Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/25/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1022 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM MST SUN NOV 23 2014
...SNOW CONTINUES FOR THE MOUNTAINS TODAY...QUICK BURST OF RAIN AND
SNOW SHOWERS FOR PORTIONS OF THE SE PLAINS THIS MORNING...
UPPER TROF IS MOVING THROUGH WESTERN CO WITH HEAVY SNOW FALLING
ALONG THE CONTDVD BASED ON WEB CAMS. HAVE EVEN SEEN PERIODS OF
MODERATE SNOW ACROSS NORTHERN PORTIONS OF THE SAN LUIS VALLEY AT
SAGUACHE AND JUST SOUTH VILLA GROVE IN CDOT CAMS. MEANWHILE...COLD
FRONT HAS CROSSED THE PALMER DIVIDE AND STARTING TO SEE SNOW FILL IN
ACROSS EL PASO COUNTY AS OF 4 AM.
AS UPPER TROF CONTINUES TO MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
COLORADO THIS MORNING...SHOULD SEE RAIN/SNOW SPREAD SOUTHEASTWARD
ACROSS THE PLAINS. MODELS ARE A LOT HEAVIER HANDED WITH
PRECIPITATION ACROSS THE PLAINS THAN THE RUNS FROM LAST NIGHT...AND
THAT LOOKS REASONABLE AS THE UPPER TROF LOOKS A LITTLE SHARPER...AND
WINDS BEHIND THE FRONT LOOK MORE NORTHERLY...AND EVEN A TAD
NORTHEASTERLY THIS MORNING. COLD FRONT SHOULD RACE THROUGH THE
SOUTHEAST PLAINS BY 12-13Z...WITH STRONG NORTH WINDS GUSTING TO 40
MPH AT TIMES. RAIN AND SNOW SHOWERS RACE SOUTHWARD BEHIND THE
FRONT...WITH PRECIPITATION MOST WIDESPREAD ACROSS THE PALMER DIVIDE
THROUGH 15Z...THEN ACROSS THE NRN RATON RIDGE AND LOWER EAST FACING
SLOPES OF THE WETS AND SANGRES THROUGH ROUGHLY 18Z. NAM12 AND
ESPECIALLY ITS 06Z RUN HAS REALLY COME IN HOT WITH SNOWFALL AMOUNTS
FOR THE SE MTS...INDICATING 5-10 INCHES ACROSS WESTERN
HUERFANO...SOUTHERN CUSTER AND WESTERN LAS ANIMAS COUNTIES THROUGH
THIS AFTERNOON. GFS SHOWS GENERALLY 2-4 INCHES. RAP13 HAS AROUND 2-
4 INCHES ACROSS NRN EL PASO...AND 1-6 ACROSS THE SE MTS/SRN I-25
CORRIDOR. WITH LINGERING INSTABILITY THROUGH THE AFTERNOON...HIGH
RES MODELS ARE PROBABLY CORRECT IN KEEPING CONVECTIVE BANDS OF SNOW
SHOWERS GOING THROUGH THE AFTERNOON IN AND NEAR THE MOUNTAINS. ONCE
THE MAIN UPPER LIFT MOVES EAST OF THE AREA AFTER 18Z...AREAL
COVERAGE OF SHOWERS SHOULD DECREASE CONSIDERABLY. THAT SAID...HAVE
SEEN CASES LIKE THIS WHERE A PERSISTENT NARROW BAND CAN ACCUMULATE
LOCALLY HEAVY AMOUNTS OF SNOW...WHILE A COUPLE MILES EITHER SIDE GET
NEXT TO NOTHING. SO THE CONVECTIVE WILD CARD WILL BE A CHALLENGE
WITH SNOWFALL AMOUNTS TODAY. EITHER WAY...NAM12 SEEMS TO BE
SUFFERING FROM TOO MUCH CONVECTION IN THE MODEL RESULTING IN AMOUNTS
THAT LOOK TOO HEAVY AND WIDESPREAD. HAVE TRENDED GRIDS TOWARDS A
RAP AND HRRR BLEND FOR NOW.
MEANWHILE...SNOW WILL CONTINUE TO FALL HEAVY ALONG THE CONTINENTAL
DIVIDE THROUGH THE MORNING BEFORE TAILING BACK SOME DURING THE
AFTERNOON AS UPPER FORCING WEAKENS. NORTHWEST FLOW WILL KEEP
OROGRAPHIC SNOW CONTINUING ACROSS THE CENTRAL MOUNTAINS THROUGH
TONIGHT...BUT ACCUMULATIONS REMAIN ON THE LIGHTER SIDE UNTIL THE
NEXT WAVE MOVES IN LATE TONIGHT AND CONTINUES INTO MONDAY. CURRENT
SET OF HEADLINES PARES OUT THE SOUTHWEST MOUNTAINS AT 5 PM AND THE
LOWER ELEVATIONS OF LAKE COUNTY AND WESTERN CHAFFEE COUNTY BY 11 PM
THIS EVENING. SUSPECT THESE MAY BE ABLE TO BE TAKEN DOWN
SOONER...BUT WITH THE POSSIBILITY FOR CONVECTIVE SNOW BURSTS IN THE
AFTERNOON...AM HESITANT TO MODIFY ENDING TIMES JUST YET. CENTRAL
MOUNTAIN HEADLINES ABOVE 11KFT CONTINUE THROUGH MONDAY
AFTERNOON...AND THIS SEEMS THE BEST WAY TO HANDLE THE EVENT GIVEN
THE PERSISTENT SNOW EVEN THOUGH IT MAY DECREASE IN INTENSITY FOR A
TIME THIS AFTERNOON AND EVENING. MEANWHILE...CONVECTIVE SNOW SHOWERS
ACROSS THE SE MTS/ADJACENT I-25 CORRIDOR SHOULD DIMINISH DURING THE
EVENING HOURS WITH DRY CONDITIONS RETURNING TO THE SE MTS BY
MIDNIGHT. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM MST SUN NOV 23 2014
PRIMARY LONGER TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...GUSTY
WINDS AT TIMES AND POPS(PRIMARILY OVER THE CENTRAL MOUNTAINS AT
TIMES).
OTHER THAN GUSTY WINDS AND SNOW OVER PORTIONS OF THE CONTINENTAL
DIVIDE AT TIMES(ESPECIALLY OVER THE CENTRAL MOUNTAINS)...EXPECT A
BASICALLY DRY AND MILD METEOROLOGICAL PATTERN TO GRACE THE
CWFA...ESPECIALLY FROM TUESDAY INTO THANKSGIVING WEEKEND.
INITIALLY...ACCUMULATING SNOW AS WELL AS GUSTY WINDS ARE PROJECTED
TO CONTINUE OVER THE CENTRAL MOUNTAINS INTO AT LEAST MONDAY AS
ADEQUATE ATMOSPHERIC MOISTURE IN COMBINATION WITH ANOTHER UPPER
DISTURBANCE IMPACTS THE REGION...THEREFORE WILL CONTINUE THE
WINTER STORM WARNING FOR PUBLIC ZONES 58 AND 60 THROUGH MONDAY
AFTERNOON.
ELSEWHERE OVER THE FORECAST DISTRICT...LOW-GRADE TO NIL POPS AS
WELL AS LOCALIZED GUSTY WINDS ARE ANTICIPATED FROM MONDAY INTO
TUESDAY. IN ADDITION...GENERALLY BELOW SEASONAL TEMPERATURES ARE
ALSO PROJECTED OVER SOUTHERN COLORADO FROM MONDAY INTO AT LEAST
TUESDAY MORNING.
THEN...AS BASICALLY DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS
OVER THE FORECAST DISTRICT FROM WEDNESDAY INTO THANKSGIVING
WEEKEND...PROJECT THAT DRY CONDITIONS WILL BE COMMON-PLACE IN
COMBINATION WITH MILD TEMPERATURES.
REGARDING TEMPERATURES...RECENT GFS40 AND DGEX SOLUTIONS INDICATE
WARMER TEMPERATURES THAN THE LATEST ECMWF SOLUTION OVER EASTERN
PORTIONS OF THE FORECAST DISTRICT...ESPECIALLY FROM FRIDAY INTO
SATURDAY AS THE ECMWF SOLUTION ALLOWS COOLER EASTERLY FLOW TO
DEVELOP OVER THESE LOCATIONS DURING THIS TIME-FRAME.
HOWEVER...THE DGEX...ECMWF AND GFS40 SOLUTIONS ALL SUGGEST THAT
THANKSGIVING DAY SHOULD EXPERIENCE THE WARMEST TEMPERATURES
DURING THE LONGER TERM IN COMBINATION WITH DRY CONDITIONS.
FINALLY...THE STRONGEST WINDS DURING THE LONGER TERM ARE
ANTICIPATED FROM TUESDAY INTO WEDNESDAY MORNING AND THEN AGAIN
DURING THANKSGIVING WEEKEND AT TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1013 AM MST SUN NOV 23 2014
MAIN AREA OF SNOW HAS SHIFTED SOUTH OF KCOS AND KPUB...AND WHILE
BOTH SITES MAY SEE SOME ISOLATED -SHSN REDEVELOP THIS
AFTERNOON...EXPECT CIGS/VIS TO REMAIN VFR THROUGH THE REMAINDER OF
THE DAY AND INTO TONIGHT. WINDS WILL CONTINUE OUT OF THE NORTH THE
NEXT 24 HRS...WITH OCCASIONAL GUSTS TO 25 KTS BOTH TERMINALS. AT
KALS...EXPECT VFR CONDITIONS AS THREAT OF -SHSN HAS JUST ABOUT
ENDED WITH MOST SNOWFALL REMAINING OVER THE MOUNTAINS DURING THE
AFTERNOON AND EARLY EVENING. OVER THE MOUNTAINS...AREAS OF
IFR/LIFR CONDITIONS DUE TO SNOW WILL PERSIST OVER THE
SANGRES/WETS/SRN I-25 CORRIDOR INTO THE EVENING...WITH MAINLY
SCATTERED SNOW SHOWERS AND PATCHY MVFR/IFR ELSEWHERE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ064-
066-068.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR COZ059-
061.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060.
&&
$$
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
454 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM MST SUN NOV 23 2014
...SNOW CONTINUES FOR THE MOUNTAINS TODAY...QUICK BURST OF RAIN AND
SNOW SHOWERS FOR PORTIONS OF THE SE PLAINS THIS MORNING...
UPPER TROF IS MOVING THROUGH WESTERN CO WITH HEAVY SNOW FALLING
ALONG THE CONTDVD BASED ON WEB CAMS. HAVE EVEN SEEN PERIODS OF
MODERATE SNOW ACROSS NORTHERN PORTIONS OF THE SAN LUIS VALLEY AT
SAGUACHE AND JUST SOUTH VILLA GROVE IN CDOT CAMS. MEANWHILE...COLD
FRONT HAS CROSSED THE PALMER DIVIDE AND STARTING TO SEE SNOW FILL IN
ACROSS EL PASO COUNTY AS OF 4 AM.
AS UPPER TROF CONTINUES TO MOVE FROM NORTHWEST TO SOUTHEAST ACROSS
COLORADO THIS MORNING...SHOULD SEE RAIN/SNOW SPREAD SOUTHEASTWARD
ACROSS THE PLAINS. MODELS ARE A LOT HEAVIER HANDED WITH
PRECIPITATION ACROSS THE PLAINS THAN THE RUNS FROM LAST NIGHT...AND
THAT LOOKS REASONABLE AS THE UPPER TROF LOOKS A LITTLE SHARPER...AND
WINDS BEHIND THE FRONT LOOK MORE NORTHERLY...AND EVEN A TAD
NORTHEASTERLY THIS MORNING. COLD FRONT SHOULD RACE THROUGH THE
SOUTHEAST PLAINS BY 12-13Z...WITH STRONG NORTH WINDS GUSTING TO 40
MPH AT TIMES. RAIN AND SNOW SHOWERS RACE SOUTHWARD BEHIND THE
FRONT...WITH PRECIPITATION MOST WIDESPREAD ACROSS THE PALMER DIVIDE
THROUGH 15Z...THEN ACROSS THE NRN RATON RIDGE AND LOWER EAST FACING
SLOPES OF THE WETS AND SANGRES THROUGH ROUGHLY 18Z. NAM12 AND
ESPECIALLY ITS 06Z RUN HAS REALLY COME IN HOT WITH SNOWFALL AMOUNTS
FOR THE SE MTS...INDICATING 5-10 INCHES ACROSS WESTERN
HUERFANO...SOUTHERN CUSTER AND WESTERN LAS ANIMAS COUNTIES THROUGH
THIS AFTERNOON. GFS SHOWS GENERALLY 2-4 INCHES. RAP13 HAS AROUND 2-
4 INCHES ACROSS NRN EL PASO...AND 1-6 ACROSS THE SE MTS/SRN I-25
CORRIDOR. WITH LINGERING INSTABILITY THROUGH THE AFTERNOON...HIGH
RES MODELS ARE PROBABLY CORRECT IN KEEPING CONVECTIVE BANDS OF SNOW
SHOWERS GOING THROUGH THE AFTERNOON IN AND NEAR THE MOUNTAINS. ONCE
THE MAIN UPPER LIFT MOVES EAST OF THE AREA AFTER 18Z...AREAL
COVERAGE OF SHOWERS SHOULD DECREASE CONSIDERABLY. THAT SAID...HAVE
SEEN CASES LIKE THIS WHERE A PERSISTENT NARROW BAND CAN ACCUMULATE
LOCALLY HEAVY AMOUNTS OF SNOW...WHILE A COUPLE MILES EITHER SIDE GET
NEXT TO NOTHING. SO THE CONVECTIVE WILD CARD WILL BE A CHALLENGE
WITH SNOWFALL AMOUNTS TODAY. EITHER WAY...NAM12 SEEMS TO BE
SUFFERING FROM TOO MUCH CONVECTION IN THE MODEL RESULTING IN AMOUNTS
THAT LOOK TOO HEAVY AND WIDESPREAD. HAVE TRENDED GRIDS TOWARDS A
RAP AND HRRR BLEND FOR NOW.
MEANWHILE...SNOW WILL CONTINUE TO FALL HEAVY ALONG THE CONTINENTAL
DIVIDE THROUGH THE MORNING BEFORE TAILING BACK SOME DURING THE
AFTERNOON AS UPPER FORCING WEAKENS. NORTHWEST FLOW WILL KEEP
OROGRAPHIC SNOW CONTINUING ACROSS THE CENTRAL MOUNTAINS THROUGH
TONIGHT...BUT ACCUMULATIONS REMAIN ON THE LIGHTER SIDE UNTIL THE
NEXT WAVE MOVES IN LATE TONIGHT AND CONTINUES INTO MONDAY. CURRENT
SET OF HEADLINES PARES OUT THE SOUTHWEST MOUNTAINS AT 5 PM AND THE
LOWER ELEVATIONS OF LAKE COUNTY AND WESTERN CHAFFEE COUNTY BY 11 PM
THIS EVENING. SUSPECT THESE MAY BE ABLE TO BE TAKEN DOWN
SOONER...BUT WITH THE POSSIBILITY FOR CONVECTIVE SNOW BURSTS IN THE
AFTERNOON...AM HESITANT TO MODIFY ENDING TIMES JUST YET. CENTRAL
MOUNTAIN HEADLINES ABOVE 11KFT CONTINUE THROUGH MONDAY
AFTERNOON...AND THIS SEEMS THE BEST WAY TO HANDLE THE EVENT GIVEN
THE PERSISTENT SNOW EVEN THOUGH IT MAY DECREASE IN INTENSITY FOR A
TIME THIS AFTERNOON AND EVENING. MEANWHILE...CONVECTIVE SNOW SHOWERS
ACROSS THE SE MTS/ADJACENT I-25 CORRIDOR SHOULD DIMINISH DURING THE
EVENING HOURS WITH DRY CONDITIONS RETURNING TO THE SE MTS BY
MIDNIGHT. -KT
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM MST SUN NOV 23 2014
PRIMARY LONGER TERM METEOROLOGICAL ISSUES ARE TEMPERATURES...GUSTY
WINDS AT TIMES AND POPS(PRIMARILY OVER THE CENTRAL MOUNTAINS AT
TIMES).
OTHER THAN GUSTY WINDS AND SNOW OVER PORTIONS OF THE CONTINENTAL
DIVIDE AT TIMES(ESPECIALLY OVER THE CENTRAL MOUNTAINS)...EXPECT A
BASICALLY DRY AND MILD METEOROLOGICAL PATTERN TO GRACE THE
CWFA...ESPECIALLY FROM TUESDAY INTO THANKSGIVING WEEKEND.
INITIALLY...ACCUMULATING SNOW AS WELL AS GUSTY WINDS ARE PROJECTED
TO CONTINUE OVER THE CENTRAL MOUNTAINS INTO AT LEAST MONDAY AS
ADEQUATE ATMOSPHERIC MOISTURE IN COMBINATION WITH ANOTHER UPPER
DISTURBANCE IMPACTS THE REGION...THEREFORE WILL CONTINUE THE
WINTER STORM WARNING FOR PUBLIC ZONES 58 AND 60 THROUGH MONDAY
AFTERNOON.
ELSEWHERE OVER THE FORECAST DISTRICT...LOW-GRADE TO NIL POPS AS
WELL AS LOCALIZED GUSTY WINDS ARE ANTICIPATED FROM MONDAY INTO
TUESDAY. IN ADDITION...GENERALLY BELOW SEASONAL TEMPERATURES ARE
ALSO PROJECTED OVER SOUTHERN COLORADO FROM MONDAY INTO AT LEAST
TUESDAY MORNING.
THEN...AS BASICALLY DRY NORTHWESTERLY TO ZONAL UPPER FLOW DEVELOPS
OVER THE FORECAST DISTRICT FROM WEDNESDAY INTO THANKSGIVING
WEEKEND...PROJECT THAT DRY CONDITIONS WILL BE COMMON-PLACE IN
COMBINATION WITH MILD TEMPERATURES.
REGARDING TEMPERATURES...RECENT GFS40 AND DGEX SOLUTIONS INDICATE
WARMER TEMPERATURES THAN THE LATEST ECMWF SOLUTION OVER EASTERN
PORTIONS OF THE FORECAST DISTRICT...ESPECIALLY FROM FRIDAY INTO
SATURDAY AS THE ECMWF SOLUTION ALLOWS COOLER EASTERLY FLOW TO
DEVELOP OVER THESE LOCATIONS DURING THIS TIME-FRAME.
HOWEVER...THE DGEX...ECMWF AND GFS40 SOLUTIONS ALL SUGGEST THAT
THANKSGIVING DAY SHOULD EXPERIENCE THE WARMEST TEMPERATURES
DURING THE LONGER TERM IN COMBINATION WITH DRY CONDITIONS.
FINALLY...THE STRONGEST WINDS DURING THE LONGER TERM ARE
ANTICIPATED FROM TUESDAY INTO WEDNESDAY MORNING AND THEN AGAIN
DURING THANKSGIVING WEEKEND AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 454 AM MST SUN NOV 23 2014
BAND OF -SHRASN WILL CONTINUE TO DROP SOUTHWARD ACROSS
PORTIONS OF THE SOUTHEAST PLAINS THIS MORNING BEHIND A COLD FRONT
PACKING NORTH WINDS 20-40 KT. THIS FRONT WILL DROP THROUGH ALL OF
SE CO BY 12-13Z. BRUNT OF SNOW SHOWER ACTIVITY WILL BE FOCUSED
ALONG THE NORTHERN SLOPES OF THE PALMER DIVIDE AND THE RATON
RIDGE...AND THE NORTHEAST FACING SLOPES OF PIKES PEAK/TELLER
COUNTY...THE WET MOUNTAINS AND SANGRE DE CRISTO MOUNTAINS AND SRN I-
25 CORRIDOR. IFR TO LIFR CIGS/VIS WILL BE POSSIBLE IN THESE AREAS
WITH SNOW SHOWERS...ESPECIALLY DURING THE MORNING HOURS. KCOS HAS
THE BEST CHANCE FOR SEEING SOME SNOW THIS MORNING...WITH
TEMPERATURES DROPPING QUICKLY THROUGH 15Z...AND THE POSSIBILITY FOR A
QUICK UP TO 1/2 INCH OF SNOW AT THE TERMINAL. KPUB MAY SEE A BRIEF -
SHRASN VCNTY OF THE AIRPORT AS WELL...THOUGH PROBABILITY LOOKS
LOWER. MVFR CIGS WILL BE POSSIBLE AT BOTH KCOS AND KPUB WITH
SHOWERS. THIS WILL BE A QUICK BLAST...WITH SHOWERS ENDING FOR THE
MOST PART BY 16Z. NORTH WINDS GUSTING TO 30-35 KTS WILL BE POSSIBLE
THIS MORNING FOR BOTH KCOS AND KPUB WITH GUSTS DROPPING BACK INTO
THE 25 KT RANGE IN THE AFTERNOON.
KALS WILL BE LESS LIKELY TO BE IMPACTED BY -SHSN TODAY SO WILL LEAVE
IT OUT OF THE TAFS FOR NOW. SHOULD SEE WINDS INCREASE AT KALS FROM
THE NORTHWEST BY LATE MORNING WITH GUSTS TO 25 KTS POSSIBLE THROUGH
THE DAY. CIGS WILL LIKELY REMAIN VFR.
WIDESPREAD MTN OBSCURATIONS CAN BE EXPECTED THIS MORNING ACROSS MOST
OF THE AREA. THE SOUTHEAST MTS AND THE EASTERN SAN JUANS WILL START
TO SEE SOME PARTIAL CLEARING IN THE AFTERNOON THOUGH CONVECTIVE SNOW
SHOWERS MAY CAUSE SOME LOCALIZED OBSCURATIONS AT TIMES THROUGH THE
AFTERNOON. CONDITIONS ARE EXPECTED TO REMAIN IFR TO LIFR ACROSS THE
CENTRAL MOUNTAINS WHERE OROGRAPHIC SNOW SHOWERS WILL CONTINUE INTO
TONIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ064-
066-068.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR COZ059-
061.
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1233 AM MST SUN NOV 23 2014
.UPDATE...
ISSUED AT 1233 AM MST SUN NOV 23 2014
UPDATED TO DROP WINTER WEATHER ADVISORY FOR THE EASTERN UINTA
BASIN. HEAVY SNOWFALL HAS SHIFTED TO THE SOUTHEAST WITH THE COLD
FRONT WHICH SWEPT ACROSS THE AREA DURING THE EVENING. SCATTERED
SNOWFALL WILL CONTINUE OVER PORTIONS OF THE VALLEY...HOWEVER
ADDITIONAL ACCUMULATIONS WILL BE LIGHT.
UPDATE ISSUED AT 858 PM MST SAT NOV 22 2014
A QUICK SHOT OF SNOWFALL AHEAD OF THE FRONT CAUSED A QUICK INCH OF
SNOW IN THE TOWN OF VERNAL AND SURROUNDING COMMUNITIES. DO NOT
ANTICIPATE MUCH MORE ACCUMULATION BUT DECIDED TO ISSUE ADVISORY
FOR THAT ZONE AS LOCAL DISPATCH REPORTS NUMEROUS CAR ACCIDENTS
ACROSS THE AREA. THINK IT BETTER TO GET THE WORD OUT FOR THOSE
INDIVIDUALS CONSIDERING DRIVING TONIGHT. NO OTHER CHANGES TO
CURRENT WINTER HIGHLIGHTS.
UPDATE ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 955 PM MST SAT NOV 22 2014
WIDESPREAD PRECIPITATION HAS DEVELOPED ACROSS THE AREA EARLIER
THIS EVENING...WITH SNOW IN THE HIGHER VALLEYS AND MOUNTAINS...AND
RAIN IN THE LOWER WEST-CENTRAL AND SOUTHERN VALLEYS. SNOW LEVELS
ARE EXPECTED TO DROP INTO THE VALLEY BOTTOMS BY AROUND 09Z
TONIGHT. SNOW WILL DIMINISH FROM THE WEST ON SUNDAY. HOWEVER THE
COLORADO MOUNTAINS WILL CONTINUE TO SEE GOOD SNOWFALL RATES
THROUGH SUNDAY AFTERNOON AND EVENING. FLIGHT RESTRICTIONS ACROSS
MUCH OF THE AREA ARE EXPECTED TONIGHT AND INTO SUNDAY WITH
CIGS/VSBY DROPPING INTO THE MVFR/IFR CATEGORIES AT TIMES. TAF
SITES MOST AFFECTED WILL BE KASE...KTEX...KRIL...KEGE. ALSO
MOUNTAINS WILL BE OBSCURED IN SNOW AND LOW CLOUDS. STRONG WEST TO
NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING SNOW IN THE MOUNTAINS
AND EXPOSED AREAS.
THESE STRONG WINDS AT MOUNTAINTOP LEVEL WILL ALSO RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST THIS AFTERNOON FOR COZ007-
008-011-014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
UTZ023.
&&
$$
UPDATE...NL
SHORT TERM...CC
LONG TERM...JOE
AVIATION...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
955 PM MST SAT NOV 22 2014
.UPDATE...
ISSUED AT 858 PM MST SAT NOV 22 2014
A QUICK SHOT OF SNOWFALL AHEAD OF THE FRONT CAUSED A QUICK INCH OF
SNOW IN THE TOWN OF VERNAL AND SURROUNDING COMMUNITIES. DO NOT
ANTICIPATE MUCH MORE ACCUMULATION BUT DECIDED TO ISSUE ADVISORY
FOR THAT ZONE AS LOCAL DISPATCH REPORTS NUMEROUS CAR ACCIDENTS
ACROSS THE AREA. THINK IT BETTER TO GET THE WORD OUT FOR THOSE
INDIVIDUALS CONSIDERING DRIVING TONIGHT. NO OTHER CHANGES TO
CURRENT WINTER HIGHLIGHTS.
UPDATE ISSUED AT 725 PM MST SAT NOV 22 2014
THE SURFACE COLD FRONT HAS ENTERED WRN WY AND IS DRAPED DOWN TO
THE SE THROUGH CENTRAL UTAH. A FEW LIGHTNING STRIKES ARE STILL
BEING OBSERVED ALONG THE FRONT BUT THE NUMBER HAS DROPPED
DRAMATICALLY IN THE LAST FEW HOURS. THIS TREND WILL CONTINUE
THROUGH THE EVENING HOURS. THE RADAR MOSAIC SHOWS WIDESPREAD
PRECIP ACROSS THE CWA THIS EVENING WITH MANY AREAS REPORTING...OR
HAVING REPORTED...SHOWERS OVER THE LAST FEW HOURS. THIS WILL
CONTINUE AS THE FRONT APPROACHES. BOTH THE HRRR AND NAM12
INITIALIZED WELL AND BRING THE FRONT THROUGH NRN AREAS BY ABOUT
MIDNIGHT...REACHING THE GRAND VALLEY AROUND 0300L AND THEN THE SAN
JUANS BY DAYBREAK. SNOTELS REPORTING A FEW INCHES OF SNOW FOR THE
PARK/GORE RANGES WHILE ONE SNOTEL IN ERN UT REPORTING AROUND 6
INCHES. CURRENT FORECAST CAPTURING CURRENT WEATHER WELL SO MADE NO
CHANGES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 318 PM MST SAT NOV 22 2014
SATELLITE AND ANALYSIS SHOWS THE COLD FRONT OVER NW UT AND
NORTHERN NV ASSOCIATED WITH THE STORM SYSTEM TO MOVE THROUGH THE
AREA TONIGHT. RADAR SHOWS AN AREA OF LOWER CLOUDS AND SCATTERED
SHOWERS MOVING THROUGH CENTRAL CO WITH SOME SHOWERS REPORTED ALONG
INTERSTATE 70 EAST OF GRAND JUNCTION. THE FRONT SHOULD MOVE
THROUGH NORTHWEST CO BY ABOUT MIDNIGHT AND THEN DRAG THROUGH THE
REST OF THE AREA OVERNIGHT. THE BEST COLD ADVECTION AND DYNAMIC
SUPPORT SHOULD MOVE THROUGH BETWEEN ABOUT 04Z AND 12Z. FOLLOWING
FRONTAL PASSAGE...FROM NW TO SE ACROSS THE AREA TONIGHT...WINDS AT
MTN TOP LEVEL WILL SHIFT TO THE NW AND BECOME MORE NORTHERLY WITH
TIME SUNDAY. THIS WILL SHIFT THE FOCUS OF BEST SNOWFALL FROM WEST
TO NNW FACING SLOPES.
MOISTURE STEADILY ERODES SUNDAY...AS FORECAST SOUNDINGS SHOW ONLY
A SHALLOW SURFACE-BASED SATURATED LAYER REMAINING OVER THE
NORTHERN HALF OF THE AREA. TEMPERATURES IN THIS LAYER ARE IN THE
FAVORABLE RANGE FOR DENDRITIC GROWTH WITH A STRONG LAPSE RATE. IN
THESE CONDITIONS OROGRAPHIC SNOWFALL SHOULD CONTINUE IN THE
NORTHERN AND CENTRAL MOUNTAINS...BUT DIMINISH OVER THE VALLEYS AND
PLATEAUS. THE SOUNDING OVER THE SOUTHERN HALF OF THE AREA BECOMES
EVEN DRIER SO THERE A PAUSE IN SNOWFALL SHOULD OCCUR OVER MUCH OF
THE SOUTHERN MOUNTAINS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 318 PM MST SAT NOV 22 2014
MONDAY IN NW FLOW A STRONG COLD DISTURBANCE DROPS THROUGH THE
REGION. AN ASSOCIATED -33C COLD CORE STEEPENS LAPSE RATES.
MOISTURE IS LIMITED AND WITH THE JET DIGGING THROUGH UTAH
DYNAMICS ARE NOT OVERLY IMPRESSIVE. BUT COLD ADVECTION...NW
OROGRAPHICS...AND THE SNOW PRODUCTION LAYER AT MTN TOP LEVEL
(-12C AT 700MB) WILL COMBINE TO PRODUCE ANOTHER ROUND OF
SIGNIFICANT SNOWFALL OVER THE NORTHERN AND CENTRAL MTNS. THE
CURRENT HIGHLIGHTS FOR MONDAY LOOK ON TRACK...THOUGH THE NW SAN
JUAN MTNS MAY NEED AN ADVISORY. HAVE RAISED POPS THERE. THE SNOW
SHOULD BE QUITE DRY FOR NOVEMBER...IN THE 20:1 RANGE.
SNOWFALL FINALLY DIMINISHES THROUGH MONDAY NIGHT AS THE TROUGH AND
ASSOCIATED JET SLIDES SE. THE MOIST MARGINALLY UNSTABLE LAYER
SHRINKS TOP DOWN INTO TUESDAY SO SOME SCATTERED SNOW SHOWERS ARE
EXPECTED IN THE EASTERN MTNS THROUGH TUESDAY AFTERNOON WITH LITTLE
ACCUMULATION EXPECTED.
TUESDAY NIGHT THROUGH SATURDAY...THE WEST COAST RIDGE SLOWLY
PROGRESSES INLAND BRINGING DRY CONDITIONS AND PERSISTENT VALLEY
INVERSIONS. UNDERCUT GUIDANCE TEMPERATURES INTO FRIDAY AS THE
RIDGE BUILDS OVER THE FORECAST AREA AND DEAMPLIFIES. THIS PROMISES
DRY CONDITIONS FOR THANKSGIVING. SATURDAY MODEL TIMING BREAKS
SOMEWHAT WITH THE GFS DIGGING THE NEXT TROUGH INTO WA-OR WHILE THE
EC HOLDS IT OFFSHORE. IF THE GFS VERIFIES WE MAY HAVE SHOWERS OVER
THE NORTH BY SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 955 PM MST SAT NOV 22 2014
WIDESPREAD PRECIPITATION HAS DEVELOPED ACROSS THE AREA EARLIER
THIS EVENING...WITH SNOW IN THE HIGHER VALLEYS AND MOUNTAINS...AND
RAIN IN THE LOWER WEST-CENTRAL AND SOUTHERN VALLEYS. SNOW LEVELS
ARE EXPECTED TO DROP INTO THE VALLEY BOTTOMS BY AROUND 09Z
TONIGHT. SNOW WILL DIMINISH FROM THE WEST ON SUNDAY. HOWEVER THE
COLORADO MOUNTAINS WILL CONTINUE TO SEE GOOD SNOWFALL RATES
THROUGH SUNDAY AFTERNOON AND EVENING. FLIGHT RESTRICTIONS ACROSS
MUCH OF THE AREA ARE EXPECTED TONIGHT AND INTO SUNDAY WITH
CIGS/VSBY DROPPING INTO THE MVFR/IFR CATEGORIES AT TIMES. TAF
SITES MOST AFFECTED WILL BE KASE...KTEX...KRIL...KEGE. ALSO
MOUNTAINS WILL BE OBSCURED IN SNOW AND LOW CLOUDS. STRONG WEST TO
NORTHWEST WINDS WILL CAUSE AREAS OF BLOWING SNOW IN THE MOUNTAINS
AND EXPOSED AREAS.
THESE STRONG WINDS AT MOUNTAINTOP LEVEL WILL ALSO RESULT IN
MODERATE TO STRONG TURBULENCE...ESPECIALLY IN THE LEE OF HIGHER
TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ002-003.
WINTER WEATHER ADVISORY UNTIL 3 PM MST SUNDAY FOR COZ007-008-011-
014-018-019.
WINTER STORM WARNING UNTIL 6 PM MST MONDAY FOR COZ004-005-009-
010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR UTZ024.
WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR UTZ023.
&&
$$
UPDATE...TGR
SHORT TERM...CC
LONG TERM...JOE
AVIATION...EH
AREA FORECAST DISCUSSION
NWS ALBANY NY
649 PM EST MON NOV 24 2014
.SYNOPSIS...
A COLD FRONT WILL SWEEP ACROSS THE AREA THIS EVENING USHERING IN
A COOLER AIRMASS FOR TUESDAY. TEMPERATURES WILL STILL BE ABOVE
NORMAL TUESDAY...HOWEVER COLDER AIR BE USHERED IN TUESDAY NIGHT.
THE REGION WILL BE IMPACTED BY A COASTAL LOW WEDNESDAY AND
WEDNESDAY NIGHT WHICH WILL BRING A WIDESPREAD SNOWFALL TO THE AREA
THAT WILL SIGNIFICANTLY IMPACT HOLIDAY TRAVEL. HEAVY SNOWFALL IS
EXPECTED ACROSS WESTERN NEW ENGLAND AND MUCH OF EASTERN NEW YORK
WITH THE HEAVIEST SNOW DURING THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TUESDAY/...
RECORD WARMTH TODAY WITH RECORD HIGH TEMPERATURES BROKEN AT
ALBANY...GLENS FALLS AND POUGHKEEPSIE.
ALBANY...70 DEGREES TODAY (OLD RECORD: 69 DEGREES 1979)
GLENS FALLS...68 DEGREES TODAY (OLD RECORD: 67 DEGREES 1999)
POUGHKEEPSIE...71 DEGREES TODAY (OLD RECORD: 68 DEGREES 1979)
AS OF 649 PM EST...A COLD FRONT WILL SWEEP ACROSS THE AREA THIS
EVENING. LATEST REGIONAL MOSAIC RADAR SHOWS A BAND OF HEAVY
SHOWERS AHEAD OF THIS COLD FRONT MOVING FROM THE TUG HILL PLATEAU
TOWARDS THE WESTERN ADIRONDACKS. THERE EVEN HAVE BEEN A FEW
RUMBLES OF THUNDER WITH THIS ACTIVITY WELL NORTH OF OLD FORGE. THE
3KM HRRR SHOWS THIS ACTIVITY WILL MOVE NORTHEAST ACROSS THE
WESTERN AND SOUTHERN ADIRONDACKS OVER THE NEXT FEW HOURS. OUTSIDE
OF THESE AREAS...IT LOOKS TO REMAIN FAIRLY DRY.
A COOLER AIR MASS WILL BE USHERED IN WITH THE PASSAGE OF THE FRONT.
IT WILL STILL BE A MILD NIGHT FOR LATE NOVEMBER WITH LOWS SIMILAR
TO WHAT THE DAYTIME HIGHS SHOULD BE. TEMPERATURES TONIGHT WILL
FALL INTO THE 40S WITH 30S ACROSS THE SOUTHERN ADIRONDACKS AND
EASTERN CATSKILLS.
LONGWAVE TROUGH OVER THE CONUS DIGS OVER THE SOUTHERN PLAINS WITH
SOUTHWEST FLOW ALONG THE EAST COAST. SOME SHORT ENERGY WILL MOVE
THROUGH THIS QUICK FLOW WITH AN ASSOCIATED COLD FRONT WHICH WILL
OPEN THE DOOR FOR COLDER AIR TO BE USHERED IN. WILL HAVE WEAK
RIDGING AT THE SURFACE. SHOWERS SHOULD CONFINED TO THE SOUTHERN
ADIRONDACKS. COOLER BUT STILL ABOVE NORMAL HIGHS BY 5 TO 10
DEGREES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
WINTER STORM WATCH REMAINS IN EFFECT FOR WEDNESDAY AND WEDNESDAY
NIGHT FOR ALL BUT HERKIMER AND HAMILTON COUNTIES.
THIS STORM WILL SIGNIFICANTLY IMPACT HOLIDAY TRAVEL...MAKING
DRIVING DANGEROUS AT TIMES WITH SNOW COVERED ROADS AND POOR
VISIBILITIES.
SNOW WILL SPREAD FROM SOUTH TO NORTH ACROSS THE AREA BEGINNING
WEDNESDAY MORNING REACHING THE CAPITAL DISTRICT BY EARLY
AFTERNOON. THE SNOW WILL BE THE HEAVIEST DURING THE AFTERNOON AND
EVENING HOURS WITH SNOWFALL RATES OF 1 TO 2 INCHES AN HOUR WITH
THE HEAVIEST SNOW. THE SNOW IS EXPECTED TO TAPER OFF LATE
WEDNESDAY NIGHT.
SOUTHERN STREAM ENERGY WILL RESULT IN THE DEVELOPMENT OF A LOW
ALONG THE SOUTHEAST COAST TUESDAY NIGHT. THIS LOW WILL MOVE
NORTHEASTWARD ALONG THE COLD FRONT THAT WILL SWEEP THROUGH THE
REGION THIS EVENING (MONDAY EVENING). IT APPEARS THE NORTHERN
STREAM ENERGY WILL NOT PHASE WITH THE SOUTHERN STREAM ENERGY WHICH
WILL KEEP THE STORM PROGRESSIVE. GUIDANCE KEEPS THE LOW OFF THE
COAST...THE QUESTION IS HOW FAR OFFSHORE. THE ECMWF CONTINUES TO
HAVE A TRACK JUST TO THE WEST OF GFS AND NAM...AND A BIT SOUTH IN
TIMING PASSING THE LOW SOUTH OF LONG ISLAND WEDNESDAY EVENING.
HOWEVER THE ECMWF TRACK WITH IN THE SPREAD OF THE GFSENSEMBLES
MEMBERS. THE ECMWF HAS SHIFTED A BIT EASTWARD. ALL GUIDANCE
INDICATES MESOSCALE BANDING WILL OCCUR WITH THIS STORM ESPECIALLY
TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT.
OUR TOTAL SNOWFALL FORECAST MAP HAS BEEN POSTED TO THE WEB AND CAN
BE FOUND AT ON OUR WINTER WEATHER HAZARD BRIEFING PAGE AT
WWW.WEATHER.GOV/ALY/EMWINTER
AT THIS TIME...WE HAVE 10 TO 14 INCHES FORECAST FOR THE
TACONICS...BERKSHIRES...SOUTHERN VERMONT...LITCHFIELD COUNTY AND
A PORTION OF THE MID HUDSON VALLEY. AMOUNTS DECREASE AS YOU HEAD
NORTHWESTWARD WITH AROUND 8 INCHES ACROSS THE CAPITAL DISTRICT
WITH LESS THAN 7 INCHES ACROSS HAMILTON AND HERKIMER COUNTIES
(THAT`S WHY THEY ARE NOT INCLUDED IN THE WINTER STORM WATCH).
ANY CHANGE IN THE TRACK OF THE LOW WILL HAVE AN IMPACT ON EXPECTED
SNOWFALL AMOUNTS.
TEMPERATURES ARE EXPECTED TO FALL INTO THE 20S AND LOWER 30S
TUESDAY NIGHT AND ONLY RECOVER INTO THE UPPER 20S TO MID 30S ON
WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE PERIOD BEGINS WITH THE REGION STILL BEING IMPACTING BY AN EARLY
NOR`EASTER WHICH WILL BE DEPARTING INTO THE GULF OF MAINE COME
THANKSGIVING MORNING. THERE WILL BE LEFTOVER SCATTERED SNOW
SHOWERS IN THE MORNING...BUT BY AFTERNOON...ANY SNOW SHOWERS
SHOULD BE CONFINED TO THE LEE OF LAKE OF ONTARIO AS WELL AS
SOUTHERN VERMONT.
THE REMAINDER OF THE REGION WILL BE DRY WITH SOME PEEKS OF
SUNSHINE...AND TEMPERATURES IN THE 30S ALONG WITH A GUSTY WIND WHICH
COULD PRODUCE A LITTLE BLOWING SNOW...ESPECIALLY IN THE OUTLYING
AREAS.
IT TURNS COLD THURSDAY NIGHT WITH WITH LOWS IN THE TEENS TO AROUND
20. THERE COULD BE STILL BE SOME LINGERING LAKE EFFECT SNOW SHOWERS
ACROSS THE ADIRONDACKS AND SOUTHERN VERMONT. DRY ELSEWHERE WITH A
CLEAR TO PARTLY CLOUDY SKY AND A DIMINISHING BREEZE.
FRIDAY INTO FRIDAY NIGHT ...HIGH PRESSURE WILL CREST TO OUR SOUTH.
IT WILL REMAIN COLD WITH MAINLY DRY CONDITIONS OTHER THAN A FEW
FLURRIES OR SNOW SHOWERS SCATTERED OVER THE ELEVATED TERRAIN. HIGHS
WILL ONLY BE RANGE FROM THE MID 20S TO LOWER 30S. LOWS WILL
GENERALLY BE IN THE TEENS FRIDAY NIGHT.
SATURDAY THE HIGH MOVES TO OUR EAST...INDUCING A SOUTHERLY FLOW.
THIS SOUTHERLY FLOW WILL BEGIN A MODERATING TREND...AND WARM AIR
ADVECTION COULD TRIGGER A LITTLE LIGHT SNOW OR ACROSS SOME
SECTIONS.
THE SOUTHERLY FLOW CONTINUES INTO SUNDAY WITH SLIGHT CHANCES OF RAIN
OR SNOW SHOWER ACTIVITY...MAINLY OVER NORTHERN SECTIONS. A COLD
FRONT LOOKS TO WORK TOWARD OUR REGION WITH PERHAPS A FEW
SHOWERS...FOLLOWED BY ANOTHER HIGH PRESSURE BUILDING IN FROM THE
NORTH.
HIGH TEMPERATURES SUNDAY WILL MODERATE INTO THE MID 30S NORTH TO MID
40S SOUTH...LOWS MID 20S TO LOWER 30S. HIGHS MONDAY WILL BE FROM THE
MID 30S TO LOWER 40S AGO.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED TONIGHT INTO TUESDAY.
A BRIEF PERIOD OF MVFR CIGS IS POSSIBLE THIS EVENING AT KPSF
ALONG/AHEAD OF A COLD FRONTAL PASSAGE...OTHERWISE BKN LOWER CLOUDS
AT 3500-5000 FT SHOULD BREAK UP LATE TONIGHT AS DRIER AIR MOVES IN
BEHIND THE BOUNDARY. SOUTH WINDS WILL BECOME SOUTHWEST AROUND 10
KTS WITH A FEW HIGHER GUSTS TONIGHT. THESE WINDS WILL BECOME
WESTERLY FOR TUESDAY AT SIMILAR SPEEDS. JUST SOME SCT DIURNAL CU
AND PASSING HIGH LEVEL CLOUDS ARE EXPECTED ON TUESDAY.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
WED-WED NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN.
THANKSGIVING DAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
THU NIGHT-FRI: NO OPERATIONAL IMPACT. NO SIG WX.
FRI NIGHT-SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGIC PROBLEMS ARE EXPECTED THIS WEEK.
WILL HAVE SOME SHOWERS ACROSS THE MAINLY THE SOUTHERN ADIRONDACKS
THIS EVENING AND TUESDAY EVENING...OTHERWISE DRY WEATHER IS
EXPECTED INTO TUESDAY NIGHT. THE REGION WILL BE IMPACTED BY A
COASTAL LOW WEDNESDAY AND WEDNESDAY NIGHT WHICH WILL BRING A
WIDESPREAD SNOWFALL TO THE AREA. HEAVY SNOWFALL IS EXPECTED
ACROSS WESTERN NEW ENGLAND AND MUCH OF EASTERN NEW YORK WITH THE
HEAVIEST SNOW DURING THE AFTERNOON AND EVENING HOURS.
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...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR NYZ039>043-047>054-058>061-063>066-082>084.
MA...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/FRUGIS
SHORT TERM...IAA
LONG TERM...HWJIV
AVIATION...FRUGIS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 AM EST SUN NOV 23 2014
.SYNOPSIS...
MOISTURE ALREADY RETURNING TO THE AREA AS SHOWERS CONTINUE TO PUSH
NORTHWARD ACROSS THE GA/SC. EXPECT PLENTY OF RAINFALL TO OCCUR
TODAY AND TONIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND
IS EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED THE FORECAST FOR THE REMAINDER OF THE OVERNIGHT PERIOD AS
88D REGIONAL SHOWS SHOWERS MOVING QUICKLY NORTHWARD ACROSS THE
PALMETTO STATE. MODELS CONTINUE TO SHOW IMPRESSIVE ISENTROPIC LIFT
DEVELOPING NORTHWARD THROUGH THE OVERNIGHT HOURS INTO THE DAYTIME
HOURS. THIS WILL HELP DEVELOP THE VERY WEAK SURFACE WEDGE THAT
WILL REMAIN IN PLACE THROUGH MOST OF THE DAY. THE HRRR MODEL
APPEARS TO BE ON TRACK WITH CURRENT RADAR TRENDS. AS THE RAIN
FILLS IN ACROSS THE STATE AND THE AIRMASS BECOMES NEARLY
SATURATED...EXPECT TEMPERATURES TO LEVEL OUT AND BE SLOW TO MOVE
UPWARD THROUGH THE DAY. EXPECT TEMPERATURES TO REMAIN IN THE
MIDDLE 40S TO LOWER 50S THROUGH THE REMAINDER OF THE NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
DETERIORATING CONDITIONS THROUGH THE FORECAST PERIOD TODAY.
SURFACE HIGH PRESSURE RIDGE OVER THE AREA WILL WEAKEN TODAY AS LOW
PRESSURE DEVELOPS IN RESPONSE TO AN APPROACHING SHORTWAVE THAT
WILL CROSS THE AREA THIS EVENING. INCREASING SOUTHEASTERLY LOW
LEVEL FLOW WILL ALSO INCREASE MOISTURE AND RESULT IN THICKENING
AND LOWERING CLOUDS THROUGH THE MORNING HOURS. STRONG MOISTURE
ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK SURFACE WEDGE
WITH MVFR CIGS EXPECTED AFTER 09Z. WIDESPREAD RAINFALL WILL MOVE
OVER THE REGION DURING THE MORNING HOURS AND CONTINUE THROUGH THE
DAY TODAY. DETERIORATING CONDITIONS WITH CIGS DROPPING TO IFR BY
12Z AGS/DNL AND CAE/CUB/OGB BY 15Z...WITH LIFR BECOMING POSSIBLE.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS AND SOME THUNDERSTORMS TO FORM. WINDS WILL
GENERALLY BE FROM THE EAST AND GRADUALLY VEER TO THE SOUTHEAST AND
EVENTUALLY SOUTH AS THE WARM FRONT LIFTS NORTH THROUGH THE REGION.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS THROUGH MONDAY AS A LOW PRESSURE
SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1254 AM EST SUN NOV 23 2014
.SYNOPSIS...
