WILL CONFINE ANY ISOLD THUNDER
MENTION GOING FORWARD TO SRN AND ERN SECTIONS THROUGH LATE AFTN.
SHEAR PROFILES REMAIN TOO WEAK FOR ANY SEVERE CONVECTION.
ANTICIPATE FROPA ACROSS THE MTNS THIS EVENING...BUT THEN THE
BOUNDARY WILL WASH OUT OVER THE PIEDMONT OR POSSIBLY GET HUNG UP
NEAR THE HIGHER TERRAIN OF THE SRN MTNS AND GRADUALLY DISSIPATE. THE
PASSING UPPER TROUGH WILL DEEPEN FURTHER TONIGHT...AND POSSIBLY CUT
OFF JUST EAST OF OUR FORECAST AREA...WITH STRONGER SFC WAVE
FORMATION LIKELY OUT OVER THE COASTAL PLAIN OVERNIGHT. THIS WILL
SLOW THE DEEP LAYER DRYING FROM THE WEST...AND LEAD TO A MORE
GRADUAL WEST TO EAST DROPOFF IN POPS. IN ADDITION...SUBFREEZING 850
MB TEMPS WILL ARRIVE ALONG THE SPINE OF THE SRN APPALACHIANS TOWARD
06Z. SCATTERED WESTERN MTNS SNOW SHOWERS OVERNIGHT COULD LEAD TO
VERY LIGHT ACCUMS IN THE TN BORDER COUNTIES...HOWEVER...THE LOW
LEVEL UPSLOPE FLOW WILL BE MORE NRLY THAN DESIRED FOR DECENT UPSLOPE
PRECIPITATION. CANNOT RULE OUT SOME LIGHT ICING GIVEN THE SHALLOW
MOISTURE PROFILES AND POSSIBLE LINGERING WARM NOSE...BUT RAIN/SNOW
IS PREFERRED BY THE CONSENSUS PROFILES.
FINALLY...WEAK DEFORMATION ZONE FORCING W OF THE COASTAL LOW...ALONG
WITH LINGERING 850 MB MOISTURE IN THE NRLY FLOW...WILL LIKELY ALLOW
CLOUDS TO PERSIST OVER THE WRN CAROLINAS THROUGH MUCH OF TUESDAY.
HOWEVER...NO FURTHER SHOWERS ARE EXPECTED THIS FAR W. TEMPERATURES
WILL BE NEAR CLIMATOLOGY...EXCEPT COOLER THAN CLIMO IN WRN NC.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
AS OF 145 PM MONDAY...TUESDAY NIGHT AND WED SHOULD BE QUIET ACROSS
THE WESTERN CAROLINAS AND NE GA AS SHORT WAVE RIDGING DEVLOPS ACROSS
THE AREA. HOWEVER...THE FLOW WILL QUICKLY AMPLIFY ON THURSDAY AS A
SHARP UPPER TROUGH QUICKLY DIGS SE OUT OF CANADA WITH A LONG WAVE
TROUGH DEVELOPING OVER THE EASTERN U.S. ON THURSDAY. THE DIGGING
UPPER TROUGH WILL SPAWN A CLIPPER LOW WHICH IS FORECAST TO MOVE WELL
NORTH OF THE AREA...BUT IS ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE FORECAST AREA ON THURSDAY. THE FRONT WILL BE MOISTURE STARVED SO
DESPITE THE RATHER IMPRESSIVE UPPER AIR DYNAMICS...LITTLE IN THE WAY
OF PRECIP WILL ACCOMPANY THE FRONT OUTSIDE THE MOUNTAINS EXCEPT
PERHAPS SOME SPRINKLES/FLURRIES WITH THE PASSAGE OF THE UPPER TROUGH
THU AFTERNOON. HOWEVER...THE DEVELOPING NW FLOW WILL SQEEZE OUT SOME
MAINLY UPSLOPE INDUCED SNOW SHOWERS IN THE MOUTNAINS ON THU...BUT
RIGHT NOW ACCUMULATIONS LOOK TO BE ON THE LIGHT SIDE EVEN THOUGH
FORECAST SOUNDINGS LOOK SOMEWHAT CONVECTIVE. THEREFORE...WOULD NOT
BE SURPRISED IF ADVISORY LEVEL SNOW ACCUMS RESULT BY LATE THU
ESPECIALLY IN THE NORTHERN MOUNTAINS. THE BIG STORY WILL BE THE
PLUNGING TEMPS. MAX TEMPS IN THE MOUNTAINS ON THURSDAY WILL OCCUR IN
THE EARLY MORNING THEN FALLING THROUGHOUT THE DAY AS 850 TEMPS FALL
WELL INTO THE NEGATIVE TEENS. OUTSIDE THE MOUNTAINS AS
USUAL...DOWNSLOPE FLOW WILL MITIGATE COLD ADVECTION INITIALLY BUT
WILL EVENTUALLY BE OVERWHELMED BY CAA IN THE AFTERNOON. MAX TEMPS
OUTSIDE THE MOUNTAINS LOOK TO OCCUR IN THE EARLY AFTEERNOON AND THEN
FALL OFF AS 850 TEMPS FALL INTO THE NEGATIVE LOWER TEENS BY 00Z FRI.
WINDS WILL ALSO INCREASE AND BECOME GUSTY ON THURSDAY BUT LOOK TO
REMAIN BELOW ADVISORY LEVELS AT THIS POINT. MAX TEMPS SHOULD BE NEAR
CLIMO ON WED AND THEN WELL BELOW CLIMO IN THE MOUNTAINS THU AND
ABOUT A CATEGORY BELOW EAST OF THE MOUNTAINS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 210 PM MONDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON FRIDAY
WITH A HIGHLY AMPLIFIED UPPER TROF AXIS RIGHT OVER THE CAROLINAS AND
STEEP UPPER RIDGING OVER THE WESTERN CONUS. OVER THE NEXT 24
HRS...THE TROF AXIS LIFTS TO THE NE HOWEVER WE WILL LIKELY REMAIN
UNDER BROAD UPPER TROFFING THRU MOST OF THE PERIOD. ON SAT...THE
TROF AMPLIFIES AGAIN AND BRINGS ANOTHER ROUND OF IMPRESSIVE PVA AND
COLD AIR OVER THE REGION. BY EARLY MON...THIS ENERGY LIFTS NE AND
HEIGHTS RISE AS THE UPPER PATTERN FLATTENS OUT. IT SHOULD BE NOTED
THAT THE OVERALL MODEL AGREEMENT FOR THE PERIOD LOOKS ESPECIALLY
GOOD.
AT THE SFC...SIGNIFICANT CAA WILL BE UNDERWAY BY LATE THURS/EARLY
FRI AS COLD CANADIAN HIGH PRESSURE PUSHES INTO THE REGION FROM THE
NW. OVER THE NEXT 24 HRS...A LOW IS EXPECTED TO DEVELOP OVER THE
GREAT LAKES AND DRIFT SE...YET ITS LOOKING LIKE MOST OF THE DEEPER
MOISTURE ASSOCIATED WITH THAT SYSTEM WILL REMAIN TO OUR NORTH. AS
THE LOW TRACKS EASTWARD...ANOTHER STRONG CANADIAN HIGH MOVES INTO
THE REGION ON SUNDAY BRINGING SOME OF THE COLDEST/DRIEST AIR OF THE
SEASON. THE HIGH IS EXPECTED TO REMAIN OVER THE AREA THRU NEW DAY 7
WHICH IS NEXT MONDAY. THE ONLY POPS I CARRY FOR THE PERIOD ARE SMALL
AREAS OF SLIGHT CHANCE OVER THE NORTHERN MTS LATE THURS/EARLY FRI
AND SAT. OTHERWISE...IT WILL BE DRY. MORE NOTEWORTHY WILL BE WELL
BELOW NORMAL TEMPS ON FRI AND SUN WITH EQUALLY DRY DEWPTS. THESE
TEMPS COUPLED WITH GUSTY WINDS COULD CAUSE SOME FIRE DANGER ISSUES
AND WIND CHILL CONCERNS EARLY FRIDAY AND SUNDAY...ESPECIALLY OVER
THE HIGHER ELEVATIONS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AT KCLT...LIFR CIGS IN LIGHT SHOWERS WILL CONTINUE OVER THE NEXT
SEVERAL HOURS BEFORE THE PRECIP DRYING OUT BY AROUND 8Z WITH CIGS
LIFTING TO ABOUT 800FT RANGE. AN UPPER LOW WILL CONTINUE TO SLOWLY
MOVE EASTWARD THROUGH THE DAYBREAK...YIELDING N/NNELY FLOW AND IFR
CLOUDS. EXPECT GUSTY NNE WINDS OF 15-22KTS TO DEVELOP AND CIGS
SHOULD LIFT INTO THE MVFR LVL BY THIS MORNING AS SURFACE PRESSURE
GRADIENT TIGHTENS UP BEHIND THE DEPARTING LOW. AS DRY HIGH PRESSURE
FURTHER BUILDS IN...CIGS SHOULD RISE TO VFR LVL BY MIDDAY. GUSTY
WINDS SHOULD SUBSIDE BEYOND 22Z...BUT WILL REMAIN AROUND 7-10KT
RANGE.
ELSEWHERE...AREAS OF LIGHT SHOWERS OVER THE NC PIEDMONT AND PORTIONS
OF THE EASTERN UPSTATE SC SHOULD TAPER OFF OVER THE NEXT FEW HOURS
AS THE UPPER LOW ASSOCIATED WITH PRECIP SHIELD FURTHER MOVES OFF TO
THE EAST. AN INTRUSION OF DRY SLOT BEHIND THE DEPARTING LOW WILL
YIELD VFR CIGS ACROSS MUCH OF THE REGION OVERNIGHT EXCEPT KAVL WHERE
IFR/MVFR CLOUDS SHOULD LINGER AT LEAST THRU DAYBREAK. WINDS SHOULD
INCREASE THRU THE OVERNIGHT...BECOMING GUSTY AT TIMES BY EARLY THIS
MORNING AS PRESSURE GRADIENT TIGHTENS UP BETWEEN THE DEPARTING LOW
AND HIGH PRESSURE TO THE NW. EXPECT VFR CONDITIONS TO PREVAIL TODAY
UNDER THE INFLUENCE OF BUILDING HIGH PRESSURE. GUSTY WINDS OF
10-20KTS SHOULD DECREASE TO AROUND 5-10KT BY THE AFTERNOON.
OUTLOOK...DRYING CONDITIONS ARE EXPECTED LATE TUE THROUGH WED. A
COLD FRONT WILL CROSS THE REGION FROM THE NW ON THU...BUT WITH
LIMITED MOISTURE. BREEZY TO WINDY CONDITIONS ARE EXPECTED BEHIND THE
FRONT THU THROUGH FRI...WITH COLDER TEMPERATURES.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 80% MED 79% HIGH 97% HIGH 100%
KGSP MED 65% HIGH 92% HIGH 100% HIGH 100%
KAVL LOW 57% MED 73% HIGH 100% HIGH 100%
KHKY LOW 25% MED 65% HIGH 100% HIGH 100%
KGMU MED 63% HIGH 85% HIGH 100% HIGH 100%
KAND LOW 58% MED 74% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...ARK/HG
SHORT TERM...LG
LONG TERM...JPT
AVIATION...JOH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1056 PM CST MON FEB 9 2015
.UPDATE...
ISSUED AT 848 PM CST MON FEB 9 2015
HAVE UPDATED THE FORECAST TONIGHT TO ADD A DENSE FOG ADVISORY FOR
SOUTH CENTRAL SOUTH DAKOTA. CURRENT WEB CAMS IN KIMBALL LOOK
FAIRLY DAUNTING...AND CHAMBERLAIN WEB CAMS SHOW STRATUS HANGING
JUST ABOVE THE GROUND. HRRR AND RAP BOTH SHOW DENSE FOG DEVELOPING ACROSS
CENTRAL SOUTH DAKOTA THIS EVENING. QUESTIONS REMAIN AS TO HOW LONG
THE DENSE FOG WILL STICK AROUND. STRONG AND DEEP WARM AIR
ADVECTION ACROSS SOUTH CENTRAL SOUTH DAKOTA MAY ALLOW FOR STEADY
IF NOT RISING TEMPERATURES TONIGHT ACROSS CENTRAL SOUTH DAKOTA.
WITH STRONG WARM AIR ADVECTION...EXPECT SOME SHOWERS TO DEVELOP
TOWARDS THE 06Z TIME FRAME ACROSS CENTRAL SOUTH DAKOTA THROUGH THE
OVERNIGHT. THE SHOWERS MAY NOT BE SO PROBLEMATIC ACROSS CENTRAL
SOUTH DAKOTA AS LONG AS TEMPERATURES AT THE SURFACE REMAIN ABOVE
FREEZING...BUT SHOWERS ARE EXPECTED TO SHIFT EAST INTO THE COLDER
AIR CREATING A SET UP FOR FREEZING RAIN AND SLEET. FOR NOW...THE
AREAL COVERAGE LOOKS GOOD FOR FREEZING RAIN...BUT LOWERED ICING
POTENTIAL ACROSS THE WEST WITH WARMER TEMPERATURES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM CST MON FEB 9 2015
MAIN FOCUS IN THE SHORT TERM WILL BE A POTENT UPPER LEVEL TROUGH
TRACKING EAST ACROSS THE NORTHERN PLAINS. THE LOW STRATUS WILL
LINGER THIS EVENING AS LIGHT SOUTHEAST WINDS INCREASE AHEAD OF THE
WAVE. LIGHT PRECIPITATION WILL BEGIN SPREADING INTO THE WESTERN
FORECAST AREA LATER THIS EVENING AS MID AND HIGH CLOUDS ARRIVE WITH
THE WAVE. PRECIPITATION WILL GRADUALLY SPREAD EAST
OVERNIGHT...REACHING THE INTERSTATE 29 CORRIDOR IN THE EARLY MORNING
HOURS AND OUR FAR EASTERN FORECAST AREA LATE TONIGHT. THE LOW CLOUDS
WILL PERSIST...BUT THE MAIN CONCERN WILL BE THE RATHER SIGNIFICANT
DRY LEVELS FROM 750 TO 850 MB BETWEEN THE CLOUD LAYERS. WE DO SEE
SOME WEAK LIFT IN BOTH LAYERS...WHICH COULD SPELL MORE FREEZING
DRIZZLE TYPE PRECIPITATION...BUT ALSO THINK THAT SOME IMPACT FROM
THE MID CLOUDS WILL POINT TO AT LEAST SOME POTENTIAL FOR LIGHT
MEASURABLE PRECIPITATION. WITH THE MODELS TAKING THE BEST FORCING
AND SUPPORT JUST TO OUR NORTH...OUR BEST POTENTIAL WILL BE NORTH OF
INTERSTATE 90. PRECIPITATION TAPERS OFF TUESDAY MORNING FROM WEST TO
EAST AND SHOULD BE LARGELY DONE BY MIDDAY.
FORECAST SOUNDINGS SHOW THAT THE MAIN PRECIPITATION WILL BE RAIN.
WITH THE VAST MAJORITY OF THE FORECAST AREA EXPECTED TO BE AT OR
BELOW FREEZING...FREEZING RAIN SHOULD BE THE MAIN TYPE. A LITTLE
ELEVATED INSTABILITY DOES TRACK ACROSS OUR NORTHERN HALF...WHICH MAY
ALLOW MORE OF A SHOWERY ELEMENT LATE TONIGHT. SLEET WILL ALSO BE A
POSSIBILITY MAINLY EAST CENTRAL SD INTO SOUTHWEST MINNESOTA. THERE
REMAINS SOME UNCERTAINTY ON THE IMPACT OF SOME LIGHT ICING WITH THE
FREEZING RAIN BUT IT DOES NOT TAKE MUCH ICE TO CREATE SLIPPERY
SURFACES AND UNTREATED ROADWAYS. DECIDED TO GO WITH A FREEZING RAIN
ADVISORY LATE TONIGHT THROUGH TUESDAY MORNING FOR THE HIGHWAY 14
CORRIDOR INTO THE SIOUX FALLS AREA WHERE THE BEST POTENTIAL FOR SOME
LIGHT ICE ACCUMULATION IS POSSIBLE - YET EVEN HERE AM ONLY EXPECTING
LESS THAN 0.05 INCHES. DEBATED LEAVING THE FSD AREA OUT OF THE
ADVISORY...BUT GIVEN THE TIMING OF THE ICE POTENTIAL WILL BE AROUND
THE MORNING COMMUTE FELT THAT THE ADVISORY WOULD GIVE THE PROPER
HEADS UP FOR A POSSIBLE SLICK COMMUTE. WE WILL HAVE TO SEE IF AND
HOW THE CONVECTIVE ELEMENT PLAYS OUT...WHICH MAY REQUIRE ADJUSTING
THE ADVISORY ZONES.
CLOUDS START CLEARING IN SOUTH CENTRAL SD IN THE AFTERNOON BUT
LINGER THROUGH THE DAY ELSEWHERE. BUT THE BREEZY SOUTHERLY WINDS
TURNING NORTHWESTERLY BEHIND THE FRONT SHOULD ALLOW SOME DECENT
WARMING REGARDLESS. HIGHS WILL BE MILDER IN THE UPPER 30S TO MID
50S...SO ANY SLICK SPOTS ON ROADWAYS SHOULD MELT IN THE AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM CST MON FEB 9 2015
A STRONG COLD FRONT WILL BLAST THROUGH THE AREA ON TUESDAY NIGHT.
WITH THE COLD AIR ADVECTION AND A STEEPENING GRADIENT IT WILL BECOME
INCREASINGLY WINDY DURING THE NIGHT. A SECONDARY SHORTWAVE WILL DROP
SOUTHWARD ON A NORTHWESTERLY UPPER LEVEL FLOW OVERNIGHT...AND WITH
A SATURATED DENDRITIC LAYER KEPT WITH SCATTERED FLURRIES IN PORTIONS
OF OUR NORTH AND EAST LATER IN THE NIGHT. WITH THE COLD AIR
ADVECTION LOWS WILLS DROP DOWN INTO THE MID TEENS TO LOWER 20S.
HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS ON WEDNESDAY AND
WEDNESDAY NIGHT. IT WILL REMAIN BREEZY THROUGH THE DAY HOWEVER WITH
GOOD MIXING...AND WINDS WILL ONLY SLOWLY FALL OFF ON WEDNESDAY
NIGHT. WITH THERMAL PROFILES CONTINUING TO COOL...HIGHS ON WEDNESDAY
WILL ONLY BE IN THE TEENS NORTHEAST TO NEAR 30 ALONG THE MO RIVER
CORRIDOR...DROPPING OFF TO JUST EITHER SIDE OF ZERO ON WEDNESDAY
NIGHT.
THE RIDGE AXIS SLIDES ACROSS THE REGION ON THURSDAY...WITH THE BRUNT
OF THE COLDER AIR SITTING OVER THE AREA HIGHS WILL ONLY MAKE IT INTO
THE TEENS TO MID 20S. AS THE HIGH MOVES OFF TO THE EAST...A
SOUTHERLY FLOW RETURNS TO THE REGION ON THURSDAY NIGHT...AND
OVERNIGHT LOWS WILL BE VERY SIMILAR TO THURSDAYS HIGHS...REMAINING
NEARLY STEADY IN THE TEENS AND LOWER 20S. MODELS IN DECENT AGREEMENT
ON A COLD FRONTAL PASSAGE ON FRIDAY MORNING...BUT WITH GOOD MIXING
BEHIND THE FRONT IT WILL REMAIN MILD WITH HIGHS ON FRIDAY BACK ABOVE
NORMAL...IN THE UPPER 20S TO LOWER 40S.
THE ROLLERCOASTER RIDE IN TEMPERATURES CONTINUES INTO THE EXTENDED
WITH VARIOUS WAVES PASSING TO OUR EAST IN A NORTHWESTERLY UPPER
LEVEL FLOW. AFTER A COOL DOWN ON SATURDAY...TEMPERATURES LOOK TO
REBOUND FOR THE BEGINNING OF NEXT WEEK. IT APPEARS TO BE DRY THROUGH
MOST OF THE EXTENDED...BEFORE INDICATIONS OF POSSIBLE PRECIPITATION
ON MONDAY AS ANOTHER SHORTWAVE SLIDES INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1051 PM CST MON FEB 9 2015
LOW STRATUS AND AREAS OF FOG TO CONTINUE THROUGH THE FORECAST
PERIOD. THINK THE FOG WILL REMAIN CONTAINED MAINLY WEST OF THE
JAMES...SO HAVE RAISED VISIBILITIES IIN NEW TAFS. WAVE MOVING
THROUGH THE AREA WILL PRODUCE LIGHT FREEZING RAIN TO THE NORTH
ALONG HIGHWAY 14...WITH LESSER AMOUNTS TO THE SOUTH. REMOVED
MENTION OF FREEZING RAIN AT KHON BECAUSE IT MAY BE TOO WARM. WAS
CLOSE TO REMOVING MENTION OF FREEZING RAIN AT KFSD AS WELL...AND
NEXT SHIFT MAY BEFORE ISSUING THE TAFS. GUSTY NORTHWEST WINDS WILL
INCREASE FROM NORTHWEST TO SOUTHEAST TOMORROW IMPROVING CEILINGS
INTO THE MVFR RANGE. &&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...DENSE FOG ADVISORY UNTIL 9 AM CST TUESDAY FOR SDZ050-052-057>059-
063-064-068.
FREEZING RAIN ADVISORY UNTIL NOON CST TUESDAY FOR SDZ038>040-
052>056-061-062.
MN...FREEZING RAIN ADVISORY UNTIL NOON CST TUESDAY FOR MNZ071-072-097-
098.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1130 AM CST TUE FEB 10 2015
.AVIATION...
VFR CONDITIONS WILL LIKELY PERSIST INTO THIS EVENING OVER ALL THE
SITES AS HIGH PRESSURE DRIFTS OVERHEAD AND EAST OF THE AREA.
SOUTHEASTERLY WINDS WERE ALREADY DEVELOPING AT 17Z AND THE
INCREASED MOISTURE ADVECTION WILL AFFECT SOUTHEAST TEXAS LATER
TONIGHT. THE 14Z RUN OF THE HRRR FORECASTS THE BEST CHANCES FOR
FOG AFTER 06Z WEST OF THE INTERSTATE 45 CORRIDOR AND OVER THE
COASTAL COUNTIES. NAMBUFR MODEL SOUNDING FORECASTS SHOWS THE BEST
POTENTIAL BETWEEN ABOUT 09Z AND 15Z. ALTHOUGH THE FOG COULD LIFT
TO AN IFR DECK FROM 15Z TO 18Z...DID NOT THINK CHANCES FOR THIS
SCENARIO WERE GOOD. THE 12Z FORECAST LOOKED ON TRACK AND ONLY
MADE A FEW MINOR TWEAKS BY ADDING THE POSSIBILITY OF SHALLOW
DENSER FOG. ALSO LIKED THE PLACEMENT OF THE DENSER FOG CHANCES
OVER KSGR AND KLBX. KHOU WILL PROBABLY BE ON THE EDGE BUT WAS NOT
CONFIDENT ENOUGH TO ADD LOWER VISIBILITY AT THIS TIME.
40
&&
.PREV DISCUSSION... /ISSUED 952 AM CST TUE FEB 10 2015/
DISCUSSION...
CURRENT FCST IN GOOD SHAPE. VERY FEW CHANGES MADE FOR THE
UPDATE. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 78 47 72 47 59 / 0 0 10 10 10
HOUSTON (IAH) 77 47 71 49 61 / 0 0 10 10 10
GALVESTON (GLS) 67 52 65 53 60 / 0 0 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...47
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
950 AM EST TUE FEB 10 2015
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTH CAROLINAS WILL DRIFT EAST AND
OFFSHORE TODAY. HIGH PRESSURE WILL BUILD IN ON WEDNESDAY. AN
ARCTIC COLD FRONT MOVES THROUGH ON THURSDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM EST TUESDAY...
RADAR TRENDS SHOW STEEP DECLINE IN RETURNS THIS MORNING WITH JUST
SOME SPOTTY LIGHT PRECIPITATION FOR SOUTHSIDE VA AND THE PIEDMONT.
THIS WILL BE GONE BY NOONTIME. LOW LEVEL TEMPERATURE PROFILE IS
COLD ENOUGH TO SUPPORT A FEW FLAKES AND HAVE RECEIVED A FEW
REPORTS INDICATING SUCH...BUT NOTHING OF ANY CONSEQUENCE IS
EXPECTED. FREEZING FOG SITUATION WEST OF THE BLUE RIDGE IS
IMPROVING AND CONDITIONS ARE NOT EXPECTED TO PERSIST PAST MID
MORNING. HAVE NOT RECEIVED ANY REPORTS OF SLICK TRAVEL SO LIKELY
JUST SOME RIME ICING IN THE TREES AND SUCH.
VISIBLE SATELLITE IMAGES SHOW A GOOD AMOUNT OF CLEARING IN THE
NORTH CAROLINA FOOTHILLS...AND EVEN SOME BREAKS FURTHER NORTH INTO
THE NRV AND ALLEGHANY HIGHLANDS. MODELS ARE FAIRLY AGGRESSIVE WITH
CLEARING THINGS OUT TODAY BUT AM NOT CURRENTLY WILLING TO BUY OFF
ON THIS IN ITS ENTIRETY. WILL GO WITH THE IDEA OF IMPROVING
CONDITIONS WORKING THEIR WAY UP EAST OF THE BLUE RIDGE AS SFC LOW
PULLS AWAY FROM THE AREA AND NWLY FLOW KEEPS ENOUGH UPSLOPE
ENHANCEMENT OF LOW LEVEL MOISTURE TO MAINTAIN SOME CLOUDINESS.
THIS WILL IMPACT TEMPERATURES AS MORE SUN MEANS MORE HEAT SO WILL
BUMP MAX VALUES UP A BIT FROM THE NC FOOTHILLS INTO THE PIEDMONT.
IF THE CLEARING IS INDEED AS PRONOUNCED AS MODELS CURRENTLY
ADVERTISE TEMPS WILL LIKELY WARM FURTHER AND WILL HAVE TO ADJUST
VALUES UP AGAIN EARLY THIS AFTERNOON.
PREVIOUS AFD...
MAIN 500 MB SHORT WAVE WAS TRACKING ACROSS NORTH CAROLINA WITH THE
ASSOCIATED SURFACE LOW OFF THE COAST OF SOUTH CAROLINA. MODELS HAVE
THE 500 MB LOW CUTTING OFF THIS MORNING THEN MOVING SLOWLY EAST. AT
THE SURFACE...THE LARGEST PRESSURE FALLS WERE OFF THE CAROLINA
COAST. BY LATE THIS MORNING THE LOW WILL BE WELL OFFSHORE.
WINDS BECOME LIGHT AND VARIABLE OVER THE MOUNTAINS TONIGHT AS A
RIDGE OF HIGH PRESSURE MOVES INTO THE AREA. EXPECTING SOME GUSTY
WINDS IN THE EAST THIS MORNING THEN WINDS WILL DIMINISH THIS
AFTERNOON AND OVERNIGHT. STAYED CLOSE TO BIAS CORRECTED GUIDANCE
FOR OVERNIGHT LOWS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 345 AM EST TUESDAY...
WILL START WEDNESDAY OFF WITH ZONAL WEST TO EAST WIND FLOW BECOMING
INCREASINGLY ESTABLISHED FOR THE CENTRAL APPALACHIANS...AS LOW
PRESSURE OFF THE ATLANTIC COAST MOVES AWAY...AND A DEEP UPPER LEVEL
TROUGH BEGINS TO DIG ACROSS THE GREAT LAKES FROM NORTHERN CANADA.
HIGH PRESSURE WILL ALREADY BE ESTABLISHED IN THE LOW LEVELS...MAKING
FOR MOSTLY CLEAR SKIES. ABUNDANT SUNSHINE AND DOWNSLOPE WINDFLOW
WILL COMBINE TO PUSH AFTERNOON TEMPERATURES INTO THE UPPER 40S TO
MID 50S AREAWIDE. CLOUD COVER WILL INCREASE DURING THE EVENING
HOWEVER AS THE UPPER LEVEL TROUGH CONTINUES ITS APPROACH...WITH AN
ASSOCIATED ARCTIC COLD FRONT MAKING ITS WAY TOWARD THE APPALACHIAN
CHAIN THROUGH THE NIGHT...TRIGGERING LIGHT SNOW SHOWERS ACROSS THE
WESTERN RIDGES TOWARD DAWN THURSDAY.
THE ARCTIC COLD FRONT WILL BEGIN ITS PASSAGE ACROSS OUR AREA
THURSDAY MORNING...ENTERING SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN
EMPIRE AROUND SUNRISE...AND REACHING THE COASTAL PLAIN BY MID
AFTERNOON. HIGH TEMPERATURES FOR THURSDAY WILL OCCUR DURING THE
MORNING JUST AHEAD OF FRONTAL PASSAGE. THE AIR BEHIND THE FRONT IS
COLD ENOUGH THAT IT WILL OVERCOME NORMAL DAYTIME HEATING...AND
THEREFORE WE WILL SEE TEMPERATURES STEADILY DROP THROUGH THE
AFTERNOON. HIGHS WILL RANGE FROM AROUND THE FREEZING MARK WEST OF
INTERSTATE 77...TO THE MID AND UPPER 40S ACROSS THE SOUTHSIDE.
SNOW SHOWERS CAN BE EXPECTED ALONG THE WESTERN RIDGES DURING THE
AFTERNOON...HOWEVER WINDS WILL NOT TRULY SHIFT NORTHWESTERLY UNTIL
EARLY EVENING ACROSS THE MOUNTAINS...WHEN THE BASE OF THE UPPER
TROUGH PASSES OVERHEAD. THE NORTHWESTERLY WIND SHIFT WILL BE FROM
THE PERFECT DIRECTION TO DRAW MOISTURE FROM LAKE MICHIGAN THURSDAY
EVENING INTO EARLY FRIDAY MORNING...WHEN THE HIGHEST SNOWFALL
ACCUMULATIONS ARE EXPECTED. 850MB TEMPERATURES FALLING INTO THE -16C
TO -20C RANGE ALONG THE WESTERN RIDGES WILL SUPPORT SNOW TO LIQUID
RATIOS IN THE 20:1 TO 25:1 RANGE. IN ADDITION...STRONG WINDS AND
UNIDIRECTIONAL FLOW MAY SUPPORT SNOW STREAMERS...WHERE NARROW BANDS
OF LOCALIZED HEAVY SNOW MAY OCCUR...POSSIBLY REACHING INTO THE NEW
RIVER VALLEY. WIND GUSTS OF 45 TO 50 MPH WILL BE COMMON ALONG THE
HIGHER RIDGES DURING THE EVENING...WELL INTO WIND ADVISORY CRITERIA.
BY SUNRISE FRIDAY...TEMPERATURES WILL HAVE FALLEN INTO THE POSITIVE
SINGLE DIGITS ACROSS THE MOUNTAINS...AND INTO THE LOW TO MID TEENS
ACROSS THE PIEDMONT. THESE COLD TEMPERATURES...WHEN FACTORING IN THE
STRONG WINDS...WILL CAUSE WIND CHILLS TO RANGE FROM NEAR ZERO ACROSS
THE SOUTHSIDE...TO THE NEGATIVE TEENS WEST OF THE BLUE RIDGE...
POSSIBLY AS LOW AS -30F IN A FEW SPOTS ALONG THE INTERSTATE 64
CORRIDOR. WIND SPEEDS WILL DECREASE HEADING INTO FRIDAY AFTERNOON...
ALLOWING WIND CHILLS TO RISE ABOVE ZERO MOST LOCATIONS. WINDS WILL
SHIFT MORE WESTERLY LATE IN THE DAY...WITH CLOUD COVER DECREASING...
WHICH WILL HELP AFTERNOON TEMPERATURES REBOUND INTO THE LOW 20S WEST
AND THE LOW 30S EAST. FRIDAY NIGHT TEMPERATURES WILL NOT BE AS
CHILLY...HOLDING IN THE TEENS MOST LOCATIONS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM EST MONDAY...
BOTH THE GFS AND ECMWF KEEP NORTHWEST FLOW WITH A TROUGH/LOW NEAR
JAMES BAY AND RIDGING OVER THE WESTERN U.S. THROUGH SUNDAY.
A SHORTWAVE TROUGH IS FORECASTED TO ROTATE AROUND THE LONGWAVE
PATTERN THROUGH THE GREAT LAKES REGION AND INTO NEW ENGLAND.
THE SOUTHERN EXTENT OF THE ENERGY AND MOISTURE WITH THIS FEATURE IS
SLIGHTLY DIFFERENT DEPENDING ON MODEL CHOICE. STILL LEANING TOWARDS
THE DRIER AND LESS AMPLIFIED SOLUTION WITH RICHER MOISTURE NORTH OF
THE AREA. PLACED ISOLATED TO SCATTERED POPS IN THE WEST WITH THE
BEST CHANCES IN THE NORTHWEST FOR SATURDAY INTO SATURDAY NIGHT.
WINDS INCREASE SATURDAY INTO SATURDAY NIGHT WITH HEALTHY 4 TO 8 MB 6
HOUR PRESSURE RISES. HIGHS ON SATURDAY WILL VARY FROM THE LOWER 20S
IN THE NORTHWEST MOUNTAINS TO THE LOWER 40S IN THE PIEDMONTS.
THE COMBINATION OF WINDS AND TEMPERATURES WILL PRODUCE WIND CHILLS
BELOW ZERO AT THE HIGHER ELEVATIONS SATURDAY NIGHT INTO SUNDAY
MORNING. ACTUAL LOW TEMPERATURES SATURDAY WILL DROP INTO SINGLE
DIGITS TO MID TEENS. HIGH PRESSURE WILL SLOWLY SLIDE EAST SUNDAY
INTO SUNDAY NIGHT. HIGHS SUNDAY WILL VARY FRO THE MID TEENS IN THE
NORTHWEST TO LOWER 30S IN THE SOUTHEAST. ANOTHER COLD SUNDAY NIGHT
WITH LOW TEMPERATURES GENERALLY FROM THE SINGLE DIGITS AND TEENS.
THE HIGH CENTER MOVES SOUTHEAST ON MONDAY AND UPPER FLOW FLATTENS.
THE HIGH CENTER PUSHES OFF INTO THE ATLANTIC OCEAN MONDAY NIGHT INTO
TUESDAY. A COLD FRONT APPROACHES FROM THE WEST ON TUESDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AS OF 705 AM EST TUESDAY...
THERE WAS IFR FOG AND FREEZING FOG ALONG THE WEST SLOPES OF THE
APPALACHIANS EARLY THIS MORNING. MODELS WERE SUGGESTING LITTLE
IMPROVEMENT IN THE IFR CONDITIONS AT KBLF BEFORE NOON.
WESTERN EDGE OF A LARGE SHIELD OF PRECIPITATION EXTENDED FROM
KLYH TO KMTV THIS MORNING WITH WIDESPREAD MVFR CEILINGS AND
VISIBILITIES WITHIN THE PRECIPITATION...INCLUDING AT KLYH AND
KDAN. GETTING A FEW REPORTS OF SNOW MIXING IN WITH THE FAR
WESTERN EDGE OF THE PRECIPITATION.
EXPECTING THE RAIN TO END AT KLYH AND KDAN BY 17Z/NOON BASED ON
THE HRRR AND LOCAL WRF MODELS. BUT LOW CONFIDENCE ON THE TIMING
OF CEILINGS AND VISIBILITIES TODAY. THE EARLIEST THERE MAY BE ANY
VFR CEILINGS IS 20Z/3PM. AS LOW PRESSURE DEEPENS OFF THE COAST
TODAY...ENOUGH OF A PRESSURE GRADIENT FOR WIND GUSTS AROUND 20
KNOTS AT KLYH AND KDAN.
HIGH PRESSURE BUILDS IN OVER THE MOUNTAINS TONIGHT RESULTING IN
LIGHT AND VARIABLE WINDS. HAVE ADDED IFR FOG AND CEILINGS IN AT
KBLF AND KLWB OVERNIGHT WITH MEDIUM CONFIDENCE OF FOG FORMATION.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE AND COLDER AIR WILL BUILD IN BEHIND THE COLD FRONT
WITH VFR FOR WEDNESDAY.
UPSLOPE SNOW SHOWERS ARE EXPECTED IN THE MOUNTAINS ON WEDNESDAY
NIGHT AND THURSDAY ALONG WITH A SHARP DROP IN TEMPERATURES
THURSDAY AND THURSDAY NIGHT BEHIND AN ARCTIC COLD FRONT. WIND
GUSTS BEHIND THE FRONT ON THURSDAY NIGHT MAY REACH 40-50 KNOTS IN
THE HIGHER ELEVATIONS.
HIGH PRESSURE BUILDS IN ALLOWING FOR DIMINISHING WINDS ON FRIDAY
WITH SOME LINGERING MVFR CIGS POSSIBLE OVER THE SOUTHEAST WEST VA
LOCATIONS.
ANOTHER FAST MOVING ARCTIC FRONT ARRIVES SATURDAY WITH A
RESUMPTION OF UPSLOPE SNOW SHOWERS INCLUDING MVFR CIGS/VSBYS ALONG
WITH INCREASING NORTHWEST WINDS THAT COULD AGAIN GUST TO 50 KNOTS
BY LATE IN THE DAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...MBS/AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
709 AM EST TUE FEB 10 2015
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTH CAROLINAS WILL DRIFT EAST AND
OFFSHORE TODAY. HIGH PRESSURE WILL BUILD IN ON WEDNESDAY. AN
ARCTIC COLD FRONT MOVES THROUGH ON THURSDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EST TUESDAY...
MAIN 500 MB SHORT WAVE WAS TRACKING ACROSS NORTH CAROLINA WITH THE
ASSOCIATED SURFACE LOW OFF THE COAST OF SOUTH CAROLINA. MODELS HAVE
THE 500 MB LOW CUTTING OFF THIS MORNING THEN MOVING SLOWLY EAST. AT
THE SURFACE...THE LARGEST PRESSURE FALLS WERE OFF THE CAROLINA
COAST. BY LATE THIS MORNING THE LOW WILL BE WELL OFFSHORE.
WESTERN EDGE OF THE PRECIPITATION EXTENDED FROM LEXINGTON TO
HILLSVILLE AT 400 AM. THE PRECIPITATION WILL GRADUALLY END FROM WEST
TO EAST TODAY. LOCAL WRF AND HRRR MODELS SHOWED BACK EDGE EXITING
THE FAR EASTERN COUNTY WARNING AREA AROUND 1PM. THERE MAY BE SOME
CLEARING LATE IN THE DAY IN THE SOUTHERN FOOTHILLS BUT OVERALL CLOUD
COVER AND PRECIPITATION WILL HOLD TEMPERATURES DOWN. HAVE LEANED
TOWARD COOLER LAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY.
TEMPERATURES AND DEW POINTS WERE DROPPING THIS MORNING FROM BOTH THE
NORTH AND THE WEST. MESONET DATA SHOWED SOME TEMPERATURES AROUND
FREEZING ALONG THE BLUE RIDGE IN ROCKBRIDGE COUNTY...IN TAZEWELL
COUNTY AND IN THE HIGHER ELEVATIONS OF WATAUGA COUNTY. THESE HIGHER
ELEVATIONS WILL BE IN THE CLOUDS THIS MORNING SO SOME FREEZING FOG
IS POSSIBLE. VERY LIGHT ICING IN POSSIBLE ALONG THE BLUE RIDGE
BETWEEN ROCKBRIDGE AND AMHERST COUNTIES ON THE EXTREME WESTERN EDGE
OF THE PRECIPITATION SHIELD.
WINDS BECOME LIGHT AND VARIABLE OVER THE MOUNTAINS TONIGHT AS A
RIDGE OF HIGH PRESSURE MOVES INTO THE AREA. EXPECTING SOME GUSTY
WINDS IN THE EAST THIS MORNING THEN WINDS WILL DIMINISH THIS
AFTERNOON AND OVERNIGHT. STAYED CLOSE TO BIAS CORRECTED GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 345 AM EST TUESDAY...
WILL START WEDNESDAY OFF WITH ZONAL WEST TO EAST WIND FLOW BECOMING
INCREASINGLY ESTABLISHED FOR THE CENTRAL APPALACHIANS...AS LOW
PRESSURE OFF THE ATLANTIC COAST MOVES AWAY...AND A DEEP UPPER LEVEL
TROUGH BEGINS TO DIG ACROSS THE GREAT LAKES FROM NORTHERN CANADA.
HIGH PRESSURE WILL ALREADY BE ESTABLISHED IN THE LOW LEVELS...MAKING
FOR MOSTLY CLEAR SKIES. ABUNDANT SUNSHINE AND DOWNSLOPE WINDFLOW
WILL COMBINE TO PUSH AFTERNOON TEMPERATURES INTO THE UPPER 40S TO
MID 50S AREAWIDE. CLOUD COVER WILL INCREASE DURING THE EVENING
HOWEVER AS THE UPPER LEVEL TROUGH CONTINUES ITS APPROACH...WITH AN
ASSOCIATED ARCTIC COLD FRONT MAKING ITS WAY TOWARD THE APPALACHIAN
CHAIN THROUGH THE NIGHT...TRIGGERING LIGHT SNOW SHOWERS ACROSS THE
WESTERN RIDGES TOWARD DAWN THURSDAY.
THE ARCTIC COLD FRONT WILL BEGIN ITS PASSAGE ACROSS OUR AREA
THURSDAY MORNING...ENTERING SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN
EMPIRE AROUND SUNRISE...AND REACHING THE COASTAL PLAIN BY MID
AFTERNOON. HIGH TEMPERATURES FOR THURSDAY WILL OCCUR DURING THE
MORNING JUST AHEAD OF FRONTAL PASSAGE. THE AIR BEHIND THE FRONT IS
COLD ENOUGH THAT IT WILL OVERCOME NORMAL DAYTIME HEATING...AND
THEREFORE WE WILL SEE TEMPERATURES STEADILY DROP THROUGH THE
AFTERNOON. HIGHS WILL RANGE FROM AROUND THE FREEZING MARK WEST OF
INTERSTATE 77...TO THE MID AND UPPER 40S ACROSS THE SOUTHSIDE.
SNOW SHOWERS CAN BE EXPECTED ALONG THE WESTERN RIDGES DURING THE
AFTERNOON...HOWEVER WINDS WILL NOT TRULY SHIFT NORTHWESTERLY UNTIL
EARLY EVENING ACROSS THE MOUNTAINS...WHEN THE BASE OF THE UPPER
TROUGH PASSES OVERHEAD. THE NORTHWESTERLY WIND SHIFT WILL BE FROM
THE PERFECT DIRECTION TO DRAW MOISTURE FROM LAKE MICHIGAN THURSDAY
EVENING INTO EARLY FRIDAY MORNING...WHEN THE HIGHEST SNOWFALL
ACCUMULATIONS ARE EXPECTED. 850MB TEMPERATURES FALLING INTO THE -16C
TO -20C RANGE ALONG THE WESTERN RIDGES WILL SUPPORT SNOW TO LIQUID
RATIOS IN THE 20:1 TO 25:1 RANGE. IN ADDITION...STRONG WINDS AND
UNIDIRECTIONAL FLOW MAY SUPPORT SNOW STREAMERS...WHERE NARROW BANDS
OF LOCALIZED HEAVY SNOW MAY OCCUR...POSSIBLY REACHING INTO THE NEW
RIVER VALLEY. WIND GUSTS OF 45 TO 50 MPH WILL BE COMMON ALONG THE
HIGHER RIDGES DURING THE EVENING...WELL INTO WIND ADVISORY CRITERIA.
BY SUNRISE FRIDAY...TEMPERATURES WILL HAVE FALLEN INTO THE POSITIVE
SINGLE DIGITS ACROSS THE MOUNTAINS...AND INTO THE LOW TO MID TEENS
ACROSS THE PIEDMONT. THESE COLD TEMPERATURES...WHEN FACTORING IN THE
STRONG WINDS...WILL CAUSE WIND CHILLS TO RANGE FROM NEAR ZERO ACROSS
THE SOUTHSIDE...TO THE NEGATIVE TEENS WEST OF THE BLUE RIDGE...
POSSIBLY AS LOW AS -30F IN A FEW SPOTS ALONG THE INTERSTATE 64
CORRIDOR. WIND SPEEDS WILL DECREASE HEADING INTO FRIDAY AFTERNOON...
ALLOWING WIND CHILLS TO RISE ABOVE ZERO MOST LOCATIONS. WINDS WILL
SHIFT MORE WESTERLY LATE IN THE DAY...WITH CLOUD COVER DECREASING...
WHICH WILL HELP AFTERNOON TEMPERATURES REBOUND INTO THE LOW 20S WEST
AND THE LOW 30S EAST. FRIDAY NIGHT TEMPERATURES WILL NOT BE AS
CHILLY...HOLDING IN THE TEENS MOST LOCATIONS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM EST MONDAY...
BOTH THE GFS AND ECMWF KEEP NORTHWEST FLOW WITH A TROUGH/LOW NEAR
JAMES BAY AND RIDGING OVER THE WESTERN U.S. THROUGH SUNDAY.
