Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/26/15
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
646 PM MST WED FEB 25 2015
.UPDATE...
ISSUED AT 646 PM MST WED FEB 25 2015
SCATTERED SNOW SHOWERS HAVE BEEN SPILLING INTO THE WEST CENTRAL
VALLEYS. HRRR MODEL SHOWING SNOW SHOWER ACTIVITY MOVING INTO
MONTROSE LATER THIS EVENING. BOOSTED VALLEY POPS THIS EVENING TO
REFLECT CURRENT SHORT TERM TRENDS.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM MST WED FEB 25 2015
MOIST...UNSTABLE CONDITIONS HAVE KEPT SNOW SHOWERS GOING ALL DAY
ACROSS WESTERN COLORADO AND THIS WILL CONTINUE INTO THE LATE
EVENING HOURS. THE COOL ADVECTIVE NORTHWEST FLOW IS FAVORING MANY
NORTH AND WEST FACING ASPECTS FROM THE FLAT TOPS AND NORTHERN
PLATEAUS TO THE NORTHERN SAN JUANS. WEBCAMS SHOW THE INTENSITY OF
THE CONVECTIVE SNOW SHOWERS WITH VISIBILITIES DROPPING QUICKLY AS
SNOW RATES INCREASE. HOWEVER LOOKING AT AREA WEB CAMS ROADWAYS ARE
STAYING IN FAIRLY GOOD SHAPE...EVEN OVER THE HIGHER PASSES.
SNOTELS HAVE PICKED UP THIS AFTERNOON WITH THE ADDED OCTANE BUT
STILL THE MAJORITY ARE IN THE 2 TO 4 INCH RANGE. SNOW STAKES SHOW
THE SAME AT LOCAL SKI AREAS. WATER VAPOR IMAGERY INDICATES THE
WAVE DRIVING THESE SHOWERS IS DROPPING ACROSS SOUTHWEST WYOMING
LATE THIS AFTERNOON AND WILL BE SHEARING ACROSS THE COLORADO UTAH
BORDER THROUGH THE EVENING. THOUGH SOME BOOST WILL BE LOST AT
SUNSET SHOWERS SHOULD CONTINUE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS THROUGH LATE EVENING...ENDING OVERNIGHT. SOME SHOWERS
ARE LIKELY TO LEAK INTO THE LOWER VALLEYS OF WESTERN COLORADO
ALONG I-70 AND NORTHWARD AS WELL BUT LITTLE ACCUMULATION IS
EXPECTED. SUBSIDENCE AND INCREASING STABILITY IN THE TRANSITION
AREA BETWEEN THE DEPARTING WAVE AND THE NEXT ENERGY DIGGING TO OUR
WEST LOOKS TO BRING A RATHER SIGNIFICANT BREAK THURSDAY MORNING
FOR OUR CWA. LIGHT OROGRAPHIC SNOW SHOWERS COULD REMAIN OVER THE
DIVIDE MOUNTAINS OVER THE NEXT 24 HOURS AS DENDRITIC TEMPERATURES
AT MOUNTAIN TOP LEVEL WILL BE IN THE SWEET SPOT. ADDITIONAL LIGHT
ACCUMULATIONS WILL BE POSSIBLE BUT SNOW RATES NOT EXCESSIVE. HIGH
LEVEL MOISTURE WILL BEGIN TO MAKE IT/S WAY BACK INTO THE GREAT
BASIN THROUGH THE DAY AS ANOTHER UPSTREAM WAVE MOVES THROUGH THE
NORTHWEST FLOW INTO THE GREAT BASIN. INSTABILITY WILL BE PRESENT
BUT NOT QUITE AS ROBUST AS THIS AFTERNOON AND JET SUPPORT RETREATS
TO THE WEST. EXPECT INCREASING POPS MAINLY ON THE TERRAIN ON
THURSDAY AFTERNOON WITH SOME DECREASE IN ACTIVITY AT SUNSET.
THURSDAY NIGHT THE WAVE TAKES A TIGHTER CYCLONIC CURVE ACROSS THE
4 CORNERS AS THE UPPER JET BEGINS TO CURVE ALOFT. THIS WILL LIKELY
KEEP SOME SNOW GOING IN THE HILLS FAVORING THE SOUTHERN CWA
THROUGH THE NIGHT BUT AGAIN ONLY LIGHT ACCUMULATIONS ARE EXPECTED.
UPSTREAM ACROSS THE LEFT COAST FROM SO.CAL NORTHWARD...300K
SURFACES SHOW A HEALTHY SURGE OF PACIFIC MOISTURE BEING
TRANSPORTED INLAND AS OUR WEATHER MAKER FOR THE WEEKEND DROPS
ACROSS THE PACIFIC NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MST WED FEB 25 2015
WELCOME TO WEEKEND STORM NUMBER TWO UNDER THIS NEW IMPROVED
WEATHER PATTERN. THIS STORM IS NOTABLE FOR ITS EXTENDED PERIOD OF
PERSISTENT SHOWERS...PERHAPS THROUGH NEXT WEDNESDAY.
THE FIRST OF TWO PACIFIC TROUGHS SLIDES DOWN THE WEST COAST
EVENTUALLY CLOSING OFF ALONG THE SOUTHERN CALIFORNIA COAST BY
SUNDAY. DESCENT MOISTURE AND GOOD OROGRAPHICS WITH PERIODS OF
UPPER LEVEL SUPPORT SHOULD PRODUCE GOOD SNOWFALL FROM THE FOUR
CORNERS NE TO THE WEST ELK MOUNTAINS. A WINTER STORM WATCH HAS
BEEN ISSUED FOR THESE ZONES.
FRIDAY-FRIDAY NIGHT...IN MILD WARM MOIST ADVECTION...SHOWERS WILL
INCREASE ACROSS THE SOUTH. OROGRAPHICS WILL FAVOR SW-FACING
SLOPES.
SATURDAY-SATURDAY NIGHT THE PATTERN AMPLIFIES AS THE LOW DIGS
DOWN THE COAST. THE 120KT JET OVER NEW MEXICO LIFTS ACROSS THE SAN
JUAN MTNS INTO THE WEST ELKS. 700MB WINDS INCREASE TO 40KTS UNDER
THE JET. A SURFACE-700MB LOW DEEPENS IN SE UTAH ADDING TO THE
OROGRAPHIC COMPONENT INTO THE SOUTHERN MOUNTAIN SLOPES. 700MB
TEMPERATURES AROUND -4C WOULD PRODUCE AFTERNOON SNOW LEVELS
AROUND 7KFT. THE JET SHIFTS EAST ON SUNDAY FOR SOME DIMINISHING OF
THE MOUNTAIN WINDS BUT MOIST OROGRAPHIC SNOW REMAINS IN PLACE.
FOR MONDAY THE 18Z GFS HAS SLOWED DOWN TO MATCH THE EC TIMING WITH
THE PROGRESSION OF THIS FIRST LOW OFF TO THE SE. THE SFC LOW
LIFTS THROUGH THE SOUTH THRU THE DAY. A DOWN TURN OF SHOWERS IS
EXPECTED MONDAY NIGHT AND WE HAVE ENDED THE WINTER STORM WATCH
HERE.
BUT ALREADY BY TUESDAY A COLDER TROUGH HAS DIVED DOWN THE COAST
SETTLING OVER THE GREAT BASIN. A STRONG COLD FRONT PASSES ON
TUESDAY DRIVING SNOW LEVELS TO THE LOWEST ELEVATIONS AND
EFFICIENTLY TURNING ANY AVAILABLE MOISTURE TO SNOW. TUESDAY NIGHT
INTO WEDNESDAY THE FLOW TURNS TO COLD ADVECTIVE NORTH WITH SNOW
LINGERING ALONG THE NORTH-FACING SLOPES BUT STILL FAVORING THE
SOUTH WHERE MOISTURE IS DEEPEST. HIGHLIGHTS ARE EXPECTED WITH THIS
SECOND LOW ALSO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 526 PM MST WED FEB 25 2015
ISOLATED THUNDERSTORMS OVER NW COLORADO UNTIL 02Z THIS EVENING
WITH A MIXTURE OF SNOW AND GRAUPEL. NUMEROUS SNOW SHOWERS WILL
EXIST OVER THE HIGHER TERRAIN WITH LIMITED CIGS/VIS...ESPECIALLY
AT MOUNTAIN AIRFIELDS SUCH AS KASE/KTEX. THERE IS A 40 PERCENT
CHANCE THAT SNOW SHOWERS WILL AFFECT KGJT...KMTJ AND KRIL THIS
EVENING WITH A BRIEF PERIOD OF LOWER CIGS/VIS. IMPROVING
CONDITIONS ARE EXPECTED IN THE 06Z-12Z PERIOD.
NO AVIATION HAZARDS ARE EXPECTED IN THE 12Z-18Z PERIOD...BUT SNOW
SHOWERS WILL DEVELOPING OVER THE WRN COLORADO MOUNTAINS AFTER 18Z
AND WILL BE IN THE VICINITY OF KASE...KEGE AND KTEX.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH MONDAY EVENING
FOR COZ012-014-018-019-022-023.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...15
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1113 PM MST MON FEB 23 2015
.UPDATE...
ISSUED AT 1113 PM MST MON FEB 23 2015
UPDATED FORECAST TO EXPIRE WSW FOR ZONE 68.
UPDATE ISSUED AT 813 PM MST MON FEB 23 2015
UPDATED TO LOWER LOWS A TAD AS TEMPERATURES HAVE DROPPED WITH
FRESH SNOW COVER AND CLEARING SKIES. SHOULD CONTINUE TO SEE
TEMPERATURES DROP THROUGH MIDNIGHT AND THEN SLOWLY WARM...ESPECIALLY
OVER AND NEAR THE HIGHER TERRRAIN...AS TEMPS ALOFT WARM AND MID LEVEL
FLOW BECOMES MORE WESTERLY.
UPDATE ISSUED AT 509 PM MST MON FEB 23 2015
UPDATED FORECAST TO EXPIRE WSW FOR ZONES 66 AND 67.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM MST MON FEB 23 2015
AN UPR LOW OVR CA TODAY IS EXPECTED TO MOVE EASTWARD TONIGHT...
MOVING INTO NORTH CENTRAL AZ BY 12Z TUE...AND THEN WEAKENING AND
MOVING SOUTHEASTWARD THRU NM ON TUE.
SNOW HAS CONTINUED FALLING OVER THE MTNS AND HIGH VALLEYS THIS
AFTERNOON. IN THE SAN LUIS VALLEY THE SNOW HAS NOT BEEN WIDESPREAD
AND IT FAIRLY SPOTTY AND WL CANCEL SNOW ADVISORY AT 3 PM.
OVER THE SANGRE DE CRISTO MTNS THE SNOW IS ALSO BECOMING MORE
SPOTTY...EXCEPT OVR THE FAR SRN AREAS NR THE NEW MEXICO BORDER. WL
ALLOW THAT ADVISORY TO EXPIRE AT 3 PM.
THE NAM AND HRRR SHOW PCPN CHANCE DECREASING RAPIDLY IN THE EVENING
HOURS OVR MOST OF THE MTNS AND HIGH VALLEY AREAS. THE NAM KEEPS
WIDESPREAD SNOW OVR THE ERN SAN JUANS EARLY IN THE EVENING. WEB CAMS
SHOULD LITTLE IN THE WAY OF SNOWFALL CURRENTLY AT LXV AND MONARCH
PASS...SO WL CANCEL THE WARNINGS FOR LAKE AND CHAFFEE COUNTIES AT 3
PM...ALONG WITH CANCELING WARNINGS FOR ZONES 64 AND 65...BUT WL
LEAVE WARNINGS IN EFFECT UNTIL 5 PM FOR ZONES 66 AND 67. WL LEAVE
THE WARNING FOR THE ERN SAN JUANS (ZONE 68) IN EFFECT UNTIL 06Z.
ERN SAN JUANS COULD GET ANOTHER FEW INCHES IN THE EVENING
HOURS...WITH LITTLE ADDITIONAL ACCUMULATION AFTER MIDNIGHT AS THE
SNOW TAPERS OFF.
BY 09Z THE NAM SHOWS DRY WX OVR THE ENTIRE FORECAST AREA...WITH DRY
CONDITIONS THRU AT LEAST MIDMORNING TUE. THE NAM THEN SHOWS THE
POTENTIAL FOR SOME LIGHT PCPN AGAIN OVR THE SW MTNS AS THE UPR LOW
MOVES INTO NM. HOWEVER THE GFS HAS LIGHT PCPN CONTINUING OVR THE SW
MTNS AND THE SANGRES THRU THE NIGHT AND THRU TUE. THE ECMWF IS
SIMILAR TO THE GFS BUT DOES NOT SPREAD THE PCPN ON TUE QUITE AS FAR
NORTH. HAVE DECIDED TO KEEP LOW POPS OVR THE SANGRES AND PORTIONS
OF THE CENTRAL MTNS THRU TONIGHT AND TUE...WITH HIGHER POPS OVR THE
SW MTNS DURING THIS SAME TIME-FRAME...BUT NOT EXPECTING ANYTHING
MORE THAN SOME LIGHT ACCUMULATIONS.
IT IS POSSIBLE FOR THE SAN LUIS VALLEY TO SEE SOME VERY LIGHT SNOW
DEVELOP AGAIN AS LOW CLOUDS COVER MUCH OF THE AREA.
TEMPS WL BE WARMER ON TUE...BUT THE SNOW COVER IN MANY LOCATIONS WL
LIMIT THE AMOUNT OF WARMING AND SO WL STAY BELOW GUIDANCE IN MANY
AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM MST MON FEB 23 2015
...ACTIVE AND COLD WEATHER PATTERN TO CONTINUE...
MODELS IN GOOD AGREEMENT WITH ACTIVE WEATHER PERSISTING THROUGH
THE EXTENDED PERIOD. SEVERAL DISTURBANCES WILL KEEP PERIODS OF
MODERATE TO HEAVY SNOW GOING FOR MOST OF SOUTHERN COLORADO.
TUESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL BE EXITING THE
DESERT SOUTHWEST INTO TEXAS EARLY TUESDAY NIGHT. LIGHT LINGERING
SNOWFALL OVER THE SOUTHERN SAN JUANS SHOULD COME TO AN END BY
MIDNIGHT. A SECONDARY DISTURBANCE WILL BE DROPPING SOUTH OUT OF
THE NORTHERN ROCKIES LATE TUESDAY NIGHT WITH LIGHT SNOW DEVELOPING
OVER THE CENTRAL MOUNTAINS BY WEDNESDAY MORNING.
WEDNESDAY AND THURSDAY...THE SHORTWAVE OVER THE NORTHERN ROCKIES
IS FORECAST TO STRENGTHEN AND DROP SOUTH ACROSS COLORADO THROUGH
THIS PERIOD. THERE ARE A FEW SLIGHT MODEL DIFFERENCES WHICH COULD
PLAY A ROLE IN HOW MUCH SNOW SOME AREAS SEE. SNOW WILL BE ON THE
INCREASE OVER THE CENTRAL MOUNTAINS WEDNESDAY MORNING AND SPREAD
SOUTH AND EAST INTO THE PALMER DIVIDE BY WEDNESDAY AFTERNOON.
ACROSS THE PLAINS...A STRONG COLD FRONT IS FORECAST TO DROP SOUTH
BY LATE WEDNESDAY AFTERNOON. FLOW BEHIND THE COLD FRONT IS
FORECAST TO TRANSITION NORTHEASTERLY HELPING TO PRODUCE LOW LEVEL
UPSLOPE FLOW AS THE UPPER DISTURBANCE DROPS ACROSS THE AREA.
HEAVY SNOW IS LIKELY TO DEVELOP OVER THE EASTERN MOUNTAINS...DOWN
INTO THE I-25 CORRIDOR WEDNESDAY EVENING AND CONTINUE INTO
THURSDAY MORNING. SNOW TOTALS LOOK TO BE HIGHEST OVER THE CENTRAL
MOUNTAINS WHERE ANOTHER FOOT OR MORE OF SNOW IS EXPECTED...WHILE
THE LOWER ELEVATIONS ALONG THE I-25 CORRIDOR WILL SEE 2 TO 6
INCHES. LIGHT SNOW IS EXPECTED ACROSS ALL THE EASTERN PLAINS WITH
1 TO 3 INCHES POSSIBLE. THE MAIN MODEL DIFFERENCE IS WITH THE NAM
WHICH KEEPS LOW AND MID LEVEL FLOW A BIT MORE NORTHERLY...WHICH
WOULD LIMIT UPSLOPE EFFECTS AND SNOW TOTALS ALONG THE I-25
CORRIDOR. THIS WILL NEED TO BE MONITORED. THE HEAVIEST SNOW WILL
COME TO AN END BY LATE THURSDAY MORNING...WITH LIGHT SNOW LIKELY
LINGERING ACROSS THE AREA THROUGH THURSDAY NIGHT. TEMPERATURES
WILL BE COLD WITH 30S FOR HIGHS ON WEDNESDAY...WITH 20S ON
THURSDAY.
FRIDAY...BROAD NORTHWEST FLOW WILL TRANSITION TO SOUTHWESTERLY
FLOW AS THE NEXT UPPER LEVEL DISTURBANCE DROPS SOUTH ALONG THE
WEST COAST. WEAK ENERGY MOVING ACROSS THE REGION WILL LIKELY KEEP
LIGHT SNOW GOING OVER THE MOUNTAINS. TEMPERATURES WILL REMAIN COLD
ACROSS THE PLAINS WITH 20S FOR HIGHS.
SATURDAY THROUGH MONDAY...THE UPPER SYSTEM ALONG THE WEST COAST IS
FORECAST TO STRENGTHEN AND SLOWLY DRIFT SOUTH INTO SOUTHERN
CALIFORNIA BY EARLY NEXT WEEK. SOUTHWESTERLY FLOW WILL TAP INTO
SUBTROPICAL MOISTURE AND SPREAD IT NORTHEASTWARD ACROSS COLORADO.
THIS WILL SET THE STAGE FOR HEAVY SNOWFALL ALONG THE CONTINENTAL
DIVIDE THROUGH THE WEEKEND...WITH THE HEAVIEST SNOWFALL OVER THE
SAN JUAN RANGE. MODELS KEEP LIGHT SNOW ACROSS ALL OF SOUTHERN
COLORADO THROUGH THE WEEKEND. COLD AIR WILL REMAIN IN PLACE WITH
30S FOR HIGHS ACROSS THE LOWER ELEVATIONS. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1020 PM MST MON FEB 23 2015
VFR CONDITIONS WITH A GENERALLY LIGHT DIURNAL WIND REGIME EXPECTED
AT COS AND PUB OVER THE NEXT 24 HOURS.
EXPECTING IFR AND LIFR FOG TO DEVELOP AT ALS THROUGH THE EARLY
MORNING HOURS WITH FOG DISSIPATING AFT 16Z AND VFR CONDITIONS
THEREAFTER.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1020 PM MST MON FEB 23 2015
.UPDATE...
ISSUED AT 813 PM MST MON FEB 23 2015
UPDATED TO LOWER LOWS A TAD AS TEMPERATURES HAVE DROPPED WITH
FRESH SNOW COVER AND CLEARING SKIES. SHOULD CONTINUE TO SEE
TEMPERATURES DROP THROUGH MIDNIGHT AND THEN SLOWLY WARM...ESPECIALLY
OVER AND NEAR THE HIGHER TERRRAIN...AS TEMPS ALOFT WARM AND MID LEVEL
FLOW BECOMES MORE WESTERLY.
UPDATE ISSUED AT 509 PM MST MON FEB 23 2015
UPDATED FORECAST TO EXPIRE WSW FOR ZONES 66 AND 67.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM MST MON FEB 23 2015
AN UPR LOW OVR CA TODAY IS EXPECTED TO MOVE EASTWARD TONIGHT...
MOVING INTO NORTH CENTRAL AZ BY 12Z TUE...AND THEN WEAKENING AND
MOVING SOUTHEASTWARD THRU NM ON TUE.
SNOW HAS CONTINUED FALLING OVER THE MTNS AND HIGH VALLEYS THIS
AFTERNOON. IN THE SAN LUIS VALLEY THE SNOW HAS NOT BEEN WIDESPREAD
AND IT FAIRLY SPOTTY AND WL CANCEL SNOW ADVISORY AT 3 PM.
OVER THE SANGRE DE CRISTO MTNS THE SNOW IS ALSO BECOMING MORE
SPOTTY...EXCEPT OVR THE FAR SRN AREAS NR THE NEW MEXICO BORDER. WL
ALLOW THAT ADVISORY TO EXPIRE AT 3 PM.
THE NAM AND HRRR SHOW PCPN CHANCE DECREASING RAPIDLY IN THE EVENING
HOURS OVR MOST OF THE MTNS AND HIGH VALLEY AREAS. THE NAM KEEPS
WIDESPREAD SNOW OVR THE ERN SAN JUANS EARLY IN THE EVENING. WEB CAMS
SHOULD LITTLE IN THE WAY OF SNOWFALL CURRENTLY AT LXV AND MONARCH
PASS...SO WL CANCEL THE WARNINGS FOR LAKE AND CHAFFEE COUNTIES AT 3
PM...ALONG WITH CANCELING WARNINGS FOR ZONES 64 AND 65...BUT WL
LEAVE WARNINGS IN EFFECT UNTIL 5 PM FOR ZONES 66 AND 67. WL LEAVE
THE WARNING FOR THE ERN SAN JUANS (ZONE 68) IN EFFECT UNTIL 06Z.
ERN SAN JUANS COULD GET ANOTHER FEW INCHES IN THE EVENING
HOURS...WITH LITTLE ADDITIONAL ACCUMULATION AFTER MIDNIGHT AS THE
SNOW TAPERS OFF.
BY 09Z THE NAM SHOWS DRY WX OVR THE ENTIRE FORECAST AREA...WITH DRY
CONDITIONS THRU AT LEAST MIDMORNING TUE. THE NAM THEN SHOWS THE
POTENTIAL FOR SOME LIGHT PCPN AGAIN OVR THE SW MTNS AS THE UPR LOW
MOVES INTO NM. HOWEVER THE GFS HAS LIGHT PCPN CONTINUING OVR THE SW
MTNS AND THE SANGRES THRU THE NIGHT AND THRU TUE. THE ECMWF IS
SIMILAR TO THE GFS BUT DOES NOT SPREAD THE PCPN ON TUE QUITE AS FAR
NORTH. HAVE DECIDED TO KEEP LOW POPS OVR THE SANGRES AND PORTIONS
OF THE CENTRAL MTNS THRU TONIGHT AND TUE...WITH HIGHER POPS OVR THE
SW MTNS DURING THIS SAME TIME-FRAME...BUT NOT EXPECTING ANYTHING
MORE THAN SOME LIGHT ACCUMULATIONS.
IT IS POSSIBLE FOR THE SAN LUIS VALLEY TO SEE SOME VERY LIGHT SNOW
DEVELOP AGAIN AS LOW CLOUDS COVER MUCH OF THE AREA.
TEMPS WL BE WARMER ON TUE...BUT THE SNOW COVER IN MANY LOCATIONS WL
LIMIT THE AMOUNT OF WARMING AND SO WL STAY BELOW GUIDANCE IN MANY
AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM MST MON FEB 23 2015
...ACTIVE AND COLD WEATHER PATTERN TO CONTINUE...
MODELS IN GOOD AGREEMENT WITH ACTIVE WEATHER PERSISTING THROUGH
THE EXTENDED PERIOD. SEVERAL DISTURBANCES WILL KEEP PERIODS OF
MODERATE TO HEAVY SNOW GOING FOR MOST OF SOUTHERN COLORADO.
TUESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL BE EXITING THE
DESERT SOUTHWEST INTO TEXAS EARLY TUESDAY NIGHT. LIGHT LINGERING
SNOWFALL OVER THE SOUTHERN SAN JUANS SHOULD COME TO AN END BY
MIDNIGHT. A SECONDARY DISTURBANCE WILL BE DROPPING SOUTH OUT OF
THE NORTHERN ROCKIES LATE TUESDAY NIGHT WITH LIGHT SNOW DEVELOPING
OVER THE CENTRAL MOUNTAINS BY WEDNESDAY MORNING.
WEDNESDAY AND THURSDAY...THE SHORTWAVE OVER THE NORTHERN ROCKIES
IS FORECAST TO STRENGTHEN AND DROP SOUTH ACROSS COLORADO THROUGH
THIS PERIOD. THERE ARE A FEW SLIGHT MODEL DIFFERENCES WHICH COULD
PLAY A ROLE IN HOW MUCH SNOW SOME AREAS SEE. SNOW WILL BE ON THE
INCREASE OVER THE CENTRAL MOUNTAINS WEDNESDAY MORNING AND SPREAD
SOUTH AND EAST INTO THE PALMER DIVIDE BY WEDNESDAY AFTERNOON.
ACROSS THE PLAINS...A STRONG COLD FRONT IS FORECAST TO DROP SOUTH
BY LATE WEDNESDAY AFTERNOON. FLOW BEHIND THE COLD FRONT IS
FORECAST TO TRANSITION NORTHEASTERLY HELPING TO PRODUCE LOW LEVEL
UPSLOPE FLOW AS THE UPPER DISTURBANCE DROPS ACROSS THE AREA.
HEAVY SNOW IS LIKELY TO DEVELOP OVER THE EASTERN MOUNTAINS...DOWN
INTO THE I-25 CORRIDOR WEDNESDAY EVENING AND CONTINUE INTO
THURSDAY MORNING. SNOW TOTALS LOOK TO BE HIGHEST OVER THE CENTRAL
MOUNTAINS WHERE ANOTHER FOOT OR MORE OF SNOW IS EXPECTED...WHILE
THE LOWER ELEVATIONS ALONG THE I-25 CORRIDOR WILL SEE 2 TO 6
INCHES. LIGHT SNOW IS EXPECTED ACROSS ALL THE EASTERN PLAINS WITH
1 TO 3 INCHES POSSIBLE. THE MAIN MODEL DIFFERENCE IS WITH THE NAM
WHICH KEEPS LOW AND MID LEVEL FLOW A BIT MORE NORTHERLY...WHICH
WOULD LIMIT UPSLOPE EFFECTS AND SNOW TOTALS ALONG THE I-25
CORRIDOR. THIS WILL NEED TO BE MONITORED. THE HEAVIEST SNOW WILL
COME TO AN END BY LATE THURSDAY MORNING...WITH LIGHT SNOW LIKELY
LINGERING ACROSS THE AREA THROUGH THURSDAY NIGHT. TEMPERATURES
WILL BE COLD WITH 30S FOR HIGHS ON WEDNESDAY...WITH 20S ON
THURSDAY.
FRIDAY...BROAD NORTHWEST FLOW WILL TRANSITION TO SOUTHWESTERLY
FLOW AS THE NEXT UPPER LEVEL DISTURBANCE DROPS SOUTH ALONG THE
WEST COAST. WEAK ENERGY MOVING ACROSS THE REGION WILL LIKELY KEEP
LIGHT SNOW GOING OVER THE MOUNTAINS. TEMPERATURES WILL REMAIN COLD
ACROSS THE PLAINS WITH 20S FOR HIGHS.
SATURDAY THROUGH MONDAY...THE UPPER SYSTEM ALONG THE WEST COAST IS
FORECAST TO STRENGTHEN AND SLOWLY DRIFT SOUTH INTO SOUTHERN
CALIFORNIA BY EARLY NEXT WEEK. SOUTHWESTERLY FLOW WILL TAP INTO
SUBTROPICAL MOISTURE AND SPREAD IT NORTHEASTWARD ACROSS COLORADO.
THIS WILL SET THE STAGE FOR HEAVY SNOWFALL ALONG THE CONTINENTAL
DIVIDE THROUGH THE WEEKEND...WITH THE HEAVIEST SNOWFALL OVER THE
SAN JUAN RANGE. MODELS KEEP LIGHT SNOW ACROSS ALL OF SOUTHERN
COLORADO THROUGH THE WEEKEND. COLD AIR WILL REMAIN IN PLACE WITH
30S FOR HIGHS ACROSS THE LOWER ELEVATIONS. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1020 PM MST MON FEB 23 2015
VFR CONDITIONS WITH A GENERALLY LIGHT DIURNAL WIND REGIME EXPECTED
AT COS AND PUB OVER THE NEXT 24 HOURS.
EXPECTING IFR AND LIFR FOG TO DEVELOP AT ALS THROUGH THE EARLY
MORNING HOURS WITH FOG DISSIPATING AFT 16Z AND VFR CONDITIONS
THEREAFTER.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR COZ068.
&&
$$
UPDATE...MW
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
946 PM EST WED FEB 25 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO WEAKEN AND PUSH OUT TO SEA TONIGHT. A
COASTAL LOW WILL MOVE TO OUR SOUTH AND EAST TONIGHT INTO THURSDAY.
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC LATE FRIDAY INTO
EARLY SUNDAY. THE HIGH WILL BUILD OFFSHORE AHEAD OF A COLD FRONT
THAT IS EXPECTED TO PASS THROUGH SUNDAY NIGHT INTO MONDAY. HIGH
PRESSURE WILL BRIEFLY RETURN MONDAY NIGHT INTO TUESDAY, BEFORE
RETREATING NORTHEASTWARD AS A SYSTEM APPROACHES FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WITH THIS UPDATE WE ARE GOING TO UPGRADE SUSSEX COUNTY DELAWARE TO
WARNINGS AND ADD A TIER OF ADVISORIES FARTHER TO THE NORTH. IN A
VERY CONFLICTING WINTER THERE WAS CONFLICTED VERIFICATION THROUGH
00Z. BOTH THE GFS AND ECMWF VERIFIED BEST WITH THE PCPN MASS
FIELDS (WRF-NMMB AND SREF MEAN WAS TOO FAR NORTHWEST). PROBLEM
GOING FORWARD IS THAT THEY SPLIT WITH THE NORTHWESTERN EXTENT OF
THE PCPN. LATEST 00Z WRF-NMMB HAD A SHIFT TO THE SE IN ITS
HEAVIER PCPN AXIS TO THE SE AND THIS WOULD MAKE SENSE GIVEN
ABOVE. RAP HAS BEEN PRETTY BULLISH WITH ITS PCPN THIS EVENING,
BUT IT TOO IS VERIFYING TOO WET IN THE CAROLINAS.
WHILE THIS ALL SEEMS TO POINT TO LESS, FORECAST SOUNDINGS ARE
SHOWING MODERATE OMEGA WITHIN THE SNOW GROWTH AREA IN THE
SOUTHEASTERN PART OF OUR CWA FOR A FEW HOURS ON THURSDAY MORNING.
SO APPLYING A 15:1 RATIO EVEN TO THE DRIEST GFS SOLUTION WOULD GET
SUSSEX COUNTY TO WARNING CRITERIA, WHICH WE UPGRADED. THE NEXT
SLICE UPWARD WITHOUT CORROBORATION FROM THE HRRR AND THE 18Z CAN
RGEM, WE LEFT AS ADVISORIES.
WE ADDED A WINT WX ADVISORY FROM CECIL NEWD INTO BURLINGTON AND
OCEAN MAINLY BECAUSE THE SNOW IS EXPECTED TO FALL DURING THE
MORNING COMMUTE. THERE IS UNCERTAINTY AS MODELS ARE STRUGGLING
WITH SFC DEW POINTS (THEY ARE DRIER THAN THEY ARE PREDICTING), BUT
THERE REMAINS A DECENT NEG TILT SHORT WAVE WHICH DOES PASS THROUGH
THE AREA.
WITH CLOUDS ROLLING IN, WE GENERALLY UPPED TEMPERATURES BY A FEW
DEGREES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
SNOW SHOULD BE FALLING ACROSS THE SOUTHERN AREAS WITH A PUSH
NORTHWARD THROUGH THE MORNING. THE MORNING COMMUTE IS LIKELY TO BE
IMPACTED AND CAUTION WILL BE NEEDED ON THE AREA ROADWAYS. THERE WAS
A SLIGHT NORTHWARD PUSH WITH THE 12Z MODEL GUIDANCE AND WE HAVE
UPPED THE SNOW TOTALS ACROSS THE REGION, WITH THE HIGHEST AMOUNTS
REMAINING ACROSS SOUTHERN DELAWARE. NORTH OF THE I-95 CORRIDOR, THE
AIR REMAINS A BIT DRIER AND NOT EXPECTING MUCH, IF ANY, SNOW
ACCUMULATION TO OCCUR. AREAS ALONG THE I-95 CORRIDOR WILL SEE AROUND
AN INCH OR LESS WITH AMOUNTS INCREASING AS YOU HEAD TO THE SOUTH AND
EAST. ACROSS SOUTHERN DELAWARE, EXPECT AROUND 3 TO 5 INCHES OF SNOW
TO FALL, WITH HIGHEST AMOUNTS CLOSER TO THE MARYLAND BORDER. THERE
IS SOME INDICATION IN SOME OF THE MODEL GUIDANCE THAT HIGHER AMOUNTS
ARE POSSIBLE, ESPECIALLY ACROSS SOUTHERN DELAWARE, SOUTHERN EASTERN
SHORE OF MARYLAND AND EXTREME SOUTHERN NEW JERSEY, AS QPF AMOUNTS
ARE EDGING HIGHER WITH THE 12Z MODEL RUNS AND THIS WILL NEED TO BE
WATCHED AS THIS SYSTEM DEVELOPS AND PUSHES NORTHWARD. A SLIGHT
NORTHERLY PUSH TO THE CURRENT FORECAST TRACK WOULD INCREASE AMOUNTS,
ESPECIALLY ACROSS THE SOUTH.
TEMPERATURES WILL GENERALLY BE IN THE 20S ACROSS THE FORECAST AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
ANY PRECIPITATION ASSOCIATED WITH THE STORM SYSTEM OVERNIGHT
WEDNESDAY INTO THURSDAY MORNING SHOULD FULLY PULL AWAY FROM THE AREA
BY THURSDAY EVENING. HOWEVER, AS WE MOVE INTO THE OVERNIGHT THURSDAY
INTO THE EARLY PART OF FRIDAY, ANOTHER AREA OF LOW-MID LEVEL
MOISTURE SLIDES ACROSS THE AREA WHILE A SHORT WAVE APPROACHES FROM
HE WEST. IT`S POSSIBLE THERE MAY BE JUST ENOUGH LIFT AND MOISTURE
COMBINED TO CREATE AN AREA OF LIGHT SNOW SHOWERS ACROSS A PORTION OF
THE AREA. THIS MOISTURE WILL PULL AWAY FROM THE AREA DURING THE DAY
FRIDAY AND ANY SHOWER ACTIVITY SHOULD END BY THE AFTERNOON.
AS WE MOVE INTO FRIDAY NIGHT, AND CONTINUING THROUGH SATURDAY AND
SATURDAY NIGHT, HIGH PRESSURE BUILDS ACROSS THE EAST COAST. THIS
WILL PROVIDE TRANQUIL WEATHER ACROSS THE AREA. THE ONLY PROBLEM WITH
THIS TRANQUIL WEATHER IS TEMPERATURES WILL REMAIN WELL BELOW NORMAL.
THE HIGH BUILDS OFFSHORE DURING THE DAY SUNDAY, ALLOWING FOR RETURN
FLOW TO DEVELOP. MOISTURE INCREASES AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT DOES NOT ACTUALLY MOVE INTO THE AREA UNTIL
OVERNIGHT SUNDAY INTO MONDAY. THERE COULD BE A FEW SHOWERS
DEVELOPING TO OUR WEST AS EARLY AS SUNDAY AFTERNOON, BUT THE MAIN
AREA OF PRECIPITATION IS EXPECTED OVERNIGHT SUNDAY INTO MONDAY
MORNING IN ASSOCIATION WITH THE FRONTAL PASSAGE. PTYPES COULD BECOME
A CONCERN FOR PORTIONS OF THE AREA, STARTING AS SNOW, THEN CHANGING
TO A WINTRY MIX AND/OR RAIN FOR A PORTION OF THE AREA LATER INTO
SUNDAY NIGHT/MONDAY MORNING.
HIGH PRESSURE AND PRECIPITATION FREE FORECAST BRIEFLY BUILDS INTO THE
MONDAY NIGHT INTO TUESDAY. HOWEVER, BY LATE TUESDAY THERE COULD BE
SOME LIGHT PRECIPITATION MOVING INTO THE AREA AHEAD OF THE NEXT
STORM SYSTEM APPROACHING FROM THE SOUTH. THE GFS AND ECMWF SHOW AN
AREA OF LOW PRESSURE LIFTING THROUGH THE MID-WEST TUESDAY NIGHT INTO
WEDNESDAY, ALTHOUGH THERE IS SOME SLIGHT TIMING DIFFERENCES, AND
LIFTING A COMPLEX FRONTAL SYSTEM INTO OUR AREA. PTYPES COULD AGAIN
BECOME A PROBLEM ACROSS THE AREA, WITH THE PRECIPITATION POSSIBLY
STARTING AS SNOW, THEN CHANGING TO A WINTRY MIX AND/OR RAIN FOR A
PORTION OF THE AREA OVERNIGHT TUESDAY INTO WEDNESDAY MORNING.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
00Z TAFS VFR FOR THIS EVENING AND MOST OF OVERNIGHT GOING DOWN TO
IFR KPHL METRO AREA SOUTHEAST THURSDAY MORNING, MIGHT REMAIN MVFR
DUE TO CIGS THURSDAY AFTERNOON.
THIS EVENING...VFR WITH HIGH LEVEL CIG MOVING IN. WIND DIRECTION
AN AVERAGE FOR FORECAST PERIOD AS THEY WILL BE VEERING TO THE
NORTH. SPEEDS LIGHT.
OVERNIGHT...KRDG AND KABE AS WELL AS PHL METRO AIRPORTS REMAINING
VFR WITH A LOWERING CIG. NORTH TO NORTHEAST WINDS INCREASING TO
AROUND 10 KTS, LIGHTER FAR NORTHWEST TERMINALS. AT KACY AND KMIV,
BECOMING IFR (VSBYS) LATE IN SNOW. THERE IS A CHANCE A MVFR CIG
MIGHT DEVELOP PRIOR. NORTHNORTHEAST WINDS INCREASING TO 10 TO 15
KNOTS WITH SOME HIGHER GUSTS.
THURSDAY MORNING...KACY AND KMIV IFR (VSBYS MOSTLY) IN SNOW.
IMPROVING LATE. NORTHNORTHEAST WINDS AVERAGING 10 TO 15 KNOTS WITH
SOME GUSTS 20 TO 25 KNOTS. KPHL METRO AIRPORTS BECOMING MVFR TO
IFR IN SNOW. CIGS OR VSBYS CAUSE. REGION WILL BE NEAR NORTHWEST
EDGE OF STEADY SNOW, SO CONFIDENCE IS MODERATE. NORTHNORTHEAST
WINDS 10 TO 15 KNOTS. KABE AND KRDG SHOULD REMAIN MAINLY VFR IN
SNOW FLURRIES.
THURSDAY AFTERNOON...PREVAILING MVFR CONDITIONS DUE TO CIGS. VSBY
REDUCING SNOW SHOULD BE DONE. NORTH TO NORTHEAST WINDS BECOMING
LIGHTER WITH AVERAGE SPEEDS CLOSE TO 10 KNOTS.
THURSDAY EVENING...KPHL TAF BECOMING VFR WITH A HIGHER BASED CIG.
OUTLOOK...
THURSDAY NIGHT-FRIDAY...MOSTLY VFR WITH MVFR CIGS POSSIBLE.
FRIDAY NIGHT-SUNDAY...VFR. LIGHT NORTHWEST-WEST WINDS, BECOMING
SOUTHWEST SUNDAY.
SUNDAY NIGHT-MONDAY...LOWERING CONDITIONS WITH MVFR/IFR DEVELOPING.
A WINTRY MIX LIKELY ACROSS PORTIONS OF THE AREA, BECOMING RAIN ON
MONDAY.
&&
.MARINE...
THE SMALL CRAFT ADVISORY ON THE NORTHERN OCEAN WATERS HAS
BEEN EXTENDED THROUGH 22Z THURSDAY. A SMALL CRAFT ADVISORY HAS BEEN
RAISED ON THE LOWER DELAWARE BAY AND THE SOUTHERN OCEAN WATERS
STARTING AT 09Z THURSDAY AND ENDING AT 22Z THURSDAY.
WESTERLY WINDS WILL VEER TO THE NORTHEAST OVERNIGHT AND BECOME GUSTY
THROUGH THE DAY ON THURSDAY. IN ADDITION, SEAS WILL RISE IN EXCESS
OF 5 FEET. FREEZING SPRAY WILL BE POSSIBLE THROUGH THURSDAY.
OUTLOOK...
THURSDAY NIGHT-FRIDAY NIGHT...SUB SMALL CRAFT ADVISORY LEVELS
EXPECTED ACROSS THE WATERS. SEAS MAY REMAIN CLOSE TO 4 FEET.
SATURDAY-SUNDAY...SUB SMALL CRAFT ADVISORY CONDITIONS CONTINUE AS
HIGH PRESSURE BUILDS ACROSS THE WATERS.
SUNDAY NIGHT-MONDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS LIKELY
DEVELOPING AS A FRONTAL BOUNDARY APPROACHES AND CROSSES THE WATERS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY FROM 6 AM TO 1 PM EST THURSDAY FOR
NJZ016>020-026-027.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR
NJZ021>025.
DE...WINTER WEATHER ADVISORY FROM 6 AM TO 1 PM EST THURSDAY FOR
DEZ001.
WINTER STORM WARNING FROM 3 AM TO 1 PM EST THURSDAY FOR DEZ003-
004.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR
DEZ002.
MD...WINTER WEATHER ADVISORY FROM 6 AM TO 1 PM EST THURSDAY FOR
MDZ008.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST THURSDAY FOR
MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 5 PM EST THURSDAY FOR ANZ431-
452>455.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR ANZ450-451.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...GIGI
SHORT TERM...MEOLA
LONG TERM...ROBERTSON
AVIATION...ROBERTSON/MEOLA
MARINE...ROBERTSON/MEOLA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
631 PM EST WED FEB 25 2015
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO WEAKEN AND PUSH OUT TO SEA TONIGHT. A
COASTAL LOW WILL MOVE TO OUR SOUTH AND EAST TONIGHT INTO THURSDAY.
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC LATE FRIDAY INTO
EARLY SUNDAY. THE HIGH WILL BUILD OFFSHORE AHEAD OF A COLD FRONT
THAT IS EXPECTED TO PASS THROUGH SUNDAY NIGHT INTO MONDAY. HIGH
PRESSURE WILL BRIEFLY RETURN MONDAY NIGHT INTO TUESDAY, BEFORE
RETREATING NORTHEASTWARD AS A SYSTEM APPROACHES FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WE HAVE NOT MADE TOO MANY CHANGES WITH THIS UPDATE AS THE WRF-NMMB
AND GFS HAVE REMAINED IN THEIR RESPECTIVE CAMPS. WANT TO SEE WHICH
MODEL VERIFIES THE BEST AT 00Z. SLIGHT EROSION IN THE DP/DTING OF
THE RAP AND HRRR, BUT MAKING A NEGLIGIBLE DIFFERENCE AT THIS
POINT.
WE HAVE EXPANDED THE WINTER WEATHER ADVISORY TO NOW INCLUDE PARTS
OF THE EASTERN SHORE OF MARYLAND (EXCLUDING CECIL COUNTY), CENTRAL
DELAWARE AND PORTIONS OF SOUTHERN NEW JERSEY. THE ADVISORIES ARE
IN EFFECT FROM 10PM TONIGHT THROUGH THURSDAY AFTERNOON.
A BEAUTIFUL DAY TODAY ACROSS THE REGION WILL GRADUALLY BECOME
CLOUDIER THIS EVENING AS A LOW PRESSURE SYSTEM DEVELOPS JUST OFF THE
CAROLINA COAST AND STARTS TO MAKE ITS WAY TOWARDS THE NORTHEAST
TONIGHT.
THE LOW WILL PASS JUST OFF OF CAPE HATTERAS AND CONTINUE TO THE
NORTHEAST, REMAINING WELL TO THE EAST OF OUR AREA. THERMAL PROFILES
CONTINUE TO LOOK COLD AND GIVE US HIGHER CONFIDENCE THAT WE WILL SEE
SNOW AS THE ONLY PRECIPITATION TYPE WITH THIS EVENT. THE NORTHERN
EDGE OF THE PRECIPITATION WILL START TO EDGE INTO OUR FORECAST AREA
LATER TONIGHT, WITH MOST AREAS NOT SEEING ANY SNOW UNTIL AFTER
MIDNIGHT.
WITH CLOUDS FILTERING IN OVERHEAD, ESPECIALLY ACROSS THE SOUTHERN
AREAS, WE WILL NOT BE QUITE AS COLD AS THE PREVIOUS COUPLE OF
NIGHTS. LOWS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WILL
REMAIN IN THE TEENS TO LOWER 20S. AS YOU HEAD NORTH, THE CLOUDS WILL
TAKE LONGER TO GET THERE AND THERE WILL BE A PERIOD WHERE WE WILL
RADIATE FAIRLY WELL. EXPECT LOWS TO DROP INTO THE SINGLE DIGITS TO
THE LOWER TEENS IN THOSE AREAS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
SNOW SHOULD BE FALLING ACROSS THE SOUTHERN AREAS WITH A PUSH
NORTHWARD THROUGH THE MORNING. THE MORNING COMMUTE IS LIKELY TO BE
IMPACTED AND CAUTION WILL BE NEEDED ON THE AREA ROADWAYS. THERE WAS
A SLIGHT NORTHWARD PUSH WITH THE 12Z MODEL GUIDANCE AND WE HAVE
UPPED THE SNOW TOTALS ACROSS THE REGION, WITH THE HIGHEST AMOUNTS
REMAINING ACROSS SOUTHERN DELAWARE. NORTH OF THE I-95 CORRIDOR, THE
AIR REMAINS A BIT DRIER AND NOT EXPECTING MUCH, IF ANY, SNOW
ACCUMULATION TO OCCUR. AREAS ALONG THE I-95 CORRIDOR WILL SEE AROUND
AN INCH OR LESS WITH AMOUNTS INCREASING AS YOU HEAD TO THE SOUTH AND
EAST. ACROSS SOUTHERN DELAWARE, EXPECT AROUND 3 TO 5 INCHES OF SNOW
TO FALL, WITH HIGHEST AMOUNTS CLOSER TO THE MARYLAND BORDER. THERE
IS SOME INDICATION IN SOME OF THE MODEL GUIDANCE THAT HIGHER AMOUNTS
ARE POSSIBLE, ESPECIALLY ACROSS SOUTHERN DELAWARE, SOUTHERN EASTERN
SHORE OF MARYLAND AND EXTREME SOUTHERN NEW JERSEY, AS QPF AMOUNTS
ARE EDGING HIGHER WITH THE 12Z MODEL RUNS AND THIS WILL NEED TO BE
WATCHED AS THIS SYSTEM DEVELOPS AND PUSHES NORTHWARD. A SLIGHT
NORTHERLY PUSH TO THE CURRENT FORECAST TRACK WOULD INCREASE AMOUNTS,
ESPECIALLY ACROSS THE SOUTH.
TEMPERATURES WILL GENERALLY BE IN THE 20S ACROSS THE FORECAST AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
ANY PRECIPITATION ASSOCIATED WITH THE STORM SYSTEM OVERNIGHT
WEDNESDAY INTO THURSDAY MORNING SHOULD FULLY PULL AWAY FROM THE AREA
BY THURSDAY EVENING. HOWEVER, AS WE MOVE INTO THE OVERNIGHT THURSDAY
INTO THE EARLY PART OF FRIDAY, ANOTHER AREA OF LOW-MID LEVEL
MOISTURE SLIDES ACROSS THE AREA WHILE A SHORT WAVE APPROACHES FROM
HE WEST. IT`S POSSIBLE THERE MAY BE JUST ENOUGH LIFT AND MOISTURE
COMBINED TO CREATE AN AREA OF LIGHT SNOW SHOWERS ACROSS A PORTION OF
THE AREA. THIS MOISTURE WILL PULL AWAY FROM THE AREA DURING THE DAY
FRIDAY AND ANY SHOWER ACTIVITY SHOULD END BY THE AFTERNOON.
AS WE MOVE INTO FRIDAY NIGHT, AND CONTINUING THROUGH SATURDAY AND
SATURDAY NIGHT, HIGH PRESSURE BUILDS ACROSS THE EAST COAST. THIS
WILL PROVIDE TRANQUIL WEATHER ACROSS THE AREA. THE ONLY PROBLEM WITH
THIS TRANQUIL WEATHER IS TEMPERATURES WILL REMAIN WELL BELOW NORMAL.
THE HIGH BUILDS OFFSHORE DURING THE DAY SUNDAY, ALLOWING FOR RETURN
FLOW TO DEVELOP. MOISTURE INCREASES AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT DOES NOT ACTUALLY MOVE INTO THE AREA UNTIL
OVERNIGHT SUNDAY INTO MONDAY. THERE COULD BE A FEW SHOWERS
DEVELOPING TO OUR WEST AS EARLY AS SUNDAY AFTERNOON, BUT THE MAIN
AREA OF PRECIPITATION IS EXPECTED OVERNIGHT SUNDAY INTO MONDAY
MORNING IN ASSOCIATION WITH THE FRONTAL PASSAGE. PTYPES COULD BECOME
A CONCERN FOR PORTIONS OF THE AREA, STARTING AS SNOW, THEN CHANGING
TO A WINTRY MIX AND/OR RAIN FOR A PORTION OF THE AREA LATER INTO
SUNDAY NIGHT/MONDAY MORNING.
HIGH PRESSURE AND PRECIPITATION FREE FORECAST BRIEFLY BUILDS INTO THE
MONDAY NIGHT INTO TUESDAY. HOWEVER, BY LATE TUESDAY THERE COULD BE
SOME LIGHT PRECIPITATION MOVING INTO THE AREA AHEAD OF THE NEXT
STORM SYSTEM APPROACHING FROM THE SOUTH. THE GFS AND ECMWF SHOW AN
AREA OF LOW PRESSURE LIFTING THROUGH THE MID-WEST TUESDAY NIGHT INTO
WEDNESDAY, ALTHOUGH THERE IS SOME SLIGHT TIMING DIFFERENCES, AND
LIFTING A COMPLEX FRONTAL SYSTEM INTO OUR AREA. PTYPES COULD AGAIN
BECOME A PROBLEM ACROSS THE AREA, WITH THE PRECIPITATION POSSIBLY
STARTING AS SNOW, THEN CHANGING TO A WINTRY MIX AND/OR RAIN FOR A
PORTION OF THE AREA OVERNIGHT TUESDAY INTO WEDNESDAY MORNING.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
00Z TAFS VFR FOR THIS EVENING AND MOST OF OVERNIGHT GOING DOWN TO
IFR KPHL METRO AREA SOUTHEAST THURSDAY MORNING, MIGHT REMAIN MVFR
DUE TO CIGS THURSDAY AFTERNOON.
THIS EVENING...VFR WITH HIGH LEVEL CIG MOVING IN. WIND DIRECTION
AN AVERAGE FOR FORECAST PERIOD AS THEY WILL BE VEERING TO THE
NORTH. SPEEDS LIGHT.
OVERNIGHT...KRDG AND KABE AS WELL AS PHL METRO AIRPORTS REMAINING
VFR WITH A LOWERING CIG. NORTH TO NORTHEAST WINDS INCREASING TO
AROUND 10 KTS, LIGHTER FAR NORTHWEST TERMINALS. AT KACY AND KMIV,
BECOMING IFR (VSBYS) LATE IN SNOW. THERE IS A CHANCE A MVFR CIG
MIGHT DEVELOP PRIOR. NORTHNORTHEAST WINDS INCREASING TO 10 TO 15
KNOTS WITH SOME HIGHER GUSTS.
THURSDAY MORNING...KACY AND KMIV IFR (VSBYS MOSTLY) IN SNOW.
IMPROVING LATE. NORTHNORTHEAST WINDS AVERAGING 10 TO 15 KNOTS WITH
SOME GUSTS 20 TO 25 KNOTS. KPHL METRO AIRPORTS BECOMING MVFR TO
IFR IN SNOW. CIGS OR VSBYS CAUSE. REGION WILL BE NEAR NORTHWEST
EDGE OF STEADY SNOW, SO CONFIDENCE IS MODERATE. NORTHNORTHEAST
WINDS 10 TO 15 KNOTS. KABE AND KRDG SHOULD REMAIN MAINLY VFR IN
SNOW FLURRIES.
THURSDAY AFTERNOON...PREVAILING MVFR CONDITIONS DUE TO CIGS. VSBY
REDUCING SNOW SHOULD BE DONE. NORTH TO NORTHEAST WINDS BECOMING
LIGHTER WITH AVERAGE SPEEDS CLOSE TO 10 KNOTS.
THURSDAY EVENING...KPHL TAF BECOMING VFR WITH A HIGHER BASED CIG.
OUTLOOK...
THURSDAY NIGHT-FRIDAY...MOSTLY VFR WITH MVFR CIGS POSSIBLE.
FRIDAY NIGHT-SUNDAY...VFR. LIGHT NORTHWEST-WEST WINDS, BECOMING
SOUTHWEST SUNDAY.
SUNDAY NIGHT-MONDAY...LOWERING CONDITIONS WITH MVFR/IFR DEVELOPING.
A WINTRY MIX LIKELY ACROSS PORTIONS OF THE AREA, BECOMING RAIN ON
MONDAY.
&&
.MARINE...
THE SMALL CRAFT ADVISORY ON THE NORTHERN OCEAN WATERS HAS
BEEN EXTENDED THROUGH 22Z THURSDAY. A SMALL CRAFT ADVISORY HAS BEEN
RAISED ON THE LOWER DELAWARE BAY AND THE SOUTHERN OCEAN WATERS
STARTING AT 09Z THURSDAY AND ENDING AT 22Z THURSDAY.
WESTERLY WINDS WILL VEER TO THE NORTHEAST OVERNIGHT AND BECOME GUSTY
THROUGH THE DAY ON THURSDAY. IN ADDITION, SEAS WILL RISE IN EXCESS
OF 5 FEET. FREEZING SPRAY WILL BE POSSIBLE THROUGH THURSDAY.
OUTLOOK...
THURSDAY NIGHT-FRIDAY NIGHT...SUB SMALL CRAFT ADVISORY LEVELS
EXPECTED ACROSS THE WATERS. SEAS MAY REMAIN CLOSE TO 4 FEET.
SATURDAY-SUNDAY...SUB SMALL CRAFT ADVISORY CONDITIONS CONTINUE AS
HIGH PRESSURE BUILDS ACROSS THE WATERS.
SUNDAY NIGHT-MONDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS LIKELY
DEVELOPING AS A FRONTAL BOUNDARY APPROACHES AND CROSSES THE WATERS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR NJZ021>025.
DE...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR DEZ002>004.
MD...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 5 PM EST THURSDAY FOR ANZ431-
452>455.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR ANZ450-451.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...GIGI/MEOLA
SHORT TERM...MEOLA
LONG TERM...ROBERTSON
AVIATION...ROBERTSON/MEOLA
MARINE...ROBERTSON/MEOLA
AREA FORECAST DISCUSSION
NWS KEY WEST FL
300 PM EST TUE FEB 24 2015
.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200
MB)...LATEST AVAILABLE IR IMAGERY OVERLAID WITH MODEL STREAMLINE
ANALYSIS AS OF 200 PM THIS AFTERNOON CONTINUES TO DEPICT LOW
AMPLITUDE TROUGHING IN PLACE ACROSS THE NORTHERN
HALF OF THE CONUS...WITH ZONAL FLOW REMAINING ACROSS THE SOUTHERN
CONUS...THE GULF OF MEXICO...SOUTH FLORIDA AND THE FLORIDA
KEYS...WITH 75 KNOT WESTERLIES AT 250 MB ACROSS THE KEYS.
AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS...AS OF 200
PM...SURFACE TO 700 MB...LATEST MARINE AND LAND SURFACE OBSERVATIONS
COMBINED WITH ANALYSIS OVERLAID ON IR IMAGERY DETAILS A WEAKENED
1025 MB COLD HIGH CENTER NEAR THE 40N 70W METEOROLOGICAL BENCHMARK.
CLOSER TO THE KEYS AND WELL TO THE SOUTH OF THAT FEATURE...THERE IS
A STATIONARY FRONT ANALYZED FROM 1015 MB LOW PRESSURE EAST OF CHARLESTON
SOUTH CAROLINA TO ACROSS NORTH FLORIDA THENCE TO THE BAY OF CAMPECHE.
THIS FRONT SEPARATES MILD TO WARM AND VERY HUMID AIR FROM A COLD
AND DAMP AIRMASS.
.CURRENTLY...VISIBLE SATELLITE IMAGERY INDICATES THAT THE FOG HAS
DISSIPATED ACROSS THE NEARSHORE WATERS NORTH OF THE LOWER AND MIDDLE KEYS
WITH MORE DENSE FOG STILL OVER GMZ033-034. ELSEWHERE SKIES ARE SUNNY...WITH
TEMPERATURES ACROSS THE ISLANDS IN THE UPPER 70S ACROSS THE UPPER KEYS AND
MID 70S ACROSS THE LOWER AND MIDDLE KEYS. C-MAN STATIONS ALONG THE FLORIDA
REEF ARE VARIABLE NEAR 5 KNOTS...AND OVER THE ISLANDS.
.SHORT TERM...TODAY THROUGH FRIDAY...LIGHT AND VARIABLE WINDS
WILL CONTINUE THIS EVENING...BUT THERE ARE MIXED INDICATIONS THAT
WINDS WILL BECOME NORTHERLY AROUND SUNSET...WHICH WILL DRAG THE
AREAS OF FOG BACK SOUTHWARD. THE MESOSCALE HRRR SEEMS TO BE MORE VARIABLE
WHEN COMPARED TO THE GFS WHICH IS MORE TO THE SOUTHEAST...
BUT BASED ON THE CLOSE PROXIMITY OF THIS FOG BANK TO THE IMMEDIATE NORTH
OF THE LOWER AND MIDDLE KEYS AND CLOSENESS TO FLORIDA BAY...THE FOG BANK
WILL NEED LITTLE MOVEMENT TO MOVE BACK ACROSS THE KEYS AFTER SUNSET. FOR
NOW WILL INDICATE THAT AREAS OF FOG ARE MORE LIKELY ACROSS THE LOWER KEYS
AND IMMEDIATE SURROUNDING WATERS INSIDE THE 5 FATHOM LINE. WILL LEAVE THE
DENSE FOG ADVISORY IN PLACE ACROSS GMZ033 AND GMZ034.
THEN AFTER MIDNIGHT WINDS ARE EXPECTED TO BECOME MORE EASTERLY WHICH WILL
ALLOW FOR WARMER AIR TO MOVE ACROSS THE KEYS AND INCREASE DEWPOINT DEPRESSIONS
WHICH WILL LIFT THE FOG. DURING WEDNESDAY LOW PRESSURE DEVELOPING ALONG
THE COLD FRONT TO THE NORTH WILL ALLOW FOR WINDS TO MODERATE...AND
FRESH SOUTH WINDS ARE INDICATED AS LOWER PRESSURE DEEPENS EAST OF FLORIDA.
THEREAFTER...HOWEVER...THE ASSOCIATED SURFACE FRONT WITH THIS LOW PRESSURE
NEVER GETS TO THE KEYS. LOWER TO MID LEVEL MOISTURE INCREASES BEGINNING
LATE WEDNESDAY NIGHT AND THURSDAY AND THURSDAY NIGHT.
SOME WEAK IMPULSES ALOFT IN TANDEM WITH INCREASED LOWER TO MIDDLE LEVEL
MOISTURE AND WEAK DIRECTIONAL AND SPEED SHEAR WILL PROMPT MIDDLE OF THE
ROAD CHANCES FOR SHOWERS THURSDAY AND THURSDAY NIGHT WITH SLIGHT CHANCES
FOR THUNDER AS WELL. THE SURFACE FRONT NOW LOOKS TO PULL THROUGH DURING FRIDAY
BUT ISOLATED SHOWERS ARE STILL INDICATED AS THE SURFACE BOUNDARY REMAINS
NEARBY.
EXTENDED...FRIDAY NIGHT THROUGH EARLY NEXT WEEK...A MORE SPRINGLIKE PATTERN
IS INDICATED AS HIGH PRESSURE OFF THE EAST COAST WILL GENERATE FRESH EAST
BREEZES ACROSS THE KEYS AND SURROUNDING WATERS. ISOLATED SHOWERS WILL BE
LIKELY LATE NIGHT/EARLY MORNING GIVEN THE NEAR SURFACE FLUXES. TEMPERATURES
AROUND 80 AND LOWS NEAR 70 WILL BE HELD IN THE GRIDS.
&&
.MARINE...DENSE FOG ADVISORY FOR GMZ033-034 THROUGH THIS EVENING...THEN
IMPROVEMENT IS INDICATED AFTER MIDNIGHT. A DENSE FOG ADVISORY MAY BE
REQUIRED ACROSS GMZ031-032-35 THIS EVENING AS THE FOG BANK IS IN CLOSE
PROXIMITY TO THE KEYS. THIS WILL BE MONITORED ON THE EVENING SHIFT.
THE NEXT HEADLINES ARE EXPECTED FOR SCEC ON WEDNESDAY NIGHT AS LOW PRESSURE
DEVELOPS ACROSS THE GULF...THEN WINDS AND SEAS LET DOWN UNTIL
FRIDAY NIGHT WHEN STRONG HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST
FOR THE WEEKEND.
&&
.AVIATION... LOW STRATUS IS EXPECTED TO REMAIN NORTH OF THE LOWER
AND MIDDLE KEYS THROUGH THE BALANCE OF THIS AFTERNOON AND INTO THIS
EVENING. MVFR...OR EVEN BRIEF IFR...CIGS AND VSBYS ARE POSSIBLE
AGAIN LATER IN THE EVENING THANKS TO LIGHT BREEZES AND THE RESIDENT
MOIST AIRMASS. WINDS ARE EXPECTED PICK UP A MORE DEFINITE EASTERLY
COMPONENT THROUGH THE OVERNIGHT PERIOD...BUT REMAIN AT OR BELOW 10
KNOTS.
&&
.CLIMATE... ON THIS DATE IN KEYS WEATHER HISTORY...IN 1901...THE
DAILY LOW TEMPERATURE RECORD OF 53 DEGREES WAS RECORDED IN KEY WEST.
THIS IS A LONG-STANDING RECORD FOR FEBRUARY 24 IN KEY WEST.
TEMPERATURE RECORDS FOR KEY WEST DATE BACK TO 1872.
&&
.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 68 80 74 81 / - 10 10 40
MARATHON 68 82 74 83 / - 10 10 40
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...DENSE FOG ADVISORY UNTIL 11 PM EST THIS EVENING FOR GMZ033-034.
&&
$$
PUBLIC/MARINE.........FUTTERMAN
AVIATION/NOWCASTS.....04
DATA COLLECTION.......CHESSER
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AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1025 PM EST WED FEB 25 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH MOVING INTO THE AREA. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND 100
AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE COLDEST
CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST OF THE
AREA BEFORE 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW IN THE NORTH PART WHERE WE HAVE POSTED A
WINTER STORM WARNING. THE LATEST RAP HAS INDICATED A WARMING TREND
IN THE NORTH PART INDICATING PRECIPITATION MAY NOT BECOME ALL
SNOW. MOISTURE ALSO APPEARS TO BECOME SHALLOW AND BELOW THE SNOW
GROWTH AREA BEHIND THE MID-LEVEL SHORTWAVE TROUGH DURING THE
EARLY MORNING HOURS. THE MAIN PRECIPITATION TYPE MAY BECOME DRIZZLE
WITH FREEZING DRIZZLE POSSIBLE IN THE NORTH PART.
FARTHER SOUTH...THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE
FREEZING IN THE CSRA AND CENTRAL PART OVERNIGHT. THIS APPEARS ON
TRACK BASED ON OBSERVATION TRENDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS THROUGH THE TAF PERIOD.
MVFR AND IFR CONDITIONS HAVE OVERTAKEN THE TAF SITES AS RAIN MOVES
INTO THE AREA. LOW PRESSURE SYSTEM WILL MOVE SOUTH OF THE TAF
SITES OVERNIGHT CONTINUING THE RAIN THROUGH THURSDAY MORNING. SNOW
IS EXPECTED TO REMAIN WELL NORTH OF AGS/DNL/OGB...HOWEVER CAE/CUB
MAY SEE SNOW MIX WITH THE RAIN OVERNIGHT WITH NO ACCUMULATION
EXPECTED. WITH DRIER AIR MOVING IN TUESDAY MORNING RAIN WILL
CHANGE TO DRIZZLE THEN END BY MIDDAY. CIGS WILL REMAIN MVFR FROM
MIDDAY THROUGH THE END OF THE TAF PERIOD AS THE FRONTAL BOUNDARY
REMAINS ACROSS THE REGION. LIGHT AND VARIABLE WINDS WILL VEER TO
NORTHERLY OVERNIGHT AND REMAIN 8 KNOTS OR LESS THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS
CONTINUING THROUGH FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED
ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
845 PM EST WED FEB 25 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA. CONFIDENCE IS HIGH FOR ACCUMULATING
SNOW ACROSS THE EXTREME NORTH PART...ESPECIALLY IN LANCASTER
COUNTY.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH OVER ALABAMA THIS EVENING. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND
100 AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE
COLDEST CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST
OF THE AREA BY 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW WILL BECOME ALL SNOW IN THE NORTH PART WHERE
WE HAVE POSTED A WINTER STORM WARNING. CONFIDENCE IS HIGH FOR ALL
SNOW IN LANCASTER COUNTY. EXPECT DECREASING SNOW AMOUNTS TO THE
EAST AND SOUTHEAST BECAUSE OF MORE OF A MIX WITH SLEET AND RAIN.
TEMPERATURES WILL FALL TO AROUND OR SLIGHTLY BELOW FREEZING IN THE
NORTH.
SNOWFALL AMOUNTS OF 2 TO 3 INCHES APPEAR LIKELY ACROSS
MAINLY THE NORTH PORTIONS OF NEWBERRY... FAIRFIELD...KERSHAW...AND
WESTERN CHESTERFIELD COUNTIES. IN ADDITION...SNOWFALL AMOUNTS OF
3-6 INCHES MAY OCCUR OVER PARTS OF LANCASTER COUNTY WITH THE
HIGHEST TOTALS IN THE LANCASTER PANHANDLE AREA. AS THE MID-LEVEL DRY
SLOT OVERSPREADS THE AREA WITH MOISTURE BECOMING SHALLOW
DURING THE EARLY MORNING HOURS THE PRECIPITATION TYPE SHOULD
BECOME MAINLY DRIZZLE WITH FREEZING DRIZZLE POSSIBLE IN THE NORTH
PART.
FARTHER SOUTH...THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE
FREEZING IN THE CSRA AND CENTRAL PART OVERNIGHT. THIS APPEARS ON
TRACK BASED ON OBSERVATION TRENDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS THROUGH THE TAF PERIOD.
MVFR AND IFR CONDITIONS HAVE OVERTAKEN THE TAF SITES AS RAIN MOVES
INTO THE AREA. LOW PRESSURE SYSTEM WILL MOVE SOUTH OF THE TAF
SITES OVERNIGHT CONTINUING THE RAIN THROUGH THURSDAY MORNING. SNOW
IS EXPECTED TO REMAIN WELL NORTH OF AGS/DNL/OGB...HOWEVER CAE/CUB
MAY SEE SNOW MIX WITH THE RAIN OVERNIGHT WITH NO ACCUMULATION
EXPECTED. WITH DRIER AIR MOVING IN TUESDAY MORNING RAIN WILL
CHANGE TO DRIZZLE THEN END BY MIDDAY. CIGS WILL REMAIN MVFR FROM
MIDDAY THROUGH THE END OF THE TAF PERIOD AS THE FRONTAL BOUNDARY
REMAINS ACROSS THE REGION. LIGHT AND VARIABLE WINDS WILL VEER TO
NORTHERLY OVERNIGHT AND REMAIN 8 KNOTS OR LESS THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS
CONTINUING THROUGH FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED
ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
703 PM EST WED FEB 25 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA. CONFIDENCE IS HIGH FOR ACCUMULATING
SNOW ACROSS THE EXTREME NORTH PART...ESPECIALLY IN LANCASTER
COUNTY.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH OVER ALABAMA THIS EVENING. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND
100 AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE
COLDEST CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST
OF THE AREA BY 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW WILL BECOME ALL SNOW IN THE NORTH PART WHERE
WE HAVE POSTED A WINTER STORM WARNING. CONFIDENCE IS VERY HIGH FOR
ALL SNOW IN LANCASTER COUNTY. EXPECT DECREASING SNOW AMOUNTS TO
THE EAST AND SOUTHEAST BECAUSE OF MORE OF A MIX WITH SLEET.
TEMPERATURES WILL FALL TO AROUND OR SLIGHTLY BELOW FREEZING IN THE
NORTH. SNOWFALL AMOUNTS OF 2 TO 3 INCHES APPEAR LIKELY ACROSS
MAINLY THE NORTH PORTIONS OF NEWBERRY... FAIRFIELD...KERSHAW...AND
WESTERN CHESTERFIELD COUNTIES. IN ADDITION...SNOWFALL AMOUNTS OF
3-6 INCHES MAY OCCUR OVER PARTS OF LANCASTER COUNTY WITH THE
HIGHEST TOTALS IN THE LANCASTER PANHANDLE AREA.
FARTHER SOUTH...A PERIOD OF SLEET HAS OCCURRED IN THE CSRA AND
CENTRAL PART OF THE FORECAST AREA AT THE ONSET OF PRECIPITATION.
THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE FREEZING IN THE CSRA
AND CENTRAL PART OVERNIGHT. THIS APPEARS ON TRACK BASED ON
OBSERVATION TRENDS.
WIDESPREAD PRECIPITATION THROUGH THE OVERNIGHT THEN DIMINISHING
TOWARD MORNING AS SURFACE LOW MOVES OFF THE NORTH CAROLINA COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS THROUGH THE TAF PERIOD.
MVFR AND IFR CONDITIONS HAVE OVERTAKEN THE TAF SITES AS RAIN MOVES
INTO THE AREA. LOW PRESSURE SYSTEM WILL MOVE SOUTH OF THE TAF
SITES OVERNIGHT CONTINUING THE RAIN THROUGH THURSDAY MORNING. SNOW
IS EXPECTED TO REMAIN WELL NORTH OF AGS/DNL/OGB...HOWEVER CAE/CUB
MAY SEE SNOW MIX WITH THE RAIN OVERNIGHT WITH NO ACCUMULATION
EXPECTED. WITH DRIER AIR MOVING IN TUESDAY MORNING RAIN WILL
CHANGE TO DRIZZLE THEN END BY MIDDAY. CIGS WILL REMAIN MVFR FROM
MIDDAY THROUGH THE END OF THE TAF PERIOD AS THE FRONTAL BOUNDARY
REMAINS ACROSS THE REGION. LIGHT AND VARIABLE WINDS WILL VEER TO
NORTHERLY OVERNIGHT AND REMAIN 8 KNOTS OR LESS THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS
CONTINUING THROUGH FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED
ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
637 PM EST WED FEB 25 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA. CONFIDENCE IS HIGH FOR ACCUMULATING
SNOW ACROSS THE EXTREME NORTH PART...ESPECIALLY IN LANCASTER
COUNTY.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH OVER ALABAMA THIS EVENING. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND
100 AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE
COLDEST CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST
OF THE AREA BY 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW WILL BECOME ALL SNOW IN THE NORTH PART WHERE
WE HAVE POSTED A WINTER STORM WARNING. CONFIDENCE IS VERY HIGH FOR
ALL SNOW IN LANCASTER COUNTY. EXPECT DECREASING SNOW AMOUNTS TO
THE EAST AND SOUTHEAST BECAUSE OF MORE OF A MIX WITH SLEET.
TEMPERATURES WILL FALL TO AROUND OR SLIGHTLY BELOW FREEZING IN THE
NORTH. SNOWFALL AMOUNTS OF 2 TO 3 INCHES APPEAR LIKELY ACROSS
MAINLY THE NORTH PORTIONS OF NEWBERRY... FAIRFIELD...KERSHAW...AND
WESTERN CHESTERFIELD COUNTIES. IN ADDITION...SNOWFALL AMOUNTS OF
3-6 INCHES MAY OCCUR OVER PARTS OF LANCASTER COUNTY WITH THE
HIGHEST TOTALS IN THE LANCASTER PANHANDLE AREA.
FARTHER SOUTH...A PERIOD OF SLEET HAS OCCURRED IN THE CSRA AND
CENTRAL PART OF THE FORECAST AREA AT THE ONSET OF PRECIPITATION.
THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE FREEZING IN THE CSRA
AND CENTRAL PART OVERNIGHT. THIS APPEARS ON TRACK BASED ON
OBSERVATION TRENDS.
WIDESPREAD PRECIPITATION THROUGH THE OVERNIGHT THEN DIMINISHING
TOWARD MORNING AS SURFACE LOW MOVES OFF THE NORTH CAROLINA COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS DEVELOPING THROUGH THE EVENING AND
THROUGH TONIGHT AT ALL TAF SITES.
LOW MVFR CIGS CONTINUE ACROSS THE AREA WITH VFR VSBYS. PRECIPITATION
WILL BE MOVING INTO THE AREA FROM WEST TO EAST BETWEEN 21Z-00Z.
EXPECT CIGS TO BECOME IFR AFTER ONSET OF PRECIP WITH GENERALLY
MVFR VSBYS. AT THIS TIME IT APPEARS AS IF IT WILL REMAIN WARM
ENOUGH AT ALL TAF SITES SO THAT THE PRECIP WILL FALL AS ALL RAIN.
HOWEVER AREAS JUST TO THE WEST OF THE CSRA AND CENTRAL MIDLANDS
WILL HAVE THE POTENTIAL FOR SOME SNOWFALL LATE TONIGHT INTO THURSDAY
MORNING. WINDS WILL BE EASTERLY 5 TO 10 KTS EARLY TONIGHT BECOMING
NORTHERLY AROUND 10KTS LATE TONIGHT.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS THROUGH
FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR SCZ015-016-
020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
705 AM EST TUE FEB 24 2015
.SYNOPSIS...
DEVELOPING LOW PRESSURE WILL TRACK ALONG AN OFFSHORE STATIONARY FRONT
TODAY. WEAK HIGH PRESSURE ACROSS THE AREA WEDNESDAY WILL GIVE WAY
TO A STRONGER LOW PRESSURE SYSTEM FROM THE GULF OF MEXICO. THAT
SYSTEM WILL THEN TRACK THROUGH EXTREME SOUTHEAST GEORGIA AND
NORTHERN FLORIDA AND THEN OFF THE SOUTHEAST UNITED STATES COAST
WEDNESDAY NIGHT. STRONG AND COLDER CANADIAN HIGH PRESSURE FROM THE
GREAT PLAINS WILL THEN EXPAND TO BECOME THE PRIMARY WEATHER
FEATURE THURSDAY THROUGH SATURDAY. A COASTAL TROUGH WILL FORM JUST
OFFSHORE SUNDAY...BEFORE LIFTING NORTH OF THE REGION AS ATLANTIC
HIGH PRESSURE STRETCHES ACROSS THE LOCAL AREA NEXT MONDAY AND
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
FOR THE MORNING UPDATE WE HAVE MAINTAINED THE FREEZING RAIN
ADVISORY AS BEFORE...BUT HAVE DELAYED THE START AND END TIMES BY
ABOUT AN HOUR OR TWO GIVEN LATEST TEMP AND WET BULB TRENDS. LOW
PRESSURE WILL CONTINUE TO STRENGTHEN A COUPLE OF HUNDRED MILES SE
OF THE FORECAST AREA THIS MORNING AND EARLY AFTERNOON AS IT HEADS
NE. THIS INTENSIFICATION WILL DRAW COLDER AIR IN FROM THE NORTH.
RAINFALL COVERAGE WILL INCREASE AND AS IT DOES SO THE RAIN WILL
BECOME MODERATE IN INTENSITY. THIS IN TURN WILL ALLOW FOR
EVAPORATIVE COOLING TO LOWER TEMPS DOWN CLOSER TO 32F OVER THE
CHARLESTON QUAD-COUNTY REGION FROM ABOUT 9 AM-2PM...AND FOR
ALLENDALE...HAMPTON AND SCREVEN FROM ABOUT 10 AM-1 PM. AS A
RESULT THE RAIN WILL BEGIN TO FREEZE ON MAINLY ELEVATED SURFACES.
TODAY...THE PRIMARY FORECAST ISSUE REVOLVES AROUND THE POTENTIAL
FOR A LIGHT FREEZING RAIN EVENT THAT MAY IMPACT A PORTION OF THE
FORECAST AREA. MODEL GUIDANCE HAS TRENDED WARMER WITH TEMPERATURES
FOR THE MORNING AND EARLY AFTERNOON...AND THIS HAS NECESSITATED
SOME CHANGES TO ICE POTENTIAL. THE OVERALL SYNOPTIC SETUP FEATURES
NEARLY ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVE ENERGY MOVING
SWIFTLY EASTWARD INTO THE REGION. PVA AND SOME UPPER DIVERGENCE
ALOFT IS HELPING TO PROVIDE SOME LARGE SCALE SUPPORT IN ADDITION
TO LOW LEVEL FORCING IN FORM OF ISENTROPIC ASCENT. AT THE
SURFACE...1030 MB HIGH PRESSURE IS CURRENTLY SETTLING IN ACROSS
THE MID ATLANTIC AND PROVIDING A NICE COLD AIR DAMMING EVENT AND
SUPPLYING SOME COLD/DRY AIR NEAR THE SURFACE. THE HIGH WILL
QUICKLY RETREAT TO THE NORTHEAST THIS AFTERNOON AS A SURFACE LOW
DEVELOPS ALONG A RESIDUAL STATIONARY FRONT OFF THE SOUTHEAST
COAST. WIDESPREAD PRECIPITATION WILL BREAK OUT ACROSS THE REGION
IN RESPONSE TO THE LOW AND UPPER LEVEL FORCING COINCIDENT WITH
TEMPERATURES IN SOME AREAS FALLING NEAR OR JUST BELOW FREEZING
THIS MORNING AND EARLY THIS AFTERNOON.
AS STATED ABOVE...ALMOST ALL OF THE 24/00Z GUIDANCE HAS TRENDED
WARMER INCLUDING THE HI-RES MODELS SUCH AS THE HRRR AND THE RAP.
THESE RAPID UPDATE MODELS CONTINUE TO DO AN EXCELLENT JOB WITH THE
UPSTREAM PRECIPITATION AS WELL AS HOURLY TEMPERATURES...SO THEY
HAVE BEEN RELIED UPON HEAVILY FOR THE DETAILS OF THE FORECAST.
COLD AND DRY LOW LEVEL AIR WILL FILTER INTO THE FORECAST AREA
BEGINNING AROUND SUNRISE AND CONTINUE THROUGH THE LATE MORNING
BEFORE THE DAMMING HIGH MOVES TO A LESS THAN IDEAL POSITION. AS
PRECIPITATION BREAKS OUT...TEMPERATURES WILL FALL TO NEAR OR BELOW
FREEZING MAINLY ACROSS A CORE PORTION OF COUNTIES INCLUDING
BERKELEY...CHARLESTON...DORCHESTER...AND COLLETON COUNTIES. MORE
MARGINAL FREEZING TEMPERATURES ARE EXPECTED ACROSS
HAMPTON...ALLENDALE...AND SCREVEN COUNTIES. MODEL SOUNDINGS SHOW A
PROMINENT WARM NOSE DEVELOPING OVER THE SHALLOW COLD LAYER SO THE
PREDOMINANT PRECIPITATION TYPE WILL BE FREEZING RAIN. TEMPERATURES
WILL THEN WARM AND THE FREEZING LINE WILL LIFT NORTHWARD LATE THIS
AFTERNOON. THE PEAK TIME FOR FREEZING RAIN WILL ROUGHLY OCCUR FROM
AROUND 7-9 AM AT THE BEGINNING TO AROUND NOON-1PM AT THE END.
ACCRETION WILL OCCUR MAINLY ON ELEVATED SURFACE INCLUDING
BRIDGES...TREES...TREE LIMBS...AND SOME POWER LINES. TOTAL ICE
ACCUMULATIONS WILL RANGE FROM TRACE AMOUNTS UP TO AROUND A TENTH
OF AN INCH. THE HIGHEST AMOUNTS ARE EXPECTED ROUGHLY AROUND MONCKS
CORNER TO SUMMERVILLE AND NEARBY LOCATIONS. TOTAL LIQUID
ACCUMULATION AMOUNTS WILL RANGE FROM AROUND ONE TO TWO TENTHS OF
AN INCH INLAND TO UP TO THREE TENTHS OF A INCH CLOSER TO THE
COAST.
TONIGHT...PRECIPITATION WILL COME TO A CLOSE THIS EVENING AS THE
LOW PULLS AWAY AND FORCING WANES. THE REST OF THE OVERNIGHT WILL
REMAIN MOSTLY CLOUDY WITH CHILLY TEMPERATURES. IN FACT...GIVEN THE
PRECIPITATION THAT WILL FALL DURING THE DAY WE MAY SEE SOME BLACK
ICE ISSUES ESPECIALLY ACROSS THE TRI-COUNTY REGION AS WELL AS
COLLETON COUNTY. FREEZING TEMPERATURES ARE EXPECTED IN THESE AREAS
AND MID TO UPPER 30S IN MOST OTHER AREAS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY...AN INITIALLY STRONG SHORT WAVE MOVING EASTWARD THROUGH
TEXAS AT THE START OF THE PERIOD WILL DAMPEN OUT AS IT TRAVELS
QUICKLY THROUGH THE NORTHERN GULF COAST STATES DURING THE DAY. THIS
FEATURE IS BEING DRIVEN BY A POWERFUL 140 KT UPPER JET AND A 90-100
KT MID LEVEL JET. THIS WILL INDUCE CYCLOGENESIS OVER THE NORTHERN
GULF OF MEXICO AND A DEVELOPING WARM FRONT THAT EXTENDS EAST ACROSS
THE FLORIDA PENINSULA. THIS IS THE OLD BAROCLINIC ZONE THAT WILL
HAVE BEEN TO OUR SOUTH AND SE FROM TODAY. THERE IS A SUBSTANTIAL
POCKET OF DRY AIR EARLY IN THE DAY FROM ABOUT 850-500 MB AND SINKING
MOTION UNDERNEATH A MESO-HIGH THAT IS ATOP THE FORECAST ZONES.
ISENTROPIC ASCENT WILL START TO DEVELOP DURING THE LATER PORTION OF
THE DAY ON VARIOUS LEVELS...AND FORCING FOR ASCENT WILL START TO
OVERSPREAD THE AREA IN ADVANCE OF THE SURFACE LOW AND ITS ASSOCIATED
FEATURES ALOFT. THIS ALLOWS FOR OVER-RUNNING RAINS TO INITIATE
DURING THE AFTERNOON...EXPANDING FROM WEST/SW TO EAST/NE. JUST ABOUT
EVERYWHERE SHOULD BE RAINING BY DARK. QPF WILL RANGE FROM ABOUT 1/10
TO 1/4 INCH IN THE CHARLESTON TRI-COUNTY REGION TO AS MUCH AS 1/2 TO
2/3 INCHES WEST OF SAVANNAH.
THERE WILL LIKELY STILL BE SOME CONCERNS IN REGARDS TO BLACK ICE IN
THE EARLY GOING ACROSS INLAND PARTS OF THE CHARLESTON QUAD-COUNTY
AREA...BUT TEMPS LOOK TO CLIMB ABOVE FREEZING BY 9 AM. CONSIDERABLE
CLOUD COVER AND THE INCREASING COVERAGE OF RAIN WILL BE NEGATED
SLIGHTLY BY SOME WARM ADVECTION...BUT WE/RE RESTRICTED TO BASICALLY
UPPER 40S NORTH TO THE LOWER 50S SOUTH.
WEDNESDAY NIGHT...THE DAMPENING PERTURBATION ALOFT WILL MOVE
DIRECTLY OVERHEAD AROUND 00-06Z...PASSING INTO THE ATLANTIC BY
DAYBREAK THURSDAY. STRONG WIND FIELDS WILL ACCOMPANY THE IMPULSE AND
CAUSES THE GULF SURFACE LOW TO EITHER TRACK THROUGH NORTHERN FLORIDA
OR REDEVELOP OFF THE SE COAST AFTER MIDNIGHT. AN ABUNDANCE OF DEEP
MOISTURE AND LARGE SCALE FORCING FOR ASCENT WILL EQUATE TO PLENTY OF
RAINFALL WITH NEAR 100 POPS ALL SECTIONS THE FIRST HALF OF THE
NIGHT. CHANCES WILL DIMINISH BEHIND THE EXITING SHORT WAVE AND
SURFACE LOW LATE AT NIGHT. AN ADDITIONAL 3/4 TO 1 INCH OF RAIN
WILL OCCUR.
THERE IS AT LEAST A SMALL WINDOW OF OPPORTUNITY FOR VERY WEAK
SURFACE BASED DESTABILIZATION TO OCCUR IN PROXIMITY TO THE SURFACE
LOW. GIVEN THE ASSOCIATED STRONG WIND FIELDS AND WIND SHEAR THERE
MIGHT BE A RISK FOR A FEW T-STORMS TO OCCUR. FOR NOW THOUGH THE
PROBABILITY IS TOO REMOTE TO INCLUDE MENTION IN THE FORECAST.
THURSDAY...WHILE A BROAD CYCLONIC FLOW WILL PREVAIL ALOFT A SUBTLE
TRANSIENT HIGH PRESSURE WEDGE WILL PREVAIL IN WAKE OF THE ATLANTIC
LOW. THE BULK OF THE RAINS WILL HAVE PULLED OFFSHORE IN THE
MORNING...BUT THERE REMAINS A DECENT INVERSION WITHIN THE WEDGE
REGIME TO KEEP CONDITIONS DAMP AND CHILLY. WITHIN A NORTHERLY
SYNOPTIC FLOW...COLD AIR ADVECTION AND PLENTY OF CLOUDS WE/RE
LOOKING AT HIGHS AGAIN NO MORE THAN UPPER 40S AND LOWER 50S. COLD
ADVECTION WILL CONTINUE THURSDAY NIGHT AS THE LEADING EDGE OF
ARCTIC HIGH PRESSURE IN THE GREAT PLAINS FILTERS IN FROM THE NW.
SUB- FREEZING TEMPS ARE ANTICIPATED OVER THE NW TIER.
FRIDAY...A 1042 MB ARCTIC HIGH WILL EXPAND EASTWARD AND COVERS MUCH
OF THE EASTERN HALF OF THE NATION...INCLUDING THE LOCAL REGION. A
CHILLY AND DRY AIR MASS WILL PREVAIL...BUT GIVEN BETTER INSOLATION
THAN RECENT DAYS WE MIGHT BE ABLE TO ADD A COUPLE OF DEGREES ON TO
OUR MAX TEMPS. EVEN SO...WE/RE STILL FAR BELOW NORMAL FOR THE LAST
DAY OF WHAT WILL TURN OUT TO BE A VERY COLD FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
ZONAL FLOW OR FLAT RIDGING WILL EXIST ALOFT LATE IN THE WEEK INTO
EARLY NEXT WEEK. SIMULTANEOUSLY THE ARCTIC HIGH WILL GRADUALLY START
TO MODIFY AS IT REACHES THE EAST COAST SATURDAY...INTO THE ATLANTIC
SUNDAY...BEFORE STRETCHING BACK ACROSS OUR AREA MONDAY AND TUESDAY.
DURING THIS TRANSITION A COASTAL TROUGH FORMS OVER THE NEARBY
WATERS...NEAR THE WESTERN WALL OF THE GULF STREAM SATURDAY...BEFORE
IT LIFTS NORTH AND TRANSITIONS INTO A WARM FRONT NORTH OF THE AREA
EARLY NEXT WEEK. THE RETURN FLOW OFF THE ATLANTIC AND THE PROXIMITY
TO THE TROUGH COULD GENERATE A FEW SHOWERS...BUT PROBABILITIES ARE
LOW AT THIS TIME. SATURDAY IS STILL FAR BELOW CLIMATOLOGICAL
NORMS...BUT A WARMING TREND WILL GET UNDERWAY SUNDAY...LEADING TO
WARMER CONDITIONS MONDAY AND TUESDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
KCHS...LIGHT RAINS AND LOW-END MVFR CEILINGS WILL GIVE WAY TO IFR
CONDITIONS AS THE RAIN STARTS TO FREEZE AS TEMPS DROP DURING THE
MID-MORNING. THESE CONDITIONS WILL CONTINUE INTO EARLY
AFTERNOON...BEFORE THE TEMPS RISE A COUPLE OF DEGREES AND THE
PRECIP CHANGES BACK TO RAIN. AS ATLANTIC LOW PRESSURE PULLS AWAY
LATE IN THE DAY AND TONIGHT THE RAIN WILL COME TO AN END. EVEN
SO...ABUNDANT MOISTURE TRAPPED BENEATH A SHARP INVERSION WILL KEEP
IFR CONDITIONS THROUGH 12Z WEDNESDAY.
KSAV...IFR CONDITIONS WILL BE THE RULE AT THE TERMINAL THROUGH 12Z
WEDNESDAY...WITH PLENTY OF MOISTURE CAUGHT UNDERNEATH A SHARP
INVERSION. LIGHT RAINS AND DRIZZLE EARLY IN THE CYCLE WILL BECOME
A STEADY MODERATE RAIN FROM ABOUT 14Z-18Z...BEFORE GRADUALLY
TAPERING OFF DURING MID AFTERNOON AS ATLANTIC LOW PRESSURE PULLS
AWAY.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS OF VARYING
CATEGORIES WILL PREVAIL THE VAST MAJORITY OF THE TIME INTO INTO
THURSDAY OR THURSDAY NIGHT. VFR CONDITIONS SHOULD RETURN FOR FRIDAY
AND SATURDAY.
&&
.MARINE...