MOISTURE WILL RETURN TO THE REGION TONIGHT THROUGH SUNDAY
NIGHT...WITH PLENTY OF RAINFALL EXPECTED TO OCCUR SUNDAY INTO
SUNDAY NIGHT. A FRONT WILL MOVE INTO THE REGION MONDAY AND IS
EXPECTED TO STALL NEAR THE COAST TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DRY WEATHER WILL OCCUR FOR THE FIRST PART OF THE FORECAST
WITH RAIN OVERSPREADING THE AREA LATER TONIGHT AND INTO THE
OVERNIGHT PERIOD. HIGH PRESSURE WILL CONTINUE AT THE
SURFACE...ALTHOUGH THE CENTER OF THE HIGH WILL PUSH FURTHER OFF
THE COAST OVERNIGHT. VERY WEAK SURFACE WEDGE SHOULD REMAIN ACROSS
THE AREA THROUGH MUCH OF THE NIGHT. ALOFT...ALTHOUGH WE START OFF
DRY...CLOUDS AND MOISTURE WILL RAPIDLY BE ON THE INCREASE...ESPECIALLY
ACROSS THE SOUTHWESTERN CWA AS ISENTROPIC LIFT STRENGTHENS AND
MOVES OVER THE SURFACE WEDGE. REGIONAL RADAR LOOP SHOWS SHOWERS
ACROSS NORTHERN FLORIDA AND SOUTHEASTERN GEORGIA SHIFTING NORTHEAST
INTO THE FORECAST AREA. THE HRRR MODEL APPEARS TO BE ON TRACK
WITH CURRENT RADAR TRENDS...SO HAVE SPED UP THE TIMING OF THE
SHOWERS FILLING IN FROM SOUTHWEST TO NORTHEAST ACROSS THE FA.
TEMPERATURES MAY BE SOMEWHAT TRICKY TONIGHT. CLOUDS WILL CONTINUE
TO INCREASE AND TEMPERATURES SHOULD BECOME NEARLY STEADY OR EVEN
RISE SLIGHTLY FOR THE REMAINDER OF THE NIGHT. NORTHERN COUNTIES
SHOULD CONTINUE TO FALL UNTIL LATE TONIGHT BEFORE BECOMING STEADY
TOWARDS MORNING. FOR NOW...LOWS AROUND 50 ACROSS THE SOUTH...AND
AROUND 40 ACROSS THE NORTH STILL REASONABLE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
BY SUNDAY...S/W WILL BE ACROSS THE LOWER MS RIVER VALLEY. LOW
PRESSURE DEVELOPING ACROSS THE SOUTHERN PLAINS. A WARM FRONT TO
OUR SOUTH WILL BEGIN TO TRY AND PUSH NORTHWARD THROUGH THE DAY ON
SUNDAY/SUNDAY NIGHT. LOOKING A MODEL LI FIELDS ALONG WITH SOME
WEAK SURFACE RIDING AND SFC WINDS FROM THE NE/E FOR MUCH OF THE
DAY ON SUNDAY. THIS INDICATES AT LEAST SOME WEAK WEDGE CONDITIONS
ACROSS MUCH OF THE CWA...ESPECIALLY ACROSS THE NORTHERN/CENTRAL
MIDLANDS ALONG WITH THE NRN CSRA. WITH INCREASING ISENTROPIC LIFT
AND MOISTURE FLUX INTO THE REGION. ANY RAINFALL SHOULD HELP
SUSTAIN WEDGE CONDITIONS. HOWEVER...BY LATE IN THE DAY SUNDAY AND
SUNDAY NIGHT...SURFACE FLOW WILL INCREASE FROM THE SE AND S AS 50
TO 60 KT LOW LEVEL JET APPROACHES. PW VALUES WILL RISE
DRAMATICALLY THROUGH THE PERIOD TO WELL ABOVE 1.5
INCHES...APPROACHING NEARLY 2.0 INCHES...BY SUNDAY AFTERNOON. THIS
IS MUCH HIGHER THAN CLIMATOLOGY FOR MID/LATE NOVEMBER. WITH SUCH
IMPRESSIVE ISENTROPIC LIFT AND MOISTURE FLUX...THE RAIN WILL BE
HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS
SUNDAY/SUNDAY NIGHT. AS THE WARM FRONT TRIES TO MOVE
NORTH/NORTHWEST ACROSS THE AREA LATE SUNDAY INTO SUNDAY
NIGHT...THE AIRMASS ACROSS THE AREA WILL BECOME MORE UNSTABLE.
THIS IS ESPECIALLY TRUE ACROSS THE EASTERN PORTION OF THE CWA
SOUTH OF I-20. SPC DAY TWO HAS THE SERN HALF OF THE PALMETTO STATE
IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS. THIS IS WHERE THE BEST
SHEAR AND INSTABILITY WILL DEVELOP. HAVE MENTIONED ISOLATED TO
CHANCE OF THUNDERSTORMS FROM LATE SUNDAY AFTERNOON INTO SUNDAY
ACROSS MUCH OF THE AREA DEVELOPING FIRST IN THE SERN PORTION OF
THE CWA AND THEN NORTH/NORTHWEST INTO THE REMAINDER OF THE CWA.
RAINFALL AMOUNTS FROM 1.5 TO 2 INCHES...WITH LOCALLY HEAVIER
AMOUNTS...WILL BE POSSIBLE BY SUNDAY NIGHT.
ON MONDAY...THE COLD FRONT ASSOCIATED WITH THE LOW IN THE PLAINS
WILL TRY TO PUSH EASTWARD ACROSS THE AREA...BUT BY
AFTERNOON/EVENING BECOMES PARALLEL TO THE UPPER FLOW AND WILL
LIKELY SLOW/STALL ALONG THE COASTAL PLAIN OR NEAR THE COAST. THIS
IS WHERE MODELS BEGIN TO DISAGREE ON HOW FAR THE FRONT WILL PUSH
EASTWARD. AT THIS TIME...HAVE CONTINUE TO KEEP A CHANCE OF
SHRA/TSRA THROUGH MONDAY WITH FRONT IN THE VICINITY.
AS FOR TEMPERATURES...THEY WILL BE VERY TRICKY ON SUNDAY WITH
WEDGE AND APPROACHING WARM FRONT FROM THE SOUTH. HAVE STAYED ON
THE LOW SIDE OF GUIDANCE FOR SUNDAY WITH A TIGHT TEMPERATURE
GRADIENT FROM NW TO SE. THE HIGH FOR SUNDAY WILL MOST LIKELY OCCUR
DURING THE EVENING HOURS AS THE WARM FRONT PUSHES NWD.
TEMPERATURES WILL BE DRAMATICALLY WARMER ON MONDAY WITH BREEZY
SOUTH/SOUTHWEST WINDS AHEAD OF THE COLD FRONT WITH ALL OF THE
GUIDANCE IN THE MID/UPPER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNCERTAINTIES CONTINUE IN THE FORECAST THROUGH THE MIDDLE OF NEXT
WEEK. LATEST GFS/PREVIOUS ECMWF MODELS BEGIN TO SHIFT THE MAIN UPPER
TROUGH AXIS EASTWARD AS ENERGY DROPS INTO THE BASE OF THE TROUGH
ACROSS THE SOUTHERN PLAINS BY TUE/TUE NIGHT. BY TUE NIGHT...BOTH
MODELS BEGIN TO DEVELOP LOW PRESSURE IN THE GULF OF MEXICO AND
BRING A SYSTEM UP ALONG THE EAST COAST. THIS LOOKS SLIGHTLY MORE
WESTWARD WITH PRECIPITATION SHIELD AS WELL AS COOLER THAN PREVIOUS
RUNS. HAVE LOWERED HIGHS ON WEDNESDAY A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. BY THURSDAY AND FRIDAY...BOTH MODELS HAVE TROFINESS
ACROSS THE EASTERN HALF OF THE COUNTRY...WITH HIGH PRESSURE
BUILDING INTO THE REGION AT THE SURFACE. DRY WEATHER THANKSGIVING
DAY THROUGH SATURDAY. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
DETERIORATING CONDITIONS THROUGH THE FORECAST PERIOD TODAY.
SURFACE HIGH PRESSURE RIDGE OVER THE AREA WILL WEAKEN TODAY AS LOW
PRESSURE DEVELOPS IN RESPONSE TO AN APPROACHING SHORTWAVE THAT
WILL CROSS THE AREA THIS EVENING. INCREASING SOUTHEASTERLY LOW
LEVEL FLOW WILL ALSO INCREASE MOISTURE AND RESULT IN THICKENING
AND LOWERING CLOUDS THROUGH THE MORNING HOURS. STRONG MOISTURE
ADVECTION WILL GET LIFTED ISENTROPICALLY OVER A WEAK SURFACE WEDGE
WITH MVFR CIGS EXPECTED AFTER 09Z. WIDESPREAD RAINFALL WILL MOVE
OVER THE REGION DURING THE MORNING HOURS AND CONTINUE THROUGH THE
DAY TODAY. DETERIORATING CONDITIONS WITH CIGS DROPPING TO IFR BY
12Z AGS/DNL AND CAE/CUB/OGB BY 15Z...WITH LIFR BECOMING POSSIBLE.
THERE MAY BE A BRIEF PERIOD BETWEEN 21Z AND 00Z AFTER THE WARM
FRONTAL PASSAGE BUT BEFORE THE COLD FRONTAL PASSAGE WHERE CEILINGS
MAY RECOVER AND SHOWERS BECOME LIGHT. HOWEVER THE TAF SITES WILL BE
IN THE WARM SECTOR AND INSTABILITY WILL INCREASE POSSIBLY ALLOWING
FOR MORE SHOWERS AND SOME THUNDERSTORMS TO FORM. WINDS WILL
GENERALLY BE FROM THE EAST AND GRADUALLY VEER TO THE SOUTHEAST AND
EVENTUALLY SOUTH AS THE WARM FRONT LIFTS NORTH THROUGH THE REGION.
EXTENDED AVIATION OUTLOOK...CEILING AND VISIBILITY RESTRICTIONS
ARE LIKELY IN RAIN SHOWERS THROUGH MONDAY AS A LOW PRESSURE
SYSTEM AFFECTS THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ030.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
903 PM CST MON NOV 24 2014
.UPDATE...
830 PM CST
MINOR ADDITIONAL TWEAKS TO GOING FORECAST TONIGHT...MAINLY TO
REFINE POPS FOR ADDITIONAL SCATTERED SNOW SHOWERS/FLURRIES
OVERNIGHT AND TO LOWER TEMPS A BIT WITH PERSISTENT COLD ADVECTION.
REPORTS OF FREEZING DRIZZLE HAVE TAPERED OFF AT MID-EVENING AS
ANTICIPATED PER FORECAST SOUNDING TRENDS. A COMPARISON OF ILX/DVN
00Z RAOBS SHOWS THE MINOR DIFFERENCE IN LOW LEVEL SATURATION DEPTH
WITH THE TOP OF THE ILX MOIST LAYER JUST BELOW 700 HPA AND -14C
WHILE AT DVN IT IS AT 650 HPA AND -18C AND THUS MORE LIKELY TO
CONTAIN ICE AND PRODUCE SNOW. RAP SOUNDING AND IR SATELLITE
TRENDS INDICATE THAT FREEZING DRIZZLE SHOULD BE LESS OF AN ISSUE
FOR REMAINDER OF THE EVENING AS THE COLUMN CONTINUES TO COOL AND
MOISTURE DEEPENS AGAIN WITH APPROACH OF SHORT WAVE APPROACHING
FROM NORTHEAST IA. THIS WAVE IS EXPECTED TO CONTINUE TO PRODUCE
SCATTERED SNOW SHOWERS AS IT MOVES INTO THE CWA OVERNIGHT...THOUGH
HRRR/NAM BOTH INDICATE A DECREASE IN COVERAGE AFTER MIDNIGHT OVER
OUR NORTHERN CWA. THUS WHILE FLURRIES/SNOW SHOWERS WILL BE AROUND
THROUGH MUCH OF THE NIGHT...IT APPEARS THAT ANY LIGHT ADDITIONAL
MEASURABLE SNOW (JUST A COUPLE TENTHS PERHAPS) WILL BE LIMITED TO
NORTHERN PARTS OF NORTH CENTRAL IL. SNOW SHOWERS SHOULD TAPER OFF
TO JUST FLURRIES AFTER 07-09Z (2-4 AM CST) WITH PASSAGE OF
NORTHEAST IA VORT...BASED ON EXTRAPOLATION OF RADAR LOOP.
OTHERWISE...HAVE LOWERED MIN TEMPS JUST A BIT OVERNIGHT AS WE WERE
ALREADY WITHIN A COUPLE OF DEGREES OF FORECAST MINS OUT WEST.
BLENDED IN A BIT OF MAV/MET MOS GUIDANCE WHICH LOWERED MINS ABOUT
2 DEGREES IN MANY PLACES. WINDS CONTINUE TO GUST ABOVE 35 MPH IN A
FEW SPOTS...BUT WILL GRADUALLY DIMINISH OVERNIGHT AS GRADIENT
SLOWLY WEAKENS AND SURFACE PRESSURE RISE MAXIMA CONTINUES TO EXIT
TO OUR NORTHEAST.
RATZER
&&
.SHORT TERM...
302 PM CST
THROUGH WEDNESDAY...
TONIGHT...
PRIMARY SNOW BAND/DEFORMATION AXIS HAS SHIFTED NORTH BUT
WILL STILL SEE OCCASIONAL SNOW SHOWERS MOVING INTO NORTHERN ILLINOIS
INTO THE EVENING RUSH. SOME OF THESE COULD DROP VISIBILITY DOWN
UNDER 1 MILE AT TIMES...ESPECIALLY AS WINDS CONTINUE TO GUST CLOSE
TO 45 MPH AT TIMES. GOING TO SHIFT END TIME OF ADVISORY FOR
NORTH/NW CWA TO 00Z...WITH THE WIDESPREAD ACCUMULATING SNOW
ALREADY HAVING ENDED. COULD SEE SOME LINGERING LIGHT
SNOW/FLURRIES LATE EVE/OVERNIGHT AS ADDITIONAL UPPER LEVEL ENERGY
TRAVERSES AREA IN CYCLONIC FLOW ALOFT. STRATUS DECK WILL
COUNTERACT LOW LEVEL CAA TO KEEP TEMP FALL IN CHECK TONIGHT...BUT
STILL ANTICIPATING LOW- MID 20S BY DAYBREAK TUESDAY.
TUESDAY/TUES NIGHT...
OTHER THAN POSSIBLY A FEW FLURRIES IN NORTHEAST
IL/NW IN IN THE AM AS SOME LIFT REMAINS OVER THE AREA...LAKE EFFECT
FOCUS WILL LIKELY BE TO OUR EAST WITH WESTERLY FLOW. QUESTION IS
DOES STRATUS ERODE DURING AFTERNOON INTO EVENING. AS IS
TYPICAL...WRF/NAM GUIDANCE IS MOST BULLISH ON LOW LEVEL
MOISTURE...WHILE REMAINDER OF GUIDANCE DOES ENABLE DRY AIR TO MOVE
IN LATE DAY INTO TUESDAY EVENING. CONFIDENCE IS NOT THE
HIGHEST...BUT HAVE TRENDED A BIT MORE OPTIMISTIC WITH CLOUD COVER.
WARM ADVECTION WILL RAMP UP ALOFT IN ADVANCE OF CLIPPER SYSTEM
TOMORROW NIGHT...BUT WITH A TRANSIENT SURFACE RIDGE OVER THE
AREA...CLEAR/PCLOUDY SKIES COULD ENABLE A MORE SIGNIFICANT
TEMPERATURE FALL FROM HIGHS IN THE UPPER 20S-LOW 30S. THIS IS
PARTICULARLY THE CASE FOR AREAS THAT PUT DOWN SNOW COVER TODAY. HAVE
ADJUSTED LOW TEMPS DOWN A FEW DEGREES...TO UPPER TEENS IN NORTHWEST
TO LOW-MID 20S ELSEWHERE.
WEDNESDAY...
DECIDED TREND ON GUIDANCE AND ENSEMBLES TODAY HAS BEEN TO TRACK
CLIPPER MAINLY SOUTH OF THE CWA...AND HAVE ADJUSTED POPS DOWNWARD
CHANCE SOUTHWEST CWA AND SLIGHT CHANCE ELSEWHERE. UPPER LEVEL ENERGY
ASSOCIATED WITH THIS SYSTEM WAS STILL OFF OF THE BRITISH COLUMBIA
COAST AT RAOB TIME. GIVEN TENDENCY FOR LARGE SHIFTS IN THE SHORT
TERM GUIDANCE WITH THE TRACK OF SUBTLE FEATURES SUCH AS
CLIPPERS...HAVE NOT GONE WITH A COMPLETELY DRY FORECAST YET.
HOWEVER...IF TRENDS CONTINUE...ONLY THE FAR SOUTHWEST CWA WOULD SEE
ANY SENSIBLE WX IMPACTS. TEMPS LOOK TO RISE INTO THE LOW-MID
30S...WITH A FEW DEGREES ABOVE THIS POSSIBLE IF CLIPPER TRACKS
COMPLETELY SOUTH OF THE CWA. THIS WILL BE IN ADVANCE OF NEXT SURGE
OF MODIFIED ARCTIC AIR FOR THANKSGIVING DAY.
RC
&&
.LONG TERM...
WEDNESDAY NIGHT THROUGH TUESDAY...
A SECONDARY TROUGH AXIS WILL CROSS THE REGION WEDNESDAY NIGHT...BUT
OUTSIDE OF BULLISH CANADIAN MODEL...LITTLE SUPPORT FOR ANYTHING MORE
THAN SLIGHT POPS. BIG STORY IS GLANCING BLOW OF ARCTIC AIR SENDING
H85 TEMPS INTO THE LOW-MID MINUS TEENS CELSIUS ON THANKSGIVING
DAY...ONLY SUPPORTING HIGHS FROM THE MID 20S TO LOWER 30S...COLDEST
WHERE THERE WILL STILL BE SOME LEFTOVER SNOW COVER. LAKE EFFECT
FOCUS LOOKS TO BE EAST OF OUR NW IN COUNTIES...BUT WILL STILL NEED
TO MONITOR DUE TO FAVORABLE PARAMETERS.
UPPER LEVEL PATTERN CONTINUES TO LOOK TO QUICKLY SHIFT TO MORE ZONAL
ON LATEST GUIDANCE...SUPPORTING A RAPID MODERATING TREND. PRIOR TO
THAT...GUIDANCE DOES BREAK OUT SOME LIGHT WAA PRECIP ON FRIDAY AS AN
UPPER LEVEL WAVE MOVES OVER THE REGION. BETTER FORCING LOOKS TO BE
INTO SOUTHERN WI AT THIS TIME...BUT STILL A WAYS OUT. HAVE INDICATED
SLIGHT POPS FOR LIGHT SNOW...WITH A MIX OR TRANSITION TO RAIN BY
AFTERNOON FOR PARTS OF AREA AS BOUNDARY LAYER WARMS ABOVE FREEZING.
LOW PRESSURE OVER NORTHERN PLAINS LOOKS TO ADVECT IN A MUCH WARMER
AIR MASS ON SOUTHWEST FLOW ON SATURDAY. H85 TEMPS WARMING TO
POSSIBLY UPWARDS OF +10C COULD SPELL READINGS WELL INTO THE 50S (!)
FOR AT LEAST PORTIONS OF AREA IF TRENDS HOLD. DESPITE FLOW REMAINING
ZONAL...SIGNS THAT COLD AIR OVER CANADA AND FAR NORTHERN TIER COULD
TRY TO OOZE SOUTH LATER INTO THE WEEKEND INTO EARLY NEXT WEEK. THIS
WOULD SET UP A BAROCLINIC ZONE AND POSSIBLY LOW PRECIP CHANCES
RETURNING.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LINGERING LIGHT SNOW SHOWERS MAY REDUCE VSBY BRIEFLY THE NEXT
FEW HOURS. ANOTHER ROUND OF LIGHT SNOW SHOWERS POSSIBLE AFTER
MIDNIGHT BUT MAY DIMINISH AS IT ARRIVES. IFR VSBY POSSIBLE IF IT
HOLDS TOGETHER.
* WEST-SOUTHWEST WINDS GUSTING TO AROUND 30 KT DIMINISH OVERNIGHT.
* MVFR CIGS PERSIST THROUGH TONIGHT AND MAY CONTINUE TOMORROW AS
WELL.
MDB
//DISCUSSION...UPDATED 03Z...
SNOW SHOWER COVERAGE AND INTENSITY HAS DIMINISHED OVER THE LAST
HOUR BUT AM STILL WATCHING ANOTHER UPPER WAVE GENERATING BANDS OF
SNOW ACROSS NORTHEAST IOWA. WILL CONTINUE TO MENTION TEMPO IFR
VSBY MAINLY AFTER MIDNIGHT BUT THE SNOW SHOWERS MAY DIMINISH AS
THE APPROACH...THOUGH HAVE GOOD CONFIDENCE THEY WILL BE MAINTAINED
AS THEY REACH RFD. OTHERWISE WEST-SOUTHWEST WINDS ARE BEGINNING TO
EASE WITH FEW GUSTS OVER 30 KT. THIS DOWNWARD TREND WILL CONTINUE
INTO THE OVERNIGHT.
FROM 00Z...
A SERIES OF UPPER DISTURBANCES WILL CONTINUE TO DRIVE BANDS OF
SNOW SHOWERS INTO THE OVERNIGHT HOURS. MAY SEE A BIT OF A BREAK IN
THE COVERAGE LATE THIS EVENING BUT ANOTHER WAVE COMING ACROSS
NORTHEAST IOWA WILL LIKELY BRING AN INCREASE IN ACTIVITY AROUND
MIDNIGHT INTO THE OVERNIGHT. WILL INDICATE TEMPO IFR VSBY BASED ON
UPSTREAM TRENDS. ACCUMULATION WILL BE LIGHT WITH LESS THAN A HALF
INCH ADDITIONAL EXPECTED.
AM A LITTLE CONCERNED ABOUT SOME LIGHT FREEZING DRIZZLE THIS
EVENING AS WELL AS MOISTURE ALOFT DECREASES FOR A TIME. AREAS
SOUTH OF THE TERMINALS ARE STARTING TO REPORT THIS AND IT IS MORE
FAVORED TO THE SOUTH BUT IT IS POSSIBLE SOME COULD OCCUR AT THE
TERMINALS. POTENTIAL OF OCCURRENCE IS TOO LOW TO INCLUDE IN THE
TAF FOR NOW BUT WILL MONITOR.
WEST-SOUTHWEST WINDS WILL CONTINUE TO GUST TO AROUND 35 KT THROUGH
EARLY EVENING WITH SNOW SHOWERS HELPING THEM TO OCCUR. EXPECT
GUSTS TO STEADILY DECREASE LATER THIS EVENING INTO THE OVERNIGHT.
MVFR CIGS PERSIST AND SHOULD DO SO OVERNIGHT BUT MAY LIFT A FEW
HUNDRED FEET AT TIMES. LIGHTER WEST WINDS ARE EXPECTED TUESDAY
WITH MVFR STRATUS TO START THE MORNING. HAVE LOW CONFIDENCE IN HOW
LONG MVFR MAY PERSIST OR IF IT LIFTS TO VFR OR SCATTERS AT SOME
POINT DURING THE DAY. WILL LIKELY NEED TO ADJUST THIS WITH LATER
UPDATES.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN SOME LINGERING LIGHT SNOW SHOWERS. MEDIUM
CONFIDENCE THAT COVERAGE WILL INCREASE AFTER MIDNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN MVFR CIGS PERSISTING TONIGHT WITH LOW
CONFIDENCE IN HOW LONG THEY MAY LAST TUESDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SOUTH WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
MDB
&&
.MARINE...
235 PM CST
LOW PRESSURE THAT MOVED OVER THE STRAITS THIS MORNING AND DRAGGED A
COLD FRONT ACROSS THE LAKE WILL HAVE LIFTED INTO THE JAMES BAY AREA
LATE THIS EVENING. STRONG WEST GALES ACROSS THE SOUTH HALF OF THE
LAKE WILL PERSIST INTO THE OVERNIGHT HOURS...WITH GUSTY BUT WEAKER
NORTHWEST WINDS ACROSS THE NORTHERN HALF OF THE LAKE. SNOW MOVES
OUT TONIGHT EXCEPT FOR LINGERING LAKE EFFECT ALONG THE MICHIGAN
SHORE.
WINDS REMAIN WESTERLY BUT RELAX DURING THE DAY TUESDAY AND THEN
RELAX FURTHER BY WEDNESDAY IN A WEAK AND DISORGANIZED PRESSURE
GRADIENT. BY WEDNESDAY NIGHT INTO THURSDAY THE PATTERN BECOMES
BETTER ORGANIZED AGAIN AND WINDS PICK UP FROM THE WEST TO NORTH.
WEATHER REMAINS MOSTLY QUIET THIS WEEK AFTER TONIGHT ASIDE FROM A
BRIEF SHOT OF SNOW AGAIN LATE WEDNESDAY AND THE MICHIGAN SIDE LAKE
EFFECT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
830 PM CST MON NOV 24 2014
.UPDATE...
830 PM CST
MINOR ADDITIONAL TWEAKS TO GOING FORECAST TONIGHT...MAINLY TO
REFINE POPS FOR ADDITIONAL SCATTERED SNOW SHOWERS/FLURRIES
OVERNIGHT AND TO LOWER TEMPS A BIT WITH PERSISTENT COLD ADVECTION.
REPORTS OF FREEZING DRIZZLE HAVE TAPERED OFF AT MID-EVENING AS
ANTICIPATED PER FORECAST SOUNDING TRENDS. A COMPARISON OF ILX/DVN
00Z RAOBS SHOWS THE MINOR DIFFERENCE IN LOW LEVEL SATURATION DEPTH
WITH THE TOP OF THE ILX MOIST LAYER JUST BELOW 700 HPA AND -14C
WHILE AT DVN IT IS AT 650 HPA AND -18C AND THUS MORE LIKELY TO
CONTAIN ICE AND PRODUCE SNOW. RAP SOUNDING AND IR SATELLITE
TRENDS INDICATE THAT FREEZING DRIZZLE SHOULD BE LESS OF AN ISSUE
FOR REMAINDER OF THE EVENING AS THE COLUMN CONTINUES TO COOL AND
MOISTURE DEEPENS AGAIN WITH APPROACH OF SHORT WAVE APPROACHING
FROM NORTHEAST IA. THIS WAVE IS EXPECTED TO CONTINUE TO PRODUCE
SCATTERED SNOW SHOWERS AS IT MOVES INTO THE CWA OVERNIGHT...THOUGH
HRRR/NAM BOTH INDICATE A DECREASE IN COVERAGE AFTER MIDNIGHT OVER
OUR NORTHERN CWA. THUS WHILE FLURRIES/SNOW SHOWERS WILL BE AROUND
THROUGH MUCH OF THE NIGHT...IT APPEARS THAT ANY LIGHT ADDITIONAL
MEASURABLE SNOW (JUST A COUPLE TENTHS PERHAPS) WILL BE LIMITED TO
NORTHERN PARTS OF NORTH CENTRAL IL. SNOW SHOWERS SHOULD TAPER OFF
TO JUST FLURRIES AFTER 07-09Z (2-4 AM CST) WITH PASSAGE OF
NORTHEAST IA VORT...BASED ON EXTRAPOLATION OF RADAR LOOP.
OTHERWISE...HAVE LOWERED MIN TEMPS JUST A BIT OVERNIGHT AS WE WERE
ALREADY WITHIN A COUPLE OF DEGREES OF FORECAST MINS OUT WEST.
BLENDED IN A BIT OF MAV/MET MOS GUIDANCE WHICH LOWERED MINS ABOUT
2 DEGREES IN MANY PLACES. WINDS CONTINUE TO GUST ABOVE 35 MPH IN A
FEW SPOTS...BUT WILL GRADUALLY DIMINISH OVERNIGHT AS GRADIENT
SLOWLY WEAKENS AND SURFACE PRESSURE RISE MAXIMA CONTINUES TO EXIT
TO OUR NORTHEAST.
RATZER
&&
.SHORT TERM...
302 PM CST
THROUGH WEDNESDAY...
TONIGHT...
PRIMARY SNOW BAND/DEFORMATION AXIS HAS SHIFTED NORTH BUT
WILL STILL SEE OCCASIONAL SNOW SHOWERS MOVING INTO NORTHERN ILLINOIS
INTO THE EVENING RUSH. SOME OF THESE COULD DROP VISIBILITY DOWN
UNDER 1 MILE AT TIMES...ESPECIALLY AS WINDS CONTINUE TO GUST CLOSE
TO 45 MPH AT TIMES. GOING TO SHIFT END TIME OF ADVISORY FOR
NORTH/NW CWA TO 00Z...WITH THE WIDESPREAD ACCUMULATING SNOW
ALREADY HAVING ENDED. COULD SEE SOME LINGERING LIGHT
SNOW/FLURRIES LATE EVE/OVERNIGHT AS ADDITIONAL UPPER LEVEL ENERGY
TRAVERSES AREA IN CYCLONIC FLOW ALOFT. STRATUS DECK WILL
COUNTERACT LOW LEVEL CAA TO KEEP TEMP FALL IN CHECK TONIGHT...BUT
STILL ANTICIPATING LOW- MID 20S BY DAYBREAK TUESDAY.
TUESDAY/TUES NIGHT...
OTHER THAN POSSIBLY A FEW FLURRIES IN NORTHEAST
IL/NW IN IN THE AM AS SOME LIFT REMAINS OVER THE AREA...LAKE EFFECT
FOCUS WILL LIKELY BE TO OUR EAST WITH WESTERLY FLOW. QUESTION IS
DOES STRATUS ERODE DURING AFTERNOON INTO EVENING. AS IS
TYPICAL...WRF/NAM GUIDANCE IS MOST BULLISH ON LOW LEVEL
MOISTURE...WHILE REMAINDER OF GUIDANCE DOES ENABLE DRY AIR TO MOVE
IN LATE DAY INTO TUESDAY EVENING. CONFIDENCE IS NOT THE
HIGHEST...BUT HAVE TRENDED A BIT MORE OPTIMISTIC WITH CLOUD COVER.
WARM ADVECTION WILL RAMP UP ALOFT IN ADVANCE OF CLIPPER SYSTEM
TOMORROW NIGHT...BUT WITH A TRANSIENT SURFACE RIDGE OVER THE
AREA...CLEAR/PCLOUDY SKIES COULD ENABLE A MORE SIGNIFICANT
TEMPERATURE FALL FROM HIGHS IN THE UPPER 20S-LOW 30S. THIS IS
PARTICULARLY THE CASE FOR AREAS THAT PUT DOWN SNOW COVER TODAY. HAVE
ADJUSTED LOW TEMPS DOWN A FEW DEGREES...TO UPPER TEENS IN NORTHWEST
TO LOW-MID 20S ELSEWHERE.
WEDNESDAY...
DECIDED TREND ON GUIDANCE AND ENSEMBLES TODAY HAS BEEN TO TRACK
CLIPPER MAINLY SOUTH OF THE CWA...AND HAVE ADJUSTED POPS DOWNWARD
CHANCE SOUTHWEST CWA AND SLIGHT CHANCE ELSEWHERE. UPPER LEVEL ENERGY
ASSOCIATED WITH THIS SYSTEM WAS STILL OFF OF THE BRITISH COLUMBIA
COAST AT RAOB TIME. GIVEN TENDENCY FOR LARGE SHIFTS IN THE SHORT
TERM GUIDANCE WITH THE TRACK OF SUBTLE FEATURES SUCH AS
CLIPPERS...HAVE NOT GONE WITH A COMPLETELY DRY FORECAST YET.
HOWEVER...IF TRENDS CONTINUE...ONLY THE FAR SOUTHWEST CWA WOULD SEE
ANY SENSIBLE WX IMPACTS. TEMPS LOOK TO RISE INTO THE LOW-MID
30S...WITH A FEW DEGREES ABOVE THIS POSSIBLE IF CLIPPER TRACKS
COMPLETELY SOUTH OF THE CWA. THIS WILL BE IN ADVANCE OF NEXT SURGE
OF MODIFIED ARCTIC AIR FOR THANKSGIVING DAY.
RC
&&
.LONG TERM...
WEDNESDAY NIGHT THROUGH TUESDAY...
A SECONDARY TROUGH AXIS WILL CROSS THE REGION WEDNESDAY NIGHT...BUT
OUTSIDE OF BULLISH CANADIAN MODEL...LITTLE SUPPORT FOR ANYTHING MORE
THAN SLIGHT POPS. BIG STORY IS GLANCING BLOW OF ARCTIC AIR SENDING
H85 TEMPS INTO THE LOW-MID MINUS TEENS CELSIUS ON THANKSGIVING
DAY...ONLY SUPPORTING HIGHS FROM THE MID 20S TO LOWER 30S...COLDEST
WHERE THERE WILL STILL BE SOME LEFTOVER SNOW COVER. LAKE EFFECT
FOCUS LOOKS TO BE EAST OF OUR NW IN COUNTIES...BUT WILL STILL NEED
TO MONITOR DUE TO FAVORABLE PARAMETERS.
UPPER LEVEL PATTERN CONTINUES TO LOOK TO QUICKLY SHIFT TO MORE ZONAL
ON LATEST GUIDANCE...SUPPORTING A RAPID MODERATING TREND. PRIOR TO
THAT...GUIDANCE DOES BREAK OUT SOME LIGHT WAA PRECIP ON FRIDAY AS AN
UPPER LEVEL WAVE MOVES OVER THE REGION. BETTER FORCING LOOKS TO BE
INTO SOUTHERN WI AT THIS TIME...BUT STILL A WAYS OUT. HAVE INDICATED
SLIGHT POPS FOR LIGHT SNOW...WITH A MIX OR TRANSITION TO RAIN BY
AFTERNOON FOR PARTS OF AREA AS BOUNDARY LAYER WARMS ABOVE FREEZING.
LOW PRESSURE OVER NORTHERN PLAINS LOOKS TO ADVECT IN A MUCH WARMER
AIR MASS ON SOUTHWEST FLOW ON SATURDAY. H85 TEMPS WARMING TO
POSSIBLY UPWARDS OF +10C COULD SPELL READINGS WELL INTO THE 50S (!)
FOR AT LEAST PORTIONS OF AREA IF TRENDS HOLD. DESPITE FLOW REMAINING
ZONAL...SIGNS THAT COLD AIR OVER CANADA AND FAR NORTHERN TIER COULD
TRY TO OOZE SOUTH LATER INTO THE WEEKEND INTO EARLY NEXT WEEK. THIS
WOULD SET UP A BAROCLINIC ZONE AND POSSIBLY LOW PRECIP CHANCES
RETURNING.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* INTERMITTENT SNOW SHOWERS THROUGH THE OVERNIGHT WITH BRIEF IFR
VSBY AT TIMES.
* LOW CHANCE FOR SOME PATCHY LIGHT FREEZING DRIZZLE INTO MID
EVENING.
* WEST-SOUTHWEST WINDS GUSTING AROUND 35 KT THROUGH EARLY EVENING
THEN GRADUALLY DIMINISH OVERNIGHT.
* MVFR CIGS PERSIST THROUGH TONIGHT AND MAY CONTINUE TOMORROW AS
WELL.
MDB
//DISCUSSION...UPDATED 00Z...
A SERIES OF UPPER DISTURBANCES WILL CONTINUE TO DRIVE BANDS OF
SNOW SHOWERS INTO THE OVERNIGHT HOURS. MAY SEE A BIT OF A BREAK IN
THE COVERAGE LATE THIS EVENING BUT ANOTHER WAVE COMING ACROSS
NORTHEAST IOWA WILL LIKELY BRING AN INCREASE IN ACTIVITY AROUND
MIDNIGHT INTO THE OVERNIGHT. WILL INDICATE TEMPO IFR VSBY BASED ON
UPSTREAM TRENDS. ACCUMULATION WILL BE LIGHT WITH LESS THAN A HALF
INCH ADDITIONAL EXPECTED.
AM A LITTLE CONCERNED ABOUT SOME LIGHT FREEZING DRIZZLE THIS
EVENING AS WELL AS MOISTURE ALOFT DECREASES FOR A TIME. AREAS
SOUTH OF THE TERMINALS ARE STARTING TO REPORT THIS AND IT IS MORE
FAVORED TO THE SOUTH BUT IT IS POSSIBLE SOME COULD OCCUR AT THE
TERMINALS. POTENTIAL OF OCCURRENCE IS TOO LOW TO INCLUDE IN THE
TAF FOR NOW BUT WILL MONITOR.
WEST-SOUTHWEST WINDS WILL CONTINUE TO GUST TO AROUND 35 KT THROUGH
EARLY EVENING WITH SNOW SHOWERS HELPING THEM TO OCCUR. EXPECT
GUSTS TO STEADILY DECREASE LATER THIS EVENING INTO THE OVERNIGHT.
MVFR CIGS PERSIST AND SHOULD DO SO OVERNIGHT BUT MAY LIFT A FEW
HUNDRED FEET AT TIMES. LIGHTER WEST WINDS ARE EXPECTED TUESDAY
WITH MVFR STRATUS TO START THE MORNING. HAVE LOW CONFIDENCE IN HOW
LONG MVFR MAY PERSIST OR IF IT LIFTS TO VFR OR SCATTERS AT SOME
POINT DURING THE DAY. WILL LIKELY ENED TO ADJUST THIS WITH LATER
UPDATES.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN INTERMITTENT SNOW SHOWERS THROUGH AT LEAST EARLY
TONIGHT. MEDIUM CONFIDENCE THAT BRIEF IFR VSBY WILL OCCUR AT
TIMES.
* MEDIUM-HIGH CONIFDENCE THAT THREAT FOR -FZDZ IS LOW AND WOULD BE
VERY LIGHT INTO MID EVENING IF IT DID OCCUR.
* HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN MVFR CIGS PERSISTING TONIGHT WITH LOW
CONFIDENCE IN HOW LONG THEY MAY LAST TUESDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SOUTH WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
MDB
&&
.MARINE...
235 PM CST
LOW PRESSURE THAT MOVED OVER THE STRAITS THIS MORNING AND DRAGGED A
COLD FRONT ACROSS THE LAKE WILL HAVE LIFTED INTO THE JAMES BAY AREA
LATE THIS EVENING. STRONG WEST GALES ACROSS THE SOUTH HALF OF THE
LAKE WILL PERSIST INTO THE OVERNIGHT HOURS...WITH GUSTY BUT WEAKER
NORTHWEST WINDS ACROSS THE NORTHERN HALF OF THE LAKE. SNOW MOVES
OUT TONIGHT EXCEPT FOR LINGERING LAKE EFFECT ALONG THE MICHIGAN
SHORE.
WINDS REMAIN WESTERLY BUT RELAX DURING THE DAY TUESDAY AND THEN
RELAX FURTHER BY WEDNESDAY IN A WEAK AND DISORGANIZED PRESSURE
GRADIENT. BY WEDNESDAY NIGHT INTO THURSDAY THE PATTERN BECOMES
BETTER ORGANIZED AGAIN AND WINDS PICK UP FROM THE WEST TO NORTH.
WEATHER REMAINS MOSTLY QUIET THIS WEEK AFTER TONIGHT ASIDE FROM A
BRIEF SHOT OF SNOW AGAIN LATE WEDNESDAY AND THE MICHIGAN SIDE LAKE
EFFECT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
416 PM CST SUN NOV 23 2014
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* RAIN WITH IFR CIGS AND VARIABLE 2-4SM VSBY THROUGH THE EVENING.
IFR LOWERS TOWARDS 500 FT EARLY EVENING. LIGHTER RAIN OR DRIZZLE
AND IFR CIGS/VSBY PERSISTS THROUGH THE NIGHT.
* SOUTHEAST WINDS TURN LIGHT SOUTHWEST OR EVEN VARIABLE LATE THIS
EVENING.
* WINDS VEERING SOUTHWEST TO WEST BY LATE TOMORROW MORNING AND
INCREASING TO 20G30KT BY AROUND NOON WITH OCCASIONAL HIGHER
GUSTS POSSIBLE.
* RAIN WILL TRANSITION TO SNOW DURG THE LATE MORNING TO EARLY
AFTERNOON HOURS...WITH LIGHT SNOW CONTINUING THROUGH THE
AFTERNOON.
MDB
//DISCUSSION...UPDATED 22Z...
NO MAJOR CHANGES IN FORECAST THINKING LATE THIS AFTERNOON WITH IFR
CIGS AND RAIN NOW SPREAD ACROSS THE TERMINALS. VSBY LOOKS TO
FLUCTUATE BETWEEN 2 AND 4SM WITH INTERMITTENT HIGHER VALUES AS
RAIN INTENSITY CHANGES. MOST INTENSE RAIN SHOULD FALL BETWEEN
ABOUT NOW AND MID EVENING. WIND TRENDS REMAIN ON TRACK BUT THERE
MAY BE A PERIOD OF LIGHT AND VARIABLE WINDS AS SURFACE LOW
PRESSURE PASSES NEARBY OR OVERHEAD EARLY TONIGHT.
MDB
FROM 18Z...
LATEST RADAR IMAGERY SHOWING AN AREA OF WIDESPREAD RAIN MOVING NWRN
ALG THE MISSISSIPPI RIVER AND OVER NWRN IL...WITH MORE SHOWERY
PCPN OVER NERN IL AND INTO NWRN IN. RFD WILL LIKELY SEE THE STEADY
RAIN INITIALLY...BUT BASED ON THE LATEST RADAR TRENDS...THE MORE
WIDESPREAD...STEADY RAIN SHOULD MOVE INTO THE CHICAGO AREA
TERMINALS THROUGH THE EARLY AFTERNOON HOURS. CIGS HAVE ALREADY
DROPPED TO MVFR AND ANTICIPATE THAT CIGS SHOULD CONTINUE TO LOWER
AS RAIN FALLS THROUGH THE STRATUS LAYER...SATURATING BASES
DOWNWARD AND ALLOWING CIGS TO DROP INTO IFR LEVELS THROUGH THE
AFTERNOON. AS THE STEADIER RAIN AND HIGHER DEWPOINTS CONTINUE TO
STREAM NEWD...VIS WILL BEGIN TO DROP S WELL...INITIALLY TO MVFR
LEVELS THROUGH THE EARLY AFTERNOON AND THEN TO IFR LEVELS BY LATE
AFTERNOON. IFR CONDITIONS SHOULD THEN PERSIST THROUGH THE EVENING
AND OVERNIGHT...AND POSSIBLE EVEN EXTEND THROUGH TOMORROW MORNING.
WINDS WILL START OUT SLY AT THE INITIAL TIME...BUT EXPECT
DIRECTION TO BECOME SELY BY LATE AFTERNOON AS A MID LEVEL IMPULSE
TRACKS NWD AND SFC LOW PRESSURE DEVELOPS OVER MISSOURI LATE
AFTERNOON INTO EARLY EVENING. THE LOW IS EXPECTED TO TRACK INTO
LOWER MICHIGAN BY MONDAY MORNING...CAUSING WINDS TO VEER TO SWLY
DURG THE MORNING HOURS. AN ASSOCIATED COLD FRONT SHOULD PASS
ACROSS THE REGION AS THE SFC LOW MOVES INTO LOWER MICHIGAN...AND
COLDER AIR WILL BEING TO FILTER ACROSS THE REGION THROUGH THE
MORNING AS WINDS CONTINUE TO VEER TO WLY BY EARLY AFTERNOON. THE
INFLUX OF COLDER AIR WILL CAUSE PCPN TO GRADUALLY SHIFT OVER TO A
RAIN/SNOW MIX BY LATE MORNING AND THEN CHANGE OVER TO ALL SNOW BY
ARND NOON. PCPN RATES WILL DECREASE FOLLOWING THE PASSAGE OF THE
COLD FRONT...BUT WINDS WILL QUICKLY INCREASE WITH GUSTS TO 30 KT
OR OR BY AROUND NOON AS WELL. THE COMBINATION OF LIGHT SNOW AND
STRONG WINDS WILL KEEP VIS RESTRICTED TO IFR LEVELS THROUGH MUCH
OF THE DAY TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN CIG/VIS TRENDS.
* HIGH CONFIDENCE IN PCPN TRENDS...BUT MEDIUM CONFIDENCE IN THE
TIMING OF THE TRANSITION FROM PREVAILING RAIN TO PREVAILING
SNOW.
* HIGH CONFIDENCE IN WIND TRENDS...BUT HAVE SOME CONCERN FOR GUSTS
HIGHER THAN 30-32KT TOMORROW AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SNOW SHOWERS LIKELY. GUSTY BUT DIMINISHING WEST WINDS.
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
NORTHWEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW.
SATURDAY...VFR.
KMD
&&
.MARINE...
237 PM...LOW PRESSURE OVER NORTHERN MINNESOTA WILL CONTINUE TO
WEAKEN AS IT REACHES WESTERN LAKE SUPERIOR THIS EVENING. LOW
PRESSURE OVER OKLAHOMA WILL MOVE NORTHEAST ACROSS THE LAKE TONIGHT
ABSORBING THE WEAKENING LOW OVER LAKE SUPERIOR. THE TRACK OF THIS
LOW HAS CONTINUED TO DRIFT A LITTLE FURTHER EAST WITH EACH RUN AND
THE LOW NOW PASSES EAST OF LAKE SUPERIOR...MOVING OVER EASTERN
ONTARIO MONDAY WITH A PRESSURE NEAR 28.8 INCHES. THIS WILL DELAY
THE ONSET OF GALES BY A FEW HOURS...UNTIL LATE MORNING ACROSS THE
SOUTHERN PART OF THE LAKE AND THEN TO LATE AFTERNOON ACROSS THE
NORTHERN PART. UPGRADED THE GALE WATCH TO A GALE WARNING FOR THE
SOUTH HALF BUT MAINTAINED THE WATCH ACROSS THE NORTHERN HALF.
GALES WILL DIMINISH BY DAYBREAK TUESDAY WITH WINDS STEADILY
DIMINISHING TUESDAY AS HIGH PRESSURE MOVES ACROSS THE SOUTHERN
LAKES AND OHIO VALLEY. ANOTHER LOW WILL MOVE ACROSS THE LAKES
REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 PM MONDAY TO 3 AM TUESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
314 PM CST Sun Nov 23 2014
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1155 AM CST SUN NOV 23 2014
MVFR ceilings of 1-2k ft have developed over central IL airports late
this morning and expect ceilings to lower to IFR during the
afternoon and tonight. VFR visibilities at midday lower to 2-4
miles during mid and late afternoon and continue tonight as rain
showers become more widespread and heavier. Currently no
thunderstorms over IL and nearby states, but isolated
thunderstorms still expected to develop this afternoon and
evening, though coverage too limited to pin point donw in the
TAFS. Rain showers to mix with or change to light snow from west
to east during Monday morning with vsbys as low as 1-2 miles at
PIA and BMI, while 2-4 miles vsbys further south along I-72. SSE
winds 12-17 kts with gusts 18-24 kts this afternoon to diminish
closer to 10 kts this evening and then veer sw by overnight and
WSW later tonight into Monday morning and increase to 17-22 kts
and gusts 25-30 kts by 15Z/9 am Monday.
Deepening 994 mb low pressure just north of Oklahoma City in
central OK at midday to turn northeast and track into central IL
this evening as it deepens to 987 mb. Low pressure then tracks
into western lower MI late tonight as it deepens further to 980 mb
and pulls a strong cold front east across central IL between 08Z-
12Z. Very tight pressure gradient behing cold front to bring the
strong WSW winds by Monday morning along with the colder air
changing the light rain to light snow and more widespread over
northern airports of PIA and BMI.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
AREA FORECAST DISCUSSION
NWS JACKSON KY
945 PM EST MON NOV 24 2014
.UPDATE...
ISSUED AT 944 PM EST MON NOV 24 2014
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUD COVER
MOVING INTO CENTRAL KENTUCKY. THIS IS ASSOCIATED WITH A NEARLY
STATIONARY LOW OVER THE GREAT LAKES AND A WEAK SURFACE TROUGH IS
BRINGING SOME LOW LEVEL MOISTURE INTO THE AREA. THE BULK OF THIS
CLOUD COVER IS NOT EXPECTED TO MOVE INTO FAR EASTERN KENTUCKY AND
ADJUSTED THE FORECAST TO HAVE THE BULK OF THE CLOUD COVER EXIT THE
AREA TO THE NORTHEAST BY THE MORNING. THE OTHER CONCERN WAS THE
TEMPERATURES ACROSS THE AREA. TEMPS REMAIN QUITE WARM AND THE COOLER
AIR IS SLOW TO FILTER INTO THE AREA. IN FACT SOME GUSTY NORTHWEST
WINDS ARE STILL OCCURRING. HAVE UPDATED THE FORECAST TO HIGHLIGHT
THESE CHANGES. A NEW ZFP HAS BEEN ISSUED.