A SHORTWAVE TROUGH IS FORECASTED TO ROTATE AROUND THE LONGWAVE
PATTERN THROUGH THE GREAT LAKES REGION AND INTO NEW ENGLAND.
THE SOUTHERN EXTENT OF THE ENERGY AND MOISTURE WITH THIS FEATURE IS
SLIGHTLY DIFFERENT DEPENDING ON MODEL CHOICE. STILL LEANING TOWARDS
THE DRIER AND LESS AMPLIFIED SOLUTION WITH RICHER MOISTURE NORTH OF
THE AREA. PLACED ISOLATED TO SCATTERED POPS IN THE WEST WITH THE
BEST CHANCES IN THE NORTHWEST FOR SATURDAY INTO SATURDAY NIGHT.
WINDS INCREASE SATURDAY INTO SATURDAY NIGHT WITH HEALTHY 4 TO 8 MB 6
HOUR PRESSURE RISES. HIGHS ON SATURDAY WILL VARY FROM THE LOWER 20S
IN THE NORTHWEST MOUNTAINS TO THE LOWER 40S IN THE PIEDMONTS.
THE COMBINATION OF WINDS AND TEMPERATURES WILL PRODUCE WIND CHILLS
BELOW ZERO AT THE HIGHER ELEVATIONS SATURDAY NIGHT INTO SUNDAY
MORNING. ACTUAL LOW TEMPERATURES SATURDAY WILL DROP INTO SINGLE
DIGITS TO MID TEENS. HIGH PRESSURE WILL SLOWLY SLIDE EAST SUNDAY
INTO SUNDAY NIGHT. HIGHS SUNDAY WILL VARY FRO THE MID TEENS IN THE
NORTHWEST TO LOWER 30S IN THE SOUTHEAST. ANOTHER COLD SUNDAY NIGHT
WITH LOW TEMPERATURES GENERALLY FROM THE SINGLE DIGITS AND TEENS.
THE HIGH CENTER MOVES SOUTHEAST ON MONDAY AND UPPER FLOW FLATTENS.
THE HIGH CENTER PUSHES OFF INTO THE ATLANTIC OCEAN MONDAY NIGHT INTO
TUESDAY. A COLD FRONT APPROACHES FROM THE WEST ON TUESDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 705 AM EST TUESDAY...
THERE WAS IFR FOG AND FREEZING FOG ALONG THE WEST SLOPES OF THE
APPALACHIANS EARLY THIS MORNING. MODELS WERE SUGGESTING LITTLE
IMPROVEMENT IN THE IFR CONDITIONS AT KBLF BEFORE NOON.
WESTERN EDGE OF A LARGE SHIELD OF PRECIPITATION EXTENDED FROM
KLYH TO KMTV THIS MORNING WITH WIDESPREAD MVFR CEILINGS AND
VISIBILITIES WITHIN THE PRECIPITATION...INCLUDING AT KLYH AND
KDAN. GETTING A FEW REPORTS OF SNOW MIXING IN WITH THE FAR
WESTERN EDGE OF THE PRECIPITATION.
EXPECTING THE RAIN TO END AT KLYH AND KDAN BY 17Z/NOON BASED ON
THE HRRR AND LOCAL WRF MODELS. BUT LOW CONFIDENCE ON THE TIMING
OF CEILINGS AND VISIBILITIES TODAY. THE EARLIEST THERE MAY BE ANY
VFR CEILINGS IS 20Z/3PM. AS LOW PRESSURE DEEPENS OFF THE COAST
TODAY...ENOUGH OF A PRESSURE GRADIENT FOR WIND GUSTS AROUND 20
KNOTS AT KLYH AND KDAN.
HIGH PRESSURE BUILDS IN OVER THE MOUNTAINS TONIGHT RESULTING IN
LIGHT AND VARIABLE WINDS. HAVE ADDED IFR FOG AND CEILINGS IN AT
KBLF AND KLWB OVERNIGHT WITH MEDIUM CONFIDENCE OF FOG FORMATION.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE AND COLDER AIR WILL BUILD IN BEHIND THE COLD FRONT
WITH VFR FOR WEDNESDAY.
UPSLOPE SNOW SHOWERS ARE EXPECTED IN THE MOUNTAINS ON WEDNESDAY
NIGHT AND THURSDAY ALONG WITH A SHARP DROP IN TEMPERATURES
THURSDAY AND THURSDAY NIGHT BEHIND AN ARCTIC COLD FRONT. WIND
GUSTS BEHIND THE FRONT ON THURSDAY NIGHT MAY REACH 40-50 KNOTS IN
THE HIGHER ELEVATIONS.
HIGH PRESSURE BUILDS IN ALLOWING FOR DIMINISHING WINDS ON FRIDAY
WITH SOME LINGERING MVFR CIGS POSSIBLE OVER THE SOUTHEAST WEST VA
LOCATIONS.
ANOTHER FAST MOVING ARCTIC FRONT ARRIVES SATURDAY WITH A
RESUMPTION OF UPSLOPE SNOW SHOWERS INCLUDING MVFR CIGS/VSBYS ALONG
WITH INCREASING NORTHWEST WINDS THAT COULD AGAIN GUST TO 50 KNOTS
BY LATE IN THE DAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
442 AM EST TUE FEB 10 2015
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTH CAROLINAS WILL DRIFT EAST AND
OFFSHORE TODAY. HIGH PRESSURE WILL BUILD IN ON WEDNESDAY. AN
ARCTIC COLD FRONT MOVES THROUGH ON THURSDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EST TUESDAY...
MAIN 500 MB SHORT WAVE WAS TRACKING ACROSS NORTH CAROLINA WITH THE
ASSOCIATED SURFACE LOW OFF THE COAST OF SOUTH CAROLINA. MODELS HAVE
THE 500 MB LOW CUTTING OFF THIS MORNING THEN MOVING SLOWLY EAST. AT
THE SURFACE...THE LARGEST PRESSURE FALLS WERE OFF THE CAROLINA
COAST. BY LATE THIS MORNING THE LOW WILL BE WELL OFFSHORE.
WESTERN EDGE OF THE PRECIPITATION EXTENDED FROM LEXINGTON TO
HILLSVILLE AT 400 AM. THE PRECIPITATION WILL GRADUALLY END FROM WEST
TO EAST TODAY. LOCAL WRF AND HRRR MODELS SHOWED BACK EDGE EXITING
THE FAR EASTERN COUNTY WARNING AREA AROUND 1PM. THERE MAY BE SOME
CLEARING LATE IN THE DAY IN THE SOUTHERN FOOTHILLS BUT OVERALL CLOUD
COVER AND PRECIPITATION WILL HOLD TEMPERATURES DOWN. HAVE LEANED
TOWARD COOLER LAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY.
TEMPERATURES AND DEW POINTS WERE DROPPING THIS MORNING FROM BOTH THE
NORTH AND THE WEST. MESONET DATA SHOWED SOME TEMPERATURES AROUND
FREEZING ALONG THE BLUE RIDGE IN ROCKBRIDGE COUNTY...IN TAZEWELL
COUNTY AND IN THE HIGHER ELEVATIONS OF WATAUGA COUNTY. THESE HIGHER
ELEVATIONS WILL BE IN THE CLOUDS THIS MORNING SO SOME FREEZING FOG
IS POSSIBLE. VERY LIGHT ICING IN POSSIBLE ALONG THE BLUE RIDGE
BETWEEN ROCKBRIDGE AND AMHERST COUNTIES ON THE EXTREME WESTERN EDGE
OF THE PRECIPITATION SHIELD.
WINDS BECOME LIGHT AND VARIABLE OVER THE MOUNTAINS TONIGHT AS A
RIDGE OF HIGH PRESSURE MOVES INTO THE AREA. EXPECTING SOME GUSTY
WINDS IN THE EAST THIS MORNING THEN WINDS WILL DIMINISH THIS
AFTERNOON AND OVERNIGHT. STAYED CLOSE TO BIAS CORRECTED GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 345 AM EST TUESDAY...
WILL START WEDNESDAY OFF WITH ZONAL WEST TO EAST WIND FLOW BECOMING
INCREASINGLY ESTABLISHED FOR THE CENTRAL APPALACHIANS...AS LOW
PRESSURE OFF THE ATLANTIC COAST MOVES AWAY...AND A DEEP UPPER LEVEL
TROUGH BEGINS TO DIG ACROSS THE GREAT LAKES FROM NORTHERN CANADA.
HIGH PRESSURE WILL ALREADY BE ESTABLISHED IN THE LOW LEVELS...MAKING
FOR MOSTLY CLEAR SKIES. ABUNDANT SUNSHINE AND DOWNSLOPE WINDFLOW
WILL COMBINE TO PUSH AFTERNOON TEMPERATURES INTO THE UPPER 40S TO
MID 50S AREAWIDE. CLOUD COVER WILL INCREASE DURING THE EVENING
HOWEVER AS THE UPPER LEVEL TROUGH CONTINUES ITS APPROACH...WITH AN
ASSOCIATED ARCTIC COLD FRONT MAKING ITS WAY TOWARD THE APPALACHIAN
CHAIN THROUGH THE NIGHT...TRIGGERING LIGHT SNOW SHOWERS ACROSS THE
WESTERN RIDGES TOWARD DAWN THURSDAY.
THE ARCTIC COLD FRONT WILL BEGIN ITS PASSAGE ACROSS OUR AREA
THURSDAY MORNING...ENTERING SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN
EMPIRE AROUND SUNRISE...AND REACHING THE COASTAL PLAIN BY MID
AFTERNOON. HIGH TEMPERATURES FOR THURSDAY WILL OCCUR DURING THE
MORNING JUST AHEAD OF FRONTAL PASSAGE. THE AIR BEHIND THE FRONT IS
COLD ENOUGH THAT IT WILL OVERCOME NORMAL DAYTIME HEATING...AND
THEREFORE WE WILL SEE TEMPERATURES STEADILY DROP THROUGH THE
AFTERNOON. HIGHS WILL RANGE FROM AROUND THE FREEZING MARK WEST OF
INTERSTATE 77...TO THE MID AND UPPER 40S ACROSS THE SOUTHSIDE.
SNOW SHOWERS CAN BE EXPECTED ALONG THE WESTERN RIDGES DURING THE
AFTERNOON...HOWEVER WINDS WILL NOT TRULY SHIFT NORTHWESTERLY UNTIL
EARLY EVENING ACROSS THE MOUNTAINS...WHEN THE BASE OF THE UPPER
TROUGH PASSES OVERHEAD. THE NORTHWESTERLY WIND SHIFT WILL BE FROM
THE PERFECT DIRECTION TO DRAW MOISTURE FROM LAKE MICHIGAN THURSDAY
EVENING INTO EARLY FRIDAY MORNING...WHEN THE HIGHEST SNOWFALL
ACCUMULATIONS ARE EXPECTED. 850MB TEMPERATURES FALLING INTO THE -16C
TO -20C RANGE ALONG THE WESTERN RIDGES WILL SUPPORT SNOW TO LIQUID
RATIOS IN THE 20:1 TO 25:1 RANGE. IN ADDITION...STRONG WINDS AND
UNIDIRECTIONAL FLOW MAY SUPPORT SNOW STREAMERS...WHERE NARROW BANDS
OF LOCALIZED HEAVY SNOW MAY OCCUR...POSSIBLY REACHING INTO THE NEW
RIVER VALLEY. WIND GUSTS OF 45 TO 50 MPH WILL BE COMMON ALONG THE
HIGHER RIDGES DURING THE EVENING...WELL INTO WIND ADVISORY CRITERIA.
BY SUNRISE FRIDAY...TEMPERATURES WILL HAVE FALLEN INTO THE POSITIVE
SINGLE DIGITS ACROSS THE MOUNTAINS...AND INTO THE LOW TO MID TEENS
ACROSS THE PIEDMONT. THESE COLD TEMPERATURES...WHEN FACTORING IN THE
STRONG WINDS...WILL CAUSE WIND CHILLS TO RANGE FROM NEAR ZERO ACROSS
THE SOUTHSIDE...TO THE NEGATIVE TEENS WEST OF THE BLUE RIDGE...
POSSIBLY AS LOW AS -30F IN A FEW SPOTS ALONG THE INTERSTATE 64
CORRIDOR. WIND SPEEDS WILL DECREASE HEADING INTO FRIDAY AFTERNOON...
ALLOWING WIND CHILLS TO RISE ABOVE ZERO MOST LOCATIONS. WINDS WILL
SHIFT MORE WESTERLY LATE IN THE DAY...WITH CLOUD COVER DECREASING...
WHICH WILL HELP AFTERNOON TEMPERATURES REBOUND INTO THE LOW 20S WEST
AND THE LOW 30S EAST. FRIDAY NIGHT TEMPERATURES WILL NOT BE AS
CHILLY...HOLDING IN THE TEENS MOST LOCATIONS.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM EST MONDAY...
BOTH THE GFS AND ECMWF KEEP NORTHWEST FLOW WITH A TROUGH/LOW NEAR
JAMES BAY AND RIDGING OVER THE WESTERN U.S. THROUGH SUNDAY.
A SHORTWAVE TROUGH IS FORECASTED TO ROTATE AROUND THE LONGWAVE
PATTERN THROUGH THE GREAT LAKES REGION AND INTO NEW ENGLAND.
THE SOUTHERN EXTENT OF THE ENERGY AND MOISTURE WITH THIS FEATURE IS
SLIGHTLY DIFFERENT DEPENDING ON MODEL CHOICE. STILL LEANING TOWARDS
THE DRIER AND LESS AMPLIFIED SOLUTION WITH RICHER MOISTURE NORTH OF
THE AREA. PLACED ISOLATED TO SCATTERED POPS IN THE WEST WITH THE
BEST CHANCES IN THE NORTHWEST FOR SATURDAY INTO SATURDAY NIGHT.
WINDS INCREASE SATURDAY INTO SATURDAY NIGHT WITH HEALTHY 4 TO 8 MB 6
HOUR PRESSURE RISES. HIGHS ON SATURDAY WILL VARY FROM THE LOWER 20S
IN THE NORTHWEST MOUNTAINS TO THE LOWER 40S IN THE PIEDMONTS.
THE COMBINATION OF WINDS AND TEMPERATURES WILL PRODUCE WIND CHILLS
BELOW ZERO AT THE HIGHER ELEVATIONS SATURDAY NIGHT INTO SUNDAY
MORNING. ACTUAL LOW TEMPERATURES SATURDAY WILL DROP INTO SINGLE
DIGITS TO MID TEENS. HIGH PRESSURE WILL SLOWLY SLIDE EAST SUNDAY
INTO SUNDAY NIGHT. HIGHS SUNDAY WILL VARY FRO THE MID TEENS IN THE
NORTHWEST TO LOWER 30S IN THE SOUTHEAST. ANOTHER COLD SUNDAY NIGHT
WITH LOW TEMPERATURES GENERALLY FROM THE SINGLE DIGITS AND TEENS.
THE HIGH CENTER MOVES SOUTHEAST ON MONDAY AND UPPER FLOW FLATTENS.
THE HIGH CENTER PUSHES OFF INTO THE ATLANTIC OCEAN MONDAY NIGHT INTO
TUESDAY. A COLD FRONT APPROACHES FROM THE WEST ON TUESDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AS OF 1115 PM EST MONDAY...
RATHER COMPLEX SCENARIO TONIGHT WITH WEAK LOW PRESSURE OVER THE
CAROLINAS AND A RESIDUAL FRONT NOW TO THE SOUTH OF THE REGION.
RAINFALL REMAINS QUITE PATCHY IN ALL AREAS EXCEPT OVER THE SE
WHERE CORRIDOR OF LIFT TO THE NW OF THE FRONT AND WEAK SURFACE
LOW HAS AN AXIS OF LIGHT/MODERATE RAINFALL PERSISTING AROUND KDAN
IN THE DEVELOPING DEFORMATION ZONE. OVERALL DEEPER MOISTURE WILL
BE SLOW TO EXIT GIVEN GRADUAL CUTTING OFF NATURE TO THE 5H SYSTEM
ALOFT WITH MAIN CHANGES WITH LOW LEVEL ADVECTION OF MOISTURE AND
COLDER AIR THROUGH MORNING. THUS STILL EXPECTING THE DEVELOPMENT
OF IFR MOST SITES OVERNIGHT WITH NE FLOW BLUE RIDGE EAST AND A
MORE NW UPSLOPE COMPONENT OUT WEST. OTHERWISE APPEARS MOST CLOUD
BASES TO DROP INTO IFR SHORTLY AFTER MIDNIGHT...WITH MVFR TO IFR
VSBYS POSSIBLE AT KDAN...AND IN SPOTS OVER THE WEST IN FOG
INCLUDING LIGHT SNOW/SLEET OR PATCHY FREEZING RAIN LATE.
SURFACE LOW SHIFTS OFFSHORE EARLY TUESDAY AND DEEPENS AS THE UPPER
SYSTEM CATCHES UP WHICH HELPS TO HOLD THE DEFORMATION ZONE OVER SE
SECTIONS INTO AT LEAST TUESDAY MORNING. BUFKIT SOUNDINGS HAVE
CONTINUED TO SLOW DOWN THE EXODUS OF DEEPER MOISTURE FROM
KLYH/KDAN SO LINGERING SOME LIGHT RAIN IN BOTH LOCATIONS INTO
TUESDAY MORNING. APPEARS WILL STAY LIQUID GIVEN RATHER WARM
BOUNDARY LAYER AND TEMPS ALOFT REMAINING JUST ABOVE FREEZING BUT
SOMETHING TO WATCH AROUND KLYH WHERE COULD BE A BRIEF PERIOD OF
-SN/PL NEAR THE END OF THE EVENT. OTHERWISE LOOKING FOR GRADUAL
DRYING FROM THE NORTH TUESDAY AFTERNOON BUT WILL BE SLOW UNDER THE
INVERSION SO KEEPING MVFR CIGS MOST SPOTS UNTIL EARLY OR MID
AFTERNOON BEFORE LIFTING INTO VFR LEVELS INTO TUESDAY EVENING
OUTSIDE OF KBLF WHERE FORECAST SOUNDINGS SHOW MVFR CIGS
PERSISTING.
EXTENDED AVIATION DISCUSSION...
HIGH PRESSURE AND COLDER AIR IS EXPECTED TO BUILD IN BEHIND THE
COLD FRONT WITH A RETURN TO VFR FOR WEDNESDAY. UPSLOPE SNOW
SHOWERS ARE EXPECTED IN THE MOUNTAINS ON WEDNESDAY NIGHT AND
THURSDAY ALONG WITH A SHARP DROP IN TEMPERATURES THURSDAY AND
THURSDAY NIGHT BEHIND AN ARCTIC COLD FRONT. WIND GUSTS BEHIND THE
FRONT ON THURSDAY NIGHT MAY REACH 40-50 KNOTS IN THE HIGHER
ELEVATIONS. HIGH PRESSURE BUILDS IN ALLOWING FOR DIMINISHING WINDS
ON FRIDAY WITH SOME LINGERING MVFR CIGS POSSIBLE OVER THE
SOUTHEAST WEST VA LOCATIONS. ANOTHER FAST MOVING ARCTIC FRONT
ARRIVES SATURDAY WITH A RESUMPTION OF UPSLOPE SNOW SHOWERS
INCLUDING MVFR CIGS/VSBYS ALONG WITH INCREASING NORTHWEST WINDS
THAT COULD AGAIN GUST TO 50 KNOTS BY LATE IN THE DAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...AMS/JH/MBS
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
929 PM CST WED FEB 11 2015
.UPDATE...
THE HRRR HAS THE BEST HANDLE ON THE APPROACHING SNOW
SHOWERS WITH THE SIMULATED RADAR OUTPUT...ALTHOUGH THERE IS A
DELAY IN SPINNING UP THE SNOW SHOWERS.
WIND CHILLS SHOULD DROP TO AROUND 15 BELOW TO 18 BELOW BY SUNRISE
AND INTO MID MORNING.
&&
.AVIATION/06Z TAFS/...
MVFR CIGS WILL SPREAD ACROSS THE AREA FROM THE WEST TONIGHT ALONG
WITH A PERIOD OF SNOW SHOWERS. MAINLY MVFR VSBYS BUT BRIEF IFR
VSBYS POSSIBLE...ESPECIALLY AS WINDS PICK UP.
ACCUMULATIONS...IF ANY...WILL BE A DUSTING TO A COUPLE TENTHS OF
AN INCH AT BEST. EXPECT VFR CONDITIONS STARTING THURSDAY MORNING
AS CLOUDS SCATTER OUT.
&&
.MARINE...
GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH THURSDAY MORNING. A
SMALL CRAFT ADVISORY IS IN EFFECT THROUGH MIDNIGHT. STRONG NORTHWEST
WINDS AND COLD ADVECTION WILL INCREASE TONIGHT AS A STRONG UPPER
TROUGH MOVES THROUGH THE REGION. NORTHWEST GALE FORCE WIND GUSTS
ARE EXPECTED TONIGHT THROUGH THURSDAY MORNING AND A GALE WARNING
IS IN EFFECT FROM MIDNIGHT TO NOON ON THURSDAY. WAVES WILL BUILD
TO 3 TO 7 FEET WITH HIGHEST WAVES TOWARD OPEN WATER. A HEAVY
FREEZING SPRAY WARNING IS ALSO IN EFFECT DUE TO THE VERY COLD
TEMPERATURES AND HIGH WAVES.
&&
.PREV DISCUSSION... /ISSUED 321 PM CST WED FEB 11 2015/
TONIGHT AND THURSDAY - CONFIDENCE MEDIUM
THE BACK EDGE OF CLOUD COVER IS SLOWLY PUSHING ACROSS
WESTERN WISCONSIN. MESO MODELS INDICATE THIS DRIER AIR WILL MOVE INTO
SOUTHERN WISCONSIN THIS EVENING SO SOME SCATTERING OF CLOUDS IS
LIKELY FOR A FEW HOURS. A DEEP 500MB TROUGH WITH STRONG
VORTICITY MAXIMUM DIVES SOUTH THROUGH THE STATE OVERNIGHT. THERE IS
WEAK LOW TO MID LEVEL FRONTOGENESIS...Q VECTOR CONVERGENCE..AND STEEP
LOW LEVEL LAPSE RATES OVER SOUTHERN WI MAINLY BEFORE MIDNIGHT AHEAD
OF THE VORT MAX. THUS HAVE A CHANCE OF LIGHT SNOW SHOWERS WITH A
DUSTING TO A COUPLE TENTHS OF SNOW POSSIBLE.
BRISK NORTHWEST WINDS WILL CONTINUE THROUGH THURSDAY MORNING. MODELS
ARE IN GOOD AGREEMENT INDICATING 925 MB TEMPS OF AROUND -20C
THURSDAY MORNING YIELDING SINGLE DIGITS TEMPS TONIGHT AND TOMORROW.
WIND CHILL VALUES LOOK TO BE NEAR -20C FOR A FEW HOURS IN THE
NORTHEAST CWA. SKIES WILL BE MOSTLY SUNNY AND WINDS WILL DIMINISH
WEST TO EAST ACROSS THE STATE ON THURSDAY AS HIGH PRESSURE APPROACHES
FROM THE WEST.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
MEDIUM.
A PROGRESSIVE HIGH PRESSURE SYSTEM WILL SLIDE ACROSS THE AREA
THURSDAY NIGHT WITH ANOTHER MID LEVEL SHORT WAVE WITH LEADING
WARM AIR ADVECTION HITTING ON FRIDAY. THE RIDGE WILL BRING A GOOD
OPPORTUNITY FOR STRONG RADIATIONAL COOLING IN THE EVENING.
HOWEVER...HOW LOW TEMPS GO DEPENDS ON HOW QUICK THE HIGH CLOUDS
FROM THE APPROACHING WARM ADVECTION GET IN HERE AND PUT THE SKIDS
ON THE DROP. THE ECMWF IS VERY AGGRESSIVE WITH THE LOW TEMPS SO
I/LL DO SOMEWHAT OF A BLEND OF THE EC AND THE CONSENSUS OF OTHER
MODELS. THE COLDEST LOCATION WILL BE IN THE EASTERN FORECAST
AREA...WHILE THE HILLS IN THE SOUTHWEST WILL LIKELY SEE A RETURN
FLOW /MORE WIND/ AND CLOUDS EARLIER...HALTING THE TEMP DROP.
MODEL SOUNDINGS SHOW DEEP SATURATION WITH THE TROF COMING IN ON
FRIDAY. BOTH THE NAM AND THE GFS SHOW SATURATION IN THE DENDRITE
ZONE EXCEEDING 10KFT. UPPED POPS A BIT MORE...AND THIS TREND MAY
CONTINUE IF MODELS REMAIN CONSISTENT. AMOUNTS SHOULD STAY AT AN
INCH OR LESS...SO NOTHING MAJOR. WILL HANG ONTO SOME LIGHT SNOW
INTO THE EVENING AS LAPSE RATES REALLY STEEPEN WITH STRONG COLD
AIR ADVECTION MOVING IN ON BRISK NORTHERLY WINDS.
SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
A VERY COLD AIRMASS WILL SETTLE ACROSS THE REGION THIS WEEKEND AS
HIGH PRESSURE MOVES IN. IT WILL BE DRY...BUT HIGH TEMPS BOTH DAYS
WILL ONLY BE IN THE SINGLE DIGITS ABOVE ZERO. SATURDAY NIGHT WILL
FEATURE SOME OF THE COLDEST TEMPS WE/VE SEEN ALL SEASON. LOWS
SATURDAY NIGHT MAY BE 5 BELOW TO NEARLY 15 BELOW IN SOME SPOTS.
WIND CHILLS 20 TO 30 BELOW.
MONDAY AND TUESDAY...FORECAST CONFIDENCE IS LOW.
THIS PERIOD FEATURES A SURFACE LOW PRESSURE SYSTEM THAT THE GFS
AND THE ECMWF TAKE ACROSS THE LOWER MS RIVER VALLEY...THEN UP THE
EAST COAST. THE NORTHERN EXTENT OF THE PRECIP SHIELD JUST CLIPS
SOUTHERN WISCONSIN WITH SOME LIGHT SNOW. WE ALWAYS HAVE TO KEEP AN
EYE ON THESE SYSTEMS AS THEY TEND TO DRIFT FARTHER NORTH WITH
TIME...BUT NOT ALWAYS. IN FACT...THE MODELS ON THIS MORNING/S 12Z
RUN HAVE SHIFTED SOUTH. THE UPPER LEVEL PATTERN UNDERGOES A MAJOR
TRANSFORMATION DURING THIS TIME WITH A DEEP LATITUDINAL TROF
DIGGING OVER THE CENTRAL HIGH PLAINS...A SHIFT FROM OUR COLD
NORTHWEST FLOW. SO AGAIN...THERE IS MUCH TO BE UNCERTAIN ABOUT.
AVIATION/00Z TAFS/...
CLEARING LINE IS SLOWLY PUSHING ACROSS WESTERN WISCONSIN. THERE MAY
BE A FEW HOURS OF FEW TO SCATTERED CLOUDS LATE THIS AFTERNOON AND
EVENING. THEN SCATTERED LIGHT SNOW SHOWERS AND 1500 TO 2000FT
CEILINGS ARE EXPECTED MAINLY BEFORE MIDNIGHT. THINK
ACCUMULATIONS...IF ANY...WILL BE A DUSTING TO A COUPLE TENTHS OF AN
INCH AT BEST. VISIBILITIES COULD BRIEFLY GET DOWN TO 1-3SM WITHIN
SOME OF THE SHOWERS. EXPECT VFR CONDITIONS STARTING THURSDAY
MORNING.
GUSTY NORTHWEST WINDS WILL CONTINUE THROUGH THURSDAY MORNING. A
SMALL CRAFT ADVISORY IS IN EFFECT THROUGH MIDNIGHT. STRONG NORTHWEST
WINDS AND COLD ADVECTION WILL INCREASE TONIGHT AS A STRONG UPPER
TROUGH MOVES THROUGH THE REGION. NORTHWESTERLY GALE FORCE WIND GUSTS
ARE POSSIBLE TONIGHT THROUGH THURSDAY MORNING AND A GALE WARNING IS
IN EFFECT FROM MIDNIGHT TO NOON ON THU. WAVES WILL BUILD TO 3 TO 8
FEET WITH HIGHEST WAVES TOWARD OPEN WATER. A HEAVY FREEZING SPRAY
WARNING IS ALSO IN EFFECT DUE TO THE VERY COLD TEMPERATURES AND HIGH
WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...HEAVY FREEZING SPRAY WARNING FROM MIDNIGHT TONIGHT TO NOON CST
THURSDAY FOR LMZ643>646.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
GALE WARNING FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY FOR
LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/THURSDAY AND AVIATION/MARINE...MARQUARDT
THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
409 AM CST TUE FEB 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CST TUE FEB 10 2015
AT 3 PM...A VIGOROUS VORT MAX WAS LOCATED OVER SOUTH CENTRAL SOUTH
DAKOTA. THIS SYSTEM SHOWS UP REALLY WELL ON THE WATER VAPOR
IMAGERY. SIOUX FALLS AND ABERDEEN RADARS ARE ALREADY SHOWING SOME
CONVECTIVE ELEMENTS TO THEIR PRECIPITATION ECHOS OVER EASTERN
SOUTH DAKOTA. VAD WIND PROFILES SHOW STRONG 925 MB MOISTURE
TRANSPORT AHEAD OF THIS WAVE. HASTINGS NEBRASKA HAS A 925 MB WIND
OF 50 KNOTS AND SIOUX FALLS IS 25 KNOTS. THE 10.00Z MESO MODELS
ARE IN FAIRLY GOOD AGREEMENT THAT THIS SYSTEM WILL MOVE EAST TO
THE INTERSTATE 35 CORRIDOR BY NOON. AHEAD OF THIS WAVE THERE WILL
BE STRONG 900 TO 800 MB AND 700 TO 500 MB FRONTOGENESIS. THIS
IS LOCATED BELOW A LAYER INSTABILITY LOCATED BETWEEN 500 AND
300 MB. LAPSE RATES IN THIS LAYER ARE RUNNING 8 TO 9 C/KM. IN
ADDITION...CAPES ARE RUNNING UP TO 200 J/KG ALONG AND SOUTH OF
INTERSTATE 94. DUE TO THIS INSTABILITY ADDED ISOLATED THUNDER TO
THE FORECAST. THIS CONVECTION GREATLY COMPLICATES THE
PRECIPITATION TYPE THE FORECAST AS IT COULD RESULT IN SLEET AND
SNOW. IN ADDITION...THE CONVECTION COULD INCREASE THE SNOW RATES.
THIS BAND OF PRECIPITATION WILL LAST 2 TO 3 HOURS...AND THEN
TRANSITION TO FREEZING DRIZZLE/DRIZZLE AS WE LOSE ICE. SOME OF THE
MESO MODELS SHOW THAT AS THE COMMA HEAD /ASSOCIATED WITH THE VORT
MAX/ MOVES ACROSS THE AREA...THERE COULD BE THE TRANSITION BACK TO
SNOW AGAIN. TOTAL SNOW AMOUNTS OF 2 TO 4 INCHES OF SNOW LOOK
LIKELY ACROSS CLARK AND TAYLOR COUNTIES FROM THIS AFTERNOON
THROUGH MIDNIGHT...1 TO 2 INCHES ALONG AND NORTH OF INTERSTATE
90...AND LESS THAN AN INCH ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. IN ADDITION TO THE SNOW...THERE WILL UP TO A TENTH OF
AN INCH OF ICE. DUE TO THE COMBINATION OF WINTER PRECIPITATION
TYPES...ISSUED A WINTER WEATHER ADVISORY FOR MOST OF THE AREA. THE
ONLY EXCEPTION ARE FAYETTE AND CLAYTON COUNTIES IN NORTHEAST
IOWA...AND GRANT COUNTY IN SOUTHWEST WISCONSIN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 409 AM CST TUE FEB 10 2015
ON WEDNESDAY MORNING...STRONG COLD AIR ADVECTION WILL MOVE INTO
THE AREA. THIS WILL CAUSE TEMPERATURES TO SLOWLY FALL.
ON WEDNESDAY AFTERNOON AND NIGHT...THE MODELS CONTINUE TO SHOW
THAT A VIGOROUS SHORT WAVE TROUGH WILL MOVE SOUTH THROUGH THE
AREA. WITH 950 TO 900 MB LAPSE RATES AROUND 8 C/KM...THERE WILL BE
ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED SNOW SHOWERS.
ADDITIONAL SNOWFALL AMOUNTS WILL BE LESS THAN A HALF INCH. IN
ADDITION TO THE SNOW...NORTHWEST WINDS WILL GUST INTO THE 30 TO 40
MPH RANGE WEST OF THE MISSISSIPPI RIVER AND 20 TO 30 MPH ACROSS
THE REMAINDER OF THE AREA. THIS COULD CAUSE SOME BLOWING AND
DRIFTING SNOW ALONG AND NORTH OF INTERSTATE 90.
ON FRIDAY NIGHT AND SATURDAY MORNING...THE MODELS HAVE SHIFTED
THE NEXT STRONG SHORT WAVE A BIT FURTHER EAST. AS A RESULT...THE
STRONGEST WIND GUSTS WILL JUST MISS OUR AREA. HOWEVER...THEY WILL
STILL GUST INTO THE 25 TO 35 MPH RANGE ACROSS WESTERN
WISCONSIN...AND 20 TO 30 MPH WEST OF THE MISSISSIPPI RIVER.
WITH OUR AREA BEING IN THE WESTERN PERIPHERY OF THIS COLD AIR
MASS...WE CONTINUE TO SEE SOME UNCERTAINTY WITH THE TEMPERATURES.
HOWEVER THE ECMWF STANDARD DEVIATIONS HAVE DROPPED FROM WHERE
THEY WERE YESTERDAY. SATURDAY CONTINUES TO LOOK LIKE THE COLDEST
DAY. OUR CURRENT FORECAST FOR THAT DAY STILL LOOKS TO BE A BIT
TOO WARM COMPARED TO THE GFS AND ECMWF GUIDANCE. IF THIS TREND
CONTINUES...WE MAY HAVE TO DROP IT ANOTHER 5 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1116 PM CST MON FEB 9 2015
SHORT WAVE TROUGH CURRENTLY OVER EASTERN WYOMING WILL CONTINUE TO
MOVE NORTHEAST AND ACROSS THE REGION TUESDAY. THE 10.00Z NAM SHOWS
THAT THIS WAVE SHOULD BE ABLE TO PRODUCE A SHORT PERIOD OF STRONG
PV ADVECTION IN THE 500-300 MB LAYER TUESDAY AFTERNOON. AS A WEAK
SURFACE LOW TRACKS ACROSS CENTRAL MINNESOTA...A WARM FRONT IS
EXPECTED TO COME ACROSS WITH THE SHORT WAVE TROUGH WITH 5 TO 6
UBAR/S OF UP GLIDE ON THE 285K ISENTROPIC SURFACE ALONG AND BEHIND
THE WARM FRONT. THE FRONTOGENESIS LOOKS TO BE VERY WEAK AND
DISORGANIZED WITH THIS SYSTEM. THE RAP FOR SEVERAL RUNS HAS BEEN
SUGGESTING THAT SOME WEAK INSTABILITY COULD COME IN WITH THIS
SYSTEM WITH UP TO 100 J/KG OF MU CAPE IN THE WARM SECTOR AND TRIES
TO SHOW THE SNOW GOING CONVECTIVE WITH RATES OF 1 TO 2 INCHES PER
HOUR. HOWEVER...THE HRRR KEEPS THESE CONDITIONS FARTHER
NORTH...CLOSER TO THE SURFACE LOW AND SHORT WAVE TROUGH WHILE THE
NAM DOES NOT SHOW THIS AT ALL. FOR NOW...FEEL THE RAP IS A BIT OF
AN OUTLIER AND WILL NOT INDICATE ANY CONVECTIVE SNOWS. THERE
SHOULD STILL BE ENOUGH FORCING FOR A GOOD BURST OF SNOW ALONG AND
BEHIND THE WARM FRONT WITH BOTH TAF SITES GOING DOWN TO IFR FOR A
TWO TO THREE HOUR PERIOD BEFORE LIKELY COMING BACK UP TO MVFR. HOW
LONG THE LIGHT SNOW THEN PERSISTS IS SOMEWHAT QUESTIONABLE. WITH
THE BEST FORCING OFF TO THE EAST WITH THE SHORT WAVE
TROUGH...THERE IS JUST SOME WEAK ISENTROPIC UP GLIDE IN THE WARM
SECTOR. IF THIS IS ENOUGH TO PRODUCE SOME PRECIPITATION...THE NAM
WOULD SUGGEST A LOSS OF ICE FOR A CHANCE OF FREEZING DRIZZLE
TUESDAY EVENING. FOR NOW...HAVE NOT INCLUDED THIS AS CONFIDENCE IS
NOT HIGH ENOUGH THAT THERE WILL BE ANY PRECIPITATION AT THAT TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ032.
WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR WIZ017-029-033-034-041>044-053>055.
MN...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR MNZ079-086>088-094>096.
IA...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ008>011-018-019.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1116 PM CST MON FEB 9 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM CST MON FEB 9 2015
MODELS REMAIN IN GOOD AGREEMENT WITH SLIDING AN UPPER LEVEL
SHORTWAVE TROUGH ACROSS THE PLAINS AND THEN OVER NORTHERN PARTS OF
THE REGION TUE. CONSENSUS HAS SHIFTED TO A MORE NORTHERN TRACK FOR
THIS SYSTEM...ALA WHAT THE EC WAS SUGGESTING YESTERDAY. WILL FOLLOW
THIS FOR PCPN CHANCES. IN ADDITION...TRENDS ALSO HAVE MOVED TO A
SLIGHTLY SLOWER SOLUTION...WHICH LOOKS REASONABLE.
SWATH OF OF 925-700 MB WARMING LEADS THE SHORTWAVE...WITH SOME OF
THIS LIFT LIKELY GOING INTO DEEPENING THE SATURATION. GOOD RISES ON
THE 280-295 K SURFACES TOO...GREATER ACROSS CENTRAL MN/NORTHERN WI
TUE AFTERNOON-EVENING. THE DEEPER...STRONG QG CONVERGENCE IS LOCATED
IN THE SAME AREA-TIME FRAME.
NORTH-SOUTH RUNNING TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS
SUGGEST THE SATURATED LAYER WOULD BE COLD ENOUGH TO SUPPORT ICE BY
THE TIME PCPN BECOMES LIKELY. THE SATURATION LOOKS LIKE IT WILL COME
FROM THE TOP DOWN. GFS/NAM BUFKIT SOUNDINGS HINT THAT THERE COULD BE
NEAR SFC MOISTURE TO CONTEND WITH...BUT DON/T THINK THIS IS A
CERTAINTY. AND IF SO...THAT CLOUD LAYER LOOKS TO SHALLOW TO SUPPORT
DRIZZLE PRODUCTION...ESPECIALLY INITIALLY. STILL SEE SOME THREAT FOR
FREEZING DRIZZLE ACROSS THE FAR SOUTH AND WILL CONTINUE A MENTION
FOR PARTS OF NORTHEAST IA/SOUTHWEST WI.
FOR SNOW TOTALS...HIGHEST AMOUNTS CONTINUE TO HOLD TO THE
NORTH...WITH RATIOS ON THE LOWER SIDE. 2-3 INCHES LOOK REASONABLE
NORTH OF HIGHWAY 29 IN NORTH-CENTRAL WI...DECREASING QUICKLY AS YOU
MOVE SOUTH TOWARD I-90.
WINDS WILL PICK UP BY WEDNESDAY IN THE WAKE OF THE DEPARTING LOW
PRESSURE SYSTEM. TIGHT PRESSURE GRADIENT SHOULD RESULT IN SUSTAINED
WIND OF 15 TO 25 MPH...WITH GUSTS UPWARDS OF 35 MPH IN THE WIND
PRONE AREAS. COULD HAVE SOME BLOWING SNOW ISSUES FOR THOSE LOCATIONS
WHERE THE SNOW FALLS TUE - MOSTLY NORTH OF I-90. CURRENT SNOWPACK IS
OLDER AND WILL BE HARD TO MOVE.
WITH WINDS STAYING STIFF INTO THU MORNING...AND A PUSH OF COLD AIR
MOVING DOWN FROM CANADA...WIND CHILL ARE EXPECTED TO FALL INTO THE
-15 TO -25 RANGE. MIGHT NEED A WIND CHILL ADVISORY THU MORNING FOR A
PORTION OF THE AREA.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 245 PM CST MON FEB 9 2015
GFS/ECMWF IN GOOD AGREEMENT WITH DROPPING A VIGOROUS UPPER LEVEL
SHORTWAVE TROUGH OVER THE GREAT LAKES FRI AFTERNOON-SAT. CURRENT
TRACK WOULD KEEP THE BULK OF THE SYSTEM/S FORCING EAST OF THE LOCAL
FORECAST AREA. WEST-EAST RUNNING X-SECTIONS AND SOUNDINGS POINT TO A
SHALLOWING IN THE CLOUD LAYER THE FARTHER WEST YOU MOVE FROM THE
HEART OF THE SHORTWAVE...BUT THE SATURATED LAYER IS STILL COLD
ENOUGH FOR ICE IN THE CLOUD. DON/T THINK FREEZING DRIZZLE WILL BE
CONCERN. BUT...GIVEN THE PROXIMITY OF THE SYSTEM AND SOME LOW LEVEL
WARM AIR ADVECTION...CAN/T RULE OUT A CHANCE FOR LIGHT SNOW EAST OF
THE MISSISSIPPI RIVER. AMOUNTS LOOK MINIMAL AT THIS TIME. EXPECT
SOME SHIFT IN THE SYSTEM AS WE APPROACH THE WEEKEND.
WHILE THE SHORTWAVE ISN/T EXPECTED TO BRING MUCH SNOW TO THE AREA AT
THIS TIME...IT DOES LOOK LIKE IT WILL PACK A PUNCH WHEN IT COMES TO
WINDS. INCREASING PRESSURE GRADIENT FOR FRI NIGHT/SAT MORNING WITH A
STRONG PRESSURE COUPLET. PRESSURE GRADIENT MAGNITUDES VIA THE GFS
AND ECMWF SUGGEST GUSTS FROM 40 TO 50 KTS EAST OF THE MISSISSIPPI
RIVER...AS DOES MOMENTUM TRANSFER TO THE SFC IN BUFKIT SOUNDINGS.
THIS DOESN/T TAKE INTO ACCOUNT THE HIGHER WINDS THAT USUALLY OCCUR
IN THE OPEN/UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA. STRONG
WINDS WOULD LIKELY OCCUR FOR THE BETTER PART OF SAT...WITH
IMPROVEMENT BY LATE AFTERNOON AS HIGH PRESSURE STARTS TO PUSH IN
FROM THE WEST.
AS IT STANDS RIGHT NOW...HIGH WIND WATCHES COULD BE NEEDED...WITH
UPGRADES TO ADVISORIES OR WARNINGS FOR FRI NIGHT-SATURDAY. BLOWING
SNOW WOULD LIKELY ALSO BECOME AN ISSUE WHERE LIGHT SNOW HAS
RECENTLY FALLEN. TRAVEL COULD/WOULD BE IMPACTED.
ANOTHER SHOT OF ARCTIC AIR FOR THE WEEKEND WITH 850 MB TEMPS AS COLD
AS -28 C SAT. HIGHS COULD STRUGGLE TO REACH THE TEENS. ADD IN THE
STRONG WINDS...AND WIND CHILLS COULD BECOME A CONCERN FRI NIGHT/SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1116 PM CST MON FEB 9 2015
SHORT WAVE TROUGH CURRENTLY OVER EASTERN WYOMING WILL CONTINUE TO
MOVE NORTHEAST AND ACROSS THE REGION TUESDAY. THE 10.00Z NAM SHOWS
THAT THIS WAVE SHOULD BE ABLE TO PRODUCE A SHORT PERIOD OF STRONG
PV ADVECTION IN THE 500-300 MB LAYER TUESDAY AFTERNOON. AS A WEAK
SURFACE LOW TRACKS ACROSS CENTRAL MINNESOTA...A WARM FRONT IS
EXPECTED TO COME ACROSS WITH THE SHORT WAVE TROUGH WITH 5 TO 6
UBAR/S OF UP GLIDE ON THE 285K ISENTROPIC SURFACE ALONG AND BEHIND
THE WARM FRONT. THE FRONTOGENESIS LOOKS TO BE VERY WEAK AND
DISORGANIZED WITH THIS SYSTEM. THE RAP FOR SEVERAL RUNS HAS BEEN
SUGGESTING THAT SOME WEAK INSTABILITY COULD COME IN WITH THIS
SYSTEM WITH UP TO 100 J/KG OF MU CAPE IN THE WARM SECTOR AND TRIES
TO SHOW THE SNOW GOING CONVECTIVE WITH RATES OF 1 TO 2 INCHES PER
HOUR. HOWEVER...THE HRRR KEEPS THESE CONDITIONS FARTHER
NORTH...CLOSER TO THE SURFACE LOW AND SHORT WAVE TROUGH WHILE THE
NAM DOES NOT SHOW THIS AT ALL. FOR NOW...FEEL THE RAP IS A BIT OF
AN OUTLIER AND WILL NOT INDICATE ANY CONVECTIVE SNOWS. THERE
SHOULD STILL BE ENOUGH FORCING FOR A GOOD BURST OF SNOW ALONG AND
BEHIND THE WARM FRONT WITH BOTH TAF SITES GOING DOWN TO IFR FOR A
TWO TO THREE HOUR PERIOD BEFORE LIKELY COMING BACK UP TO MVFR. HOW
LONG THE LIGHT SNOW THEN PERSISTS IS SOMEWHAT QUESTIONABLE. WITH
THE BEST FORCING OFF TO THE EAST WITH THE SHORT WAVE
TROUGH...THERE IS JUST SOME WEAK ISENTROPIC UP GLIDE IN THE WARM
SECTOR. IF THIS IS ENOUGH TO PRODUCE SOME PRECIPITATION...THE NAM
WOULD SUGGEST A LOSS OF ICE FOR A CHANCE OF FREEZING DRIZZLE
TUESDAY EVENING. FOR NOW...HAVE NOT INCLUDED THIS AS CONFIDENCE IS
NOT HIGH ENOUGH THAT THERE WILL BE ANY PRECIPITATION AT THAT TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 AM CST THU FEB 12 2015
.SHORT TERM...