TODAY AND TONIGHT...WITH HIGH PRESSURE CENTERED TO THE NORTHEAST
AND AN AREA OF LOW PRESSURE DEVELOPING JUST TO THE EAST...A TIGHT
NORTHEAST PRESSURE GRADIENT WILL BE MAINTAINED. THIS WILL CONTINUE
TO SUPPORT SMALL CRAFT ADVISORY WINDS AND ELEVATED SEAS FOR ALL
WATERS. WINDS WILL BEGIN TO TURN MORE NORTH AND NORTHWESTERLY LATE
THIS AFTERNOON AS THE LOW BEGINS TO PULL AWAY. THE GRADIENT WILL
GRADUALLY RELAX AND THE ONGOING ADVISORIES WILL BE ABLE TO COME
DOWN THROUGH THE AFTERNOON WITH THE LONE EXCEPTION OF THE OUTER
GEORGIA WATERS. OVERNIGHT...CONDITIONS WILL FURTHER IMPROVE WITH
WEAKENING WINDS AND DIMINISHING SEAS.
WEDNESDAY...NOT MUCH IN THE WAY OF WINDS AND SEAS WITH A BUBBLE HIGH
ACROSS THE AREA. BUT THIS IS ONLY TEMPORARY AS CONDITIONS WILL START
TO DETERIORATE TOWARD EVENING AS A DEVELOPING LOW IN THE GULF OF
MEXICO TRACKS EAST.
WEDNESDAY NIGHT AND THURSDAY...THE SURFACE LOW WILL MOVE OVER
NORTHERN FLORIDA OR REFORM IN THE NEARBY ATLANTIC AFTER MIDNIGHT
WEDNESDAY NIGHT...DEPENDING FURTHER AS IT REACHES THE GULF STREAM
WATERS AND LIFTS RAPIDLY NE THEREAFTER. DEPENDING UPON THE EXACT
EVOLUTION OF THE LOW WE/LL LIKELY REQUIRE SMALL CRAFT ADVISORIES
WEDNESDAY NIGHT. THEN WITH COLD ADVECTION BEHIND THE SYSTEM THURSDAY
ADDITIONAL ADVISORIES ARE LIKELY. THERE EXISTS A LOW CHANCE OF SOME
T-STORMS WEDNESDAY NIGHT NEAR THE TRACK OF THE SURFACE LOW. GIVEN
STRONG VERTICAL WIND FIELDS THERE MIGHT BE A FEW STRONG STORMS.
FRIDAY THROUGH SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL BUILD
TO THE NORTH...WHILE A COASTAL TROUGH TAKES SHAPE SATURDAY. THE HIGH
WILL SLIDE INTO THE ATLANTIC SUNDAY AS THE COASTAL TROUGH TRANSFORMS
INTO A NORTHWARD LIFTING WARM FRONT. THERE REMAINS A STRONG GRADIENT
AROUND THE HUGE ANTICYCLONE TO THE NORTH AND SMALL CRAFT ADVISORIES
AGAIN SEEM LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
GAZ088.
SC...FREEZING RAIN ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
SCZ043>045-050-052.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
SCZ040-042.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ330.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
421 AM EST TUE FEB 24 2015
.SYNOPSIS...
DEVELOPING LOW PRESSURE WILL TRACK ALONG AN OFFSHORE STATIONARY FRONT
TODAY. WEAK HIGH PRESSURE ACROSS THE AREA WEDNESDAY WILL GIVE WAY
TO A STRONGER LOW PRESSURE SYSTEM FROM THE GULF OF MEXICO. THAT
SYSTEM WILL THEN TRACK THROUGH EXTREME SOUTHEAST GEORGIA AND
NORTHERN FLORIDA AND THEN OFF THE SOUTHEAST UNITED STATES COAST
WEDNESDAY NIGHT. STRONG AND COLDER CANADIAN HIGH PRESSURE FROM THE
GREAT PLAINS WILL THEN EXPAND TO BECOME THE PRIMARY WEATHER
FEATURE THURSDAY THROUGH SATURDAY. A COASTAL TROUGH WILL FORM JUST
OFFSHORE SUNDAY...BEFORE LIFTING NORTH OF THE REGION AS ATLANTIC
HIGH PRESSURE STRETCHES ACROSS THE LOCAL AREA NEXT MONDAY AND
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...THE PRIMARY FORECAST ISSUE REVOLVES AROUND THE POTENTIAL
FOR A LIGHT FREEZING RAIN EVENT THAT MAY IMPACT A PORTION OF THE
FORECAST AREA. MODEL GUIDANCE HAS TRENDED WARMER WITH TEMPERATURES
FOR THE MORNING AND EARLY AFTERNOON...AND THIS HAS NECESSITATED
SOME CHANGES TO ICE POTENTIAL. THE OVERALL SYNOPTIC SETUP FEATURES
NEARLY ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVE ENERGY MOVING
SWIFTLY EASTWARD INTO THE REGION. PVA AND SOME UPPER DIVERGENCE
ALOFT IS HELPING TO PROVIDE SOME LARGE SCALE SUPPORT IN ADDITION
TO LOW LEVEL FORCING IN FORM OF ISENTROPIC ASCENT. AT THE
SURFACE...1030 MB HIGH PRESSURE IS CURRENTLY SETTLING IN ACROSS
THE MID ATLANTIC AND PROVIDING A NICE COLD AIR DAMMING EVENT AND
SUPPLYING SOME COLD/DRY AIR NEAR THE SURFACE. THE HIGH WILL
QUICKLY RETREAT TO THE NORTHEAST THIS AFTERNOON AS A SURFACE LOW
DEVELOPS ALONG A RESIDUAL STATIONARY FRONT OFF THE SOUTHEAST
COAST. WIDESPREAD PRECIPITATION WILL BREAK OUT ACROSS THE REGION
IN RESPONSE TO THE LOW AND UPPER LEVEL FORCING COINCIDENT WITH
TEMPERATURES IN SOME AREAS FALLING NEAR OR JUST BELOW FREEZING
THIS MORNING AND EARLY THIS AFTERNOON.
AS STATED ABOVE...ALMOST ALL OF THE 24/00Z GUIDANCE HAS TRENDED
WARMER INCLUDING THE HI-RES MODELS SUCH AS THE HRRR AND THE RAP.
THESE RAPID UPDATE MODELS CONTINUE TO DO AN EXCELLENT JOB WITH THE
UPSTREAM PRECIPITATION AS WELL AS HOURLY TEMPERATURES...SO THEY
HAVE BEEN RELIED UPON HEAVILY FOR THE DETAILS OF THE FORECAST.
COLD AND DRY LOW LEVEL AIR WILL FILTER INTO THE FORECAST AREA
BEGINNING AROUND SUNRISE AND CONTINUE THROUGH THE LATE MORNING
BEFORE THE DAMMING HIGH MOVES TO A LESS THAN IDEAL POSITION. AS
PRECIPITATION BREAKS OUT...TEMPERATURES WILL FALL TO NEAR OR BELOW
FREEZING MAINLY ACROSS A CORE PORTION OF COUNTIES INCLUDING
BERKELEY...CHARLESTON...DORCHESTER...AND COLLETON COUNTIES. MORE
MARGINAL FREEZING TEMPERATURES ARE EXPECTED ACROSS
HAMPTON...ALLENDALE...AND SCREVEN COUNTIES. MODEL SOUNDINGS SHOW A
PROMINENT WARM NOSE DEVELOPING OVER THE SHALLOW COLD LAYER SO THE
PREDOMINANT PRECIPITATION TYPE WILL BE FREEZING RAIN. TEMPERATURES
WILL THEN WARM AND THE FREEZING LINE WILL LIFT NORTHWARD LATE THIS
AFTERNOON. THE PEAK TIME FOR FREEZING RAIN WILL ROUGHLY OCCUR FROM
AROUND 7-9 AM AT THE BEGINNING TO AROUND NOON-1PM AT THE END.
ACCRETION WILL OCCUR MAINLY ON ELEVATED SURFACE INCLUDING
BRIDGES...TREES...TREE LIMBS...AND SOME POWER LINES. TOTAL ICE
ACCUMULATIONS WILL RANGE FROM TRACE AMOUNTS UP TO AROUND A TENTH
OF AN INCH. THE HIGHEST AMOUNTS ARE EXPECTED ROUGHLY AROUND MONCKS
CORNER TO SUMMERVILLE AND NEARBY LOCATIONS. TOTAL LIQUID
ACCUMULATION AMOUNTS WILL RANGE FROM AROUND ONE TO TWO TENTHS OF
AN INCH INLAND TO UP TO THREE TENTHS OF A INCH CLOSER TO THE
COAST.
TONIGHT...PRECIPITATION WILL COME TO A CLOSE THIS EVENING AS THE
LOW PULLS AWAY AND FORCING WANES. THE REST OF THE OVERNIGHT WILL
REMAIN MOSTLY CLOUDY WITH CHILLY TEMPERATURES. IN FACT...GIVEN THE
PRECIPITATION THAT WILL FALL DURING THE DAY WE MAY SEE SOME BLACK
ICE ISSUES ESPECIALLY ACROSS THE TRI-COUNTY REGION AS WELL AS
COLLETON COUNTY. FREEZING TEMPERATURES ARE EXPECTED IN THESE AREAS
AND MID TO UPPER 30S IN MOST OTHER AREAS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY...AN INITIALLY STRONG SHORT WAVE MOVING EASTWARD THROUGH
TEXAS AT THE START OF THE PERIOD WILL DAMPEN OUT AS IT TRAVELS
QUICKLY THROUGH THE NORTHERN GULF COAST STATES DURING THE DAY. THIS
FEATURE IS BEING DRIVEN BY A POWERFUL 140 KT UPPER JET AND A 90-100
KT MID LEVEL JET. THIS WILL INDUCE CYCLOGENESIS OVER THE NORTHERN
GULF OF MEXICO AND A DEVELOPING WARM FRONT THAT EXTENDS EAST ACROSS
THE FLORIDA PENINSULA. THIS IS THE OLD BAROCLINIC ZONE THAT WILL
HAVE BEEN TO OUR SOUTH AND SE FROM TODAY. THERE IS A SUBSTANTIAL
POCKET OF DRY AIR EARLY IN THE DAY FROM ABOUT 850-500 MB AND SINKING
MOTION UNDERNEATH A MESO-HIGH THAT IS ATOP THE FORECAST ZONES.
ISENTROPIC ASCENT WILL START TO DEVELOP DURING THE LATER PORTION OF
THE DAY ON VARIOUS LEVELS...AND FORCING FOR ASCENT WILL START TO
OVERSPREAD THE AREA IN ADVANCE OF THE SURFACE LOW AND ITS ASSOCIATED
FEATURES ALOFT. THIS ALLOWS FOR OVER-RUNNING RAINS TO INITIATE
DURING THE AFTERNOON...EXPANDING FROM WEST/SW TO EAST/NE. JUST ABOUT
EVERYWHERE SHOULD BE RAINING BY DARK. QPF WILL RANGE FROM ABOUT 1/10
TO 1/4 INCH IN THE CHARLESTON TRI-COUNTY REGION TO AS MUCH AS 1/2 TO
2/3 INCHES WEST OF SAVANNAH.
THERE WILL LIKELY STILL BE SOME CONCERNS IN REGARDS TO BLACK ICE IN
THE EARLY GOING ACROSS INLAND PARTS OF THE CHARLESTON QUAD-COUNTY
AREA...BUT TEMPS LOOK TO CLIMB ABOVE FREEZING BY 9 AM. CONSIDERABLE
CLOUD COVER AND THE INCREASING COVERAGE OF RAIN WILL BE NEGATED
SLIGHTLY BY SOME WARM ADVECTION...BUT WE/RE RESTRICTED TO BASICALLY
UPPER 40S NORTH TO THE LOWER 50S SOUTH.
WEDNESDAY NIGHT...THE DAMPENING PERTURBATION ALOFT WILL MOVE
DIRECTLY OVERHEAD AROUND 00-06Z...PASSING INTO THE ATLANTIC BY
DAYBREAK THURSDAY. STRONG WIND FIELDS WILL ACCOMPANY THE IMPULSE AND
CAUSES THE GULF SURFACE LOW TO EITHER TRACK THROUGH NORTHERN FLORIDA
OR REDEVELOP OFF THE SE COAST AFTER MIDNIGHT. AN ABUNDANCE OF DEEP
MOISTURE AND LARGE SCALE FORCING FOR ASCENT WILL EQUATE TO PLENTY OF
RAINFALL WITH NEAR 100 POPS ALL SECTIONS THE FIRST HALF OF THE
NIGHT. CHANCES WILL DIMINISH BEHIND THE EXITING SHORT WAVE AND
SURFACE LOW LATE AT NIGHT. AN ADDITIONAL 3/4 TO 1 INCH OF RAIN
WILL OCCUR.
THERE IS AT LEAST A SMALL WINDOW OF OPPORTUNITY FOR VERY WEAK
SURFACE BASED DESTABILIZATION TO OCCUR IN PROXIMITY TO THE SURFACE
LOW. GIVEN THE ASSOCIATED STRONG WIND FIELDS AND WIND SHEAR THERE
MIGHT BE A RISK FOR A FEW T-STORMS TO OCCUR. FOR NOW THOUGH THE
PROBABILITY IS TOO REMOTE TO INCLUDE MENTION IN THE FORECAST.
THURSDAY...WHILE A BROAD CYCLONIC FLOW WILL PREVAIL ALOFT A SUBTLE
TRANSIENT HIGH PRESSURE WEDGE WILL PREVAIL IN WAKE OF THE ATLANTIC
LOW. THE BULK OF THE RAINS WILL HAVE PULLED OFFSHORE IN THE
MORNING...BUT THERE REMAINS A DECENT INVERSION WITHIN THE WEDGE
REGIME TO KEEP CONDITIONS DAMP AND CHILLY. WITHIN A NORTHERLY
SYNOPTIC FLOW...COLD AIR ADVECTION AND PLENTY OF CLOUDS WE/RE
LOOKING AT HIGHS AGAIN NO MORE THAN UPPER 40S AND LOWER 50S. COLD
ADVECTION WILL CONTINUE THURSDAY NIGHT AS THE LEADING EDGE OF
ARCTIC HIGH PRESSURE IN THE GREAT PLAINS FILTERS IN FROM THE NW.
SUB- FREEZING TEMPS ARE ANTICIPATED OVER THE NW TIER.
FRIDAY...A 1042 MB ARCTIC HIGH WILL EXPAND EASTWARD AND COVERS MUCH
OF THE EASTERN HALF OF THE NATION...INCLUDING THE LOCAL REGION. A
CHILLY AND DRY AIR MASS WILL PREVAIL...BUT GIVEN BETTER INSOLATION
THAN RECENT DAYS WE MIGHT BE ABLE TO ADD A COUPLE OF DEGREES ON TO
OUR MAX TEMPS. EVEN SO...WE/RE STILL FAR BELOW NORMAL FOR THE LAST
DAY OF WHAT WILL TURN OUT TO BE A VERY COLD FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
ZONAL FLOW OR FLAT RIDGING WILL EXIST ALOFT LATE IN THE WEEK INTO
EARLY NEXT WEEK. SIMULTANEOUSLY THE ARCTIC HIGH WILL GRADUALLY START
TO MODIFY AS IT REACHES THE EAST COAST SATURDAY...INTO THE ATLANTIC
SUNDAY...BEFORE STRETCHING BACK ACROSS OUR AREA MONDAY AND TUESDAY.
DURING THIS TRANSITION A COASTAL TROUGH FORMS OVER THE NEARBY
WATERS...NEAR THE WESTERN WALL OF THE GULF STREAM SATURDAY...BEFORE
IT LIFTS NORTH AND TRANSITIONS INTO A WARM FRONT NORTH OF THE AREA
EARLY NEXT WEEK. THE RETURN FLOW OFF THE ATLANTIC AND THE PROXIMITY
TO THE TROUGH COULD GENERATE A FEW SHOWERS...BUT PROBABILITIES ARE
LOW AT THIS TIME. SATURDAY IS STILL FAR BELOW CLIMATOLOGICAL
NORMS...BUT A WARMING TREND WILL GET UNDERWAY SUNDAY...LEADING TO
WARMER CONDITIONS MONDAY AND TUESDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
KCHS...VFR CONDITIONS WILL BE SHORT-LIVED AS ABUNDANT LOW LEVEL
MOISTURE WILL RESULT IN CEILINGS LOWERING TO MVFR LEVELS BY 09Z.
SOME DRIZZLE OR ISOLATED LIGHT SHOWERS WILL THEN DEVELOP LATE
TONIGHT...BUT PRECIPITATION WILL NOT PICK UP IN INTENSITY UNTIL
AFTER 14Z WHICH IS WHEN CEILINGS WILL LOWER IFR LEVELS AND
VISIBILITIES BECOME REDUCED. IT APPEARS THAT SURFACE TEMPERATURES
WILL BE NEAR FREEZING FROM ABOUT 14-18Z...THUS FREEZING RAIN IS
INCLUDED IN THE FORECAST DURING THIS TIME. AS TEMPERATURES WARM
AFTER 18Z...THE THREAT FOR FREEZING RAIN WILL END BUT RAIN WILL
CONTINUE AT THE TERMINAL THROUGH ABOUT 23Z. IFR CONDITIONS DUE TO
LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z WEDNESDAY.
KSAV...ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN MVFR CEILINGS AT
THE START OF THE FORECAST PERIOD. SOME DRIZZLE OR ISOLATED LIGHT
SHOWERS WILL THEN DEVELOP LATE TONIGHT...BUT PRECIPITATION WILL NOT
PICK UP IN INTENSITY UNTIL AFTER 14Z WHICH IS WHEN CEILINGS WILL
LOWER IFR LEVELS AND VISIBILITIES BECOME REDUCED. TEMPERATURES WILL
REMAIN ABOVE FREEZING...THUS NO POTENTIAL FOR ANY FREEZING RAIN TO
OCCUR. RAIN WILL CONTINUE AT THE TERMINAL THROUGH ABOUT 22Z. IFR
CONDITIONS DUE TO LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z
WEDNESDAY.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS OF VARYING
CATEGORIES WILL PREVAIL THE VAST MAJORITY OF THE TIME INTO INTO
THURSDAY OR THURSDAY NIGHT. VFR CONDITIONS SHOULD RETURN FOR FRIDAY
AND SATURDAY.
&&
.MARINE...
TODAY AND TONIGHT...WITH HIGH PRESSURE CENTERED TO THE NORTHEAST
AND AN AREA OF LOW PRESSURE DEVELOPING JUST TO THE EAST...A TIGHT
NORTHEAST PRESSURE GRADIENT WILL BE MAINTAINED. THIS WILL CONTINUE
TO SUPPORT SMALL CRAFT ADVISORY WINDS AND ELEVATED SEAS FOR ALL
WATERS. WINDS WILL BEGIN TO TURN MORE NORTH AND NORTHWESTERLY LATE
THIS AFTERNOON AS THE LOW BEGINS TO PULL AWAY. THE GRADIENT WILL
GRADUALLY RELAX AND THE ONGOING ADVISORIES WILL BE ABLE TO COME
DOWN THROUGH THE AFTERNOON WITH THE LONE EXCEPTION OF THE OUTER
GEORGIA WATERS. OVERNIGHT...CONDITIONS WILL FURTHER IMPROVE WITH
WEAKENING WINDS AND DIMINISHING SEAS.
WEDNESDAY...NOT MUCH IN THE WAY OF WINDS AND SEAS WITH A BUBBLE HIGH
ACROSS THE AREA. BUT THIS IS ONLY TEMPORARY AS CONDITIONS WILL START
TO DETERIORATE TOWARD EVENING AS A DEVELOPING LOW IN THE GULF OF
MEXICO TRACKS EAST.
WEDNESDAY NIGHT AND THURSDAY...THE SURFACE LOW WILL MOVE OVER
NORTHERN FLORIDA OR REFORM IN THE NEARBY ATLANTIC AFTER MIDNIGHT
WEDNESDAY NIGHT...DEPENDING FURTHER AS IT REACHES THE GULF STREAM
WATERS AND LIFTS RAPIDLY NE THEREAFTER. DEPENDING UPON THE EXACT
EVOLUTION OF THE LOW WE/LL LIKELY REQUIRE SMALL CRAFT ADVISORIES
WEDNESDAY NIGHT. THEN WITH COLD ADVECTION BEHIND THE SYSTEM THURSDAY
ADDITIONAL ADVISORIES ARE LIKELY. THERE EXISTS A LOW CHANCE OF SOME
T-STORMS WEDNESDAY NIGHT NEAR THE TRACK OF THE SURFACE LOW. GIVEN
STRONG VERTICAL WIND FIELDS THERE MIGHT BE A FEW STRONG STORMS.
FRIDAY THROUGH SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL BUILD
TO THE NORTH...WHILE A COASTAL TROUGH TAKES SHAPE SATURDAY. THE HIGH
WILL SLIDE INTO THE ATLANTIC SUNDAY AS THE COASTAL TROUGH TRANSFORMS
INTO A NORTHWARD LIFTING WARM FRONT. THERE REMAINS A STRONG GRADIENT
AROUND THE HUGE ANTICYCLONE TO THE NORTH AND SMALL CRAFT ADVISORIES
AGAIN SEEM LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR GAZ088.
SC...FREEZING RAIN ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
SCZ043>045-050-052.
FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR SCZ040-042.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ330.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...BSH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
354 AM EST TUE FEB 24 2015
.SYNOPSIS...
DEVELOPING LOW PRESSURE WILL TRACK ALONG AN OFFSHORE STATIONARY FRONT
TODAY. WEAK HIGH PRESSURE ACROSS THE AREA WEDNESDAY WILL GIVE WAY
TO A STRONGER LOW PRESSURE SYSTEM FROM THE GULF OF MEXICO. THAT
SYSTEM WILL THEN TRACK THROUGH EXTREME SOUTHEAST GEORGIA AND
NORTHERN FLORIDA AND THEN OFF THE SOUTHEAST UNITED STATES COAST
WEDNESDAY NIGHT. STRONG AND COLDER CANADIAN HIGH PRESSURE FROM THE
GREAT PLAINS WILL THEN EXPAND TO BECOME THE PRIMARY WEATHER
FEATURE THURSDAY THROUGH SATURDAY. A COASTAL TROUGH WILL FORM JUST
OFFSHORE SUNDAY...BEFORE LIFTING NORTH OF THE REGION AS ATLANTIC
HIGH PRESSURE STRETCHES ACROSS THE LOCAL AREA NEXT MONDAY AND
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...THE PRIMARY FORECAST ISSUE REVOLVES AROUND THE POTENTIAL
FOR A LIGHT FREEZING RAIN EVENT THAT MAY IMPACT A PORTION OF THE
FORECAST AREA. MODEL GUIDANCE HAS TRENDED WARMER WITH TEMPERATURES
FOR THE MORNING AND EARLY AFTERNOON...AND THIS HAS NECESSITATED
SOME CHANGES TO ICE POTENTIAL. THE OVERALL SYNOPTIC SETUP FEATURES
NEARLY ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVE ENERGY MOVING
SWIFTLY EASTWARD INTO THE REGION. PVA AND SOME UPPER DIVERGENCE
ALOFT IS HELPING TO PROVIDE SOME LARGE SCALE SUPPORT IN ADDITION
TO LOW LEVEL FORCING IN FORM OF ISENTROPIC ASCENT. AT THE
SURFACE...1030 MB HIGH PRESSURE IS CURRENTLY SETTLING IN ACROSS
THE MID ATLANTIC AND PROVIDING A NICE COLD AIR DAMMING EVENT AND
SUPPLYING SOME COLD/DRY AIR NEAR THE SURFACE. THE HIGH WILL
QUICKLY RETREAT TO THE NORTHEAST THIS AFTERNOON AS A SURFACE LOW
DEVELOPS ALONG A RESIDUAL STATIONARY FRONT OFF THE SOUTHEAST
COAST. WIDESPREAD PRECIPITATION WILL BREAK OUT ACROSS THE REGION
IN RESPONSE TO THE LOW AND UPPER LEVEL FORCING COINCIDENT WITH
TEMPERATURES IN SOME AREAS FALLING NEAR OR JUST BELOW FREEZING
THIS MORNING AND EARLY THIS AFTERNOON.
AS STATED ABOVE...ALMOST ALL OF THE 24/00Z GUIDANCE HAS TRENDED
WARMER INCLUDING THE HI-RES MODELS SUCH AS THE HRRR AND THE RAP.
THESE RAPID UPDATE MODELS CONTINUE TO DO AN EXCELLENT JOB WITH THE
UPSTREAM PRECIPITATION AS WELL AS HOURLY TEMPERATURES...SO THEY
HAVE BEEN RELIED UPON HEAVILY FOR THE DETAILS OF THE FORECAST.
COLD AND DRY LOW LEVEL AIR WILL FILTER INTO THE FORECAST AREA
BEGINNING AROUND SUNRISE AND CONTINUE THROUGH THE LATE MORNING
BEFORE THE DAMMING HIGH MOVES TO A LESS THAN IDEAL POSITION. AS
PRECIPITATION BREAKS OUT...TEMPERATURES WILL FALL TO NEAR OR BELOW
FREEZING MAINLY ACROSS A CORE PORTION OF COUNTIES INCLUDING
BERKELEY...CHARLESTON...DORCHESTER...AND COLLETON COUNTIES. MORE
MARGINAL FREEZING TEMPERATURES ARE EXPECTED ACROSS
HAMPTON...ALLENDALE...AND SCREVEN COUNTIES. MODEL SOUNDINGS SHOW A
PROMINENT WARM NOSE DEVELOPING OVER THE SHALLOW COLD LAYER SO THE
PREDOMINANT PRECIPITATION TYPE WILL BE FREEZING RAIN. TEMPERATURES
WILL THEN WARM AND THE FREEZING LINE WILL LIFT NORTHWARD LATE THIS
AFTERNOON. THE PEAK TIME FOR FREEZING RAIN WILL ROUGHLY OCCUR FROM
AROUND 7-9 AM AT THE BEGINNING TO AROUND NOON-1PM AT THE END.
ACCRETION WILL OCCUR MAINLY ON ELEVATED SURFACE INCLUDING
BRIDGES...TREES...TREE LIMBS...AND SOME POWER LINES. TOTAL ICE
ACCUMULATIONS WILL RANGE FROM TRACE AMOUNTS UP TO AROUND A TENTH
OF AN INCH. THE HIGHEST AMOUNTS ARE EXPECTED ROUGHLY AROUND MONCKS
CORNER TO SUMMERVILLE AND NEARBY LOCATIONS. TOTAL LIQUID
ACCUMULATION AMOUNTS WILL RANGE FROM AROUND ONE TO TWO TENTHS OF
AN INCH INLAND TO UP TO THREE TENTHS OF A INCH CLOSER TO THE
COAST.
TONIGHT...PRECIPITATION WILL COME TO A CLOSE THIS EVENING AS THE
LOW PULLS AWAY AND FORCING WANES. THE REST OF THE OVERNIGHT WILL
REMAIN MOSTLY CLOUDY WITH CHILLY TEMPERATURES. IN FACT...GIVEN THE
PRECIPITATION THAT WILL FALL DURING THE DAY WE MAY SEE SOME BLACK
ICE ISSUES ESPECIALLY ACROSS THE TRI-COUNTY REGION AS WELL AS
COLLETON COUNTY. FREEZING TEMPERATURES ARE EXPECTED IN THESE AREAS
AND MID TO UPPER 30S IN MOST OTHER AREAS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY...AN INITIALLY STRONG SHORT WAVE MOVING EASTWARD THROUGH
TEXAS AT THE START OF THE PERIOD WILL DAMPEN OUT AS IT TRAVELS
QUICKLY THROUGH THE NORTHERN GULF COAST STATES DURING THE DAY. THIS
FEATURE IS BEING DRIVEN BY A POWERFUL 140 KT UPPER JET AND A 90-100
KT MID LEVEL JET. THIS WILL INDUCE CYCLOGENESIS OVER THE NORTHERN
GULF OF MEXICO AND A DEVELOPING WARM FRONT THAT EXTENDS EAST ACROSS
THE FLORIDA PENINSULA. THIS IS THE OLD BAROCLINIC ZONE THAT WILL
HAVE BEEN TO OUR SOUTH AND SE FROM TODAY. THERE IS A SUBSTANTIAL
POCKET OF DRY AIR EARLY IN THE DAY FROM ABOUT 850-500 MB AND SINKING
MOTION UNDERNEATH A MESO-HIGH THAT IS ATOP THE FORECAST ZONES.
ISENTROPIC ASCENT WILL START TO DEVELOP DURING THE LATER PORTION OF
THE DAY ON VARIOUS LEVELS...AND FORCING FOR ASCENT WILL START TO
OVERSPREAD THE AREA IN ADVANCE OF THE SURFACE LOW AND ITS ASSOCIATED
FEATURES ALOFT. THIS ALLOWS FOR OVER-RUNNING RAINS TO INITIATE
DURING THE AFTERNOON...EXPANDING FROM WEST/SW TO EAST/NE. JUST ABOUT
EVERYWHERE SHOULD BE RAINING BY DARK. QPF WILL RANGE FROM ABOUT 1/10
TO 1/4 INCH IN THE CHARLESTON TRI-COUNTY REGION TO AS MUCH AS 1/2 TO
2/3 INCHES WEST OF SAVANNAH.
THERE WILL LIKELY STILL BE SOME CONCERNS IN REGARDS TO BLACK ICE IN
THE EARLY GOING ACROSS INLAND PARTS OF THE CHARLESTON QUAD-COUNTY
AREA...BUT TEMPS LOOK TO CLIMB ABOVE FREEZING BY 9 AM. CONSIDERABLE
CLOUD COVER AND THE INCREASING COVERAGE OF RAIN WILL BE NEGATED
SLIGHTLY BY SOME WARM ADVECTION...BUT WE/RE RESTRICTED TO BASICALLY
UPPER 40S NORTH TO THE LOWER 50S SOUTH.
WEDNESDAY NIGHT...THE DAMPENING PERTURBATION ALOFT WILL MOVE
DIRECTLY OVERHEAD AROUND 00-06Z...PASSING INTO THE ATLANTIC BY
DAYBREAK THURSDAY. STRONG WIND FIELDS WILL ACCOMPANY THE IMPULSE AND
CAUSES THE GULF SURFACE LOW TO EITHER TRACK THROUGH NORTHERN FLORIDA
OR REDEVELOP OFF THE SE COAST AFTER MIDNIGHT. AN ABUNDANCE OF DEEP
MOISTURE AND LARGE SCALE FORCING FOR ASCENT WILL EQUATE TO PLENTY OF
RAINFALL WITH NEAR 100 POPS ALL SECTIONS THE FIRST HALF OF THE
NIGHT. CHANCES WILL DIMINISH BEHIND THE EXITING SHORT WAVE AND
SURFACE LOW LATE AT NIGHT.
THERE IS AT LEAST A SMALL WINDOW OF OPPORTUNITY FOR VERY WEAK
SURFACE BASED DESTABILIZATION TO OCCUR IN PROXIMITY TO THE SURFACE
LOW. GIVEN THE ASSOCIATED STRONG WIND FIELDS AND WIND SHEAR THERE
MIGHT BE A RISK FOR A FEW T-STORMS TO OCCUR. FOR NOW THOUGH THE
PROBABILITY IS TOO REMOTE TO INCLUDE MENTION IN THE FORECAST.
THURSDAY...WHILE A BROAD CYCLONIC FLOW WILL PREVAIL ALOFT A SUBTLE
TRANSIENT HIGH PRESSURE WEDGE WILL PREVAIL IN WAKE OF THE ATLANTIC
LOW. THE BULK OF THE RAINS WILL HAVE PULLED OFFSHORE IN THE
MORNING...BUT THERE REMAINS A A DECENT INVERSION WITHIN THE WEDGE
REGIME TO KEEP CONDITIONS DAMP AND CHILLY. WITHIN A NORTHERLY
SYNOPTIC FLOW...COLD AIR ADVECTION AND PLENTY OF CLOUDS WE/RE
LOOKING AT HIGHS AGAIN NO MORE THAN UPPER 40S AND LOWER 50S. COLD
ADVECTION WILL CONTINUE THURSDAY NIGHT AS THE LEADING EDGE OF ARCTIC
HIGH PRESSURE IN THE GREAT PLAINS FILTERS IN FROM THE NW. SUB-
FREEZING TEMPS ARE ANTICIPATED OVER THE NW TIER.
FRIDAY...A 1042 MB ARCTIC HIGH WILL EXPAND EASTWARD AND COVERS MUCH
OF THE EASTERN HALF OF THE NATION...INCLUDING THE LOCAL REGION. A
CHILLY AND DRY AIR MASS WILL PREVAIL...BUT GIVEN BETTER INSOLATION
THAN RECENT DAYS WE MIGHT BE ABLE TO ADD A COUPLE OF DEGREES ON TO
OUR MAX TEMPS. EVEN SO...WE/RE STILL FAR BELOW NORMAL FOR THE LAST
DAY OF WHAT WILL TURN OUT TO BE A VERY COLD FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
ZONAL FLOW OR FLAT RIDGING WILL EXIST ALOFT LATE IN THE WEEK INTO
EARLY NEXT WEEK. SIMULTANEOUSLY THE ARCTIC HIGH WILL GRADUALLY START
TO MODIFY AS IT REACHES THE EAST COAST SATURDAY...INTO THE ATLANTIC
SUNDAY...BEFORE STRETCHING BACK ACROSS OUR AREA MONDAY AND TUESDAY.
DURING THIS TRANSITION A COASTAL TROUGH FORMS OVER THE NEARBY
WATERS...NEAR THE WESTERN WALL OF THE GULF STREAM SATURDAY...BEFORE
IT LIFTS NORTH AND TRANSITIONS INTO A WARM FRONT NORTH OF THE AREA
EARLY NEXT WEEK. THE RETURN FLOW OFF THE ATLANTIC AND THE PROXIMITY
TO THE TROUGH COULD GENERATE A FEW SHOWERS...BUT PROBABILITIES ARE
LOW AT THIS TIME. SATURDAY IS STILL FAR BELOW CLIMATOLOGICAL
NORMS...BUT A WARMING TREND WILL GET UNDERWAY SUNDAY...LEADING TO
WARMER CONDITIONS MONDAY AND TUESDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
KCHS...VFR CONDITIONS WILL BE SHORT-LIVED AS ABUNDANT LOW LEVEL
MOISTURE WILL RESULT IN CEILINGS LOWERING TO MVFR LEVELS BY 09Z.
SOME DRIZZLE OR ISOLATED LIGHT SHOWERS WILL THEN DEVELOP LATE
TONIGHT...BUT PRECIPITATION WILL NOT PICK UP IN INTENSITY UNTIL
AFTER 14Z WHICH IS WHEN CEILINGS WILL LOWER IFR LEVELS AND
VISIBILITIES BECOME REDUCED. IT APPEARS THAT SURFACE TEMPERATURES
WILL BE NEAR FREEZING FROM ABOUT 14-18Z...THUS FREEZING RAIN IS
INCLUDED IN THE FORECAST DURING THIS TIME. AS TEMPERATURES WARM
AFTER 18Z...THE THREAT FOR FREEZING RAIN WILL END BUT RAIN WILL
CONTINUE AT THE TERMINAL THROUGH ABOUT 23Z. IFR CONDITIONS DUE TO
LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z WEDNESDAY.
KSAV...ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN MVFR CEILINGS AT
THE START OF THE FORECAST PERIOD. SOME DRIZZLE OR ISOLATED LIGHT
SHOWERS WILL THEN DEVELOP LATE TONIGHT...BUT PRECIPITATION WILL NOT
PICK UP IN INTENSITY UNTIL AFTER 14Z WHICH IS WHEN CEILINGS WILL
LOWER IFR LEVELS AND VISIBILITIES BECOME REDUCED. TEMPERATURES WILL
REMAIN ABOVE FREEZING...THUS NO POTENTIAL FOR ANY FREEZING RAIN TO
OCCUR. RAIN WILL CONTINUE AT THE TERMINAL THROUGH ABOUT 22Z. IFR
CONDITIONS DUE TO LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z
WEDNESDAY.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS OF VARYING
CATEGORIES WILL PREVAIL THE VAST MAJORITY OF THE TIME INTO INTO
THURSDAY OR THURSDAY NIGHT. VFR CONDITIONS SHOULD RETURN FOR FRIDAY
AND SATURDAY.
&&
.MARINE...
TODAY AND TONIGHT...WITH HIGH PRESSURE CENTERED TO THE NORTHEAST
AND AN AREA OF LOW PRESSURE DEVELOPING JUST TO THE EAST...A TIGHT
NORTHEAST PRESSURE GRADIENT WILL BE MAINTAINED. THIS WILL CONTINUE
TO SUPPORT SMALL CRAFT ADVISORY WINDS AND ELEVATED SEAS FOR ALL
WATERS. WINDS WILL BEGIN TO TURN MORE NORTH AND NORTHWESTERLY LATE
THIS AFTERNOON AS THE LOW BEGINS TO PULL AWAY. THE GRADIENT WILL
GRADUALLY RELAX AND THE ONGOING ADVISORIES WILL BE ABLE TO COME
DOWN THROUGH THE AFTERNOON WITH THE LONE EXCEPTION OF THE OUTER
GEORGIA WATERS. OVERNIGHT...CONDITIONS WILL FURTHER IMPROVE WITH
WEAKENING WINDS AND DIMINISHING SEAS.
WEDNESDAY...NOT MUCH IN THE WAY OF WINDS AND SEAS WITH A BUBBLE HIGH
ACROSS THE AREA. BUT THIS IS ONLY TEMPORARY AS CONDITIONS WILL START
TO DETERIORATE TOWARD EVENING AS A DEVELOPING LOW IN THE GULF OF
MEXICO TRACKS EAST.
WEDNESDAY NIGHT AND THURSDAY...THE SURFACE LOW WILL MOVE OVER
NORTHERN FLORIDA OR REFORM IN THE NEARBY ATLANTIC AFTER MIDNIGHT
WEDNESDAY NIGHT...DEPENDING FURTHER AS IT REACHES THE GULF STREAM
WATERS AND LIFTS RAPIDLY NE THEREAFTER. DEPENDING UPON THE EXACT
EVOLUTION OF THE LOW WE/LL LIKELY REQUIRE SMALL CRAFT ADVISORIES
WEDNESDAY NIGHT. THEN WITH COLD ADVECTION BEHIND THE SYSTEM THURSDAY
ADDITIONAL ADVISORIES ARE LIKELY. THERE EXISTS A LOW CHANCE OF SOME
T-STORMS WEDNESDAY NIGHT NEAR THE TRACK OF THE SURFACE LOW. GIVEN
STRONG VERTICAL WIND FIELDS THERE MIGHT BE A FEW STRONG STORMS.
FRIDAY THROUGH SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL BUILD
TO THE NORTH...WHILE A COASTAL TROUGH TAKES SHAPE SATURDAY. THE HIGH
WILL SLIDE INTO THE ATLANTIC SUNDAY AS THE COASTAL TROUGH TRANSFORMS
INTO A NORTHWARD LIFTING WARM FRONT. THERE REMAINS A STRONG GRADIENT
AROUND THE HUGE ANTICYCLONE TO THE NORTH AND SMALL CRAFT ADVISORIES
AGAIN SEEM LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR GAZ088.
SC...FREEZING RAIN ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
SCZ043>045-050-052.
FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR SCZ040-042.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ330.
&&
$$
NEAR TERM...BSH
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...BSH
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
207 AM EST TUE FEB 24 2015
.SYNOPSIS...
A COLD FRONT WILL STALL SOUTH OF THE AREA TONIGHT. DEVELOPING LOW
PRESSURE WILL TRACK ALONG THE STATIONARY FRONT TUESDAY. HIGH PRESSURE
WILL BRIEFLY BUILD IN TUESDAY NIGHT INTO EARLY WEDNESDAY...FOLLOWED
BY STRONGER LOW PRESSURE FROM THE GULF OF MEXICO THAT TRACKS
THROUGH SOUTHEAST GEORGIA AND NORTHERN FLORIDA AND THEN OFF THE
SOUTHEAST UNITED STATES COAST WEDNESDAY NIGHT. STRONG HIGH
PRESSURE CENTERED NORTH OF THE AREA WILL THEN EXPAND TO BECOME THE
PRIMARY WEATHER FEATURE LATE IN THE WEEK INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY THIS MORNING...SOME NOTEWORTHY CHANGES HAVE BEEN MADE TO THE
FORECAST FOR THE IMPENDING WINTER WEATHER EVENT BASED ON TRENDS IN
RECENT MODEL GUIDANCE. OVERALL...MODEL GUIDANCE HAS TRENDED WARMER
WITH TEMPERATURES...WETTER WITH PRECIPITATION AMOUNTS...AND LATER
WITH THE ONSET OF PRECIPITATION AFTER SUNRISE. THE WARMING TREND
IS MOST NOTICEABLE ON THE SOUTHERN PERIPHERY OF THE ONGOING
FREEZING RAIN ADVISORY. VIRTUALLY EVERY MODEL AND GUIDANCE SOURCE
FEATURES SOME DEGREE OF A WARMING TREND AND OVERALL CONFIDENCE IN
THESE CHANGES IS HIGH. ALSO...BASED ON CURRENT RADAR TRENDS AND
FOLLOWING THE RECENT RUNS OF THE HRRR AND RAP WHICH SEEM TO HAVE
THE BEST HANDLE ON THE EVOLUTION OF UPSTREAM PRECIPITATION...IT
APPEARS THAT RAIN CHANCES DO NOT REALLY RAMP UP UNTIL AFTER
SUNRISE AND MORE INTO THE MID MORNING HOURS. AS SUCH THE FOLLOWING
COUNTIES HAVE BEEN DROPPED FROM THE ADVISORY
INCLUDING...JENKINS...JASPER...BEAUFORT...AND COASTAL COLLETON.
INSTEAD...THE FOCUS FOR FREEZING RAIN AND POSSIBLE ICE ACCRETION
IS ACROSS A CORE AREA THAT STRETCHES ROUGHLY FROM
BERKELEY...ACROSS NORTHERN CHARLESTON...DORCHESTER...AND COLLETON
COUNTIES. FURTHER TO THE WEST...AMOUNTS LOOK TO BE TRACE AMOUNTS
FOR THE MOST PART. PRECIPITATION WILL DIMINISH IN THE AFTERNOON
AND THE MAIN TIME PERIOD FOR FREEZING RAIN WILL BE FROM AROUND 7
AM TO 1 PM IN THE CORE OF THE COLD AIR.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
TUESDAY NIGHT...SURFACE LOW PRESSURE OFFSHORE WILL BE MOVING
FARTHER OFFSHORE BRINGING AN END TO ANY LIGHT PRECIPITATION. THE
MAIN CONCERN IS TEMPERATURES FALLING TO FREEZING ACROSS MAINLY
JUST INTERIOR PORTIONS OF SOUTHEAST SC...GENERALLY NORTH AND WEST
OF A LINE FROM AROUND MCCLELLANVILLE TO CHARLESTON TO WALTERBORO.
THIS COULD LEAD TO SOME BLACK ICE AS ANY WET ROADWAYS COULD
FREEZE. ELSEWHERE LOWS SHOULD BE IN THE MID TO UPPER 30S...EXCEPT
CLOSER TO 40 ALONG THE GA COAST.
WEDNESDAY AND WEDNESDAY NIGHT...EXPECT A CHILLY BUT DRY START TO THE
DAY WITH WEAK HIGH PRESSURE DOMINATING. AM CONCERNED THERE COULD BE
A LITTLE BLACK ICE ACROSS INTERIOR SC AROUND DAYBREAK BUT THEN TEMPS
LOOK TO WARM ABOVE FREEZING TO NEAR 50 DEGREES AHEAD OF A DEEPENING
LOW PRESSURE SYSTEM MOVING TOWARD THE AREA FROM THE NORTHERN GULF OF
MEXICO WHICH SHOULD TRACK THROUGH SOUTHEAST GEORGIA AND/OR NORTHERN
FLORIDA AND OFF THE SOUTHEAST US COAST WEDNESDAY NIGHT. PLENTY OF
DEEP MOISTURE AND LARGE SCALE LIFT WILL LEAD TO STEADY RAINFALL
OVERSPREADING THE AREA LATE WEDNESDAY FROM WEST TO EAST...CONTINUING
INTO THE FIRST PART OF WEDNESDAY NIGHT AND THEN TAPERING OFF FROM
WEST TO EAST TOWARD DAYBREAK THURSDAY...POSSIBLY ENDING AS SOME
DRIZZLE. TEMPERATURES WILL BE FALLING WEDNESDAY NIGHT BUT SHOULD
REMAIN ABOVE FREEZING SO NO FROZEN PRECIPITATION/BLACK ICE ISSUES
ARE ANTICIPATED. RAINFALL AMOUNTS LOOK TO BE AROUND AN INCH TO AN
INCH AND A HALF THIS PERIOD.
THURSDAY...DEEPER MOISTURE WILL BE OFFSHORE ALTHOUGH SOME LINGERING
LOW-LEVEL MOISTURE COULD KEEP SOME LIGHT RAIN/DRIZZLE
AROUND...ESPECIALLY NEAR THE COAST. TEMPERATURES WILL BE WELL BELOW
NORMAL...ONLY TOPPING OUT IN THE MID TO UPPER 40S AROUND CHARLESTON
RANGING FROM THE LOWER 50S OVER SOUTHEAST GEORGIA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A HUMONGOUS AND ROBUST 1040 MB CANADIAN HIGH BUILDING OUT OF THE
GREAT PLAINS WILL EXPAND EAST AND SOUTH AND COVERS MUCH OF THE
NATION EAST OF THE ROCKIES...INCLUDING THE LOCAL AREA. THIS LEADS TO
DRY AND CHILLY CONDITIONS INTO FRIDAY...BEFORE THE HIGH SHIFTS INTO
THE ATLANTIC OVER THE WEEKEND AND EARLY NEXT WEEK AND TEMPS BEGIN TO
MODERATE. A COASTAL TROUGH WILL LIKELY FORM DURING THIS TRANSITION
JUST OFF OUR COAST...AND WE LOOK FOR AT LEAST A SMALL CHANCE OF
SHOWERS IN RESPONSE.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
KCHS...VFR CONDITIONS WILL BE SHORT-LIVED AS ABUNDANT LOW LEVEL
MOISTURE WILL RESULT IN CEILINGS LOWERING TO MVFR LEVELS BY 09Z.
SOME DRIZZLE OR ISOLATED LIGHT SHOWERS WILL THEN DEVELOP LATE
TONIGHT...BUT PRECIPITATION WILL NOT PICK UP IN INTENSITY UNTIL
AFTER 14Z WHICH IS WHEN CEILINGS WILL LOWER IFR LEVELS AND
VISIBILITIES BECOME REDUCED. IT APPEARS THAT SURFACE TEMPERATURES
WILL BE NEAR FREEZING FROM ABOUT 14-18Z...THUS FREEZING RAIN IS
INCLUDED IN THE FORECAST DURING THIS TIME. AS TEMPERATURES WARM
AFTER 18Z...THE THREAT FOR FREEZING RAIN WILL END BUT RAIN WILL
CONTINUE AT THE TERMINAL THROUGH ABOUT 23Z. IFR CONDITIONS DUE TO
LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z WEDNESDAY.
KSAV...ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN MVFR CEILINGS AT
THE START OF THE FORECAST PERIOD. SOME DRIZZLE OR ISOLATED LIGHT
SHOWERS WILL THEN DEVELOP LATE TONIGHT...BUT PRECIPITATION WILL NOT
PICK UP IN INTENSITY UNTIL AFTER 14Z WHICH IS WHEN CEILINGS WILL
LOWER IFR LEVELS AND VISIBILITIES BECOME REDUCED. TEMPERATURES WILL
REMAIN ABOVE FREEZING...THUS NO POTENTIAL FOR ANY FREEZING RAIN TO
OCCUR. RAIN WILL CONTINUE AT THE TERMINAL THROUGH ABOUT 22Z. IFR
CONDITIONS DUE TO LOW CEILINGS WILL THEN PREVAIL THROUGH 06Z
WEDNESDAY.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS OF VARYING
CATEGORIES WILL CONTINUE MUCH OF THE TIME INTO THURSDAY...ALTHOUGH
INTERLUDES OF VFR ARE POSSIBLE BETWEEN RAIN EVENTS.
&&
.MARINE...
MAINTAINED SCAS FOR ALL WATERS TONIGHT INTO TUESDAY TO ADDRESS
A SURGE OF COLD ADVECTION/INCREASED MARINE LAYER INSTABILITY.
WINDS WILL GUST 25-30 KTS AND SEAS WILL RANGE FROM AS HIGH AS 6-7
FT WITHIN NEARSHORE WATERS TO 8-9 FT BEYOND 20 NM.
WHILE WE CAN/T RULE OUT A LITTLE FREEZING RAIN IN CHARLESTON
HARBOR TUESDAY...FREEZING RAIN IS MORE LIKELY JUST INLAND.
TUESDAY NIGHT THROUGH SATURDAY...IMPROVING CONDITIONS TUE NIGHT/WED
AS LOW PRESSURE MOVES FARTHER AWAY...THEN CONDITIONS WILL GO BACK
DOWNHILL LATE WEDNESDAY INTO THURSDAY AS STRENGTHENING LOW PRESSURE
ALONG THE GULF COAST TRACKS THROUGH SOUTHEAST GEORGIA AND THE NEARBY
COASTAL WATERS. SMALL CRAFT ADVISORIES ARE AGAIN LIKELY DURING THIS
PERIOD. STRENGTHENING HIGH PRESSURE LATE IN THE WEEK WILL THEN
MAINTAIN POOR CONDITIONS WITH ADVISORIES LIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR GAZ088.
SC...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM
EST THIS AFTERNOON FOR SCZ043>045-050-052.
FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 2 PM EST THIS
AFTERNOON FOR SCZ040-042.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ330.
&&
$$
NEAR TERM...BSH
SHORT TERM...RJB
LONG TERM...
AVIATION...JAQ/RJB
MARINE...RJB/SPR
AREA FORECAST DISCUSSION...DELAYED
NWS JACKSON KY
919 PM EST WED FEB 25 2015
.UPDATE...
ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 735 PM EST WED FEB 25 2015
EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE FIRST PART OF THE
TAF PERIOD. LOOK FOR HIGH CIGS TO DROP TOWARD MVFR BY 02Z IN THE
FAR SOUTH AND BETWEEN 4Z AND 8Z AT THE TAF SITES AS SNOW MOVES
INTO THE AREA FROM THE SOUTH...AS THE ATMOSPHERE SATURATES...CIGS
AND OR VIS OF IFR OR LOWER WILL BE POSSIBLE FOR A FEW HOURS.
THESE LOWER CIGS WILL ACCOMPANY THE NORTHERN FRINGE OF A
SIGNIFICANT WINTER STORM SYSTEM PASSING THROUGH THE SOUTHEAST
PARTS OF THE NATION BRINGING A PERIOD OF SNOW TO THE AREA. THE
HEAVIEST AND HARDEST OF THE SNOW SHOULD FALL SOUTHEAST OF
SME...LOZ...JKL AND SJS. SYM WILL BE LEAST AFFECTED. THE SNOW
WILL TAPER OFF AND CIGS WILL START TO IMPROVE 11Z TO 16Z. WINDS
WILL BE LIGHT AND VARIABLE THROUGH LATE EVENING FOR MOST PLACES
BEFORE SWITCHING TO THE NORTHEAST AND NORTH AT BETWEEN 5 AND 10
KTS 10Z TO 16Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR KYZ079-080-
083>088-107-109-110-112>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
1239 PM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 1052 AM EST TUE FEB 24 2015
HAVE MADE A FEW TWEAKS TO THE FORECAST GRIDS THROUGH AROUND NOON
TODAY. RADAR IMAGERY HAS SHOWN QUITE CLEARLY OVER THE PAST HOUR OR
SO THAT PREVIOUSLY FORECASTED SNOWFALL HAS BEEN OCCURRING A BIT
FURTHER NORTH AND WEST THAT ANTICIPATED. THEREFORE...MODIFIED THE
GRIDS FOR PRECIPITATION PROBABILITIES...QPF...SNOWFALL AMTS...AND
WEATHER TYPE TO REFLECT THE CURRENT TRENDS IN THE ACTUAL WEATHER.
AT THIS TIME IT APPEARS THAT THE SNOW SHOULD BE EXITING THE AREA
SOMETIME BETWEEN NOON AND 1 PM TODAY. A ZONE UPDATE WILL BE ISSUED
SHORTLY TO ACCOUNT FOR THE CHANGING WEATHER AND GRID UPDATES. WILL
ISSUE ANOTHER ZONE UPDATE THIS AFTERNOON ONCE THE SNOW HAS MOVED
OUT OF THE AREA AND OUR WINTER WEATHER ADVISORY IS NO LONGER IN
EFFECT. THE HAZARDOUS WEATHER OUTLOOK WILL ALSO BE UPDATED TO
ACCOUNT FOR THE ADDITIONAL IMPACTS THE SNOW IS HAVING IN FLOYD AND
PIKE COUNTIES. A SPECIAL WEATHER STATEMENT AND GRAPHICAL NOWCAST
HAVE ALSO BEEN ISSUED TO ADDRESS THE SNOW AND ANY IMPACTS IT MAY
BE HAVING. THE PRIMARY IMPACTS FROM THE SNOW THAT HAS BEEN
OCCURRING OUTSIDE OF OUR WINTER WEATHER ADVISORY HAVE BEEN GOING
ON IN SOUTHEASTERN PIKE COUNTY AND SOUTHERN FLOYD COUNTY. THE SNOW
HAS BEEN FALLING HARD ENOUGH IN THOSE TWO AREAS TO ACCUMULATE ON
AREA ROADWAYS. THE SPS AND GRAPHICAL NOWCAST THAT WERE MENTIONED
BEFORE ARE ADDRESSING THOSE ISSUES AS WELL.
UPDATE ISSUED AT 643 AM EST TUE FEB 24 2015
DID A QUICK UPDATE TO POPS TO ACCOUNT FOR ON GOING LIGHT SNOW
ACROSS THE TN/VA BORDER THIS MORNING. THIS SYSTEM IS EXPECTED TO
CONTINUE TO MOVE OUT OF THE REGION AROUND MIDDAY. OTHERWISE JUST
MADE UPDATES FOR OBS AND TRENDS.
UPDATE ISSUED AT 427 AM EST TUE FEB 24 2015
DID A QUICK UPDATE AS MESONET SITES AT WHITLEY CITY AND
BARBOURVILLE ARE REPORTING SOME LIGHT PRECIP...AND PICTURE ON
SOCIAL MEDIA SHOWING A DUSTING IN BARBOURVILLE THIS MORNING. ALSO
MONTICELLO AND MIDDLESBORO ARE BOTH REPORTING LIGHT SNOW THIS
HOUR. THE HRRR HAS THE BEST HANDLE ON THIS SYSTEM THIS MORNING SO
LEANED TOWARD IT TO GET A BETTER POP TREND. GIVEN THAT THIS IS
LIGHT IN NATURE AT THIS POINT THINK THE CURRENT ADVISORY AND SPS
PLACEMENT WILL HANDLE THIS. THAT SAID DID UPDATE POPS/QPF/SNOW TO
HANDLE THESE REPORTS AND ALSO UPDATED WITH LATEST OBS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST TUE FEB 24 2015
THIS MORNING WSR-88D RADAR DOES HAVE SOME LIGHT RETURNS ACROSS THE
SOUTHERN TIER OF COUNTIES ALONG AND NEAR THE TN/VA BORDER THIS
MORNING. MUCH OF THIS IS LIGHT IN NATURE THIS MORNING AS DRYER AIR
IS IN PLACE ACROSS THE REGION. THAT SAID DO STILL THINK THE
AIR MASS RIGHT ALONG THE VA/TN BORDER HAS THE BEST CHANCE TO
MOISTENING UP THIS MORNING. STATIONS ACROSS EASTERN TN VALLEY AND
NE TN ARE SEEING SOME LIGHT TO MODERATE SNOW THIS MORNING WHERE
AIR MASS HAS MODIFIED. OVERNIGHT 00Z ECMWF ALSO TRENDED WEST IN
THE DIRECTION OF THE OTHER MODELS WITH BEST CHANCE OF POPS ACROSS
THE TIER OF COUNTIES NEAR THE VA BORDER. ALSO SHOULD MENTION THE
HRRR HAS CONTINUED TO PAINT LIGHT RETURNS ACROSS THE SAME REGION
OF CONCERN. STILL OPTED TO ADJUST SNOW TOTALS DOWN SLIGHTLY
ESPECIALLY WITH THE DRY AIR STILL ENTRENCHED ACROSS THE REGION.
WHILE THERE CONTINUES TO BE UNCERTAINTY WITH REGARDS TO THIS
SYSTEM THINK ADVISORY LOCATIONS STILL SEEM REASONABLE WITH BEST
CHANCES OF SNOW IN THE HIGHER TERRAIN. THE DISTURBANCE WILL PIVOT
OUT OF THE REGION THROUGH THE DAY TODAY. GIVEN THE SHARP CUTOFF ON
MUCH OF EASTERN KY WILL IN FACT NOT BE AFFECTED BY THIS STORM
SYSTEM BESIDES CLOUD COVER. MUCH OF THE BLUEGRASS WILL LIKELY SEE
MOSTLY SUNNY SKIES. CLOUDS WILL INCREASE FROM NW TO SE THIS
EVENING INTO WEDNESDAY AS ANOTHER FRONTAL BOUNDARY DROPS ACROSS
THE REGION. RIGHT NOW LIMITED MOISTURE WITH THIS WEAK FRONT WOULD
SUGGEST ONLY FLURRIES AT THIS POINT WITH THIS SYSTEM. OTHERWISE
EXPECT MOSTLY CLOUDY AND NOT AS COLD CONDITIONS TONIGHT WITH LOWS
IN THE UPPER TEENS TO LOWER 20S. WEDNESDAY EXPECT MOSTLY CLOUDY
SKIES AND HIGHS IN THE MID TO UPPER 30S. THERE IS A SLIGHT CHANCE
OF POPS ACROSS THE FAR SW LATE...HOWEVER UNCERTAINTY EXISTS ON
THIS NEXT WAVE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 AM EST TUE FEB 24 2015
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. THE SOUTHERN JET STREAM REMAIN QUITE
ACTIVE INTO THURSDAY WITH A SHORTWAVE TRACKING ALONG THE SOUTHEAST
CONUS WHILE ALSO ALONG THE NORTHERN STREAM...ANOTHER WAVE TRACKS
INTO THE MIDWEST. THE UPPER TROUGH FOR THIS PERIOD SEEMS
POSITIONED A BIT FURTHER TOT HE EAST OVER THE NEW ENGLAND
AREA...ALLOWING THESE FEATURES TO MOVE STRAIGHT INTO THE ATLANTIC.
THE WAVE ALONG THE SOUTHERN BRINGS PRECIP UP INTO SOUTHERN KY AND
INTO SOUTHEASTERN PORTIONS AS IT MOVES OFF TO THE EAST. THIS TRACK
IS FURTHER TO THE NORTH THAN IN PREVIOUS RUNS. THIS COUPLED WITH
THE NORTHERN STREAM WAVE BRINGING ARCTIC AIR AND ADDITIONAL
CHANCES FOR SNOW...WILL KEEP POPS ACROSS ALL OF EAST KENTUCKY
THROUGH THURSDAY AND FINALLY EXITING THURSDAY NIGHT. THE GFS IS
MORE DRY ON THIS SCENARIO WITH THE EURO AND ESPECIALLY THE NAM
BEING INDICATIVE OF ACCUMULATING SNOWFALL. THE SUPER BLEND ALSO
KEEPS POPS IN THROUGH THE FIRST FEW PERIODS OF THE EXTENDED AS
WELL. THE ARCTIC AIR IN PLACE COUPLED WITH A REINFORCING SHOT OF
COLD AIR WILL KEEP PRECIP TYPE SNOW WITH A POSSIBLE MIX IN THE
SOUTH AS SOME TEMPS THERE COULD GET INTO THE MID 30S FOR HIGHS ON
THURSDAY. FOR NOW GENERALLY WENT WITH SNOWFALL AMOUNTS IN THE 1 TO
2 INCH RANGE AND THOSE WERE IN THE FAR EAST AS THAT SHORTWAVE
MOVING ALONG THE SOUTHERN STREAM WILL BRING THE DEFORMATION ZONE
OVER THE SOUTHEAST FOR SOME PERIOD OF TIME.
THE REST OF THE EXTENDED WILL BE IN TRANSITION AS THE UPPER LEVEL
FLOW BECOMES MORE PROGRESSIVE AND BY THE WEEKEND...MID LEVEL
RIDGING BEGINS TO DEVELOP OVER THE EASTERN CONUS. ALSO AT THE
SURFACE...HIGH PRESSURE SETS UP AND MOVES FROM THE UPPER PLAINS
AND INTO THE OHIO VALLEY BY FRIDAY AND KEEPS THE AREA DRY INTO
SATURDAY. WITH HIGH PRESSURE THEN SHIFTING OFF TO THE EAST...THE
AREA WILL THEN SOUTHWEST FLOW HEADING INTO SUNDAY AND MONDAY. THIS
WILL BRING TEMPS UP TO NORMAL TEMPS FOR THE START OF THE NEW WEEK.
WITH THIS...WILL BRING THE NEXT SYSTEM INTO EASTERN KENTUCKY.
TEMPS BEING THIS WARM WILL LEAD TO AN ALL RAIN EVENT SUNDAY INTO
MONDAY. THE PATTERN SUGGESTS THIS REMAIN PROGRESSIVE BUT THE
CHANCE OF RAIN HERE ALLOWS ALOT OF CONFIDENCE AS THE SUPER BLEND
CAME IN WITH HIGH POPS FOR THIS EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM EST TUE FEB 24 2015
IT LOOKS LIKE THE TAF SITES WILL BE EXPERIENCING VFR CONDITIONS
FOR THE MAJORITY OF THE TAF PERIOD. CLOUDS WILL CONTINUE TO
SCATTER OUT FROM EAST TO WEST THIS AFTERNOON AND THROUGH THE
OVERNIGHT PERIOD. ANOTHER WEATHER SYSTEM IS FORECAST TO PASS
ACROSS THE AREA LATE TONIGHT...WHICH WOULD BRING ANOTHER SWATH OF
LOW AND MIDDLE LEVEL CLOUDS INTO OUR AREA. THE TAF SITES CAN
EXPECT MVFR CIGS OF AROUND 2.5K FROM 10Z ONWARD...AND PERHAPS EVEN
A FEW SNOW FLURRIES. WINDS WILL BE GENERALLY FROM THE
WEST...NORTHWEST AND THEN NORTH AT 5 TO 10 MPH THROUGH THE END OF
THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...AR
SHORT TERM...DJ
LONG TERM...SHALLENBERGER
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
1053 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 1052 AM EST TUE FEB 24 2015
HAVE MADE A FEW TWEAKS TO THE FORECAST GRIDS THROUGH AROUND NOON
TODAY. RADAR IMAGERY HAS SHOWN QUITE CLEARLY OVER THE PAST HOUR OR
SO THAT PREVIOUSLY FORECASTED SNOWFALL HAS BEEN OCCURRING A BIT
FURTHER NORTH AND WEST THAT ANTICIPATED. THEREFORE...MODIFIED THE
GRIDS FOR PRECIPITATION PROBABILITIES...QPF...SNOWFALL AMTS...AND
WEATHER TYPE TO REFLECT THE CURRENT TRENDS IN THE ACTUAL WEATHER.
AT THIS TIME IT APPEARS THAT THE SNOW SHOULD BE EXITING THE AREA
SOMETIME BETWEEN NOON AND 1 PM TODAY. A ZONE UPDATE WILL BE ISSUED
SHORTLY TO ACCOUNT FOR THE CHANGING WEATHER AND GRID UPDATES. WILL
ISSUE ANOTHER ZONE UPDATE THIS AFTERNOON ONCE THE SNOW HAS MOVED
OUT OF THE AREA AND OUR WINTER WEATHER ADVISORY IS NO LONGER IN
EFFECT. THE HAZARDOUS WEATHER OUTLOOK WILL ALSO BE UPDATED TO
ACCOUNT FOR THE ADDITIONAL IMPACTS THE SNOW IS HAVING IN FLOYD AND
PIKE COUNTIES. A SPECIAL WEATHER STATEMENT AND GRAPHICAL NOWCAST
HAVE ALSO BEEN ISSUED TO ADDRESS THE SNOW AND ANY IMPACTS IT MAY
BE HAVING. THE PRIMARY IMPACTS FROM THE SNOW THAT HAS BEEN
OCCURRING OUTSIDE OF OUR WINTER WEATHER ADVISORY HAVE BEEN GOING
ON IN SOUTHEASTERN PIKE COUNTY AND SOUTHERN FLOYD COUNTY. THE SNOW
HAS BEEN FALLING HARD ENOUGH IN THOSE TWO AREAS TO ACCUMULATE ON
AREA ROADWAYS. THE SPS AND GRAPHICAL NOWCAST THAT WERE MENTIONED
BEFORE ARE ADDRESSING THOSE ISSUES AS WELL.
UPDATE ISSUED AT 643 AM EST TUE FEB 24 2015
DID A QUICK UPDATE TO POPS TO ACCOUNT FOR ON GOING LIGHT SNOW
ACROSS THE TN/VA BORDER THIS MORNING. THIS SYSTEM IS EXPECTED TO
CONTINUE TO MOVE OUT OF THE REGION AROUND MIDDAY. OTHERWISE JUST
MADE UPDATES FOR OBS AND TRENDS.
UPDATE ISSUED AT 427 AM EST TUE FEB 24 2015
DID A QUICK UPDATE AS MESONET SITES AT WHITLEY CITY AND
BARBOURVILLE ARE REPORTING SOME LIGHT PRECIP...AND PICTURE ON
SOCIAL MEDIA SHOWING A DUSTING IN BARBOURVILLE THIS MORNING. ALSO
MONTICELLO AND MIDDLESBORO ARE BOTH REPORTING LIGHT SNOW THIS
HOUR. THE HRRR HAS THE BEST HANDLE ON THIS SYSTEM THIS MORNING SO
LEANED TOWARD IT TO GET A BETTER POP TREND. GIVEN THAT THIS IS
LIGHT IN NATURE AT THIS POINT THINK THE CURRENT ADVISORY AND SPS
PLACEMENT WILL HANDLE THIS. THAT SAID DID UPDATE POPS/QPF/SNOW TO
HANDLE THESE REPORTS AND ALSO UPDATED WITH LATEST OBS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST TUE FEB 24 2015
THIS MORNING WSR-88D RADAR DOES HAVE SOME LIGHT RETURNS ACROSS THE
SOUTHERN TIER OF COUNTIES ALONG AND NEAR THE TN/VA BORDER THIS
MORNING. MUCH OF THIS IS LIGHT IN NATURE THIS MORNING AS DRYER AIR
IS IN PLACE ACROSS THE REGION. THAT SAID DO STILL THINK THE
AIR MASS RIGHT ALONG THE VA/TN BORDER HAS THE BEST CHANCE TO
MOISTENING UP THIS MORNING. STATIONS ACROSS EASTERN TN VALLEY AND
NE TN ARE SEEING SOME LIGHT TO MODERATE SNOW THIS MORNING WHERE
AIR MASS HAS MODIFIED. OVERNIGHT 00Z ECMWF ALSO TRENDED WEST IN
THE DIRECTION OF THE OTHER MODELS WITH BEST CHANCE OF POPS ACROSS
THE TIER OF COUNTIES NEAR THE VA BORDER. ALSO SHOULD MENTION THE
HRRR HAS CONTINUED TO PAINT LIGHT RETURNS ACROSS THE SAME REGION
OF CONCERN. STILL OPTED TO ADJUST SNOW TOTALS DOWN SLIGHTLY
ESPECIALLY WITH THE DRY AIR STILL ENTRENCHED ACROSS THE REGION.
WHILE THERE CONTINUES TO BE UNCERTAINTY WITH REGARDS TO THIS
SYSTEM THINK ADVISORY LOCATIONS STILL SEEM REASONABLE WITH BEST
CHANCES OF SNOW IN THE HIGHER TERRAIN. THE DISTURBANCE WILL PIVOT
OUT OF THE REGION THROUGH THE DAY TODAY. GIVEN THE SHARP CUTOFF ON
MUCH OF EASTERN KY WILL IN FACT NOT BE AFFECTED BY THIS STORM
SYSTEM BESIDES CLOUD COVER. MUCH OF THE BLUEGRASS WILL LIKELY SEE
MOSTLY SUNNY SKIES. CLOUDS WILL INCREASE FROM NW TO SE THIS
EVENING INTO WEDNESDAY AS ANOTHER FRONTAL BOUNDARY DROPS ACROSS
THE REGION. RIGHT NOW LIMITED MOISTURE WITH THIS WEAK FRONT WOULD
SUGGEST ONLY FLURRIES AT THIS POINT WITH THIS SYSTEM. OTHERWISE
EXPECT MOSTLY CLOUDY AND NOT AS COLD CONDITIONS TONIGHT WITH LOWS
IN THE UPPER TEENS TO LOWER 20S. WEDNESDAY EXPECT MOSTLY CLOUDY
SKIES AND HIGHS IN THE MID TO UPPER 30S. THERE IS A SLIGHT CHANCE
OF POPS ACROSS THE FAR SW LATE...HOWEVER UNCERTAINTY EXISTS ON
THIS NEXT WAVE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 AM EST TUE FEB 24 2015
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. THE SOUTHERN JET STREAM REMAIN QUITE
ACTIVE INTO THURSDAY WITH A SHORTWAVE TRACKING ALONG THE SOUTHEAST
CONUS WHILE ALSO ALONG THE NORTHERN STREAM...ANOTHER WAVE TRACKS
INTO THE MIDWEST. THE UPPER TROUGH FOR THIS PERIOD SEEMS
POSITIONED A BIT FURTHER TOT HE EAST OVER THE NEW ENGLAND
AREA...ALLOWING THESE FEATURES TO MOVE STRAIGHT INTO THE ATLANTIC.
THE WAVE ALONG THE SOUTHERN BRINGS PRECIP UP INTO SOUTHERN KY AND
INTO SOUTHEASTERN PORTIONS AS IT MOVES OFF TO THE EAST. THIS TRACK
IS FURTHER TO THE NORTH THAN IN PREVIOUS RUNS. THIS COUPLED WITH
THE NORTHERN STREAM WAVE BRINGING ARCTIC AIR AND ADDITIONAL
CHANCES FOR SNOW...WILL KEEP POPS ACROSS ALL OF EAST KENTUCKY
THROUGH THURSDAY AND FINALLY EXITING THURSDAY NIGHT. THE GFS IS
MORE DRY ON THIS SCENARIO WITH THE EURO AND ESPECIALLY THE NAM
BEING INDICATIVE OF ACCUMULATING SNOWFALL. THE SUPER BLEND ALSO
KEEPS POPS IN THROUGH THE FIRST FEW PERIODS OF THE EXTENDED AS
WELL. THE ARCTIC AIR IN PLACE COUPLED WITH A REINFORCING SHOT OF
COLD AIR WILL KEEP PRECIP TYPE SNOW WITH A POSSIBLE MIX IN THE
SOUTH AS SOME TEMPS THERE COULD GET INTO THE MID 30S FOR HIGHS ON
THURSDAY. FOR NOW GENERALLY WENT WITH SNOWFALL AMOUNTS IN THE 1 TO
2 INCH RANGE AND THOSE WERE IN THE FAR EAST AS THAT SHORTWAVE
MOVING ALONG THE SOUTHERN STREAM WILL BRING THE DEFORMATION ZONE
OVER THE SOUTHEAST FOR SOME PERIOD OF TIME.
THE REST OF THE EXTENDED WILL BE IN TRANSITION AS THE UPPER LEVEL
FLOW BECOMES MORE PROGRESSIVE AND BY THE WEEKEND...MID LEVEL
RIDGING BEGINS TO DEVELOP OVER THE EASTERN CONUS. ALSO AT THE
SURFACE...HIGH PRESSURE SETS UP AND MOVES FROM THE UPPER PLAINS
AND INTO THE OHIO VALLEY BY FRIDAY AND KEEPS THE AREA DRY INTO
SATURDAY. WITH HIGH PRESSURE THEN SHIFTING OFF TO THE EAST...THE
AREA WILL THEN SOUTHWEST FLOW HEADING INTO SUNDAY AND MONDAY. THIS
WILL BRING TEMPS UP TO NORMAL TEMPS FOR THE START OF THE NEW WEEK.
WITH THIS...WILL BRING THE NEXT SYSTEM INTO EASTERN KENTUCKY.
TEMPS BEING THIS WARM WILL LEAD TO AN ALL RAIN EVENT SUNDAY INTO
MONDAY. THE PATTERN SUGGESTS THIS REMAIN PROGRESSIVE BUT THE
CHANCE OF RAIN HERE ALLOWS ALOT OF CONFIDENCE AS THE SUPER BLEND
CAME IN WITH HIGH POPS FOR THIS EVENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM EST TUE FEB 24 2015
MOST TAF SITES HAVE EVADED THE LOWER CLOUD DECK SKIRTING THE THE
SOUTHERN PORTION OF THE REGION NEAR THE TN/VA BORDER THIS MORNING.
THIS DISTURBANCE WILL MOVE EAST THROUGH THE DAY AND GIVEN THE DRY
AIR IN PLACE HAVE OPTED TO KEEP SITES VFR THIS ISSUANCE. THERE IS
SOME QUESTION AS WE MOVE INTO TONIGHT AS FRONTAL BOUNDARY
APPROACHES AND MOVES THROUGH THE REGION WEDNESDAY. THIS WILL
BRING THE POSSIBILITY OF SNOW FLURRIES TO PORTIONS OF THE EASTERN
KY AND POTENTIAL FOR A LOWER DECK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...AR
SHORT TERM...DJ
LONG TERM...SHALLENBERGER
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
644 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 643 AM EST TUE FEB 24 2015
DID A QUICK UPDATE TO POPS TO ACCOUNT FOR ON GOING LIGHT SNOW
ACROSS THE TN/VA BORDER THIS MORNING. THIS SYSTEM IS EXPECTED TO
CONTINUE TO MOVE OUT OF THE REGION AROUND MIDDAY. OTHERWISE JUST
MADE UPDATES FOR OBS AND TRENDS.
UPDATE ISSUED AT 427 AM EST TUE FEB 24 2015
DID A QUICK UPDATE AS MESONET SITES AT WHITLEY CITY AND
BARBOURVILLE ARE REPORTING SOME LIGHT PRECIP...AND PICTURE ON
SOCIAL MEDIA SHOWING A DUSTING IN BARBOURVILLE THIS MORNING. ALSO
MONTICELLO AND MIDDLESBORO ARE BOTH REPORTING LIGHT SNOW THIS
HOUR. THE HRRR HAS THE BEST HANDLE ON THIS SYSTEM THIS MORNING SO
LEANED TOWARD IT TO GET A BETTER POP TREND. GIVEN THAT THIS IS
LIGHT IN NATURE AT THIS POINT THINK THE CURRENT ADVISORY AND SPS
PLACEMENT WILL HANDLE THIS. THAT SAID DID UPDATE POPS/QPF/SNOW TO
HANDLE THESE REPORTS AND ALSO UPDATED WITH LATEST OBS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST TUE FEB 24 2015
THIS MORNING WSR-88D RADAR DOES HAVE SOME LIGHT RETURNS ACROSS THE
SOUTHERN TIER OF COUNTIES ALONG AND NEAR THE TN/VA BORDER THIS
MORNING. MUCH OF THIS IS LIGHT IN NATURE THIS MORNING AS DRYER AIR
IS IN PLACE ACROSS THE REGION. THAT SAID DO STILL THINK THE
AIRMASS RIGHT ALONG THE VA/TN BORDER HAS THE BEST CHANCE TO
MOISTENING UP THIS MORNING. STATIONS ACROSS EASTERN TN VALLEY AND
NE TN ARE SEEING SOME LIGHT TO MODERATE SNOW THIS MORNING WHERE
AIRMASS HAS MODIFIED. OVERNIGHT 00Z ECMWF ALSO TRENDED WEST IN THE
DIRECTION OF THE OTHER MODELS WITH BEST CHANCE OF POPS ACROSS THE
TIER OF COUNTIES NEAR THE VA BORDER. ALSO SHOULD MENTION THE HRRR
HAS CONTINUED TO PAINT LIGHT RETURNS ACROSS THE SAME REGION OF
CONCERN. STILL OPTED TO ADJUST SNOW TOTALS DOWN SLIGHTLY
ESPECIALLY WITH THE DRY AIR STILL ENTRENCHED ACROSS THE REGION.
WHILE THERE CONTINUES TO BE UNCERTAINTY WITH REGARDS TO THIS
SYSTEM THINK ADVISORY LOCATIONS STILL SEEM REASONABLE WITH BEST
CHANCES OF SNOW IN THE HIGHER TERRAIN. THE DISTURBANCE WILL PIVOT
OUT OF THE REGION THROUGH THE DAY TODAY. GIVEN THE SHARP CUTOFF ON
MUCH OF EASTERN KY WILL IN FACT NOT BE AFFECTED BY THIS STORM
SYSTEM BESIDES CLOUD COVER. MUCH OF THE BLUEGRASS WILL LIKELY SEE
MOSTLY SUNNY SKIES. CLOUDS WILL INCREASE FROM NW TO SE THIS
EVENING INTO WEDNESDAY AS ANOTHER FRONTAL BOUNDARY DROPS ACROSS
THE REGION. RIGHT NOW LIMITED MOISTURE WITH THIS WEAK FRONT WOULD
SUGGEST ONLY FLURRIES AT THIS POINT WITH THIS SYSTEM. OTHERWISE
EXPECT MOSTLY CLOUDY AND NOT AS COLD CONDITIONS TONIGHT WITH LOWS
IN THE UPPER TEENS TO LOWER 20S. WEDNESDAY EXPECT MOSTLY CLOUDY
SKIES AND HIGHS IN THE MID TO UPPER 30S. THERE IS A SLIGHT CHANCE
OF POPS ACROSS THE FAR SW LATE...HOWEVER UNCERTAINTY EXISTS ON
THIS NEXT WAVE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 AM EST TUE FEB 24 2015
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. THE SOUTHERN JET STREAM REMAIN QUITE
ACTIVE INTO THURSDAY WITH A SHORTWAVE TRACKING ALONG THE SOUTHEAST
CONUS WHILE ALSO ALONG THE NORTHERN STREAM...ANOTHER WAVE TRACKS
INTO THE MIDWEST. THE UPPER TROUGH FOR THIS PERIOD SEEMS
POSITIONED A BIT FURTHER TOT HE EAST OVER THE NEW ENGLAND
AREA...ALLOWING THESE FEATURES TO MOVE STRAIGHT INTO THE ATLANTIC.
THE WAVE ALONG THE SOUTHERN BRINGS PRECIP UP INTO SOUTHERN KY AND
INTO SOUTHEASTERN PORTIONS AS IT MOVES OFF TO THE EAST. THIS TRACK
IS FURTHER TO THE NORTH THAN IN PREVIOUS RUNS. THIS COUPLED WITH
THE NORTHERN STREAM WAVE BRINGING ARCTIC AIR AND ADDITIONAL
CHANCES FOR SNOW...WILL KEEP POPS ACROSS ALL OF EAST KENTUCKY
THROUGH THURSDAY AND FINALLY EXITING THURSDAY NIGHT. THE GFS IS
MORE DRY ON THIS SCENARIO WITH THE EURO AND ESPECIALLY THE NAM
BEING INDICATIVE OF ACCUMULATING SNOWFALL. THE SUPER BLEND ALSO
KEEPS POPS IN THROUGH THE FIRST FEW PERIODS OF THE EXTENDED AS
WELL. THE ARCTIC AIR IN PLACE COUPLED WITH A REINFORCING SHOT OF
COLD AIR WILL KEEP PRECIP TYPE SNOW WITH A POSSIBLE MIX IN THE
SOUTH AS SOME TEMPS THERE COULD GET INTO THE MID 30S FOR HIGHS ON
THURSDAY. FOR NOW GENERALLY WENT WITH SNOWFALL AMOUNTS IN THE 1 TO
2 INCH RANGE AND THOSE WERE IN THE FAR EAST AS THAT SHORTWAVE
MOVING ALONG THE SOUTHERN STREAM WILL BRING THE DEFORMATION ZONE
OVER THE SOUTHEAST FOR SOME PERIOD OF TIME.
THE REST OF THE EXTENDED WILL BE IN TRANSITION AS THE UPPER LEVEL
FLOW BECOMES MORE PROGRESSIVE AND BY THE WEEKEND...MID LEVEL
RIDGING BEGINS TO DEVELOP OVER THE EASTERN CONUS. ALSO AT THE
SURFACE...HIGH PRESSURE SETS UP AND MOVES FROM THE UPPER PLAINS
AND INTO THE OHIO VALLEY BY FRIDAY AND KEEPS THE AREA DRY INTO
SATURDAY. WITH HIGH PRESSURE THEN SHIFTING OFF TO THE EAST...THE
AREA WILL THEN SOUTHWEST FLOW HEADING INTO SUNDAY AND MONDAY. THIS
WILL BRING TEMPS UP TO NORMAL TEMPS FOR THE START OF THE NEW WEEK.
WITH THIS...WILL BRING THE NEXT SYSTEM INTO EASTERN KENTUCKY.
TEMPS BEING THIS WARM WILL LEAD TO AN ALL RAIN EVENT SUNDAY INTO
MONDAY. THE PATTERN SUGGESTS THIS REMAIN PROGRESSIVE BUT THE
CHANCE OF RAIN HERE ALLOWS ALOT OF CONFIDENCE AS THE SUPER BLEND
CAME IN WITH HIGH POPS FOR THIS EVENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM EST TUE FEB 24 2015
MOST TAF SITES HAVE EVADED THE LOWER CLOUD DECK SKIRTING THE THE
SOUTHERN PORTION OF THE REGION NEAR THE TN/VA BORDER THIS MORNING.
THIS DISTURBANCE WILL MOVE EAST THROUGH THE DAY AND GIVEN THE DRY
AIR IN PLACE HAVE OPTED TO KEEP SITES VFR THIS ISSUANCE. THERE IS
SOME QUESTION AS WE MOVE INTO TONIGHT AS FRONTAL BOUNDARY
APPROACHES AND MOVES THROUGH THE REGION WEDNESDAY. THIS WILL
BRING THE POSSIBILITY OF SNOW FLURRIES TO PORTIONS OF THE EASTERN
KY AND POTENTIAL FOR A LOWER DECK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...DJ
SHORT TERM...DJ
LONG TERM...SHALLENBERGER
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
634 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 427 AM EST TUE FEB 24 2015
DID A QUICK UPDATE AS MESONET SITES AT WHITLEY CITY AND
BARBOURVILLE ARE REPORTING SOME LIGHT PRECIP...AND PICTURE ON
SOCIAL MEDIA SHOWING A DUSTING IN BARBOURVILLE THIS MORNING. ALSO
MONTICELLO AND MIDDLESBORO ARE BOTH REPORTING LIGHT SNOW THIS
HOUR. THE HRRR HAS THE BEST HANDLE ON THIS SYSTEM THIS MORNING SO
LEANED TOWARD IT TO GET A BETTER POP TREND. GIVEN THAT THIS IS
LIGHT IN NATURE AT THIS POINT THINK THE CURRENT ADVISORY AND SPS
PLACEMENT WILL HANDLE THIS. THAT SAID DID UPDATE POPS/QPF/SNOW TO
HANDLE THESE REPORTS AND ALSO UPDATED WITH LATEST OBS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST TUE FEB 24 2015
THIS MORNING WSR-88D RADAR DOES HAVE SOME LIGHT RETURNS ACROSS THE
SOUTHERN TIER OF COUNTIES ALONG AND NEAR THE TN/VA BORDER THIS
MORNING. MUCH OF THIS IS LIGHT IN NATURE THIS MORNING AS DRYER AIR
IS IN PLACE ACROSS THE REGION. THAT SAID DO STILL THINK THE
AIRMASS RIGHT ALONG THE VA/TN BORDER HAS THE BEST CHANCE TO
MOISTENING UP THIS MORNING. STATIONS ACROSS EASTERN TN VALLEY AND
NE TN ARE SEEING SOME LIGHT TO MODERATE SNOW THIS MORNING WHERE
AIRMASS HAS MODIFIED. OVERNIGHT 00Z ECMWF ALSO TRENDED WEST IN THE
DIRECTION OF THE OTHER MODELS WITH BEST CHANCE OF POPS ACROSS THE
TIER OF COUNTIES NEAR THE VA BORDER. ALSO SHOULD MENTION THE HRRR
HAS CONTINUED TO PAINT LIGHT RETURNS ACROSS THE SAME REGION OF
CONCERN. STILL OPTED TO ADJUST SNOW TOTALS DOWN SLIGHTLY
ESPECIALLY WITH THE DRY AIR STILL ENTRENCHED ACROSS THE REGION.
WHILE THERE CONTINUES TO BE UNCERTAINTY WITH REGARDS TO THIS
SYSTEM THINK ADVISORY LOCATIONS STILL SEEM REASONABLE WITH BEST
CHANCES OF SNOW IN THE HIGHER TERRAIN. THE DISTURBANCE WILL PIVOT
OUT OF THE REGION THROUGH THE DAY TODAY. GIVEN THE SHARP CUTOFF ON
MUCH OF EASTERN KY WILL IN FACT NOT BE AFFECTED BY THIS STORM
SYSTEM BESIDES CLOUD COVER. MUCH OF THE BLUEGRASS WILL LIKELY SEE
MOSTLY SUNNY SKIES. CLOUDS WILL INCREASE FROM NW TO SE THIS
EVENING INTO WEDNESDAY AS ANOTHER FRONTAL BOUNDARY DROPS ACROSS
THE REGION. RIGHT NOW LIMITED MOISTURE WITH THIS WEAK FRONT WOULD
SUGGEST ONLY FLURRIES AT THIS POINT WITH THIS SYSTEM. OTHERWISE
EXPECT MOSTLY CLOUDY AND NOT AS COLD CONDITIONS TONIGHT WITH LOWS
IN THE UPPER TEENS TO LOWER 20S. WEDNESDAY EXPECT MOSTLY CLOUDY
SKIES AND HIGHS IN THE MID TO UPPER 30S. THERE IS A SLIGHT CHANCE
OF POPS ACROSS THE FAR SW LATE...HOWEVER UNCERTAINTY EXISTS ON
THIS NEXT WAVE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 AM EST TUE FEB 24 2015
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. THE SOUTHERN JET STREAM REMAIN QUITE
ACTIVE INTO THURSDAY WITH A SHORTWAVE TRACKING ALONG THE SOUTHEAST
CONUS WHILE ALSO ALONG THE NORTHERN STREAM...ANOTHER WAVE TRACKS
INTO THE MIDWEST. THE UPPER TROUGH FOR THIS PERIOD SEEMS
POSITIONED A BIT FURTHER TOT HE EAST OVER THE NEW ENGLAND
AREA...ALLOWING THESE FEATURES TO MOVE STRAIGHT INTO THE ATLANTIC.
THE WAVE ALONG THE SOUTHERN BRINGS PRECIP UP INTO SOUTHERN KY AND
INTO SOUTHEASTERN PORTIONS AS IT MOVES OFF TO THE EAST. THIS TRACK
IS FURTHER TO THE NORTH THAN IN PREVIOUS RUNS. THIS COUPLED WITH
THE NORTHERN STREAM WAVE BRINGING ARCTIC AIR AND ADDITIONAL
CHANCES FOR SNOW...WILL KEEP POPS ACROSS ALL OF EAST KENTUCKY
THROUGH THURSDAY AND FINALLY EXITING THURSDAY NIGHT. THE GFS IS
MORE DRY ON THIS SCENARIO WITH THE EURO AND ESPECIALLY THE NAM
BEING INDICATIVE OF ACCUMULATING SNOWFALL. THE SUPER BLEND ALSO
KEEPS POPS IN THROUGH THE FIRST FEW PERIODS OF THE EXTENDED AS
WELL. THE ARCTIC AIR IN PLACE COUPLED WITH A REINFORCING SHOT OF
COLD AIR WILL KEEP PRECIP TYPE SNOW WITH A POSSIBLE MIX IN THE
SOUTH AS SOME TEMPS THERE COULD GET INTO THE MID 30S FOR HIGHS ON
THURSDAY. FOR NOW GENERALLY WENT WITH SNOWFALL AMOUNTS IN THE 1 TO
2 INCH RANGE AND THOSE WERE IN THE FAR EAST AS THAT SHORTWAVE
MOVING ALONG THE SOUTHERN STREAM WILL BRING THE DEFORMATION ZONE
OVER THE SOUTHEAST FOR SOME PERIOD OF TIME.
THE REST OF THE EXTENDED WILL BE IN TRANSITION AS THE UPPER LEVEL
FLOW BECOMES MORE PROGRESSIVE AND BY THE WEEKEND...MID LEVEL
RIDGING BEGINS TO DEVELOP OVER THE EASTERN CONUS. ALSO AT THE
SURFACE...HIGH PRESSURE SETS UP AND MOVES FROM THE UPPER PLAINS
AND INTO THE OHIO VALLEY BY FRIDAY AND KEEPS THE AREA DRY INTO
SATURDAY. WITH HIGH PRESSURE THEN SHIFTING OFF TO THE EAST...THE
AREA WILL THEN SOUTHWEST FLOW HEADING INTO SUNDAY AND MONDAY. THIS
WILL BRING TEMPS UP TO NORMAL TEMPS FOR THE START OF THE NEW WEEK.
WITH THIS...WILL BRING THE NEXT SYSTEM INTO EASTERN KENTUCKY.
TEMPS BEING THIS WARM WILL LEAD TO AN ALL RAIN EVENT SUNDAY INTO
MONDAY. THE PATTERN SUGGESTS THIS REMAIN PROGRESSIVE BUT THE
CHANCE OF RAIN HERE ALLOWS ALOT OF CONFIDENCE AS THE SUPER BLEND
CAME IN WITH HIGH POPS FOR THIS EVENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 634 AM EST TUE FEB 24 2015
MOST TAF SITES HAVE EVADED THE LOWER CLOUD DECK SKIRTING THE THE
SOUTHERN PORTION OF THE REGION NEAR THE TN/VA BORDER THIS MORNING.