UPDATE ISSUED AT 651 PM EST MON NOV 24 2014
THE COLD FRONT AND ASSOCIATED LOW PRESSURE SYSTEM CONTINUE TO TRACK
OFF TO THE NORTHEAST THIS EVENING. WITH THIS A LESSENING GRADIENT IS
OCCURRING AND WINDS HAVE REALLY LESSENED ACROSS THE AREA. THOUGH A FEW
20 TO 25 MPH GUSTS ARE STILL POSSIBLE...HAVE DECIDED TO CANCEL THE
WIND ADVISORY AN HOUR EARLY. THIS IS ALSO LINING UP WITH
COLLABORATION WITH NEIGHBORING OFFICES AS WELL. OTHERWISE...DROPPING
TEMPS THIS EVENING WITH COLDER AIR MOVING INTO THE AREA WILL CONTINUE
AND THE CURRENT FORECAST HAS THIS IN CHECK. WILL LET THE OTHER
PARAMETERS OF THE FORECAST RIDE BUT WILL SEND OUT A NEW ZFP TO TAKE
OUT THE NPW.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM EST MON NOV 24 2014
19Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING NORTHEAST
AWAY FROM THE GREAT LAKES. FROM THIS...A STRONG...BUT NOW DRY...COLD
FRONT IS PRESSING THROUGH EAST KENTUCKY. AHEAD OF THIS BOUNDARY...
STRONG SOUTHWEST WINDS ARE GUSTING ROUTINELY INTO THE 35 TO 45 MPH
RANGE WITH A FEW GUSTS EXCEEDING 50 MPH. THE OFFICE HAS RECEIVED
NUMEROUS REPORTS OF TREE DAMAGE AND POWER OUTAGES DUE TO THE WINDS.
THESE WINDS HAVE ALSO SUPPORTED TEMPERATURES IN THE UPPER 60S AND
LOWER 70S WITH DEWPOINTS IN THE MID 40S FOR MUCH OF THE AFTERNOON AND
THEY REMAIN THERE IN FAR EASTERN KENTUCKY. HOWEVER...ON THE OTHER
SIDE OF THE BOUNDARY THE WINDS REMAIN SOUTHWEST BUT ARE NOT QUITE AS
STRONG AND ARE BRINGING IN A DIFFERENT AIR MASS. AS SUCH...
TEMPERATURES DROPPING THROUGH THE 50S ARE NOW REACHING THE WESTERN
EXTENT OF THE CWA ALONG WITH DEWPOINTS HEADED FOR THE 30S. THE WINDS
REMAIN AT ADVISORY LEVEL IN THE EAST BUT ARE NOT QUITE THERE IN THE
WEST. AS THEY FURTHER SETTLE WE WILL LIKELY BE ABLE TO DROP THE
ADVISORY EARLY. FOR NOW...THOUGH...WILL CONTINUE TO LET IT RIDE FOR
THE ENTIRE CWA THROUGH 00Z.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP...AND FULL-
LATITUDE...TROUGH CROSSING THE OHIO VALLEY AND GREAT LAKES TODAY INTO
TUESDAY. HOWEVER...A SOUTHWESTERN EXTENT OF THE LARGER TROUGH WILL
REMAIN STRETCHED INTO SOUTHWESTERN TEXAS AND IT IS THIS SECTION
THAT TIGHTENS UP AND MOVES EAST LATER TUESDAY. THE SOUTHERN
ENERGY...IN CONJUNCTION WITH SOME MOVING THROUGH THE MID MISSISSIPPI
VALLEY WILL SWEEP THROUGH THE DEEP SOUTH AND ACROSS THE TENNESSEE
VALLEY ON TUESDAY NIGHT. OF NOTE ALSO...A CLUSTER OF ENERGY WILL BE
RIDING SOUTHEAST THROUGH THE CENTRAL PLAINS AT DAWN WEDNESDAY. WITH
THE MODEL AGREEMENT HAVE FAVORED THE NAM12 AND HRRR INITIALLY AND
THEN A BLEND OF THE ECMWF AND NAM12 FOR WX DETAILS INTO WEDNESDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE WINDS SETTLING DOWN THIS EVENING FROM
WEST TO EAST AS THE GRADIENT RELAXES. IT WILL ALSO MEAN A COOLER
EVENING...BUT NOWHERE NEAR AS COLD AS IT HAS BEEN OF LATE. TUESDAY
WILL CERTAINLY BE A COOLER DAY BUT A QUIETER ONE AS WE WILL BE
BETWEEN SYSTEMS. A DEVELOPING SFC LOW ALONG THE SOUTHEAST COAST WILL
START TO SPREAD HIGH CLOUDS INTO THE AREA FROM THE SOUTHEAST BY
EVENING. LOOK FOR THESE TO THICKEN AND LOWER WITH TIME THAT NIGHT AS
THE SOUTHEAST PORTION OF THE CWA IS BRUSHED BY THE PCPN SHIELD FROM
THIS NASCENT COASTAL SYSTEM. HAVE CONTINUED THE THREAT OF RAIN OR
SNOW PRIMARILY IN THE COUNTIES BORDERING VIRGINIA...BUT NOT
ANTICIPATING MUCH IN THE WAY OF ACCUMULATIONS EXCEPT PERHAPS A TOUCH
OF IT JUST ON THE PEAK OF BLACK MOUNTAIN.
USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH THE
NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR
TERRAIN BASED ADJUSTMENTS TONIGHT AND TUESDAY NIGHT TO THE LOWS. AS
FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET NUMBERS FOR
TUESDAY NIGHT AND DRY OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM EST MON NOV 24 2014
THERE WILL BE A DEVELOPING SURFACE LOW OFF THE CAROLINA COAST BEGINNING
THE PERIOD AND THE FRONTOGENESIS IS AIDED BY A BROAD TROUGH/EMBEDDED
SHORTWAVE ENERGY SWING THROUGH THE EASTERN U.S. THOROUGH THE PERIOD.
THIS COASTAL LOW IS EXPECTED TO MOVE NE ALONG THE ATLANTIC SEABOARD
WEDNESDAY INTO THURSDAY. ANOTHER EMBEDDED SHORTWAVE WILL EXIT THE
UPPER PLAINS AND DROP SE INTO THE OHIO AND TENNESSEE VALLEYS
WEDNESDAY NIGHT INTO THURSDAY. SURFACE HIGH WILL BUILD EAST LATER
THURSDAY INTO FRIDAY. UPPER LEVELS WILL BEGIN TO BECOME MORE ZONAL
WITH SURFACE FRONT DEVELOPING ACROSS PORTIONS OF THE OHIO VALLEY
GOING INTO SUNDAY INTO MONDAY.
SENSIBLE WEATHER... GIVEN SYNOPTIC SETUP LOW PRESSURE MOVING ALONG
THE ATLANTIC COAST COULD BRING SLIGHT TO CHANCES MAINLY RAIN/SNOW
SHOWERS ACROSS THE EASTERN AND SOUTHEASTERN PORTIONS OF THE REGION
EARLY WEDNESDAY...BEFORE TRANSITIONING TO RAIN SHOWERS THROUGH THE
DAY WEDNESDAY. THIS LOW WILL TRACK NORTH AND EAST WHILE AFOREMENTIONED
DISTURBANCE DROPS SE ACROSS THE REGION WEDNESDAY NIGHT. THERE IS
BETTER AGREEMENT WITH MODELS SO DID OPT TO BRING POPS UP A BIT FOR
THIS SYSTEM. THIS SYSTEM IS EXPECTED TO BRING SLIGHT TO CHANCE
RAIN/SNOW SHOWERS ACROSS EASTERN KY WEDNESDAY NIGHT. THURSDAY MUCH OF
THE REGION WILL WARM UP SO EXPECT MOST OF THE ACTIVITY WILL
TRANSITION TO RAIN SHOWERS BEFORE EXITING THE REGION LATE IN THE DAY
ON THURSDAY. AFTER THIS IT IS EXPECTED TO BE QUIET AND MOSTLY CLEAR
CONDITIONS TIL WE GET TO THE SATURDAY TIME FRAME. DURING THIS TIME
MODELS ARE NOT IN GOOD AGREEMENT ON TIMING/DEVELOPMENT OF NEXT
SYSTEM. RIGHT NOW THINKING WILL ONLY GO WITH SLIGHT CHANCES OF RAIN
SHOWERS SATURDAY...THEN TRANSITION TO SLIGHT/CHANCE RAINS SHOWERS AS
FRONT SLOW PROGRESSES SOUTH ACROSS THE REGION GOING INTO SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 651 PM EST MON NOV 24 2014
THE COLD FRONT THAT BROUGHT THE STRONG WINDS HAS MOVED OFF TO THE
EAST AND MOSTLY CLEAR SKIES ARE MOVING INTO THE AREA. TONIGHT AND
THROUGH THE DAY TUESDAY THE CONDITIONS WILL BE VFR. LIGHT NORTHWEST
WINDS WILL CONTINUE AT MOST LOCATIONS TONIGHT AND THE DAY ON TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
652 PM EST MON NOV 24 2014
.UPDATE...
ISSUED AT 651 PM EST MON NOV 24 2014
THE COLD FRONT AND ASSOCIATED LOW PRESSURE SYSTEM CONTINUE TO TRACK
OFF TO THE NORTHEAST THIS EVENING. WITH THIS A LESSENING GRADIENT IS
OCCURRING AND WINDS HAVE REALLY LESSENED ACROSS THE AREA. THOUGH A FEW
20 TO 25 MPH GUSTS ARE STILL POSSIBLE...HAVE DECIDED TO CANCEL THE
WIND ADVISORY AN HOUR EARLY. THIS IS ALSO LINING UP WITH
COLLABORATION WITH NEIGHBORING OFFICES AS WELL. OTHERWISE...DROPPING
TEMPS THIS EVENING WITH COLDER AIR MOVING INTO THE AREA WILL CONTINUE
AND THE CURRENT FORECAST HAS THIS IN CHECK. WILL LET THE OTHER
PARAMETERS OF THE FORECAST RIDE BUT WILL SEND OUT A NEW ZFP TO TAKE
OUT THE NPW.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM EST MON NOV 24 2014
19Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING NORTHEAST
AWAY FROM THE GREAT LAKES. FROM THIS...A STRONG...BUT NOW DRY...COLD
FRONT IS PRESSING THROUGH EAST KENTUCKY. AHEAD OF THIS BOUNDARY...
STRONG SOUTHWEST WINDS ARE GUSTING ROUTINELY INTO THE 35 TO 45 MPH
RANGE WITH A FEW GUSTS EXCEEDING 50 MPH. THE OFFICE HAS RECEIVED
NUMEROUS REPORTS OF TREE DAMAGE AND POWER OUTAGES DUE TO THE WINDS.
THESE WINDS HAVE ALSO SUPPORTED TEMPERATURES IN THE UPPER 60S AND
LOWER 70S WITH DEWPOINTS IN THE MID 40S FOR MUCH OF THE AFTERNOON AND
THEY REMAIN THERE IN FAR EASTERN KENTUCKY. HOWEVER...ON THE OTHER
SIDE OF THE BOUNDARY THE WINDS REMAIN SOUTHWEST BUT ARE NOT QUITE AS
STRONG AND ARE BRINGING IN A DIFFERENT AIR MASS. AS SUCH...
TEMPERATURES DROPPING THROUGH THE 50S ARE NOW REACHING THE WESTERN
EXTENT OF THE CWA ALONG WITH DEWPOINTS HEADED FOR THE 30S. THE WINDS
REMAIN AT ADVISORY LEVEL IN THE EAST BUT ARE NOT QUITE THERE IN THE
WEST. AS THEY FURTHER SETTLE WE WILL LIKELY BE ABLE TO DROP THE
ADVISORY EARLY. FOR NOW...THOUGH...WILL CONTINUE TO LET IT RIDE FOR
THE ENTIRE CWA THROUGH 00Z.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP...AND FULL-
LATITUDE...TROUGH CROSSING THE OHIO VALLEY AND GREAT LAKES TODAY INTO
TUESDAY. HOWEVER...A SOUTHWESTERN EXTENT OF THE LARGER TROUGH WILL
REMAIN STRETCHED INTO SOUTHWESTERN TEXAS AND IT IS THIS SECTION
THAT TIGHTENS UP AND MOVES EAST LATER TUESDAY. THE SOUTHERN
ENERGY...IN CONJUNCTION WITH SOME MOVING THROUGH THE MID MISSISSIPPI
VALLEY WILL SWEEP THROUGH THE DEEP SOUTH AND ACROSS THE TENNESSEE
VALLEY ON TUESDAY NIGHT. OF NOTE ALSO...A CLUSTER OF ENERGY WILL BE
RIDING SOUTHEAST THROUGH THE CENTRAL PLAINS AT DAWN WEDNESDAY. WITH
THE MODEL AGREEMENT HAVE FAVORED THE NAM12 AND HRRR INITIALLY AND
THEN A BLEND OF THE ECMWF AND NAM12 FOR WX DETAILS INTO WEDNESDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE WINDS SETTLING DOWN THIS EVENING FROM
WEST TO EAST AS THE GRADIENT RELAXES. IT WILL ALSO MEAN A COOLER
EVENING...BUT NOWHERE NEAR AS COLD AS IT HAS BEEN OF LATE. TUESDAY
WILL CERTAINLY BE A COOLER DAY BUT A QUIETER ONE AS WE WILL BE
BETWEEN SYSTEMS. A DEVELOPING SFC LOW ALONG THE SOUTHEAST COAST WILL
START TO SPREAD HIGH CLOUDS INTO THE AREA FROM THE SOUTHEAST BY
EVENING. LOOK FOR THESE TO THICKEN AND LOWER WITH TIME THAT NIGHT AS
THE SOUTHEAST PORTION OF THE CWA IS BRUSHED BY THE PCPN SHIELD FROM
THIS NASCENT COASTAL SYSTEM. HAVE CONTINUED THE THREAT OF RAIN OR
SNOW PRIMARILY IN THE COUNTIES BORDERING VIRGINIA...BUT NOT
ANTICIPATING MUCH IN THE WAY OF ACCUMULATIONS EXCEPT PERHAPS A TOUCH
OF IT JUST ON THE PEAK OF BLACK MOUNTAIN.
USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH THE
NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR
TERRAIN BASED ADJUSTMENTS TONIGHT AND TUESDAY NIGHT TO THE LOWS. AS
FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET NUMBERS FOR
TUESDAY NIGHT AND DRY OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM EST MON NOV 24 2014
THERE WILL BE A DEVELOPING SURFACE LOW OFF THE CAROLINA COAST BEGINNING
THE PERIOD AND THE FRONTOGENESIS IS AIDED BY A BROAD TROUGH/EMBEDDED
SHORTWAVE ENERGY SWING THROUGH THE EASTERN U.S. THOROUGH THE PERIOD.
THIS COASTAL LOW IS EXPECTED TO MOVE NE ALONG THE ATLANTIC SEABOARD
WEDNESDAY INTO THURSDAY. ANOTHER EMBEDDED SHORTWAVE WILL EXIT THE
UPPER PLAINS AND DROP SE INTO THE OHIO AND TENNESSEE VALLEYS
WEDNESDAY NIGHT INTO THURSDAY. SURFACE HIGH WILL BUILD EAST LATER
THURSDAY INTO FRIDAY. UPPER LEVELS WILL BEGIN TO BECOME MORE ZONAL
WITH SURFACE FRONT DEVELOPING ACROSS PORTIONS OF THE OHIO VALLEY
GOING INTO SUNDAY INTO MONDAY.
SENSIBLE WEATHER... GIVEN SYNOPTIC SETUP LOW PRESSURE MOVING ALONG
THE ATLANTIC COAST COULD BRING SLIGHT TO CHANCES MAINLY RAIN/SNOW
SHOWERS ACROSS THE EASTERN AND SOUTHEASTERN PORTIONS OF THE REGION
EARLY WEDNESDAY...BEFORE TRANSITIONING TO RAIN SHOWERS THROUGH THE
DAY WEDNESDAY. THIS LOW WILL TRACK NORTH AND EAST WHILE AFOREMENTIONED
DISTURBANCE DROPS SE ACROSS THE REGION WEDNESDAY NIGHT. THERE IS
BETTER AGREEMENT WITH MODELS SO DID OPT TO BRING POPS UP A BIT FOR
THIS SYSTEM. THIS SYSTEM IS EXPECTED TO BRING SLIGHT TO CHANCE
RAIN/SNOW SHOWERS ACROSS EASTERN KY WEDNESDAY NIGHT. THURSDAY MUCH OF
THE REGION WILL WARM UP SO EXPECT MOST OF THE ACTIVITY WILL
TRANSITION TO RAIN SHOWERS BEFORE EXITING THE REGION LATE IN THE DAY
ON THURSDAY. AFTER THIS IT IS EXPECTED TO BE QUIET AND MOSTLY CLEAR
CONDITIONS TIL WE GET TO THE SATURDAY TIME FRAME. DURING THIS TIME
MODELS ARE NOT IN GOOD AGREEMENT ON TIMING/DEVELOPMENT OF NEXT
SYSTEM. RIGHT NOW THINKING WILL ONLY GO WITH SLIGHT CHANCES OF RAIN
SHOWERS SATURDAY...THEN TRANSITION TO SLIGHT/CHANCE RAINS SHOWERS AS
FRONT SLOW PROGRESSES SOUTH ACROSS THE REGION GOING INTO SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 651 PM EST MON NOV 24 2014
THE COLD FRONT THAT BROUGHT THE STRONG WINDS HAS MOVED OFF TO THE
EAST AND MOSTLY CLEAR SKIES ARE MOVING INTO THE AREA. TONIGHT AND
THROUGH THE DAY TUESDAY THE CONDITIONS WILL BE VFR. LIGHT NORTHWEST
WINDS WILL CONTINUE AT MOST LOCATIONS TONIGHT AND THE DAY ON TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
605 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 PM EST MON NOV 24 2014
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON THE POTENTIAL
FOR AT LEAST SOME MARGINAL ADVY LES TOTALS ON WED INTO EARLY
THANKSGIVING ASSOCIATED WITH A SHRTWV DIGGING SEWD THRU THE UPR LKS.
FORTUNATELY FOR THOSE INTERESTED IN TRAVEL ON THANKSGIVING...MODELS
HAVE CONTINUED TREND TOWARD LESS PHASING BTWN A PAIR OF SHRTWVS THAT
WL LIMIT THE POTENTIAL FOR HEAVIER SN AWAY FM LK SUP. TEMPS WL RUN
BLO TO WELL BLO NORMAL ON TUE NGT INTO FRI WITH AN UPR TROF
DEEPENING OVER ERN NAMERICA. AS THIS TROF GIVES WAY TO A MORE ZONAL
FLOW THIS WEEKEND...A MORE CHANGEABLE PATTERN WL DOMINATE WITH
WARMER AIR IN STORE FOR SAT.
TUE NGT...A WEAK SFC HI PRES UNDER SUBTLE SHRTWV RDGING/AREA OF DEEP
LYR QVECTOR DVGC WL DOMINATE MOST OF THE NGT AND BRING DRY WX TO
MOST OF THE CWA. THE BEST CHC FOR SOME PCPN WL BE OVER THE NW CWA
NEAR A STATIONARY FNT ORIENTED W-E OVER LK SUP. H85 TEMPS ANRD -13C
MAY SUPPORT A LK EFFECT COMPONENT...ESPECIALLY LATE WHEN SOME DPVA/
DEEP LYR QVECTOR CNVGC IN ADVANCE OF A SHRTWV DIGGING SEWD TOWARD
THE CNDN/MN BORDER IS FCST TO ARRIVE. EXPECT THE LOWEST MIN TEMPS
OVER THE INTERIOR SCENTRAL AND E WHERE THE NEGATIVE DYNAMICS SHOULD
LINGER THRU THE NGT IN THE PRESENCE OF PWAT UNDER 0.25 INCH AND
MINIMIZE CLD COVER EXCEPT FOR SOME HIER CLDS SPILLING INTO UPR MI
AHEAD OF THE INCOMING SHRWTV.
WED...SHRTWV APRCHG FM THE NW IS FCST TO MOVE INTO WRN LK SUP BY 00Z
THU...WITH DPVA/DEEP LYR QVECTOR CNVGC INVADING UPR MI. BUT SINCE
THE MODELS HAVE TRENDED TOWARD LESS PHASING BTWN THIS SHRTWV AND
ANOTHER STRONGER DISTURBANCE DIGGING SEWD IN THE MID MS RIVER VALLEY
THAT WL ROB THE AREA OF DEEPER MSTR AND LEAVE PWAT NO HIER THAN
ABOUT 0.25-0.30 INCH...ACCOMPANYING SN OVER THE CWA SHOULD BE
RELATIVELY LGT. THE BEST CHC FOR MORE SN WL BE IN THE N WIND SN
BELTS NEAR LK SUP AS THE H925 FLOW SHIFTS TO THE N COINCIDENT WITH
PASSING NRN SHRTWV AND ALLOWS FOR SOME LES AS H85 TEMPS FALL TO ARND
-15C OVER THE NW BY 00Z WED. SN TOTALS IN THAT AREA MAY ALSO BE
BOOSTED A BIT BY RATHER DEEP DGZ BTWN ABOUT 4-9K FT MSL EVEN THOUGH
MORE SHARPER UVV IS NOT FCST WITHIN THAT LYR. NOT OUT OF THE
QUESTION THE FLOW MAY BACK SUFFICIENTLY TO THE SW IN ADVANCE OF THE
SHRTWV TO ALLOW FOR A PERIOD OF SOME LK EFFECT SN OFF LK MI INTO THE
SE CWA IN THE PRESENCE OF H85 TEMPS NEAR -10C.
WED NGT...STEADY NNW WIND IN THE WAKE OF PASSING SHRTWV IS FCST TO
ADVECT H85 TEMPS AS LO AS -20C OVER THE KEWEENAW BY 12Z THU. THERE
MAY BE SOME ADVY LVL LES IN THE FAVORED SN BELTS AS THERE WL BE A
PERIOD WHERE THE FAVORABLE CAA/CYC NNW FLOW IS COINCIDENT WITH
DEEPER MSTR/SOME DEEP LYR QVECTOR CNVGC THAT WL LIKELY BRING SOME
LIGHTER SN EVEN TO THE SCENTRAL. THE ARRIVAL OF SOME DNVA/DEEP LYR
QVECTOR DVGC LATER AT NGT IS PROGGED TO SHARPLY LOWER INVRN BASE
TOWARD H85...WHICH SHOULD BRING ABOUT A DIMINISHING TREND IN THE LES
OVER AT LEAST THE W HALF. THE 12Z GFS IS FASTEST WITH THIS
DIMINISHING TREND.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN
BELTS E OF MARQUETTE...BUT LO INVRN BASE BLO H85 SHOWN ON THE FCST
SDNGS UNDER THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. AS THE SFC
RDG AXIS SHIFTS TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING
LES WL SHIFT OUT INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN
THE EVNG BEFORE MORE HI CLDS ASSOCIATED WITH DVLPG ISENTROPIC ASCENT
OVERSPREAD THE AREA W-E.
FRI INTO SAT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES THAT WL BE FORCING
THIS CHANGE IN THE UPR PATTERN IS PROGGED BY MOST OF THE MEDIUM
RANGE GUIDANCE IS FCST TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN
ON FRI TO THE NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS
INTO MN. THE LATEST MODEL GUIDANCE HINTS THE HEAVIER PCPN ASSOCIATED
WITH THIS WARM AIR RETURN ON FRI MAY FALL TO THE SW IN WI. EXPECT
THE HIER POPS OVER THE ERN CWA WITH SW FLOW OF COLD AIR OFF LK MI
ALLOWING FOR SOME LES INTO THAT AREA ON FRI. AS A SHRTWV WITHIN THE
ZONAL FLOW SHIFTS EWD NEAR THE CNDN BORDER...A SFC LO PRES WL SHIFT
EWD AND JUST N OF LK SUP ON SAT. MOST OF THE GUIDANCE SHOWS H85
TEMPS RISING TO AOA 0C OVER AT LEAST THE S HALF OF THE CWA ON SAT...
INDICATING THE POTENTIAL FOR SOME MIXED PCPN. GFS FCST SDNGS SHOW AN
ELEVATED WARM LYR...SO INCLUDED A MENTION OF SOME FREEZING RA OVER
THE SCENTRAL WHERE THE WARM WEDGE H85 TEMPS ARE OVER 0C. THE MODELS
SUCH AS THE 12Z GFS AND ESPECIALLY THE 12Z CND THAT SHOW THE DEEPEST
SFC LO/FARTHER N TRACK ACTUALLY INDICATE UPR MI MIGHT SEE SOME DRY
SLOTTING AS THE H85 WARM FNT SHIFTS TO THE N OF THE CWA AND H85
TEMPS RISE AS HI AS 5-6C...SO POPS WL BE LOWEST OVER THE S.
SUN/MON...AS THE SHRTWV/SFC LO SHIFT INTO QUEBEC SAT NGT/SUN...
ATTENDANT COLD FNT WL SWING THRU UPR MI AND BRING A RETURN OF COLDER
AIR AND SOME LES FOR SUN. TRAILING HI PRES WL PASS TRHU THE CENTRAL
GREAT LKS ON SUN NGT...ENDING THIS LES. AS THE HI SHIFTS TOWARD NEW
ENGLAND...EXPECT A RETURN SW FLOW OF WARMER AIR TO DVLP ON MON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 605 PM EST MON NOV 24 2014
IFR/LIFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT BEFORE
IMPROVING TO MVFR ON TUESDAY AS DRIER AIR MOVES IN. ALL SITES WILL
ALSO SEE NORTH-NORTHEAST WINDS GUST TO 30+ KT THROUGH THIS EVENING
CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST TUESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ248>251-265>267.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...KC
AVIATION...07
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 PM EST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM MONDAY TO 4 PM EST TUESDAY
FOR MIZ006-007-085.
DENSE FOG ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ004>007-010>014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ MONDAY TO 7
AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM MONDAY TO 1 PM EST TUESDAY
FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
304 PM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM MONDAY TO 4 PM EST TUESDAY
FOR MIZ006-007-085.
DENSE FOG ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ004>007-010>014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ MONDAY TO 7
AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM MONDAY TO 1 PM EST TUESDAY
FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1259 PM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1258 PM EST SUN NOV 23 2014
WITH LOW LEVEL MOIST/WARM ADVECTION CONTINUING INTO THE AREA
SHOULD...PERSISTENT LOW CIGS AND FOG WILL CONTINUE INTO TONIGHT.
VLIFR CONDITIONS BELOW LANDING MINS ARE LIKELY TO PERSIST THIS
AFTERNOON AT KSAW WITH THE UPSLOPE FLOW HELPING TO MAINTAIN THE
DENSE FOG. SOME IMPROVEMENT MAY BE POSSIBLE WHEN RAIN MOVES IN THIS
EVENING AND OVERNIGHT. CONFIDENCE IN TIMING WHEN THE FOG MAY DIMINISH
IS UNCERTAIN. OTHERWISE...IFR/LIFR CIGS WILL ALSO PERSIST AT IWD AND
CMX BUT SHOULD NOT BE AS LOW WITH A MORE DOWNSLOPE SRLY WIND
COMPONENT. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST OF THE AREA
MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY STRENGTHEN WITH
ANY RAIN CHANGING TO SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ004>007-010>014-085.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 723 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA WILL RESULT IN LOWERING OF
CIGS TODAY AS THE MOIST LOW-LEVELS WILL BE ONLY BE AIDED BY
ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING UPSLOPE FLOW AT
KCMX AND KSAW. EXPECT VLIFR VSBYS IN FOG AT KSAW AT LEAST THROUGH
THIS MORNING. DZ WILL GIVE WAY TO RAIN LATER TODAY INTO TONIGHT AS
CONDITIONS STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST PERIOD AT
ALL SITES. RAIN WILL CHANGE OVER TO SNOW AT KIWD AFT 09Z TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKESHORE FLOOD ADVISORY FROM 11 AM MONDAY TO 6 AM EST TUESDAY
FOR MIZ001-003-005>007.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
601 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 558 AM EST SUN NOV 23 2014
COMPLEX DEEPENING LOW PRESSURE SYSTEM AND ASSOCIATED SNOW/BLSN
MONDAY AND MONDAY NIGHT IS MAIN ISSUE.
WV LOOP AND 00Z RAOBS SHOW SPLIT FLOW OVER THE CONUS. STRONG
SHORTWAVE NOTED IN NORTHERN STREAM IS CROSSING SASKATCHEWAN WITH
VIGOROUS PAIR OF SHORTWAVES IN THE SOUTHERN STREAM OVER THE SOUTHERN
PLAINS AND INTO EAST TX. AT DAYBREAK ON MONDAY...SHORTWAVE CURRENTLY
OVER KS WILL BE LIFTING TOWARD UPPER GREAT LAKES. ASSOCIATED SFC LOW
WILL BE IN PROCESS OF DEEPENING TO AROUND 980MB VCTY OF NORTHERN
LOWER MICHIGAN OR EASTERN UPR MICHIGAN. WIDESPREAD PRECIPITATION
SHOULD BE ONGOING DUE TO LIFT FM H7-H5 Q-VECTOR CONVERGENCE FM LEAD
SHORTWAVE...RIGHT ENTRANCE FORCING FM JET STREAK OVER NORTHERN
ONTARIO...AND H85-H7 MOISTURE ADVECTION WRAPPING AHEAD OF SFC-H85
LOW. SOUNDINGS SHOW COOLING BLO 900MB LEADING TO INITIAL CHANGEOVER
FROM RAIN TO SNOW OVER WESTERN THIRD OF CWA. EXPECTED RAIN/SNOW LINE
FOLLOWS 925MB TEMP OF 0C PRETTY WELL.
SNOW AMOUNTS ON MONDAY DEPEND ON EXTENT OF MOISTURE INGESTED INTO
THE SFC LOW...AND MORE SPECIFICALLY HOW MUCH OF THIS DEEP MOISTURE
IS ADVECTED FARTHER TO THE WEST OF THE SFC LOW BACK INTO THE COLD
AIR. AT THIS TIME...ONLY MODEL THAT IS REALLY EMPHATIC WITH STRONGER
AND SLOWER SFC LOW AND THUS MORE DEEP MOISTURE TO WORK WITH IS THE
00Z/06Z NAM. OTHER MODELS AND ENSEMBLES...INCLUDING THE 00Z GFS AND
ECMWF AND 21Z SREF...AND TO A LESSER DEGREE THE 00Z GEM...ARE MORE
PROGRESSIVE WITH THE LOW AND ULTIMATELY HAVE LESS DEEPER MOISTURE
AND SYNOPTIC QPF LINGERING INTO MONDAY AFTN. USING MORE MIDDLE OF
ROAD APPROACH AS DO NOT HAVE ENOUGH CONFIDENCE TO TREND TOWARD
WETTER NAM IDEA. LESSER QPF ALONG WITH SNOW-LIQUID RATIOS THAT
BARELY RISE ABOVE 10:1 MOST OF MONDAY...RESULTED IN SOLID ADVISORY
LEVEL SNOWS OF 2-4 INCHES OR MAYBE 3-5 INCHES...HEAVIEST OVER FAR
WESTERN CWA WHERE PTYPE IS SNOW FOR LONGEST DURATION. LESS THAN 1
INCH OF SNOW DURING THE DAYTIME FOR EAST WITH A LATER CHANGEOVER.
GOING WITH PREFERRED GFS/ECMWF IDEA FOR MONDAY NIGHT...SHORTWAVE
MOVING NORTHEAST OVER THE WESTERN GREAT LAKES IS CAUGHT UP SOME BY
ANOTHER SHORTWAVE LEFT OVER THE CURRENT TROUGH OVER SASKATCHEWAN.
SWATH OF MODERATE SNOW SHOULD RESULT...MAINLY OVER NORTH AND EAST
CWA. ENOUGH COLD AIR WORKING IN BY THAT TIME TO LEAD TO LAKE
ENHANCEMENT OFF LK SUPERIOR. SIGNAL STILL THERE THAT SECONDARY AREA
OF SYNOPTIC FORCING/LIFT LINKS UP WITH MOST IDEAL LAKE ENHANCEMENT
VCNTY OF NNW WIND SNOW BELTS OF ALGER/NORTHERN SCHOOLCRAFT COUNTIES.
LATEST 12 HR SNOW AMOUNTS ARE PUSHING WARNING CRITERIA OF 6 INCHES
FOR THESE AREAS. MODERATE SNOW ACCUMULATIONS WILL CONTINUE ALONG
MUCH OF LK SUPERIOR...BUT SNOW AMOUNTS SHOULD BE ON THE DECLINE
ALONG THE WI BORDER AS BETTER FORCING MISSES THAT AREA TO THE EAST.
FROM AT STRICTLY SNOW AMOUNT CRITERIA...EVENT LOOKS TO BE SOLID ADVY
MONDAY INTO MONDAY NIGHT. SNOW ON TUESDAY SHOULD BE ON THE WANE AS
EVEN THOUGH IT IS BECOMING COLDER FOR LAKE EFFECT...SUPPLEMENTAL
LARGER SCALE FORCING IS ON THE WANE. SOUNDINGS INDICATE LESSENING
CYCLONIC FLOW WILL REALLY PUT THE KABOSH ON LINGERING LAKE EFFECT ON
TUESDAY. ONE ASPECT OF THE SYSTEM THAT CANNOT BE DISCOUNTED THOUGH
IS THE WIND. SFC LOW DEEPENS AS IT LIFTS EAST OF LK SUPERIOR AND ON
TO THE NORTHEAST ON MONDAY NIGHT TRACKING TOWARD JAMES BAY. AT THE
PEAK...PRESSURE GRADIENT WEST TO EAST FROM DLH TO SSM IS 20 MB LATE
MONDAY AFTN INTO MONDAY EVENING. SOUNDINGS INDICATE 35+ KT WINDS
ABOVE H9 WITH 40+ KTS ABOVE H8. GIVEN THE DEGREE OF MIXING WITH THE
COLD AIR ADVECTION EXPECTED...SEEMS REASONABLE THAT MOST AREAS WILL
SEE GUSTS 30-40 MPH. BLOWING SNOW/POOR VSBY MAY BECOME PRETTY BIG
FACTOR OVER MUCH OF THE AREA WITH THE STRONG WINDS.
SINCE THIS EVENT SEEMS TO BE HEADING TOWARD MORE OF AN ADVY EVENT
INSTEAD OF A WARNING...DECIDED TO NOT ISSUE A WATCH AND INSTEAD
ISSUE ANOTHER SPECIAL WEATHER STATEMENT. DID EXPAND THE SPS TO
INCLUDE ALL OF THE CWA WITH THE POTENTIAL FOR MODERATE SNOW AND BLSN
OVER MUCH OF THE AREA.
REST OF THE WEEK COULD FEATURE HIGHER IMPACT WEATHER FOR THE TRAVEL
TIME AROUND THANKSGIVING AND THE HOLIDAY ITSELF. DETAILS FAR FROM
CERTAIN BUT AFTER A LULL FOR MOST AREAS ON TUESDAY NIGHT /MINS
POSSIBLY NEAR 0F OVER INTERIOR CNTRL CWA WITH ENOUGH CLEARING TUE
NIGHT/...ANOTHER PAIR OF SHORTWAVES ARE FORECAST TO SLIDE SOUTHEAST
OVER THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT. GFS WEAKER THAN
THE ECMWF WITH THE SFC TROUGH AND THAT AFFECTS THE DEGREE OF
CYCLONIC FLOW AND LAKE ENHANCED SNOW THAT DEVELOPS AS THE SYSTEM
MOVES BY. ALSO COULD SEE MORE STRONG WINDS DUE TO TIGHTER PRESSURE
GRADIENT...ESPECIALLY NEAR LK SUPERIOR OVER THE WEST. HAVE LIKELY
POPS ALONG MOST OF THE NORTHERN PART OF CWA LATER WEDNESDAY INTO
WEDNESDAY NIGHT AND ALSO FOR THANKSGIVING NEAR LK SUPERIOR FOR
NNW-NW FLOW LAKE EFFECT. OVER-WATER INSTABILITY NON-ISSUE AS H85
TEMPS FALL BLO -15C WED NIGHT AND TREND TOWARD -20C ON THANKSGIVING.
TEMPS WILL STRUGGLE THROUGH THE TEENS ON THANKSGIVING MAKING IT MORE
LIKE LATE DECEMBER OR JANUARY. RECORD LOW MAX AT NWS MQT FOR 27
NOVEMBER IS 18 SET IN 1967. COULD BE CLOSE TO THAT MARK.
COLD AIRMASS WILL KEEP LAKE EFFECT GOING TO CLOSE THE WEEK...MAINLY
FOR WNW-WSW FLOW REGIMES...SO MOSTLY LOOKING AT KEWEENAW AND ALONG
LK SUPERIOR TO EAST OF MARQUETTE. IF THERE IS ANY MODERATION IN
TEMPS IT PROBABLY WILL NOT BE UNTIL LATE IN THE WEEKEND OR EVEN
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
525 AM EST SUN NOV 23 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM EST SUN NOV 23 2014
MAIN FORECAST CONCERNS INCLUDE DENSE FOG THIS MORNING...TIMING THE
ONSET OF PCPN LATER TODAY AND THEN THE CHANGEOVER TO SNOW LATE
TONIGHT IN THE WEST.
WV IMAGERY AND RUC ANALYSIS SHOWS A VIGOROUS SRN STREAM SHORTWAVE
OFF THE TX GULF COAST WITH A STRONG SHORTWAVE AND ASSOC 150+ KNOT
250 MB JET MOVING OFF THE PAC NW INTO NRN NEVADA. ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO WRN ND. AT THE SFC...SRLY FLOW PREVAILED FROM
THE GULF TOWARD THE UPPER MS VALLEY AND NRN GREAT LAKES REGION BTWN
HIGH PRES OVER THE MID ATLANTIC AND A 993 MB LOW OVER ND. WAA AND
LOW CLOUD COVER HAVE MAINTAINED TEMPS IN THE MID AND UPPER 30S
ACROSS UPPER MI EARLY THIS MORNING. THE WARM AIR MOVING OVER THE
MOSTLY SNOWPACKED GROUND HAS ALSO RESULTED IN DENSE FOG ACROSS MUCH
OF THE ERN TWO THIRDS OF UPPER MI THIS MORNING.
TODAY...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
STRONG MOISTURE ADVECTION/TRANSPORT CONTINUES AND 850-700 MB FGEN
INCREASES. EXPECT THE BETTER CHANCE FOR RAIN OVER THE SOUTH CENTRAL
AND EAST IN PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS
THE MID-LVL DRY LAYER MOISTENS UP ANY DRIZZLE SHOULD CHANGE OVER TO
RAIN BY MID TO LATE AFTERNOON. EXPECT TEMPS WILL CLIMB ABOVE NORMAL
INTO THE LOW TO MID 40S. WARM AIR MOVING OVER THE COLD SNOW PACK HAS
RESULTED IN DENSE FOG THIS MORNING SO HAVE POSTED A DENSE FOG
ADVISORY THROUGH 16Z FOR ALL BUT THE FAR FOUR WESTERN COUNTIES OF
THE CWA.
TONIGHT...CONTINUED INCREASE IN DEEP LAYER Q-VECT
CONVERGENCE...DEVELOPMENT OF COUPLED UPPER JET STRUCTURE AND
ENHANCED 850-700 MB FGEN WILL LEAD TO WIDESPREAD RAINFALL ACROSS
MUCH OF THE CWA BY EVENING. MODEL AVERAGED QPF RANGES FROM .25 WEST
TO .75 SOUTHEAST. MODEL SNDGS AND CRITICAL 1000-850 MB THICKNESSES
SUGGEST RAIN WILL BEGIN TO SWITCH OVER TO SNOW FAR WEST AROUND 09Z
BUT WITH SNOW/WATER RATIOS RISING TO ONLY AROUND 6-7/1 BY 12Z MON
EXPECT SNOW ACCUMULATION TO BE LESS THAN AN INCH FOR THE FAR WEST BY
12Z MONDAY. THERE IS POTENTIAL FOR FOG TO BE AN ISSUE WITH RAIN OVER
THE SNOWPACK SO THIS WILL BE SOMETHING TO WATCH LATER TODAY. TEMPS WILL
RANGE FM THE LOWER 30S WEST TO UPPER 30S EAST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 523 AM EST SUN NOV 23 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL
MOVE TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL
INCREASE TO GALES 40-45 KTS BY MONDAY MORNING INTO MONDAY NIGHT.
EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD AIR POURS
ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER THE
NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ004>007-010>014-085.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 10 AM MONDAY TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM MONDAY TO 2 AM EST TUESDAY FOR LSZ242>245-
263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TO 9 PM EST /8 PM CST/
MONDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
115 AM EST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 420 PM EST SAT NOV 22 2014
WV IMAGERY AND RUC ANALYSIS INDICATED ZONAL FLOW ACROSS THE NRN
CONUS WITH A STRONG 170 KNOT 250 MB JET MOVING INTO THE PAC NW. A
SHORTWAVE TROUGH WAS MOVING THROUGH SRN SASK AND NRN MT. A VIGOROUS
SRN SHORTWAVE TROUGH WAS LOCATED OVER WRN TEXAS. AT THE SFC...SRLY
FLOW PREVAILED FROM THE GULF TOWARD THE UPPER MS VALLEY AND NRN
LAKES BTWN HIGH PRES OVER THE MID ATLANTIC AND A 984 MB LOW INTO SRN
SASK. WAA HAS PUSHED TEMPS INTO THE MID AND UPPER 30S ACROSS UPPER
MI. ALTHOUGH THE LOW LEVEL MOISTURE THINNED OUT ENOUGH FOR SOME
SUNSHINE THIS AFTERNOON...ESPECIALLY IN DOWNSLOPE LOCATIONS...CLOUDS
OVER NRN WI AND WRN UPPER MI WERE FILLING IN AGAIN ACROSS THE AREA.
TONIGHT...ANY LINGERING DRY LOW LEVEL AIR WILL FILL IN TONIGHT WITH
STRONG LOW LEVEL MOISTURE ADVECTION THIS EVENING. SO...EXPECT BETTER
CHANCES FOR PCPN AS DRIZZLE OR POSSIBLY FREEZING DRIZZLE AS A
SUBSTANTIAL DRY LAYER REMAINS ABOVE 900 MB. SOME FOG WILL BE POSSIBLE
AS WELL AS DEWPOINTS CLIMB TO AROUND FREEZING OR SLIGHTLY ABOVE BY
LATE TONIGHT. EXPECT THE BEST CHANCE FOR DRIZZLE OVER CNTRL UPPER MI
WITH AN UPSLOPE LOW LEVEL WIND COMPONENT SUPPORT...AND OVER THE EAST
CWA WITH ADDED MOISTURE OFF OF LAKE MICHIGAN. TEMPS MAY DROP OFF TO
NEAR FREEZING THIS EVENING AND SLOWLY CLIMB OVERNIGHT.
HOWEVER...SINCE MANY ROAD SURFACES MAY STILL BE BELOW FREEZING...ANY
DRIZZLE THAT FALLS COULD CREATE ICY/SLIPPERY CONDITIONS ON UNTREATED
ROADS.
SUN...EXPECT PCPN CHANCES TO GRADUALLY INCREASE THROUGH THE DAY AS
THE STRONG MOISTURE ADVECTION CONTINUES AND 850-700 MB FGEN
INCREASES. THE GREATEST CHANCE IS EXPECTED OVER THE EAST IN
PROXIMITY TO THE STRONGER DYNAMICS AND BEST MOISTURE. AS THE DRY
LAYER FILLS IN ANY DRIZZLE WILL CHANGE OVER TO RAIN BY MID TO LATE
AFTERNOON. TEMPS WILL CLIMB ABOVE NORMAL INTO THE LOW TO MID 40S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT NOV 22 2014
QUITE AN ACTIVE START TO THE PERIOD AS THE PHASING OF NORTHERN AND
SOUTHERN ENERGY WILL BE UNDERWAY ACROSS THE UPPER GREAT LAKES.
MODERATE RAINFALL SUNDAY NIGHT WILL GIVE WAY TO A TRANSITION TO SNOW
ON MONDAY AS THE SYSTEM MOVES NE OF THE REGION. THE INGREDIENTS ARE
STILL THERE FOR MODERATE TO POSSIBLY HEAVY SNOW ACROSS AT LEAST THE
WESTERN CWA MONDAY AFTERNOON AND NIGHT. AFTER A REPRIEVE LATE
TUESDAY...A CLIPPER SYSTEM LOOKS TO BRING LIGHT TO POSSIBLY MODERATE
SNOWFALL WEDNESDAY AFTERNOON INTO THANKSGIVING.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FIRST A LOOK AT THE OVERALL
SYNOPTIC PATTERN. TWO POTENT MID-LEVEL SHORTWAVES...ONE TRACKING
EASTWARD OVER THE NORTHERN PLAINS AND THE OTHER MOVING NORTHEASTWARD
NEAR SOUTHERN IL AT 00Z MONDAY WILL BEGIN TO MERGE ACROSS THE UPPER
GREAT LAKES. THE NORTHERN STREAM IS A BIT SLOWER REACHING THE REGION
THAN THE SOUTHERN STREAM...RESULTING IN A BROADENING OF THE TROUGH
BY MONDAY MORNING. MEANWHILE...A DEVELOPING MODEST COUPLED JET
PATTERN WILL DEVELOP OVER THE UPPER GREAT LAKES. THE SOUTHERN WAVE
WILL BE OF MOST INTEREST INITIALLY AS IT INDUCES A RAPIDLY DEEPENING
LOW OVER ILLINOIS AT THE START OF THE PERIOD. WITH THE 12/18Z NAM
RUNS COMING INTO BETTER AGREEMENT WITH THE OTHER MODELS...CONFIDENCE
IS NOW HIGHER REGARDING THE OVERALL EVOLUTION OF THE SYSTEM. THE SFC
LOW IS PROGGED TO TRACK NEAR THE STRAITS OF MACKINAC AROUND 12Z
MONDAY. THE GEM/NAM/ECMWF HINT AT A SLIGHT DEVIATION TO THE LEFT/NW
MONDAY MORNING...WITH THE LOW CROSSING NEAR SAULT STE MARIE. THIS
LOOKS REASONABLE AS THE INFLUENCE OF THE NORTHERN TROUGH APPROACHES.
A LINGERING TROUGH WILL THEN REMAIN ACROSS UPPER MI ON MONDAY AS THE
MID-LEVEL TROUGH AXIS REACHES THE REGION AND THE SFC LOW MOVES TO
JUST SE OF JAMES BAY.
NOW A LOOK AT THE OVERALL PRECIP TYPE AND INTENSITY. MID/UPPER-LEVEL
DYNAMICS AND LOW-LEVEL THERMODYNAMICS SUPPORT MODERATE RAIN ACROSS
MAINLY CENTRAL AND EASTERN UPPER MI SUNDAY NIGHT. THE RIGHT ENTRANCE
OF A DEVELOPING...ALBEIT ANTICYCLONICALLY CURVED...UPPER JET WILL
MAXIMIZE UPPER DIVERGENCE OVER CENTRAL AND EASTERN UPPER MI WHILE
MID-LEVEL Q-VECTOR CONVERGENCE PEAKS OVER NORTHERN LOWER MI.
MEANWHILE...LOW-LEVEL MOISTURE TRANSPORT WILL BE RATHER IMPRESSIVE
ACROSS THE EASTERN CWA...THEN QUICKLY DIMINISH TOWARD THE WESTERN
CWA. A SUFFICIENTLY DEEP LOW-LEVEL WARM LAYER WILL KEEP PRECIP ALL
RAIN ACROSS THE CWA...THOUGH A TRANSITION TO SNOW WILL BE UNDERWAY
LATE SUNDAY NIGHT ACROSS THE WEST AS CAA BEGINS BEHIND THE LOW. ALL
THIS TOGETHER FAVORS MODERATE RAIN ACROSS THE EAST HALF SUNDAY
NIGHT...WITH AN INITIALLY SHARP CUTOFF TO THE WEST BEFORE THE
NORTHERN WAVE APPROACHES OVERNIGHT.
CAA TAKING HOLD ON MONDAY WILL QUICKLY TRANSITION THE RAIN TO SNOW
FROM WEST TO EAST THROUGHOUT THE DAY. THERE ARE SOME INDICATIONS
THAT A LOW-LEVEL WARM LAYER MAY TRY TO WRAP AROUND THE BACK SIDE OF
THE LOW LATE MORNING MORNING INTO THE AFTERNOON. SOME SLEET MAY MIX
IN WITH THE RAIN/SNOW...BUT THE TRANSITION FROM ALL RAIN SNOW SHOULD
NOT TAKE MORE THAN AN HOUR OR TWO. THINK THAT EVEN THE SHORELINE
LOCATIONS SHOULD TRANSITION QUICKLY GIVEN THEN COLDER THAN AVERAGE
LAKE TEMPS. TRANSITION TIMES LOOK TO BE AROUND 09Z FOR IWD...12Z FOR
A LINE FROM HOUGHTON TO IRON RIVER...AND 15Z FOR A LINE FROM
MARQUETTE TO IMT. BY 21Z...ALL BUT POSSIBLY LUCE COUNTY SHOULD
TRANSITION TO SNOW.