254 AM CST
THROUGH FRIDAY...
MAIN FOCUS FOR TODAY WILL BE ON THE DEVELOPING LES BAND/S...AND
POSITIONING. LOBE OF VORTICITY WAS PIVOTING EAST ACROSS NORTHERN IL
EARLY THIS MORNING...WITH SOME MOISTURE BEING SQUEEZED OUT AND
PRODUCING FLURRIES/LGT SNOW. WITH THE PROGRESSIVE FLOW...THIS
FEATURE SHOULD HAVE PUSHED EAST OF THE FORECAST AREA SHORTLY AFT
DAYBREAK. IN ADDITION EXPECT JUST SOME LINGERING FLURRIES...BUT SHUD
END SHORTLY AFTER DAYBREAK. RADAR IMAGERY OVER LAKE MICHIGAN
INDICATES A LITTLE ORGANIZATION TRYING TO FORM ALONG THE EASTERN
SHORE...HOWEVER IT COULD STILL TAKE A FEW HOURS UNTIL THE BETTER
BAND DEVELOPS. WITH THE SHORTWAVE PIVOTING EAST ACROSS THE
REGION...WINDS ARE QUICKLY TURNING TO A 330-350 DEG DIRECTION. THIS
WILL TAP INTO THE LONGER FETCH FOR LES DEVELOPMENT...WHICH IS
SUPPORTED BY THE HI-RES GUIDANCE.
WEAK CONVERGENCE WILL DEVELOP ALONG THE EASTERN SHORE OF LAKE
MICHIGAN ARND DAYBREAK...WITH A WEAK MESO-LOW TRYING TO FORM BASED
ON THE LOCAL ARW SOLUTION. LAPSE RATES REMAIN STEEP THROUGH EARLY
THIS EVE...WITH THE MESO-LOW PROGGED TO BLEED WEST/SOUTHWEST ACROSS
THE SOUTHERN TIP OF THE LAKE. THIS WOULD POSSIBLY BRING THE LES BAND
WEST TOWARDS LAKE COUNTY INDIANA...BUT FOR THE MOST PART IT STILL
APPEARS THE BULK OF THE SNOW BAND WILL IMPACT A PORTION OF NORTHEAST
PORTER COUNTY TO SOUTHWEST LWR MI. THE GRADIENT TIGHTENS UP THIS
MORNING...AND WILL ALLOW NORTH TO SLIGHTLY NORTHWEST WINDS TO GUST
BETWEEN 30-40MPH. THE GRADIENT IS JUST A TOUCH STRONGER OVER THE
LAKE...WHICH COULD ALLOW SOME HIGHER GUSTS TO 45 MPH ACROSS
LAKE/PORTER COUNTIES. NO PLANS TO CHANGE THE CURRENT HEADLINE...WITH
TOTAL SNOWFALL BETWEEN 3 AND 6 INCHES IN FAR NORTHEAST PORTER
COUNTY...HOWEVER IF THE CONVERGENCE AND MESO-LOW CAN DRIFT WEST
EARLIER...THIS WOULD BRING HIGHER TOTALS WEST INTO NORTHEAST LAKE
COUNTY.
SFC TEMPS HAVE BEEN SLOWED IN COOLING DUE TO THE CLOUD
COVER...HOWEVER THIS WILL BE TEMPORARY AS THE POTENT 850MB THERMAL
TROUGH OF -18 TO -22 DEG C AIR ARRIVES BY DAYBREAK. WITH STRONG COLD
AIR ADVECTION TODAY...TEMPS WILL LIKELY NOT MOVE MUCH FROM THE
SINGLE DIGITS ABOVE ZERO. THE FAR SOUTHERN PORTIONS OF THE FORECAST
AREA COULD SEE TEMPS HOVER IN THE LOW TEENS...BUT WILL LIKELY FALL
INTO THE SINGLE DIGITS BY THIS AFTERNOON.
THIS EVENING THE MESO-LOW IS PROGGED TO WEAKEN AS WINDS BACK
NORTHWESTERLY AND EVENTUALLY WEST LATE TONIGHT. HIGH PRESSURE WILL
BE SLIDING SOUTHEAST ACROSS CENTRAL IL. THIS WILL ALLOW THE LES BAND
TO MOVE BACK EAST OF PORTER COUNTY LATE THIS EVENING. WITH MINIMAL
CLOUD COVER TONIGHT...EXPECT TEMPS TO QUICKLY COOL. DESPITE WINDS
SLOWLY DIMINISHING...WINDS CHILLS TONIGHT WILL DIP INTO THE SINGLE
DIGITS BELOW ZERO.
DRY AIR WILL LINGER INTO MUCH OF FRI...AS THE SFC RIDGE SLIDES EAST.
WARM AIR WILL TRY TO QUICKLY ADVECT NORTHEAST...ALLOWING TEMPS TO
REBOUND INTO THE LOW/MID 20S. ENSEMBLES CONTINUE TO DOWNPLAY THE
PRECIP FOR FRI...WITH ONLY A FEW MEMBERS INDICATING ANY PRECIP NOW.
EXPECT GIVEN THE EXPANSIVE DRY WEDGE...THAT WHILE SOME ISENTROPIC
ASCENT WILL OCCUR...THAT ANY PRECIP WILL LIKELY BE NORTH IN WISC.
HAVE TRENDED DRIER...WITH ONLY A SLT CHC POPS FRI MORNING. A
SHORTWAVE WILL BE SLIDING EAST ACROSS LAKE HURON FRI NGT...WITH A
TRAILING BOUNDARY STRETCHING WEST ACROSS WISC. MOISTURE IS BEING
PROGGED ALONG THE BOUNDARY AS IT SLIDES SOUTH ACROSS THE FORECAST
AREA LATE FRI NGT/SAT MORNING...WHICH COULD PRODUCE SOME FLURRIES OR
LGT SNOW.
BEACHLER
&&
.LONG TERM...
254 AM CST
SATURDAY THROUGH WEDNESDAY...
ANOTHER PUNCH OF ARCTIC AIR ARRIVES SAT WITH A POTENT SFC RIDGE
DIVING SOUTH FROM CENTRAL CANADA. ENSEMBLES CONTINUE TO DEMONSTRATE
A HIGH CONFIDENCE IN THE 850MB THERMAL TROUGH OF -24 TO -26 DEG C
ARRIVING SAT/SUN...MAKING IT TOUGH FOR TEMPS SAT/SUN TO WARM BEYOND
THE SINGLE DIGITS ABOVE ZERO. THEN AS THE SFC RIDGE ERODES THE CLOUD
COVER SAT NGT...TEMPS WILL RADIATE TO -5 TO -12 DEG. WINDS WILL
LIKELY REMAIN BLUSTERY...POSSIBLY CREATING DANGEROUS WIND CHILL
CONDITIONS OF -20 TO -30 DEG INTO EARLY SUN. LES LOOKS ONCE AGAIN
FAVORABLE FOR PORTIONS OF NORTHWEST IN SAT NGT/SUN.
ENSEMBLES SUGGEST THE THERMAL TROUGH WILL RELAX MON/TUE...ALLOWING
SFC TEMPS TO WARM BACK TO THE 20S. THE LONGWAVE PATTERN BEGINS TO
AMPLIFY MON...WITH THE STRENGTHENING RIDGING APPROACHING EASTERN
ALASKA. ADDITIONALLY ENSEMBLES ARE SUGGESTING SOME DEGREE OF
BLOCKING ACROSS THE NORTH ATLANTIC...WHICH LIKELY WILL AID IN THE
DIGGING TROUGH ACROSS THE CONUS BY TUE. THIS SOLUTION WOULD LIKELY
POINT TOWARDS A RETURN TO SUB-SEASONAL TEMPERATURES. WITH A DIGGING
TROUGH ACROSS THE CENTRAL CONUS...THE LIKELIHOOD OF AN ACTIVE
PATTERN FOR TUE/WED LOOKS GOOD.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SNOW/IFR VIS THRU 12Z.
* STRONG/GUSTY NORTHWEST WINDS THRU THIS AFTERNOON. CMS
//DISCUSSION...UPDATED 09Z...
LIGHT SNOW HAS BECOME PREVAILING OVER THE ENTIRE AREA EARLY THIS
MORNING WITH VISIBILITIES DROPPING TO AROUND 2SM...OCCASIONALLY
LOWER. BACK EDGE OF THIS LIGHT SNOW IS CROSSING THE IL/WI STATE
LINE AND SHOULD GRADUALLY MOVE SOUTH OF THE TERMINALS IN THE 11Z
TO 13Z TIME PERIOD. SOME ENHANCEMENT OVER THE FAR SOUTHERN END OF
THE LAKE WILL MOVE INTO NORTHWEST INDIANA AND GYY WITH VIS TO 1SM
OR PERHAPS BRIEFLY LOWER. CMS
PREVIOUS 06Z DISCUSSION...
A SECONDARY COLD FRONT/TROUGH WILL BE MOVING SOUTH ACROSS THE
TERMINALS OVERNIGHT AND WITH IT THE POTENTIAL FOR SNOW SHOWERS
THAT MAY DROP VISIBILITIES TO IFR. THE STRONGEST OF THESE SNOW
SHOWERS CURRENTLY ARE MOVING ACROSS SOUTHWEST WI AND NORTHEAST IA.
HOW FAR EAST THESE EXTEND...INCLUDING INTO THE CHICAGO AREA TAFS
IS A BIT UNCERTAIN BUT MAINTAINED TEMPO WITH TWEAKED TIMING. MID
CLOUDS CURRENTLY PUSHING ACROSS THE AREA WILL LOWER TO 3-5KFT WITH
MVFR CIGS WITH ANY SNOW SHOWERS. CIGS LIKELY TO REMAIN VFR INTO
THURSDAY MORNING...THOUGH SOME MVFR IS POSSIBLE.
LAKE EFFECT SNOW WILL CONTINUE TO DEVELOP OVERNIGHT AND SLOWLY
MOVE WEST INTO NORTHWEST INDIANA THURSDAY MORNING. MAINTAINED
MENTION AT GYY...BUT ITS POSSIBLE THE LAKE EFFECT SNOW WILL REMAIN
JUST EAST OF GYY. AT THIS POINT...TOO CLOSE TO CALL FOR GYY. THIS
LAKE EFFECT SNOW IS NOT EXPECTED TO MOVE ANY FURTHER WEST THAN
GYY.
NORTHWEST WINDS HAVE DIMINISHED SOME THIS EVENING WITH SOME AREAS
NOT SHOWING GUSTS. EXPECT WINDS TO SLOWLY INCREASE AS LOWER CLOUDS
AND COLDER AIR ARRIVE. STILL APPEARS THE STRONG SPEEDS/GUSTS WILL
OCCUR FROM JUST BEFORE DAYBREAK THROUGH LATE MORNING...THEN SPEEDS
WILL SLOWLY BUT STEADILY DIMINISH THURSDAY AFTERNOON...BECOMING
LIGHT WESTERLY THURSDAY EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH FOR LIGHT SNOW/IFR VIS THRU 12Z.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...PERIOD OF -SHSN WITH IFR VSBY PROBABLE.
SATURDAY...CHANCE OF FLURRIES AND MVFR CIGS. STRONG NW WINDS.
SUNDAY...VFR PROBABLE.
MONDAY...VFR DURING DAY...SNOW AND IFR AT NIGHT.
TUESDAY...MVFR CIGS POSSIBLE.
IZZI
&&
.MARINE...
325 AM...HIGH PRESSURE BUILDING ACROSS THE NORTHERN PLAINS AND
UPPER MIDWEST WILL SLOWLY WEAKEN AS IT REACHES THE SOUTHERN LAKES
AND OHIO VALLEY FRIDAY MORNING. NORTHERLY GALES WILL GRADUALLY
DIMINISH FROM NORTH TO SOUTH THIS AFTERNOON. AS THE HIGH PASSES
ACROSS THE LAKE...SPEEDS WILL DROP INTO THE 10KT RANGE THEN TURN
SOUTHWESTERLY BY FRIDAY MORNING AHEAD OF THE NEXT LOW WHICH WILL
MOVE SOUTHEAST ACROSS ONTARIO FRIDAY. THE GRADIENT WILL STEADILY
TIGHTEN...WITH WINDS INCREASING TO 25-30KT FRIDAY AFTERNOON. WINDS
WILL SHIFT NORTHWEST BEHIND A TRAILING COLD FRONT FRIDAY NIGHT...
THEN INCREASE TO GALE FORCE BY SATURDAY MORNING AS ANOTHER STRONG
ARCTIC HIGH BUILDS SOUTH ACROSS THE NORTHERN PLAINS AND UPPER
MIDWEST SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS HIGH WILL
PASS OVER THE LAKE SUNDAY WITH DIMINISHING WINDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...WINTER WEATHER ADVISORY...INZ002 UNTIL 6 PM THURSDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 PM THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM
THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
258 AM CST Thu Feb 12 2015
.SHORT TERM...(Today)
ISSUED AT 257 AM CST THU FEB 12 2015
A surface wave is currently moving through the area with cloudy
skies, gusty winds up to around 35 mph, and a brief period of light
snow/flurries. By 12Z, the light snow will have ended over most of
the area, but winds will still be gusty and clouds could still be
around. Eastern and southeastern areas of the CWA might still some
flurries, but with issuance of the new forecast, will not have any
light snow/flurries mentioned. Skies should become partly to mostly
sunny during the morning hours as well. Cold Arctic high pressure
will build in behind this wave and this will keep temps around 15
degrees below normal across the whole area. With sun angle getting
higher, and should be lots of sun this afternoon, and winds should
be on the decrease; will follow closer to the warmer guidance, the
MAV.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 257 AM CST THU FEB 12 2015
Shortwave currently rounding the top of the ridge west of the
Rockies will be racing southeast, arriving in our area Friday
morning. Not a lot of moisture available until the morning hours,
and the forecast soundings show a sizable dry column below 750 mb.
NAM and Canadian models are most bullish with squeezing out a
hundredth or two as far south as southern Illinois in the warm air
advection pattern, while the GFS and ECMWF quickly shift any
measurable precip across Iowa/northern Missouri to the northeast.
Largely went with a chance of flurries across the northern CWA with
this feature, with some 20% PoP`s in the far north. Should see some
temperatures above freezing west of Springfield, the best shot of
seeing above-freezing temperatures for the next week.
Well-advertised Arctic surge will quickly overspread the Midwest
late Friday night and Saturday, as a strong closed upper low drops
southeast. The latest models have nudged this low a bit further
east. As a result, the NAM and GFS are indicating more of a glancing
blow from this surge, while the ECMWF and Canadian models remain a
little more in the coldest air. Not much change in thinking for
Saturday`s temperatures though, as highs will occur early and
temperatures will steadily fall after that. Will likely see some
wind gusts to around 35 mph on Saturday with the surge, and winds
stay up enough overnight to continue suggesting advisory-level wind
chills north of I-72 Saturday night, when actual lows will be a few
degrees either side of zero.
Forecast for early next week remains challenging. Broadening upper
trough will be digging down the spine of the Rockies Monday night,
before shifting eastward through mid week. The GFS and ECMWF models
are showing some discrepancies in the development of a surface
cyclone just ahead of this, as a piece of energy ejects from an
upper low over the Baja which will be shearing out. The ECMWF has
not changed too much from the morning run, largely keeping our area
dry until Tuesday morning when the incoming trough boots the system
northeast. The GFS is a little faster and further north, with
overrunning precipitation by Monday afternoon and periodic snow over
the southeast half of the forecast area until late Tuesday evening,
when the deformation zone on the back side moves east of the area.
Have made some refinements in the PoP`s as a result, limiting the
likely PoP`s to areas south of I-70. Another Arctic surge follows
mid week, although the ECMWF is slower by about 12-18 hours than the
GFS solution.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1105 PM CST WED FEB 11 2015
An Arctic cold front will sweep across the area early this morning
accompanied by gusty northwest winds, scattered flurries and cigs
deteriorating to MVFR once again. Leading edge of the clouds pushing
across west central IL with another band over northeast Iowa into
south central Wisconsin. Latest guidance suggests a rapid push to
the southeast with both cloud bands as the colder air rushes in
during the early morning hours. RAP and HRRR forecast soundings
indicate the clouds should begin to push southeast out of our
area in the 16z-20z time frame as large scale subsidence/sinking
air settles in across the area in the wake of the strong upper
wave tracking to our north. We should see VFR conditions during
the afternoon although the gusty northwest winds are expected to
continue with a quick diminishing trend setting in late in the
afternoon as the center of the cold air mass settles in from the
northwest.
Look for northwest winds of 15 to 20 kts overnight with a few
gusts around 30 kts at times. Northwest to north winds are
expected across the TAF sites on Thursday with speeds of 13 to 18
kts with gusts in the 25-30 kt range into early afternoon before
wind gusts diminish as we head towards late afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Auten
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1142 PM CST WED FEB 11 2015
.UPDATE...
823 PM CST
FOR EVENING UPDATE...
MADE A COUPLE OF MINOR CHANGES TO GOING FORECAST...NAMELY TO MOVE
TIMING OF SCATTERED SNOW SHOWERS BACK A BIT UNTIL MIDNIGHT AND
AFTER...ADJUSTED CLOUD COVER EARLIER FOR PERIOD OF CLEARING THIS
EVENING...AND LOWERED OVERNIGHT MINS JUST A DEGREE OR TWO IN A FEW
SPOTS.
ARCTIC AIR SPREADING IN FROM THE NORTHWEST THIS EVENING AS SECONDARY
COLD FRONT WAS MOVING INTO NORTHWEST IL AS OF 02Z. STRONG GRADIENT
AND STEEP LOW LEVEL LAPSE RATES WILL ALSO HELP WINDS PICK UP A BIT
OVERNIGHT...AS GRADIENT TIGHTENS AHEAD OF STRONG ARCTIC HIGH OOZING
SOUTH FROM SASKATCHEWAN/MANITOBA INTO THE NORTHERN PLAINS. TEMPS
HAVE ALREADY DROPPED INTO THE LOWER TEENS ACROSS NORTHEAST IA AND
SOUTHWEST WI...AND INTO THE LOW SINGLE DIGITS FARTHER UPSTREAM
ACROSS MINNESOTA. THIS AIR MASS WILL SPREAD INTO OUR AREA OVERNIGHT
WITH WINDS GUSTING TO AROUND 35 MPH AT TIMES IN SOME SPOTS. BASED ON
UPSTREAM TEMP TRENDS HAVE NUDGED OVERNIGHT MINS DOWN 1-2 DEGREES
MAINLY ACROSS NORTHERN IL. TEMPS NOT EXPECTED TO BUDGE UPWARD MUCH
TOMORROW DESPITE SOME SUNSHINE...WITH BLUSTERY NORTHWEST WINDS
CONTINUING TO ADVECT ARCTIC AIR ACROSS THE AREA.
CLOUDS HAVE CLEARED TEMPORARILY BEHIND AFTERNOON DISTURBANCE...
THOUGH STRONG SHORT WAVE NOTED DIGGING SOUTHEAST ACROSS MINNESOTA
WILL BRING CLOUDS AND SCATTERED SNOW SHOWERS BACK TO THE AREA FROM
ABOUT MIDNIGHT ONWARD. BASED ON TIMING IR 11-3.9 MICRON SATELLITE
IMAGERY HAVE PUSHED SNOW SHOWERS BACK A BIT IN TIMING OVER IL TO
MAINLY AFTER MIDNIGHT. WHILE COVERAGE WILL NOT BE UNIFORM...STEEP
LAPSE RATES AND COLD COLUMN TEMPS SHOULD SUPPORT FAIRLY WIDESPREAD
SNOW SHOWERS UNDER THE MID-LEVEL VORT. GOING FORECAST OF A FEW
TENTHS TO A HALF INCH IN ANY ONE SPOT APPEAR REASONABLE.
HAVE MADE NO CHANGES TO LAKE EFFECT SNOW AND ASSOCIATED WINTER
WEATHER ADVISORY FOR PORTER COUNTY. REGIONAL RADAR MOSAIC DEPICTS
INCREASING COVERAGE OF LAKE-INDUCED SNOW SHOWERS OVER WESTERN LOWER
MICHIGAN...WITH LOW LEVEL WIND FIELD EXPECTED TO VEER MORE NORTHERLY
OVERNIGHT. THIS SHOULD SUPPORT DEVELOPMENT OF STRONG SINGLE-BAND LES
PLUME INTO SOUTHWEST MI/NORTHERN IN...EVENTUALLY BACKING INTO PORTER
COUNTY DURING THE PRE-DAWN HOURS OF THURSDAY MORNING. LATEST
HIGH-RES GUIDANCE (RAP/HRRR) APPEAR STEADY WITH THEIR DEPICTION
THROUGH THEIR VALID TIMES INTO TOMORROW MORNING.
RATZER
&&
.SHORT TERM...
309 PM CST
THROUGH THURSDAY...
MULTIPLE WINTER WEATHER CONCERNS IN THE SHORT TERM...MOST
SIGNIFICANTLY WITH LAKE EFFECT SNOW LATE TONIGHT INTO THURSDAY
AFTERNOON FOR PORTER COUNTY INDIANA. HAVE ISSUED A WINTER WEATHER
ADVISORY FOR MIDNIGHT THROUGH 6PM THURSDAY EVENING FOR A COMBINATION
OF SEVERAL INCHES OF LAKE EFFECT SNOW...PLUS VERY STRONG AND NEAR
WIND ADVISORY CRITERIA WINDS THAT WILL CREATE BLOWING AND DRIFTING
SNOW AND FURTHER REDUCE VISIBILITY.
MAIN FEATURES OF NOTE THIS AFTERNOON ARE STRONG ARCTIC FRONT
TRAILING FROM CLIPPER EAST OF LAKE SUPERIOR...EXPANSIVE ~1045 MB
ARCTIC HIGH OVER CANADIAN PRAIRIES AND STOUT MID/UPPER LEVEL WAVE
DIVING FROM CANADIAN PRAIRIES INTO NORTHERN PLAINS. THE ARCTIC FRONT
HAS PUSHED THROUGH THE AREA...SO TEMPERATURES WILL FALL STEADILY
THROUGH THURSDAY MORNING AS A PUNCH OF 850 MB TEMPERATURES AT OR
JUST BELOW -20C ARRIVE BY EARLY THURSDAY. AFOREMENTIONED UPPER
WAVE...WITH ASSOCIATED STRONG FORCING DESPITE SOMEWHAT LIMITED
MOISTURE...SHOULD TOUCH OFF AT LEAST SCATTERED SNOW SHOWERS EVEN FOR
AREAS AWAY FROM LAKE MICHIGAN. THESE SNOW SHOWERS SHOULD PROGRESS
SOUTHEAST WITH THE VORT PATH LATE THIS EVENING THROUGH THE
OVERNIGHT...EXITING THE SOUTHERN CWA BY EARLY THURSDAY. HAVE BUMPED
UP POPS TO MID/HIGH CHANCE WHERE CONFIDENCE IS HIGHER ON BETTER SNOW
SHOWER COVERAGE AND BROAD BRUSHED LIGHT SNOW ACCUMULATIONS. THIS
APPEARS TO BE A SCENARIO WHERE NOT ALL LOCATIONS WILL SEE MEASURABLE
SNOW OR EVEN A DUSTING...BUT SOME SPOTS COULD SEE A HALF INCH OR SO.
HIGH RATIO ARCTIC AIR MASS WILL FLUFF UP WHATEVER QPF CAN BE
SQUEEZED OUT.
NOW ONTO THE LAKE EFFECT SETUP...MODEL SOUNDINGS SUGGEST VERY
IMPRESSIVE PARAMETERS TAKING SHAPE WITH INVERSION HEIGHTS AT OR
SLIGHTLY ABOVE 10KFT...DELTA TS OVER 20C AND AT POSSIBLY UPWARDS OF
800 J/KG LAKE INDUCED CAPE IN HEART OF BAND. AS PARAMETERS
IMPROVE...BOUNDARY LAYER WINDS WILL BE STRENGTHENING...WHICH COULD
AFFECT BAND ORGANIZATION FOR A TIME. ALSO...INITIALLY...WINDS WILL
BE WEST-NORTHWEST THROUGH FIRST PART OF TONIGHT...KEEPING ACTIVITY
MAINLY EAST OF PORTER COUNTY. AS STRONG UPPER VORT MAX PUSHES ACROSS
AREA WITH ENHANCED PUSH OF COLD AIR AS WELL AS SFC TROUGH
PASSAGE...WINDS WILL SHIFT TO NORTH-NORTHWEST LATE TONIGHT INTO
THURSDAY MORNING...LIKELY BRINGING AT LEAST NORTHEAST PORTER COUNTY
INTO PERIODS OF MODERATE TO EVEN HEAVY LAKE EFFECT SNOW SHOWERS.
AS THERE ALWAYS IS...GUIDANCE VARIES ON PLACEMENT OF BAND AND HOW
LONG IT WILL LINGER OVER AREA. OUR LOCAL MODEL ACTUALLY TAKES
LONGEST TO BRING BAND INTO PORTER BUT THEN DEPICTS A
MESOLOW/ENHANCED CONVERGENCE TO KEEP LAKE EFFECT OVER COUNTY
POSSIBLY AS LATE AS LATE THURSDAY AFTERNOON. THIS WILL BE SOMETHING
TO MONITOR. HAVE KEPT CATEGORICAL POPS THROUGH THURSDAY
AFTERNOON...BUT PEAK TIME SHOULD BE ROUGHLY 9Z TONIGHT THROUGH
17Z-18Z THURSDAY BEFORE WEAKENING TAKES PLACE OR BAND SHIFTS EAST.
DID NOT MAKE A HUGE CHANGE IN PREVIOUS FORECAST...WITH SNOW AMOUNTS
UNDER 2 INCHES IN FAR SW PORTER TO UP TO 6 INCHES IN THE NORTHEAST
NEAR LAKE MI. THERE COULD BE UP TO AN INCH OR SO IN PORTIONS OF LAKE
AND JASPER COUNTIES ADJACENT TO PORTER COUNTY. CONFIDENCE IS ONLY
MEDIUM ON TOP END AMOUNTS BECAUSE OF POTENTIAL FOR LA PORTE AND
BERRIEN COUNTIES TO RECEIVE BRUNT OF THE SNOW.
ADDING TO THE CONCERN IS THE VERY STRONG NNW WINDS THAT WILL BE
OCCURRING AS THE SNOW FALLS...WITH GUSTS ON THE LAKEFRONT POSSIBLY
AS HIGH AS 45 MPH AT TIMES THURSDAY MORNING. THIS WILL LIKELY RESULT
IN BLOWING/DRIFTING SNOW AND SUBSTANTIAL VISIBILITY REDUCTIONS WHERE
THE MODERATE TO HEAVY SNOW IS FALLING. HAVE ISSUED A WINTER WEATHER
ADVISORY AS OPPOSED TO LAKE EFFECT SNOW ADVISORY FOR PORTER COUNTY
DUE TO POTENTIAL FOR NEAR ADVISORY CRITERIA WINDS AND
BLOWING/DRIFTING ISSUES POSED BY THE WIND. FELT IT PRUDENT TO ISSUE
THE ADVISORY DESPITE SOMEWHAT LOWER CONFIDENCE IN SIGNIFICANT ACCUMS
BEING OBSERVED BECAUSE THE WINDS WILL LIKELY CAUSE HAZARDOUS
CONDITIONS EVEN WITH LIGHTER SNOW AMOUNTS. TRAVEL ON I-80 THURSDAY
MORNING COULD BECOME QUITE DICEY...SO CHECK UP ON LATEST UPDATES
BEFORE TRAVELING.
FOR THE REST OF THE AREA...THURSDAY WILL BE VERY WINDY AND
COLD...WITH HIGHS STRUGGLING TO REACH THE LOWER-MID TEENS. STRONGEST
WINDS WILL BE THURSDAY MORNING...POSSIBLY REACHING 35 TO 40 MPH AT
TIMES...BEFORE GRADUALLY DIMINISHING IN THE AFTERNOON AS THE HIGH
PRESSURE BUILDS IN. MORNING WIND CHILL VALUES ARE EXPECTED TO RANGE
FROM 5 BELOW TO 20 BELOW IN THE COLDEST SPOTS. DRESS APPROPRIATELY
IF SPENDING PROLONGED TIME OUTDOORS ON THURSDAY.
RC
&&
.LONG TERM...
335 PM CST
THURSDAY NIGHT THROUGH SUNDAY...
A COLD AND ACTIVE PATTERN WILL CONTINUE INTO NEXT WORK WEEK. PRIMARY
CONCERNS ARE: LIGHT SNOW ON FRIDAY AND FRIDAY NIGHT/EARLY
SATURDAY...BITTERLY COLD AND VERY WINDY CONDITIONS ON VALENTINES
DAY...ANOTHER POTENTIALLY SIGNIFICANT LAKE EFFECT SNOW EVENT
SATURDAY NIGHT INTO SUNDAY...AND A POSSIBLY MORE WIDESPREAD SNOW
PRODUCER MONDAY AND MONDAY NIGHT.
ARCTIC HIGH PRESSURE WILL BE OVER THE AREA THURSDAY NIGHT...BUT WARM
ADVECTION ALOFT AND INCREASING CLOUD COVER IN ADVANCE OF NEXT
CLIPPER SYSTEM WILL PREVENT TEMPERATURES FROM BOTTOMING OUT. COULD
SEE A FEW SPOTS IN NORTHERN ILLINOIS DIP TO NEAR OR JUST BELOW ZERO.
CLIPPER WILL TRACK WELL NORTH OF CWA ACROSS NORTHERN LAKES ON FRIDAY
AND BEST FORCING WILL ALSO MOVE TO THE NORTH. HOWEVER...BROAD ASCENT
IN WARM ADVECTION WING OF SYSTEM...ALONG WITH SOME HELP FROM AN
UPPER SHORT WAVE SHOULD SPREAD AN AREA OF LIGHT SNOW TOWARD AND
ACROSS CWA. HAVE INCREASED POPS SLIGHTLY...BUT CONFIDENCE IS NOT
HIGH IN ALL AREAS SEEING MEASURABLE SNOW WITH WEAK/BROAD FORCING.
WHERE IT OCCURS...COULD SEE MAYBE UP TO A HALF INCH OF SNOW. FRIDAY
WILL BE THE "WARM" DAY OF THE NEXT SEVERAL...WITH LOCAL 925/850 MB
CLIMO SUPPORTING LOW-MID 20S FOR HIGHS. HAVE SOME CONCERN WITH MODEL
SOUNDINGS SHOWING LOSS OF SATURATION IN DGZ LATER FRIDAY BUT STILL
WEAK ASCENT...WHICH COULD MAKE FREEZING DRIZZLE A POSSIBILITY. HAVE
NOT ADDED IT TO GRIDS YET.
SIMILAR SETUP TO TONIGHT WILL OCCUR FRIDAY NIGHT INTO SATURDAY WITH
VORT MAX EMBEDDED IN AMPLIFIED UPPER TROUGH PIVOTING ACROSS AREA AS
NEARLY 1050 MB ARCTIC HIGH DRIVES A PUSH OF 850 MB TEMP OF COLDER
THAN -25C INTO AREA BY SATURDAY MORNING. FORCING FROM VORT MAX AND
STEEPENING LOW LEVEL LAPSE RATES COULD AGAIN TOUCH OFF SNOW
SHOWERS BEHIND STRONG ARCTIC FRONT. 12Z GFS IS MOST BULLISH ON
THIS SCENARIO COMPARED TO OTHER MODELS...BUT IT IS A REASONABLE
DEPICTION...SO DID BUMP UP POPS TO SLIGHT/LOW END CHANCE. TIMING
OF HEART OF THERMAL TROUGH VARIED ON TODAYS GUIDANCE BUT IT WILL
BE OVERHEAD ON VALENTINES DAY...SO TEMPERATURES ARE LIKELY TO FALL
INTO SINGLE DIGITS AFTER MORNING HEIGHTS. BIGGER STORY WILL BE
WINDS GUSTING TO 30 TO 40 MPH AT TIMES...BRINGING WIND CHILLS OF
10-20 BELOW THROUGH THE AFTERNOON AND EVENING. WILL LIKELY NEED A
WIND CHILL ADVISORY LATE SATURDAY INTO SUNDAY MORNING. THE BLAST
OF COLD AIR WILL ALSO PROVIDE ANOTHER EXCELLENT TO EXTREME LAKE
EFFECT SETUP WITH MODELS SHOWING GOOD AGREEMENT ON THIS THE PAST
SEVERAL DAYS. IF AT LEAST PARTS OF NW IN GET INTO THIS
ACTION...VERY SIGNIFICANT ACCUMULATIONS ARE POSSIBLE. SOME GLOBAL
GUIDANCE/NAMELY CANADIAN...HAS FOR SEVERAL RUNS INSISTED ON BAND
DRIFTING WESTWARD SUNDAY MORNING. HIGH TEMPERATURES SUNDAY SHOULD
ONLY TOP OUT IN THE UPPER SINGLE DIGITS TO LOW/MID TEENS AS
THERMAL TROUGH GRADUALLY SLIDES EAST.
MONDAY THROUGH WEDNESDAY...
ATTENTION THEN TURNS TO MID-LEVEL ENERGY GATHERING IN
SOUTHWEST...ALONG WITH A NORTHERN STREAM WAVE DIVING INTO NORTHERN
PLAINS. MODELS ARE HAVING FITS ON WHAT DEGREE OF PHASING OCCURS
BETWEEN THE SOUTHERN AND NORTHERN STREAM AS THESE PIECES SHIFT INTO
THE CENTER OF THE COUNTRY. HOWEVER...AT LEAST A PERIOD OF WARM
ADVECTION DRIVEN SNOW IS POSSIBLE MONDAY OR MONDAY NIGHT. HAVE
LIKELY POPS IN SOUTHERN THIRD OF CWA FOR NOW ON MONDAY NIGHT. THIS
PERIOD CERTAINLY BEARS WATCHING...AS SOME ENSEMBLE MEMBERS HAVE
OFFERED POTENTIAL FOR A MORE SIGNIFICANT SYSTEM TO IMPACT OUR
REGION. ANOTHER SHOT OF BITTERLY COLD AIR WILL ARRIVE BEHIND
WHATEVER HAPPENS MONDAY/MONDAY NIGHT.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* CHANCE OF SNOW SHOWERS/IFR VIS OVERNIGHT.
* STRONG/GUSTY NORTHWEST WINDS THRU THURSDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 06Z...
A SECONDARY COLD FRONT/TROUGH WILL BE MOVING SOUTH ACROSS THE
TERMINALS OVERNIGHT AND WITH IT THE POTENTIAL FOR SNOW SHOWERS
THAT MAY DROP VISIBILITIES TO IFR. THE STRONGEST OF THESE SNOW
SHOWERS CURRENTLY ARE MOVING ACROSS SOUTHWEST WI AND NORTHEAST IA.
HOW FAR EAST THESE EXTEND...INCLUDING INTO THE CHICAGO AREA TAFS
IS A BIT UNCERTAIN BUT MAINTAINED TEMPO WITH TWEAKED TIMING. MID
CLOUDS CURRENTLY PUSHING ACROSS THE AREA WILL LOWER TO 3-5KFT WITH
MVFR CIGS WITH ANY SNOW SHOWERS. CIGS LIKELY TO REMAIN VFR INTO
THURSDAY MORNING...THOUGH SOME MVFR IS POSSIBLE.
LAKE EFFECT SNOW WILL CONTINUE TO DEVELOP OVERNIGHT AND SLOWLY
MOVE WEST INTO NORTHWEST INDIANA THURSDAY MORNING. MAINTAINED
MENTION AT GYY...BUT ITS POSSIBLE THE LAKE EFFECT SNOW WILL REMAIN
JUST EAST OF GYY. AT THIS POINT...TOO CLOSE TO CALL FOR GYY. THIS
LAKE EFFECT SNOW IS NOT EXPECTED TO MOVE ANY FURTHER WEST THAN
GYY.
NORTHWEST WINDS HAVE DIMINISHED SOME THIS EVENING WITH SOME AREAS
NOT SHOWING GUSTS. EXPECT WINDS TO SLOWLY INCREASE AS LOWER CLOUDS
AND COLDER AIR ARRIVE. STILL APPEARS THE STRONG SPEEDS/GUSTS WILL
OCCUR FROM JUST BEFORE DAYBREAK THROUGH LATE MORNING...THEN SPEEDS
WILL SLOWLY BUT STEADILY DIMINISH THURSDAY AFTERNOON...BECOMING
LIGHT WESTERLY THURSDAY EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW FOR SNOW SHOWERS/IFR VIS OVERNIGHT.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...PERIOD OF -SHSN WITH IFR VSBY PROBABLE.
SATURDAY...CHANCE OF FLURRIES AND MVFR CIGS. STRONG NW WINDS.
SUNDAY...VFR PROBABLE.
MONDAY...VFR DURING DAY...SNOW AND IFR AT NIGHT.
TUESDAY...MVFR CIGS POSSIBLE.
IZZI
&&
.MARINE...
233 PM CST
A SERIES OF STRONG COLD FRONTS WILL BRING PERIODS OF GALE FORCE
WINDS AND HIGH WAVES TO LAKE MICHIGAN FOR THE UPCOMING DAYS...WITH
CHANGING WINDS AS WELL. THIS WILL OCCUR TONIGHT AS STRONG HIGH
PRESSURE BUILDS ACROSS THE UPPER MIDWEST TONIGHT...WHILE LOW
PRESSURE CONTINUES EASTWARD TO THE ATLANTIC SEABOARD. AFTER A BREAK
THURSDAY NIGHT INTO FRIDAY AS THE HIGH PASSES OVER THE
LAKE...ANOTHER LOW DIVING SOUTHEAST THROUGH ONTARIO WILL PASS OVER
THE NORTHERN TIER OF THE LAKE FRIDAY NIGHT...WITH ITS ASSOCIATED
COLD FRONT CLEARING THE SOUTH END OF THE LAKE BY SATURDAY MORNING.
STRONG HIGH PRESSURE BUILDS IN BEHIND THIS SYSTEM AS WELL...WHICH
WILL LIKELY RESULT IN ANOTHER PERIOD OF NORTHWESTERLY TO NORTHERLY
GALES ON SATURDAY. THE HIGH WILL SHIFT OVER THE LAKE SUNDAY.
AFTERWARDS...ANOTHER LOW WILL MOVE EAST THROUGH HUDSON BAY ON MONDAY
FOR A PERIOD OF SW WINDS...BUT ITS ASSOCIATED COLD FRONT WILL MOVE
OVER THE LAKE ON TUESDAY BRINGING A RETURN TO GUSTY NW WINDS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...WINTER WEATHER ADVISORY...INZ002 UNTIL 6 PM THURSDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM THURSDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM
THURSDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 3 PM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL MIDNIGHT
THURSDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1115 PM CST Wed Feb 11 2015
.UPDATE...
ISSUED AT 845 PM CST WED FEB 11 2015
Latest surface map indicating a secondary cold front was tracking
quickly southeast across southern Wisconsin through central Iowa.
North of the buondary, temperatures this evening have fallen into
the single digits above and below zero over southern Minnesota and
expect some of that very cold air to spill into our area during the
early morning hours accompanied by gusty winds and scattered flurries.
Fairly strong 3 hourly pressure rises noted just behind the fast
moving cold front which should translate into increasing northwest
winds again towards morning which will drive wind chills down to
between -10 to -15 north and from zero to -10 across the south by
dawn Thursday. Will adjust the flurry chances further to the
south and west for late tonight, otherwise, no other changes were
needed to the grids. Will have an updated ZFP out by 915 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 303 PM CST WED FEB 11 2015
1005 mb low pressure deepening just east of Lake Superior has its
polar cold front extending southward through central IN into western
KY/TN. Overcast stratocumulus cloud deck cover central and southeast
IL with ceilings 1-3k ft. Brisk WNW winds 12-22 mph and gusts of
22-35 mph was slowly cooling temps this afternoon. Mercury readings
range from 28F at Galesburg to 46F at Mount Carmel airport. Wind
chills currently getting as cold as 15F at Galesburg, 16F in Macomb
and 17F in Bloomington. A vigorous northern stream short wave along
the ND/MN/Canadian border will dive se into central IL/IN by sunrise
and across the Ohio river valley by 18z/noon Thu. Latest forecast
models are showing some light qpf over ne counties overnight with
this short wave and bumped up pops to 20-40% in our ne counties
overnight with a dusting of snow (less than a half inch from Peoria
to Bloomington to Paris ne. Flurries possible elsewhere tonight with
mostly cloudy skies with some clearing nw of IL river later tonight
behind short wave. Lows overnight range from near 5F at Galesburg to
mid teens se of I-70. Gusty nw winds continue tonight and wind
chills get down to 10-14F below zero over northern counties later
tonight into Thu morning and still shy of wind chill advisory
criteria.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 303 PM CST WED FEB 11 2015
Ridging over the Pacific coast keeping much of the Midwest in
modified northwesterly flow and in line for a few rounds of Arctic
air moving into the region through the forecast. Precip in the way
of light snow/flurries making a return over the weekend...but the
next big chance for a system is reserved for the beginning of the
work week. Tomorrow...behind today`s front, temps signif colder with
highs only climbing into the teens at the sfc with -19C to -20C at
850mb. Even with partly cloudy skies early clearing to mostly sunny
by the afternoon...Cold temps remain. Brisk winds out of the north
in the 15 to 25mph range will keep the wind chills in the single
digits above and below zero throughout the day. Brief round of high
pressure dominance Thursday night with light winds under the ridge
axis...shifting to the east for Friday and southerly winds kick in
yet again, resulting in warmer highs for Friday. NAM and GFS in
agreement with the production of some QPF for Saturday as a wave
dives into the broader scale trof over the Great Lakes aloft. Not a
lot of confidence at this point in such a fast moving system without
good separation from the main wave...and keeping the pops very low
at this point for Saturday. Significant cold air on the way behind
it though, and temps dropping Sat night and into Sunday with the
cold snap. Increasing pressure gradient btwn sfc systems resulting
in stronger winds with the cold air and apparent temps drop into
wind chill advisory criteria for Sunday morning, though too far out
to consider the headline just yet.
Monday another system moves in out of the west/southwest and spreads
snowfall across the region. At this point in time, indications that
the forecast soundings are all below freezing and the precip will
likely be all snow. However, a lot of variables with this system,
including the WAA ahead of the low... and the track itself, with the
ECMWF having a far more southerly track leaving much of the northern
tier of the state dry. Too many variables for a strong confidence
across the board on the system to start the work week for snowfall
amounts.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1105 PM CST WED FEB 11 2015
An Arctic cold front will sweep across the area early this morning
accompanied by gusty northwest winds, scattered flurries and cigs
deteriorating to MVFR once again. Leading edge of the clouds pushing
across west central IL with another band over northeast Iowa into
south central Wisconsin. Latest guidance suggests a rapid push to
the southeast with both cloud bands as the colder air rushes in
during the early morning hours. RAP and HRRR forecast soundings
indicate the clouds should begin to push southeast out of our
area in the 16z-20z time frame as large scale subsidence/sinking
air settles in across the area in the wake of the strong upper
wave tracking to our north. We should see VFR conditions during
the afternoon although the gusty northwest winds are expected to
continue with a quick diminishing trend setting in late in the
afternoon as the center of the cold air mass settles in from the
northwest.
Look for northwest winds of 15 to 20 kts overnight with a few
gusts around 30 kts at times. Northwest to north winds are
expected across the TAF sites on Thursday with speeds of 13 to 18
kts with gusts in the 25-30 kt range into early afternoon before
wind gusts diminish as we head towards late afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...07
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
322 AM EST THU FEB 12 2015
.SYNOPSIS...
SNOW SHOWERS AND FRIGID ARCTIC AIR WILL PLAGUE THE UPPER OHIO
VALLEY REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE COLD FRONT HAS COMPLETED A SWEEP OF THE UPPER OHIO
REGION WITH SNOW SHOWERS EXPECTED TO CONTINUE AS THE AXIS OF THE
DEEPENING UPPER SHORTWAVE TROUGH DIGS EASTWARD. THAT AXIS WAS OVER
LAKE MICHIGAN AS OF 08Z...AND IS PROGGED TO ARRIVE OVER THE UPPER
OHIO BY MIDDAY.