THIS DISTURBANCE WILL MOVE EAST THROUGH THE DAY AND GIVEN THE DRY
AIR IN PLACE HAVE OPTED TO KEEP SITES VFR THIS ISSUANCE. THERE IS
SOME QUESTION AS WE MOVE INTO TONIGHT AS FRONTAL BOUNDARY
APPROACHES AND MOVES THROUGH THE REGION WEDNESDAY. THIS WILL
BRING THE POSSIBILITY OF SNOW FLURRIES TO PORTIONS OF THE EASTERN
KY AND POTENTIAL FOR A LOWER DECK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...DJ
SHORT TERM...DJ
LONG TERM...SHALLENBERGER
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
428 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 427 AM EST TUE FEB 24 2015
DID A QUICK UPDATE AS MESONET SITES AT WHITLEY CITY AND
BARBOURVILLE ARE REPORTING SOME LIGHT PRECIP...AND PICTURE ON
SOCIAL MEDIA SHOWING A DUSTING IN BARBOURVILLE THIS MORNING. ALSO
MONTICELLO AND MIDDLESBORO ARE BOTH REPORTING LIGHT SNOW THIS
HOUR. THE HRRR HAS THE BEST HANDLE ON THIS SYSTEM THIS MORNING SO
LEANED TOWARD IT TO GET A BETTER POP TREND. GIVEN THAT THIS IS
LIGHT IN NATURE AT THIS POINT THINK THE CURRENT ADVISORY AND SPS
PLACEMENT WILL HANDLE THIS. THAT SAID DID UPDATE POPS/QPF/SNOW TO
HANDLE THESE REPORTS AND ALSO UPDATED WITH LATEST OBS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 355 AM EST TUE FEB 24 2015
THIS MORNING WSR-88D RADAR DOES HAVE SOME LIGHT RETURNS ACROSS THE
SOUTHERN TIER OF COUNTIES ALONG AND NEAR THE TN/VA BORDER THIS
MORNING. MUCH OF THIS IS LIGHT IN NATURE THIS MORNING AS DRYER AIR
IS IN PLACE ACROSS THE REGION. THAT SAID DO STILL THINK THE
AIRMASS RIGHT ALONG THE VA/TN BORDER HAS THE BEST CHANCE TO
MOISTENING UP THIS MORNING. STATIONS ACROSS EASTERN TN VALLEY AND
NE TN ARE SEEING SOME LIGHT TO MODERATE SNOW THIS MORNING WHERE
AIRMASS HAS MODIFIED. OVERNIGHT 00Z ECMWF ALSO TRENDED WEST IN THE
DIRECTION OF THE OTHER MODELS WITH BEST CHANCE OF POPS ACROSS THE
TIER OF COUNTIES NEAR THE VA BORDER. ALSO SHOULD MENTION THE HRRR
HAS CONTINUED TO PAINT LIGHT RETURNS ACROSS THE SAME REGION OF
CONCERN. STILL OPTED TO ADJUST SNOW TOTALS DOWN SLIGHTLY
ESPECIALLY WITH THE DRY AIR STILL ENTRENCHED ACROSS THE REGION.
WHILE THERE CONTINUES TO BE UNCERTAINTY WITH REGARDS TO THIS
SYSTEM THINK ADVISORY LOCATIONS STILL SEEM REASONABLE WITH BEST
CHANCES OF SNOW IN THE HIGHER TERRAIN. THE DISTURBANCE WILL PIVOT
OUT OF THE REGION THROUGH THE DAY TODAY. GIVEN THE SHARP CUTOFF ON
MUCH OF EASTERN KY WILL IN FACT NOT BE AFFECTED BY THIS STORM
SYSTEM BESIDES CLOUD COVER. MUCH OF THE BLUEGRASS WILL LIKELY SEE
MOSTLY SUNNY SKIES. CLOUDS WILL INCREASE FROM NW TO SE THIS
EVENING INTO WEDNESDAY AS ANOTHER FRONTAL BOUNDARY DROPS ACROSS
THE REGION. RIGHT NOW LIMITED MOISTURE WITH THIS WEAK FRONT WOULD
SUGGEST ONLY FLURRIES AT THIS POINT WITH THIS SYSTEM. OTHERWISE
EXPECT MOSTLY CLOUDY AND NOT AS COLD CONDITIONS TONIGHT WITH LOWS
IN THE UPPER TEENS TO LOWER 20S. WEDNESDAY EXPECT MOSTLY CLOUDY
SKIES AND HIGHS IN THE MID TO UPPER 30S. THERE IS A SLIGHT CHANCE
OF POPS ACROSS THE FAR SW LATE...HOWEVER UNCERTAINTY EXISTS ON
THIS NEXT WAVE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 AM EST TUE FEB 24 2015
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. THE SOUTHERN JET STREAM REMAIN QUITE
ACTIVE INTO THURSDAY WITH A SHORTWAVE TRACKING ALONG THE SOUTHEAST
CONUS WHILE ALSO ALONG THE NORTHERN STREAM...ANOTHER WAVE TRACKS
INTO THE MIDWEST. THE UPPER TROUGH FOR THIS PERIOD SEEMS
POSITIONED A BIT FURTHER TOT HE EAST OVER THE NEW ENGLAND
AREA...ALLOWING THESE FEATURES TO MOVE STRAIGHT INTO THE ATLANTIC.
THE WAVE ALONG THE SOUTHERN BRINGS PRECIP UP INTO SOUTHERN KY AND
INTO SOUTHEASTERN PORTIONS AS IT MOVES OFF TO THE EAST. THIS TRACK
IS FURTHER TO THE NORTH THAN IN PREVIOUS RUNS. THIS COUPLED WITH
THE NORTHERN STREAM WAVE BRINGING ARCTIC AIR AND ADDITIONAL
CHANCES FOR SNOW...WILL KEEP POPS ACROSS ALL OF EAST KENTUCKY
THROUGH THURSDAY AND FINALLY EXITING THURSDAY NIGHT. THE GFS IS
MORE DRY ON THIS SCENARIO WITH THE EURO AND ESPECIALLY THE NAM
BEING INDICATIVE OF ACCUMULATING SNOWFALL. THE SUPER BLEND ALSO
KEEPS POPS IN THROUGH THE FIRST FEW PERIODS OF THE EXTENDED AS
WELL. THE ARCTIC AIR IN PLACE COUPLED WITH A REINFORCING SHOT OF
COLD AIR WILL KEEP PRECIP TYPE SNOW WITH A POSSIBLE MIX IN THE
SOUTH AS SOME TEMPS THERE COULD GET INTO THE MID 30S FOR HIGHS ON
THURSDAY. FOR NOW GENERALLY WENT WITH SNOWFALL AMOUNTS IN THE 1 TO
2 INCH RANGE AND THOSE WERE IN THE FAR EAST AS THAT SHORTWAVE
MOVING ALONG THE SOUTHERN STREAM WILL BRING THE DEFORMATION ZONE
OVER THE SOUTHEAST FOR SOME PERIOD OF TIME.
THE REST OF THE EXTENDED WILL BE IN TRANSITION AS THE UPPER LEVEL
FLOW BECOMES MORE PROGRESSIVE AND BY THE WEEKEND...MID LEVEL
RIDGING BEGINS TO DEVELOP OVER THE EASTERN CONUS. ALSO AT THE
SURFACE...HIGH PRESSURE SETS UP AND MOVES FROM THE UPPER PLAINS
AND INTO THE OHIO VALLEY BY FRIDAY AND KEEPS THE AREA DRY INTO
SATURDAY. WITH HIGH PRESSURE THEN SHIFTING OFF TO THE EAST...THE
AREA WILL THEN SOUTHWEST FLOW HEADING INTO SUNDAY AND MONDAY. THIS
WILL BRING TEMPS UP TO NORMAL TEMPS FOR THE START OF THE NEW WEEK.
WITH THIS...WILL BRING THE NEXT SYSTEM INTO EASTERN KENTUCKY.
TEMPS BEING THIS WARM WILL LEAD TO AN ALL RAIN EVENT SUNDAY INTO
MONDAY. THE PATTERN SUGGESTS THIS REMAIN PROGRESSIVE BUT THE
CHANCE OF RAIN HERE ALLOWS ALOT OF CONFIDENCE AS THE SUPER BLEND
CAME IN WITH HIGH POPS FOR THIS EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1241 AM EST TUE FEB 24 2015
STARTING OUT THE PERIOD WITH VFR FOR TAF SITES ACROSS EASTERN KY.
A AREA OF LOW PRESSURE TRACKING NORTH OUT OF THE TN VALLEY WILL
EVENTUALLY SPREAD LOWER CLOUD DECK INTO THE REGION OVERNIGHT.
QUESTIONS REMAIN ON HOW FAR THE PRECIP FROM THIS WILL SPREAD AND
WHAT AFFECT THE DRYER AIRMASS WILL HAVE ON THIS. RIGHT NOW HAVE A
MVFR DECK MAKING IT UP TO LOZ...JKL AND SJS BY 10Z WITH SNOW
POSSIBLE IN THE AREA OF THESE SITES. THEREFORE HAVE KEPT IT VCSH
AT THIS POINT. OTHERWISE SOME CLEARING WILL BE POSSIBLE LATE IN
THE TAF PERIOD AHEAD OF NEXT STORM SYSTEM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...DJ
SHORT TERM...DJ
LONG TERM...SHALLENBERGER
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
109 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 108 AM EST TUE FEB 24 2015
QUICK UPDATE TO FRESHEN GRIDS WITH LATEST OBS AND TRENDS.
OTHERWISE WILL CONTINUE TO MONITOR SNOW POTENTIAL OVERNIGHT WITH
SOME CONCERNS ABOUT THE DRY AIRMASS IN PLACE. NO MAJOR CHANGES
EXPECTED AT THIS TIME.
UPDATE ISSUED AT 1000 PM EST MON FEB 23 2015
AFTER REVIEW OF THE 0Z NAM AND 21Z SREF OPTED TO GO WITH A WINTER
WEATHER ADVISORY FOR BELL...HARLAN...AND LETCHER COUNTIES AND
OPTED TO INCREASE POPS A BIT FURTHER AND UP AMOUNTS A TAD BASED ON
THIS GUIDANCE TO THE 1 TO 3 INCH RANGE. SREF PROB OF GREATER THAN
1 INCH IN 12 HOURS IN THAT AREA IS 50 TO 80 PERCENT. THE HIGHEST
AMOUNTS SHOULD OCCUR RIGHT ON THE VA BORDER.
THERE SHOULD BE A VERY SHARP CUTOFF ON THE NORTHERN EDGE. IN
COUNTIES JUST NORTH AND WEST ACCUMULATIONS SHOULD RANGE FROM A
DUSTING OR JUST FLURRIES FROM WHITLEY CITY TO LONDON EAST AND
NORTHEAST TO TO NEAR HAZARD TO SOUTH OF PRESTONSBURG TO THE BELFRY
AND SOUTH WILLIAMSON AREA. AMOUNTS OF ABOUT HALF AN INCH TO AN
INCH ARE ANTICIPATED IN EXTREME SOUTHERN AND SOUTHEASTERN
WHITLEY...KNOX...CLAY...LESLIE...PERRY...KNOTT...FLOYD AND PIKE
COUNTIES.
THE SPS WILL BE UPDATED ACCORDINGLY WITH HOURLY GRIDS FRESHENED
BASED ON OBSERVATION TRENDS.
UPDATE ISSUED AT 845 PM EST MON FEB 23 2015
SEVERAL UPDATES WERE NEEDED FOR THIS UPDATE AS THE 18Z GFS AND 18Z
NAM AS WELL AS 21Z SREF AND HRR AND RAP RUNS ALL POINT TOWARD SNOW
FROM SYSTEM MOVING ACROSS THE SOUTHEASTERN STATES REACHING THE VA
AND SOME OF THE TN BORDER COUNTIES OVERNIGHT INTO TUESDAY MORNING.
MEANWHILE...THE FAR NORTH MAY REMAIN CLEAR MUCH OF THAT TIME. WITH
THE COLD AIRMASS IN PLACE AND SNOW ON THE GROUND...IT STILL
APPEARS SINGLE DIGITS AND LOW TEEN ARE GENERALLY EXPECTED FOR
OVERNIGHT LOWS. THE EXCEPTIONS WILL BE MID TEENS NEAR THE TN/VA/KY
BORDER AREA AND SOME BELOW ZERO READINGS ALONG AND NORTH OF THE
INTERSTATE 64 CORRIDOR.
HOWEVER...SIGNIFICANT CHANGES WERE NEEDED IN THE FAR SOUTH AND
SOUTHEAST. POPS WERE INCREASED INTO THE HIGH CHANCE TO LIKELY
RANGE LATE TONIGHT AND ON TUESDAY MORNING FOR THOSE LOCATIONS
MENTIONED ABOVE WITH A SHARP CUTOFF TO THE NORTH. MOST OF THE SNOW
SHOULD BE ALONG OR GENERALLY SOUTH OF A STEARNS TO LONDON TO
HAZARD TO PIKEVILLE TO SOUTH WILLIAMSON LINE. A DUSTING TO 2
INCHES IS EXPECTED IN THAT AREA WITH THE HIGHEST AMOUNTS NEAR THE
VA BORDER. SOME GUIDANCE WOULD POINT TOWARD SLIGHTLY HIGHER
AMOUNTS...BUT HAVE TRENDED UP SIGNIFICANTLY ATTM. THE MOST
WIDESPREAD AMOUNTS OF 1 INCH OR MORE IN THE FORECAST ATTM IS FOR
BELL...HARLAN AND LETCHER COUNTIES AND WILL CONTINUE TO EVALUATE
WHETHER OR NOT AN ADVISORY MAY BE NEEDED FOR THAT AREA AS THE 0Z
GUIDANCE ARRIVES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 332 PM EST MON FEB 23 2015
THE PRIMARY FORECAST ISSUE IN THE SHORT TERM WILL THE EXTREMELY
COLD TEMPERATURES EXPECTED ACROSS THE AREA LATE TONIGHT THROUGH
EARLY TOMORROW MORNING. THE LATEST SURFACE OBS CLEARLY SHOW A
LARGE RIDGE OF HIGH PRESSURE CONTINUE TO MOVE SOUTHEASTWARD OUT OF
EAST CENTRAL PLAINS. AS THIS RIDGE MAKES ITS WAY ACROSS THE OHIO
AND TENNESSEE VALLEY REGIONS...IT WILL PULL FRIGID ARCTIC AIR
SOUTHWARD ALONG WITH IT. EVEN THOUGH TONIGHTS TEMPERATURES DO NOT
LOOK LIKE THEY WILL BE QUITE AS COLD AS PREVIOUSLY FORECAST...WE
WILL LIKELY STILL SEE SINGLE LOWS ACROSS A LARGE PORTION OF THE
AREA OVERNIGHT. DURING THE DAY TODAY...CLOUD COVER SCATTERED OUT
MUCH QUICKER THAN PREVIOUSLY FORECAST. AS A RESULT...TEMPERATURES
ACROSS THE AREA HAVE BEEN A FEW DEGREES WARMER. ANOTHER FACTOR
THAT MAY KEEP TEMPERATURES SLIGHTLY WARMER TONIGHT IS THE PASSAGE
OF A FAST MOVING AREA OF LOW PRESSURE. THIS FEATURE IS CURRENTLY
MOVING OUT OF THE SOUTHERN PLAINS...AND IS EXPECTED TO TRACK
EASTWARD ACROSS THE TENNESSEE VALLEY OVERNIGHT. AS IT DOES
SO...LOW AND MIDDLE LEVEL CLOUD COVER WILL GRADUALLY INCREASE.
THESE CLOUDS WOULD ACT TO KEEP TEMPERATURES SLIGHTLY WARMER. FOR
NOW THE FORECAST IS CALLING FOR MOSTLY ABOVE ZERO TEMPERATURES IN
OUR FAR NORTH...WITH THE EXCEPTION OF A FEW VALLEY LOCATIONS...
EVERYONE SHOULD STAY ABOVE ZERO...IF ONLY SLIGHTLY. HIGHS ON
TUESDAY SHOULD BE ABLE TO WARM INTO THE 30S FOR MOST FOLKS...AS
SOUTHERLY WINDS BECOME ESTABLISHED IN THE ZONE BETWEEN THE AREA OF
LOW PRESSURE MENTIONED BEFORE...AND A RIDGE OF HIGH PRESSURE THAT
IS FORECAST TO CONTINUE DRIFTING SOUTHWARD INTO THE WESTERN GULF
OF MEXICO. THE ONLY PRECIPITATION EXPECTED IN THE SHORT TERM WILL
LIKELY OCCUR LATE TOMORROW NIGHT...AS SOME SNOW FLURRIES MAY
DEVELOP IN THE COLD WESTERLY FLOW THAT IS FORECAST TO SET UP
ACROSS THE AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 PM EST MON FEB 23 2015
COLD NORTHWEST FLOW WILL PERSIST THROUGH THE END OF THE WORK WEEK
WITH SEVERAL WEAK IMPULSES PASSING BY FROM TIME TO TIME. EACH OF
THESE COULD SPAWN SOME FLURRIES...BUT OUR BEST SHOT OF SNOW WILL
COME ON THURSDAY AND THURSDAY EVENING. EVEN THIS SYSTEM IS LACKING
ANY DEEP MOISTURE THOUGH SO WOULD ONLY EXPECT LIGHT ACCUMULATIONS.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL. IN FACT...A
REINFORCING SHOT OF ARCTIC AIR WILL FOLLOW OUR THURSDAY SYSTEM
WITH SINGLE DIGIT LOWS FORECAST FOR MOST AREAS THURSDAY NIGHT...
AND IN THE VALLEYS AGAIN FRIDAY NIGHT.
THE LONGWAVE PATTERN WILL SHIFT OVER THE WEEKEND AS A TROUGH DIGS
IN OVER THE SOUTHWEST CONUS AND HEIGHTS RISE OVER OUR AREA IN
RESPONSE. THE DEVELOPING SOUTHWEST FLOW WILL CAUSE A MODERATING
TREND. UNFORTUNATELY IT WILL ALSO BRING WITH IT INCREASING
MOISTURE...AND IN TIME...INCREASING RAIN CHANCES. SOME MIXED
PRECIP IS POSSIBLE AT THE ONSET SATURDAY NIGHT INTO SUNDAY
MORNING...BUT BASED ON CURRENT MODEL RUNS PTYPE IS EXPECTED TO BE
ALL RAIN BY NOON ON SUNDAY WITH RAIN LIKELY SUNDAY NIGHT THROUGH
MONDAY AT LEAST. WITH ONE TO TWO INCHES OF WATER LOCKED UP IN OUR
SNOW PACK...AND MORE IN THE HARDER HIT AREAS OF THE HEADWATERS OF
OUR RIVERS...ANY WARM UP AND RAIN IN THE FORECAST IS TROUBLING.
THIS SYSTEM WILL HAVE TO BE MONITORED CLOSELY DUE TO POTENTIAL
FLOODING CONCERNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1241 AM EST TUE FEB 24 2015
STARTING OUT THE PERIOD WITH VFR FOR TAF SITES ACROSS EASTERN KY.
A AREA OF LOW PRESSURE TRACKING NORTH OUT OF THE TN VALLEY WILL
EVENTUALLY SPREAD LOWER CLOUD DECK INTO THE REGION OVERNIGHT.
QUESTIONS REMAIN ON HOW FAR THE PRECIP FROM THIS WILL SPREAD AND
WHAT AFFECT THE DRYER AIRMASS WILL HAVE ON THIS. RIGHT NOW HAVE A
MVFR DECK MAKING IT UP TO LOZ...JKL AND SJS BY 10Z WITH SNOW
POSSIBLE IN THE AREA OF THESE SITES. THEREFORE HAVE KEPT IT VCSH
AT THIS POINT. OTHERWISE SOME CLEARING WILL BE POSSIBLE LATE IN
THE TAF PERIOD AHEAD OF NEXT STORM SYSTEM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...DJ
SHORT TERM...AR
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1243 AM EST TUE FEB 24 2015
.UPDATE...
ISSUED AT 1000 PM EST MON FEB 23 2015
AFTER REVIEW OF THE 0Z NAM AND 21Z SREF OPTED TO GO WITH A WINTER
WEATHER ADVISORY FOR BELL...HARLAN...AND LETCHER COUNTIES AND
OPTED TO INCREASE POPS A BIT FURTHER AND UP AMOUNTS A TAD BASED ON
THIS GUIDANCE TO THE 1 TO 3 INCH RANGE. SREF PROB OF GREATER THAN
1 INCH IN 12 HOURS IN THAT AREA IS 50 TO 80 PERCENT. THE HIGHEST
AMOUNTS SHOULD OCCUR RIGHT ON THE VA BORDER.
THERE SHOULD BE A VERY SHARP CUTOFF ON THE NORTHERN EDGE. IN
COUNTIES JUST NORTH AND WEST ACCUMULATIONS SHOULD RANGE FROM A
DUSTING OR JUST FLURRIES FROM WHITLEY CITY TO LONDON EAST AND
NORTHEAST TO TO NEAR HAZARD TO SOUTH OF PRESTONSBURG TO THE BELFRY
AND SOUTH WILLIAMSON AREA. AMOUNTS OF ABOUT HALF AN INCH TO AN
INCH ARE ANTICIPATED IN EXTREME SOUTHERN AND SOUTHEASTERN
WHITLEY...KNOX...CLAY...LESLIE...PERRY...KNOTT...FLOYD AND PIKE
COUNTIES.
THE SPS WILL BE UPDATED ACCORDINGLY WITH HOURLY GRIDS FRESHENED
BASED ON OBSERVATION TRENDS.
UPDATE ISSUED AT 845 PM EST MON FEB 23 2015
SEVERAL UPDATES WERE NEEDED FOR THIS UPDATE AS THE 18Z GFS AND 18Z
NAM AS WELL AS 21Z SREF AND HRR AND RAP RUNS ALL POINT TOWARD SNOW
FROM SYSTEM MOVING ACROSS THE SOUTHEASTERN STATES REACHING THE VA
AND SOME OF THE TN BORDER COUNTIES OVERNIGHT INTO TUESDAY MORNING.
MEANWHILE...THE FAR NORTH MAY REMAIN CLEAR MUCH OF THAT TIME. WITH
THE COLD AIRMASS IN PLACE AND SNOW ON THE GROUND...IT STILL
APPEARS SINGLE DIGITS AND LOW TEEN ARE GENERALLY EXPECTED FOR
OVERNIGHT LOWS. THE EXCEPTIONS WILL BE MID TEENS NEAR THE TN/VA/KY
BORDER AREA AND SOME BELOW ZERO READINGS ALONG AND NORTH OF THE
INTERSTATE 64 CORRIDOR.
HOWEVER...SIGNIFICANT CHANGES WERE NEEDED IN THE FAR SOUTH AND
SOUTHEAST. POPS WERE INCREASED INTO THE HIGH CHANCE TO LIKELY
RANGE LATE TONIGHT AND ON TUESDAY MORNING FOR THOSE LOCATIONS
MENTIONED ABOVE WITH A SHARP CUTOFF TO THE NORTH. MOST OF THE SNOW
SHOULD BE ALONG OR GENERALLY SOUTH OF A STEARNS TO LONDON TO
HAZARD TO PIKEVILLE TO SOUTH WILLIAMSON LINE. A DUSTING TO 2
INCHES IS EXPECTED IN THAT AREA WITH THE HIGHEST AMOUNTS NEAR THE
VA BORDER. SOME GUIDANCE WOULD POINT TOWARD SLIGHTLY HIGHER
AMOUNTS...BUT HAVE TRENDED UP SIGNIFICANTLY ATTM. THE MOST
WIDESPREAD AMOUNTS OF 1 INCH OR MORE IN THE FORECAST ATTM IS FOR
BELL...HARLAN AND LETCHER COUNTIES AND WILL CONTINUE TO EVALUATE
WHETHER OR NOT AN ADVISORY MAY BE NEEDED FOR THAT AREA AS THE 0Z
GUIDANCE ARRIVES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 332 PM EST MON FEB 23 2015
THE PRIMARY FORECAST ISSUE IN THE SHORT TERM WILL THE EXTREMELY
COLD TEMPERATURES EXPECTED ACROSS THE AREA LATE TONIGHT THROUGH
EARLY TOMORROW MORNING. THE LATEST SURFACE OBS CLEARLY SHOW A
LARGE RIDGE OF HIGH PRESSURE CONTINUE TO MOVE SOUTHEASTWARD OUT OF
EAST CENTRAL PLAINS. AS THIS RIDGE MAKES ITS WAY ACROSS THE OHIO
AND TENNESSEE VALLEY REGIONS...IT WILL PULL FRIGID ARCTIC AIR
SOUTHWARD ALONG WITH IT. EVEN THOUGH TONIGHTS TEMPERATURES DO NOT
LOOK LIKE THEY WILL BE QUITE AS COLD AS PREVIOUSLY FORECAST...WE
WILL LIKELY STILL SEE SINGLE LOWS ACROSS A LARGE PORTION OF THE
AREA OVERNIGHT. DURING THE DAY TODAY...CLOUD COVER SCATTERED OUT
MUCH QUICKER THAN PREVIOUSLY FORECAST. AS A RESULT...TEMPERATURES
ACROSS THE AREA HAVE BEEN A FEW DEGREES WARMER. ANOTHER FACTOR
THAT MAY KEEP TEMPERATURES SLIGHTLY WARMER TONIGHT IS THE PASSAGE
OF A FAST MOVING AREA OF LOW PRESSURE. THIS FEATURE IS CURRENTLY
MOVING OUT OF THE SOUTHERN PLAINS...AND IS EXPECTED TO TRACK
EASTWARD ACROSS THE TENNESSEE VALLEY OVERNIGHT. AS IT DOES
SO...LOW AND MIDDLE LEVEL CLOUD COVER WILL GRADUALLY INCREASE.
THESE CLOUDS WOULD ACT TO KEEP TEMPERATURES SLIGHTLY WARMER. FOR
NOW THE FORECAST IS CALLING FOR MOSTLY ABOVE ZERO TEMPERATURES IN
OUR FAR NORTH...WITH THE EXCEPTION OF A FEW VALLEY LOCATIONS...
EVERYONE SHOULD STAY ABOVE ZERO...IF ONLY SLIGHTLY. HIGHS ON
TUESDAY SHOULD BE ABLE TO WARM INTO THE 30S FOR MOST FOLKS...AS
SOUTHERLY WINDS BECOME ESTABLISHED IN THE ZONE BETWEEN THE AREA OF
LOW PRESSURE MENTIONED BEFORE...AND A RIDGE OF HIGH PRESSURE THAT
IS FORECAST TO CONTINUE DRIFTING SOUTHWARD INTO THE WESTERN GULF
OF MEXICO. THE ONLY PRECIPITATION EXPECTED IN THE SHORT TERM WILL
LIKELY OCCUR LATE TOMORROW NIGHT...AS SOME SNOW FLURRIES MAY
DEVELOP IN THE COLD WESTERLY FLOW THAT IS FORECAST TO SET UP
ACROSS THE AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 PM EST MON FEB 23 2015
COLD NORTHWEST FLOW WILL PERSIST THROUGH THE END OF THE WORK WEEK
WITH SEVERAL WEAK IMPULSES PASSING BY FROM TIME TO TIME. EACH OF
THESE COULD SPAWN SOME FLURRIES...BUT OUR BEST SHOT OF SNOW WILL
COME ON THURSDAY AND THURSDAY EVENING. EVEN THIS SYSTEM IS LACKING
ANY DEEP MOISTURE THOUGH SO WOULD ONLY EXPECT LIGHT ACCUMULATIONS.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL. IN FACT...A
REINFORCING SHOT OF ARCTIC AIR WILL FOLLOW OUR THURSDAY SYSTEM
WITH SINGLE DIGIT LOWS FORECAST FOR MOST AREAS THURSDAY NIGHT...
AND IN THE VALLEYS AGAIN FRIDAY NIGHT.
THE LONGWAVE PATTERN WILL SHIFT OVER THE WEEKEND AS A TROUGH DIGS
IN OVER THE SOUTHWEST CONUS AND HEIGHTS RISE OVER OUR AREA IN
RESPONSE. THE DEVELOPING SOUTHWEST FLOW WILL CAUSE A MODERATING
TREND. UNFORTUNATELY IT WILL ALSO BRING WITH IT INCREASING
MOISTURE...AND IN TIME...INCREASING RAIN CHANCES. SOME MIXED
PRECIP IS POSSIBLE AT THE ONSET SATURDAY NIGHT INTO SUNDAY
MORNING...BUT BASED ON CURRENT MODEL RUNS PTYPE IS EXPECTED TO BE
ALL RAIN BY NOON ON SUNDAY WITH RAIN LIKELY SUNDAY NIGHT THROUGH
MONDAY AT LEAST. WITH ONE TO TWO INCHES OF WATER LOCKED UP IN OUR
SNOW PACK...AND MORE IN THE HARDER HIT AREAS OF THE HEADWATERS OF
OUR RIVERS...ANY WARM UP AND RAIN IN THE FORECAST IS TROUBLING.
THIS SYSTEM WILL HAVE TO BE MONITORED CLOSELY DUE TO POTENTIAL
FLOODING CONCERNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1241 AM EST TUE FEB 24 2015
STARTING OUT THE PERIOD WITH VFR FOR TAF SITES ACROSS EASTERN KY.
A AREA OF LOW PRESSURE TRACKING NORTH OUT OF THE TN VALLEY WILL
EVENTUALLY SPREAD LOWER CLOUD DECK INTO THE REGION OVERNIGHT.
QUESTIONS REMAIN ON HOW FAR THE PRECIP FROM THIS WILL SPREAD AND
WHAT AFFECT THE DRYER AIRMASS WILL HAVE ON THIS. RIGHT NOW HAVE A
MVFR DECK MAKING IT UP TO LOZ...JKL AND SJS BY 10Z WITH SNOW
POSSIBLE IN THE AREA OF THESE SITES. THEREFORE HAVE KEPT IT VCSH
AT THIS POINT. OTHERWISE SOME CLEARING WILL BE POSSIBLE LATE IN
THE TAF PERIOD AHEAD OF NEXT STORM SYSTEM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ087-
088-118.
&&
$$
UPDATE...JP
SHORT TERM...AR
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1211 AM EST TUE FEB 24 2015
.SYNOPSIS...
COLD HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT THEN SLIDE
SOUTH OF THE REGION ON TUESDAY. A TROUGH OF LOW PRESSURE WILL
APPROACH TUESDAY NIGHT. LOW PRESSURE WILL DEVELOP SOUTH OF THE AREA
EARLY WEDNESDAY AND TRACK INTO THE MARITIMES WEDNESDAY AFTERNOON.
&&
.NEAR TERM /THROUGH TODAY/...
1210 AM UPDATE...NO SIGNIFICANT CHANGES WERE NEEDED WITH THIS
UPDATE. THE STREAMER OF LIGHT SNOW THAT WAS BLOWING OFF THE ST
LAWRENCE HAS BEEN WANING OVER THE PAST FEW HOURS. THIS IS TO BE
EXPECTED AS WINDS ARE STARTING TO DIE DOWN AS WELL. THIS DOWNWARD
TREND IN THE WINDS WILL CONTINUE THROUGH DAYBREAK. EVEN STILL,
WITH VERY COLD TEMPERATURES WIND CHILLS OF -20F TO -35F ARE
EXPECTED. SOME OF THE HIGHER ELEVATIONS MAY SEE VALUES APPROACHING
-40F FOR A TIME, BUT THIS WILL BE HIGHLY LOCALIZED AND WINDS
SHOULD DROP TO 10 MPH OR LESS SHORTLY. THEREFORE, THE WIND CHILL
ADVISORY STILL LOOKS GOOD.
PREVIOUS DISCUSSION...THE MAIN CHALLENGES THIS TERM WILL BE
STREAMERS OFF THE ST. LAWRENCE, WIND CHILLS AND OF COURSE
TEMPERATURES.
LATEST VISIBLE SATELLITE IMAGERY SHOWED CLOUDS MOVING E OFF THE ST
LAWRENCE. LLVL CONVERGENCE SHOWING UP ON THE SURFACE ANALYSIS
ACROSS FAR NORTHERN MAINE(THE CROWN MOST PARTICULARLY. PERIODS OF
LIGHT SNOW FOR NW AND NE AROOSTOOK COUNTY COULD BRING AN INCH OF
SNOW BY THIS EVENING AND THEN WINDS BEGIN TO LET UP. MODEL SOUNDINGS
SUPPORT DEEP MOISTURE THROUGH 800MBS W/SOME WEAK FORCING ALOFT.
DECIDED TO BOOST POPS UP ACROSS THE FAR NORTHERN AREAS(60-80%) TO
ACCOUNT FOR THE SNOW. THE RAP/NAM12 AND HRRR MESOSCALE MODELS
WERE DOING WELL W/THIS SETUP. AREAS OF BLOWING SNOW A FACTOR INTO
THE EVENING AND WILL CONTINUE THAT WORDING IN THE FORECAST THROUGH
9 PM. HISTORICALLY, CLOUDS AND STREAMERS BREAK UP AS THE WINDS
SHIFT MORE TO THE WEST AND THE AIRMASS DRIES OUT. THIS IS SHOWN TO
BE THE CASE LATER THIS EVENING. FURTHER S, BASICALLY CLEAR SKIES
W/SOME SCT CLOUDS FROM TIME TO TIME. THIS WILL LEAD TO SOME VERY
COLD IF NOT BITTERLY COLD TEMPERATURES OVERNIGHT INTO TUESDAY
MORNING. WE ARE TALKING 15 TO 25 BELOW ACROSS THE NORTH AND WEST
AND PERHAPS 30 BELOW IN THE SHELTERED AREAS. CENTRAL AND DOWNEAST
WILL 10 TO 15 BELOW EVEN TO THE COAST. DANGEROUS WIND CHILLS ARE
ON THE DOCKET THROUGH EARLY TUESDAY APPROACHING WARNING
CRITERIA(-35F) ACROSS THE NORTHERN AND WESTERN AREAS. ATTM,
DECIDED TO STAY W/WIND CHILL ADVISORIES AS THE WINDOW LOOKS TO BE
SHORT(<3 HRS) FOR WIND CHILLS TO HIT <-35F AND WINDS ARE FORECAST
TO DROP OFF BELOW 10 MPH.
TUESDAY WILL START OUT SUNNY AND VERY COLD W/HIGH PRES RIDGING
INTO THE REGION. THE RIDGE AXIS IF FORECAST TO SLIDE THROUGH THE
REGION QUICKLY DURING THE DAY W/CLOUDS ON THE INCREASE BY THE
AFTERNOON. DAYTIME TEMPERATURES ACROSS THE NORTHERN 1/2 OF THE CWA
IN THE SINGLE NUMBER WHILE CENTRAL AND DOWNEAST WILL SEE 10 TO 15
AT BEST AND THE WARMER TEMPERATURES TOWARD THE COAST.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
A TROUGH OF LOW PRESSURE WILL APPROACH FROM THE GREAT LAKES TUESDAY
NIGHT. A SMALL AREA OF LOW PRESSURE WILL DEVELOP ALONG THE
SOUTHEASTERN EDGE OF THE TROUGH, OFF THE SOUTHERN NEW ENGLAND COAST,
LATE TUESDAY NIGHT. THE FORECAST CHALLENGE WILL BE IN DETERMINING
HOW QUICKLY THIS LOW DEVELOPS AND HOW CLOSE THE LOW WILL TRACK TO
OUR REGION ON WEDNESDAY. LATEST FORECAST GUIDANCE CARRIES THE LOW
INTO THE GULF OF MAINE WEDNESDAY MORNING SPREADING SNOW ACROSS
DOWNEAST AREAS VERY EARLY WEDNESDAY MORNING THEN ON UP ACROSS EAST
CENTRAL AND NORTHEASTERN AREAS LATER WEDNESDAY MORNING. THIS IS A
SMALL, FAST MOVING LOW AND APPEARS WILL NOT BE IN THE AREA LONG
ENOUGH TO PRODUCE HEAVY SNOW ACCUMULATIONS. A LIGHT TO MODERATE
SNOWFALL OF 3 TO 5 INCHES CURRENTLY APPEARS MOST LIKELY FROM
DOWNEAST AREAS NORTHWARD INTO EASTERN AREAS OF NORTHERN MAINE
THROUGH WEDNESDAY MIDDAY BEFORE THE LOW LIFTS OUT. THE NAM...GFS
AND ECMWF ALL OFFER SIMILAR SOLUTIONS AND HAVE BEEN CONSISTENT
WITH PREVIOUS RUNS SHOWING JUST A QUICK SNOWFALL OF MODERATE
INTENSITY ACROSS EASTERN AREAS WITH THIS SYSTEM. THE LOW WILL
CONTINUE TO INTENSIFY WEDNESDAY AFTERNOON BUT WILL BE QUICK TO
LIFT NORTHEAST AND AWAY THROUGH THE MARITIMES AS DRY AND BREEZY
WEATHER FOLLOWS. SNOW SHOULD TAPER OFF LATE WEDNESDAY MORNING
DOWNEAST AND WEDNESDAY AFTERNOON ACROSS THE NORTHEAST. HIGH
PRESSURE WILL THEN BRING DRY AND COLD CONDITIONS WEDNESDAY NIGHT
INTO THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A LARGE AREA OF HIGH PRESSURE PUSHING INTO THE EAST WILL MAINTAIN
DRY WEATHER THURSDAY NIGHT THROUGH THE COMING WEEKEND. TEMPS AHEAD
OF THE HIGH WILL BE WELL BELOW NORMAL INTO SATURDAY, THEN WARM UP
CLOSER TO NORMAL LATE IN THE WEEKEND IN THE RETURN FLOW BEHIND THE
HIGH ON SUNDAY. CLOUDS WILL INCREASE ON SUNDAY AND SOME SNOW IS
POSSIBLE SUNDAY NIGHT INTO MONDAY AS A TROUGH AND WEAK FRONTAL
SYSTEM PUSH IN FROM THE WEST. AT THIS TIME THE SYSTEM SUNDAY NIGHT
INTO MONDAY LOOKS LIKE A PROGRESSIVE OPEN WAVE WITH ONLY LIGHT TO
MODERATE SNOW EXPECTED. DRIER CONDITIONS SHOULD RETURN BEHIND A COLD
FRONT LATER MONDAY INTO MONDAY NIGHT.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: MVFR W/IFR VSBYS THROUGH EARLY EVENING ACROSS THE
NORTHERN TERMINALS(NORTH OF KHUL) DUE TO THE STREAMERS OFF THE ST.
LAWRENCE. FURTHER SOUTH, GENERALLY VFR. CLOUDS AND LIGHT SNOW
ACROSS THE NORTH WILL END LATER THIS EVENING AS WINDS DROP OFF
LEADING TO VFR. IT LOOKS LIKE VFR FOR THE ENTIRE AVIATION SECTOR
FOR TUESDAY.
SHORT TERM: VFR CONDITIONS TUESDAY NIGHT WILL LOWER TO MVFR THEN
IFR VERY LATE AT NIGHT. IFR CONDITIONS IN SNOW ARE EXPECTED
WEDNESDAY MORNING. CONDITIONS MAY IMPROVE TO VFR DOWNEAST
WEDNESDAY AFTERNOON AND MVFR ACROSS THE NORTH WEDNESDAY AFTERNOON.
MAINLY VFR CONDITIONS ARE EXPECTED WEDNESDAY NIGHT AND THURSDAY
WITH THE POSSIBLE EXCEPTION OF SOME MVFR CONDITIONS IN THE ST JOHN
VALLEY. VFR CONDITIONS ARE THEN EXPECTED THURSDAY NIGHT THROUGH
SATURDAY.
&&
.MARINE...
NEAR TERM: WINDS ARE NOW HITTING GALE FORCE(35 KTS) ESPECIALLY
OVER THE OUTER ZONES AS THE CAA IS HITTING IN EARNEST. WINDS WILL
INCREASE FOR A WHILE THIS EVENING W/GUSTS TO 40 KTS. THE NAM12 WAS
DOING WELL W/THE CURRENT SETUP. WINDS WILL START DROPPING OFF
LATER TONIGHT AS HIGH PRES TO THE SW RIDGES EASTWARD. GALE WARNING
WILL REMAIN THROUGH TUESDAY MORNING. EVENING CREW CAN ASSESS THIS
FURTHER W/THE LATER GUIDANCE. HEAVY FREEZING SPRAY EXPECTED
TONIGHT INTO EARLY TUESDAY THE WARNING IS UP FOR HEAVY ICING
POTENTIAL. SEAS ARE COMING UP BUT WERE SLOWER TO RESPOND. SEAS
SHOULD TOP OUT AROUND 8 FT OVER THE OUTER ZONES THIS EVENING AND
THEN BEGIN TO SUBSIDE LATER TONIGHT AS WINDS DROP OFF.
SHORT TERM: AN SCA MAY BE NEEDED LATE TUESDAY NIGHT THROUGH
WEDNESDAY AS LOW PRESSURE LIFTS ACROSS THE WATERS. HIGH PRESSURE
BUILDING OVER THE AREA SHOULD BRING MAINLY RELATIVELY LIGHT WINDS
LATE THIS WEEKEND INTO THE COMING WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ001>006-010-011-031-032.
WIND CHILL ADVISORY UNTIL 7 AM EST THIS MORNING FOR MEZ015>017-
029-030.
MARINE...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
ANZ050>052.
GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...HASTINGS/HEWITT/BLOOMER
MARINE...HASTINGS/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1214 PM EST TUE FEB 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 504 AM EST TUE FEB 24 2015
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM N
CNTRL CANADA INTO THE WRN LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO THE NW CONUS. WAA AND ISENTROPIC
LIFT AHEAD OF A SHORTWAVE TROUGH FROM NW ONTARIO INTO FAR NRN MN
SUPPORTED LIGHT SNOW ACROSS UPPER MICHIGAN WITH VSBY GENERALLY IN
THE 1-3SM RANGE. ANOTHER COMPACT UPSTREAM SHRTWV OR PV ANOMALY WAS
LOCATED OVER NRN MANITOBA. AT THE SFC...GUSTY SOUTHWEST WINDS AHEAD
OF TROUGH FROM NW ONTARIO INTO ERN MN WERE GRADUALLY DIMINISHING
EARLY THIS MORNING.
TODAY...EXPECT THAT THE WAA/ISENTROPIC LIFT WILL PRODUCE SNOW
AMOUNTS OF AN INCH OR TWO...GREATEST FROM THE KEWEENAW INTO THE ERN
CWA...IN LINE WITH THE STRONGEST LIFT. SNOW MAY ALSO INCREASE THIS
MORNING OVER THE WEST AS THE TROUGH AND SHRTWV MOVE THROUGH WITH A
PERIOD OF ENHANCED LOW LEVEL CONV. ALTHOUGH THE WRN LAKE IS MOSTLY
FROZEN THERE MAY BE ENOUGH GAPS IN THE ICE COVER FOR SOME ADDITIONAL
HEAT/MOISTURE TO BOOST THE SNOW. 230 SW FLOW OFF OF NRN LAKE
MICHIGAN WILL KEEP ADDITIONAL LES MAINLY E OF THE CWA. BY THIS
AFTERNON...THE NRN MANITOBA SHRTWV COULD SUPPORT A PERIOD OF HEAVIER
SNOW INTO CNTRL UPPER MI FOR A FEW HOURS GIVEN THE FORCING WITH THIS
FEATURE AND STEEP SFC-700 MB LAPSE RATES AS A -30C 700 MB COLD POOL
MOVES THROUGH. THIS COULD PRODUCE LOCAL ACCUMULATIONS OF AN INCH OR
TWO.
TONIGHT...ANOTHER BATCH OF COLD AIR WILL FOLLOW THE SHRTWV AS WINDS
VEER TO THE NW AND CAA DROPS 850 MB TEMPS INTO THE -23C TO -27C
RANGE. THE EXTENSIVE ICE COVER WILL SIGNFICANTLY REDUCE ANY LES
POTENTIAL BUT WITH THE RECENT STRONG WINDS A FEW MORE GAPS COULD
ALLOW SOME BANDS TO DEVELOP WITH LIGHT ACCUMULATIONS OF AN INCH OR
LESS...ESPECIALLY WITH THE LONGER FETCH INTO THE ERN CWA. ALTHOUGH
SOME LINGERING CLOUD COVER WILL LIMIT TEMP FALL...EXPECT MIN TEMPS
DOWN TO -7F TO -14F WITH WIND CHILL VALUES TO NEAR ADVISORY LEVELS
OF -25. HOWEVER...WINDS ARE ALSO EXPECTED TO DIMINISH TO NEAR 5 MPH
IN THE COLDEST AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE FEB 24 2015
WITH AN OVERALL DIMINISHING TREND IN THE LES...WITH THE
MOVING/BREAKING ICE HAVING A SIGNIFICANT IMPACT ON WHAT WE AREA ABLE
TO GET IN OUR NW TO W FLOW THAT WILL REMAIN THROUGH FRIDAY. EXPECT A
FEW STREAMERS OF LES OFF OPEN AREAS...IMPACTING PRIMARILY ALGER AND
N LUCE COUNTIES.
THE MAIN STORY FOR THIS PERIOD WILL BE LOW TEMPS AND THE POTENTIAL
FOR NEAR ADVISORY WIND CHILLS AGAIN. INCLUDED IN THE HWO THE MENTION
OF WIND CHILL READINGS OF 20 BELOW TO NEAR 30 BELOW ZERO THROUGH MID
MORNING WEDNESDAY...AND AGAIN WEDNESDAY NIGHT INTO THURSDAY MORNING.
THE TIME OF NEAR CRITICAL WIND CHILL VALUES WILL LIKELY BE SHORTER
THURSDAY NIGHT INTO EARLY FRIDAY MORNING. MAY NOT HOIST WIND CHILL
ADVISORIES FOR THESE PERIODS OVER THE ENTIRE CWA AS WINDS MAY NOT
GET TO THE 10MPH OR GREATER THRESHOLD. GENERALLY WE HAVE BEEN TOO
STRINGENT ON THE WIND SIDE OF THE CRITERIA WHEN WIND CHILLS HAVE
BEEN GETTING CLOSER TO WARNING LEVELS.
KEPT WITH VERY COLD AIR SETTLING IN WEDNESDAY NIGHT/THURSDAY
MORNING...WITH THE TRADITIONAL COLD SPOTS FALLING -20 TO -25F. THE
LONGWAVE TROUGH IS BASICALLY OVERHEAD...AND 850MB TEMPS -23 TO
-25C...AND THE SFC RIDGE EXPANDING ACROSS THE UPPER GREAT LAKES FROM
CENTRAL CANADA AND THE N PLAINS STATES.
OFFSHORE WINDS FRIDAY THROUGH SATURDAY SHOULD RESULT IN DRY WEATHER
FOR ALL OF UPPER MI. OPTED FOR A MODEL BLEND FOR SATURDAY NIGHT
THROUGH THE REST OF THE PERIOD...ONCE AGAIN LIMITED THE LES
POTENTIAL TO CHANCE AT MOST GIVEN THE ICE COVER OVER MUCH OF LAKE
SUPERIOR. THE SNOW POTENTIAL IS BECOMING LESS IMPRESSIVE
SUNDAY...WITH MUCH OF THE MOISTURE UNABLE TO RISE MUCH FARTHER N
THAN S WI.
AS NOTED FROM PREVIOUS LONG TERM DISCUSSION... FEBRUARY 2015 IS A
LOCK TO BREAK LAST YEAR/S RECORD COLD FEBRUARY. THROUGH THE
22ND...THE AVERAGE TEMP THIS MONTH HAS BEEN 2.9 DEGREES. PERFORMING
A ROUGH CALCULATION BASED OFF THE FORECAST DATA...WE SHOULD END UP
RIGHT AROUND 2.5 DEGREES FOR THE AVERAGE TEMPERATURE THIS MONTH AT
NWS MARQUETTE. THAT WOULD BEAT THE RECORD OF 5.6 DEGREES SET JUST
LAST YEAR. AT OTHER SITES WITH LONGER PERIODS OF RECORD...THIS
FEBRUARY WILL LIKELY END UP AS A TOP 5 OR TOP 10 COLDEST FEBRUARY.
MANY SITES HAVE 1936 AS THE COLDEST FEBRUARY ON RECORD...WHICH AT
IRONWOOD EVEN ENDED UP WITH AN AVERAGE TEMPERATURE BELOW ZERO
(ALMOST 4 DEGREES COLDER THAN WHAT HAS OCCURRED THIS MONTH).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1214 PM EST TUE FEB 24 2015
A REINFORCING DISTURBANCE AND ATTENDANT ARCTIC COLD FRONT WILL BRING
MORE SHSN/GUSTY NW WINDS/BLSN IN THE AFTERNOON IN THE PRESENCE OF
DIURNAL HEATING AND CAA THAT SHARPEN LOW LEVEL LAPSE RATES. ALTHOUGH
EXTENSIVE ICE COVER WL LIMIT THE INTENSITY OF THE LES...THE BLSN AT
THE MORE EXPOSED CMX LOCATION WILL LIKELY RESULT IN IFR VSBYS AT
LEAST PART OF THE TIME UNTIL THE EVNG...WHEN LARGER SCALE STRONG
SUBSIDENCE IN THE WAKE OF THIS DISTURBANCE SUPPRESSES THE LES OVER
THE ENTIRE AREA. CONDITIONS AT SAW WILL STAY MVFR FOR THE PERIOD
AND IWD WILL GO FROM MVFR TO VFR THIS EVENING AS DRIER AIR MOVES IN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EST TUE FEB 24 2015
SOUTHWEST GALES AROUND 35 KTS WILL DIMINISH EARLY THIS MORNING AS A
TROUGH MOVES INTO THE AREA. A COLD FRONT WILL MOVE ACROSS LAKE
SUPERIOR TODAY AND SHIFT WINDS TO THE NORTHWEST...BRINGING THE
POTENTIAL FOR A FEW GALE FORCE GUSTS TO 35 KNOTS BEHIND THE FRONT
OVER THE EASTERN LAKE. A HIGH PRESSURE RIDGE WILL BUILD BACK INTO
THE AREA WEDNESDAY AND REMAIN INTO SATURDAY...LEADING TO GENERALLY
LIGHT WINDS BELOW 20KTS. ICE COVER IS EXTENSIVE...SO FREEZING SPRAY
IS NOT A PROBLEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EST TUE FEB 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 504 AM EST TUE FEB 24 2015
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM N
CNTRL CANADA INTO THE WRN LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO THE NW CONUS. WAA AND ISENTROPIC
LIFT AHEAD OF A SHORTWAVE TROUGH FROM NW ONTARIO INTO FAR NRN MN
SUPPORTED LIGHT SNOW ACROSS UPPER MICHIGAN WITH VSBY GENERALLY IN
THE 1-3SM RANGE. ANOTHER COMPACT UPSTREAM SHRTWV OR PV ANOMALY WAS
LOCATED OVER NRN MANITOBA. AT THE SFC...GUSTY SOUTHWEST WINDS AHEAD
OF TROUGH FROM NW ONTARIO INTO ERN MN WERE GRADUALLY DIMINISHING
EARLY THIS MORNING.
TODAY...EXPECT THAT THE WAA/ISENTROPIC LIFT WILL PRODUCE SNOW
AMOUNTS OF AN INCH OR TWO...GREATEST FROM THE KEWEENAW INTO THE ERN
CWA...IN LINE WITH THE STRONGEST LIFT. SNOW MAY ALSO INCREASE THIS
MORNING OVER THE WEST AS THE TROUGH AND SHRTWV MOVE THROUGH WITH A
PERIOD OF ENHANCED LOW LEVEL CONV. ALTHOUGH THE WRN LAKE IS MOSTLY
FROZEN THERE MAY BE ENOUGH GAPS IN THE ICE COVER FOR SOME ADDITIONAL
HEAT/MOISTURE TO BOOST THE SNOW. 230 SW FLOW OFF OF NRN LAKE
MICHIGAN WILL KEEP ADDITIONAL LES MAINLY E OF THE CWA. BY THIS
AFTERNON...THE NRN MANITOBA SHRTWV COULD SUPPORT A PERIOD OF HEAVIER
SNOW INTO CNTRL UPPER MI FOR A FEW HOURS GIVEN THE FORCING WITH THIS
FEATURE AND STEEP SFC-700 MB LAPSE RATES AS A -30C 700 MB COLD POOL
MOVES THROUGH. THIS COULD PRODUCE LOCAL ACCUMULATIONS OF AN INCH OR
TWO.
TONIGHT...ANOTHER BATCH OF COLD AIR WILL FOLLOW THE SHRTWV AS WINDS
VEER TO THE NW AND CAA DROPS 850 MB TEMPS INTO THE -23C TO -27C
RANGE. THE EXTENSIVE ICE COVER WILL SIGNFICANTLY REDUCE ANY LES
POTENTIAL BUT WITH THE RECENT STRONG WINDS A FEW MORE GAPS COULD
ALLOW SOME BANDS TO DEVELOP WITH LIGHT ACCUMULATIONS OF AN INCH OR
LESS...ESPECIALLY WITH THE LONGER FETCH INTO THE ERN CWA. ALTHOUGH
SOME LINGERING CLOUD COVER WILL LIMIT TEMP FALL...EXPECT MIN TEMPS
DOWN TO -7F TO -14F WITH WIND CHILL VALUES TO NEAR ADVISORY LEVELS
OF -25. HOWEVER...WINDS ARE ALSO EXPECTED TO DIMINISH TO NEAR 5 MPH
IN THE COLDEST AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE FEB 24 2015
WITH AN OVERALL DIMINISHING TREND IN THE LES...WITH THE
MOVING/BREAKING ICE HAVING A SIGNIFICANT IMPACT ON WHAT WE AREA ABLE
TO GET IN OUR NW TO W FLOW THAT WILL REMAIN THROUGH FRIDAY. EXPECT A
FEW STREAMERS OF LES OFF OPEN AREAS...IMPACTING PRIMARILY ALGER AND
N LUCE COUNTIES.
THE MAIN STORY FOR THIS PERIOD WILL BE LOW TEMPS AND THE POTENTIAL
FOR NEAR ADVISORY WIND CHILLS AGAIN. INCLUDED IN THE HWO THE MENTION
OF WIND CHILL READINGS OF 20 BELOW TO NEAR 30 BELOW ZERO THROUGH MID
MORNING WEDNESDAY...AND AGAIN WEDNESDAY NIGHT INTO THURSDAY MORNING.
THE TIME OF NEAR CRITICAL WIND CHILL VALUES WILL LIKELY BE SHORTER
THURSDAY NIGHT INTO EARLY FRIDAY MORNING. MAY NOT HOIST WIND CHILL
ADVISORIES FOR THESE PERIODS OVER THE ENTIRE CWA AS WINDS MAY NOT
GET TO THE 10MPH OR GREATER THRESHOLD. GENERALLY WE HAVE BEEN TOO
STRINGENT ON THE WIND SIDE OF THE CRITERIA WHEN WIND CHILLS HAVE
BEEN GETTING CLOSER TO WARNING LEVELS.
KEPT WITH VERY COLD AIR SETTLING IN WEDNESDAY NIGHT/THURSDAY
MORNING...WITH THE TRADITIONAL COLD SPOTS FALLING -20 TO -25F. THE
LONGWAVE TROUGH IS BASICALLY OVERHEAD...AND 850MB TEMPS -23 TO
-25C...AND THE SFC RIDGE EXPANDING ACROSS THE UPPER GREAT LAKES FROM
CENTRAL CANADA AND THE N PLAINS STATES.
OFFSHORE WINDS FRIDAY THROUGH SATURDAY SHOULD RESULT IN DRY WEATHER
FOR ALL OF UPPER MI. OPTED FOR A MODEL BLEND FOR SATURDAY NIGHT
THROUGH THE REST OF THE PERIOD...ONCE AGAIN LIMITED THE LES
POTENTIAL TO CHANCE AT MOST GIVEN THE ICE COVER OVER MUCH OF LAKE
SUPERIOR. THE SNOW POTENTIAL IS BECOMING LESS IMPRESSIVE
SUNDAY...WITH MUCH OF THE MOISTURE UNABLE TO RISE MUCH FARTHER N
THAN S WI.
AS NOTED FROM PREVIOUS LONG TERM DISCUSSION... FEBRUARY 2015 IS A
LOCK TO BREAK LAST YEAR/S RECORD COLD FEBRUARY. THROUGH THE
22ND...THE AVERAGE TEMP THIS MONTH HAS BEEN 2.9 DEGREES. PERFORMING
A ROUGH CALCULATION BASED OFF THE FORECAST DATA...WE SHOULD END UP
RIGHT AROUND 2.5 DEGREES FOR THE AVERAGE TEMPERATURE THIS MONTH AT
NWS MARQUETTE. THAT WOULD BEAT THE RECORD OF 5.6 DEGREES SET JUST
LAST YEAR. AT OTHER SITES WITH LONGER PERIODS OF RECORD...THIS
FEBRUARY WILL LIKELY END UP AS A TOP 5 OR TOP 10 COLDEST FEBRUARY.
MANY SITES HAVE 1936 AS THE COLDEST FEBRUARY ON RECORD...WHICH AT
IRONWOOD EVEN ENDED UP WITH AN AVERAGE TEMPERATURE BELOW ZERO
(ALMOST 4 DEGREES COLDER THAN WHAT HAS OCCURRED THIS MONTH).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM EST TUE FEB 24 2015
AN AREA OF -SN IN ADVANCE OF AN APPROACHING COLD FRONT WILL
BRING A PERIOD OF MVFR CONDIITONS FOR SAW/IWD AND IFR AT CMX.
THE PERSISTENT IFR VSBYS WITH FALLING -SN AND SOME BLSN WHIPPED UP
BY GUSTY SW WINDS AT CMX WILL IS DUE TO THE CLOSER TRACK OF THE
ASSOCIATED SHRTWV AND DEEPER MOISTURE. ALTHOUGH THERE MAY BE SOME
IMPROVEMENT IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE AND STRONGER
DYNAMIC FORCING THIS MORNING...A REINFORCING DISTURBANCE AND
ATTENDANT ARCTIC COLD FRONT WILL BRING MORE SHSN/GUSTY NW WINDS/BLSN
IN THE AFTERNOON IN THE PRESENCE OF DIURNAL HEATING AND CAA THAT
SHARPEN LOW LEVEL LAPSE RATES. ALTHOUGH EXTENSIVE ICE COVER WILL
LIMIT THE INTENSITY OF THE LES...THE BLSN AT THE MORE EXPOSED CMX
LOCATION WILL LIKELY RESULT IN IFR VSBYS AT LEAST PART OF THE TIME
UNTIL THE EVNG...WHEN LARGER SCALE STRONG SUBSIDENCE IN THE WAKE OF
THIS DISTURBANCE SUPPRESSES THE LES OVER THE ENTIRE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EST TUE FEB 24 2015
SOUTHWEST GALES AROUND 35 KTS WILL DIMINISH EARLY THIS MORNING AS A
TROUGH MOVES INTO THE AREA. A COLD FRONT WILL MOVE ACROSS LAKE
SUPERIOR TODAY AND SHIFT WINDS TO THE NORTHWEST...BRINGING THE
POTENTIAL FOR A FEW GALE FORCE GUSTS TO 35 KNOTS BEHIND THE FRONT
OVER THE EASTERN LAKE. A HIGH PRESSURE RIDGE WILL BUILD BACK INTO
THE AREA WEDNESDAY AND REMAIN INTO SATURDAY...LEADING TO GENERALLY
LIGHT WINDS BELOW 20KTS. ICE COVER IS EXTENSIVE...SO FREEZING SPRAY
IS NOT A PROBLEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
505 AM EST TUE FEB 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 504 AM EST TUE FEB 24 2015
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM N
CNTRL CANADA INTO THE WRN LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO THE NW CONUS. WAA AND ISENTROPIC
LIFT AHEAD OF A SHORTWAVE TROUGH FROM NW ONTARIO INTO FAR NRN MN
SUPPORTED LIGHT SNOW ACROSS UPPER MICHIGAN WITH VSBY GENERALLY IN
THE 1-3SM RANGE. ANOTHER COMPACT UPSTREAM SHRTWV OR PV ANOMALY WAS
LOCATED OVER NRN MANITOBA. AT THE SFC...GUSTY SOUTHWEST WINDS AHEAD
OF TROUGH FROM NW ONTARIO INTO ERN MN WERE GRADUALLY DIMINISHING
EARLY THIS MORNING.
TODAY...EXPECT THAT THE WAA/ISENTROPIC LIFT WILL PRODUCE SNOW
AMOUNTS OF AN INCH OR TWO...GREATEST FROM THE KEWEENAW INTO THE ERN
CWA...IN LINE WITH THE STRONGEST LIFT. SNOW MAY ALSO INCREASE THIS
MORNING OVER THE WEST AS THE TROUGH AND SHRTWV MOVE THROUGH WITH A
PERIOD OF ENHANCED LOW LEVEL CONV. ALTHOUGH THE WRN LAKE IS MOSTLY
FROZEN THERE MAY BE ENOUGH GAPS IN THE ICE COVER FOR SOME ADDITIONAL
HEAT/MOISTURE TO BOOST THE SNOW. 230 SW FLOW OFF OF NRN LAKE
MICHIGAN WILL KEEP ADDITIONAL LES MAINLY E OF THE CWA. BY THIS
AFTERNON...THE NRN MANITOBA SHRTWV COULD SUPPORT A PERIOD OF HEAVIER
SNOW INTO CNTRL UPPER MI FOR A FEW HOURS GIVEN THE FORCING WITH THIS
FEATURE AND STEEP SFC-700 MB LAPSE RATES AS A -30C 700 MB COLD POOL
MOVES THROUGH. THIS COULD PRODUCE LOCAL ACCUMULATIONS OF AN INCH OR
TWO.
TONIGHT...ANOTHER BATCH OF COLD AIR WILL FOLLOW THE SHRTWV AS WINDS
VEER TO THE NW AND CAA DROPS 850 MB TEMPS INTO THE -23C TO -27C
RANGE. THE EXTENSIVE ICE COVER WILL SIGNFICANTLY REDUCE ANY LES
POTENTIAL BUT WITH THE RECENT STRONG WINDS A FEW MORE GAPS COULD
ALLOW SOME BANDS TO DEVELOP WITH LIGHT ACCUMULATIONS OF AN INCH OR
LESS...ESPECIALLY WITH THE LONGER FETCH INTO THE ERN CWA. ALTHOUGH
SOME LINGERING CLOUD COVER WILL LIMIT TEMP FALL...EXPECT MIN TEMPS
DOWN TO -7F TO -14F WITH WIND CHILL VALUES TO NEAR ADVISORY LEVELS
OF -25. HOWEVER...WINDS ARE ALSO EXPECTED TO DIMINISH TO NEAR 5 MPH
IN THE COLDEST AREAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 446 AM EST TUE FEB 24 2015
WITH AN OVERALL DIMINISHING TREND IN THE LES...WITH THE
MOVING/BREAKING ICE HAVING A SIGNIFICANT IMPACT ON WHAT WE AREA ABLE
TO GET IN OUR NW TO W FLOW THAT WILL REMAIN THROUGH FRIDAY. EXPECT A
FEW STREAMERS OF LES OFF OPEN AREAS...IMPACTING PRIMARILY ALGER AND
N LUCE COUNTIES.
THE MAIN STORY FOR THIS PERIOD WILL BE LOW TEMPS AND THE POTENTIAL
FOR NEAR ADVISORY WIND CHILLS AGAIN. INCLUDED IN THE HWO THE MENTION
OF WIND CHILL READINGS OF 20 BELOW TO NEAR 30 BELOW ZERO THROUGH MID
MORNING WEDNESDAY...AND AGAIN WEDNESDAY NIGHT INTO THURSDAY MORNING.
THE TIME OF NEAR CRITICAL WIND CHILL VALUES WILL LIKELY BE SHORTER
THURSDAY NIGHT INTO EARLY FRIDAY MORNING. MAY NOT HOIST WIND CHILL
ADVISORIES FOR THESE PERIODS OVER THE ENTIRE CWA AS WINDS MAY NOT
GET TO THE 10MPH OR GREATER THRESHOLD. GENERALLY WE HAVE BEEN TOO
STRINGENT ON THE WIND SIDE OF THE CRITERIA WHEN WIND CHILLS HAVE
BEEN GETTING CLOSER TO WARNING LEVELS.
KEPT WITH VERY COLD AIR SETTLING IN WEDNESDAY NIGHT/THURSDAY
MORNING...WITH THE TRADITIONAL COLD SPOTS FALLING -20 TO -25F. THE
LONGWAVE TROUGH IS BASICALLY OVERHEAD...AND 850MB TEMPS -23 TO
-25C...AND THE SFC RIDGE EXPANDING ACROSS THE UPPER GREAT LAKES FROM
CENTRAL CANADA AND THE N PLAINS STATES.
OFFSHORE WINDS FRIDAY THROUGH SATURDAY SHOULD RESULT IN DRY WEATHER
FOR ALL OF UPPER MI. OPTED FOR A MODEL BLEND FOR SATURDAY NIGHT
THROUGH THE REST OF THE PERIOD...ONCE AGAIN LIMITED THE LES
POTENTIAL TO CHANCE AT MOST GIVEN THE ICE COVER OVER MUCH OF LAKE
SUPERIOR. THE SNOW POTENTIAL IS BECOMING LESS IMPRESSIVE
SUNDAY...WITH MUCH OF THE MOISTURE UNABLE TO RISE MUCH FARTHER N
THAN S WI.
AS NOTED FROM PREVIOUS LONG TERM DISCUSSION... FEBRUARY 2015 IS A
LOCK TO BREAK LAST YEAR/S RECORD COLD FEBRUARY. THROUGH THE
22ND...THE AVERAGE TEMP THIS MONTH HAS BEEN 2.9 DEGREES. PERFORMING
A ROUGH CALCULATION BASED OFF THE FORECAST DATA...WE SHOULD END UP
RIGHT AROUND 2.5 DEGREES FOR THE AVERAGE TEMPERATURE THIS MONTH AT
NWS MARQUETTE. THAT WOULD BEAT THE RECORD OF 5.6 DEGREES SET JUST
LAST YEAR. AT OTHER SITES WITH LONGER PERIODS OF RECORD...THIS
FEBRUARY WILL LIKELY END UP AS A TOP 5 OR TOP 10 COLDEST FEBRUARY.
MANY SITES HAVE 1936 AS THE COLDEST FEBRUARY ON RECORD...WHICH AT
IRONWOOD EVEN ENDED UP WITH AN AVERAGE TEMPERATURE BELOW ZERO
(ALMOST 4 DEGREES COLDER THAN WHAT HAS OCCURRED THIS MONTH).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM EST TUE FEB 24 2015
AN AREA OF -SN IN ADVANCE OF AN APRCHG COLD FNT WL OVERSPREAD UPR MI
EARLY THIS MRNG...BRINGING A PERIOD OF MVFR AND PERHAPS IFR
CONDITIONS. THE BEST CHC FOR PERSISTENT IFR VSBYS DUE TO THE FALLING
-SN AND SOME BLSN WHIPPED UP BY GUSTY SW WINDS WL BE AT CMX...CLOSER
TO THE TRACK OF THE ASSOCIATED SHRTWV AND DEEPER MSTR. ALTHOUGH
THERE MAY BE SOME IMPROVEMENT IMMEDIATELY FOLLOWING THE FROPA AND
STRONGER DYNAMIC FORCING AFTER SUNRISE THIS MRNG...A REINFORCING
DISTURBANCE AND ATTENDANT ARCTIC COLD FROPA WL BRING MORE SHSN/GUSTY
NW WINDS/BLSN IN THE AFTN IN THE PRESENCE OF DIURNAL HEATING AND CAA
THAT SHARPEN LLVL LAPSE RATES. ALTHOUGH EXTENSIVE ICE COVER WL LIMIT
THE INTENSITY OF THE LES...THE BLSN AT THE MORE EXPOSED CMX LOCATION
WL LIKELY RESULT IN IFR VSBYS AT LEAST PART OF THE TIME UNTIL THE
EVNG...WHEN LARGER SCALE STRONG SUBSIDENCE IN THE WAKE OF THIS
DISTURBANCE SUPPRESSES THE LES OVER THE ENTIRE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 504 AM EST TUE FEB 24 2015
SOUTHWEST GALES AROUND 35 KTS WILL DIMINISH EARLY THIS MORNING AS A
TROUGH MOVES INTO THE AREA. A COLD FRONT WILL MOVE ACROSS LAKE
SUPERIOR TODAY AND SHIFT WINDS TO THE NORTHWEST...BRINGING THE
POTENTIAL FOR A FEW GALE FORCE GUSTS TO 35 KNOTS BEHIND THE FRONT
OVER THE EASTERN LAKE. A HIGH PRESSURE RIDGE WILL BUILD BACK INTO
THE AREA WEDNESDAY AND REMAIN INTO SATURDAY...LEADING TO GENERALLY
LIGHT WINDS BELOW 20KTS. ICE COVER IS EXTENSIVE...SO FREEZING SPRAY
IS NOT A PROBLEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1129 PM EST MON FEB 23 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 239 PM EST MON FEB 23 2015
A FAST MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD THROUGH
ONTARIO TONIGHT AND TUESDAY. THIS SYSTEM WILL PROVIDE THE GREAT
LAKES REGION WITH WINDY CONDITIONS AND SOME SNOW. CONSIDERABLE
DRIFTING SNOW WILL BE POSSIBLE ON TUESDAY. ANOTHER ARCTIC AIRMASS
WILL TRACK IN BEHIND THIS DEPARTING STORM AND PERSIST INTO THE
WEEKEND.
&&
.UPDATE...
ISSUED AT 902 PM EST MON FEB 23 2015
NO HEADLINE OR SIGNIFICANT FCST CHANGES ARE NECESSARY TONIGHT. A
CONSENSUS OF LATEST SHORT RANGE GUIDANCE STILL SUGGESTS THAT SNOW
AMOUNTS WITH THE SYSTEM TUESDAY WILL BE FAIRLY LIGHT OVERALL WITH
THE RELATIVELY HIGHEST AMOUNTS OF UP TO 3 TO 5 INCHES NEAR TO NW
OF A LINE FROM KMKG TO KRQB. MOST OF OUR AREA WILL ONLY GET AN
INCH OR TWO OF SNOW WITH THIS SYSTEM. HOWEVER THE COMBINATION OF
STRONG WINDS AND THE SNOW WILL RESULT IN SOME HAZARDOUS TRAVEL
CONDITIONS FROM MID TO LATE MORNING THROUGH TUESDAY EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 239 PM EST MON FEB 23 2015
THE MAIN ISSUE DEALS WITH THE IMPACT OF THE LOW PRESSURE SYSTEM
THAT TRACKS THROUGH ONTARIO TONIGHT AND TUESDAY. OVERALL IT LOOKS
LIKE ENOUGH IMPACTS TO WARRANT HEADLINES FOR THE ENTIRE REGION.
I DID CHECK IN WITH A COUPLE OF ROAD COMMISSIONS AND THEY
INDICATED THAT WINDS OVER 30 MPH WILL LEAD TO CONSIDERABLE
DRIFTING OF THE SNOW...ESPECIALLY IN RURAL AREAS. EVEN SOME
HIGHWAYS COULD BE IMPACTED. THE RUC MODEL SHOWS GUSTS TOPPING 40
KNOTS FROM NEAR GRAND RAPIDS NORTHEAST THROUGH MOUNT PLEASANT AND
BETTER THAN 35 KNOTS ELSEWHERE. THERE IS A SECONDARY MAX ALONG THE
LAKESHORE NORTH OF MUSKEGON...WITH BETTER THAN 40 KNOTS POSSIBLE.
I AM NOT CERTAIN WILL SEE SUCH HIGH WINDS. HOWEVER ENOUGH RISK
THERE TO GO WITH A HEADLINE. THE MAIN WINDOW OF STRONG WINDS
RANGES FROM 09Z TO 18Z FOR LUDINGTON...13Z TO 21Z FOR GRAND RAPIDS
AND 16Z TO 23Z FOR JACKSON.
SNOW ON TUESDAY WILL BE A SECONDARY CONCERN FOR THIS SYSTEM WITH AMOUNTS
EXPECTED TO RANGE FROM 2 TO 4 INCHES OF LAKE ENHANCED SNOW UP
NORTH FROM LUDINGTON TO HARRISON. FURTHER SOUTH GRAND RAPIDS AND
MOUNT PLEASANT ROUGHLY 1 TO 3 INCHES...TO AN INCH OR LESS FOR
JACKSON AND LANSING. STILL...WITH GUSTY WINDS AND SNOW...
VISIBILITIES COULD BE REDUCED CONSIDERABLY AT TIMES. LOCATIONS
SOUTHEAST OF GRAND RAPIDS COULD START THE DAY OFF WITH SOME SUN.
WIND CHILL VALUES ON TUESDAY COULD START OFF AROUND -15 DEGREES...
WHICH IS HAZARDOUS.
TUESDAY NIGHT AFTER A LULL IN THE WIND...WE COULD SEE A RETURN OF
SNOW AND POSSIBLE IMPACTS...MAINLY AFTER MIDNIGHT. WILL NEED TO
ASSESS THIS POSSIBILITY WITH LATER FORECASTS.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 239 PM EST MON FEB 23 2015
THE FOCUS OF THE LONG TERM IS THE EVOLUTION OF A SOUTHERN STREAM
SYSTEM THAT BOTH THE GFS AND ECMWF HAVE LATCHED ONTO FOR A COUPLE OF
DAYS NOW. CONDITIONS LOOK PRETTY DRY...BUT COLD FROM THURSDAY
THROUGH SATURDAY...AND LIKELY MONDAY TOO. HOWEVER IT`S THE PERIOD
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT THAT PROMISES TO BE
INTERESTING.
IT/S LOOKING INCREASINGLY LIKELY THAT PCPN WILL DEVELOP OVER THE SW
CWA SATURDAY EVENING...LIKELY AS SNOW...AND CONTINUE THROUGH SUNDAY.
THE GULF IS WIDE OPEN DUE TO HIGH PRESSURE NEAR THE EAST COAST AND
SO THERE WILL BE A STRONG INFLUX OF MOISTURE. DESPITE THE MOISTURE
CONTENT OF THIS SYSTEM...IT STILL HAS SOME ISSUES. ECMWF AND GFS
BOTH SHOW THIS BEGINNING AS AN INVERTED TROUGH AND THEN PHASING WITH
A NORTHERN STREAM CLIPPER AS IT PUSHES A COLD FRONT THROUGH THE CWA.
THIS ISN/T THE CLASSIC STRENGTHENING CLOSED LOW THAT MOVES FROM THE
SOUTHERN PLAINS NEWD. AT LEAST NOT YET. QPF WITH THE SYSTEM IS PROGD
IN THE 2/3 TO 3/4 INCH RANGE...WHICH IF ALL SNOW WOULD CERTAINLY BE
PLOWABLE. THE WARMER ECMWF WOULD LIKELY TURN PCPN TO MIXED RAIN AND
SNOW ACROSS THE SOUTHERN CWA. FOR CONTINUITY SAKE WE KEPT THE PCPN
AS SNOW IN THE GRIDS FOR NOW.
ALL OF THE PCPN WILL LIKELY END MONDAY AS THE SYSTEM MOVES EAST AND
ANOTHER SHOT OF COLD AIR MOVES SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1122 PM EST MON FEB 23 2015
THE MAIN AVIATION ISSUE OVER THE NEXT 24 HOURS IS THE WINDS.
SOUTHWEST WINDS WILL INCREASE OVERNIGHT TO 15 TO 25 KNOTS AND
AFTER DAYBREAK TO 20 TO 30 KNOTS WITH SOME GUSTS AS HIGH AS 40
KNOTS. THE HIGHEST WINDS APPEAR TO OCCUR BETWEEN 12Z AND 18Z.
THE STRONG WINDS WILL RESULT IN AREAS OF BLOWING SNOW DEVELOPING
BEFORE THE SNOW MOVES IN WHICH COULD LEAD TO REDUCE VSBYS AND
SLICK RUNWAY CONDITIONS FOR THE MORNING RUSH.
THE FALLING SNOW WILL SPREAD INTO THE REGION FROM NORTHWEST TO
SOUTHEAST... REACHING MKG AROUND 15Z AND LAN/JXN AROUND 19Z. THE
HEAVIEST SNOW AND LOWEST VSBYS WILL BE AT MKG AND GRR SO WILL KEEP
PREDOMINATELY IFR VSBYS TUESDAY AFTERNOON AT THESE TWO SITES AND
MOSTLY MVFR VSBYS AT THE OTHER TERMINALS. THERE IS A POTENTIAL
HOWEVER FOR IFR TO DEVELOP AT ALL THE TERMINALS DEPENDING ON THE
EXTENT OF THE BLOWING SNOW.
WINDS DIMINISHING AFTER 00Z WED BUT STILL 10 TO 20 KTS... AND
CIGS/VSBYS REMAINING PREDOMINATELY MVFR. CANT RULE OUT SOME IFR
VSBYS IN SNOW SHOWERS PERSISTING BEYOND 00Z WED BUT WAS NOT
CONFIDENT ENOUGH TO HAVE IN THE TAFS.
&&
.HYDROLOGY...
ISSUED AT 239 PM EST MON FEB 23 2015
WITH NO MAJOR WARM UPS OR RAINFALL HEADED OUR WAY IN THE NEAR
FUTURE...RUNOFF WILL BE LIMITED. SERIOUS ICE JAMS AND FLOODING
CONCERNS ARE UNLIKELY UNTIL A SIGNIFICANT WARM UP AND RAINFALL
OCCUR. CONSIDERABLE ICE DOES EXIST IN THE RIVERS SO WE WILL NEED
TO MONITOR TRENDS CLOSELY. FOR NOW WITH CONDITIONS STABLE DUE TO
THE ARCTIC AIRMASS IN PLACE...THE RISK IS SOMEWHAT LIMITED FOR
FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 4 AM TO 7 PM EST TUESDAY FOR
MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...NONE.
&&
$$
UPDATE...LAURENS
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...04
AVIATION...MEADE
HYDROLOGY...MJS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
956 AM CST TUE FEB 24 2015
.UPDATE...FOR THE MOST PART...PRECIP IS OVER ACROSS THE AREA
THIS MORNING. THERE HAVE BEEN A FEW EXCEPTIONS WITH A REPORT OR TWO
OF FREEZING DRIZZLE OR FLURRIES. THIS IS LIKELY DUE TO SOME VERY
LIGHT PRECIP BEING SQUEEZED OUT IN THE LOWER ATMOSPHERE. LOOK FOR
THAT TO SHUT OFF AS THE LAYER DRIES OUT THROUGH MIDDAY AND THE
AFTERNOON. MOST OF THE AREA WILL REMAIN CLOUDY INTO EARLY
AFTERNOON...BUT LOOK FOR THINNING OF CLOUDS FROM THE NORTH AND SOME
FILTERED SUNSHINE WILL EXIST LATER THIS AFTERNOON FOR NORTHERN
SECTIONS. THE MORNING FORECAST WAS ADJUSTED TO REMOVE THE ADVISORY
WORDING AND ANY MENTION OF PRECIP. LOOK FOR TEMPS TODAY TO SLOWLY
CLIMB WITH MOST OF OUR W/NW STRUGGLING TO REACH 32-34 DEGREES. THE
REST OF THE AREA E/SE HALF WILL SLOWLY WARM AND RANGE FROM THE UPPER
30S TO LOWER 40S.
THE FORECAST NOW SHIFTS TO THE NEXT WINTER WEATHER EVENT. THIS LOOKS
BE IN THE FORM OF SNOW AND HEAVY SNOW FOR MUCH OF THE NORTHERN HALF
OF THE FORECAST AREA. CURRENT FORECAST ELEMENTS HAVE NOT BEEN
CHANGED...BUT SOME ADJUSTMENTS MAY BE NEEDED BASED OFF THE LATEST
FORECAST GUIDANCE. WHILE 2-4 INCHES WILL COVER THE MAIN AXIS...THERE
WILL LIKELY BE SOME LOCATIONS THAT SEE A BIT MORE...POSSIBLY CLOSER
TO 6 INCHES. THE FORECAST LATER TODAY WILL TRY AND IRON THESE
DETAILS OUT. ADDITIONALLY...LOOK FOR THE CURRENT WINTER STORM WATCH
TO BE UPGRADED TO A WARNING BY AFTERNOON. AGAIN...MORE SPECIFICS ON
THIS NEXT EVENT IN THE NEXT FORECAST. /CME/
&&
.AVIATION...WINTRY PRECIPITATION HAS ENDED AT TAF SITES THIS
MORNING. THAT SAID...A MIX OF IFR...MVFR...AND VFR FLIGHT STATUSES
ARE CURRENTLY BEING OBSERVED AT SITES THIS MORNING AS CEILINGS VARY
ACROSS THE REGION. THESE CEILINGS WILL IMPROVE A BIT THIS
AFTERNOON...BUT A MIX OF MVFR AND VFR CEILINGS ARE STILL EXPECTED TO
CONTINUE THROUGH THE FORECAST PERIOD. PRECIPITATION WILL RE-ENTER
THE FORECAST EARLY WEDNESDAY MORNING. THIS WILL PRIMARILY BE IN THE
FORM OF SNOW ALONG THE HIGHWAY 82 CORRIDOR (KGLH...KGWO...AND
KGTR)...BUT MORE OF A MIX OF LIGHT SLEET AND LIGHT SNOW COULD AFFECT
SITES AS FAR SOUTH AS THE INTERSTATE 20 CORRIDOR (KHKS...KJAN...AND
KMEI). THESE SCENARIOS WILL OBVIOUSLY RESULT IN SOME ACCUMULATION
OF FROZEN PRECIPITATION ON AIRCRAFT...RUNWAYS...AND TARMACS. WINDS
TODAY WILL BE FROM THE NORTHWEST BETWEEN 5-8 KNOTS...AND WILL
SUBSIDE TO AROUND 3-5 KNOTS FROM THE NORTHWEST TONIGHT. /19/
&&
.PREV DISCUSSION... /ISSUED 437 AM CST TUE FEB 24 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...CONTINUING TO SEE PATCHY
LIGHT FREEZING RAIN/DRIZZLE POPPING UP ON RADAR OVER CENTRAL/EAST
AND SOUTH SECTIONS THIS MORNING AS HRRR IS STILL INDICATING SOME WEAK
ISENTROPIC ASCENT LINGERING IN THESE AREAS UNTIL MID MORNING. WILL
KEEP THE FREEZING RAIN ADVISORY RUNNING UNTIL MID MORNING DUE TO
EXISTING ICE PROBLEMS CONTINUING A BIT LONGER. EXPECT SURFACE TEMPS
WILL BE SLOW TO RISE OVER AREAS THAT HAD ICE ACCUMULATIONS. COOLING
DUE TO MELTING...PERSISTENT CLOUD COVER AND LIGHT NORTHERLY WINDS
WILL ALL CONTRIBUTE TO A RATHER CHILLY DAY.
MOVING INTO TONIGHT EMPHASIS QUICKLY SWITCHES TO NEXT LOOMING EVENT
ON THE HORIZON. 110 KNOT UPPER LEVEL JET WILL QUICKLY MOVE PHASING
COLD CORE LOW...PRESENTLY OVER AZ...EAST THROUGH THE DAY INTO THIS
EVENING. MORE PRECIP TO BEGIN MOVING BACK INTO THE AREA AFTER
MIDNIGHT TONIGHT AHEAD OF THE ADVANCING COLD CORE. MAY INITIALLY
HAVE TO PUT UP WITH SOME MORE LIGHT FREEZING RAIN OVER CENTRAL AND
SW SECTIONS AS SURFACE TEMPS WILL BE BELOW FREEZING IN THESE AREAS
WHEN PRECIP BEGINS.
AS THE COLD CORE NEARS THE AREA...COOLING IN THE COLUMN WILL
INCREASE ALLOWING WIDESPREAD SNOWS TO BREAK OUT OVER THE NORTHERN
THIRD OF THE AREA. IMPRESSIVE SNOW SOUNDINGS SEEN IN THE EC AND NAM
BUFR DATA...WITH MORE OF A MIXED BAG OF RAIN/SLEET/SNOW OVER CENTRAL
SECTIONS THROUGH THE DAY. THE VERTICAL WIND FIELD WITH THIS SYSTEM
WILL LEAD TO STRONG ADIABATIC FORCING AND WIDESPREAD 2 TO 4 INCH
SNOW AMOUNTS. SOME DIABATIC CONTRIBUTION LOOKS POSSIBLE AS WELL AS
NAM MODEL SOUNDINGS ARE INDICATING 6-7C/KM H7-H5 LAPSE RATES OVER
THE SOUTHERN TWO THIRDS. MAY SEE SOME EMBEDDED THUNDER IN THE
HEAVIER BANDS. WILL CONTINUE WITH THE WATCH...BUT ADD A FEW EXTRA
COUNTIES ON THE SOUTHERN EDGE BASED ON CURRENT EXPECTED AMOUNTS.
EXPECT THE CENTRAL SECTIONS THAT OBSERVE THE MIXED BAG WILL SEE A
CHANGEOVER TO ALL SNOW BY LATE WEDNESDAY AFTERNOON/EARLY EVENING
BEFORE ENDING AS THE COMMA HEAD/DEFORMATION ZONE MOVES ACROSS THE
AREA. ALL PRECIP WILL COME TO AN END BY MIDNIGHT./26/
LONG TERM...THURSDAY THROUGH TUESDAY...THINGS FINALLY WILL QUIET
DOWN ACROSS THE ARKLAMISS AT LEAST IN THE MID TERM. BROAD UPPER
TROUGHING AND NORTHERLY SURFACE FLOW WILL PREVAIL ON THURSDAY WITH
COOL HIGH TEMPERATURES IN THE 40S OVER MUCH OF THE AREA. ANOTHER
COLD FRONT WILL DROP SOUTH ACROSS THE AREA THURSDAY AFTERNOON/
EVENING WHICH WILL MAINLY BE A REINFORCING SHOT OF COLD AIR. SURFACE
HIGH PRESSURE RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY FROM
A HIGH CENTERED OVER THE WESTERN PORTIONS OF THE OHIO VALLEY.
TEMPERATURES WILL CONTINUE TO BE COOL WITH LOWS IN THE 20S AND HIGHS
ONLY CLIMBING INTO THE 40S TO AROUND 50 IN THE SOUTH ONCE AGAIN ON
FRIDAY.
AS THE SURFACE HIGH SHIFTS TO THE EAST COAST ON SATURDAY THE SURFACE
FLOW WILL BECOME MORE EASTERLY AND EVENTUALLY SOUTHEASTERLY BY
SUNDAY. TEMPERATURES WILL BE ON THE RISE ON SATURDAY AND ESPECIALLY
ON SUNDAY WITH HIGHS BACK UP INTO THE 60S AND POSSIBLY LOW 70S IN
THE SOUTH. THE GLOBAL MODELS ARE IN PRETTY GOOD AGREEMENT OF
INCREASING CHANCES OF SHOWERS/THUNDERSTORMS ON MONDAY WITH BOTH OF
THE MODELS INDICATING THAT THERE COULD BE SOME POTENTIAL FOR SEVERE
DURING THE MONDAY/TUESDAY TIMEFRAME WITH CONTINUED WARM TEMPERATURES.
/15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 31 35 29 / 3 45 100 34
MERIDIAN 41 31 37 30 / 4 32 100 42
VICKSBURG 35 31 35 30 / 3 56 100 28
HATTIESBURG 44 35 41 32 / 4 48 100 36
NATCHEZ 37 30 36 31 / 3 68 100 26
GREENVILLE 33 30 33 27 / 0 30 97 27
GREENWOOD 35 29 33 27 / 0 23 97 33
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR MSZ018-019-025>045.
LA...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR LAZ007>009.
AR...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR ARZ074-075.
&&
$$
CME/19/
AREA FORECAST DISCUSSION
NWS JACKSON MS
437 AM CST TUE FEB 24 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...CONTINUING TO SEE PATCHY
LIGHT FREEZING RAIN/DRIZZLE POPPING UP ON RADAR OVER CENTRAL/EAST
AND SOUTH SECTIONS THIS MORNING AS HRRR IS STILL INDICATING SOME WEAK
ISENTROPIC ASCENT LINGERING IN THESE AREAS UNTIL MID MORNING. WILL
KEEP THE FREEZING RAIN ADVISORY RUNNING UNTIL MID MORNING DUE TO
EXISTING ICE PROBLEMS CONTINUING A BIT LONGER. EXPECT SURFACE TEMPS
WILL BE SLOW TO RISE OVER AREAS THAT HAD ICE ACCUMULATIONS. COOLING
DUE TO MELTING...PERSISTENT CLOUD COVER AND LIGHT NORTHERLY WINDS
WILL ALL CONTRIBUTE TO A RATHER CHILLY DAY.
MOVING INTO TONIGHT EMPHASIS QUICKLY SWITCHES TO NEXT LOOMING EVENT
ON THE HORIZON. 110 KNOT UPPER LEVEL JET WILL QUICKLY MOVE PHASING
COLD CORE LOW...PRESENTLY OVER AZ...EAST THROUGH THE DAY INTO THIS
EVENING. MORE PRECIP TO BEGIN MOVING BACK INTO THE AREA AFTER
MIDNIGHT TONIGHT AHEAD OF THE ADVANCING COLD CORE. MAY INITIALLY
HAVE TO PUT UP WITH SOME MORE LIGHT FREEZING RAIN OVER CENTRAL AND
SW SECTIONS AS SURFACE TEMPS WILL BE BELOW FREEZING IN THESE AREAS
WHEN PRECIP BEGINS.
AS THE COLD CORE NEARS THE AREA...COOLING IN THE COLUMN WILL
INCREASE ALLOWING WIDESPREAD SNOWS TO BREAK OUT OVER THE NORTHERN
THIRD OF THE AREA. IMPRESSIVE SNOW SOUNDINGS SEEN IN THE EC AND NAM
BUFR DATA...WITH MORE OF A MIXED BAG OF RAIN/SLEET/SNOW OVER CENTRAL
SECTIONS THROUGH THE DAY. THE VERTICAL WIND FIELD WITH THIS SYSTEM
WILL LEAD TO STRONG ADIABATIC FORCING AND WIDESPREAD 2 TO 4 INCH
SNOW AMOUNTS. SOME DIABATIC CONTRIBUTION LOOKS POSSIBLE AS WELL AS
NAM MODEL SOUNDINGS ARE INDICATING 6-7C/KM H7-H5 LAPSE RATES OVER
THE SOUTHERN TWO THIRDS. MAY SEE SOME EMBEDDED THUNDER IN THE
HEAVIER BANDS. WILL CONTINUE WITH THE WATCH...BUT ADD A FEW EXTRA
COUNTIES ON THE SOUTHERN EDGE BASED ON CURRENT EXPECTED AMOUNTS.