A FAIRLY IMPRESSIVE MID-LEVEL FGEN/DEFORMATION ZONE WILL SET UP OVER
THE WESTERN CWA BY MONDAY AFTERNOON. WITH SOME SNOWFLAKE FRACTURING
FROM THE HIGHER WINDS AND THE MAX LIFT INITIALLY OCCURRING AT TEMPS
JUST A BIT WARMER THAN THE DGZ...SNOW RATIOS MAY REMAIN LOW /10 TO
1/ THROUGH MONDAY MORNING. AS TEMPS CONTINUE TO FALL IN TO THE
AFTERNOON SNOW RATIOS WILL BE ON THE RISE ACROSS THE WEST. LOW-LEVEL
WINDS AVERAGING OUT THE NORTH COMBINED WITH LAKE-850MB DELTA TEMPS
SURPASSING 10C SUPPORT DECENT LAKE-ENHANCEMENT FOR THE NORTH WIND
SNOW BELTS THROUGHOUT MONDAY. THIS PATTERN WILL CONTINUE INTO MONDAY
EVENING AS THE CONSOLIDATED TROUGH SLOWS OVER THE AREA AND KEEPS A
SFC TROUGH EXTENDED ACROSS MUCH OF EASTERN UPPER MI. ON TOP OF THE
SNOW...THE CAA WITH A STRONG WNW TO ESE ISALLOBARIC COMPONENT FROM
THE RAPIDLY DEEPENING LOW WILL YIELD A QUICK INCREASE IN WIND FROM
THE N/NNW.
WHEN ALL IS SAID AND DONE...SNOWFALL MONDAY AND MONDAY NIGHT IS
EXPECTED TO BE 6 TO 10 INCHES BASICALLY NORTH OF M-28 AND WEST OF
MARQUETTE. ELSEWHERE ACROSS THE CWA...2-4 INCHES IS EXPECTED.
HOWEVER...HIGHER AMOUNTS OF UP TO 6 INCHES WILL BE POSSIBLE FOR THE
NNW WIND SNOW BELTS FROM SHOT POINT TO GRAND MARAIS. THREW AROUND
THE IDEA OF A WINTER STORM WATCH FOR THE NW HALF...BUT DECIDED
AGAINST IT GIVEN SOME DETAILS IN QPF AND PLACEMENT OF FORCING THAT
NEED TO BE IRONED OUT. HOWEVER...WINTER WX ADVISORY CRITERIA SHOULD
BE MET. HAVE OPTED TO ISSUE A SPECIAL WX STATEMENT AT THIS TIME TO
HIGHLIGHT THE POTENTIAL...BUT ALSO NOTE THE UNCERTAINTY IN AMOUNTS.
MAIN IMPACTS WILL BE RATHER SLUSHY ROADS IN THE AFTERNOON FOLLOWED
BY BLOWING AND DRIFTING OF THE SNOW OVERNIGHT AS SNOW RATIOS
INCREASE.
TUESDAY THROUGH WEDNESDAY NIGHT...WEAK MID-LEVEL RIDGING...LOW-LEVEL
WAA AND INVERSION HEIGHTS FALLING BELOW 3KFT WILL PUT A QUICK END TO
THE LES FROM WEST TO EAST THROUGHOUT THE DAY. A CLIPPER SHORTWAVE
WILL TRACK SE INTO THE UPPER MS VALLEY LATE TUESDAY. THE SHORTWAVE
LOOKS TO GET CAUGHT UP IN A LARGER-SCALE TROUGH OVER HUDSON
BAY...ULTIMATELY SLOWING ITS PROGRESSING AND SHIFTING IT TO A ENE
TRACK. WHERE THIS TAKES PLACE WILL BE CRUCIAL FOR DETERMINING SNOW
PROBABILITY/AMOUNTS FOR THE CWA. THE GFS IS THE FASTEST...BRINGING
WIDESPREAD ACCUMULATING SNOW TO THE AREA LATE TUESDAY NIGHT INTO
WEDNESDAY AFTERNOON. THE ECMWF TAKES AN INITIALLY MORE AGGRESSIVE
EVOLUTION...RESULTING THE THE TROUGH DIGGING FARTHER SOUTHEAST
BEFORE PIVOTING ACROSS SOUTHERN LAKE/LOWER MI. WITH THIS
SCENARIO...MOST OF THE SNOW HOLDS OFF UNTIL WEDNESDAY NIGHT. THE GEM
FOLLOWS A SOLUTION IN THE MIDDLE...BUT LEANS MORE IN LINE WITH THE
GFS. ATTM...CANNOT REALLY PIN DOWN AMOUNTS AND EXACT TIMING...THOUGH
THE PROSPECTS FOR SEVERAL INCHES OF ACCUMULATING SNOW SOMETIME LATE
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT ARE GROWING.
THANKSGIVING...DEPENDING ON WHAT MODEL SOLUTION PANS
OUT...WIDESPREAD SNOW MAY LINGER THROUGH THE MORNING OR END BEFORE
DAYBREAK. EITHER WAY...CAA BEHIND THE CLIPPER SHOULD YIELD LES FOR
THE N/NNW WIND BELTS DURING THE DAY. IT STILL LOOKS COLD...WITH
TEMPS MORE IN LINE WITH CHRISTMAS RATHER THAN THANKSGIVING.
HOWEVER...WITH THE SLOWER SOLUTION...THE ECMWF HAS A HARDER TIME
BRINGING THE COLDEST AIR INTO THE REGION.
FRIDAY AND SATURDAY...LONG RANGE MODELS HAVE BACKED OFF SOMEWHERE ON
A TRANSITION TO A MORE ZONAL AND MILD PATTERN BEGINNING FRIDAY AND
DELAY IT UNTIL LATE IN THE WEEKEND. THE OVERALL PATTERN LOOKS QUIET
BESIDE SOME LES FOR THE WNW WIND SNOW BELTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 112 AM EST SUN NOV 23 2014
MOISTURE CONTINUING TO FLOW INTO THE AREA SHOULD RESULT IN LOWERING
OF CIGS FALLING TO LIFR LATE TONIGHT AS THE MOIST LOW-LEVELS WILL BE
ONLY BE AIDED BY ADDITIONAL MOISTURE AND HELPED ALONG BY DEVELOPING
UPSLOPE FLOW AT KCMX AND KSAW. THESE SITES WILL PROBABLY SEE DRIZZLE
AND FOG AS WELL WITH VSBY LIKELY REACHING IFR LATE TONIGHT.
CONDITIONS WILL STAY LIFR/VLIFR THROUGH THE REST OF THE FORECAST
PERIOD AT ALL SITES. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EST SAT NOV 22 2014
SOUTH WINDS WILL INCREASE ON SUNDAY...ESPECIALLY OVER EASTERN
SECTIONS...BUT SHOULD REMAIN 30 KTS OR LESS. WINDS WILL BE VARIABLE
SUNDAY NIGHT AS TROUGH CROSSES LAKE SUPERIOR. A DEEPENING LOW WILL MOVE
TO EAST OF LAKE SUPERIOR ON MONDAY. NORTHERLY WINDS WILL INCREASE TO
GALES 40-45 KTS MONDAY AFTN INTO MONDAY NIGHT. WINDS DIMINISH TO 25
KTS OR LESS LATER TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS
ON THURSDAY AS COLD AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE
BUILDING OVER THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE
LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ248>250-265-266.
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ242>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
610 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT TROUGH COMING INTO CENTRAL BRITISH COLUMBIA ON TOP
OF EAST PACIFIC RIDGING...AND MORE TROUGHING COVERING MUCH OF
CENTRAL NORTH AMERICA. WITHIN THIS BROAD TROUGH...A SHORTWAVE WAS
PRESENT OVER EASTERN IOWA/NORTHERN IL...WHICH DPVA FROM IT COMBINED
WITH A BAND OF MID LEVEL FRONTOGENESIS HAS ALLOWED A BAND OF SNOW TO
PERSIST FROM WESTERN INTO SOUTHERN WI. ADDITIONAL SNOW SHOWERS HAVE
BEEN TAKING PLACE ACROSS MUCH OF MN INTO IA...MOSTLY ASSOCIATED WITH
INSTABILITY PRODUCED FROM COOL MID LEVEL TEMPS ALOFT AND RELATIVELY
WARMER TEMPS/DEWPOINTS AT THE SURFACE. RAP 700MB TEMPS SHOWED
READING IN THE -12 TO -13C RANGE...MEANWHILE SURFACE TEMPS HAVE
COOLED INTO THE TEENS AND 20S...WARMEST IN WESTERN WI. A TIGHT
PRESSURE GRADIENT IN PLACE...BETWEEN A SURFACE RIDGE OVER THE
WESTERN PLAINS AND A LOW PRESSURE TROUGH IN NORTHERN LOWER MI...HAS
PRODUCED GUSTS OF 30-40 MPH. THE STRONGEST GUSTS HAVE BEEN CONFINED
TO SOUTHWEST AND SOUTH CENTRAL MN WHERE THE DEEPEST MIXING HAS BEEN
TAKING PLACE. FARTHER TO THE WEST...A LARGE EXPANSE OF CLEARING
DOMINATES A LOT OF THE PLAINS...ASSOCIATED WITH THE SURFACE RIDGE
AND VERY DRY AIR. PRECIPITABLE WATER VALUES THERE ARE IN THE 0.1-0.2
INCH RANGE.
THE FOCUS FOR ATTENTION BEGINS TO SHIFT TO THAT POTENT TROUGH OVER
CENTRAL BRITISH COLUMBIA. GOOD MODEL CONSENSUS EXISTS FOR THE TROUGH
TO DIG DOWN INTO THE WESTERN DAKOTAS BY 00Z WEDNESDAY...ALLOWING
WEAK RIDGING TO BUILD OVER THE FORECAST AREA. ADDITIONALLY...THE
NEXT POTENT TROUGH WILL HELP PUSH THE CURRENT SHORTWAVE TROUGH AND
700MB COOL AIR SITUATED OVER THE FORECAST AREA OFF TO THE EAST.
FOR TONIGHT...ANTICIPATING SNOW SHOWERS OVER MINNESOTA TO DIMINISH
QUICKLY THIS EVENING WITH LOSS OF DAYTIME HEATING. FIGURE
SOMEWHERE AROUND 03Z THEY SHOULD HAVE ENDED...IN AGREEMENT WITH A
LOT OF HI RESOLUTION MODEL GUIDANCE. THE SNOW OVER WESTERN WI WILL
TAKE LONGER TO END BEING ASSOCIATED WITH THE MID LEVEL
FRONTOGENESIS BAND THERE...SOMEWHERE AROUND 06Z. CURRENT WINTER
WEATHER ADVISORY END TIME STILL LOOKS GOOD. REGARDING THE WIND
ADVISORY...PRESENT WINDS ARE MARGINAL TO KEEP IT GOING.
HOWEVER...SINCE CONDITIONS REMAIN BRISK FOR THE REST OF THE
AFTERNOON AND WINDS ARE STILL ON TRACK TO DIMINISH THIS
EVENING...PLAN ON LETTING THE WIND ADVISORY EXPIRE AT 6 PM. CLEARING
ACROSS THE PLAINS SHOULD MAKE ITS WAY WEST TO EAST ACROSS A LOT OF
THE FORECAST AREA...PERHAPS EVEN INTO WESTERN WI BY 12Z. THE
CLEARING COMBINED WITH A WEAKENING PRESSURE GRADIENT AND ALREADY
COOL TEMPERATURES SHOULD ALLOW READINGS TO DIP INTO THE SINGLE
DIGITS OVER WEST-CENTRAL MN. TEENS ARE LIKELY ELSEWHERE WITH MORE
CLOUDS AND WIND. IT SHOULD BE NOTED THAT MORE CLOUDS ARE LIKELY TO
COME INTO WESTERN SECTIONS OF THE FORECAST AREA BY 12Z...AHEAD OF
THE APPROACHING POTENT TROUGH.
ON TUESDAY...CLOUDS WILL MARCH THEIR WAY WEST TO EAST ACROSS THE
FORECAST AREA AGAIN AS THE POTENT TROUGH MOVES INTO THE WESTERN
DAKOTAS. ANY PRECIPITATION DOES LOOK TO REMAIN TO THE WEST PRIOR TO
00Z WEDNESDAY...THOUGH. ALTHOUGH THERE MIGHT BE MORE CLOUDS...
INCREASING SOUTHWESTERLY FLOW AHEAD OF THE AFTERNOON SHOULD HELP
GIVE TEMPERATURES A BOOST. IN FACT...925MB READINGS CLIMB FROM
AROUND -10C AT 12Z TO -4 TO -7C BY 00Z...WARMEST NEAR MANKATO AND
NEW ULM. MOST LOCATIONS SHOULD SEE HIGHS IN THE 20S...WITH 30S
POSSIBLE NEAR THE MN RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
MAIN FOCUS STARTING OFF THE PERIOD IS THE POTENT SHORTWAVE TROUGH
CURRENTLY IN CENTRAL BRITISH COLUMBIA. THERE HAS BEEN A MAJOR TREND
OVER THE PAST 2 DAYS TO DIG THIS TROUGH FARTHER SOUTHWEST...
ESPECIALLY IN THE ECMWF. THIS TREND APPEARS TO BE RELATED TO THE
CURRENT CENTRAL NORTH AMERICA TROUGH BEING MORE AMPLIFIED THAN
PREVIOUSLY PROGGED. AS A RESULT OF THIS TREND...THERE IS A CHANCE
SUGGESTED BY THE 24.12Z GFS THAT MUCH OF THE AREA COULD BE MISSED BY
THIS SYSTEM. THIS WOULD BE GOOD NEWS FOR TRAVELERS. IN THE GFS...THE
SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW DIVE DOWN TO NEAR
THE KANSAS CITY AREA BY 12Z...WITH THE ISENTROPIC LIFT/MID LEVEL
FRONTOGENESIS ZONE BRUSHING THE MN RIVER VALLEY WITH SOME SNOW
BETWEEN 06-18Z WEDNESDAY. HAVE TRENDED THE FORECAST DRIER TO ACCOUNT
FOR THE MODEL TREND...BUT QPF AND POPS MAY NEED TO BE REDUCED
FURTHER. TEMPERATURES SHOULD NOT DROP MUCH TUESDAY NIGHT WITH THE
CLOUDS IN PLACE AND EVEN SOME SLIGHT WARM ADVECTION POSSIBLE. FOR
WEDNESDAY...HIGHS ARE LIKELY TO OCCUR BY NOON AS COLD ADVECTION
LOOKS TO COMMENCE IN THE WAKE OF THE TROUGH. THE AMOUNT OF ADVECTION
DEPENDS ON HOW FAR SOUTH THE TROUGH DIGS...THUS THESE READINGS ARE
SUBJECT TO CHANGE.
DRY AND COLDER CONDITIONS REMAIN PROGGED TO AFFECT THE AREA FOR
WEDNESDAY NIGHT AND THANKSGIVING...AS ARCTIC HIGH PRESSURE MOVES IN
FROM THE NORTHWEST. 925MB TEMPS TOPPING OUT IN THE -10 TO -16C RANGE
WILL ONLY ALLOW FOR HIGHS IN THE TEENS.
A PATTERN CHANGE IS IN THE OFFERING FOR THURSDAY NIGHT INTO EARLY
NEXT WEEK WITH MODELS ADVERTISING A SERIES OF TROUGHS MOVING INTO
THE WESTERN U.S.. THIS RESULTS IN A MORE ZONAL FLOW PATTERN
DOWNSTREAM TO EVENTUALLY SOUTHWESTERLY EARLY NEXT WEEK. THE SWITCH
TO ZONAL FLOW RESULTS IN A WARM ADVECTION REGIME THURSDAY NIGHT AND
FRIDAY. ON THE NOSE OF THE WARM ADVECTION...A MID-LEVEL
FRONTOGENESIS SNOWFALL BAND LOOKS TO SETUP FROM THE DAKOTAS THROUGH
MINNESOTA AND WISCONSIN. EXACT PLACEMENT AND AMOUNTS ARE YET TO BE
DETERMINED...BUT THE FOCUS RIGHT NOW GENERALLY APPEARS ALONG/NORTH
OF I-94. THE WARM FRONT LOOKS TO LIFT THROUGH MUCH OF THE FORECAST
AREA FRIDAY NIGHT. THEN FOR SATURDAY...A SHORTWAVE CROSSES THE AREA
IN THE ZONAL FLOW...SENDING A COLD FRONT THROUGH. THIS PERIOD COULD
BE TRICKY FOR HIGHS. IF THE FRONT IS SLOWER...HIGHS COULD EASILY TOP
OUT IN THE 40S. HOWEVER...AT THE CURRENT SPEED...UPPER 20S TO MID
30S SEEM MORE REASONABLE. DESPITE THE ZONAL FLOW...AN ARCTIC LOW
LEVEL INTRUSION LOOKS TO AFFECT THE AREA FOR SATURDAY NIGHT AND
SUNDAY...ACCOMPANIED BY ARCTIC HIGH PRESSURE...NOTED BY 925MB TEMPS
ABOUT 5C COLDER THAN AT 850MB. THOSE 925MB TEMPS ON SUNDAY RANGING
FROM -10 TO -15C MEANS BACK TO HIGHS IN THE TEENS. WE SHOULD BEGIN
TO DISLODGE THE COLD AIR ON MONDAY WITH THE UPPER FLOW TURNING
SOUTHWESTERLY...ALLOWING FOR A REBOUND BACK INTO THE 20S FOR HIGHS.
CONDITIONS LOOK TO REMAIN DRY FOR MONDAY WITH ARCTIC HIGH PRESSURE
IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 610 PM CST MON NOV 24 2014
MVFR CIGS ARE IN PLACE OVER THE MAJORITY OF MINNESOTA AND
WISCONSIN...BUT CLEARING IS STARTING TO PUSH EASTWARD INTO WESTERN
MINNESOTA. THIS TREND WILL CONTINUE THROUGH THE NIGHT WITH VFR
CONDITIONS GRADUALLY RETURNING. THE SNOW HAS ABOUT ENDED...BUT A FEW
FLURRIES CANNOT BE RULED OUT ACROSS WI AND SRN MN. SOME MVFR CIGS
COULD RETURN LATE SATURDAY AS ANOTHER SYSTEM APPROACHES. WINDS WILL
EASE THIS EVENING AND BECOME LIGHT/VARIABLE TUESDAY AFTERNOON.
KMSP...BEST TIMING FOR VFR CONDITIONS IS ABOUT 06Z...BUT IT COULD
COME A BIT EARLIER. SOME HIGH/MID LEVEL CLOUDS MAY STICK AROUND
TUESDAY MORNING BEFORE LOWER MVFR CLOUDS RETURN LATE TUESDAY.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CHC -SN EARLY. WINDS NW 10-15KTS.
THU...VFR. WINDS LIGHT/VARIABLE.
FRI...VFR/CHC MVFR AND -SN. WINDS S 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ016-
026>028.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...RETRANSMISSION
NWS TWIN CITIES/CHANHASSEN MN ISSUED BY
NATIONAL WEATHER SERVICE LA CROSSE WI 249 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT TROUGH COMING INTO CENTRAL BRITISH COLUMBIA ON TOP
OF EAST PACIFIC RIDGING...AND MORE TROUGHING COVERING MUCH OF
CENTRAL NORTH AMERICA. WITHIN THIS BROAD TROUGH...A SHORTWAVE WAS
PRESENT OVER EASTERN IOWA/NORTHERN IL...WHICH DPVA FROM IT COMBINED
WITH A BAND OF MID LEVEL FRONTOGENESIS HAS ALLOWED A BAND OF SNOW TO
PERSIST FROM WESTERN INTO SOUTHERN WI. ADDITIONAL SNOW SHOWERS HAVE
BEEN TAKING PLACE ACROSS MUCH OF MN INTO IA...MOSTLY ASSOCIATED WITH
INSTABILITY PRODUCED FROM COOL MID LEVEL TEMPS ALOFT AND RELATIVELY
WARMER TEMPS/DEWPOINTS AT THE SURFACE. RAP 700MB TEMPS SHOWED
READING IN THE -12 TO -13C RANGE...MEANWHILE SURFACE TEMPS HAVE
COOLED INTO THE TEENS AND 20S...WARMEST IN WESTERN WI. A TIGHT
PRESSURE GRADIENT IN PLACE...BETWEEN A SURFACE RIDGE OVER THE
WESTERN PLAINS AND A LOW PRESSURE TROUGH IN NORTHERN LOWER MI...HAS
PRODUCED GUSTS OF 30-40 MPH. THE STRONGEST GUSTS HAVE BEEN CONFINED
TO SOUTHWEST AND SOUTH CENTRAL MN WHERE THE DEEPEST MIXING HAS BEEN
TAKING PLACE. FARTHER TO THE WEST...A LARGE EXPANSE OF CLEARING
DOMINATES A LOT OF THE PLAINS...ASSOCIATED WITH THE SURFACE RIDGE
AND VERY DRY AIR. PRECIPITABLE WATER VALUES THERE ARE IN THE 0.1-0.2
INCH RANGE.
THE FOCUS FOR ATTENTION BEGINS TO SHIFT TO THAT POTENT TROUGH OVER
CENTRAL BRITISH COLUMBIA. GOOD MODEL CONSENSUS EXISTS FOR THE TROUGH
TO DIG DOWN INTO THE WESTERN DAKOTAS BY 00Z WEDNESDAY...ALLOWING
WEAK RIDGING TO BUILD OVER THE FORECAST AREA. ADDITIONALLY...THE
NEXT POTENT TROUGH WILL HELP PUSH THE CURRENT SHORTWAVE TROUGH AND
700MB COOL AIR SITUATED OVER THE FORECAST AREA OFF TO THE EAST.
FOR TONIGHT...ANTICIPATING SNOW SHOWERS OVER MINNESOTA TO DIMINISH
QUICKLY THIS EVENING WITH LOSS OF DAYTIME HEATING. FIGURE
SOMEWHERE AROUND 03Z THEY SHOULD HAVE ENDED...IN AGREEMENT WITH A
LOT OF HI RESOLUTION MODEL GUIDANCE. THE SNOW OVER WESTERN WI WILL
TAKE LONGER TO END BEING ASSOCIATED WITH THE MID LEVEL
FRONTOGENESIS BAND THERE...SOMEWHERE AROUND 06Z. CURRENT WINTER
WEATHER ADVISORY END TIME STILL LOOKS GOOD. REGARDING THE WIND
ADVISORY...PRESENT WINDS ARE MARGINAL TO KEEP IT GOING.
HOWEVER...SINCE CONDITIONS REMAIN BRISK FOR THE REST OF THE
AFTERNOON AND WINDS ARE STILL ON TRACK TO DIMINISH THIS
EVENING...PLAN ON LETTING THE WIND ADVISORY EXPIRE AT 6 PM. CLEARING
ACROSS THE PLAINS SHOULD MAKE ITS WAY WEST TO EAST ACROSS A LOT OF
THE FORECAST AREA...PERHAPS EVEN INTO WESTERN WI BY 12Z. THE
CLEARING COMBINED WITH A WEAKENING PRESSURE GRADIENT AND ALREADY
COOL TEMPERATURES SHOULD ALLOW READINGS TO DIP INTO THE SINGLE
DIGITS OVER WEST-CENTRAL MN. TEENS ARE LIKELY ELSEWHERE WITH MORE
CLOUDS AND WIND. IT SHOULD BE NOTED THAT MORE CLOUDS ARE LIKELY TO
COME INTO WESTERN SECTIONS OF THE FORECAST AREA BY 12Z...AHEAD OF
THE APPROACHING POTENT TROUGH.
ON TUESDAY...CLOUDS WILL MARCH THEIR WAY WEST TO EAST ACROSS THE
FORECAST AREA AGAIN AS THE POTENT TROUGH MOVES INTO THE WESTERN
DAKOTAS. ANY PRECIPITATION DOES LOOK TO REMAIN TO THE WEST PRIOR TO
00Z WEDNESDAY...THOUGH. ALTHOUGH THERE MIGHT BE MORE CLOUDS...
INCREASING SOUTHWESTERLY FLOW AHEAD OF THE AFTERNOON SHOULD HELP
GIVE TEMPERATURES A BOOST. IN FACT...925MB READINGS CLIMB FROM
AROUND -10C AT 12Z TO -4 TO -7C BY 00Z...WARMEST NEAR MANKATO AND
NEW ULM. MOST LOCATIONS SHOULD SEE HIGHS IN THE 20S...WITH 30S
POSSIBLE NEAR THE MN RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
MAIN FOCUS STARTING OFF THE PERIOD IS THE POTENT SHORTWAVE TROUGH
CURRENTLY IN CENTRAL BRITISH COLUMBIA. THERE HAS BEEN A MAJOR TREND
OVER THE PAST 2 DAYS TO DIG THIS TROUGH FARTHER SOUTHWEST...
ESPECIALLY IN THE ECMWF. THIS TREND APPEARS TO BE RELATED TO THE
CURRENT CENTRAL NORTH AMERICA TROUGH BEING MORE AMPLIFIED THAN
PREVIOUSLY PROGGED. AS A RESULT OF THIS TREND...THERE IS A CHANCE
SUGGESTED BY THE 24.12Z GFS THAT MUCH OF THE AREA COULD BE MISSED BY
THIS SYSTEM. THIS WOULD BE GOOD NEWS FOR TRAVELERS. IN THE GFS...THE
SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW DIVE DOWN TO NEAR
THE KANSAS CITY AREA BY 12Z...WITH THE ISENTROPIC LIFT/MID LEVEL
FRONTOGENESIS ZONE BRUSHING THE MN RIVER VALLEY WITH SOME SNOW
BETWEEN 06-18Z WEDNESDAY. HAVE TRENDED THE FORECAST DRIER TO ACCOUNT
FOR THE MODEL TREND...BUT QPF AND POPS MAY NEED TO BE REDUCED
FURTHER. TEMPERATURES SHOULD NOT DROP MUCH TUESDAY NIGHT WITH THE
CLOUDS IN PLACE AND EVEN SOME SLIGHT WARM ADVECTION POSSIBLE. FOR
WEDNESDAY...HIGHS ARE LIKELY TO OCCUR BY NOON AS COLD ADVECTION
LOOKS TO COMMENCE IN THE WAKE OF THE TROUGH. THE AMOUNT OF ADVECTION
DEPENDS ON HOW FAR SOUTH THE TROUGH DIGS...THUS THESE READINGS ARE
SUBJECT TO CHANGE.
DRY AND COLDER CONDITIONS REMAIN PROGGED TO AFFECT THE AREA FOR
WEDNESDAY NIGHT AND THANKSGIVING...AS ARCTIC HIGH PRESSURE MOVES IN
FROM THE NORTHWEST. 925MB TEMPS TOPPING OUT IN THE -10 TO -16C RANGE
WILL ONLY ALLOW FOR HIGHS IN THE TEENS.
A PATTERN CHANGE IS IN THE OFFERING FOR THURSDAY NIGHT INTO EARLY
NEXT WEEK WITH MODELS ADVERTISING A SERIES OF TROUGHS MOVING INTO
THE WESTERN U.S.. THIS RESULTS IN A MORE ZONAL FLOW PATTERN
DOWNSTREAM TO EVENTUALLY SOUTHWESTERLY EARLY NEXT WEEK. THE SWITCH
TO ZONAL FLOW RESULTS IN A WARM ADVECTION REGIME THURSDAY NIGHT AND
FRIDAY. ON THE NOSE OF THE WARM ADVECTION...A MID-LEVEL
FRONTOGENESIS SNOWFALL BAND LOOKS TO SETUP FROM THE DAKOTAS THROUGH
MINNESOTA AND WISCONSIN. EXACT PLACEMENT AND AMOUNTS ARE YET TO BE
DETERMINED...BUT THE FOCUS RIGHT NOW GENERALLY APPEARS ALONG/NORTH
OF I-94. THE WARM FRONT LOOKS TO LIFT THROUGH MUCH OF THE FORECAST
AREA FRIDAY NIGHT. THEN FOR SATURDAY...A SHORTWAVE CROSSES THE AREA
IN THE ZONAL FLOW...SENDING A COLD FRONT THROUGH. THIS PERIOD COULD
BE TRICKY FOR HIGHS. IF THE FRONT IS SLOWER...HIGHS COULD EASILY TOP
OUT IN THE 40S. HOWEVER...AT THE CURRENT SPEED...UPPER 20S TO MID
30S SEEM MORE REASONABLE. DESPITE THE ZONAL FLOW...AN ARCTIC LOW
LEVEL INTRUSION LOOKS TO AFFECT THE AREA FOR SATURDAY NIGHT AND
SUNDAY...ACCOMPANIED BY ARCTIC HIGH PRESSURE...NOTED BY 925MB TEMPS
ABOUT 5C COLDER THAN AT 850MB. THOSE 925MB TEMPS ON SUNDAY RANGING
FROM -10 TO -15C MEANS BACK TO HIGHS IN THE TEENS. WE SHOULD BEGIN
TO DISLODGE THE COLD AIR ON MONDAY WITH THE UPPER FLOW TURNING
SOUTHWESTERLY...ALLOWING FOR A REBOUND BACK INTO THE 20S FOR HIGHS.
CONDITIONS LOOK TO REMAIN DRY FOR MONDAY WITH ARCTIC HIGH PRESSURE
IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM CST MON NOV 24 2014
MIX OF CONDITIONS TODAY AS DEFORMATION SNOW BAND CONTINUES TO IMPACT
WESTERN WISCONSIN WITH SNOW SHOWERS AND STRONG NORTHWEST WINDS
IMPACTING MINNESOTA. MVFR AND IFR CONDITIONS PREVAIL.
POCKET OF STEEPER LAPSE RATES PRODUCING CONVECTIVE SNOW SHOWERS
ACROSS CENTRAL MINNESOTA WILL CONTINUE TO SHIFT SOUTH AND SOUTHEAST
AROUND UPPER SYSTEM WITH OTHER AREAS OF LIGHT SNOW MOVING SOUTH AS
WELL. WILL HAVE TO ACCOUNT FOR OCCASIONAL LOWER VISIBILITIES THIS
AFTERNOON YET BEFORE SYSTEM EXITS TO THE EAST...ALTHOUGH CEILINGS
RELATIVELY STABLE.
SHORT BREAK BEHIND THIS SYSTEM SO WILL ATTEMPT TO TIME CLEARING IN
FROM THE WEST...ALBEIT DELAYED A LITTLE FROM EARLIER TRENDS.
MEANWHILE ANOTHER SHORT WAVE TROUGH ENTERS THE PICTURE QUICKLY
TUESDAY SO WILL SEE INCREASE IN CLOUDS IN WESTERN MINNESOTA TOWARDS
LATTER PART OF FORECAST...WITH VFR CONDITIONS.
KMSP...
MSP BETWEEN SNOW SHOWERS TO THE WEST AND DEFORMATION SNOW
AREA AREA TO THE EAST. THESE MVFR CONDITIONS WILL GIVE WAY TO LIGHT
SNOW SPREADING IN FROM THE NORTH THIS AFTERNOON WHICH COULD CREATE
POCKETS OF IFR. BY EVENING SYSTEM SHOULD PUSH FAR ENOUGH EAST
LEAVING JUST MVFR CEILINGS WITH SLOW BREAK UP IN CLOUDS FROM WEST TO
EAST OVERNIGHT. WINDS WILL ALSO BEGIN TO DECREASE OUT OF THE
NORTHWEST AND BACK TO MORE SOUTHWEST DIRECTION ON TUESDAY...AHEAD OF
NEXT WAVE.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS W 5-10 KT BECOMING SE.
WED...MVFR/IFR CHC -SN EARLY. WINDS NW 10-15KTS.
THU...VFR. WINDS LIGHT/VARIABLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ054>056-064-065-
073>075-082>084-091>093.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ016-
026>028.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1145 AM CST SUN NOV 23 2014
.UPDATE...
ISSUED AT 1132 AM CST SUN NOV 23 2014
JUST EXTENDED THE DENSE FOG ADVY FOR AREAS EAST OF I-35 THROUGH
00Z. AT THE MOMENT...A COLD FRONT EXTENDS MORE OR LESS DOWN
I-35...FOG EAST OF IT AND MUCH IMPROVED CONDITIONS AND A BAND OF
DEFORMATION RAIN TO THE WEST. A QUICK TOURS OF WEBCAMS ACROSS THE
CITIES SHOWS QUITE THE IMPRESSIVE GRADIENT IN CONDITIONS...WITH
494 GOING FROM 1/4SM VISIBILITY AT MN-5 TO JUST HAZY CONDITIONS AT
MN-77 ALONG I-94 WE ARE SEEING THE SAME THING...WITH GOOD
VISIBILITIES IN MINNEAPOLIS...BUT DENSE FOG IN ST. PAUL...WITH
MN-280 ACTING AS THE DELINEATION LINE AT THIS POINT.
WITH THE HRRR SHOWING LOW VISBYS REMAINING ACROSS WRN WI THROUGH
AT LEAST 00Z...DECIDED TO EXTEND THE ADVY THROUGH THEN. WE WILL
REASSESS THE ADVY LATER THIS AFTERNOON TO PROBABLY KNOCK OF A FEW
OF THE COUNTIES ON THE WEST SIDE AND DECIDE IF WE NEED TO GO ANY
LONGER INTO THE NIGHT OF THE FAR ERN MPX CWA COUNTIES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CST SUN NOV 23 2014
THE SURFACE TROUGH NOSING INTO THE FORECAST AREA WILL CONTINUE TO
FOSTER AREAS OF DENSE FOG FOR AREAS GENERALLY NORTH OF INTERSTATE
94 THIS MORNING NORTH OF THE WARM FRONT THAT/S BISECTING THE
FORECAST AREA. HAVE EXTENDED THE DENSE FOG ADVISORY THROUGH THE
MORNING HOURS...WITH LITTLE IMPROVEMENT IN VISIBILITY EXPECTED
UNTIL THEN.
THE AFOREMENTIONED WARM FRONT WILL CONTINUE TO LIFT NORTH ACROSS
THE AREA TODAY...WITH ONGOING LIGHT PRECIPITATION POSSIBLE THROUGH
THE DAY. THE GOOD NEWS IS THAT TEMPERATURES HAVE CLIMBED ABOVE THE
FREEZING MARK ACROSS THE ENTIRE FORECAST AREA...THEREFORE
MINIMIZING THE CONCERN FOR FREEZING PRECIPITATION DURING THE
DAYTIME HOURS.
THIS EVENING...AS COLDER AIR INFILTRATES THE AIR IN RELATION TO THE
PASSING COLD FRONT...SHOULD SEE THE PRECIPITATION TYPE TRANSITION
TO ALL SNOW. WINDS BEHIND THE FRONT WILL BE SIGNIFICANT...WITH
SUSTAINED SPEEDS ACROSS WEST CENTRAL MN BETWEEN 25 MPH AND 30 MPH
WITH GUSTS TO AROUND 30 MPH. BLOWING SNOW CONCERNS HAVE DIMINISHED
A BIT GIVEN THE AFFECTS THE ANTECEDENT PRECIP AND SNOWMELT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN NOV 23 2014
ONLY A FEW MINOR CHGS IN THE EXTENDED PERIOD WITH THE COLD THAN
NORMAL CONDS CONTINUING WITH SMALL CHC/S OF SNOW.
OVERALL...THE MEAN UPPER FLOW REMAINS FROM THE N/NW THIS WEEK.
THE 5-DAY 50H MEAN /GFS/GEM/EC/ IS CONSISTENT WITH THE UPPER LOW
PARKED NORTH OF HUDSON BAY THRU THIS WEEK. THE BIGGEST CHG IS
ASSOCIATED WITH THE BREAK DOWN OF THE UPPER RIDGE ACROSS THE
WEST...WHICH MAY LEAD TO A MORE PROGRESSIVE/ZONAL FLOW BY THE WEEK
OF DECEMBER 1ST. TEMPS WILL BE COLDEST MONDAY THRU THURSDAY...WITH
SOME MODIFICATIONS NEXT WEEKEND.
MONDAY WILL BE WINDY WITH SOME PATCHY BLOWING SNOW WHERE WINDS GUSTS
IN THE 30 TO 40 MPH RANGE. HOWEVER...SNOWFALL WILL BE LIMITED IN THE
TYPICAL AREAS OF WC/SW/SC MN MONDAY WITH ONLY A LIGHT DUSTING
EXPECTED. PLUS WARM TEMPS OVER THE PAST 24 TO 36 HRS HAS ALLOWED A
CREST TO FORM ON THE SNOW COVER...LIMITING BLOWING SNOW POTENTIAL.
FOR PRECIPITATION RELATED CHGS NEXT WEEK...A FAST MOVING SHRTWV AND
ASSOCIATED SFC LOW WILL MOVE ACROSS THE PLAINS/MIDWEST WED. THERE
REMAINS A FAIRLY STRONG JET STREAK WITH THIS SYSTEM...LEADING TO AN
ENHANCED AREA OF LARGE SCALE LIFT IN THE EXIT REGION OF THIS JET IN
THE UPPER MIDWEST. MOISTURE LEVELS REMAIN LIMITED...SO HEAVIER
SNOWFALL AMTS WILL BE BASED ON THE LOCATION OF THE SFC LOW AND MID
LEVEL FRONTOGENESIS. HAVE INCREASED TO 50% FOR WEDNESDAY BASED ON
THE STRONGER JET STREAK AND SFC LOW LOCATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM CST SUN NOV 23 2014
MVFR CIGS/VSBYS WILL PERSIST THIS MORNING AS A WARM FRONT LIFTS
ACROSS THE AREA. THE WORST CONDITIONS /AND LOWEST CIGS AND VSYS/
WILL OCCUR NORTH OF THE TAF SITES...BUT AN IMPROVEMENT SHOULD BE
SEEN THIS AFTERNOON AT THE MN SITES. A COLD FRONT WORKS ACROSS THE
AREA THIS EVE...WITH GUSTY NORTHWEST WINDS DEVELOPING IN ITS WAKE.
REAS OF DRIZZLE/RAIN OVER WI SITES/PRIMARILY KEAU/ WILL TRANSITION
TO SNOW AFTER SUNSET...WITH KMSP ON THE WESTERN EDGE OF THE SNOW/PRECIP.
KMSP...
VSBYS SHOULD REMAIN AROUND 5-6SM WITH AREAS OF FOG THROUGH THE
MORNING. TOUGH CALL ON THE TIMING FOR VFR CIGS...IF ANYTHING
EXPECT THE TAF IS TOO OPTIMISTIC IN GOING TO VFR BY 14Z. FROPA
OCCURS THIS AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AROUND
21Z...AND GUSTS INTO THE MID/UPPER 20S DEVELOPING THIS EVE AND
PERSISTING INTO SUNDAY...WITH SUB-1800 FT CIGS RETURING.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ053-
061>063.
WI...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ014>016-
023-025-027-028.
&&
$$
UPDATE...MPG
SHORT TERM...LS
LONG TERM...JLT
AVIATION...LS
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1211 AM CST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
MAIN CONCERN DURING THE SHORT TERM PERIOD IS THE TREND OF STRATUS
AND THE POTENTIAL EXTENT OF FOG TONIGHT. A SECONDARY CONCERN IS WITH
PRECIP POTENTIAL TONIGHT INTO SUNDAY...THOUGH MODELS CONTINUE TO
SHOW PRECIP AMOUNTS BEING PRETTY UNDERWHELMING THROUGH SUNDAY ACROSS
THE ENTIRE MPX AREA...WITH DEEPER MOISTURE GOING ACROSS ERN WI AND
MICHIGAN.
EXTENSIVE STRATUS ACROSS ALL BUT THE NW PORTION OF THE MPX CWA HAS
HELD TEMPERATURES IN CHECK ALL DAY. LOOKING TO THE SOUTH...THERE ARE
A COUPLE OF MOISTURE SURGES HEADING OUR WAY. THE FIRST IS QUICKLY
MOVING INTO NRN IA AND WILL LIKELY BE TO THE I-90 CORRIDOR BY 00Z
THIS EVENING. IT IS CHARACTERIZED BY DEWPS IN THE 40S AND MORE
CONCERNING FOR THE CLOUD FORECAST TONIGHT...CLEAR SKIES. THE SECOND
MOISTURE SURGE IS JUST NOW GETTING TO I-80 AND IT IS ASSOCIATED WITH
DEWPS IN THE 50S...AND A RETURN TO LIFR STRATUS AND FOG. THE
ECMWF/GEM SHOW THIS SECOND MOISTURE SURGE AND ITS ASSOCIATED LOWER
50 DEWPS GETTING CLEAR UP TO I-90 SUNDAY MORNING BEFORE GETTING
SHUNTED OFF TO THE EAST. CERTAINLY DEWPS IN THE 40S WITH SNOW ON THE
GROUND FAVORS STRATUS CONTINUING THROUGH THE NIGHT AND THE CURRENT
FORECAST CERTAINLY READS THAT WAY...BUT WE WILL HAVE WATCH HOW THAT
CLEARING EVOLVES.
FOR FOG...ONE THING WE ARE POSITIVE ABOUT IS IT WILL BE HAZY TROUGH
THE NIGHT GIVEN DEWPS ABOVE FREEZING WITH SNOW ON THE GROUND. THERE
WAS TALK OF A DENSE FOG ADVISORY...BUT NOT CONFIDENT ENOUGH ON WHERE
TO PUT ONE OTHER THAN ANYONE UNDER STRATUS NOW...WHICH IS JUST ABOUT
OUR ENTIRE CWA AND DID NOT WANT TO ISSUE SUCH A LARGE ADVY AT THIS
POINT. ON TOP OF THAT...WE WILL BE MAINTAINING 8-12 KT WINDS THROUGH
THE NIGHT...SO THAT WILL SUPPLY A CERTAIN DEGREE OF MIXING AS WELL.
NOT TO MENTION WE HAVE THAT CLEARING RACING NORTH OUT OF IA. AT THIS
POINT...HIGHEST CONFIDENCE IN DENSE FOG IS WHERE OUR DEEPEST SNOW
RESIDES ACROSS THE NRN MPX CWA. THE HRRR WOULD SUPPORT THIS IDEA AS
IT DOES SHOW VSBYS IMPROVING THROUGH THE NIGHT ACROSS SRN MN AS THAT
SLUG OF SLIGHTLY DRIER AIR ACROSS IA WORKS INTO MN.
FOR TEMPERATURES...THEY MAY GO NOTHING BUT UP THROUGH THE NIGHT.
FIRST RUN OF THE HOURLY TEMPERATURE TOOL WITH THE LOCAL SUPERBLEND
BROUGHT A TEMPERATURE OF 53 TO ALBERT LEA BY 7Z TONIGHT. DID NOT GO
QUITE THAT AGGRESSIVE...BUT DO THINK MUCH OF THE AREA EAST OF A NEW
ULM TO MORA LINE WILL RISE INTO THE 40S OVERNIGHT. GIVEN THE MILD
START...ALSO GAVE HIGHS SUNDAY A BIT OF AN UPWARD NUDGE TO ABOUT A
50/50 BLEND BETWEEN THE PREVIOUS FORECAST AND THE 22.12 GEM/ECMWF.
THE GEM/ECMWF SHOW HIGHS IN THE LOW 50S FOR SE MN/WRN WI TOMORROW.
GIVEN THE EXTENSIVE CLOUD COVER...DO NOT THINK WE WILL GET THAT
HIGH...BUT DO HAVE HIGHS INTO THE MID/UPPER 40S FOR ALL BUT WRN AND
CENTRAL MN.
FOR PRECIP...THAT CONTINUES TO LOOK UNDERWHELMING. OUR BIGGEST
PROBLEM THROUGH TONIGHT CONTINUES TO BE THE FACT THAT THE ATMO CAN
NOT TAKE ON MUCH MORE MOISTURE BELOW 900 MB...BUT ABOVE THAT...ITS
BONE DRY. CONTINUED TO RUN WITH HIGHEST POPS SUNDAY OUT IN ERN AREAS
AS THEY WILL BE CLOSER TO THE H85 MOISTURE TRANSPORT...BUT LIKING
THE IDEA THE GFS/SREF/NMM/ARW SHOW OF A NARROW BAND OF RAIN CENTERED
ON FGEN IN THE H7-H6 LAYER COMING OUT OF SODAK TONIGHT AND WORKING
ACROSS SRN MN THROUGH SUNDAY MORNING. THE 22.18 HOPWRF MEMBERS ALSO
SHOW THIS BAND OF PRECIP BY 9Z /THE END OF THOSE RUNS/ MOVING INTO
THE WRN PORTION OF THE FSD FORECAST AREA...SIMILAR TO WHAT THE
MODELS MENTIONED ABOVE SHOW. DID BOOST POPS IN SW MN INTO THE HIGH
CHANCE CATEGORY SUNDAY MORNING FOR NOW. THIS MAY VERY WILL END UP
BEING THE BEST CHANCE AT SEEING MEASURABLE PRECIP WITH THIS SYSTEM
FOR MUCH OF OUR MN FORECAST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 238 PM CST SAT NOV 22 2014
SUNDAY NIGHT THROUGH MONDAY WILL BRING A PERIOD OF STRONG WINDS
AND LIGHT PRECIPITATION TO THE FORECAST AREA...IN THE WAKE OF A
DEEPENING MID LATITUDE CYCLONE. THE STRONGEST WINDS ARE EXPECTED
ACROSS THE WESTERN FORECAST AREA AND THE HIGHEST POTENTIAL FOR
ACCUMULATING SNOW REMAINS ACROSS FAR EASTERN MN...BUT ESPECIALLY
IN WEST CENTRAL WI.
BY 00Z MONDAY...RAPID CYCLOGENESIS WILL BE ONGOING IN THE MID
MISSISSIPPI RIVER VALLEY IN RESPONSE TO A DEEP TROUGH DIGGING IN
ACROSS THE CENTRAL CONUS AND A LARGE AREA OF 120-150M 500MB 12-HR
HEIGHTS FALLS MOVING ACROSS THE AREA. THE AMOUNT OF DEEPENING IS
STILL QUITE VARIABLE DEPENDING ON WHICH 12Z SOLUTION ONE CHOOSES TO
FOLLOW. THE 22.12Z GFS IS BY FAR AND AWAY THE MOST AGGRESSIVE IN
STRENGTHENING THE LOW OVER THE SOUTHERN HALF OF LAKE MICHIGAN BY
06Z MONDAY TO 975MB...969MB OVER NORTHERN MICHIGAN BY 12Z...AND
966MB AS IT MOVES NORTH OF THE GREAT LAKES BY 18Z. THE NAM AND
ECMWF SEEM MORE REASONABLE WITH A BIT MORE MODEST DEEPENING.
TYPICALLY...THE KIND OF DEEPENING THE GFS IS SHOWING ONLY OCCURS
WITH VERY STRONG BAROCLINICITY AND/OR A NEGATIVELY TILTED UPPER
TROUGH. WE REALLY DON`T HAVE EITHER. THERE IS STRONG COLD
ADVECTION AND A DECENT TEMPERATURE GRADIENT ACROSS THE MID/UPPER
MISSISSIPPI VALLEY...BUT THEY SEEM MORE IN LINE WITH THE NAM/ECMWF
THAT ARE BIT MORE PROGRESSIVE WITH THE LOW AND NOT AS WOUND UP.
THEREFORE...WE DID NOT JUMP ON THE GFS SNOWFALL FORECAST THAT
WOULD GIVE 6-8" TO PORTIONS OF WEST CENTRAL WI. WE THINK THE
HEAVIEST PRECIP SHOULD BE EAST OF THE FORECAST AREA AND THE
DYNAMIC COOLING ON THE BACK SIDE OF THE LOW WILL BE WEAKER THAN
THE GFS INDICATES. IT IS NOTABLE THAT THE 22.15Z SREF AND GEM ALSO
SHOW THE POTENTIAL FOR SEVERAL INCHES OF SNOW NEAR OR JUST EAST OF
THE FORECAST AREA. THIS IS SOMETHING TO FOLLOW OVER THE NEXT 12-18
HOURS...BUT WE SIMPLY DIDN`T HAVE ENOUGH CONFIDENCE TO ISSUE A
WINTER STORM WATCH AT THIS POINT. FURTHERMORE...EVEN WITH THE
EXPECTED STRONG WINDS...THE WARM TODAY HAS LIKELY LIMITED THE
AMOUNT OF SNOW AVAILABLE FOR BLOWING AND DRIFTING. THERE WERE A
LOT OF HIGHS IN THE UPPER 30S AND LOWER 40S IN WESTERN MN TODAY.