DEEPENING MIXING LEVELS AND COLD UPSLOPING FLOW OUT OF THE GREAT
LAKES WILL RESULT IN MORE SNOW SHOWERS...WITH ACCUMULATION CONCERNS
CONTINUING FOR THE RIDGES WHERE DIRECT...AND STRENGTHENING UPSLOPE
IS FORECAST TO SPAWN STRONG...BUT SHALLOW OMEGA FIELDS INTO A
FALLING DENDRITIC GROWTH ZONE. EARLY AFTERNOON APPEARS THE BEST TIME
FOR RAPID ACCUMULATION IN THOSE AREAS...WITH INCREASING SUBSIDENCE
AND DRY ADVECTION...AS EXHIBITED BY RAPID RAP AND NAM MIXING RATIO
DIMINISHMENT...PROVIDING INHIBITION THEREAFTER. THE WINTER WEATHER
ADVISORY FOR THE RIDGES HAS BEEN MAINTAINED...DESPITE RATHER LIGHT
CONSENSUS GUIDANCE TOTALS.
OTHERWISE...SNOW SQUALLS WILL LIKELY IMPACT AREAS OUTSIDE THE RIDGES
PERIODICALLY UNTIL THE AFOREMENTIONED LIMITATIONS DOMINATE.
LAST...AND DEFINITELY NOT LEAST...THIS FRONT...AS ADVERTISED...WILL
LEAD AN ARCTIC AIRMASS OVER THE REGION...WITH PERIODIC REIFORCEMENT
OCCURRING THROUGH EARLY NEXT WEEK. GIVEN UPSTREAM TEMPERATURE
READINGS AND CONSISTENT GUIDANCE OVER THE PAST FEW DAYS...HAVE
TWEAKED TONIGHTS READINGS USING ADJUSTED NAM GUIDANCE PRIMARILY.
SUFFICIENT SUSTAINED WIND WITH THAT TEMPERATURE FORECAST HAS
SPAWNED THE NECESSITY FOR A WIND CHILL ADVISORY...IN EFFECT FOR
TONIGHT AND FRIDAY MORNING. -10 TO -20 BELOW WIND CHILLS CAN BE
ANTICIPATED REGIONWIDE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE IS FORECAST TO BRIEFLY BUILD BEHIND THE EXITING ARCTIC
COLD FRONT ON FRI. TEMPERATURES WILL RECOVER SOMEWHAT AS ANOTHER STRONG
UPSTREAM SHORTWAVE INTIATES WARM ADVECTION WITH ITS APPROACH...BUT
HIGHS WILL REMAIN WELL BELOW THE AVERAGES. THAT SHORTWAVE WILL
SPAWN MORE SNOW SHOWERS ON SATURDAY...FORECAST FOR WHICH WAS BASED
ON GFS PRECIPITATION PROBABILITIES AND AMOUNTS...AND SEND ANOTHER
ARCTIC FRONT ACROSS THE REGION WITH TEMPERATURES ON SUNDAY MORNING
PROJECTED UNDER THE ZERO MARK. WIND CHILL INDICES WILL BE DANGEROUSLY
LOW...SO MORE HEADLINES SHOULD BE ANTICIPATED. SUNDAY HIGHS WERE
FORECAST ABOUT 30 DEGREES UNDER THE AVERAGES USING WPC GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
ECMWF AND GFS WERE IN VERY GOOD AGREEMENT IN DEPICTIONS OF UPPER
FLOW INTO NEXT WEEK. IN GENERAL...SOME BRIEF TEMPERATURE MODERATION
ON ZONAL TO SOUTHWEST FLOW WILL BE BOUGHT WITH LIKELY SNOW...AND
POSSIBLY RAIN SOUTH OF PIT AS AN AMPLIFYING SHORTWAVE DIGS TOWARD
THE COAST ON TUESDAY OR WEDNESDAY. PROLONGED MOISTURE ADVECTION
AND ASCENT MAY CAUSE PROBLEMS...SITUATIONAL MONITORING IS UNDERWAY.
PASSAGE OF THAT SYSTEM IS PROGGED TO USHER IN MORE COLD WITH BOTH
SOLUTIONS INDICATED DEVELOPMENT OF A BROAD...HIGH AMPLITUDE NORTH
AMERICAN TROUGH BY WEEKS END. WPC GUIDANCE WAS IN LINE WITH THESE
TRENDS AND FEW ADJUSTMENTS TO THAT DATA SET WERE NEEDED FOR THE
LONG TERM FORECAST.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SCATTERED SNOW SHOWERS WILL CONTINUE THIS MORNING ZZV AND MGW
KEEPING MVFR CEILINGS AND THE REST OF THE TERMINALS GENERALLY
DROPPING TO IFR CEILINGS. A MORE MODERATE AREA OF SNOW SHOWERS IS
EXPECTED TO CROSS THE REGION FROM NEAR SUNRISE AT FKL TO NOON AT
MGW. ALTHOUGH IFR CONDITIONS ARE GENERALLY EXPECTED WITH THE
SNOW...CANNOT RULE OUT BRIEF LIFR CONDITIONS. WINDS WILL ALSO
BECOME GUSTY THROUGH THE REST OF THE DAY...AROUND 25 KTS. SNOW
SHOULD DIMINISH IN COVERAGE LATE AFTERNOON WITH GUSTS ENDING
DURING THE EVENING HOURS AS SURFACE RIDGE MOVES INTO THE REGION.
OUTLOOK.../FRIDAY THROUGH MONDAY/...
VFR EXPECTED FRIDAY INTO FRIDAY EVENING. RESTRICTIONS ARE THEN
LIKELY FRIDAY NIGHT THROUGH SUNDAY WITH LOW PRESSURE AFFECTING THE
REGION. VFR THEN EXPECTED SUNDAY NIGHT AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR MDZ001.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 1 AM EST
FRIDAY FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 1 AM EST
FRIDAY FOR PAZ074-076.
WV...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR WVZ001>004-012-021>023-041.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 1 AM EST
FRIDAY FOR WVZ023-041.
&&
$$
15/33
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1227 AM EST THU FEB 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EST WED FEB 11 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A DEEPENING UPR
TROF OVER CENTRAL NAMERICA DOWNSTREAM OF A RDG OVER THE W. SEVERAL
SHRTWVS ARE EMBEDDED WITHIN THIS TROF...AND THEIR PRESENCE IS
RESPONSIBLE FOR 00Z-12Z H3 HGT FALLS IN EXCESS OF 200M AT YPL. THE
FIRST DISTURBANCE THAT BROUGHT THE LIGHT SN LAST NGT IS NOW MOVING E
INTO WRN QUEBEC. A SECOND SHRTWV THAT BROUGHT ANOTHER ROUND OF MORE
WDSPRD LIGHT SN THIS MRNG IS NOW MOVING TO THE E OF THE AREA...WITH
SUBSIDENCE IN ITS WAKE...WHICH LOWERED THE INVRN BASE TO H9 AT INL
AT 12Z...NOW RESTRICTING SN SHOWERS MAINLY TO AREAS NEAR LK SUP
IMPACTED BY THE COLD NW FLOW IN ITS WAKE. NW SFC WINDS HAVE BEEN
GUSTING AS HI AS 35 MPH...RESULTING IN SOME BLSN/REDUCED VSBYS.
LOOKING TO THE NW... AN EVEN STRONGER SHRTWV IS DIGGING SEWD THRU
MANITOBA AND TOWARD NW MN. 12Z H85-7 TEMPS WERE AS LO AS -30C/-28C
AT THE PAS MANITOBA WITHIN THE COLD SURGE ACCOMPANYING THIS SHRTWV.
THE 12Z RAOB AT THAT SITE ALSO SHOWED A FAIRLY MOIST LYR UP TO JUST
ABOVE H7.
MAIN FCST CONCERNS THRU THU ARE NUMEROUS AND RELATED TO GOING
HEADLINES/LES COVERAGE/AMOUNTS/WINDS AND BLSN AS WELL AS WIND CHILLS
THAT WL ACCOMPANY THIS INCOMING ARCTIC SURGE ASSOCIATED WITH
MANITOBA SHRTWV.
LATE TODAY/TNGT...SHRTWV NOW DIGGING THRU SRN MANITBOA IS FCST TO
DIVE TO NEAR THE MN ARROWHEAD BY 00Z AND INTO THE LOWER LKS BY 12Z
THU. THE ARRIVAL OF THE STRONGER DYNAMIC FORCING/DEEPER MSTR/CYC NW
VEERING N FLOW THIS EVNG ASSOCIATED WITH THIS DISTURBANCE WL BRING A
PERIOD OF LK ENHANCED SN IN AREAS FAVORED BY THESE WINDS AS THE
ACCOMPANYING CAA CAUSES H85 TEMPS TO BOTTOM OUT AS LO AS -25C TO
-27C BY 12Z THU. MIXING OF THE H925 WINDS AS HI AS 35-40 KTS WITH
THE VIGOROUS CAA WL CAUSE VERY GUSTY WINDS AND BLSN AS WELL...
ESPECIALLY IN OPEN AREAS NEAR LK SUP. STEADILY SHIFTING WINDS AND
THE ARRIVAL OF THE VERY COLD AIR THAT WL NEARLY ELIMINATE THE DGZ
AND GUSTY WINDS THAT WL FRAGMENT THE SN FLAKES AND FURTHER LOWER SN/
WATER RATIOS WL LIMIT LES AMOUNTS. THE HIER RES MODELS INDICATE THE
HEAVIEST SN WL FALL IN WRN ALGER COUNTY...WITH MORE PERSISTENT LLVL
CNVGC THERE ENHANCED BY THE PRESENCE OF A LARGE AMOUNT OF ICE BTWN
THE KEWEENAW AND MARQUETTE THAT WL ENHANCE A BIT OF A WNW LAND
BREEZE COMPONENT OFF THE W HALF OF UPR MI. THE STRONG LLVL WINDS WL
BLOW THESE SN SHOWERS FARTHER INLAND AND INTO DELTA COUNTY. THE ICE
COVER OVER FAR ERN LK SUP AND VEERING FLOW TO THE N THAT LIMITS
OVERWATER TRAJECTORY INTO LUCE COUNTY WL HAMPER SN ACCUMS OVER THE
FAR ERN CWA. THE COMBINATION OF THE STRONG WINDS/LO TEMPS FALLING
BLO ZERO WL CAUSE WIND CHILLS TO DIP AS LO AS -25F TO PERHAPS -30F.
LATE TNGT...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC/STEADILY RISING H5
HGTS...FCST UP TO 100M BTWN 06Z-12Z OVER THE FAR W AT IWD...IN THE
WAKE OF THE DIGGING SHRTWV ARE FCST TO SHARPLY LOWER THE SUBSIDENCE
INVRN BASE TOWARD 2K FT AT IWD WL BRING A DIMINISHING TREND TO THE
LES. WEAKENING PRES GRADIENT/DIMINISHING LLVL WINDS FOLLOWING SHIFT
OF PRES CENTER TO THE E OF UPR MI WL CAUSE THE BLSN TO SUBSIDE A BIT
AS WELL.
THU...STEADILY RISING HGTS UNDER THE DNVA/LARGE SCALE QVECTOR DVGC
IN THE WAKE OF DEPARTING SHRTWV TOWARD THE MID ATLANTIC STATES AND
AHEAD OF SHRTWV RDG AXIS MOVING TOWARD THE UPR LKS THAT CAUSE A
CONTINUED LOWERING OF THE INVRN BASE TOWARD 2-3K FT EVEN OVER THE E
HALF LATE IN THE DAY WL BRING ABOUT A DIMINISHING TREND OF THE
LES...LATER OVER THE E. DIMINISHING/BACKING WINDS TOWARD THE NW WITH
APRCH OF SFC HI PRES RDG UNVER THE SUBSIDENCE WL CAUSE THE HEAVIER
LES OVER WRN ALGER COUNTY TO SHIFT TO THE E.
AS FOR THE HEADLINES...ALTHOUGH A GOOD DEAL OF ICE COVER IN THE LK
SUP NEARSHORE AREAS WL LIMIT SN TOTALS A BIT COMPARED TO WHAT WOULD
HAVE HAPPENED EARLY IN THE SEASON...GUSTY WINDS/BLSN EXACERBATED BY
THE NEARSHORE SN COVERED ICE WL BE SUFFICIENT TO WARRANT CONTINUED
HEADLINES. WILL CONTINUE THE WARNING FOR ALGER COUNTY GIVEN SUPPORT
FM THE HI RES MODELS FOR THE HEAVIEST QPF IN THE WESTERN PART OF
THAT COUNTY. ADDED WIND CHILL ADVYS FOR LUCE AND DICKINSON/IRON
COUNTIES WITH WIND CHILLS FALLING AS LO AS -28F IN THE PRESENCE OF
SUSTAINED N WIND NEAR 10 MPH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 500 PM EST WED FEB 11 2015
THE REGION IS NOW AMIDST AN ACTIVE PATTERN THAT WILL CONTINUE
THROUGH THE PERIOD. THIS PATTERN IS SOMEWHAT REMINISCENT TO LAST
WINTER AS A BROAD TROUGH BUILDS ACROSS EASTERN NORTH AMERICA.
CONCERNS CONTINUE TO GROW FOR POOR CONDITIONS FRIDAY NIGHT AND
SATURDAY WITH THE ARRIVAL OF SOME OF THE COLDEST AIR OF THE SEASON.
STRONG WINDS WILL LEAD TO VERY LOW VISIBILITIES ALONG LAKE
SUPERIOR...WITH BLIZZARD CONDITIONS QUITE POSSIBLE ALONG LAKE
SUPERIOR TO START THE WEEKEND.
THURSDAY NIGHT...A BROAD TROUGH CENTERED NEAR EASTERN HUDSON BAY
WILL SLOWLY SHIFT NORTHEASTWARD AS AN ASSOCIATED SFC TROUGH TRACKS
ACROSS THE LOWER GREAT LAKES. A SUBTLE RIDGE WILL SHIFT ACROSS THE
CWA THURSDAY NIGHT. HOWEVER...WITH COLD AIR LINGERING AROUND AND
INVERSION HEIGHTS REMAINING AROUND 3KFT...SOME LES WILL CONTINUE
ACROSS THE EAST BEFORE WINDS BACK TO THE SW BY DAYBREAK FRIDAY.
FRIDAY THROUGH SATURDAY...A STRENGTHENING UPPER JET COMBINED WITH A
POTENT SHORTWAVE TROUGH DIGGING SE INTO NW ONTARIO WILL INDUCE A SFC
LOW NORTH OF LAKE SUPERIOR FRIDAY MORNING. WEAK ISENTROPIC LIFT
AHEAD OF THIS LOW WILL SPREAD LIGHT SNOW ACROSS MUCH OF THE CWA
DURING THE DAY FRIDAY...WITH ACCUMULATIONS GENERALLY AROUND AN INCH.
BY EARLY-AFTERNOON...THE COLD FRONT ASSOCIATED WITH THE SFC LOW WILL
BE NEARING THE WESTERN CWA. H8 TEMPS FALLING FROM -15 TO -30C OVER
12-18 HOURS WILL ALLOW FOR A RAPID ONSET OF LAKE EFFECT SNOW FOR THE
NW-WIND SNOW BELTS ACROSS THE WEST BY LATE FRIDAY AFTERNOON. THE
WIND WILL QUICKLY BECOME NORTHERLY FOR ALL OF UPPER MI SATURDAY
EVENING AS THE SFC LOW TRACKS INTO NW LAKE HURON/GEORGIAN BAY.
TEMPERATURES WILL FALL QUICKLY...WITH HIGHS FAILING TO RISE ABOVE
ZERO FOR MOST OF THE AREA ON SATURDAY. WITH BLUSTERLY
CONDITIONS...WIND CHILLS WILL BE -20 TO -30F LATE FRIDAY NIGHT
THROUGH SATURDAY NIGHT.
THERE IS LITTLE DOUBT THAT WINDS WILL BE QUITE STRONG /GUSTING OVER
40MPH ALONG LAKE SUPERIOR/ BEHIND THIS FRONT AS AN ARCTIC HIGH OF
APPROX 1050MB BUILDS SE OUT OF SASKATCHEWAN AND THE 1005MB LOW MOVES
TOWARD THE LOWER GREAT LAKES. HOWEVER...THE STRENGTH OF THE PRESSURE
GRADIENT WILL DEPEND HEAVILY ON HOW THE UPPER JET AND MID-LEVEL
TROUGH INTERACT AS THE LOW MOVES AWAY FROM THE AREA. THE BEST
FORCING ON THE LEFT-EXIT OF THE JET LOOKS TO BE SOMEWHAT REMOVED TO
THE SOUTH OF THE MAIN SHORTWAVE ENERGY. IF THESE FEATURES CAN COME
INTO BETTER ALIGNMENT TO PRODUCE A STRONGER LOW...BLIZZARD
CONDITIONS WOULD BE LIKELY ALONG MUCH OF LAKE SUPERIOR FRIDAY NIGHT
THROUGH SATURDAY. THE AFOREMENTIONED ISSUES ALSO PRODUCE A STRONG
ISALLOBARIC WIND COMPONENT THAT IS MORE PERPENDICULAR THAN PARALLEL
TO THE GRADIENT WIND...THUS PROVIDING ONLY MARGINAL ENHANCEMENT TO
THE OVERALL WINDS.
WITH THE VERY COLD...AND RATHER DRY...ARCTIC AIR...SNOWFLAKE
PRODUCTION WILL BE DIFFICULT. THE EXPECTATIONS IS FOR VERY SMALL LOW-
RATIO SNOWFLAKES BY LATE FRIDAY NIGHT. FOR THIS REASON...SNOW
AMOUNTS ARE NOT OF UTMOST CONCERN WITH THIS SYSTEM. THE COMBINATION
OF THE STRONG WINDS AND SMALL SNOWFLAKE SIZE WILL GREATLY REDUCE
VISIBILITY. WHITE-OUT CONDITIONS ARE EXPECTED AT TIMES ALONG LAKE
SUPERIOR...ESPECIALLY SATURDAY MORNING. THE ONE MAJOR WILD CARD WILL
BE THE EVOLUTION OF THE ICE PACK ON LAKE SUPERIOR. ICE MODEL
FORECASTS INDICATE THAT TONIGHTS WINDS WILL GREATLY COMPACT THE ICE
ALONG THE SOUTHERN SHORE OF LAKE SUPERIOR. THIS WOULD PROVIDE MORE
OPEN WATER FOR LES PRODUCTION FOR THE WEEKEND. ADDITIONALLY...THE
ICE SHELF OFF SHORE WILL BE YET ANOTHER SOURCE OF SNOW FOR THE WINDS
TO BLOW AROUND NEAR THE SHORELINES.
WHILE BLIZZARD CONDITIONS ARE APPEARING MORE LIKELY FOR MUCH OF THE
KEWEENAW AND AREAS FROM BIG BAY TO GRAND MARAIS ALONG LAKE SUPERIOR
FRIDAY NIGHT THROUGH SATURDAY...HAVE DECIDED TO HOLD OFF ON ANY
HEADLINES AT THIS TIME FOR TWO REASONS. FIRST...THE MESSAGE
PERTAINING TO ONGOING ADVISORIES AND HEADLINES HIGHLIGHTING TONIGHTS
WEATHER MAY GET MIXED WITH ANY WATCHES FOR FRI NIGHT AND SAT.
SECOND...FORECASTER CONCENSUS IS TO SEE WHAT HAPPENS TONIGHT IN
ORDER TO GET A SAMPLE OF WHAT FRIDAY NIGHT AND SAT MAY HOLD. IF
CONDITIONS TONIGHT BECOME QUITE POOR...CONFIDENCE WILL SIGNIFICANTLY
INCREASE FOR BLIZZARD CONDITIONS EARLY THIS WEEKEND. ANY HEADLINES
MAY NOT BE ISSUED UNTIL THURSDAY...AND COULD SKIP ANY WATCHES AND GO
STRAIGHT TO A WARNING IF NEED BE.
SATURDAY NIGHT AND SUNDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE
FOR THE NORTH WIND SNOW BELTS AS A WEAK SECONDARY TROUGH TRACKS
ACROSS THE AREA IN THE EVENING. A MID-LEVEL/SFC RIDGE BUILDING IN
FROM THE NORTHERN PLAINS LATE SATURDAY NIGHT WILL INCREASE
CONVERGENCE ACROSS THE EASTERN LAKE. THIS MAY LEAD TO A CONTINUED
DOMINATE LES BAND BETWEEN MARQUETTE AND MUNISING AS INVERSION
HEIGHTS REMAIN AROUND 5KFT. THIS LES WILL QUICKLY SHIFT OFF SHORE
DURING THE DAY SUNDAY AS THE RIDGE WORKS ACROSS LAKE SUPERIOR.
MONDAY THROUGH WEDNESDAY...A BROAD TROUGH MOVING IN FROM SOUTH-
CENTRAL CANADA WILL BRING SMALL CHANCES OF SNOW FOR MONDAY. THIS
TROUGH WILL AMPLIFY MONDAY NIGHT AND CROSS UPPER MI TUESDAY INTO
TUESDAY NIGHT. THIS WILL BRING ANOTHER ROUND OF BREEZY CONDITIONS
AND INCREASED LES FOR THE NW-WIND SNOW BELTS. HOWEVER...CONDITIONS
ARE NET EXPECTED TO BE AS BAD AS EARLY THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1226 AM EST THU FEB 12 2015
A STRONG DISTURBANCE WITH CONSIDERABLE DYNAMIC FORCING AND DEEP
MOISTURE HAS BROUGHT AN INCREASE IN SNOW SHOWERS ACROSS THE AREA
TONIGHT WITH STRONG NNW WINDS THAT WILL CAUSE CONSIDERABLE
BLSN...IFR TO VLIFR CONDITIONS ARE EXPECTED AT ALL 3 TAF SITES. THE
MOST SEVERE WIND AND BLOWING SNOW IS EXPECTED AT SAW. WITH STRONG
SUBSIDENCE/DIMINISHING WINDS AND BLSN FOLLOWING THE PASSAGE OF THIS
DISTURBANCE...CONDITIONS WILL SLOWLY IMPROVE TO MVFR LATE TONIGHT
THROUGH THU MORNING. BACKING AND DIMINISHING WINDS AS HIGH PRES
BUILDS INTO THE AREA WILL ALLOW CONDITIONS TO IMPROVE TO VFR BY LATE
AFTERNOON OR EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST WED FEB 11 2015
ONGOING GALES/HEAVY FREEZING SPRAY WILL DIMINISH W-E LATE TONIGHT
AND THU WITH THE APPROACH OF A HI PRES RIDGE/WEAKER PRES GRADIENT
AND DIMINISHING WINDS/WAVES. ANOTHER ROUND OF GALES/HEAVY FREEZING
SPRAY ASSOCIATED WITH ANOTHER ARCTIC AIR INVASION WILL DEVELOP FRI
NIGHT AND PERSIST THRU SAT. NOT OUT OF THE QUESTION THERE COULD BE
SOME STORM FORCE GUSTS ON SAT...ESPECIALLY OVER THE E HALF.
LOW PRESSURE NEAR GEORGIAN BAY WILL SLIDE ACROSS NEW ENGLAND THROUGH
THURSDAY AND DEEPEN. HIGH PRESSURE OVER SASKATCHEWAN WILL THEN
SETTLE OVER THE MID MISSISSIPPI RIVER VALLEY BY THURSDAY AFTERNOON
WITH A RIDGE EXTENDING NORTHWARD ACROSS THE UPPER GREAT LAKES.
EXPECT THE RIDGE TO REACH THE LOWER GREAT LAKES ON FRIDAY AS LOW
PRESSURE MOVES FROM NORTHERN ONTARIO TO LAKE SUPERIOR. THE LOW WILL
DEEPEN AS IT REACHES THE LOWER GREAT LAKES ON SATURDAY AND JUST OFF
THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE BUILDING FROM CENTRAL
CANADA INTO THE NORTHERN PLAINS ON SATURDAY WILL CROSS THE GREAT
LAKES THROUGH MONDAY AS A LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING
FOR MIZ001>004-009-084.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ013-
085.
WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR MIZ010-011.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ005.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ006.
WIND CHILL ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 PM EST
THIS AFTERNOON FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
LSZ264-267.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ265-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ266.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ266.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ264.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ263.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TK
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
406 AM EST THU FEB 12 2015
.SYNOPSIS...
ARCTIC AIR WILL MOVE INTO THE REGION TODAY...BRINGING SNOW SHOWERS
AND FALLING TEMPERATURES. HIGH PRESSURE WILL SETTLE INTO THE REGION
FOR FRIDAY...BEFORE ANOTHER COLD FRONT MOVES IN ON SATURDAY. THIS
WILL BRING MORE SNOW AND EVEN COLDER TEMPERATURES FOR THE REST OF
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON SURFACE OBSERVATIONS AND RECENT RAP ANALYSES...THE
LEADING EDGE OF A COLD ARCTIC AIR MASS IS NOW MOVING SOUTHWARD
ACROSS SOUTHERN LOWER MICHIGAN. THIS WILL CROSS INTO NORTHERN
OHIO IN THE NEXT FEW HOURS...WITH INCREASING CONVERGENCE LEADING
TO INCREASING SNOW SHOWER COVERAGE AND INTENSITY. EARLIER THIS
MORNING ACROSS THE ILN FORECAST AREA...SHALLOW LOW-LEVEL MOISTURE
PRODUCED DRIZZLE AND FREEZING DRIZZLE. AS CONFIRMED BY SURFACE
OBS...THERE IS NOW ENOUGH MOISTURE PRESENT TO PRODUCE CLOUD
ICE...AND LEAVE SNOW AS THE ONLY PRECIPITATION TYPE. HRRR/RAP RUNS
HAVE BEEN USED TO HELP TIME OUT THE ARCTIC FRONT...AND THUS THE
MOST LIKELY TIMING FOR THE GREATEST COVERAGE OF SNOW SHOWERS. POPS
AND WIND GRIDS HAVE BEEN REFINED IN DETAIL USING THIS INFORMATION.
THE CONCERN FOR POTENTIALLY HEAVY SNOW SHOWERS (SNOW SQUALLS)
REMAINS LEGITIMATE...WITH SEVERAL FACTORS ADDING UP TO SUGGEST
SUCH A THREAT COULD OCCUR. THE ARCTIC FRONT WILL BRING TWO CHANGES
TO THE WEATHER ON ITS OWN. THE FIRST IS A SIGNIFICANT INCREASE IN
WIND SPEED. AS THE WIND DIRECTION SHIFTS FROM WNW TO NW...WINDS
WILL BEGIN TO GUST TO AROUND 30 KNOTS. EVEN AHEAD OF THE
FRONT...SOME GUSTS INTO THE 20-25 KNOT RANGE HAVE BEEN
OBSERVED...WITH THE PRESSURE GRADIENT ALREADY BEGINNING TO
TIGHTEN. THE SECOND FACTOR IS THE RAPID DROP IN TEMPERATURES.
SURFACE THETA-E IMAGES DEPICT A VERY SHARP GRADIENT ALONG THE
FRONT...INDICATING THE STRENGTH OF THE TRANSITION. ON THE BACK
SIDE OF THE FRONT...TEMPERATURES WILL FALL THROUGH THE
DAY...FORCING THE USE OF A VERY-NON-DIURNAL TEMPERATURE TRACE. THE
COLD AND WINDY WEATHER WILL BE A BAD SET OF BACKGROUND CONDITIONS
FOR THE DEVELOPMENT OF CONVECTIVE SNOW SHOWERS...AND BUFKIT
SOUNDINGS CONTINUE TO INDICATE WEAK INSTABILITY THAT IS AT LEAST
PARTIALLY IN THE FAVORABLE DENDRITIC GROWTH ZONE (CENTERED AROUND
-15 CELSIUS)...WITH VERY STEEP LOW-LEVEL LAPSE RATES. ALTHOUGH
THIS IS PLENTY ENOUGH TO BE CONCERNED ABOUT...THERE REMAINS ONE
FINAL PIECE OF THE PUZZLE. THE MIDDLE OHIO VALLEY IS LOCATED IN
THE PATH OF AN INTENSE POTENTIAL VORTICITY ANOMALY (WITH THE 1.5
PV SURFACE GETTING AS LOW AS 800MB). THE CENTER OF THIS ANOMALY
WILL MOVE SOUTHEAST THROUGH INDIANA THIS MORNING...AND INTO
KENTUCKY BY EARLY AFTERNOON. UNDER AND AHEAD OF THIS...STABILITY
WILL BE FURTHER DECREASED...ENHANCING THE ASCENT FOR WHATEVER SNOW
SHOWERS ARE DEVELOPING ALONG THE FRONT. THE JUXTAPOSITION OF THESE
TWO FORCING MECHANISMS APPEARS MOST LIKELY TO BE MAXIMIZED OVER
THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE ILN FORECAST AREA
BETWEEN 15Z AND 19Z. THUS...WHILE THE POTENTIAL FOR HAZARDOUS SNOW
SQUALLS EXISTS ACROSS THE ENTIRE FORECAST AREA THIS MORNING...IT
IS IN THIS AREA AND TIME PERIOD WHERE THE CONCERN IS HIGHEST.
WITH BOTH FRONTAL AND UPPER FORCING QUICKLY DIMINISHING AFTER
18Z...POPS WERE REDUCED SIGNIFICANTLY IN THE SECOND HALF OF THE
DAY. EVEN IF SOME LIGHT SNOW REMAINS POSSIBLE...IT AT LEAST
APPEARS ALMOST CERTAIN THAT THE THREAT FOR ANY HEAVY SNOW SHOWERS
WILL BE ALL BUT GONE DURING THE AFTERNOON HOURS. THOUGH PUTTING
ACCUMULATION NUMBERS ON A SNOW SHOWER SCENARIO IS
DIFFICULT...ACCUMULATIONS WILL LIKELY BE A FEW TENTHS OUTSIDE OF
THE HEAVIER SHOWERS...WITH UP TO AN INCH (MAYBE A LITTLE MORE IN
ISOLATED CASES) FOR LOCATIONS THAT EXPERIENCE THE HEAVIER SQUALLS.
AFTER COLLABORATION WITH SURROUNDING FORECAST OFFICES...A SPECIAL
WEATHER STATEMENT WILL CONTINUE TO BE USED TO HIGHLIGHT THE SNOW
SQUALL THREAT. CURRENT HIGH-RES DATA SUGGESTS THAT FOR ANY GIVEN
LOCATION...THE THREAT SHOULD BE BRIEF ENOUGH TO LIMIT THE
USEFULNESS OF AN ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
ON THURSDAY NIGHT...SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
FROM THE WEST. WITH COLD ADVECTION CONTINUING THROUGH FRIDAY
MORNING...TEMPERATURES WILL EASILY DROP INTO THE SINGLE
DIGITS...WITH THE POSSIBILITY FOR SOME VALUES NEAR ZERO IN THE
NORTHERN CWA. ALTHOUGH WINDS WILL BE DECREASING AS THE HIGH MOVES
IN...THERE WILL STILL BE ENOUGH WIND TO LEAD TO WIND CHILLS THAT
APPROACH ADVISORY CRITERIA IN THE NORTH AND NORTHEAST CWA. THIS IS
ENOUGH TO CONTINUE A MENTION IN THE HWO...BUT AS VALUES ONLY GET
INTO THE -4 TO -8 DEGREE RANGE FOR AN HOUR OR TWO IN THE FAR
NORTHEAST (SUCH AS THE STRETCH FROM HARDIN TO LICKING
COUNTIES)...THERE DOES NOT APPEAR TO BE ANY NEED FOR A WIND CHILL
ADVISORY.
THOUGH FRIDAY WILL BE COOL AND DRY...WINDS WILL BE SHIFTING BACK
TO THE SOUTHWEST...AS WEAK WARM ADVECTION IS EXPECTED TO BEGIN.
FROM HERE...IT APPEARS THAT THE ENTIRE WEDNESDAY-THURSDAY FORECAST
CYCLE APPEARS LIKELY TO REPEAT ITSELF AGAIN ON FRIDAY-SATURDAY.
HOWEVER...THE STARTING POINT WILL BE COOLER...LEAVING SNOW AS THE
ONLY PRECIPITATION TYPE IN THE FORECAST THROUGH FRIDAY AND
SATURDAY. THE INITIAL SHOT OF THETA-E ADVECTION ALOFT WILL BRING A
SLIGHT CHANCE FOR SOME FLURRIES ON FRIDAY AFTERNOON AND EVENING.
HOWEVER...APPRECIABLE PRECIPITATION WILL REMAIN WELL NORTH OF THE
FORECAST AREA UNTIL SATURDAY MORNING.
A STRENGTHENING SURFACE LOW IS FORECAST TO MOVE SOUTHEAST THROUGH
THE GREAT LAKES...WITH ANOTHER ARCTIC COLD FRONT PUSHING INTO THE
OHIO VALLEY DURING THE LATE MORNING AND AFTERNOON HOURS. THE TREND
WITH THE STRENGTH OF THIS FRONT AND THE POTENTIAL FOR SNOW APPEARS
TO BE SLIGHTLY UPWARD WITH THE 00Z MODEL RUNS. THE SURFACE LOW
WILL BE QUITE A BIT STRONGER THAN THE THURSDAY LOW...AND IN
ADDITION TO ANOTHER POTENTIAL VORTICITY ANOMALY...UPPER JET
SUPPORT WILL BE STRONGER AS WELL (WITH A 500MB NORTHWESTERLY STREAK
OF OVER 120 KNOTS PUSHING THROUGH NORTHERN ILLINOIS AND INTO
KENTUCKY). BUFKIT SOUNDINGS SUGGEST A LITTLE MORE INSTABILITY THAN
THE THURSDAY EVENT...AND SLIGHTLY STRONGER WIND GUSTS AS
WELL...WITH GOOD AGREEMENT ON THESE PARAMETERS ON RECENT RUNS OF
BOTH THE GFS/NAM (THOUGH THE ECMWF IS SLIGHTLY WEAKER ON THESE
FINER DETAILS...THIS COULD ALSO BE A FUNCTION OF ITS LACK OF
RESOLUTION ON AWIPS). THUS...ANOTHER ROUND OF SNOW IS EXPECTED
SATURDAY (WITH ACCUMULATIONS THAT COULD BE AN INCH OR TWO)...WITH
THE POTENTIAL FOR SNOW SQUALLS AND ALL THE USUAL HAZARDS THEY
BRING.
BY SUNDAY MORNING...FRIGID AIR WILL BE IN PLACE ACROSS THE ENTIRE
CWA...LIKELY ALSO AIDED BY A LITTLE BIT OF SNOW ON THE GROUND.
MIN TEMPS ARE EXPECTED TO RANGE FROM AROUND 5 DEGREES (FAR SOUTH)
TO -5 DEGREES (FAR NORTH). COMBINED WITH NORTHERLY FLOW OF AROUND
10 KNOTS...WIND CHILLS WILL RANGE FROM -5 DEGREES (FAR SOUTH) TO
-25 DEGREES (FAR NORTH). HEADLINES WILL LIKELY BE REQUIRED. RECORD
LOWS FOR SUNDAY (FEBRUARY 15) ARE AS FOLLOWS.
CVG...-1...2007
CMH...-4...1978
DAY...-5...2007
AS COLD ADVECTION IS EXPECTED TO CONTINUE THROUGH THE DAY ON
SUNDAY...THE DIURNAL CURVE WILL BE FAIRLY SMALL...AIDED ONLY BY
SOME SUN AS SKIES BECOME MOSTLY CLEAR. THE MAX TEMP FORECAST
RANGES FROM 5 TO 15 DEGREES. HERE ARE THE RECORD LOW MAXIMUM
TEMPERATURES FOR SUNDAY (FEBRUARY 15).
CVG...13...1920
CMH...12...1920
DAY...11...1920
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE HIGH AXIS CROSSES AND WEAKENS SIGNIFICANTLY EARLY MONDAY AND
SHOULD ALLOW FOR SOME SUN AND WEAKER WINDS FROM A SLIGHTLY LESS
COLD AIRMASS TO SEE READINGS REBOUND INTO THE 20S. FLOW WILL TURN
SOUTHWEST AND LIMIT NIGHTTIME FALLS WITH A WARM PUSH MONDAY NIGHT
AND TUESDAY AHEAD OF THE NEXT COLD FRONTAL PASSAGE.
THE NEXT SYSTEM ON TUESDAY IS BEING PROGGED TO COME FROM THE GULF
STATES AND THE TN VALLEY AND BE WELL AHEAD OF THE POSITIVE TILTED
L/W TROUGH OVER THE CENTRAL U.S. THIS LEADS ME TO NOTE THAT THE
PREVIOUS SYSTEMS PROMISING MUCH SNOW IN THE REGION WERE OF SIMILAR
ORIGIN WITH LITTLE UPPER SUPPORT. CONFIDENCE IN THE FORECAST TANKS
FOR THE LAST DAY OR SO IN THE FORECAST BUT HAS THE POTENTIAL FOR A
WINTER EVENT OVER THE REGION.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
A POTENT...BUT FAST MOVING...MID LEVEL TROUGH WILL PUSH THROUGH
THE GREAT LAKES AND OHIO VALLEY TODAY. LARGE SCALE ASCENT AHEAD OF
THIS FEATURE...ALONG WITH INCREASING INSTABILITY...WILL RESULT IN
NUMEROUS SNOW SHOWERS LATER THIS MORNING. IN ADDITION...A FOCUSED
LOW LEVEL BOUNDARY WILL MOVE ACROSS THE TAF SITES. THIS BOUNDARY
WILL MARK AN AREA OF ENHANCED SNOW SHOWERS/SNOW SQUALLS WITH THE
POTENTIAL FOR VISIBILITIES TO DROP BRIEFLY TO A MILE OR LESS. AVIATORS
CAN EXPECT MVFR CEILINGS AND VISIBILITIES IN SNOW SHOWERS THIS
MORNING WITH IFR OR LESS CONDITIONS IN THE HEAVIER SNOW
SHOWERS/SQUALLS. ONCE THE MAIN MID LEVEL TROUGH AXIS MOVES
BY...SNOW SHOWER COVERAGE SHOULD DECREASE MARKEDLY AS LARGE SCALE
SUBSIDENCE TAKES OVER. THIS WILL BRING CEILINGS BACK TO VFR BY THE
AFTERNOON HOURS. AN INCREASING PRESSURE GRADIENT A DEEPER MIXING
TODAY WILL BRING GUSTY NORTHWEST WINDS OF 15 TO 20 KNOTS WITH
GUSTS AROUND 30 KNOTS.
FOR TONIGHT...AN AREA OF HIGH PRESSURE WILL MOVE TOWARD THE
REGION. WINDS WILL GRADUALLY DECREASE THIS EVENING. THERE SHOULD
BE A MIX OF SCATTERED STRATOCUMULUS CLOUDS AND HIGH CLOUDS WITH
VFR CONDITIONS EXPECTED.
OUTLOOK...MVFR CEILINGS AND MVFR/IFR VISIBILITIES POSSIBLE SATURDAY
AND SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
111 AM EST THU FEB 12 2015
.SYNOPSIS...
ARCTIC AIR WILL PUSH INTO THE COMMONWEALTH OVERNIGHT AND
THURSDAY. SNOW SHOWERS AND SNOW SQUALLS WILL CROSS CENTRAL
PENNSYLVANIA THURSDAY MORNING AND AFTERNOON BEFORE BITTERLY COLD
AIR ARRIVES AND DANGEROUSLY LOW WIND CHILLS OCCUR THURSDAY NIGHT
AND FRIDAY. ANOTHER POTENT UPPER LEVEL SHORTWAVE AND ASSOCIATED
CLIPPER WILL DELIVER AN EVEN COLDER SHOT OF ARCTIC AIR TO THE
REGION ON SUNDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE DIVING SE ACROSS
WISCONSIN AT 0530Z. LG SCALE FORCING AHEAD OF THIS FEATURE IS
SUPPORTING SOME LIGHT SNOW FROM WESTERN NY STATE SW INTO OHIO.
ARCTIC COLD FRONT AT 05Z LIES ACROSS S ONTARIO INTO S MICHIGAN. AS
SHORTWAVE PRESSES EAST...EXPECT PERIODS OF LGT SNOW TO FALL OVR
THE ALLEGHENY PLATEAU EARLY THIS MORNING. UPSTREAM REPORTS ACROSS
SE OHIO/SW PA INDICATE SOME FZDZ...WHERE CLOUD TOP TEMPS REMAIN
RELATIVELY WARM. LATEST RAP OUTPUT INDICATES CLOUD TOP TEMPS AOA
-10C COULD SUPPORT A BIT OF FZDZ ACROSS THE LAUREL HIGHLANDS UNTIL
DEEPER/COLDER CLOUD TOPS ARRIVE ARND 08Z-09Z. SOME BRIEFLY HEAVIER
SNOW SHOWERS/SQUALLS COULD AFFECT PARTS OF THE NW MTNS ARND
DAWN...AS ARCTIC COLD FRONT ARRIVES.
LATEST NEAR TERM MDL OUTPUT CONTINUES TO INDICATE ONLY LIGHT
SNOW ACCUMS TONIGHT ACROSS THE ALLEGHENY PLATEAU. BLEND OF EARLIER MDL
QPF AND LATEST HRRR SUGGEST ACCUMS WILL GENERALLY BE LESS THAN AN
INCH ACROSS THE ALLEGHENY PLATEAU...WITH NO MORE THAN A DUSTING
LIKELY ELSEWHERE. CLOUD COVER AND SWRLY FLOW AHEAD OF APPROACHING ARCTIC
COLD FRONT SHOULD RESULT IN A RELATIVELY MILD NIGHT...WITH MIN
TEMPS MOSTLY IN THE 20S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
QPF VERY LIGHT AND UPSLOPE FETCH/FEED NOT ENTIRELY FAVORABLE FOR
SOMERSET COUNTY TO REALLY GET HAMMERED WITH HEAVY SNOW THIS
PERIOD. WILL TAKE THE WATCH AND CONVERT IT TO AN ADVY AND KEEP
MENTIONS OF BLSN...AS WINDS WILL BE PRETTY NASTY. ACCUMS WILL BE
TOUGH TO MEASURE ANYWAY...BUT QPF SO LIGHT - ON THE ORDER OF A
TENTH OF AN INCH - THAT ACCUMS MORE THAN 5 INCHES EVEN ON THE
RIDGES IS UNLIKELY.
WILL KEEP THINKING ABOUT THE WIND CHILL WATCH...IT LOOKS LIKE A
SOLID WARNING IN THE NORTH...BUT AN ADVY WILL BE NECESSARY
ELSEWHERE...BUT HOW FAR SE TO GO WITH IT IS A QUESTION. NO NEED TO
ACT RIGHT AWAY...AND WILL HOLD ONTO THE WIND CHILL WATCH FOR THE
TIME BEING.
PREV...
ARCTIC COLD FRONT WILL SWEEP THRU MOST OF CENTRAL PA BTWN 12Z-18Z
THU BASED ON 12Z GUIDANCE AND BTV SNSQ PARAMETER. SENT I80 EMAIL
NOTIFICATION FOR LINE OF SQUALLS EXPECTED TO CROSS CENTRAL PA THU
MORNING INTO THU AFTERNOON. STEEP LOWER TROPOSPHERIC LAPSE
RATES...COMBINED WITH STRONG LG SCALE FORCING AHEAD OF MID LVL
SHORTWAVE...WILL GENERATE LOCALLY HEAVY SNOW SHOWERS AND SQUALLS
EVEN INTO THE SUSQ VALLEY. ACCUMS THURSDAY SHOULD BE GENERALLY
LESS THAN AN INCH...BUT COULD POTENTIALLY CREATE FLASH FREEZE
CONCERNS OVR THE LOWER SUSQ VALLEY...WHERE ABV FREEZING TEMPS AND
INITIAL MELTING OF SNOW ON ROADS IS POSSIBLE.
OTHER CONCERN IS FOR STRONG UPSLOPE INTO THE LAUREL HIGHLANDS TO
PRODUCE SEVERAL INCHES OF SNOWFALL OVER SOMERSET COUNTY. NW
WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN THE
AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS. THE
STRONGEST WINDS WILL LIKELY NOT DEVELOP UNTIL THURSDAY EVENING...AS
PRES GRADIENT TIGHTENS WEST OF RAPIDLY DEVELOPING COASTAL STORM
SOUTH OF CAPE COD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
CURRENT ENSEMBLES AND MODEL SOUNDINGS GIVE FURTHER CREDENCE AND
SUPPORT FOR FREQUENT GUSTS TO ARND 35KTS ACROSS MUCH OF CENTRAL
PA BTWN 00Z- 06Z FRIDAY. GUSTY WINDS WILL CONTINUE THROUGH FRIDAY
MORNING. THE STRONG WINDS IN CONJUNCTION W/ARRIVAL OF ARCTIC AIR
MASS WILL LIKELY RESULT WIDESPREAD WIND CHILLS THU NIGHT BTWN
10-20 BLW ZERO. ACROSS THE N MTNS...APPARENT TEMPS IN THE 25-30BLW
RANGE ARE POSSIBLE. CONFIDENCE IN TEMPERATURES AND HAVE THEREFORE
ISSUED A WIND CHILL WATCH UP THERE AND WILL CONTINUE TO MENTION
POSSIBILITY OF DANGEROUS WCHILLS ACROSS THE CENTRAL COUNTIES.