EXPECT THE CENTRAL SECTIONS THAT OBSERVE THE MIXED BAG WILL SEE A
CHANGEOVER TO ALL SNOW BY LATE WEDNESDAY AFTERNOON/EARLY EVENING
BEFORE ENDING AS THE COMMA HEAD/DEFORMATION ZONE MOVES ACROSS THE
AREA. ALL PRECIP WILL COME TO AN END BY MIDNIGHT./26/
.LONG TERM...THURSDAY THROUGH TUESDAY...THINGS FINALLY WILL QUIET
DOWN ACROSS THE ARKLAMISS AT LEAST IN THE MID TERM. BROAD UPPER
TROUGHING AND NORTHERLY SURFACE FLOW WILL PREVAIL ON THURSDAY WITH
COOL HIGH TEMPERATURES IN THE 40S OVER MUCH OF THE AREA. ANOTHER
COLD FRONT WILL DROP SOUTH ACROSS THE AREA THURSDAY AFTERNOON/
EVENING WHICH WILL MAINLY BE A REINFORCING SHOT OF COLD AIR. SURFACE
HIGH PRESSURE RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY FROM
A HIGH CENTERED OVER THE WESTERN PORTIONS OF THE OHIO VALLEY.
TEMPERATURES WILL CONTINUE TO BE COOL WITH LOWS IN THE 20S AND HIGHS
ONLY CLIMBING INTO THE 40S TO AROUND 50 IN THE SOUTH ONCE AGAIN ON
FRIDAY.
AS THE SURFACE HIGH SHIFTS TO THE EAST COAST ON SATURDAY THE SURFACE
FLOW WILL BECOME MORE EASTERLY AND EVENTUALLY SOUTHEASTERLY BY
SUNDAY. TEMPERATURES WILL BE ON THE RISE ON SATURDAY AND ESPECIALLY
ON SUNDAY WITH HIGHS BACK UP INTO THE 60S AND POSSIBLY LOW 70S IN
THE SOUTH. THE GLOBAL MODELS ARE IN PRETTY GOOD AGREEMENT OF
INCREASING CHANCES OF SHOWERS/THUNDERSTORMS ON MONDAY WITH BOTH OF
THE MODELS INDICATING THAT THERE COULD BE SOME POTENTIAL FOR SEVERE
DURING THE MONDAY/TUESDAY TIMEFRAME WITH CONTINUED WARM TEMPERATURES.
/15/
&&
.AVIATION...LIGHT FREEZING RAIN/DRIZZLE WILL BE SEEN AT JAN/HKS/MEI
UNTIL 15Z. IFR CIGS/MVFR VSBYS WILL ALSO CONTINUE AT THESE SITES AS
WELL AS HBG...BUT RISE TO MVFR CIGS/VFR VSBYS THEREAFTER. VFR CIGS
WILL CONTINUE AT GLH/GWO/GTR./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 31 35 29 / 19 45 100 34
MERIDIAN 41 31 37 30 / 24 32 100 42
VICKSBURG 35 31 35 30 / 13 56 100 28
HATTIESBURG 44 35 41 32 / 35 48 100 36
NATCHEZ 37 30 36 31 / 28 68 100 26
GREENVILLE 33 30 33 27 / 7 30 97 27
GREENWOOD 35 29 33 27 / 10 23 97 33
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ038-
039-043>062.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR MSZ018-019-025>045.
LA...FREEZING RAIN ADVISORY UNTIL 9 AM CST THIS MORNING FOR
LAZ023>026.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR LAZ007>009.
AR...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR ARZ074-075.
&&
$$
GARRETT/15/
AREA FORECAST DISCUSSION
NWS JACKSON MS
1013 PM CST MON FEB 23 2015
.UPDATE...
HAVE OPTED TO EXTEND THE FREEZING RAIN ADVISORY UNTIL MID MORNING
BASED ON LATEST GUIDANCE TRENDS. RECENT HRRR OUTPUT AND NAM/GFS
GUIDANCE SUPPORT IDEA OF LINGERING -FZRA/FZDZ IN THE 12-15Z TIME
FRAME AND WITH TEMPERATURES LIKELY DROPPING INTO THE MID/UPPER 20S
OVER MUCH OF THE AREA...EXPECT FAIRLY DIFFICULT TRAVEL CONDITIONS TO
CONTINUE. HAVING SAID THAT...EXPECT MOST SIGNIFICANT ICE
ACCUMULATIONS NOT TO PERSIST MUCH AFTER MIDNIGHT AS MID LEVEL WINDS
VEER WITH PASSING WAVE AND ISENTROPIC LIFT DIMINISHES. HAVE FOLLOWED
HRRR IDEA OF KEEPING TEMPERATURES BELOW FREEZING FOR A LONGER
DURATION IN THE MORNING AS LOW CLOUDS AND WEAK NORTHERLY FLOW SHOULD
SLOW DOWN HEATING. /EC/
&&
.PREV DISCUSSION... /ISSUED 710 PM CST MON FEB 23 2015/
UPDATE...
MADE UPDATES TO INCREASE COVERAGE OF FREEZING RAIN AND UP ICE AMOUNTS
IN SW TO CENTRAL MS WHERE CONVECTIVE BANDS OF FZRA/IP ARE FOCUSING.
SE PROGRESSION OF FREEZING LINE GENERALLY IN THE BALLPARK BUT MADE
SLIGHT EDITS. WILL BE WATCHING CLOSELY CONTINUED SHOWERY PCPN
TRAINING ALONG THE I-20 CORRIDOR ALONG/W OF JACKSON METRO AREA AS
SOME LOCATIONS COULD FLIRT WITH ICE STORM CRITERIA IF THIS CONTINUES
AS RECENT HRRR RUNS SUGGEST. WILL ALSO BE CONSIDERING EXTENDING FZRA
ADVISORY A LITTLE FARTHER E/SE. /EC/
PREV DISCUSSION... /ISSUED 400 PM CST MON FEB 23 2015/
.WINTRY WEATHER WILL CONTINUE TO AFFECT THE AREA TONIGHT AND THEN
AGAIN WEDNESDAY...
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...FREEZING
TEMPERATURES WERE BEING OBSERVED AT MID AFTERNOON GENERALLY
NORTHWEST OF A LINE FROM STARKVILLE TO RAYMOND TO JUST WEST OF
NATCHEZ. LOCAL RADARS WERE SHOWING PRECIPITATION ALONG AND NORTH OF
INTERSTATE 20 WHERE NUMEROUS REPORTS OF LIGHT FREEZING RAIN...MIXED
WITH LIGHT SLEET HAVE BEEN REPORTED. WATER VAPOR IMAGERY/RUC
ANALYSIS WAS SHOWING A WEAK SHORTWAVE OVER OUR CWA THAT WAS HELPING
DRIVE THE PRECIPITATION ACROSS OUR AREA. THIS SHORTWAVE WILL SHIFT
EAST OF OUR CWA BY THIS EVENING BUT ADDITIONAL PRECIPITATION IS
EXPECTED TONIGHT WITH THE HEAVIEST AMOUNTS ALONG AND SOUTH OF
INTERSTATE 20. TEMPERATURES WILL CONTINUE TO DROP TONIGHT AS THE
PRECIPITATION FALLS RESULTING IN ADDITIONAL LIGHT FREEZING RAIN AND
MIXING WITH LIGHT SLEET ACROSS THE NORTH. CURRENT THINKING IS THAT
OUR SOUTHEAST COUNTIES WILL REMAIN AT OR JUST ABOVE FREEZING
MITIGATING ANY WINTRY PRECIPITATION HAZARDS BUT FREEZING RAIN
ADVISORY WILL LIKELY CONTINUE ACROSS MUCH OF THE AREA UNTIL THE RAIN
ENDS TUESDAY MORNING. IF IT LOOKS LIKE SUBFREEZING TEMPERATURES WILL
SURGE A LITTLE FARTHER SOUTHEAST THIS EVENING...THE REMAINDER OF OUR
CWA MAY COME UNDER AN ADVISORY. ICE ACCUMULATIONS ARE EXPECTED TO
REMAIN BELOW A QUARTER OF AN INCH SO A WINTER STORM WARNING IS NOT
ANTICIPATED TONIGHT. TUESDAY SURFACE HIGH PRESSURE WILL SETTLE OVER
OUR CWA HELPING BRING AN END TO THE PRECIPITATION BUT PLENTY OF
CLOUD COVER LOOKS TO REMAIN. TEMPERATURES ARE EXPECTED TO RISE ABOVE
FREEZING AT ALL LOCATIONS BUT NOT UNTIL THE AFTERNOON OVER THE DELTA
MELTING ANY REMAINING ICE. THE DRY WEATHER TUESDAY AFTERNOON WILL
ONLY LAST INTO THE EVENING AS CHANCES FOR PRECIPITATION WILL
INCREASE AFTER MIDNIGHT TUESDAY NIGHT. TUESDAY A CLOSED LOW WILL
SHIFT SOUTH OF THE FOUR CORNERS REGION THEN OPEN UP AND TRACK EAST
OVER THE SOUTHERN PLAINS TUESDAY NIGHT. THIS WILL HELP DEVELOP A
SURFACE LOW ALONG THE TEXAS GULF COAST BY WEDNESDAY MORNING. THIS
LOW WILL TRACK EAST AS THE UPPER LEVEL TROUGH APPROACHES OUR CWA
FROM THE WEST. WIDESPREAD PRECIPITATION IS EXPECTED BACK OVER OUR
CWA BY WEDNESDAY MORNING WHILE BELOW FREEZING ARE EXPECTED OVER MOST
OF OUR CWA. MODEL CONSENSUS SOUNDINGS SUGGEST THE LIGHT RAIN WILL
SPREAD UP FROM THE SOUTHWEST AFTER MIDNIGHT AND CHANGE OVER TO SNOW
AS IT MOVES OVER THE NORTHERN HALF OF OUR CWA. CURRENT THINKING
SUGGESTS TWO TO FOUR INCHES OF SNOW POSSIBLE ACROSS OUR HIGHWAY 82
CORRIDOR AND A MIXTURE OF RAIN SLEET AND SNOW ACROSS THE CENTRAL
PORTIONS OF OUR AREA WITH ONE TO TWO INCHES OF SNOW POSSIBLE. MAINLY
A COLD RAIN IS EXPECTED ACROSS OUR SOUTHERN ZONES. A WINTER STORM
WATCH HAS BEEN ISSUED FOR WEDNESDAY FOR LOCATIONS ALONG AND NORTH OF
A BASTROP TO BELZONI TO MACON LINE. EXPECT FURTHER REFINEMENTS IN
LATER FORECASTS OF THIS EVENT AS THERE ARE INDICATIONS HIGHER
AMOUNTS COULD BE POSSIBLE...THEN AGAIN LESSER AMOUNTS COULD OCCUR IF
THE COLD CORE TRACK IS DIFFERENT. THE PRECIPITATION IS EXPECTED TO
END EARLY WEDNESDAY EVENING AS THE LOW PRESSURE SYSTEM SHIFTS EAST
OF MISSISSIPPI. /22/
LONG TERM...THURSDAY THROUGH MONDAY...ANOTHER COLD FRONT WILL MOVE
ACROSS THE AREA ON THURSDAY WITH HIGH PRESSURE BUILDING IN BEHIND
IT. HIGH PRESSURE RIDGING FROM A HIGH CENTERED OVER THE OHIO VALLEY
WILL PREVAIL ACROSS THE AREA ON FRIDAY WITH COOL HIGH TEMPERATURES
IN THE 40S. AS THE SURFACE HIGH SHIFTS TO THE EAST COAST ON SATURDAY
THE SURFACE FLOW WILL BECOME MORE EASTERLY AND EVENTUALLY
SOUTHEASTERLY BY SUNDAY. TEMPERATURES WILL BE ON THE RISE ON
SATURDAY AND ESPECIALLY ON SUNDAY WITH HIGHS BACK UP INTO THE 60S.
THE GLOBAL MODELS ARE IN PRETTY GOOD AGREEMENT OF INCREASING CHANCES
OF SHOWERS/THUNDERSTORMS ON MONDAY./15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 29 40 32 37 / 89 18 45 100
MERIDIAN 31 44 32 38 / 86 22 32 100
VICKSBURG 25 39 31 37 / 89 17 56 100
HATTIESBURG 35 47 35 42 / 60 30 48 100
NATCHEZ 28 41 32 39 / 90 29 68 100
GREENVILLE 22 36 30 35 / 61 7 30 97
GREENWOOD 26 37 29 35 / 68 8 23 97
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FREEZING RAIN ADVISORY UNTIL 9 AM CST TUESDAY FOR MSZ037>039-
042>062.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR MSZ018-019-025>041.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MSZ018-
019-025>036-040-041.
LA...FREEZING RAIN ADVISORY UNTIL 9 AM CST TUESDAY FOR LAZ015-016-
023>026.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR LAZ007>009.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
LAZ007>009.
AR...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR ARZ074-075.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ARZ074-
075.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
546 PM CST WED FEB 25 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
LATEST RADAR SHOWS THE RAIN AND SNOW IS MOVING OUT OF THE FORECAST
AREA THIS AFTERNOON. THERE HAVE BEEN A FEW FLURRIES BEHIND THE MAIN
BAND...BUT EVEN THOSE ARE DIMINISHING THIS AFTERNOON. SURFACE
ANALYSIS HAS THE COLD FRONT ALREADY THROUGH THE FORECAST AREA AND
GUSTY NORTH WINDS ACROSS THE AREA. TEMPERATURES HAVE BEEN FALLING
FOR MUCH OF THE AREA THIS AFTERNOON.
MAIN QUESTION THIS AFTERNOON IS HOW QUICKLY THE PRECIPITATION WILL
MOVE OUT OF THE FORECAST AREA. THE RAP AND THE WRF BOTH INDICATE THE
PRECIPITATION SHOULD BE AN AFTERNOON EVENT AND BE DONE BEFORE THIS
EVENING. EVEN THE NAM AND THE GFS HAS IT ENDING BEFORE 00Z. WILL
START THE EVENING WITH A DRY FORECAST.
A SURFACE HIGH PRESSURE BUILDS IN THE DAKOTAS TONIGHT AND THURSDAY.
THIS WILL PUSH THE MOISTURE AND CLOUDS OUT OF THE AREA. SINCE THE
CENTER OF THE HIGH REMAINS TO THE NORTHEAST THROUGH THE
PERIOD...THERE WILL BE A FEW CLOUDS AROUND...BUT EXPECT CLOUDS TO
DIMINISH GRADUALLY LATE TONIGHT INTO THURSDAY.
THE COLD AIR HAS ALREADY STARTED TO MOVE INTO THE AREA THIS
AFTERNOON AND TEMPERATURES FOR MUCH OF THE AREA ARE COOLER NOW THAN
EARLIER. THE TEMPERATURES WILL CONTINUE TO PLUMMET TONIGHT WITH THE
DIMINISHING CLOUDS. THE COLD AIR REMAINS FIRMLY IN PLACE FOR
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
THE FOCUS OF THE LONG TERM FORECAST CENTERS AROUND PRECIPITATION
CHANCES OVER THE WEEKEND AND BEGINNING OF THE WORK WEEK AS WELL AS
BELOW NORMAL TEMPERATURES.
HEADING INTO THE LONG TERM...A DEEP UPPER LEVEL TROUGH WILL DIG
SOUTH ACROSS THE WESTERN COAST PROVIDING OUR WINTER WEATHER FOR THE
NEXT SEVERAL DAYS. THIS TROUGH WILL ALLOW MULTIPLE DISTURBANCES TO
TREK ACROSS THE CENTRAL PLAINS...WITH THE FIRST PASSING THROUGH
DURING THE WEEKEND TIMEFRAME AND THE SECOND HITTING MONDAY INTO
TUESDAY.
BY SATURDAY MORNING THE MAIN UPPER LEVEL LOW WILL BE POSITIONED
ALONG THE CALIFORNIA NEVADA BORDER WITH THE MID LEVEL LOW SLIGHTLY
EAST. THE FIRST ROUND OF MID LEVEL WAVES WILL BEGIN TO SLIDE THROUGH
THE PLAINS BY SATURDAY MORNING AHEAD OF THE PARENT LOW SYSTEM. IN
ADDITION TO THE WAVE...WARM AIR ADVECTION ACROSS THE PLAINS WILL
FUEL PLENTY OF MID LEVEL MOISTURE ACROSS THE REGION. WHILE THE GFS
IS STRONGER THAN THE ECMWF...BOTH MODEL SOLUTIONS SUGGEST GOOD
ISENTROPIC LIFT ESPECIALLY ACROSS KANSAS THROUGH THE WEEKEND.
FINALLY...A COLD FRONT WILL SLIDE THROUGH THE AREA SUNDAY MORNING
WITH AT LEAST SOME FRONTOGENETIC LIFT ALONG ITS BOUNDARY. ALTHOUGH
THIS IS NOT A MAJOR SYNOPTIC SETUP...BUT RATHER A MINOR
WAVE...SEVERAL KEY COMPONENTS ARE COMING TOGETHER TO FORM A DECENT
CHANCE FOR SNOW SATURDAY INTO SUNDAY MORNING. WITH MODEL AGREEMENT
LEANING TOWARDS BETTER LIFT OVER KANSAS...PLACED HIGHER AMOUNTS OVER
NORTH CENTRAL KANSAS. CURRENT MODEL TRENDS INDICATE THE POTENTIAL
FOR AT LEAST A COUPLE OF INCHES OF SNOW BY THE END OF THE WEEKEND
ACROSS NORTH CENTRAL KANSAS...POSSIBLY ADVISORY CRITERIA...WITH
LESSER AMOUNTS FARTHER NORTH.
THE NEXT SYSTEM SLIDES THROUGH MONDAY INTO TUESDAY...AND IS SOMEWHAT
MORE INTRIGUING. WHILE THE MAIN UPPER LEVEL LOW SLOWLY SHIFTS ACROSS
THE ROCKY MOUNTAINS...THE MID LEVEL LOW SURGES NORTHWARD ACROSS
NORTHERN NEBRASKA AND DAKOTAS. STRONG WARM AIR ADVECTION AND
SOUTHEASTERLY WINDS WILL BRING PLENTY OF MOISTURE AGAIN TO THE
CENTRAL PLAINS. ISENTROPIC LIFT IS BETTER IN BOTH THE GFS AND ECMWF
THAN THE WEEKEND STORM. AND ANOTHER COLD FRONT WILL DRAG ACROSS THE
CWA BY TUESDAY AFTERNOON. LOOKING AT ANOTHER ROUND OF SNOW FOR THE
FORECAST AREA. AT THIS TIME...ITS TOO EARLY TO DETERMINE
AMOUNTS...BUT RIGHT NOW MODELS FOCUS HEAVIER BANDS NORTH OF
INTERSTATE 80.
COLD TEMPERATURES CONTINUE THROUGHOUT THE LONG TERM...WITH AT LEAST
TWO SHOTS OF REINFORCING COLD AIR...AND LITTLE TO ANY WARM UPS. BOTH
COLD FRONTS...SUNDAY AND TUESDAY BRING VERY COLD 850 MB AIR TO THE
REGION...THE COLDER OF THE TWO ON TUESDAY. 850 TEMPERATURES DIP TO
NEAR 15 DEGREES BELOW BY WEDNESDAY AFTER THE COLD FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 538 PM CST WED FEB 25 2015
IN A TIGHT PRESSURE GRADIENT...WINDS WILL REMAIN STEADY/GUSTY INTO
THE OVERNIGHT HOURS BEFORE DECREASING DURING THE DAY ON THURSDAY
AS THE SURFACE GRADIENT RELAXES. MVFR CIGS ARE EXPECTED INTO
TONIGHT WITH CLOUDS SCATTERING THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...SALTZMAN
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
405 PM EST TUE FEB 24 2015
.SYNOPSIS...
A MID-LEVEL SHORTWAVE AND SURFACE COLD FRONT WILL MOVE ACROSS THE
LOWER GREAT LAKES TONIGHT BRINGING THE NEXT ROUND OF ACCUMULATING
SNOW SHOWERS. ONLY AN INCH OR TWO IS EXPECTED. COLDER AIR IN THE
WAKE OF THE FRONT WILL HOLD TEMPERATURES AT LEAST 20 DEGREES BELOW
NORMAL FOR WEDNESDAY AND THURSDAY...WITH LAKE EFFECT SNOWS BRINGING
A FEW MORE INCHES OF SNOW EAST OF LAKE ONTARIO.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
CLOUDS ARE INCREASING ACROSS WESTERN AND NORTH CENTRAL NEW YORK THIS
AFTERNOON AHEAD OF THE NEXT MID-LEVEL SHORTWAVE AND ARCTIC COLD FRONT
APPROACHING FROM THE CENTRAL GREAT LAKES. SURFACE ANALYSIS PLACES
THE PARENT LOW OVER THE SOUTHERN TIP OF JAMES BAY WITH THE FRONT
EXTENDING SOUTHWEST ACROSS NORTHERN LOWER MICHIGAN TO NEAR CHICAGO
WHILE THE MID-LEVEL SHORTWAVE IS NOW SHIFTING JUST EAST OF MICHIGAN
AS OBSERVED ON REGIONAL RADAR BY A BAND OF SNOW. THE LEADING
SHORTWAVE WILL BRING AN INITIAL PERIOD OF SNOW SHOWERS THIS EVENING
WITH THE COLD FRONT CONTINUING TO PROVIDE SUFFICIENT LIFT FOR SNOW
SHOWERS OVERNIGHT. MESOSCALE MODELS INCLUDING THE HRRR AND REGIONAL
GEM MODEL BRING IN SNOW SHOWERS ACROSS FAR WESTERN NEW YORK ALONG
THE SHORTWAVE TROUGH BEGINNING AROUND 7PM SHIFTING EAST TO
NORTH-CENTRAL NEW YORK BY MIDNIGHT. ANOTHER PERIOD OF SNOW SHOWERS
IS EXPECTED ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT.
WHILE MOST LOCATIONS SHOULD PICK UP A FRESH HALF TO ONE INCH
OVERNIGHT SOME UPSLOPING ACROSS THE CHAUTAUQUA RIDGE TO THE BOSTON
HILLS AND OVER THE TUG HILL COULD BRING UP TO TWO INCHES. THE COLD
AIR MASS LOOKS TO SUPPORT SNOW RATIO OVERNIGHT NEAR 20:1.
TEMPERATURES AHEAD OF THE COLD FRONT WILL HANG IN THE TEENS TONIGHT
THEN DROP TO NEAR 10 DEGREES BEHIND THE FRONT.
THE COLD FRONT WILL PUSH EAST ACROSS NEW YORK WEDNESDAY MORNING WITH
LINGERING SNOW SHOWERS TAPERING OFF ACROSS THE SOUTHERN TIER AND
NORTH COUNTY. THE COLDER WESTERLY FLOW BEHIND THE FRONT WILL KICK
OFF SOME LAKE EFFECT SNOW SHOWERS EAST OF LAKE ONTARIO THROUGH THE
DAY WEDNESDAY INTO WEDNESDAY EVENING. THE 270-280 FLOW SHOULD KEEP
THE SNOW FOCUSED ACROSS MAINLY NORTHERN OSWEGO COUNTY AND FAR
SOUTHWESTERN LEWIS COUNTY ACROSS THE TUG HILL. THE LIMITED PERIOD OF
ENHANCED EQUILIBRIUM HEIGHTS UP TO 10KFT DURING THE AFTERNOON AND
PRESENT ICE COVER AND SLUSH OVER THE EASTERN END OF THE LAKE SHOULD
KEEP SNOW TOTALS LIMITED TO THE 3-6 INCH RANGE WITH THE HIGHER END
AMOUNTS FOCUSED ACROSS THE TUG HILL. A LAKE EFFECT SNOW ADVISORY HAS
BEEN ISSUED TO COVER FOR THIS SNOW BAND. OUTSIDE OF THE LAKE EFFECT
SNOW TEMPERATURES WILL FALL THROUGH THE DAY INTO THE SINGLE DIGITS
BEHIND THE FRONT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
LAKE EFFECT SNOW SHOULD BE ONGOING EAST OF LAKE ONTARIO WEDNESDAY
EVENING. BY THIS TIME WE SHOULD KNOW HOW MUCH ICE ON THE LAKE WILL
LIMIT LAKE EFFECT SNOW...WITH LATEST VISIBLE SATELLITE SHOWING
SIGNIFICANT PATCHES BUT ALSO SIGNIFICANT BREAKS IN THE ICE COVERAGE.
TYPICALLY WHEN THIS HAPPENS ON LAKE ERIE THESE BREAKS ARE AMPLE FOR
A LAKE RESPONSE...WHICH CAN OFTEN BE UNDERDONE BY MODEL QPF
DEPENDING ON THE ICE COVERAGE IN THE MODEL. WINDS WILL SHIFT FROM
THE WEST TO NORTHWEST WEDNESDAY EVENING WHICH WILL PUSH WHATEVER
LAKE EFFECT BAND THERE IS QUICKLY SOUTHWARD LATE WEDNESDAY EVENING.
OSWEGO COUNTY STILL COULD PICK UP ANOTHER INCH OR TWO WEDNESDAY
EVENING BEFORE THE BAND SHIFTS SOUTH AND BECOMES LESS ORGANIZED.
THIS LESS ORGANIZED BAND MAY BRING AN INCH SOUTH OF LAKE ONTARIO
FROM WEAK MULTIPLE BANDS LATE WEDNESDAY NIGHT.
A WEAK MID-LEVEL TROUGH WILL APPROACH THE REGION ON THURSDAY WHICH
WILL BRING SOME MID LEVEL CLOUDS AND POSSIBLY SOME LIGHT SNOW OR
FLURRIES TO ALL AREAS. ACCUMULATIONS FROM THIS SHOULD BE VERY LIGHT
(THINK DUSTING). THE ONLY EXCEPTION IS ACROSS THE NIAGARA
FRONTIER...WHERE A NORTHEASTERLY FLOW MAY TAKE ADVANTAGE OF THE LIMITED
OPEN WATERS ON LAKE ONTARIO. THIS COMBINED WITH SYNOPTIC MOISTURE
MAY BE ENOUGH TO BRING AN INCH OR TWO ON THURSDAY.
STRONG SURFACE HIGH PRESSURE ACROSS THE PLAINS STATES WILL RIDGE
INTO THE GREAT LAKES REGION THROUGH FRIDAY. MEANWHILE THE WEAK UPPER
LEVEL TROUGH WILL SHEAR OUT AS IT MOVES ACROSS THE REGION THROUGH
FRIDAY. LIGHT NORTHERLY WINDS THURSDAY NIGHT WILL SHIFT BACK TO THE
WEST WHICH WILL LIFT LIGHT LAKE EFFECT SNOWS BACK TO THE EASTERN
LAKE ONTARIO REGION. THE WEAK FLOW...LAKE ICE...AND LIMITED MOISTURE
SHOULD KEEP ANY ACCUMULATIONS ON THE LIGHT SIDE.
THE TEMPERATURE FORECAST WILL BE TRICKY DURING THE
PERIOD...ESPECIALLY NIGHTTIME LOWS. WINDS WILL BE FAIRLY LIGHT
THROUGHOUT THE PERIOD...BUT CLOUD COVER WILL VARY BASED ON SYNOPTIC
AND MESOSCALE FEATURES. WITH LIGHT WINDS OVERNIGHT LOWS WILL BE
CONSIDERABLY COLDER IN AREAS WHICH DO CLEAR OUT. THIS UNCERTAINTY
ASIDE...THERE IS NO QUESTION THAT IT WILL BE COLD....WITH DAYTIME
HIGHS 10 TO 15 DEGREES ON THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL
LARGELY BE BELOW ZERO...BUT TEMPERATURES COULD DROP INTO THE MINUS
TEENS OR COLDER IN INTERIOR SECTIONS. THE BEST CHANCE FOR THE
COLDEST TEMPERATURES IS IN THE NORTH COUNTRY WHERE SKIES ARE MOST
LIKELY TO CLEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL GRADUALLY MOVE ACROSS THE REGION FRIDAY NIGHT
THROUGH SATURDAY NIGHT. THIS WILL BRING GENERALLY FAIR WEATHER
OUTSIDE OF SOME LIGHT LAKE EFFECT SNOW EAST OF LAKE ONTARIO WHICH
WILL WEAKEN AND LIFT NORTH WITH TIME. LOWS ON FRIDAY NIGHT SHOULD
ONCE AGAIN DROP BELOW ZERO IN MANY AREAS...WITH THE COLDEST
TEMPERATURES PROBABLY IN THE VALLEYS OF THE SOUTHERN TIER WHICH WILL
BE CLOSE TO THE CENTER OF THE HIGH. TEMPERATURES WILL REMAIN ON THE
COOL SIDE WITH HIGHS SATURDAY IN THE UPPER TEENS TO AROUND 20.
THE PATTERN BECOMES MORE COMPLEX ON SUNDAY WITH A SPLIT FLOW WHERE
THE SOUTHERN BRANCH EXTENDS FROM THE SOUTHWESTERN STATES TO THE
GREAT LAKES REGION. THIS PATTERN TENDS TO BE ACTIVE ONE FOR OUR
REGION...BUT IT IS DIFFICULT FOR GUIDANCE TO FORECAST PHASING
BETWEEN THE TWO BRANCHES. THIS PATTERN SHOULD ALSO BRING
TEMPERATURES A BIT CLOSER TO NORMAL EARLY NEXT WEEK...EVEN IF THEY
WILL STILL BE BELOW NORMAL.
12Z GUIDANCE HAS TRENDED WEAKER WITH AN INITIAL WAVE (SUNDAY NIGHT)
AND INSTEAD KEYS ON A STRONGER SYSTEM LATE TUESDAY. THERE IS STILL
PLENTY OF TIME FOR FUTURE MODEL SHIFTS...BUT THIS TREND SEEMS
REASONABLE SINCE IT TRACKS THE SUNDAY SYSTEM FURTHER SOUTH AND
YIELDS A COLDER SOLUTION. GUIDANCE NOW SUGGESTS AN ALL SNOW...BUT
LIGHTER EVENT...ON SUNDAY NIGHT. ITS WORTH NOTING THE GGEM HAS
SHIFTED SO FAR SOUTH THAT IT MISSES...BUT WITH THE 12Z GFS/ECMWF
STILL BRINGING SOME SNOW WILL KEEP LIKELY POPS.
EXPECT A BRIEF BREAK BETWEEN SYSTEMS LATE MONDAY AND INTO
TUESDAY...BUT GFS/ECMWF GUIDANCE HAS BEEN IN FAIRLY GOOD AGREEMENT
BRINGING ANOTHER MORE SIGNIFICANT WAVE TOWARD OUR REGION LATE
TUESDAY. MORE LIKELY THAN NOT...IT WILL BE COLD ENOUGH FOR SNOW WITH
THIS SYSTEM...BUT IT IS STILL A BIT TOO FAR OUT FOR SPECIFICS.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PERSIST THROUGH THIS AFTERNOON WITH GUSTY
SOUTHWESTERLY WINDS AHEAD OF A COLD FRONT NEAR THE CENTRAL GREAT
LAKES. AREAS OF BLOWING SNOW ARE POSSIBLE WITH THESE STRONGER WINDS.
SNOW SHOWERS WILL SPREAD ACROSS THE AREA FROM WEST TO EAST WITH THE
PASSAGE OF A COLD FRONT THIS EVENING...BRINGING PERIODS OF MVFR CIGS
AND IFR VIS. BLOWING SNOW COULD BECOME MORE WIDESPREAD WITHIN AND
AFTER THE SNOW SHOWERS OVERNIGHT WITH WESTERLY WINDS BEHIND THE COLD
FRONT. MOST AREAS SHOULD SEE SNOW ENDING BY 12Z WITH AN EXCEPTION OF
EAST OF LAKE ONTARIO WHERE LAKE EFFECT SNOW IS EXPECTED TO SET UP
BETWEEN KART AND KSYR.
OUTLOOK...
WEDNESDAY NIGHT...VFR.
THURSDAY...MVFR IN CHANCE OF SNOW SHOWERS.
FRIDAY AND SATURDAY...MAINLY VFR WITH IFR IN LAKE EFFECT SNOW.
SUNDAY...MVFR IN LIKELY SNOW SHOWERS.
&&
.MARINE...
SOUTHWESTERLY WINDS WITH GUSTS PUSHING TO 30 KNOTS AHEAD OF A COLD
FRONT THIS EVENING. WINDS WILL THEN TURN WESTERLY TO NORTHWESTERLY
WEDNESDAY INTO WEDNESDAY NIGHT WITH THE PASSAGE OF THE ARCTIC
FRONT. SMALL CRAFT ADVISORIES FOR OPEN WATER PORTIONS OF LAKE
ONTARIO THROUGH LATE WEDNESDAY EVENING.
&&
.CLIMATE...
---THIS FEBRUARY IS WRAPPING UP TO BE ONE OF THE COLDEST AND
SNOWIEST MONTHS IN OUR PRIMARY CLIMATE STATIONS HISTORY. THE
CONTINUED NORTHWEST FLOW OF BITTERLY COLD AIR HAS LEFT THE MONTH
OF FEBRUARY A HISTORIC MONTH THAT WILL BE A BENCHMARK MARK FOR
YEARS TO COME. BELOW ARE THE COLDEST MONTHS IN EACH STATIONS
HISTORY. TEMPERATURE RECORDS FOR BUFFALO AND ROCHESTER GO BACK TO
1871...WHILE TEMPERATURE RECORDS IN WATERTOWN GO BACK TO 1950.
STATION: VALUE (F) MONTH (YEAR)
BUFFALO 11.6 FEB (1934)
13.4 FEB (1875)
13.8 JAN (1977)
14.1 JAN (1918)
14.6 FEB (1885)
14.9 FEB (1979)
15.5 FEB (1978)
15.6 JAN (1920)
15.6 JAN (1912)
16.2 JAN (1945)
ROCHESTER 12.6 FEB (1934)
13.7 FEB (1979)
14.4 FEB (1875)
14.5 FEB (1885)
14.8 JAN (1918)
14.9 JAN (1994)
15.2 JAN (1945)
15.5 JAN (1977)
15.7 JAN (1981)
16.1 JAN (1920)
WATERTOWN 6.4 DEC (1989)
6.5 JAN (1970)
6.9 JAN (1994)
7.9 FEB (1978)
8.0 JAN (1981)
8.1 JAN (2004)
8.4 FEB (1979)
10.0 JAN (2003)
10.1 JAN (1977)
10.3 JAN (1961)
CURRENT MONTHLY AVERAGE TEMPERATURES ARE LISTED ON THE CF6 CLIMATE
PRODUCT.
---FEBRUARY HAS ALSO BEEN A SNOWY MONTH AS A PERSISTENT TRACK OF
CLIPPERS WITHIN A NORTHWEST FLOW HAS MAINTAINED NICKEL AND DIME
SNOWS THROUGH THE MONTH...THIS AFTER A SIGNIFICANT SYNOPTIC STORM TO
START FEBRUARY. BELOW ARE THE TOP SNOWIEST FEBRUARY`S ON RECORD.
SNOWFALL RECORDS GO BACK TO 1884.
STATION: SNOW (IN) YEAR
BUFFALO 1 54.2 1958
2 49.5 1960
3 44.3 2015 (DATA THROUGH 2/21)
ROCHESTER 1 64.8 1958
2 58.3 1960
3 46.5 2007
4 42.7 1910
5 41.7 2015 (DATA THROUGH 2/21)
---IT IS POSSIBLE THAT BUFFALO REMAINS BELOW FREEZING THE ENTIRE
MONTH OF FEBRUARY. THIS HAS HAPPENED ONCE BEFORE...IN THE YEAR 1978.
---ROCHESTER HAS HAD 7 DAYS THIS MONTH WITH MINIMUM TEMPERATURES
FALLING BELOW ZERO. BELOW IS A LIST OF GREATEST NUMBER OF DAYS
IN FEBRUARY WITH MINIMUM TEMPERATURES BELOW ZERO...
NUMBER YEAR
10 1979
8 1934
7 1963
7 1875
7 2015 (DATA THROUGH 2/21)
THE GREATEST NUMBER OF DAYS IN A WINTER SEASON IN ROCHESTER THAT
HAVE MINIMUM TEMPERATURES FALL BELOW ZERO IS 15 DAYS SET BACK IN
1884-85.
---WATERTOWN HAS HAD 14 DAYS THIS MONTH WITH MINIMUM TEMPERATURES
FALLING BELOW ZERO. BELOW IS A LIST OF GREATEST NUMBER OF DAYS IN
FEBRUARY WITH MINIMUM TEMPERATURES BELOW ZERO...
NUMBER YEAR
16 1978
15 1993
15 1979
14 2015 (DATA THROUGH 2/21)
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 7 AM WEDNESDAY TO MIDNIGHT EST
WEDNESDAY NIGHT FOR NYZ006-008.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR
LOZ043.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT
FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR LOZ044.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...SMITH
MARINE...SMITH
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
644 PM EST WED FEB 25 2015
.SYNOPSIS...
LOW PRESSURE WILL BRING MOSTLY RAIN TO THE AREA TONIGHT. SNOW WILL
FALL MAINLY WEST OF INTERSTATE 95...WITH A COUPLE INCHES POSSIBLE.
ARCTIC HIGH PRESSURE WILL BUILD IN THURSDAY INTO THE WEEKEND
BRINGING COLD TEMPERATURES AND EVENTUALLY SOME CLEARING SKIES.
MOISTURE WILL RETURN FOR THE NEW WEEK WITH TEMPERATURES CONTINUING
TO SHOW QUITE A BIT OF DAY TO DAY VARIABILITY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 630 PM WEDNESDAY...LARGE SPREAD NOTED IN THE MAGNITUDE OF THE
WARM NOSE ALOFT IN THE LATEST MODEL GUIDANCE. THE 18Z NAM WAS ON THE
WARM EXTREME AND IS BEING DISCOUNTED. THE 18Z GFS AND 22Z RUC WERE
CLOSER TO EACH OTHER AND SUGGEST A NARROWER BUT STILL DEEP WARM NOSE
WHICH WILL LIMIT THE AMOUNT OF SNOW ABLE TO MAKE IT TO THE GROUND
WEST OF I-95 THIS EVENING. AFTER MIDNIGHT THE COLUMN MAY STILL COOL
SUFFICIENTLY TO ALLOW MORE SUBSTANTIAL SNOW TO DEVELOP.
COMPLICATING ALL THIS IS CONSIDERABLE SLEET AND EVEN SOME SNOW BEING
REPORTED ON THE FRONT EDGE OF ALL THIS PRECIPITATION COMING INTO THE
AREA. MY EXPECTATION IS AS WARM ADVECTION CONTINUES THIS SHOULD
BECOME MAINLY A RAIN EVENT OVER THE NEXT HOUR IN ALL BUT THE WESTERN
PORTIONS OF DARLINGTON AND MARLBORO COUNTIES. I AM ALSO CONCERNED
ABOUT SHALLOW COLD AIR SWEEPING SOUTHWARD AROUND
SUNRISE...POTENTIALLY CREATING FREEZING RAIN SOUTH OF WHERE WE
CURRENTLY HAVE WINTER WEATHER ADVISORIES POSTED. I WILL INVESTIGATE
THIS POTENTIAL FURTHER THIS EVENING...BUT MY BIGGEST CONCERN IS
ACROSS PORTIONS OF COLUMBUS...NORTHERN HORRY...MARION AND FLORENCE
COUNTIES IN THE 5-9 AM TIME FRAME THURSDAY MORNING.
I HAVE MADE NO SIGNIFICANT CHANGES TO THE FORECAST OTHER THAN ADDING
IN THE EVENING FROZEN PRECIPITATION WE ARE NOW EXPERIENCING...AND
INCREASING STORM-TOTAL SNOWFALL TOTALS SLIGHTLY ACROSS
WESTERN/NORTHERN SECTIONS OF DARLINGTON AND MARLBORO COUNTIES.
COUNTY AVERAGES FOR SNOWFALL SHOULD REMAIN 1-2 INCHES...BUT I
SUSPECT THAT EXTREME NORTHERN MARLBORO COUNTY NEAR THE RICHMOND
COUNTY LINE COULD BE LOOKING AT 3-4 INCHES ON THE GROUND BY TOMORROW
MORNING. DISCUSSION FROM 300 PM FOLLOWS...
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FOR OUR NORTHERN TIER OF
COUNTIES...FROM PENDER AND BLADEN...ACROSS ROBESON AND DILLON AND
THEN WEST OF INTERSTATE 95 TO INCLUDE MARLBORO AND DARLINGTON
COUNTIES. THE ADVISORY IS IN EFFECT FOR A MIXED BAG OF WINTRY
PRECIPITATION TO INCLUDE...SLEET...SNOW AND FREEZING RAIN. THE
HEAVIEST OF THE PRECIPITATION IS EXPECTED FROM MID EVE THROUGH ABOUT
3/4 AM...ALTHOUGH WINTRY WEATHER WILL PERSIST INTO THU MORNING IN
THESE AREAS. THE PRECIPITATION IS EXPECTED TO BEGIN AS RAIN
THROUGHOUT THE FORECAST AREA WITH TEMPS ABOVE FREEZING.
AS THE PRECIPITATION GROWS HEAVIER...IT WILL HELP TO COOL THE
COLUMN. THE ENVIRONMENT SHOULD SUPPORT SOME ACCUMULATING SNOW AND
SLEET...ESPECIALLY MID AND LATE EVE WHEN DYNAMIC COOLING SHOULD BE
STRONGEST...AND MAINLY ACROSS THE ADVISORY AREA. OVERALL...THE MODEL
TREND HAS BEEN WARMER IN THE LOWER LEVELS AND A SIGNIFICANT PORTION
OF THE COLUMN IS EXPECTED TO RISE A DEG OR TWO ABOVE ZERO DEG C LATE
EVE AND INTO THE OVERNIGHT HOURS. THIS WILL MELT THE SNOW AS IT
FALLS TO THE GROUND. BELOW 2 KFT OR SO...TEMPS ACROSS THE ADVISORY
AREA WILL DROP TO OR JUST BELOW FREEZING. THE TOP-DOWN METHODOLOGY
IS SUPPORTING MORE IN THE WAY OF SLEET DURING THE HEIGHT OF THE
STORM WHICH WOULD RESULT IN LESS FROZEN ACCUMULATION ON THE GROUND
ALL THINGS BEING EQUAL. ALSO...WITHOUT A COLD PARENT HIGH TO OUR
N...WET BULB TEMPS WILL STRUGGLE TO REMAIN BELOW FREEZING. HIGHER
WET BULB TEMPS SHOULD HELP TO LIMIT THE AMOUNT OF FREEZING RAIN.
ALSO...TEMPS THIS AFTERNOON HAVE MANAGED TO REACH INTO THE 40S
ACROSS MOST OF THE ADVISORY AREA AND THIS WILL ALSO HELP TO
ALLEVIATE ACCUMULATIONS OF SNOW...SLEET AND ICE...ESPECIALLY DURING
THE EARLY EVE HOURS.
WE ARE EXPECTING THE GREATEST AMOUNT OF SNOW AND SLEET FROM N OF
DARLINGTON TO BENNETTSVILLE TO N OF LUMBERTON. IN THIS AREA...
SNOW/SLEET AMOUNTS NEAR OF JUST IN EXCESS OF AN INCH ARE POSSIBLE.
SOME FROZEN ACCUMULATION IS FORECAST AS FAR SOUTH AS FLORENCE TO
DILLON TO NEAR ELIZABETHTOWN...MAINLY IN THE FORM OF SLEET HERE. AS
FAR AS FREEZING RAIN ACCRETION...THE RISK FOR THIS WILL BE HIGHEST
VERY LATE TONIGHT AND THU MORNING WHEN AIR TEMPS WILL BE RIGHT
AROUND FREEZING. BY THIS TIME...THERE WILL BE NO ICE IN THE CLOUDS
AND SOME DRY SLOTTING WILL LIKELY HAVE NOSED INTO THE AREA. THUS...
QPF AMOUNTS WILL BE SIGNIFICANTLY LESS. WILL FORECAST LESS THAN A
TENTH OF AN INCH OF ICE FROM THE NW CORNER OF PENDER COUNTY THROUGH
EYF AND LBT TO BEAR BBP AND HARTSVILLE. ELSEWHERE ACROSS THE
FORECAST AREA...WE ARE FORECASTING A COLD RAIN. TOTAL QPF FOR THIS
EVENT...ON THE ORDER OF ONE TO ONE AND TWO-THIRDS OF AN INCH.
A VIGOROUS SOUTHERN STREAM SHORTWAVE WILL FURTHER DEAMPLIFY AS IT
PUSHES EAST INTO THE LOWER MS VLY...THEN NORTHEAST ACROSS THE MID
ATLANTIC AS IT BECOMES ABSORBED INTO THE FAST MID LEVEL FLOW.
SURFACE LOW PRESSURE...DEVELOPING IN THE NORTHERN GULF OF MEXICO...
WILL MOVE NE ACROSS THE COASTAL CAROLINAS TONIGHT...INTENSIFYING
JUST OFF THE NORTH CAROLINA COAST AROUND DAYBREAK THU. THIS SYSTEM
WILL TAP GULF OF MEXICO MOISTURE AND BRING IT NORTHWARD...INTO A
COLDER AIRMASS ACROSS THE CAROLINAS AND MID-ATLANTIC. ALONG AND EAST
OF THE LOW TRACK...IT WILL BE JUST A LITTLE TOO WARM TO SUPPORT ANY
WINTRY PRECIPITATION. AS YOU MOVE PROGRESSIVELY N AND W OF THE LOW
TRACK...THE RISK OF WINTRY WEATHER INCREASES AS DO THE ACCUMULATIONS
OF SNOW...SLEET AND ICE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...ACTIVE WEATHER WILL BE LIMITED TO THE FIRST
FEW HOURS OF THE PERIOD AS LOW PRESSURE RACES AWAY FROM THE
REGION. THE MAIN FORCING WILL BE LONG GONE LEAVING LOW LEVEL
MOISTURE IN THE FORM OF LIGHT RAIN SHOWERS AND MOSTLY DRIZZLE FOR
THE MORNING HOURS. I DID LEAVE AN HOUR OR TWO OF FREEZING RAIN FOR
THE NORTHERN PARTS OF THE ADVISORY AREA BUT TEMPERATURES SHOULD
SLOWLY PLOD TO ABOVE FREEZING IN THESE AREAS BY MID MORNING.
BEYOND THIS ARCTIC HIGH PRESSURE BUILDS INTO THE AREA THROUGH THE
REMAINDER OF THE PERIOD. CLOUDS WILL BE VERY SLOW TO SCOUR OUT
WITH LOW CEILINGS TRAPPED BELOW THE INVERSION. SOME SUNSHINE
SHOULD BREAK OUT FOR FRIDAY AFTERNOON. FOR THIS REASON I HAVE
OPTED FOR SLIGHTLY COOLER DAYTIME HIGHS AND SLIGHTLY MODERATED
OVERNIGHT LOWS VS THE MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...NOT SURE WHEN WE`LL SEE SUNSHINE AGAIN.
AFTER A RAIN-FREE BUT PROBABLY CLOUDY DAY SATURDAY THE LONG TERM
WILL BECOME INCREASINGLY UNSETTLED. SATURDAY THOUGH BRINGS ZONAL MID
LEVEL FLOW BUT ALSO LOW LEVEL MOISTURE TRAPPED BENEATH DEEP
INVERSION OR PERHAPS NEARLY ISOTHERMAL LAYER AS LARGE SURFACE HIGH
PROGRESSES EAST WITH ITS CENTER WELL TO OUR NORTH. SUNDAY THE HIGH
TAKES ON MORE OF A WEDGE-LIKE ELONGATION INTO THE CAROLINAS.
TROUGHINESS DEVELOPS OFFSHORE AS WELL BUT NOW APPEARS MUCH WEAKER.
AS SUCH MODELS HAVE BACKED OFF ON RAIN CHANCES FOR SUNDAY BUT SOME
LOW POPS STILL LIKELY WARRANTED FOR COASTAL AREAS. SUNDAY HIGHS HAD
TO BE LOWERED CONSIDERABLY AS THE WEDGE WILL LIKELY SPONSOR A DREARY
DAY WITH TEMPS MIRED IN THE 40S (MEANWHILE THE NORMAL HIGH CONTINUES
TO CREEP UPWARDS...NOW 63 FOR ILM). SPEAKING OF HIGHS IN THE
60S...MONDAY MAY BE OUR BEST CHANCE TO SEE AS SUCH. THE WEDGE BREAKS
DOWN ONLY TO GIVE WAY TO A DECELERATING COLD FRONT. HIGHS MAY CLIMB
CLOSE TO SEASONABLE DESPITE FAIRLY HIGH RAIN CHANCES. UNSETTLED
WEATHER WILL LAST INTO TUESDAY INTO WEDNESDAY BUT THE TEMPERATURES
BUST POTENTIAL APPEARS LARGE ESPECIALLY TUESDAY. HIGH PRESSURE WEDGE
ON TUESDAY COULD BRING ANOTHER COOL AND RAINY DAY INSTEAD OF THE
SEASONABLE WEATHER IN THE CURRENT FORECAST (IN ONE RUN THE MEX FCST
WENT FROM 65 TO 52!). FOR WEDNESDAY THE SETUP IS RATHER SIMILAR TO
MONDAY WHEREIN THE WEDGE MAY BREAK DOWN FOR A NEAR IMMEDIATE ARRIVAL
OF A COLD FRONT, THE END RESULT BEING A RAINY BUT SEASONABLE DAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...PRECIPITATION MOVING INTO THE AREA FROM THE SW WITH
-RAPL MIX ACROSS FLORENCE AND ROBESON COUNTIES BUT NOT AT THE ASOS
SITES. WILL MENTION AT KFLO AND KLBT IN TEMPO GROUP A -RAPL MIX.
EXPECT ALL RAIN EVENT ACROSS THE COASTAL TERMINALS THROUGHOUT THE
NIGHT WITH MAX UVM BETWEEN 04Z-08Z HAVE BROUGHT DOWN SITES TO LIFR
IN TEMPO GROUPS TO ACCOUNT FOR THIS. MODEL SOUNDING DATA ALONG THE
COASTAL SITES STILL SHOW DRY AREA BETWEEN H9 AND H7 BUT THIS QUICKLY
MOISTEN UP AND BY 02Z COLUMN IS SATURATED AND STAYS THAT WAY TO
ABOUT 12Z WHEN DRY SLOT WORKS ITS WAY ACROSS THE TERMINALS. WILL CUT
OFF PRECIPITATION AROUND THIS TIME BUT KEEP TERMINALS IN MVFR WITH
CEILING AND VSBY THROUGHOUT THE DAY. FOR KLBT WILL HAVE A TEMPO
GROUP FROM 04Z-08Z FOR -SNPL WITH A PREVAILING GROUP AT 08Z FOR
-SNPL BEFORE MIXING BACK WITH -RA BY 10Z. WILL NOT HAVE -FZRA OR -PL
AT FLO AFT 03Z. WINDS WILL BE MAINLY FROM THE NE TO E AT 10-15 KTS
WITH SOME HIGHER GUSTS AS 60-70 KT JET IS LOCATED AT H7 THROUGHOUT
THE NIGHT WITH 95 KT WINDS AT H5. WOULD EXPECT SOME TURBULENCE
THROUGHOUT THIS LEVEL WITH WIND SPEED SHEAR. HIGH CONFIDENCE
OVERNIGHT IN IFR CONDITIONS AT TERMINALS ESPECIALLY FROM 04-08Z.
EXTENDED OUTLOOK...MVFR/IFR ON THURSDAY AND AGAIN ON SUNDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE...
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM WEDNESDAY...THE ONLY CHANGE TO THE FORECAST WAS TO SLOW
DOWN THE RATE OF INCREASE IN FORECAST SEA HEIGHTS OVERNIGHT. OUR
LOCAL SWAN WAVE MODEL HAS A WELL-KNOWN BIAS OF INCREASING SEAS MUCH
TOO QUICKLY IN PERIODS OF STRENGTHENING WIND. NO OTHER SIGNIFICANT
CHANGES ARE NECESSARY. DISCUSSION FROM 300 PM FOLLOWS...
LOW PRESSURE WILL MOVE OUT OF THE GULF OF MEXICO THIS EVE AND THEN
UP THE CAROLINA COAST...INTENSIFYING OFF THE NORTH CAROLINA COAST
TOWARD DAYBREAK AND ON THU. THE PRESSURE GRADIENT IS EXPECTED TO
BECOME SUFFICIENTLY TIGHT TO SUPPORT 20 TO 25 KT WINDS. THE
DIRECTION WILL BE NE THROUGH THE EVE...BACKING TO THE N OVERNIGHT.
SEAS WILL RESPOND TO THE INCREASING WINDS...BUILDING UP TO 6 TO 9
FT...10 FT SEAS ARE POSSIBLE AROUND FRYING PAN SHOALS. SEAS WILL BE
LOWER ACROSS THE VERY NEAR SHORE WATERS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND
DEPARTING LOW PRESSURE AND WILL BE THE MAIN PLAYER DURING THE SHORT
TERM FOR THE MARINE COMMUNITY. INITIALLY A NORTHERLY FLOW OF 15-20
KNOTS WILL BE IN PLACE. BY THURSDAY AFTERNOON SPEEDS DROP TO 10-15
KNOTS LEANING HEAVILY TO THE HIGHER SIDE OF THE RANGE. WITH THE
SPRAWLING HIGH MOVING SLOWLY...THE COLD AIR ADVECTION ARRIVES IN THE
SAME MANNER AND WINDS WILL REMAIN HERE UNTIL BASICALLY THE END OF
THE PERIOD. THERE MAY BE A SUBTLE BUT BRIEF LULL EARLY SATURDAY
FOLLOWED BY AN INCREASE ONCE AGAIN AS THE EARLY STAGES OF A COASTAL
TROUGH FORM. SEAS WILL BE HIGHEST EARLY WITH 5-8 FEET CONTINUING. BY
LATER THURSDAY AFTERNOON...A MORE MODERATE RANGE OF 2-4 FEET
DEVELOPS. THE EXPIRATION OF THE SMALL CRAFT ADVISORY LATE IN THE DAY
LOOKS OK.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...LARGE AREA OF EASTBOUND HIGH PRESSURE ON
SATURDAY SLIDING ACROSS OHIO VALLEY. THIS LEADS TO A BROAD SWATH OF
NORTHEASTERLY FLOW ALONG MUCH OF THE EAST COAST. CONDITIONS MAY GET
CLOSE TO SCEC/SCA CUTOFF ESPECIALLY ALONG THE LESS SHELTERED NC
WATERS. SUNDAY THIS HIGH MOVES FURTHER EAST BUT LEAVES BEHIND A
RIDGE AXIS INTO THE CAROLINAS. AT THE SAME TIME AN OFFSHORE
TROUGHINESS SHOULD WEAKEN AND VEER THE FLOW. PRETTY COMPLEX SETUP
HEADING INTO MONDAY WITH THE WEDGE BREAKING DOWN LEAVING BEHIND HIGH
DUE EAST OF THE REGION AND A COLD FRONT DROPPING INTO THE UPSTATE
REGION OF THE CAROLINAS WHILE DECELERATING. SOUTHWESTERLY FLOW
AHEAD OF THE FRONT VEERS CONSIDERABLY OVER AT LEAST NORTHERN WATERS
DEPENDING ON THE SPEED OF THE BOUNDARY. A NE FLOW RETURNS AREA-WIDE
BY MONDAY NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
THURSDAY FOR SCZ017-023-024.
NC...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
THURSDAY FOR NCZ087-096-105.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...RJD/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
304 PM EST TUE FEB 24 2015
.SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE ALONG THE SOUTHEAST
COAST THIS AFTERNOON... FOLLOWED BY A SECOND WAVE OF LOW PRESSURE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM TUESDAY...
...WINTER WEATHER ADVISORY CONTINUES UNTIL THIS AFTERNOON FOR THE
WESTERN PIEDMONT AND UNTIL THIS EVENING FOR THE CENTRAL PIEDMONT AND
COASTAL PLAIN....
PERIODS OF HIGH LIQUID-TO-FROZEN RATIO SNOW CONTINUES THIS MORNING
IN ASSOCIATION WITH A LOBE OF VORTICITY ACCOMPANYING A SPEED MAX
OVER THE GULF COAST STATES AND WARM ADVECTION AHEAD OF A WAVE AT
850MB. SNOWFALL REPORTS VARY FROM COUNTY TO COUNTY DUE TO THE
NATURE OF THE SNOW BUT A GENERAL HALF INCH TO TWO INCHES HAS BEEN
THE RULE SO FAR...WITH THE HIGHEST AMOUNTS IN THE NORTHWEST
PIEDMONT. THE WARM ADVECTION CONTINUES PER MORNING RAOB ANALYSIS
AND THE LEADING EDGE OF THE DCVA AND 60-90M HEIGHT FALLS IS
ENCROACHING ON THE WESTERN PIEDMONT. IR IMAGERY AND MIXED PHASE
PRODUCTS SHOW WARMING CLOUD TOPS NOW ACROSS THE WESTERN PIEDMONT AND
THAT LINES UP WELL WITH THE BACK EDGE OF HEAVIER SNOW ON
RADAR...WHICH IS APPROACHING THE US HWY 1 CORRIDOR. THERE IS A BAND
OF PRECIP BACK TOWARD COLUMBIA SC THAT SHOULD BE THE MAIN AREA OF
PRECIP THAT CLIPS THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
AFTERNOON AND EARLY EVENING. OF NOTE IS SOME STRONG FGEN FROM 925-
850MB AND NEGATIVE EPV ALONG THE NC/SC BORDER WHICH MAY BE LEADING
TO SOME CONDITIONAL SYMMETRIC INSTABILITY ABOVE THE COLD DOME AND
EXPLAIN SOME OF THE BANDING ON RADAR. RAP SOUNDINGS STILL SUPPORT A
CHANGEOVER IN THE AREA FROM KFAY TO KGSB AND SOUTHEAST...AND DUAL
POL (CC) DATA IS STARTING TO SHOW THIS. NO CHANGES TO THE ADVISORY
THIS MORNING AND WILL REEVALUATE THE POSSIBILITY OF CANCELING EARLY
IN THE WEST AFTER NOON.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 PM TUESDAY...
MODEL GUIDANCE CONTINUES TO SUGGEST A POTENTIALLY SIGNIFICANT WINTER
STORM FOR MOST OF THE NC PIEDMONT AND NORTHERN AND CENTRAL COASTAL
PLAIN...AND POSSIBLY ALL OF CENTRAL NC...WEDNESDAY NIGHT. A WINTER
STORM WATCH WILL BE ISSUED SHORTLY.
HIGH PRESSURE OVER NC ON WEDNESDAY WILL RETREAT NORTHWARD AS THE
SURFACE LOW OVER THE GULF MOVES NE THROUGH NORTHERN FL AND ALONG THE
SOUTHEAST U.S COAST THROUGH THURSDAY MORNING. HIGHS ARE EXPECTED TO
BE BELOW GUIDANCE AND RANGE IN THE LOWER 40S BUT COULD BE SUPPRESSED
EVEN FURTHER BY SNOW COVER AND MELTING. PRECIPITATION IS EXPECTED TO
SPREAD INTO THE SOUTHERN AND WESTERN PIEDMONT AROUND SUNSET OR
SHORTLY THEREAFTER...BEFORE OVERSPREADING THE REMAINDER OF CENTRAL
NC OVERNIGHT. PARTIAL THICKNESS VALUES HEAVILY WEIGHTED TOWARD THE
FAVORED GFS AND ECMWF SOLUTIONS...WOULD FAVOR MOSTLY SNOW OVER THE
PIEDMONT AND NORTHERN COASTAL PLAIN...WITH A MIX OF RAIN AND
SNOW...OR POSSIBLY SLEET FROM MEB TO FAY TO GSB AND POINTS SOUTH.
THE POSITION OF THE LOW AND IT`S PROXIMITY TO THE NC COAST WILL
LARGELY IMPACT THE AMOUNT AND TYPE OF PRECIPITATION THAT OCCURS.
REGARDLESS...THERE IS A HIGH PROBABILITY THAT THE NORTHERN HALF TO
TWO THIRDS OF THE AREA WILL SEE AT LEAST 2-4 INCHES OF SNOW...WITH
THE POTENTIAL FOR HIGHER AMOUNTS IN AN AXIS FROM NEAR SANFORD TO
RALEIGH TO ROANOKE RAPIDS WITH 6 INCHES OF SNOW. THE LARGEST
UNCERTAINTY IN SNOWFALL AMOUNTS WILL BE ACROSS THE NORTH NEAR THE VA
BORDER ON THE NORTHERN PERIPHERY OF THE HEAVIEST PRECIPITATION
AMOUNTS. OTHER UNCERTAINTY LIES WITH THE P-TYPE ACROSS THE SOUTH
WHERE TEMPERATURES WILL STRUGGLE TO FALL TO FREEZING. WHILE
OVERNIGHT LOWS ACROSS THE NORTH WILL DIP INTO THE UPPER 20S TO
AROUND 30 DEGREES WITH GOOD CONFIDENCE THAT PRECIP WILL BE MOSTLY
SNOW. ACROSS THE SOUTH THE LOW WILL HOVER AROUND FREEZING...WHICH
WILL HAVE A BIG IMPACT OF P-TYPE AND ACCUMULATIONS. GENERALLY
SPEAKING...CONFIDENCE IS HIGH THAT THIS EVENT WILL BE
SIGNIFICANT...HOWEVER THE EXACT AMOUNTS ACROSS THE REGION AND P-
TYPES IN THE SOUTH ARE STILL SOMEWHAT UNCERTAIN.
PRECIPITATION PROBABILITIES WILL DECREASE SIGNIFICANTLY AFTER 12Z
THURSDAY AS THE LOW MOVES AWAY FROM THE COAST AND HIGH PRESSURE
BUILDS IN ONCE AGAIN. SOME LINGERING LIGHT SNOW IS POSSIBLE IN THE
EAST BUT THE SNOW THREAT SHOULD ABATE QUICKLY THURSDAY MORNING AS
THE ATMOSPHERE DRIES IN THE ICE NUCLEATION REGION. THIS SHOULD
RESULT IN PERIODS OF DRIZZLE AND SPOTTY RAIN WHICH COULD FALL AS A
PERIOD OF FREEZING RAIN OR DRIZZLE ACROSS THE NORTH AS TEMPERATURES
STRUGGLE TO CLIMB ABOVE FREEZING. ADDITIONAL SPOTTY PRECIPITATION
MAY REDEVELOP IN THE NW DURING THE DAY AS HIGHS SHOULD MAKE IT INTO
THE MID TO UPPER 30S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
AS THE COASTAL LOW RESPONSIBLE FOR THE WINTER WEATHER LIFTS UP THE
EAST ATLANTIC...A 1040 HPA HIGH BUILDING ACROSS THE OHIO VALLEY WILL
PUSH A REINFORCING SURGE OF ARCTIC AIR INTO THE REGION THURSDAY
NIGHT...WHICH WILL LINGER THROUGH SATURDAY. CLOUDINESS WILL BE
EXTENSIVE AND THERE WILL BE AN INITIAL CHANCE OF SNOW FLURRIES
THURSDAY NIGHT...PERHAPS LINGERING INTO FRIDAY...AS THE COLD AIR
SURGE COMMENCES AND IS AIDED BY WEAK PERTURBATIONS IN THE FAST
SOUTHWEST FLOW ALOFT. CLOUDINESS WILL BE EXTENSIVE AND AFTER A
MORNING LOW IN THE LOWER 20S...HIGHS ON FRIDAY WILL STRUGGLE TO
REACH 40.
THE CAD PROCESS CONTINUES WITH COLD AIR FIRMLY ENTRENCHED ON
SATURDAY. AIDED BY BY ANY PERTURBATIONS IN THE CONTINUED VERY FAST
WEST-SOUTHWEST FLOW AOLFT..THERE COULD YET BE LINGERING LIGHT
FLURRIES IN THE FOOTHILLS OR FAR WEST PIEDMONT. HIGHS SATURDAY WILL
BE SIMILAR OR A DEGREE COOLER...STILL WITHIN A COUPLE DEGREES OF 40.
AS WE OFTEN SEE IN STRONG COLD AIR DAMMING SCENARIOS...THE
BAROCLINIC ZONE ALONG THE COAST INDUCES AN INVERTED TROF...WHICH IN
TURN BEGINS TO INCREASE MOISTURE ADVECTION/ISENTROPIC LIFT OVER THE
COLD DOME BY SUNDAY MORNING. WILL BE INTRODUCING LOW CHANCE POPS
INITIALLY SUNDAY MORNING...WHICH COULD BE IN THE FORM OF A MIX OF
RAIN/SNOW/ICY STUFF...IN THE WESTERN HALF OF THE AREA IF IT
COMMENCES EARLY ENOUGH. WILL HAVE POPS RAMPING UP TO CHANCE CATEGORY
BY SUNDAY NIGHT...ALTHOUGH PRECIP WILL BE IN THE FORM OF RAIN AS THE
RIDGING WEAKENS AND OVERNIGHT MINS HOLD IN THE MID 30S TO AROUND 40.
A STRONG LOW PRESSURE AREA LIFTING OUT OF THE MIDWEST TOWARDS THE
OHIO VALLEY EARLY NEXT WEEK WILL ALLOW A RICH GULF TAP...ENSURING
GOOD CHANCES OF RAIN MONDAY INTO TUESDAY. AT PRESENT MODELS KEEP THE
EAST COAST IN THE WARM SECTOR WITH HIGHS IN THE 50S BOTH DAYS...BUT
IT DOES RESEMBLE AN IN-SITU DAMMING EVENT WHICH WOULD SHAVE 10
DEGREES (OR MORE) OFF HIGHS MONDAY AND TUESDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1230 PM TUESDAY...
24HR TAF PERIOD: THE BROAD ARE OF WINTER PRECIP WILL CONTINUE TO
TRANSLATE EAST OVER THE NEXT SEVERAL HOURS AND WILL TAPER OFF
AREAWIDE THROUGH THE AFTERNOON HOURS. THE MAIN P-TYPE REMAINS SNOW
ACROSS MUCH OF THE AREA...HOWEVER KFAY HAS RECENTLY REPORTED A MIX
(LIGHTLY SNOW/SLEET/SOME FREEZING RAIN). EXPECT WIDESPREAD IFR TO
MVFR CEILINGS WITH INTERMITTENT VISIBILITY RESTRICTIONS AS LOW AS
IFR WITHIN THE HEAVIER SNOW BANDS. CIGS MAY LIFT SOME OVERNIGHT AND
VFR CONDITIONS MAY PREVAIL. HOWEVER...THERE ARE SOME INDICATIONS OF
SOME FOG...ESPECIALLY ACROSS THE EAST. REGARDLESS...VFR CONDITIONS
ARE EXPECTED TO RETURN BRIEFLY ON WEDNESDAY BEFORE THE NEXT SYSTEM
IMPACTS THE AREA WEDNESDAY NIGHT AND THURSDAY.
OUTLOOK: AFTER A BRIEF REPRIEVE ON WEDNESDAY...AN AREA OF LOW
PRESSURE TRACKING ALONG THE SOUTHEAST COAST WEDNESDAY NIGHT AND INTO
THURSDAY WILL BRING CHANCE FOR SUB-VFR CONDITIONS WITH A WINTRY MIX
LIKELY. VFR CONDITIONS SHOULD RETURN BY FRIDAY AS CHILLY HIGH
PRESSURE BUILDS INTO THE AREA FOR THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ007>011-
024>028-040>043-076>078-085-086-088-089. WINTER WEATHER ADVISORY
UNTIL 7 PM EST THIS EVENING FOR NCZ021>023-038-039-073>075-083-084.
&&
$$
SYNOPSIS...SEC
NEAR TERM...CBL/BLS
SHORT TERM...KC
LONG TERM...MLM
AVIATION...KRD/CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1234 PM EST TUE FEB 24 2015
.SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE ALONG THE SOUTHEAST
COAST THIS AFTERNOON... FOLLOWED BY A SECOND WAVE OF LOW PRESSURE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM TUESDAY...
...WINTER WEATHER ADVISORY CONTINUES UNTIL THIS AFTERNOON FOR THE
WESTERN PIEDMONT AND UNTIL THIS EVENING FOR THE CENTRAL PIEDMONT AND
COASTAL PLAIN....
PERIODS OF HIGH LIQUID-TO-FROZEN RATIO SNOW CONTINUES THIS MORNING
IN ASSOCIATION WITH A LOBE OF VORTICITY ACCOMPANYING A SPEED MAX
OVER THE GULF COAST STATES AND WARM ADVECTION AHEAD OF A WAVE AT
850MB. SNOWFALL REPORTS VARY FROM COUNTY TO COUNTY DUE TO THE
NATURE OF THE SNOW BUT A GENERAL HALF INCH TO TWO INCHES HAS BEEN
THE RULE SO FAR...WITH THE HIGHEST AMOUNTS IN THE NORTHWEST
PIEDMONT. THE WARM ADVECTION CONTINUES PER MORNING RAOB ANALYSIS
AND THE LEADING EDGE OF THE DCVA AND 60-90M HEIGHT FALLS IS
ENCROACHING ON THE WESTERN PIEDMONT. IR IMAGERY AND MIXED PHASE
PRODUCTS SHOW WARMING CLOUD TOPS NOW ACROSS THE WESTERN PIEDMONT AND
THAT LINES UP WELL WITH THE BACK EDGE OF HEAVIER SNOW ON
RADAR...WHICH IS APPROACHING THE US HWY 1 CORRIDOR. THERE IS A BAND
OF PRECIP BACK TOWARD COLUMBIA SC THAT SHOULD BE THE MAIN AREA OF
PRECIP THAT CLIPS THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
AFTERNOON AND EARLY EVENING. OF NOTE IS SOME STRONG FGEN FROM 925-
850MB AND NEGATIVE EPV ALONG THE NC/SC BORDER WHICH MAY BE LEADING
TO SOME CONDITIONAL SYMMETRIC INSTABILITY ABOVE THE COLD DOME AND
EXPLAIN SOME OF THE BANDING ON RADAR. RAP SOUNDINGS STILL SUPPORT A
CHANGEOVER IN THE AREA FROM KFAY TO KGSB AND SOUTHEAST...AND DUAL
POL (CC) DATA IS STARTING TO SHOW THIS. NO CHANGES TO THE ADVISORY
THIS MORNING AND WILL REEVALUATE THE POSSIBILITY OF CANCELING EARLY
IN THE WEST AFTER NOON.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 430 AM TUESDAY...
MODEL GUIDANCE CONVERGING TOWARD A POTENTIALLY SIGNIFICANT WINTER
STORM FOR MOST OF THE NC PIEDMONT AND NORTHERN AND CENTRAL COASTAL
PLAIN...AND POSSIBLY ALL OF CENTRAL NC...WED NIGHT.
BRIEF S/W RIDGING AND INFLUENCE OF LINGERING AND SIGNIFICANTLY
WEAKENED/MODIFIED (1015-1020 MB) ARCTIC HIGH PRESSURE WILL RESULT IN
A CLEAR START TO THE DAY WED...BUT WITH INCREASING AND CONSIDERABLE
HIGH CLOUDS BY AFTERNOON...DOWNSTREAM OF AN INITIALLY CLOSED LOW
OVER THE SW US THAT WILL DEAMPLIFY/SHEAR EAST ACROSS THE NORTHERN
GULF COAST STATES AND CAROLINAS BY WED NIGHT. THE THICKENING CLOUDS
WILL SERVE TO HOLD TEMPERATURES SHY OF FULL SUN VALUES...WITH MOSTLY
LOWER TO MIDDLE 40S EXPECTED.
THE APPROACH OF THE DEAMPLIFYING WAVE ALOFT WILL RESULT IN NORTHERN
GOM CYCLOGENESIS...WITH THE ASSOCIATED SFC LOW THEN EXPECTED TO
TRACK ACROSS THE NORTHERN FL PENINSULA WED EVE AND OFF THE SE US
COAST BY THU EARLY THU. PRECIPITATION IS EXPECTED TO SPREAD INTO THE
SOUTHERN AND WESTERN PIEDMONT AROUND SUNSET OR SHORTLY THEREAFTER...
BEFORE OVERSPREADING THE REMAINDER OF CENTRAL NC OVERNIGHT. PARTIAL
THICKNESS VALUES HEAVILY WEIGHTED TOWARD THE FAVORED 00Z ECMWF...
WHICH FITS RIGHT IN THE THE MIDDLE OF A MULTI-MODEL AND RUN ENSEMBLE
CONSENSU...WOULD FAVOR MOSTLY SNOW OVER THE PIEDMONT AND NORTHERN
COASTAL PLAIN...WITH A MIX OF RAIN AND SNOW...TRANSITIONING TO
FREEZING RAIN OR RAIN FROM MEB TO FAY TO GSB AND POINTS SOUTH.
HOWEVER...EVEN THOSE SOUTHERN AREAS MAY REMAIN MOSTLY SNOW...WHICH
WOULD ALLOW HIGHER SNOW TOTALS TO EXTEND FARTHER SOUTH.
TWO THINGS JUMP OUT WITH THIS POTENTIAL WINTER STORM. THE FIRST IS
THE PARENT COLD HIGH...AN ARCTIC ONE AROUND 1045 MB...WILL BE
CENTERED OVER SOUTHERN MANITOBA - WELL WEST OF AN IDEAL POSITION FOR
A BIG WINTER STORM FOR CENTRAL NC. THE SECOND...HOWEVER...IS THAT
THE PRECEDING ARCTIC HIGH OVER THE AREA THIS MORNING...ALTHOUGH
DRAMATICALLY WEAKENED BY WED NIGHT...MAY BE JUST COLD ENOUGH...WITH
SFC TEMPERATURES DURING THE EVENT AROUND OR JUST BELOW 32 DEGREES.
AND IN FACT...PROJECTED PARTIAL THICKNESS VALUES INVOF AND NORTH OF
US HIGHWAY 64 ARE IN THE RANGE TYPICAL OF SIGNIFICANT WINTER STORMS
OF GREATER THAN 6 INCHES OF SNOW...BASED ON AN EXTENSIVE WINTER
WEATHER DATABASE CHAMPIONED BY KERMIT KEETER. WHILE QPF FROM THE
FAVORED 00Z ECMWF SOLUTION...WHICH RANGES FROM TWO OR THREE TENTHS
OVER THE NW PIEDMONT TO FIVE OR SIX TENTHS OVER THE SANDHILLS AND
SOUTHERN COASTAL PLAIN...WOULD NOT SUPPORT SNOW TOTALS QUITE THAT
HIGH...THEY WOULD SUPPORT A SWATH OF SEVERAL INCHES OF SNOW - MOST
LIKELY INVOF US HIGHWAY 64 WHERE THE RELATIVE HIGHEST QPF WILL
OVERLAP WITH PROJECTED THERMAL PROFILES/PARTIAL THICKNESS VALUES
SUPPORTIVE OF ALL SNOW.
A WINTER STORM WATCH WILL LIKELY BE ISSUED LATER TODAY FOR MUCH OF
CENTRAL NC.
AFTER LINGERING LIGHT SNOW...OR FREEZING DRIZZLE NORTH TO DRIZZLE
SOUTH...OWING TO A LOSS OF SATURATION ALOFT/IN THE ICE NUCLEATION
ZONE...SKIES WILL BE VARIABLY CLOUDY THU. THE APPROACH OF A WEAK
CLIPPER LOW AND ATTENDING SHORTWAVE TROUGH COULD CAUSE A FEW RAIN OR
SNOW SHOWERS TO SPILL EAST OF THE APPALACHIANS AND INTO THE PIEDMONT
DURING THE AFTERNOON...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED...
WITH TEMPERATURES MOSTLY 35 TO 40 DEGREES. COLDER AND PARTIAL
CLEARING WITH LOWS IN THE LOWER 20S THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 200 AM TUESDAY...
HIGH PRESSURE WILL BUILD EASTWARD FROM THE NORTHERN PLAINS INTO THE
MIDATLANTIC FRI INTO SAT... WITH BELOW NORMAL TEMPS ACROSS THE AREA.
PRECIP IS POSSIBLE SUN INTO MONDAY WITH THE APPROACH OF A COLD
FRONT. MOISTURE RETURN BEGINS LATER ON SATURDAY... AND IN SITU CAD
IS POSSIBLE WITH LIGHT PRECIP MOVING IN TO THE AREA SUNDAY AND HIGH
PRESSURE WEDGING DOWN THE EAST COAST. FRONT LOOKS TO PROGRESS IN TO
THE AREA MONDAY... POTENTIALLY AS A BACKDOOR FRONT. SECOND WAVE MAY
DEVELOP ALONG THE FRONT... AND WOULD BRING ANOTHER CAD EVENT FOR
TUESDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1230 PM TUESDAY...
24HR TAF PERIOD: THE BROAD ARE OF WINTER PRECIP WILL CONTINUE TO
TRANSLATE EAST OVER THE NEXT SEVERAL HOURS AND WILL TAPER OFF
AREAWIDE THROUGH THE AFTERNOON HOURS. THE MAIN P-TYPE REMAINS SNOW
ACROSS MUCH OF THE AREA...HOWEVER KFAY HAS RECENTLY REPORTED A MIX
(LIGHTLY SNOW/SLEET/SOME FREEZING RAIN). EXPECT WIDESPREAD IFR TO
MVFR CEILINGS WITH INTERMITTENT VISIBILITY RESTRICTIONS AS LOW AS
IFR WITHIN THE HEAVIER SNOW BANDS. CIGS MAY LIFT SOME OVERNIGHT AND
VFR CONDITIONS MAY PREVAIL. HOWEVER...THERE ARE SOME INDICATIONS OF
SOME FOG...ESPECIALLY ACROSS THE EAST. REGARDLESS...VFR CONDITIONS
ARE EXPECTED TO RETURN BRIEFLY ON WEDNESDAY BEFORE THE NEXT SYSTEM
IMPACTS THE AREA WEDNESDAY NIGHT AND THURSDAY.
OUTLOOK: AFTER A BRIEF REPRIEVE ON WEDNESDAY...AN AREA OF LOW
PRESSURE TRACKING ALONG THE SOUTHEAST COAST WEDNESDAY NIGHT AND INTO
THURSDAY WILL BRING CHANCE FOR SUB-VFR CONDITIONS WITH A WINTRY MIX
LIKELY. VFR CONDITIONS SHOULD RETURN BY FRIDAY AS CHILLY HIGH
PRESSURE BUILDS INTO THE AREA FOR THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ007>011-
024>028-040>043-076>078-085-086-088-089. WINTER WEATHER ADVISORY
UNTIL 7 PM EST THIS EVENING FOR NCZ021>023-038-039-073>075-083-084.
&&
$$
SYNOPSIS...SEC
NEAR TERM...CBL/BLS
SHORT TERM...RAH
LONG TERM...SEC
AVIATION...KRD/CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1100 AM EST TUE FEB 24 2015
.SYNOPSIS...AN AREA OF LOW PRESSURE WILL MOVE ALONG THE SOUTHEAST
COAST THIS AFTERNOON... FOLLOWED BY A SECOND WAVE OF LOW PRESSURE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM TUESDAY...
...WINTER WEATHER ADVISORY CONTINUES UNTIL THIS AFTERNOON FOR THE
WESTERN PIEDMONT AND UNTIL THIS EVENING FOR THE CENTRAL PIEDMONT AND
COASTAL PLAIN....
PERIODS OF HIGH LIQUID-TO-FROZEN RATIO SNOW CONTINUES THIS MORNING
IN ASSOCIATION WITH A LOBE OF VORTICITY ACCOMPANYING A SPEED MAX
OVER THE GULF COAST STATES AND WARM ADVECTION AHEAD OF A WAVE AT
850MB. SNOWFALL REPORTS VARY FROM COUNTY TO COUNTY DUE TO THE
NATURE OF THE SNOW BUT A GENERAL HALF INCH TO TWO INCHES HAS BEEN
THE RULE SO FAR...WITH THE HIGHEST AMOUNTS IN THE NORTHWEST
PIEDMONT. THE WARM ADVECTION CONTINUES PER MORNING RAOB ANALYSIS
AND THE LEADING EDGE OF THE DCVA AND 60-90M HEIGHT FALLS IS
ENCROACHING ON THE WESTERN PIEDMONT. IR IMAGERY AND MIXED PHASE
PRODUCTS SHOW WARMING CLOUD TOPS NOW ACROSS THE WESTERN PIEDMONT AND
THAT LINES UP WELL WITH THE BACK EDGE OF HEAVIER SNOW ON
RADAR...WHICH IS APPROACHING THE US HWY 1 CORRIDOR. THERE IS A BAND
OF PRECIP BACK TOWARD COLUMBIA SC THAT SHOULD BE THE MAIN AREA OF
PRECIP THAT CLIPS THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
AFTERNOON AND EARLY EVENING. OF NOTE IS SOME STRONG FGEN FROM 925-
850MB AND NEGATIVE EPV ALONG THE NC/SC BORDER WHICH MAY BE LEADING
TO SOME CONDITIONAL SYMMETRIC INSTABILITY ABOVE THE COLD DOME AND
EXPLAIN SOME OF THE BANDING ON RADAR. RAP SOUNDINGS STILL SUPPORT A
CHANGEOVER IN THE AREA FROM KFAY TO KGSB AND SOUTHEAST...AND DUAL
POL (CC) DATA IS STARTING TO SHOW THIS. NO CHANGES TO THE ADVISORY
THIS MORNING AND WILL REEVALUATE THE POSSIBILITY OF CANCELING EARLY
IN THE WEST AFTER NOON.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 430 AM TUESDAY...
MODEL GUIDANCE CONVERGING TOWARD A POTENTIALLY SIGNIFICANT WINTER
STORM FOR MOST OF THE NC PIEDMONT AND NORTHERN AND CENTRAL COASTAL
PLAIN...AND POSSIBLY ALL OF CENTRAL NC...WED NIGHT.
BRIEF S/W RIDGING AND INFLUENCE OF LINGERING AND SIGNIFICANTLY
WEAKENED/MODIFIED (1015-1020 MB) ARCTIC HIGH PRESSURE WILL RESULT IN
A CLEAR START TO THE DAY WED...BUT WITH INCREASING AND CONSIDERABLE
HIGH CLOUDS BY AFTERNOON...DOWNSTREAM OF AN INITIALLY CLOSED LOW
OVER THE SW US THAT WILL DEAMPLIFY/SHEAR EAST ACROSS THE NORTHERN
GULF COAST STATES AND CAROLINAS BY WED NIGHT. THE THICKENING CLOUDS
WILL SERVE TO HOLD TEMPERATURES SHY OF FULL SUN VALUES...WITH MOSTLY
LOWER TO MIDDLE 40S EXPECTED.
THE APPROACH OF THE DEAMPLIFYING WAVE ALOFT WILL RESULT IN NORTHERN
GOM CYCLOGENESIS...WITH THE ASSOCIATED SFC LOW THEN EXPECTED TO
TRACK ACROSS THE NORTHERN FL PENINSULA WED EVE AND OFF THE SE US
COAST BY THU EARLY THU. PRECIPITATION IS EXPECTED TO SPREAD INTO THE
SOUTHERN AND WESTERN PIEDMONT AROUND SUNSET OR SHORTLY THEREAFTER...
BEFORE OVERSPREADING THE REMAINDER OF CENTRAL NC OVERNIGHT. PARTIAL
THICKNESS VALUES HEAVILY WEIGHTED TOWARD THE FAVORED 00Z ECMWF...
WHICH FITS RIGHT IN THE THE MIDDLE OF A MULTI-MODEL AND RUN ENSEMBLE
CONSENSU...WOULD FAVOR MOSTLY SNOW OVER THE PIEDMONT AND NORTHERN
COASTAL PLAIN...WITH A MIX OF RAIN AND SNOW...TRANSITIONING TO
FREEZING RAIN OR RAIN FROM MEB TO FAY TO GSB AND POINTS SOUTH.
HOWEVER...EVEN THOSE SOUTHERN AREAS MAY REMAIN MOSTLY SNOW...WHICH
WOULD ALLOW HIGHER SNOW TOTALS TO EXTEND FARTHER SOUTH.
TWO THINGS JUMP OUT WITH THIS POTENTIAL WINTER STORM. THE FIRST IS
THE PARENT COLD HIGH...AN ARCTIC ONE AROUND 1045 MB...WILL BE
CENTERED OVER SOUTHERN MANITOBA - WELL WEST OF AN IDEAL POSITION FOR
A BIG WINTER STORM FOR CENTRAL NC. THE SECOND...HOWEVER...IS THAT
THE PRECEDING ARCTIC HIGH OVER THE AREA THIS MORNING...ALTHOUGH
DRAMATICALLY WEAKENED BY WED NIGHT...MAY BE JUST COLD ENOUGH...WITH
SFC TEMPERATURES DURING THE EVENT AROUND OR JUST BELOW 32 DEGREES.
AND IN FACT...PROJECTED PARTIAL THICKNESS VALUES INVOF AND NORTH OF
US HIGHWAY 64 ARE IN THE RANGE TYPICAL OF SIGNIFICANT WINTER STORMS
OF GREATER THAN 6 INCHES OF SNOW...BASED ON AN EXTENSIVE WINTER
WEATHER DATABASE CHAMPIONED BY KERMIT KEETER. WHILE QPF FROM THE
FAVORED 00Z ECMWF SOLUTION...WHICH RANGES FROM TWO OR THREE TENTHS
OVER THE NW PIEDMONT TO FIVE OR SIX TENTHS OVER THE SANDHILLS AND
SOUTHERN COASTAL PLAIN...WOULD NOT SUPPORT SNOW TOTALS QUITE THAT
HIGH...THEY WOULD SUPPORT A SWATH OF SEVERAL INCHES OF SNOW - MOST
LIKELY INVOF US HIGHWAY 64 WHERE THE RELATIVE HIGHEST QPF WILL
OVERLAP WITH PROJECTED THERMAL PROFILES/PARTIAL THICKNESS VALUES
SUPPORTIVE OF ALL SNOW.
A WINTER STORM WATCH WILL LIKELY BE ISSUED LATER TODAY FOR MUCH OF
CENTRAL NC.
AFTER LINGERING LIGHT SNOW...OR FREEZING DRIZZLE NORTH TO DRIZZLE
SOUTH...OWING TO A LOSS OF SATURATION ALOFT/IN THE ICE NUCLEATION
ZONE...SKIES WILL BE VARIABLY CLOUDY THU. THE APPROACH OF A WEAK
CLIPPER LOW AND ATTENDING SHORTWAVE TROUGH COULD CAUSE A FEW RAIN OR
SNOW SHOWERS TO SPILL EAST OF THE APPALACHIANS AND INTO THE PIEDMONT
DURING THE AFTERNOON...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED...
WITH TEMPERATURES MOSTLY 35 TO 40 DEGREES. COLDER AND PARTIAL
CLEARING WITH LOWS IN THE LOWER 20S THU NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 200 AM TUESDAY...
HIGH PRESSURE WILL BUILD EASTWARD FROM THE NORTHERN PLAINS INTO THE
MIDATLANTIC FRI INTO SAT... WITH BELOW NORMAL TEMPS ACROSS THE AREA.
PRECIP IS POSSIBLE SUN INTO MONDAY WITH THE APPROACH OF A COLD
FRONT. MOISTURE RETURN BEGINS LATER ON SATURDAY... AND IN SITU CAD
IS POSSIBLE WITH LIGHT PRECIP MOVING IN TO THE AREA SUNDAY AND HIGH
PRESSURE WEDGING DOWN THE EAST COAST. FRONT LOOKS TO PROGRESS IN TO
THE AREA MONDAY... POTENTIALLY AS A BACKDOOR FRONT. SECOND WAVE MAY
DEVELOP ALONG THE FRONT... AND WOULD BRING ANOTHER CAD EVENT FOR
TUESDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 640 AM TUESDAY...
24HR TAF PERIOD: LIGHT PRECIPITATION WILL CONTINUE TO OVERSPREAD THE
AREA AS AN UPPER LEVEL DISTURBANCE TRACKS THROUGH THE SOUTHEASTERN
US. AIRMASS IS COLD ENOUGH THAT PRECIPITATION WILL FALL AS ALL SNOW
ACROSS MUCH OF THE AREA. THE EXCEPTION WILL BE AT KFAY WHERE SNOW
COULD MIX OR CHANGEOVER TO SLEET AND FREEZING RAIN BY THE AFTERNOON
AND EVENING. EXPECT WIDESPREAD IFR TO MVFR CEILINGS WITH
INTERMITTENT VISIBILITY RESTRICTIONS AS LOW AS IFR WITHIN THE
HEAVIER SNOW BANDS...WITH THE WORST CONDITIONS EXPECTED AT KFAY AND
KRWI. THE SNOW SHOULD EXIT THE AREA BETWEEN 18Z-20Z IN THE WEST TO
00-03Z IN THE EAST.
VFR CONDITIONS ARE EXPECTED TO RETURN BRIEFLY ON WEDNESDAY BEFORE
THE NEXT SYSTEM IMPACTS THE AREA WEDNESDAY NIGHT AND THURSDAY.
OUTLOOK: AFTER A BRIEF REPRIEVE ON WEDNESDAY...AN AREA OF LOW
PRESSURE TRACKING ALONG THE SOUTHEAST COAST WEDNESDAY NIGHT AND INTO
THURSDAY WILL BRING CHANCE FOR SUB-VFR CONDITIONS WITH A WINTRY MIX
LIKELY. VFR CONDITIONS SHOULD RETURN BU FRIDAY AS CHILLY HIGH
PRESSURE BUILDS INTO THE AREA FOR THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ007>011-
024>028-040>043-076>078-085-086-088-089. WINTER WEATHER ADVISORY
UNTIL 7 PM EST THIS EVENING FOR NCZ021>023-038-039-073>075-083-084.
&&
$$
SYNOPSIS...SEC
NEAR TERM...CBL/BLS
SHORT TERM...RAH
LONG TERM...SEC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1132 PM CST MON FEB 23 2015
.UPDATE...
ISSUED AT 934 PM CST MON FEB 23 2015
WINDS UPSTREAM WITH THE COLD FROPA GUSTING TO 30-40 MPH...AND
MODEL GUIDANCE INDICATES WINDS ALOFT SHOULD STRENGTHEN A BIT MORE.
THIS LEAVES THE PREVIOUS UPDATE IN GOOD SHAPE. STILL ANTICIPATE A
BRIEF (UP TO AN HOUR) PERIOD OF STRONGER WINDS/LOW VSBY BETWEEN 06Z-
12Z. BEFORE THE COLD FROPA...MILD TEMPS WILL CONTINUE.