THE NEXT SYSTEM TO WATCH ARRIVES ON WEDNESDAY AND THERE IS AGAIN
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF. THE ECMWF HAS A
POTENT CLIPPER SYSTEM WITH 1-4" OF SNOW...IMPRESSIVE COLD
ADVECTION AND A TIGHT PRESSURE GRADIENT ON THE BACK SIDE OF THE
SYSTEM. THE 22.12Z ECMWF HAS SUSTAINED 25-30KTS NEAR THE ND/SD/MN
BORDER EARLY WEDNESDAY MORNING - QUITE IMPRESSIVE GIVEN ITS
COARSER RESOLUTION. THE GFS HAS A WEAK SURFACE TROUGH AND MUCH
LESS LIFT. THIS MID WEEK SYSTEM PRETTY MUCH LOCKS IN OUR CHANCE
FOR A WELL BELOW NORMAL THANKSGIVING. IT LOOKS VERY COLD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1202 AM CST SUN NOV 23 2014
IMPRESSIVE WARM FRONT HAS MARCHED WELL INTO SOUTHERN MINNESOTA
LATE THIS EVENING WITH CONDITIONS IMPROVING TO THE SOUTH OF
IT...IN SOME CASES TO MVFR OR VFR. THINK ALL THE TAF SITES WILL
IMPROVE SOME THROUGH THE NIGHT IF THE WARM FRONT CONTINUES TO PUSH
NORTH...BUT CAUTION IS ADVISED AS CONDITIONS ARE DETEIORATING
SLOWLY AGAIN ACROSS NORTHERN IOWA. THIS MOISTURE COULD KEEP CIGS
IN LONGER ACROSS ERN MN AND WRN WI. RWF AND AXN APPEAR TO BE IN
THE BEST LOCATIONS FOR GREATEST IMPROVMENTS WITH UPSTREAM OBS VFR.
RAIN WILL PUSH INTO WRN WI SYUNDAY AFTERNOON...WITH SNOW ON THE
WESTERN PERIPHERY...POSSIBLY AS FAR WEST AS MSP.
KMSP...CONDITIONS HAVE IMPROVED QUITE A BIT IN THE LAST COUPLE
HOURS...BUT THAT TREND MAY HAVE STALLED FOR THE REST OF THE NIGHT.
COULD SEE VIS AND CIGS FLUCTUATE UP AND DOWN FOR THE NEXT SEVERAL
HOURS AS SURROUNDING OBS INDICATE. CONDS SHOULD LARGELY BE
MVFR...HOWEVER.
/OUTLOOK FOR KMSP/
MON...MVFR/IFR CIGS CHC -SN. WINDS NW 20G30 KT.
TUE...VFR. WINDS W 5-10 KT.
WED...MVFR/IFR CHC -SN. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR MNZ041>045-
047>053-057>063-066-068>070-078.
WI...DENSE FOG ADVISORY UNTIL 8 AM CST THIS MORNING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1207 AM CST Sun Nov 23 2014
.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014
Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014
Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains. Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area. This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z. While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight. By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough. With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.
Britt
.LONG TERM: (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014
Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains. The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region. The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday. There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL. Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front. The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains. As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL. Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL. Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area. An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday. The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014
Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.
Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
711 PM EST MON NOV 24 2014
.SYNOPSIS...
AN ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE NORTH
COUNTRY THROUGH EARLY THANKSGIVING DAY. A STRONG LOW PRESSURE
SYSTEM PASSING TO OUR NORTH AND WEST ACROSS ONTARIO AND
SOUTHWESTERN QUEBEC WILL CONTINUE TO BRING BREEZY TO WINDY
CONDITIONS...AND VERY MILD CONDITIONS THROUGH TONIGHT. THE
STRONGEST WINDS ARE EXPECTED ACROSS THE ST. LAWRENCE VALLEY AND
NORTHERN ADIRONDACKS. RECORD WARMTH TODAY WILL BE REPLACED BY MORE
SEASONABLE TEMPERATURES ON TUESDAY...AS A TRAILING COLD FRONT
SWEEPS EASTWARD ACROSS NORTHERN NEW YORK AND VERMONT. AFTER A
BRIEF PERIOD OF HIGH PRESSURE LATE TUESDAY AND TUESDAY NIGHT...A
DEVELOPING COASTAL STORM IS EXPECTED TO BRING ACCUMULATING SNOW
ACROSS EASTERN AND SOUTH-CENTRAL VERMONT WEDNESDAY AFTERNOON AND
EVENING...CONTINUING THROUGH WEDNESDAY NIGHT. LIGHTER SNOWS ARE
POSSIBLE ACROSS THE CHAMPLAIN VALLEY AND POINTS
WESTWARD...DEPENDING ON THE EXACT TRACK OF THIS SYSTEM. SLOW
TRAVEL DUE TO SNOWFALL AND SLICK ROADWAYS IS EXPECTED WEDNESDAY
AFTERNOON THROUGH EARLY THANKSGIVING MORNING...ESPECIALLY ACROSS
EASTERN AND SOUTH-CENTRAL SECTIONS OF VERMONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 631 PM EST MONDAY... THE WIND ADVISORY IS STILL IN EFFECT
ACROSS THE ST. LAWRENCE VALLEY AND NORTHERN ADIRONDACKS THROUGH
15Z TUESDAY. THE WINDS ACROSS THE ST LAWRENCE VALLEY ARE STILL
GUSTING TO 35-45 AND WITH THE LOW LEVEL JET AT 850 STILL BLOWING
SOUTH WEST AT 60-70 KTS EXPECT SOME OF THE GUSTS TO BE ABLE TO
CONTINUE MIXING DOWN WITH SOME DOWNSLOPE POTENTIAL OVER THE
ADIRONDACKS. THE RAP SHOWS THE PRESSURE GRADIENT WILL TIGHTEN AS
THE COLD FRONT GETS CLOSER TO THE AREA OVERNIGHT SO GUSTS 45-50
KNOTS WILL BE EXPECTED. CONCERNING THE ESTF UPDATE THE MAIN
CHANGES WERE TO CONTINUE TO INCREASE THE TEMPERATURES IN THE VERY
NEAR TERM AS GUIDANCE DIDN`T CAPTURE HOW MIXED TODAY WOULD BECOME
AND WAS COOLING THE AREA ABOUT 3-5 DEGREES TO MUCH.
PREVIOUSLY AS OF 311 PM EST MONDAY...HAVE CONTINUED THE WIND
ADVISORY ACROSS THE ST. LAWRENCE VALLEY AND NORTHERN ADIRONDACKS
THROUGH 15Z TUESDAY. GETTING SOME AFTERNOON GUSTS 35-45 MPH WITH
BROAD REGION OF STRONG WIND FIELDS AND WITH WELL-MIXED PBL
CONDITIONS IN PLACE. STRONG PRESSURE GRADIENT IN PLACE SOUTHEAST
OF DEEP LOW ACROSS NRN ONTARIO. THE STRONG LOW-LEVEL WIND FIELDS
HAVE PROMOTED GOOD MIXING AND THE DEEP MIXING HAS ALLOWED SKIES TO
BECOME PARTLY TO MOSTLY SUNNY. THE RESULT HAS ALSO BEEN NEAR
RECORD TO RECORD WARMTH THIS AFTERNOON...WITH VALLEY HIGHS IN THE
MID TO UPPER 60S...AND 70F AT KMSS. A RECORD REPORT WILL BE SENT
LATER THIS AFTERNOON AS HIGHS ARE REACHED.
CONCERN FOR LATE THIS EVENING AND OVERNIGHT IS COLD FRONT AND
EMBEDDED SHORTWAVE TROUGH IN STRONG SWLY FLOW...EVIDENT AT 18Z IN
WATER VAPOR IMAGERY ACROSS SERN MICHIGAN AND NWRN OHIO. THIS
FEATURE WILL TRACK NEWD...AND COMBINATION OF STEEP LAPSE RATES
BEHIND THE FRONT AND STRONG MID-LEVEL WINDS WILL RESULT IN A
PERIOD OF 45-55 MPH WIND GUSTS ACROSS THE ST. LAWRENCE VALLEY
03-09Z TONIGHT...AND GENERALLY 40-50 MPH ACROSS THE ADIRONDACKS.
WINDS OF 45-55 MPH ARE OCCURRING THIS AFTERNOON IN SERN MICHIGAN
AND WESTERN OHIO.
FOR OUR WIND ADVISORY AREA...IMPACTS LIKELY TO INCLUDE SOME
ISOLATED POWER OUTAGES AND DIFFICULT DRIVING FOR THOSE WITH HIGH
PROFILE VEHICLES. BREEZY CONDITIONS ACROSS VT AS WELL...BUT
REMAINING BELOW 40 MPH.
GENERALLY DRY TONIGHT...BUT A FEW LAKE EFFECT RAIN SHOWERS ARE
POSSIBLE ESPECIALLY BEHIND THE FRONT ACROSS SRN ST. LAWRENCE
COUNTY (AFTER MIDNIGHT). TEMPERATURE PROFILES GRADUALLY COOL...AND
MAY YIELD A FEW WET SNOW FLAKES ACROSS THE ADIRONDACKS TOWARD
DAYBREAK TUESDAY. LOW TEMPERATURES TONIGHT GENERALLY 41-46F
AREAWIDE WITH BREEZY TO WINDY CONDITIONS...AND DROPPING INTO THE
MID 30S FOR THE NRN ADIRONDACKS TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 311 PM EST MONDAY...HIGH PRESSURE BRIEFLY IN CONTROL
TUESDAY AND TUESDAY NIGHT BRINGING GENERALLY DRY WEATHER
CONDITIONS. WILL SEE LOW-LEVEL COLD ADVECTION THROUGH THE
DAY...WHICH WILL OFFSET DIURNAL TRENDS TO A LARGE DEGREE.
TEMPERATURES WILL RISE A FEW DEGREES INTO THE UPR 40S...AND WINDS
WILL BE WESTERLY AT 10-20 MPH. KEPT LOWS TUESDAY NIGHT NEAR MOS
CONSENSUS...MAINLY IN THE UPPER 20S TO LOWER 30S.
A NOR`EASTER WILL BRING VARYING AMOUNTS OF SNOW TO THE NORTH
COUNTRY BEGINNING WEDNESDAY AFTERNOON...BUT THE QUESTION IS HOW
FAR NORTH AND WEST ANY SIGNIFICANT ACCUMULATIONS WILL OCCUR INTO
VERMONT AND NORTHERN NY. THE TRACK OF THE LOW PRESSURE SYSTEM IS
PARAMOUNT...OF COURSE...AND THERE HAS BEEN A SLIGHT SEWD SHIFT IN
THE 12Z GFS/NAM GUIDANCE...WITH THE 12Z GFS JUST SOUTHEAST OF THE
40N 70W BENCHMARK. THIS PLACES MOST OF OUR FORECAST AREA ON THE
NORTHWEST FRINGE. THE 12Z NAM IS EVEN FURTHER SOUTHEAST...AND
OFFERS EXACTLY ZERO PRECIPITATION AT MONTPELIER AND POINTS NORTH
AND WEST. THE 12Z GFS GIVES ABOUT 0.20" OF LIQUID EQUIVALENT AT
MONTPELIER...AND LOWER AMOUNTS NORTH AND WEST. MEANWHILE...THE 12Z
ECMWF IS WELL INSIDE THE BENCHMARK AND WOULD OFFER THE SNOWIEST
SOLUTION FOR THE NORTH COUNTRY. IT/S A BIT UNUSUAL TO SEE THIS
MUCH SPREAD IN THE OPERATIONAL MODEL RUNS AT 48-60 HOURS OUT...BUT
THAT IS THE SITUATION. WE/LL BASICALLY TAKEN A BLEND OF THE
GFS/ECMWF AT THIS POINT IN TIME. SNOW WILL BE WET IN CHARACTER
WITH TEMPERATURES NEAR TO SLIGHTLY ABOVE FREEZING. LOOKING AT SNOW
RATIOS AROUND 13:1. SO...IT APPEARS GREATEST POTENTIAL WINTER
TRAVEL IMPACTS WILL BE ACROSS CENTRAL/ERN VT COUNTIES...WHERE SNOW
COVERED ROADS AND LOW VISIBILITY WILL CAUSE SLOW HOLIDAY TRAVEL
CONDITIONS WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. WILL ISSUE
A WINTER STORM WATCH FOR RUTLAND/WINDSOR/ORANGE AT THIS
TIME...WHERE POTENTIAL FOR 6"+ APPEARS A 50/50 PROPOSITION.
FURTHER NORTH AND WEST...LIGHTER SNOW ACCUMULATIONS POSSIBLE...AND
APPEARS MORE IN LINE WITH A POSSIBLE ADVISORY. WILL BE MONITORING
MODEL TRENDS, OF COURSE, FOR BETTER CONSENSUS AS THE EVENT
APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 350 PM EST MONDAY...PRETTY QUIET WEATHER FOR THE EXTENDED
IN COMPARISON TO THE SHORT TERM. BY THURSDAY MORNING LOW WILL BE
PULLING FURTHER AWAY FROM THE AREA. SOME LINGERING UPSLOPE
NORTHWEST FLOW SNOW SHOWERS ARE EXPECTED...THOUGH NOT SIGNIFICANT
ACCUMULATIONS. A SHORTWAVE MOVING THROUGH THE AREA FRIDAY WILL
BRING ANOTHER CHANCE FOR SNOW SHOWERS. A WARM FRONT CROSSES THE
AREA SATURDAY NIGHT WITH A LOW PRESSURE SYSTEM LIFTING NORTH INTO
CANADA...THE COLD FRONT CROSSES THE AREA SUNDAY EVENING. THERE
WILL BE A CHANCE FOR SNOW SHOWERS WITH EACH OF THE FRONTAL
PASSAGES. SURFACE HIGH WILL RIDGE INTO THE AREA FOR THE BEGINNING
OF THE WORK WEEK. THE ENTIRE LONG TERM PORTION OF THE FORECAST
WILL FEATURE BELOW NORMAL TEMPERATURES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THROUGH 00Z WEDNESDAY...MAINLY VFR THRU THE PERIOD. THE MAIN
IMPACT IS STRONG SSW WINDS BECOMING SW DURING THIS EVENING WITH
APPROACH OF COLD FRONT THAT WILL HAVE A BRIEF PERIOD OF SHRA THRU
03Z AND REMAINING BRISK/STRONG OVERNIGHT THEN GRADUAL DIMINISH ON
TUESDAY.
GREATEST WINDS IN ST LAWRENCE VALLEY REGION WITH SW WINDS POSSIBLY
GUSTING TO 50 MPH.
OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY...
00Z WEDNESDAY - 18Z WEDNESDAY...GENERALLY VFR.
18Z WEDNESDAY - 00Z FRIDAY...LOW PRESSURE MOVES NE JUST OFF THE
NEW ENGLAND COAST WITH IFR IN SNOW/SNOW SHOWERS.
00Z FRIDAY - 00Z SUN...MAINLY MVFR WITH LCL IFR IN SNOW SHOWERS.
&&
.MARINE...
A LAKE WIND ADVISORY WILL CONTINUE TO BE IN EFFECT THIS EVENING AS
WINDS WILL BE INCREASING TO 20 TO 30 KNOTS WITH WAVES 2 TO 4 FEET
ON AVERAGE. A COLD FRONT WILL BRING A GRADUAL SHIFT TO SOUTHWEST
THIS EVENING WHEN THE STRONGEST WINDS ARE EXPECTED. SOUTHWEST
WINDS WILL GRADUALLY SUBSIDE DURING TUESDAY AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR VTZ010>012-019.
NY...WIND ADVISORY UNTIL 10 AM EST TUESDAY FOR NYZ026-027-029>031-
087.
&&
$$
SYNOPSIS...BANACOS/DEAL
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...SLW
MARINE...DEAL
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
651 PM EST MON NOV 24 2014
.SYNOPSIS...
AN ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE NORTH
COUNTRY THROUGH EARLY THANKSGIVING DAY. A STRONG LOW PRESSURE
SYSTEM PASSING TO OUR NORTH AND WEST ACROSS ONTARIO AND
SOUTHWESTERN QUEBEC WILL CONTINUE TO BRING BREEZY TO WINDY
CONDITIONS...AND VERY MILD CONDITIONS THROUGH TONIGHT. THE
STRONGEST WINDS ARE EXPECTED ACROSS THE ST. LAWRENCE VALLEY AND
NORTHERN ADIRONDACKS. RECORD WARMTH TODAY WILL BE REPLACED BY MORE
SEASONABLE TEMPERATURES ON TUESDAY...AS A TRAILING COLD FRONT
SWEEPS EASTWARD ACROSS NORTHERN NEW YORK AND VERMONT. AFTER A
BRIEF PERIOD OF HIGH PRESSURE LATE TUESDAY AND TUESDAY NIGHT...A
DEVELOPING COASTAL STORM IS EXPECTED TO BRING ACCUMULATING SNOW
ACROSS EASTERN AND SOUTH-CENTRAL VERMONT WEDNESDAY AFTERNOON AND
EVENING...CONTINUING THROUGH WEDNESDAY NIGHT. LIGHTER SNOWS ARE
POSSIBLE ACROSS THE CHAMPLAIN VALLEY AND POINTS
WESTWARD...DEPENDING ON THE EXACT TRACK OF THIS SYSTEM. SLOW
TRAVEL DUE TO SNOWFALL AND SLICK ROADWAYS IS EXPECTED WEDNESDAY
AFTERNOON THROUGH EARLY THANKSGIVING MORNING...ESPECIALLY ACROSS
EASTERN AND SOUTH-CENTRAL SECTIONS OF VERMONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 631 PM EST MONDAY... THE WIND ADVISORY IS STILL IN EFFECT
ACROSS THE ST. LAWRENCE VALLEY AND NORTHERN ADIRONDACKS THROUGH
15Z TUESDAY. THE WINDS ACROSS THE ST LAWRENCE VALLEY ARE STILL
GUSTING TO 35-45 AND WITH THE LOW LEVEL JET AT 850 STILL BLOWING
SOUTH WEST AT 60-70 KTS EXPECT SOME OF THE GUSTS TO BE ABLE TO
CONTINUE MIXING DOWN WITH SOME DOWNSLOPE POTENTIAL OVER THE
ADIRONDACKS. THE RAP SHOWS THE PRESSURE GRADIENT WILL TIGHTEN AS
THE COLD FRONT GETS CLOSER TO THE AREA OVERNIGHT SO GUSTS 45-50
KNOTS WILL BE EXPECTED. CONCERNING THE ESTF UPDATE THE MAIN
CHANGES WERE TO CONTINUE TO INCREASE THE TEMPERATURES IN THE VERY
NEAR TERM AS GUIDANCE DIDN`T CAPTURE HOW MIXED TODAY WOULD BECOME
AND WAS COOLING THE AREA ABOUT 3-5 DEGREES TO MUCH.
PREVIOUSLY AS OF 311 PM EST MONDAY...HAVE CONTINUED THE WIND
ADVISORY ACROSS THE ST. LAWRENCE VALLEY AND NORTHERN ADIRONDACKS
THROUGH 15Z TUESDAY. GETTING SOME AFTERNOON GUSTS 35-45 MPH WITH
BROAD REGION OF STRONG WIND FIELDS AND WITH WELL-MIXED PBL
CONDITIONS IN PLACE. STRONG PRESSURE GRADIENT IN PLACE SOUTHEAST
OF DEEP LOW ACROSS NRN ONTARIO. THE STRONG LOW-LEVEL WIND FIELDS
HAVE PROMOTED GOOD MIXING AND THE DEEP MIXING HAS ALLOWED SKIES TO
BECOME PARTLY TO MOSTLY SUNNY. THE RESULT HAS ALSO BEEN NEAR
RECORD TO RECORD WARMTH THIS AFTERNOON...WITH VALLEY HIGHS IN THE
MID TO UPPER 60S...AND 70F AT KMSS. A RECORD REPORT WILL BE SENT
LATER THIS AFTERNOON AS HIGHS ARE REACHED.
CONCERN FOR LATE THIS EVENING AND OVERNIGHT IS COLD FRONT AND
EMBEDDED SHORTWAVE TROUGH IN STRONG SWLY FLOW...EVIDENT AT 18Z IN
WATER VAPOR IMAGERY ACROSS SERN MICHIGAN AND NWRN OHIO. THIS
FEATURE WILL TRACK NEWD...AND COMBINATION OF STEEP LAPSE RATES
BEHIND THE FRONT AND STRONG MID-LEVEL WINDS WILL RESULT IN A
PERIOD OF 45-55 MPH WIND GUSTS ACROSS THE ST. LAWRENCE VALLEY
03-09Z TONIGHT...AND GENERALLY 40-50 MPH ACROSS THE ADIRONDACKS.
WINDS OF 45-55 MPH ARE OCCURRING THIS AFTERNOON IN SERN MICHIGAN
AND WESTERN OHIO.
FOR OUR WIND ADVISORY AREA...IMPACTS LIKELY TO INCLUDE SOME
ISOLATED POWER OUTAGES AND DIFFICULT DRIVING FOR THOSE WITH HIGH
PROFILE VEHICLES. BREEZY CONDITIONS ACROSS VT AS WELL...BUT
REMAINING BELOW 40 MPH.
GENERALLY DRY TONIGHT...BUT A FEW LAKE EFFECT RAIN SHOWERS ARE
POSSIBLE ESPECIALLY BEHIND THE FRONT ACROSS SRN ST. LAWRENCE
COUNTY (AFTER MIDNIGHT). TEMPERATURE PROFILES GRADUALLY COOL...AND
MAY YIELD A FEW WET SNOW FLAKES ACROSS THE ADIRONDACKS TOWARD
DAYBREAK TUESDAY. LOW TEMPERATURES TONIGHT GENERALLY 41-46F
AREAWIDE WITH BREEZY TO WINDY CONDITIONS...AND DROPPING INTO THE
MID 30S FOR THE NRN ADIRONDACKS TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 311 PM EST MONDAY...HIGH PRESSURE BRIEFLY IN CONTROL
TUESDAY AND TUESDAY NIGHT BRINGING GENERALLY DRY WEATHER
CONDITIONS. WILL SEE LOW-LEVEL COLD ADVECTION THROUGH THE
DAY...WHICH WILL OFFSET DIURNAL TRENDS TO A LARGE DEGREE.
TEMPERATURES WILL RISE A FEW DEGREES INTO THE UPR 40S...AND WINDS
WILL BE WESTERLY AT 10-20 MPH. KEPT LOWS TUESDAY NIGHT NEAR MOS
CONSENSUS...MAINLY IN THE UPPER 20S TO LOWER 30S.
A NOR`EASTER WILL BRING VARYING AMOUNTS OF SNOW TO THE NORTH
COUNTRY BEGINNING WEDNESDAY AFTERNOON...BUT THE QUESTION IS HOW
FAR NORTH AND WEST ANY SIGNIFICANT ACCUMULATIONS WILL OCCUR INTO
VERMONT AND NORTHERN NY. THE TRACK OF THE LOW PRESSURE SYSTEM IS
PARAMOUNT...OF COURSE...AND THERE HAS BEEN A SLIGHT SEWD SHIFT IN
THE 12Z GFS/NAM GUIDANCE...WITH THE 12Z GFS JUST SOUTHEAST OF THE
40N 70W BENCHMARK. THIS PLACES MOST OF OUR FORECAST AREA ON THE
NORTHWEST FRINGE. THE 12Z NAM IS EVEN FURTHER SOUTHEAST...AND
OFFERS EXACTLY ZERO PRECIPITATION AT MONTPELIER AND POINTS NORTH
AND WEST. THE 12Z GFS GIVES ABOUT 0.20" OF LIQUID EQUIVALENT AT
MONTPELIER...AND LOWER AMOUNTS NORTH AND WEST. MEANWHILE...THE 12Z
ECMWF IS WELL INSIDE THE BENCHMARK AND WOULD OFFER THE SNOWIEST
SOLUTION FOR THE NORTH COUNTRY. IT/S A BIT UNUSUAL TO SEE THIS
MUCH SPREAD IN THE OPERATIONAL MODEL RUNS AT 48-60 HOURS OUT...BUT
THAT IS THE SITUATION. WE/LL BASICALLY TAKEN A BLEND OF THE
GFS/ECMWF AT THIS POINT IN TIME. SNOW WILL BE WET IN CHARACTER
WITH TEMPERATURES NEAR TO SLIGHTLY ABOVE FREEZING. LOOKING AT SNOW
RATIOS AROUND 13:1. SO...IT APPEARS GREATEST POTENTIAL WINTER
TRAVEL IMPACTS WILL BE ACROSS CENTRAL/ERN VT COUNTIES...WHERE SNOW
COVERED ROADS AND LOW VISIBILITY WILL CAUSE SLOW HOLIDAY TRAVEL
CONDITIONS WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. WILL ISSUE
A WINTER STORM WATCH FOR RUTLAND/WINDSOR/ORANGE AT THIS
TIME...WHERE POTENTIAL FOR 6"+ APPEARS A 50/50 PROPOSITION.
FURTHER NORTH AND WEST...LIGHTER SNOW ACCUMULATIONS POSSIBLE...AND
APPEARS MORE IN LINE WITH A POSSIBLE ADVISORY. WILL BE MONITORING
MODEL TRENDS, OF COURSE, FOR BETTER CONSENSUS AS THE EVENT
APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 350 PM EST MONDAY...PRETTY QUIET WEATHER FOR THE EXTENDED
IN COMPARISON TO THE SHORT TERM. BY THURSDAY MORNING LOW WILL BE
PULLING FURTHER AWAY FROM THE AREA. SOME LINGERING UPSLOPE
NORTHWEST FLOW SNOW SHOWERS ARE EXPECTED...THOUGH NOT SIGNIFICANT
ACCUMULATIONS. A SHORTWAVE MOVING THROUGH THE AREA FRIDAY WILL
BRING ANOTHER CHANCE FOR SNOW SHOWERS. A WARM FRONT CROSSES THE
AREA SATURDAY NIGHT WITH A LOW PRESSURE SYSTEM LIFTING NORTH INTO
CANADA...THE COLD FRONT CROSSES THE AREA SUNDAY EVENING. THERE
WILL BE A CHANCE FOR SNOW SHOWERS WITH EACH OF THE FRONTAL
PASSAGES. SURFACE HIGH WILL RIDGE INTO THE AREA FOR THE BEGINNING
OF THE WORK WEEK. THE ENTIRE LONG TERM PORTION OF THE FORECAST
WILL FEATURE BELOW NORMAL TEMPERATURES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...THREAT OF LLWS FOR NEXT COUPLE HOURS WITH
WINDS 2000-4000FT OF 45-70KT. FINALLY VFR EVERYWHERE AT 18Z. WINDS
ARE SOUTH AND SOUTHEAST 10 TO 20 KNOTS GUSTING LOCALLY TO 30 KTS.
WINDS WILL GRADUALLY BACK AROUND TO THE SOUTH AND SOUTHWEST DURING
THE AFTERNOON AND EVENING AND SOME GUSTS OF 30 TO 40 KTS POSSIBLE
AS A COLD FRONT MAKES IT WAY INTO NORTHERN NY. COULD BE A
SCATTERED SHOWER BUT LEFT OUT FOR NOW.
OUTLOOK 18Z TUESDAY THROUGH SATURDAY...
18Z TUESDAY - 00Z THURSDAY...GENERALLY VFR WITH MVFR/IFR CIGS/VIS
IN LAKE EFFECT SNOW POSSIBLE AT SLK.
00Z THURSDAY - 00Z FRIDAY...LOW PRESSURE MOVES NE JUST OFF THE
NEW ENGLAND COAST WITH IFR IN SNOW/SNOW SHOWERS.
00Z FRIDAY - 00Z SUN...MAINLY MVFR WITH LCL IFR IN SNOW SHOWERS.
&&
.MARINE...
A LAKE WIND ADVISORY WILL CONTINUE TO BE IN EFFECT THIS EVENING AS
WINDS WILL BE INCREASING TO 20 TO 30 KNOTS WITH WAVES 2 TO 4 FEET
ON AVERAGE. A COLD FRONT WILL BRING A GRADUAL SHIFT TO SOUTHWEST
THIS EVENING WHEN THE STRONGEST WINDS ARE EXPECTED. SOUTHWEST
WINDS WILL GRADUALLY SUBSIDE DURING TUESDAY AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR VTZ010>012-019.
NY...WIND ADVISORY UNTIL 10 AM EST TUESDAY FOR NYZ026-027-029>031-
087.
&&
$$
SYNOPSIS...DEAL/BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...NEILES
AVIATION...NEILES
MARINE...DEAL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1017 PM EST MON NOV 24 2014
.SYNOPSIS...
MILD TEMPERATURES AND UNSETTLED WEATHER IS EXPECTED TONIGHT AHEAD OF
A COLD FRONT THAT WILL MOVE THROUGH THE AREA TUESDAY MORNING. COOL
AND WET CONDITIONS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY AS
DEEPENING LOW PRESSURE MOVES NORTH ALONG THE FRONT STALLED OFFSHORE.
SKIES WILL CLEAR OUT ON THANKSGIVING DAY...WITH TEMPERATURES RUNNING
SEVERAL DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM MONDAY...THE SURFACE COLD FRONT EXTENDS FROM
NORTH-CENTRAL GEORGIA ACROSS THE NC/TN BORDER REGION. EAST OF THIS
FRONT A SOUTHERLY WIND CONTINUES FROM FLORIDA AND THE BAHAMAS INTO
THE EASTERN CAROLINAS. IN THE UPPER LEVELS A STRIPE OF DIFLUENCE
EXISTS EXTENDING FROM THE FLORIDA PANHANDLE INTO EAST-CENTRAL NORTH
CAROLINA...THE RESULT OF ACCELERATING FLOW INTO THE RIGHT-ENTRANCE
REGION OF A 250 MB JET STREAK FROM ARKANSAS INTO NEW YORK STATE.
THIS DIVERGENCE HAS SUPPORTED A NARROW BUT PERSISTENT REGION OF
RAINFALL (AND EARLIER ELEVATED CONVECTION) ACROSS THE SC PEE DEE
REGION INTO LUMBERTON. LATEST HIGH-RES HRRR RUNS SHOW WE SHOULD
ENTER A RELATIVE LULL IN PRECIPITATION COVERAGE OVER THE NEXT 2-4
HOURS...BUT INCREASING SOUTHERLY FLOW AND ISENTROPIC LIFT CENTERED
ON THE 305K ISENTROPIC SURFACE (~750 MB OR 8000 FEET AGL) SHOULD
LEAD TO INCREASING COVERAGE OF RAIN AGAIN LATE TONIGHT INTO THE
DAYLIGHT HOURS TUESDAY.
ALTHOUGH THE 18Z GFS HAD A FAIRLY FAST EASTWARD MOVEMENT OF THE COLD
FRONT OFF THE COAST LATE TONIGHT WITH NW WINDS DEPICTED OVER THE
COASTAL WATERS BY 12Z TUE...THE BULK OF THE OTHER GUIDANCE SHOWS A
MUCH SLOWER EASTWARD MOVEMENT OF THE BOUNDARY WITH SW WINDS
CONTINUING. GIVEN THE CURRENT POSITION OF THE FRONT I AM INCLINED TO
BELIEVE THE SLOWER GUIDANCE...AND HAVE ADJUSTED FORECAST WINDS &
TEMPS ACCORDINGLY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...INCREASED CONFIDENCE IN SUBSTANTIAL RAINFALL
ESPECIALLY ALONG THE COAST THROUGH THE PERIOD. COLD FRONT PUSHES OFF
THE COAST AND DECELERATES EARLY TUESDAY. THE COLD AIR ADVECTION AND
DEEP MOISTURE BOTH LAG BEHIND AND THERE SHOULD BE JUST ENOUGH
STRUNG OUT VORTICITY AND LOW LEVEL CONVERGENCE FOR OCCASIONAL LIGHT
RAIN THROUGH THE DAY. TEMPS WILL BE FAIRLY CLOSE TO CLIMO DESPITE
THE WIDESPREAD CLOUDS AND RAINFALL. SEVERAL INGREDIENTS THEN COME
TOGETHER TUESDAY NIGHT FOR SOME RATHER IMPRESSIVE DYNAMICS AND
POTENTIAL HEAVY RAIN. MID LEVEL IMPULSE CURRENTLY OVER SRN TX SWINGS
THROUGH THE TROUGH AND GIVES IT A WEAK NEGATIVE TILT. SURFACE LOW
DEVELOPS ALONG THE FRONT OFFSHORE. STRONG SSWRLY LOW LEVEL JET
DEVELOPS IN ASSOC WITH THIS WAVE WHILE WEAK ISALLOBARIC COMPONENT
TURNS FLOW INTO THE LOW WEST OF IT...I.E. OVER LANDMASS. THIS
RESULTS IN AN IMPRESSIVE THERMAL GRADIENT...850MB TEMPS NEAR 15C
JUST OFF COAST AND DOWN TO 2 C OVER WRN ZONES BY 12Z WED. THE
RESULTING LOW LEVEL FRONTOGENESIS IS SOME OF THE STRONGEST I`VE SEEN
IN A WHILE...WITH THE GFS FORECASTING VALUES OF 100-200 UNITS. IT IS
ALSO TOUGH TO RULE OUT A NARROW ZONE OF CONDITIONAL SYMMETRIC
INSTABILITY DEVELOPING RIGHT OVER THE IMMEDIATE (MAINLY NC) COAST
AND ADJACENT WATERS. DURING THE OVERNIGHT HOURS THIS LOW LEVEL
FORCING MAY EVEN COUPLE WITH DEEPER ASCENT FROM THE DEVELOPING UPPER
JET CONFIGURATION AS THE RIGHT ENTRANCE OF A 190KT UPPER JET MOVES
INTO PA. IN FACT GFS CROSS SECTIONS FOR A TIME SHOW ASCENT CLEAR
THROUGH THE DEPTH OF THE COLUMN. WITH AT LEAST SOME CONNECTION TO
GOMEX MOISTURE THIS SETUP COULD EASILY YIELD 2-2.5 INCHES OF
RAINFALL ALONG THE IMMEDIATE COAST BEFORE THE RAIN TAPERS OFF MIDDAY
WEDNESDAY OR WEDNESDAY AFTERNOON. THE BULK OF THE RAIN WILL FALL
OVERNIGHT TUESDAY TO PERHAPS AS LATE AS DAYBREAK WED. THEREAFTER
THE DEEP MOISTURE AND UPPER FORCING SHIFT OFFSHORE. LIGHTER RAIN WED
MORNING THEN GIVES WAY TO A DRYING TREND AS COLD AIR ADVECTION
BEGINS CRANKING UP BY 18Z. WEDNESDAY AFTERNOON HIGHS WILL NOT BE
MUCH HIGHER THAN TUESDAY NIGHT LOWS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING OVER THE SOUTHEAST AT THE
START OF THE PERIOD WILL LIFT NORTHEAST FRI WITH PROGRESSIVE FLOW
DEVELOPING FOR THE WEEKEND. MID LEVEL TROUGH HELPS PUSH REMAINS OF
DRY COLD FRONT THROUGH EARLY FRI WITH HIGH PRESSURE BUILDING IN FOR
THE WEEKEND. PROGRESSIVE FLOW QUICKLY PUSHES THE CENTER OF THE HIGH
OFFSHORE WITH RETURN FLOW DEVELOPING AS EARLY AS MIDDAY SAT. DEEP
DRY WESTERLY FLOW WILL HELP KEEP THE REGION DRY THROUGH THE END OF
THE PERIOD. TEMPERATURES BELOW CLIMO FOR THE FIRST HALF OF THE
PERIOD WILL START A STEADY CLIMB BACK TO CLIMO EARLY NEXT WEEK AS
HIGH MOVES FARTHER OFF THE COAST AND RETURN FLOW STRENGTHENS. LATE
IN THE PERIOD A WEAK BACKDOOR COLD FRONT WILL TRY TO MOVE SOUTH
ACROSS THE AREA. LATEST GFS KEEPS THIS FEATURE NORTH WHILE ECMWF
PUSHES IT SOUTH. WILL FAVOR THE ECMWF SOLUTION...WHICH IS FAVORED BY
WPC...FOR NOW BUT CONFIDENCE IS LOW.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...CONDITIONS WILL DETERIORATE TONIGHT AS IFR/LIFR STRATUS
AND VSBYS PLAGUE OUR COASTAL TERMINALS. IFR CONDITIONS HAVE
PREVAILED FOR MUCH OF THE DAY AT THE COASTAL SITES...INCLUDING SOME
PATCHY SEA FOG AT KCRE/KMYR. ALTHOUGH OBS MAY FLUCTUATE BETWEEN
MVFR/IFR THIS EVENING...EXPECT MORE PERSISTENT IFR/LIFR CONDITIONS
AFTER MIDNIGHT AS MOIST SOUTHWEST FLOW AND PATCHY -RA CONTINUE AHEAD
OF A COLD FRONT. MEANWHILE...KFLO/KLBT WILL REMAIN VFR FOR MUCH OF
TONIGHT...EXCEPT FOR TEMPO MVFR/IFR CONDITIONS ASSOCIATED WITH
EMBEDDED SHRA ACTIVITY AHEAD OF THE FRONT. IFR STRATUS COULD EXPAND
INLAND TOWARD DAYBREAK...BUT CONFIDENCE IS LOW/MODERATE THAT CIGS
WILL STAY BELOW 1KFT AT KFLO/KLBT EARLY TUE.
PCPN COVERAGE SHOULD INCREASE INTO TUE MORNING AS THE FRONT MOVES
THROUGH THE CWA. THE BOUNDARY BECOMES POORLY DEFINED AS IT REACHES
OUR AREA...SO A PERIOD OF LIGHT/VRBL WINDS IS POSSIBLE WHILE WINDS
SHIFT FROM SOUTHWEST TO NORTHWEST. DEEP MOISTURE AND UPPER SUPPORT
WILL CONTINUE TO PROMOTE -RA THROUGH MUCH OF THE DAY EVEN BEHIND THE
FRONT. EXPECT IFR CIGS TO PREVAIL ALONG THE COAST AND MVFR INLAND...
WITH VSBY RESTRICTIONS POSSIBLE IN HEAVIER RAINFALL.
EXTENDED OUTLOOK...RAIN WITH MVFR/IFR CIGS WILL PERSIST INTO WED
AFTN...ESPECIALLY ALONG THE COAST. EXPECT GUSTY WINDS LATE TUE/EARLY
WED...IN ADDITION TO HEAVIER PCPN THAT WILL REDUCE VSBYS TO MVFR/IFR
AT TIMES. VFR LATE WED THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM MONDAY...A COLD FRONT IS ANALYZED EXTENDING FROM
NORTH-CENTRAL GEORGIA NORTHWARD ACROSS THE NC-TN BORDER REGION. THE
BOUNDARY WILL MOVE STEADILY EASTWARD TONIGHT BUT SHOULD REMAIN
INLAND FROM THE COAST EVEN AT DAYBREAK TUESDAY. SOUTH-SOUTHWEST
WINDS CONTINUE ACROSS THE AREA BRINGING UNSEASONABLY HUMID AIR
NORTHWARD FROM FLORIDA AND THE BAHAMAS. AS THIS SUBTROPICAL AIR
CROSSES THE CHILLY NEARSHORE OCEAN PATCHY SEA FOG HAS DEVELOPED...
MAINLY ALONG THE SC COAST ALTHOUGH PATCHY SEA FOG IS ALSO POSSIBLE
ALONG THE BRUNSWICK COUNTY COAST AND POINTS NORTH AS WELL.
THE BULK OF THE RAINFALL SHOULD REMAIN INLAND TONIGHT..ALTHOUGH
TOWARD DAYBREAK RAIN CHANCES WILL INCREASE FROM SOUTH TO NORTH
LEADING UP TO A RATHER SUBSTANTIAL TWO-DAY HEAVY RAINFALL EVENT
TUE-WED.
SEAS REMAIN QUITE LARGE ESPECIALLY GIVEN THE WIND SPEEDS WE ARE
OBSERVING. THIS IS MAINLY DUE TO SOUTHERLY SWELL FROM THE RELATIVELY
LONG FETCH OF STRONG WINDS FROM THE BAHAMAS TO THE CAROLINAS OVER
THE PAST THREE DAYS. A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT
FOR THESE SEAS TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...COLD FRONT PUSHES THROUGH EARLY TUESDAY WITH
LITTLE FANFARE OTHER THAN A WIND SHIFT BUT A VERY DYNAMIC SETUP
ALOFT WILL LEAD TO A RAPID DECAY IN CONDITIONS TUESDAY NIGHT. LIGHT
OFFSHORE WINDS MUCH OF THE DAY TUESDAY AS THE FRONT SLOWS. STRONG
SYSTEM SWINGING OUT OF SOUTHERN TEXAS TO THEN CAUSE FAIRLY RAPID
PRESSURE FALLS ALONG THE BOUNDARY TUESDAY NIGHT INTO WEDNESDAY. AS
THIS LOW CRANKS UP AND MOVES BY CONDITIONS SHOULD RAMP UP TO SMALL
CRAFT ADVISORY LEVELS. BY WEDNESDAY MORNING THE STILL DEEPENING LOW
ACCELERATES OFF TO OUR NORTH AND EAST. STRONG OFFSHORE WINDS STILL
LIKELY WORTHY OF AN ADVISORY LIKELY CONTINUE IN THE ENSUING COLD
SURGE AND SEAS WILL SIMILARLY BE HESITANT TO FALL BELOW CRITERIA
BEFORE WEDNESDAY NIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...PINCHED GRADIENT THU INTO FRI WILL MAINTAIN
OFFSHORE FLOW IN THE 15 TO 20 KT RANGE INTO FRI. GRADIENT WEAKENS
MIDDAY FRI FOLLOWING PASSAGE OF REMAINS OF DRY COLD FRONT. NORTH TO
NORTHWEST FLOW ON FRI WILL WEAKEN AS SURFACE HIGH BUILDS INTO THE
REGION...MOVING OVERHEAD LATE IN THE DAY. WINDS WILL BECOME LIGHT
AND VARIABLE LATER FRI AND SAT AS THE SURFACE RIDGE AXIS LINGERS IN
THE REGION. SEAS 2 TO 4 FT THU INTO FRI WILL DROP TO 2 FT OR LESS AS
WINDS BECOME LIGHT AND VARIABLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR
AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION...UPDATED
NWS WILMINGTON NC
447 PM EST SUN NOV 23 2014
.SYNOPSIS...
MILD AND UNSETTLED WEATHER CAN BE EXPECTED OVERNIGHT INTO MONDAY
AS A STORM SYSTEM RISES OUT OF THE GULF OF MEXICO. ISOLATED SEVERE
THUNDERSTORMS REMAIN POSSIBLE OVERNIGHT AND ON MONDAY. A COLD
FRONT WILL CROSS THE COAST AND STALL OFFSHORE TUESDAY. COOL AND
WET CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE
MOVES NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES
WILL BEGIN A CLEARING TREND ON THANKSGIVING...WITH TEMPERATURES
RUNNING SEVERAL DEGREES BELOW NORMAL THURSDAY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 4 PM SUNDAY...WARM ADVECTION ZONE ALOFT HAS LIFTED TO OUR
NORTH EVEN AS SURFACE BOUNDARY LAGS WELL TO OUR SOUTH. AS A RESULT
THE ISENTROPIC UP-GLIDE ACROSS THE REGION APPEARS TO HAVE WEAKENED TO
THE POINT THAT RAINFALL MAY BE QUITE LIGHT FOR THE NEXT SEVERAL
HOURS. LOOKING FOR RADAR TO FILL LATER ON FROM SW TO NE AS ENERGY
FROM THE WEAKENING VORT NOW SEEN OVER MS IMPINGES UPON THE REGION.
IN THE MEANTIME TOUGH TO SAY HOW MUCH RAIN THE AREA SEES AND MODEL
GUIDANCE IS QUITE OVERDONE. THE UPPER WAVE WILL BE WEAKENING AND
THUS ACCELERATING...LOOKS LIKE ANY TIME SOON AFTER 03Z IT MAY START
AFFECTING THE REGION. LOW LEVEL WIND FIELDS CURRENTLY IN THE PROCESS
OF STRENGTHENING DRAMATICALLY ALTHOUGH CHS AND KLTX VWPS SHOW THAT
THE WRF IS TOO FAST AND TOO STRONG. ACCORD TO THE MORE TEMPERED GFS
A SOLID 50KT AT JUST 925MB CAN BE EXPECTED ALONG THE COAST BY 00Z
AND AREA-WIDE BY 06Z. PAIR THIS WITH STEADY OR RISING TEMPERATURES
AND THERE IS STILL A WIDOW OF OPPORTUNITY FOR SHALLOW CONVECTION
TORNADOES INVOF OF THE WARM FRONT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...LOOKING FOR TWO MAIN AREAS OF HEAVIER PRECIP...THE
FIRST BATCH WITH A SLUG OF GULF MOISTURE AND ISENTROPIC LIFT THIS
AFTERNOON...THE SECOND BATCH TONIGHT WITH A VIGOROUS VORT MAX.
TONIGHT WILL BE INTERESTING WITH VERY STRONG HELICITY BUT NO CAPE
TO SPEAK OF. NEVERTHELESS AN ISOLATED SEVERE STORM IS POSSIBLE
MAINLY NEAR THE COAST. VORT WILL ROTATE THROUGH THE REGION BY
06-07Z. MODELS REALLY BRING CEILINGS/VIS DOWN ONCE THE VORT MOVES
THROUGH...WITH PRECIP SLOWLY SHUTTING OFF. THE MODELS REALLY WANT
TO KEEP VISIBILITIES LIFR THROUGH MOST OF THE BACK IN PERIOD...BUT
WITH WINDS OVER 10 KTS...THINK THIS MAY BE OVERDONE. LOOK FOR
GUSTY SOUTHWEST WINDS MONDAY WITH CEILINGS REMAINING IFR THROUGH
MOST IF NOT ALL THE FORECAST PERIOD.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 445 PM SUNDAY...A NON-CONVECTIVE WIND GUST TO 45 KNOTS
WITHIN THE PAST HOUR AT THE FRYING PAN SHOALS BUOY CERTAINLY
GRABBED MY ATTENTION. A GALE WARNING HAS THEREFORE BEEN ISSUED FOR
THE NC WATERS...VALID NOW THROUGH MIDNIGHT. VIRTUALLY ALL SHORT-
RANGE GUIDANCE (LATEST RRR AND RUC PLUS THE 18Z NAM) BRING A SWATH
OF EVEN STRONGER WINDS IN THE 1000-950 MB LAYER ACROSS THE COASTAL
WATERS BETWEEN NOW AND MIDNIGHT. THE ONLY FACTOR DIMINISHING WIND
SPEEDS DOWN HERE AT THE SURFACE IS STRONG BOUNDARY LAYER STABILITY
INDUCED BY COLD OCEAN SURFACE TEMPERATURES AND SUBSEQUENT
INHIBITED VERTICAL MIXING OF STRONGER WINDS FROM ALOFT. WATER
TEMPERATURES ARE IN THE 50S SOUTHWEST OF CAPE FEAR ALONG THE UPPER
SOUTH CAROLINA COAST... AND THIS SHOULD PREVENT WINDS FROM
INCREASING ABOVE 30 KNOTS EVEN AT 20 MILES DISTANCE FROM SHORE.
PREVIOUS DISCUSSION FROM 400 PM FOLLOWS...
DRAMATIC INCREASE IN MARINE WINDS LAST THREE HOURS AS 41013 NOW A
SOLID 29KT WITH OCCASIONAL GUSTS TO GALE FORCE. AND WHILE A SHORT-
FUSED GALE WARNING MAY BE PREFERRED BY THE NEXT SHIFT CURRENTLY
HOPING THAT COOLER SHELF WATERS WILL RETARD MANY GALE FORCE GUSTS
FROM MIXING DOWN TO THE SURFACE DESPITE THE SCREAMING LOW LEVEL
JET ALL NIGHT. ADDITIONAL CONCERN AFTER COLLAB WITH CHS THAT BUOYS
MAY BE EXPERIENCING STRONGER WINDS AND GUSTS THAN NEAR SHORE
WATERS ON ACCOUNT OF THE HEAVIER PRECIP OUT THERE AND THUS DEEPER
MIXING. A STRONG ADVISORY STILL IN EFFECT THROUGH THE PERIOD AND
BEYOND.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST TUESDAY
FOR AMZ250-252.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...MBB/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
652 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND...RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM SUNDAY...S/W UPPER RIDGE ACROSS THE AREA ATTM...WILL
GIVE WAY TO THE APPROACH OF A POTENT SOUTHERN STREAM MID-LEVEL S/W
TROF FROM THE GULF COAST STATES THIS AFTN. MODELS INDICATE A
NEGATIVE TILT TO THIS UPPER S/W TROF AS IT LIFTS FROM THE FL
PANHANDLE NORTHEASTWARD ACROSS THE CAROLINAS THIS EVENING AND
OVERNIGHT.