MOSTLY FROZEN LAKES AND DRYNESS OF ARCTIC AIR MASS SHOULD PRECLUDE
ANYTHING MORE THAN SCT -SHSN OVR THE W MTNS THU NIGHT WITH ANY
ADDITIONAL ACCUMS LESS THAN AN INCH.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER
SEASON SO FAR WITH ANOMALOUSLY LOW GEFS MEAN 925 MB TEMPS OF ARND
-18C LIKELY SUPPORTING HIGH TEMPS NO BETTER THAN THE SINGLE
DIGITS ACROSS THE NORTHERN MTNS...TO THE UPPER TEENS ACROSS THE
SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND PARTLY
TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE NW MTNS
MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU WITH A
CHANCE FOR FLURRIES FRIDAY NIGHT INTO SATURDAY.
THE CLIPPER WILL TRACK ACROSS THE CWA LATE FRIDAY NIGHT INTO
SATURDAY...ACCOMPANIED BY NUMEROUS SNOW SHOWERS INTO SATURDAY
DAYTIME...AND PERIODS OF STEADY SNOW INTO SATURDAY EVENING. MODELS
DIFFER ON THE PLACEMENT OF THE UPPER LEVEL LOW...AND AS SUCH THERE
IS SOME VARIANCE ON THE AMOUNT OF QPF AND CORRESPONDING SNOW
AMOUNTS WITH THIS SYSTEM. THE EC MODEL GUIDANCE INDICATES A
CLOSED MID/UPPER LOW CENTER FORMING OVER CENTRAL/ERN PENN BEFORE
SCOOTING QUICKLY EAST OFF THE MID ATLANTIC COAST. AIR BEHIND THIS
SYSTEM WILL BE EVEN A FEW-SVRL DEG F COLDER THAN THE INITIAL LATE
WEEK CLIPPER. TEMPS SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW
NORMAL VALUES/ SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS
EMBEDDED IN THE LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GEFS TEMP PLUMES AND ECENS MOS INDICATE THE COLDEST TEMPS OF THIS
OUTBREAK WILL LIKELY OCCUR SUN NIGHT...AS ARCTIC HIGH PRESSURE
SYSTEM BUILDS INTO THE STATE. SHOULD THE WIND DIMINISH AND SKIES
CLEAR OUT QUICK ENOUGH...WIDESPREAD RECORD MINS ARE POSSIBLE.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN CONUS TROF A LITTLE FURTHER TO
THE WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING
FOR SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT
HEADS EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND
AT THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE
CENTRAL AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING
ON WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN
AND SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY
REBOUND BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
ABOVE AVG CONFIDENCE IN PROLONGED IFR AT BFD/JST TERMINALS IN ZOB
SECTOR GIVEN INCREASINGLY COLD/BLUSTERY WNW FLOW IN WAKE OF
ARCTIC FRONT. MVFR CIGS SHOULD PREVAIL ACROSS THE CENTRAL TAFS
WITH LOW VFR 050 CIGS AT MDT/LNS. TIMING OF ARCTIC FRONT AND
ASSOCIATED BURSTS OF +SHSN/SNSQ WILL STILL NEED TO BE REFINED WITH
FAVORED WINDOW 12-15Z WEST...15-18Z CENTRAL AND 18-21Z SOUTHEAST.
SFC WINDS 270-300 BCMG 290-320 AND INCREASING INTO TONIGHT WITH
GUSTS 25-35KTS. CONDS SHOULD IMPROVE EAST OF THE MTNS BY TONIGHT
WITH RESTRICTIONS LKLY PERSISTING AT BFD/JST INTO FRIDAY MORNING.
OUTLOOK...
FRI...MVFR/IFR WITH -SHSN WEST EARLY...THEN GRADUALLY IMPROVING.
SAT...BCMG MVFR/IFR WITH -SN. FROPA FOLLOWED BY GUSTY WNW WINDS.
SUN...MVFR/IFR WEST IN -SHSN. STRONG GUSTY WNW WINDS.
MON...MVFR/IFR WITH -SHSN EARLY...THEN VFR LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR
PAZ004>006-037-042.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 1 AM EST
FRIDAY FOR PAZ033.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1244 AM EST THU FEB 12 2015
.SYNOPSIS...
ARCTIC AIR WILL PUSH INTO THE COMMONWEALTH OVERNIGHT AND
THURSDAY. SNOW SHOWERS AND SNOW SQUALLS WILL CROSS CENTRAL
PENNSYLVANIA THURSDAY MORNING AND AFTERNOON BEFORE BITTERLY COLD
AIR ARRIVES AND DANGEROUSLY LOW WIND CHILLS OCCUR THURSDAY NIGHT
AND FRIDAY. ANOTHER POTENT UPPER LEVEL SHORTWAVE AND ASSOCIATED
CLIPPER WILL DELIVER AN EVEN COLDER SHOT OF ARCTIC AIR TO THE
REGION ON SUNDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WATER VAPOR LOOP SHOWS POTENT SHORTWAVE DIVING SE ACROSS
WISCONSIN AT 0530Z. LG SCALE FORCING AHEAD OF THIS FEATURE IS
SUPPORTING SOME LIGHT SNOW FROM WESTERN NY STATE SW INTO OHIO.
ARCTIC COLD FRONT AT 05Z LIES ACROSS S ONTARIO INTO S MICHIGAN. AS
SHORTWAVE PRESSES EAST...EXPECT PERIODS OF LGT SNOW TO FALL OVR
THE ALLEGHENY PLATEAU EARLY THIS MORNING. UPSTREAM REPORTS ACROSS
SE OHIO/SW PA INDICATE SOME FZDZ...WHERE CLOUD TOP TEMPS REMAIN
RELATIVELY WARM. LATEST RAP OUTPUT INDICATES CLOUD TOP TEMPS AOA
-10C COULD SUPPORT A BIT OF FZDZ ACROSS THE LAUREL HIGHLANDS UNTIL
DEEPER/COLDER CLOUD TOPS ARRIVE ARND 08Z-09Z. SOME BRIEFLY HEAVIER
SNOW SHOWERS/SQUALLS COULD AFFECT PARTS OF THE NW MTNS ARND
DAWN...AS ARCTIC COLD FRONT ARRIVES.
LATEST NEAR TERM MDL OUTPUT CONTINUES TO INDICATE ONLY LIGHT
SNOW ACCUMS TONIGHT ACROSS THE ALLEGHENY PLATEAU. BLEND OF EARLIER MDL
QPF AND LATEST HRRR SUGGEST ACCUMS WILL GENERALLY BE LESS THAN AN
INCH ACROSS THE ALLEGHENY PLATEAU...WITH NO MORE THAN A DUSTING
LIKELY ELSEWHERE. CLOUD COVER AND SWRLY FLOW AHEAD OF APPROACHING ARCTIC
COLD FRONT SHOULD RESULT IN A RELATIVELY MILD NIGHT...WITH MIN
TEMPS MOSTLY IN THE 20S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/...
QPF VERY LIGHT AND UPSLOPE FETCH/FEED NOT ENTIRELY FAVORABLE FOR
SOMERSET COUNTY TO REALLY GET HAMMERED WITH HEAVY SNOW THIS
PERIOD. WILL TAKE THE WATCH AND CONVERT IT TO AN ADVY AND KEEP
MENTIONS OF BLSN...AS WINDS WILL BE PRETTY NASTY. ACCUMS WILL BE
TOUGH TO MEASURE ANYWAY...BUT QPF SO LIGHT - ON THE ORDER OF A
TENTH OF AN INCH - THAT ACCUMS MORE THAN 5 INCHES EVEN ON THE
RIDGES IS UNLIKELY.
WILL KEEP THINKING ABOUT THE WIND CHILL WATCH...IT LOOKS LIKE A
SOLID WARNING IN THE NORTH...BUT AN ADVY WILL BE NECESSARY
ELSEWHERE...BUT HOW FAR SE TO GO WITH IT IS A QUESTION. NO NEED TO
ACT RIGHT AWAY...AND WILL HOLD ONTO THE WIND CHILL WATCH FOR THE
TIME BEING.
PREV...
ARCTIC COLD FRONT WILL SWEEP THRU MOST OF CENTRAL PA BTWN 12Z-18Z
THU BASED ON 12Z GUIDANCE AND BTV SNSQ PARAMETER. SENT I80 EMAIL
NOTIFICATION FOR LINE OF SQUALLS EXPECTED TO CROSS CENTRAL PA THU
MORNING INTO THU AFTERNOON. STEEP LOWER TROPOSPHERIC LAPSE
RATES...COMBINED WITH STRONG LG SCALE FORCING AHEAD OF MID LVL
SHORTWAVE...WILL GENERATE LOCALLY HEAVY SNOW SHOWERS AND SQUALLS
EVEN INTO THE SUSQ VALLEY. ACCUMS THURSDAY SHOULD BE GENERALLY
LESS THAN AN INCH...BUT COULD POTENTIALLY CREATE FLASH FREEZE
CONCERNS OVR THE LOWER SUSQ VALLEY...WHERE ABV FREEZING TEMPS AND
INITIAL MELTING OF SNOW ON ROADS IS POSSIBLE.
OTHER CONCERN IS FOR STRONG UPSLOPE INTO THE LAUREL HIGHLANDS TO
PRODUCE SEVERAL INCHES OF SNOWFALL OVER SOMERSET COUNTY. IN COLLAB
WITH PBZ AND LWX...ISSUED WINTER STORM WATCH FOR SOMERSET COUNTY
WITH A GENERAL 4 TO 8 INCHES WITH HIGHER AMOUNTS POSSIBLE ON THE
RIDGES FROM ~12Z THU TO 06Z FRI NIGHT.
NW WINDS INCREASING TO 10-18 KTS WITH GUSTS OCNLY TO 25-30 KTS IN
THE AFTERNOON WILL USHER IN BITTERLY COLD TEMPS AND WIND CHILLS.
THE STRONGEST WINDS WILL LIKELY NOT DEVELOP UNTIL THURSDAY
EVENING...AS PRES GRADIENT TIGHTENS WEST OF RAPIDLY DEVELOPING
COASTAL STORM SOUTH OF CAPE COD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
CURRENT ENEMBLES AND MODEL SOUNDINGS GIVE FURTHER CREDENCE AND
SUPPORT FOR FREQUENT GUSTS TO ARND 35KTS ACROSS MUCH OF CENTRAL
PA BTWN 00Z- 06Z FRIDAY. GUSTY WINDS WILL CONTINUE THROUGH FRIDAY
MORNING. THE STRONG WINDS IN CONJUNCTION W/ARRIVAL OF ARCTIC AIR
MASS WILL LIKELY RESULT WIDESPREAD WIND CHILLS THU NIGHT BTWN
10-20 BLW ZERO. ACROSS THE N MTNS...APPARENT TEMPS IN THE 25-30BLW
RANGE ARE POSSIBLE. CONFIDENCE IN TEMPERATURES AND HAVE THEREFORE
ISSUED A WIND CHILL WATCH UP THERE AND WILL CONTINUE TO MENTION
POSSIBILITY OF DANGEROUS WCHILLS ACROSS THE CENTRAL COUNTIES.
MOSTLY FROZEN LAKES AND DRYNESS OF ARCTIC AIR MASS SHOULD PRECLUDE
ANYTHING MORE THAN SCT -SHSN OVR THE W MTNS THU NIGHT WITH ANY
ADDITIONAL ACCUMS LESS THAN AN INCH.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER
SEASON SO FAR WITH ANOMALOUSLY LOW GEFS MEAN 925 MB TEMPS OF ARND
-18C LIKELY SUPPORTING HIGH TEMPS NO BETTER THAN THE SINGLE
DIGITS ACROSS THE NORTHERN MTNS...TO THE UPPER TEENS ACROSS THE
SOUTHERN VALLEYS.
AN EXTENSIVE RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION FRIDAY
INTO EARLY FRIDAY NIGHT WITH SLOWLY DECREASING NW WINDS AND PARTLY
TO MOSTLY SUNNY SKIES ACROSS THE CENTRAL AND SE ZONES. THE NW MTNS
MAY HAVE A TOUGH TIME BREAKING UP THE SHALLOW STRATO CU WITH A
CHANCE FOR FLURRIES FRIDAY NIGHT INTO SATURDAY.
THE CLIPPER WILL TRACK ACROSS THE CWA LATE FRIDAY NIGHT INTO
SATURDAY...ACCOMPANIED BY NUMEROUS SNOW SHOWERS INTO SATURDAY
DAYTIME...AND PERIODS OF STEADY SNOW INTO SATURDAY EVENING. MODELS
DIFFER ON THE PLACEMENT OF THE UPPER LEVEL LOW...AND AS SUCH THERE
IS SOME VARIANCE ON THE AMOUNT OF QPF AND CORRESPONDING SNOW
AMOUNTS WITH THIS SYSTEM. THE EC MODEL GUIDANCE INDICATES A
CLOSED MID/UPPER LOW CENTER FORMING OVER CENTRAL/ERN PENN BEFORE
SCOOTING QUICKLY EAST OFF THE MID ATLANTIC COAST. AIR BEHIND THIS
SYSTEM WILL BE EVEN A FEW-SVRL DEG F COLDER THAN THE INITIAL LATE
WEEK CLIPPER. TEMPS SHOULD STEADILY FALL /FROM THEIR ALREADY BELOW
NORMAL VALUES/ SATURDAY AFTERNOON/EVENING...WITH A FEW SQUALLS
EMBEDDED IN THE LARGER SCALE AREAS OF LIGHTER SNOW.
AS THE SFC LOW RAPIDLY DEEPENS JUST OFF THE MID ATLANTIC/SRN NEW
ENGLAND COAST SAT NIGHT/SUNDAY...NW WINDS WILL INCREASE TO
SUSTAINED SPEEDS IN THE TEENS-LOW 20 KT RANGE WITH GUSTS UP TO 30
KTS...SIMILAR OR COLDER WIND CHILLS /THAN THURSDAY NIGHT`S ARE
EXPECTED BY VERY EARLY SUNDAY/.
A TRUE TASTE OF THE ARCTIC WILL BE PLATED UP FOR RESIDENTS OF
PENN SUNDAY...WITH MEAN GEFS 850 MB TEMPS BOTTOMING OUT IN THE
LOW-MID -20C RANGE - RESULTING IN SFC MAX TEMPS POSSIBLY STAYING
JUST BELOW ZERO ACROSS THE NRN MTNS...AND ONLY REACHING THE UPPER
SINGLE DIGITS TO MID TEENS AT BEST ACROSS THE CENTRAL AND SRN
PORTIONS OF THE STATE.
GEFS TEMP PLUMES AND ECENS MOS INDICATE THE COLDEST TEMPS OF THIS
OUTBREAK WILL LIKELY OCCUR SUN NIGHT...AS ARCTIC HIGH PRESSURE
SYSTEM BUILDS INTO THE STATE. SHOULD THE WIND DIMINISH AND SKIES
CLEAR OUT QUICK ENOUGH...WIDESPREAD RECORD MINS ARE POSSIBLE.
THE THIRD DIGGING SHORTWAVE /POSSIBLE CABOOSE/ TUESDAY...MAY HELP
TO BRIEFLY CARVE OUT THE MEAN ERN CONUS TROF A LITTLE FURTHER TO
THE WEST /WHILE TEAMING UP WITH SOME SRN STREAM ENERGY/ ALLOWING
FOR SOME GOMEX MOISTURE TO BE PICKED UP BY THE SYSTEM BEFORE IT
HEADS EAST- NORTHEAST TWD THE VA/MID ATLANTIC COAST. FOR NOW...AND
AT THIS TIME RANGE WILL GO WITH ABOVE CLIMO POPS ACROSS THE
CENTRAL AND EAST FOR CHC OF LIGHT SNOW OR SNOW SHOWERS /DEPENDING
ON WHETHER WE SEE A DOMINANT NRN STREAM CLIPPER...OR PHASING NRN
AND SRN STREAM FEATURES/. TEMPS MONDAY AND TUESDAY WILL SLOWLY
REBOUND BUT LIKELY STAY SEVERAL DEG F BELOW NORMAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
FEW SNOW SHOWERS TO THE EAST.
NOT SEEING MUCH TO THE WEST.
EXPECT CONDITIONS TO LOWER...AS HIGHER DEWPOINTS WORK EASTWARD
FROM OH.
EARLIER DISCUSSION BELOW.
00Z...
MAIN AREA OF HEAVIER RADAR RETURNS NOW OVER NORTH CENTRAL PA.
MADE A FEW ADJUSTMENTS TO THE 00Z TAF PACKAGE.
21Z...
MADE SOME LARGE CHANGES TO TAFS AT 21Z.
FIRST ISSUE IS FAST MOVING BANDS OF SNOW SHOWERS. SNOW MAY COME
DOWN HARD FOR A SHORT TIME. MODELS FAR FASTER WITH THIS THAN
EVEN THE 06Z RUN LAST EVENING BEFORE I LEFT. BANDS OF SNOW WELL
AHEAD OF THE COLD FRONT AND UPPER LEVEL TROUGH.
SECOND ISSUE WAS TO ADD ANOTHER GROUP PRIOR TO 18Z THU...GUSTY
WINDS LIKELY BEFORE THAT TIME. SOME DIRECTIONAL SHEAR...THUS
HARD TO SEE A LOT OF HEAVY SQUALLS WITH THE FRONT OR OFF THE
LAKES.
OUTLOOK...
FRI...MVFR/IFR WITH -SHSN WEST...MAINLY EARLY. VFR LATE.
SAT...MVFR/IFR WITH -SN.
SUN...MVFR/IFR WEST IN -SHSN. VERY COLD TEMPERATURES...AND GUSTY
WINDS ALL AREAS.
MON...MVFR/IFR WITH -SHSN EARLY...THEN VFR LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR
PAZ004>006-037-042.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 1 AM EST
FRIDAY FOR PAZ033.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1000 PM MST WED FEB 11 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 220 PM MST WED FEB 11 2015
OVERALL A QUIET FORECAST PERIOD. CLOUDS ARE STARTING TO THIN ACROSS
MUCH OF THE AREA AS UPPER RIDGING BUILDS INTO THE REGION. PLENTY OF
LOW TO MID LEVEL MOISTURE IS STILL PRESENT TO OUR NORTH AND EAST AS
EVIDENCED BY WIDESPREAD CLOUDS OVER THE DAKOTAS ON AFTERNOON VISIBLE
SATELLITE IMAGERY. THE LATEST NAM BRINGS CONSIDERABLE BOUNDARY LAYER
MOISTURE SOUTHWESTWARD INTO THE CWA LATE TONIGHT. FORECAST SOUNDINGS
SHOW A 3000 TO 5000 FT DEPTH OF SATURATION OVER EAST CENTRAL WY INTO
THE NORTHERN PANHANDLE AFTER 06Z THU...SO BELIEVE WE COULD SEE SOME
PATCHY FOG EVEN THOUGH WIND DIRECTIONS DO NOT APPEAR TO BE FAVORABLE
FOR VERY LOW CIGS. ALL OF THIS SATURATION SHOULD BE WARMER THAN -10C
GIVEN THERMAL PROFILES...AND WITH SUB- FREEZING SURFACE TEMPERATURES
WE CANNOT ENTIRELY RULE OUT SOME FREEZING DRIZZLE. NOT EXPECTING TO
SEE ANYTHING MEASURABLE...SO POPS REMAIN NIL.
WARMER FOR THU AS LOW-LEVEL DOWNSLOPE FLOW RETURNS TO AREAS EAST OF
THE LARAMIE RANGE. LATEST MOS GUIDANCE HINTS AT HIGHS APPROACHING 60
F OVER THE PANHANDLE...BUT THIS COULD BE TEMPERED BY THICK CIRRUS AS
THE MODELS AGREE ON HIGH H5-H3 RH VALUES WITH A STRONG H25 JET JUST
TO OUR NORTHEAST. GENERALLY STAYED IN THE 50S. WINDS COULD BE A BIT
OF AN ISSUE AROUND 12Z THU. THE H85 CAG-CPR GRADIENT PEAKS AROUND 50
METERS AT THAT TIME AND THE NAM SUGGESTS AROUND 45 KTS AT H75. MAIN
LIMITING FACTOR WILL BE OVERALL WEAK SUBSIDENCE AND THE SHORT LIVED
NATURE OF THE STRONGER GRADIENT...SO KEPT THE FORECAST BELOW WARNING
CRITERIA FOR THE ARLINGTON GAP. BORDEAUX SHOULD SEE AN INCREASE IN
WINDS DURING THE LATE MORNING AND AFTERNOON AS THE STRONGEST SURFACE
PRESSURE FALLS SPREAD ACROSS SOUTH CENTRAL SD AND STRENGTHEN WEST TO
EAST ORIENTED LOW-LEVEL GRADIENTS. MIXING WILL BE STRONGER THEN AS
WELL...BUT FLOW ALOFT WILL BE ON THE DOWNTREND. GUSTS SHOULD PEAK IN
THE 50-55 MPH RANGE...SO DO NOT THINK A WATCH IS NEEDED. DRY NW FLOW
ALOFT CONTINUES INTO FRI ON THE EAST SIDE OF THE RIDGE. TEMPERATURES
WILL BE SIMILAR TO THU WITH H7 TEMPS STAYING BETWEEN -1 AND -4 DEG C
ACROSS THE AREA.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 250 PM MST WED FEB 11 2015
12Z MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT PROGGING THE UPPER RIDGE
PATTERN TO DEAMPLIFY AS TROUGHING TAKES SHAPE OVER THE NORTHERN ROCKIES.
THIS TROUGH WILL MOVE ACROSS THE FORECAST AREA LATE SATURDAY. A LEE
SIDE TROUGH TO TAKE SHAPE OVER THE EASTERN PLAINS OF WY/CO SATURDAY
AND SHIFTS EAST INTO WESTERN NE BY SUNDAY. SATURDAY WILL BE THE LAST
OF A LONG STRETCH OF MILD AND DRY DAYS WITH HIGHS IN THE 40S AND 50S
AS A MAJOR UPPER LEVEL PATTERN SHIFT TAKE PLACE LATE IN THE WEEKEND
AND INTO EARLY NEXT WEEK. SHORTWAVE ENERGY MOVES ONSHORE FROM THE
PACIFIC NORTHWEST AND CAUSES A AMPLIFICATION OF THE TROUGH OVER
THE GREAT BASIN AND ROCKIES MONDAY AND TUESDAY. THIS WILL OPEN THE
DOOR FOR ARCTIC AIR TO PLUNGE SOUTHWARD INTO THE REGION. A SURFACE
LOW DEVELOPS OVER EASTERN UT/WESTERN CO SUNDAY NIGHT AND TRACKS
SOUTHEAST TO THE VICINITY OF THE TX/OK PANHANDLES BY LATE MONDAY.
NORTH TO NORTHEAST FLOW LOW LEVEL FLOW...ABUNDANT MOISTURE AND
LIFT IN LEFT FRONT QUADRANT OF UPPER JET WILL SET THE STAGE FOR
WIDESPREAD WINTRY PRECIPITATION A GOOD BET SUNDAY NIGHT THROUGH
MONDAY NIGHT. TOO EARLY TO PREDICT SNOW ACCUMULATIONS...BUT
CONFIDENCE IS INCREASING THAT MUCH OF THE FORECAST AREA WILL SEE
SOME MEASURABLE SNOWFALL. GUSTY NORTHEASTERLY WINDS WILL RESULT IN
BLOWING/DRIFTING SNOW.
HIGH TEMPERATURES SUNDAY WILL BE ABOUT 10 DEGREES COOLER THAN
SATURDAY WITH 30S AND 40S. THE IMPACT OF THE ARCTIC AIR MASS WILL
BEGIN TO BE REALIZED MONDAY WITH HIGHS IN THE TEENS AND 20S. SINGLE
DIGITS AND TEENS ARE FORECAST FOR HIGH TEMPERATURES TUESDAY. LOWS
WILL DIP INTO THE SINGLE DIGITS MONDAY NIGHT...WITH SOME SINGLE
DIGITS BELOW ZERO POSSIBLE TUESDAY NIGHT. FORTUNATELY...WINDS WILL
BE LIGHTER WITH WIND CHILLS IN THE TEENS BELOW ZERO. UPPER TROUGH
SHIFTS EAST WITH RISING LOW/MID LEVEL HEIGHTS/THICKNESSES
RESULTING IN MODERATING TEMPERATURES WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 953 PM MST WED FEB 11 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAF PACKAGE. SHOWING A BAND
OF LOW CLOUDS MOVING INTO THE PANHANDLE THROUGH THE OVERNIGHT
HOURS. CAN SEE THE LOW CLOUDS ON THE 11-3.9U SATELLITE
IMAGERY...THOUGH IT DOES LOOK LIKE MOST OF THE LOW CLOUDS WILL
STAY EAST. VFR CONDITIONS BY MID MORNING FOR ALL LOCATIONS WITH
GUSTY WEST WINDS.
&&
.FIRE WEATHER...
ISSUED AT 220 PM MST WED FEB 11 2015
NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE OVER THE
SOUTHERN LARAMIE RANGE AND ADJACENT PLAINS/FOOTHILLS THU AFTERNOON.
GUSTY WESTERLY DOWNSLOPE WINDS WILL COMBINE WITH MINIMUM RH VALUES
BETWEEN 10 AND 15 PERCENT. FUELS ARE NOT FAVORABLE FOR LARGE FIRE
GROWTH AT THIS TIME. OTHERWISE MINIMAL FIRE WEATHER CONCERNS ARE
EXPECTED OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...MJ
AVIATION...GCC
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
509 AM CST THU FEB 12 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 111 AM CST THU FEB 12 2015
TODAY:
A FAIRLY BENIGN WEATHER DAY IS EXPECTED TODAY. A BACKDOOR COLD FRONT
WILL APPROACH HALF OF THE FORECAST AREA BY MORNING AND THEN STALL OUT.
THIS BOUNDARY WILL RETURN NORTH AS A WARM FRONT THROUGH THE DAY. THE
WESTERN ZONES - LOCATIONS LIKE SYRACUSE, ELKHART, AND HUGOTON WILL BE
FIRMLY IN THE WARM SECTOR AND SHOULD SEE HIGHS IN THE UPPER 50S. FARTHER
EAST WILL BE INFLUENCED MORE BY THE COLD HIGH PRESSURE CENTER LOCATED
ACROSS THE MIDWEST AND SHOULD SEE HIGHS ONLY TOPPING OUT TO THE LOWER
40S. ELEVATED FIRE WEATHER CONDITIONS ARE NOT EXPECTED - EVEN IN THE
WARMEST LOCATIONS - AS RELATIVE HUMIDITIES WILL NOT DROP LOW ENOUGH.
NO PRECIPITATION IS EXPECTED TODAY.
TONIGHT:
A WEAK FRONT WILL MOVE ACROSS THE REGION THROUGH THE OVERNIGHT WITH
MAIN IMPACT IN THE FORM OF A WIND SHIFT. HAVE GONE WITH SLIGHTLY COOLER
LOWS AS INDICATED BY THE NAM. IN ADDITION, VERIFICATION SHOWS A SLIGHT
WARM BIAS IN THE MODELS FOR LOWS. GIVEN HOW DRY THE ATMOSPHERE IS EXPECTED
TO BE, IT WOULDN`T TAKE MUCH TO RADIATE DOWNWARD. TWO CAVEATS TO THIS
IS IF THE WINDS WILL GO LIGHT AND HOW MUCH HIGH LEVEL CIRRIFORM CLOUDS
WILL IMPACT LOWS - IF AT ALL. POPS WILL CONTINUE AT ZERO PERCENT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 238 AM CST THU FEB 12 2015
A NORTHWEST DOWNSLOPE FLOW WILL IMPROVE FRIDAY WHICH WILL ALLOW
THE COLD AIR THAT INVADED WESTERN KANSAS ON THURSDAY TO QUICKLY
ERODE FROM WEST TO EAST. GIVEN THE WARMUP FORECAST BY THE GFS AND
NAM IN THE 900MB TO 850MB LEVEL THE PREVIOUS FORECAST STILL LOOKS
ON TRACK WITH HIGH REBOUNDING BACK INTO THE UPPER 50S TO LOWER
60S. GIVEN THE EXPECTED SKY COVER WILL TREND TOWARDS THE WARMER
MAV GUIDANCE FOR HIGHS NEAR THE COLORADO BORDER.
FURTHER NORTH ON FRIDAY AN UPPER LEVEL TROUGH WILL MOVE SOUTH
ACROSS MANITOBA AND WESTERN ONTARIO. AS THIS UPPER LEVEL SYSTEM
APPROACHES THE WESTERN GREAT LAKES A COLD FRONT WILL BEGIN TO EXIT
CANADA AND BEGIN TO CROSS THE NORTHERN PLAINS. MODELS APPEAR TO BE
IN GOOD AGREEMENT WITH THE NEXT COLD FRONT CROSSING WESTERN KANSAS
EARLY SATURDAY WHICH WILL BRING AN END TO THE BRIEF WARMING TREND,
ESPECIALLY IN THE NORTH. 850MB 24HOUR TEMPERATURE TRENDS FROM 00Z
SATURDAY TO 00Z SUNDAY INDICATED A 8C TO 13C FALL IN TEMPERATURES
BEHIND THIS FRONT. 00Z 850MB TEMPERATURES AT 00Z SUNDAY ARE
FORECAST TO RANGE FROM 0C TO AROUND -5C FOR ALL BUT EXTREME
SOUTHWEST KANSAS NEAR ELKHART AND LIBERAL WHERE THE FRONTAL
PASSAGE IS EXPECTED TO OCCUR LAST. BASED ON THE COOLING EXPECTED
IN THE LOWER LEVELS ALONG WITH THE POTENTIAL FOR INCREASING STATUS
BEHIND THIS FRONT WILL TREND TOWARDS THE COOLER MET GUIDANCE FOR
HIGHS NORTH OF DODGE CITY. FURTHER SOUTH WHERE TIMING OF THE FRONT
WILL BE LATER AND SOMEWHAT UNCLEAR WILL STAY CLOSE TO THE PREVIOUS
FORECAST WITH HIGHS IN THE LIBERAL AND ELKHART AREA BEING MAINLY
IN THE MID 60S. WINDY CONDITIONS ARE ALSO EXPECTED BEHIND THIS
COLD FRONT GIVEN THE TIGHT SURFACE PRESSURE GRADIENT AND THE 0-1KM
MEAN WINDS.
COLD AIR WILL CONTINUE TO MOVE INTO WESTERN KANSAS ON SUNDAY AS
THE SURFACE RIDGE AXIS CROSSES THE CENTRAL PLAINS. ALSO ON SUNDAY
AN UPPER LEVEL RIDGE AXIS WILL AMPLIFY JUST OFF THE COAST OF
BRITISH COLUMBIA AND AN UPPER LEVEL TROUGH WILL BEGIN TO MOVE
SOUTHEAST OUT OF CANADA INTO THE PACIFIC NORTHWEST. AS THIS NEXT
UPPER LEVEL SYSTEM APPROACHES THE CENTRAL ROCKIES FROM THE WEST
THE CHANCE FOR PRECIPITATION WILL BEGIN TO IMPROVE AS WARM AIR
ADVECTION/ISENTROPIC LIFT BEGINS TO IMPROVE OVER SOUTHWEST KANSAS.
AT THIS TIME PRECIPITATION TYPE ON SUNDAY NIGHT AND EARLY MONDAY
IS STILL SOMEWHAT UNCLEAR SO WILL KEEP PRECIPITATION TYPE
RAIN/FREEZING RAIN OR SNOW. THE MODEL SOUNDINGS DO INDICATED IF
LIQUID OR FREEZING PRECIPITATION DOES DEVELOP ON MONDAY IT SHOULD
CHANGE TO ALL SNOW MONDAY NIGHT.
THERE WILL BE A CHANCE FOR SNOW THROUGH TUESDAY AFTERNOON AS THE
UPPER LEVEL TROUGH CROSSES THE CENTRAL HIGH PLAINS AND A SECONDARY
COLD FRONT CROSSES WESTERN KANSAS. 850MB TEMPERATURE TRENDS
INDICATE ANOTHER 7 TO 12C FALL BETWEEN 00Z TUESDAY AND 00Z
WEDNESDAY. ON TUESDAY NIGHT HIGH PRESSURE AT THE SURFACE WILL
BEGIN TO BUILDS INTO WESTERN KANSAS AND THE UPPER LEVEL TROUGH
MOVES INTO EASTERN KANSAS. GIVEN THE CLEARING CONDITIONS AND
DECREASING WINDS LATE TUESDAY AND TUESDAY NIGHT WILL LOWER THE
LATEST CREXTENDEDFCST_INIT MINS FOR TUESDAY NIGHT BY AT LEAST 5
DEGREES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 508 AM CST THU FEB 12 2015
HRRR APPEARS TO HAVE A DECENT HANDLE WITH THE STATUS THAT WAS
MOVING SOUTH ACROSS NORTH CENTRAL KANSAS EARLIER THIS MORNING.
FOLLOWING THE HRRR TREND AND 06Z NAM BUFR SOUNDINGS THE POTENTIAL
EXIST FOR A PERIOD OF MVFR CEILINGS AT HAYS BETWEEN 12Z AND 15Z.
ELSEWHERE MOISTURE SPREADING ACROSS WESTERN KANSAS LATER THIS
MORNING WILL TO BE AT OR ABOVE THE 800MB LEVEL SO VFR CONDITIONS
CAN BE EXPECTED TODAY. NORTHEASTERLY WINDS AT 10 TO 15 MPH WILL
GRADUALLY VEER TO THE SOUTHEAST BY 18Z, AND THEN INCREASE INTO THE
15 TO 20 KNOT RANGE BY 21Z. AFTER SUNSET THE SOUTHEAST WINDS WILL
FALL BACK INTO THE 10 TO 15 KNOT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 30 60 34 / 0 0 0 0
GCK 54 30 62 33 / 0 0 0 0
EHA 59 33 64 37 / 0 0 0 0
LBL 57 31 63 34 / 0 0 0 0
HYS 39 28 57 34 / 0 0 0 0
P28 40 30 60 33 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
841 AM EST THU FEB 12 2015
.SYNOPSIS...
SNOW SHOWERS AND FRIGID ARCTIC AIR WILL PLAGUE THE UPPER OHIO
VALLEY REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHARP MIDLEVEL SHORTWAVE STARTING TO DIG INTO EASTERN OH/NW PA PER
WV LOOP. MODERATE TO HEAVY SNOW SHOWERS ARE ARRIVING ALONG WITH
IT...WITH VIS DROPPING TO 1/4 MILE IN THE HEAVIEST. HAVE UPPED
POPS TO CATEGORICAL AREAWIDE. KEPT SNOW AMOUNTS INTACT FOR NOW BUT
WILL NEED TO WATCH THESE FOR LOCALIZED HEAVIER AMOUNTS IN BANDS.
TEMPERATURES WILL BE FALLING THIS AFTERNOON IN STRONG COLD
ADVECTION...BLENDED IN LAMP GUIDANCE WITH PREVIOUS NUMBERS FOR
HOURLY DETAILS. CL
PREVIOUS DISCUSSION...
DEEPENING MIXING LEVELS AND COLD UPSLOPING FLOW OUT OF THE GREAT
LAKES WILL RESULT IN MORE SNOW SHOWERS...WITH ACCUMULATION CONCERNS
CONTINUING FOR THE RIDGES WHERE DIRECT...AND STRENGTHENING UPSLOPE
IS FORECAST TO SPAWN STRONG...BUT SHALLOW OMEGA FIELDS INTO A
FALLING DENDRITIC GROWTH ZONE. EARLY AFTERNOON APPEARS THE BEST TIME
FOR RAPID ACCUMULATION IN THOSE AREAS...WITH INCREASING SUBSIDENCE
AND DRY ADVECTION...AS EXHIBITED BY RAPID RAP AND NAM MIXING RATIO
DIMINISHMENT...PROVIDING INHIBITION THEREAFTER. THE WINTER WEATHER
ADVISORY FOR THE RIDGES HAS BEEN MAINTAINED...DESPITE RATHER LIGHT
CONSENSUS GUIDANCE TOTALS.
OTHERWISE...SNOW SQUALLS WILL LIKELY IMPACT AREAS OUTSIDE THE RIDGES
PERIODICALLY UNTIL THE AFOREMENTIONED LIMITATIONS DOMINATE.
LAST...AND DEFINITELY NOT LEAST...THIS FRONT...AS ADVERTISED...WILL
LEAD AN ARCTIC AIRMASS OVER THE REGION...WITH PERIODIC REINFORCEMENT
OCCURRING THROUGH EARLY NEXT WEEK. GIVEN UPSTREAM TEMPERATURE
READINGS AND CONSISTENT GUIDANCE OVER THE PAST FEW DAYS...HAVE
TWEAKED TONIGHTS READINGS USING ADJUSTED NAM GUIDANCE PRIMARILY.
SUFFICIENT SUSTAINED WIND WITH THAT TEMPERATURE FORECAST HAS
SPAWNED THE NECESSITY FOR A WIND CHILL ADVISORY...IN EFFECT FOR
TONIGHT AND FRIDAY MORNING. -10 TO -20 BELOW WIND CHILLS CAN BE
ANTICIPATED REGIONWIDE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE IS FORECAST TO BRIEFLY ON FRI. TEMPERATURES WILL
RECOVER SOMEWHAT AS ANOTHER STRONG UPSTREAM SHORTWAVE INITIATES WARM
ADVECTION WITH ITS APPROACH...BUT HIGHS WILL REMAIN WELL BELOW THE
AVERAGES. THAT SHORTWAVE WILL SPAWN MORE SNOW SHOWERS ON
SATURDAY...FORECAST FOR WHICH WAS BASED ON GFS PRECIPITATION
PROBABILITIES AND AMOUNTS...AND SEND ANOTHER ARCTIC FRONT ACROSS THE
REGION WITH TEMPERATURES ON SUNDAY MORNING PROJECTED UNDER THE ZERO
MARK. WIND CHILL INDICES WILL BE DANGEROUSLY LOW...SO MORE HEADLINES
SHOULD BE ANTICIPATED. SUNDAY HIGHS WERE FORECAST ABOUT 30 DEGREES
UNDER THE AVERAGES USING WPC GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
ECMWF AND GFS WERE IN VERY GOOD AGREEMENT IN DEPICTIONS OF UPPER
FLOW INTO NEXT WEEK. IN GENERAL...SOME BRIEF TEMPERATURE MODERATION
ON ZONAL TO SOUTHWEST FLOW WILL BE BOUGHT WITH LIKELY SNOW...AND
POSSIBLY RAIN SOUTH OF PIT AS AN AMPLIFYING SHORTWAVE DIGS TOWARD
THE COAST ON TUESDAY OR WEDNESDAY. PROLONGED MOISTURE ADVECTION
AND ASCENT MAY CAUSE PROBLEMS...SITUATIONAL MONITORING IS UNDERWAY.
PASSAGE OF THAT SYSTEM IS PROGGED TO USHER IN MORE COLD WITH BOTH
SOLUTIONS INDICATING DEVELOPMENT OF A BROAD...HIGH AMPLITUDE NORTH
AMERICAN TROUGH BY WEEKS END. WPC GUIDANCE WAS IN LINE WITH THESE
TRENDS AND FEW ADJUSTMENTS WERE NEEDED FOR THE LONG TERM FORECAST.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IMMEDIATELY BEFORE 12Z TAF ISSUANCE...CEILINGS AT MANY AIRPORTS
HAVE RISEN TO VFR...ALTHOUGH THIS IS NOT EXPECTED TO LAST VERY
LONG WITH CONDITIONS THE REST OF THE NIGHT HAVING BEEN MVFR.
ALTHOUGH SNOW SHOWER COVERAGE HAS DIMINISHED ACROSS THE FORECAST
AREA AS OF 11Z...ADDITIONAL SNOW SHOWERS ARE EXPECTED TO MOVE INTO
THE REGION FROM THE NORTHWEST. STILL ANTICIPATE THAT AN AREA OF
MORE MODERATE SNOW SHOWERS WILL DEVELOP LATE MORNING INTO EARLY
AFTERNOON SOMEWHERE ALONG A LINE FROM ZZV/HLG/LBE AND TRACK TO THE
SOUTH INTO MGW. THIS REGION WOULD BE THE MOST LIKELY TO HAVE
IFR/LIFR CONDITIONS IN SNOW SQUALLS. WINDS WILL ALSO BECOME GUSTY
THROUGH MUCH OF THE DAY...AROUND 25 KTS. BOTH SNOW SHOWER COVERAGE
AND GUSTY WINDS SHOULD DIMINISH DURING THE EVENING AND OVERNIGHT
HOURS AS SURFACE RIDGE BUILDS IN FROM THE WEST.
OUTLOOK.../FRIDAY THROUGH MONDAY/...
VFR EXPECTED FRIDAY INTO FRIDAY EVENING. RESTRICTIONS ARE THEN
LIKELY FRIDAY NIGHT THROUGH SUNDAY WITH LOW PRESSURE AFFECTING THE
REGION. VFR THEN EXPECTED SUNDAY NIGHT AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR MDZ001.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ074-076.
WV...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR WVZ001>004-012-021>023-041.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
641 AM EST THU FEB 12 2015
.SYNOPSIS...
SNOW SHOWERS AND FRIGID ARCTIC AIR WILL PLAGUE THE UPPER OHIO
VALLEY REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE SURFACE COLD FRONT HAS COMPLETED A SWEEP OF THE UPPER OHIO
REGION WITH SNOW SHOWERS EXPECTED TO CONTINUE AS THE AXIS OF THE
DEEPENING UPPER SHORTWAVE TROUGH DIGS EASTWARD. THAT AXIS WAS OVER
LAKE MICHIGAN AS OF 08Z...AND IS PROGGED TO ARRIVE OVER THE UPPER
OHIO BY MIDDAY.
DEEPENING MIXING LEVELS AND COLD UPSLOPING FLOW OUT OF THE GREAT
LAKES WILL RESULT IN MORE SNOW SHOWERS...WITH ACCUMULATION CONCERNS
CONTINUING FOR THE RIDGES WHERE DIRECT...AND STRENGTHENING UPSLOPE
IS FORECAST TO SPAWN STRONG...BUT SHALLOW OMEGA FIELDS INTO A
FALLING DENDRITIC GROWTH ZONE. EARLY AFTERNOON APPEARS THE BEST TIME
FOR RAPID ACCUMULATION IN THOSE AREAS...WITH INCREASING SUBSIDENCE
AND DRY ADVECTION...AS EXHIBITED BY RAPID RAP AND NAM MIXING RATIO
DIMINISHMENT...PROVIDING INHIBITION THEREAFTER. THE WINTER WEATHER
ADVISORY FOR THE RIDGES HAS BEEN MAINTAINED...DESPITE RATHER LIGHT
CONSENSUS GUIDANCE TOTALS.
OTHERWISE...SNOW SQUALLS WILL LIKELY IMPACT AREAS OUTSIDE THE RIDGES
PERIODICALLY UNTIL THE AFOREMENTIONED LIMITATIONS DOMINATE.
LAST...AND DEFINITELY NOT LEAST...THIS FRONT...AS ADVERTISED...WILL
LEAD AN ARCTIC AIRMASS OVER THE REGION...WITH PERIODIC REINFORCEMENT
OCCURRING THROUGH EARLY NEXT WEEK. GIVEN UPSTREAM TEMPERATURE
READINGS AND CONSISTENT GUIDANCE OVER THE PAST FEW DAYS...HAVE
TWEAKED TONIGHTS READINGS USING ADJUSTED NAM GUIDANCE PRIMARILY.
SUFFICIENT SUSTAINED WIND WITH THAT TEMPERATURE FORECAST HAS
SPAWNED THE NECESSITY FOR A WIND CHILL ADVISORY...IN EFFECT FOR
TONIGHT AND FRIDAY MORNING. -10 TO -20 BELOW WIND CHILLS CAN BE
ANTICIPATED REGIONWIDE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC HIGH PRESSURE IS FORECAST TO BRIEFLY ON FRI. TEMPERATURES WILL
RECOVER SOMEWHAT AS ANOTHER STRONG UPSTREAM SHORTWAVE INITIATES WARM
ADVECTION WITH ITS APPROACH...BUT HIGHS WILL REMAIN WELL BELOW THE
AVERAGES. THAT SHORTWAVE WILL SPAWN MORE SNOW SHOWERS ON
SATURDAY...FORECAST FOR WHICH WAS BASED ON GFS PRECIPITATION
PROBABILITIES AND AMOUNTS...AND SEND ANOTHER ARCTIC FRONT ACROSS THE
REGION WITH TEMPERATURES ON SUNDAY MORNING PROJECTED UNDER THE ZERO
MARK. WIND CHILL INDICES WILL BE DANGEROUSLY LOW...SO MORE HEADLINES
SHOULD BE ANTICIPATED. SUNDAY HIGHS WERE FORECAST ABOUT 30 DEGREES
UNDER THE AVERAGES USING WPC GUIDANCE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
ECMWF AND GFS WERE IN VERY GOOD AGREEMENT IN DEPICTIONS OF UPPER
FLOW INTO NEXT WEEK. IN GENERAL...SOME BRIEF TEMPERATURE MODERATION
ON ZONAL TO SOUTHWEST FLOW WILL BE BOUGHT WITH LIKELY SNOW...AND
POSSIBLY RAIN SOUTH OF PIT AS AN AMPLIFYING SHORTWAVE DIGS TOWARD
THE COAST ON TUESDAY OR WEDNESDAY. PROLONGED MOISTURE ADVECTION
AND ASCENT MAY CAUSE PROBLEMS...SITUATIONAL MONITORING IS UNDERWAY.