UPDATE ISSUED AT 705 PM CST MON FEB 23 2015
COLD FRONT TONIGHT WILL BE THE MAIN UPDATE CONCERN. RAP INDICATING
A BRIEF PERIOD OF STRONG 925MB-850MB COLD AIR ADVECTION 06Z-12Z
PROPAGATING FROM NORTH TO SOUTH ACROSS THE REGION. THIS WILL BE
ASSOCIATED WITH @40KT WINDS ALOFT. ALTHOUGH A PROLONGED PERIOD OF
STRONG NORTH WINDS ARE NOT EXPECTED...THERE WILL LIKELY BE A BRIEF
PERIOD OF GUSTY WINDS TO 40-45 MPH. WILL INCREASE WIND GUSTS
DURING FROM 06Z-12Z...AND INTRODUCE PATCHY BLOWING SNOW. THE
CURRENT SNOWPACK HAS BEEN BLOWN AROUND QUITE A BIT...WHICH SHOULD
LIMIT THE BLOWABLE SNOW ON THE GROUND. WILL KEEP THE ISOLD-
SCATTERED SNOW SHOWERS AS WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 305 PM CST MON FEB 23 2015
LATE AFTERNOON AND TONIGHT...MODERATE SOUTHWESTERLY WINDS IN THE
LATE AFTERNOON WILL STEADILY GIVE WAY TO A WEST NORTHWEST FLOW
THROUGH THE EVENING HOURS AS A COLD FRONTAL BAND DROPS THROUGH THE
AREA. LAYERED LOW CLOUDS AND PATCHY SNOW FLURRIES APPEAR TO BE
ACCOMPANYING THE SYSTEM...AND EXTEND WELL NORTHWARD THROUGHOUT
EASTERN SASK AND MANITOBA. THESE BANDED LOW CLOUDS SHOULD PERSIST
THROUGHOUT THE OVERNIGHT AND PROVIDE SOME INSULATION TO PRESERVE
OUR MILD HEAT GAINS FROM TODAY. MODERATE NORTHERLY WINDS AND BRIEF
PERIODS OF VERY LIGHT SNOW OR SNOW FLURRIES SHOULD ACCOMPANY THIS
FRONTAL BAND INTO EARLY MORNING...THOUGH OVERALL SNOWFALL SHOULD
REMAIN SCANT. MORE PERSISTENT LIGHT SNOW IS MOST PROBABLE OVER
THE LAKE OF THE WOODS AND RED LAKES REGION WHERE SNOW
ACCUMULATIONS COULD APPROACH AN INCH.
TUESDAY...EXPECT PATCHY LOW CLOUDS AND SUN WITH STEADILY COOLING
TEMPERATURES THROUGHOUT THE DAY...AS WINDS BECOME MORE NORTHERLY
AND ARCTIC AIR BEGINS TO OVERSPREAD THE AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 PM CST MON FEB 23 2015
WEDNESDAY THROUGH THURSDAY...NORTHERLY BLAYER FLOW AND COLD
ADVECTION PATTERN STRENGTHENS INTO WEDNESDAY WITH THE ARCTIC HIGH
SLIDING SOUTHWARD THROUGH SASK...HEADED FOR THE CENTRAL DAKOTAS
BY THURSDAY. PATCHY LOW CLOUDS ARE POSSIBLE THROUGH THE DAY WITH
FAIR SKIES ALOFT AND TEMPERATURES RUNNING 10-15 DEGREES BELOW
SEASONAL NORMALS.
THURSDAY NIGHT TO SUNDAY...THE OVERALL PATTERN CONTINUES TO BE
COOL AND DRY AS SURFACE HIGH PRESSURE REMAINS IN CONTROL. AN UPPER
LEVEL TROF WILL ROTATE AROUND UPPER LOW PRESSURE LOCATED OVER
HUDSON BAY...AND SHIFT ACROSS THE AREA EARLY IN THE PERIOD
REINFORCING THE COOLER TEMPERATURES. AS A RESULT...THE STORM TRACK
IS EXPECTED TO SHIFT SOUTH. THIS WILL KEEP THE BEST CHANCES FOR
PCPN MAINLY SOUTH OF THE FORECAST AREA...ALTHOUGH SOME LIGHT PCPN
MAY BE EXPECTED ACROSS THE FAR ERN ZONES LATE SATURDAY INTO
SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1132 PM CST MON FEB 23 2015
ANTICIPATE A BRIEF PERIOD OF STRONG NORTH WINDS AND MVFR CIGS/VSBY
WITH THE PASSAGE OF A COLD FRONT BEFORE SUNRISE. VFR CONDITIONS
EXPECTED ON TUESDAY WITH GUSTY NORTH WINDS DIMINISHING BY LATE IN
THE DAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...GUST
LONG TERM...GUST/HOPKINS
AVIATION...TG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1241 AM EST TUE FEB 24 2015
.SYNOPSIS...
ARCTIC HIGH PRESSURE BUILDING IN FOR TONIGHT. COLD FRONT TUESDAY
NIGHT. NO STRONG SYSTEMS INTO THURSDAY. HIGH PRESSURE FRIDAY INTO THE
BEGINNING OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
645 PM UPDATE...
A TRICKY FCST TONIGHT INTO TOMORROW. FIRST OFF LOW TEMPS. THERE IS
A CONCERN THAT MID LEVEL CLOUDS DEPICTED ON NAM WILL CUT OFF
RADIATIONAL COOLING ALONG AND S OF I64 AFTER MIDNIGHT. ALSO WAA IN
THE LOW LEVELS WILL TEND TO NIX COOLING ON THE RIDGES. WILL HOLD
WITH PREVIOUS LOW TEMP FORECAST FOR NOW AND MONITOR TRENDS.
OTHERWISE...TRIED TO HIT A FEW MORE COLD SPOTS IN THE N LOWLANDS
WITH LOWER NEGATIVE NUMBERS.
AS FOR TOMORROW...THERE IS A NOTICEABLE TREND NW IN THE PRECIP WITH
AN INVERTED SURFACE TROF EXTENDING WELL N OF SURFACE LOW. THIS
INVERTED TROF AND ASSOCIATED LIFT ALONG WITH MID LEVEL WAVE
SUPPORTS SNOW INTO SW VA AND POTENTIALLY PORTIONS OF SE WV TUESDAY
MORNING. 18Z NAM/18Z GFS/RECENT RUC AND HRRR SUPPORT BUMPING POPS
UP INTO LIKELY AND INSERT UP TO AN INCH OF ACCUMULATION FOR OUR SW
VA COUNTIES. COULD SEE A SKIFF ON OUR E SLOPES OF SE WV AS WELL.
PREVIOUS DISCUSSION BELOW...
LAST OF THE STRATOCUMULUS LIFTING AND THINNING OVER MOUNTAIN
COUNTIES AT 19Z. TEMPERATURES HAVE REBOUNDED A FEW DEGREES IN THE
LOWLANDS WITH THE LATE FEBRUARY SUNSHINE. MEANWHILE...SOME CIRRUS
HEADING TOWARD OUR KY/VA/WV TRI STATE.
FIGURING ON PATCHES OF MID DECK ESPECIALLY 06Z TO 12Z ACROSS SRN WV
INTO SW VA MOSTLY S OF HTS-CRW. ALSO WARMING WILL BE OCCURRING AT
THE 925 TO 850 MB LEVEL OVERNIGHT. SO IN COMPARISON TO LAST
THURSDAY NIGHT/FRIDAY MORNING THIS COLD SNAP DOES NOT MEASURING UP.
THAT BEING SAID...THERE WILL BE LESS CLOUDS AND LESS WIND IN THE
ELKINS VICINITY THIS TIME AROUND...SO WILL GO COLDER
THERE...COMPARED TO LAST THURSDAY NIGHT/FRIDAY MORNING. HAVE SOME
MINIMUMS OF MINUS 15 TO MINUS 18 IN THE SHELTERED MOUNTAIN
VALLEYS...WHILE RIDGES CLOSER TO ZERO. ALSO LOWERED NORTH CENTRAL
MINIMUM A BIT FROM PREVIOUS FORECAST WITH THE CLEARER SKY AND LIGHT
WINDS. ANOTHER COLD SPOT SHOULD BE INTERIOR SE OHIO...STILL MINUS 5
TO MINUS 10. CAN NOT GET TOO CARRIED AWAY THERE THOUGH...SINCE 925
MB FLOW INCREASING 09Z TO 12Z. INCREASED MINIMUM TEMPERATURE
SLIGHTLY FROM BKW ON SW INTO VA OVERNIGHT TO TAKE IN ACCOUNT THOSE
PATCHES OF MID CLOUDS RETURNING FROM THE WEST...AND MAYBE THE WIND
STIRS FROM THE SE OVER THOSE RIDGES AND SOUTHERN PLATEAU 06Z TO
12Z. SO OVERALL...TIGHTENED UP THE NORTH TO SOUTH GRADIENT IN
MINIMUM TEMPERATURE. BUT THERE WILL STILL SOME LOCAL EFFECTS TOO
BETWEEN HILLTOPS AND HOLLOWS.
WILL KEEP MEASURABLE POPS AOB 20 PCT ACROSS SOUTHWEST VIRGINIA LATE
TONIGHT AS MOISTURE INCREASES.
STILL PLENTY OF SUNSHINE FIGURED...NO MAJOR CHANGES MADE TO OUR
PREVIOUS MAXIMUM TEMPERATURE.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
MODELS CONTINUE TO SHOW A COLD FRONT PUSHING THROUGH THE REGION
TUESDAY NIGHT. MODELS SHOW LIMITED MOISTURE WITH THE FRONT AND WITH
THE UPSLOPE BEHIND THE FRONT...SO WILL LOWER POPS SOME FOR TUESDAY
NIGHT AND WEDNESDAY.
AN UPPER LEVEL DISTURBANCE THEN MOVES OVER WEDNESDAY NIGHT AND
THURSDAY. MODELS ALL SHOW THIS DISTURBANCE...BUT VARY CONSIDERABLY
WITH MOISTURE AND LIFT UNDER THE DISTURBANCE. WILL INCLUDE SOME
SMALL POPS...BUT CONFIDENCE IS NOT HIGH WITH THIS SYSTEM.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE ARRIVING FRIDAY. GFS AND ECMWF A BIT DIFFERENT ON
TIMING...WITH THE GFS BEING SLOWER BRINGING THE HIGH IN THUS TRYING
TO LINGER PRECIP A LITTLE LONGER. WILL HAVE LIGHT SNOW SHOWERS
TAPERING OFF TO FLURRIES BEFORE ENDING THURSDAY NIGHT INTO FRIDAY.
LINGERING THE LONGEST IN THE NORTHERN MOUNTAINS. THIS SPEED
DIFFERENCE IN THE MODELS ALSO CARRIES OVER INTO THE NEXT SYSTEM...A
LOW RIDING UP THE OHIO RIVER VALLEY. THE 00Z ECMWF WAS A GOOD 24
HOURS FASTER THAN THE 12Z GFS BRINGING PRECIPITATION INTO THE
CWA...HOWEVER THE 12Z ECMWF HAS SLOWED THINGS DOWN. WITH SUCH LARGE
DISCREPANCY WILL STICK CLOSE TO WPC ON...ALTHOUGH WENT A BIT SLOWER
BRINGING INITIAL PRECIPITATION IN BASED ON 12Z GFS AND ECMWF
GUIDANCE. THIS BRINGS MEASURABLE PRECIP IN SUNDAY...WITH COLD FRONT
CROSSING SUNDAY NIGHT OR MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
INVERTED SURFACE TROUGH OF LOW PRESSURE BRINGS LIGHT SNOW TO THE
SOUTHERN MOUNTAINS AFTER 12Z TODAY...AFFECTING THE BKW TERMINAL
WITH IFR CEILINGS AND VISIBILITIES. IMPROVEMENTS EXPECTED WITH THE
SNOW LIFTING OUT AFTER 21Z TODAY. EKN WILL GET INTO LOWER
CEILINGS...BUT CHANCES FOR SNOW ARE LOWER THERE AND DO NOT HAVE
THEM IN PREVAILING SNOW...NOR ARE THEY IN MVFR SKIES.
ELSEWHERE...CLEAR THROUGH THE MORNING HOURS WITH PASSING MID/HIGH
LEVEL FEW-SCT CLOUDS THROUGH 00Z. CEILINGS LOWER AHEAD OF A
REINFORCING COLD FRONT FROM THE NORTHWEST WITH LOW END CHANCES OF
SNOW RAMPING UP. FOR THIS FORECAST...PKB ONLY COMES DOWN TO 3.5KFT
AT 03Z WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING OF SNOW/CEILINGS/VISIBILITIES AT BKW
COULD VARY BY AN HOUR OR TWO.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/24/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H M M H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/RPY/MZ
NEAR TERM...KTB/30
SHORT TERM...RPY/MZ
LONG TERM...ARJ
AVIATION...26
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
723 PM CST WED FEB 25 2015
.UPDATE...
LATEST RADAR IMAGERY AND REPORTS INDICATE SNOW CONTINUES TO
INCREASE ACROSS THE CWA...WITH REPORTS OF 2 TO 4 INCHES ALREADY IN
SOUTHERN GILES...COFFEE...AND GRUNDY COUNTIES. BASED ON THESE
REPORTS AND AN INTENSE BAND OF MODERATE TO HEAVY SNOW ON
RADAR...HAVE EXPANDED THE WINTER STORM WARNING NORTHWARD UP THE
PLATEAU INTO CUMBERLAND COUNTY. THESE COUNTIES CAN EXPECT 2 TO 4
INCHES OF SNOW...WITH ISOLATED AMOUNTS UP TO 6 INCHES.
FURTHER TO THE NORTHWEST...DRY AIR CONTINUES TO LIMIT SNOW
REACHING THE GROUND AS SHOWN BY THE UNSATURATED AIR BELOW 700MB
PER 00Z OHX SOUNDING. HOWEVER...AS UPPER LOW OVER NORTH
MISSISSIPPI MOVES ACROSS THE AREA THIS EVENING AND
TONIGHT...EXPECT CONTINUED COOLING/LIFT ALOFT TO HELP SATURATE
THE LOW LEVELS AND LEAD TO SNOW REACHING THE SURFACE THROUGHOUT
THE ADVISORY AREA. IN FACT...LATEST REPORTS FROM WEST TENNESSEE
INDICATE 1 INCH OF SNOW ALREADY IN CHESTER COUNTY NEAR THE CORE OF
THE UPPER LOW. CONSIDERABLE UNCERTAINTY REMAINS ON HOW MUCH SNOW
WILL ACCUMULATE...AS SHORT TERM GUIDANCE REMAINS QUITE MARGINAL
FOR CRITERIA LEVEL ACCUMULATIONS IN THE NORTHWEST PART OF THE
ADVISORY AREA. WILL KEEP ADVISORY AS IS FOR NOW AND CONTINUE TO
WATCH TRENDS AND REPORTS THIS EVENING.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 543 PM CST WED FEB 25 2015/
UPDATE...
00Z AVIATION UPDATE.
AVIATION...
SNOW IS SLOWLY WORKING ITS WAY INTO THE REGION...WITH THE MAIN
IMPACTS LIKELY TO BE FOR KCSV. KBNA WILL SEE SOME SNOW LATER THIS
EVENING AND INTO THE EARLY MORNING...BUT KCKV MAY ONLY SEE LITTLE
IF ANY SNOW. CURRENT STORM TRACK WILL HAVE IT A BIT FURTHER
SOUTH...BUT WONT RULE OUT LIGHT SNOW FOR KCKV. EARLY SNOW SHOULD
MOISTEN THE LOW LEVELS...BRINGING CEILINGS DOWN ESPECIALLY AT
KCSV. MODELS INDICATE LOW MVFR AND IFR FOR KCSV THROUGH THE
OVERNIGHT HOURS WITH OCCASIONAL LIFR POSSIBLE AND MVFR FOR OTHER
TWO TERMINALS. WINDS SHOULD BE LIGHT AND OUT OF THE NORTH.
PREV DISCUSSION... /ISSUED 519 PM CST WED FEB 25 2015/
MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS A BAND OF LIGHT TO MODERATE SNOW HAS
SET UP FROM EXTREME SOUTHERN LAWRENCE COUNTY NORTHEASTWARD INTO
VAN BUREN COUNTY. SEVERAL REPORTS OF LIGHT SNOW IN ALL OF THE
COUNTIES ALONG THE ALABAMA BORDER WITH NUMEROUS REPORTS OF HEAVY
SNOW TO THE SOUTH IN NORTHERN ALABAMA. 18Z NAM SUGGESTS THIS BAND
OF LIGHT TO MODERATE SNOW WILL PERSIST THROUGH THE EVENING WHILE
DEVELOPING NORTHEAST TOWARDS CUMBERLAND COUNTY. CONCERNED THAT
WITH BANDING ALREADY IN PLACE AND MANY MORE HOURS OF SNOW
EXPECTED IN OUR SOUTHEAST ZONES...COFFEE/WARREN/VAN
BUREN/WHITE/CUMBERLAND COUNTIES MAY REACH WARNING CRITERIA AND
NEED TO BE ADDED TO THE WINTER STORM WARNING. WILL COORDINATE WITH
SURROUNDING OFFICES AND MONITOR TRENDS BEFORE DECIDING.
FURTHER NORTH AND WEST...DRY AIR CONTINUES TO LIMIT SATURATION OF
THE LOW LEVEL AIRMASS AS SHOWN BY DEWPOINT DEPRESSIONS AS HIGH AS
15 DEGREES AT BNA...WHICH HAS KEPT SNOW FROM REACHING THE SURFACE
SO FAR. THIS COMBINED WITH LIMITED NORTHWARD EXTENT OF PRECIP
SHIELD TO OUR WEST...ALONG WITH 18Z NAM AND LATEST HRRR SHOWING
LIMITED MOISTURE...BRINGS CONSIDERABLE CONCERN ON WHETHER SNOW
WILL REACH ADVISORY CRITERIA AS FAR NORTH AS OUR CURRENT
ADVISORY. WILL CONTINUE TO MONITOR TRENDS...BUT THE CURRENT
WINTER WEATHER ADVISORY MAY NEED TO BE TRIMMED BACK IF TRENDS
PERSIST.
SHAMBURGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR TNZ008>011-
027>034-056>065-075-093.
WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR TNZ066-077>080-
094-095.
&&
$$
55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
543 PM CST WED FEB 25 2015
.UPDATE...
00Z AVIATION UPDATE.
&&
.AVIATION...
SNOW IS SLOWLY WORKING ITS WAY INTO THE REGION...WITH THE MAIN
IMPACTS LIKELY TO BE FOR KCSV. KBNA WILL SEE SOME SNOW LATER THIS
EVENING AND INTO THE EARLY MORNING...BUT KCKV MAY ONLY SEE LITTLE
IF ANY SNOW. CURRENT STORM TRACK WILL HAVE IT A BIT FURTHER
SOUTH...BUT WONT RULE OUT LIGHT SNOW FOR KCKV. EARLY SNOW SHOULD
MOISTEN THE LOW LEVELS...BRINGING CEILINGS DOWN ESPECIALLY AT
KCSV. MODELS INDICATE LOW MVFR AND IFR FOR KCSV THROUGH THE
OVERNIGHT HOURS WITH OCCASIONAL LIFR POSSIBLE AND MVFR FOR OTHER
TWO TERMINALS. WINDS SHOULD BE LIGHT AND OUT OF THE NORTH.
&&
.PREV DISCUSSION... /ISSUED 519 PM CST WED FEB 25 2015/
MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS A BAND OF LIGHT TO MODERATE SNOW HAS
SET UP FROM EXTREME SOUTHERN LAWRENCE COUNTY NORTHEASTWARD INTO
VAN BUREN COUNTY. SEVERAL REPORTS OF LIGHT SNOW IN ALL OF THE
COUNTIES ALONG THE ALABAMA BORDER WITH NUMEROUS REPORTS OF HEAVY
SNOW TO THE SOUTH IN NORTHERN ALABAMA. 18Z NAM SUGGESTS THIS BAND
OF LIGHT TO MODERATE SNOW WILL PERSIST THROUGH THE EVENING WHILE
DEVELOPING NORTHEAST TOWARDS CUMBERLAND COUNTY. CONCERNED THAT
WITH BANDING ALREADY IN PLACE AND MANY MORE HOURS OF SNOW
EXPECTED IN OUR SOUTHEAST ZONES...COFFEE/WARREN/VAN
BUREN/WHITE/CUMBERLAND COUNTIES MAY REACH WARNING CRITERIA AND
NEED TO BE ADDED TO THE WINTER STORM WARNING. WILL COORDINATE WITH
SURROUNDING OFFICES AND MONITOR TRENDS BEFORE DECIDING.
FURTHER NORTH AND WEST...DRY AIR CONTINUES TO LIMIT SATURATION OF
THE LOW LEVEL AIRMASS AS SHOWN BY DEWPOINT DEPRESSIONS AS HIGH AS
15 DEGREES AT BNA...WHICH HAS KEPT SNOW FROM REACHING THE SURFACE
SO FAR. THIS COMBINED WITH LIMITED NORTHWARD EXTENT OF PRECIP
SHIELD TO OUR WEST...ALONG WITH 18Z NAM AND LATEST HRRR SHOWING
LIMITED MOISTURE...BRINGS CONSIDERABLE CONCERN ON WHETHER SNOW
WILL REACH ADVISORY CRITERIA AS FAR NORTH AS OUR CURRENT
ADVISORY. WILL CONTINUE TO MONITOR TRENDS...BUT THE CURRENT
WINTER WEATHER ADVISORY MAY NEED TO BE TRIMMED BACK IF TRENDS
PERSIST.
SHAMBURGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR TNZ008>011-
027>034-056>066-075-077-078-080.
WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR TNZ079-093>095.
&&
$$
06
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
519 PM CST WED FEB 25 2015
.MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS A BAND OF LIGHT TO MODERATE SNOW HAS
SET UP FROM EXTREME SOUTHERN LAWRENCE COUNTY NORTHEASTWARD INTO
VAN BUREN COUNTY. SEVERAL REPORTS OF LIGHT SNOW IN ALL OF THE
COUNTIES ALONG THE ALABAMA BORDER WITH NUMEROUS REPORTS OF HEAVY
SNOW TO THE SOUTH IN NORTHERN ALABAMA. 18Z NAM SUGGESTS THIS BAND
OF LIGHT TO MODERATE SNOW WILL PERSIST THROUGH THE EVENING WHILE
DEVELOPING NORTHEAST TOWARDS CUMBERLAND COUNTY. CONCERNED THAT
WITH BANDING ALREADY IN PLACE AND MANY MORE HOURS OF SNOW
EXPECTED IN OUR SOUTHEAST ZONES...COFFEE/WARREN/VAN
BUREN/WHITE/CUMBERLAND COUNTIES MAY REACH WARNING CRITERIA AND
NEED TO BE ADDED TO THE WINTER STORM WARNING. WILL COORDINATE WITH
SURROUNDING OFFICES AND MONITOR TRENDS BEFORE DECIDING.
FURTHER NORTH AND WEST...DRY AIR CONTINUES TO LIMIT SATURATION OF
THE LOW LEVEL AIRMASS AS SHOWN BY DEWPOINT DEPRESSIONS AS HIGH AS
15 DEGREES AT BNA...WHICH HAS KEPT SNOW FROM REACHING THE SURFACE
SO FAR. THIS COMBINED WITH LIMITED NORTHWARD EXTENT OF PRECIP
SHIELD TO OUR WEST...ALONG WITH 18Z NAM AND LATEST HRRR SHOWING
LIMITED MOISTURE...BRINGS CONSIDERABLE CONCERN ON WHETHER SNOW
WILL REACH ADVISORY CRITERIA AS FAR NORTH AS OUR CURRENT
ADVISORY. WILL CONTINUE TO MONITOR TRENDS...BUT THE CURRENT
WINTER WEATHER ADVISORY MAY NEED TO BE TRIMMED BACK IF TRENDS
PERSIST.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 134 PM CST WED FEB 25 2015/
DISCUSSION...CURRENT RADAR LOOP SHOWS LIGHT ECHOES NOW MOVING
INTO SOUTHERN MIDDLE TENNESSEE, ALTHOUGH TEMPS ACROSS THE MID
STATE ARE FOR THE MOST PART SLIGHTLY ABOVE FREEZING. HOWEVER,
LARGE DEW POINT SPREADS (15-20F) DO LEAVE SOME ROOM FOR
EVAPORATIVE COOLING. TEMPS UPSTREAM WHERE IT HAS ALREADY BEEN
PRECIPITATING ARE RIGHT AROUND FREEZING, SO BELIEVE MOST OF THE
PRECIPITATION WE SEE THIS AFTERNOON WILL BE SNOW. LATEST HPC
SNOWFALL PROGS ARE CONSISTENT WITH THE AMOUNTS WE HAVE BEEN
FORECASTING, SO AM GOING TO LEAVE THE SNOW GRIDS ALONE THIS
FORECAST. NAM BRINGS THE DEEPEST MOISTURE THROUGH MIDDLE TENNESSEE
BETWEEN 00Z & 06Z, WITH SNOW TAPERING OFF FROM WEST TO EAST AFTER
06Z. LOOK FOR SOME LINGERING LIGHT SNOW OR FLURRIES TOMORROW AS A
SECONDARY WAVE PUSHES THROUGH BUT WE SHOULD REMAIN DRY UNTIL LATER
IN THE WEEKEND WHEN THE NEXT ACTIVE SYSTEM MOVES IN. MODELS ARE
HINTING AT A SPRING-LIKE FRONTAL SYSTEM ON TUESDAY AS MUCH WARMER
TEMPERATURES AND A STRONG LOW-LEVEL JET APPEAR TO SET THE TABLE
FOR THUNDERSTORMS BEFORE WE TURN COLDER AGAIN.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR TNZ008>011-
027>034-056>066-075-077-078-080.
WINTER STORM WARNING UNTIL 6 AM CST THURSDAY FOR TNZ079-093>095.
&&
$$
55
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1115 AM CST TUE FEB 24 2015
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...
MVFR CONDITIONS EXPECTED THIS AFTERNOON WITH MOISTURE TRAPPED
BENEATH A STRONG TEMPERATURE INVERSION. SFC HIGH PRESSURE OVER
SOUTH TEXAS WILL ALLOW WINDS TO REMAIN MAINLY NORTH BUT DECREASE
SIGNIFICANTLY BY EVENING. A STRONG UPPER LEVEL DISTURBANCE WILL
APPROACH TONIGHT AND THIS FEATURE WILL GENERATE PRECIP BETWEEN
09-15Z. KCLL AND KUTS COULD GET A MIXTURE OF RAIN/SNOW OR ICE
PELLETS BETWEEN 11-15Z AS DYNAMICAL AND EVAPORATIVE COOLING
COOL THE THERMAL PROFILE TO NEAR 0 C. 43
&&
.PREV DISCUSSION... /ISSUED 1049 AM CST TUE FEB 24 2015/
UPDATE...
A DRY...COLD AND LOW OVERCAST TUESDAY AS ENTRENCHED NORTH-
NORTHEAST FLOW REINFORCES THIS MOST RECENT COLD AIR ADVECTION
PATTERN. A FEW REPORTS OF LIGHT FZRA/FZDZ AND SNOW (GRAINS)
DURING THE EVENING INTO EARLY TUESDAY MORNING HOURS ACROSS BRAZOS
AND WALKER COUNTIES. A SHARP TROUGH PASSAGE THROUGH WEDNESDAY
MORNING PRESENTS A NEW CHALLENGE UP NORTH. A QUICK HITTER...THIS
TROUGH WILL QUICKLY PULL IN COLD MID-LEVEL AIR ATOP AN ALREADY
NEAR FREEZING PROFILE. WAY UP NORTH OVER MADISON...HOUSTON...AND
TRINITY COUNTIES SOME NPW PROGS INDICATE THE EXISTENCE OF HIGH
LEVEL ICE CRYSTAL SEEDING. THESE CRYSTALS MAY FALL INTO A DRY
MID-LAYER. THEORETICALLY...DUE TO EVAPORATIVE COOLING...THIS
LAYER SHOULD SATURATE UP AND FALL BACK TO BELOW FREEZING. WITH A
VERY SHALLOW NEAR SURFACE WARM LAYER...IT SHOULDN`T BE DEEP ENOUGH
TO TOTALLY MELT ICE CRYSTALS/SNOWFLAKES COMPLETELY...LEADING TO A
MIXTURE OF SNOW AND ICE PELLETS. THE NAM SOLUTION IS OF FAR
NORTHERN HOUSTON COUNTY ACCUMULATIONS OF AROUND A HALF AN INCH...
THE GFS IS MUCH WARMER AND DRIER. THE RAP ALSO HINTS AT THIS FAR
NORTHERN COUNTY OCCURRENCE...LIGHT RAIN AND SLEET MIXTURE MAY
EXTEND AS FAR SOUTH AS A COLLEGE STATION TO HUNTSVILLE TO
LIVINGSTON LINE. THE MAJORITY OF THE CWA WILL EXPERIENCE RAIN OR
SHOWERY WEATHER THROUGH WEDNESDAY MORNING. A COOL AND PARTIALLY
CLOUDY WEDNESDAY AS AN OVERCAST AND MORE WET MORNING IN THE MID
30S ONLY WARMS INTO THE UPPER 40S (NORTH) TO LOWER 50S (COAST).
31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 41 35 51 35 55 / 20 50 50 10 10
HOUSTON (IAH) 43 36 53 37 57 / 20 50 50 10 10
GALVESTON (GLS) 44 43 53 44 56 / 20 50 50 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1049 AM CST TUE FEB 24 2015
.UPDATE...
A DRY...COLD AND LOW OVERCAST TUESDAY AS ENTRENCHED NORTH-
NORTHEAST FLOW REINFORCES THIS MOST RECENT COLD AIR ADVECTION
PATTERN. A FEW REPORTS OF LIGHT FZRA/FZDZ AND SNOW (GRAINS)
DURING THE EVENING INTO EARLY TUESDAY MORNING HOURS ACROSS BRAZOS
AND WALKER COUNTIES. A SHARP TROUGH PASSAGE THROUGH WEDNESDAY
MORNING PRESENTS A NEW CHALLENGE UP NORTH. A QUICK HITTER...THIS
TROUGH WILL QUICKLY PULL IN COLD MID-LEVEL AIR ATOP AN ALREADY
NEAR FREEZING PROFILE. WAY UP NORTH OVER MADISON...HOUSTON...AND
TRINITY COUNTIES SOME NPW PROGS INDICATE THE EXISTENCE OF HIGH
LEVEL ICE CRYSTAL SEEDING. THESE CRYSTALS MAY FALL INTO A DRY
MID-LAYER. THEORETICALLY...DUE TO EVAPORATIVE COOLING...THIS
LAYER SHOULD SATURATE UP AND FALL BACK TO BELOW FREEZING. WITH A
VERY SHALLOW NEAR SURFACE WARM LAYER...IT SHOULDN`T BE DEEP ENOUGH
TO TOTALLY MELT ICE CRYSTALS/SNOWFLAKES COMPLETELY...LEADING TO A
MIXTURE OF SNOW AND ICE PELLETS. THE NAM SOLUTION IS OF FAR
NORTHERN HOUSTON COUNTY ACCUMULATIONS OF AROUND A HALF AN INCH...
THE GFS IS MUCH WARMER AND DRIER. THE RAP ALSO HINTS AT THIS FAR
NORTHERN COUNTY OCCURRENCE...LIGHT RAIN AND SLEET MIXTURE MAY
EXTEND AS FAR SOUTH AS A COLLEGE STATION TO HUNTSVILLE TO
LIVINGSTON LINE. THE MAJORITY OF THE CWA WILL EXPERIENCE RAIN OR
SHOWERY WEATHER THROUGH WEDNESDAY MORNING. A COOL AND PARTIALLY
CLOUDY WEDNESDAY AS AN OVERCAST AND MORE WET MORNING IN THE MID
30S ONLY WARMS INTO THE UPPER 40S (NORTH) TO LOWER 50S (COAST).
31
&&
.PREV DISCUSSION... /ISSUED 532 AM CST TUE FEB 24 2015/
AVIATION...
A MIX OF MVFR AND IFR CEILINGS SHOULD ALL BE MVFR LATER THIS
MORNING AND THROUGHOUT THIS AFTERNOON. EXPECT NORTH WINDS TO
GRADUALLY DECREASE AS THE DAY PROGRESSES. LOWERING CEILINGS
ALONG WITH A CHANCE FOR MAINLY LIGHT RAIN SHOULD MATERIALIZE
LATE TONIGHT THROUGH WEDNESDAY MORNING WITH A DISTURBANCE ON
TRACK TO MOVE ACROSS THE AREA. ALL AREA SURFACE TEMPERATURES
ARE EXPECTED TO REMAIN ABOVE FREEZING...SO -RA TO BE CARRIED
WITH THIS DISTURBANCE. 42
&&
PREV DISCUSSION... /ISSUED 423 AM CST TUE FEB 24 2015/
DISCUSSION...
FREEZING LINE THIS MORNING STRETCHES FROM JUST SOUTH OF COLLEGE
STATION TO CONROE AND EASTWARD INTO NORTHERN LIBERTY COUNTY. ASIDE
FROM A FEW LIGHT SHOWERS MOVING NORTHEASTWARD ACROSS FORT BEND
COUNTY NOT MUCH IS SHOWING ON AREA RADARS ALTHOUGH WITH THE
SHALLOW MOISTURE IN PLACE ACROSS THE REGION IT IS POSSIBLE THAT
SOME LOCATIONS MAY SEE SOME VERY LIGHT DRIZZLE THAT WONT BE
DETECTED. WILL KEEP THE FREEZING RAIN ADVISORY IN PLACE TO ACCOUNT
FOR ANY DRIZZLE ACROSS SUB FREEZING AREAS ALTHOUGH IMPACTS ARE
EXPECTED TO BE SLIGHT...PRIMARILY TO ELEVATED ROADWAYS AND
BRIDGES. TEMPERATURES WILL RISE ABOVE FREEZING BY 9AM WITH
AFTERNOON HIGHS IN THE LOW TO MID 40S ACROSS THE REGION.
RAIN CHANCES RETURN QUICKLY ON WEDNESDAY AS THE UPPER LOW ACROSS
THE SOUTHWESTERN UNITED STATES EVOLVES INTO A SHARP SHORTWAVE
TROUGH WHICH WILL MOVE ACROSS THE STATE. THIS WILL BRING ANOTHER
ROUND OF WINTER WEATHER TO NORTH CENTRAL TEXAS BUT TEMPERATURES
ACROSS OUR NORTHERN COUNTIES ARE WARM ENOUGH TO SUPPORT RAIN
ONLY...EVEN WITH THE COLDER NAM PROFILES. WONT TOTALLY RULE OUT
THE CHANCE TO SEE A BRIEF PERIOD WEDNESDAY MORNING WITH SOME SLEET
MIXED IN ACROSS HOUSTON OR TRINITY COUNTIES GIVEN THE STRENGTH OF
THE LIFT ASSOCIATED WITH THE TROUGH. SURFACE TEMPERATURES WILL BE
IN THE MID TO UPPER 30S SO NO IMPACTS ARE EXPECTED AND WILL ONLY
MENTION LIQUID PRECIPITATION IN THE FORECAST THIS MORNING FOR ALL
AREAS.
DRY CONDITIONS ARE EXPECTED FOR THURSDAY AND FRIDAY IN THE WAKE OF
THIS SYSTEM. WINDS TURN ONSHORE HEADING INTO THE WEEKEND BRINGING
INCREASING TEMPERATURES AND A CHANCE FOR SHOWERS ACROSS THE
REGION. NEXT COLD FRONT LOOKS TO ARRIVE SOMETIME EARLY NEXT WEEK. 38
&&
MARINE...
NORTH TO NORTHEAST WINDS WILL PERSIST THROUGH THE END OF THE WEEK.
PERIODS OF CAUTION OR ADVISORY LEVELS WINDS WILL BE POSSIBLE.
ONSHORE WINDS RETURN TO THE AREA AND STRENGTHEN OVER THE WEEKEND
AS HIGH PRESSURE MOVES OFF TO THE EAST. CAUTION FLAGS ARE LIKELY...
AND ADVISORIES MIGHT BE NEEDED. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 41 35 51 35 55 / 20 50 50 10 10
HOUSTON (IAH) 43 36 53 37 57 / 20 50 50 10 10
GALVESTON (GLS) 44 43 53 44 56 / 20 50 50 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...31
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1157 PM EST MON FEB 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE FROM THE OHIO VALLEY EAST INTO
PENNSYLVANIA BY TUESDAY MORNING...THEN OFFSHORE BY THE END OF THE
DAY. AN INVERTED TROUGH WILL SET UP ACROSS THE MOUNTAINS TONIGHT. TWO
COLD FRONTS WILL CROSS THE REGION THIS WEEK...ONE ON
WEDNESDAY...AND THE NEXT ON THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1135 PM EST MONDAY...
STILL WATCHING MOISTURE SOUTHWEST OF US THIS EVENING. 00Z MODELS
COMING IN WETTER THOUGH SEEM TO BE INITIALIZING TOO MUCH OVERALL.
LATEST HRRR DOES FORM SNOW OVER THE MTNS OF NC IN THE NEXT HOUR OR
TWO. TIMING OF SNOW APPEARS BETWEEN 1AM AND 4 AM IN THE NC MTNS TO
FAR SW VA...FINALLY REACHING NWD TOWARD SE WV AROUND BLF TO BCB
AND SOUTH BY DAWN...THOUGH AMOUNTS WILL MAINLY BE LIGHT
HERE...FLURRIES. NEXT ISSUE WILL BE HOW MUCH FALLS/LENGTH OF TIME.
THINK THE MODELS ARE IN GOOD AGREEMENT THAT GENERALLY AROUND 2
INCHES OR LESS WILL OCCUR WITH LOCALLY HIGHER AMOUNTS TOWARD BEECH
MTN AND SOUTH OR WEST. LIGHT SNOW WILL ALSO SPREAD WELL EAST
TOWARD THE PIEDMONT DURING THE DAY TUESDAY AMOUNTING TO A DUSTING
OR LESS.
HAVE A SPECIAL WX STATEMENT OUT FOR THE FAR SW CWA THROUGH
MORNING TO ACCOUNT FOR SNOW ACCUMULATIONS.
MINOR ADJUSTMENTS MADE TO TEMPS OVERNIGHT AS STILL LOOKING COLDER
IN THE NORTH WITH LESS CLOUDS.
PREVIOUS VALID DISCUSSION...
COMBINATION OF CLOUD COVER AND WIND WILL IMPACT MINIMUM
TEMPERATURES TONIGHT. SINCE WINDS DROP OFF BEFORE THE CLOUD COVER
MOVES BACK IN THERE WILL BE A SHARP DROP IN TEMPERATURES DURING
THE EVENING AND THEN TEMPERATURES BECOME STEADY FOR LATE TONIGHT.
HAVE ALSO LOWERED MAXIMUM TEMPERATURES FOR TUESDAY WITH THE CLOUD
COVER AND AIR MASS THAT WILL KEEP HIGHS 15 TO 25 DEGREES BELOW
NORMAL.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 345 PM EST MONDAY...
A WEAK COLD FRONT SLIDES ACROSS THE REGION TUESDAY NIGHT AND STALLS
OVER THE COASTAL PIEDMONT. THIS FRONT WILL MAINLY KEEP THE AREA
TEMPERATURES BELOW NORMAL. THE STALLED FRONT WILL BE REPLACED BY AN
INVERTED TROUGH ON WEDNESDAY. THIS TROUGH WILL HELP GUIDE MOISTURE
INTO THE REGION FROM A DISTURBANCE TRACKING ACROSS THE GULF COAST.
WITH THE LATEST 12Z MODELS...THE SURFACE LOW WILL TRACK ACROSS THE
SOUTHEASTERN UNITED STATES WEDNESDAY NIGHT...THEN OFF THE COAST
THURSDAY. SHORT WAVES/DEFORMATION ZONE ON THE NORTHERN PERIPHERY OF
THIS DISTURBANCE IS EXPECTED TO TRACK OVER THE SOUTHERN APPALACHIANS
WEDNESDAY EVENING...THEN OVER NORTH CAROLINA...CLIPPING SOUTHSIDE
VA...THURSDAY MORNING. THIS DEFORMATION ZONE IS FORECASTED TO TRACK
EAST-NORTHEAST AND INTO COLDER AIR WITH MAIN P-TYPE BEING SNOW. THE
NAM IS THE MOST BULL-ISH ON AMOUNTS WITH 1-3 INCHES ALONG THE VA/NC
BORDER...5-6 INCHES TOWARDS RALEIGH. THE GFS IS UNDER A HALF
/0.50/ OF AN INCH FOR THE AREA AND AROUND 3 INCHES TOWARDS RALEIGH.
FOR NOW...WILL KEEP HIGHEST CHANCE POPS SOUTH AND MAKE A FIRST GUESS
OF 1-2 INCHES ALONG AND SOUTH OF THE NC/VA BORDER.
THIS DISTURBANCE TRACKS EAST OF THE AREA BY THURSDAY MORNING...THEN
ANOTHER COLD FRONT ENTERS THE AREA FROM THE NORTH LATE THURSDAY
AFTERNOON INTO THURSDAY NIGHT. SHORT WAVES AND MOISTURE ALONG THIS
FRONT WILL BRING LIGHT SNOW TO MAINLY MOUNTAIN COUNTIES THURSDAY
AFTERNOON/NIGHT. PRECIPITATION CHANCES ARE POSSIBLE EAST OF THE BLUE
RIDGE THURSDAY NIGHT AS THE FRONT ROLLS THROUGH. ANOTHER FIRST GUESS
OF 1-2 INCHES WEST (POSSIBLY 3-4 ALONG RIDGES) TO LESS THAN HALF OF
AN INCH EAST.
THIS FORECAST IS SUBJECT TO CHANGE...ESPECIALLY IF THE NORTHERN AND
SOUTHERN STREAM PHASE...DRAWING IN MORE MOISTURE. OR IF THE
SOUTHEASTERN DISTURBANCE DOMINATES...PULLING MOISTURE OUT OF THE
AREA...LEAVING LITTLE FOR THE FRONT TO WORK WITH.
TEMPERATURES FORECAST WILL REMAIN CHALLENGING AS LONG AS SNOWPACK
REMAINS IN THE AREA. ANY CLEARING OVERNIGHT WILL SEND TEMPERATURES
CRASHING BELOW GUIDANCE. DURING THE DAY...ALBEDO WILL KEEP
TEMPERATURES FROM WARMING TO QUICKLY...THUS WILL TREND BELOW
GUIDANCE ON AFTERNOON HIGHS NORTH OF HWY 460.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 315 PM EST SUNDAY...
VERY COLD TEMPERATURES TO START THE EXTENDED PERIOD BUT TRENDING TO
AT OR ABOVE NORMAL BY THE END OF THE PERIOD AS UPPER LEVEL PATTERN
GOES FROM A BROAD CONUS TROF TO A SPLIT FLOW REGIME WITH THE
SOUTHERN STREAM BRINGING WARMER SWLY FLOW TO OUR AREA. WHILE MODELS
HAVE A DECENT CONSENSUS ON THE BROAD SCALE PATTERN THERE ARE ENOUGH
DIFFERENCES IN THE DETAILS AND TIMING TO KEEP A DEGREE OF
UNCERTAINTY IN OUR FORECAST FOR THE WEEKEND AND INTO THE FIRST PART
OF NEXT WEEK.
COLD HIGH PRESSURE AT THE SURFACE WILL BE BUILDING INTO THE AREA
FRIDAY AND THEN WEDGING DOWN THE EASTERN SEABOARD THIS WEEKEND AS IT
SLIDES OFF THE COAST. THERE LOOKS TO BE ENOUGH MOISTURE AROUND
AND...COMBINED WITH A SERIES OF UPPER LEVEL SHORT WAVES AND SOME
GENTLE UPSLOPE AS THE HIGH BUILDS IN AND WEDGES DOWN THE COASTAL
PLAIN...THIS WARRANTS SLGT CHC/LOW CHC POPS FOR NUISANCE TYPE
RAIN/SNOW SHOWERS INTO SATURDAY. THEN AS MOIST SWLY FLOW STARTS TO
INCREASE WE WILL SEE OUR CHANCES OF PRECIPITATION INCREASE ALONG
WITH OUR TEMPERATURES AS WE HEAD INTO SUNDAY. HANDLING OF EVENTS
THIS WEEKEND IS WHERE MODELS HAVE SOMEWHAT DIVERGENT SOLUTIONS
ESPECIALLY REGARDING PROGRESSION OF SYSTEMS AND TIMING. THUS...HAVE
MEDIUM CONFIDENCE AT BEST IN POPS AND LOW CONFIDENCE IN PTYPE SUNDAY
AND SUNDAY NIGHT. WILL HAVE TO AWAIT FUTURE MODEL RUNS TO BUILD A
BETTER CONSENSUS BEFORE MAKING DETAILED SPECULATIONS ON WINTER
WEATHER POTENTIAL.
BY MONDAY...LOW PRESSURE MOVING THROUGH THE NORTHEASTERN US WILL PUSH
A COLD FRONT INTO OUR REGION AND BRING A GOOD CHANCE OF RAIN AS WE
START OFF NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1150 PM EST MONDAY...
VFR TO BECOME MVFR OR WORSE BY 12Z ACROSS MOST OF THE CWA...AS
FLOW TURNS MORE EAST THEN SOUTHEAST WITH INVERTED TROUGH OVER THE
MTNS. LIGHT SNOW WILL AFFECT AREAS ALONG AND SOUTH OF A BLF-DAN
LINE...WITH BLF HAVING BEST THREAT OF SEEING MVFR OR WORSE VSBYS.
MAIN ISSUE WILL BE OVER THE NC MTNS WHERE MORE SNOW OCCURS THOUGH
AMOUNTS ARE EXPECTED TO BE LIGHT.
MODELS CONTINUE TO SHOW CIGS AT LEAST STAYING MVFR OR WORSE
THROUGH THE DAY...WITH SOME INCREASE TO VFR AT MOST LOCATIONS BY
LATER TUESDAY EVENING.
EXTENDED AVIATION DISCUSSION...
A CLIPPER SYSTEM WILL BRING A RETURN OF SCATTERED SNOW SHOWERS
ACROSS SE WV AND POCKETS OF SUB- VFR CONDITIONS WEDNESDAY.
AFTER SOUTHERN STREAM SYSTEM WILL BRING A CHANCE OF MVFR CEILINGS
AND SNOW TO NORTH CAROLINA AND SOUTHERN VIRGINIA LATE WEDNESDAY
AND WEDNESDAY NIGHT.
YET ANOTHER CLIPPER MAY CROSS THE AREA THURSDAY NIGHT INTO
FRIDAY.
WHILE LESS PROBABLE...THE WESTERN EXTENT OF A COASTAL SYSTEM
COULD TEAM UP WITH THE CLIPPER AND BRING THE EASTERN PORTION OF
THE FORECAST REGION A GREATER COVERAGE OF WINTRY PRECIPITATION ON
FRIDAY.
&&
.CLIMATE...
TUESDAY MORNING HIGH PRESSURE WILL BE OVERHEAD. LIGHT
WINDS...ALONG WITH EXISTING SNOW COVER...WILL ALLOW TEMPERATURES
TO FALL INTO THE TEENS AND SINGLE DIGITS BY TUESDAY
MORNING...PENDING CLOUD COVER. SEVERAL CLIMATE STATIONS ARE
EXPECTED TO APPROACH RECORD LOW TEMPERATURES. HERE ARE THE CURRENT
RECORDS FOR TUESDAY.
2/24 REC LOWYEAR
ROA 71967
LYH101947
DAN101964
BCB 31968
BLF-11967
LWB 9 2009
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/WP
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...AMS/PM/WP
CLIMATE...CF
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
940 PM CST WED FEB 25 2015
.UPDATE...LAKE EFFECT SNOW SHOWERS WILL GET BETTER ORGANIZED
DURING THE OVERNIGHT AS A NELY 1000-850 MB FLOW INCREASES TO 20
KTS AND LAKE TO 850 MB TEMP DIFFERENCES REACH 20C. MESOSCALE
MODELS ARE SHOWING THE MOST ENHANCED BANDING OVER SE MKE COUNTY
INTO RAC COUNTY. THE SNOW BAND WILL THEN BEGIN TO SHIFT SEWD AFTER
10Z AND MOSTLY EXIT EASTERN RACINE AND KENOSHA COUNTIES BY 15Z.
WENT WITH A 2-3 INCH FORECAST OVER THESE AREAS USING GUIDANCE
FROM THE LAKE EFFECT SNOW CHART.
&&
.AVIATION/06Z TAFS/...VFR CONDITIONS WILL PREVAIL FOR KMSN AND
KUES FOR THU AND THU NT AS RELATIVELY DRY AND COLD AIR MOVES INTO
THE REGION. FOR FAR SE WI INCLUDING KMKE AND KENW...LAKE EFFECT
SNOW SHOWERS WILL BE PERSISTENT THU AM THROUGH ABOUT 12-15Z. CIGS
WILL MAINLY RANGE FROM 1.0-1.9 KFT ALTHOUGH BRIEFLY LESS THAN 1.0
KFT WITH THE HEAVIER BURSTS OF LAKE EFFECT SNOW. VARIABILITY IS
EXPECTED WITH THE VSBYS GIVEN THE SHOWERY NATURE OF LAKE EFFECT
SNOW BUT WILL MAINLY RANGE FROM 1-2SM...SOMETIMES LOWER OR HIGHER.
VFR CONDITIONS WILL THEN PREVAIL BY LATE MORNING OR EARLY
AFTERNOON OVER FAR SE WI AND CONTINUE THROUGH THU NT.
&&
.PREV DISCUSSION... /ISSUED 306 PM CST WED FEB 25 2015/
TONIGHT - CONFIDENCE...MEDIUM
SNOW CONTINUES TO SLOWLY SHIFT EASTWARD THROUGH SRN WI OVERCOMING
THE DRY LOW LAYERS THAT WERE EVIDENT ON 12Z GRB SOUNDINGS. WITH THE
SATURATION HAS COME VSBYS DOWN TO 1/2 TO 3/4SM AT TIMES...ESP SW OF
KMSN. RADAR ANIMATION CONTINUES TO SUPPORT THE MODEL TRENDS OF
KEEPING BEST ACCUMS ALONG AND SOUTH OF I-94 CORRIDOR WITH THE
SYSTEMS BEST ACCUMS MISSING US ACROSS NORTHERN ILLINOIS. SO WILL
HAVE HIGHEST POPS AND ACCUMS IN THE SOUTHERN COUNTIES. THE OTHER
CONSIDERATION IS THE LAKE EFFECT POTENTIAL. TERMINAL DOPPLER HAS
BEEN SHOWING THE BAND HOLDING OFFSHORE THOUGH RAP SOUNDINGS DO SHOW
ONSHORE COMPONENT WITH DELTA T VALUES OF AROUND 21. EQUILIBRIUM
LEVELS ALSO PUSH 6K FEET. HAVE BUMPED UP SOME AMOUNTS A BIT ESP FROM
SE MKE CNTY THROUGH ERN RAC/ENW COUNTIES. WHILE ICE IS EVIDENT
THERE ARE ENOUGH BREAKS/SLUSHINESS TO ALLOW THE NECESSARY
INSTABILITY TO BE REALIZED FOR THE LAKE EFFECT. SO OVERALL 1-2 OF
SYSTEM SNOW FOR MAINLY SRN HALF OF THE CWA WITH SOME ISOLD 3 INCH
AMOUNTS ADJACENT TO THE LAKE SOUTH OF KMKE TO WI/IL BORDER KENW DUE
TO ADDED INFLUENCE OF LAKE EFFECT.
THURSDAY - CONFIDENCE...MEDIUM
STILL SEEING SOME LINGERING ONSHORE COMPONENT DURING THE MORNING HOURS
SO THE GFS/NAM IDEA OF HANGING ONTO SOME LES POTENTIAL SEEMS REASONABLE.
ENOUGH NNW FETCH ESTABLISHED BY MIDDAY AND INTO THE AFTERNOON HOURS TO
REMOVE LES FROM GRIDS. 850 THERMAL TROUGH WILL BE IN PLACE WITH 925
TEMPS -17C TO -19C. SO MUCH BELOW NORMAL TEMPS EXPECTED WITH HIGHS UPPER
SINGLE DIGITS/LOW TEENS.
SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
HIGH PRESSURE MOVES INTO THE REGION FRIDAY AND WINDS WILL BACK
FROM A MORE NORTHERLY DIRECTION TO THE NORTHWEST AND WEST BY
FRIDAY AFTERNOON. HIGHS FRIDAY WILL GENERALLY BE BETWEEN 10 AND 15.
THIS AREA OF HIGH PRESSURE SHOULD KEEP CONDITIONS QUIET THROUGH
THE DAY SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF IS PROGGING A POTENT 140KT 250 MB JET STREAK TO TRANSLATE
INTO THE REGION EARLY SUNDAY. SOUTHERN WISCONSIN WILL BE IN THE
LEFT EXIT REGION WITH SOME ASSOCIATED UPPER LEVEL DIVERGENCE. THIS
ALONG WITH A 500 MB SHORTWAVE DISTURBANCE LOOKS TO BRING A SYSTEM
INTO THE REGION FROM THE SOUTHWEST. THE GFS LOOKS TO BE MORE
BULLISH WITH THE 500 MB ENERGY THAN THE ECMWF ACCORDING TO THE
LATEST RUNS. 850 MB WARM AIR ADVECTION AND SOUTHERLY WINDS WILL
HELP BRING IN MOIST LOW LEVEL AIR AS WELL. THE BULK OF THE QPF
AMOUNTS LOOK TO STAY FURTHER SOUTH...OUT OF OUR FORECAST
AREA...BUT NOT BY MUCH. ALSO...THE ECMWF IS SLIGHTLY FASTER THAN
THE GFS REGARDING THE ONSET OF THE PRECIPITATION BY A FEW HOURS.
STILL SOME UNCERTAINTY AS TO THE LOCATION OF THE MAIN QPF AXIS.
ANOTHER SHOT OF COLD AIR ALONG WITH SOME NORTHWEST WINDS AS HIGH
PRESSURE RETURNS TO THE REGION MONDAY ONCE THE SUNDAY SYSTEM
MOVES OUT.
ANOTHER SYSTEM LOOKS TO MOVE INTO THE REGION FOR TUESDAY AS
ANOTHER PULSE OF 500 MB POSITIVE VORTICITY ENERGY TRANSLATES INTO
THE REGION...ALONG WITH BEING IN THE RIGHT ENTRANCE REGION OF A
STRONG 180KT 250 MB JET STREAK AND UPPER LEVEL DIVERGENCE. THERE
IS STILL MUCH UNCERTAINTY WITH THIS PARTICULAR EVENT. CURRENT SNOW
ACCUMULATIONS COULD BE BETWEEN 5 AND 6 INCHES ACROSS THE FORECAST
AREA. AT THE MOMENT...THE TIMING OF THE BULK OF THE SNOW WILL BE
DURING THE DAY TUESDAY. WE WILL CONTINUE TO MONITOR THE
PRECIPITATION TIMING AND AMOUNTS.
AVIATION/00Z TAFS/...WATER VAPOR SHOWS SHORTWAVE RIDING EAST
FROM IA. MEANWHILE SURFACE LOW DROPPING SE INTO ERN KS/WRN MO.
MODELS IN GOOD AGREEMENT IN SPREADING SNOW ACROSS REMAINDER OF SE
WI THIS AFTN AND EVE WITH ONSHORE COMPONENT LEADING TO SOME LAKE
EFFECT SNOWS AS WELL. SO EXPECTING SOME IFR CIGS AND PERHAPS SOME
LIFR VSBYS...BUT MOSTLY IFR VSBYS. LAKE EFFECT WRAPS UP THURSDAY
MORNING. SO OVERALL 1-2 OF SYSTEM SNOW FOR MAINLY SRN HALF OF THE
CWA WITH SOME ISOLD 3 INCH AMOUNTS NEAR LAKE MI DUE TO ADDED
INFLUENCE OF LAKE EFFECT.
MARINE...WIND GUSTS WL GET CLOSE TO SMALL CRAFT ADVY FOR A TIME
TONIGHT AS PRESSURE GRADIENT TIGHTENS DUE TO LOW PRESSURE PASSING
WELL SOUTH OF THE AREA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...GEHRING
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...JTS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 238 PM CST TUE FEB 24 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN ARCTIC
COLD FRONT STRETCHING FROM AROUND WAUTOMA TO MARINETTE AND MOVING
EAST EARLY THIS AFTERNOON. SNOW SHOWERS DEVELOPED AHEAD OF THE
FRONT EARLIER TODAY AND LOCALLY DROPPED VSBYS TO A QUARTER OF A
MILE. THESE SNOW SHOWERS ARE NOW ENTERING LAKE MICHIGAN. OTHER
WEAKER SNOW SHOWERS EXIST RIGHT BEHIND THE FRONT. EXCEPT FOR THE
SNOW BELT...THESE SNOW SHOWERS SHOULD EXIT BY THE START OF THE
EVENING. WINDS ARE BECOMING STRONG AND GUSTY BEHIND THE FRONT WITH
SOME OBS REACHING UP TO 35 KNOTS OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN. THESE GUSTY WINDS WILL SPREAD INTO EASTERN WISCONSIN
LATER THIS AFTERNOON. SOME CONCERN FOR THE DOOR PENINSULA AS WIND
DIRECTION AND PRESSURE RISES ARE FAVORABLE FOR NEAR WIND ADVISORY
WIND GUSTS FOR A FEW HOURS. THINK WILL FALL JUST SHORT OF THOSE
TYPES OF GUSTS THOUGH. PLENTY OF STRATO-CU AND SNOW SHOWERS WITHIN THE
ARCTIC AIR OVER THE ARROWHEAD AND HEADING TOWARDS NORTHERN
WISCONSIN. WINDS/TEMPS/WIND CHILLS/AND SNOW POTENTIAL ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...THE ARCTIC COLD FRONT WILL EXIT NORTHEAST WISCONSIN LATE
IN THE AFTERNOON OR EARLY THIS EVENING. SHOULD SEE PRETTY GOOD WIND
GUSTS UP TO 40 MPH OVER DOOR COUNTY AS STRONG PRESSURE RISES ARRIVE
BEHIND THE FRONT EARLY THIS EVENING. GUSTS BETWEEN 30 AND 35 MPH
ARE POSSIBLE ELSEWHERE. THE WINDS SHOULD THEN SUBSIDE PRETTY
QUICKLY BY MID-EVENING AS ARCTIC AIR PLUNGES ACROSS NORTH-CENTRAL
AND NORTHEAST WISCONSIN...THOUGH WINDS SHOULD NOT DECOUPLE.
SCATTERED SNOW SHOWERS WILL LIKELY FOLLOW THE ARRIVAL OF THE
ARCTIC AIR ACROSS THE NORTH THIS EVENING...THEN DIMINISH/RETREAT
TO THE SNOWBELT AREAS OVERNIGHT. THE COMBINATION OF TEMPS FALLING
TO AROUND 10 OR 12 BELOW OVER N-C WISCONSIN AND PERSISTENT
NORTHWEST WINDS WILL HAVE WIND CHILLS FALLING BETWEEN 20 TO 25
BELOW OVER N-C WISCONSIN AND GENERALLY 10 TO 15 BELOW ELSEWHERE.
IN COORDINATION WITH WFOS MARQUETTE AND DULUTH...WILL NOT ISSUE A
WIND CHILL ADVISORY AND WILL INSTEAD HIGHLIGHT THE THREAT IN A
SPS.
WEDNESDAY...ARCTIC HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE
REGION AS A WEAK DISTURBANCE SLIDES SOUTHEAST ACROSS THE CENTRAL
GREAT PLAINS. WILL SEE MID AND HIGH CLOUDS SPREAD OVERHEAD FROM
THIS DISTURBANCE...BUT NO REAL THREAT OF PRECIP THIS FAR INTO THE
ARCTIC AIR. BITTERLY COLD WIND CHILLS WILL BE MODERATING BY 9 OR 10
IN THE MORNING TO BETWEEN 10 AND 20 BELOW OVER N-C WISCONSIN. HIGHS
WILL BE RANGING FROM 5 TO 10 ABOVE OVER N-C WI TO 10 TO 15 FARTHER
SOUTH AND EAST.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 238 PM CST TUE FEB 24 2015
PATTERN ALOFT IS BEGINNING TO CHANGE...BUT NOT BEFORE ONE MORE
BATCH OF ARCTIC AIR PUSHES INTO THE AREA. EVENTUALLY A WESTERN
TROUGH WILL EMERGE AS THE RIDGE PREVIOUSLY IN PLACE REFORMS MORE
OVER THE PACIFIC. THE EASTERN TROUGH WILL RETREAT NORTH...AND
SOMETHING RESEMBLING A SOUTHERN STREAM WILL START TO BRING
SOUTHWEST FLOW ALOFT INTO WISCONSIN. THIS WILL BRING A WARMER AND
MORE MOIST AIRMASS FROM THE SOUTHWEST. THE RESULT WILL BE A SLOW
MODERATION OF TEMPERATURES THROUGH THE REST OF THE WEEK...FOLLOWED
BY CHANCES FOR SNOW LATE THIS WEEKEND AND EARLY NEXT WEEK.
WEDNESDAY NIGHT THROUGH SATURDAY...
PRIMARY FORECAST CHALLENGE IN THIS STRETCH WILL BE EARLY ON AS A NEW
ARCTIC AIRMASS SURGES INTO THE AREA WITH WEDNESDAY AND THURSDAY
NIGHTS SEEING THE LOWEST TEMPERATURES. HOWEVER...THE DEEP EASTERN
TROUGH PATTERN WE HAVE SEEN LATELY WILL BE DEAMPLIFYING. THIS MAY
HELP BLUNT THE DROP IN TEMPERATURES. IT WILL STILL BE VERY COLD
AND A PORTION OF THE AREA...PRIMARILY IN NORTH CENTRAL
WISCONSIN...MAY REQUIRE WIND CHILL ADVISORIES. EACH NIGHT HAS
ISSUES THOUGH. A SHORTWAVE WILL BE PASSING RELATIVELY NEAR THE
AREA WEDNESDAY NIGHT...AND THOUGH IT HAS APPEARED FOR SOME TIME
THAT IT WILL PASS WELL TO OUR SOUTH...GUIDANCE HAS DRIFTED NORTH
TODAY. IT IS POSSIBLE THAT FURTHER DRIFT MAY RESULT IN MORE
CLOUDINESS WHICH WOULD HELP ARREST THE FALL OF TEMPERATURES. ON
THURSDAY NIGHT...COLD TEMPERATURES WILL BE DRIVEN LARGELY BY THE
POTENTIAL FOR STRONG RADIATIONAL COOLING. BUT JUST HOW LOW WE GO
WILL DEPEND ON CLOUD COVER AND WHETHER OR NOT WINDS WILL BE CALM
OVERNIGHT...BOTH DIFFICULT THINGS TO FORECAST AT THIS RANGE. AFTER
THESE NIGHTS...THE AFOREMENTIONED PATTERN CHANGE SHOULD ENCOURAGE
A MODERATION OF TEMPERATURES FOR THE REST OF THE WEEK...THOUGH WE
ARE ONLY LOOKING TO AN INCREASE TO A LITTLE BELOW NORMAL FROM WELL
BELOW NORMAL.
ADDITIONALLY...THERE IS A SLIGHTLY INCREASED AREA OF OPEN WATER ON
LAKES SUPERIOR AND MICHIGAN AFTER RECENT GUSTY WINDS. THOUGH THE
WATER IS SURELY COLD...THE AIRMASS WILL BE COLDER AND WITH SOME
ONSHORE WIND TRAJECTORIES WEDNESDAY NIGHT...LAKE EFFECT FLURRIES
ARE NOT IMPOSSIBLE FOR THE VILAS COUNTY SNOW BELT AND PORTIONS OF
THE LAKE MICHIGAN SHORELINE IN EAST CENTRAL
WISCONSIN...PARTICULARLY THE BIT OF MANITOWOC COUNTY THAT JUTS OUT
INTO THE LAKE AT DIFFERENT ANGLE THAN THE REST OF THE SHORELINE.
SATURDAY NIGHT THROUGH TUESDAY...
WITH MORE SOUTHWEST FLOW ALOFT...A MID-LEVEL SHORTWAVE AND A WEAK
SURFACE LOW REFLECTION WILL BRING A CHANCE FOR SNOW TO THE AREA IN
THE SECOND HALF OF THE WEEKEND. AFTER A LARGE JUMP NORTH IN THE
MODEL GUIDANCE YESTERDAY THE ENVELOPE HAS SETTLED BACK TO THE
SOUTH A LITTLE BIT TODAY. THOUGH AT FIRST GLANCE IT APPEARS LIKE
THE AREA MAY STILL SEE A FAIR SHOT FOR SOME SYNOPTIC LIFT...A
DEEPER INVESTIGATION REVEALED LESS POTENTIAL THAN IT FIRST SEEMED.
STILL...THE WARMER AND MOISTER ADVECTION FROM THE SOUTHWEST MAKES
THE IDEA OF AT LEAST A LITTLE SNOW REASONABLE...PARTICULARLY IN
CENTRAL AND EAST CENTRAL WISCONSIN. IN THIS SCENARIO...IT WOULD BE
APPROPRIATE TO EXPECT SNOW TOTALS OF AROUND TWO INCHES OR LESS. A
COLD FRONT ASSOCIATED WITH A LOW AND ITS ATTENDANT SHORTWAVE IN
THE NORTHERN STREAM WILL SHIFT WINDS TO NORTHWESTERLY AND CUT OFF
THE SNOW. FORTUNATELY THE MORE ZONAL FLOW LOOKS TO PREVENT A
STRONG SURGE OF COLD AIR TO CHOP DOWN TEMPERATURES BEHIND THE
FRONT AT THIS TIME.
HOWEVER...AFTER ALL THIS TALK...IT IS IMPORTANT TO REMEMBER THAT
IT IS ONLY TUESDAY. THOUGH A BROAD SCENARIO IS PRESENT IN ALL THE
GUIDANCE AND CONFIDENCE IN THAT IS MODERATE TO HIGH...CONFIDENCE
IN THE DETAILS THIS FAR OUT IS RELATIVELY LOW...AND COULD HAVE
SIGNIFICANT INFLUENCES ON THE SENSIBLE WEATHER WITH THIS FEATURE.
IT WOULD NOT BE WISE TO RULE OUT A SOUTHERN MISS NOR HIGHER
SNOWFALL POTENTIAL FROM A NORTHWARD DEVIATION JUST YET.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1104 AM CST TUE FEB 24 2015
AN ARCTIC COLD FRONT WILL PASS ACROSS THE REGION THIS
AFTERNOON FROM NORTHWEST TO SOUTHEAST. AHEAD OF THE
FRONT...SCATTERED SNOW SHOWERS AND FLURRIES ARE LIKELY...AND A
FEW SNOW SHOWERS COULD BECOME BRIEFLY HEAVY...DROPPING VSBYS TO A
HALF MILE FOR A SHORT TIME. BREEZY SOUTHWEST WINDS WILL TURN TO
THE NORTHWEST BEHIND THE FRONT AND BECOME GUSTY. GUSTS TO REACH 25
TO 30 KTS. SKIES WILL CLEAR BEHIND THE FRONT LEADING TO VFR
CONDITIONS FOR THE REST OF THE TAF PERIOD. GUSTY WINDS WILL
DIMINISH THIS EVENING.
MPC.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1122 AM CST TUE FEB 24 2015
.UPDATE...WATER VAPOR/RAP COMBO SHOWS SHORTWAVE AXIS ENTERING SRN
WI. THIS RESULTED IN SEVERAL AREAS OF MAINLY LIGHT SNOW SHOWERS.
FRONTALLY INDUCED BAND OF SCT SHSN SHIFTING SE FROM CNTRL WI. THIS
WILL COME THROUGH THIS AFTERNOON AND THE HRRR HAS A PRETTY GOOD
HANDLE ON THESE TRENDS. POST FRONTAL PRESSURE RISE AREA MOVING
INTO NW WI AND ALL OF MN.
PC
&&
.AVIATION/18Z TAFS/...POCKETS OF SNOW SHOWERS CONTINUE ASSOCIATED
WITH SHORTWAVE TROUGH MOVING THROUGH SRN WI. MORE SCT SHSN ARE
MOVING SE FROM CNTRL WI. EXPECT THESE TO SWING THROUGH THIS
AFTERNOON WITH RAPID CLEARING IN THE WAKE. SO SOME MVFR CIGS/VSBYS
AT TIMES WITH ISOLATED IFR VSBYS IN SOME OF THE HEAVIER SNOW
SHOWERS. THESE WILL BE MOVING ALONG WITH MINOR ACCUMS. NEXT
SHORTWAVE WILL INCREASE MID DECK ON WEDNESDAY THOUGH WILL KEEP ANY
AFTERNOON SNOW CHANCES SW OF KMSN.
PC
&&
.PREV DISCUSSION... /ISSUED 904 AM CST TUE FEB 24 2015/
UPDATE...HAVE MADE A QUICK UPDATE TO BOOST POPS UP EVERYWHERE
WITH AREA RADAR MOSAIC SHOWING INITIAL BAND MOVG THROUGH SE WI AND
SECONDARY AREA SWINGING SE FROM KARX AREA. SOME DECENT RETURNS
WITH KARX VSBY DOWN TO 2SM. STILL LOOKING AT MINOR ACCUMS...FEW
TENTHS.
PC
PREV DISCUSSION... /ISSUED 330 AM CST TUE FEB 24 2015/
TODAY...FORECAST CONFIDENCE IS MEDIUM.
WILL CONTINUE LIKELY WORDING FOR A PERIOD OF -SN THIS MORNING
MAINLY OVER CENTRAL AND EASTERN PORTIONS OF CWA. IMPRESSIVE LAYER
Q-VECTOR CONVERGENCE OF 20 UNITS EXTENDS FROM THROUGH THE LOW TO
MID-LAYERS. Q-VECTOR CONVERGENCE A RESULT OF STRONG WARM AIR
ADVECTION AND STRONG SHORT WAVE TROUGH CURRENTLY ADVANCING INTO
NRN MN...WHICH IS TIED TO LEFT EXIT REGION OF UPPER JET. THIS WAVE
RIDING ON THE HEELS OF FIRST WAVE CURRENTLY MOVING EWD ACROSS NRN
WI.
FIRST WAVE SERVING TO MOISTEN MID-LEVELS WITH PATCHY -SN FALLING
ACROSS NRN WI. SECOND WAVE WL HAVE A BIT MORE LOW TO MID-LEVEL
MOISTURE TO WORK WITH AS COLUMN PWAT INCREASES TO AROUND A QUARTER
INCH THIS MRNG. SHORT RANGE GUIDANCE ALSO SHOWS A BRIEF PERIOD OF
FRONTOGENETICAL FORCING SLIDING ACROSS SRN WI LATER THIS MRNG.
POTENTIAL FOR ONE HALF INCH UP TO ONE INCH OF SNOW IN NORTHEAST
CWA. WL BE LUCKY TO GET MEASUREABLE LIQUID PRECIP ACROSS SOUTHWEST
CWA.
DESPITE LOSS OF MID-LEVEL MOISTURE THIS AFTERNOON...ARCTIC FRONT
EXPECTED TO MOVE ACROSS SRN WI. LINGERING LOW LEVEL RH UP TO 5K
FEET...PARTIALLY IN DENDRITIC GROWTH ZONE...AND STEEP LOW LEVEL
LAPSE RATES AS FRONT SLIDES THRU. HENCE KEPT SOME LOWER POPS FOR
POTENTIAL OF SCT -SHSN ACROSS ERN CWA. RAP SOUNDINGS SHOWS LOW
LEVEL RH DECREASING RAPIDLY IN THE LATE AFTN WHILE NAM HOLDS ONTO
DEEPER MOISTURE INTO THE EVE. FOR NOW KEPT EVENING /AFTER 00Z/
DRY.
925H TEMPS WARM TO -6 TO -8. HOWEVER CLOUDS AND BREEZY SOUTHWEST
TO WEST WINDS WL KEEP DAYTIME HIGHS IN CHECK. EXPECT HIGHS TO PEAK
IN THE MID 20S TO AROUND 30.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
ARCTIC FRONT SLIDES ACROSS SRN WI TNGT ALLOWING COLD AIR TO
RETURN ON NORTHWEST WINDS. LOW LEVEL MIXING OF DRY AIR SHOULD
RESULT IN CLEARING SKIES OVERNIGHT WITH OVERNIGHT TEMPS RETURNING
TO THE SINGLE DIGITS ABV ZERO. MAY HAVE SOME GUSTS TO 25 KTS IN
THE LATE AFTN AND EARLY EVE RESULTING IN PATCHY BLOWING SNOW WITH
BEST CHANCE IN THE NORTHEAST. OTHERWISE...NOT EXPECTING MUCH BS
FROM CURRENT SNOW COVER DUE TO CRUST.
SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
MODELS ARE IN DECENT AGREEMENT WITH SHOWING A GENEARL NORTHWEST
FLOW AT 500 MB ACROSS THE REGION DURING THIS PERIOD. THEY DO SHOW
SOME DIFFERENCES WITH TIMING AND PLACEMENT OF QPF WITH CLIPPER
SYSTEM SLIDING SOUTHEAST THROUGH THE REGION. ALL MODELS SHOW THE
BULK OF THE QPF AND UPWARD VERTICAL MOTION FIELDS MISSING THE AREA
TO THE SOUTHWEST WEDNESDAY NIGHT.
THE CANADIAN MODEL IS THE MOST AGGRESSIVE WITH QPF OVER MOST OF
THE AREA...WITH THE NAM/GFS/ECMWF BRUSHING THE FAR SOUTH. THEY
ALSO SHOW SOME LAKE EFFECT SNOW SHOWER POTENTIAL WEDNESDAY
NIGHT...WITH NORTHEAST WINDS AND MOISTURE BELOW AND ABOVE THE
INVERSION. DELTA T VALUES ARE QUITE FAVORABLE...THOUGH DECENT ICE
COVERAGE ON THE LAKE MAY LIMIT LAKE EFFECT POTENTIAL.
FOR NOW...WILL MAINTAIN LOW POPS IN THE FAR SOUTH AND SOUTHEAST
COUNTIES FOR MAINLY WEDNESDAY NIGHT...HANGING ON IN THE FAR
SOUTHEAST INTO THURSDAY MORNING. LITTLE TO NO SNOW IS EXPECTED AT
THIS TIME.
ANOTHER SHOT OF COLD AIR ADVECTION OCCURS WEDNESDAY NIGHT INTO
THURSDAY...AS ARCTIC HIGH PRESSURE MOVES SOUTHEAST THROUGH THE
NORTHERN PLAINS. THIS WILL BRING REINFORCING SHOT OF ARCTIC AIR
INTO THE AREA. QUIET WEATHER IS EXPECTED BY THURSDAY AFTERNOON AND
NIGHT ACROSS THE AREA.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF GENERALLY CHANGE 500 MB FLOW TO A MORE ZONAL LOOK FOR
FRIDAY INTO SATURDAY...LINGERING INTO MONDAY. THEY BRING A SHOT OF
WARM AIR ADVECTION SATURDAY NIGHT WITH DEEP MOISTURE AND GOOD
UPWARD VERTICAL MOTION IN THE DENDRITE SNOW CRYSTAL GROWTH ZONE. COLD
FRONT THEN SLOWLY MOVES EAST SOUTHEAST THROUGH THE AREA
SUNDAY...BEFORE EXITING SUNDAY NIGHT. CONTINUED HIGH POPS FOR
SATURDAY NIGHT INTO SUNDAY...WITH SEVERAL INCHES OF SNOWFALL
POSSIBLE. MORE COLD AIR LOOKS ON TAP FOR MONDAY...WITH ANOTHER
ARCTIC HIGH IN THE REGION.
AVIATION/12Z TAFS/...
ENOUGH FORCING AS DESCRIBED ABOVE TO WARRANT A BRIEF PERIOD OF
LOWER VSBYS AND CIGS AT ERN TAF SITES LATER THIS MRNG. WL DROP TO
MVFR CIGS/VSBYS AS AREAS OF -SN MOVE THRU. MAY BE A FEW LINGERING
-SHSN IN THE AFTN WITH CIGS POSSIBLY LINGERING AROUND MVFR LEVELS.
EXPECT TREND TOWARD VFR IN THE LATE AFTN OR EVE. LOW LEVEL WIND
SHEAR WILL CONTINUE THRU THE LATE MRNG.
MARINE...
HIGH RESOLUTION VISIBLE SATELLITE FROM MONDAY SHOWED WIDESPREAD
ICE COVER FROM THE SHORE EXTENDING OUT TO AROUND 10 MILES INTO
LAKE MI. STRONG SOUTHWEST WINDS DEVELOPED OVERNIGHT DUE TO THE
RAPIDLY TIGHTENING PRESSURE GRADIENT...HOWEVER AIR TEMPS REMAINED
QUITE COLD. TEMPS ONLY WARM INTO THE 20S TODAY WITH WINDS
DIMINISHING SOMEWHAT THIS AFTN BEFORE THE COLD AIR RETURNS
TONIGHT.
THINKING A FEW AREAS OF OPEN WATER MAY FORM BUT NOT EXPECTED TO
BE WIDESPREAD. STRONGEST WINDS ARE EXPECTED THIS MORNING WITH COLD
TEMPS...WITH SOME ABATEMENT THIS AFTN AND EVE AS TEMPS WARM INTO
THE 20S. A FEW GALE GUSTS TO 35 KTS POSSIBLE BUT NOT EXPECTED TO
BE FREQUENT ENOUGH TO WARRANT UPGRADING TO GALE WARNING AT THIS
TIME. WL CONTINUE SMALL CRAFT ADVY INTO TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
904 AM CST TUE FEB 24 2015
.UPDATE...HAVE MADE A QUICK UPDATE TO BOOST POPS UP EVERYWHERE
WITH AREA RADAR MOSAIC SHOWING INITIAL BAND MOVG THROUGH SE WI AND
SECONDARY AREA SWINGING SE FROM KARX AREA. SOME DECENT RETURNS
WITH KARX VSBY DOWN TO 2SM. STILL LOOKING AT MINOR ACCUMS...FEW
TENTHS.
PC
&&
.PREV DISCUSSION... /ISSUED 330 AM CST TUE FEB 24 2015/
TODAY...FORECAST CONFIDENCE IS MEDIUM.
WILL CONTINUE LIKELY WORDING FOR A PERIOD OF -SN THIS MORNING
MAINLY OVER CENTRAL AND EASTERN PORTIONS OF CWA. IMPRESSIVE LAYER
Q-VECTOR CONVERGENCE OF 20 UNITS EXTENDS FROM THROUGH THE LOW TO
MID-LAYERS. Q-VECTOR CONVERGENCE A RESULT OF STRONG WARM AIR
ADVECTION AND STRONG SHORT WAVE TROUGH CURRENTLY ADVANCING INTO
NRN MN...WHICH IS TIED TO LEFT EXIT REGION OF UPPER JET. THIS WAVE
RIDING ON THE HEELS OF FIRST WAVE CURRENTLY MOVING EWD ACROSS NRN
WI.
FIRST WAVE SERVING TO MOISTEN MID-LEVELS WITH PATCHY -SN FALLING
ACROSS NRN WI. SECOND WAVE WL HAVE A BIT MORE LOW TO MID-LEVEL
MOISTURE TO WORK WITH AS COLUMN PWAT INCREASES TO AROUND A QUARTER
INCH THIS MRNG. SHORT RANGE GUIDANCE ALSO SHOWS A BRIEF PERIOD OF
FRONTOGENETICAL FORCING SLIDING ACROSS SRN WI LATER THIS MRNG.
POTENTIAL FOR ONE HALF INCH UP TO ONE INCH OF SNOW IN NORTHEAST
CWA. WL BE LUCKY TO GET MEASUREABLE LIQUID PRECIP ACROSS SOUTHWEST
CWA.
DESPITE LOSS OF MID-LEVEL MOISTURE THIS AFTERNOON...ARCTIC FRONT
EXPECTED TO MOVE ACROSS SRN WI. LINGERING LOW LEVEL RH UP TO 5K
FEET...PARTIALLY IN DENDRITIC GROWTH ZONE...AND STEEP LOW LEVEL
LAPSE RATES AS FRONT SLIDES THRU. HENCE KEPT SOME LOWER POPS FOR
POTENTIAL OF SCT -SHSN ACROSS ERN CWA. RAP SOUNDINGS SHOWS LOW
LEVEL RH DECREASING RAPIDLY IN THE LATE AFTN WHILE NAM HOLDS ONTO
DEEPER MOISTURE INTO THE EVE. FOR NOW KEPT EVENING /AFTER 00Z/
DRY.
925H TEMPS WARM TO -6 TO -8. HOWEVER CLOUDS AND BREEZY SOUTHWEST
TO WEST WINDS WL KEEP DAYTIME HIGHS IN CHECK. EXPECT HIGHS TO PEAK
IN THE MID 20S TO AROUND 30.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
ARCTIC FRONT SLIDES ACROSS SRN WI TNGT ALLOWING COLD AIR TO
RETURN ON NORTHWEST WINDS. LOW LEVEL MIXING OF DRY AIR SHOULD
RESULT IN CLEARING SKIES OVERNIGHT WITH OVERNIGHT TEMPS RETURNING
TO THE SINGLE DIGITS ABV ZERO. MAY HAVE SOME GUSTS TO 25 KTS IN
THE LATE AFTN AND EARLY EVE RESULTING IN PATCHY BLOWING SNOW WITH
BEST CHANCE IN THE NORTHEAST. OTHERWISE...NOT EXPECTING MUCH BS
FROM CURRENT SNOW COVER DUE TO CRUST.
SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
MODELS ARE IN DECENT AGREEMENT WITH SHOWING A GENEARL NORTHWEST
FLOW AT 500 MB ACROSS THE REGION DURING THIS PERIOD. THEY DO SHOW
SOME DIFFERENCES WITH TIMING AND PLACEMENT OF QPF WITH CLIPPER
SYSTEM SLIDING SOUTHEAST THROUGH THE REGION. ALL MODELS SHOW THE
BULK OF THE QPF AND UPWARD VERTICAL MOTION FIELDS MISSING THE AREA
TO THE SOUTHWEST WEDNESDAY NIGHT.
THE CANADIAN MODEL IS THE MOST AGGRESSIVE WITH QPF OVER MOST OF
THE AREA...WITH THE NAM/GFS/ECMWF BRUSHING THE FAR SOUTH. THEY
ALSO SHOW SOME LAKE EFFECT SNOW SHOWER POTENTIAL WEDNESDAY
NIGHT...WITH NORTHEAST WINDS AND MOISTURE BELOW AND ABOVE THE
INVERSION. DELTA T VALUES ARE QUITE FAVORABLE...THOUGH DECENT ICE
COVERAGE ON THE LAKE MAY LIMIT LAKE EFFECT POTENTIAL.
FOR NOW...WILL MAINTAIN LOW POPS IN THE FAR SOUTH AND SOUTHEAST
COUNTIES FOR MAINLY WEDNESDAY NIGHT...HANGING ON IN THE FAR
SOUTHEAST INTO THURSDAY MORNING. LITTLE TO NO SNOW IS EXPECTED AT
THIS TIME.
ANOTHER SHOT OF COLD AIR ADVECTION OCCURS WEDNESDAY NIGHT INTO
THURSDAY...AS ARCTIC HIGH PRESSURE MOVES SOUTHEAST THROUGH THE
NORTHERN PLAINS. THIS WILL BRING REINFORCING SHOT OF ARCTIC AIR
INTO THE AREA. QUIET WEATHER IS EXPECTED BY THURSDAY AFTERNOON AND
NIGHT ACROSS THE AREA.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF GENERALLY CHANGE 500 MB FLOW TO A MORE ZONAL LOOK FOR
FRIDAY INTO SATURDAY...LINGERING INTO MONDAY. THEY BRING A SHOT OF
WARM AIR ADVECTION SATURDAY NIGHT WITH DEEP MOISTURE AND GOOD
UPWARD VERTICAL MOTION IN THE DENDRITE SNOW CRYSTAL GROWTH ZONE. COLD
FRONT THEN SLOWLY MOVES EAST SOUTHEAST THROUGH THE AREA
SUNDAY...BEFORE EXITING SUNDAY NIGHT. CONTINUED HIGH POPS FOR
SATURDAY NIGHT INTO SUNDAY...WITH SEVERAL INCHES OF SNOWFALL
POSSIBLE. MORE COLD AIR LOOKS ON TAP FOR MONDAY...WITH ANOTHER
ARCTIC HIGH IN THE REGION.
AVIATION/12Z TAFS/...
ENOUGH FORCING AS DESCRIBED ABOVE TO WARRANT A BRIEF PERIOD OF
LOWER VSBYS AND CIGS AT ERN TAF SITES LATER THIS MRNG. WL DROP TO
MVFR CIGS/VSBYS AS AREAS OF -SN MOVE THRU. MAY BE A FEW LINGERING
-SHSN IN THE AFTN WITH CIGS POSSIBLY LINGERING AROUND MVFR LEVELS.
EXPECT TREND TOWARD VFR IN THE LATE AFTN OR EVE. LOW LEVEL WIND
SHEAR WILL CONTINUE THRU THE LATE MRNG.
MARINE...
HIGH RESOLUTION VISIBLE SATELLITE FROM MONDAY SHOWED WIDESPREAD
ICE COVER FROM THE SHORE EXTENDING OUT TO AROUND 10 MILES INTO
LAKE MI. STRONG SOUTHWEST WINDS DEVELOPED OVERNIGHT DUE TO THE
RAPIDLY TIGHTENING PRESSURE GRADIENT...HOWEVER AIR TEMPS REMAINED
QUITE COLD. TEMPS ONLY WARM INTO THE 20S TODAY WITH WINDS
DIMINISHING SOMEWHAT THIS AFTN BEFORE THE COLD AIR RETURNS
TONIGHT.
THINKING A FEW AREAS OF OPEN WATER MAY FORM BUT NOT EXPECTED TO
BE WIDESPREAD. STRONGEST WINDS ARE EXPECTED THIS MORNING WITH COLD
TEMPS...WITH SOME ABATEMENT THIS AFTN AND EVE AS TEMPS WARM INTO
THE 20S. A FEW GALE GUSTS TO 35 KTS POSSIBLE BUT NOT EXPECTED TO
BE FREQUENT ENOUGH TO WARRANT UPGRADING TO GALE WARNING AT THIS
TIME. WL CONTINUE SMALL CRAFT ADVY INTO TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
526 AM CST TUE FEB 24 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CST TUE FEB 24 2015
MAIN FCST CONCERNS THIS PERIOD...-SN CHANCES THIS MORNING...
TEMPERATURES TRENDS AS THE NEXT ARCTIC HIGH BUILDS IN.
DATA ANALYSIS AT 06Z HAD LOW PRESSURE NEAR THE SOUTHWEST SHORES OF
HUDSONS BAY WITH A TROUGH/WARM FRONT TO THE SOUTHWEST TO SOUTHEAST
SD. STRONG PRESSURE GRADIENT/SOUTHWEST FLOW AHEAD OF THIS TROUGH/
FRONT WAS PUSHING WARMER AIR ACROSS MN/IA/WI...WITH TEMPS CONTINUING
TO RISE EARLY THIS MORNING. TEMPS IN THE MID 20S TO LOW 30S ACROSS
WESTERN/SOUTHERN MN NEAR/BEHIND THE FRONT EARLY THIS MORNING.
SECONDARY/NEXT ARCTIC FRONT WAS NEAR THE US/CAN BORDER. FORCING/LIFT
WITH THE TROUGH/FRONT AND SHORTWAVE ENERGY DROPPING SOUTHEAST WAS
TRYING TO PRODUCE SOME SNOW INTO NORTHERN WI...BUT THIS FIGHTING
SOME RATHER DRY AIR IN THE 850-600MB LAYER. SNOW EARLY THIS MORNING
GENERALLY LIMITED TO NORTHERN 1/4 OF MN.
24.00Z MODEL RUNS GENERALLY INITIALIZED WELL. SOLUTIONS QUITE
SIMILAR AS RATHER STRONG SHORTWAVE ENERGY DROPS QUICKLY ACROSS THE
WESTERN GREAT LAKES TODAY AND THE NEXT IN LINE NORTHWEST FLOW
SHORTWAVE MOVES TO NEAR THE US/CAN BORDER BY 12Z WED. TREND FAVORS
FASTER OF THE EARLIER RUNS ON THE PASSING SHORTWAVE TODAY AND
STRONGER OF EARLIER RUNS WITH THE ENERGY DROPPING TOWARD ND LATE
TONIGHT. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...SHORTWAVES AND THEIR FORCING/LIFT MOVE RATHER
QUICKLY SOUTHEAST PAST THE FCST AREA THIS MORNING...AS DOES THE
SFC/LOWER LEVEL TROUGH AND QG/FN CONVERGENCE WITH IT. GIVEN THE FAST
SPEED OF THE FORCING...AND IT STRUGGLING TO OVERCOME THE DRY 850-
600MB LAYER...HAVE LOWER MOST -SN CHANCES SOUTHWEST OF I-94 AND
LIMITED THEM TO MAINLY BEFORE 18Z. THIS AFTERNOON/TONIGHT DRY AS LOW
LEVEL COLD ADVECTION/NEXT ARCTIC HIGH BUILDS INTO THE UPPER MIDWEST.
LEAD TROUGH/WARM FRONT SLIDES INTO/ACROSS THE AREA THIS MORNING...
WITH THE COLD FRONT TO FOLLOW THRU THE EARLY/MID AFTERNOON HOURS.
WARM WEDGE BETWEEN THE 2 FRONTS TO SLIDE ACROSS THE FCST AREA DURING
THE LATE MORNING/EARLY AFTERNOON HOURS. WITH TEMPS ALREADY AROUND 30F
WEST OF THE TWIN CITIES...HIGHS IN THE UPPER 20S TO LOW 30S FOR MUCH
OF THE FCST AREA TODAY CONTINUE TO LOOK GOOD. STEEPER LOW LEVEL
LAPSE RATES AND COLD ADVECTION/SUBSIDENCE TO WINDS BRISK/GUSTY AS
THEY SWING TO THE NORTHWEST THRU THE DAY. STRONGER OF THE LOW LEVEL
COLD ADVECTION/COOLING SPREADS ACROSS THE AREA LATE THIS AFTERNOON/
EVENING WITH THE COLDEST OF THE AIR...SUB-ZERO LOWS TONIGHT...
DROPPING ACROSS THE WI PORTION OF THE FCST AREA. USED A BLEND OF THE
GUIDANCE HIGHS/LOWS FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 337 AM CST TUE FEB 24 2015
MAIN FCST CONCERNS FOR WED THRU THU NIGHT...SNOW CHANCE ACROSS THE
SOUTHWEST END OF THE FCST AREA WED...COLD TEMPERATURES THRU THE
PERIOD.