THE SFC WARM FRONT SOMEWHAT WELL DISPLACED FROM THE SFC LOW THAT
IS MOVING NNE ACROSS THE CENTRAL U.S. TO THE GREAT LAKES BY MONDAY
DAYBREAK...WILL BE THE FOCUS OF THIS FCST. WHATS LEFT OF A WEAK
WEDGE ACROSS THE INLAND CWA THIS MORNING...WILL GIVE WAY TO THE
APPROACHING WARM FRONT THIS AFTN...WHICH LIFTS NORTHWARD ACROSS
THE FA LATER THIS EVENING THROUGH THE EARLY PRE-DAWN MON HOURS.
STRATIFORM RAINS IE. EXCELLENT ISENTROPIC LIFT...AHEAD OF THE
WARM FRONT AS MOISTURE FROM BOTH THE ATLANTIC AND GULF OF MEXICO
SOURCE AREAS ARE UTILIZED. DECENT WIND DIRECTION VEERING PROFILE
FROM THE SFC TO 700 MB THIS AFTERNOON AND EVENING ALONG WITH WIND
SPEEDS RANGING FROM 20-30 KT AT THE SFC...UP TO 60 KT AT 925 MB.
WITH WIND SHEAR LIKE THIS...ANY CONVECTION THAT TAPS INTO THESE
WINDS MAY PRODUCE DAMAGING WIND GUSTS OR EVEN THE POSSIBILITY OF A
TORNADO DUE TO FAVORABLE HELICITIES. WILL CONTINUE TO MENTION THE
SEVERE CONVECTIVE THREAT IN THE HWO. OVERALL...THE AVBL INSTABILITY
IE. CAPE...WILL LIKELY BE THE DETERMINING FACTOR FOR POTENTIAL
CONVECTIVE DEVELOPMENT ACROSS THE FA.
AN ABNORMAL DIURNAL TEMP CURVE WILL BE FORECAST THIS PACKAGE...
WITH TODAYS HIGHS LIKELY OCCURRING LATE THIS AFTERNOON...AND
TONIGHTS LOWS LIKELY THIS EVENING WITH STEADY OR EVEN RISING TEMPS
LATE THIS EVENING AND OVERNIGHT. ROUGHLY THE FORECAST AREA WILL BE
LOOKING AT 1 TO 2 INCH RAINFALL AMOUNTS TODAY THROUGH DAYBREAK
MON.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...A SLOW DETERIORATION OF CONDITIONS IS EXPECTED THROUGH THE
MORNING HOURS AS ISENTROPIC LIFT SLOWLY INCREASES. FIRST BATCH OF
PRECIP IS MOVING THROUGH THE REGION...POORLY DEPICTED BY THE HRRR BY
THE WAY. A SECOND AND MORE WIDESPREAD WAVE WITH MOVE THROUGH LATER
THIS MORNING. MODERATE RAIN WILL BE LIKELY WITH PRECIPITATION
INDUCED CEILINGS LOWERING TO IFR THIS AFTERNOON. ONLY MODERATE
CONFIDENCE WITH THE TIMING OF CEILINGS. MOST OF THE PRECIP TODAY
WILL BE STRATIFORM...HOWEVER COULD NOT RULE OUT A RUMBLE TOWARD
EVENING.
THIS EVENING...AN UPPER VORT MAX WILL SWEEP THROUGH THE REGION.
STRONG HELICITY BUT LITTLE TO NO CAPE WILL HARD TO RECONCILE.
BELIEVE THERE WILL BE A NARROW BAND OF CONVECTION THAT SHOULD PUSH
TO THE COAST BY 05-06Z. BEHIND THE VORT EXPECT THE PRECIP TO SHUT
OFF WITH MAINLY MVFR CEILINGS REMAINING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE LOCAL WATERS WILL BE SUBJECT TO AN
EXTENDED PERIOD OF SCA CONDITIONS COMMENCING LATER THIS MORNING
AND LASTING INTO THE SHORT TERM PERIOD. INCREASING ONSHORE E TO SE
WINDS DURING TODAY...WILL VEER TO THE SOUTH AS THE WARM FRONT
LIFTS NORTHWARD ACROSS THE LOCAL WATERS FROM LATE THIS AFTN
THROUGH MIDNIGHT TONIGHT. THE SFC PG WILL FURTHER TIGHTEN ACROSS
THE LOCAL WATERS AS THE PARENT LOW ACROSS THE CENTRAL U.S. DEEPENS
AS IT LIFTS TO THE GREAT LAKES BY MON DAYBREAK. LOOKING AT SPEEDS
IN THE 15 TO 25 KT RANGE WITH GUSTS TO 30 KT BY THIS AFTERNOON...
FURTHER INCREASING TO 20 TO 30 KT WITH FEW GUSTS TO GALE FORCE. IF
WATER TEMPS WERE SLIGHTLY WARMER IN THE 60S INSTEAD OF THE 50S...A
GALE WARNING WOULD PROBABLY HAVE BEEN ISSUED...ALTHOUGH STILL NOT
OUT OF THE QUESTION GIVEN THE PASSAGE OF A DECENT UPPER S/W TROF
ACROSS THE SE UNITED STATES. SIGNIFICANT SEAS WILL QUICKLY BUILD
AS ONSHORE WINDS MAKE SURE OF THAT. SIG. SEAS WILL PEAK THIS
EVENING AND OVERNIGHT...IN THE 8 TO 12 FOOT RANGE...FOLLOWED BY A
VERY SLOW SUBSIDING TREND THERE-AFTER IN SUBSEQUENT PERIODS. WIND
DRIVEN WAVES WILL DOMINATE SIGNIFICANT SEAS...WITH AVERAGE PERIODS
IN THE 5.0 TO 6.5 SECONDS RANGE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
635 AM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON AND
TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND PUSH
OFFSHORE BY EARLY TUESDAY. LOW PRESSURE WILL DEVELOP ALONG THE FRONT
LATE TUESDAY NIGHT AND MOVE NORTHEAST OFFSHORE OF THE COAST WEDNESDAY.
THE LOW WILL DEPART TO THE NORTHEAST WEDNESDAY NIGHT WITH HIGH PRESSURE
BUILDING OVER THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM SUNDAY...SHIELD OF MOSTLY LIGHT RAIN HAS ARRIVED IN
OUR FAR SOUTHERN CWA. HAVE ADJUSTED POPS TO BEGIN RAINFALL
EARLIER...ALTHOUGH HEAVIER RAIN IS NOT LIKELY TO ARRIVE UNTIL THE
AFTERNOON HOURS. THE WARM FRONT WILL CONTINUE TO PROGRESS NORTH
THROUGH THE DAY. THE 3KM HRRR STILL INDICATES THAT THE STEADIER
AND HEAVIER RAIN WILL ARRIVE AROUND MIDDAY AND CONTINUE INTO
TONIGHT. TEMPERATURES CONTINUE TO SLOWLY RISE...ESPECIALLY NEAR
THE COAST. AS WARM FRONT SURGES NORTH...TEMPERATURES SHOULD
RECOVER TO HIGHS IN THE MID/UPPER 60S AREA-WIDE THIS AFTERNOON.
DEWPOINTS SHOULD ALSO RECOVER TO THE UPPER 50S BY AFTERNOON. POPS
INCREASE TO CATEGORICAL OVER ROUGHLY THE SOUTHWESTERN HALF OF THE
CWA BY EARLY AFTERNOON. RAIN CHANCES REMAIN LOWER OVER THE
NORTHEASTERN HALF AS DEWPOINT RECOVERY WILL TAKE A BIT LONGER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUNDAY...BY THIS EVENING...INSTABILITY INCREASES FROM
THE SOUTH AS STRONG WARM FRONT MOVES NORTH. VERY IMPRESSIVE LOW-
LEVEL SHEAR VALUES INDICATED BY FORECAST SOUNDINGS...WITH SRH
HELICITY VALUES UPWARDS OF 600-700 BY 00Z TONIGHT. THIS COINCIDES
WITH THE ARRIVAL OF THE INSTABILITY AND MOST OF THE CWA REMAINS IN
A SLIGHT RISK OF SEVERE TSTMS. THE PRIMARY THREAT WILL BE STRONG
DAMAGING WINDS AND THE RISK OF ISOLATED TORNADOES GIVEN THIS SHEAR
ENVIRONMENT. THE TORNADO/SEVERE THREAT SHOULD WANE AFTER 06Z AS
THE FLOW BECOMES MORE UNIDIRECTIONAL. IN ADDITION TO THE SEVERE
THREAT...QPF TOTALS OF 1 TO 2 INCHES WILL BE POSSIBLE AS DEEP
MOISTURE IS ADVECTED FROM THE ATLANTIC WITH VERY IMPRESSIVE LOW-
LEVEL MOISTURE TRANSPORT. GIVEN THE WARM SW WINDS...EXPECT
TEMPERATURES TO FALL VERY LITTLE TONIGHT...LIKELY REMAINING IN THE
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUN...LARGE UPPER TROUGH OVER THE CENTRAL PART OF THE
COUNTRY WITH LOTS OF ENERGY ROTATING AROUND IT WILL MAKE FOR AN
ACTIVE PERIOD INTO THANKSGIVING WITH HIGH PRESSURE TAKING HOLD
THROUGH THE REMAINDER OF THE PERIOD. THIS ACTIVE WEATHER COULD
HAMPER HOLIDAY TRAVEL PLANS.
TROUGH WILL CONTINUE TO DIG INTO THE SOUTHERN TIER STATES THROUGH
MID WEEK THEN LIFT THROUGH THE SOUTHEAST AND MID ATLANTIC THROUGH
THE END OF THE WEEK. MOST OF THE PRECIPITATION CHANCES WILL END BY
MONDAY MORNING ASSOCIATED WITH A VIGOROUS SHRTWV MOVING THROUGH THE
AREA. KEPT SMALL CHANCE POPS IN ON MONDAY UNTIL THE FIRST COLD FRONT
MOVES THROUGH THE AREA TUESDAY NIGHT. WON`T GET MUCH OF A BREAK AS
STRONG UPPER LEVEL ENERGY WILL SWING THROUGH THE BASE OF THE UPPER
TROUGH HELPING TO FORM A WAVE ON THE SURFACE FRONT IN THE GULF
TUESDAY THAT WILL MOVE UP THE EAST COAST DURING THE NIGHT TUESDAY
NIGHT. CROSS SECTIONS SHOWING DEEP LAYER MOISTURE AND GOOD LIFT. AS
MENTIONED. THE 00Z GFS AND ECMWF ARE NOW CLOSER IN PHASE
WITH THEIR SOLUTIONS WITH DEEP THE TROUGH AND AREA OF LOW PRESSURE
DEEPENING ALONG THE COAST WEDNESDAY BUT STILL HAVE DIFFERENCES THAT
WILL AFFECT THE FCST...ESPECIALLY ON THE EXACT TRACK OF THE LOW AND
STRENGTH OF WINDS. MODELS DO BOTH PRODUCE A GOOD AMOUNT OF QPF WITH
HEAVY RAINS AND WINDY CONDITIONS DEVELOPING LATE TUESDAY NIGHT AND
CONTINUING THROUGH THE DAY WEDNESDAY WITH PRECIPITATION ENDING
WEDNESDAY NIGHT AS THE LOW PULLS AWAY FROM THE COAST. THE AREA WILL
LIKELY SEE 1 TO 2 INCHES OR RAIN FROM LATE TUESDAY NIGHT THROUGH THE
EVENING WEDNESDAY. INCREASED POPS TO LIKELY INLAND TO CATEGORICAL
ALONG THE COAST WEDNESDAY.
THE GFS SHOWS A CHANCE THERE WILL BE A BIT OF MOISTURE LEFT ACROSS
THE AREA AS A SURGE OF COLD AIR GETS USHERED IN BEHIND THE DEPARTING
SYSTEM WEDNESDAY NIGHT. THAT COULD RESULT IN A BRIEF RAIN SNOW MIX
OR PERHAPS FLURRIES. THE ECMWF SEEMS TO MORE LIKELY HAVE MOST OF THE
MOISTURE DEPART BEFORE COLDER AIR. NOT MUCH CONFIDENCE ON WHICH
SOLUTION WILL BE RIGHT AT THIS POINT BUT OPTED FOR MORE LIKELY
KEEPING PRECIPITATION ALL RAIN HERE. EVEN IF WE DID SEE A FEW FLAKES
WEDNESDAY NIGHT DO NOT EXPECT IT WOULD NOT AMOUNT TO ANYTHING.
THURSDAY INTO SATURDAY DRIER AND COOL HIGH PRESSURE BUILDS OVER THE
AREA WITH MOSTLY SUNNY SKIES BUT BELOW NORMAL TEMPERATURES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 630 AM SUNDAY...WIDESPREAD LIGHT RAIN NOW SPREADING INTO THE
REGION. THE RAIN IS FALLING FROM GENERALLY A MID CLOUD DECK BUT
CEILINGS SHOULD LOWER THROUGH THE MORNING WITH WIDESPREAD MVFR
CEILINGS THROUGH THE BALANCE OF THE DAY. AS THE ATMOSPHERE BECOMES
MORE UNSTABLE LATER THIS EVENING...EXPECT STRONG GUSTY S/SW WINDS
WITH LOCALLY STRONG TO SEVERE TSTMS POSSIBLE. EXPECT CEILINGS AND
VSBYS TO DROP TO MVFR BY TONIGHT WITH WIDESPREAD PRECIPITATION.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...MVFR/IFR CONDITIONS SHOULD IMPROVE TO MVFR TO VFR
ON MONDAY AFTER THE WARM FRONT AND VIGOROUS SHRTWV PASSES THROUGH
THE AREA. THERE WILL STILL BE A SMALL CHANCE OF RAIN WITH SUB VFR
CONDITIONS POSSIBLE IN THE PRECIPITATION MONDAY AND TUESDAY. A
STRONG LOW PRESSURE WILL MOVE UP THE COAST TUESDAY NIGHT WITH IFR
CONDITIONS LIKELY...IN ADDITION TO RAIN AND STRONG WINDS THROUGH THE
DAY WEDNESDAY. BY THU HIGH PRESSURE BUILDS IN AND VFR CONDITIONS
RETURN.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 635 AM SUNDAY...LIGHT SE/S WINDS THIS MORNING WITH SEAS 1 TO
3 FEET. THIS WILL GIVE WAY TO INCREASING WINDS DURING THE
AFTERNOON AS STRONG WARM FRONT SURGES NORTH. A GALE WARNING WAS
POSTED EARLIER FROM THIS EVENING THROUGH LATE MONDAY AFTERNOON. BY
TONIGHT...S/SW WINDS INCREASE TO 25 TO 35 KNOTS WITH A FEW GUSTS
TO 40 KNOTS LIKELY WITH SEAS BUILDING TO AS HIGH AS 15 FEET PER
LOCAL NWPS/SWAN MODEL. THESE GUSTY WINDS AND ROUGH SEAS WILL
ACCOMPANIED BY AREAS OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS...SOME
STRONG. NO CHANGES TO THE MARINE FORECAST WITH THIS UPDATE.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...WILL HAVE A CONTINUED PERIOD OF STRONG GUSTY
SOUTHERLY WINDS CONTINUING INTO MONDAY SLOWLY DIMINISHING FROM WEST
TO EAST AS THE COLD FRONT APPROACHES THE AREA. GALE CONDITIONS WILL
END BY LATE MONDAY ACROSS THE CENTRAL WATERS BUT SEAS WILL REMAIN
TREACHEROUS THROUGH MONDAY NIGHT. A WEAK COLD FRONT MOVES THROUGH
MONDAY NIGHT WITH LIGHT NORTHERLY WINDS FOR THE DAY TUESDAY.
STRONG LOW PRESSURE WILL DEVELOP ALONG THE FRONT OFF THE COAST
TUESDAY NIGHT AND MOVE UP THE COAST WEDNESDAY. THE GFS AND ECMWF
DIFFER A BIT ON THE LOCATION AND TIMING OF THE FRONT WITH THE 00Z
ECMWF KEEPING IT RIGHT ALONG THE COAST WHICH RESULTS IN LIGHTER
WINDS ON WEDNESDAY. FAVORED PREVIOUS FCST AND GFS FOR KEEPING THE
LOW JUST OFF THE COAST WHICH MAY ALLOW GALE CONDITIONS TO DEVELOP
WEDNESDAY WITH THIS FEATURE. CURRENT FCST HAS GUSTS TO GALE FORCE ON
WED IN STRONG NORTHERLY FLOW. SEAS 10 TO 12 FEET ARE POSSIBLE
WEDNESDAY INTO WEDNESDAY NIGHT AS A RESULT. CONDITIONS ONLY SLOWLY
IMPROVE BY THANKSGIVING MORNING...WITH SEAS FALLING BELOW 6 FEET IN
THE CENTRAL WATERS LATE IN THE DAY ON THANKSGIVING. WINDS WILL
EVENTUALLY BECOME LIGHT BY THE WEEKEND AS HIGH PRESSURE BUILDS OVER
THE AREA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
AMZ130-131-135>137-150-152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...RSB
AVIATION...RSB/CTC
MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
605 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND...RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM SUNDAY...S/W UPPER RIDGE ACROSS THE AREA ATTM...WILL
GIVE WAY TO THE APPROACH OF A POTENT SOUTHERN STREAM S/W
TROF FROM THE GULF COAST STATES THIS AFTN. MODELS INDICATE A
NEGATIVELY TILT TO THIS UPPER S/W TROF AS IT LIFTS FROM THE FL
PANHANDLE NORTHEASTWARD ACROSS THE CAROLINAS THIS EVENING AND
OVERNIGHT.
THE SFC WARM FRONT SOMEWHAT WELL DISPLACED FROM THE SFC LOW THAT
IS MOVING NNE ACROSS THE CENTRAL U.S. TO THE GREAT LAKES BY MONDAY
DAYBREAK. WHATS LEFT OF A WEAK WEDGE ACROSS THE INLAND CWA THIS
MORNING WILL GIVE TO THE APPROACHING WARM FRONT THIS AFTN...WHICH
LIFTS NORTHWARD ACROSS THE FA LATER THIS EVENING THROUGH THE EARLY
PRE-DAWN MON HOURS. STRATIFORM RAINS IE. EXCELLENT ISENTROPIC LIFT
AHEAD OF THE WARM FRONT AS MOISTURE FROM BOTH THE ATLANTIC AND
GULF OF MEXICO ARE UTILIZED. DECENT WIND DIRECTION VEERING
PROFILE FROM THE SFC TO 700 MB THIS AFTERNOON AND EVENING WITH
WIND SPEEDS RANGING FROM 20-30 KT AT THE SFC...UP TO 60 KT AT 925
MB. WITH WIND SHEAR LIKE THIS...ANY CONVECTION THAT TAPS INTO
THESE WINDS MAY PRODUCE DAMAGING WIND GUSTS OR EVEN THE
POSSIBILITY OF A TORNADO DUE TO FAVORABLE HELICITIES. WILL
CONTINUE TO MENTION THE SEVERE CONVECTIVE THREAT IN THE HWO.
OVERALL...THE AVBL INSTABILITY...IE. CAPE...WILL LIKELY BE THE
DETERMINING FACTOR FOR POTENTIAL CONVECTIVE DEVELOPMENT ACROSS
THE FA.
AN ABNORMAL DIURNAL TEMP CURVE WILL BE FORECAST THIS
PACKAGE...WITH TODAYS HIGHS LIKELY OCCURRING LATE THIS
AFTERNOON...AND TONIGHTS LOWS LIKELY THIS EVENING WITH STEADY OR
EVEN RISING TEMPS LATE THIS EVENING AND OVERNIGHT. ROUGHLY THE
FORECAST AREA WILL BE LOOKING AT 1 TO 2 INCH RAINFALL AMOUNTS
TODAY THROUGH DAYBREAK MON.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...A SLOW DETERIORATION OF CONDITIONS IS EXPECTED THROUGH THE
MORNING HOURS AS ISENTROPIC LIFT SLOWLY INCREASES. FIRST BATCH OF
PRECIP IS MOVING THROUGH THE REGION...POORLY DEPICTED BY THE HRRR BY
THE WAY. A SECOND AND MORE WIDESPREAD WAVE WITH MOVE THROUGH LATER
THIS MORNING. MODERATE RAIN WILL BE LIKELY WITH PRECIPITATION
INDUCED CEILINGS LOWERING TO IFR THIS AFTERNOON. ONLY MODERATE
CONFIDENCE WITH THE TIMING OF CEILINGS. MOST OF THE PRECIP TODAY
WILL BE STRATIFORM...HOWEVER COULD NOT RULE OUT A RUMBLE TOWARD
EVENING.
THIS EVENING...AN UPPER VORT MAX WILL SWEEP THROUGH THE REGION.
STRONG HELICITY BUT LITTLE TO NO CAPE WILL HARD TO RECONCILE.
BELIEVE THERE WILL BE A NARROW BAND OF CONVECTION THAT SHOULD PUSH
TO THE COAST BY 05-06Z. BEHIND THE VORT EXPECT THE PRECIP TO SHUT
OFF WITH MAINLY MVFR CEILINGS REMAINING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM SUNDAY...THE LOCAL WATERS WILL BE SUBJECT TO AN
EXTENDED PERIOD OF SCA CONDITIONS COMMENCING LATER THIS MORNING
AND LASTING INTO THE SHORT TERM PERIOD. INCREASING ONSHORE E TO
SE WINDS DURING TODAY...WILL VEER TO THE SOUTH AS THE WARM FRONT
LIFTS NORTHWARD ACROSS THE LOCAL WATERS FROM LATE THIS AFTN TO
MIDNIGHT TONIGHT. THE SFC PG WILL FURTHER TIGHTEN ACROSS THE LOCAL
WATERS AS THE PARENT LOW ACROSS THE CENTRAL U.S. DEEPENS AS IT
LIFTS TO THE GREAT LAKES BY MON DAYBREAK. LOOKING AT SPEEDS IN THE
15 TO 25 KT RANGE WITH GUSTS TO 30 KT THIS AFTERNOON...FURTHER
INCREASING TO 20 TO 30 KT WITH FEW GUSTS TO GALE FORCE. IF WATER
TEMPS WERE SLIGHTLY WARMER IN THE 60S INSTEAD OF THE 50S...A GALE
WARNING WOULD PROBABLY HAVE BEEN ISSUED...ALTHOUGH STILL NOT OUT
OF THE QUESTION...GIVEN THE PASSAGE OF A DECENT UPPER S/W TROF
ACROSS THE SE U.S. SIGNIFICANT SEAS WILL QUICKLY BUILD AS ONSHORE
WINDS MAKE SURE OF THAT. SIG. SEAS WILL PEAK THIS EVENING AND
OVERNIGHT...IN THE 8 TO 12 FOOT RANGE...FOLLOWED BY A VERY SLOW
SUBSIDING TREND THERE-AFTER IN SUBSEQUENT PERIODS. WIND DRIVEN
WAVES WILL DOMINATE SIGNIFICANT SEAS...WITH AVERAGE PERIODS IN THE
5.0 TO 6.5 SECONDS RANGE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
354 AM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON AND
TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND PUSH
OFFSHORE BY EARLY TUESDAY. LOW PRESSURE WILL DEVELOP ALONG THE FRONT
LATE TUESDAY NIGHT AND MOVE NORTHEAST OFFSHORE OF THE COAST WEDNESDAY.
THE LOW WILL DEPART TO THE NORTHEAST WEDNESDAY NIGHT WITH HIGH PRESSURE
BUILDING OVER THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 330 AM SUNDAY...A WARM FRONT WILL MOVE NORTH THROUGH THE
DAY WITH WIDESPREAD LIGHT TO MODERATE RAIN ARRIVING THIS MORNING.
THE RAIN SHOULD BECOME STEADY BY EARLY AFTERNOON PER LATEST 3KM
HRRR AND RUC MODELS. TEMPERATURES TRICKY WITH COASTAL TROUGH
CURRENTLY IN PLACE WITH 61 DEGREES AT CAPE LOOKOUT BUT 41 IN
MOREHEAD CITY. AS WARM FRONT SURGES NORTH...TEMPERATURES SHOULD
RECOVER TO HIGHS IN THE MID/UPPER 60S AREA-WIDE. DEWPOINTS
CURRENTLY IN THE 30S SHOULD RECOVER TO THE UPPER 50S BY AFTERNOON.
POPS INCREASE TO CATEGORICAL OVER ROUGHLY THE SOUTHWESTERN HALF OF
THE CWA BY EARLY AFTERNOON. RAIN CHANCES REMAIN LOWER OVER THE
NORTHEASTERN HALF AS DEWPOINT RECOVERY WILL TAKE A BIT LONGER.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM SUNDAY...BY THIS EVENING...INSTABILITY INCREASES FROM
THE SOUTH AS STRONG WARM FRONT MOVES NORTH. VERY IMPRESSIVE LOW-
LEVEL SHEAR VALUES INDICATED BY FORECAST SOUNDINGS...WITH SRH
HELICITY VALUES UPWARDS OF 600-700 BY 00Z TONIGHT. THIS COINCIDES
WITH THE ARRIVAL OF THE INSTABILITY AND MOST OF THE CWA REMAINS IN
A SLIGHT RISK OF SEVERE TSTMS. THE PRIMARY THREAT WILL BE STRONG
DAMAGING WINDS AND THE RISK OF ISOLATED TORNADOES GIVEN THIS SHEAR
ENVIRONMENT. THE TORNADO/SEVERE THREAT SHOULD WANE AFTER 06Z AS
THE FLOW BECOMES MORE UNIDIRECTIONAL. IN ADDITION TO THE SEVERE
THREAT...QPF TOTALS OF 1 TO 2 INCHES WILL BE POSSIBLE AS DEEP
MOISTURE IS ADVECTED FROM THE ATLANTIC WITH VERY IMPRESSIVE LOW-
LEVEL MOISTURE TRANSPORT. GIVEN THE WARM SW WINDS...EXPECT
TEMPERATURES TO FALL VERY LITTLE TONIGHT...LIKELY REMAINING IN THE
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUN...LARGE UPPER TROUGH OVER THE CENTRAL PART OF THE
COUNTRY WITH LOTS OF ENERGY ROTATING AROUND IT WILL MAKE FOR AN
ACTIVE PERIOD INTO THANKSGIVING WITH HIGH PRESSURE TAKING HOLD
THROUGH THE REMAINDER OF THE PERIOD. THIS ACTIVE WEATHER COULD
HAMPER HOLIDAY TRAVEL PLANS.
TROUGH WILL CONTINUE TO DIG INTO THE SOUTHERN TIER STATES THROUGH
MID WEEK THEN LIFT THROUGH THE SOUTHEAST AND MID ATLANTIC THROUGH
THE END OF THE WEEK. MOST OF THE PRECIPITATION CHANCES WILL END BY
MONDAY MORNING ASSOCIATED WITH A VIGOROUS SHRTWV MOVING THROUGH THE
AREA. KEPT SMALL CHANCE POPS IN ON MONDAY UNTIL THE FIRST COLD FRONT
MOVES THROUGH THE AREA TUESDAY NIGHT. WON`T GET MUCH OF A BREAK AS
STRONG UPPER LEVEL ENERGY WILL SWING THROUGH THE BASE OF THE UPPER
TROUGH HELPING TO FORM A WAVE ON THE SURFACE FRONT IN THE GULF
TUESDAY THAT WILL MOVE UP THE EAST COAST DURING THE NIGHT TUESDAY
NIGHT. CROSS SECTIONS SHOWING DEEP LAYER MOISTURE AND GOOD LIFT. AS
MENTIONED. THE 00Z GFS AND ECMWF ARE NOW CLOSER IN PHASE
WITH THEIR SOLUTIONS WITH DEEP THE TROUGH AND AREA OF LOW PRESSURE
DEEPENING ALONG THE COAST WEDNESDAY BUT STILL HAVE DIFFERENCES THAT
WILL AFFECT THE FCST...ESPECIALLY ON THE EXACT TRACK OF THE LOW AND
STRENGTH OF WINDS. MODELS DO BOTH PRODUCE A GOOD AMOUNT OF QPF WITH
HEAVY RAINS AND WINDY CONDITIONS DEVELOPING LATE TUESDAY NIGHT AND
CONTINUING THROUGH THE DAY WEDNESDAY WITH PRECIPITATION ENDING
WEDNESDAY NIGHT AS THE LOW PULLS AWAY FROM THE COAST. THE AREA WILL
LIKELY SEE 1 TO 2 INCHES OR RAIN FROM LATE TUESDAY NIGHT THROUGH THE
EVENING WEDNESDAY. INCREASED POPS TO LIKELY INLAND TO CATEGORICAL
ALONG THE COAST WEDNESDAY.
THE GFS SHOWS A CHANCE THERE WILL BE A BIT OF MOISTURE LEFT ACROSS
THE AREA AS A SURGE OF COLD AIR GETS USHERED IN BEHIND THE DEPARTING
SYSTEM WEDNESDAY NIGHT. THAT COULD RESULT IN A BRIEF RAIN SNOW MIX
OR PERHAPS FLURRIES. THE ECMWF SEEMS TO MORE LIKELY HAVE MOST OF THE
MOISTURE DEPART BEFORE COLDER AIR. NOT MUCH CONFIDENCE ON WHICH
SOLUTION WILL BE RIGHT AT THIS POINT BUT OPTED FOR MORE LIKELY
KEEPING PRECIPITATION ALL RAIN HERE. EVEN IF WE DID SEE A FEW FLAKES
WEDNESDAY NIGHT DO NOT EXPECT IT WOULD NOT AMOUNT TO ANYTHING.
THURSDAY INTO SATURDAY DRIER AND COOL HIGH PRESSURE BUILDS OVER THE
AREA WITH MOSTLY SUNNY SKIES BUT BELOW NORMAL TEMPERATURES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 1250 AM SUNDAY...VFR CONDITIONS SHOULD PREVAIL OVERNIGHT
AND INTO THE AFTERNOON HOURS ON SUNDAY AS HIGH CLOUDS THICKEN.
WARM FRONT WILL SURGE NORTH DURING THE AFTERNOON WITH DEWPOINTS
INCREASING AND S/SE WINDS BECOMING GUSTY WITH SHOWERS BECOMING
WIDESPREAD. SOME LOCALLY STRONG TSTMS MAY BE POSSIBLE TONIGHT WITH
GUSTY WINDS. EXPECT CEILINGS AND VSBYS TO DROP TO MVFR BY LATE
AFTERNOON INTO TONIGHT WITH WIDESPREAD PRECIPITATION.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...MVFR/IFR CONDITIONS SHOULD IMPROVE TO MVFR TO VFR
ON MONDAY AFTER THE WARM FRONT AND VIGOROUS SHRTWV PASSES THROUGH
THE AREA. THERE WILL STILL BE A SMALL CHANCE OF RAIN WITH SUB VFR
CONDITIONS POSSIBLE IN THE PRECIPITATION MONDAY AND TUESDAY. A
STRONG LOW PRESSURE WILL MOVE UP THE COAST TUESDAY NIGHT WITH IFR
CONDITIONS LIKELY...IN ADDITION TO RAIN AND STRONG WINDS THROUGH THE
DAY WEDNESDAY. BY THU HIGH PRESSURE BUILDS IN AND VFR CONDITIONS
RETURN.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 340 AM SUNDAY...WILL UPGRADE GALE WATCH TO A GALE WARNING
BEGINNING THIS EVENING AND RUNNING THROUGH LATE MONDAY. LIGHT
SOUTHWEST WINDS CURRENTLY WITH SEAS 1 TO 3 FEET. AS A STRONG WARM
FRONT SURGES NORTH LATER THIS AFTERNOON...SE/ S WINDS SHOULD
INCREASE TO 15 TO 20 KNOTS WITH SEAS BUILDING TO 3 TO 5 FEET. BY
TONIGHT...S/SW WINDS INCREASE TO 25 TO 35 KNOTS WITH A FEW GUSTS
TO 40 KNOTS LIKELY WITH SEAS BUILDING TO AS HIGH AS 15 FEET PER
LOCAL NWPS/SWAN MODEL. THESE GUSTY WINDS AND ROUGH SEAS WILL
ACCOMPANIED BY AREAS OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS...SOME
STRONG.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM SUN...WILL HAVE A CONTINUED PERIOD OF STRONG GUSTY
SOUTHERLY WINDS CONTINUING INTO MONDAY SLOWLY DIMINISHING FROM WEST
TO EAST AS THE COLD FRONT APPROACHES THE AREA. GALE CONDITIONS WILL
END BY LATE MONDAY ACROSS THE CENTRAL WATERS BUT SEAS WILL REMAIN
TREACHEROUS THROUGH MONDAY NIGHT. A WEAK COLD FRONT MOVES THROUGH
MONDAY NIGHT WITH LIGHT NORTHERLY WINDS FOR THE DAY TUESDAY.
STRONG LOW PRESSURE WILL DEVELOP ALONG THE FRONT OFF THE COAST
TUESDAY NIGHT AND MOVE UP THE COAST WEDNESDAY. THE GFS AND ECMWF
DIFFER A BIT ON THE LOCATION AND TIMING OF THE FRONT WITH THE 00Z
ECMWF KEEPING IT RIGHT ALONG THE COAST WHICH RESULTS IN LIGHTER
WINDS ON WEDNESDAY. FAVORED PREVIOUS FCST AND GFS FOR KEEPING THE
LOW JUST OFF THE COAST WHICH MAY ALLOW GALE CONDITIONS TO DEVELOP
WEDNESDAY WITH THIS FEATURE. CURRENT FCST HAS GUSTS TO GALE FORCE ON
WED IN STRONG NORTHERLY FLOW. SEAS 10 TO 12 FEET ARE POSSIBLE
WEDNESDAY INTO WEDNESDAY NIGHT AS A RESULT. CONDITIONS ONLY SLOWLY
IMPROVE BY THANKSGIVING MORNING...WITH SEAS FALLING BELOW 6 FEET IN
THE CENTRAL WATERS LATE IN THE DAY ON THANKSGIVING. WINDS WILL
EVENTUALLY BECOME LIGHT BY THE WEEKEND AS HIGH PRESSURE BUILDS OVER
THE AREA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
AMZ130-131-135-137-150-152-154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...RSB
AVIATION...RSB/CTC
MARINE...RSB/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
333 AM EST SUN NOV 23 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BRING WIND....RAIN AND POSSIBLY A FEW
STRONG THUNDERSTORMS TO THE AREA TODAY. RAIN WILL RETURN LATE
TUESDAY AND WEDNESDAY AFTER A BREAK MONDAY. THANKSGIVING DAY TO
THE END OF THE FORECAST PERIOD LOOKS DRY AND COLD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 940 PM SATURDAY...HIGH CLOUDS ARE OVERSPREADING THE
CAROLINAS WHILE MOISTURE ALSO INCREASES IN THE LOW LEVELS DUE TO
EAST-SOUTHEASTERLY FLOW OFF THE ATLANTIC OCEAN. IT SHOULD ONLY
TAKE ANOTHER 3-5 HOURS TO SEE MOSTLY CLOUDY TO CLOUDY SKIES IN
PLACE ACROSS THE ENTIRE FORECAST AREA...AND MORE IMPORTANTLY TO
SEE RAIN DEVELOPING ACROSS NE SOUTH CAROLINA. BASED ON THE LATEST
RADAR SUMMARY AND 23Z HRRR RUNS...I HAVE SPED UP THE INTRODUCTION
OF RAIN CHANCES TO THE FORECAST BY SEVERAL HOURS AND HAVE
INCREASED POPS THROUGH DAYBREAK AS WELL. EVEN ACROSS THE SANTEE
RIVER RIVER AREA I STILL ONLY THINK A FEW HUNDREDTHS OF AN INCH
WILL FALL BEFORE DAYBREAK. MORE SUBSTANTIAL MOISTURE ADVECTION AND
SYNOPTIC FORCING WILL ARRIVE DURING THE DAY TOMORROW.
TEMPERATURES SHOULD BE VERY NEAR THEIR LOWEST READINGS OF THE NIGHT
NOW. RADIATIONAL COOLING CONDITIONS SHOULD DETERIORATE FROM THIS
POINT FORWARD AS CLOUD COVERAGE INCREASES. AFTER DRAWING THE LATEST
HOURLY TEMPERATURE CURVES IN THE DIGITAL FORECAST I NOTED THE TEXT
FORMATTER USED THE "RISING TEMPERATURE" PHRASE FOR SOME COASTAL
ZONES TONIGHT. THIS IS GOOD AND DESCRIBES THE ANTICIPATED SHAPE OF
HOURLY TEMPERATURE CURVES NEAR THE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...A BROAD SOUTHWEST FLOW ALOFT WILL CONTINUE
MONDAY AND TUESDAY WITH THE AFFECTS OF MASSIVE LOW PRESSURE OVER
THE GREAT LAKES LINGERING MONDAY. A WEAK PRESSURE TROUGH APPEARS
TO BE THE CATALYST FOR A FEW SHOWERS MONDAY WITH A DRY 24 HOURS OR
SO ENSUING.
THE SOUTHWEST FLOW WILL BE ENHANCED LATER TUESDAY AS A MID LEVEL
TROUGH MOVES INTO THE TENNESSEE VALLEY. A POTENT 300MB JET WITH THE
RIGHT ENTRANCE REGION BECOMING FAVORABLY PLACED LATER TUESDAY AND
EARLY WEDNESDAY WORKS IN TANDEM WITH A DEEP MOISTURE PLUME AND
WIDESPREAD RAIN DEVELOPS ONCE AGAIN. I HAVE INCREASED POPS FOR LATE
IN THE PERIOD TO ADDRESS. NO CHANGES TO THE TEMPERATURE FORECAST
WITH A WARM DAY IN STORE MONDAY COOLING SOME 10-15 DEGREES TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO PAINT A WET
SCENARIO FOR WEDNESDAY AS LOW PRESSURE...WELL OFFSHORE WITH
EXCELLENT UPPER LEVEL SUPPORT WORKS TOGETHER. IT HAS BEEN
INTERESTING SEEING HE 850MB ZERO ISOTHERM MOVING INTO THE AREA
WITH PRECIPITATION BUT SOUNDINGS SHOW THE LOWER LEVELS JUST A BIT
TOO WARM FOR ANY FROZEN PRECIPITATION. I RAISED POPS INCREMENTALLY
TO ADDRESS THE GOOD MODEL CONTINUITY AND INCREASED CONFIDENCE.
BEYOND THIS THE MID LEVEL PATTERN WILL BECOME ZONAL BY THE WEEKEND
WITH HIGH PRESSURE AT THE SURFACE FOR THE MOST PART. THERE WILL BE
A DRY COLD FRONT THAT MOVES ACROSS FRIDAY BUT LITTLE ELSE.
TEMPERATURES REMAIN BELOW CLIMATOLOGY THROUGHOUT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST OVERNIGHT INTO THE
DAYTIME SUNDAY MORNING HOURS...WITH CONDITIONS GRADUALLY
DETERIORATING TO MVFR AND THEN IFR/LIFR TOWARDS THE END OF THE
06Z ISSUANCE PERIOD. LOW CIGS AND REDUCED VSBY FROM PCPN AND
FOG...WITH CONVECTION POSSIBLE ALONG AND/OR AFTER THE WFP THIS
AFTERNOON AND NIGHT.
VFR EXPECTED AT ALL TERMINALS OVERNIGHT AS LIGHT WINDS AND
SCT/BKN MID TO HIGH LEVEL CLOUDS MOVE IN. AFTER DAYBREAK...LOW TO
MID LEVEL CLOUDS WILL FURTHER INFILTRATE WITH CEILINGS STEADILY
LOWERING THRUOUT THE DAY AS THE WARM FRONT/COASTAL FRONT EITHER
PUSHES INLAND BEFORE ALTOGETHER LIFTING TO THE NORTH LATE THIS
AFTERNOON THRU THIS EVENING. INCREASING CHANCES FOR STRATIFORM
RAINS THROUGHOUT THE DAY. MODERATE RAIN AT TIMES...LOWERING CIGS
AND REDUCED VSBY FROM BOTH PCPN AND FOG WILL COMBINE TO CREATE
DETERIORATING CONDITIONS THIS AFTERNOON THRU THE EVENING HOURS.
ISOLATED THUNDERSTORMS REMAIN POSSIBLE IN THE VICINITY OF THE
COASTAL FRONT AND LIFTING WARM FRONT. BUT GIVEN LOWER CONFIDENCE
OF TIMING...HAVE OPTED TO NOT INTRODUCE ATTM. AS FOR WINDS...
EXPECT A VEERING TREND COMMENCING WITH VARIABLE OR NORTHEAST WINDS
OVERNIGHT...BECOMING EAST TO SOUTHEAST AS THE COASTAL FRONT AND
WARM FRONT APPROACH THIS AFTERNOON...AND BECOMING SOUTHERLY AFTER
THE WFP THIS EVENING. INITIALLY...SUSTAINED WINDS AROUND 5
KT...INCREASING TO 10 KTS DAYTIME SUNDAY MORNING...FURTHER
INCREASING TO AROUND 15+ KTS LATE THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SATURDAY...NO SIGNIFICANT CHANGE ARE NEEDED TO THE
FORECAST LATE THIS EVENING. OBSERVATIONS SHOW VEERING WINDS ACROSS
THE WATERS...MAINLY E TO NE ALONG THE BEACHES WITH SE WINDS OUT AT
THE FRYING PAN SHOALS BUOY. THE WARM FRONT SHOULD MAKE RAPID
PROGRESS TOWARD THE BEACHES OVERNIGHT WITH RISING TEMPERATURES
EXPECTED. FORTUNATELY THE MASSIVE INCREASE IN WIND SPEEDS WILL HOLD
OFF UNTIL DURING THE DAY SUNDAY. SEAS 2-3 FEET (LOCALLY 4 FEET IN
THE OUTER PORTION OF THE COASTAL WATERS) SHOULD CONTINUE THROUGH THE
NIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SMALL CRAFT CONDITIONS WILL CONTINUE MONDAY VIA
A STRONG SOUTHWEST FLOW OF 20-25 KNOTS AND SEAS OF 5-8 FEET. THE
WINDS WILL DIMINISH TUESDAY MORNING AND TURN TO THE WEST AS A WEAK
COLD FRONT PASSES. SEAS SHOULD FALL TO BELOW THE SMALL CRAFT
THRESHOLD SETTLING NICELY INTO A RANGE OF 2-4 FEET. ELEMENTS WILL
REMAIN TRANQUIL FOR THE REMAINDER OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...FAIRLY BRISK NORTHWEST WINDS WEDNESDAY AS LOW
PRESSURE MOVES WELL OFFSHORE. SPEEDS WILL BE 20-25 KNOTS. WINDS
DIMINISH DRAMATICALLY THURSDAY AS A WEAK WESTERLY FLOW DEVELOPS.
SEAS WILL BE HIGHEST WEDNESDAY WITH 3-7 FEET...HIGHEST OFFSHORE.
VALUES DROP TO 2-4 FEET THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA/MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
123 AM EST SUN NOV 23 2014
.SYNOPSIS...
CLOUDS WILL INCREASE OVERNIGHT AHEAD OF A STORM SYSTEM TAKING
SHAPE IN THE GULF OF MEXICO. THIS SYSTEM WILL BRING MILD AND WET
WEATHER SUNDAY AND MONDAY AS IT LIFTS NORTHEAST. STRONG
THUNDERSTORMS WILL BE POSSIBLE LATE SUNDAY THROUGH EARLY MONDAY. A
COLD FRONT WILL CROSS THE COAST EARLY TUESDAY...STALLING OFFSHORE.
DEEPENING LOW PRESSURE WILL FORM ALONG THIS FRONT...BRINGING A COOL
WET CONDITIONS WEDNESDAY. CLEARING WEATHER IS EXPECTED THANKSGIVING
DAY WITH BELOW NORMAL TEMPERATURES THROUGH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 940 PM SATURDAY...HIGH CLOUDS ARE OVERSPREADING THE
CAROLINAS WHILE MOISTURE ALSO INCREASES IN THE LOW LEVELS DUE TO
EAST-SOUTHEASTERLY FLOW OFF THE ATLANTIC OCEAN. IT SHOULD ONLY
TAKE ANOTHER 3-5 HOURS TO SEE MOSTLY CLOUDY TO CLOUDY SKIES IN
PLACE ACROSS THE ENTIRE FORECAST AREA...AND MORE IMPORTANTLY TO
SEE RAIN DEVELOPING ACROSS NE SOUTH CAROLINA. BASED ON THE LATEST
RADAR SUMMARY AND 23Z HRRR RUNS...I HAVE SPED UP THE INTRODUCTION
OF RAIN CHANCES TO THE FORECAST BY SEVERAL HOURS AND HAVE
INCREASED POPS THROUGH DAYBREAK AS WELL. EVEN ACROSS THE SANTEE
RIVER RIVER AREA I STILL ONLY THINK A FEW HUNDREDTHS OF AN INCH
WILL FALL BEFORE DAYBREAK. MORE SUBSTANTIAL MOISTURE ADVECTION AND
SYNOPTIC FORCING WILL ARRIVE DURING THE DAY TOMORROW.
TEMPERATURES SHOULD BE VERY NEAR THEIR LOWEST READINGS OF THE NIGHT
NOW. RADIATIONAL COOLING CONDITIONS SHOULD DETERIORATE FROM THIS
POINT FORWARD AS CLOUD COVERAGE INCREASES. AFTER DRAWING THE LATEST
HOURLY TEMPERATURE CURVES IN THE DIGITAL FORECAST I NOTED THE TEXT
FORMATTER USED THE "RISING TEMPERATURE" PHRASE FOR SOME COASTAL
ZONES TONIGHT. THIS IS GOOD AND DESCRIBES THE ANTICIPATED SHAPE OF
HOURLY TEMPERATURE CURVES NEAR THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 336 PM SATURDAY...PRIMARY HEADLINE THIS PERIOD...STRONG TO
SEVERE TSTM POTENTIAL LATE SUNDAY THROUGH EARLY MONDAY. LOW-LEVEL
SE WINDS WILL INTENSIFY...TRANSPORTING MOISTURE RICH GULF STREAM
AIR INTO THE COASTAL ZONES ELEVATING BOUNDARY LAYER DEWPOINTS.
A DEVELOPING AXIS OF POSITIVE MIXED-LAYERED CAPES WILL ORIENT
ITSELF ALONG OR JUST OFF THE COAST SUNDAY NIGHT THROUGH MONDAY
MORNING. THE HIGHEST HELICITY VALUES FAR PRECEDE THE MAXIMUM OF
ML-CAPE BUT SOME OVERLAP OF MODERATE CAPE/HELICITY EXISTS TO
WARRANT A CHANCE OF SEVERE STORMS...ALTHOUGH DIURNAL COOLING WILL
AND SLIGHT CHILLED INSHORE SST VALUES COULD OFFSET INCREASING
CONVECTIVE INTENSITY TRENDS.
NEXT NOTEWORTHY ITEM...PRECEDING THIS SEVERE POTENTIAL PLENTY
STRATIFORM RAIN APPEARS LIKELY...AND THE LATEST WPC QPF FORECAST
FOR SUNDAY AND MONDAY PAINTS 1.5-2.5 INCHES OF RAIN FOR OUR AREA
FOR THE 2-DAY PERIOD. STRATIFORM WILL TRANSITIONS TO CONVECTION AS
THE WARM FRONT LIFTS NORTH OF THE AREA INTO EARLY MONDAY.
EXCEPTIONALLY MILD MONDAY WITH MAXIMUM TEMPERATURES WELL INTO THE
70S IN A DEEP AND MOIST SW WIND FLOW ATOP THE AREA...AND FROPA
NEAR END OF THE PERIOD PRIOR TO DAYBREAK TUESDAY. COOLEST PORTION
OF PERIOD DAYBREAK SUNDAY WITH CLOUDS AND MIDDLE 40S. HIGHEST POP
VALUES SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 336 PM SATURDAY...LINGERING FRONT STALLED OFF THE EAST COAST
TUE INTO WED AND SHORTWAVE DROPPING INTO THE WESTERN GULF WILL
BRING RAIN TO THE AREA DURING THE MIDDLE OF NEXT WEEK. WEAK
SURFACE WAVE DEVELOPING ON THE BOUNDARY OVER SOUTHERN FL EARLY TUE
WILL BE ENHANCED BY THE AFOREMENTIONED SHORTWAVE. AS THE LOW
TRACKS NORTHEAST ALONG THE FRONT...JUST OFF THE SE COAST...RAIN
WILL SPREAD OVER MUCH OF THE CAROLINAS. WED LOOKS AS THOUGH IT
COULD BE A MISERABLE DAY WITH THE FORECAST AREA ON THE COOL SIDE
OF THE LOW AND PERIODS OF HEAVY RAIN POSSIBLE. HIGHS WED MAY STAY
IN THE MID 40S WITH AROUND 50 ALONG THE COAST AND HAVE TRENDED
HIGHS DOWN.