PASSAGE OF THAT SYSTEM IS PROGGED TO USHER IN MORE COLD WITH BOTH
SOLUTIONS INDICATING DEVELOPMENT OF A BROAD...HIGH AMPLITUDE NORTH
AMERICAN TROUGH BY WEEKS END. WPC GUIDANCE WAS IN LINE WITH THESE
TRENDS AND FEW ADJUSTMENTS WERE NEEDED FOR THE LONG TERM FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
IMMEDIATELY BEFORE 12Z TAF ISSUANCE...CEILINGS AT MANY AIRPORTS
HAVE RISEN TO VFR...ALTHOUGH THIS IS NOT EXPECTED TO LAST VERY
LONG WITH CONDITIONS THE REST OF THE NIGHT HAVING BEEN MVFR.
ALTHOUGH SNOW SHOWER COVERAGE HAS DIMINISHED ACROSS THE FORECAST
AREA AS OF 11Z...ADDITIONAL SNOW SHOWERS ARE EXPECTED TO MOVE INTO
THE REGION FROM THE NORTHWEST. STILL ANTICIPATE THAT AN AREA OF
MORE MODERATE SNOW SHOWERS WILL DEVELOP LATE MORNING INTO EARLY
AFTERNOON SOMEWHERE ALONG A LINE FROM ZZV/HLG/LBE AND TRACK TO THE
SOUTH INTO MGW. THIS REGION WOULD BE THE MOST LIKELY TO HAVE
IFR/LIFR CONDITIONS IN SNOW SQUALLS. WINDS WILL ALSO BECOME GUSTY
THROUGH MUCH OF THE DAY...AROUND 25 KTS. BOTH SNOW SHOWER COVERAGE
AND GUSTY WINDS SHOULD DIMINISH DURING THE EVENING AND OVERNIGHT
HOURS AS SURFACE RIDGE BUILDS IN FROM THE WEST.
OUTLOOK.../FRIDAY THROUGH MONDAY/...
VFR EXPECTED FRIDAY INTO FRIDAY EVENING. RESTRICTIONS ARE THEN
LIKELY FRIDAY NIGHT THROUGH SUNDAY WITH LOW PRESSURE AFFECTING THE
REGION. VFR THEN EXPECTED SUNDAY NIGHT AND MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR MDZ001.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ074-076.
WV...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO NOON EST FRIDAY
FOR WVZ001>004-012-021>023-041.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
957 AM EST THU FEB 12 2015
.SYNOPSIS...
COLDER WITH WIND BLOWN SNOW SHOWERS TODAY IN THE WAKE OF AN ARCTIC
FRONT CROSSING FIRST THING THIS MORNING. THIS SCENARIO REPEATS
ITSELF SATURDAY AFTERNOON AND NIGHT. LOW PRESSURE TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
TRACKING A S/W TROF AND SFC FRONT TO CROSS THIS AFTN. TEMPS AHEAD
OF THIS HAVE GENERALLY BEEN STEADY STATE...EXCEPT FOR SOME RISES
WHERE HOLES IN THE CLOUDS ARE SHOWING UP. REARRANGED POPS USING
LATEST HRRR WHICH HAS A GOOD HANDLE ON THE SITUATION. ELECTED TO
CODE UP SOME ISOLATED THUNDER ALONG AND S OF I64 THIS AFTN. QUITE A
BIT OF INSTABILITY SHOWING UP...EVEN UP TO H7. IN FACT...NEGATIVE
SFC DELTA THETA E COINCIDES QUITE NICELY WITH MAX OMEGA...ALL
WITHIN DENDTRITIC SNOW GROWTH LAYER. GLANCING AT BTV SNOW SQUALL
PARAMETER ALSO STRONGLY SUGGESTS INTENSE SQUALLS THIS AFTERNOON.
TIMING FOR THIS LOOKS BE IN THE 2 TO 5 PM TIME RANGE. SO...EXPECT
SOME INTENSE SNOW SQUALLS WHICH COULD LAY DOWN COATINGS TO ONE
INCHERS ALONG WITH REDUCED VSBY. WILL LEAVE HEADLINES AS
IS...ALTHOUGH LOOKING LESS LIKELY OF MEETING CRITERIA THRESHOLDS
OUTSIDE OF THE MOUNTAINS.
PREVIOUS DISCUSSION BELOW...
SFC TEMPERATURES HAVE FALLEN BELOW FREEZING DESPITE SW FLOW AND
OVERCAST SKY AHEAD OF AN APPROACHING ARCTIC FRONT EARLY THIS
MORNING. THE AIR ALOFT IS PROGGED TO SUPPORT SNOW BUT RAIN HAS
MATERIALIZED OUT AHEAD OF THE COLD FRONT WITH H85 TEMPERATURES
PROGGED AT -6 TO -8C AND TEMPERATURES BELOW FREEZING EVEN JUST
ABOVE THE DECK. THEREFORE HAVE REVISED THE WINTER WEATHER
ADVISORIES FOR A TOUCH OF FREEZING RAIN BEFORE DAWN.
THE COLD FRONT IS ALSO ABOUT THREE HOURS BEHIND SCHEDULE WHICH
HELPED TO LEAVE THE OPENING FOR FREEZING RAIN...NOT CROSSING THE
OHIO RIVER UNTIL 09Z THIS MORNING. PRECIPITATION WITH THE FRONT HAS
BEEN LIGHT AND BRIEF.
EXPECT PRECIPITATION WITH THE FRONT TO BECOME MORE WIDESPREAD ONCE
IT HITS THE MOUNTAINS FIRST THING THIS MORNING...AND THEN UPSLOPE
FLOW IN ITS WAKE SHOULD KEEP THE SNOW SHOWERS GOING THERE.
MEANWHILE...THE STRONG UPPER LEVEL S/W TROUGH DRIVING THE ARCTIC
FRONT THROUGH THE AREA...WHICH SHOULD STILL OCCUR BY DAWN...PIVOTS
THROUGH LATE THIS MORNING AND EARLY THIS AFTERNOON. THIS WILL BRING
THE BEST OPPORTUNITY FOR ACCUMULATING SNOW SHOWERS ACROSS THE
LOWLANDS DURING THIS TIME...IN A BANDED FASHION SHIFTING SWD THROUGH
THE FCST AREA DURING THIS TIME...BEFORE EVEN FURTHER ENHANCING THE
SNOWFALL IN THE MOUNTAINS.
BASED ON THE TIMING OF THE UPPER FEATURE...AND THE MOIST LAYER
PROGGED TO BECOME VERY SHALLOW IN ITS WAKE...HAVE ENDED THE SNOWFALL
EARLIER OUT ACROSS THE LOWLANDS. IF THIS IDEA HOLDS UP...THE WINTER
WEATHER ADVISORY MAY BE ALLOWED TO END EARLY THERE. HAVE A LITTLE
LESS SNOW THIS MORNING COMPARED WITH PREVIOUS FCST GIVEN SLOWER
TRENDS...BUT OVERALL SNOWFALL AMOUNTS ARE STILL VERY CLOSE TO
PREVIOUS FCST AND NESTLED WITHIN ADVISORY VALUES FOR THE RESPECTIVE
AREAS INVOLVED.
HAVE GUSTY WINDS INTO TONIGHT BUT WITH PEAK GUSTS 25 TO 30 KTS
ACROSS THE LOWLANDS AND 35 TO 40 KTS OVER THE HIGHER TERRAIN SO NO
WIND ADVISORY IS NEEDED...BUT WIND CHILL VALUES DO GET DRIVEN DOWN
INTO THE TEENS BELOW ZERO TONIGHT IN OUR HIGHEST MOUNTAINOUS
COUNTIES. HAVE THEREFORE ISSUED WIND CHILL ADVISORIES FOR
POCAHONTAS AND RANDOLPH COUNTIES FOR TONIGHT AND FRI MORNING.
USED THE MET / NAM FOR TEMPERATURES...WHICH FALL SLOWLY THIS MORNING
AND THEN MORE STOUTLY THIS AFTERNOON AND TONIGHT...BUT HIGHS AND
LOWS ARE STILL CLOSE TO PREVIOUS FCST AND CURRENT GUIDANCE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
THURSDAY NIGHT WILL END THE SNOW SHOWERS OVER THE MOUNTAINS...BUT
WILL KEEP FLURRIES GOING WITH THE SIGNIFICANTLY COLDER AIR IN PLACE.
THIS IS ONE OF THOSE SCENARIOS WHERE FLURRIES WILL FALL IF CLOUDS
EXIST AS 850MB TEMPERATURES WILL GET INTO THE -20C RANGE. THE FIRST
ARCTIC HIGH PRESSURE SYSTEM FILTERS IN...TRIES TO CLEAR THE SKY
BRIEFLY...AND WILL BE QUICKLY EVICTED BY AN ENFORCING CLIPPER SYSTEM
RUNNING THROUGH THE GREAT LAKES. FIGURE THIS ENTIRE TRANSITION WILL
OCCUR ON THE QUICKER SIDE...SO HAVE MINIMAL CLEARING OVERALL WITH
MOISTURE FROM THE CLIPPER ARRIVING LATE FRIDAY. SNOW SHOWERS BEGIN
FRIDAY NIGHT...MOST PLENTIFUL ACROSS THE NORTHERN THIRD OF THE
CWA...AND THEN MORE FOR THE MOUNTAINS SATURDAY. EXPECTING MODEST
ACCUMULATIONS INTO SATURDAY.
NO MAJOR CHANGES TO THE TEMPERATURE FORECASTS...WITH WELL ADVERTISED
COLD AND THEN COLDER AIRMASSES SETTLING INTO PLACE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
USED A BLEND OF THE GFS/ECMWF/GEFS ENSEMBLE MEAN/ AND ECMWF ENSEMBLE
MEAN. THIS HAS ARCTIC AIR MOVING INTO THE AREA SATURDAY NIGHT AND
REMAINING ON SUNDAY WITH SOME UPSLOPE SNOW. HIGH PRESSURE THEN MOVES
OVER MONDAY. NEXT SYSTEM IS TUESDAY INTO WEDNESDAY. MODELS HAVE BEEN
WAFFLING ON WHETHER THIS SYSTEM MOVES NORTH OR SOUTH OF THE AREA.
FOR NOW...WILL INCLUDE A WARM WEDGE WITH THE SYSTEM
TUESDAY...ALTHOUGH PRECIPITATION ARRIVING MONDAY NIGHT INTO TUESDAY
MORNING COULD BE INTERESTING.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
ARCTIC FRONT WAS JUST CROSSING THE MOUNTAINS AS 12Z APPROACHED.
THIS HAD LEFT A BRIEF OPPORTUNITY FOR FZRA WHICH SHOULD BE OVER
WITH...AS COLDER AIR BEHIND THE ARCTIC FRONT ARRIVES.
LOW MVFR TO IFR CIGS...ALONG WITH BRIEF MVFR VSBY IN SNOW SHOWERS IN
THE WAKE OF THE FRONT THIS MORNING. THE SNOW SHOWERS WILL BECOME
MORE NUMEROUS DURING THE DAY AS A STRONG UPPER LEVEL SYSTEM
CROSSES. THE ATMOSPHERE WILL BE UNSTABLE THU MAINLY ON ACCOUNT OF
COLD AIR ALOFT...SO CONDITIONS WILL VARY AMONG THE BILLOWING SNOW
CLOUDS...FROM VFR OUTSIDE THE SNOW SHOWERS IN A DEEP MIXING LAYER TO
IFR IN THE HEAVIER SNOW SHOWERS...EVEN SNOW SQUALLS AND GENERALLY
BLUSTERY CONDITIONS.
THE SNOW SHOWERS WILL BEGIN TO DIMINISH MID AFTERNOON IN THE MIDDLE
OHIO VALLEY AS THE UPPER LEVEL SYSTEM MOVES ON BY. THE SNOW SHOWERS
WILL DIMINISH BY LATE AFTERNOON ACROSS THE REMAINDER OF THE WV
LOWLANDS...AND THEN GRADUALLY DIMINISH OVER THE MOUNTAINS
OVERNIGHT. CIGS WILL BE VFR AS THE SNOW SHOWERS END...BUT MAY DROP
BACK TO MVFR TOWARD DAWN FRI.
W SFC FLOW WILL BECOME W TO NW AND GRADUALLY STRENGTHEN AND BECOME
GUSTY THIS AFTERNOON WITH PEAK GUSTS OF 25 TO 30 KTS. THESE STRONG
WINDS WILL ONLY DIMINISH A LITTLE TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: TIMING OF LOWER CIGS THIS MORNING MAY VARY.
CONDITIONS WILL BECOME HIGHLY VARIABLE IN SNOW SHOWERS MIDDAY AND
AFTERNOON.
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 H L M H M M
HTS CONSISTENCY H H H H H H H L H M H H
BKW CONSISTENCY H H H H H H M H H L L M
EKN CONSISTENCY H H H H M H H M L L M M
PKB CONSISTENCY H H H H H H H M H H H H
CKB CONSISTENCY H H H H H H M H M H H H
AFTER 12Z FRIDAY...
IFR AT TIMES SATURDAY NIGHT INTO SUNDAY IN THE WAKE OF AN ARCTIC
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR WVZ008>011-
013>020-024>040-046-047.
WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR WVZ046-047.
OH...NONE.
KY...NONE.
VA...WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR VAZ003-004.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/30
SHORT TERM...SL
LONG TERM...RPY
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
942 AM EST THU FEB 12 2015
.SYNOPSIS...
ARCTIC AIR WILL MOVE INTO THE REGION TODAY...BRINGING SNOW SHOWERS
AND FALLING TEMPERATURES. HIGH PRESSURE WILL SETTLE INTO THE REGION
FOR FRIDAY...BEFORE ANOTHER COLD FRONT MOVES IN ON SATURDAY. THIS
WILL BRING MORE SNOW AND EVEN COLDER TEMPERATURES FOR THE REST OF
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SNOW SHOWERS CONTINUE TO PROGRESS SOUTH SOUTHEAST ACROSS THE
REGION. SNOW SQUALL PARAMETER FROM THE RAP SHOWS A STRONGER SIGNAL
OVER THE NEXT SEVERAL HOURS AS IT PROGRESSES ACROSS THE SOUTHEAST
PART OF THE FORECAST AREAS. RADAR TRENDS SUGGEST THAT THERE IS
SOME ORGANIZATION STARTING TO DEVELOP IN THE STRONGER ECHOES. SO
THIS MIGHT BE THE GENESIS OF SQUALLS WHICH COULD BRING TEMPORARY
WHITEOUT CONDITIONS. IMMEDIATELY BEHIND THIS SNOW SHOWER ACTIVITY
DIMINISHES RATHER QUICKLY. LOOKS LIKE PRECIPITATION WILL COME TO
AN END SHORTLY IN WEST CENTRAL OHIO AND THIS SHOULD PROGRESS
ACROSS THE REGION THROUGH THE DAY WITH THE EXCEPTION OF FAR
WESTERN COUNTIES WHICH COULD HAVE SOME PERSISTENT ACTIVITY FROM A
STREAMER OFF LAKE MICHIGAN. WHERE FLOW IS ORIGINATING OVER THE
LOWER PENINSULA AS OPPOSED TO OFF THE LAKES...CLOUDS SHOULD START
TO DIMINISH LATER TODAY. SLOWLY FALLING TEMPERATURES WILL OCCUR
THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
ON THURSDAY NIGHT...SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
FROM THE WEST. WITH COLD ADVECTION CONTINUING THROUGH FRIDAY
MORNING...TEMPERATURES WILL EASILY DROP INTO THE SINGLE
DIGITS...WITH THE POSSIBILITY FOR SOME VALUES NEAR ZERO IN THE
NORTHERN CWA. ALTHOUGH WINDS WILL BE DECREASING AS THE HIGH MOVES
IN...THERE WILL STILL BE ENOUGH WIND TO LEAD TO WIND CHILLS THAT
APPROACH ADVISORY CRITERIA IN THE NORTH AND NORTHEAST CWA. THIS IS
ENOUGH TO CONTINUE A MENTION IN THE HWO...BUT AS VALUES ONLY GET
INTO THE -4 TO -8 DEGREE RANGE FOR AN HOUR OR TWO IN THE FAR
NORTHEAST (SUCH AS THE STRETCH FROM HARDIN TO LICKING
COUNTIES)...THERE DOES NOT APPEAR TO BE ANY NEED FOR A WIND CHILL
ADVISORY.
THOUGH FRIDAY WILL BE COOL AND DRY...WINDS WILL BE SHIFTING BACK
TO THE SOUTHWEST...AS WEAK WARM ADVECTION IS EXPECTED TO BEGIN.
FROM HERE...IT APPEARS THAT THE ENTIRE WEDNESDAY-THURSDAY FORECAST
CYCLE APPEARS LIKELY TO REPEAT ITSELF AGAIN ON FRIDAY-SATURDAY.
HOWEVER...THE STARTING POINT WILL BE COOLER...LEAVING SNOW AS THE
ONLY PRECIPITATION TYPE IN THE FORECAST THROUGH FRIDAY AND
SATURDAY. THE INITIAL SHOT OF THETA-E ADVECTION ALOFT WILL BRING A
SLIGHT CHANCE FOR SOME FLURRIES ON FRIDAY AFTERNOON AND EVENING.
HOWEVER...APPRECIABLE PRECIPITATION WILL REMAIN WELL NORTH OF THE
FORECAST AREA UNTIL SATURDAY MORNING.
A STRENGTHENING SURFACE LOW IS FORECAST TO MOVE SOUTHEAST THROUGH
THE GREAT LAKES...WITH ANOTHER ARCTIC COLD FRONT PUSHING INTO THE
OHIO VALLEY DURING THE LATE MORNING AND AFTERNOON HOURS. THE TREND
WITH THE STRENGTH OF THIS FRONT AND THE POTENTIAL FOR SNOW APPEARS
TO BE SLIGHTLY UPWARD WITH THE 00Z MODEL RUNS. THE SURFACE LOW
WILL BE QUITE A BIT STRONGER THAN THE THURSDAY LOW...AND IN
ADDITION TO ANOTHER POTENTIAL VORTICITY ANOMALY...UPPER JET
SUPPORT WILL BE STRONGER AS WELL (WITH A 500MB NORTHWESTERLY STREAK
OF OVER 120 KNOTS PUSHING THROUGH NORTHERN ILLINOIS AND INTO
KENTUCKY). BUFKIT SOUNDINGS SUGGEST A LITTLE MORE INSTABILITY THAN
THE THURSDAY EVENT...AND SLIGHTLY STRONGER WIND GUSTS AS
WELL...WITH GOOD AGREEMENT ON THESE PARAMETERS ON RECENT RUNS OF
BOTH THE GFS/NAM (THOUGH THE ECMWF IS SLIGHTLY WEAKER ON THESE
FINER DETAILS...THIS COULD ALSO BE A FUNCTION OF ITS LACK OF
RESOLUTION ON AWIPS). THUS...ANOTHER ROUND OF SNOW IS EXPECTED
SATURDAY (WITH ACCUMULATIONS THAT COULD BE AN INCH OR TWO)...WITH
THE POTENTIAL FOR SNOW SQUALLS AND ALL THE USUAL HAZARDS THEY
BRING.
BY SUNDAY MORNING...FRIGID AIR WILL BE IN PLACE ACROSS THE ENTIRE
CWA...LIKELY ALSO AIDED BY A LITTLE BIT OF SNOW ON THE GROUND.
MIN TEMPS ARE EXPECTED TO RANGE FROM AROUND 5 DEGREES (FAR SOUTH)
TO -5 DEGREES (FAR NORTH). COMBINED WITH NORTHERLY FLOW OF AROUND
10 KNOTS...WIND CHILLS WILL RANGE FROM -5 DEGREES (FAR SOUTH) TO
-25 DEGREES (FAR NORTH). HEADLINES WILL LIKELY BE REQUIRED. RECORD
LOWS FOR SUNDAY (FEBRUARY 15) ARE AS FOLLOWS.
CVG...-1...2007
CMH...-4...1978
DAY...-5...2007
AS COLD ADVECTION IS EXPECTED TO CONTINUE THROUGH THE DAY ON
SUNDAY...THE DIURNAL CURVE WILL BE FAIRLY SMALL...AIDED ONLY BY
SOME SUN AS SKIES BECOME MOSTLY CLEAR. THE MAX TEMP FORECAST
RANGES FROM 5 TO 15 DEGREES. HERE ARE THE RECORD LOW MAXIMUM
TEMPERATURES FOR SUNDAY (FEBRUARY 15).
CVG...13...1920
CMH...12...1920
DAY...11...1920
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE HIGH AXIS CROSSES AND WEAKENS SIGNIFICANTLY EARLY MONDAY AND
SHOULD ALLOW FOR SOME SUN AND WEAKER WINDS FROM A SLIGHTLY LESS
COLD AIRMASS TO SEE READINGS REBOUND INTO THE 20S. FLOW WILL TURN
SOUTHWEST AND LIMIT NIGHTTIME FALLS WITH A WARM PUSH MONDAY NIGHT
AND TUESDAY AHEAD OF THE NEXT COLD FRONTAL PASSAGE.
THE NEXT SYSTEM ON TUESDAY IS BEING PROGGED TO COME FROM THE GULF
STATES AND THE TN VALLEY AND BE WELL AHEAD OF THE POSITIVE TILTED
L/W TROUGH OVER THE CENTRAL U.S. THIS LEADS ME TO NOTE THAT THE
PREVIOUS SYSTEMS PROMISING MUCH SNOW IN THE REGION WERE OF SIMILAR
ORIGIN WITH LITTLE UPPER SUPPORT. CONFIDENCE IN THE FORECAST TANKS
FOR THE LAST DAY OR SO IN THE FORECAST BUT HAS THE POTENTIAL FOR A
WINTER EVENT OVER THE REGION.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A POTENT...BUT FAST MOVING...MID LEVEL TROUGH WILL PUSH THROUGH
THE GREAT LAKES AND OHIO VALLEY TODAY. LARGE SCALE ASCENT AHEAD OF
THIS FEATURE...ALONG WITH INCREASING INSTABILITY...WILL RESULT IN
NUMEROUS SNOW SHOWERS THIS MORNING. IN ADDITION...A FOCUSED LOW
LEVEL BOUNDARY (ARCTIC FRONT) WILL MOVE ACROSS THE TAF SITES. THIS
BOUNDARY WILL MARK AN AREA OF ENHANCED SNOW SHOWERS/SNOW SQUALLS
WITH THE POTENTIAL FOR VISIBILITIES TO DROP BRIEFLY TO A MILE OR
LESS. AVIATORS CAN EXPECT MVFR CEILINGS AND VISIBILITIES IN SNOW
SHOWERS THIS MORNING WITH IFR OR LESS CONDITIONS IN THE HEAVIER
SNOW SHOWERS/SQUALLS. ONCE THE MAIN MID LEVEL TROUGH AXIS MOVES
BY...SNOW SHOWER COVERAGE SHOULD DECREASE MARKEDLY AS LARGE SCALE
SUBSIDENCE TAKES OVER. THIS SHOULD BRING CEILINGS BACK TO VFR BY
THE AFTERNOON HOURS. AN INCREASING PRESSURE GRADIENT A DEEPER
MIXING TODAY WILL BRING GUSTY NORTHWEST WINDS OF 15 TO 20 KNOTS
WITH GUSTS AROUND 30 KNOTS.
FOR TONIGHT...AN AREA OF HIGH PRESSURE WILL MOVE TOWARD THE
REGION. WINDS WILL GRADUALLY DECREASE THIS EVENING. ANY REMAINING
STRATOCUMULUS CLOUDS SHOULD DISSIPATE WITH SOME SCT-BKN HIGH
CLOUDS STREAMING IN FROM THE NORTHWEST.
OUTLOOK...MVFR CEILINGS AND MVFR/IFR VISIBILITIES POSSIBLE SATURDAY
AND SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
608 AM EST THU FEB 12 2015
.SYNOPSIS...
ARCTIC AIR WILL MOVE INTO THE REGION TODAY...BRINGING SNOW SHOWERS
AND FALLING TEMPERATURES. HIGH PRESSURE WILL SETTLE INTO THE REGION
FOR FRIDAY...BEFORE ANOTHER COLD FRONT MOVES IN ON SATURDAY. THIS
WILL BRING MORE SNOW AND EVEN COLDER TEMPERATURES FOR THE REST OF
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON SURFACE OBSERVATIONS AND RECENT RAP ANALYSES...THE
LEADING EDGE OF A COLD ARCTIC AIR MASS IS NOW MOVING SOUTHWARD
ACROSS SOUTHERN LOWER MICHIGAN. THIS WILL CROSS INTO NORTHERN
OHIO IN THE NEXT FEW HOURS...WITH INCREASING CONVERGENCE LEADING
TO INCREASING SNOW SHOWER COVERAGE AND INTENSITY. EARLIER THIS
MORNING ACROSS THE ILN FORECAST AREA...SHALLOW LOW-LEVEL MOISTURE
PRODUCED DRIZZLE AND FREEZING DRIZZLE. AS CONFIRMED BY SURFACE
OBS...THERE IS NOW ENOUGH MOISTURE PRESENT TO PRODUCE CLOUD
ICE...AND LEAVE SNOW AS THE ONLY PRECIPITATION TYPE. HRRR/RAP RUNS
HAVE BEEN USED TO HELP TIME OUT THE ARCTIC FRONT...AND THUS THE
MOST LIKELY TIMING FOR THE GREATEST COVERAGE OF SNOW SHOWERS. POPS
AND WIND GRIDS HAVE BEEN REFINED IN DETAIL USING THIS INFORMATION.
THE CONCERN FOR POTENTIALLY HEAVY SNOW SHOWERS (SNOW SQUALLS)
REMAINS LEGITIMATE...WITH SEVERAL FACTORS ADDING UP TO SUGGEST
SUCH A THREAT COULD OCCUR. THE ARCTIC FRONT WILL BRING TWO CHANGES
TO THE WEATHER ON ITS OWN. THE FIRST IS A SIGNIFICANT INCREASE IN
WIND SPEED. AS THE WIND DIRECTION SHIFTS FROM WNW TO NW...WINDS
WILL BEGIN TO GUST TO AROUND 30 KNOTS. EVEN AHEAD OF THE
FRONT...SOME GUSTS INTO THE 20-25 KNOT RANGE HAVE BEEN
OBSERVED...WITH THE PRESSURE GRADIENT ALREADY BEGINNING TO
TIGHTEN. THE SECOND FACTOR IS THE RAPID DROP IN TEMPERATURES.
SURFACE THETA-E IMAGES DEPICT A VERY SHARP GRADIENT ALONG THE
FRONT...INDICATING THE STRENGTH OF THE TRANSITION. ON THE BACK
SIDE OF THE FRONT...TEMPERATURES WILL FALL THROUGH THE
DAY...FORCING THE USE OF A VERY-NON-DIURNAL TEMPERATURE TRACE. THE
COLD AND WINDY WEATHER WILL BE A BAD SET OF BACKGROUND CONDITIONS
FOR THE DEVELOPMENT OF CONVECTIVE SNOW SHOWERS...AND BUFKIT
SOUNDINGS CONTINUE TO INDICATE WEAK INSTABILITY THAT IS AT LEAST
PARTIALLY IN THE FAVORABLE DENDRITIC GROWTH ZONE (CENTERED AROUND
-15 CELSIUS)...WITH VERY STEEP LOW-LEVEL LAPSE RATES. ALTHOUGH
THIS IS PLENTY ENOUGH TO BE CONCERNED ABOUT...THERE REMAINS ONE
FINAL PIECE OF THE PUZZLE. THE MIDDLE OHIO VALLEY IS LOCATED IN
THE PATH OF AN INTENSE POTENTIAL VORTICITY ANOMALY (WITH THE 1.5
PV SURFACE GETTING AS LOW AS 800MB). THE CENTER OF THIS ANOMALY
WILL MOVE SOUTHEAST THROUGH INDIANA THIS MORNING...AND INTO
KENTUCKY BY EARLY AFTERNOON. UNDER AND AHEAD OF THIS...STABILITY
WILL BE FURTHER DECREASED...ENHANCING THE ASCENT FOR WHATEVER SNOW
SHOWERS ARE DEVELOPING ALONG THE FRONT. THE JUXTAPOSITION OF THESE
TWO FORCING MECHANISMS APPEARS MOST LIKELY TO BE MAXIMIZED OVER
THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE ILN FORECAST AREA
BETWEEN 15Z AND 19Z. THUS...WHILE THE POTENTIAL FOR HAZARDOUS SNOW
SQUALLS EXISTS ACROSS THE ENTIRE FORECAST AREA THIS MORNING...IT
IS IN THIS AREA AND TIME PERIOD WHERE THE CONCERN IS HIGHEST.
WITH BOTH FRONTAL AND UPPER FORCING QUICKLY DIMINISHING AFTER
18Z...POPS WERE REDUCED SIGNIFICANTLY IN THE SECOND HALF OF THE
DAY. EVEN IF SOME LIGHT SNOW REMAINS POSSIBLE...IT AT LEAST
APPEARS ALMOST CERTAIN THAT THE THREAT FOR ANY HEAVY SNOW SHOWERS
WILL BE ALL BUT GONE DURING THE AFTERNOON HOURS. THOUGH PUTTING
ACCUMULATION NUMBERS ON A SNOW SHOWER SCENARIO IS
DIFFICULT...ACCUMULATIONS WILL LIKELY BE A FEW TENTHS OUTSIDE OF
THE HEAVIER SHOWERS...WITH UP TO AN INCH (MAYBE A LITTLE MORE IN
ISOLATED CASES) FOR LOCATIONS THAT EXPERIENCE THE HEAVIER SQUALLS.
AFTER COLLABORATION WITH SURROUNDING FORECAST OFFICES...A SPECIAL
WEATHER STATEMENT WILL CONTINUE TO BE USED TO HIGHLIGHT THE SNOW
SQUALL THREAT. CURRENT HIGH-RES DATA SUGGESTS THAT FOR ANY GIVEN
LOCATION...THE THREAT SHOULD BE BRIEF ENOUGH TO LIMIT THE
USEFULNESS OF AN ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
ON THURSDAY NIGHT...SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
FROM THE WEST. WITH COLD ADVECTION CONTINUING THROUGH FRIDAY
MORNING...TEMPERATURES WILL EASILY DROP INTO THE SINGLE
DIGITS...WITH THE POSSIBILITY FOR SOME VALUES NEAR ZERO IN THE
NORTHERN CWA. ALTHOUGH WINDS WILL BE DECREASING AS THE HIGH MOVES
IN...THERE WILL STILL BE ENOUGH WIND TO LEAD TO WIND CHILLS THAT
APPROACH ADVISORY CRITERIA IN THE NORTH AND NORTHEAST CWA. THIS IS
ENOUGH TO CONTINUE A MENTION IN THE HWO...BUT AS VALUES ONLY GET
INTO THE -4 TO -8 DEGREE RANGE FOR AN HOUR OR TWO IN THE FAR
NORTHEAST (SUCH AS THE STRETCH FROM HARDIN TO LICKING
COUNTIES)...THERE DOES NOT APPEAR TO BE ANY NEED FOR A WIND CHILL
ADVISORY.
THOUGH FRIDAY WILL BE COOL AND DRY...WINDS WILL BE SHIFTING BACK
TO THE SOUTHWEST...AS WEAK WARM ADVECTION IS EXPECTED TO BEGIN.
FROM HERE...IT APPEARS THAT THE ENTIRE WEDNESDAY-THURSDAY FORECAST
CYCLE APPEARS LIKELY TO REPEAT ITSELF AGAIN ON FRIDAY-SATURDAY.
HOWEVER...THE STARTING POINT WILL BE COOLER...LEAVING SNOW AS THE
ONLY PRECIPITATION TYPE IN THE FORECAST THROUGH FRIDAY AND
SATURDAY. THE INITIAL SHOT OF THETA-E ADVECTION ALOFT WILL BRING A
SLIGHT CHANCE FOR SOME FLURRIES ON FRIDAY AFTERNOON AND EVENING.
HOWEVER...APPRECIABLE PRECIPITATION WILL REMAIN WELL NORTH OF THE
FORECAST AREA UNTIL SATURDAY MORNING.
A STRENGTHENING SURFACE LOW IS FORECAST TO MOVE SOUTHEAST THROUGH
THE GREAT LAKES...WITH ANOTHER ARCTIC COLD FRONT PUSHING INTO THE
OHIO VALLEY DURING THE LATE MORNING AND AFTERNOON HOURS. THE TREND
WITH THE STRENGTH OF THIS FRONT AND THE POTENTIAL FOR SNOW APPEARS
TO BE SLIGHTLY UPWARD WITH THE 00Z MODEL RUNS. THE SURFACE LOW
WILL BE QUITE A BIT STRONGER THAN THE THURSDAY LOW...AND IN
ADDITION TO ANOTHER POTENTIAL VORTICITY ANOMALY...UPPER JET
SUPPORT WILL BE STRONGER AS WELL (WITH A 500MB NORTHWESTERLY STREAK
OF OVER 120 KNOTS PUSHING THROUGH NORTHERN ILLINOIS AND INTO
KENTUCKY). BUFKIT SOUNDINGS SUGGEST A LITTLE MORE INSTABILITY THAN
THE THURSDAY EVENT...AND SLIGHTLY STRONGER WIND GUSTS AS
WELL...WITH GOOD AGREEMENT ON THESE PARAMETERS ON RECENT RUNS OF
BOTH THE GFS/NAM (THOUGH THE ECMWF IS SLIGHTLY WEAKER ON THESE
FINER DETAILS...THIS COULD ALSO BE A FUNCTION OF ITS LACK OF
RESOLUTION ON AWIPS). THUS...ANOTHER ROUND OF SNOW IS EXPECTED
SATURDAY (WITH ACCUMULATIONS THAT COULD BE AN INCH OR TWO)...WITH
THE POTENTIAL FOR SNOW SQUALLS AND ALL THE USUAL HAZARDS THEY
BRING.
BY SUNDAY MORNING...FRIGID AIR WILL BE IN PLACE ACROSS THE ENTIRE
CWA...LIKELY ALSO AIDED BY A LITTLE BIT OF SNOW ON THE GROUND.
MIN TEMPS ARE EXPECTED TO RANGE FROM AROUND 5 DEGREES (FAR SOUTH)
TO -5 DEGREES (FAR NORTH). COMBINED WITH NORTHERLY FLOW OF AROUND
10 KNOTS...WIND CHILLS WILL RANGE FROM -5 DEGREES (FAR SOUTH) TO
-25 DEGREES (FAR NORTH). HEADLINES WILL LIKELY BE REQUIRED. RECORD
LOWS FOR SUNDAY (FEBRUARY 15) ARE AS FOLLOWS.
CVG...-1...2007
CMH...-4...1978
DAY...-5...2007
AS COLD ADVECTION IS EXPECTED TO CONTINUE THROUGH THE DAY ON
SUNDAY...THE DIURNAL CURVE WILL BE FAIRLY SMALL...AIDED ONLY BY
SOME SUN AS SKIES BECOME MOSTLY CLEAR. THE MAX TEMP FORECAST
RANGES FROM 5 TO 15 DEGREES. HERE ARE THE RECORD LOW MAXIMUM
TEMPERATURES FOR SUNDAY (FEBRUARY 15).
CVG...13...1920
CMH...12...1920
DAY...11...1920
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE HIGH AXIS CROSSES AND WEAKENS SIGNIFICANTLY EARLY MONDAY AND
SHOULD ALLOW FOR SOME SUN AND WEAKER WINDS FROM A SLIGHTLY LESS
COLD AIRMASS TO SEE READINGS REBOUND INTO THE 20S. FLOW WILL TURN
SOUTHWEST AND LIMIT NIGHTTIME FALLS WITH A WARM PUSH MONDAY NIGHT
AND TUESDAY AHEAD OF THE NEXT COLD FRONTAL PASSAGE.
THE NEXT SYSTEM ON TUESDAY IS BEING PROGGED TO COME FROM THE GULF
STATES AND THE TN VALLEY AND BE WELL AHEAD OF THE POSITIVE TILTED
L/W TROUGH OVER THE CENTRAL U.S. THIS LEADS ME TO NOTE THAT THE
PREVIOUS SYSTEMS PROMISING MUCH SNOW IN THE REGION WERE OF SIMILAR
ORIGIN WITH LITTLE UPPER SUPPORT. CONFIDENCE IN THE FORECAST TANKS
FOR THE LAST DAY OR SO IN THE FORECAST BUT HAS THE POTENTIAL FOR A
WINTER EVENT OVER THE REGION.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
A POTENT...BUT FAST MOVING...MID LEVEL TROUGH WILL PUSH THROUGH
THE GREAT LAKES AND OHIO VALLEY TODAY. LARGE SCALE ASCENT AHEAD OF
THIS FEATURE...ALONG WITH INCREASING INSTABILITY...WILL RESULT IN
NUMEROUS SNOW SHOWERS THIS MORNING. IN ADDITION...A FOCUSED LOW
LEVEL BOUNDARY (ARCTIC FRONT) WILL MOVE ACROSS THE TAF SITES. THIS
BOUNDARY WILL MARK AN AREA OF ENHANCED SNOW SHOWERS/SNOW SQUALLS
WITH THE POTENTIAL FOR VISIBILITIES TO DROP BRIEFLY TO A MILE OR
LESS. AVIATORS CAN EXPECT MVFR CEILINGS AND VISIBILITIES IN SNOW
SHOWERS THIS MORNING WITH IFR OR LESS CONDITIONS IN THE HEAVIER
SNOW SHOWERS/SQUALLS. ONCE THE MAIN MID LEVEL TROUGH AXIS MOVES
BY...SNOW SHOWER COVERAGE SHOULD DECREASE MARKEDLY AS LARGE SCALE
SUBSIDENCE TAKES OVER. THIS SHOULD BRING CEILINGS BACK TO VFR BY
THE AFTERNOON HOURS. AN INCREASING PRESSURE GRADIENT A DEEPER
MIXING TODAY WILL BRING GUSTY NORTHWEST WINDS OF 15 TO 20 KNOTS
WITH GUSTS AROUND 30 KNOTS.
FOR TONIGHT...AN AREA OF HIGH PRESSURE WILL MOVE TOWARD THE
REGION. WINDS WILL GRADUALLY DECREASE THIS EVENING. ANY REMAINING
STRATOCUMULUS CLOUDS SHOULD DISSIPATE WITH SOME SCT-BKN HIGH
CLOUDS STREAMING IN FROM THE NORTHWEST.
OUTLOOK...MVFR CEILINGS AND MVFR/IFR VISIBILITIES POSSIBLE SATURDAY
AND SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...FRANKS
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
917 AM CST THU FEB 12 2015
.UPDATE...
UPDATED FOR ADDING MORNING CLOUD COVER...SNOW FLURRIES AND HIGHER
WIND GUSTS.
&&
.DISCUSSION...
POST FRONTAL ARCTIC AIRMASS IS UNDERWAY ACROSS THE MIDSOUTH WITH
BAND OF STRATOCUMULUS SURGING SOUTH. OCCASIONAL SNOW FLURRIES HAVE
ALSO BEEN REPORTED ACROSS PORTIONS OF WEST TENNESSEE. FINALLY
SEEING HIGHER WIND GUSTS ACROSS NORTHEAST ARKANSAS AND THE
BOOTHEEL OF MISSOURI. HAVE UPDATED THE MORNING FORECAST
ACCORDINGLY.
JAB
&&
.PREV DISCUSSION... /ISSUED 538 AM CST THU FEB 12 2015/
UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 421 AM CST THU FEB 12 2015/
DISCUSSION...09Z SURFACE ANALYSIS PLACES AN ARCTIC COLD FRONT
FROM THE APPALACHIANS BACK THROUGH GEORGIA AND THE NORTHERN GULF
COAST. BEHIND THIS FRONT...COLD AIR ADVECTION HAS DROPPED
TEMPERATURES INTO THE MIDDLE 20S NORTH OF I-40 AND 3OS SOUTH AS OF
4 AM CST. WINTRY PRECIPITATION POTENTIAL EARLY NEXT WEEK IS THE
PREDOMINANT CONCERN AND FOCUS IN THIS MORNING/S FORECAST ISSUANCE.
SHORT TERM...(TODAY THROUGH SATURDAY)...COLD AIR ADVECTION BEHIND
AN ARCTIC COLD FRONT WILL BRING PRECIPITATION FREE WEATHER TO THE
MID SOUTH TODAY AND TONIGHT. AS A RESULT...TEMPERATURES WILL
ONLY RISE THE 30S AT MOST LOCATIONS WITH LOW TEMPERATURES TONIGHT
FALLING BACK INTO THE TEENS TO AROUND 20 DEGREES.
TEMPERATURES WILL MODERATE INTO FRIDAY NIGHT ACROSS THE MID SOUTH
AS SOUTHERLY WINDS ON THE BACK SIDE OF HIGH PRESSURE RETURN TO THE
LOWER MISSISSIPPI VALLEY. ANOTHER COLD FRONT IS EXPECTED TO PUSH
THROUGH THE REGION ON SATURDAY BUT NO PRECIPITATION IS
ANTICIPATED AT THIS MOMENT WITH ITS PASSAGE AS MODELS SUGGEST BEST
MOISTURE AND FORCING WILL BE TO THE NORTHEAST OF THE FORECAST
AREA.
LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)...COLD AIR
ADVECTION BEHIND ANOTHER ARCTIC COLD FRONT WILL BRING VERY COLD
TEMPERATURES IN THE TEENS AT MOST LOCATIONS BY SUNDAY MORNING.
THESE COLD TEMPERATURES COMBINED WITH GUSTY NORTH-NORTHEAST WINDS
MAY RESULT IN WIND CHILL READINGS APPROACHING ZERO OR FALLING
BELOW ZERO LATE SATURDAY NIGHT TOWARDS SUNDAY MORNING.
HOWEVER...THE PRIMARY CONCERN IN THE LONG TERM FORECAST IS FOR
WASHINGTON/S BIRTHDAY INTO NEXT TUESDAY NIGHT AS THE COLD FRONT
BEGINS TO RETURN BACK NORTH AS A WARM FRONT MONDAY AND A STRONGER
ARCTIC COLD FRONT DIVES SOUTH INTO THE LOWER MISSISSIPPI VALLEY ON
TUESDAY. EVEN THOUGH LONG TERM MODELS HAVE BEEN TRENDING SLIGHTLY
COOLER...UNCERTAINTY STILL REMAINS WITH EXACT PRECIPITATION TYPES.
LAST NIGHT/S 00Z GFS/ECMWF MODEL SOUNDINGS INDICATED A POTENTIAL
FOR RAIN...FREEZING RAIN...SLEET...AND SNOW NORTH OF I-40 AT TIMES
THROUGH THE PERIOD...AND PERHAPS REACHING AS FAR SOUTH AS THE
I-40 CORRIDOR. AS COLDER AIR FILTERS INTO THE REGION LATER
TUESDAY INTO TUESDAY NIGHT...ANY RAIN SHOULD TRANSITION TO SNOW
BEFORE ENDING. IN ADDITION TO THE WINTRY PRECIPITATION
POTENTIAL...ELEVATED INSTABILITY MAY RESULT IN THE FORMATION OF
EMBEDDED THUNDERSTORMS ON TUESDAY MAINLY ALONG AREAS TOWARDS CENTRAL
MISSISSIPPI. WILL MENTION WINTRY PRECIPITATION THREAT IN
HAZARDOUS WEATHER OUTLOOK. EXACT PRECIPITATION TYPES MAY NEED TO
BE ADJUSTED AS NECESSARY AS THIS POTENTIAL EVENT DRAWS CLOSER.
STAY TUNED... TEMPERATURES THROUGH THIS PERIOD OVERALL ARE
EXPECTED TO REMAIN WELL BELOW NORMAL FOR FEBRUARY.
CJC
AVIATION...
12Z TAFS
ARCTIC AIR WILL SPREAD THROUGH THE MIDSOUTH TODAY AND PERSIST
THROUGH THE PERIOD. A CLOUD DECK ABOVE FL025 WAS DROPPING SOUTH
THROUGH MO AT 1130Z. HRRR MODEL GUIDANCE SHOWED THIS DECK
AFFECTING MIDSOUTH TERMINALS PRIOR TO DISSIPATION BY 18Z.