24.00Z MODELS TRENDING TOWARD A COMPROMISE AS THE SHORTWAVE ENERGY
NEAR THE ND/CAN BORDER WED MORNING DROPS SOUTHEAST TOWARD IA/MO WED/
WED NIGHT. TREND FAVORS STRONGER OF THE EARLIER MODELS WITH THIS
FEATURE. TIGHTENING CONSENSUS FOR ANOTHER COLD MID LEVEL TROUGH TO
SLIDE ACROSS THE UPPER MIDWEST THU/THU NIGHT...WITH YET ANOTHER
ARCTIC HIGH TO DROP INTO THE NORTHERN PLAINS/UPPER MIDWEST UNDER IT.
FCST CONFIDENCE IN THE WED THRU THU NIGHT PERIOD IS GENERALLY GOOD.
STRONGER SHORTWAVE DROPPING TOWARD WESTERN IA WED THEN NORTHERN MO
WED NIGHT GENERATES MORE DIVERGENCE/LIFT ALOFT AS IT PASSES. BULK OF
THIS REMAINS WEST OF THE FCST AREA BUT DOES CLIP MAINLY THE
NORTHEAST IA PORTION OF IT. ROUND OF LOWER LEVEL THERMO-DYNAMIC
FORCING AND STRONGER 850-500MB QG CONVERGENCE SIGNAL ACCOMPANY THIS
WAVE...ALSO CLIPPING THE SOUTHWEST END OF THE FCST AREA. HOWEVER...
MODEL SOUNDINGS/X-SECTIONS SHOW THIS FORCING/LIFT IS ONCE AGAIN
BATTLING DRY AIR IN THE 900-700MB LAYER AND NORTHERLY FLOW OUT OF
THE NEXT ARCTIC HIGH BUILDING INTO THE NORTH-CENTRAL CONUS. CAN-GEM
THE MOST ROBUST WITH SATURATION AND SNOW INTO THE FCST AREA WED
WHILE GFS AND HI-RES NMM/ARW TEND TO KEEP ANY SNOW WED/WED EVENING
OUT OF THE FCST AREA. FOR NOW WILL MAINTAIN A SMALL -SN CHANCE
ACROSS MAINLY THE NORTHEAST IA PORTION OF THE FCST AREA WED...WHICH
BLENDS WELL WITH NEIGHBORING GRIDS. ONCE THIS WAVE PASSES...WED
NIGHT THRU THU NIGHT DOMINATED BY THE NEXT ARCTIC HIGH AND ITS COLD
AIRMASS SETTLING INTO THE REGION. 925MB TEMPS OF -13C TO -16C ACROSS
THE FCST AREA AT 00Z THU COOL TO AROUND -19C TO -20C FOR THU NIGHT.
850MB TEMPS FOR THE SAME TIME TRENDING 2 TO 3 STANDARD DEVIATIONS
BELOW NORMAL. WED NIGHT THRU THU NIGHT TO CONTINUE THE TREND OF MUCH
BELOW NORMAL TEMPERATURES WE/VE SEEN MUCH OF FEB. MAY YET NEED MORE
WIND CHILL ADVISORIES FOR LATE WED NIGHT/THU MORNING WITH SUB-ZERO
TEMPS AND NORTH WINDS OF 5-10MPH. USED A BLEND OF THE GUIDANCE
HIGHS/LOWS FOR WED THRU THU NIGHT...BUT WITH LIGHT WINDS/DECOUPLING
THU NIGHT LOWS COULD BE MUCH COLDER IN SHELTERED LOW LAYING AREAS.
FOR FRIDAY THRU MONDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...SNOW CHANCES SAT NIGHT/SUN...
CONTINUED BELOW NORMAL TEMPERATURES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 24.00Z CONTINUE TO ADVERTISE A PATTERN
SHIFT DURING THE FRI-MON PERIOD...TOWARD MORE TROUGHING OVER THE
WESTERN CONUS AND RISING HGTS OVER EASTERN NOAM. SURPRISINGLY GOOD
BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY FRI INTO SUN...AT LEAST
WITH THE LONGER WAVE FEATURES. PLENTY OF LONGWAVE AND SHORTWAVE
DETAIL DIFFERENCES BY LATER SUN AND MON...BUT THIS NOT UNEXPECTED
WITH A POTENTIAL PATTERN TRANSITION IN THE DAY 6/7 TIME-FRAME.
FCST CONFIDENCE IS GENERALLY AVERAGE IN THE FRI THRU MON PERIOD.
ARCTIC HIGH PRESSURE TO BE OVER THE AREA TO START THE PERIOD...
DRIFTING SOUTHEAST FRI/FRI NIGHT...WITH A RETURN OF LOW LEVEL WARM
ADVECTION AND SLOW MODERATION TEMPS FRI INTO SAT. HGTS CONTINUE TO
RISE SAT AS TROUGHING DIGS INTO THE WESTERN CONUS. BY SAT NIGHT...
SOUTHWEST FLOW ALOFT STARTS TO SPREAD MOISTURE NORTHWARD AHEAD OF
THE WESTERN TROUGHING AND TOWARD/INTO THE FCST AREA. PLENTY OF
DETAIL DIFFERENCES WITH THIS...SFC FEATURE POSITIONS AND SHORTWAVE
ENERGY IN THE FLOW TO AID IN LIFTING. LATEST TREND/CONSENSUS
INDICATES THE DEEPER MOISTURE/GREATER LIFT...AND SNOW CHANCES SAT
NIGHT/SUN MAY REMAIN SOUTH OF THE FCST AREA. UNTIL THE DETAILS
SETTLE DOWN...SNOW CHANCES IN THE 30-50 PERCENT RANGE /HIGHEST
SOUTH/ FOR SAT NIGHT/SUN APPEAR REASONABLE. TEMPERATURES BY THE
WEEKEND LOOKING TO COME OUT OF THE DEEP-FREEZE AS THE LOW LEVEL FLOW
BECOME SOUTH AND SOUTHWEST...BUT STILL REMAINING BELOW NORMAL. HIGH
PRESSURE/DRIER AIR RETURN MONDAY HOWEVER THIS HIGH LOOKS TO BE MORE
OF PACIFIC/WESTERN CAN ORIGIN VS. ARCTIC. MODEL/ENSEMBLE CONSENSUS
OF HIGHS/LOWS FOR FRI THRU MON APPEARS WELL TRENDED AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 526 AM CST TUE FEB 24 2015
THE WARM FRONT WAS STARTING TO APPROACH BOTH TAF SITES FROM THE
WEST...WHICH HAS ALLOWED THE GRADIENT TO RELAX AND THE GUSTS TO
CALM DOWN. ONCE THE WARM FRONT GOES THROUGH...THE WINDS WILL COME
AROUND TO THE WEST AND WILL ALSO SEE THE CEILINGS COME DOWN TO
EITHER MVFR OR LOW VFR. UPSTREAM OBSERVATIONS INDICATE SOME LIGHT
SNOW IS FALLING OVER NORTHWEST MINNESOTA AND THE 24.08Z HRRR
INDICATES THIS SHOULD HOLD TOGETHER LONG ENOUGH TO PRODUCE A SHORT
WINDOW OF SOME LIGHT SNOW. THE UPSTREAM OBSERVATIONS INDICATE
EITHER IFR OR MVFR VISIBILITIES WITH THE LIGHT SNOW.
HOWEVER...WITH THE HRRR SHOWING A DIMINISHING TREND AS THE SNOW
WORKS INTO DRIER LOW LEVEL AIR...WILL ONLY TAKE THE VISIBILITY
DOWN TO MVFR. THE SNOW SHOULD END AS THE COLD FRONT COMES THROUGH
AND SWINGS THE WINDS AROUND TO THE NORTHWEST. THE 24.06Z NAM SHOWS
GOOD LOW LEVEL LAPSE RATES DEVELOPING BEHIND THE FRONT FOR ANOTHER
ROUND OF WIND GUSTS OF 25 TO 30 KNOTS. VFR CONDITIONS EXPECTED TO
DEVELOP DURING THE AFTERNOON AS THE CLOUDS SCATTER OUT AND THEN
LOOK FOR THE GUSTS TO DIMINISH AROUND SUNSET WITH THE SUSTAINED
SPEEDS DROPPING BELOW 10 KNOTS THIS EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM...RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CST TUE FEB 24 2015
.TODAY...FORECAST CONFIDENCE IS MEDIUM.
WILL CONTINUE LIKELY WORDING FOR A PERIOD OF -SN THIS MORNING
MAINLY OVER CENTRAL AND EASTERN PORTIONS OF CWA. IMPRESSIVE LAYER
Q-VECTOR CONVERGENCE OF 20 UNITS EXTENDS FROM THROUGH THE LOW TO
MID-LAYERS. Q-VECTOR CONVERGENCE A RESULT OF STRONG WARM AIR
ADVECTION AND STRONG SHORT WAVE TROUGH CURRENTLY ADVANCING INTO
NRN MN...WHICH IS TIED TO LEFT EXIT REGION OF UPPER JET. THIS WAVE
RIDING ON THE HEELS OF FIRST WAVE CURRENTLY MOVING EWD ACROSS NRN
WI.
FIRST WAVE SERVING TO MOISTEN MID-LEVELS WITH PATCHY -SN FALLING
ACROSS NRN WI. SECOND WAVE WL HAVE A BIT MORE LOW TO MID-LEVEL
MOISTURE TO WORK WITH AS COLUMN PWAT INCREASES TO AROUND A QUARTER
INCH THIS MRNG. SHORT RANGE GUIDANCE ALSO SHOWS A BRIEF PERIOD OF
FRONTOGENETICAL FORCING SLIDING ACROSS SRN WI LATER THIS MRNG.
POTENTIAL FOR ONE HALF INCH UP TO ONE INCH OF SNOW IN NORTHEAST
CWA. WL BE LUCKY TO GET MEASUREABLE LIQUID PRECIP ACROSS SOUTHWEST
CWA.
DESPITE LOSS OF MID-LEVEL MOISTURE THIS AFTERNOON...ARCTIC FRONT
EXPECTED TO MOVE ACROSS SRN WI. LINGERING LOW LEVEL RH UP TO 5K
FEET...PARTIALLY IN DENDRITIC GROWTH ZONE...AND STEEP LOW LEVEL
LAPSE RATES AS FRONT SLIDES THRU. HENCE KEPT SOME LOWER POPS FOR
POTENTIAL OF SCT -SHSN ACROSS ERN CWA. RAP SOUNDINGS SHOWS LOW
LEVEL RH DECREASING RAPIDLY IN THE LATE AFTN WHILE NAM HOLDS ONTO
DEEPER MOISTURE INTO THE EVE. FOR NOW KEPT EVENING /AFTER 00Z/
DRY.
925H TEMPS WARM TO -6 TO -8. HOWEVER CLOUDS AND BREEZY SOUTHWEST
TO WEST WINDS WL KEEP DAYTIME HIGHS IN CHECK. EXPECT HIGHS TO PEAK
IN THE MID 20S TO AROUND 30.
.TONIGHT...FORECAST CONFIDENCE IS HIGH.
ARCTIC FRONT SLIDES ACROSS SRN WI TNGT ALLOWING COLD AIR TO
RETURN ON NORTHWEST WINDS. LOW LEVEL MIXING OF DRY AIR SHOULD
RESULT IN CLEARING SKIES OVERNIGHT WITH OVERNIGHT TEMPS RETURNING
TO THE SINGLE DIGITS ABV ZERO. MAY HAVE SOME GUSTS TO 25 KTS IN
THE LATE AFTN AND EARLY EVE RESULTING IN PATCHY BLOWING SNOW WITH
BEST CHANCE IN THE NORTHEAST. OTHERWISE...NOT EXPECTING MUCH BS
FROM CURRENT SNOW COVER DUE TO CRUST.
.SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
MODELS ARE IN DECENT AGREEMENT WITH SHOWING A GENEARL NORTHWEST
FLOW AT 500 MB ACROSS THE REGION DURING THIS PERIOD. THEY DO SHOW
SOME DIFFERENCES WITH TIMING AND PLACEMENT OF QPF WITH CLIPPER
SYSTEM SLIDING SOUTHEAST THROUGH THE REGION. ALL MODELS SHOW THE
BULK OF THE QPF AND UPWARD VERTICAL MOTION FIELDS MISSING THE AREA
TO THE SOUTHWEST WEDNESDAY NIGHT.
THE CANADIAN MODEL IS THE MOST AGGRESSIVE WITH QPF OVER MOST OF
THE AREA...WITH THE NAM/GFS/ECMWF BRUSHING THE FAR SOUTH. THEY
ALSO SHOW SOME LAKE EFFECT SNOW SHOWER POTENTIAL WEDNESDAY
NIGHT...WITH NORTHEAST WINDS AND MOISTURE BELOW AND ABOVE THE
INVERSION. DELTA T VALUES ARE QUITE FAVORABLE...THOUGH DECENT ICE
COVERAGE ON THE LAKE MAY LIMIT LAKE EFFECT POTENTIAL.
FOR NOW...WILL MAINTAIN LOW POPS IN THE FAR SOUTH AND SOUTHEAST
COUNTIES FOR MAINLY WEDNESDAY NIGHT...HANGING ON IN THE FAR
SOUTHEAST INTO THURSDAY MORNING. LITTLE TO NO SNOW IS EXPECTED AT
THIS TIME.
ANOTHER SHOT OF COLD AIR ADVECTION OCCURS WEDNESDAY NIGHT INTO
THURSDAY...AS ARCTIC HIGH PRESSURE MOVES SOUTHEAST THROUGH THE
NORTHERN PLAINS. THIS WILL BRING REINFORCING SHOT OF ARCTIC AIR
INTO THE AREA. QUIET WEATHER IS EXPECTED BY THURSDAY AFTERNOON AND
NIGHT ACROSS THE AREA.
.LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF GENERALLY CHANGE 500 MB FLOW TO A MORE ZONAL LOOK FOR
FRIDAY INTO SATURDAY...LINGERING INTO MONDAY. THEY BRING A SHOT OF
WARM AIR ADVECTION SATURDAY NIGHT WITH DEEP MOISTURE AND GOOD
UPWARD VERTICAL MOTION IN THE DENDRITE SNOW CRYSTAL GROWTH ZONE. COLD
FRONT THEN SLOWLY MOVES EAST SOUTHEAST THROUGH THE AREA
SUNDAY...BEFORE EXITING SUNDAY NIGHT. CONTINUED HIGH POPS FOR
SATURDAY NIGHT INTO SUNDAY...WITH SEVERAL INCHES OF SNOWFALL
POSSIBLE. MORE COLD AIR LOOKS ON TAP FOR MONDAY...WITH ANOTHER
ARCTIC HIGH IN THE REGION.
&&
.AVIATION/12Z TAFS/...
ENOUGH FORCING AS DESCRIBED ABOVE TO WARRANT A BRIEF PERIOD OF
LOWER VSBYS AND CIGS AT ERN TAF SITES LATER THIS MRNG. WL DROP TO
MVFR CIGS/VSBYS AS AREAS OF -SN MOVE THRU. MAY BE A FEW LINGERING
-SHSN IN THE AFTN WITH CIGS POSSIBLY LINGERING AROUND MVFR LEVELS.
EXPECT TREND TOWARD VFR IN THE LATE AFTN OR EVE. LOW LEVEL WIND
SHEAR WILL CONTINUE THRU THE LATE MRNG.
&&
.MARINE...
HIGH RESOLUTION VISIBLE SATELLITE FROM MONDAY SHOWED WIDESPREAD
ICE COVER FROM THE SHORE EXTENDING OUT TO AROUND 10 MILES INTO
LAKE MI. STRONG SOUTHWEST WINDS DEVELOPED OVERNIGHT DUE TO THE
RAPIDLY TIGHTENING PRESSURE GRADIENT...HOWEVER AIR TEMPS REMAINED
QUITE COLD. TEMPS ONLY WARM INTO THE 20S TODAY WITH WINDS
DIMINISHING SOMEWHAT THIS AFTN BEFORE THE COLD AIR RETURNS
TONIGHT.
THINKING A FEW AREAS OF OPEN WATER MAY FORM BUT NOT EXPECTED TO
BE WIDESPREAD. STRONGEST WINDS ARE EXPECTED THIS MORNING WITH COLD
TEMPS...WITH SOME ABATEMENT THIS AFTN AND EVE AS TEMPS WARM INTO
THE 20S. A FEW GALE GUSTS TO 35 KTS POSSIBLE BUT NOT EXPECTED TO
BE FREQUENT ENOUGH TO WARRANT UPGRADING TO GALE WARNING AT THIS
TIME. WL CONTINUE SMALL CRAFT ADVY INTO TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1036 PM CST MON FEB 23 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 253 PM CST MON FEB 23 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE SETTLING OVER THE MID-MISSISSIPPI VALLEY AND EXTENDING
ACROSS THE EASTERN GREAT LAKES. CLEAR SKIES REMAIN ACROSS MOST OF
THE REGION EARLY THIS AFTERNOON WITH WIND CHILLS WARMING INTO THE 5
TO 15 BELOW RANGE. CLOUDS ARE INCREASING OVER THE NORTHERN PLAINS
AHEAD OF A SHORTWAVE DIVING SOUTHEAST OVER LAKE WINNIPEG. LIGHT
SNOW AND BLOWING SNOW ARE OCCURRING AHEAD OF THIS SHORTWAVE BUT
THESE ARE OCCURRING MAINLY NORTH OF THE BORDER. SOME WIND GUSTS ARE
REACHING BETWEEN 30 AND 35 KNOTS. AS THIS SHORTWAVE AND A MORE
POTENT WAVE BEHIND IT MOVING INTO THE REGION...SNOWFALL POTENTIAL
AND IMPACTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LEAD SHORTWAVE TROUGH OVER THE LAKE WINNIPEG REGION WILL
WEAKEN AS IT MOVES INTO THE REGION THIS EVENING. THE ARCTIC AIRMASS
AHEAD OF THIS WAVE IS VERY DRY...WHICH SHOULD KEEP THE AREA
PRECIP-FREE THROUGH THE EVENING. THEN AS A SECONDARY AND STRONGER
SHORTWAVE ARRIVES LATE TONIGHT...STRONG FORCING SHOULD PUSH AN AREA
OF LIGHT SNOW ACROSS THE REGION FROM NORTHWEST TO
SOUTHEAST...POSSIBLY MAKING IT INTO THE FOX VALLEY BY 12Z. ALTHOUGH
ACCUMULATIONS ARE EXPECTED TO REMAIN UNDER AN INCH...GUSTY SOUTHWEST
WINDS AHEAD OF THE SHORTWAVE WILL LEAD TO BLOWING AND DRIFTING SNOW
IN THE OPEN COUNTRY. THE CLOUDS AND WIND WILL PREVENT TEMPS FROM
FALLING MUCH TONIGHT...AND WILL GO WITH LOWS IN THE MIDDLE SINGLE
DIGITS ABOVE ZERO. WIND CHILLS WILL CONTINUE TO RANGE FROM 10 TO 20
BELOW THIS EVENING...THEN WARM AS TEMPERATURES RISE OVERNIGHT.
TUESDAY...THE LIGHT SNOW WILL CONTINUE TO SPREAD ACROSS THE FOX
VALLEY AND LAKESHORE AREAS EARLY IN THE MORNING BEFORE EXITING LATE
IN THE MORNING. MID-LEVEL MOISTURE PEELS OUT BEHIND THE SHORTWAVE
DURING THE AFTERNOON...BUT STEEPENING LOW LEVEL LAPSE RATES WITHIN A
BROKEN CLOUD DECK COULD YIELD SCATTERED FLURRIES. ADDITIONAL
ACCUMULATIONS COULD REACH UP TO A HALF INCH. GUSTY SOUTHWEST WINDS
IN THE MORNING WILL TURN TO THE WEST AND THEN NORTHWEST IN THE
AFTERNOON AND WILL PROMOTE BLOWING AND DRIFTING SNOW. WIND
TRAJECTORIES WILL BE PARALLEL TO DOOR COUNTY INITIALLY...BUT AS
WINDS VEER TO THE WEST AND THEN NORTHWEST...BLOWING AND DRIFTING
SNOW WILL INCREASINGLY BECOME A HAZARD TO THE WESTERN HALF OF THE
COUNTY EVEN AS WINDS SUBSIDE SOMEWHAT WITH THE APPROACH OF A SURFACE
TROUGH. SOME DISCUSSION WHETHER DOOR COUNTY WILL NEED A SNOW AND
BLOWING SNOW ADVISORY FOR TOMORROW. THINK WINDS WILL BE SOUTHWEST
THROUGH MOST OF THE SNOW FALL TOMORROW MORNING AND AM UNCERTAIN HOW
CONDITIONS WILL BE AFTER SEVERAL HOURS OF BLOWING/DRIFTING SNOW
PRIOR TO THIS. WILL ISSUE AN SPS HIGHLIGHTING THIS HAZARD.
TEMPERATURES WILL BE THE WARMEST IN SEVERAL DAYS...AND RANGE FROM
THE LOWER 20S TO LOWER 30S.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 253 PM CST MON FEB 23 2015
A BIT OF A CHANGE IN THE UPPER FLOW PATTERN IS IN THE
OFFING...WITH THE WESTERN RIDGE DRIFTING WEST OVER THE PACIFIC AND
A CUT OFF LOW DEVELOPING OVER THE SOUTHWEST...SETTING UP SOMETHING
MORE AKIN TO A SPLIT FLOW PATTERN AS THE WEEK GROWS LATE. THE
NORTHERN STREAM STILL HOLDS SIGNIFICANT SWAY IN OUR AREA
UNFORTUNATELY...AND THE IMPACT ON SENSIBLE WEATHER IS UNLIKELY TO
BE SIGNIFICANT UNTIL LATE THIS WEEKEND OR EARLY NEXT WEEK.
SATELLITE IMAGERY INDICATES A PATCH OF SOMEWHAT OPEN WATERS ON
LAKE SUPERIOR ALONG A LAKE EFFECT FETCH FOR NORTH CENTRAL
WISCONSIN...AND BREEZY SOUTHWEST WINDS IN THE SHORT TERM SHOULD
KEEP THAT AREA FROM FREEZING OVER. THIS LEAVES POTENTIAL FOR
LINGERING LAKE EFFECT FLURRIES OR SNOW SHOWERS TUESDAY NIGHT
IN THE NORTH CENTRAL SNOW BELT...THOUGH ACCUMULATIONS SHOULD BE
SLIGHT TO NIL. GUSTY WINDS WILL BE DIMINISHING THROUGH THE EVENING
HOURS AS THE PRESSURE GRADIENT LOOSENS...BRINGING AN END TO
POTENTIAL FOR BLOWING SNOW.
ANOTHER BEEFY HIGH WILL FOLLOW IN TO GIVE US ANOTHER PLUNGE IN
TEMPERATURES...BUT BEFORE THAT A SHORTWAVE WILL SHOOT THROUGH
THE UPPER TROUGH. THE GEM STUBBORNLY BRINGS FLURRIES OR EXTREMELY
LIGHT ACCUMULATIONS TO PORTIONS OF CENTRAL AND EAST CENTRAL
WISCONSIN. THE REST OF THE GUIDANCE SHUNTS EVERYTHING WELL SOUTH
OF THE AREA...AND THE FORECAST JOINS THAT CAMP IN KEEPING THINGS
DRY HERE.
THE MAIN STORY FOR THE SECOND HALF OF THE WORK WEEK...AGAIN...WILL
BE SIGNIFICANTLY BELOW NORMAL TEMPS. THE COLD AIR REACHES ITS
NADIR WEDNESDAY AFTERNOON INTO THURSDAY. HIGHS IN THE SINGLE
DIGITS TO LOW/MID TEENS ARE EXPECTED WITH LOWS BELOW ZERO. WIND
CHILL ADVISORIES MAY RETURN FOR ANOTHER SEQUEL...BUT THIS COLD
PUSH DOES NOT LOOK TO MATCH PREVIOUS ITERATIONS...SO THERE IS LESS
CONFIDENCE IN THAT AT THIS TIME. THE ARCTIC AIR MASS BEGINS TO
MODERATE ON FRIDAY AND ESPECIALLY THIS WEEKEND...BUT TEMPERATURES
STILL LOOK TO REMAIN BELOW NORMAL.
HEADING INTO THE WEEKEND...AS A TROUGH DIGS OVER THE WEST COAST
AND THE FLOW ALOFT BECOMES SOUTHWESTERLY. THIS FLOW WILL PUSH IN A
SLUG OF MOISTURE FROM THE SOUTHERN PLAINS FOR THE SECOND HALF OF
THE WEEKEND. MODELS ARE IN AGREEMENT SHOWING THE MOISTURE AND
PUSH OF WARMER AIR. HOWEVER...THERE IS SPREAD IN HOW FAR NORTH
THIS AIR GETS...WITH SIGNIFICANT IMPACTS ON SNOW POTENTIAL. THE
CANADIAN HOLDS COLD AIR OVER THE GREAT LAKES AND SENDS YET ANOTHER
WINTER STORM THROUGH THE MID-SOUTH AND FAR AWAY FROM OUR AREA. THE
GFS AND ECMWF ARE MORE READY TO BRING A MORE SIGNIFICANT SYSTEM
TOWARDS THE GREAT LAKES. AT THIS TIME IT AGAIN APPEARS THAT THE
HIGHEST SNOWFALL TOTALS WILL MISS THE AREA. HOWEVER...IT IS
POSSIBLE...GIVEN THE CURRENT GUIDANCE ENVELOPE...FOR ENOUGH
SNOWFALL TO MEET ADVISORY CRITERIA IN CENTRAL AND EAST CENTRAL
WISCONSIN. ULTIMATELY...THE MODEL SOLUTIONS ARE RELATIVELY FRAGILE
THIS FAR OUT...AND THE BEST ADVICE IS TO FOLLOW UPDATED FORECASTS
AS THE WEEK CONTINUES.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1000 PM CST MON FEB 23 2015
GUSTY SOUTHWEST WINDS WILL CONTINUE OVERNIGHT INTO TUESDAY MORNING...
THEN SHIFT TO THE WEST OR NORTHWEST DURING THE DAY TUESDAY. LOW LEVEL
WIND SHEAR WILL CONTINUE INTO TUESDAY MORNING. LIGHT SNOW ACROSS
NORTHERN MINNESOTA WILL OVERSPREAD MUCH OF NORTH-CENTRAL AND NORTHEAST
WISCONSIN LATE TONIGHT INTO TUESDAY MORNING. PROGRESSION OF THE SNOW
IS A LITTLE SLOWER DUE TO SATURATION ISSUES. LIGHT WILL END ACROSS
SOUTH LATE TUESDAY MORNING OR EARLY AFTERNOON...LINGERING LONGER INTO
THE AFTERNOON ACROSS THE NORTH. VFR CIGS WILL GIVE WAY TO MVFR CIGS
LATE TONIGHT AND TUESDAY MORNING ACROSS THE NORTH...THEN BECOME VFR
AGAIN LATER TUESDAY AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......ECKBERG
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1205 AM MST THU FEB 26 2015
.UPDATE...
ISSUED AT 1203 AM MST THU FEB 26 2015
QUICK UPDATE TO PRECIPITATION FORECAST THROUGH THE EARLY MORNING
HOURS. SHOWERS HAVE TAPERED OFF EXCEPT FOR A FEW ISO SHOWERS OVER
THE CENTRAL MTNS OF WESTERN CO AND THE SAN JUANS. WEATHER SHOULD
BE RELATIVELY QUIET UNTIL AROUND NOON THURSDAY.
UPDATE ISSUED AT 646 PM MST WED FEB 25 2015
SCATTERED SNOW SHOWERS HAVE BEEN SPILLING INTO THE WEST CENTRAL
VALLEYS. HRRR MODEL SHOWING SNOW SHOWER ACTIVITY MOVING INTO
MONTROSE LATER THIS EVENING. BOOSTED VALLEY POPS THIS EVENING TO
REFLECT CURRENT SHORT TERM TRENDS.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM MST WED FEB 25 2015
MOIST...UNSTABLE CONDITIONS HAVE KEPT SNOW SHOWERS GOING ALL DAY
ACROSS WESTERN COLORADO AND THIS WILL CONTINUE INTO THE LATE
EVENING HOURS. THE COOL ADVECTIVE NORTHWEST FLOW IS FAVORING MANY
NORTH AND WEST FACING ASPECTS FROM THE FLAT TOPS AND NORTHERN
PLATEAUS TO THE NORTHERN SAN JUANS. WEBCAMS SHOW THE INTENSITY OF
THE CONVECTIVE SNOW SHOWERS WITH VISIBILITIES DROPPING QUICKLY AS
SNOW RATES INCREASE. HOWEVER LOOKING AT AREA WEB CAMS ROADWAYS ARE
STAYING IN FAIRLY GOOD SHAPE...EVEN OVER THE HIGHER PASSES.
SNOTELS HAVE PICKED UP THIS AFTERNOON WITH THE ADDED OCTANE BUT
STILL THE MAJORITY ARE IN THE 2 TO 4 INCH RANGE. SNOW STAKES SHOW
THE SAME AT LOCAL SKI AREAS. WATER VAPOR IMAGERY INDICATES THE
WAVE DRIVING THESE SHOWERS IS DROPPING ACROSS SOUTHWEST WYOMING
LATE THIS AFTERNOON AND WILL BE SHEARING ACROSS THE COLORADO UTAH
BORDER THROUGH THE EVENING. THOUGH SOME BOOST WILL BE LOST AT
SUNSET SHOWERS SHOULD CONTINUE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS THROUGH LATE EVENING...ENDING OVERNIGHT. SOME SHOWERS
ARE LIKELY TO LEAK INTO THE LOWER VALLEYS OF WESTERN COLORADO
ALONG I-70 AND NORTHWARD AS WELL BUT LITTLE ACCUMULATION IS
EXPECTED. SUBSIDENCE AND INCREASING STABILITY IN THE TRANSITION
AREA BETWEEN THE DEPARTING WAVE AND THE NEXT ENERGY DIGGING TO OUR
WEST LOOKS TO BRING A RATHER SIGNIFICANT BREAK THURSDAY MORNING
FOR OUR CWA. LIGHT OROGRAPHIC SNOW SHOWERS COULD REMAIN OVER THE
DIVIDE MOUNTAINS OVER THE NEXT 24 HOURS AS DENDRITIC TEMPERATURES
AT MOUNTAIN TOP LEVEL WILL BE IN THE SWEET SPOT. ADDITIONAL LIGHT
ACCUMULATIONS WILL BE POSSIBLE BUT SNOW RATES NOT EXCESSIVE. HIGH
LEVEL MOISTURE WILL BEGIN TO MAKE IT/S WAY BACK INTO THE GREAT
BASIN THROUGH THE DAY AS ANOTHER UPSTREAM WAVE MOVES THROUGH THE
NORTHWEST FLOW INTO THE GREAT BASIN. INSTABILITY WILL BE PRESENT
BUT NOT QUITE AS ROBUST AS THIS AFTERNOON AND JET SUPPORT RETREATS
TO THE WEST. EXPECT INCREASING POPS MAINLY ON THE TERRAIN ON
THURSDAY AFTERNOON WITH SOME DECREASE IN ACTIVITY AT SUNSET.
THURSDAY NIGHT THE WAVE TAKES A TIGHTER CYCLONIC CURVE ACROSS THE
4 CORNERS AS THE UPPER JET BEGINS TO CURVE ALOFT. THIS WILL LIKELY
KEEP SOME SNOW GOING IN THE HILLS FAVORING THE SOUTHERN CWA
THROUGH THE NIGHT BUT AGAIN ONLY LIGHT ACCUMULATIONS ARE EXPECTED.
UPSTREAM ACROSS THE LEFT COAST FROM SO.CAL NORTHWARD...300K
SURFACES SHOW A HEALTHY SURGE OF PACIFIC MOISTURE BEING
TRANSPORTED INLAND AS OUR WEATHER MAKER FOR THE WEEKEND DROPS
ACROSS THE PACIFIC NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MST WED FEB 25 2015
WELCOME TO WEEKEND STORM NUMBER TWO UNDER THIS NEW IMPROVED
WEATHER PATTERN. THIS STORM IS NOTABLE FOR ITS EXTENDED PERIOD OF
PERSISTENT SHOWERS...PERHAPS THROUGH NEXT WEDNESDAY.
THE FIRST OF TWO PACIFIC TROUGHS SLIDES DOWN THE WEST COAST
EVENTUALLY CLOSING OFF ALONG THE SOUTHERN CALIFORNIA COAST BY
SUNDAY. DESCENT MOISTURE AND GOOD OROGRAPHICS WITH PERIODS OF
UPPER LEVEL SUPPORT SHOULD PRODUCE GOOD SNOWFALL FROM THE FOUR
CORNERS NE TO THE WEST ELK MOUNTAINS. A WINTER STORM WATCH HAS
BEEN ISSUED FOR THESE ZONES.
FRIDAY-FRIDAY NIGHT...IN MILD WARM MOIST ADVECTION...SHOWERS WILL
INCREASE ACROSS THE SOUTH. OROGRAPHICS WILL FAVOR SW-FACING
SLOPES.
SATURDAY-SATURDAY NIGHT THE PATTERN AMPLIFIES AS THE LOW DIGS
DOWN THE COAST. THE 120KT JET OVER NEW MEXICO LIFTS ACROSS THE SAN
JUAN MTNS INTO THE WEST ELKS. 700MB WINDS INCREASE TO 40KTS UNDER
THE JET. A SURFACE-700MB LOW DEEPENS IN SE UTAH ADDING TO THE
OROGRAPHIC COMPONENT INTO THE SOUTHERN MOUNTAIN SLOPES. 700MB
TEMPERATURES AROUND -4C WOULD PRODUCE AFTERNOON SNOW LEVELS
AROUND 7KFT. THE JET SHIFTS EAST ON SUNDAY FOR SOME DIMINISHING OF
THE MOUNTAIN WINDS BUT MOIST OROGRAPHIC SNOW REMAINS IN PLACE.
FOR MONDAY THE 18Z GFS HAS SLOWED DOWN TO MATCH THE EC TIMING WITH
THE PROGRESSION OF THIS FIRST LOW OFF TO THE SE. THE SFC LOW
LIFTS THROUGH THE SOUTH THRU THE DAY. A DOWN TURN OF SHOWERS IS
EXPECTED MONDAY NIGHT AND WE HAVE ENDED THE WINTER STORM WATCH
HERE.
BUT ALREADY BY TUESDAY A COLDER TROUGH HAS DIVED DOWN THE COAST
SETTLING OVER THE GREAT BASIN. A STRONG COLD FRONT PASSES ON
TUESDAY DRIVING SNOW LEVELS TO THE LOWEST ELEVATIONS AND
EFFICIENTLY TURNING ANY AVAILABLE MOISTURE TO SNOW. TUESDAY NIGHT
INTO WEDNESDAY THE FLOW TURNS TO COLD ADVECTIVE NORTH WITH SNOW
LINGERING ALONG THE NORTH-FACING SLOPES BUT STILL FAVORING THE
SOUTH WHERE MOISTURE IS DEEPEST. HIGHLIGHTS ARE EXPECTED WITH THIS
SECOND LOW ALSO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1042 PM MST WED FEB 25 2015
SCATTERED SHOWERS CONTINUE ACROSS WEST CENTRAL COLORADO AND THE
SOUTHWESTERN COLORADO MOUNTAINS. SHOWERS ARE EXPECTED TO TAPER OFF
BY 12Z THURSDAY MORNING. VFR CONDITIONS EXPECTED BETWEEN 12Z AND
18Z THURSDAY...BUT MORE SNOW WILL DEVELOP OVER WESTERN COLORADO
(MAINLY IN THE MOUNTAINS) AFTER 18Z INCLUDING KASE...KEGE...AND
KTEX. ALL TAF SITES HAVE A CHANCE OF RECEIVING PRECIPITATION AFTER
00Z THURSDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH MONDAY EVENING
FOR COZ012-014-018-019-022-023.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...JOE
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1046 PM MST WED FEB 25 2015
.UPDATE...
ISSUED AT 646 PM MST WED FEB 25 2015
SCATTERED SNOW SHOWERS HAVE BEEN SPILLING INTO THE WEST CENTRAL
VALLEYS. HRRR MODEL SHOWING SNOW SHOWER ACTIVITY MOVING INTO
MONTROSE LATER THIS EVENING. BOOSTED VALLEY POPS THIS EVENING TO
REFLECT CURRENT SHORT TERM TRENDS.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM MST WED FEB 25 2015
MOIST...UNSTABLE CONDITIONS HAVE KEPT SNOW SHOWERS GOING ALL DAY
ACROSS WESTERN COLORADO AND THIS WILL CONTINUE INTO THE LATE
EVENING HOURS. THE COOL ADVECTIVE NORTHWEST FLOW IS FAVORING MANY
NORTH AND WEST FACING ASPECTS FROM THE FLAT TOPS AND NORTHERN
PLATEAUS TO THE NORTHERN SAN JUANS. WEBCAMS SHOW THE INTENSITY OF
THE CONVECTIVE SNOW SHOWERS WITH VISIBILITIES DROPPING QUICKLY AS
SNOW RATES INCREASE. HOWEVER LOOKING AT AREA WEB CAMS ROADWAYS ARE
STAYING IN FAIRLY GOOD SHAPE...EVEN OVER THE HIGHER PASSES.
SNOTELS HAVE PICKED UP THIS AFTERNOON WITH THE ADDED OCTANE BUT
STILL THE MAJORITY ARE IN THE 2 TO 4 INCH RANGE. SNOW STAKES SHOW
THE SAME AT LOCAL SKI AREAS. WATER VAPOR IMAGERY INDICATES THE
WAVE DRIVING THESE SHOWERS IS DROPPING ACROSS SOUTHWEST WYOMING
LATE THIS AFTERNOON AND WILL BE SHEARING ACROSS THE COLORADO UTAH
BORDER THROUGH THE EVENING. THOUGH SOME BOOST WILL BE LOST AT
SUNSET SHOWERS SHOULD CONTINUE ACROSS THE CENTRAL AND SOUTHERN
MOUNTAINS THROUGH LATE EVENING...ENDING OVERNIGHT. SOME SHOWERS
ARE LIKELY TO LEAK INTO THE LOWER VALLEYS OF WESTERN COLORADO
ALONG I-70 AND NORTHWARD AS WELL BUT LITTLE ACCUMULATION IS
EXPECTED. SUBSIDENCE AND INCREASING STABILITY IN THE TRANSITION
AREA BETWEEN THE DEPARTING WAVE AND THE NEXT ENERGY DIGGING TO OUR
WEST LOOKS TO BRING A RATHER SIGNIFICANT BREAK THURSDAY MORNING
FOR OUR CWA. LIGHT OROGRAPHIC SNOW SHOWERS COULD REMAIN OVER THE
DIVIDE MOUNTAINS OVER THE NEXT 24 HOURS AS DENDRITIC TEMPERATURES
AT MOUNTAIN TOP LEVEL WILL BE IN THE SWEET SPOT. ADDITIONAL LIGHT
ACCUMULATIONS WILL BE POSSIBLE BUT SNOW RATES NOT EXCESSIVE. HIGH
LEVEL MOISTURE WILL BEGIN TO MAKE IT/S WAY BACK INTO THE GREAT
BASIN THROUGH THE DAY AS ANOTHER UPSTREAM WAVE MOVES THROUGH THE
NORTHWEST FLOW INTO THE GREAT BASIN. INSTABILITY WILL BE PRESENT
BUT NOT QUITE AS ROBUST AS THIS AFTERNOON AND JET SUPPORT RETREATS
TO THE WEST. EXPECT INCREASING POPS MAINLY ON THE TERRAIN ON
THURSDAY AFTERNOON WITH SOME DECREASE IN ACTIVITY AT SUNSET.
THURSDAY NIGHT THE WAVE TAKES A TIGHTER CYCLONIC CURVE ACROSS THE
4 CORNERS AS THE UPPER JET BEGINS TO CURVE ALOFT. THIS WILL LIKELY
KEEP SOME SNOW GOING IN THE HILLS FAVORING THE SOUTHERN CWA
THROUGH THE NIGHT BUT AGAIN ONLY LIGHT ACCUMULATIONS ARE EXPECTED.
UPSTREAM ACROSS THE LEFT COAST FROM SO.CAL NORTHWARD...300K
SURFACES SHOW A HEALTHY SURGE OF PACIFIC MOISTURE BEING
TRANSPORTED INLAND AS OUR WEATHER MAKER FOR THE WEEKEND DROPS
ACROSS THE PACIFIC NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MST WED FEB 25 2015
WELCOME TO WEEKEND STORM NUMBER TWO UNDER THIS NEW IMPROVED
WEATHER PATTERN. THIS STORM IS NOTABLE FOR ITS EXTENDED PERIOD OF
PERSISTENT SHOWERS...PERHAPS THROUGH NEXT WEDNESDAY.
THE FIRST OF TWO PACIFIC TROUGHS SLIDES DOWN THE WEST COAST
EVENTUALLY CLOSING OFF ALONG THE SOUTHERN CALIFORNIA COAST BY
SUNDAY. DESCENT MOISTURE AND GOOD OROGRAPHICS WITH PERIODS OF
UPPER LEVEL SUPPORT SHOULD PRODUCE GOOD SNOWFALL FROM THE FOUR
CORNERS NE TO THE WEST ELK MOUNTAINS. A WINTER STORM WATCH HAS
BEEN ISSUED FOR THESE ZONES.
FRIDAY-FRIDAY NIGHT...IN MILD WARM MOIST ADVECTION...SHOWERS WILL
INCREASE ACROSS THE SOUTH. OROGRAPHICS WILL FAVOR SW-FACING
SLOPES.
SATURDAY-SATURDAY NIGHT THE PATTERN AMPLIFIES AS THE LOW DIGS
DOWN THE COAST. THE 120KT JET OVER NEW MEXICO LIFTS ACROSS THE SAN
JUAN MTNS INTO THE WEST ELKS. 700MB WINDS INCREASE TO 40KTS UNDER
THE JET. A SURFACE-700MB LOW DEEPENS IN SE UTAH ADDING TO THE
OROGRAPHIC COMPONENT INTO THE SOUTHERN MOUNTAIN SLOPES. 700MB
TEMPERATURES AROUND -4C WOULD PRODUCE AFTERNOON SNOW LEVELS
AROUND 7KFT. THE JET SHIFTS EAST ON SUNDAY FOR SOME DIMINISHING OF
THE MOUNTAIN WINDS BUT MOIST OROGRAPHIC SNOW REMAINS IN PLACE.
FOR MONDAY THE 18Z GFS HAS SLOWED DOWN TO MATCH THE EC TIMING WITH
THE PROGRESSION OF THIS FIRST LOW OFF TO THE SE. THE SFC LOW
LIFTS THROUGH THE SOUTH THRU THE DAY. A DOWN TURN OF SHOWERS IS
EXPECTED MONDAY NIGHT AND WE HAVE ENDED THE WINTER STORM WATCH
HERE.
BUT ALREADY BY TUESDAY A COLDER TROUGH HAS DIVED DOWN THE COAST
SETTLING OVER THE GREAT BASIN. A STRONG COLD FRONT PASSES ON
TUESDAY DRIVING SNOW LEVELS TO THE LOWEST ELEVATIONS AND
EFFICIENTLY TURNING ANY AVAILABLE MOISTURE TO SNOW. TUESDAY NIGHT
INTO WEDNESDAY THE FLOW TURNS TO COLD ADVECTIVE NORTH WITH SNOW
LINGERING ALONG THE NORTH-FACING SLOPES BUT STILL FAVORING THE
SOUTH WHERE MOISTURE IS DEEPEST. HIGHLIGHTS ARE EXPECTED WITH THIS
SECOND LOW ALSO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1042 PM MST WED FEB 25 2015
SCATTERED SHOWERS CONTINUE ACROSS WEST CENTRAL COLORADO AND THE
SOUTHWESTERN COLORADO MOUNTAINS. SHOWERS ARE EXPECTED TO TAPER OFF
BY 12Z THURSDAY MORNING. VFR CONDITIONS EXPECTED BETWEEN 12Z AND
18Z THURSDAY...BUT MORE SNOW WILL DEVELOP OVER WESTERN COLORADO
(MAINLY IN THE MOUNTAINS) AFTER 18Z INCLUDING KASE...KEGE...AND
KTEX. ALL TAF SITES HAVE A CHANCE OF RECEIVING PRECIPITATION AFTER
00Z THURSDAY EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WATCH FROM FRIDAY MORNING THROUGH MONDAY EVENING
FOR COZ012-014-018-019-022-023.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...15
LONG TERM...JOE
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
335 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE APPEARS TO BE GENERAL MODEL AGREEMENT ON OVERALL FEATURES
THROUGH TODAY. ALOFT...WEAK SHORTWAVE TRAVERSES QUICKLY SW TO
NE...PASSING JUST SOUTH OF THE AREA. SFC LOW PRESSURE OFF THE MID
ATLANTIC THIS MORNING MOVES NORTHEAST TODAY...PASSING TO THE SOUTH
OF THE 40N/70W BENCHMARK.
BEST LIFT ASSOCIATED WITH UPPER SHORTWAVE AND JET WILL REMAIN TO THE
SOUTH OF THE AREA. ANALYSIS OF HIGH RES MODELS CONTINUES TO INDICATE
LIGHT PRECIP APPROACHING CSTL ZONES BY 12Z...WITH LIGHT PRECIP
IMPACTING CSTL ZONES FOR A SHORT PERIOD THIS MORNING INTO THE EARLY
AFTERNOON. CONCERN THOUGH FOR FALLING DEW POINTS THIS
MORNING...THUS PLENTY OF DRY AIR TO SATURATE.
SIMULATED REFLECTIVITY FROM LATEST HRRR AND WRF-NMM INDICATED
POTENTIAL LIGHT SNOW CLIPPING LONG ISLAND...WITH THE BEST CHANCE
FOR MEASURABLE SNOW CSTL AND EASTERN LI AND INTO SE CT.
SPOTTY LIGHT SNOW CAN BE EXPECTED ACROSS THE INTERIOR...WITH
LOWER CHANCES FOR MEASURABLE. WILL MAINTAIN SIMILAR POPS FROM
PREVIOUS...LAYERED FROM CHANCE NW TO LIKELY EAST. TIMING OF ANY
LIGHT SNOW THAT COULD POSSIBLY MEASURE WOULD BE 14Z THROUGH 19Z.
GENERALLY UNDER AN INCH FOR CSTL LOCALES WITH PERHAPS A COATING
ELSEWHERE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN 20
DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL PASS WELL TO THE SE OF THE TERMINALS TODAY. HIGH
PRESSURE BUILDS IN TONIGHT.
VFR TO START THE TAF PERIOD. LOWERING CLOUDS WITH PASSING LOW
PRESSURE MAY PRODUCE SOME LIGHT SNOW AND MVFR CIGS MAINLY FROM LATE
MORNING INTO EARLY AFTERNOON. HIGH CONFIDENCE IN VFR THIS EVENING.
N-NE WINDS 5-10 KT THIS MORNING BECOME 8-12 KT DURING THE LATE
MORNING AND AFTERNOON...THEN DIMINISH THIS EVENING.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KLGA FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KEWR FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KHPN FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
KISP FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z.
.OUTLOOK FOR 06Z FRI THROUGH MON...
.LATE THU NIGHT-SUNDAY...VFR.
.SUNDAY NIGHT-MON...LIGHT SNOW POSSIBLY MIXED WITH RAIN. MVFR CONDS
POSSIBLE.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. AFTER COLLAB WITH
SURROUNDING OFFICES...WILL ISSUE A SCA FOR THE OCEAN WATERS TODAY.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL SOUTH
OF LONG ISLAND...WILL COME CLOSE TO 25 KTS. IN ADDITION...SEAS PER
WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE BUOYS. BORDERLINE...BUT
SCA ALREADY IN EFFECT FOR THE WATERS OFF NJ AND NEW ENGLAND...SO
WILL FOLLOW FOR CONTINUITY.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KTS...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
A FEW HUNDREDTHS OF LIQUID EQUIVALENT IS POSSIBLE TODAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...BC/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...DS
MARINE...BC/PW
HYDROLOGY...BC/PW
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST THU FEB 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION TONIGHT. A
SOUTHERN STREAM STORM SHOULD PASS WELL TO OUR SOUTH ON THURSDAY...
BUT COULD BRING SOME LIGHT SNOW TO AREAS WELL SOUTH OF ALBANY...
WITH A WEAK DISTURBANCE PASSING BY TO THE NORTH... POSSIBLY
BRINGING SOME LIGHT SNOW TO THE REST OF THE REGION...ESPECIALLY
NORTH AND WEST OF ALBANY. ANOTHER HIGH PRESSURE AND MORE COLD
WEATHER WILL FINISH OFF OUR SECOND COLDEST FEBRUARY ON RECORD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM EST...A STORM SYSTEM IS LOCATED OVER THE SOUTHEAST
AND IS LIFTING NORTHEAST TOWARDS THE MID ATLANTIC STATES. ALTHOUGH
THE BULK OF THE MOISTURE WITH THIS SYSTEM IS SHIFTING OFFSHORE...A
LARGE SHIELD OF MID AND HIGH LEVEL CLOUDS ARE STREAMING UP FROM
THE SOUTHWEST TOWARDS OUR AREA. WITH LIGHT WINDS AND RELATIVELY
CLEAR SKIES IN PLACE...TEMPS HAVE DROPPED QUICKLY THIS EVENING
INTO THE SINGLE DIGITS AND TEENS. HOWEVER...TEMPS WILL STOP
FALLING AS FAST WITH THE CLOUDS MOVING INTO THE AREA. OVERNIGHT
LOWS WILL GENERALLY BE 0 TO 10...ALTHOUGH THE SRN ADIRONDACKS AND
LAKE GEORGE-GLENS FALLS AREA WILL SEE LOWS ZERO TO 10 BELOW...AS
CLOUDS WILL TAKE THE LONGEST TO REACH THOSE NORTHERN AREAS.
THE 04Z 3KM HRRR SHOWS IT REMAINING PRECIP FREE OVERNIGHT.
HOWEVER...SOME VERY LIGHT SNOW SHOWERS OR FLURRIES MAY TRY TO MOVE
TOWARDS THE MID HUDSON VALLEY TOWARDS SUNRISE...ALTHOUGH WITH VERY
DRY LOW LEVELS IN PLACE...IT/S EXPECTED THAT ANY OF THIS PRECIP
WILL LIKELY DRY UP BEFORE IT REACHES THE SURFACE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A POTENT SOUTHERN STREAM STORM LOOKS TO BRING A SIGNIFICANT
SNOWFALL TO THE SOUTHEAST AND MID ATLANTIC REGION. THIS STORM
SHOULD STAY WELL TO OUR SOUTH. HOWEVER...A WEAK DISTURBANCE IN THE
NORTHERN STREAM...NOTICEABLE ON THE H20 WATER VAPOR LOOP OVER
THE UPPER MIDWEST MIGHT HAVE JUST ENOUGH MOISTURE ON THE NORTHERN
FRINGE OF THE STORM...TO GENERATE A LITTLE LIGHT SNOW OR FLURRIES
IN OUR PARTS COME THURSDAY. ANY FLURRIES OR LIGHT SNOW LOOK TO
OVERSPREAD THE REGION AFTER DAYBREAK...BUT WILL MAINLY ONLY AFFECT
THE FAR SOUTHEASTERN AREAS OF THE CWA. AT MOST...A DUSTING OF SNOW
WILL OCCUR.
IT WILL COLD WITH MORE CLOUDS THAN SUNSHINE...ESPECIALLY ALBANY
SOUTHWARD. LOOK FOR HIGHS GENERALLY IN THE TEENS TO AROUND 20. A
NORTH WIND WILL AVERAGE 5 TO 15 MPH.
THURSDAY NIGHT...THE WEAK NORTHERN SYSTEM (AND THE MUCH STRONG
SOUTHERN STORM) WILL PULL AWAY AND ALLOW A LARGE HIGH PRESSURE TO
BUILD IN TO OUR SOUTH. THIS WILL PROVIDE ANOTHER SHORT OF VERY COLD
ARCTIC...NOT QUITE AS COLD AS ITS PREDECESSORS...BUT COLD ENOUGH TO
POTENTIALLY GIVE ALBANY TWO BELOW ZERO NIGHTS (THURSDAY AND FRIDAY
NIGHTS). OUTLYING AREAS LOOK TO REACH DOUBLE DIGITS BELOW ZERO EACH
NIGHT.
IF ALBANY WERE TO GO BELOW ZERO BOTH THESE THURSDAY AND FRIDAY
NIGHTS...WE WOULD TIE THE MOST NIGHTS BELOW ZERO IN ANY FEBRUARY
WITH 13 (LAST HAPPENED IN 1914). WE ALSO LOOK TO HAVE A LOCK ON THE
SECOND COLDEST FEBRUARY EVER AND STILL HAVE A SHOT AT OUR COLDEST ON
RECORD...12.1 DEGREES SET BACK IN 1934.
SUNSHINE ON FRIDAY AND ESPECIALLY SATURDAY SHOULD SEND HIGHS
GENERALLY BACK INTO THE TEENS FROM THE CAPITAL REGION
NORTHWARD...AND LOWER AND EVEN SOME MID 20S TO THE SOUTH OF ALBANY.
KEEP IN MIND NORMAL HIGHS FOR THE CAPITAL REGION WILL BE IN THE
UPPER 30S AT THIS POINT SO WE WILL STILL BE WAY BELOW AVERAGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST. IN ADDITION...THE STORM TRACK...WHICH HAS
BEEN TEMPORARILY DEFLECTED MAINLY SOUTH OF THE REGION IN THE NEAR-
AND SHORT-TERM...WILL BEGIN TO LIFT BACK NORTH...OFFERING SOME
THREATS FOR AT LEAST LIGHT-MODERATE PRECIP LATE SUN INTO EARLY
MON...THEN AGAIN FOR LATE TUE-WED. HERE ARE SOME MORE SPECIFICS...
SAT NT-MON...HIGH PRESSURE SHOULD BRING GENERALLY CLEAR AND COLD
CONDITIONS FOR SAT NT/SUN AM...WITH MIN TEMPS LIKELY FALLING BELOW
ZERO IN MOST AREAS. THEN...A PV ANOMALY IN THE NORTHERN STREAM IS
EXPECTED TO PASS NORTH OF THE GREAT LAKES LATER SUN INTO SUN NT.
SOME SOUTHERN STREAM MOISTURE...ASSOCIATED WITH A BROAD MID/UPPER
LEVEL SOUTHWEST FLOW MAY BECOME ENTRAINED INTO THE APPROACHING UPPER
LEVEL DYNAMICS WITH THIS SYSTEM...ALLOWING FOR LIGHT TO POSSIBLY
MODERATE SNOW TO DEVELOP SUN AFTERNOON/EVENING...AND CONTINUING INTO
MUCH OF SUN NT BEFORE TAPERING OFF FROM NW TO SE MON AM. QPF IS
HIGHEST ON THE ECMWF...WHERE AROUND 0.35-0.50 LIQUID EQUIVALENT IS
INDICATED...GREATEST FOR AREAS NEAR AND ESP NORTH OF INTERSTATE 90.
FORECAST THERMAL PROFILES APPEAR FAVORABLE FOR ALL SNOW...SO THERE
COULD BE SOME MODERATE AMTS...PARTICULARLY AGAIN IN THE MOHAWK
VALLEY/LAKE GEORGE/SARATOGA REGIONS INTO SOUTHERN VT. AT THIS
TIME...WILL INDICATE HIGH CHC POPS FOR LATE SUN...THEN LIKELY FOR
SUN NT FROM I-90 NORTHWARD...AND HIGH CHC TO THE SOUTH. TEMPS
SHOULD BE MAINLY IN THE 20S TO LOWER 30S FOR SUN MAXES...AND TEENS
TO LOWER/MID 20S IN VALLEY AREAS FOR SUN NT/MON AM...WARMEST
ACROSS THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD CO CT. ON
MON...AFTER ANY STEADIER PRECIP TAPERS OFF...CLOUDS AND SOME
SPOTTY FLURRIES OR EVEN DRIZZLE MAY LINGER...AS MAX TEMPS REACH
THE LOWER/MID 30S IN VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
MON NT-WED...HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION FOR MON NT-
EARLY TUE...BEFORE ANOTHER PV ANOMALY...THIS ONE ORIGINATING IN THE
SOUTHERN STREAM...APPROACHES FROM THE SOUTHWEST LATER TUE INTO WED.
THERE IS MUCH UNCERTAINTY REGARDING THIS FEATURE...AND WHETHER IT
SHEARS OUT IN THE STRONGLY MID/UPPER LEVEL SOUTHWEST CONFLUENT FLOW
EXTENDING FROM THE SOUTHERN ROCKIES INTO THE NORTHEAST STATES...AND
ALSO WHERE THE LOW/MID LEVEL THERMAL GRADIENT SETS UP. BOTH THE
12Z/25 GFS AND ECMWF SUGGEST THAT THE PV ANOMALY WEAKENS AS IT
TRACKS TOWARD THE GREAT LAKES REGION. HOWEVER...A SURGE OF
ISENTROPIC LIFT DEVELOPS AHEAD OF THE FEATURE...WITH VARYING DEGREES
ON NORTHWARD EXTENT AND RESULTING PRECIP. THE DETERMINISTIC GFS
SUGGEST POSSIBLY A QUICK SURGE OF SNOW OR A WINTRY MIX DEVELOPING
LATE TUE OR TUE NT...GRADUALLY TAPERING OFF WED AM...POSSIBLY AS A
LIGHT MIX OR EVEN RAIN/DRIZZLE...WHILE THE ECMWF SUGGESTS MOST OF
THE PRECIP TRACKS SOUTH OF THE REGION...WHICH IS MUCH FARTHER SOUTH
THAN ITS PREVIOUS CYCLES. MEANWHILE...THE 12Z/25 GEFS VARY
SIGNIFICANTLY IN HANDLING THE TRACK OF ANY ASSOCIATED SFC
SYSTEM...WITH SOME SUGGESTING A N/W TRACK ALLOWING FOR WARMING AND
MORE RAIN ACROSS THE REGION...AND OTHERS FURTHER S AND E WITH SNOW
OR A WINTRY MIX. AT THIS TIME...DUE TO SIGNIFICANT
UNCERTAINTY...WILL FAVOR A COLDER SOLUTION...BUT ALSO FURTHER N WITH
THE PRECIP...WITH CHANCES FOR SNOW FOR LATE TUE INTO EARLY WED. MON
NT/TUE AM SHOULD BE QUITE COLD WITH MINS MAINLY IN THE SINGLE DIGITS
TO LOWER TEENS...AND TUE MAXES IN THE 20S...WITH PERHAPS SOME LOWER
30S IN VALLEY AREAS SOUTH OF ALBANY. TUE NT/WED AM MINS SHOULD ONLY
FALL INTO THE 20S FOR MOST AREAS...WITH WED MAX TEMPS POSSIBLY
RISING INTO THE 30S FOR VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT SOUTHERN
STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST AND TRACKS
EAST-NORTHEAST OUT TO SEA. RIDGING WILL BUILD BACK IN AS THE STORM
MOVES FARTHER AWAY FROM THE COAST.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL OVERSPREAD THE REGION AND
THICKEN AND LOWER TODAY. THE NORTHERN EDGE OF THE PRECIPITATION
SHIELD ASSOCIATED WITH THE STORM IS EXPECTED TO POSSIBLY REACHED
KPOU WITH LIGHT SNOW THIS MORNING INTO THE EARLY AFTERNOON.
OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE OTHER TAF SITES
LATER IN THE AFTERNOON INTO THE EVENING WITH SOME FLURRIES
POSSIBLE.
LIGHT MAINLY NORTHWEST TO NORTHEAST WINDS ARE EXPECTED THROUGH THE
TAF PERIOD...06Z/FRIDAY.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV/FRUGIS
LONG TERM...KL
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1259 AM EST THU FEB 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION TONIGHT. A
SOUTHERN STREAM STORM SHOULD PASS WELL TO OUR SOUTH ON THURSDAY...
BUT COULD BRING SOME LIGHT SNOW TO AREAS WELL SOUTH OF ALBANY...
WITH A WEAK DISTURBANCE PASSING BY TO THE NORTH... POSSIBLY
BRINGING SOME LIGHT SNOW TO THE REST OF THE REGION...ESPECIALLY
NORTH AND WEST OF ALBANY. ANOTHER HIGH PRESSURE AND MORE COLD
WEATHER WILL FINISH OFF OUR SECOND COLDEST FEBRUARY ON RECORD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1259 AM EST...A STORM SYSTEM IS LOCATED OVER THE SOUTHEAST
AND IS LIFTING NORTHEAST TOWARDS THE MID ATLANTIC STATES.
ALTHOUGH THE BULK OF THE MOISTURE WITH THIS SYSTEM IS SHIFTING
OFFSHORE...A LARGE SHIELD OF MID AND HIGH LEVEL CLOUDS ARE
STREAMING UP FROM THE SOUTHWEST TOWARDS OUR AREA. WITH LIGHT WINDS
AND RELATIVELY CLEAR SKIES IN PLACE...TEMPS HAVE DROPPED QUICKLY
THIS EVENING INTO THE SINGLE DIGITS AND TEENS. HOWEVER...TEMPS
WILL STOP FALLING AS FAST WITH THE CLOUDS MOVING INTO THE AREA.
OVERNIGHT LOWS WILL GENERALLY BE 0 TO 10...ALTHOUGH THE SRN
ADIRONDACKS AND LAKE GEORGE-GLENS FALLS AREA WILL SEE LOWS ZERO TO
10 BELOW...AS CLOUDS WILL TAKE THE LONGEST TO REACH THOSE NORTHERN
AREAS.
THE 04Z 3KM HRRR SHOWS IT REMAINING PRECIP FREE OVERNIGHT.
HOWEVER...SOME VERY LIGHT SNOW SHOWERS OR FLURRIES MAY TRY TO MOVE
TOWARDS THE MID HUDSON VALLEY TOWARDS SUNRISE...ALTHOUGH WITH VERY
DRY LOW LEVELS IN PLACE...IT/S EXPECTED THAT ANY OF THIS PRECIP
WILL LIKELY DRY UP BEFORE TI REACHES THE SURFACE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A POTENT SOUTHERN STREAM STORM LOOKS TO BRING A SIGNIFICANT
SNOWFALL TO THE SOUTHEAST AND MID ATLANTIC REGION. THIS STORM
SHOULD STAY WELL TO OUR SOUTH. HOWEVER...A WEAK DISTURBANCE IN THE
NORTHERN STREAM...NOTICEABLE ON THE H20 WATER VAPOR LOOP OVER
THE UPPER MIDWEST MIGHT HAVE JUST ENOUGH MOISTURE ON THE NORTHERN
FRINGE OF THE STORM...TO GENERATE A LITTLE LIGHT SNOW OR FLURRIES
IN OUR PARTS COME THURSDAY. ANY FLURRIES OR LIGHT SNOW LOOK TO
OVERSPREAD THE REGION AFTER DAYBREAK...BUT WILL MAINLY ONLY AFFECT
THE FAR SOUTHEASTERN AREAS OF THE CWA. AT MOST...A DUSTING OF SNOW
WILL OCCUR.
IT WILL COLD WITH MORE CLOUDS THAN SUNSHINE...ESPECIALLY ALBANY
SOUTHWARD. LOOK FOR HIGHS GENERALLY IN THE TEENS TO AROUND 20. A
NORTH WIND WILL AVERAGE 5 TO 15 MPH.
THURSDAY NIGHT...THE WEAK NORTHERN SYSTEM (AND THE MUCH STRONG
SOUTHERN STORM) WILL PULL AWAY AND ALLOW A LARGE HIGH PRESSURE TO
BUILD IN TO OUR SOUTH. THIS WILL PROVIDE ANOTHER SHORT OF VERY COLD
ARCTIC...NOT QUITE AS COLD AS ITS PREDECESSORS...BUT COLD ENOUGH TO
POTENTIALLY GIVE ALBANY TWO BELOW ZERO NIGHTS (THURSDAY AND FRIDAY
NIGHTS). OUTLYING AREAS LOOK TO REACH DOUBLE DIGITS BELOW ZERO EACH
NIGHT.
IF ALBANY WERE TO GO BELOW ZERO BOTH THESE THURSDAY AND FRIDAY
NIGHTS...WE WOULD TIE THE MOST NIGHTS BELOW ZERO IN ANY FEBRUARY
WITH 13 (LAST HAPPENED IN 1914). WE ALSO LOOK TO HAVE A LOCK ON THE
SECOND COLDEST FEBRUARY EVER AND STILL HAVE A SHOT AT OUR COLDEST ON
RECORD...12.1 DEGREES SET BACK IN 1934.
SUNSHINE ON FRIDAY AND ESPECIALLY SATURDAY SHOULD SEND HIGHS
GENERALLY BACK INTO THE TEENS FROM THE CAPITAL REGION
NORTHWARD...AND LOWER AND EVEN SOME MID 20S TO THE SOUTH OF ALBANY.
KEEP IN MIND NORMAL HIGHS FOR THE CAPITAL REGION WILL BE IN THE
UPPER 30S AT THIS POINT SO WE WILL STILL BE WAY BELOW AVERAGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST. IN ADDITION...THE STORM TRACK...WHICH HAS
BEEN TEMPORARILY DEFLECTED MAINLY SOUTH OF THE REGION IN THE NEAR-
AND SHORT-TERM...WILL BEGIN TO LIFT BACK NORTH...OFFERING SOME
THREATS FOR AT LEAST LIGHT-MODERATE PRECIP LATE SUN INTO EARLY
MON...THEN AGAIN FOR LATE TUE-WED. HERE ARE SOME MORE SPECIFICS...
SAT NT-MON...HIGH PRESSURE SHOULD BRING GENERALLY CLEAR AND COLD
CONDITIONS FOR SAT NT/SUN AM...WITH MIN TEMPS LIKELY FALLING BELOW
ZERO IN MOST AREAS. THEN...A PV ANOMALY IN THE NORTHERN STREAM IS
EXPECTED TO PASS NORTH OF THE GREAT LAKES LATER SUN INTO SUN NT.
SOME SOUTHERN STREAM MOISTURE...ASSOCIATED WITH A BROAD MID/UPPER
LEVEL SOUTHWEST FLOW MAY BECOME ENTRAINED INTO THE APPROACHING UPPER
LEVEL DYNAMICS WITH THIS SYSTEM...ALLOWING FOR LIGHT TO POSSIBLY
MODERATE SNOW TO DEVELOP SUN AFTERNOON/EVENING...AND CONTINUING INTO
MUCH OF SUN NT BEFORE TAPERING OFF FROM NW TO SE MON AM. QPF IS
HIGHEST ON THE ECMWF...WHERE AROUND 0.35-0.50 LIQUID EQUIVALENT IS
INDICATED...GREATEST FOR AREAS NEAR AND ESP NORTH OF INTERSTATE 90.
FORECAST THERMAL PROFILES APPEAR FAVORABLE FOR ALL SNOW...SO THERE
COULD BE SOME MODERATE AMTS...PARTICULARLY AGAIN IN THE MOHAWK
VALLEY/LAKE GEORGE/SARATOGA REGIONS INTO SOUTHERN VT. AT THIS
TIME...WILL INDICATE HIGH CHC POPS FOR LATE SUN...THEN LIKELY FOR
SUN NT FROM I-90 NORTHWARD...AND HIGH CHC TO THE SOUTH. TEMPS
SHOULD BE MAINLY IN THE 20S TO LOWER 30S FOR SUN MAXES...AND TEENS
TO LOWER/MID 20S IN VALLEY AREAS FOR SUN NT/MON AM...WARMEST
ACROSS THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD CO CT. ON
MON...AFTER ANY STEADIER PRECIP TAPERS OFF...CLOUDS AND SOME
SPOTTY FLURRIES OR EVEN DRIZZLE MAY LINGER...AS MAX TEMPS REACH
THE LOWER/MID 30S IN VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
MON NT-WED...HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION FOR MON NT-
EARLY TUE...BEFORE ANOTHER PV ANOMALY...THIS ONE ORIGINATING IN THE
SOUTHERN STREAM...APPROACHES FROM THE SOUTHWEST LATER TUE INTO WED.
THERE IS MUCH UNCERTAINTY REGARDING THIS FEATURE...AND WHETHER IT
SHEARS OUT IN THE STRONGLY MID/UPPER LEVEL SOUTHWEST CONFLUENT FLOW
EXTENDING FROM THE SOUTHERN ROCKIES INTO THE NORTHEAST STATES...AND
ALSO WHERE THE LOW/MID LEVEL THERMAL GRADIENT SETS UP. BOTH THE
12Z/25 GFS AND ECMWF SUGGEST THAT THE PV ANOMALY WEAKENS AS IT
TRACKS TOWARD THE GREAT LAKES REGION. HOWEVER...A SURGE OF
ISENTROPIC LIFT DEVELOPS AHEAD OF THE FEATURE...WITH VARYING DEGREES
ON NORTHWARD EXTENT AND RESULTING PRECIP. THE DETERMINISTIC GFS
SUGGEST POSSIBLY A QUICK SURGE OF SNOW OR A WINTRY MIX DEVELOPING
LATE TUE OR TUE NT...GRADUALLY TAPERING OFF WED AM...POSSIBLY AS A
LIGHT MIX OR EVEN RAIN/DRIZZLE...WHILE THE ECMWF SUGGESTS MOST OF
THE PRECIP TRACKS SOUTH OF THE REGION...WHICH IS MUCH FARTHER SOUTH
THAN ITS PREVIOUS CYCLES. MEANWHILE...THE 12Z/25 GEFS VARY
SIGNIFICANTLY IN HANDLING THE TRACK OF ANY ASSOCIATED SFC
SYSTEM...WITH SOME SUGGESTING A N/W TRACK ALLOWING FOR WARMING AND
MORE RAIN ACROSS THE REGION...AND OTHERS FURTHER S AND E WITH SNOW
OR A WINTRY MIX. AT THIS TIME...DUE TO SIGNIFICANT
UNCERTAINTY...WILL FAVOR A COLDER SOLUTION...BUT ALSO FURTHER N WITH
THE PRECIP...WITH CHANCES FOR SNOW FOR LATE TUE INTO EARLY WED. MON
NT/TUE AM SHOULD BE QUITE COLD WITH MINS MAINLY IN THE SINGLE DIGITS
TO LOWER TEENS...AND TUE MAXES IN THE 20S...WITH PERHAPS SOME LOWER
30S IN VALLEY AREAS SOUTH OF ALBANY. TUE NT/WED AM MINS SHOULD ONLY
FALL INTO THE 20S FOR MOST AREAS...WITH WED MAX TEMPS POSSIBLY
RISING INTO THE 30S FOR VALLEYS...AND 25-30 ACROSS HIGHER ELEVATIONS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT SOUTHERN
STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST AND TRACKS
EAST-NORTHEAST OUT TO SEA. RIDGING WILL BUILD BACK IN AS THE STORM
MOVES FARTHER AWAY FROM THE COAST.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL OVERSPREAD THE REGION AND
THICKEN AND LOWER TODAY. THE NORTHERN EDGE OF THE PRECIPITATION
SHIELD ASSOCIATED WITH THE STORM IS EXPECTED TO POSSIBLY REACHED
KPOU WITH LIGHT SNOW THIS MORNING INTO THE EARLY AFTERNOON.
OTHERWISE MVFR CONDITIONS ARE POSSIBLE AT THE OTHER TAF SITES
LATER IN THE AFTERNOON INTO THE EVENING WITH SOME FLURRIES
POSSIBLE.
LIGHT MAINLY NORTHWEST TO NORTHEAST WINDS ARE EXPECTED THROUGH THE
TAF PERIOD...06Z/FRIDAY.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV/FRUGIS
LONG TERM...KL
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
424 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST COASTAL LOW CONTINUES TO LIFT NORTHEAST OFF THE CAROLINA
COAST. SNOW HAS BEEN REPORTED IN SOUTHERN DELMARVA, BUT AS OF 330 AM
REMAINS JUST SOUTH OF OUR CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
CEILINGS SHOULD GRADUALLY LOWER THROUGH 12Z AS SNOW APPROACHES FROM
THE SOUTH. STILL SOME UNCERTAINTY IF THE WESTERN TAF SITES, KABE AND
KRDG, WILL SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY SITES, KPHL,
KILG, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT SNOW IS
POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN WILL BE THE
LAST TO BE AFFECTED). AT KMIV AND KACY, MOSTLY LIGHT BUT SOME
PERIODS OF MODERATE TO HEAVY SNOW SNOW WILL BE POSSIBLE FOR A
MAJORITY OF THE MORNING. BY 18Z HOWEVER, SNOW SHOULD BE MOVING OUT
OF THE REGION, THOUGH TIME HEIGHT DISPLAYS OF THE GFS SHOW MVFR
CEILINGS LINGERING THROUGH THE DAY TIME HOURS.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>020-026-027.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ021>025.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ002.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EST THU FEB 26 2015
.DISCUSSION...
...A FEW STRONG STORMS POSSIBLE THIS MORNING WITH GUSTY WINDS...
TODAY-TONIGHT...PRE FRONTAL SQUALL LINE MOVING EASTWARD AT 40 TO
50 MPH WILL AFFECT THE NORTH HALF OF THE AREA BEFORE SUNRISE AND
AREAS SOUTHWARD THROUGH THE LATE MORNING. THE LINE SHOULD SLOW IN
SOUTHERN SECTIONS WHILE WEAKENING...BUT PERSIST THROUGH AFTERNOON
OR EARLY EVENING. LATEST HRRR MODEL SHOWS SOME REINVIGORATED
CONVECTION IN THE SOUTH THIS AFTERNOON AS SOME HEATING INTO THE
UPPER 70S OR LOWER 80S OCCURS.
DUE TO THE FAST CELL MOVEMENT...WILL HAVE TO WATCH FOR STRONG
WIND GUSTS ESPECIALLY THIS MORNING. BY AFTERNOON LOW LEVEL WIND
FIELDS WILL START TO EASE BUT STILL A QUITE FAST CELL MOTION WILL
PERSIST.
COLD FRONT WILL SLIDE INTO SOUTH FLORIDA THIS EVENING BUT
CONSIDERABLE CLOUDS WILL LINGER. ENOUGH DRYING SHOULD OCCUR TO
TAKE OUT MENTION OF SHOWER CHANCES BY LATE EVENING EXCEPT FOR THE
FAR SOUTH.
FRI-SAT...MODELS REMAIN IN FAIRLY GOOD AGREEMENT SHOWING FRONTAL
BOUNDARY MEANDERING OVER SOUTH FLORIDA DURING THE PERIOD. STOUT
SOUTHWEST AND WESTERLY FLOW ALOFT ON TOP OF SHALLOW NORTHERLY FLOW
AT THE SURFACE WILL KEEP CLOUD COVER HIGH THROUGH SATURDAY. WEAK
UPGLIDE IN TANDEM WITH SHORTWAVE ENERGY MOVING OVERHEAD WILL ALLOW
FOR SOME LIGHT RAIN SHOWERS TO DEVELOP...WITH THE BEST CHANCE
ACROSS OUR SOUTHERN ZONES. KEPT RAIN CHANCES BETWEEN 20 AND 30
PERCENT FOR THE PERIOD...MAINLY GIVEN THE FACT THAT RAINFALL
TOTALS ARE EXPECTED TO BE LIGHT.
HIGH PRESSURE MOVING OFF THE MID ATLANTIC COAST LATE SATURDAY INTO
SUNDAY WILL TRANSITION OUR WINDS ONSHORE. FAIRLY TIGHT GRADIENT
WILL PRODUCE BREEZY TO WINDY CONDITIONS...ESPECIALLY ALONG THE
COAST.
SUN-WED...BOUNDARY WILL MOVE BACK NORTH AS A WARM FRONT LATE THIS
WEEKEND...ALLOWING TEMPS TO CLIMB AND CLOUD COVER TO GRADUALLY
DECREASE. TEMPERATURES ABOVE CLIMO EXPECTED MONDAY AND CONTINUING
INTO MID WEEK AS RIDGING DEVELOPS TO OUR EAST. WARM SOUTHERLY FLOW
WILL ALLOW TEMPERATURES TO WARM INTO THE 80S ACROSS MUCH OF THE
AREA...EXCEPT ALONG THE IMMEDIATE COASTLINE WHERE TEMPERATURES WILL
BE MODERATED BY THE CHILLY ATLANTIC.
&&
.AVIATION...
FAST MOVING PRE FRONTAL SQUALL LINE WILL TRAVERSE MOST OF THE
TERMINALS EARLY THIS MORNING. SOME STRONG WIND GUSTS 40-50 MPH ARE
POSSIBLE. KVRB-KSUA SHOULD SEE A CHANCE FOR SHOWERS/STORMS FROM
LATE MORNING INTO THE AFTERNOON. BEHIND THE LINE...OCCASIONAL MVFR
CEILINGS ARE EXPECTED TO LINGER THROUGH TONIGHT.
&&
.MARINE...
TODAY-TONIGHT...GUSTY SOUTHWEST WINDS CURRENTLY OCCURRING AHEAD OF
COLD FRONT AND PRODUCING HAZARDOUS BOATING. ADDITIONALLY...A FAST
MOVING SQUALL LINE WILL AFFECT THE WATERS FROM CANAVERAL NORTHWARD
THROUGH SUNRISE. SHOWERS AND SLIGHT CHANCE OF STORMS WILL OCCUR
SOUTHWARD THROUGH LATE MORNING AND AFTERNOON.
MARINERS SHOULD EXPECT SPECIAL MARINE WARNINGS EARLY THIS
MORNING...ESPECIALLY SEBASTIAN INLET NORTHWARD.
GUSTY WINDS WILL PERSIST OFFSHORE UNTIL ABOUT MIDDAY. THEN AS
FRONTAL TROUGH MOVES THROUGH...EXPECT WEST/NORTHWEST WINDS 10-15
KNOTS THIS AFTERNOON AND TURNING NORTHERLY THIS EVENING.
FRI-SUN...NORTHERLY WINDS ON FRIDAY WILL BEGIN TRANSITIONING TO THE
NORTHEAST FRIDAY NIGHT AS HIGH PRESSURE BUILDS ACROSS THE EASTERN
US. THE LOCAL PRESSURE GRADIENT WILL TIGHTEN ON SATURDAY...
INCREASING ONSHORE WINDS TO 20 TO 25 KNOTS WITH HIGHER GUSTS. POOR
BOATING CONDITIONS WILL RESULT WITH SEAS OFFSHORE EXPECTED TO
BUILD UP TO 8 TO 10 FEET BY EARLY SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 67 46 62 52 / 60 10 10 30
MCO 70 51 67 53 / 60 10 20 30
MLB 73 53 67 59 / 70 30 30 30
VRB 78 58 69 61 / 70 50 30 30
LEE 67 49 66 50 / 50 10 10 30
SFB 68 47 65 51 / 60 10 20 30
ORL 69 49 66 52 / 60 10 20 30
FPR 79 57 70 62 / 70 50 30 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 AM EST THIS MORNING FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD
COUNTY LINE TO SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE
20-60 NM- SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM...LASCODY
LONG TERM....ULRICH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1258 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN FLORIDA THIS EVENING WILL TRACK
NORTHEASTWARD ALONG THE GEORGIA AND SOUTH CAROLINA COAST LATE
TONIGHT. COLD AND DRY HIGH PRESSURE WILL BUILD INTO THE AREA
FRIDAY AND SATURDAY. TEMPERATURES WILL REMAIN BELOW NORMAL.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WINTER STORM WARNING REMAINS IN EFFECT FOR PARTS OF THE NORTHERN
AND WESTERN FORECAST AREA.
PRECIPITATION HAS OVERSPREAD THE FORECAST AREA MAINLY ASSOCIATED
WITH ISENTROPIC LIFT...AND MOISTURE AND INSTABILITY AHEAD OF THE
MID-LEVEL SHORTWAVE TROUGH MOVING INTO THE AREA. THE MODELS
INDICATE THE GREATEST ISENTROPIC LIFT WILL OCCUR UNTIL AROUND 100
AM. SATELLITE TRENDS SUPPORT A PROGRESSIVE PATTERN. THE COLDEST
CLOUD TOPS INDICATING THE STRONGEST LIFT SHOULD SHIFT EAST OF THE
AREA BEFORE 100 AM.
THE LATEST OBSERVATIONS AND MODEL DATA INDICATE A MIX OF
RAIN...SLEET AND SNOW IN THE NORTH PART WHERE WE HAVE POSTED A
WINTER STORM WARNING. THE LATEST RAP HAS INDICATED A WARMING TREND
IN THE NORTH PART INDICATING PRECIPITATION MAY NOT BECOME ALL
SNOW. MOISTURE ALSO APPEARS TO BECOME SHALLOW AND BELOW THE SNOW
GROWTH AREA BEHIND THE MID-LEVEL SHORTWAVE TROUGH DURING THE
EARLY MORNING HOURS. THE MAIN PRECIPITATION TYPE MAY BECOME DRIZZLE
WITH FREEZING DRIZZLE POSSIBLE IN THE NORTH PART.
FARTHER SOUTH...THE LATEST RAP KEEPS THE LOWEST LAYERS ABOVE
FREEZING IN THE CSRA AND CENTRAL PART OVERNIGHT. THIS APPEARS ON
TRACK BASED ON OBSERVATION TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
THE SYSTEM RAPIDLY MOVES AWAY FROM THE REGION DURING THE DAY
THURSDAY. STILL PLENTY OF SHALLOW/LEVEL MOISTURE AROUND FOR
CLOUDS AND PERHAPS MORNING DRIZZLE. MODELS INDICATE UPPER LEVEL
ENERGY CROSSING THE REGION IN SOUTHWEST FLOW ALOFT. TEMPERATURES
WILL BE ABLE TO CLIMB BACK TO THE MIDDLE 40S ACROSS THE
SOUTH...WITH THE MIDDLE/UPPER 30S EXPECTED ACROSS THE NORTH WITH
SNOW COVER. LOWS IN THE MID 20S NORTH TO LOWER 30S SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LARGE COLD CANADIAN HIGH PRESSURE WILL BUILD EASTWARD FROM THE
CENTRAL MS RIVER VALLEY ON FRIDAY TO THE CENTRAL APPALACHIANS AND
OHIO VALLEY ON SATURDAY. DRY WEATHER WEATHER ALONG WITH BELOW NORMAL
TEMPERATURES EXPECT FRIDAY INTO SATURDAY WITH PWAT AT OR BELOW 0.50
INCHES. POSSIBLE WEDGE SET UP LATE IN THE WEEKEND WITH TROUGH/WEAK
LOW PRESSURE DEVELOPING ALONG THE SOUTH CAROLINA COAST. ISENTROPIC
LIFT AND INCREASING MOISTURE IS EXPECTED TO INCREASE SATURDAY NIGHT
INTO SUNDAY AS SURFACE HIGH PRESSURE MOVES OFF THE COAST AND A LOW
PRESSURE SYSTEM APPROACHES FROM THE WEST. CHANCE OF RAIN SUNDAY
THROUGH WEDNESDAY. SHOULD SEE WARMING TEMPERATURES MONDAY INTO
WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVER THE EASTERN CONUS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN RESTRICTIONS THROUGH THE TAF PERIOD.
RAIN CONTINUES TO CROSS THE TAF SITES ALONG WITH IFR...PATCHY
LIFR...CONDITIONS. LOW PRESSURE ALONG THE GA COAST WILL MOVE
NORTHWARD THROUGH THE TAF PERIOD WITH LOW LEVEL MOISTURE REMAINING
LINGERING. PRECIPITATION WILL REMAIN ALL RAIN THROUGH THE PERIOD
WITH RAIN DIMINISHING TO DRIZZLE DURING THE EARLY MORNING HOURS.
CIGS WILL IMPROVE TO MVFR AROUND 16Z WITH DRIZZLE COMING TO AN
END. WINDS WILL BE NORTHERLY AT 10 KNOTS OR LESS THROUGH
22Z...THEN DIMINISH TO LIGHT AND VARIABLE FOR THE REST OF THE
PERIOD.
EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN RESTRICTIONS
CONTINUING THROUGH FRIDAY AS A FRONTAL BOUNDARY REMAINS STALLED
ACROSS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR SCZ015-
016-020>022.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
255 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1037 PM MST WED FEB 25 2015
MVFR CONDITIONS ARE EXPECTED AT KGLD AND KMCK OVERNIGHT DUE TO
METARS UPSTREAM SHOWING MVFR CIGS. STRATUS WILL BE SLOW TO BREAK
UP AT KGLD. KMCK WILL BECOME VFR BY MIDDAY AND REMAIN VFR THROUGH
THE REST OF THIS FORECAST PERIOD. THE FORECAST SOUNDING FOR KGLD
INDICATES STRATUS SHOULD RETURN THURSDAY EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
159 AM EST THU FEB 26 2015
.UPDATE...
ISSUED AT 158 AM EST THU FEB 26 2015
UPDATED THE FORECAST TO HIGHLIGHT A BANDED AREA OF PRECIP THAT HAS
DEVELOPED ALONG A LINE FROM MT VERNON AND NORTHEAST THROUGH WEST
LIBERTY. THIS HAS DEVELOPED ALONG A 700MB LINE OF FRONTOGENESIS
AND WILL SATURATE THE LOWER LEVELS IN A SHORT PERIOD OF TIME. WITH
THIS...THE HRRR AND SREF INDICATE OF A PERIOD OF TIME RESIDENCE
TIME THROUGH THE NEXT COUPLE OF HOURS. THIS WILL BE ENOUGH PERIOD
OF TIME FOR GREATER THAN AN INCH TO POSSIBLY TWO INCHES ALONG THIS
LINE...ESPECIALLY WITH THE LOW THAT IS SLOW TO EXIT TO THE EAST. A
NEW ZFP HAS BEEN SENT OUT FOR THIS UPDATE AND THE WSW HAS BEEN
EXTENDED TO A TIER OF COUNTIES TO THE NORTH.
UPDATE ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM EST THU FEB 26 2015
LOW LEVEL CIGS AND SNOWFALL WILL CONTINUE TO CREEP NORTH AND
NORTHEASTWARD THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM TRACKS
EAST ACROSS THE APPALACHIAN RANGE TONIGHT. THESE BELOW IFR CIGS
AT TIMES AND LOW VISIBILITY WILL CONTINUE AT MOST OF THE TAF SITES
BESIDES SYM THROUGH 14Z. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE OR MAINLY OUT OF THE NORTH. HEADING INTO THE
AFTERNOON...THE SNOW WILL TRANSITION INTO UPSLOPE SNOW SHOWERS
THROUGH THE AFTERNOON WITH MAINLY FLURRIES AND A PERSISTENT MVFR
CIGS THROUGH THE REST OF THE TAF PERIOD. WINDS WILL INCREASE OUT
OF THE NORTHWEST THROUGH THIS PERIOD AS WELL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
KYZ058>060-068-069-079-080-083>088-106>120.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1222 AM EST THU FEB 26 2015
.UPDATE...
ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM EST THU FEB 26 2015
LOW LEVEL CIGS AND SNOWFALL WILL CONTINUE TO CREEP NORTH AND
NORTHEASTWARD THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM TRACKS
EAST ACROSS THE APPALACHIAN RANGE TONIGHT. THESE BELOW IFR CIGS
AT TIMES AND LOW VISIBILITY WILL CONTINUE AT MOST OF THE TAF SITES
BESIDES SYM THROUGH 14Z. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE OR MAINLY OUT OF THE NORTH. HEADING INTO THE
AFTERNOON...THE SNOW WILL TRANSITION INTO UPSLOPE SNOW SHOWERS
THROUGH THE AFTERNOON WITH MAINLY FLURRIES AND A PERSISTENT MVFR
CIGS THROUGH THE REST OF THE TAF PERIOD. WINDS WILL INCREASE OUT
OF THE NORTHWEST THROUGH THIS PERIOD AS WELL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR KYZ079-
080-083>088-107-109-110-112>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1133 PM EST WED FEB 25 2015
.UPDATE...
ISSUED AT 1125 PM EST WED FEB 25 2015
GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS AND NEAR
TERM GUIDANCE. SNOW HAS BEEN REPORTED TO BE REACHING THE GROUND
FROM MCCREARY COUNTY OVER TO KNOX COUNTY AND LESLIE COUNTY TO
LETCHER COUNTY. SOCIAL MEDIA WOULD INDICATE ABOUT HALF AN INCH OR
SO OF NEW SNOW IN HARLAN COUNTY. THE ONLY OTHER CHANGE WITH THIS
UPDATE WAS TO INCREASE QPF SLIGHTLY ALONG THE VA BORDER WHICH LED
TO SOLID 2 TO 3 INCH AMOUNTS FROM BELL COUNTY THROUGH HARLAN
COUNTY INTO LETCHER COUNTY. AT 2000 FEET AND ABOVE IN THESE
COUNTIES AS WELL AS PIKE COUNTY IN THE FLATWOODS AREAS TOTALS
AROUND 4 INCHES WILL BE POSSIBLE. THERE IS STILL SOME UNCERTAINTY
IN THE NORTHWARD EXTENT OF THE SHARP CUTOFF WITH SOME WAFFLING
FROM RUN TO RUN OF THE HRRR. HOWEVER...THE AVERAGE OF THE PAST FEW
HOURS STILL SUPPORTS THE CURRENT AREAL EXTENT OF THE ADVISORY.
UPDATE ISSUED AT 800 PM EST WED FEB 25 2015
SOME MINOR ADJUSTMENTS HAVE BEEN MADE TO HOURLY GRIDS FOR THE
OVERNIGHT PERIOD INTO EARLY ON THURSDAY. INITIALLY THESE WERE
BASED ON RECENT OBSERVATION AND RADAR TRENDS AS WELL AS THE RECENT
22Z AND 23Z HRRR RUNS WITH A CONSIDERATION OF 21Z SREF QPF AS
WELL. THIS LED TO COOLING OFF THE HIGHER TERRAIN WHERE WETBULBING
APPEARS TO ALREADY HAVE BEGUN AND QPF WAS NUDGED UP A TAD FOR
THESE HIGHER TERRAIN LOCATIONS BORDERING VA. THE TOP OF BLACK MTN
HAS AN RH NEAR 75 PERCENT.
AT THIS POINT...WE ARE IN THE WAIT FOR THE ATMOSPHERE TO CONTINUE
MOISTENING UP FROM THE TOP DOWN. UPSTREAM OF EASTERN KY...THE
SNOW IS NOW REACHING THE GROUND IN THE KTYS AND KGKT OR KNOXVILLE
AND SEVIERVILLE/GATLINBURG AREAS AS WELL AS AT KCSV AND KOQT.