RAPID DRYING WILL COMMENCE LATE WED INTO WED NIGHT AS 5H TROUGH
AXIS LIFTS NORTHEAST AND DEEP DRY AIR ARRIVES. BY THU AM
PRECIPITABLE WATER VALUES WILL BE AROUND 0.40 INCH AND SOUNDINGS
SHOW STRONG DOWNWARD MOTION. LATER HALF OF THE PERIOD REMAINS A
QUESTION WITH LATEST GFS/ECMWF DISAGREEING ON THE
STRENGTH/AMPLITUDE OF THE NEXT MID LEVEL TROUGH. GFS DEVELOPS
ZONAL FLOW ALOFT FRI/SAT WHILE THE ECMWF MAINTAINS 5H TROUGHING
INTO THE START OF THE WEEKEND. BOTH SOLUTIONS WOULD RESULT IN A
DRY FORECAST BUT WITH DIFFERENCES IN TEMPERATURES AND POSSIBLY
AFTERNOON CLOUD COVER. GFS ENSEMBLES ARE NOT VERY HELPFUL WITH
ROUGHLY AN EQUAL SPLIT BETWEEN THE 2 SOLUTIONS. INHERITED FORECAST
IS BASICALLY A BLEND OF THE GFS/ECMWF AND WILL CONTINUE WITH THIS
THINKING UNTIL THERE IS BETTER AGREEMENT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...EXPECT VFR CONDITIONS TO PERSIST OVERNIGHT INTO THE
DAYTIME SUNDAY MORNING HOURS...WITH CONDITIONS GRADUALLY
DETERIORATING TO MVFR AND THEN IFR/LIFR TOWARDS THE END OF THE
06Z ISSUANCE PERIOD. LOW CIGS AND REDUCED VSBY FROM PCPN AND
FOG...WITH CONVECTION POSSIBLE ALONG AND/OR AFTER THE WFP THIS
AFTERNOON AND NIGHT.
VFR EXPECTED AT ALL TERMINALS OVERNIGHT AS LIGHT WINDS AND
SCT/BKN MID TO HIGH LEVEL CLOUDS MOVE IN. AFTER DAYBREAK...LOW TO
MID LEVEL CLOUDS WILL FURTHER INFILTRATE WITH CEILINGS STEADILY
LOWERING THRUOUT THE DAY AS THE WARM FRONT/COASTAL FRONT EITHER
PUSHES INLAND BEFORE ALTOGETHER LIFTING TO THE NORTH LATE THIS
AFTERNOON THRU THIS EVENING. INCREASING CHANCES FOR STRATIFORM
RAINS THROUGHOUT THE DAY. MODERATE RAIN AT TIMES...LOWERING CIGS
AND REDUCED VSBY FROM BOTH PCPN AND FOG WILL COMBINE TO CREATE
DETERIORATING CONDITIONS THIS AFTERNOON THRU THE EVENING HOURS.
ISOLATED THUNDERSTORMS REMAIN POSSIBLE IN THE VICINITY OF THE
COASTAL FRONT AND LIFTING WARM FRONT. BUT GIVEN LOWER CONFIDENCE
OF TIMING...HAVE OPTED TO NOT INTRODUCE ATTM. AS FOR WINDS...
EXPECT A VEERING TREND COMMENCING WITH VARIABLE OR NORTHEAST WINDS
OVERNIGHT...BECOMING EAST TO SOUTHEAST AS THE COASTAL FRONT AND
WARM FRONT APPROACH THIS AFTERNOON...AND BECOMING SOUTHERLY AFTER
THE WFP THIS EVENING. INITIALLY...SUSTAINED WINDS AROUND 5
KT...INCREASING TO 10 KTS DAYTIME SUNDAY MORNING...FURTHER
INCREASING TO AROUND 15+ KTS LATE THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AND
POSSIBLY THROUGH TUESDAY...WITH OCCASIONAL SHOWERS AND MVFR/IFR
CONDITIONS. VFR LATE TUESDAY AFTERNOON WITH POSSIBLE MVFR
CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM SATURDAY...NO SIGNIFICANT CHANGE ARE NEEDED TO THE
FORECAST LATE THIS EVENING. OBSERVATIONS SHOW VEERING WINDS ACROSS
THE WATERS...MAINLY E TO NE ALONG THE BEACHES WITH SE WINDS OUT AT
THE FRYING PAN SHOALS BUOY. THE WARM FRONT SHOULD MAKE RAPID
PROGRESS TOWARD THE BEACHES OVERNIGHT WITH RISING TEMPERATURES
EXPECTED. FORTUNATELY THE MASSIVE INCREASE IN WIND SPEEDS WILL HOLD
OFF UNTIL DURING THE DAY SUNDAY. SEAS 2-3 FEET (LOCALLY 4 FEET IN
THE OUTER PORTION OF THE COASTAL WATERS) SHOULD CONTINUE THROUGH THE
NIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 336 PM SATURDAY...DETERIORATING MARINE CONDITIONS SUNDAY AS SE
WINDS CRANK UP TO 15-25 KT AHEAD OF AN APPROACHING WARM FRONT. S
AND SW BLUSTERY FLOW TO FOLLOW FOR MONDAY 15-25 KT...WHILE SEAS
PEAK MAINLY SUNDAY NIGHT DURING MAXIMUM IN S-SE WIND OFFSHORE OF
6-10 FEET AND HIGHEST OUTER WATERS. STRONG TO SEVERE THUNDERSTORMS
POSSIBLE SUNDAY NIGHT THROUGH MONDAY...GULF STREAM LATE MONDAY.
VENTURING OFFSHORE IS DISCOURAGED FOR SMALL CRAFT VESSELS SUNDAY AND
MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 336 PM SATURDAY...FRONT STALLED OFF THE COAST TUE WILL HELP
MAINTAIN LIGHT NORTHERLY FLOW. LOW PRESSURE DEVELOPING ON THE FRONT
LATE TUE WILL TRACK NORTHEAST WED...PASSING JUST EAST OF THE WATERS.
AS THE LOW DEVELOPS THE GRADIENT WILL TIGHTEN UP WITH SPEEDS
INCREASING TO 20 TO 25 KT WED. LOW EXITS NORTHEAST WED NIGHT WITH
WINDS BACKING TO WESTERLY AS THE LOW EXITS. GRADIENT DECREASES WITH
SPEEDS DROPPING TO 10 TO 15 KT BY THU MORNING. SEAS 2 TO 3 FT ON TUE
WILL BUILD TO 4 TO 7 FT LATE WED IN RESPONSE TO INCREASED NORTHERLY
FLOW. DEVELOPMENT OF OFFSHORE FLOW BEHIND THE EXITING LOW DROPS SEAS
TO 2 TO 4 FT WED NIGHT AND AROUND 2 FT THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 AM EST
TUESDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
933 PM CST MON NOV 24 2014
.UPDATE...
ISSUED AT 933 PM CST MON NOV 24 2014
SO ONLY -SN OR FLURRIES BE REPORTED BY UPSTREAM OBSERVATIONS. NO
ACCUMULATION EXPECTED...AND IF FREEZING DRIZZLE DOES OCCUR (AS THE
DRY LAYER ALOFT MOVES OVER THE REGION) IT SHOULD BE VERY LIGHT AND
PATCHY AND LIKELY WILL NOT CAUSE ANY PROBLEMS (THIS IS FOR THE
DEVILS LAKE BASIN AND SOUTHWARD).
UPDATE ISSUED AT 656 PM CST MON NOV 24 2014
WEAK UPPER SHORTWAVE PRODUCING RADAR RETURNS ACROSS SOUTHWEST
MANITOBA INTO NORTH CENTRAL AND NORTHWEST NORTH DAKOTA. A FEW OB
SITES INDICATING -SN WITH VSBY IN THE 2SM-5SM RANGE. WILL KEEP THE
SCHC POPS FOR LATER THIS EVENING INTO THE OVERNIGHT HOURS FOR THE
FAR WESTERN FA. THE RAP AND HRRR ALSO INDICATE QPF HERE...ALBEIT
VERY LIGHT. THE MAIN CONCERN WITH THIS QPF IS THAT A DRY LAYER
ALOFT WILL BE MOVING INTO THIS REGION AFTER MIDNIGHT...AND WITH
THE LOW-LEVEL MOIST LAYER MEAN TEMPERATURES AROUND -5C TO
-8C...SUPERCOOLED WATER DROPLETS ARE POSSIBLE. INSERTED PATCHY
FREEZING DRIZZLE INTO THE FORECAST FOR THE DEVILS LAKE BASIN AND
SOUTHWARD.
WILL ALSO ISSUE A SPS FOR THE SNOWFALL POTENTIAL TUESDAY
EVENING/OVERNIGHT. WFO BIS HAS A STATEMENT ISSUED...AND IT WOULD
BE BEST TO KEEP THE MESSAGE WITHIN NORTH DAKOTA CONSISTENT.
PLUS...A FEW INDICATIONS FOR MESO-SCALE BANDING (STEEP MID-LEVEL
LAPSE RATE...FRONTOGENESIS...POSSIBLE CONDITIONAL
INSTABILITY)...AND HIGHER RESOLUTION MODELS INDICATING A NARROW
BAND OF QPF UP TO AROUND 0.4 INCHES (SO COULD BE A NARROW BAND OF
3-5 INCHES...BUT LOCATION OF THIS BAND COULD BE ANYWHERE).
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 333 PM CST MON NOV 24 2014
FCST CHALLENGE IS LOW TEMPS TONIGHT AND THEN SNOW THREAT TUESDAY
NIGHT. FOR TONIGHT...SKIES GENERALLY CLEAR OVER MUCH OF ERN/CNTRL
ND WITH LINGERING CLOUDS ROUGHLY ROSEAU TO FARGO TO FORMAN EAST.
CLOUDS IN THE EAST WILL SLOWLY DIMINISH AS LOW PRESSURE MOVES
INTO UPPER MICHIGAN. EXPECT A PERIOD OF CLEAR SKY THIS EVENING IN
ERN ND AND AS WINDS LIGHTEN TEMPS COULD FALL QUICKLY IN SOME
SPOTS. VARIABLE SNOW COVER WILL MAKE LOW TEMPS TOUGH...BUT
GENERALLY EXPECT SINGLE DIGITS. THERE IS A SHORT WAVE IN
SASKATCHEWAN THAT WILL MOVE SOUTHEAST. THERE HAS BEEN SOME VERY
LIGHT WITH THIS ON CANADIAN RADAR BUT MODELS INDICATE PRECIP WILL
DRY OUT MORE AS IT MOVES EAST INTO SFC HIGH. DID KEEP 20 POP FOR
ANY LIGHT SNOW THAT MAY MAKE IT INTO WRN FCST AREA TOWARD MIDNIGHT
OR A BIT AFTER. CLOUDS COMING INTO THE WEST SHOULD MAKE TEMP FALL
STOP AND TEMPS RISE A BIT.
ALBERTA CLIPPER SYSTEM FOR LATER TUESDAY HANDLED A BIT BETTER NOW
WITH CONSENSUS IS TO TAKE SFC LOW THRU SOUTHWESTERN ND INTO
EASTERN SD WITH BAND OF 2-3 INCH SNOWFALL WILLISTON TO CARRINGTON
TO ABOUT WAHPETON-FORMAN AREA. LESSER AMOUNTS EAST OF THIS BUT
STILL EXPECT ENOUGH MOISTURE INTO THE COLDER AIRMASS NORTHEAST OF
THE LOW TO SQUEEZE OUT SOME LIGHT SNOW TUES NIGHT. LOOK FOR A
PERIOD OF WIND (20-25 KTS) SRN VALLEY LATE TUES NIGHT SO WILL NEED
TO WATCH THAT FOR ANY BLOWING SNOW ISSUES IF FORECAST PANS OUT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 PM CST MON NOV 24 2014
BLUSTERY AND COLD WEDNESDAY AS HIGH DROPS SOUTH. NEXT SHORT WAVE
DUE TO MOVE EAST FROM SOUTHERN B.C. INTO MONTANA AND NORTHWESTERN
NORTH DAKOTA THANKSGIVING DAY WITH LIGHT SNOW REACHING DVL BASIN
THURSDAY LATE AFTN. THIS IS A MORE PACIFIC HYBRID TYPE SYSTEM AND
MODELS TYPICALLY HAVE A HARD TIME WITH THESE AND WITH THERMAL
BOUNDARY IN PLACE TRACK OF SYSTEM MAY CHANGE.
THURSDAY NIGHT TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE LONG
HOLIDAY WEEKEND WEATHER. CHC OF SNOW THURSDAY NIGHT THROUGH SATURDAY
NIGHT AS 500MB FLOW BECOMES NEARLY ZONAL AND A BAROCLINIC ZONE SETS
UP ACROSS THE NORTHERN PLAINS. BEST CHC WILL BE THURSDAY NIGHT
ACROSS THE ENTIRE CWFA AS WAA OCCURS AND TEMPS RISE OVERNIGHT.
LESSER CHCS CONTINUING INTO THE WEEKEND ESPECIALLY ACROSS THE
NORTHERN TIER. THE BAROCLINIC ZONE WILL BE PUSHED SOUTH OF THE AREA
AS 1036MB HIGH PRESSURE MOVES INTO THE REGION SUNDAY...ENDING THE
PCPN THREAT. MAX TEMPS WILL BE BLO END OF NOVEMBER NORMALS WITH 20S
FRI FALLING INTO THE TEENS AND SINGLE DIGITS SATURDAY THROUGH
MONDAY WITH SUNDAY BEING THE COLDEST DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 656 PM CST MON NOV 24 2014
VFR CONDITIONS TO START...BUT AN AREA OF MVFR CIGS APPROACHING THE
REGION FROM THE NORTHWEST...AND SHOULD AFFECT ALL TAF SITES
TONIGHT OR EARLY TUESDAY MORNING. THESE CIGS WILL LIKELY CONTINUE
THROUGH MUCH OF THE DAY ON TUESDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
656 PM CST MON NOV 24 2014
.UPDATE...
ISSUED AT 656 PM CST MON NOV 24 2014
WEAK UPPER SHORTWAVE PRODUCING RADAR RETURNS ACROSS SOUTHWEST
MANITOBA INTO NORTH CENTRAL AND NORTHWEST NORTH DAKOTA. A FEW OB
SITES INDICATING -SN WITH VSBY IN THE 2SM-5SM RANGE. WILL KEEP THE
SCHC POPS FOR LATER THIS EVENING INTO THE OVERNIGHT HOURS FOR THE
FAR WESTERN FA. THE RAP AND HRRR ALSO INDICATE QPF HERE...ALBEIT
VERY LIGHT. THE MAIN CONCERN WITH THIS QPF IS THAT A DRY LAYER
ALOFT WILL BE MOVING INTO THIS REGION AFTER MIDNIGHT...AND WITH
THE LOW-LEVEL MOIST LAYER MEAN TEMPERATURES AROUND -5C TO
-8C...SUPERCOOLED WATER DROPLETS ARE POSSIBLE. INSERTED PATCHY
FREEZING DRIZZLE INTO THE FORECAST FOR THE DEVILS LAKE BASIN AND
SOUTHWARD.
WILL ALSO ISSUE A SPS FOR THE SNOWFALL POTENTIAL TUESDAY
EVENING/OVERNIGHT. WFO BIS HAS A STATEMENT ISSUED...AND IT WOULD
BE BEST TO KEEP THE MESSAGE WITHIN NORTH DAKOTA CONSISTENT.
PLUS...A FEW INDICATIONS FOR MESO-SCALE BANDING (STEEP MID-LEVEL
LAPSE RATE...FRONTOGENESIS...POSSIBLE CONDITIONAL
INSTABILITY)...AND HIGHER RESOLUTION MODELS INDICATING A NARROW
BAND OF QPF UP TO AROUND 0.4 INCHES (SO COULD BE A NARROW BAND OF
3-5 INCHES...BUT LOCATION OF THIS BAND COULD BE ANYWHERE).
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 333 PM CST MON NOV 24 2014
FCST CHALLENGE IS LOW TEMPS TONIGHT AND THEN SNOW THREAT TUESDAY
NIGHT. FOR TONIGHT...SKIES GENERALLY CLEAR OVER MUCH OF ERN/CNTRL
ND WITH LINGERING CLOUDS ROUGHLY ROSEAU TO FARGO TO FORMAN EAST.
CLOUDS IN THE EAST WILL SLOWLY DIMINISH AS LOW PRESSURE MOVES
INTO UPPER MICHIGAN. EXPECT A PERIOD OF CLEAR SKY THIS EVENING IN
ERN ND AND AS WINDS LIGHTEN TEMPS COULD FALL QUICKLY IN SOME
SPOTS. VARIABLE SNOW COVER WILL MAKE LOW TEMPS TOUGH...BUT
GENERALLY EXPECT SINGLE DIGITS. THERE IS A SHORT WAVE IN
SASKATCHEWAN THAT WILL MOVE SOUTHEAST. THERE HAS BEEN SOME VERY
LIGHT WITH THIS ON CANADIAN RADAR BUT MODELS INDICATE PRECIP WILL
DRY OUT MORE AS IT MOVES EAST INTO SFC HIGH. DID KEEP 20 POP FOR
ANY LIGHT SNOW THAT MAY MAKE IT INTO WRN FCST AREA TOWARD MIDNIGHT
OR A BIT AFTER. CLOUDS COMING INTO THE WEST SHOULD MAKE TEMP FALL
STOP AND TEMPS RISE A BIT.
ALBERTA CLIPPER SYSTEM FOR LATER TUESDAY HANDLED A BIT BETTER NOW
WITH CONSENSUS IS TO TAKE SFC LOW THRU SOUTHWESTERN ND INTO
EASTERN SD WITH BAND OF 2-3 INCH SNOWFALL WILLISTON TO CARRINGTON
TO ABOUT WAHPETON-FORMAN AREA. LESSER AMOUNTS EAST OF THIS BUT
STILL EXPECT ENOUGH MOISTURE INTO THE COLDER AIRMASS NORTHEAST OF
THE LOW TO SQUEEZE OUT SOME LIGHT SNOW TUES NIGHT. LOOK FOR A
PERIOD OF WIND (20-25 KTS) SRN VALLEY LATE TUES NIGHT SO WILL NEED
TO WATCH THAT FOR ANY BLOWING SNOW ISSUES IF FORECAST PANS OUT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 PM CST MON NOV 24 2014
BLUSTERY AND COLD WEDNESDAY AS HIGH DROPS SOUTH. NEXT SHORT WAVE
DUE TO MOVE EAST FROM SOUTHERN B.C. INTO MONTANA AND NORTHWESTERN
NORTH DAKOTA THANKSGIVING DAY WITH LIGHT SNOW REACHING DVL BASIN
THURSDAY LATE AFTN. THIS IS A MORE PACIFIC HYBRID TYPE SYSTEM AND
MODELS TYPICALLY HAVE A HARD TIME WITH THESE AND WITH THERMAL
BOUNDARY IN PLACE TRACK OF SYSTEM MAY CHANGE.
THURSDAY NIGHT TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE LONG
HOLIDAY WEEKEND WEATHER. CHC OF SNOW THURSDAY NIGHT THROUGH SATURDAY
NIGHT AS 500MB FLOW BECOMES NEARLY ZONAL AND A BAROCLINIC ZONE SETS
UP ACROSS THE NORTHERN PLAINS. BEST CHC WILL BE THURSDAY NIGHT
ACROSS THE ENTIRE CWFA AS WAA OCCURS AND TEMPS RISE OVERNIGHT.
LESSER CHCS CONTINUING INTO THE WEEKEND ESPECIALLY ACROSS THE
NORTHERN TIER. THE BAROCLINIC ZONE WILL BE PUSHED SOUTH OF THE AREA
AS 1036MB HIGH PRESSURE MOVES INTO THE REGION SUNDAY...ENDING THE
PCPN THREAT. MAX TEMPS WILL BE BLO END OF NOVEMBER NORMALS WITH 20S
FRI FALLING INTO THE TEENS AND SINGLE DIGITS SATURDAY THROUGH
MONDAY WITH SUNDAY BEING THE COLDEST DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 656 PM CST MON NOV 24 2014
VFR CONDITIONS TO START...BUT AN AREA OF MVFR CIGS APPROACHING THE
REGION FROM THE NORTHWEST...AND SHOULD AFFECT ALL TAF SITES
TONIGHT OR EARLY TUESDAY MORNING. THESE CIGS WILL LIKELY CONTINUE
THROUGH MUCH OF THE DAY ON TUESDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1258 AM EST SUN NOV 23 2014
.SYNOPSIS...
MAINLY CLOUDY SKIES WITH EMBEDDED SHOWERS FROM TIME TO TIME
ARE IN STORE FOR TONIGHT IN A RELATIVELY MOIST AND MILD SOUTHWESTERLY
FLOW. FOR SUNDAY AND SUNDAY NIGHT...DEEPENING LOW PRESSURE WILL
PULL A LARGE SWATH OF MOISTURE NORTHWARD...RESULTING IN WIDESPREAD
RAIN SHOWERS. MORE SHOWERS AND WINDY CONDITIONS WILL ACCOMPANY A
COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST 00Z NAM-WRF...HRRR AND RAP INDICATE THAT AREA OF SHOWERS
OVER EAST CENTRAL ILLINOIS/WEST CENTRAL INDIANA WILL EXPAND AND
PIVOT NORTHEAST OVERNIGHT. THIS PCPN IS IN RESPONSE TO AN
EMBEDDED S/WV AND LOW LEVEL JET WITHIN A MOIST SOUTHWEST PLUME.
HAVE INCREASED POPS TO LIKELY FOR NORTHWESTERN ZONES AFTER
MIDNIGHT WITH POPS RAPIDLY DECREASING AS ONE GOES TOWARD THE OHIO
RIVER. SKIES WILL BE MAINLY CLOUDY FOR MOST LOCATIONS.
TEMPERATURES HAVE ALREADY FALLEN OFF CONSIDERABLY IN SOUTH CENTRAL
OHIO AND NORTHEAST KENTUCKY WHILE IT REMAINS MILD ELSEWHERE. WE
SHOULD SEE A GRADUAL DECREASE IN TEMPERATURES NORTHERN/WESTERN
ZONES OVERNIGHT WITH SOME RECOVERY EXPECTED SOUTHEAST AS CLOUDS
THICKEN AND PERHAPS A LITTLE WIND PICKS UP.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AN ELONGATED AREA OF LOW PRESSURE WILL BE STRENGTHENING TO THE
WEST ON SUNDAY. MOISTURE ARRIVING ON AN INCREASING SOUTHERLY FLOW
WILL OVERSPREAD THE AREA...BRINGING RAIN SHOWERS TO ALL LOCATIONS
BY SUNDAY EVENING. THE SHOWERS ARE LIKELY TO CONTINUE SUNDAY NIGHT
AND MONDAY AS THE LOW MOVES NORTH AND DEEPENS OVER THE GREAT
LAKES...WHILE DRAGGING A STRONG COLD FRONT FROM THE WEST. LOOKS
LIKE THE AREA COULD RECEIVE AROUND AN INCH OF RAINFALL ON AVERAGE
BY MONDAY AFTERNOON. SHOWERS SHOULD END MONDAY NIGHT AS THE SYSTEM
LIFTS NORTHEAST.
ANOTHER PROBLEM WILL INVOLVE STRONG WINDS...ESPECIALLY ON MONDAY IN
THE VICINITY OF THE COLD FRONT. CURRENT INDICATIONS ARE THAT
NUMEROUS GUSTS OF 35 TO 45 MPH ARE PROBABLE. IF CONDITIONS ARE
AS SUGGESTED BY THE WINDIER MAV GUIDANCE...THEN A WIND ADVISORY
MAY BE NEEDED.
WARM ADVECTION WILL BRING HIGHS INTO THE MID 50S TO AROUND 60 ON
SUNDAY. HIGHS ON MONDAY SHOULD STAY IN THE 50S WITH COLDER AIR
FILTERING IN FROM THE WEST MONDAY AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
BELOW NORMAL HEIGHTS WITH MEAN TROF OVER THE NATIONS MID SECTION TO
START THE LONG TERM FORECAST PERIOD. PRECIPITATION SHOULD STAY NORTH
OF ILN/S FA WITH SFC HIGH PRESSURE BUILDING INTO THE OHIO VALLEY
TUESDAY. TEMPERATURES WILL BE CLOSE TO 15 DEGREES BELOW NORMAL...
WITH HIGHS FROM THE LOWER 30S NORTH TO THE LOWER 40S SE.
ILN/S FA BETWEEN SYSTEMS ON WED AS SFC HIGH PRESSURE SHIFTS EAST ON
WED. BELOW NORMAL TEMPERATURES TO CONTINUE WITH HIGHS RANGING FROM
THE MID 30S NORTH TO THE LOWER 40S SOUTH.
CLIPPER TYPE SYSTEM TO DROP SE THRU THE GREAT LAKES WITH ASSOCIATED
COLD FRONT SWEEPING EAST THRU ILN/S FA EARLY THURSDAY. WILL BRING
SNOW IN WED NIGHT AND CONTINUE INTO THURSDAY. SOME PCPN MIX WITH BE
POSSIBLE ACRS THE SOUTH. HAVE LEANED TOWARD THE COLDER ECMWF SOLN
AND HAVE LIMITED ANY MIX TO THE SE. BEST POPS ACRS THE NORTH CLOSER
TO THE SFC WAVE. EARLY HIGHS ON THURSDAY TO RANGE FROM THE LOWER 30S
NW TO NEAR 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO BUILD IN ON FRIDAY PROVIDING CONTD COLD
TEMPERATURES AND DRY CONDITIONS. HIGHS ON FRIDAY TO RANGE FROM THE
LOWER 30S NW TO THE UPR 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION AS MID LEVEL FLOW BACKS
WESTERLY. A QUICK RETURN LOW LEVEL FLOW TO DEVELOP ON THE BACK SIDE
OF THE RETREATING HIGH. WILL HOLD OFF ON ANY WAA PCPN UNTIL SATURDAY
NIGHT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AREA OF SHOWERS WILL SKIM KDAY AND KCMH/KLCK WITH A BRIEF MVFR
SHOWER POSSIBLE AT KDAY BEFORE DAYBREAK. AREA MOVES ENE AND
A BRIEF LULL IN SHOWERS OVER THE REGION IS FOUND UNTIL ABOUT NOON
WITH MVFR CIGS. SCATTERED SHOWERS IN THE AFTERNOON MAY PRECEDE
THE MAIN BODY OF HEAVIER RAIN WHICH SHOULD ENTER BEFORE NIGHTFALL.
PREVAILING RAIN WITH IFR CIGS/VSBYS AND A POTENTIAL FOR LIFR
CONDITIONS AT TIMES WILL BE FOUND THROUGH THE END OF THE VALID TAF
PERIOD WITH THE EXCEPTION OF A DRY PUNCH NOTED TO BEGIN AT
KCVG/KLUK 4-5Z. VFR SHOWERS WILL STILL BE POSSIBLE IN THE EXPECTED
LULL THAT SHOULD LAST THROUGH DAYBREAK IN MOST LOCATIONS. SOUTH
WINDS OVERNIGHT WILL SEE GUSTS TO 25 AND 30KT.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES TO CONTINUE INTO
MONDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION. GUSTY
SOUTHWEST WINDS AROUND 35 KNOTS LIKELY MONDAY INTO MONDAY NIGHT.
MVFR CEILINGS POSSIBLE MONDAY NIGHT INTO TUESDAY. MVFR/IFR
CONDITIONS POSSIBLE THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...HICKMAN
SHORT TERM...CONIGLIO/HICKMAN
LONG TERM...AR
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS TULSA OK
243 PM CST SUN NOV 23 2014
.DISCUSSION...
STRONG SHORTWAVE TROUGH COMING IN FROM THE NORTHWEST THIS
AFTERNOON. THE SURFACE FRONT IS WORKING ITS WAY EAST ACROSS
OKLAHOMA...ROUGHLY NEAR THE I-35 CORRIDOR. SOLID BAND OF RAIN
SHOWERS HAS DEVELOPED BEHIND THE FRONT WHERE THE BETTER LOW-MID
LEVEL COLD FRONTOGENETIC FORCING LIES. THE LATEST HRRR ALSO
DEVELOPS SHOWERS AND SOME THUNDER ALONG AND AHEAD OF THE SURFACE
FRONT LATE THIS AFTERNOON AND INTO THE EVENING ACROSS FAR NE OK
AND NW AR. WILL MAINTAIN HIGHEST POPS NEAR THE KS AND MO BORDERS
FOR THIS EVENING. AFTER THIS WAVE PASSES BY...THE REMAINDER OF THE
FORECAST WILL BE DRY. THERE WILL BE A NARROW WINDOW THIS EVENING
WHERE NORTHWEST WINDS BEHIND THE FRONT MAY GET GUSTY ENOUGH TO
FLIRT WITH ADVISORY CRITERIA ACROSS NE OK. NEVERTHELESS...EXPECT A
BREEZY NIGHT AHEAD.
AFTER A WARM DAY TODAY...TEMPS WILL TAIL OFF TO START THE WEEK.
THE COOLEST MORNING WILL PROBABLY BE TUESDAY MORNING. WARMING
TREND THEN KICKS IN BY THE MIDDLE OF THE WEEK AND CONTINUES INTO
THE HOLIDAY WEEKEND. POOR MODEL RUN TO RUN CONSISTENCY CONTINUES
FOR THE HOLIDAY WEEKEND...ESPECIALLY WITH THE ECMWF. THIS MODEL
HAS STRUGGLED WITH THE DEGREE OF UPPER RIDGING ACROSS THE WESTERN
CONUS FOR DAYS AND DAYS...LEAVING OUR AREA WITH DRASTICALLY
DIFFERENT FORECASTS FROM DAY TO DAY. AFTER SUGGESTING A FRONT FOR
NEXT WEEKEND...IT HAS NOW FLOPPED BACK TO A WARM...LESS
AMPLIFIED...MORE PROGRESSIVE REGIME. THE GFS SHOWS A FRONT
DROPPING IN BY THE LATTER PART OF THE WEEKEND...BUT CONFIDENCE IS
LOW...SO STAYED WITH A BLEND OF SOLUTIONS TOWARD DAY 7 AND WILL
MAINTAIN DRY FORECAST. THE BOTTOM LINE IS THAT IT STILL APPEAR
THAT HOLIDAY TRAVEL WILL BE A GO...WHICH IS GOOD NEWS FOR MANY OF
US.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 36 56 30 51 / 40 0 0 10
FSM 39 56 31 53 / 20 0 0 10
MLC 37 58 31 54 / 20 0 0 10
BVO 35 55 24 50 / 50 0 0 10
FYV 34 50 25 47 / 50 0 0 10
BYV 35 47 26 46 / 70 10 0 10
MKO 36 57 29 51 / 30 0 0 10
MIO 34 51 26 47 / 80 0 0 10
F10 37 57 31 52 / 30 0 0 10
HHW 39 60 33 58 / 10 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS MEDFORD OR
913 AM PST SUN NOV 23 2014
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CLOUD COVER THINING OUT
OVER THE NORTHERN PART OF THE FORECAST AREA AND IS GRADUALLY
PUSHING SOUTH. MEANWHILE LOW CLOUDS AND PATCHY FOG WILL PERSIST IN
THE WESTSIDE VALLEYS FOR A FEW MORE HOURS THEN WILL BE REPLACED BY
HIGH CLOUDS. DID NOT SEE ANY EVIDENCE OF PRECIPITATION THIS
MORNING, SO REMOVED ANY MENTION OF PRECIP FOR THIS MORNING AND
AFTERNOON. NEXT WE`LL TAKE A CLOSER LOOK AT PRECIPITATION CHANCES
FOR MONDAY. THE 12Z NAM CONTINUES TO TREND WET. THE GFS HAS ALSO
TRENDED WETTER THE PAST COUPLE OF RUNS, SO CONFIDENCE IS HIGHER
WE`LL HAVE A HIGH POP, LOW QPF EVENT, ESPECIALLY WEST OF THE
CASCADES. -PETRUCELLI
&&
.AVIATION...BASED ON THE 23/12Z TAF CYCLE...VFR CIGS HAVE
DEVELOPED AT KOTH AND KRBG AND EXPECT VFR CONDITIONS TO CONTINUE
INTO THIS AFTERNOON, BUT MOUNTAINS WILL REMAIN PARTLY OBSCURED.
IFR/LIFR CIGS/FOG IN THE ROGUE, ILLINOIS AND WESTERN SISKYOU
COUNTY VALLEYS WILL CONTINUE FOR A FEW MORE HOURS. VFR CIGS WITH
PARTIAL MOUNTAIN OBSCURATIONS ARE EXPECTED THIS AFTERNOON INTO
THIS EVENING. OVERNIGHT, EXPECT AREAS OF VALLEY IFR CIGS IN
PATCHY FOG TO DEVELOP FOR AREAS WEST OF THE CASCADES.
&&
.MARINE...UPDATED 4AM PST SAT NOV 22 2014... STEEP WEST SWELL WILL
PERSIST TODAY INTO MONDAY, THEN SLOWLY DIMINISH MONDAY EVENING AND
TUESDAY. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE WATERS SUNDAY
NIGHT AND MONDAY. WINDS ARE EXPECTED TO BE MAINLY LIGHT AND
SOUTHERLY AROUND 10 TO 20 KT ON MONDAY. ALTHOUGH AT LEAST ONE MODEL
SHOWS 25 KT SMALL CRAFT ADVISORY WINDS POSSIBLE MONDAY INTO MONDAY
EVENING. WEAK HIGH PRESSURE IS EXPECTED TUESDAY INTO WEDNESDAY.
THEN A COUPLE FRONTAL SYSTEMS WILL MOVE INTO THE WATERS WEDNESDAY
NIGHT THROUGH FRIDAY, BRINGING AN INCREASE IN SOUTH WINDS AND
SEAS.
&&
.PREV DISCUSSION... /ISSUED 420 AM PST SUN NOV 23 2014/
DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
420 AM PST SUN NOV 23 2014
UPDATED AVIATION AND MARINE DISCUSSIONS
.DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.AVIATION...BASED ON THE 23/12Z TAF CYCLE...LOW LEVEL MOISTURE
COMBINED WITH HIGH CLOUDS AND WEAK STABILITY IS BRINGING A MIX OF
LOW CLOUDS AND FOG IN INLAND VALLEYS THIS MORNING. EXPECT IFR/LIFR
CIGS/FOG IN THE VALLEYS WEST OF THE SOUTHERN OREGON CASCADES,
INCLUDING KMFR AND KRBG AND POSSIBLY IN NORTHERN CALIFORNIA THIS
MORNING. EAST SIDE AREAS WILL HAVE A MIX OF VFR AND MVFR CIGS THIS
MORNING. ALONG THE COAST, EXPECT MAINLY VFR CONDITIONS WITH LOCAL
MVFR CIGS. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR THIS AFTERNOON
AND CONTINUE INTO THIS EVENING. THEN OVERNIGHT, EXPECT AREAS OF
VALLEY IFR CIGS IN PATCHY FOG TO DEVELOP FOR AREAS WEST OF THE
CASCADES. /CC
&&
.MARINE...UPDATED 4AM PST SAT NOV 22 2014... STEEP WEST SWELL WILL
PERSIST TODAY INTO MONDAY, THEN SLOWLY DIMINISH MONDAY EVENING AND
TUESDAY. A WARM FRONT WILL LIFT NORTHWARD THROUGH THE WATERS SUNDAY
NIGHT AND MONDAY. WINDS ARE EXPECTED TO BE MAINLY LIGHT AND
SOUTHERLY AROUND 10 TO 20 KT ON MONDAY. ALTHOUGH AT LEAST ONE MODEL
SHOWS 25 KT SMALL CRAFT ADVISORY WINDS POSSIBLE MONDAY INTO MONDAY
EVENING. WEAK HIGH PRESSURE IS EXPECTED TUESDAY INTO WEDNESDAY.
THEN A COUPLE FRONTAL SYSTEMS WILL MOVE INTO THE WATERS WEDNESDAY
NIGHT THROUGH FRIDAY, BRINGING AN INCREASE IN SOUTH WINDS AND SEAS.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
BTL/CC/MAS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
406 AM PST SUN NOV 23 2014
.DISCUSSION...
SEVERAL SNOTELS NORTH OF HIGHWAY 140 FROM FOURMILE LAKE NORTH TO
SUMMIT LAKE RELIABLY INDICATE BETWEEN 3 AND 6 INCHES OF NEW SNOW
ACCUMULATED IN THE LAST 24 HOURS BETWEEN 5000 FOOT AND 6200 FOOT
ELEVATIONS. WE EXPECT TO HAVE A NEW REPORT FROM CRATER LAKE
NATIONAL PARK LATER THIS MORNING, WHICH MAY HAVE RECEIVED A LITTLE
MORE THAN TEHSE MENTIONED SNOTELS. FURTHER SOUTH, FROM LAKE OF
THE WOODS TO MOUNT ASHLAND, SNOW REPORTS ABOVE 5000 FEET WERE 1 TO
3 INCHES.
THIS MORNING A 100 TO 130 KNOTS JET STREAM IS STILL PRESENT OVER
THE FORECAST AREA AT 30,000 FT MSL. THIS JET IS STREAMING HIGH
CLOUDS ACROSS THE AREA, WITH LOWER CLOUDS AND SOME FOG BELOW AT
MANY LOCATIONS. WE EXPECT THAT THESE CLOUDS WILL CONTINUE ACROSS
THE FORECAST AREA THROUGH MUCH OF THE DAY AS THE JET STREAM
REMAINS NEARLY STATIONARY, AND ACTUALLY STRENGTHENS SOME TO
120-145 KNOTS.
TODAY AND THEN MORE SO TONIGHT THROUGH TUESDAY THERE SUBSTANTIAL
DISAGREEMENT AMONGST THE MODELS AS TO HOW MUCH PRECIPITATION WILL
FALL ACROSS THE AREA AND WHERE IT WILL FALL. THE HRRR IS
INDICATING PRECIPITATION ALONG THE COAST AND COAST RANGE TODAY.
THE NAM AND SREF MODELS SHOW WIDESPREAD LIGHT PRECIPITATION
BEGINNING THIS EVENING AND CONTINUING THROUGH TUESDAY AFFECTING
NEARLY ALL OF THE FORECAST AREA, AT TIMES, WHEREAS THE GFS AND
ECMWF SHOW LESSER AMOUNTS AND KEEP IT MORE IN THE CASCADES, UMPQUA
BASIN, AND THE OREGON CASCADES. THIS PATTERN IS A FAVORABLE ONE
FOR LIGHT OVERRUNNING PRECIPITATION. WE OFTEN TERM IT A `HIGH
PRECIPITATION PROBABILITY, BUT LOW QPF` TYPE OF EVENT WHEN THIS
PATTERN OCCURS. HOWEVER, GIVEN MODEL DIFFERENCES, WHILE POPS HAVE
BEEN INCREASED, THEY MAY NEED TO BE INCREASED A BIT MORE,
ESPECIALLY IN THE HIGHER CONFIDENCE AREAS MENTIONED. IT IS NOTABLE
THAT THE 06Z GFS HAS TRENDED MORE TOWARD THE NAM12 AND SREF AND
THE THE 06Z NAM12 STUCK TO THE SAME SOLUTION AS WAS DEPICTED ON
THE 00Z RUN. THIS LENDS INCREASING CONFIDENCE IN THE WETTER NAM12
AND SREF SOLUTIONS. WITH THIS LIGHT PRECIPITATION, SNOW LEVELS
WILL BE OF SOME CONCERN, THOUGH IT APPEARS THAT THE OVERRUNNING IS
WEAK ENOUGH THAT WE SHOULD BE LOOKING AT RAIN AND SNOW RATHER THAN
ANY FREEZING RAIN.
SUNDAY THROUGH WEDNESDAY TEMPERATURES WILL BE WARMING
SIGNIFICANTLY ALOFT. IN FACT, THEY WARM TO ABOVE FREEZING TO ABOUT
THE 11,000 FOOT LEVEL. LOW DEWPOINTS SHOULD HELP TO PROTECT THE
SNOW PACK FROM TOO MUCH LOSS, BUT IT WILL STILL BE VERY NOTABLY
WARM. DUE TO GENERALLY LIGHT WINDS, HAVE UNDERCUT MODEL
TEMPERATURES GUIDANCE FOR HIGHS AT INTERIOR VALLEY LOCATIONS FOR
THIS TIME PERIOD.
IT DOES STILL LOOK LIKE A RETURN TO WET WEATHER THIS UPCOMING
WEEKEND. DETAILS ARE STILL TO BE DETERMINED, BUT SNOW LEVELS
LOOK AS IF THEY ARE MOST LIKELY TO BE ON THE HIGH SIDE WITH THAT
FRONTAL SYSTEM. IT CURRENTLY APPEARS THESE SNOW LEVELS WILL
REMAIN ABOVE THE PRIMARY MOUNTAIN PASSES THROUGH NEXT WEEKEND. BTL
&&
.AVIATION...FOR THE 23/06Z TAF CYCLE...THERE IS LOW CONFIDENCE IN
WHETHER THERE ARE CIGS VERSUS FOG OVERNIGHT INTO SUNDAY MORNING DUE
TO UNCERTAIN STABILITY PARAMETERS. USUALLY AFTER A RAIN EVENT,
IT IS TOO UNSTABLE THE FIRST NIGHT FOR WIDESPREAD FOG TO FORM.
HOWEVER, MANY AREAS HAVE CLEARED THIS EVENING, AND THE BOUNDARY
LAYER IS VERY MOIST. THIS COULD SPELL FOG IN AREAS THAT STABILIZE.
THERE SHOULD BE AT LEAST SOME IFR/LIFR CIGS/FOG IN THE VALLEYS
WEST OF THE CASCADES, INCLUDING KMFR AND KRBG AND ALSO IN NORTHERN
CALIFORNIA. EAST SIDE AREAS AND THE COAST WILL HAVE A MIX OF VFR
AND MVFR CIGS, THOUGH PATCHY IFR CANNOT BE RULED OUT THERE EITHER.
SPILDE
&&
.MARINE...UPDATED 8PM PST SAT NOV 22 2014...
WESTERLY SWELL WILL PERSIST THE REMAINDER OF THIS WEEKEND THEN
SLOW DIMINISH INTO NEXT WEEK. A WARM FRONT WILL LIFT NORTHWARD
THROUGH THE WATERS SUNDAY NIGHT INTO MONDAY WITH LIGHT SOUTH WINDS
AND SOME LIGHT RAIN. MAINLY LIGHT SOUTH TO SOUTHWEST WINDS ARE
EXPECTED THROUGH MIDWEEK. A FRONTAL SYSTEM WILL MOVE IN WEDNESDAY
NIGHT INTO THURSDAY THAT MAY BRING AN INCREASE IN SOUTH WINDS AND
SEAS. UNSETTLED WEATHER IS EXPECTED LATE THIS WEEK INTO THE
WEEKEND. SPILDE
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST MONDAY
FOR PZZ350-356-370-376.
$$
BTL/CC/MAS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1057 PM CST SAT NOV 22 2014
.UPDATE...
ISSUED AT 940 PM CST SAT NOV 22 2014
STRATUS CONTINUES TO MOVE BACK INTO THE REGION TONIGHT. HRRR AND
RAP SEEM TO HAVE A GOOD HANDLE ON THIS...KEEPING MOST OF THE
STRATUS ALONG AND EAST OF INTERSTATE 29. SIGNAL FOR DENSE FOG IN
THE MODELS IS LESS THAN LAST NIGHT AND CURRENTLY NOT SEEING MUCH
OUT THERE. WILL KEEP FOG IN THE FORECAST...BUT PROBABILITY OF
WIDESPREAD DENSE FOG SEEMS TO BE DECREASING...ALTHOUGH WILL NEED
TO CONTINUE TO MONITOR.
OTHERWISE WATCHING SOME LIGHT PRECIPITATION THAT WILL TRY TO MOVE
ACROSS THE REGION TONIGHT INTO TOMORROW ASSOCIATED WITH A PRETTY
GOOD AREA OF MID LEVEL FRONTOGENESIS. WILL HAVE TO OVERCOME QUITE
A BIT OF DRY AIR IN THE LOW LEVELS...BUT STILL COULD SEE SOME
LIGHT PRECIPITATION WORK FROM WEST TO EAST INTO EARLY TOMORROW
AFTERNOON. DID GO AHEAD AND CHANGE PRECIPITATION TYPE TO ALL RAIN
THOUGH. EXPECT SURFACE TEMPERATURES TO REMAIN ABOVE FREEZING...AND
MODEL SOUNDINGS SUGGEST PLAIN RAIN IS THE MOST LIKELY PRECIPITATION
TYPE. SREF PROBABILITIES ALSO BACK THIS UP...SO FELT COMFORTABLE
REMOVING MENTION OF SNOW. CAN NOT COMPLETELY RULE OUT A FEW FLAKES
MIXED IN...BUT SHOULD MAINLY BE A CHILLY LIGHT RAIN IF ANYTHING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
ANOTHER DIFFICULT FORECAST IN THE SHORT TERM AS LOW CLOUDS AND
STRATUS STRUGGLING TO ERODE ACROSS THE EASTERN HALF OF THE FORECAST
AREA. WHERE THE STRATUS HAS ERODED...TEMPERATURES HAVE RECOVERED
NICELY IN THE 40S AND 50S...BUT ACROSS THE EAST UNDER THE BLANKET OF
LOW CLOUDS...TEMPERATURES HAVE REMAINED STEADY IN THE 30S. EXPECT
THE EAST TO FILL BACK IN WITH LOW CLOUDS AND FOG TONIGHT...AND MAY
HAVE TO ISSUE A DENSE FOG ADVISORY TONIGHT FOR PORTIONS OF THE
FORECAST AREA. BEST CHANCES APPEAR TO BE ALONG AND EAST OF A LINE
FROM VERMILLION TO MARSHALL AND EAST. EXPECT VISIBILITIES TO
IMPROVE AS SURFACE TROUGH SHIFTS EAST AND WINDS BECOME NORTHWEST
DRYING OUT THE LOW LEVELS. WITH THE PASSAGE OF THE TROUGH...COULD
HAVE A SMALL AMOUNT OF PRECIPITATION WITH STRONG 700 MB
FRONTOGENESIS COINCIDING WITH WEAK DIV Q ALOFT. PRECIP TYPE COULD
BE A REAL CONCERN THROUGH THE MORNING HOURS WITH TEMPERATURES AT
THE SURFACE NEAR FREEZING. TOUGH CALL IN TERMS OF PRECIP
TYPE...FOR NOW...KEPT PRECIP TYPES CONFINED TO RAIN OR SNOW...BUT
COULD BE POTENTIAL FOR FREEZING RAIN WITH WARM DRY LAYER IN THE
LOWEST 2000 FEET OF THE ATMOSPHERE. EXPECT PRECIP TO BE ALL RAIN
AS IT SHIFTS FURTHER EAST INTO LOCATIONS WHERE TEMPERATURES REMAIN
ABOVE FREEZING. HIGH TEMPERATURES A TOUGH CALL ON SUNDAY...WITH
925 HPA TEMPS COOLING FROM NEAR 10C DOWN CLOSER TO 5C BY 0Z
MONDAY. FURTHER BACK TO THE NORTHWEST...925 HPA TEMPS HOVER IN THE
LOWER SINGLE DIGITS LEADING TO A RELATIVELY SMALL DIURNAL
FLUCTUATION UNDER A MOSTLY CLOUDY SKY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 415 PM CST SAT NOV 22 2014
BY SUNDAY NIGHT...NORTHWEST WINDS INCREASE TO 20 TO 30 MPH WITH
HIGHER GUSTS TO 45 MPH. COLDER AIR BEGINS RUSHING BACK INTO THE
REGION...WITH TEMPERATURES DROPPING BACK BELOW FREEZING IN THE
EVENING AND REACHING THE TEENS AND LOWER 20S BY DAYBREAK MONDAY. AS
THE NORTHERN STREAM UPPER TROUGH DIGS INTO THE NORTHERN PLAINS AND
MERGES WITH THE SOUTHERN STREAM WAVE TO OUR EAST...SOME SCATTERED
LIGHT SNOWFALL WILL TRACK SOUTHEAST ACROSS THE FORECAST
AREA...HOWEVER THE BETTER FORCING REMAINS TO OUR EAST AND WITHOUT A
GREAT DEAL OF MOISTURE...ANY SNOWFALL WILL BE ON THE LIGHT SIDE.