OTHERWISE... VFR WILL PREVAIL THE NEXT 24 HOURS.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
538 AM CST THU FEB 12 2015
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 421 AM CST THU FEB 12 2015/
DISCUSSION...09Z SURFACE ANALYSIS PLACES AN ARCTIC COLD FRONT
FROM THE APPALACHIANS BACK THROUGH GEORGIA AND THE NORTHERN GULF
COAST. BEHIND THIS FRONT...COLD AIR ADVECTION HAS DROPPED
TEMPERATURES INTO THE MIDDLE 20S NORTH OF I-40 AND 3OS SOUTH AS OF
4 AM CST. WINTRY PRECIPITATION POTENTIAL EARLY NEXT WEEK IS THE
PREDOMINANT CONCERN AND FOCUS IN THIS MORNING/S FORECAST ISSUANCE.
SHORT TERM...(TODAY THROUGH SATURDAY)...COLD AIR ADVECTION BEHIND
AN ARCTIC COLD FRONT WILL BRING PRECIPITATION FREE WEATHER TO THE
MID SOUTH TODAY AND TONIGHT. AS A RESULT...TEMPERATURES WILL
ONLY RISE THE 30S AT MOST LOCATIONS WITH LOW TEMPERATURES TONIGHT
FALLING BACK INTO THE TEENS TO AROUND 20 DEGREES.
TEMPERATURES WILL MODERATE INTO FRIDAY NIGHT ACROSS THE MID SOUTH
AS SOUTHERLY WINDS ON THE BACK SIDE OF HIGH PRESSURE RETURN TO THE
LOWER MISSISSIPPI VALLEY. ANOTHER COLD FRONT IS EXPECTED TO PUSH
THROUGH THE REGION ON SATURDAY BUT NO PRECIPITATION IS
ANTICIPATED AT THIS MOMENT WITH ITS PASSAGE AS MODELS SUGGEST BEST
MOISTURE AND FORCING WILL BE TO THE NORTHEAST OF THE FORECAST
AREA.
LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)...COLD AIR
ADVECTION BEHIND ANOTHER ARCTIC COLD FRONT WILL BRING VERY COLD
TEMPERATURES IN THE TEENS AT MOST LOCATIONS BY SUNDAY MORNING.
THESE COLD TEMPERATURES COMBINED WITH GUSTY NORTH-NORTHEAST WINDS
MAY RESULT IN WIND CHILL READINGS APPROACHING ZERO OR FALLING
BELOW ZERO LATE SATURDAY NIGHT TOWARDS SUNDAY MORNING.
HOWEVER...THE PRIMARY CONCERN IN THE LONG TERM FORECAST IS FOR
WASHINGTON/S BIRTHDAY INTO NEXT TUESDAY NIGHT AS THE COLD FRONT
BEGINS TO RETURN BACK NORTH AS A WARM FRONT MONDAY AND A STRONGER
ARCTIC COLD FRONT DIVES SOUTH INTO THE LOWER MISSISSIPPI VALLEY ON
TUESDAY. EVEN THOUGH LONG TERM MODELS HAVE BEEN TRENDING SLIGHTLY
COOLER...UNCERTAINTY STILL REMAINS WITH EXACT PRECIPITATION TYPES.
LAST NIGHT/S 00Z GFS/ECMWF MODEL SOUNDINGS INDICATED A POTENTIAL
FOR RAIN...FREEZING RAIN...SLEET...AND SNOW NORTH OF I-40 AT TIMES
THROUGH THE PERIOD...AND PERHAPS REACHING AS FAR SOUTH AS THE
I-40 CORRIDOR. AS COLDER AIR FILTERS INTO THE REGION LATER
TUESDAY INTO TUESDAY NIGHT...ANY RAIN SHOULD TRANSITION TO SNOW
BEFORE ENDING. IN ADDITION TO THE WINTRY PRECIPITATION
POTENTIAL...ELEVATED INSTABILITY MAY RESULT IN THE FORMATION OF
EMBEDDED THUNDERSTORMS ON TUESDAY MAINLY ALONG AREAS TOWARDS CENTRAL
MISSISSIPPI. WILL MENTION WINTRY PRECIPITATION THREAT IN
HAZARDOUS WEATHER OUTLOOK. EXACT PRECIPITATION TYPES MAY NEED TO
BE ADJUSTED AS NECESSARY AS THIS POTENTIAL EVENT DRAWS CLOSER.
STAY TUNED... TEMPERATURES THROUGH THIS PERIOD OVERALL ARE
EXPECTED TO REMAIN WELL BELOW NORMAL FOR FEBRUARY.
CJC
&&
.AVIATION...
12Z TAFS
ARCTIC AIR WILL SPREAD THROUGH THE MIDSOUTH TODAY AND PERSIST
THROUGH THE PERIOD. A CLOUD DECK ABOVE FL025 WAS DROPPING SOUTH
THROUGH MO AT 1130Z. HRRR MODEL GUIDANCE SHOWED THIS DECK
AFFECTING MIDSOUTH TERMINALS PRIOR TO DISSIPATION BY 18Z.
OTHERWISE... VFR WILL PREVAIL THE NEXT 24 HOURS.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
433 AM PST THU FEB 12 2015
.SYNOPSIS...
A weak warm front will cross the area today bringing light rain
or sprinkles to portions of the Inland Northwest. The greatest
threat of measurable rain will impact locations near the Cascades
and Canadian border. Otherwise look for the warm temperatures to
continue with a few record highs possible on Friday and Saturday.
A weak cold front will move through the region on Saturday
bringing a good chance of precipitation for most locations. An
even stronger cold front will push through the area on Sunday
bringing a chance of rain and snow to extreme eastern Washington
and the Idaho Panhandle. Cooler temperatures will then prevail
from late Sunday and into early next week.
&&
.DISCUSSION...
Today and Tonight...The strong upper level ridge will continue to
amplify over the Inland Northwest today. Despite its growing
presence there will be some minor weather issues to contend with
namely in response to plume of moisture rounding its western
flank. The latest radar mosaic was showing a plume of light
precipitation extending from the Olympic Peninsula southeast into
the Lewiston area. Thus far precipitation east of the Cascades has
been rather limited however there was a brief sprinkle noted at
Pullman earlier this morning. This feature is likely a weak warm
front and should drift slowly northward through the day. As it
nudges toward the Canadian border we expect the precipitation
chances will increase . This is due to a strengthening of the
isentropic ascent focused over the northern third of the forecast
area combined with growing orographic lift associated with the
south-southwest winds through the 850-700 mb layer. The biggest
question is will the precipitation be measurable. For most of the
Columbia Basin...Spokane/CdA area...and Wenatchee area we suspect
the answer is no. Sprinkles will be possible this morning...but
not much more. Farther north the odds for measurable rain look
much better. Pops have been raised but perhaps may need to be
boosted even more. The HRRR model is downplaying the chances for
precipitation for all locations except along the Canadian
border...but then again its not exactly nailing the current
situation. Nonetheless its a rather minor event with snow levels
remaining above all but the highest mountains and any
precipitation which falls will likely be less than a tenth of an
inch. The abundance of high and mid level clouds associated with
this front should minimize the fog coverage this morning at least
compared to yesterday morning but we still expect to see some
develop later this morning. For tonight the warm front is expected
to lift north of the Canadian border as a weak shortwave,
currently near 44n/132w, rounds the top of the ridge. The only
location which could still see some light precipitation tonight
will be near the Cascades as the shortwave tracks brushes through
that area. Mid and high level clouds will then decrease overnight
leading to a better chance of fog by morning. Temperatures will
continue their string of significantly warmer than normal
readings. Highs today will generally range from the mid 40s to the
50s...or generally around 10 degrees above normal. fx
Friday through Saturday: The upper level ridge remains in place
one more day before big changes are on the way. The 850 mb
temperatures are quite warm, and models are showing a surge of
drier air punching into southern and central WA during the
afternoon. This should provide enough clearing to allow surface
temperatures to warm quite nicely. Temperatures will range from
10 to more than 15 degrees above average for this time of the
year. Record high temperatures are possible across most of the
valleys of eastern WA and north ID. Friday night clouds will
increase ahead of the next weak weather feature. This will keep
temperatures pretty warm. Models have sped up the timing of the
next feature a bit. Have increased chance of precipitation late
Friday night into Saturday morning for most of northern WA...and
as far south as Spokane County. This wave will move through early
in the day and by the afternoon the rain showers should be mostly
confined to north ID. In addition, drier air moves in as well, as
there is slightly better mixing and winds as well temperatures
will once again approach near record highs for portions of central
WA.
Sunday through Thursday: Sunday the ridge begins to amplify off
the west coast and the Pac NW get under a more northwesterly flow.
This will usher in colder temperatures and a chance of mountain
snow across northeast WA and north ID Sunday and Monday. By Sunday
night drier air once again moves in, so colder nights are expected
with Wednesday night expected to be the coldest, but even at that,
it is only a few degrees below average for this time of the year.
By Thursday we start to moderate our temperatures but our forecast
will remain dry. /Nisbet
&&
.AVIATION...
12Z TAFS: Bands of thick mid and high clouds will pour into
the area today with areas of light rain or sprinkles impacting the
GEG-SFF-COE corridor this morning. The rain will not impede
visibilities much...however there is an area of IFR fog/stratus
teasing this area. Not sure how expansive it is...so not sure how
long it will persist. Chances are good that it will ease quicker
than yesterday with the warm front and associated precipitation slowly
moving toward the Canadian Border. However through
18z...confidence in timing the ins and outs of fog will be quite
difficult. Other sites have a much easier forecast with variable
amounts of high and mid level clouds. These clouds should clear
from south to north through tonight. Whether or not this allows
IFR fog/cigs to reform tonight is questionable but some of the MOS
guidance is hinting at it. The clearer the skies are going into
the evening...the better the chances of fog reforming overnight.
fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 37 55 39 52 34 / 10 10 0 40 30 10
Coeur d`Alene 51 36 53 39 50 33 / 10 10 0 30 50 10
Pullman 56 41 58 42 52 36 / 0 0 0 10 20 10
Lewiston 60 41 62 45 57 38 / 0 0 0 10 10 0
Colville 49 36 53 38 53 33 / 30 10 0 40 30 10
Sandpoint 46 34 52 35 47 33 / 30 10 0 20 40 10
Kellogg 49 37 52 40 45 34 / 10 10 0 10 50 20
Moses Lake 54 37 54 40 57 36 / 0 0 0 10 10 0
Wenatchee 53 38 51 39 55 36 / 0 0 0 10 10 0
Omak 50 37 50 39 53 34 / 20 10 0 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
325 AM MST THU FEB 12 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 325 AM MST THU FEB 12 2015
WEATHER EXPECTED TO BE PRETTY QUIET THIS PERIOD WITH TEMPERATURES
REMAINING MILD ACROSS THE CWA TODAY THROUGH FRIDAY. NWLY FLOW
ALOFT THROUGH FRIDAY WILL BRING VARYING AMOUNTS OF MAINLY HIGH
CLOUDS WITH ONE DECENT SIZED AREA NOW MOVING SSE ACROSS THE
WESTERN DAKOTAS INTO NW NEBRASKA. IN ADDITION SOME LOW CLOUDS NOW
OVER THE PANHANDLE IN A WEAK UPSLOPE FLOW REGIME ON THE WESTERN
PERIPHERY OF A COOL SFC HIGH MOVING SSE OVER THE NORTHERN PLAINS.
THIS HAS HELPED TO KEEP TEMPS UP A BIT AND HOLD OFF ANY FOG
FORMATION THUS HAVE REMOVED THE MENTION OF PATCHY FREEZING DRIZZLE
THERE FOR THIS MORNING. SHOULD SEE A DECREASE IN CLOUDS ACROSS
THE REGION THIS AFTERNOON AND EVENING AS THE LATEST SURGE OF HIGH
LEVEL MOISTURE DROPS FARTHER SE AND OUT OF THE AREA AND THE COOLER
AIR OVER THE PLAINS SHIFTS EASTWARD. LEE TROFFING DEVELOPING OVER
THE HIGH PLAINS TODAY WILL INCREASE THE SFC PRESSURE GRADIENT
ACROSS SE WY AND RESULT IN SOME GUSTY WINDS AROUND THE MTNS BUT
NOT LOOKING TOO STRONG.
NEXT SURGE OF COOLER AIR WILL MOVE SOUTH OUT OF CENTRAL CANADA
FRIDAY NIGHT AND INTO THE NORTHERN AND CENTRAL PLAINS SATURDAY.
SOME OF THIS COOLER AIR WILL BACK WESTWARD ACROSS THE NEBRASKA
PANHANDLE AND POSSIBLY FAR EASTERN WY SAT MORNING INTO THE
AFTERNOON. THIS WILL MAKE MAX TEMPS OVER THAT AREA A BIT TRICKY
SATURDAY DEPENDING ON HOW FAR AND STRONG THE COOLER AIR SURGE
TURNS OUT IN THAT AREA AND HOW MUCH ASSOCIATED CLOUD COVER
ACCOMPANIES IT. REMAINING DRY OTHERWISE
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 AM MST THU FEB 12 2015
THE RECENT UNSEASONABLE WARMTH WILL COME TO AN ABRUPT END EARLY
NEXT WEEK AS A MAJOR PATTERN SHIFT BRINGS A RETURN TO WINTRY
CONDITIONS. BEFORE THEN...RELATIVELY DRY NORTHWEST FLOW WILL
YIELD ONE MORE DAY OF GENERALLY BENIGN CONDITIONS SUNDAY. THE
WARM PREFRONTAL AIR MASS WILL BOOST HIGHS INTO THE MID 40S MOST
LOCATIONS. THE WRITING WILL BE ON THE WALL BY SUNDAY THO...AS
RIDGE AMPLIFICATION OVER THE ERN PACIFIC SENDS A 140KT POLAR JET
PLUNGING INTO WRN NOAM. STRONG SHORTWAVE ENERGY ON THE NOSE OF THE
POLAR JET WILL DIVE SOUTHEAST TOWARDS UTAH/SW WYOMING BY SUNRISE
MONDAY. AT THE SFC...THE REFLECTED PRESSURE FALLS AHEAD OF THE
SYSTEM WILL SEND A STRONG COLD FROPA THRU THE CWA SUNDAY NT. WINDS
WILL TURN NNE IN ITS WAKE AND COMBINE WITH FAVORABLE POSITIONING
OF THE NOSE OF THE POLAR JET TO PRODUCE WIDESPREAD ACCUMULATING
SNOW BEGINNING SUNDAY NT AND CONTINUING THROUGH MONDAY NT. AS CAN
BE EXPECTED...TIMING AND RESIDENCE TIME DIFFERENCES EXIST IN THE
MEDIUM RANGE MODELS WITH THE ECMWF IMPACTING THE REGION THE
EARLIEST AND LINGERING SNOW THE LONGEST EVEN INTO TUESDAY.
REGARDLESS OF THE EVENTUAL MODEL VICTOR CONFIDENCE IS INCREASING
OF THIS WINTRY OUTCOME. HAVE CONTINUED THE TREND OF PUSHING SNOW
CHANCES UP...NOW INTO LIKELY CATEGORY MOST AREAS FOR SUNDAY
NT...MONDAY AND MONDAY NT. GUSTY NORTHEAST WIND WILL ACCOMPANY THE
SNOW AS WELL ESPECIALLY DURING DAYLIGHT HOURS ON MONDAY. GFS PROGS
SUGGEST 30-35 KNOTS AT THE TOP OF THE MIXED LAYER MAY BE ABLE TO
SFC. HAVE ADDED AREAS OF BLOWING SNOW TO THE SE WY PORTION OF THE
AREA MONDAY AFTERNOON. IF CURRENT PROGS HOLD...THE COMBINATION OF
ACCUMULATING SNOW AND GUSTY WINDS COULD HAVE HEFTY IMPACTS ON AREA
TRAVEL SUNDAY NT THRU EARLY TUESDAY. STAY TUNED. THE OTHER STORY
WILL BE THE ACCOMPANYING FRIGID TEMPS. HIGHS MONDAY WILL ONLY
REACH THE 20S...WITH SINGLE DIGITS/LOW TEENS EXPECTED FOR TUESDAY.
MODELS SUGGEST SOME TEMPERATURE MODERATION FOR WED- THU...THOUGH
WITH THE EXPECTED SNOWPACK IN PLACE...IT WILL LIKELY BE SLOWER
THAN CURRENTLY PROGD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 953 PM MST WED FEB 11 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAF PACKAGE. SHOWING A BAND
OF LOW CLOUDS MOVING INTO THE PANHANDLE THROUGH THE OVERNIGHT
HOURS. CAN SEE THE LOW CLOUDS ON THE 11-3.9U SATELLITE
IMAGERY...THOUGH IT DOES LOOK LIKE MOST OF THE LOW CLOUDS WILL
STAY EAST. VFR CONDITIONS BY MID MORNING FOR ALL LOCATIONS WITH
GUSTY WEST WINDS.
&&
.FIRE WEATHER...
ISSUED AT 325 AM MST THU FEB 12 2015
NO SIGNIFICANT CONCERNS ANTICIPATED THROUGH THE WEEKEND WITH
WEATHER FACTORS REMAINING MOSTLY NON-CRITICAL. SOME LOCALLY GUSTY
WINDS AROUND THE SE WY MTNS TODAY. COLDER CONDITIONS LOOK TO
ARRIVE BY MONDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RE
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
315 PM EST THU FEB 12 2015
.DISCUSSION...
TONIGHT/FRIDAY...
DRY/STABLE WX AS A DEEP W/NW FLOW PATTERN OVER THE GOMEX/DEEP SOUTH
PUSHES A DRY COLD FRONT THRU CENTRAL FL...AIDED BY A 120KT JET
STREAK LIFTING OFF THE MID ATLC COAST AND A 120KT JET DIGGING OUT OF
THE NRN PLAINS. RAP ANALYSIS CONTINUES TO SHOW LIMITED UPSTREAM
MOISTURE WITH MEAN RH VALUES BLO 50PCT THRU THE H100-H50 LYR. THE
12Z SOUNDINGS SHOW THE REGIONAL AIRMASS UNDER A SMOTHERING
SUBSIDENCE INVERSION IN THE H100-H85 LYR WITH PWAT VALUES AOB 0.50".
WHAT LITTLE MOISTURE THAT HAS MANAGED TO POOL WITHIN THE FRONTAL
TROF WILL NOT BE SUFFICIENT TO GENERATE ANYTHING MORE THAN A MID/UPR
LVL SCT DECK AT BEST.
WILL GO WITH CLR/MCLR SKIES OVERNIGHT. COLD AIR ADVECTION PATTERN
AS THE SFC PGRAD TIGHTENS BEHIND THE FRONT WILL PREVENT DECOUPLING
BUT WILL BE INSUFFICIENT TO GENERATE SFC WNDS HIGHER THAN 10MPH.
MIN TEMPS BOTTOMING OUT IN THE M/U30S W OF I-95 AND N OF I-4...
U30S/M40S ALONG THE COAST S OF I-4. WHILE NRLY SFC WINDS WILL
GENERATE WIND CHILLS IN THE L/M30S OVER MUCH OF THE CWA...L30S PSBL
ALONG N OF 1-4...SUSTAINED SPEEDS BLO 10MPH DOES NOT QUITE MEET
CRITERIA FOR A WIND CHILLS ADVISORY. COLD AIR ADVECTION PATTERN WILL
CONT INTO FRI. DESPITE MSUNNY SKIES...MAX TEMPS FRI WILL HOLD IN THE
L/M60S OVER MOST OF THE CWA...U60S PSBL VCNTY OF LAKE OKEECHOBEE.
SAT-WED...(EDITED FM PREV DISC)
TEMPERATURES WILL REMAIN BELOW NORMAL OVER THE WEEKEND AND INTO
EARLY NEXT WEEK. COOL HIGH PRESSURE TO START OUT SATURDAY WITH
ANOTHER REINFORCING SHOT OF COLD AIR ARRIVING VIA THE NEXT COLD
FRONT EARLY SUNDAY. A TEMPORARY UPTICK IN TEMPS TUE-WED AS FLOW
VEERS AROUND TO S-SW AHEAD OF NEXT FRONT.
12Z RUNS OF GFS AND ECMWF MOS GUIDANCE CONTINUE TREND INDICATING
SATURDAY WILL BE THE COLDEST MORNING WITH MANY LOCATIONS DROPPING
INTO THE MID TO UPPER 30S. THE TREASURE COAST AND BARRIER ISLAND OF
BREVARD SHOULD HOLD IN THE LOW TO MID 40S. NORMALLY COLDER RURAL
SPOTS NORTH AND WEST OF ORLANDO MAY BRIEFLY REACH FREEZING. DAYTIME
HIGHS THIS WEEKEND WILL BE QUITE COOL...MOSTLY IN THE 60S...BUT WITH
PLENTY OF SUNSHINE. AFTER A COLD START ON MONDAY...WINDS ARE
FORECAST TO TURN ONSHORE DURING THE DAYTIME AND BEGIN TO MODIFY THE
COLD DRY AIRMASS. A RAPID WARMUP IS EXPECTED BY TUE WITH HIGHS IN
THE MID 70S AS FLOW TURNS SOUTHERLY.
ANY ABOVE NORMAL TEMPS ON TUE LOOK TO BE SHORT LIVED AS BOTH GFS AND
ECMWF SHOW A DEEP UPPER TROUGH REDEVELOPING OVER THE PLAINS STATES
AND PUSHES EAST ACROSS FL LATE IN THE WEEK. THIS PATTERN WILL
SUPPORT ANOTHER COLD FRONTAL PASSAGE WEDNESDAY WITH ENOUGH UPPER
SUPPORT TO PRODUCE A CHANCE FOR RAIN. LOW POPS START LATE TUE NIGHT
ACROSS THE NORTH...THEN CHANCE/SCATTERED CATEGORY ALL AREAS DAYTIME
WED. HIGH PRESSURE BUILDING IN BEHIND THIS FRONT MAY PRODUCE ANOTHER
OUTBREAK OF MUCH BELOW NORMAL TEMPS LATE NEXT WEEK. MOS GUIDANCE IS
NOT INDICATING FREEZING TEMPS AT THIS TIME. BUT EVEN THOUGH THE DAYS
ARE GETTING LONGER...FREEZING TEMPS ARE POSSIBLE INTO LATE FEB
CLIMATOLOGICALLY. ONCE WE GET INTO THE MONTH OF MARCH...THE THREAT
FOR FREEZING TEMPS DECREASES MARKEDLY.
&&
.AVIATION...THRU 13/18Z
SFC WINDS: THRU 13/00Z...W 8-12KTS. BTWN 13/00Z-13/03Z...BCMG NW
7-11KTS...CONTG THRU 13/12Z.
VSBYS/WX/CIGS: BTWN 13/09Z-13/14Z LCL MVFR BR/STRATUS...OTHERWISE
VFR ALL SITES.
&&
.MARINE... TONIGHT-FRIDAY...HAZARDOUS BOATING CONDITIONS TO CONTINUE
ACRS THE LCL ATLC AS A DRY COLD FRONT SWEEPS THRU CENTRAL FL.
MODERATE TO FRESH N/NW BREEZE WILL BEGIN TO BEAT DOWN THE SWELL BY
FRI AFTN... BUT WITH SEAS HOLDING IN THE 6-8FT RANGE NEARSHORE AND
7-9FT RANGE OFFSHORE THRU DAYBREAK FRI...UP TO 10FT IN THE GULF
STREAM. DOMINANT PDS BTWN 13-14SEC. BOATING CONDITIONS WILL BE
HAZARDOUS NEAR INLETS DURING THE OUTGOING TIDES. WILL MAINTAIN THE
CURRENT SCA FOR SEAS THRU 03Z TONIGHT...SWITCHING TO A FULL SCA BTWN
03Z-15Z. WHILE CONDITIONS WILL IMPROVE SLOWLY AFT 18Z FRI...WILL
EXTEND GULF STREAM/OFFSHORE SCA THRU 03Z SAT AS THE OPPOSING NRLY
BREEZE/SRLY CURRENT WILL MAINTAIN ROUGH CONDITIONS PAST SUNSET.
SAT-MON...(FM PREV) PATTERN WILL SUPPORT PROLONGED NORTHERLY OR
OFFSHORE FLOW THROUGH THE WEEKEND WITH A COUPLE OF STRONG COLD
FRONTS BRINGING SURGES OF NORTH WINDS. ANOTHER COLD FRONT WILL BRING
A SECONDARY SURGE OF NORTH WINDS BY SUNDAY MORNING. WINDS FINALLY
TURN ONSHORE (NE-E) MONDAY AS HIGH PRESSURE PUSHES INTO THE ATLC.
BOATING CONDITIONS WILL REMAIN POOR TO HAZARDOUS ESPECIALLY IN THE
GULF STREAM.
&&
.FIRE WEATHER... LATEST MODEL TRENDS INDICATE VERY DRY AIR MASS INTO
CENTRAL FL THRU THE END OF THE WEEK. LEADING EDGE OF THE DRY AIR
WILL IMPACT CENTRAL FL FRI AFT... ANTICIPATE MIN RH VALUES BTWN 30-
35PCT FOR 4-6HRS OVER THE INTERIOR ALONG AND WEST OF THE FL TURNPIKE
AND N OF THE I-4 CORRIDOR. CRUX OF THE DRY AIR WILL PUSH IN SAT AFT
WITH MIN 30-35PCT MIN RH VALUES FOR 6-8HRS AREAWIDE WITH AREAS ALONG
AND N OF I-4 FALLING TO 25-30PCT FOR 4-6HRS. NW SFC WINDS NOT
EXPECTED TO EXCEED 12MPH...EVEN SO FIRE WX WATCHES AND/OR RED FLAG
WARNINGS MAY BECOME NECESSARY IF TREND HOLDS THROUGH LATER RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 43 57 35 61 / 0 0 0 0
MCO 43 62 39 63 / 0 0 0 0
MLB 47 62 40 62 / 0 0 0 0
VRB 47 64 42 64 / 0 0 0 0
LEE 40 59 37 62 / 0 0 0 0
SFB 43 59 37 63 / 0 0 0 0
ORL 44 61 41 63 / 0 0 0 0
FPR 47 64 42 65 / 0 0 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...HIGH SURF ADVISORY UNTIL 3 AM EST FRIDAY FOR COASTAL VOLUSIA
COUNTY-INDIAN RIVER-MARTIN-NORTHERN BREVARD COUNTY-SOUTHERN
BREVARD COUNTY-ST. LUCIE.
AM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY
FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-
VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EST THIS
EVENING FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-
20 NM-FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 PM EST FRIDAY
FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...GLITTO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
400 PM CST THU FEB 12 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 400 PM CST THU FEB 12 2015
SNOW ENDING THIS EVENING SOUTHEAST AND LIGHT SNOW ON FRIDAY
HIGHLIGHT THE SHORT TERM.
LIGHT SNOW FOCUSED ACROSS THE JAMES RIVER VALLEY AS OF 2130 UTC
WILL CONTINUE TO QUICKLY DIMINISH BY EARLY THIS EVENING BASED UPON
RADAR TRENDS AND THE 19 UTC HRRR SIMULATED REFLECTIVITY. THE 12
AND INCOMING 18 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN AGREEMENT
ON A BAND OF LIGHT SNOW DEVELOPING ACROSS NORTHWEST AND CENTRAL
NORTH DAKOTA DURING THE DAY ON FRIDAY IN ASSOCIATION WITH THE
BAROCLINIC ZONE ON THE LEADING EDGE OF THE NEXT ARCTIC HIGH THAT
WILL PROPAGATE INTO THE NORTHERN PLAINS FRIDAY AFTERNOON AND
EVENING. SNOWFALL AMOUNTS OF LESS THAN ONE INCH ARE EXPECTED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 PM CST THU FEB 12 2015
A COLD FRONT IS EXPECTED TO SWING THROUGH THE AREA FRIDAY. SOME
LIGHT SNOW IS POSSIBLE ALONG THE FRONT AS SURFACE LOW PRESSURE
DEVELOPS ACROSS EASTERN MONTANA. COLD CANADIAN AIR WILL THEN
FILTER INTO THE REGION FRIDAY NIGHT INTO SATURDAY. WIND CHILL
HEADLINES MAY BE NEEDED EAST OF THE MISSOURI RIVER SATURDAY.
THE LATEST 12 UTC MODELS CONTINUE THE TREND OF PREVIOUS
RUNS...WITH A SHORTWAVE AND INVERTED TROUGH SLIDING THROUGH
WESTERN AND CENTRAL NORTH DAKOTA LATE SATURDAY AFTERNOON THROUGH
SUNDAY. WIDESPREAD SNOW AMOUNTS BETWEEN ONE AND FOUR INCHES APPEAR
LIKELY BY SUNDAY EVENING. NORTHERN NORTH DAKOTA APPEARS TO BE
FAVORED TO RECEIVE THE HIGHEST SNOWFALL TOTALS WITH THIS EVENT.
SCATTERED SNOW COULD LINGER THROUGH MONDAY AS STRONG COLD AIR
ADVECTION TAKES HOLD.
THE ECMWF CONTINUES ITS DRY AND COLD FORECAST MONDAY NIGHT
THROUGH WEDNESDAY. HOWEVER THE LATEST GFS RUN BRINGS A CLIPPER
THROUGH NORTH DAKOTA WEDNESDAY AND PRODUCES SOME LIGHT SNOW. WIND
CHILL HEADLINES MAY BE NEEDED MONDAY NIGHT AND TUESDAY NIGHT FOR
AREAS EAST OF THE MISSOURI RIVER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 400 PM CST THU FEB 12 2015
MVFR STRATUS AND FLURRIES WILL CONTINUE ACROSS MUCH OF WESTERN AND
CENTRAL NORTH DAKOTA THIS AFTERNOON AND THROUGH THE NIGHT. A BAND
OF LIGHT SNOW MAY IMPACT KISN/KMOT/KBIS/KJMS FRIDAY AFTERNOON WITH
MVFR/IFR VISIBILITIES POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...AJ
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
102 PM CST THU FEB 12 2015
.UPDATE...
ISSUED AT 103 PM CST THU FEB 12 2015
MAIN CHANGE WITH MID DAY UPDATE IS WIND CHILL HEADLINES. GENERALLY
WIND CHILL VALUES WERE 10 TO 20 BELOW AT 11 AM CST. THEREFORE
ALLOWED WIND CHILL ADVISORY TO EXPIRE.
UPDATE ISSUED AT 422 PM CST THU FEB 12 2015
FORECAST CHALLENGE FOR AM UPDATE IS CURRENT WIND CHILL HEADLINES
AND TIMING/EASTWARD EXTENT OF LIGHT SNOW MAINLY IN THE WEST THIS
EVENING AND TONIGHT. NORTHEAST ZONES HAVE CALM WINDS AND WIND CHILL
VALUES ARE BORDERLINE CRITERIA...AND ELSEWHERE RIGHT AROUND
THRESHOLD VALUE OF 25 BELOW. WILL ALLOW ADVISORY TO EXPIRE AT 12
PM OR CANCEL AFTER 11 AM OBS IF MAJORITY OF SITES ARE ABOVE 25
BELOW. HRRR IS REALLY KEEPING SNOWFALL WEST AND KEEPING MOST OF
NORTHEAST ZONES DRY. WILL AWAIT GFS/ECMWF MODELS BEFORE
CHANGING...BUT FOR NOW HAVE UPDATED THROUGH 00Z POPS AND WILL KEEP
LIKELIES ONLY IN THE WESTERN ZONES BORDERING WFO BIS. NOT SURE HOW
MUCH WILL ARRIVE IN THE RRV ON EAST.
UPDATE ISSUED AT 643 AM CST THU FEB 12 2015
NO CHANGES TO THE FORECAST THIS MORNING...WIND CHILL HEADLINES GO
THROUGH 18Z...TEMPS RANGE FROM EIGHT BELOW IN SE ND TO 27 BELOW AT
FOSSTON AND BROOKS MN. A SLOW RECOVERY WITH MAX TEMPS IN THE LATE
IN THE DAY OR NEAR MIDNIGHT AS SOUTH WINDS AND CLOUDS RAISE TEMPS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 342 AM CST THU FEB 12 2015
CHALLENGE FOR TODAY WILL BE PLACEMENT OF -SN CHANCES AS WEAK TEMP
ADVECTION INITIATES LIFT ACROSS THE NORTHERN PLAINS.
WIND CHILL HEADLINES SET TO EXPIRE AT 18Z WILL BE LEFT IN PLACE
EVEN WITH WINDS DECREASING. EXCELLENT SET UP FOR COLD
TEMPERATURES WITH THE FRESH SNOW LIGHT WINDS AND CLEAR SKIES THIS
MORNING. TEMP RECOVERY WILL BE SLOW WITH WEAK MIXING THRU EARLY
AFTN. INCREASING CLOUDS AND RETURN FLOW FROM WEST TO EAST DEVELOP
THIS AFTN WITH MODELS SLOWER AND WEAKER IN DEVELOPING WAA SNOW
BAND. KEPT THE LIKELY POPS FROM THE DVL INTO THE RRV 21Z-00Z AND
THEN TAPERING OFF CHANCES AS THE BAND MOVES EAST. THE TRENDS FROM
12Z TO 00Z AND NOW 06Z NAM CONTINUE TO BE LESSER CHANCES ACROSS
THE NORTH AND BEST CHANCE FOR SNOW IN SE ND. NOT CONFIDENT ENOUGH
TO LOWER THE LIKELY POPS IN THE NORTH AS A LOW QPF HIGH POP EVENT
POSSIBLE...NONETHELESS SNOW ACCUMULATIONS WILL JUST BE AN INCH AT
MOST.
STEADY TO INCREASING TEMPS EXPECTED TONIGHT WITH CLOUDS AND LIGHT WEST
WINDS. TEMPS EXPECTED TO CLIMB INTO THE TEENS FRIDAY AFTN AHEAD OF
THE NEXT SURGE OF ARCTIC AIR.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 AM CST THU FEB 12 2015
FRIDAY NIGHT FRESH ARCTIC AIRMASS SURGES SOUTH ACROSS THE FORECAST
AREA WITH 20 TO 30KTS AT 925MB FUNNELING DOWN THE VALLEY. WITH LAPSE
RATES IN THE 8 TO 10 C/KM RANGE WILL ADD CHC OF -SN AND FLURRIES
TO THE 21Z-06Z TIME FRAME.
CAA CONTINUES INTO THE FIRST HALF OF SATURDAY WITH MINIMAL TEMP
RECOVERY WITH HIGHS IN THE 5 TO 10 BELOW RANGE. SFC HIGH DRIFTS
EAST AND TEMP FALLOFF SHOULD BE QUICK ACROSS THE EAST WITH RETURN
FLOW STEADY TEMPS ACROSS THE WEST...POSSIBLY MAKING STEADY OR RISING
TEMPS OVERNIGHT ALONG AND WEST OF THE RRV.
FOR THE SUNDAY THROUGH THURSDAY PERIOD...AREA REMAINS IN
NORTH-NORTHWEST FLOW ALOFT AS STRONG 500 MB TROUGH REMAINS OVER THE
NORTHEASTERN U.S. THIS WILL KEEP TEMPS BELOW NORMAL NEXT WEEK. A
COUPLE OF WEAK UPPER LEVEL SYSTEMS WILL DROP SOUTHEAST THROUGH THE
AREA...ONE ON SUNDAY...WHICH WILL GIVE A CHANCE FOR SOME LIGHT
SNOW. BUT OVERALL PATTERN IS NOT A STORMY ONE JUST COLD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 103 PM CST THU FEB 12 2015
MOSTLY VFR CIGS THIS AFTN INTO EVENING...WITH A CHANCE FOR LIGHT
SNOW TAKING DVL DOWN TO MVFR VSBYS WITH SNOW. CONFIDENT NOT HIGH
ENOUGH FOR OTHER TAF SITE AREAS TO RECEIVE SNOW...SO WILL LEAVE
VFR WITH VFR CIGS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...JK
LONG TERM...JK/RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1023 AM CST THU FEB 12 2015
.UPDATE...
ISSUED AT 422 PM CST THU FEB 12 2015
FORECAST CHALLENGE FOR AM UPDATE IS CURRENT WIND CHILL HEADLINES
AND TIMING/EASTWARD EXTENT OF LIGHT SNOW MAINLY IN THE WEST THIS
EVENING AND TONIGHT. NORTHEAST ZONES HAVE CALM WINDS AND WIND CHILL
VALUES ARE BORDERLINE CRITERIA...AND ELSEWHERE RIGHT AROUND
THRESHOLD VALUE OF 25 BELOW. WILL ALLOW ADVISORY TO EXPIRE AT 12
PM OR CANCEL AFTER 11 AM OBS IF MAJORITY OF SITES ARE ABOVE 25
BELOW. HRRR IS REALLY KEEPING SNOWFALL WEST AND KEEPING MOST OF
NORTHEAST ZONES DRY. WILL AWAIT GFS/ECMWF MODELS BEFORE
CHANGING...BUT FOR NOW HAVE UPDATED THROUGH 00Z POPS AND WILL KEEP
LIKELIES ONLY IN THE WESTERN ZONES BORDERING WFO BIS. NOT SURE HOW
MUCH WILL ARRIVE IN THE RRV ON EAST.
UPDATE ISSUED AT 643 AM CST THU FEB 12 2015
NO CHANGES TO THE FORECAST THIS MORNING...WIND CHILL HEADLINES GO
THROUGH 18Z...TEMPS RANGE FROM EIGHT BELOW IN SE ND TO 27 BELOW AT
FOSSTON AND BROOKS MN. A SLOW RECOVERY WITH MAX TEMPS IN THE LATE
IN THE DAY OR NEAR MIDNIGHT AS SOUTH WINDS AND CLOUDS RAISE TEMPS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 342 AM CST THU FEB 12 2015
CHALLENGE FOR TODAY WILL BE PLACEMENT OF -SN CHANCES AS WEAK TEMP
ADVECTION INITIATES LIFT ACROSS THE NORTHERN PLAINS.
WIND CHILL HEADLINES SET TO EXPIRE AT 18Z WILL BE LEFT IN PLACE
EVEN WITH WINDS DECREASING. EXCELLENT SET UP FOR COLD
TEMPERATURES WITH THE FRESH SNOW LIGHT WINDS AND CLEAR SKIES THIS
MORNING. TEMP RECOVERY WILL BE SLOW WITH WEAK MIXING THRU EARLY
AFTN. INCREASING CLOUDS AND RETURN FLOW FROM WEST TO EAST DEVELOP
THIS AFTN WITH MODELS SLOWER AND WEAKER IN DEVELOPING WAA SNOW
BAND. KEPT THE LIKELY POPS FROM THE DVL INTO THE RRV 21Z-00Z AND
THEN TAPERING OFF CHANCES AS THE BAND MOVES EAST. THE TRENDS FROM
12Z TO 00Z AND NOW 06Z NAM CONTINUE TO BE LESSER CHANCES ACROSS
THE NORTH AND BEST CHANCE FOR SNOW IN SE ND. NOT CONFIDENT ENOUGH
TO LOWER THE LIKELY POPS IN THE NORTH AS A LOW QPF HIGH POP EVENT
POSSIBLE...NONETHELESS SNOW ACCUMULATIONS WILL JUST BE AN INCH AT
MOST.
STEADY TO INCREASING TEMPS EXPECTED TONIGHT WITH CLOUDS AND LIGHT WEST
WINDS. TEMPS EXPECTED TO CLIMB INTO THE TEENS FRIDAY AFTN AHEAD OF
THE NEXT SURGE OF ARCTIC AIR.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 AM CST THU FEB 12 2015
FRIDAY NIGHT FRESH ARCTIC AIRMASS SURGES SOUTH ACROSS THE FORECAST
AREA WITH 20 TO 30KTS AT 925MB FUNNELING DOWN THE VALLEY. WITH LAPSE
RATES IN THE 8 TO 10 C/KM RANGE WILL ADD CHC OF -SN AND FLURRIES
TO THE 21Z-06Z TIME FRAME.
CAA CONTINUES INTO THE FIRST HALF OF SATURDAY WITH MINIMAL TEMP
RECOVERY WITH HIGHS IN THE 5 TO 10 BELOW RANGE. SFC HIGH DRIFTS
EAST AND TEMP FALLOFF SHOULD BE QUICK ACROSS THE EAST WITH RETURN
FLOW STEADY TEMPS ACROSS THE WEST...POSSIBLY MAKING STEADY OR RISING
TEMPS OVERNIGHT ALONG AND WEST OF THE RRV.
FOR THE SUNDAY THROUGH THURSDAY PERIOD...AREA REMAINS IN
NORTH-NORTHWEST FLOW ALOFT AS STRONG 500 MB TROUGH REMAINS OVER THE
NORTHEASTERN U.S. THIS WILL KEEP TEMPS BELOW NORMAL NEXT WEEK. A
COUPLE OF WEAK UPPER LEVEL SYSTEMS WILL DROP SOUTHEAST THROUGH THE
AREA...ONE ON SUNDAY...WHICH WILL GIVE A CHANCE FOR SOME LIGHT
SNOW. BUT OVERALL PATTERN IS NOT A STORMY ONE JUST COLD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 643 AM CST THU FEB 12 2015
VFR WITH VRB WINDS FOR THE FIRST HALF OF THE DAY SOUTHERLY WINDS
DEVELOPING AS RETURN FLOW SETS UP...-SN LATE TODAY WITH MVFR CIGS
POSSIBLE THOUGH NOT CONFIDENT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...SPEICHER
SHORT TERM...JK
LONG TERM...JK/RIDDLE
AVIATION...JK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
454 PM EST THU FEB 12 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS AND A FEW SQUALLS TO
CENTRAL PENNSYLVANIA TODAY FOLLOWED BY FRIGID TEMPERATURES TONIGHT
INTO EARLY FRIDAY. ANOTHER ARCTIC BLAST IS EXPECTED THIS WEEKEND
ALONG WITH ACCUMULATING SNOW FOR MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE AREA OF CONVECTIVE SNOW HAS ENDED AND THE MAIN ARCTIC COLD
FRONT WILL PUSH NW TO SE THRU CENTRAL PA THROUGH THIS EVE. UPSLOPE
FLOW WILL CONTINUE ACROSS THE LAURELS...HOWEVER LATEST HRRR SHOWS
DECREASED SNOW FALL...WITH ONLY LIGHT ACCUMULATIONS POSSIBLE INTO
FRIDAY MORNING.
THE ADVECTION OF COLD ARCTIC AIR AND INCREASING WNW WINDS WITH
FREQUENT GUSTS BETWEEN 25-40MPH ON THE BACKSIDE OF DEEPENING
OFFSHORE LOW WILL CREATE FRIGID WIND CHILLS ACROSS THE AREA
TONIGHT INTO EARLY FRIDAY. WIND CHILL WARNING FOR THE NORTHERN
TIER REMAINS WITH EXTREMELY DANGEROUS READINGS IN THE -25 TO -35
BELOW ZERO RANGE. EXPANDED THE WIND CHILL ADVISORY TO INCLUDE THE
REST OF THE COUNTIES BASED ON DROPPING MODEL TEMPS AND INCREASE
GRADIENT WHICH SHOULD ALLOW WINDS TO REMAIN SUSTAINED INTO THE
OVERNIGHT PERIOD WITH WIND CHILLS DROPPING TO 15 BELOW ZERO.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE RIDGE WILL BUILD INTO THE REGION FRIDAY...BRINGING
SLOWLY DECREASING NW WINDS AND PARTLY TO MOSTLY SUNNY SKIES ACROSS
THE CENTRAL AND SE ZONES. THE NW MTNS MAY HAVE A TOUGH TIME BREAKING
UP THE SHALLOW STRATO CU AND SCT FLURRIES.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY LOW GEFS MEAN 925 MB TEMPS OF ARND
-18C LIKELY SUPPORTING HIGH TEMPS NO BETTER THAN THE SINGLE
DIGITS ACROSS THE NORTHERN MTNS...TO THE UPPER TEENS ACROSS THE
SOUTHERN VALLEYS.
ANOTHER TROUGH IS EXPECTED TO DROP DOWN THROUGH THE REGION EARLY
SATURDAY MORNING. THIS SYSTEM HAS A DEEPER TROUGH WITH WINDS OUT
OF THE SOUTHWEST. WITH A DECENT SHORTWAVE...AND STRONG LLJ THERE
IS A GOOD CHANCE FOR ANOTHER ROUND OF SNOW SQUALLS SATURDAY INTO
SATURDAY NIGHT. EVEN COLDER AIR LOOKS TO ADVECT INTO THE REGION
SATURDAY NIGHT INTO SUNDAY...WITH THE WINDS PERSISTING INTO THE
EVENING HOURS. GOOD CONFIDENCE IN LOW WIND CHILLS SATURDAY
EVENING.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
LONG TERM WILL BE PUNCTUATED BY BRUTALLY COLD AIRMASS TO BEGIN THE
PERIOD...WITH FRIGID WIND CHILLS AND MINI MAX RECORDS LIKELY
ACROSS MUCH OF CENTRAL PA ON SUNDAY. STRONG CLIPPER DROPS ACROSS
THE EASTERN GLAKS SAT NIGHT AND DEEPENS RAPIDLY OVER LONG ISLAND
AND ALONG THE SOUTHERN NEW ENGLAND COAST...LIKELY THROWING
ACCUMULATING SNOW OVER THE POCONO PLATEAU THROUGH SUNDAY MORNING.