BASED ON THIS...THE RECENT HRRR SEEMS TO HAVE A DECENT HANDLE ON
NORTHWARD PROGRESS OF THE AREA OF SNOW. THIS SHOULD BRING THE SNOW
INTO THE SOUTHERN PART OF THE CWA AROUND WHITLEY...HARLAN AND BELL
COUNTIES AROUND OR SHORTLY BEFORE 10 PM AND THEN GRADUALLY SPREAD
NORTH AND EAST. HOWEVER...THE 18Z OPERATIONAL RUNS AND THE RECENT
NEAR TERM GUIDANCE SUCH AS THE HRRR RUNS INDICATE THAT THE SNOW
WILL PROBABLY NOT MAKE IT MUCH FURTHER NORTH THE NORTHERN END OF
THE ADVISORY AS THERE WILL BE A SHARP NORTH OR NORTHWEST CUTOFF.
IN FACT...ACROSS THE NORTHERN TIER OF THE ADVISORY AMOUNTS COULD
RANGE FROM NOT MORE THAN A DUSTING IN THE NORTHERN OR NORTHWESTERN
END OF THE COUNTIES TO AN INCH OR MORE IN THE SOUTHERN END OF
THESE COUNTIES. IT STILL APPEARS THAT 2 TO 3 INCHES SHOULD BE
COMMON FROM SOUTHERN WHITELY COUNTY THROUGH BELL COUNTY NORTHEAST
ACROSS HARLAN AND LETCHER COUNTIES TO SOUTHERN PIKE COUNTY.
AMOUNTS AROUND 4 INCHES CANNOT BE RULED OUT ABOVE 3000 FEET.
POPS WERE RAISED FROM LIKELY TO CATEGORICAL FOR NEARLY ALL OF THE
AREA OF THE COUNTIES ON THE NORTHERN END OF THE ADVISORY. THE
SLIGHTLY HIGHER QPF LED TO SLIGHTLY HIGHER SNOWFALL FOR ELEVATIONS
OF 2000 FEET AND ABOVE FROM BELL COUNTY NORTHEAST TO EXTREME
SOUTHERN PIKE COUNTY. ATTM...THE ADVISORY CONTINUES TO REMAIN
VALID AND NO CHANGES ARE EXPECTED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 500 PM EST WED FEB 25 2015
20Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE APPROACHING FROM
THE NORTHWEST WHILE ANOTHER IS MOVING IN FROM THE SOUTHWEST. IT IS
THIS SOUTHERN ONE WITH ITS WELL DEVELOPED PCPN SHIELD THAT WILL
GIVE MUCH OF THE AREA A DECENT CHANCE OF ACCUMULATING SNOW LATER
TONIGHT. UNDER OVERCAST SKIES TEMPERATURES ARE PEAKING INTO THE
MID 30S WHILE THE DEWPOINTS ARE STILL IN THE MID TEENS MOST
PLACES...THOUGH LOW 20S ARE FOUND IN THE FAR SOUTHWEST PARTS OF
THE CWA. WINDS ARE GENERALLY FROM THE NORTHEAST AT AROUND 5 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH A DAMPENING BUT STILL
RATHER ROBUST SOUTHERN STREAM WAVE MOVING THROUGH THE SOUTHERN
APPALACHIANS. THIS IS TRAILED BY A ANOTHER...MORE BROAD...UPPER
LEVEL TROUGH THAT WILL CROSS THE OHIO VALLEY LATER THURSDAY AND
INTO THURSDAY NIGHT. AT THE SAME TIME...ANOTHER WEAKER WAVE WILL
PASS SOUTH OF KENTUCKY IN THE SOUTHERN STREAM. THESE STREAMS
REMAIN SEPARATE ENOUGH THROUGH THE SHORT TERM PORTION OF THE
FORECAST THAT THEIR SFC REFLECTIONS WILL LIKEWISE REMAIN ON THE
WEAKER SIDE OF POTENTIAL. GIVEN THE MODEL AGREEMENT ALOFT...AND
THE HIGHER RESOLUTION OF THE NAM12 AND HRRR...HAVE FOLLOWED THOSE
LATTER MODELS MOST CLOSELY FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE EXPANDING NORTHERN FRINGE OF THE
SOUTHERN LOW STRAFING EASTERN KENTUCKY WITH SNOW ARRIVING SHORTLY
AFTER SUNSET AND THEN QUICKLY SPREADING NORTHEAST INTO THE LATTER
PART OF THE EVENING. THE DYNAMICS OF THIS SYSTEM AS SEEN IN THE
HIGHER RESOLUTION MODELS SUGGEST THAT THE SNOW COULD COME DOWN
BRIEFLY HEAVY WHEN IT SETS IN. THE LAST COUPLE OF RUNS OF THE
HRRR AND THE 18Z NAM12 DID PUSH SOME OF THE HIGHER QPF AND OMEGA A
TAD FURTHER NORTH INTO EASTERN KENTUCKY. SO WITH THIS AGREEMENT
AND THE POTENTIAL FOR QUICK ACCUMULATIONS HAVE DECIDED TO ADD
SEVERAL MORE COUNTIES TO THE INITIAL ADVISORY FROM MARTIN WEST TO
OWSLEY COUNTY. OTHERWISE...THE FORECAST IS ON TRACK WITH BETWEEN 1
AND 2 INCHES OF ACCUMULATION POSSIBLE MOST PLACES IN THE
ADVISORY...A BIT LESS IN THE WEST AND NORTH WITH HIGHER AMOUNTS
CLOSER TO THE VIRGINIA BORDER...PARTICULARLY FOR ELEVATIONS ABOVE
2500 FEET.
THE SNOW WILL TAPER TO FLURRIES AND POSSIBLE END FOR A TIME OVER
MOST OF THE AREA BY MIDDAY THURSDAY BEFORE THE APPROACH OF THAT
NEXT MID LEVEL TROUGH AND A SFC ARCTIC FRONT. SIMILAR TO SOME OF
THE FRONTS WE HAVE SEEN SO FAR THIS WINTER...WE EXPECT SNOW SHOWER
DEVELOPMENT ALONG AND BEHIND IT INTO THE NIGHT THURSDAY WITH BEST
LIFT AND FORCING TAKING PLACE IN THE EVENING. UP TO AN INCH OF
ADDITIONAL ACCUMULATION WILL BE POSSIBLE FROM THIS SET UP...BUT
MOST PLACES WILL SEE JUST A DUSTING OR TWO OF ACCUMULATION. ARCTIC
TEMPERATURES WILL SEND READINGS INTO THE TEENS MOST PLACES BY
FRIDAY MORNING.
USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS THROUGH THE
DAY THURSDAY...WITH SOME TERRAIN BASED ADJUSTMENTS. AFTER THAT
FAVORED THE SUPERBLEND INTO FRIDAY MORNING FOR A STARTING POINT.
AS FOR POPS...ENDED UP ON THE HIGH SIDE OF GUIDANCE THROUGH THE
PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 345 PM EST WED FEB 25 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 735 PM EST WED FEB 25 2015
EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE FIRST PART OF THE
TAF PERIOD. LOOK FOR HIGH CIGS TO DROP TOWARD MVFR BY 02Z IN THE
FAR SOUTH AND BETWEEN 4Z AND 8Z AT THE TAF SITES AS SNOW MOVES
INTO THE AREA FROM THE SOUTH...AS THE ATMOSPHERE SATURATES...CIGS
AND OR VIS OF IFR OR LOWER WILL BE POSSIBLE FOR A FEW HOURS.
THESE LOWER CIGS WILL ACCOMPANY THE NORTHERN FRINGE OF A
SIGNIFICANT WINTER STORM SYSTEM PASSING THROUGH THE SOUTHEAST
PARTS OF THE NATION BRINGING A PERIOD OF SNOW TO THE AREA. THE
HEAVIEST AND HARDEST OF THE SNOW SHOULD FALL SOUTHEAST OF
SME...LOZ...JKL AND SJS. SYM WILL BE LEAST AFFECTED. THE SNOW
WILL TAPER OFF AND CIGS WILL START TO IMPROVE 11Z TO 16Z. WINDS
WILL BE LIGHT AND VARIABLE THROUGH LATE EVENING FOR MOST PLACES
BEFORE SWITCHING TO THE NORTHEAST AND NORTH AT BETWEEN 5 AND 10
KTS 10Z TO 16Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR KYZ079-080-
083>088-107-109-110-112>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1158 PM CST WED FEB 25 2015
.UPDATE...
ISSUED AT 1157 PM CST WED FEB 25 2015
SATELLITE SHOWS MID-LVL OVC HEADING SE AND THIS WILL RETARD THE
TEMP FALL THE REST OF THE NIGHT. SO LOW TEMPS WERE NUDGE UP 3-4F
AND FCST SKY COVER WAS INCREASED SUBSTANTIALLY. RADAR AND SFC OBS
SHOW FLURRY ACTIVITY DIMINISHING AND LIMITED TO MAINLY THE SE 1/4
OF THE FCST AREA. HJH DROPPED BRIEFLY TO 2.5 MI AT 1135 PM. THERE
ARE STILL SOME FLURRIES OVER THE SANDHILLS. WILL NEED TO MONITOR
FOR POTENTIAL INCLUSION INTO THE WRN PART OF THE FCST AREA
OVERNIGHT. OTHERWISE...NO CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
LATEST RADAR SHOWS THE RAIN AND SNOW IS MOVING OUT OF THE FORECAST
AREA THIS AFTERNOON. THERE HAVE BEEN A FEW FLURRIES BEHIND THE MAIN
BAND...BUT EVEN THOSE ARE DIMINISHING THIS AFTERNOON. SURFACE
ANALYSIS HAS THE COLD FRONT ALREADY THROUGH THE FORECAST AREA AND
GUSTY NORTH WINDS ACROSS THE AREA. TEMPERATURES HAVE BEEN FALLING
FOR MUCH OF THE AREA THIS AFTERNOON.
MAIN QUESTION THIS AFTERNOON IS HOW QUICKLY THE PRECIPITATION WILL
MOVE OUT OF THE FORECAST AREA. THE RAP AND THE WRF BOTH INDICATE THE
PRECIPITATION SHOULD BE AN AFTERNOON EVENT AND BE DONE BEFORE THIS
EVENING. EVEN THE NAM AND THE GFS HAS IT ENDING BEFORE 00Z. WILL
START THE EVENING WITH A DRY FORECAST.
A SURFACE HIGH PRESSURE BUILDS IN THE DAKOTAS TONIGHT AND THURSDAY.
THIS WILL PUSH THE MOISTURE AND CLOUDS OUT OF THE AREA. SINCE THE
CENTER OF THE HIGH REMAINS TO THE NORTHEAST THROUGH THE
PERIOD...THERE WILL BE A FEW CLOUDS AROUND...BUT EXPECT CLOUDS TO
DIMINISH GRADUALLY LATE TONIGHT INTO THURSDAY.
THE COLD AIR HAS ALREADY STARTED TO MOVE INTO THE AREA THIS
AFTERNOON AND TEMPERATURES FOR MUCH OF THE AREA ARE COOLER NOW THAN
EARLIER. THE TEMPERATURES WILL CONTINUE TO PLUMMET TONIGHT WITH THE
DIMINISHING CLOUDS. THE COLD AIR REMAINS FIRMLY IN PLACE FOR
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM CST WED FEB 25 2015
THE FOCUS OF THE LONG TERM FORECAST CENTERS AROUND PRECIPITATION
CHANCES OVER THE WEEKEND AND BEGINNING OF THE WORK WEEK AS WELL AS
BELOW NORMAL TEMPERATURES.
HEADING INTO THE LONG TERM...A DEEP UPPER LEVEL TROUGH WILL DIG
SOUTH ACROSS THE WESTERN COAST PROVIDING OUR WINTER WEATHER FOR THE
NEXT SEVERAL DAYS. THIS TROUGH WILL ALLOW MULTIPLE DISTURBANCES TO
TREK ACROSS THE CENTRAL PLAINS...WITH THE FIRST PASSING THROUGH
DURING THE WEEKEND TIMEFRAME AND THE SECOND HITTING MONDAY INTO
TUESDAY.
BY SATURDAY MORNING THE MAIN UPPER LEVEL LOW WILL BE POSITIONED
ALONG THE CALIFORNIA NEVADA BORDER WITH THE MID LEVEL LOW SLIGHTLY
EAST. THE FIRST ROUND OF MID LEVEL WAVES WILL BEGIN TO SLIDE THROUGH
THE PLAINS BY SATURDAY MORNING AHEAD OF THE PARENT LOW SYSTEM. IN
ADDITION TO THE WAVE...WARM AIR ADVECTION ACROSS THE PLAINS WILL
FUEL PLENTY OF MID LEVEL MOISTURE ACROSS THE REGION. WHILE THE GFS
IS STRONGER THAN THE ECMWF...BOTH MODEL SOLUTIONS SUGGEST GOOD
ISENTROPIC LIFT ESPECIALLY ACROSS KANSAS THROUGH THE WEEKEND.
FINALLY...A COLD FRONT WILL SLIDE THROUGH THE AREA SUNDAY MORNING
WITH AT LEAST SOME FRONTOGENETIC LIFT ALONG ITS BOUNDARY. ALTHOUGH
THIS IS NOT A MAJOR SYNOPTIC SETUP...BUT RATHER A MINOR
WAVE...SEVERAL KEY COMPONENTS ARE COMING TOGETHER TO FORM A DECENT
CHANCE FOR SNOW SATURDAY INTO SUNDAY MORNING. WITH MODEL AGREEMENT
LEANING TOWARDS BETTER LIFT OVER KANSAS...PLACED HIGHER AMOUNTS OVER
NORTH CENTRAL KANSAS. CURRENT MODEL TRENDS INDICATE THE POTENTIAL
FOR AT LEAST A COUPLE OF INCHES OF SNOW BY THE END OF THE WEEKEND
ACROSS NORTH CENTRAL KANSAS...POSSIBLY ADVISORY CRITERIA...WITH
LESSER AMOUNTS FARTHER NORTH.
THE NEXT SYSTEM SLIDES THROUGH MONDAY INTO TUESDAY...AND IS SOMEWHAT
MORE INTRIGUING. WHILE THE MAIN UPPER LEVEL LOW SLOWLY SHIFTS ACROSS
THE ROCKY MOUNTAINS...THE MID LEVEL LOW SURGES NORTHWARD ACROSS
NORTHERN NEBRASKA AND DAKOTAS. STRONG WARM AIR ADVECTION AND
SOUTHEASTERLY WINDS WILL BRING PLENTY OF MOISTURE AGAIN TO THE
CENTRAL PLAINS. ISENTROPIC LIFT IS BETTER IN BOTH THE GFS AND ECMWF
THAN THE WEEKEND STORM. AND ANOTHER COLD FRONT WILL DRAG ACROSS THE
CWA BY TUESDAY AFTERNOON. LOOKING AT ANOTHER ROUND OF SNOW FOR THE
FORECAST AREA. AT THIS TIME...ITS TOO EARLY TO DETERMINE
AMOUNTS...BUT RIGHT NOW MODELS FOCUS HEAVIER BANDS NORTH OF
INTERSTATE 80.
COLD TEMPERATURES CONTINUE THROUGHOUT THE LONG TERM...WITH AT LEAST
TWO SHOTS OF REINFORCING COLD AIR...AND LITTLE TO ANY WARM UPS. BOTH
COLD FRONTS...SUNDAY AND TUESDAY BRING VERY COLD 850 MB AIR TO THE
REGION...THE COLDER OF THE TWO ON TUESDAY. 850 TEMPERATURES DIP TO
NEAR 15 DEGREES BELOW BY WEDNESDAY AFTER THE COLD FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT)
ISSUED AT 1157 PM CST WED FEB 25 2015
REST OF TONIGHT: VARIABLE BETWEEN VFR AND MVFR...BUT TRENDING MORE
TOWARD VFR. SOME MVFR CIGS 2000-2500 FT REMAIN BUT ARE NOT SOLID.
EAR HAS A BETTER CHANCE OF OCCASIONAL MVFR CIGS THRU 09Z.
OTHERWISE VFR CIGS AROUND 10K FT. N WINDS WILL CONT GUSTING TO
NEAR 30 KTS AT TIMES. CONFIDENCE: MEDIUM
THU: SOME SCT STRATOCU MAY REMAIN THRU THE MORNING. THERE IS A LOT
OF UNCERTAINTY AS TO WHAT OCCURS WITH THE MID-LVL CIGS AROUND 10K
FT AS THE MODELS DO NOT HAVE A GOOD HANDLE VS WHAT IS ACTUALLY
OCCURRING ON SATELLITE. SO WHILE WE HAVE INDICATED SKC...WE MAY
NEED TO INCLUDE SOME SCT-BKN 10K FT CLOUDS AS WE MONITOR TRENDS.
GUSTINESS ENDS WITH N WINDS SETTLING AROUND 15 KTS. CONFIDENCE:
MEDIUM
THU EVE: VFR SKC. WINDS DECREASE BELOW 10 KTS AND SHIFT TO NE.
CONFIDENCE: MEDIUM
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...JCB
LONG TERM...SALTZMAN
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
EARLY ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM OVER THE CAROLINAS WILL TRACK NORTHEAST TO CAPE
HATTERAS...THEN OUT TO SEA LATER TODAY. THE NORTHERN EDGE OF IT/S
PRECIP SHEILD COULD GRAZE KLNS WITH A BRIEF PERIOD OF LGT
SNOW/LOW VSBYS BTWN 12Z-15Z BASED ON LATEST NEAR TERM MDL
GUIDANCE. CONFIDENCE ABOUT 50/50 WHETHER KLNS SEES IFR VSBYS. CHC
OF IFR VSBY AT KMDT BTWN 12Z-15Z IS EVEN LOWER...BUT NOT ZERO.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
217 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE
AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH CLOUDS NOW COVER THE AREA AND THE DOUGHNUT OF SNOW ALOFT
SHOULD SLOWLY CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY
SUNRISE RIGHT ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE
JET IS ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES
ACROSS THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER
MDLS/ENSEMBLE MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE
FAR SE AND OVER THE NW MTNS. SO WILL KEEP THE LIKELY POPS CONFINED
TO THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE
WILL BE AN INCH OR LESS...WITH A DUSTING TO AN INCH IN MOST
PLACES ALONG THE MD BORDER AND IN THE LAURELS AND NW. THE WEAKNESS
IN THE LIFT AND PERSISTENT NORTHERLY FLOW TODAY WILL KEEP THE LOW
LEVELS VERY DRY IN THE CENTRAL AND NERN PARTS OF THE CWA.
THEREFORE...HAVE JUST PUT IN SOME FLURRIES THERE. THE LOW ZIPS
AWAY AND ANY SNOW IN THE SE SHOULD MOVE AWAY/STOP BY NOON. THE
WINDS BACK TO THE NW AND SOME SNOW SHOWERS WILL REMAIN IN THE WRN
MTNS ALL DAY. TEMPS SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE
DAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND HOLD ON IN THE
LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS THURSDAY NIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE UPPER SINGLE DIGITS TO L-M20S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM OVER THE CAROLINAS WILL TRACK NORTHEAST TO CAPE
HATTERAS...THEN OUT TO SEA LATER TODAY. THE NORTHERN EDGE OF IT/S
PRECIP SHEILD COULD GRAZE KLNS WITH A BRIEF PERIOD OF LGT
SNOW/LOW VSBYS BTWN 12Z-15Z BASED ON LATEST NEAR TERM MDL
GUIDANCE. CONFIDENCE ABOUT 50/50 WHETHER KLNS SEES IFR VSBYS. CHC
OF IFR VSBY AT KMDT BTWN 12Z-15Z IS EVEN LOWER...BUT NOT ZERO.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 24TH...IPT 18.4...MDT 21.2.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
145 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE
AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH CLOUDS NOW COVER THE AREA AND THE DOUGHNUT OF SNOW ALOFT
SHOULD SLOWLY CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY
SUNRISE RIGHT ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE
JET IS ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES
ACROSS THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER
MDLS/ENSEMBLE MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE
FAR SE AND OVER THE NW MTNS. SO WILL KEEP THE LIKELY POPS CONFINED
TO THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE
WILL BE AN INCH OR LESS...WITH A DUSTING TO AN INCH IN MOST
PLACES ALONG THE MD BORDER AND IN THE LAURELS AND NW. THE WEAKNESS
IN THE LIFT AND PERSISTENT NORTHERLY FLOW TODAY WILL KEEP THE LOW
LEVELS VERY DRY IN THE CENTRAL AND NERN PARTS OF THE CWA.
THEREFORE...HAVE JUST PUT IN SOME FLURRIES THERE. THE LOW ZIPS
AWAY AND ANY SNOW IN THE SE SHOULD MOVE AWAY/STOP BY NOON. THE
WINDS BACK TO THE NW AND SOME SNOW SHOWERS WILL REMAIN IN THE WRN
MTNS ALL DAY. TEMPS SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE
DAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND HOLD ON IN THE
LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS THURSDAY NIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE UPPER SINGLE DIGITS TO L-M20S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
ARCTIC COLD FRONT WILL MOVE EAST OF THE AIRSPACE LATER THIS
EVENING. LACK OF SFC CONVERGENCE ALONG AND AHEAD OF THE FRONT HAS
HELPED TO ERODE PRACTICALLY ALL OF THE PREVIOUS...SHALLOW STRATO
CU CLOUDS.
THIN SCT CIRRUS WILL GRADUALLY THICKEN UP AND LOWER FROM SW TO NE
OVERNIGHT...BUT CONDITIONS WILL STAY VFR FOR MOST OF THE
OVERNIGHT. THE LONE EXCEPTION MAY BE AT KJST THAT COULD DIP TO
MVFR CIGS AROUND DAYBREAK THURSDAY.
MDT STRONG NW WINDS WITH THE FRONT WILL BE DECREASING AND VEERING
AROUND THROUGH THE NORTH TONIGHT...THEN TO THE NORTHEAST BY
DAYBREAK THURSDAY.
ISOLATED TO SCATTERED SNOW SHOWERS EXPECTED FOR THURSDAY...WITH
CLOUD BASES MAINLY AOA 4KFT AGL. AREAS OF MVFR CIGS AND VSBYS IN
MORE FREQUENT SNOW SHOWERS EXPECTED AT KJST AND KBFD.
OUTLOOK...
THU NIGHT...AREAS OF MVFR /MAINLY ACROSS THE NRN AND WRN MTNS/ SCTD
SNOW SHOWERS.
FRI...MAINLY DRY WITH VFR CONDITIONS.
SAT...DRY WEATHER EXPECTED WITH VFR CONDITIONS.
SUN...VFR CONDITIONS EARLY...THEN A CHANCE OF
MIXED PRECIPITATION LATE.
MON...WINTRY PCPN PSBL WITH REDUCTIONS...IMPROVING CONDS LATE.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 24TH...IPT 18.4...MDT 21.2.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...TYBURSKI
AVIATION...LAMBERT/GARTNER
CLIMATE...
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
920 PM MST WED FEB 25 2015
.UPDATE...
ISSUED AT 916 PM MST WED FEB 25 2015
LATEST RADAR IMAGERY...INFRARED SATELLITE IMAGERY AND AREA
OBSERVATIONS ARE ALL SHOWING SNOW EASING OVER THE AREA. WENT AHEAD
AND CANCELLED SNOW ADVISORY EARLY AS FURTHER ACCUMULATING SNOW NO
LONGER EXPECTED. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 309 PM MST WED FEB 25 2015
SFC COLD FRONT HAS SLID SOUTH OF THE CWFA TODAY LEAVING NORTHERLY
LLVL WINDS IN ITS WAKE. MODERATE TO AT TIMES HEAVY BANDS OF SNOW
DEVELOPED INITIALLY OVR THE HIER TERRAIN AS WELL AS ACROSS
NORTHEASTERN LARAMIE COUNTY. THIS POCKET OF MODERATE SNOW EXPANDED
AS IT SHIFTED WEST THRU MUCH OF THE DAY WITH THE MOST INTENSE AXIS
AT 21Z SETTLING ON THE SRN LARAMIE RANGE. LATEST SATELLITE PIX
SHOW CONVECTIVE ELEMENTS ESPECIALLY OVR THE HIER TERRAIN OF SRN
CARBON COUNTY WHERE INSTABILITY WAS PROGD TO BE THE GREATEST.
AREAS OF BLOWING SNOW IS ALSO A CONCERN WITH RECENT WIND GUSTS
OBSERVED AT 25- 35 MPH ACROSS SE WYOMING. IN AN EARLIER UPDATE
EXPANDED THE WINTER WEATHER ADVISORY INTO ARLINGTON AS WELL AS OVR
THE SRN LARAMIE RANGE FOOTHILLS LARAMIE COUNTY...WHERE SNOWFALL
RATES FROM BOTH WEBCAMS AND KCYS RADAR RETURNS WERE THE GREATEST.
THESE SNOWFALL RATES WILL WANE SOMEWHAT WITH INSTABILITY LOSS THIS
EVENING...THOUGH LINGERING LIGHT SNOW WILL STILL BE A GOOD
POSSIBILITY. IF SNOWFALL RATES ALLOW...EVENING SHIFT MAY BE ABLE
TO CANX THE ADVISORY EARLY. A COLD NIGHT AHEAD...ESPECIALLY ACROSS
SOUTHEAST WYOMING WHERE THE COMBINATION OF FRESH SNOWPACK AND SOME
LLVL CAA PLUMMET LOW TEMPERATURES TO AROUND 0F IN THE LARAMIE
VALLEY AND SINGLE DIGITS ELSEWHERE.
ALTHOUGH BEST SHORTWAVE ENERGY SHIFTS SOUTH OVERNIGHT...LLVL
FRONT WILL BECOME STATIONARY ACROSS CARBON COUNTY AT LEAST THRU
THE DAY ON THURSDAY. MODELS SUGGEST A SECONDARY SHORTWAVE WILL
PUSH ATOP THE FRONT PRODUCING SOME PERIODS OF LIGHT SNOW OR
FLURRIES. HIER ELEVATIONS AND AREAS NR THE CO/WY STATELINE WILL
HAVE THE BEST OPPORTUNITY TO SEE LT SNOW ON THURSDAY. ANY
ACCUMULATIONS WILL BE VERY LIGHT WITH PERHAPS UP TO AN INCH
POSSIBLE. THURSDAY WILL BE COLDER HOWEVER WITH HIGHS THAT WILL
RISE GENERALLY JUST INTO THE TEENS.
THE PATTERN BEGINS TO FLATTEN ON FRIDAY AS THE NEXT UPSTREAM
TROUGH CARVES TOWARDS THE GREAT BASIN. LLVL FLOW TURNS SOUTHEAST
AHEAD OF IT WHICH IS TYPICALLY A FAVORABLE FOG PATTERN FOR THE
CHEYENNE RIDGE AND LARAMIE COUNTY. SO IT WILL LIKELY BE A
CLOUDY/FOGGY START TO THE DAY FOR FRIDAY. FLATTENING FLOW WILL
PUSH THE FRONT EAST TO AROUND THE LARAMIE RANGE BY LATE FRIDAY.
THIS WILL HELP TEMPERATURES UP A FEW DEGREES WITH TEENS AND 20S
EXPECTED MOST AREAS. OUTSIDE OF MOUNTAIN LOCATIONS...SNOW CHANCES
WILL BE MINIMAL ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 309 PM MST WED FEB 25 2015
SATURDAY...ARCTIC AIR REMAINS ENTRENCHED THUS STILL WELL BELOW
NORMAL TEMPERATURES. SUFFICIENTLY MOIST AIRMASS PROGGED AND WITH
SOUTHWEST FLOW ALOFT AND AN APPROACHING SHORTWAVE TROUGH ALOFT AND
OROGRAPHICS...WILL SEE WIDESPREAD SNOWS OVER THE SNOWY AND SIERRA
MADRE RANGES WITH SCATTERED SNOW SHOWERS NEARBY.
SUNDAY...MOIST SOUTHWEST FLOW ALOFT CONTINUES PRODUCING WIDESPREAD
OROGRAPHIC SNOWS OVER OUR NORTHERN LARAMIE...SNOWY AND SIERRA MADRE
RANGES WITH MOSTLY DRY CONDITIONS ELSEWHERE. CONTINUED COLD WITH
ARCTIC AIR ENTRENCHED.
MONDAY...ARCTIC AIR WILL RETREAT EASTWARD WITH TEMPERATURES WARMING.
GFS LOOKS OVERDONE WITH QPF WITH THE SHORTWAVE TROUGH ALOFT MOVING
ACROSS AND PREFER THE LESS AMPLIFIED AND DRIER ECMWF VERSION WHICH
MESHES WELL WITH OUR SURROUNDING NEIGHBORING OFFICES...THUS EXPECT
SCATTERED OROGRAPHIC SNOWS OVER THE SNOWY AND SIERRA MADRE RANGES
AND DRY ELSEWHERE.
TUESDAY...COLD TEMPERATURES CONTINUE IN THE WAKE OF ANOTHER PASSING
ARCTIC COLD FRONT. MOIST WEST FLOW ALOFT AND ADEQUATE LOW AND MID
LEVEL MOISTURE WILL KEEP SCATTERED SNOWS WEST OF INTERSTATE 25 AND
MOSTLY DRY ELSEWHERE DUE TO DOWNSLOPING MID LEVEL WINDS.
WEDNESDAY...FLOW ALOFT TURNS NORTHWEST. NOW THE ECMWF LOOKS OVERDONE
WITH RESPECT TO QPF AND PREFER THE DRIER GFS VERSION SHOWING DRY AND
COLD NORTHWEST FLOW ALOFT...THUS EXPECT A WINDY DAY WITH PERHAPS A
FEW MOUNTAIN SNOW SHOWERS...AND DRY ELSEWHERE...WHICH MESHES WELL
WITH OUR SURROUNDING NEIGHBORING OFFICES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 916 PM MST WED FEB 25 2015
LATEST HRRR GUIDANCE USED FOR THE 06Z TAFS ACROSS SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE. CEILINGS ARE COMING DOWN HERE AT
KCYS AND HRRR SHOWING A SMALL PERSISTENT IFR AREA OVER KCYS. LOOKS
LIKE WE COULD GET ANOTHER SHOT AT IFR CONDITIONS THURSDAY
AFTERNOON AS THE AREA SEES A WIDESPREAD LIGHT SNOW EVENT.
&&
.FIRE WEATHER...
ISSUED AT 309 PM MST WED FEB 25 2015
COLD TEMPERATURES AND UNSETTLED CONDITIONS WILL HOLD ANY FIRE
WEATHER CONCERNS AT BAY FOR THE FORESEEABLE FUTURE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...GCC
SHORT TERM...CAH
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...CAH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
941 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE LOW PASSES WELL TO THE SE TODAY WHILE A SHORTWAVE ALOFT
SHIFTS THROUGH INTO EARLY AFTERNOON. BEST ASSOCIATED LIFT WILL BE
TO THE SOUTH. LOW LEVELS HAVING TROUBLE MOISTENING UP AS EVIDENCED
BY RADAR AND SURFACE OBS. HRRR AND RAP CONTINUE TO SHOW FOR THE
PAST FEW RUNS THAT MOST OF WHAT REACHES THE SURFACE REMAINS
OFFSHORE. HAVE LOWERED POPS FROM SLIGHT CHC NW TO CHC SE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN
20 DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES WELL TO THE SE TODAY. HIGH PRESSURE BUILDS IN
TONIGHT.
VFR THROUGH THE TAF PERIOD. REMOVED TEMPO FOR -SN FROM ALL BUT
KISP AND KJFK...AND RAISED THOSE TO VFR. IF CURRENT TRENDS
HOLD...COULD REMOVE THOSE IN FUTURE TAFS. CEILINGS GENERALLY 5-9
THOUSAND FEET THROUGH TAF PERIOD.
N-NE WINDS 8-13 KT DURING THE MORNING AND AFTERNOON...DIMINISHING
THIS EVENING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: WIND DIRECTION VARYING FROM 010-040 TRUE
(020-050 MAGNETIC) INTO THIS AFTERNOON. OCCASIONAL GUSTS TO 20KT
POSSIBLE THROUGH EARLY AFTERNOON. LOW CHANCE MVFR CEILINGS INTO
EARLY AFTERNOON.
KLGA FCSTER COMMENTS: WIND DIRECTION VARYING FROM 020-050 TRUE
(030-060 MAGNETIC) INTO THIS AFTERNOON. OCCASIONAL GUSTS TO 20KT
POSSIBLE THROUGH EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS
INTO EARLY AFTERNOON.
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. VERY LOW CHANCE MVFR CEILINGS INTO EARLY
AFTERNOON.
KISP FCSTER COMMENTS: OCCASIONAL GUSTS TO 20KT POSSIBLE THROUGH
EARLY AFTERNOON. LOW CHANCE MVFR CEILINGS INTO EARLY AFTERNOON.
.OUTLOOK FOR 12Z FRI THROUGH MON...
.FRIDAY-SUNDAY...VFR.
.SUNDAY NIGHT-MONDAY...CHANCE MVFR IN LIGHT SNOW...POSSIBLY MIXED
WITH RAIN SOUTHERN TERMINALS.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. ISSUED A SCA EARLIER
FOR THE OCEAN WATERS AFTER COLLABORATION WITH SURROUNDING OFFICES.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL
SOUTH OF LONG ISLAND...WILL COME CLOSE TO 25 KT. IN
ADDITION...SEAS PER WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE
BUOYS. BORDERLINE...BUT SCA ALREADY IN EFFECT FOR THE WATERS OFF
NJ AND NEW ENGLAND...SO WILL FOLLOW FOR CONTINUITY. LIGHT FREEZING
SPRAY IS EXPECTED DUE TO COLD WATER...COLD AIR TEMPS...ROUGH SEAS
AND 15 KT WINDS.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KT...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION EXPECTED THROUGH SATURDAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...PW/BC
NEAR TERM...JC/PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...MALOIT/DS
MARINE...PW/BC
HYDROLOGY...PW/BC
AREA FORECAST DISCUSSION
NWS ALBANY NY
657 AM EST THU FEB 26 2015
.SYNOPSIS...
A STORM PASSING OFF THE MID ATLANTIC COAST MAY ALLOW FOR
SOME FLURRIES OR SNOW SHOWERS TODAY...MAINLY FOR AREAS SOUTH AND
EAST OF ALBANY. OTHERWISE...DRY WEATHER IS EXPECTED THROUGH
SATURDAY...BUT IT WILL REMAIN RATHER FRIGID. A STORM SYSTEM LOOKS TO
BRING SOME LIGHT SNOW TO THE REGION LATE SUNDAY INTO MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 641 AM EST...AN AREA OF LOW PRESSURE IS SITUATED ALONG THE
COAST OF THE CAROLINAS...AND IS MOVING NORTHEAST OUT TOWARDS THE
WESTERN ATLANTIC OCEAN. A LARGE SHIELD OF CLOUDS ASSOCIATED WITH
THIS SYSTEM HAVE MOVED UP THE EASTERN SEABOARD...ALTHOUGH THE
COLDEST/DEEPEST CLOUD COVER IS LOCATED SOUTHEAST OF OUR AREA.
STILL...SKIES ARE CLOUDY OVER MUCH OF OUR AREA THANKS TO A JET
STREAK ASSOCIATED WITH THIS STORM SYSTEM...AND THIS LOOKS TO
CONTINUE THROUGH THE MORNING HOURS.
AS THE STORM CONTINUES TO MOVE NORTHEAST TODAY...SOME MOISTURE
WILL MOVE UP THE COAST. IT LOOKS LIKE MOST OF THIS WILL MISS OUR
AREA TO THE SOUTH AND EAST...BUT WE CANNOT RULE OUT SOME VERY
LIGHT SNOW SHOWERS OCCURRING ACROSS SOUTHEASTERN PARTS OF THE CWA.
THE 10Z 3KM HRRR SUGGEST THE MOST LIKELY TIME FOR THIS TO OCCUR
WOULD BE BETWEEN 13Z AND 18Z. HOWEVER...THE NEAREST REPORTING SITE
SHOWING SNOW IS OVER MARYLAND...SO DESPITE RADAR RETURNS SHOWING
SOME SNOW OVER SOUTHERN NY AND NORTHERN NJ...IT SEEMS THAT THE
VERY DRY AIR AT LOW LEVELS IS WINNING OUT SO FAR THIS MORNING...AS
PRECIP IS DRYING UP BEFORE IT REACHES THE SURFACE. WITH DEWPOINTS
IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...MOST OF THE QPF SHOWN
IN THE MODELS WON/T REACH THE GROUND. WE HAVE GONE WITH SLIGHT TO
LOW CHC POPS FOR SOUTHERN AREAS FOR THIS MORNING INTO EARLY THIS
AFTN...WITH A LIGHT DUSTING OF SNOW POSSIBLE...BUT IT WOULDN/T BE
SURPRISING TO SEE ANY SNOW THAT OCCURS IN OUR AREA TO BE JUST
FLURRIES WITH NO ACCUMULATION AT ALL.
IN ADDITION...A WEAK NORTHERN STREAM DISTURBANCE WILL BE MOVING
ACROSS THE UPPER GREAT LAKES LATER TODAY AND WILL BE APPROACHING
SOUTHERN CANADA BY EARLY EVENING. A SNOW SHOWER OR TWO THANKS TO
THIS SYSTEM IS POSSIBLE FOR NORTHWESTERN AREAS...MAINLY FOR THE
LATE DAY HOURS. MOISTURE IS ALSO LACKING WITH THIS SYSTEM...SO
ANY SNOW WOULD BE VERY LIGHT...AND LITTLE TO NO ACCUMULATION IS
EXPECTED WITH ACTIVITY AS WELL.
OTHERWISE...SKIES LOOK TO REMAIN CLOUDY THROUGH MUCH OF THE DAY.
TEMPS WILL REMAIN COOL...WITH 850 HPA TEMPS IN THE -11 TO -18
DEGREE C RANGE. MAX TEMPS LOOK TO MAINLY BE IN THE TEENS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
WITH THE UPPER LEVEL SHORTWAVE SLIDING BY TO THE NORTH...THERE
MAY BE A SNOW SHOWER THIS EVENING...MAINLY ACROSS THE ADIRONDACKS.
OTHERWISE...IT LOOKS TO BE DRY TONIGHT...ALTHOUGH A FAIR AMOUNT
OF CLOUDS WILL REMAIN IN PLACE. DESPITE THE CLOUDS...THE ARCTIC
AIR MASS IN PLACE WILL CONTINUE TO KEEP TEMPS RATHER COLD. MINS
WILL GENERALLY BE ZERO TO 10...ALTHOUGH THE CATSKILLS...MOHAWK
VALLEY...AND SRN GREEN MOUNTAINS WILL SEE TEMPS O TO -10 F...WITH
READINGS -5 TO -15 F OVER THE ADIRONDACKS. WINDS LOOK VERY LIGHT
TO CALM...SO NO WIND CHILL CONCERNS FOR TONIGHT.
CLOUDS WILL BREAK FOR SUNSHINE ON FRIDAY AS SFC HIGH PRESSURE
OVER GREAT LAKES AND OHIO VALLEY RIDGES INTO THE NORTHEAST. THIS
WILL CONTINUE TO ALLOW FOR DRY BUT CHILLY WEATHER. TEMPS ON FRIDAY
WILL ONCE AGAIN ONLY BE IN THE TEENS TO LOW 20S.
ANOTHER VERY COLD NIGHT IS EXPECTED FOR FRIDAY NIGHT. WITH
CLEARING SKIES...TEMPS MAY BE A LITTLE COLDER THAN THURSDAY
NIGHT...WITH BELOW ZERO READINGS FOR MOST LOCATIONS. TEMPS COULD
BE AS COLD AS -15 F OVER THE ADIRONDACKS. WITH THE HIGH PRESSURE
JUST OFF TO THE SOUTHWEST...THERE PROBABLY WON/T BE TOO MUCH
WIND...EXCEPT AT THE HIGHER ELEVATIONS. WIND CHILL VALUES MAY
APPROACH ADVISORY CRITERIA OVER THESE HIGHER ELEVATION AREAS...SO
WILL MENTION THIS IN THE HWO STATEMENT. WINDS SHOULD REMAIN LIGHT
IN ENOUGH IN VALLEY AREAS /5 MPH OR LESS/ TO NOT REQUIRE WIND
CHILL HEADLINES...BUT WE WILL CONTINUE TO MONITOR THIS CLOSELY.
IT WILL BE CONTINUED DRY ON SATURDAY...AS THE HIGH PRESSURE AREA
MOVES BY TO THE SOUTH OVER THE MID ATLANTIC. MOSTLY SUNNY SKIES
ARE EXPECTED ON SATURDAY. TEMPS WILL BE A LITTLE WARMER...WITH
HIGHS IN THE MID TEENS TO MID 20S. ANOTHER VERY COLD NIGHT IS
EXPECTED FOR SAT NIGHT...WITH LOWS 5 BELOW TO 5 ABOVE. ALTHOUGH
SKIES WILL START OFF CLEAR...SOME MID/HIGH LEVEL CLOUDS MAY START
TO INCREASE TOWARDS DAYBREAK SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE...HOWEVER NOT SIGNIFICANTLY
BELOW NORMAL LIKE HAS BEEN THE CASE FOR THE PAST COUPLE OF WEEKS.
WILL HAVE AN ACTIVE NORTHERN STREAM WITH A SYSTEM CROSSING THE
REGION SUNDAY INTO MONDAY AND ANOTHER FOR MID WEEK.
A LIGHT SNOWFALL...GENERALLY LESS THAN 4 INCHES...IS EXPECTED SUNDAY
AFTERNOON INTO MONDAY MORNING AS A LOW PRESSURE SYSTEM APPROACHES AND
CROSSES THE REGION.
A SECONDARY COLD FRONT IS EXPECTED TO SWEEP ACROSS THE REGION MONDAY
MORNING BRINGING A REINFORCING SHOT OF COLDER AIR INTO THE REGION.
SURFACE HIGH PRESSURE IS EXPECTED TO BEGIN TO BUILD IN MONDAY
AFTERNOON AND SHIFT EASTWARD ACROSS THE REGION THROUGH TUESDAY
MORNING. ALOFT RIDGING IS EXPECTED TO DEVELOP AS A DEEP TROUGH
DIGGING OVER THE WESTERN CONUS. THIS WILL RESULT IN A COLD NIGHT
MONDAY WITH LOWS MAINLY IN THE SINGLE DIGITS.
AS THE TROUGH CONTINUES TO DEEPEN AND SHIFTS/MOVES EASTWARD A LOW
PRESSURE SYSTEM WILL DEVELOP AND WITH BROAD SOUTHWEST ACROSS THE
EASTERN CONUS HEAD TOWARD THE NORTHEAST. PRECIPITATION ASSOCIATED
WITH THE SYSTEM IS ANTICIPATED TO BEGIN TO OVERSPREAD THE REGION
TUESDAY AFTERNOON AND CONTINUE THROUGH WEDNESDAY. THERE ARE
DIFFERENCES IN THE GUIDANCE WITH THE TIMING AND EXACT TRACK OF THE
SYSTEM SO HAVE RESTRICTED POPS TO CHANCE. THE OTHER CONCERN IS THE
THERMAL PROFILE. INITIALLY SNOW IS EXPECTED HOWEVER TEMPERATURES MAY
WARM UP ENOUGH FOR RAIN ESPECIALLY UP THE HUDSON VALLEY. HOW MUCH
QPF THERE WILL BE IS HIGHLY UNCERTAINTY AT THIS TIME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT
SOUTHERN STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST
THIS MORNING AND TRACKS EAST-NORTHEAST OUT TO SEA. RIDGING WILL
BUILD BACK IN AS THE STORM MOVES FARTHER AWAY FROM THE COAST
TONIGHT.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL CONTINUE TO OVERSPREAD THE
REGION THICKENING AND LOWERING. THE PRECIPITATION SHIELD ASSOCIATED
WITH THE STORM IS EXPECTED TO EXTENT IN THE LOWER/MID HUDSON VALLEY
AND SOUTHERN NEW ENGLAND. HOWEVER THE ATMOSPHERE IS RATHER DRY SO
ONLY SOME LIGHT SNOW IS EXPECTED. IN ADDITION FLURRIES ARE POSSIBLE
AS AN UPPER TROUGH AXIS APPROACHES AS NORTHERN STREAM ENERGY MOVES
INTO THE LONGWAVE TROUGH DEEPENING IT OVER THE EASTERN UNITED STATES.
MVFR CONDITIONS ARE EXPECTED AT KPOU BY EARLY THIS AFTERNOON WITH
SOME LIGHT SNOW. MVFR CEILINGS ARE EXPECTED TO DEVELOP FOR A PERIOD
BY THIS AFTERNOON INTO THE EVENING WITH SOME FLURRIES.
LIGHT MAINLY NORTHERLY WINDS.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EST THU FEB 26 2015
.SYNOPSIS...
A STORM PASSING OFF THE MID ATLANTIC COAST MAY ALLOW FOR
SOME FLURRIES OR SNOW SHOWERS TODAY...MAINLY FOR AREAS SOUTH AND
EAST OF ALBANY. OTHERWISE...DRY WEATHER IS EXPECTED THROUGH
SATURDAY...BUT IT WILL REMAIN RATHER FRIGID. A STORM SYSTEM LOOKS TO
BRING SOME LIGHT SNOW TO THE REGION LATE SUNDAY INTO MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 641 AM EST...AN AREA OF LOW PRESSURE IS SITUATED ALONG THE
COAST OF THE CAROLINAS...AND IS MOVING NORTHEAST OUT TOWARDS THE
WESTERN ATLANTIC OCEAN. A LARGE SHIELD OF CLOUDS ASSOCIATED WITH
THIS SYSTEM HAVE MOVED UP THE EASTERN SEABOARD...ALTHOUGH THE
COLDEST/DEEPEST CLOUD COVER IS LOCATED SOUTHEAST OF OUR AREA.
STILL...SKIES ARE CLOUDY OVER MUCH OF OUR AREA THANKS TO A JET
STREAK ASSOCIATED WITH THIS STORM SYSTEM...AND THIS LOOKS TO
CONTINUE THROUGH THE MORNING HOURS.
AS THE STORM CONTINUES TO MOVE NORTHEAST TODAY...SOME MOISTURE
WILL MOVE UP THE COAST. IT LOOKS LIKE MOST OF THIS WILL MISS OUR
AREA TO THE SOUTH AND EAST...BUT WE CANNOT RULE OUT SOME VERY
LIGHT SNOW SHOWERS OCCURRING ACROSS SOUTHEASTERN PARTS OF THE CWA.
THE 10Z 3KM HRRR SUGGEST THE MOST LIKELY TIME FOR THIS TO OCCUR
WOULD BE BETWEEN 13Z AND 18Z. HOWEVER...THE NEAREST REPORTING SITE
SHOWING SNOW IS OVER MARYLAND...SO DESPITE RADAR RETURNS SHOWING
SOME SNOW OVER SOUTHERN NY AND NORTHERN NJ...IT SEEMS THAT THE
VERY DRY AIR AT LOW LEVELS IS WINNING OUT SO FAR THIS MORNING...AS
PRECIP IS DRYING UP BEFORE IT REACHES THE SURFACE. WITH DEWPOINTS
IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...MOST OF THE QPF SHOWN
IN THE MODELS WON/T REACH THE GROUND. WE HAVE GONE WITH SLIGHT TO
LOW CHC POPS FOR SOUTHERN AREAS FOR THIS MORNING INTO EARLY THIS
AFTN...WITH A LIGHT DUSTING OF SNOW POSSIBLE...BUT IT WOULDN/T BE
SURPRISING TO SEE ANY SNOW THAT OCCURS IN OUR AREA TO BE JUST
FLURRIES WITH NO ACCUMULATION AT ALL.
IN ADDITION...A WEAK NORTHERN STREAM DISTURBANCE WILL BE MOVING
ACROSS THE UPPER GREAT LAKES LATER TODAY AND WILL BE APPROACHING
SOUTHERN CANADA BY EARLY EVENING. A SNOW SHOWER OR TWO THANKS TO
THIS SYSTEM IS POSSIBLE FOR NORTHWESTERN AREAS...MAINLY FOR THE
LATE DAY HOURS. MOISTURE IS ALSO LACKING WITH THIS SYSTEM...SO
ANY SNOW WOULD BE VERY LIGHT...AND LITTLE TO NO ACCUMULATION IS
EXPECTED WITH ACTIVITY AS WELL.
OTHERWISE...SKIES LOOK TO REMAIN CLOUDY THROUGH MUCH OF THE DAY.
TEMPS WILL REMAIN COOL...WITH 850 HPA TEMPS IN THE -11 TO -18
DEGREE C RANGE. MAX TEMPS LOOK TO MAINLY BE IN THE TEENS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
WITH THE UPPER LEVEL SHORTWAVE SLIDING BY TO THE NORTH...THERE
MAY BE A SNOW SHOWER THIS EVENING...MAINLY ACROSS THE ADIRONDACKS.
OTHERWISE...IT LOOKS TO BE DRY TONIGHT...ALTHOUGH A FAIR AMOUNT
OF CLOUDS WILL REMAIN IN PLACE. DESPITE THE CLOUDS...THE ARCTIC
AIR MASS IN PLACE WILL CONTINUE TO KEEP TEMPS RATHER COLD. MINS
WILL GENERALLY BE ZERO TO 10...ALTHOUGH THE CATSKILLS...MOHAWK
VALLEY...AND SRN GREEN MOUNTAINS WILL SEE TEMPS O TO -10 F...WITH
READINGS -5 TO -15 F OVER THE ADIRONDACKS. WINDS LOOK VERY LIGHT
TO CALM...SO NO WIND CHILL CONCERNS FOR TONIGHT.
CLOUDS WILL BREAK FOR SUNSHINE ON FRIDAY AS SFC HIGH PRESSURE
OVER GREAT LAKES AND OHIO VALLEY RIDGES INTO THE NORTHEAST. THIS
WILL CONTINUE TO ALLOW FOR DRY BUT CHILLY WEATHER. TEMPS ON FRIDAY
WILL ONCE AGAIN ONLY BE IN THE TEENS TO LOW 20S.
ANOTHER VERY COLD NIGHT IS EXPECTED FOR FRIDAY NIGHT. WITH
CLEARING SKIES...TEMPS MAY BE A LITTLE COLDER THAN THURSDAY
NIGHT...WITH BELOW ZERO READINGS FOR MOST LOCATIONS. TEMPS COULD
BE AS COLD AS -15 F OVER THE ADIRONDACKS. WITH THE HIGH PRESSURE
JUST OFF TO THE SOUTHWEST...THERE PROBABLY WON/T BE TOO MUCH
WIND...EXCEPT AT THE HIGHER ELEVATIONS. WIND CHILL VALUES MAY
APPROACH ADVISORY CRITERIA OVER THESE HIGHER ELEVATION AREAS...SO
WILL MENTION THIS IN THE HWO STATEMENT. WINDS SHOULD REMAIN LIGHT
IN ENOUGH IN VALLEY AREAS /5 MPH OR LESS/ TO NOT REQUIRE WIND
CHILL HEADLINES...BUT WE WILL CONTINUE TO MONITOR THIS CLOSELY.
IT WILL BE CONTINUED DRY ON SATURDAY...AS THE HIGH PRESSURE AREA
MOVES BY TO THE SOUTH OVER THE MID ATLANTIC. MOSTLY SUNNY SKIES
ARE EXPECTED ON SATURDAY. TEMPS WILL BE A LITTLE WARMER...WITH
HIGHS IN THE MID TEENS TO MID 20S. ANOTHER VERY COLD NIGHT IS
EXPECTED FOR SAT NIGHT...WITH LOWS 5 BELOW TO 5 ABOVE. ALTHOUGH
SKIES WILL START OFF CLEAR...SOME MID/HIGH LEVEL CLOUDS MAY START
TO INCREASE TOWARDS DAYBREAK SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BELOW NORMAL TEMPERATURES WILL CONTINUE...HOWEVER NOT SIGNIFICANTLY
BELOW NORMAL LIKE HAS BEEN THE CASE FOR THE PAST COUPLE OF WEEKS.
WILL HAVE AN ACTIVE NORTHERN STREAM WITH A SYSTEM CROSSING THE
REGION SUNDAY INTO MONDAY AND ANOTHER FOR MID WEEK.
A LIGHT SNOWFALL...GENERALLY LESS THAN 4 INCHES...IS EXPECTED SUNDAY
AFTERNOON INTO MONDAY MORNING AS A LOW PRESSURE SYSTEM APPROACHES AND
CROSSES THE REGION.
A SECONDARY COLD FRONT IS EXPECTED TO SWEEP ACROSS THE REGION MONDAY
MORNING BRINGING A REINFORCING SHOT OF COLDER AIR INTO THE REGION.
SURFACE HIGH PRESSURE IS EXPECTED TO BEGIN TO BUILD IN MONDAY
AFTERNOON AND SHIFT EASTWARD ACROSS THE REGION THROUGH TUESDAY
MORNING. ALOFT RIDGING IS EXPECTED TO DEVELOP AS A DEEP TROUGH
DIGGING OVER THE WESTERN CONUS. THIS WILL RESULT IN A COLD NIGHT
MONDAY WITH LOWS MAINLY IN THE SINGLE DIGITS.
AS THE TROUGH CONTINUES TO DEEPEN AND SHIFTS/MOVES EASTWARD A LOW
PRESSURE SYSTEM WILL DEVELOP AND WITH BROAD SOUTHWEST ACROSS THE
EASTERN CONUS HEAD TOWARD THE NORTHEAST. PRECIPITATION ASSOCIATED
WITH THE SYSTEM IS ANTICIPATED TO BEGIN TO OVERSPREAD THE REGION
TUESDAY AFTERNOON AND CONTINUE THROUGH WEDNESDAY. THERE ARE
DIFFERENCES IN THE GUIDANCE WITH THE TIMING AND EXACT TRACK OF THE
SYSTEM SO HAVE RESTRICTED POPS TO CHANCE. THE OTHER CONCERN IS THE
THERMAL PROFILE. INITIALLY SNOW IS EXPECTED HOWEVER TEMPERATURES MAY
WARM UP ENOUGH FOR RAIN ESPECIALLY UP THE HUDSON VALLEY. HOW MUCH
QPF THERE WILL BE IS HIGHLY UNCERTAINTY AT THIS TIME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
RIDGING OVER THE REGION WILL WEAKEN SOME TODAY AS A POTENT
SOUTHERN STREAM LOW PRESSURE SYSTEM MOVES OFF THE SOUTHEAST COAST
THIS MORNING AND TRACKS EAST-NORTHEAST OUT TO SEA. RIDGING WILL
BUILD BACK IN AS THE STORM MOVES FARTHER AWAY FROM THE COAST
TONIGHT.
CLOUDS ASSOCIATED WITH THE SYSTEM WILL CONTINUE TO OVERSPREAD THE
REGION THICKENING AND LOWERING. THE PRECIPITATION SHIELD ASSOCIATED
WITH THE STORM IS EXPECTED TO EXTEND IN THE LOWER/MID HUDSON
VALLEY AND SOUTHERN NEW ENGLAND. HOWEVER THE ATMOSPHERE IS RATHER
DRY SO ONLY SOME LIGHT SNOW IS EXPECTED. IN ADDITION FLURRIES ARE
POSSIBLE AS AN UPPER TROUGH AXIS APPROACHES AS NORTHERN STREAM
ENERGY MOVES INTO THE LONGWAVE TROUGH DEEPENING IT OVER THE
EASTERN UNITED STATES.
MVFR CONDITIONS ARE EXPECTED AT KPOU LATER THIS MORNING INTO THE
AFTERNOON. MVFR CEILINGS ARE EXPECTED TO DEVELOP FOR A PERIOD BY
THIS AFTERNOON INTO THE EVENING. LIGHT AND VARIABLE WINDS.
OUTLOOK...
FRI-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE AFTERNOON.
SUN NIGHT: HIGH OPERATIONAL IMPACT. SN LIKELY.
MON: MODERATE OPERATIONAL IMPACT. CHC SN MAINLY IN THE MORNING.
&&
.HYDROLOGY...
A FEW SNOW SHOWERS OR FLURRIES ARE POSSIBLE FOR FAR SOUTHEASTERN
AREAS ON THURSDAY...BUT TOTAL LIQUID EQUIVALENT WILL GENERALLY
ONLY BE A FEW HUNDREDTHS OF AN INCH AT MOST. OTHERWISE...IT WILL
REMAIN DRY THROUGH SUNDAY MORNING. SOME LIGHT SNOWFALL IS
POSSIBLE FOR THE REGION LATE SUNDAY THROUGH MONDAY MORNING.
TEMPERATURES WILL REMAIN BELOW FREEZING THROUGH SUNDAY NIGHT.
TEMPERATURES MAY BRIEFLY RISE ABOVE FREEZING DURING THE DAY ON
MONDAY. WITH THE CONTINUED COLD CONDITIONS IN PLACE...ICE WILL
CONTINUE TO STRENGTHEN AND THICKEN ON AREA RIVERS...STREAMS...LAKES...AND
PONDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
627 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE TRACKS TO THE SOUTHEAST TODAY. HIGH PRESSURE BUILDS
FROM THE WEST TONIGHT THROUGH SATURDAY. THE HIGH THEN SLIDES
OFFSHORE FROM SATURDAY NIGHT INTO SUNDAY. A COLD FRONT APPROACHES
FROM THE NORTHWEST LATE SUNDAY...THEN CROSSES THE AREA SUNDAY
NIGHT AND EARLY MONDAY...WITH WAVES OF LOW PRESSURE RIDING ALONG
THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE FRONT INTO TUESDAY.
ANOTHER STORM SYSTEM IMPACTS THE AREA TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE APPEARS TO BE GENERAL MODEL AGREEMENT ON OVERALL FEATURES
THROUGH TODAY. ALOFT...WEAK SHORTWAVE TRAVERSES QUICKLY SW TO
NE...PASSING JUST SOUTH OF THE AREA. SFC LOW PRESSURE OFF THE MID
ATLANTIC THIS MORNING MOVES NORTHEAST TODAY...PASSING TO THE SOUTH
OF THE 40N/70W BENCHMARK.
BEST LIFT ASSOCIATED WITH UPPER SHORTWAVE AND JET WILL REMAIN TO THE
SOUTH OF THE AREA. ANALYSIS OF HIGH RES MODELS CONTINUES TO INDICATE
LIGHT PRECIP APPROACHING CSTL ZONES THIS MORNING...WITH LIGHT PRECIP
IMPACTING CSTL ZONES FOR A SHORT PERIOD LATE THIS MORNING INTO
THE EARLY AFTERNOON. CONCERN THOUGH FOR LOW DEW POINTS THIS
MORNING...THUS PLENTY OF DRY AIR TO SATURATE.
LIGHT SNOW ACROSS SRN NJ AS OF 11Z.
SIMULATED REFLECTIVITY FROM LATEST HRRR KEEPS THE BULK OF THE
LIGHT SNOW TO THE SOUTH OF THE AREA. WRF-NMM INDICATES POTENTIAL
LIGHT SNOW CLIPPING LONG ISLAND...WITH THE BEST CHANCE FOR
MEASURABLE SNOW CSTL AND EASTERN LI AND INTO SE CT.
SPOTTY LIGHT SNOW CAN BE EXPECTED ACROSS THE INTERIOR...WITH
LOWER CHANCES FOR MEASURABLE. WILL MAINTAIN SIMILAR POPS FROM
PREVIOUS...LAYERED FROM CHANCE NW TO LIKELY EAST. TIMING OF ANY
LIGHT SNOW THAT COULD POSSIBLY MEASURE WOULD BE 14Z THROUGH 19Z.
GENERALLY UNDER AN INCH FOR CSTL LOCALES WITH PERHAPS A COATING
ELSEWHERE.
WITH COLD AIR IN PLACE...NORTH TO NORTHEAST WINDS AND PLENTY OF
CLOUD COVER WILL PREVENT TEMPS FROM RISING MUCH TODAY. BLENDED
MAV/MET AND 12Z ECS STATISTICAL MOS OVER HI RES NMM BACKGROUND.
EXPECT HIGH TEMPS GENERALLY IN THE LOWER TO MID 20S. THIS REMAIN 20
DEGREES BELOW NORMAL LEVELS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAKENING UPPER TROUGH EXTENDING FROM NE TO SW ACROSS THE GREAT
LAKES REGION MAKES SLOW PROGRESS EAST...WEAKENING AS IT DOES SO. MID
AND HIGH LEVEL MOISTURE WILL TRANSLATE TO LEFTOVER CLOUDS TONIGHT
AND INTO FRIDAY AS THIS FEATURE SLOWLY PROGRESSES EAST.
AT THE SURFACE...PREVAILING NORTHERLY FLOW CONTINUES AS RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST.
DRY WEATHER IS ANTICIPATED...ALTHOUGH CANNOT COMPLETELY RULE OUT A
FLURRY OR TWO DUE TO THE MID/UPPER LEVEL TROUGH APPROACHING.
TEMPS REMAIN COLD THROUGH FRIDAY. BLENDED MOS ONCE AGAIN. LOWS
TONIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS THE INTERIOR TO THE
TEENS ELSEWHERE. ON FRIDAY...TEMPS RISE TO THE MIDDLE 20S. STILL
QUITE COLD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF WITH HIGH PRESSURE BUILDING INTO THE
REGION FRIDAY NIGHT AND SATURDAY...THEN MOVING OFFSHORE SATURDAY
NIGHT AND SUNDAY MORNING. EXPECT DRY CONDITIONS THROUGH THIS PERIOD.
A COLD FRONT AND MID LEVEL SHORTWAVE APPROACH LATE SUNDAY AND MOVE
ACROSS THE REGION EARLY MONDAY MORNING. WE SHOULD MAINLY SEE ALL
SNOW...WITH POSSIBLY A WINTRY MIX ALONG THE COAST. FOR
SIMPLICITY...KEEPING PRECIPITATION ALL SNOW FOR NOW. IF
PRECIPITATION LINGERS INTO MONDAY AFTERNOON OVER EASTERN
ZONES...THEN THE BOUNDARY LAYER COULD WARM ENOUGH TO CHANGE THINGS
TO PLAIN RAIN BEFORE ENDING.
MONDAY NIGHT WILL BE DRY UNDER NW FLOW ALOFT AND HIGH PRESSURE
PASSING OVER THE REGION.
ANOTHER STORM SYSTEM IMPACTS THE REGION TUESDAY INTO WEDNESDAY.
THERE ARE SOME MODEL DIFFERENCES WITH THIS SYSTEM WITH RESPECT TO
THE TRACK OF THE SURFACE LOW AND THE LOCATION OF ITS ASSOCIATED
FRONTAL BOUNDARIES. WILL CONTINUE...FOR SIMPLICITY PURPOSES...NOT TO
ADDRESS THE SLEET OR FREEZING RAIN POTENTIAL AT THIS TIME.
TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL SATURDAY AND
SUNDAY...WITH A RETURN TO NEAR NORMAL ON MONDAY. TEMPERATURES FALL
BACK BELOW NORMAL ON TUESDAY...WITH TEMPERATURES APPROACHING NORMAL
ONCE AGAIN ON WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE PASSES WELL TO THE SE OF THE TERMINALS TODAY. HIGH
PRESSURE BUILDS IN TONIGHT.
VFR TO START THE TAF PERIOD. LOWERING CLOUDS WITH PASSING LOW
PRESSURE MAY PRODUCE SOME LIGHT SNOW AND MVFR CIGS MAINLY FROM LATE
MORNING INTO EARLY AFTERNOON. OTHERWISE...VFR THIS EVENING INTO THE
OVERNIGHT.
N-NE WINDS 8-13 KT DURING THE MORNING AND AFTERNOON...DIMINISHING
THIS EVENING.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KLGA FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KEWR FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KHPN FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
KISP FCSTER COMMENTS: MVFR CIGS MAY PREVAIL 15Z TO 20Z. MODERATE
CONFIDENCE VFR CONDS THIS EVENING.
.OUTLOOK FOR 12Z FRI THROUGH MON...
.FRI-SUNDAY...VFR.
.SUNDAY NIGHT-MON...LIGHT SNOW POSSIBLY MIXED WITH RAIN. MVFR CONDS
POSSIBLE.
&&
.MARINE...
AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST THIS MORNING WILL
PASS TO THE SOUTHEAST OF THE WATERS TODAY. ISSUED A SCA EARLIER
FOR THE OCEAN WATERS AFTER COLLAB WITH SURROUNDING OFFICES.
WINDS...ESPECIALLY ACROSS THE OUTER PORTION OF THE ZONES WELL
SOUTH OF LONG ISLAND...WILL COME CLOSE TO 25 KTS. IN
ADDITION...SEAS PER WAVE WATCH BUILD TO 5 FEET FOR THE OFFSHORE
BUOYS. BORDERLINE...BUT SCA ALREADY IN EFFECT FOR THE WATERS OFF
NJ AND NEW ENGLAND...SO WILL FOLLOW FOR CONTINUITY. LIGHT FREEZING
SPRAY IS EXPECTED DUE TO COLD WATER...COLD AIR TEMPS...ROUGH SEAS
AND 15 KT WINDS.
BY TONIGHT...THE LOW PASSES WELL TO THE EAST AS A RIDGE OF HIGH
PRESSURE BUILDS FROM THE WEST. PERSISTENT NORTHERLY WINDS
CONTINUE...BUT LIGHTEN. DO NOT ANTICIPATE WIND SPEEDS CLOSE TO SCA
CRITERIA TONIGHT AND FRIDAY. THE BIGGEST QUESTION IS WHAT HAPPENS TO
OCEAN SEAS. GUIDANCE SUGGESTS SEAS SUBSIDE TONIGHT...BUT BUILD CLOSE
TO 5 FEET YET AGAIN TOWARD FRIDAY MORNING DUE TO E/SE SWELL. NOT TOO
SURE ABOUT THIS...SO NO PLANS AT THIS TIME TO EXTEND THE SCA. IF
ANYTHING...A SCA FOR HAZARDOUS SEAS MAY BE NEEDED LATE TONIGHT
THROUGH FRIDAY.
FOR THE WATERS SURROUNDING LONG ISLAND...WINDS REMAIN BELOW 25
KTS...AND SEAS REMAIN RATHER TRANQUIL. SPEAKING OF SEAS...MANY OF
THE BAYS REMAIN FROZEN...AND THAT IS NOT GOING TO CHANGE ANYTIME
SOON.
SCA LEVEL SEAS COULD LINGER ON THE COASTAL OCEAN WATERS EAST OF
MORICHES INLET FRIDAY NIGHT...OTHERWISE SUB-SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED ON ALL WATERS FROM FRIDAY NIGHT INTO SUNDAY.
INCREASING SW WINDS ARE EXPECTED TO BUILD SEAS TO SCA LEVELS ON THE
COASTAL OCEAN WATERS LATE SUNDAY INTO MONDAY. NW FLOW BEHIND A COLD
FRONT COULD PRODUCE GUSTS TO SMALL CRAFT LEVELS ON ALL WATERS ON
MONDAY.
&&
.HYDROLOGY...
A FEW HUNDREDTHS OF LIQUID EQUIVALENT IS POSSIBLE TODAY.
THERE IS THE POTENTIAL FOR LIGHT TO POSSIBLY MODERATE LIQUID
EQUIVALENT TO FALL FROM SUNDAY INTO MONDAY. AT THIS TIME NO
SIGNIFICANT PRECIPITATION IS EXPECTED.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPS REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...BC/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...BC
AVIATION...DS
MARINE...BC/PW
HYDROLOGY...BC/PW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
947 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST COASTAL LOW CONTINUES TO LIFT NORTHEAST OFF THE
CAROLINA COAST. SEVERAL INCHES OF SNOW HAVE FALLEN ACROSS THE
EASTERN SHORE OF MARYLAND, CENTRAL AND SOUTHERN DELAWARE AND
SOUTHEAST NEW JERSEY. THE HIGHEST TOTAL CLOSE TO 5 INCHES WAS
RECORDED ON FENWICK ISLAND SO FAR. SNOW TOTALS WERE UPDATED WITH
THESE CURRENT REPORTS AND WITH THE PROSPECTS FOR AN ADDITIONAL HOUR
OR TWO OF STEADY SNOW POSSIBLY MODERATE TO HEAVY FOR BRIEF
INTERVALS. THIS DID RAISE TOTALS ALONG THE DELAWARE BEACHES NORTH
THROUGH ATLANTIC CITY SLIGHTLY. FURTHER NORTHWEST, DRY AIR HAS
ERODED THE NORTHERN EDGE OF THE PRECIPITATION SHIELD SUFFICIENTLY
THIS MORNING. TOTALS WERE UNDER AN INCH THROUGH WILMINGTON AND
PHILADELPHIA THIS MORNING. THE NORTHERN EXTENT OF THE WINTER
WEATHER ADVISORY HAS BEEN CANCELLED WITH ONLY SOME LINGERING
FLURRIES POSSIBLE. THE RAP AND HRRR SHOW SNOW EXITING THE BEACHES
AROUND 17Z AND THE WINTER STORM ADVISORIES/WARNINGS GO THROUGH
18Z WHERE ACCUMULATING SNOW HAS FALLEN.
DRY AIR WILL CONTINUE TO PENETRATE FURTHER SOUTH THROUGHOUT THE
DAY AND HAVE POPS TAPERING DOWN TO SLIGHT CHANCE FOR THE AFTERNOON
HOURS. ADDITIONAL SNOW SHOULD JUST BE IN THE FORM OF FLURRIES OR
VERY LIGHT SNOW THIS AFTERNOON. TEMPERATURES WERE ADJUSTED
DOWNWARD SOME WITH THE PRECIPITATION IN THE AREA. &&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
SNOW IS TRYING TO BUILD FURTHER NORTH THROUGH THE REGION. HOWEVER, IT
IS ENCOUNTERING A WALL OF DRY AIR. WESTERN TAF SITES, KABE AND
KRDG, WILL LIKELY NOT SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY
SITES, KPHL, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT
SNOW IS POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN
WILL BE THE LAST TO BE AFFECTED). THOUGH IT APPEARS THE MAIN
WINDOW FOR THIS WILL BE ENDING SOON BY 14Z-15Z. AT KILG, KMIV AND
KACY, MOSTLY LIGHT BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW
WILL BE POSSIBLE FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER,
SNOW SHOULD BE OUT OF THE REGION. TAFS REFLECT MORE OPTIMISTIC
CONDITIONS THAN WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO
BE UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ021>025.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...GAINES/JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...GAINES/HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
747 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM UPDATE...NO MAJOR CHANGES FROM THE PREVIOUS FORECAST.
HEAVIER SNOW BANDS MOVING THROUGH SOUTHERN DELMARVA AND FAR
SOUTHERN NJ NOW. EXPECT THE BULK OF THE SNOW TO OCCUR BETWEEN NOW
AND LATE THIS MORNING.
PREVIOUS NEAR TERM DISCUSSION...THE LATEST COASTAL LOW CONTINUES
TO LIFT NORTHEAST OFF THE CAROLINA COAST. SNOW HAS BEEN REPORTED
IN SOUTHERN DELMARVA, BUT AS OF 330 AM REMAINS JUST SOUTH OF OUR
CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
SNOW IS TRYING TO BUILD FURTHER NORTH THROUGH THE REGION. HOWEVER, IT
IS ENCOUNTERING A WALL OF DRY AIR. WESTERN TAF SITES, KABE AND
KRDG, WILL LIKELY NOT SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY
SITES, KPHL, KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT
SNOW IS POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN
WILL BE THE LAST TO BE AFFECTED). THOUGH IT APPEARS THE MAIN
WINDOW FOR THIS WILL BE ENDING SOON BY 14Z-15Z. AT KILG, KMIV AND
KACY, MOSTLY LIGHT BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW
WILL BE POSSIBLE FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER,
SNOW SHOULD BE OUT OF THE REGION. TAFS REFLECT MORE OPTIMISTIC
CONDITIONS THAN WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO
BE UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>027.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008-012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...GAINES/HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
652 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE SYSTEM WILL QUICKLY MOVE OFF THE NORTH CAROLINA COAST
TODAY WHILE ANOTHER ARCTIC HIGH PRESSURE SYSTEM NOSES IN BY FRIDAY.
THE HIGH WILL MOVE OFF THE COAST BY EARLY NEXT WEEK FOLLOWED BY
ANOTHER COLD FRONT PASSAGE ON MONDAY. A LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630 AM UPDATE...NO MAJOR CHANGES FROM THE PREVIOUS FORECAST.
HEAVIER SNOW BANDS MOVING THROUGH SOUTHERN DELMARVA AND FAR
SOUTHERN NJ NOW. EXPECT THE BULK OF THE SNOW TO OCCUR BETWEEN NOW
AND LATE THIS MORNING.
PREVIOUS NEAR TERM DISCUSSION...THE LATEST COASTAL LOW CONTINUES
TO LIFT NORTHEAST OFF THE CAROLINA COAST. SNOW HAS BEEN REPORTED
IN SOUTHERN DELMARVA, BUT AS OF 330 AM REMAINS JUST SOUTH OF OUR
CWA.
TIMING STILL LOOKS ON TRACK WITH A MAJORITY OF THE SNOW OCCURRING
FROM NOW THROUGH THE MORNING RUSH HOUR, THEN THE SNOW TAPERING OFF
MID DAY THROUGH THE AFTERNOON HOURS.
AS FOR AMOUNTS, TRENDED THE AMOUNTS DOWN SLIGHTLY FOR THE FOLLOWING
REASONS. FIRST, THERE HAS BEEN PERSISTENT CONVECTION OFF THE NC
COAST WHICH COULD LIMIT THE MOISTURE AND ENERGY THIS FAR NORTH.
SECOND, LATEST WV AND IR SATELLITE IMAGERY SHOW A MID AND UPPER LEVEL
DRY SLOT QUICKLY SLIDING IN FROM THE SW. AS OF 3 AM THE DRY SLOT
EXTENDED FROM SW VA UP TO THE POCONOS. THIS COULD HAVE A SIGNIFICANT
IMPACT FOR THE WESTERN EXTENT OF THE PRECIP. ALSO RELATED TO
SATELLITE, EVEN EAST OF THE DRY SLOT OVER SOUTHERN DELMARVA AND THE
ATLANTIC COASTAL WATERS THERE HAS BEEN A CLOUD TOP WARMING TREND FOR
THE LAST FEW HOURS. FINALLY, MOST OF THE HEAVIER BANDS OF SNOW WE`VE
SEEN UP STREAM SEEM TO BE ASSOCIATED WITH A BAND OF FRONTOGENESIS
WHICH HAS BEEN WELL DEPICTED BY THE RAP. THE RAP SHOWS THIS
FRONTOGENESIS BAND SLIDING EAST BEFORE IT GETS AS FAR AS OUR REGION.
FOR NOW THOUGH, WILL KEEP THE WINTER WEATHER ADVISORY AND WINTER
STORM WARNING AS SOME MODEL SOUNDINGS CONTINUE TO SHOW MODEST OMEGA
VALUES WITHIN THE DENDRITIC GROWTH ZONE, PRIMARILY IN THE FEW HOURS
AROUND THE MORNING RUSH HOUR. THUS THE TIMING OF THE SNOW MAY BE
MORE IMPACTFUL THAN THE ACTUAL AMOUNTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
TONIGHT, A WEAK MID LEVEL SHORT WAVE TROUGH LOOKS TO SIDESWIPE THE
NORTHWESTERN PORTIONS OF OUR REGION. AS A RESULT...LIGHT SNOW IS
POSSIBLE GENERALLY NORTH AND WEST OF THE PHILLY SUBURBS. MOISTURE
AVAILABILITY IS GOING TO BE PROBLEMATIC FOR THIS SYSTEM AS THERE IS
LITTLE CHANCE FOR ANY MOISTURE ADVECTION BEHIND TODAYS SYSTEM.
THEREFORE, ANY SNOW AMOUNTS SHOULD BE BELOW AN INCH.
AS FOR TEMPERATURES...STAYED CLOSE TO GUIDANCE AS MID LEVEL CLOUDS
SHOULD HELP TO LIMIT RADIATIONAL COOLING EVEN FOR LOCATIONS THAT
STILL HAVE SNOW PACK.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LAST PIECE OF MID-LEVEL ENERGY MOVES THROUGH THE REGION ON FRIDAY AS
THE BROAD SCALE TROUGHING FINALLY RELINQUISHING ITS GRASP ON OUR
REGION. THE MID-LEVELS TAKE ON MORE OF A ZONAL-ISH FLOW OVER THE
WEEKEND WITH THE NEXT EMBEDDED WAVE EXPECTED BY MONDAY FOLLOWED BY
RIDGING THROUGH THE REMAINDER OF THE PERIOD.
FRIDAY - SATURDAY...HIGH PRESSURE WILL BE SQUEEZING IN LATER ON
FRIDAY FROM THE WEST-NORTHWEST. JUST AHEAD OF THE RIDGING WILL BE A
LAST DITCH EFFORT BY THE BROAD TROUGH TO PUSH A DAMPENING SHORTWAVE
THROUGH THE REGION. WITH LIMITED AMOUNTS OF MOISTURE EXPECTED WE
CONFINED THE SLIGHT CHANCE POPS TO OUR WESTERN ZONES BEFORE DRYING
OUT LATER FRIDAY AFTERNOON. AT THIS POINT THE RIDGING WILL BE ABLE
TO EXERT ITSELF UPON THE AREA AND WE REMAIN DRY, BUT COLD, THROUGH
SATURDAY.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION LATE SUNDAY
INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE ABLE TO
MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF THE COAST
AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER POPS
UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL PASSAGE.
DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE FRONT WITH
ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A WINTRY MIX/
CHANGEOVER, MOSTLY ACROSS THE SOUTHERN HALF OF THE CWA, BY MONDAY
MORNING. THE FRONT THEN MOVES THROUGH AND ALLOWS FOR ANOTHER SHOT OF
COOLER AIR AND MORE PRECIPITATION PHASE CHANGES.
TUESDAY - WEDNEDSAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE A MIXED EVENT. IT SHOULD BE NOTED THAT SEVERAL TIMES THIS WINTER
THE NUMERICAL GUIDANCE HAS BEEN TOO STRONG WITH THE LOW PRESSURE AS
IT CROSSES THE MID-WEST AND THEREFORE OVER AMPLIFIES/WARMS THE LOW-
LEVELS. A SHIFT TO THE EAST AND A WEAKER SOLUTION WOULD LEAD TO LESS
MIXING.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
CEILINGS SHOULD GRADUALLY LOWER THROUGH 12Z AS SNOW APPROACHES FROM
THE SOUTH. STILL SOME UNCERTAINTY IF THE WESTERN TAF SITES, KABE AND
KRDG, WILL SEE ANY SNOW AT ALL. FOR THE DELAWARE VALLEY SITES, KPHL,
KPNE, AND KTTN, A 2 TO 3 HOUR PERIOD OF MOSTLY LIGHT SNOW IS
POSSIBLE BETWEEN 12 AND 16Z (SOONER AT KILG, WHILE KTTN WILL BE
THE LAST TO BE AFFECTED). AT KILG, KMIV AND KACY, MOSTLY LIGHT
BUT SOME PERIODS OF MODERATE TO HEAVY SNOW SNOW WILL BE POSSIBLE
FOR A MAJORITY OF THE MORNING. BY 18Z HOWEVER, SNOW SHOULD BE
OUT OF THE REGION. TAFS REFLECT MORE OPTOMISTIC CONDITIONS THAN
WHAT IS DEPICTED IN THE GFS LAMP AS IT APPEARS TO BE
UNDERESTIMATING THE DRY AIR IN THE BOUNDARY LAYER. THUS...THINK
THAT ONCE THE SNOW MOVES OUT CONDITIONS SHOULD RETURN TO
VFR...THOUGH THERE REMAINS A SMALL CHANCE THAT MVFR CEILINGS WILL
LINGER THROUGH THE DAY.
OVERNIGHT, CEILINGS SHOULD INCREASE BACK TO VFR, ALBEIT THE LOWER
END OF VFR. THERE IS SOME RISK OF BR DEVELOPING ACROSS THE REGION,
AND A LOW CHANCE OF ANOTHER ROUND OF -SN FOR KRDG AND KABE AFTER
06Z. HOWEVER, IN BOTH CASES THE CHANCE IS TOO LOW TO MENTION IN THE
TAFS AT THIS TIME.
OUTLOOK...
FRIDAY - SATURDAY...MOSTLY VFR. SLIGHT CHANCE FOR EARLY
AFTERNOON MVFR SNOW SHOWERS. NORTHERLY WINDS PREVAIL AS HIGH
PRESSURE NOSES IN FROM THE WEST.
SUNDAY - MONDAY...VFR TO START. CONDITIONS DETERIORATE LATE IN THE
DAY AS THE NEXT SYSTEM APPROACHES FROM THE WEST-SOUTHWEST. SOUTHERLY
WINDS EXPECTED.
&&
.MARINE...
WINDS SHOULD INCREASE SOON RESULTING IN SCA CONDITIONS FOR THE LOWER
BAY AND THE ATLANTIC COASTAL WATERS FOR MUCH OF THE DAY. WITH THE
INCREASE IN WINDS, SEAS WILL SLOWLY BUILD AS WELL (PRIMARILY ON THE
OCEAN). FOR THE OCEAN WATERS A FEW GUSTS ABOVE 30 KT ARE POSSIBLE
PRIMARILY LATE THIS MORNING INTO EARLY THIS AFTERNOON. BY EARLY THIS
EVENING, WINDS SHOULD DIMINISH BELOW 25KT, BUT SEAS ON THE OCEAN
WILL BE SLOW TO DIMINISH. THUS, HAVE EXTENDED THE SCA FOR THE OCEAN
ZONES THROUGH 06Z FOR THE NORTHERN WATERS AND 11Z FOR THE SOUTHERN
WATERS.
OUTLOOK...
FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY AHEAD OF AN
APPROACHING COLD FRONT. INCREASING SOUTHERLY WINDS AND BUILDING SEAS
EXPECTED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NJZ016>027.
DE...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
DEZ001-002.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR DEZ003-
004.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MDZ008-012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ431.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON
MARINE...HEAVENER/JOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
421 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 421 AM MST THU FEB 26 2015
2000-3000 KFT AGL CIGS WILL CONTINUE TO BE POSSIBLE AT KGLD EARLY
THIS MORNING...THOUGH VFR SHOULD PREVAIL. LIGHT SNOW WILL BEGIN
TO SPREAD NORTH AND BY LATE THIS AFTERNOON OUT OF EASTERN COLORADO
INTO NORTHWEST KANSAS. QUESTION IS WHETHER IT WILL IMPACT EITHER
TERMINAL...AND AT THIS POINT CONFIDENCE IS TOO LOW TO ADD MENTION
AT ANY POINT IN THE TAF PERIOD. THERE IS A BETTER CHANCE FOR SNOW
AT KGLD AFTER 06Z...BUT WILL NOT INCLUDE AS GUIDANCE IS STILL
SHOWING THE STRONGEST SIGNAL SOUTH. MVFR CIGS WILL LIKELY
REDEVELOP OVER THE KGLD TERMINAL LATE TONIGHT WITH INCREASING
MOISTURE. WINDS WILL SHIFT FROM THE NORTH TO THE SOUTHEAST THROUGH
THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
701 AM CST THU FEB 26 2015
.UPDATE...
ISSUED AT 700 AM CST THU FEB 26 2015
WELL...THE HRRR HAS CONSISTENTLY BEEN UNDERSELLING THE LIGHT
SNOWS OVER KSTL EARLY THIS MORNING. DECIDED TO UPDATE TO INCREASE
POPS IN THE FAR NORTHWEST TO LIKELY FOR A FEW HOURS THIS MORNING.
ALSO INCREASED QPF USING A BLEND OF THE 00Z ECMWF AND 06Z GFS...WHICH
ARE REAL SIMILAR. USING A SLR OF 14:1 GIVES CLOSER TO 3/4" OVER
PERRY COUNTY ILLINOIS THIS MORNING. STILL LOOKING FOR IT TO
DIMINISH TOWARD MIDDAY AS IT MOVES FARTHER SOUTH AND EAST ACROSS
THE AREA.
UPDATE ISSUED AT 546 AM CST THU FEB 26 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 338 AM CST THU FEB 26 2015
A BROAD AREA OF LIGHT SNOW OVER THE NORTHERN HALF OF ILLINOIS
DOWN INTO THE ST LOUIS METRO AREA APPEARS TO BE THE RESULT OF THE
RIGHT ENTRANCE REGION OF A DEPARTING WESTERLY JET ALOFT. ALL 00Z
GUIDANCE AND THE MOST RECENT HRRR...INDICATE A SIGNIFICANT
WEAKENING THROUGH DAYBREAK. THE SNOW WILL DRY TO DEVELOP SOUTHWARD
ALONG THE MS RIVER THROUGH MIDDAY AND THEN REALLY DRY UP AS IT
SPREADS EASTWARD ACROSS THE REMAINDER OF THE REGION THIS AFTERNOON
AND EARLY EVENING.
THE BEST CHANCE AT MEASURABLE SNOWFALL WILL BE ALONG AND NORTHWEST
OF A DONIPHAN MISSOURI TO MT VERNON ILLINOIS LINE THIS MORNING. UP
TO A HALF INCH WILL BE POSSIBLE...BUT MOST PLACES ARE LIKELY TO
ONLY SEE A LIGHT DUSTING. WE WILL CONTINUE TO MONITOR FOR SIGNS OF
A MORE SIGNIFICANT SNOWFALL THIS MORNING.
THIS AFTERNOON...SOME PATCHES OF LIGHT SNOW MAY RESULT IN A
DUSTING IN A FEW LOCATIONS MAINLY OVER WEST KENTUCKY AND SOUTHWEST
INDIANA. FLURRIES WILL BE POSSIBLE OVER MUCH OF THE AREA WELL INTO
THE EVENING HOURS...AS ARCTIC AIR SURGES BACK ACROSS THE REGION.
ARCTIC HIGH PRESSURE WILL SLOWLY BEGIN TO BUILD INTO THE AREA
THROUGH MIDDAY...AND THEN NORTH WINDS WILL REALLY PICK UP AND
BECOME GUSTY THROUGH THE AFTERNOON AND EVENING HOURS. THE
STRONGEST WINDS WILL BE IN THE VICINITY OF 00Z. WITH OVERCAST
CONDITIONS EXPECTED AND FAIRLY STRONG COLD ADVECTION THROUGH THE
DAY...MOST LOCATIONS WILL SEE HIGH TEMPERATURES THIS MORNING WITH
STEADY OR SLOWLY FALLING TEMPERATURES THROUGH THE AFTERNOON. USED
SOME LAMP DATA TO TRY TO REFLECT POSSIBLE HOURLY TEMPERATURE
TRENDS THROUGH THE DAY.
FOR TONIGHT...THERE MAY HAVE BEEN JUST A SLIGHT INCREASE IN
LOWS...WITH A RANGE OF 4 NEAR MT VERNON ILLINOIS TO 14 NEAR FT
CAMPBELL KENTUCKY. WIND CHILLS WILL GENERALLY RANGE FROM ZERO TO
10 BELOW FROM SOUTH TO NORTH ACROSS THE AREA LATE TONIGHT THROUGH
FRIDAY MORNING. WILL CONTINUE TO GIVE THIS A MENTION IN THE HWO.
THE ARCTIC SURFACE HIGH WILL SETTLE JUST NORTH OF THE REGION
FRIDAY AFTERNOON...SO A MODEST NORTHEAST WIND WILL CONTINUE
THROUGH THE DAY AND FRIDAY NIGHT. MAY HAVE NUDGED TEMPERATURE UP
JUST A DEGREE OR SO FROM THE PREVIOUS FORECAST FOR HIGHS FRIDAY
AND LOWS FRIDAY NIGHT. WIND CHILLS OVER THE NORTHERN HALF OF THE
AREA MAY DROPPED JUST A BELOW ZERO FOR A FEW HOURS LATE FRIDAY
NIGHT AND AREA SATURDAY MORNING. WILL ALSO MENTION THIS IN THE
HWO.
THE ARCTIC HIGH WILL QUICKLY BUILD EASTWARD SATURDAY...AS THE
FLOW ALOFT BECOMES RATHER FAST AND ZONAL. WARM ADVECTION
PRECIPITATION IS LIKELY IN THIS SCENARIO...AND THE MODELS TEND TO
BE A LITTLE SLOW WITH THE ONSET. INTRODUCED A SLIGHT CHANCE OF
SNOW TO THE FAR WESTERN PORTIONS OF SOUTHEAST MISSOURI SATURDAY
AFTERNOON JUST TO HINT AT THAT POSSIBILITY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 338 AM CST THU FEB 26 2015
BROAD WARM AIR ADVECTION WILL ALLOW FOR THE DEVELOPMENT OF
PRECIPITATION SATURDAY NIGHT WITH THE BULK OF IT OCCURRING TO OUR
WEST AND NORTH. LOW LEVELS APPEAR TO BE FAIRLY DRY DURING THE
FIRST PART OF THE EVENING BUT MOISTEN UP NICELY AFTER 06Z SUNDAY.
BEST CHANCES FOR PRECIPITATION WILL BE OVER PARTS OF SOUTHERN IL,
SOUTHWEST IN AND SEMO. ALTHOUGH WAA WILL BE ONGOING...WE WILL
LIKELY HAVE TO DEAL WITH FREEZING PRECIPITATION AT THE ONSET SINCE
WE WILL BE STARTING OUT RATHER COLD. WHILE WE MAY SEE A FEW
SNOWFLAKES EARLY IN THE EVENING, A WARM LAYER ALOFT WOULD MEAN
MORE OF A CHANCE FOR SLEET OR FREEZING RAIN LATER ON. HOWEVER,
SOUNDINGS INDICATE A FAIRLY QUICK WARM UP DURING THE OVERNIGHT
HOURS WHICH SHOULD MEAN A CHANGEOVER TO RAIN BY SOMETIME SUNDAY
MORNING.
NEXT PROBLEM WILL BE TIMING AN INCOMING FRONTAL BOUNDARY FROM THE
NORTHWEST. THE 12Z/00Z ECMWF IS FASTER IN BRINGING IT THROUGH WHILE
THE 00Z GFS IS A BIT SLOWER. THIS HAS IMPLICATIONS ON WHEN THE
HIGHEST POPS SHOULD BE ADVERTISED...I.E. SUNDAY OR SUNDAY NIGHT.
COLD AIR POURS BACK INTO THE REGION BEHIND THIS FRONT. IT LOOKS LIKE
THE PRECIPITATION WILL END BEFORE THE COLD AIR INFILTRATES BUT WILL
SHOW A WINTRY MIX POSSIBLE FOR PARTS OF THE AREA LATE SUNDAY NIGHT
INTO MONDAY JUST IN CASE.
AS WAS SEEN YESTERDAY...IT APPEARS AS THOUGH WE SHOULD HAVE A BRIEF
BREAK ON MONDAY AS HIGH PRESSURE TRIES TO BUILD IN. BUT THAT BREAK
IS DEFINITELY BRIEF AS WE COULD SEE PRECIPITATION SNEAK BACK INTO
THE REGION AS EARLY AS 00Z TUESDAY. OUR NEXT WEATHER SYSTEM DEVELOPS
IN THE ROCKIES AND THEN MOVES INTO THE SOUTH CENTRAL PLAINS EARLY IN
THE WEEK. OF COURSE THERE ARE DIFFERENCES IN THE LOCATION OF THE SFC
LOW BUT MODELS AGREE ON AGGRESSIVELY BRINGING PRECIPITATION BACK
INTO THE AREA MONDAY NIGHT. SOUNDINGS, THICKNESS VALUES AND RAW
MODEL SFC TEMPS INDICATE THAT WE SHOULD BE WARM ENOUGH FOR ALL
LIQUID AS THIS PRECIPITATION RETURNS. THERE MIGHT BE A BRIEF PERIOD
WHERE SOME FREEZING/FROZEN PRECIP IS POSSIBLE AT THE
ONSET...EARLY IN THE EVENING ON MONDAY...ESPECIALLY IN OUR FAR NORTH.
AS THE SFC LOW MOVES TOWARD THE REGION ON TUESDAY INTO TUESDAY
NIGHT...WE COULD BE DEALING WITH SOME HEAVY RAIN AND EVEN SOME
THUNDER ACROSS PORTIONS OF THE REGION BUT WHEN EXACTLY AND WHERE
REMAINS TO BE SEEN AS MODELS OBTAIN A BETTER HANDLE ON THE LOW
PLACEMENT. DEPENDING ON THE EXACT PATH OF THE SFC LOW...WINDS COULD
BECOME SOUTHERLY ACROSS THE AREA ON TUESDAY AND THAT WOULD ALLOW
TEMPERATURES TO REALLY RAMP UP. WE WILL KEEP THINGS CONSERVATIVE FOR
NOW BUT SEEING HOW THE NEW EURO HAS COME IN LINE WITH THE GFS...WILL
RAISE TEMPS. MODELS AGREE THAT THIS SYSTEM WILL MOVE OUT SOMETIME
LATE TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...
ISSUED AT 546 AM CST THU FEB 26 2015
THE LATEST GUIDANCE AND CURRENT OBSERVATIONAL TRENDS SUPPORT
PUSHING BACK THE ARRIVAL OF MVFR CEILINGS AND GUSTY NORTH WINDS
ASSOCIATED WITH THE ARCTIC SURGE TODAY. A NICE AREA OF MVFR SNOW
OVER KSTL AND POINTS NORTH IS EXPECTED TO DRY UP AS IT ATTEMPTS TO
SPREAD SOUTH AND EAST INTO OUR REGION. THREW IN A MENTION OF VFR
SNOW AT ALL SITES FOR A FEW HOURS WITH THE INTIAL ARRIVAL OF THE
MVFR CEILINGS. GUIDANCE APPEARS TO BE UNDER-ESTIMATING THE SNOW
AT THIS TIME...SO WILL HAVE TO MONITOR CLOSELY FOR MORE
SIGNIFICANT SNOWS AT ALL SITES TODAY. THERE IS SOME EVIDENCE THAT
THE MVFR CEILINGS MAY SCATTER OUT AT KEVV AND KOWB PRIOR TO 12Z
FRIDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
656 AM EST THU FEB 26 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST AND THE JET STREAM
FAVORS BROAD BUT WEAK LIFT OVER THE STATE TODAY. AN UPPER LEVEL
TROUGH WILL CROSS THE STATE TONIGHT AND EARLY ON FRIDAY. A LARGE
AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE FIRST
PART OF THE WEEKEND. THE PATTERN WILL THEN BECOME RATHER STORMY
WITH A FRONTAL BOUNDARY WAGGLING NORTH AND SOUTH OVER THE AREA
INTO MID WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
645 AM UPDATE...
KNOCKED POPS AND COVERAGE OF SHSN DOWN FOR THE NEXT FEW HOURS AND
HURRIED THE ENDING OF ANY SNOW FOR THE SE BY AN HOUR OR TWO. NO
CHANGES FOR THE WEST. CURRENT TEMPS MAY LEAD TO A MILDER
AFTERNOON...BUT LOTS OF CLOUDS STILL AROUND AND WILL HOLD STEADY
WITH THOSE NUMBERS FOR NOW. THE LIGHT SNOW IS RIGHT AT THE STATE
LINE...RIGHT ON TIME.
PREV...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM NEAR CAPE HATTERAS EARLY THIS MORNING WILL TRACK
OUT TO SEA LATER TODAY. HRRR OUTPUT AND LATEST RADAR TRENDS
SUGGEST THE STEADIEST SNOW AND ASSOC SIG VIS REDUCTIONS WILL STAY
SOUTH OF THE AREA. HOWEVER...UPSTREAM OBS SUGGEST VIS REDUCTIONS
IN THE 3-5SM RANGE ARE POSSIBLE ACROSS SOUTHERN PA BTWN 12Z-16Z.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
646 AM EST THU FEB 26 2015
.SYNOPSIS...
VERY LIGHT SNOW IS POSSIBLE OVER THE REGION TODAY AS LOW PRESSURE
MOVES OFF THE CAROLINA COAST AND THE UPPER JET STREAM FAVORS BROAD
BUT WEAK LIFT OVER THE STATE. THE UPPER LOW WILL CROSS THE STATE
EARLY ON FRIDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS
THE AREA FOR THE FIRST PART OF THE WEEKEND. THE PATTERN WILL THEN
BECOME RATHER STORMY WITH A FRONTAL BOUNDARY WAGGLING NORTH AND
SOUTH OVER THE AREA INTO MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS LOWERING AND LIGHT SNOW GETTING CLOSER TO THE STATE FROM
THE S AND FROM THE NW...IT IS SNOWING AT KEKN AND KCAK. THE
DOUGHNUT ON THE RADAR INDICATING SNOW ALOFT SHOULD CONTINUE TO
CLOSE IN AS THE PRECIP WORKS DOWN TO THE SURFACE BY SUNRISE RIGHT
ALONG THE SRN BORDER. THE LEFT EXIT REGION OF THE 120+KT JET IS
ALSO OVERHEAD AND THE FAVORABLE LIFT COULD PRODUCE FLURRIES ACROSS
THE ENTIRE AREA THIS MORNING. GFS WET VS MOST OTHER MDLS/ENSEMBLE
MEMBERS. HRRR AND RAP KEEP THE ACCUM PRECIP TO THE FAR SE AND OVER
THE NW MTNS. NAM DOES SNEAK SOME PRECIP N OF THE BORDER...BUT QPF
REMAINS LITTLE TO NONE. SO WILL KEEP THE LIKELY POPS CONFINED TO
THE FAR SE...MAINLY SRN LANCASTER/YORK COS. THE AMOUNTS THERE WILL
BE AN INCH OR LESS...WITH A DUSTING ALL ALONG THE MD BORDER AND
IN THE LAURELS AND NW. THE WEAKNESS IN THE LIFT AND PERSISTENT
NORTHERLY FLOW TODAY WILL KEEP THE LOW LEVELS VERY DRY IN THE
CENTRAL AND NERN PARTS OF THE CWA. THEREFORE...HAVE JUST PUT IN
SOME FLURRIES THERE. THE LOW ZIPS AWAY AND ANY SNOW IN THE SE
SHOULD MOVE AWAY/STOP BEFORE NOON. THE WINDS BACK TO THE NW AND
SOME SNOW SHOWERS WILL REMAIN IN THE WRN MTNS ALL DAY. TEMPS
SHOULD MOVE ONLY A FEW DEGS UP THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE UPPER TROUGH AXIS MOVES OVERHEAD LATE TONIGHT AND FRIDAY
MORNING. NW WINDS WILL KEEP AN UPSLOPE GOING IN THE WEST AS WELL.
THUS...SNOW SHOWERS WILL BE POSSIBLE - MAINLY IN THE WEST AND
SOUTHERN HALF OF THE AREA THRU FRIDAY MORNING...AND WILL PROBABLY
HOLD ON IN THE LAURELS THROUGH FRIDAY EVENING.
LOW TEMPS TONIGHT WILL BE ZERO TO 5 BELOW ACROSS THE NRN
MTNS...AND UPPER SINGLE DIGITS TO LOWER TEENS ELSEWHERE. FRIDAY
MAXES WILL BE IN THE SINGLE DIGITS TO L-M20S. THE LIGHT NW WIND
APPEARS LIKE IT SHOULD NOT BE HIGH ENOUGH TO MAKE DANGEROUS WIND
CHILLS WIDESPREAD ENOUGH FOR AN ADVY FRI MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION DRIES THINGS OUT FOR EARLY
WEEKEND. AS IT MOVES TO THE ATLANTIC COAST ON SUNDAY...RETURN FLOW
SHOULD DRAW MOISTURE UP INTO THE OHIO VALLEY. MOISTURE WILL
OVERSPREAD THE OHIO VALLEY AND SLIDE ACROSS PA IN A DISORGANIZED
PRECIPITATION PATTERN. ANOTHER BLAST OF ARCTIC AIR THEN SHOVES
THAT SYSTEM OFF TO THE EAST.
AS A SOUTHWEST UPPER FLOW SETS UP NEXT WEEK...MOISTURE WILL SPREAD
TOWARD THE AREA BY LATER TUESDAY. COLD AIR IN PLACE OVER THE
RIDGE AND VALLEY REGION COULD LEAD TO THE INITIAL PRECIPITATION
SHIELD TO BE SLEET OR FREEZING RAIN. THE BULK OF THE MOISTURE DOES
APPEAR TO TRAVEL SOUTH OF PA AT THIS TIME. UNSETTLED CONDITIONS
WILL LINGER THROUGH LATE WEEK AS THE AREA WOBBLES AROUND THE ZERO
DEGREE H850 LINE..
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM NEAR CAPE HATTERAS EARLY THIS MORNING WILL TRACK
OUT TO SEA LATER TODAY. HRRR OUTPUT AND LATEST RADAR TRENDS
SUGGEST THE STEADIEST SNOW AND ASSOC SIG VIS REDUCTIONS WILL STAY
SOUTH OF THE AREA. HOWEVER...UPSTREAM OBS SUGGEST VIS REDUCTIONS
IN THE 3-5SM RANGE ARE POSSIBLE ACROSS SOUTHERN PA BTWN 12Z-16Z.
COASTAL STORM WILL HAVE MADE IT/S CLOSEST PASS AND WILL BE
PULLING AWAY FROM THE AREA BY ARND 16Z. FOCUS WILL THEN SHIFT
TOWARD A WEAKER LOW PRES SYSTEM LIFTING NE FROM THE OHIO VALLEY.
LATEST MDL GUIDANCE SUGGESTS THIS SYSTEM WILL SPREAD LIGHT
SNOW/SIG VIS REDUCTIONS INTO THE NW MTNS /KBFD/ BY LATE AM...THEN
THE LAUREL HIGHLANDS /KJST/ DURING THE AFTN. PREDOMINANTLY IFR
CONDS APPEAR LIKELY AT THESE LOCATIONS INTO THIS EVENING...AS THE
SLOW-MOVING LOW PRES SYSTEM AND ASSOC LIGHT SNOW MOVES THRU. A
DOWNSLOPING NNW WIND SHOULD RESULT IN SOMEWHAT MORE FAVORABLE
CONDS EAST OF THE MTNS WITH WIDESPREAD MVFR CIGS AND OCNL LGT
SNOW. HOWEVER...CAN/T RULE OUT BRIEF IFR VIS REDUCTIONS THIS
EVENING AT KUNV/KAOO.
OUTLOOK...
FRI...EARLY AM LGT SNOW/VIS REDUCTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 25TH...IPT 18.0...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...TYBURSKI
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
406 AM MST THU FEB 26 2015
.SYNOPSIS...
YET ANOTHER COOL FRONT WILL MOVE WEST THROUGH MUCH OF THE BORDERLAND
TODAY...DROPPING TEMPERATURES BACK BELOW NORMAL AND PRODUCING SOME
BREEZY WINDS. THE FRONT WILL ALSO PUSH LOWER CLOUDS INTO THE
SACRAMENTO MOUNTAINS ALONG WITH A CHANCE OF LIGHT SNOW. TEMPERATURES
WILL REMAIN COOL ON FRIDAY BEFORE AN UPPER LOW MOVES DOWN OVER
NEVADA ON SATURDAY...BRINGING SOUTHWEST FLOW AND WARMER TEMPERATURES
BACK TO THE AREA FOR SATURDAY THROUGH MONDAY. THIS SOUTHWEST FLOW
WILL ALSO BRING MOISTURE IN AND BY SATURDAY ANOTHER CHANCE OF
SHOWERS WILL DEVELOP...MOSTLY WEST OF DEMING...AND THEN SLOWLY
SPREADING EAST SUNDAY AND MONDAY. MOUNTAIN AREAS COULD RECEIVE HEAVY
SNOW MONDAY AND TUESDAY.
&&
.DISCUSSION...
LOOKS LIKE THE LATEST BACK DOOR FRONT HAS REACHED THE EAST SLOPES OF
THE SACRAMENTO MOUNTAINS A SHORT WHILE AGO ALONG WITH LOW CLOUDS.
EXPECT MOST OF THESE CLOUDS TO REMAIN ALONG AND OVER THE HIGHER
TERRAIN OF THE EASTERN CWA THIS MORNING AND AFTERNOON...WHILE THE
FRONT WILL TREK WESTWARD. HRRR SHOWS FRONT REACHING EL PASO NEXT 3-6
HOURS WITH FRONT REACHING AT LEAST THE CONTINENTAL DIVIDE BY EARLY
FRIDAY MORNING...IF NOT ALL THE WAY TO THE ARIZONA BORDER. NO OTHER
WEATHER EXPECTED WITH THIS FRONT OTHER THAN COOLER TEMPERATURES BACK
BELOW NORMAL. AS THE WEST/SOUTHWEST FLOW STRENGTHENS ACROSS THE AREA
FROM ADVANCING LOW FROM THE PAC NORTHWEST...SEVERAL DISTURBANCES
WILL PASS THROUGH TONIGHT AND FRIDAY NIGHT. LIKELY WILL NOT AFFECT
THE AREA MUCH THOUGH DID KEEP LOW POPS IN FOR THE NORTHERN TIER OF
ZONES.
DEVELOPING UPPER LOW DROPS DOWN OVER CENTRAL CALIFORNIA SATURDAY...
INCREASING THE SOUTHWEST FLOW AND MOISTURE OVER THE AREA. CHANCE OF
SHOWERS WILL SPREAD TO THE GILA SATURDAY AND SATURDAY NIGHT AND THEN
ABOUT AS FAR EAST AS DEMING SUNDAY. BY SUNDAY NIGHT OR MONDAY THE
REMAINDER OF THE CWA WILL SEE A CHANCE OF SHOWERS. SHOWERS COULD
BECOME OCCASIONALLY HEAVY SUNDAY AND MONDAY AS AIRMASS BECOMES
SLIGHTLY UNSTABLE. SNOW LEVELS WILL BEGIN QUITE HIGH SATURDAY AT
AROUND 8000-9000 FT BUT THEN BEGIN LOWERING MONDAY WITH INCOMING
PACIFIC COOL FRONT...AS LOW 5000 FT IN THE NORTH...6000-7000 FT IN
THE SOUTH. MODELS...ESPECIALLY THE GFS...CONTINUE TO SHOW HEAVY SNOW
FOR BOTH GILA/BLACK RANGE MOUNTAINS AND THE SACRAMENTO MOUNTAINS.
POTENTIAL FOR VERY HEAVY SNOW IS DEFINITELY THERE.
&&
.AVIATION...VALID 26/12Z-27/12Z...
GENLY VFR. COLD FRONT PUSHING IN FROM THE EAST WILL SPREAD LOW
CLOUDS...FOG AND POSSIBLY LIGHT SNOW TO THE SACRAMENTO MOUNTAINS
THIS MORNING AND AFTERNOON. IFR CONDS WILL DEVELOP OVER THESE
MOUNTAINS...MOST PREVALENT ON THE EAST SLOPES OF THE SACRAMENTO
MOUNTAINS. AFT 00Z...BKN120 OVC 200 WITH ISOLD -SHRA BKN080 FROM
ALM-TCS NORTH. AFT 18Z SURFACE WINDS INCREASING EAST 10-20 KTS. EAST
WINDS TO 20 KTS WITH GUSTS TO 30 KTS ALONG WEST SLOPES OF TERRAIN.
&&
.FIRE WEATHER...
ANOTHER COLD FRONT WILL MOVE IN FROM THE EAST THIS MORNING AND
AFTERNOON...SPREADING COOLER TEMPERATURES AND BRISK EAST WINDS TO
MUCH OF THE FIRE ZONES EAST OF DEMING. SOME LIGHT SNOW IS POSSIBLE
OVER THE SACRAMENTO MOUNTAINS THROUGH TONIGHT. A LARGE LOW MOVES
DOWN OVER NEVADA SATURDAY AND BRINGS BACK STRONG SOUTHWEST FLOW WITH
MOISTURE. THIS WILL CREATE BREEZY TO WINDY CONDITIONS FROM SATURDAY
INTO THE FIRST HALF OF NEXT WEEK. THE SOUTHWEST FLOW WILL ALSO BRING
MOISTURE UP...WITH SHOWERS DEVELOPING WESTERN ZONES SATURDAY AND
SPREADING TO REMAINDER OF ZONES SUNDAY AND MONDAY. AS THE SNOW
LEVELS DROP SUNDAY AND MONDAY THE MOUNTAINS WILL BEGIN RECEIVING
SNOW...WHICH COULD BECOME HEAVY.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 57 33 56 35 68 / 0 0 0 0 0
SIERRA BLANCA 50 28 53 25 66 / 0 0 0 0 0
LAS CRUCES 57 31 58 30 66 / 0 0 0 0 0
ALAMOGORDO 52 29 54 31 61 / 0 20 0 0 0
CLOUDCROFT 32 18 34 23 42 / 20 50 10 10 0
TRUTH OR CONSEQUENCES 56 31 59 33 59 / 0 20 0 0 10
SILVER CITY 57 28 56 31 58 / 0 0 0 10 20
DEMING 62 30 60 32 65 / 0 0 0 0 0
LORDSBURG 67 29 63 32 64 / 0 0 0 0 10
WEST EL PASO METRO 55 34 58 36 69 / 0 0 0 0 0
DELL CITY 48 23 40 25 64 / 0 0 20 0 0
FORT HANCOCK 55 31 57 33 67 / 0 0 0 0 0
LOMA LINDA 48 28 49 26 64 / 0 0 0 0 0
FABENS 56 31 58 33 69 / 0 0 0 0 0
SANTA TERESA 57 32 58 32 68 / 0 0 0 0 0
WHITE SANDS HQ 52 30 54 30 63 / 0 0 0 0 0
JORNADA RANGE 53 25 56 25 64 / 0 0 0 0 0
HATCH 56 28 60 31 64 / 0 0 0 0 0
COLUMBUS 65 33 61 36 66 / 0 0 0 0 0
OROGRANDE 54 29 52 29 64 / 0 0 0 0 0
MAYHILL 32 17 30 21 50 / 20 60 20 10 0
MESCALERO 36 19 34 25 49 / 20 50 20 20 0
TIMBERON 37 20 35 24 49 / 10 30 10 10 0
WINSTON 51 27 46 31 56 / 0 20 0 10 20
HILLSBORO 54 30 46 31 60 / 0 10 0 0 20
SPACEPORT 57 27 56 28 61 / 0 20 0 0 0
LAKE ROBERTS 52 28 45 30 56 / 0 10 0 10 30
HURLEY 60 29 58 30 60 / 0 0 0 0 20
CLIFF 62 25 54 33 62 / 0 0 0 10 20
MULE CREEK 58 22 59 28 60 / 0 0 0 10 20
FAYWOOD 59 31 47 31 60 / 0 0 0 0 20
ANIMAS 68 30 65 38 66 / 0 0 0 0 10
HACHITA 62 28 57 33 66 / 0 0 0 0 10
ANTELOPE WELLS 67 34 63 39 67 / 0 0 0 0 10
CLOVERDALE 62 33 59 38 65 / 0 0 0 0 10
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
17 HEFNER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
506 AM CST THU FEB 26 2015
.AVIATION...
AT 5 AM...THE COLD FRONT WAS LOCATED NEAR A SAN ANGELO TO DALLAS
LINE AND IS QUICKLY MOVING SOUTH. THE FRONT SHOULD BE THROUGH
KAUS/KDRT AROUND 17Z AND THOUGH THE SAN ANTONIO SITES SHORTLY
AFTER. THERE IS A NARROW BAND OF MVFR CEILINGS JUST BEHIND THE
FRONTAL BOUNDARY AND WILL SHOW A FEW HOURS OF POST FRONTAL MVFR
IN THE I-35 TAF SITES. THE FRONT WILL ALSO BRING BREEZY NORTH
WINDS WITH GUSTS UP TO 25 KNOTS EXPECTED THIS AFTERNOON. VFR WILL
PREVAIL BY LATE AFTERNOON BUT A RETURN TO MVFR IS EXPECTED AFTER
12Z TOMORROW AS LOW-LEVEL MOISTURE INCREASES ACROSS THE REGION.
PRECIPITATION CHANCES IN THE EXTENDED PORTION OF TAF AUS AND
TAFSAT ARE TOO LOW TO MENTION AT THIS TIME.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 415 AM CST THU FEB 26 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAYS HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 45 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 47 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...29
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
415 AM CST THU FEB 26 2015
.SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAYS HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
&&
.LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 45 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 47 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...29
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
940 AM CST THU FEB 26 2015
.UPDATE...
A LAKE EFFECT SNOW ADVISORY IS IN EFFECT FOR RACINE AND KENOSHA
COUNTIES UNTIL 16Z THIS MORNING. LOOKS LIKE THE LAKE EFFECT SNOW
SQUALL IS STARTING TO SHIFT OFF TO THE EAST AS THE WINDS HAVE
STARTED BACKING TO A MORE NORTHWEST DIRECTION. THIS SHOULD HELP
MOVE THE SNOW SQUALL TO THE SOUTHEAST. MESO MODELS ALSO INDICATE
THE SNOW SQUALL WILL TAPER OFF RAPIDLY AND MOVE OUT OF THE
FORECAST AREA LATER THIS MORNING. EASTERN PORTIONS OF RACINE AND
KENOSHA WILL STILL BE DEALING WITH SOME LIGHT TO MODERATE SNOW FOR
THE NEXT HOUR OR SO.
&&
.AVIATION/18Z TAFS/...
MVFR CONDITIONS WILL PERSIST INTO THE AFTERNOON AS SOME LOW CLOUDS
WILL STICK AROUND THE AREA. ENW SHOULD SEE THE CURRENT LAKE
EFFECT SNOW SQUALL BAND QUICKLY SHIFT OFF TO THE EAST THIS MORNING.
OTHERWISE...EXPECT SOME LOW LEVEL CLOUDS...MAINLY FEW TO SCT WILL
PREVAIL THIS AFTN. SOME BKN SKIES COULD OCCUR AS LOW LEVEL LAPSE
RATES STEEPEN THIS AFTN. WINDS WILL STAY AT MORE NORTHERLY
DIRECTION THIS AFTN AND SHIFT MORE TO THE WEST AS ARCTIC HIGH
PRESSURE WILL ONCE AGAIN MOVE INTO THE REGION. COLD TEMPERATURES
WILL RETURN LATER TONIGHT. HOWEVER...WINDS SHOULD BE FAIRLY LIGHT
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 527 AM CST THU FEB 26 2015/
UPDATE...DECIDED TO EXTEND LAKE EFFECT SNOW ADVY FOR MILWAUKEE CO
UNTIL 14Z AND RACINE/KENOSHA COUNTIES UNTIL 16Z. KMKX/TMKE RADARS
SHOW ENHANCED LAKE BAND CONTINUING TO REGENERATE AND EXTENDS ABOUT
30 MILES NORTHEAST OF KMKE AND IS MOVING STEADILY SSW AT 20KTS.
THIS WILL PROBABLY BE THE LAST ROUND OF HEAVIER SNOW SHOWERS IN
SOUTHEAST MKE COUNTY BUT MAY STILL CLIP ERN RACINE/KENOSHA
COUNTIES THROUGH LATE MRNG. LATEST RAP SHOWS ENHANCED CONVERGENCE
AND OMEGA WEAKENING AND SLIDING SOUTHEAST OF KENOSHA CO BY LATE
MRNG.
&&
.TODAY...FORECAST CONFIDENCE IS MEDIUM.
PULLED TRIGGER ON LAKE EFFECT SNOW ADVY FOR THREE SOUTHEAST
COUNTIES EARLIER. OBSERVER IN OAK CREEK HAD REPORTED 4 INCHES OF
FLUFF BEFORE LAKE BAND HAD DEVELOPED. AROUND 07Z...IMPRESSIVE LAKE
EFFECT ENHANCED BAND RAPIDLY DEVELOPED OVER THE NEAR SHORE WATERS
AND SPREAD INLAND BY 0730Z. THIS WAS WHEN THE STRONGEST LOW LEVEL
CONVERGENCE AND PEAK LIFT WERE TO OCCUR OVER THE NEARSHORE
WATERS...SPREADING INLAND THRU PARTS OF THE THREE COUNTIES.
WITH BAND ORIENTATED NNE TO SSW AND MOVING TO THE SSW...HIGH SNOW
LIQUID RATIOS WOULD RESULT IN ADDITIONAL 1 TO 3 INCHES...ADDING TO
THE ALREADY 1 TO 3 INCHES THAT HAD ALREADY OCCURRED OVER MUCH OF
THE AREA.
LATEST RAP13 CONTINUES TO SHOW OMEGA LINGERING OVER SE MKE COUNTY
UNTIL ABOUT 14Z AND ERN RAC/KEN COUNTIES UNTIL 15Z OR SO. HOWEVER
DURING THIS TIME...LOW LEVEL FLOW BEGINS BACKING MORE TO THE NORTH
TO NORTHEAST...DECREASING FETCH AND LOW LEVEL RH ALSO DECREASES.
MAY NEED TO EXTEND LAKE EFFECT SNOW ADVY FOR AN HOUR OR TWO
PENDING STRENGTH OF LAKE BAND.
OTHERWISE...GRADUAL CLEARING SHOULD CONTINUE AS DRIER AIR SLIDES
ACROSS SRN WI TODAY. MAY BE SOME LINGERING SC FOR A TIME THIS AFTN
DUE TO LINGERING LOW LEVEL RH FLOW AND STEEP LOW LEVEL LAPSE
RATES.
.TONIGHT...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE RIDGE AXIS REMAINS WEST OF WI OVERNIGHT TONIGHT AS
SHORT WAVE RIDGING SETTLES IN. INCREASING SUBSIDENCE SHOULD CLEAR
SKIES OVERNIGHT AS LOW LEVEL FLOW TURNS NORTHWEST. WITH LAKE
SUPERIOR PRETTY WELL ICE-COVERED...NOT THINKING MUCH THREAT OF
LAKE CLOUDS FROM THE NORTH.
ENOUGH MIXINESS OF 3 TO 5 KTS OVERNIGHT...AND OVERNIGHT LOWS FROM
4 TO 12 BELOW...TO RESULT IN A THREE HOUR WINDOW OF WIND CHILLS
AROUND 20 BELOW. WL LET DAY SHIFT MAKE FINAL DECISION ON WIND
CHILL ADVY.
.SHORT TERM...FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH TAKING ARCTIC HIGH PRESSURE FROM
WESTERN IOWA TO NORTHERN OHIO FRIDAY AND FRIDAY NIGHT. THE HIGH
WILL BRING QUIET WEATHER BUT CONTINUED COLD TEMPERATURES. GIVEN
MOSTLY CLEAR SKIES AND STRONG INVERSION JUST ABOVE THE
SURFACE...COULD SEE RADIATIONAL COOLING WITH LOWS EVEN COLDER THAN
CURRENTLY FORECAST FRIDAY NIGHT.
WIND CHILLS AGAIN HOVER AROUND 20 BELOW ZERO FOR A COUPLE
HOURS...THOUGH WINDS MAY BE TOO LIGHT IF DECOUPLING OCCURS. LATER
SHIFTS CAN EVALUATE NEED FOR WIND CHILL ADVISORY.
WARM AIR ADVECTION SLOWLY DEVELOPS ACROSS THE AREA SATURDAY INTO
SATURDAY NIGHT...AS THE HIGH MOVES FURTHER EAST OF THE REGION.
DEEP MOISTURE SHIFTS NORTHEASTWARD INTO THE AREA SATURDAY
NIGHT...ALONG WITH INITIAL 500 MB VORTICITY MAXIMUM. SURFACE COLD
FRONT THEN SHIFTS EASTWARD THROUGH THE REGION SUNDAY. TIMING OF
THE FRONTAL PASSAGE VARIES SOMEWHAT ON THE MODELS. UPWARD VERTICAL
MOTION SATURDAY NIGHT AND SUNDAY IS WEAK TO MODEST...THOUGH DOES
TAP DENDRITE SNOW GROWTH ZONE.
SREF PROBABILITIES OF MEASURABLE PRECIPITATION ARE OVER 90
PERCENT FOR SATURDAY NIGHT. THUS...RAISED POPS ESPECIALLY LATER
SATURDAY NIGHT...WITH LIKELY VALUES IN THE SOUTHWEST COUNTIES. MAY
NEED EVEN HIGHER POPS SATURDAY NIGHT INTO SUNDAY MORNING IN LATER
FORECASTS...IF MODELS REMAIN CONSISTENT. COULD SEE 1 TO 2 INCHES
OF SNOW ACCUMULATION NORTH...TO 2 TO 3 INCHES SOUTH...HIGHEST
AMOUNTS FAR SOUTHEAST.
.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE
IS MEDIUM.
MAIN ISSUE THIS PERIOD WILL BE SYSTEM FOR TUESDAY AND
PRECIPITATION AMOUNTS/TYPES. GFS/ECMWF ARE IN SOMEWHAT BETTER
AGREEMENT WITH THE SURFACE LOW TRACK. THEY TAKE LOW FROM CENTRAL
KANSAS TO CENTRAL ILLINOIS TUESDAY...THEN INTO THE EASTERN GREAT
LAKES REGION TUESDAY NIGHT. GOOD AMOUNT OF WARM AIR ADVECTION
OCCURS MONDAY NIGHT INTO TUESDAY...WITH STRONG MOISTURE ADVECTION
AND A 500 MB VORTICITY MAXIMUM PASSAGE INTO TUESDAY NIGHT.
MODELS SHOWING THE BEST UPWARD VERTICAL MOTION OVER THE AREA
TUESDAY. GFS FORECAST SOUNDINGS ARE SUGGESTING SOME MIXINESS OF
FREEZING RAIN/SLEET IN THE FAR SOUTH AND SOUTHEAST TUESDAY. RAISED
POPS FOR MONDAY NIGHT INTO TUESDAY NIGHT...HIGHEST ON TUESDAY.
SEVERAL INCHES OF SNOW ARE POSSIBLE...WITH SLEET/FREEZING RAIN
POSSIBLE...SO STAY TUNED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM CST THIS MORNING FOR
WIZ071-072.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LMZ645-646.
&&
$$
UPDATE...JTS
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
527 AM CST THU FEB 26 2015
.UPDATE...DECIDED TO EXTEND LAKE EFFECT SNOW ADVY FOR MILWAUKEE CO
UNTIL 14Z AND RACINE/KENOSHA COUNTIES UNTIL 16Z. KMKX/TMKE RADARS
SHOW ENHANCED LAKE BAND CONTINUING TO REGENERATE AND EXTENDS ABOUT
30 MILES NORTHEAST OF KMKE AND IS MOVING STEADILY SSW AT 20KTS.
THIS WILL PROBABLY BE THE LAST ROUND OF HEAVIER SNOW SHOWERS IN
SOUTHEAST MKE COUNTY BUT MAY STILL CLIP ERN RACINE/KENOSHA
COUNTIES THROUGH LATE MRNG. LATEST RAP SHOWS ENHANCED CONVERGENCE
AND OMEGA WEAKENING AND SLIDING SOUTHEAST OF KENOSHA CO BY LATE
MRNG.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...LAKE EFFECT SNOW ADVISORY UNTIL 8 AM CST THIS MORNING FOR WIZ066.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM CST THIS MORNING FOR
WIZ071-072.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LMZ645-646.
&&
$$
UPDATE...MBK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CST THU FEB 26 2015
.SHORT TERM...
THROUGH SATURDAY...
243 PM...LAKE EFFECT IS NOW ORGANIZING INTO A SINGLE BAND AS
WINDS TURN MORE NORTHWEST ACROSS NORTHEAST IL AND THIS BAND IS
SHIFTING TO THE SOUTHEAST AND WILL BE OUT OF COOK COUNTY IN THE
NEXT HOUR OR SO. WILL BE EXPIRING LAKE COUNTY IL FROM THE WARNING
AND FOR NOW WILL LET COOK COUNTY RIDE UNTIL 6 PM...BUT IF CURRENT
TRENDS CONTINUE...IT PROBABLY WILL BE CANCELLED EARLY.
HI RES GUIDANCE IS IN REASONABLE AGREEMENT THAT THE LAKE EFFECT
BAND WILL SHIFT INTO PORTER COUNTY BY EARLY/MID EVENING...SO
EXPECTED AMOUNTS IN NORTHERN LAKE COUNTY INDIANA ARE A BIT
UNCERTAIN BUT WITH RATES OF 1-2 INCHES PER HOUR IN THE BAND...ITS
POSSIBLE SOME ISOLATED AMOUNTS OF 3 TO 6 INCHES WILL BE POSSIBLE.
MORE CONFIDENCE WITH AMOUNTS INTO NORTHERN PORTER COUNTY AS THE
BAND REMAINS THERE FROM MID EVENING THROUGH THE OVERNIGHT HOURS
WITH LOCALLY 4 TO 7 INCHES...PERHAPS MOSTLY NEAR THE LAKE. THE
BAND THEN BEGINS TO SHIFT OUT OF THE LAKE TOWARD MORNING. SO NOT
PLANNING ANY CHANGES TO THE WARNING END TIME FOR EITHER LAKE OR
PORTER COUNTIES...THOUGH CONFIDENCE REGARDING WHEN EXACTLY PRECIP
ENDS IS A BIT UNCERTAIN.
HIGH PRESSURE BUILDS ACROSS THE MIDWEST TONIGHT AND THEN MOVES
ACROSS THE AREA ON FRIDAY. WINDS WILL SLOWLY DIMINISH OVERNIGHT
BUT LIKLELY REMAIN IN THE 5-10 MPH. THIS COMBINED WITH TEMPS
DROPPING WELL BELOW ZERO AWAY FROM CHICAGO WILL RESULT IN WINDS
CHILLS 20 BELOW TO 25 BELOW ZERO ACROSS THE NORTHERN CWA AND INTO
THE 15 BELOW RANGE SOUTH OF I-80. VALUES ARE BIT MARGINAL INTO
CHICAGO AND ALONG THE I-80 CORRIDOR BUT PLAN TO ISSUE A WIND
CHILL ADVISORY OVERNIGHT INTO FRIDAY MORNING GENERALLY ALONG AND
NORTH OF I-80 IN ILLINOIS.
DESPITE THE LIGHT WINDS AND SUNNY SKIES ON FRIDAY AS THE HIGH
SLOWLY MOVES ACROSS THE AREA...THE AIRMASS WILL REMAIN VERY COLD
WITH HIGHS ONLY REACHING THE MID TO PERHAPS UPPER TEENS. TEMPS
WILL LIKELY TANK FRIDAY NIGHT AS THE HIGH SHIFTS EAST AND LIGHT
WINDS TURN SOUTHERLY. SATURDAY WILL BE DRY AND A BIT WARMER WITH
HIGHS IN THE LOWER/MIDS 20S WITH INCREASING CLOUDS IN THE
AFTERNOON. CMS
&&
.LONG TERM...
SATURDAY NIGHT THROUGH THURSDAY...
THE TIME FRAME WILL START OUT ACTIVE AS A PERIOD OF ACCUMULATING
SNOW IS APPEARING LIKELY SATURDAY NIGHT INTO SUNDAY. STEADILY
INCREASING UPPER LEVEL FLOW OUT AHEAD OF DIGGING TROUGH TO THE
NORTH WILL ALLOW SHORT WAVE ENERGY TO TRAVERSE THE REGION DURING
THIS PERIOD...WHILE ONGOING WAA PERSISTS. THIS SHOULD ALLOW SNOW
TO SPREAD NORTHEAST ACROSS THE CWA DURING THE EVENING HOURS WITH
SNOW LIKELY ACROSS MUCH OF THE CWA AFTER THE MIDNIGHT TIME
FRAME...THEN LIKELY CONTINUING INTO SUNDAY AFTERNOON. MOST
GUIDANCE IN AGREEMENT WITH OVERALL LARGE SCALE SETUP DURING THIS
TIME AND EVEN WITH THIS SNOW SPREADING OVER THE CWA.
HOWEVER...THERE DOES APPEAR TO BE SOME TIMING DIFFERENCES OF THE
ONSET AND TIMING OF BEST SNOWFALL. SO I DO FEEL IT WILL SNOW AND
HAVE LIKELY POPS OVER THE ENTIRE CWA LATE SATURDAY NIGHT INTO
SUNDAY MORNING...BUT DID NOT GO TO CATEGORICAL BASED ON THE
PREVIOUSLY MENTIONED UNCERTAINTIES. ONLY MINOR CHANGES MADE TO THE
CURRENT SNOW FORECAST WITH THE BEST FORCING AND HIGHEST SNOWFALL
TOTALS CURRENTLY EXPECTED TO BE SOUTH OF I80. WHILE MOST OF THE
CWA WILL LIKELY OBSERVE ACCUMULATING SNOWFALL...THE SOUTHERN CWA
COULD APPROACH ADVISORY TYPE SNOW. HOWEVER I WONDER IF MY CURRENT
TOTAL MIGHT BE A LITTLE TOO HIGH...ESPECIALLY WITH THE ANTICIPATED
DRIVING MECHANISMS OF THIS SNOW...BUT THE LONGER DURATION OF THIS
LIGHT TO AT TIME MODERATE SNOW COULD HELP FOR THE CURRENT FORECAST
TOTALS. SYSTEM SNOW WILL DEPART TO THE EAST LATE SUNDAY AND SUNDAY
EVENING...AS HIGH PRESSURE BUILDS ACROSS THE REGION.
EARLY NEXT WEEK APPEARS TO BEGIN QUIET...BUT WITH ACTIVE WEATHER
RETURNING THROUGH MIDWEEK. HIGHLY AMPLIFIED PATTERN WITH UPPER
LEVEL RIDGE OVER THE EASTERN US AND A DIGGING TROUGH OVER THE
WESTERN CONUS WILL BE IN PLACE ON TUESDAY...AS DEEPENING SURFACE
LOW APPROACHES THE CWA FROM THE SOUTHWEST. STRONG WARM AIR AND
MOIST ADVECTION IS ANTICIPATED MONDAY NIGHT AND ESPECIALLY
TUESDAY/TUESDAY NIGHT. THIS WILL NOT ONLY PROVIDE THE POTENTIAL
FOR INITIAL VARYING PRECIP TYPE BUT WITH ALSO STEADIER
RAINFALL...AS A BROAD AREA OF PRECIP IS EXPECTED TO ACCOMPANY THIS
SYSTEM. EC AND GFS SIMILAR WITH REGARDS TO WAA...BUT WITH THE GFS
NOT AS ROBUST WITH THE MOISTURE ADVECTION AS THE EC IS APPEARING
TO BE. IF THE EC WERE TO VERIFY...THEN SURFACE DEWPOINTS COULD
APPROACH 50 DEG AND 850MB DEWPOINTS APPROACHING 10-11C. THIS WILL
BE CONCERNING FOR POSSIBLE HYDRO ISSUES...ESPECIALLY WITH THE
ANTICIPATED SNOW THIS WEEKEND. THERMAL PROFILES SUPPORTIVE OF ALL
RAIN ON TUESDAY AND ALTHOUGH I HAVENT INCLUDED THUNDER IN THE
GRIDS AT THIS TIME...WILL NEED TO MONITOR THIS POTENTIAL AS
WELL...ESPECIALLY FOR THE SOUTHERN CWA.
RODRIGUEZ
&&
.CLIMATE...
345 AM CST
TEMPERATURES ARE FORECAST ONCE AGAIN TO BE CLOSE OR BREAK THE
FOLLOWING RECORDS THROUGH THE LATTER HALF OF THIS WEEK...INCLUDING
ONE ON FRIDAY IN ROCKFORD THAT WAS SET JUST LAST WINTER:
ROCKFORD...
TODAY FEB 26TH LOW MAXIMUM: 11 IN 1920
FRIDAY FEB 27TH LOW MAXIMUM: 15 IN 2014
SATURDAY FEB 28TH LOW: -7 IN 1962
SATURDAY FEB 28TH LOW MAXIMUM: 17 IN 1962
CHICAGO...
FRIDAY FEB 27TH LOW: -6 IN 1897
SATURDAY FEB 28TH LOW: 0 IN 1884
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHERLY WINDS 10 TO 14 KT BECOING NORTHWEST THIS EVENING.
KJB
//DISCUSSION...UPDATED 18Z...
THE FOCUS FOR LAKE EFFECT SNOW SHOWERS WILL GRADUALLY BEGIN TO SHIFT
EASTWARD INTO SOUTHERN COOK AND NORTHWESTERN INDIANA OVER THE NEXT
FEW HOURS. AREA SURFACE OBSERVATIONS INDICATE WINDS SHIFTING
NORTHERLY ACROSS LAKE AND NORTHERN COOK COUNTIES IN ILLINOIS. RADAR
TRENDS OVER THE PAST HOUR HAVE ALSO SHOWN A DECREASE IN INTENSITIES
ACROSS LAKE COUNTY ILLINOIS...WITH SEVERAL SITES NOW OUT OF THE SNOW
AREA. THESE SAME TRENDS SHOULD GRADUALLY SHIFT SOUTH AND EASTWARD
THROUGH THE AFTERNOON. A BETTER WELL DEVELOPED BAND OF LAKE EFFECT
SNOW SHOWERS WILL TRY TO MOVE OVER KMDW OVER THE NEXT HOUR OR
SO...AND THIS COULD RESULT IN ANOTHER BRIEF PERIOD OF LOW
VISIBILITIES...POSSIBLY DOWN TO A HALF MILE. CONDITIONS WILL
IMPROVE BY MID AFTERNOON AT KMDW...BUT AT KGYY PERIODS OF LAKE
EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE AFTERNOON...BEFORE
ABATING THIS EVENING.
AFTER THIS LAKE EFFECT FOCUS SHIFTS EAST OF THE TERMINALS A PERIOD
OF QUIET WEATHER IS EXPECTED FOR TONIGHT AND FRIDAY AS A SURFACE
RIDGE OF HIGH PRESSURE MOVES OVER CENTRAL ILLINOIS. WINDS ARE
EXPECTED TO BE RATHER LIGHT WITH A WESTERLY DIRECTION.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
HIGH WITH ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS.
SATURDAY...VFR THEN SNOW WITH IFR PROBABLE SATURDAY NIGHT. SOUTH
WINDS.
SUNDAY...SNOW WITH IFR POSSIBLE. SOUTHWEST WINDS.
MONDAY...VFR THEN LIGHT SNOW WITH IFR POSSIBLE MONDAY NIGHT. NORTH
WINDS.
TUESDAY...WINTRY MIX LIKELY WITH IFR. SOUTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF SNOW AND IFR. NORTHWEST WINDS.
MTF
&&
.MARINE...
215 PM CST
THE FAR NORTHERN PORTIONS OF THE LAKE REMAINS ICE COVERED AS DO
THE SOUTHERN NEARSHORE WATERS. THERE...WAVES HAVE REMOVED FROM THE
FORECAST FOR THESE AREAS.
HIGH PRESSURE EXTENDS FROM THE NORTHERN PLAINS...WITH A CENTRAL
PRESSURE OF 30.8 INCHES...SOUTH THROUGH TEXAS AND EAST ACROSS THE
GREAT LAKES. THE CENTER OF THE HIGH WILL CONTINUE TO DROP TO THE
SOUTHEAST...TO THE UPPER MISSOURI VALLEY BY FRIDAY MORNING. WITH
RIDGE AXIS EXTENDING ACROSS LAKE MICHIGAN...A CONVERGENCE BAND HAS
SET UP WITH A PLUME OF LAKE EFFECT SNOW MOVING ACROSS THE SOUTHERN
PORTIONS OF THE LAKE. AS THE CENTER OF THE HIGH CONTINUES TO
SETTLE INTO THE OHIO VALLEY FRIDAY AND FRIDAY NIGHT...WINDS OVER
THE LAKE WILL BACK FROM NORTHERLY TO WESTERLY FRIDAY NIGHT AND
SATURDAY. AS THE HIGH MOVES OFF TO THE EAST...A WEAK COLD FRONT IS
EXPECTED TO CROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT...BACKING WINDS OVER THE LAKE TO SOUTHWESTERLY. THROUGH THIS
PERIOD...WINDS WILL BE ON A GENERAL WEAKENING TREND. THE WEAK COLD
FRONT IS EXPECTED TO SWEEP ACROSS THE LAKE SUNDAY EVENING WITH
ANOTHER ARCTIC HIGH QUICKLY FOLLOWING IN IT`S WAKE. THIS HIGH WILL
TAKE A MORE NORTHERLY TRACK...WITH THE CENTER OF THE HIGH CROSSING
THE LAKE SUNDAY NIGHT AND MONDAY...LEADING TO A SHORT PERIOD OF
LIGHT AND VARIABLE WINDS. THE HIGH SHOULD THEN PUSH EAST OF THE
LAKE MONDAY AND MONDAY NIGHT AS LOW PRESSURE DEVELOPS OVER
KANSAS/NEBRASKA IN THE LEE OF THE ROCKIES...SETTING UP A PERIOD OF
SOUTHEAST WINDS AS AN ASSOCIATED WARM FRONT EXTENDS EAST OF THE
LOW...TO THE OHIO VALLEY. THE LOW IS EXPECTED TO DEEPEN TO 29.1
INCHES AS IT TRACKS NORTHEAST AND CROSSES THE MIDDLE OF LAKE
MICHIGAN TUESDAY EVENING.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ014 UNTIL 6 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...2
AM FRIDAY TO 9 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001 UNTIL 9 PM THURSDAY.
LAKE EFFECT SNOW WARNING...INZ002 UNTIL 6 AM FRIDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
249 PM CST Thu Feb 26 2015
.SHORT TERM...(Tonight)
ISSUED AT 249 PM CST THU FEB 26 2015
Will issue a wind chill advisory for areas along and north of a
Jacksonville to Springfield to Decatur to Paris line overnight into
mid Fri morning for wind chills of 15-24F below zero with the
coldest wind chills in Knox and Stark counties around dawn Friday.
Wind chills reach near or below 15F below near Galesburg around
midnight, and se toward I-72 later tonight. Lows overnight to
range from 5-10F below zero from the IL river valley nw to zero to
5F above in southeast IL from I-70 se. Broken to overcast low
clouds still cover much of IL with some clearing far west central
and northern IL near WI border. Still getting scattered light snow
showers and areas of flurries over central IL (visibilities as low as
2-5 miles) due to lingering moisture off lake MI along with a short
wave dropping se into the area. HRRR may be a bit too progressive in
clearing low clouds from north to south during early and mid
evening. Low clouds to likely decrease over IL river valley early
this evening, but thinking it may take until overnight for
decreasing of low clouds in southeast IL since short wave still
affecting southern counties tonight. Also lingered chance of
flurries from I-55 east late this afternoon and early evening and
into mid evening in southeast IL. Strong 1042 mb arctic high
pressure near the MT/ND and southern Saskatchewan border and ridging
SSE into the Great Plains to settle se into IA/MO by Friday morning
bringing dry weather and bitter cold temperatures overnight into Fri
morning. North winds 10-17 mph and gusts 18-24 mph this afternoon
will veer nw and decrease to 5-10 mph overnight.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 249 PM CST THU FEB 26 2015
Morning upper air and satellite imagery depicts trough over the
central plains with clipper shortwave moving over IL, producing
continued light snow in strong 850mb cold air advection. Wave
continuing to move east and will break up in afternoon.
Ridge of high pressure to build in overnight, again producing wind
chills. Ridge to move off to the east through Friday and into
Saturday. By Saturday afternoon, overrunning from the next system
begins to develop into plains. NAM model brings snow into western IL
and feel not unreasonable. Will therefore add slight chc pops Sat
afternoon, with main pcpn Sat night to Sunday.
Models similar in development of frontal zone from western plains
low into Ozarks, with significant lift over boundary Saturday night.
This will push snow formation into central IL Saturday night,
continuing into Sunday. Main lift is Saturday night as upper wave
moves across great lakes, with pcpn lingering into Sunday. Diminshed
the pcpn Sun night as high pressure builds in.
Upper flow changes Monday to Tuesday, with pcpn again developing
into Monday night to Tuesday as surface low center develops in
plains and moves northeast, west of cwa though. The result is that
with this feature, area stays in the warm section and so pcpn starts
as freezing rain and changes to rain. Still uncertainty though, as
the operational models are very different on the timing of the
system movement. made few changes due to these differences.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1159 AM CST THU FEB 26 2015
Light snow mainly se of the IL river at midday to gradually
diminish to scattered flurries during the afternoon. Carried vsbys
1.5-3 miles from I-55 se until mid afternoon and then mainly VFR
vsbys thereafter with flurries. MVFR ceilings to lift to low end
VFR ceilings during mid/late afternoon and then scatter out from
nw to se during mid/late evening. Another upper level short wave
to pass through IL later today and then clearing to come in behind
this feature by overnight. North winds 10-17 kts this afternoon to
veer NW and diminish to 4-8 kts by overnight and Friday morning as
1043 mb arctic high pressure over southern Sasketchewan settles
into IA/MO/IL by 18Z/noon Friday bringing fair wx and lighter winds.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from Midnight tonight to 10 AM CST Friday
FOR ILZ027>031-036>038-040>051-053-055-057.
&&
$$
SHORT TERM...07
LONG TERM...Goetsch
AVIATION...07
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1026 AM MST THU FEB 26 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
MEAN TROUGH ACROSS THE CONUS..WITH SHARP N-NW FLOW EXPECTING
ACROSS THE CENTRAL ROCKIES AND NORTHERN PLAINS. AT THE SURFACE
1042 SURFACE HIGH PRESSURE IS EXPECTING FROM THE CANADIAN/US
BORDER WITH ITS INFLUENCE EXTENDING SOUTH OVER OUR CWA AND
TOWARDS THE SOUTHERN PLAINS. RADAR SHOWS LIGHT SNOW TRANSITIONING
ALONG THE PALMER DIVIDE AND ACROSS THE SOUTHEAST PLAINS OF
COLORADO...WITH THE NORTHEAST EXTENT OVER OUR FAR SOUTHWESTERN
CWA.
GUIDANCE CONTINUES TO SHOW POTENTIAL FOR LIGHT SNOW ACROSS THE
WEST AND SOUTHWEST PARTS OF THE CWA THROUGH MOST OF THE DAY. THIS
APPEARS TO BE DRIVEN MOSTLY BY WEAK FRONTOGENETIC FORCING AND
OVERRUNNING OVER THE SHALLOW ARCTIC AIR MASS IN PLACE. ANY
SNOWFALL THIS MORNING THOUGH THE AFTERNOON APPEARS TO BE VERY
LIGHT AS DEEP MOISTURE AND LARGE SCALE FORCING DO NOT APPEAR TO BE
IN PLACE OVER OUR CWA. BY LATE AFTERNOON/EVENING A QUICK MOVING
SHORT WAVE TROUGH WILL DROP SOUTH OVER THE CWA WITH SOUNDINGS
SHOWING DEEP SATURATION WITHIN THE DENDRITIC LAYER OCCURRING BY
LATE TONIGHT- EARLY FRIDAY MORNING OVER THE SOUTHERN HALF OF OUR
CWA. BETTER SIGNAL APPEARS TO BE ALONG/SOUTH OF HIGHWAY 24 WHERE
1-2" OF SNOW IS CURRENTLY FORECAST. WHILE I CANT RULE OUT 3" TOTAL
SNOWFALL FROM THIS AFTERNOON THROUGH FRIDAY MORNING IN OUR FAR
SOUTH...CONFIDENCE IS TOO LOW FOR ADVISORY ISSUANCE.
WINDS WILL BEGIN TO INCREASE ON THE BACK SIDE OF THIS SHORTWAVE
IN THE 12-15Z TIME PERIOD FROM THE WEST TO EAST WITH DAYTIME GUSTS
FRIDAY AROUND 30 MPH. IMPACT COULD BE A BRIEF WINDOW FOR WIND
CHILLS EARLY FRIDAY MORNING NEAR OR BELOW ADVISORY CRITERIA. WHILE
THE AIR MASS IS CERTAINLY COLD ENOUGH TO RAISE THE POTENTIAL FOR
-15F WIND CHILLS...HOWEVER WE MAY NOT SEE IDEAL CONDITIONS FOR
RADIATIONAL COOLING OVER MOST OF THE CWA. INCREASING THICK CLOUD
COVER/POSSIBLE PRECIPITATION COULD LIMIT OVERNIGHT COOLING AND
LOWERS CONFIDENCE. CURRENT FORECAST SHOWS WIND CHILLS JUST
OUTSIDE CRITERIA...WITH LOWEST VALUES IN A 2-3HR WINDOW AROUND 12Z
FRIDAY MORNING.
TROUGH BEGINS TO AMPLIFY ACROSS THE WESTERN US ALLOWING H3 JET TO
SHIFT NORTH AND STRONGER FORCING TO BUILD NORTH OVER OUR CWA BY
LATE FRIDAY NIGHT INTO SATURDAY/SATURDAY NIGHT ALONG WITH
INCREASING MOISTURE ADVECTION INTO OUR SOUTHERN AND EASTERN CWA.
STRONGEST PRECIP SIGNAL IS IN OUR EAST AND SOUTHEAST CWA...WHERE
CURRENT MODEL CONSENSUS SHOWS POSSIBILITY OF 3" SNOW FALL
(ROUGHLY ALONG/EAST OF HIGHWAY 83). WILL NEED TO MONITOR THIS AS
THIS COULD BE OUR BEST CHANCE TO REACH ADVISORY CRITERIA FOR
SNOWFALL IN THE NEXT 7 DAYS.
REGARDING TEMPS THROUGH THE PERIOD...ARCTIC AIR MASS WILL BE IN
PLACE WITH ONLY SLIGHT MODERATION OCCURRING SATURDAY AHEAD OF
AMPLIFYING TROUGH. RESULT WILL BE BELOW NORMAL TEMPERATURES...WITH
DAYTIME/NIGHT TIME MAX/MINS DEPENDENT ON CLOUD COVERS INFLUENCE
ON MIXING. I TRENDED DAYTIME TEMPS BACK A LITTLE AND BUMPED
OVERNIGHT TEMPS UP (MAINLY TONIGHT) CONSIDERING ONGOING FORECAST
FOR PERSISTENT/THICK CLOUD COVER. OVERALL TEMPERATURES TRENDS
HAVE CHANGED LITTLE FROM PREVIOUS FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MST THU FEB 26 2015
AN UPPER TROUGH SWINGS THROUGH THE NORTHERN PLAINS DURING THE DAY ON
SUNDAY JUST TO THE NORTH OF THE FORECAST AREA WHILE THE SOUTHERN
BRANCH OF THE UPPER FLOW REMAINS IN PLACE EXTENDING FROM THE FAR
SOUTHWEST U.S. TO THE MID MISSISSIPPI VALLEY REGION. THE UPPER LOW
CENTER THAT HAS BEEN TRAVELING SOUTH ALONG THE WEST COAST IS KICKED
EAST AS AN OPEN WAVE OVER THE SOUTHWEST U.S. AHEAD OF A LOW PRESSURE
AREA DIVING INTO THE PACIFIC NORTHWEST WITH A STRONG JET PUSHING
SOUTH ALONG THE WEST COAST. THIS SHOULD RESULT IN AN ACTIVE WEATHER
PATTERN ACROSS THE CENTRAL HIGH PLAINS REGION THROUGH THE MIDDLE OF
NEXT WEEK AS A NUMBER OF SHORT WAVE TROUGHS LIFTING OUT OF THE MAIN
TROUGH TRANSITION THE REGION IN ADVANCE OF THE MAIN UPPER TROUGH
THAT EVENTUALLY MOVES EAST OF THE ROCKIES ON WEDNESDAY NIGHT/EARLY
THURSDAY.
EXPECT THE PRIMARY SURFACE FRONTAL ZONE TO BE PUSHED UP ALONG THE
ROCKIES AND EXTENDING EAST ACROSS MAINLY THE SOUTHERN HIGH PLAINS
WITH THE OCCASIONAL PUSH NORTH INTO THE FORECAST AREA. HAVE KEPT
TEMPERATURES COLDER THAN AVERAGE THROUGH THE EXTENDED PERIOD AS A
RESULT WITH HIGHS MAINLY IN THE 20S AND 30S AND LOWS IN THE SINGLE
DIGITS TO TEENS. HAVE ALSO BROAD BRUSHED AREAS OF SLIGHT CHANCE TO
CHANCE POPS STRETCHING ACROSS THE FORECAST AREA EACH PERIOD FROM
SUNDAY THROUGH WEDNESDAY NIGHT AS A RESULT OF THE FRONTAL ZONE BEING
IN THE VICINITY WITH THE SHORT WAVE IMPULSES ALSO STREAMING ACROSS
THE AREA. DO NOT EXPECT ANY SIGNIFICANT SNOWFALL AMOUNTS AT THIS
TIME. CONFIDENCE IS VERY LOW IN THE TIMING AND SPECIFIC SNOWFALL
AMOUNTS OVER SPECIFIC LOCATIONS SINCE EVEN SMALL SMALL DIFFERENCES
IS THE POSITION OF FEATURES COULD RESULT IN LARGE DIFFERENCES IS
THE PROBABILITIES OF RECEIVING PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1022 AM MST THU FEB 26 2015
AT KGLD...VFR EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING
HOURS ALTHOUGH MID LEVEL DECK WILL GRADUALLY THICKEN.
TONIGHT...LIGHT SNOW WILL SPREAD OUT OF EASTERN COLORADO WITH
CEILING AND VISIBILITY RESTRICTIONS LIKELY AFTER MIDNIGHT AND
CONTINUING THROUGH FRIDAY MORNING. LIFR POSSIBLE FRIDAY MORNING
WITH 1/2SM VISIBILITIES IN LIGHT TO MODERATE SNOW.
AT KMCK...VFR EXPECTED THROUGH THE PERIOD. SNOW WILL LIKELY STAY
SOUTH OF KMCK...ALTHOUGH CLOUDS WILL INCREASE AND MAY APPROACH
MVFR CEILINGS AT TIMES LATE TONIGHT AND FRIDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JSL
AVIATION...024
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EST THU FEB 26 2015
.SYNOPSIS... LOW PRESSURE WILL MOVE AWAY FROM THE NORTH CAROLINA
COAST THIS EVENING. HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD
INTO THE MID ATLANTIC ON FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 320 PM THURSDAY...
...WINTER WEATHER ADVISORY FOR BLACK ICE IN EFFECT FROM 9PM TONIGHT
THROUGH 10 AM FRIDAY...
ANOTHER COMPLICATED FORECAST FOR TONIGHT AND INTO FRIDAY WITH LOTS
OF CONSIDERATIONS INCLUDING LOW TEMPERATURES FCST ISSUES...BLACK
ICE...FOG OR FREEZING FOG AND PERHAPS SOME SPOTTY LIGHT FREEZING
RAIN OR SNOW ACROSS THE NORTHWEST PIEDMONT.
WIDESPREAD LOW OVERCAST CONTINUES ACROSS CENTRAL NC THIS AFTERNOON
WITH JUST A FEW BREAKS ACROSS THE WESTERN PIEDMONT. WHILE SOME
ADDITIONAL BREAKS MAY DEVELOP THIS EVENING...AN APPROACHING SHEARED
SHORT WAVE TROUGH ALOFT AND SHALLOW LOW LEVEL ASCENT SHOULD WORK TO
MAINTAIN A FAIR DEGREE OF CLOUDINESS OVERNIGHT. MODEL BUFR
SOUNDINGS...ESPECIALLY THE NAM/HRRR AND RAP AGGRESSIVELY COOL THE
SURFACE AND GENERATE A NOTABLE AREA OF SHALLOW STRATUS AND/OR DENSE
FOG. NOT VERY CONFIDENT ON THE HOW THIS WILL EVOLVE AND THE DEGREE
OF FOG DEVELOPMENT GIVEN MIXED SIGNALS IN THE PATTERN. CONDITIONS AT
THE GROUND LEVEL ARE VERY MOIST WITH EITHER A FRESH SNOW COVER OF
WET SNOW OR MELT WATER OR JUST DAMP CONDITIONS FROM HEAVY RAIN LAST
NIGHT. SKIES ARE NOT EXPECTED TO CLEAR MUCH OVERNIGHT SO RADIATIONAL
CONDITIONS ARE NOT IDEAL. IN ADDITION WEAK WEAK COOL ADVECTION OVER
A SNOW PACK GENERALLY ISN`T FAVORABLE FOR FOG DEVELOPMENT. STILL SOME
FOG IS EXPECTED AND WILL BE ADDED TO THE FORECAST.
TO FURTHER COMPLICATE THINGS...THE NAM AND GFS SUGGEST SOME SPOTTY
LIGHT PRECIPITATION WILL DEVELOP OVERNIGHT IN THE TRIAD AS A WEAK
SURFACE TROUGH DROPS SOUTHEAST AND A SHEARING SHORT WAVE CROSSES THE
REGION. HIGH RES CONVECTION ALLOWING MODELS ALSO GENERATE SOME
PRECIPITATION. WHILE CONFIDENCE IS LOW...FEEL IT IS PRUDENT TO ADD A
SLIGHT CHANCE OF SOME SPOTTY FREEZING DRIZZLE. THE SATURATION IS
SHALLOW BUT MAY BE SUFFICIENTLY DEEP TO APPROACH THE ICE NUCLEATION
REGION AND WARRANT THE INCLUSION OF SOME SPOTTY LIGHT SNOW. SO WEVE
ADDED A SLIGHT CHANCE OF SOME FREEZING RAIN AND LIGHT SNOW IN THE
TRIAD TONIGHT.
LOW TEMPERATURES TONIGHT ARE ALSO PROBLEMATIC GIVEN THE NEW SNOW
COVER WHICH WOULD GENERALLY PROMOTE COOLING AND LOWER TEMPERATURES.
HIGHER RESOLUTION GUIDANCE INCLUDING THE RAP AND HRRR JUMP ALL OVER
THE LOCALIZED COOLING AND SUGGEST LOWS IN THE 10-15 RANGE ACROSS
MUCH OF THE FRESH SNOW COVER AREA. GIVEN THE AMOUNT OF CLOUD COVER
AND NON IDEAL RADIATIONAL CONDITIONS...THIS SEEMS OVERDONE. ALSO THE
RIPENESS OF THE SNOW WOULD SUGGEST A LOWER CHILLING EFFECT OF THE
SNOW COMPARED TO A NEW VIRGIN SNOW COVER. HAVE GONE WITH A FORECAST
OF LOWS RANGING FROM THE 21 TO 27 DEGREES FROM NORTHEAST TO
SOUTHWEST.
WITH THESE TEMPERATURES IN MIND...EXPECT ANY LINGERING MOISTURE ON
AREA ROADS TO REFREEZE OVERNIGHT. TEMPERATURES GENERALLY WONT FALL
BELOW FREEZING UNTIL AFTER 9PM AND EXPECT REFREEZING TO BE MOST
PROBLEMATIC AFTER MIDNIGHT.
FRIDAY SHOULD FEATURE A GOOD DEAL OF CLOUDINESS TO START.
TEMPERATURES WILL SLOWLY CLIMB TO AROUND FREEZING BY 10AM ALTHOUGH
THIS COULD BE DELAYED IF CLOUD COVER HOLDS LONGER OR LOWS TONIGHT
BOTTOM OUT EVEN FURTHER THAN FORECAST. EXPECT SOME BREAKS IN THE
CLOUDS ON FRIDAY AFTERNOON WITH HIGHS CLIMBING INTO THE UPPER 30S TO
LOWER 40S. -BLAES
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
AS OF 320 PM THURSDAY...
1044 HPA HIGH BUILDING ACROSS THE GREAT LAKES BEGINS RIDGING SOUTH
INTO THE AREA. IN ADDITION...A WEAK SHORT WAVE WILL BE RACING ACROSS
THE NORTHERN TIER OF THE STATE IN FAST WEST SOUTHWEST FLOW. THE
LATEST GFS AND NMM SHOW SPOTTY SHOWERS IN THE FOOTHILLS AND A FLURRY
INTO THE FAR NORTHWEST LOOKS POSSIBLE...BUT MOISTURE WILL VERY
LIMITED (PW ~0.25 IN) AND WILL MAINTAIN A DRY...BUT MOSTLY CLOUDY
FORECAST OVERNIGHT. COOL AIRMASS IN PLACE AND REINFORCED CAA
OVERNIGHT WILL PRODUCE MINS IN THE UPPER TEENS IN THE NORTHEAST...
WITH MOSTLY LOWER 20S ACROSS THE SOUTH.
CONSIDERABLE CLOUDINESS ALONG WITH DAMMING SETTLED IN PLACE SATURDAY
WILL PRODUCE ANOTHER WELL-BELOW NORMAL DAY. HIGHS IN THE 30S...FROM
LOW 30S NORTHEAST UNDER THE RIDGE AXIS...TO NEAR 40 IN THE FAR
SOUTHWEST. MINS SATURDAY NIGHT WILL BE SIMILAR TO FRIDAY
NIGHT...PERHAPS A DEGREE OR TWO LOWER IF SKIES ARE CLEAR ENOUGH TO
PROMOTE BETTER RADIATION...WITH TEENS IN THE NORTHEAST TO MOSTLY
LOWER 20S ELSEWHERE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 320 PM THURSDAY...
THERE IS A LOT OF UNCERTAINTY AS TO PRECIPITATION TIMING AS SPLIT
FLOW PATTERN CONTINUES INTO NEXT WEEK. INITIAL COLD AIR DAMMING
SUNDAY WILL BE NUDGED OFFSHORE BY A NORTHERN STREAM SHORT WAVE AND
ASSOCIATED COLD FRONT WHICH WILL BE MOVING ACROSS THE AREA SUNDAY
NIGHT...WITH PRECIP AHEAD OF THE FRONT EARLY SUNDAY NIGHT SPREADING
INTO THE EAST AFTER MIDNIGHT. HIGHS SUNDAY WILL BE MOSTLY IN THE LOW
TO MID 40S. MINS WILL BE MODERATING A BIT SUNDAY NIGHT WITH HEAVIER
CLOUDINESS AND SCOURING OF THE ARCTIC AIRMASS KEEPING MINS IN THE
30S.
THE AIRMASS SETTLING IN BEHIND THE FRONT WILL BE CONSIDERABLY
MILDER...BUT THE OVERALL PATTERN CONTINUES TO FAVOR YET ANOTHER
TRANSITION TO A DAMMING SCENARIO BY TUESDAY. A BACKDOOR FRONT SAGS
SOUTH ON MONDAY...WITH GOOD CHANCES OF RAIN WHICH WOULD DAMPEN/DELAY
THE POTENTIAL WARMUP INTO MID WEEK. WILL MAINTAIN A WARMUP INTO THE
50S PRE-FROPA ON MONDAY...ALONG WITH RAIN WHICH WOULD PRODUCE AN IN-
SITU COOLOFF ON TUESDAY...WITH HIGHS IN THE MID 40S WEST TO MID 50S
EAST. PROBABILITY OF RAIN WILL REMAIN AT LEAST IN THE CHANCE
CATEGORY ON WEDNESDAY INTO THURSDAY AHEAD OF A STRONG FRONTAL SYSTEM
APPROACHING FROM THE WEST. THIS SLOW MOVING SYSTEMS TIMING IS NOT
VERY CERTAIN AT THIS TIME...BUT IT LOOKS LIKE IT WOULD BE ON
WEDNESDAY NIGHT...WITH WARM AIR ADVECTION AHEAD OF THE SYSTEM
WARMING US INTO THE 60S ON WEDNESDAY AND EVEN THURSDAY AS COLD AIR
ADVECTION IS DELAYED TIL LATE DAY. &&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 250 PM THURSDAY...
ADVERSE AVIATION CONDITIONS ARE EXPECTED THROUGH MUCH OF THE TAF
FORECAST PERIOD. WIDESPREAD MVFR CEILINGS ACROSS CENTRAL NC WITH
BKN-OVC BASES AROUND 1.5-2.0KFT ARE EXPECTED TO CONTINUE THIS
AFTERNOON AND EARLY EVENING AS A RESIDUAL MOISTURE AIR MASS
REMAINS IN PLACE. AREAS OF FOG AND LOW STRATUS ARE EXPECTED TO
DEVELOP THIS EVENING WITH THE DEGREE OF THE VISIBILITY RESTRICTION
AND CEILINGS STILL SOMEWHAT UNCERTAIN. BUT FOR FOR NOW WILL GO WITH
A FORECAST OF PREVAILING MVFR/IFR CIGS AND VSBYS TEMPORALLY FALLING
TO THE LIFR CIGS AND VSBYS LATE TONIGHT. CONDITIONS WILL GRADUALLY
IMPROVE WITH LINGERING FOG AN OVERCAST SKIES GIVING WAY TO SCT-BKN
CLOUDS WITH VFR BASES AROUND 3-3.5 KFT AROUND MIDDAY FRIDAY.
LOOKING FURTHER AHEAD...
GENERALLY FAIR WEATHER CONDITIONS ARE EXPECTED ON FRIDAY NIGHT
INTO SATURDAY NIGHT. AVIATION CONDITIONS ARE LIKELY TO DETEIORATE
ON SUNDAY WITH ADVERSE AVIATION CONDITIONS LIKELY PERSISTING INTO
MID WEEK. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
FRIDAY FOR NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1200 PM CST THU FEB 26 2015
.AVIATION...
A COLD FRONT ALONG A K6R6 TO KECU TO KAUS TO KRWV LINE AT 17Z WILL
MOVE STEADILY SOUTH ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS
THIS AFTERNOON. VFR SKIES WILL PRECEDE THE FRONTAL PASSAGE...THEN
WITHIN AN HOUR OR TWO OF PASSAGE...LOW END MVFR CIGS WILL MOVE IN
FROM THE NORTH. HAD EARLIER EXPECTED THE MVFR CIGS TO BREAK UP TO
FEW-SCT STRATUS THIS EVENING INTO THE OVERNIGHT HOURS. NOW EXPECT
MVFR CIGS TO HOLD THROUGH TONIGHT INTO FRIDAY AS WEAK ISENTROPIC
LIFT DEVELOPS OVERNIGHT OVER THE COLD LOWER LEVELS. BY MORNING
THERE MAY BE ENOUGH MOISTURE FOR A MIX OF -RA/DZ/FZDZ/SN AND IFR
CIGS FRIDAY. HOWEVER...CHANCES ARE TOO LOW TO MENTION AT ANY TAF
SITE AND WILL MONITOR RADAR TRENDS FOR POSSIBLE LATER MENTION.
ELY WINDS AT 5 TO 10 KTS WILL PRECEDE THE FRONT...THEN SHIFT TO
NLY AND INCREASE TO 10 TO 20 KTS WITH GUSTS TO 28 KTS AS HIGH
PRESSURE BUILDS INTO THE AREA. OVERNIGHT INTO FRIDAY...WINDS WILL
DECREASE TO 6 TO 12 KTS WHILE TURNING MORE NELY MOST AREAS AND ELY
ALONG THE RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 506 AM CST THU FEB 26 2015/
AVIATION...
AT 5 AM...THE COLD FRONT WAS LOCATED NEAR A SAN ANGELO TO DALLAS
LINE AND IS QUICKLY MOVING SOUTH. THE FRONT SHOULD BE THROUGH
KAUS/KDRT AROUND 17Z AND THOUGH THE SAN ANTONIO SITES SHORTLY
AFTER. THERE IS A NARROW BAND OF MVFR CEILINGS JUST BEHIND THE
FRONTAL BOUNDARY AND WILL SHOW A FEW HOURS OF POST FRONTAL MVFR
IN THE I-35 TAF SITES. THE FRONT WILL ALSO BRING BREEZY NORTH
WINDS WITH GUSTS UP TO 25 KNOTS EXPECTED THIS AFTERNOON. VFR WILL
PREVAIL BY LATE AFTERNOON BUT A RETURN TO MVFR IS EXPECTED AFTER
12Z TOMORROW AS LOW-LEVEL MOISTURE INCREASES ACROSS THE REGION.
PRECIPITATION CHANCES IN THE EXTENDED PORTION OF TAF AUS AND
TAFSAT ARE TOO LOW TO MENTION AT THIS TIME.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 415 AM CST THU FEB 26 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
A FEW HIGHLIGHTS IN THE SHORT TERM INCLUDE A STRONG ARCTIC FRONTAL
PASSAGE TODAY AND THE POSSIBILITY OF LIGHT WINTER PRECIPITATION ON
FRIDAY.
WATER VAPOR CHANNELS AND RAP ANALYSIS DEPICT THE BASE OF A S/WV
TROUGH AXIS PIVOTING ACROSS TEXAS THIS MORNING. THIS TROUGH...IN
CONJUNCTION WITH A STRONG SURFACE HIGH OVER THE NORTHERN PLAINS
WILL DRIVE A SUBSTANTIALLY COLD AIR MASS THROUGH THE REGION STARTING
LATE MORNING INTO THE AFTERNOON WITH MORE CLOUDS. THIS COLD FRONT IS
CURRENTLY LOCATED NEAR ABILENE AS OF 10Z AND WHILE THE COLDEST AIR
WILL LAG BEHIND THE MAIN FRONT...TODAY`S HIGHS WILL BE ABOUT 10F
DEGREES COOLER THAN YESTERDAY. GUSTY NORTH WINDS WILL OCCUR THROUGH
THE AFTERNOON AND THESE WERE INCREASED SLIGHTLY TOWARDS GFS LAMP
GUIDANCE. A WIDESPREAD FREEZE FOR MOST AREAS...OTHER THAN THE RIO
GRANDE VALLEY...IS EXPECTED FRIDAY MORNING WITH SOME READINGS
DIPPING TO THE MID TO UPPER 20S FOR THE HILL COUNTRY. WIND CHILLS
COULD FALL INTO THE TEENS FRIDAY MORNING.
HIGHS FRIDAY WILL STRUGGLE TO WARM...REACHING ONLY INTO THE MID 30S
IN THE HILL COUNTRY TO NEAR 40 ALONG THE 35 CORRIDOR AND MID 40S
TOWARDS THE COASTAL PLAINS. UNFORTUNATELY...IT APPEARS WEAK
ISENTROPIC UPGLIDE ALONG THE 290K LAYER WILL AID IN STEADY
MOISTENING OF THE BOUNDARY LAYER MID-MORNING INTO THE EVENING AND
THIS COULD LEAD TO SLIGHT CHANCES OF WINTER PRECIPITATION TYPES
ACROSS PORTIONS OF THE AREA BEFORE HIGHS ARE REACHED AND THEN AGAIN
OVERNIGHT INTO SATURDAY. NAM/GFS BUFR SOUNDINGS INDICATE THAT A
COMBINATION OF SLEET/RAIN AND SLEET/SNOW MIXES COULD OCCUR MAINLY
FOR THE HILL COUNTRY BUT NOT OUTSIDE THE POSSIBILITY OF THE I-35
CORRIDOR AS WELL. PRECIPITATION TOTALS ARE STILL LOW WITH ONLY A FEW
HUNDREDTHS LIKELY BUT IF CONCENTRATED ENOUGH...SOME MINOR IMPACTS
COULD OCCUR. WILL ISSUE AN SPECIAL WEATHER STATEMENT FOR THE HILL
COUNTRY AREA TO HIGHLIGHT THIS RISK. OVERALL CONFIDENCE IS MODERATE
GIVEN MODEL AGREEMENT ON VERTICAL PROFILES BUT ONE DETRACTOR OF
IMPACTS COULD BE THOSE PROFILES INDICATING A NEAR SURFACE DRY LAYER
THAT WOULD REQUIRE SOME ADIABATIC COOLING FOR PRECIPITATION TO MAKE
IT TO THE GROUND.
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
HIGHLIGHTS THIS PERIOD CONTINUE TO BE THE WINTER PRECIPITATION
POSSIBILITY EARLY SATURDAY MORNING AND THEN A FOCUS ON A FRONTAL
PASSAGE TUESDAY/WEDNESDAY THAT COULD BRING A ROUND OF THUNDERSTORMS
TO THE AREA.
WEAK OVER-RUNNING OF THE SHALLOW ARCTIC AIRMASS WILL CONTINUE INTO
EARLY SATURDAY AS TEMPERATURES FALL BACK BELOW FREEZING FOR THE HILL
COUNTRY. WHILE THERE WILL BE LIMITED MOISTURE IN THE MID-LEVELS...
ENOUGH SATURATION IN THE SFC-H7 LAYER COULD BE ENOUGH FOR FREEZING
DRIZZLE/MIST. TEMPERATURES WILL WARM THROUGH THE DAY SATURDAY AS
LOW-LVL FLOW SHIFTS TO THE SOUTHEAST AND WAA COMMENCES...ENDING ANY
FURTHER WINTER PRECIP RISK.
SATURDAY AFTERNOON THROUGH NEXT TUESDAY WILL BE A WARMING TREND WITH
SOLID INCREMENTAL WARM UPS EACH DAY AS STRONGER SUBTROPICAL HIGH
PRESSURE INFLUENCES THE REGION. ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS CLIMBING INTO THE 70S AND EVEN THE 80S BY EARLY
NEXT WEEK. CONCURRENTLY...A H5 TROUGH WILL DIG OVER CALIFORNIA AND
EVENTUALLY SWING EAST BY MID-WEEK. THERE REMAINS SOME DIFFERENCES IN
THE GFS/EC IN HANDLING THIS WAVE AND THUS THE TIMING OF THE
PACIFIC FRONT THAT SHOULD MOVE THROUGH THE REGION ON TUESDAY BUT IT
MAY BE DELAYED UNTIL WEDNESDAY. DESPITE THE TIMING DIFFERENCES...
ADDED MOISTURE /PWATS NEAR 90TH PERCENTILE/ LEADING TO SURFACE
INSTABILITY SHOULD EQUATE TO SOME THUNDERSTORM DEVELOPMENT. ANOTHER
DEEP ARCTIC PLUNGE LOOKS TO OCCUR THURSDAY WITH BELOW NORMAL
TEMPERATURES EXPECTED BY LATE WEEK. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 49 29 40 34 47 / 10 10 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 50 28 40 34 47 / 10 10 20 30 40
NEW BRAUNFELS MUNI AIRPORT 55 30 42 35 49 / 10 10 20 30 40
BURNET MUNI AIRPORT 42 26 35 29 43 / 10 10 20 30 40
DEL RIO INTL AIRPORT 62 36 42 36 50 / - 20 20 40 20
GEORGETOWN MUNI AIRPORT 46 27 38 31 46 / 10 10 20 30 40
HONDO MUNI AIRPORT 61 33 41 35 49 / - 10 20 30 30
SAN MARCOS MUNI AIRPORT 53 29 41 34 49 / 10 10 20 30 40
LA GRANGE - FAYETTE REGIONAL 54 31 46 37 53 / 10 10 20 30 40
SAN ANTONIO INTL AIRPORT 57 30 41 36 48 / 10 10 20 30 40
STINSON MUNI AIRPORT 59 33 43 36 50 / - 10 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
ISSUED BY NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
1200 PM CST Thu Feb 26 2015
.AVIATION...
/18Z TAFS/
MVFR ceilings will continue across the terminals through the
afternoon hours. Light snow will reduced visibilities across the
KABI terminal through early afternoon before tapering off. Some
improvement to ceilings is expected by early evening but
deteriorating flight conditions is expected again Friday morning
as an upper level disturbance affects the region. Light snow will
develop after 12Z across the northern terminals IFR conditions
likely at KABI due to steady/heavier snowfall. Some light frozen
precipitation is possible at the remaining terminals by mid to
late morning but confidence is not high enough to mention at this
time.
&&
.PREV DISCUSSION... /ISSUED 1022 AM CST Thu Feb 26 2015/
UPDATE...
Light snow continues to fall mainly across the Big Country this
morning and roads across the area are becoming snow covered and
slick. Latest HRRR indicates snow continuing through early
afternoon before tapering off. Have issued a Winter Weather
Advisory for the Big Country through 19Z today, with 1 to 3 inches
of snow is possible. Temperatures across the area will remain in
the upper 20s through early afternoon, so deteriorating road
conditions are likely.
PREV DISCUSSION... /ISSUED 528 AM CST Thu Feb 26 2015/
AVIATION...
/12Z TAFS/
Strong gusty north wind and lowering ceilings to MVFR are expected
behind a strong cold front this morning. Light rain at KABI will
transition to light snow mid morning. KABI will see the strongest
wind gusts up to 33 KTS this morning. Winds will gradually
decrease this afternoon. MVFR ceilings will return tonight over
most TAF sites, mainly after midnight.
PREV DISCUSSION... /ISSUED 433 AM CST Thu Feb 26 2015/
SHORT TERM...
(Today and Tonight)
Cold front was just south of I-20 from Big Spring to Abilene at 3
AM. There was a pre-frontal trough ahead of it, with north winds of
5 to 10 mph. Winds were north 15 to 25 mph behind it. Front should
be along a San Angelo to Brownwood line around 6 AM...and south of
I-10 by 9 AM.
A band of snow has developed in the southern Texas Panhandle down
to the Lubbock area at 3 AM, associated with an upper shortwave.
The area of snow will move east across the Big Country this
morning. It may start off as light rain, but transition to snow by
9 AM, with strong cold air advection behind the cold front.
Temperatures will not be rising much today, especially across the
Big Country, where clouds, snow, and cold air advection will keep
temperatures below freezing for much of the day. Temperatures in
the Big Country, in fact, may dip in the upper 20s mid morning,
and stay there. Snow amounts in the Big Country will be light,
perhaps 1 to 2 tenths, with a few flurries in the afternoon.
Tonight, the NAM model indicates an increasing potential for
light snow developing towards Friday morning, especially in the
Big Country, with increasing low mid/level lift and moisture over
the front. Have precipitation as snow, as sounding is well below
freezing and saturated up to -20 C (500MB) by Friday 6 AM CST.
04
LONG TERM...
(Friday through next Wednesday)
The challenge for the long term portion of the forecast remains
the winter weather event for the early portion of the long term,
generally Friday and Friday night.
Models are in fairly good agreement generally when it comes to
the overall pattern Friday into the weekend. A shortwave trough
will approach the area Friday morning, and move northeast away
from the area Friday night. At the surface, temperatures are not
expected to make it above freezing for most of the area Friday
through Friday night. With synoptic scale lift in the mid and
upper levels associated with the shortwave trough during the day
Friday, we should see saturation through the vertical column to
levels where snow can be efficiently produced. Therefore, have
mostly snow in the forecast Friday across the entire area. The
only exception is our far southern areas where there may be some
melting, then re-freezing taking place in the lower layers of the
atmosphere, and some sleet could develop with the snow. The path
of the shortwave is expected to be across the Texas panhandle and
caprock areas at this time. This would bring the best lift for our
area to locations mainly along and north of Interstate 20. It`s
well within the realm of possibilities that these areas could see
accumulating snowfall totals to Winter Weather Advisory criteria
(1-3") during the day Friday, with lesser amounts south of the Big
Country.
Friday night becomes more complicated. With the shortwave moving
off to the northeast, we lose our synoptic scale lift in the mid
and upper levels, meaning we will likely see some drying aloft.
However, we will still have saturated low levels (generally from
the surface through 5000 feet or so), and weak lift associated
with warm air advection over the top of the cold surface air mass.
With this in mind, we could see additional light precipitation
Friday night with temperatures still below freezing. Given that
snow production would likely end, and near surface temperatures
will be below freezing, the mostly likely precipitation for most
of the area would be freezing rain or freezing drizzle. Light ice
accumulations would be possible with this precipitation, and could
be near advisory criteria.
On Saturday, temperatures should warm to above freezing by late
morning or early afternoon for most of the area, and have brought
liquid precipitation back into the forecast for everywhere except
north of I-20 by Saturday afternoon, and even north of the I-20
will eventually turn to all liquid, but temperatures may still be
cool enough for some light freezing rain or drizzle into early
afternoon here.
Forecast looks to remain above freezing from Saturday night
through the end of the period, and models continue to hold on to a
chance for light rain or sprinkles through Tuesday, although any
precipitation we get should be very light.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 19 29 24 41 39 / 10 40 30 30 30
San Angelo 23 31 27 50 45 / 10 30 30 20 20
Junction 25 36 29 50 44 / 10 20 30 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 1 PM CST this afternoon FOR THE
FOLLOWING ZONES: Callahan...Fisher...Haskell...Jones...Nolan...
Shackelford...Taylor...Throckmorton.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1022 AM CST Thu Feb 26 2015
.UPDATE...
Light snow continues to fall mainly across the Big Country this
morning and roads across the area are becoming snow covered and
slick. Latest HRRR indicates snow continuing through early
afternoon before tapering off. Have issued a Winter Weather
Advisory for the Big Country through 19Z today, with 1 to 3 inches
of snow is possible. Temperatures across the area will remain in
the upper 20s through early afternoon, so deteriorating road
conditions are likely.
&&
.PREV DISCUSSION... /ISSUED 528 AM CST Thu Feb 26 2015/
AVIATION...
/12Z TAFS/
Strong gusty north wind and lowering ceilings to MVFR are expected
behind a strong cold front this morning. Light rain at KABI will
transition to light snow mid morning. KABI will see the strongest
wind gusts up to 33 KTS this morning. Winds will gradually
decrease this afternoon. MVFR ceilings will return tonight over
most TAF sites, mainly after midnight.
PREV DISCUSSION... /ISSUED 433 AM CST Thu Feb 26 2015/
SHORT TERM...
(Today and Tonight)
Cold front was just south of I-20 from Big Spring to Abilene at 3
AM. There was a pre-frontal trough ahead of it, with north winds of
5 to 10 mph. Winds were north 15 to 25 mph behind it. Front should
be along a San Angelo to Brownwood line around 6 AM...and south of
I-10 by 9 AM.
A band of snow has developed in the southern Texas Panhandle down
to the Lubbock area at 3 AM, associated with an upper shortwave.
The area of snow will move east across the Big Country this
morning. It may start off as light rain, but transition to snow by
9 AM, with strong cold air advection behind the cold front.
Temperatures will not be rising much today, especially across the
Big Country, where clouds, snow, and cold air advection will keep
temperatures below freezing for much of the day. Temperatures in
the Big Country, in fact, may dip in the upper 20s mid morning,
and stay there. Snow amounts in the Big Country will be light,
perhaps 1 to 2 tenths, with a few flurries in the afternoon.
Tonight, the NAM model indicates an increasing potential for
light snow developing towards Friday morning, especially in the
Big Country, with increasing low mid/level lift and moisture over
the front. Have precipitation as snow, as sounding is well below
freezing and saturated up to -20 C (500MB) by Friday 6 AM CST.
04
LONG TERM...
(Friday through next Wednesday)
The challenge for the long term portion of the forecast remains
the winter weather event for the early portion of the long term,
generally Friday and Friday night.
Models are in fairly good agreement generally when it comes to
the overall pattern Friday into the weekend. A shortwave trough
will approach the area Friday morning, and move northeast away
from the area Friday night. At the surface, temperatures are not
expected to make it above freezing for most of the area Friday
through Friday night. With synoptic scale lift in the mid and
upper levels associated with the shortwave trough during the day
Friday, we should see saturation through the vertical column to
levels where snow can be efficiently produced. Therefore, have
mostly snow in the forecast Friday across the entire area. The
only exception is our far southern areas where there may be some
melting, then re-freezing taking place in the lower layers of the
atmosphere, and some sleet could develop with the snow. The path
of the shortwave is expected to be across the Texas panhandle and
caprock areas at this time. This would bring the best lift for our
area to locations mainly along and north of Interstate 20. It`s
well within the realm of possibilities that these areas could see
accumulating snowfall totals to Winter Weather Advisory criteria
(1-3") during the day Friday, with lesser amounts south of the Big
Country.
Friday night becomes more complicated. With the shortwave moving
off to the northeast, we lose our synoptic scale lift in the mid
and upper levels, meaning we will likely see some drying aloft.
However, we will still have saturated low levels (generally from
the surface through 5000 feet or so), and weak lift associated
with warm air advection over the top of the cold surface air mass.
With this in mind, we could see additional light precipitation
Friday night with temperatures still below freezing. Given that
snow production would likely end, and near surface temperatures
will be below freezing, the mostly likely precipitation for most
of the area would be freezing rain or freezing drizzle. Light ice
accumulations would be possible with this precipitation, and could
be near advisory criteria.
On Saturday, temperatures should warm to above freezing by late
morning or early afternoon for most of the area, and have brought
liquid precipitation back into the forecast for everywhere except
north of I-20 by Saturday afternoon, and even north of the I-20
will eventually turn to all liquid, but temperatures may still be
cool enough for some light freezing rain or drizzle into early
afternoon here.
Forecast looks to remain above freezing from Saturday night
through the end of the period, and models continue to hold on to a
chance for light rain or sprinkles through Tuesday, although any
precipitation we get should be very light.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 31 19 29 24 41 / 80 10 40 30 30
San Angelo 33 23 31 27 50 / 10 10 30 30 20
Junction 37 25 36 29 50 / 10 10 20 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 1 PM CST this afternoon FOR THE
FOLLOWING ZONES: Callahan...Fisher...Haskell...Jones...Nolan...
Shackelford...Taylor...Throckmorton.
&&
$$
99/99