SOME DEFORMATION SNOWFALL IS POSSIBLE OVER EASTERN PORTIONS OF MY
CWA ON SUNDAY...AND HAVE KEPT ELEVATED POPS AND LIGHTER
ACCUMULATIONS IN FOR THAT LIKELIHOOD.
THE DEEP CHILL WILL PERSIST ON MONDAY AS A SUCCESSION OF NORTHERN
STREAM WAVES DROPS WELL SOUTH OF THE REGION THROUGH THE CENTRAL
AND SOUTHERN PLAINS. SURFACE HIGH WILL PROPOGATE ACROSS CENTRAL PA
MONDAY AND MONDAY NIGHT...MOVING OFFSHORE ON TUESDAY. MODEL
GUIDANCE AND EFS INDICATE PHASING OF NORTHERN AND SOUTHERN STREAM
WAVES OVER THE GULF COAST AND SOUTHEASTERN U.S. BY LATER TUE INTO
WEDNESDAY...BRINGING THE CHANCE OF SNOW TO THE REGION. COLD
NORTHWEST FLOW RESUMES FOR THE REMAINDER OF NEXT WEEK AS A MASSIVE
RIDGE OF HIGH PRESSURE COVERS THE EASTERN HALF OF THE CONUS LATER
WED-FRI.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
21Z TAFS SENT.
GUSTY WINDS INTO TONIGHT.
MOST AREAS VFR BUT MVFR AND EVEN IFR AT TIMES AT JST AND BFD
INTO FRIDAY MORNING.
OUTLOOK...
SAT...BCMG MVFR/IFR WITH -SN. FROPA FOLLOWED BY GUSTY WNW WINDS.
SUN...MVFR/IFR WEST IN -SHSN. STRONG GUSTY WNW WINDS.
MON...MVFR/IFR WITH -SHSN EARLY...THEN VFR.
TUE...MVFR/IFR WITH -SN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON EST FRIDAY FOR PAZ004>006-037-
042.
WIND CHILL ADVISORY UNTIL NOON EST FRIDAY FOR PAZ010>012-
017>019-024>028-033>036-041-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/CERU
SHORT TERM...FITZGERALD/CERU
LONG TERM...DEVOIR/FITZGERALD
AVIATION...DEVOIR/CERU/MARTIN/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
325 PM EST THU FEB 12 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS AND A FEW SQUALLS TO
CENTRAL PENNSYLVANIA TODAY FOLLOWED BY FRIGID TEMPERATURES TONIGHT
INTO EARLY FRIDAY. ANOTHER ARCTIC BLAST IS EXPECTED THIS WEEKEND
ALONG WITH ACCUMULATING SNOW FOR MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE AREA OF CONVECTIVE SNOW HAS ENDED AND THE MAIN ARCTIC COLD
FRONT WILL PUSH NW TO SE THRU CENTRAL PA THROUGH THIS EVE. UPSLOPE
FLOW WILL CONTINUE ACROSS THE LAURELS...HOWEVER LATEST HRRR SHOWS
DECREASED SNOW FALL...WITH ONLY LIGHT ACCUMULATIONS POSSIBLE INTO
FRIDAY MORNING.
THE ADVECTION OF COLD ARCTIC AIR AND INCREASING WNW WINDS WITH
FREQUENT GUSTS BETWEEN 25-40MPH ON THE BACKSIDE OF DEEPENING
OFFSHORE LOW WILL CREATE FRIGID WIND CHILLS ACROSS THE AREA
TONIGHT INTO EARLY FRIDAY. WIND CHILL WARNING FOR THE NORTHERN
TIER REMAINS WITH EXTREMELY DANGEROUS READINGS IN THE -25 TO -35
BELOW ZERO RANGE. EXPANDED THE WIND CHILL ADVISORY TO INCLUDE THE
REST OF THE COUNTIES BASED ON DROPPING MODEL TEMPS AND INCREASE
GRADIENT WHICH SHOULD ALLOW WINDS TO REMAIN SUSTAINED INTO THE
OVERNIGHT PERIOD WITH WIND CHILLS DROPPING TO 15 BELOW ZERO.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE RIDGE WILL BUILD INTO THE REGION FRIDAY...BRINGING
SLOWLY DECREASING NW WINDS AND PARTLY TO MOSTLY SUNNY SKIES ACROSS
THE CENTRAL AND SE ZONES. THE NW MTNS MAY HAVE A TOUGH TIME BREAKING
UP THE SHALLOW STRATO CU AND SCT FLURRIES.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY LOW GEFS MEAN 925 MB TEMPS OF ARND
-18C LIKELY SUPPORTING HIGH TEMPS NO BETTER THAN THE SINGLE
DIGITS ACROSS THE NORTHERN MTNS...TO THE UPPER TEENS ACROSS THE
SOUTHERN VALLEYS.
ANOTHER TROUGH IS EXPECTED TO DROP DOWN THROUGH THE REGION EARLY
SATURDAY MORNING. THIS SYSTEM HAS A DEEPER TROUGH WITH WINDS OUT
OF THE SOUTHWEST. WITH A DECENT SHORTWAVE...AND STRONG LLJ THERE
IS A GOOD CHANCE FOR ANOTHER ROUND OF SNOW SQUALLS SATURDAY INTO
SATURDAY NIGHT. EVEN COLDER AIR LOOKS TO ADVECT INTO THE REGION
SATURDAY NIGHT INTO SUNDAY...WITH THE WINDS PERSISTING INTO THE
EVENING HOURS. GOOD CONFIDENCE IN LOW WIND CHILLS SATURDAY
EVENING.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
LONG TERM WILL BE PUNCTUATED BY BRUTALLY COLD AIRMASS TO BEGIN THE
PERIOD...WITH FRIGID WIND CHILLS AND MINI MAX RECORDS LIKELY
ACROSS MUCH OF CENTRAL PA ON SUNDAY. STRONG CLIPPER DROPS ACROSS
THE EASTERN GLAKS SAT NIGHT AND DEEPENS RAPIDLY OVER LONG ISLAND
AND ALONG THE SOUTHERN NEW ENGLAND COAST...LIKELY THROWING
ACCUMULATING SNOW OVER THE POCONO PLATEAU THROUGH SUNDAY MORNING.
SOME DEFORMATION SNOWFALL IS POSSIBLE OVER EASTERN PORTIONS OF MY
CWA ON SUNDAY...AND HAVE KEPT ELEVATED POPS AND LIGHTER
ACCUMULATIONS IN FOR THAT LIKELIHOOD.
THE DEEP CHILL WILL PERSIST ON MONDAY AS A SUCCESSION OF NORTHERN
STREAM WAVES DROPS WELL SOUTH OF THE REGION THROUGH THE CENTRAL
AND SOUTHERN PLAINS. SURFACE HIGH WILL PROPOGATE ACROSS CENTRAL PA
MONDAY AND MONDAY NIGHT...MOVING OFFSHORE ON TUESDAY. MODEL
GUIDANCE AND EFS INDICATE PHASING OF NORTHERN AND SOUTHERN STREAM
WAVES OVER THE GULF COAST AND SOUTHEASTERN U.S. BY LATER TUE INTO
WEDNESDAY...BRINGING THE CHANCE OF SNOW TO THE REGION. COLD
NORTHWEST FLOW RESUMES FOR THE REMAINDER OF NEXT WEEK AS A MASSIVE
RIDGE OF HIGH PRESSURE COVERS THE EASTERN HALF OF THE CONUS LATER
WED-FRI.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
INCREASINGLY COLD/BLUSTERY WNW FLOW IN WAKE OF ARCTIC FRONT
THROUGHOUT CENTRAL PA. SFC WINDS 290-320 AND INCREASING INTO
TONIGHT WITH GUSTS 25-35KTS. CONDS SHOULD IMPROVE EAST OF THE MTNS
OVERNIGHT WITH CIG RESTRICTIONS LKLY PERSISTING AT BFD/JST INTO
FRIDAY MORNING.
OUTLOOK...
FRI...MVFR/IFR WITH -SHSN WEST EARLY...THEN GRADUALLY IMPROVING.
SAT...BCMG MVFR/IFR WITH -SN. FROPA FOLLOWED BY GUSTY WNW WINDS.
SUN...MVFR/IFR WEST IN -SHSN. STRONG GUSTY WNW WINDS.
MON...MVFR/IFR WITH -SHSN EARLY...THEN VFR LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ004>006-037-042.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ010>012-017>019-024>028-033>036-041-045-046-049>053-
056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/CERU
SHORT TERM...FITZGERALD/CERU
LONG TERM...DEVOIR/FITZGERALD
AVIATION...DEVOIR/CERU/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
314 PM EST THU FEB 12 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING SNOW SHOWERS AND A FEW SQUALLS TO
CENTRAL PENNSYLVANIA TODAY FOLLOWED BY FRIGID TEMPERATURES TONIGHT
INTO EARLY FRIDAY. ANOTHER ARCTIC BLAST IS EXPECTED THIS WEEKEND
ALONG WITH ACCUMULATING SNOW FOR MOST OF THE AREA.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE AREA OF CONVECTIVE SNOW HAS ENDED AND THE MAIN ARCTIC COLD
FRONT WILL PUSH NW TO SE THRU CENTRAL PA THROUGH THIS EVE. UPSLOPE
FLOW WILL CONTINUE ACROSS THE LAURELS...HOWEVER LATEST HRRR SHOWS
DECREASED SNOW FALL...WITH ONLY LIGHT ACCUMULATIONS POSSIBLE INTO
FRIDAY MORNING.
THE ADVECTION OF COLD ARCTIC AIR AND INCREASING WNW WINDS WITH
FREQUENT GUSTS BETWEEN 25-40MPH ON THE BACKSIDE OF DEEPENING
OFFSHORE LOW WILL CREATE FRIGID WIND CHILLS ACROSS THE AREA
TONIGHT INTO EARLY FRIDAY. WIND CHILL WARNING FOR THE NORTHERN
TIER REMAINS WITH EXTREMELY DANGEROUS READINGS IN THE -25 TO -35
BELOW ZERO RANGE. EXPANDED THE WIND CHILL ADVISORY TO INCLUDE THE
REST OF THE COUNTIES BASED ON DROPPING MODEL TEMPS AND INCREASE
GRADIENT WHICH SHOULD ALLOW WINDS TO REMAIN SUSTAINED INTO THE
OVERNIGHT PERIOD WITH WIND CHILLS DROPPING TO 15 BELOW ZERO.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE RIDGE WILL BUILD INTO THE REGION FRIDAY...BRINGING
SLOWLY DECREASING NW WINDS AND PARTLY TO MOSTLY SUNNY SKIES ACROSS
THE CENTRAL AND SE ZONES. THE NW MTNS MAY HAVE A TOUGH TIME BREAKING
UP THE SHALLOW STRATO CU AND SCT FLURRIES.
FRIDAY WILL LIKELY BE ONE OF THE COLDEST DAYS OF THE WINTER SEASON
SO FAR WITH ANOMALOUSLY LOW GEFS MEAN 925 MB TEMPS OF ARND
-18C LIKELY SUPPORTING HIGH TEMPS NO BETTER THAN THE SINGLE
DIGITS ACROSS THE NORTHERN MTNS...TO THE UPPER TEENS ACROSS THE
SOUTHERN VALLEYS.
ANOTHER TROUGH IS EXPECTED TO DROP DOWN THROUGH THE REGION EARLY
SATURDAY MORNING. THIS SYSTEM HAS A DEEPER TROUGH WITH WINDS OUT
OF THE SOUTHWEST. WITH A DECENT SHORTWAVE...AND STRONG LLJ THERE
IS A GOOD CHANCE FOR ANOTHER ROUND OF SNOW SQUALLS SATURDAY INTO
SATURDAY NIGHT. EVEN COLDER AIR LOOKS TO ADVECT INTO THE REGION
SATURDAY NIGHT INTO SUNDAY...WITH THE WINDS PERSISTING INTO THE
EVENING HOURS. GOOD CONFIDENCE IN LOW WIND CHILLS SATURDAY
EVENING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM WILL BE PUNCTUATED BY BRUTALLY COLD AIRMASS TO BEGIN THE
PERIOD...WITH FRIGID WIND CHILLS AND MINI MAX RECORDS LIKELY
ACROSS MUCH OF CENTRAL PA ON SUNDAY. STRONG CLIPPER DROPS ACROSS
THE EASTERN GLAKS SAT NIGHT AND DEEPENS RAPIDLY OVER LONG ISLAND
AND ALONG THE SOUTHERN NEW ENGLAND COAST...LIKELY THROWING
ACCUMULATING SNOW OVER THE POCONO PLATEAU THROUGH SUNDAY MORNING.
SOME DEFORMATION SNOWFALL IS POSSIBLE OVER EASTERN PORTIONS OF MY
CWA ON SUNDAY...AND HAVE KEPT ELEVATED POPS AND LIGHTER
ACCUMULATIONS IN FOR THAT LIKELIHOOD.
THE DEEP CHILL WILL PERSIST ON MONDAY AS A SUCCESSION OF NORTHERN
STREAM WAVES DROPS WELL SOUTH OF THE REGION THROUGH THE CENTRAL
AND SOUTHERN PLAINS. SURFACE HIGH WILL PROPOGATE ACROSS CENTRAL PA
MONDAY AND MONDAY NIGHT...MOVING OFFSHORE ON TUESDAY. MODEL
GUIDANCE AND EFS INDICATE PHASING OF NORTHERN AND SOUTHERN STREAM
WAVES OVER THE GULF COAST AND SOUTHEASTERN U.S. BY LATER TUE INTO
WEDNESDAY...BRINGING THE CHANCE OF SNOW TO THE REGION. COLD
NORTHWEST FLOW RESUMES FOR THE REMAINDER OF NEXT WEEK AS A MASSIVE
RIDGE OF HIGH PRESSURE COVERS THE EASTERN HALF OF THE CONUS LATER
WED-FRI.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
INCREASINGLY COLD/BLUSTERY WNW FLOW IN WAKE OF ARCTIC FRONT
THROUGHOUT CENTRAL PA. SFC WINDS 290-320 AND INCREASING INTO
TONIGHT WITH GUSTS 25-35KTS. CONDS SHOULD IMPROVE EAST OF THE MTNS
OVERNIGHT WITH CIG RESTRICTIONS LKLY PERSISTING AT BFD/JST INTO
FRIDAY MORNING.
OUTLOOK...
FRI...MVFR/IFR WITH -SHSN WEST EARLY...THEN GRADUALLY IMPROVING.
SAT...BCMG MVFR/IFR WITH -SN. FROPA FOLLOWED BY GUSTY WNW WINDS.
SUN...MVFR/IFR WEST IN -SHSN. STRONG GUSTY WNW WINDS.
MON...MVFR/IFR WITH -SHSN EARLY...THEN VFR LATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ004>006-037-042.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR PAZ010>012-017>019-024>028-033>036-041-045-046-049>053-058.
WINTER WEATHER ADVISORY UNTIL 1 AM EST FRIDAY FOR PAZ033.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/CERU
SHORT TERM...FITZGERALD/CERU
LONG TERM...DEVOIR/FITZGERALD
AVIATION...DEVOIR/CERU/STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
116 PM EST THU FEB 12 2015
.SYNOPSIS...
EXPECT THE ROBUST INFLUX OF COLD CANADIAN AIR TO CONTINUE THROUGH
FRIDAY. AN ARCTIC COLD FRONT WILL CROSS THE AREA SATURDAY
EVENING...BRINGING ANOTHER VERY COLD AIRMASS TO THE REGION BY SUNDAY.
MOISTURE IS FORECAST TO SPREAD BACK INTO THE AREA AT THE TAIL END OF
THE HOLIDAY WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
100 PM UPDATE...COLD ADVECTION HAS FINALLY GOTTEN UNDERWAY IN THE
MTNS/FOOTHILLS WITH NW GUSTS REALLY PICKING UP AND TEMPS DROPPING.
THE DELAYED WARMING HAS ALLOWED MUCH OF THE PIEDMONT TO REACH THE
UPPER 50S TO NEAR 60. REVISED TRENDS ALLOW THE PIEDMONT TO RISE A
LITTLE HIGHER BEFORE REACHING MAXES AN HR OR TWO EARLIER THAN CLIMO
BEFORE BEGINNING THE PLUNGE. HOWEVER...PERHAPS DUE TO SLIGHTLY
WINDIER CONDITIONS IN THE LATE NIGHT HRS...VIRTUALLY ALL GUIDANCE
TRENDED A LITTLE WARMER WITH LOWS TONIGHT.
BETTER MOISTURE HAS ALSO NOW REACHED THE MOUNTAINS AS ANTICIPATED
WITH RADAR RETURNS IN THE SMOKIES AND BALD MTNS SUPPORTING FAIRLY
STEADY PRECIP RATES. GUIDANCE DOES NOT REFLECT MUCH IN THE WAY OF
QPF INTO THE AFTN...BUT BASED ON SATELLITE AND RADAR AT LEAST
PERIODIC SNOWFALL IS LIKELY TO CONTINUE THRU MUCH OF THE AFTN. PROG
SOUNDINGS FROM RAP AND NAM STILL HINT AT SOME CONVECTIVE POTENTIAL.
HIT THE SNOW RATIOS A BIT HARDER THRU MID AFTN IN LINE WITH THIS
THINKING. SNOW AMOUNTS STILL JUST SUPPORT AN ADVISORY IN CONJUNCTION
WITH THE WINDS AND ASSOCIATED BLOWING SNOW AND VSBY RESTRICTIONS.
REVISED MINS AND WINDS STILL SUPPORT THE GOING WIND CHILL ADVY AND
WIND ADVY FOR THE MTNS. WILL TAKE A FINAL LOOK AT THESE BEFORE
FINISHING UP THE AFTN PACKAGE HOWEVER.
AS OF 315 AM EST THURSDAY...A POTENT UPPER SHORTWAVE TROUGH WILL DIG
SOUTHEASTWARD TOWARD THE SOUTHEASTERN STATES TODAY. POPS WILL
QUICKLY RAMP UP ALONG THE TN LINE THROUGH THE MORNING AS THE
AFOREMENTIONED LLVL MOISTURE REACHES THE APPALACHIANS WITHIN
INCREASING CAA NW FLOW REGIME. AS THE POTENT UPPER SHORTWAVE TROUGH
SWINGS ACROSS THE REGION AND AN ARCTIC HIGH PRESSURE BUILDS IN FROM
THE NW TODAY...H85 TEMPS OVER THE NC MTNS SHOULD PLUMMET INTO -6C BY
12Z THIS MORNING...AND INTO -13-15C RANGE BY 18Z TODAY. ALSO...LLVL
INSTABILITY WILL BE PRESENT ALONG THE TN LINE WHEN THE TROUGH AXIS
ASSOCIATED WITH BEST UPPER FORCING PASSES OVERHEAD THIS
AFTERNOON...AIDING IN BETTER SNOWFALL RATE IN ITS WAKE.
THEREFORE...POPS WILL PEAK IN THE HIGH LIKELY RANGE OVER THE
NORTHERN NC MTNS BY MIDDAY WITH 1-2 INCHES OF SNOW ACCUMS LIKELY
THRU THIS AFTERNOON. THE SNOW SHOULD TAPER OFF TOWARD LATE THIS
AFTERNOON AS DEEP LAYER DRYING WILL OCCUR BEHIND THE DEPARTING UPPER
TROUGH.
AS FOR THE WINDS...A VERY TIGHT SURFACE PRESSURE GRADIENT WILL SET
UP ACROSS THE CWA TODAY...LEADING TO INCREASING NW WINDS TO AROUND
20-30MPH...GUSTS TO AROUND 45-50MPH OVER THE NC MTNS. WITH THE
COMBINATION OF 1-2" OF ACCUMULATING SNOW AND STRONG NW WINDS...WILL
CONTINUE TO HIGHLIGHT THESE IN THE WINTER WEATHER ADVISORY OVER THE
TN BORDER COUNTIES. ELSEWHERE ACROSS THE HIGHER TERRAIN AND
FOOTHILLS...WILL CONTINUE THE WIND ADVISORY TODAY. AREAS OVER THE
PIEDMONT WILL SEE BELOW WIND ADVISORY CRITERIA OF 15-25 MPH OF NW
WINDS...GUSTING TO AROUND 30-40 MPH RANGE THIS AFTERNOON. THE GUSTY
WINDS SHOULD PERSIST AT LEAST THRU LATE TONIGHT BUT THE CONDITIONS
WILL DRY OUT ACROSS THE TN LINE WHERE THE CURRENT WINTER ADVISORY IS
EFFECTIVE THRU THIS EVENING. THEREFORE...ANOTHER WIND ADVISORY WAS
ISSUED TO COVER PERSISTING GUSTY WINDS ACROSS ENTIRE NC
MTN/FOOTHILLS ZONES FROM 7PM THROUGH MIDNIGHT.
TEMPS THIS AFTERNOON WILL REMAIN NEAR OR BELOW FREEZING ACROSS THE
NC MTNS...AMD MID TO UPPER 40S ELSEWHERE. TEMPS TONIGHT WILL PLUMMET
INTO THE SINGLE DIGITS/LOW 10S OVER THE NC MTNS...AND INTO U10S/L20S
ACROSS THE PIEDMONT. WITH THE HELP OF 7-10 MPH WINDS...WIND CHILL
VALUES WILL STAY 5 BELOW ACROSS THE NC MTNS. THEREFORE...WILL ISSUE
A WIND CHILL ADVISORY TONIGHT INTO FRI MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 205 AM THU...HIGH PRESSURE BUILDS IN FRIDAY BRINGING AN END TO
THE GUSTY WINDS ACROSS THE AREA AND ANY LOW WIND CHILL VALUES. THERE
WILL BE QUITE A BIT OF MID AND HIGH CLOUDS MOVING ACROSS THE AREA
DURING THE DAY. THE AIR MASS IS STILL QUITE COLD WITH HIGHS AROUND
15 DEGREES BELOW NORMAL.
A HIGH AMPLITUDE TROF WILL REMAIN OVER THE ERN CONUS FRI NITE THRU
SUN NITE AS A DEEP VORTEX MOVES SEWD OUT OF ONTARIO TO REINFORCE
ARCTIC AIR ACROSS THE SE. A MODEST REBOUND IN TEMPERATURES IS
EXPECTED FRI NIGHT AND SAT AHEAD OF AN ARCTIC COLD FRONT MOVING
TOWARD THE AREA. THE FRONT CROSSES THE REGION FROM THE NW LATE SAT
OR SAT NITE. A BRIEF SHOT OF MOISTURE IS EXPECTED WITH AND BEHIND
THE COLD FRONT ON SATURDAY. THEREFORE...EXPECT ANOTHER ROUND OF NW
FLOW SNOW SHOWERS ACROSS THE TN BORDER COUNTIES. LOW LEVEL
INSTABILITY WILL BE RELATIVELY HIGH AND IN THE ICE CRYSTAL GROWTH
REGION...WHICH COULD LEAD TO SNOW SQUALLS AND SNOWFALL AMOUNTS
HIGHER THAN WOULD BE EXPECTED GIVEN THE QUICK SHOT OF PRECIP AND
RELATIVELY LIGHT QPF. THE STRENGTH OF THE COLD AIR WILL BE THE BIGGER
STORY. THE GEFS ENSEMBLE MEAN H85 TEMP ANOMALIES WILL BE UP TO 3
STANDARD DEVIATIONS BELOW NORMAL BY SUNDAY. THE PRES GRADIENT
BETWEEN THE DEPARTING LOW AND 1044 ARCTIC HIGH OVER THE PLAINS WILL
PUSH WIND CHILL VALUES TO NEAR WARNING LEVELS IN THE NC MOUNTAINS
SUN MORNING...WITH ADVISORY CRITERIA OVER MUCH OF THE NC FOOTHILLS
AND PIEDMONT...AND THE MTNS OF THE UPSTATE AND NE GA. STRONG WIND
GUSTS ARE ALSO POSSIBLE...WITH AT LEAST ADVISORY LEVEL GUSTS ACROSS
THE NC MTNS...POSSIBLY REACHING WARNING LEVEL ACROSS THE HIGHER
ELEVATIONS. LOWS SAT NITE WILL BE 15 TO 20 DEGREES BELOW NORMAL
WHILE HIGHS SUNDAY WILL BE 20 TO 25 DEGREES BELOW NORMAL...WITH MOST
OF OUR NC COUNTIES NOT REACHING FREEZING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM THURSDAY...CONFIDENCE REMAINS ON THE LOW SIDE FOR THE
MEDIUM RANGE PART OF THE FCST...OWING TO SOME CONTINUED RUN-TO-RUN
CONSISTENCY ISSUES WITH THE MODEL GUIDANCE FOR THE NEXT SYSTEM
TOWARD THE MIDDLE OF NEXT WEEK. ALTHOUGH THERE WILL BE SOME
LINGERING WIND AND WIND CHILL ISSUES SUNDAY MORN...THE REST OF THE
FIRST PART SEEMS QUIET ENOUGH WITH A FLAT UPPER RIDGE MOVING IN AND
ACROSS THE CAROLINAS SUNDAY NIGHT THROUGH MONDAY. THE PROBLEMS BEGIN
IN EARNEST LATE MONDAY AS MOISTURE RETURNS AHEAD OF A DIGGING UPPER
TROF OVER THE PLAINS...AND FORCING SPREADS OVER THE REGION FROM THE
SW IN THE FORM OF ISENTROPIC LIFT AND UPPER DIVERGENCE IN THE RIGHT
ENTRANCE REGION OF A STRENGTHENING UPPER JET TO OUR N. THE CONSENSUS
OF THE OPERATIONAL MODELS IS THAT PRECIP WILL DEVELOP FROM THE SW
ACROSS THE FCST AREA MONDAY NIGHT...MAINLY OVER THE MTNS AND NE
GEORGIA BEFORE SUNRISE...AND THEN THE REST OF THE FCST AREA BY NOON
TUESDAY. AS THESE DEVELOPMENTS HAPPEN...A RELATIVELY COOL BUT
RELATIVELY WEAK HIGH WILL BE MOVING OFF TO THE EAST. THAT WILL
PROVIDE THE OPPORTUNITY FOR AN IN-SITU WEDGE TO DEVELOP WITH LOW
LEVEL THICKNESS LOW ENOUGH TO RESULT IN THE THREAT OF A WINTRY MIX
AT PRECIP ONSET. THE MOST LIKELY SCENARIO FOR NOW...BASED ON THE
GUIDANCE...IS FOR A SHORT PERIOD OF SLEET/SNOW AND THEN A SHORT
PERIOD OF FREEZING RAIN AS THE PRECIP MOVES IN AS A WARM NOSE
DEVELOPS. WILL STAY CONSISTENT WITH THE GUIDANCE AND INCLUDE THE
WINTRY MIX. HOWEVER...UNCERTAINTY IN THE TIMING SMEARS THIS OUT IN
THE FCST PROCESS...SO THE FCST MIGHT LOOK MORE DIRE THAN IT ACTUALLY
WILL BE. FREEZING RAIN EVENTS BECOME MORE RARE AS WE GET INTO
MID/LATE FEBRUARY...SO THE MOST LIKELY TREND WILL BE FOR WARM
ADVECTION TO WIN OUT AND LIMIT THE AMOUNT OF ANY WINTRY MIX. THAT
SAID...THE GFS AND THE ECMWF BOTH TAKE THE PRIMARY LOW UP THE SPINE
OF THE APPALACHIANS...WHICH COULD KEEP THE WINTRY MIX IN LONGER
BEFORE CHANGING ALL PRECIP OVER TO RAIN ON TUESDAY. HAVE KEPT THE
PRECIP PROBABILITY LIMITED TO THE LIKELY CATEGORY. THINGS GET
COMPLICATED AGAIN TUESDAY NIGHT AS THE ECMWF IS MUCH SLOWER MOVING
THE PRIMARY LOW NORTH OF THE AREA AND THE ASSOCIATED COLD FRONT IN
FROM THE WEST. THERE COULD BE A PERIOD OF FREEZING RAIN BEHIND THE
FRONT BEFORE THE DEEPER COLD AIR MOVES IN CHANGING THE PRECIP TO
SNOW. HOWEVER...THE GFS IS FASTER AND ANY FREEZING RAIN WOULD BE
BRIEF. THE GFS ALSO CONTINUES TO SUGGEST SOME DESTABILIZATION IS
POSSIBLE ACROSS THE SRN CWFA AHEAD OF THE FRONT. THAT COULD SPELL
SOME CONCERN FOR SEVERE WEATHER. EVEN THE SLOWER ECMWF HAS THE FRONT
BLASTING THROUGH ON WEDNESDAY...AND THE COLD AIR FOLLOWS ACROSS THE
REST OF THE FCST AREA. ONCE AGAIN...CONFIDENCE IS NOT GREAT...SO DO
NOT PUT TOO MUCH STOCK IN THE WINTER PRECIP POTENTIAL JUST YET.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR WILL PREVAIL AT ALL TERMINALS THRU THE
PERIOD. THE ONLY SITE AT RISK OF A RESTRICTIVE CIG IS KAVL...WHICH
CANNOT BE COMPLETELY RULED OUT AS SEEING AN MVFR CIG AT TIMES THIS
AFTN DUE TO UPSLOPE-DRIVEN CLOUD COVER SPILLING OVER THE SPINE OF
THE APPALACHIANS. -SHSN AND MVFR/IFR VSBYS ARE LIKELY THRU THE AFTN
AT THE HIGHER ELEVATIONS...ESP NEAR THE TENN BORDER...BUT THESE
SHOULD NOT AFFECT KAVL. GUSTY WINDS WILL BE THE PRIMARY CONCERN THRU
THIS EVENING AROUND THE REGION AS COLD HIGH PRESSURE PUSHES
IN...MAINTAINING A DEEP MIXED LAYER AND TIGHT PRS GRADIENT. AT LEAST
A COUPLE GUSTS OF 30-35 KT MAY OCCUR ACRS THE AREA...WITH KAVL
SEEING THE STRONGEST GUSTS. DIRECTIONS WILL BE SOLIDLY NW THRU THE
NIGHT THOUGH THE GRADIENT WILL RELAX ENOUGH TO ALLOW GUSTS TO CEASE
AFTER MIDNIGHT. INCREASING MID-UPPER MOISTURE FROM W TO E WILL BRING
PATCHY 150-200 CIGS FRI MRNG.
OUTLOOK...DRY BUT COLD HIGH PRESSURE WILL REMAIN OVER THE AREA THRU
SAT. HENCE...NO RESTRICTIONS. ANOTHER ARCTIC COLD FRONT WILL CROSS
THE AREA BY SAT NIGHT...WITH WINDY CONDITIONS AND MUCH COLDER
TEMPERATURES ARRIVING. A LOW PRESSURE SYSTEM WILL PASS THROUGH THE
AREA MONDAY NIGHT INTO TUESDAY NIGHT...LIKELY BRINGING PRECIPITATION
AND RESTRICTIONS.
CONFIDENCE TABLE...
13-19Z 19-01Z 01-07Z 07-12Z
KCLT HIGH 95% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 74% HIGH 100% HIGH 100% HIGH 100%
KHKY MED 77% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
WINDY CONDITIONS WILL DEVELOP ACROSS THE FORECAST AREA TODAY.
ALTHOUGH MIN RH MAY NOT QUITE BOTTOM OUT AT CRITICAL VALUES THIS
AFTN...IT COULD BE CLOSE...AND RAPID DRYING OF FUELS MAY QUICKLY
ENHANCE FIRE DANGER. WILL POST FIRE DANGER STATEMENT FOR ALL BUT THE
NC MTNS WHERE RH WILL REMAIN HIGHER. IN ADDITION...A COMBINATION OF
WINDY CONDITIONS AND DIURNALLY LOW RH WILL CONTINUE AT TIMES FRI
THROUGH SUNDAY. A SERIES OF FIRE DANGER STATEMENTS...OR POSSIBLE RED
FLAG PRODUCTS...COULD BE NEEDED AT SOME POINT.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ053-058-059-
062>065-501-503-505-507-509.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ033-
048>052.
WIND ADVISORY FROM 7 PM THIS EVENING TO MIDNIGHT EST TONIGHT
FOR NCZ033-048>052.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST FRIDAY
FOR NCZ033-048>053-058-059-062-063.
SC...NONE.
&&
$$
SYNOPSIS...CSH
NEAR TERM...JOH/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
FIRE WEATHER...JOH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
346 PM CST THU FEB 12 2015
.SYNOPSIS...ISSUED AT 239 PM CST THU FEB 12 2015
WATER VAPOR LOOP AND RUC ANALYSIS REVEALS AMPLIFIED PATTERN
FEATURING WEST COAST RIDGE AND BROAD UPSTREAM TROF ACROSS MUCH OF
NORTH AMERICA. MODELS INDICATE THIS PATTERN WILL STAY IN PLACE OVER
MUCH OF NEXT WEEK ALLOWING FOR PERIODIC SURGES OF ARCTIC AIR INTO
THE REGION RESULTING IN BLO NORMAL TEMPS. MODELS ADVERTISE ONLY
PERIODIC LIGHT PCPN WITH A FEW CLIPPER SHORTWAVES TRAVERSING AREA.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 239 PM CST THU FEB 12 2015
MINS TEMP FCST TONIGHT COULD BE TRICKY AS WINDS WILL DIE OFF WITH
SFC RDG MOVING ACROSS THE AREA. ALSO WAA MID-HIGH CLOUDS WILL BE
SPREADING INTO THE AREA AHEAD OF SHORTWAVE AND ASSOC SFC LOW DIVING
DOWN FM CENTRAL CANADA. THESE CLOUDS DEPENDING ON HOW THICK THEY ARE
MAY TEMPER RADIATIONAL COOLING UNDER LIGHT WIND REGIME. GIVEN
UNCERTAINTY WITH CLOUD THICKNESS DECIDED TO USED A BLEND OF COLDER
BASE REG GEM/ECMWF TEMPS AND MOS GUIDE TEMPS WHICH WAS CLOSE TO PREV
FCST AND IN MEDIUM RANGE OF TEMP GUIDANCE.
BACKED OFF SLIGHTLY ON POPS FOR FRI AS MODELS INDICATE BEST MOISTURE
AND ISENTROPIC ASCENT STAYING GENERALLY NORTH OF WI CLOSER TO TRACK
OF SHORTWAVE AND ASSOC SFC LOW. HAVE POPS RANGING FROM HIGH CHC
(AROUND 50 PCT) NORTH TO LOWER CHC 30-40 POPS FOR SOUTHERN PORTIONS
OF CWA. WAA WL HELP TEMPS RECOVER TO AROUND 20F...BUT MAX TEMPS
PROBABLY WON/T OCCUR UNTIL LATE IN THE DAY SO ADJUSTED DIURNAL CURVE
ACCORDINGLY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 233 PM CST THU FEB 12 2015
N-NW WINDS WILL BE ON THE INCREASE LATE FRIDAY NIGHT INTO SATURDAY
THANKS TO THE INCREASING PRESSURE GRADIENT BETWEEN THE EXITING SFC
LOW SHIFTING FROM JUST E OF LAKE SUPERIOR AT 00Z SATURDAY TO THE
LOWER GREAT LAKES SATURDAY AFTERNOON...AND THE COLD ARCTIC HIGH
SINKING ACROSS S CENTRAL CANADA AND INTO THE N PLAINS. WHILE THE
COLDEST AIR WILL REMAIN N-NE OF WI...STILL EXPECT 850MB TEMPS TO
BOTTOM OUT AROUND -27 TO -30C SATURDAY AFTERNOON. AS A
RESULT...STEADY TO FALLING TEMPERATRUES WILL BE COMMON SATURDAY AS
THIS COLDER AIR RUSHES IN. HIGHS SATURDAY MAY ONLY ONLY TOP OUT IN
THE -3 TO 7F RANGE /COLDEST NE/.
KEPT THE POTENTIAL FOR BLOWING SNOW WHERE POPS WERE OVER 14
PERCENT...AND WIND GUSTS WERE OVER 20KTS. THE BEST CHANCE OF SNOW
WILL BE OVER THE N ANE E TIER COUNTIES AS LAKE EFFECT ON STRONG
WINDS BLOW WELL INLAND AND INTO N WI.
UNDER A CLEARING SKY SATURDAY NIGHT...AND WITH WINDS OF 5-10KTS OUT
OF THE N-NNW...WIND CHILL READINGS OF 25 TO 30 BELOW ZERO WILL BE
POSSIBLE. LOOK FOR LATER UPDATES AND FORECASTS ON THIS ARCTIC
AIRMASS AND LOW WIND CHILLS.
GENEARALLY FOLLOWED A MODEL BLEND FOR MUCH OF THIS PERIOD. NO
SIGNIFICANT STORMS ANTICIPATED...BUT WITH COLD WEATHER CONTINUING.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1205 PM CST THU FEB 12 2015
EXPECT VFR CONDITIONS THROUGH TONIGHT FOR ALL TAF SITES UNDER
BUILDING HIGH PRESSURE. WARM ADVECTION/LIFT AHEAD OF THE NEXT LOW
PRES SYSTEM DESCENDING FM ONTARIO WILL THEN BRING IN SOME LIGHT
SNOW LATE FRI MORNING/AFTERNOON AS CONDITIONS LOWER TO MVFR. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......VOSS
SHORT TERM.....VOSS
LONG TERM......KF
AVIATION.......VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1011 AM CST THU FEB 12 2015
.UPDATE...
MOSTLY SUNNY SKIES WILL PREVAIL WITH SOME CIRRUS MOVING OVERHEAD
LATER THIS AFTERNOON. NORTHWEST WINDS WILL WEAKEN AS HIGH PRESSURE
PUSHES INTO THE REGION AND MOVES OVERHEAD TONIGHT. LIGHT SNOW IS
EXPECTED TO MOVE ACROSS SOUTHERN WI FROM LATE MORNING THROUGH THE
AFTERNOON. ACCUMULATIONS LOOK TO BE A FEW TENTHS OF AN INCH.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH EARLY FRIDAY. NORTHWEST WINDS WILL
WEAKEN THROUGH THE DAY AND BECOME LIGHT OVERNIGHT AS HIGH PRESSURE
MOVES OVERHEAD. WINDS WILL PICK UP SLIGHTLY AND BECOME SOUTHWESTERLY
FRIDAY. LIGHT SNOW IS EXPECTED TO MOVE ACROSS SOUTHERN WI FROM LATE
MORNING THROUGH THE AFTERNOON. ACCUMULATIONS LOOK TO BE A FEW TENTHS
OF AN INCH.
&&
.MARINE...
PRESSURE GRADIENT GRADUALLY WEAKENING AS HIGH PRESSURE IN
THE NORTHERN PLAINS EDGES CLOSER TO LAKE MICHIGAN. NORTHWEST WIND
GUSTS HAVE NOT BEEN REACHING GALE CRITERIA FOR SEVERAL HOURS AT
LAKESHORE STATIONS AND RUC SOUNDINGS OVER THE NEARSHORE WATERS
INDICATING WIND GUSTS RAPIDLY DIMINISHING TODAY. HENCE DOWNGRADED
GALE WARNING TO SMALL CRAFT ADVISORY BUT LEFT HEAVY FREEZING SPRAY
WARNING RUNNING UNTIL 18Z. KEPT SMALL CRAFT ADVY GOING UNTIL 00Z/13
HOWEVER AS WAVE HEIGHTS IN ICE FREE AREAS WILL BE SLOWER TO DECREASE
BELOW 5 FEET.
MBK
&&
.PREV DISCUSSION... /ISSUED 343 AM CST THU FEB 12 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
SNOW SHOWERS ARE QUICKLY MOVE SEWD OUT OF SE WI WITH CLEARING SKIES
BEHIND. STRONG SUBSIDENCE VIA COLD ADVECTION AND DAVA IN THE WAKE OF
THE UPPER TROUGH WILL MAINTAIN MO CLEAR TO PTLY CLOUDY SKIES TODAY.
THE BRISK NNWLY WINDS WILL GRADUALLY SUBSIDE THROUGH THE AFTERNOON
AS THE ARCTIC HIGH APPROACHES. TEMPS WILL WARM TO AROUND 10F WITH
THE TEENS BELOW ZERO FOR THE MORNING HOURS. FOR TNT...THE RIDGE AXIS
OF THE ARCTIC HIGH WILL SHIFT EWD ACROSS THE STATE WITH LGT SWLY
WINDS DEVELOPING LATE ALONG WITH AN INCREASE IN MID TO HIGH CLOUDS
VIA WARM ADVECTION. BEFORE THEN...TEMPS WILL LIKELY FALL BELOW ZERO
FOR MOST AREAS.
FRIDAY AND FRIDAY NIGHT - CONFIDENCE...MEDIUM
GRADUAL ISENTROPIC ASCENT COMBINED WITH A SHORTWAVE RIDING IN
FROM THE NORTHWEST WILL RESULT IN A PERIOD OF LIGHT SNOW ACROSS
SOUTHERN WISCONSIN. THE MODELS ARE TRENDING DRIER WITH RESPECT TO
QPF. BUT STILL LOOKING AT UP TO A 1/2 INCH OR SO OF SNOW
ACCUMULATION. THE MODELS SHOOT ANOTHER WEAK WAVE THROUGH THE FLOW
BUT FOR THE MOST PART THIS FEATURE MISSES US TO THE SOUTHWEST AS
ENERGY FROM SIGGY VORTEX CRASHES INTO WI LATER IN THE NIGHT.
STRONG 925/850 COLD ADVECTION NOTED AFTER 6Z. NO LAKE COMPONENT
THOUGH WILL KEEP SOME FLURRIES OR SMALL POPS GOING TO ACCOUNT FOR
INCREASING UPPER DYNAMICS AND THE PASSING WAVE TO THE SOUTHWEST.
BUT MAIN STORY WILL BE THE INCREASING NW WINDS AND RAMP UP OF THE
COLD ADVECTION.
SATURDAY AND SUNDAY - CONFIDENCE...MEDIUM
BRUTALLY COLD WEEKEND SHAPING UP WITH CORE OF ARCTIC AIR
ENTRENCHED ACROSS THE AREA. 925 TEMPS DOWN TO THE -20 TO -24C
RANGE WITH NORTH WINDS A BIG FACTOR RIGHT INTO SATURDAY NIGHT. A
WIND CHILL ADVISORY WILL LIKELY BE NEEDED SATURDAY NIGHT INTO
SUNDAY MORNING...HOWEVER WINDS ARE EXPECTED TO EASE ON SUNDAY AS
CORE OF HIGH PRESSURE SETTLES ACROSS THE STATE RESULTING IN A
SLACKENED PRESSURE GRADIENT. LAKE EFFECT POTENTIAL LOOKS LOW AT
THIS TIME. MODELS ALL KEEPING PRECIP OFFSHORE. TRAJECTORIES DUE
GET BORDERLINE FOR MKE CNTY SOUTHWARD THOUGH SOUNDINGS LOOK RATHER
DRY WITH FAIRLY LOW INVERSION HEIGHTS.
MONDAY THROUGH WEDNESDAY - CONFIDENCE...MEDIUM
WAS TEMPTED TO PULL POPS COMPLETELY AS BOTH GFS AND ECMWF SHOW
SYSTEM STAYING WELL SOUTH OF WI. HOWEVER SOME HINTS OF SOME WAA
PRECIP...ESP ON THE GEM...AND THE GEM IS ALSO A BIT MORE OF A
CLOSE CALL WITH THE NORTHERN FRINGE OF THE PRECIP SHIELD WITH THE
SOUTHERN LOW. SO AT THIS TIME WILL LEAVE THE FAIRLY SMALL
SUPERBLEND POPS IN PLACE. A RENEWED THERMAL RIDGE BRINGS 925 TEMPS
BACK TO AROUND -10C FOR MONDAY NIGHT BEFORE NEXT BLAST OF ARCTIC
AIR ARRIVES IN EARNEST TUESDAY INTO WEDNESDAY.
AVIATION/12Z TAFS/...BRISK NWLY WINDS WILL SUBSIDE DURING THE
AFTERNOON AND BECOME LIGHT TNT AS POLAR HIGH PRESSURE MOVES
OVERHEAD. MO CLEAR TO PTLY CLOUDY SKIES WILL PREVAIL TODAY AND TNT
WITH VFR CONDITIONS.
MARINE...A GALE WARNING AND HEAVY FREEZING SPRAY WARNING CONTINUES
UNTIL NOON TODAY. THE BRISK NNWLY WILL GRADUALLY SUBSIDE FROM LATE
THIS MORNING INTO THE AFTERNOON BUT HIGH WAVES IN ICE FREE AREAS
WILL LINGER INTO THE AFTERNOON. DUE TO THE LINGERING HIGH WAVES...A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR THE AFTERNOON. ANOTHER PERIOD
OF BRISK NWLY WINDS AND HIGH WAVES DUE TO ANOTHER ARCTIC FRONT WILL
BE FROM FRI NT INTO SAT EVENING. A SMALL CRAFT ADVISORY WILL LIKELY
BE NEEDED. WIND GUSTS COULD APPROACH GALE FORCE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...HEAVY FREEZING SPRAY WARNING UNTIL NOON CST TODAY FOR LMZ643>646.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...MARQUARDT
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
FRIDAY THROUGH WEDNESDAY...COLLAR