COULD SEE AROUND A HALF INCH TO INCH IN SOUTHWEST MINNESOTA...
OTHERWISE A FEW TENTHS OR TRACE AT BEST. ADDITIONALLY...WITH THE
GUSTY WINDS...THE LIGHT SNOW WILL BLOW AROUND A BIT...BUT AMOUNTS
WILL BE TOO LIGHT FOR ANY BLOWING SNOW MENTION. ANY EXISTING SNOW
PACK SHOULD HAVE ENOUGH OF A CRUST TO NOT CAUSE ANY BLOWING SNOW
ISSUES EITHER.
WITH THE DEEP UPPER LEVEL TROUGH SLIDING ACROSS THE WESTERN GREAT
LAKES AND SHARP RIDGING ALONG THE WEST COAST...UPPER LEVEL NORTHWEST
FLOW SETTLES INTO THE AREA. WHILE NOT PARTICULARLY A COLD
AIRMASS...TEMPERATURES REMAIN BELOW NORMAL IN THE MID 20S TO MID 30S
ON TUESDAY AND WEDNESDAY. MODELS TRACK A CLIPPER WAVE ALONG THE
UPPER FLOW...ALTHOUGH THE TIMING...TRACK AND STRENGTH OF THIS FAST
MOVING WAVE REMAINS IN POOR AGREEMENT. THE GFS IS QUITE A BIT FASTER
THAN THE OTHER MODELS...FOLLOWED BY THE ECMWF THEN THE NAM. BUT IT
SEEMS THE GENERAL CONSENSUS IS FOR THE BEST CHANCE OF LIGHT SNOW IN
OUR NORTHEASTERN COUNTIES ON TUESDAY NIGHT.
UNCERTAINTY FURTHER INCREASES WEDNESDAY AND WEDNESDAY NIGHT AS THE
BAROCLINIC ZONE SETS UP NEAR THE FORECAST AREA AND POTENTIALLY
BECOMES THE FOCUS MECHANISM OF ADDITIONAL LIGHT PRECIPITATION AS
WARM AIR ADVECTION LIFTS INTO CENTRAL SD AND THE MID MISSOURI
VALLEY. CONFIDENCE IS FAIRLY LOW WITH WHERE THIS WILL SET UP...BUT
WILL LEAVE SOME ISOLATED LIGHT SNOWFALL MENTION WEDNESDAY AND
WEDNESDAY NIGHT.
MODELS WAVER WITH BRINGING FURTHER WAVES ALONG THE FLOW...BUT NOT A
LOT OF CONFIDENCE IN THE TIMING. THANKSGIVING LOOKS TO BE THE
COLDEST DAY IN THE EXTENDED WITH HIGHS ONLY IN THE TEENS AND LOWER
20S FOLLOWED BY THURSDAY NIGHT LOWS IN THE SINGLE DIGITS. FRIDAY
TEMPERATURES MODERATE SOME INTO THE UPPER TEENS TO NEAR 30.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1055 PM CST SAT NOV 22 2014
EXPECT MVFR TO IFR CIGS AND VIS ACROSS NORTHWEST IOWA AND ADJACENT
PORTIONS OF SOUTHWEST MINNESOTA TONIGHT...SO INCLUDED MENTION IN THE
KSUX TAF. BASED ON OBS WILL KEEP KSUX MVFR...BUT IFR AND LIFR CIGS
ARE NOT TOO FAR AWAY AND COULD MOVE IN...SO SOMETHING TO WATCH.
COULD SEE SOME DENSE FOG FORM...ALTHOUGH LATEST GUIDANCE SUGGESTS
WIDESPREAD DENSE FOG IS PROBABLY BECOMING LESS LIKELY. AGAIN KFSD
WILL BE NEAR THE EDGE OF THIS STRATUS AND FOG...BUT BASED ON LATEST
MODEL GUIDANCE LEANING TOWARDS THEM STAYING VFR...BUT WILL CONTINUE
TO MONITOR. EXPECT ANY STRATUS TO CLEAR EARLY TO MID MORNING AS A
FRONT SWITCHES WINDS TO THE WEST AND NORTHWEST. COULD BE A LITTLE
LIGHT RAIN AS THE FRONT CROSSES...BUT NOT EXPECTING ANYTHING OF
SIGNIFICANCE AT THIS TIME. WINDS WILL INCREASE BEHIND THE
FRONT...AND BY LATE MORNING AND AFTERNOON EXPECTING GUSTS OF 30 TO
40 KTS TO BE COMMON AND LAST INTO THE OVERNIGHT. ALSO SHOULD SEE
STRATOCU DEVELOPMENT BEHIND THE FRONT IN THE COLD AIR ADVECTION
REGIME...WITH HEIGHTS LIKELY HIGH END MVFR OR LOW END VFR. ALSO
SHOULD BE SCATTERED FLURRIES OR SNOW SHOWERS INTO THE
OVERNIGHT...AND GIVEN THE STRONG WINDS COULD SEE BRIEF PERIODS OF
VISIBILITY REDUCTION...SO WILL HAVE TO WATCH FOR THAT AS WELL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1156 AM CST SUN NOV 23 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
18Z TAF CYCLE
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN. WINDS WILL VEER FROM
THE SE TO THE SSW AT 10-12 KTS BY THIS EVENING AND INCREASE
MARKEDLY AS THE COLD FRONT MOVES THROUGH WITH GUSTS TO 30 KTS.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1150 AM CST SUN NOV 23 2014
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
18Z TAF CYCLE
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1148 AM CST SUN NOV 23 2014
.UPDATE...
&&
.DISCUSSION...
&&
.PREV DISCUSSION... /ISSUED 1027 AM CST SUN NOV 23 2014/
UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
WIDESPREAD RAIN AND IFR CONDITIONS HAVE SPREAD ACROSS THE
MIDSOUTH. RAIN WILL END FROM SW TO NE LATE THIS AFTERNOON AS
SYSTEM LIFTS THROUGH. THERE IS A SMALL CHANCE OF A TSRA AT KTUP
BUT POTENTIAL TOO LOW TO MENTION. CONDITIONS WILL LIFT TO MVFR AS
THE RAIN ENDS. HOWEVER EXPECT LOW CLOUDS TO REMAIN OVERNIGHT INTO
MONDAY MORNING EXCEPT THEY MAY CLEAR FOR A SHORT TIME AT KTUP
LATER THIS EVENING BEFORE FILLING BACK IN.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1027 AM CST SUN NOV 23 2014
.UPDATE...
WIDESPREAD RAIN CONTINUES TO SPREAD NORTHWARD OVER THE MIDSOUTH.
RAIN WILL BE AROUND FOR MUCH OF THE DAY. RIGHT NOW...ANY THUNDER
THAT IS OCCURRING IS TO THE SOUTH AND EAST OF THE CWA. CAN/T RULE
OUT A FEW EMBEDDED THUNDERSTORMS OCCURRING LATER THIS AFTERNOON.
CURRENT TEMPERATURES ARE IN THE UPPER 50S AND WILL LIKELY HOVER
AROUND THERE FOR MOST OF THE DAY. THERE IS A WARM FRONT LOCATED
ACROSS SOUTHERN MISSISSIPPI THAT WILL SURGE NORTHWARD LATE THIS
AFTERNOON INTO THE EARLY EVENING. TEMPERATURES COULD SHOOT UP
RIGHT BEFORE THE END OF THE DAY THUS AM RELUCTANT TO LOWER
FORECASTED HIGHS. CURRENT FORECAST LOOKS GOOD FOR NOW.
KRM
&&
.DISCUSSION.../ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGE DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
12Z TAF CYCLE
CIGS WILL CONTINUE TO LOWER EARLY THIS MORNING TO MVFR CONDITIONS
AS A LARGE SHIELD OF RAINFALL APPROACHES FROM THE SOUTHWEST.
MODERATE RAINFALL WILL OVERSPREAD ALL TERMINALS BY
14/15Z...DEPENDING ON THE TERMINAL. INTERMITTENT IFR CONDITIONS
ARE LIKELY AS CIGS CONTINUE TO LOWER IN PRECIP. A GOOD SIGNAL
EXISTS FOR LOWERED VISBYS AS WELL...ESPECIALLY AT TUP WHERE BETTER
LOW LEVEL MOISTURE IS ALREADY IN PLACE. FOR THIS REASON...HAVE
INSERTED BR AT ALL TERMINALS THROUGH 00Z. BEST CHANCE FOR
THUNDERSTORMS EXISTS AT MKL AND TUP THROUGH THE EARLY
AFTERNOON. ATMOSPHERIC INSTABILITY AT MEM AND JBR DOES NOT LOOK
SUPPORTIVE OF THUNDER MENTION AT THIS TIME...BUT WILL WATCH TRENDS
THROUGH THE MORNING. SLOWLY RAISE CIGS AFTER 03-06Z AT ALL
TERMINALS AS WINDS INCREASE DRAMATICALLY FROM THE WEST WITH COLD
FRONTAL PASSAGE. THIS WILL OCCUR EARLIER AT WESTERN TERMINALS AND
LATER AT EASTERN TERMINALS. WINDS COULD GUST TOWARD 30KTS BEHIND
THE FRONT.
TVT
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
530 AM CST SUN NOV 23 2014
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 438 AM CST SUN NOV 23 2014/
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGH DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
.AVIATION...
12Z TAF CYCLE
CIGS WILL CONTINUE TO LOWER EARLY THIS MORNING TO MVFR CONDITIONS
AS A LARGE SHIELD OF RAINFALL APPROACHES FROM THE SOUTHWEST.
MODERATE RAINFALL WILL OVERSPREAD ALL TERMINALS BY
14/15Z...DEPENDING ON THE TERMINAL. INTERMITTENT IFR CONDITIONS
ARE LIKELY AS CIGS CONTINUE TO LOWER IN PRECIP. A GOOD SIGNAL
EXISTS FOR LOWERED VISBYS AS WELL...ESPECIALLY AT TUP WHERE BETTER
LOW LEVEL MOISTURE IS ALREADY IN PLACE. FOR THIS REASON...HAVE
INSERTED BR AT ALL TERMINALS THROUGH 00Z. BEST CHANCE FOR
THUNDERSTORMS EXISTS AT MKL AND TUP THROUGH THE EARLY
AFTERNOON. ATMOSPHERIC INSTABILITY AT MEM AND JBR DOES NOT LOOK
SUPPORTIVE OF THUNDER MENTION AT THIS TIME...BUT WILL WATCH TRENDS
THROUGH THE MORNING. SLOWLY RAISE CIGS AFTER 03-06Z AT ALL
TERMINALS AS WINDS INCREASE DRAMATICALLY FROM THE WEST WITH COLD
FRONTAL PASSAGE. THIS WILL OCCUR EARLIER AT WESTERN TERMINALS AND
LATER AT EASTERN TERMINALS. WINDS COULD GUST TOWARD 30KTS BEHIND
THE FRONT.
TVT
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
438 AM CST SUN NOV 23 2014
.DISCUSSION...
EARLY THIS MORNING...A MESOSCALE CONVECTIVE SYSTEM WAS MOVING
EASTWARD ALONG THE NORTHWEST GULF AHEAD OF A STRONG UPPER LEVEL
TROUGH. MOST OF THE MIDSOUTH REMAINED RAIN FREE WITH JUST SOME
PATCHY LIGHT RAIN. A WEAK FRONT EXTENDED ACROSS NORTHEAST AR AND THE
MO BOOTHEEL. SOUTHEAST WINDS WERE PUSHING MILDER AIR INTO THE AREA
TO THE SOUTHEAST OF THE FRONT WITH SOME TEMPERATURES NEAR THE 60
DEGREE MARK.
THE UPPER LEVEL TROUGH WILL MOVE EAST NORTHEASTWARD ACROSS THE
MIDSOUTH TODAY WITH A STRENGTHENING SURFACE LOW TO OUR WEST. THE GFS
INDICATES A 987 MB LOW OVER SOUTHWEST MO AT SUNSET WHILE THE ECMWF
HAS THE PRESSURE AT 992 MB. MODELS ARE STILL SHOWING WIDESPREAD
SHOWERS MOVING QUICKLY INTO THE MIDSOUTH FROM THE SOUTHWEST TODAY.
THE HRRR MODEL INDICATES THAT THE ENTIRE FORECAST AREA WILL HAVE
SOME RAIN BY NOON THAT WILL THEN PERSIST INTO THE AFTERNOON BEFORE
DIMINISHING FROM THE SOUTHWEST. SHOWERS WILL HELP TO HOLD
TEMPERATURES DOWN. THIS INITIAL UPPER LEVEL TROUGH IS FORECAST TO BE
MOVING TO THE NORTHEAST OF THE REGION BY 6 PM. PRECIPITABLE WATER
VALUES WILL CLIMB TO AROUND 1.5 INCHES TODAY AS SOUTHERLY WINDS
SURFACE AND ALOFT TAP INTO GULF MOISTURE. WILL CONTINUE TO MENTION
THE THREAT OF LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER
OUTLOOK WITH SOME HEAVY DOWNPOURS. MOST SPOTS ARE EXPECTED TO PICK
UP AROUND AN INCH OF RAIN BUT SOME LOCATIONS MAY SEE 1 1/2 INCHES.
INSTABILITY WILL BE MARGINAL AT BEST WITH THIS SYSTEM FOR MOST OF
OUR AREA. HOWEVER...MODELS DO INDICATE SOME ELEVATED INSTABILITY AND
MAYBE A LITTLE SURFACE BASED INSTABILITY DEVELOPING OVER NORTHEAST
AR AND THE MO BOOTHEEL LATE THIS AFTERNOON AND EVENING. THIS WILL BE
AHEAD OF THE SURFACE LOW OVER MO AND A COLD FRONT TRAILING TO THE
SOUTH. IN ADDITION...DIFFLUENCE ALOFT DEVELOPS OVER THE REGION AHEAD
OF A TRAILING UPPER LEVEL TROUGH. WILL MENTION A FEW STRONG
THUNDERSTORMS FOR THIS AREA LATE THIS AFTERNOON AND EARLY EVENING
WITH STRONG GUSTY WINDS AND SMALL HAIL POSSIBLE...ALTHOUGH A
LIMITING FACTOR WILL BE THAT SURFACE DEW POINTS WILL STRUGGLE TO
EVEN REACH THE 60 DEGREE MARK.
THE COLD FRONT WILL MOVE QUICKLY THROUGH THE MIDSOUTH TONIGHT WITH A
CONTINUED CHANCE OF SHOWERS ACROSS THE AREA. THE BEST CHANCE WILL BE
FROM PORTIONS OF NORTHEAST AR AND THE MO BOOTHEEL INTO PORTIONS OF
NORTHWEST TN WHERE THE BEST UPPER LEVEL DYNAMICS WILL OCCUR WITH
THE SECONDARY UPPER LEVEL TROUGH. WINDS WILL INCREASE AND TURN TO
THE SOUTHWEST AND WEST TONIGHT INTO MONDAY. FOR NOW...HAVE THE WIND
SPEEDS JUST SHY OF NEEDING A WIND ADVISORY FOR A LARGE SECTION OF
THE AREA. WILL ADD TO THE HAZARDOUS WEATHER OUTLOOK THAT A WIND
ADVISORY MAY BECOME NECESSARY. NORTHEAST MS LOOKS TO BE THE AREA
LEAST LIKELY TO NEED A WIND ADVISORY.
COOLER AND DRIER AIR WILL SPREAD INTO THE AREA MONDAY ON BREEZY
WESTERLY WINDS. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY.
TEMPERATURES WILL ONCE AGAIN DROP TO BELOW NORMAL LEVELS AND
CONTINUE THAT WAY FOR AT LEAST A FEW DAYS. KEPT THE FORECAST
PRECIPITATION FREE THROUGH SATURDAY. THE GFS DOES INDICATE A WEAK
CLIPPER TYPE SYSTEM MOVING ACROSS THE AREA WEDNESDAY BUT MOISTURE
LOOKS LIMITED WITH MAINLY JUST AN INCREASE IN MIDDLE LEVEL CLOUDS
EXPECTED.
THE ECMWF AND GFS ARE SIGNIFICANTLY DIFFERENT BEGINNING THANKSGIVING
DAY. THE ECMWF SHOWS MODIFIED ARCTIC AIR SLOWLY PUSHING INTO THE
AREA FROM THE NORTH THURSDAY AFTERNOON THROUGH SATURDAY. THE GFS
PUSHES THE COLD HIGH TO THE EAST WITH WINDS TURNING TO THE SOUTH
ACROSS THE MIDSOUTH. THIS RESULTS IN HUGH DIFFERENCES IN
TEMPERATURES FOR THE REGION...ALTHOUGH CHANCES FOR PRECIPITATION
LOOK SMALL WITH EITHER SCENARIO. FOR NOW...KEPT CLOSE TO THE
EARLIER FORECAST EXCEPT BLENDED THE TEMPERATURES A LITTLE BETTER
WITH SURROUNDING OFFICES.
JCL
&&
.AVIATION...
06Z TAF CYCLE
CIGS WILL GRADUALLY LOWER TO MVFR LEVELS TONIGHT
THEN TO IFR LEVELS AS STEADY RAIN BEGINS TOWARD MORNING.
THUNDERSTORMS ARE POSSIBLE AT MEM...MKL AND ESPECIALLY TUP
TOMORROW...ALTHOUGH NOT EXPECTED TO BE NUMEROUS. WILL INCLUDE VCTS
AT THESE 3 STATIONS AND KEEP AN EYE ON RADAR TO SEE IF PREVAILING
THUNDER IS NEEDED TOMORROW. ONCE RAIN BEGINS...IT SHOULD BE
RELATIVELY STEADY TOMORROW...MVFR VISIBILITY IS EXPECTED
THROUGHOUT THE DAY TOMORROW...POSSIBLE LOWERING TO IFR FOR BRIEF
PERIODS. SOUTHERLY WINDS WILL CONTINUE TOMORROW...INCREASING LATE
TOMORROW AFTERNOON TO 10-15KT WITH HIGHER GUSTS. WILL BRING
PREVAILING RAIN TO AN END AFTER SUNSET...BUT NOT COMFORTABLE WITH
AGGRESSIVELY IMPROVING CIGS AS SOME GUIDANCE SUGGESTS.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1154 AM CST SUN NOV 23 2014
.UPDATE...
FOR THIS AFTERNOON...TWEAKED AFTERNOON TEMPERATURES FOR THE FRONTAL
PASSAGE. WE HAVE ALREADY REACHED MAXIMUMS ACROSS MUCH OF THE AREA AND
TEMPERATURES WILL CONTINUE DOWNWARD SPIRAL FOR REST OF AFTERNOON.
UPGRADED PRECIPITATION TO CATEGORICAL VALUES AS A LARGE AREA OF LIGHT
PRECIPITATION CONTINUES TO TRAVEL SOUTHEAST ACROSS THE PANHANDLES.
LIGHT RAIN...BUT WITH COLDER AIR...FLURRIES WILL BE POSSIBLE FOR THE
AFTERNOON HOURS. A POSSIBLE DUSTING OF SNOW IN A FEW LOCATIONS OF THE
WESTERN AND NORTHERN TEXAS PANHANDLE AND OKLAHOMA PANHANDLE ...BUT
OTHERWISE DO NOT EXPECT WIDESPREAD SIGNIFICANT ACCUMULATIONS. WINDS
WILL REMAIN GUSTY AND THE WIND ADVISORY WILL CONTINUE.
PRECIPITATION...CLOUDS AND WINDS SHOULD ALL BE ON THE DECREASE AFTER
SUNSET LEADING TO A COLD OVERNIGHT.
GARCIA
&&
.PREV DISCUSSION... /ISSUED 1117 AM CST SUN NOV 23 2014/
AVIATION...
18Z TAFS...A COLD FRONT CONTINUES TO RACE SOUTHWARD ACROSS THE
PANHANDLES. WINDS BEHIND THE FRONT WILL BE A SIGNIFICANT AVIATION
CONCERN THROUGH 00Z. WINDS OF 30 KNOTS WITH GUSTS TO 40 KNOTS ARE
FORECST AT KAMA...KDHT AND KGUY. LIGHT SHOWERS WITH SOME SNOW
FLURRIES ARE ALSO FORECAST FOR MUCH OF THE AFTERNOON. THESE SHOWERS
COULD TEMPORARILY REDUCE CIELINGS AND VISIBILTIES TO MVFR CONDITIONS
FOR A FEW HOURS. AFTER 00Z SHOWERS AND WINDS WILL BE ON THE DECREASE.
WINDS WILL LIGHTEN TO LESS THAN 15 KNOTS AND EXPECT CLOUDS WILL BE
DISSIPATING WITH CLEARING AFTER 06Z.
GARCIA
PREV DISCUSSION... /ISSUED 546 AM CST SUN NOV 23 2014/
AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1117 AM CST SUN NOV 23 2014
.AVIATION...
18Z TAFS...A COLD FRONT CONTINUES TO RACE SOUTHWARD ACROSS THE
PANHANDLES. WINDS BEHIND THE FRONT WILL BE A SIGNIFICANT AVIATION
CONCERN THROUGH 00Z. WINDS OF 30 KNOTS WITH GUSTS TO 40 KNOTS ARE
FORECST AT KAMA...KDHT AND KGUY. LIGHT SHOWERS WITH SOME SNOW
FLURRIES ARE ALSO FORECAST FOR MUCH OF THE AFTERNOON. THESE SHOWERS
COULD TEMPORARILY REDUCE CIELINGS AND VISIBILTIES TO MVFR CONDITIONS
FOR A FEW HOURS. AFTER 00Z SHOWERS AND WINDS WILL BE ON THE DECREASE.
WINDS WILL LIGHTEN TO LESS THAN 15 KNOTS AND EXPECT CLOUDS WILL BE
DISSIPATING WITH CLEARING AFTER 06Z.
GARCIA
&&
.PREV DISCUSSION... /ISSUED 546 AM CST SUN NOV 23 2014/
AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
OK...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
546 AM CST SUN NOV 23 2014
.AVIATION...
12Z TAFS...A COLD FRONT WILL PUSH THROUGH THE PANHANDLES THIS
MORNING...WITH STRONG NORTH/NORTHWEST WINDS KICKING UP BEHIND IT.
WINDS WILL REACH SUSTAINED SPEEDS AROUND 30 KTS WITH GUSTS TO AROUND
40 KTS...BEFORE DISSIPATING LATE THIS AFTERNOON AS THE PRESSURE
GRADIENT BEGINS TO RELAX. AN AVIATION WEATHER WARNING WILL BE IN
EFFECT FOR KAMA FROM 14Z-22Z. A PERIOD OF MVFR CIGS IS EXPECTED
BEHIND THE FRONT...AND SOME LIGHT RAIN OR SNOW SHOWERS WILL ALSO BE
POSSIBLE FOR ABOUT A 4-HOUR PERIOD IN WAKE OF THE FRONT. COMBINATION
OF THE STRONG WINDS AND LIGHT PRECIPITATION...ALONG WITH POSSIBLE
BLDU...MAY RESULT IN SOME MVFR VSBYS. CONDITIONS WILL IMPROVE LATE
THIS AFTERNOON AS WINDS START TO DIMINISH AND VFR CONDITIONS RETURN
FOR THE REMAINDER OF THE TAF PERIOD.
KB
&&
.PREV DISCUSSION... /ISSUED 302 AM CST SUN NOV 23 2014/
DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/15
AREA FORECAST DISCUSSION
NWS AMARILLO TX
302 AM CST SUN NOV 23 2014
.DISCUSSION...
VIGOROUS UPPER LEVEL SHORT WAVE TROUGH CROSSING THE ROCKIES WILL
DRIVE A STRONG CANADIAN COLD FRONT THROUGH THE REGION THIS
MORNING. WINDS ARE EXPECTED TO REACH WIND ADVISORY CRITERIA
WITH THIS FRONT FROM LATE THIS MORNING INTO THE EARLY AFTERNOON.
SURFACE PRESSURE GRADIENT ALONG WITH 850MB AND 700 MB HEIGHT
GRADIENTS ALL POINT TO THE POTENTIAL OF SUSTAINED 35 MPH WINDS
WITH HIGHER GUSTS. HAVE ADDED THE MENTION OF BLOWING DUST WITH
THESE HIGHER WINDS AS WELL. MODELS HAVE ALSO COME IN WETTER WITH THIS
SYSTEM. LATEST TTU WRF AND HRRR MODELS SUGGEST THAT AT LEAST SOME
KIND OF BAND OF PRECIP WILL TRAVERSE THE PANHANDLES TODAY. HAVE GONE
AHEAD AND INCREASED THE POPS TO 30 PERCENT ACROSS THE PANHANDLES.
BELIEVE THAT THE PRECIP COULD BE RAIN OR SNOW. AS THE DAY WEARS ON
THE COLUMN COOLS QUITE A BIT. THE ENTIRE CLOUD LAYER REMAINS BELOW 0
DEGREES CELSIUS AND THERE IS MOISTURE IN THE -10 TO -20 DEGREE
CELSIUS RANGE TO HELP FORM SOME SNOW FLAKES. TEMPERATURES MAY
ACTUALLY HOLD STEADY OR FALL THIS AFTERNOON AS THICKNESSES CRASH. SO
WOULD NOT BE SURPRISED TO SEE SOME SNOW SHOWERS WITH TEMPERATURES IN
THE LOWER 40S.
A FEW SNOW SHOWERS MAY LINGER NEAR THE NEW MEXICO STATE LINE
TONIGHT IN THE BEST UPSLOPE AREA...BUT THEY WILL REMAIN LIGHT.
AFTER TONIGHT THIS SYSTEM MOVES OFF TO OUR EAST AND A NORTHWEST FLOW
ALOFT DOMINATES THE PANHANDLES FOR THE EARLY PART OF THE WEEK.
THE MODELS START TO DIFFER SOMEWHAT BY THANKSGIVING. THE GFS
BROADENS AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS. MEANWHILE...THE ECMWF TRIES TO CARVE OUT AN
UPPER LEVEL TROUGH FROM SOUTHWEST CANADA INTO THE CENTRAL
PLAINS...WHICH WOULD PUSH ANOTHER CANADIAN COLD FRONT THROUGH THE
AREA BY THANKSGIVING AFTERNOON LEAVING FRIDAY AND SATURDAY COLDER.
THE GFS DOES NOT BRING IN THE COLDER AIR UNTIL NEXT WEEKEND. FOR
NOW HAVE GONE WITH A COMPROMISE WITH THE TEMPERATURES. AT ANY RATE
THE MODELS REMAIN DRY AFTER TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 46 28 51 22 51 / 30 20 0 5 0
BEAVER OK 48 23 53 21 53 / 30 10 0 0 0
BOISE CITY OK 46 21 51 19 52 / 30 20 0 0 0
BORGER TX 53 30 53 25 54 / 30 10 0 0 0
BOYS RANCH TX 49 27 52 22 53 / 30 20 0 5 0
CANYON TX 48 27 54 22 52 / 30 20 0 0 0
CLARENDON TX 52 31 55 28 52 / 30 10 0 0 0
DALHART TX 49 20 53 18 51 / 30 20 0 5 0
GUYMON OK 49 22 50 21 52 / 30 10 0 0 0
HEREFORD TX 49 25 53 21 53 / 30 20 0 0 0
LIPSCOMB TX 47 26 53 24 53 / 30 10 0 0 0
PAMPA TX 45 27 49 24 48 / 30 10 0 0 0
SHAMROCK TX 54 29 57 28 53 / 30 10 0 0 0
WELLINGTON TX 57 31 60 30 54 / 30 10 0 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/15
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1149 PM CST SAT NOV 22 2014
.AVIATION...
CONVECTION HAS MOVED OFF TO THE EAST AND CONDITIONS ARE RAPIDLY
IMPROVING. FOR THE NEXT COUPLE OF HOURS WINDS IN AUSTIN AND SAN
ANTONIO WILL BE FROM THE NORTH ON THE BACK SIDE OF AN AREA OF LOW
PRESSURE. AFTER ABOUT 07Z WINDS WILL BECOME WESTERLY AND WEAKEN.
SKIES WILL BECOME MAINLY CLEAR AND THE ONLY ISSUE WILL BE THE
WINDS. WIND SPEEDS WILL INCREASE TO 10 TO 15 KTS DAYTIME TOMORROW
AND THEN WEAKEN AND SHIFT TO NORTHWEST AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED 938 PM CST SAT NOV 22 2014/
UPDATE... /CLEARING SVR WATCH COUNTIES FROM WEST...CONTINUE FFA/
AS A MINOR THREAT OF SEVERE WEATHER AND FLASH FLOODING CONTINUES
ACROSS SE COUNTIES...MUCH OF THE AREA HAS BEEN UPDATED TO REFLECT
A DECREASING CHANCE OF RAIN AND SEVERE WEATHER. THE FFA THREAT IS
LEFT IN PLACE...BUT MAY HAVE A POTENTIAL OF REMOVAL BEFORE THE END
OF THE EVENING. A FEW RIVERS AND STREAMS...MAINLY THOSE ALONG THE
EASTERN PART OF THE BALCONES ESCARPMENT...ARE OUT OF BANKS. SOME
SECONDARY ROADS WILL LIKELY REMAIN IMPASSABLE FOR A FEW MORE
HOURS. PRELIMINARY HIGHEST 2-DAY RAINFALL TOTALS APPEAR TO BE OUT
OF TRAVIS AND HAYS COUNTIES AT BETWEEN 4 AND 5.5 INCHES.
PREV DISCUSSION... /ISSUED 814 PM CST SAT NOV 22 2014/
UPDATE...
TO EXTEND SEVERE THUNDERSTORM WATCH.
DISCUSSION...
RISK OF SEVERE THUNDERSTORMS WILL CONTINUE WITH A LINE OF
THUNDERSTORMS MOVING TOWARD THE EAST. THE LINE CURRENTLY EXTENDS
FROM SAN ANTONIO TO PLEASANTON TO CROSS. AS THIS LINE MOVES TO THE
EAST THERE WILL BE A RISK FOR THUNDERSTORMS CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS. THERE IS ALSO A SLIGHT RISK FOR
TORNADOES. WE HAVE EXTENDED THE SEVERE THUNDERSTORM WATCH TO THE
COUNTIES EAST OF BEXAR AND ALONG AND SOUTH OF I-10.
PREV DISCUSSION... /ISSUED 715 PM CST SAT NOV 22 2014/
UPDATE... /SVR WATCH 557 EXTENSION INTO BEXAR...ATASCOSA/
A PROGRESSIVE SQUALL LINE IS QUICKLY SHIFTING THE SEVERE POTENTIAL
INTO THE SAN ANTONIO METRO AREA. APEX OF A CURVED SQUALL LINE
INCREASES THE POTENTIAL FOR SEVERE ACTIVITY ASSOCIATED WITH CELL
MERGERS AS NEW CONVECTION FORMS EAST OF THE LINE. CELL MERGERS
WILL ALSO BE POSSIBLE OVER PARTS OF ATASCOSA COUNTY BY 8 PM.
EXPECT TO SEE A HEAVY RAIN PRODUCING MCS TAKE SHAPE ONCE THE
MERGED CELLS MOVE EAST OF I-35...WITH DECREASING SEVERE POTENTIAL
BY 10 PM.
PREV DISCUSSION... /ISSUED 607 PM CST SAT NOV 22 2014/
UPDATE... /ISSUANCE OF FFA/
WITH THE MAJORITY OF HI-RES MODELS INDICATING LARGE AREAS OF 1-2
INCH RAINFALL STILL POSSIBLE OVER EASTERN COUNTIES...HAVE ISSUED A
FLASH FLOOD WATCH FOR COUNTIES ALONG AND EAST OF A LLANO TO SAN
ANTONIO LINE AND ALONG AND NORTH OF A SAN ANTONIO TO HALLETTSVILLE
LINE. THE FLASH FLOOD THREAT WILL PROBABLY BE ENHANCED THROUGH 9
PM OVER THE EASTERN HILL COUNTRY INTO AUSTIN METRO WITH SOME
TRAINING CELLS INCREASING FROM LAKE MEDINA TO BURNET. AFTER 9 PM...THE
FOCUS FOR FLOODING SHOULD BEGIN TO SHIFT EAST OF I-35. LCRA
HYDROMET INDICATES SEVERAL REPORTS OF 2 PLUS INCHES OF RAIN HAS
FALLEN STILL WITHIN THE PAST 6 HOURS OVER AREAS IN THE PATHS OF
NEW CONVECTION. ISOLATED MINOR RIVER RISES ARE EXPECTED...BUT
MODERATE FLOOD LEVELS ARE UNLIKELY. THE SEVERE THREAT CONTINUES
FOR MUCH OF THIS EVENING...ESPECIALLY OVER THE RIO GRANDE PLAINS.
HOWEVER...THE SEVERE THREAT SHOULD TREND TOWARD MORE ISOLATED
ACTIVITY LATE THIS EVENING.
PREV DISCUSSION... /ISSUED 349 PM CST SAT NOV 22 2014/
THE RISK OF SEVERE WEATHER AND HEAVY RAIN CONTINUES
THROUGH THIS EVENING...
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
STRONG STORMS AND HEAVY RAIN WILL CONTINUE TO AFFECT MAINLY THE
EASTERN HALF OF SOUTH CENTRAL TEXAS FOR THE NEXT SEVERAL HOURS.
THE THREAT FOR STRONG TO SEVERE WEATHER STILL EXISTS THROUGH THIS
EVENING. A SECOND ROUND OF SHOWERS AND STORMS CURRENTLY ONGOING
ACROSS THE SERRANIAS DEL BURRO (NORTHEAST MEXICO) IS FORECAST TO
PUSH EASTWARD AND ACROSS MOST OF SOUTH CENTRAL TEXAS THIS EVENING.
THE HRRR AND TECH-TECH HIRES MODELS DEVELOP AN MCS AROUND 23Z/5 PM
THIS AFTERNOON WHILE A LINE OF SHOWERS AND STORMS FORM AHEAD OF A
SURFACE CONVERGENCE ZONE (WARM SECTOR). IF THIS SCENARIO PANS
OUT...STRONG TO SEVERE STORMS ARE POSSIBLE ACROSS THE RIO
GRANDE...ESPECIALLY ALONG AND WEST OF ROCKSPRINGS TO HONDO TO
PEARSALL LINE. A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 10
PM TONIGHT FOR THE AREA ABOVE MENTIONED. MAIN WEATHER THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS. CAN`T RULE OUT AN ISOLATED
TORNADO OR TWO. SOME OF THESE STRONG STORMS WILL PRODUCE HEAVY
DOWNPOURS WITH RAINFALL ACCUMULATIONS UP TO ONE INCH PER HOUR.
THE MCS IS FORECAST TO COMBINE WITH THE SHOWERS AND STORMS
EXPECTED TO FORM ALONG THE CONVERGENCE ZONE AND MOVE EAST IN A
LINEAR FASHION...AFFECTING THE I-35 CORRIDOR AROUND 8 OR 9 PM THIS
EVENING. BY 9 PM...THE SYSTEM IS LIKELY TO TRANSITION TO A HEAVY
RAIN PRODUCER WITH STRONGER STORMS CAPABLE OF PRODUCING LARGE
HAIL. THE LINE OF STORMS WILL QUICKLY PUSH TO THE EAST BY MIDNIGHT
TONIGHT WITH RAIN CHANCES COMING TO AN END ACROSS THE ENTIRE AREA
BY 2 OR 3 AM SUNDAY. NEW RAINFALL AMOUNTS FOR THE TONIGHT PERIOD
COULD RANGE FROM 1 TO 2 INCHES AND UP TO 3 INCHES IN ISOLATED
PLACES.
ON SUNDAY...EXPECT MOSTLY SUNNY/CLEAR SKIES ACROSS SOUTH CENTRAL
TEXAS WITH BREEZY CONDITIONS. A PACIFIC COLD FRONT WILL PUSH
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE WEATHER IS EXPECTED TO BE FAIRLY QUIET FOR MUCH OF NEXT WEEK. A
WEAK FRONT WILL MOVE THROUGH THE AREA OVERNIGHT SUNDAY. THIS FRONT
IS IN RESPONSE TO AN UPPER LEVEL TROUGH MOVING THROUGH THE PLAINS.
THE WEATHER FOR THANKSGIVING SHOULD BE PRETTY SEASONAL WITH HIGHS
IN THE 60S AND LOWS IN THE 30S/40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 55 78 45 64 40 / 50 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 54 77 43 64 37 / 70 0 - - -
NEW BRAUNFELS MUNI AIRPORT 55 79 45 66 40 / 50 0 - - -
BURNET MUNI AIRPORT 52 75 42 62 38 / 40 0 - - -
DEL RIO INTL AIRPORT 50 78 46 65 38 / 10 0 - - -
GEORGETOWN MUNI AIRPORT 54 75 43 62 38 / 50 0 - - -
HONDO MUNI AIRPORT 49 77 42 65 37 / 20 0 - - -
SAN MARCOS MUNI AIRPORT 53 78 44 65 39 / 50 0 - - -
LA GRANGE - FAYETTE REGIONAL 57 78 46 64 40 / 90 0 - - -
SAN ANTONIO INTL AIRPORT 54 78 46 66 41 / 40 0 - - -
STINSON MUNI AIRPORT 54 79 46 66 41 / 20 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING
COUNTIES: BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...COMAL...
FAYETTE...GONZALES...GUADALUPE...HAYS...LAVACA...LEE...LLANO...
TRAVIS...WILLIAMSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1140 PM CST SAT NOV 22 2014
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION...
&&
.AVIATION...
MAIN LINE OF STORMS STRETCHES FROM KGLS OUT INTO THE GULF AND
SHOULD BE MOVE OUT OF THE AREA OVER THE NEXT HOUR OR TWO. A SECOND
WEAKER LINE OF STORMS WAS LOCATED WEST OF KUTS/KCXO AND THEN
MOVING TOWARDS KUTS/KCXO/KIAH. WILL KEEP MENTION OF TSRA IN TAFS
THROUGH 08Z TO ACCOUNT FOR THESE STORMS. OVERALL STORMS SHOULD BE
MOVING OUT OF THE AREA 08Z-12Z WITH CIGS IMPROVING. MODELS SHOW
DENSE FOG DEVELOPING AFTER 08Z BUT DO NOT SEE THIS HAPPENING WITH
SKIES SLOW TO CLEAR AND WINDS REMAINING. WINDS TURN SW/W DURING
THE DAY WITH SOME GOOD GUSTS. COLD FRONT SHOULD REACH AREA BETWEEN
03Z/06Z MONDAY.
39
&&
.PREV DISCUSSION... /ISSUED 1119 PM CST SAT NOV 22 2014/
DISCUSSION...
UPDATED POPS AND WEATHER...MAINLY TO TAKE OUT THE SEVERE MENTION
AND TO TWEAK THE OVERNIGHT WEATHER REGARDING THE TIMING OF THE END
OF THE RAIN CHANCES.
40
PREV DISCUSSION... /ISSUED 911 PM CST SAT NOV 22 2014/
DISCUSSION...
THE UPPER TROUGH WAS SWINGING THROUGH THE SOUTHERN PART OF THE
STATE AT 845 PM...WITH VERY GOOD DIFFLUENCE NOTED AT 300 MB
OVERHEAD OF SE TX. WITH A STATIONARY FRONT JUST WEST OF KCLL AND
CROCKETT...AM EXPECTING WIDESPREAD RAIN AND THUNDERSTORMS ACROSS
THE FORECAST AREA THROUGH MIDNIGHT. LIKE THE 01Z HRRR AND THE 00Z
NAM12 WHICH PUSHES THE BEST CHANCES FOR THUNDERSTORMS EAST OF
INTERSTATE 45 BETWEEN MIDNIGHT AND 2 AM. THIS TIMING WILL BE TIED
TO THE DEVELOPMENT AND EVOLUTION OF THE TWO DOMINATE LINES OF
CONVECTION WHICH WERE FORMING AT 9 PM. ONE WAS ALONG THE
INTERSTATE 35 CORRIDOR AND THE OTHER FROM NEAR FRIENDSWOOD AND
PEARLAND SOUTH TO JUST OFF THE MID TX COAST.
AGREE WITH SPC WITH THE UPDATED SLIGHT RISK FOR SEVERE STORMS
BEING MAINLY ALONG AND SOUTH OF A LINE FROM NEAR COLLEGE STATION
TO DAYTON IN SOUTHERN LIBERTY COUNTY. THIS MEANS THAT ISOLATED
SEVERE STORMS ARE POSSIBLE WITH THE MAIN THREATS STRONG WINDS AND
SMALL HAIL. WHERE TRAINING OF STORMS OCCUR...MINOR FLOODING IS
POSSIBLE. SOME LOCATIONS ACROSS WASHINGTON...GRIMES...AND INTO
WALKER COUNTIES HAVE ALREADY RECEIVED UP TO 3 INCHES OF RAIN.
WILL UPDATE THE FORECAST TO TWEAK THE BETTER RAIN CHANCES TO PAST
MIDNIGHT.
40
PREV DISCUSSION... /ISSUED 603 PM CST SAT NOV 22 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF KAUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.
KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.
KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.
KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 57 78 45 64 40 / 90 10 0 0 0
HOUSTON (IAH) 59 80 49 65 41 / 90 10 0 0 0
GALVESTON (GLS) 65 76 56 64 50 / 90 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST SUNDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1119 PM CST SAT NOV 22 2014
.DISCUSSION...
UPDATED POPS AND WEATHER...MAINLY TO TAKE OUT THE SEVERE MENTION
AND TO TWEAK THE OVERNIGHT WEATHER REGARDING THE TIMING OF THE END
OF THE RAIN CHANCES.
40
&&
.PREV DISCUSSION... /ISSUED 911 PM CST SAT NOV 22 2014/
DISCUSSION...
THE UPPER TROUGH WAS SWINGING THROUGH THE SOUTHERN PART OF THE
STATE AT 845 PM...WITH VERY GOOD DIFFLUENCE NOTED AT 300 MB
OVERHEAD OF SE TX. WITH A STATIONARY FRONT JUST WEST OF KCLL AND
CROCKETT...AM EXPECTING WIDESPREAD RAIN AND THUNDERSTORMS ACROSS
THE FORECAST AREA THROUGH MIDNIGHT. LIKE THE 01Z HRRR AND THE 00Z
NAM12 WHICH PUSHES THE BEST CHANCES FOR THUNDERSTORMS EAST OF
INTERSTATE 45 BETWEEN MIDNIGHT AND 2 AM. THIS TIMING WILL BE TIED
TO THE DEVELOPMENT AND EVOLUTION OF THE TWO DOMINATE LINES OF
CONVECTION WHICH WERE FORMING AT 9 PM. ONE WAS ALONG THE
INTERSTATE 35 CORRIDOR AND THE OTHER FROM NEAR FRIENDSWOOD AND
PEARLAND SOUTH TO JUST OFF THE MID TX COAST.
AGREE WITH SPC WITH THE UPDATED SLIGHT RISK FOR SEVERE STORMS
BEING MAINLY ALONG AND SOUTH OF A LINE FROM NEAR COLLEGE STATION
TO DAYTON IN SOUTHERN LIBERTY COUNTY. THIS MEANS THAT ISOLATED
SEVERE STORMS ARE POSSIBLE WITH THE MAIN THREATS STRONG WINDS AND
SMALL HAIL. WHERE TRAINING OF STORMS OCCUR...MINOR FLOODING IS
POSSIBLE. SOME LOCATIONS ACROSS WASHINGTON...GRIMES...AND INTO
WALKER COUNTIES HAVE ALREADY RECEIVED UP TO 3 INCHES OF RAIN.
WILL UPDATE THE FORECAST TO TWEAK THE BETTER RAIN CHANCES TO PAST
MIDNIGHT.
40
PREV DISCUSSION... /ISSUED 603 PM CST SAT NOV 22 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF KAUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.
KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.
KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.
KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 57 78 45 64 40 / 90 10 0 0 0
HOUSTON (IAH) 59 80 49 65 41 / 90 10 0 0 0
GALVESTON (GLS) 65 76 56 64 50 / 90 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST SUNDAY FOR
THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM CST SUNDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
256 PM PST SUN NOV 23 2014
.SYNOPSIS...A FRONT IS SHIFTING SOUTH ACROSS NW OREGON THIS
EVENING...AND SHOULD WEAKEN OVER THE AREA LATE TONIGHT. SOME
THUNDERSTORMS WILL ACCOMPANY THIS FRONT THROUGH THE EARLY EVENING.
VALLEY FOG SHOULD DEVELOP EARLY MONDAY MORNING. A WARMER FRONTAL
SYSTEM WILL BRING ADDITIONAL RAIN TO THE AREA MONDAY AFTERNOON
THROUGH THURSDAY NIGHT. A DRY DAY IS EXPECTED WEDNESDAY BEFORE
ANOTHER FRONT MOVES THROUGH ON THANKSGIVING DAY.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...THE COLD FRONT THAT STALLED
OVER SW WASHINGTON THIS MORNING HAS MOVED SOUTH INTO OREGON EARLY THIS
AFTERNOON...GENERATING PLENTY OF LIGHTNING...THUNDER AND HEAVY RAIN
FOR NW OREGON. THE FRONT...AND THUNDERSTORMS WILL CONTINUE TO MOVE
SOUTH LATE THIS AFTERNOON AS WILL THE THREAT FOR THUNDERSTORMS.
THUNDERSTORMS MAY MAKE IT DOWN TO THE SALEM AREA AROUND 4 PM AND
POSSIBLY EVEN FURTHER SOUTH THAN THAT...DOWN TO ALBANY AROUND 5 PM.
HOWEVER THE FRONT IS EXPECTED TO WEAKEN AROUND SUNSET...AND THINK THE
THREAT FOR CONVECTION WILL WEAKEN AS WELL.
THE PRECIPITATION BAND WILL PUSH SOUTH OF THE WASHINGTON CASCADES
THIS AFTERNOON AND HAVE CANCELED THE WINTER WEATHER ADVISORY. THE
RAIN WILL DECREASE AS IT MOVES SOUTH THIS EVENING...AND AM NOT SURE
WHETHER ANY RAIN WILL MAKE IT TO EUGENE. IF SO...IT SHOULD BE BRIEF
WITH LIGHT ACCUMULATIONS. EXPECT THE RAIN TO END BY MIDNIGHT TONIGHT
WITH CLEARING SKIES LEADING TO FOG IN THE INTERIOR VALLEYS BY MONDAY
MORNING.
THE NEXT FRONTAL SYSTEM WILL APPROACH MONDAY. A WARM FRONT FROM THE
SOUTH WILL MERGE WITH A COLDER FRONT TO THE NORTH OFFSHORE BEFORE
PUSHING ONSHORE MONDAY AFTERNOON. THE WARMER PORTION OF THE FRONT
WILL FIRST MOVE ONSHORE MONDAY AFTERNOON...BEFORE THE COLDER FRONT
MOVES IN MONDAY NIGHT AND TUESDAY. THE SNOW LEVELS SHOULD RISE WELL
ABOVE THE CASCADE PASSES BY MONDAY AFTERNOON.
THE FRONT SHOULD MOVE NORTH TUESDAY AFTERNOON AND EVENING AS A AN
UPPER RIDGE BUILDS OVER THE AREA AND A LARGE UPPER LOW MOVES INTO THE
NE PACIFIC. THE RAIN SHOULD MAINLY BE CONFINED TO THE NORTHERN COAST
RANGE...COAST...AND NORTHERN CASCADES BY TUESDAY EVENING. BESIDES A
FEW MORNING SHOWERS OVER SW WASHINGTON EARLY WEDNESDAY MORNING...MOST
OF WEDNESDAY WILL BE DRY. SHOULD BE A RETURN OF VALLEY FOG WEDNESDAY
MORNING.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...MODELS CONTINUE TO
SHOW A PACIFIC FRONTAL SYSTEM...ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE...MOVING ACROSS NW OREGON AND SW WASHINGTON ON
THANKSGIVING DAY. THERE ARE STILL SOME DISCREPANCIES OF WHEN THE
RAIN WILL START. THE ECMWF BRINGS THE FRONT ONSHORE DURING THE EARLY
MORNING HOURS WHILE THE GFS HOLDS OFF UNTIL DAYBREAK. EXPECT CHANCE
POPS THROUGH FRIDAY. THE MAIN UPPER LEVEL TROUGH MOVES ONSHORE OVER
THE WEEKEND AND WILL BRING A MUCH STRONGER AND WETTER SYSTEM. SNOW
LEVELS OVER THE WEEKEND COULD DROP TO THE PASSES. AS OF NOW...IT
LOOKS LIKE WE CAN EXPECT TO SEE HAZARDOUS TRAVEL CONDITIONS FOR
THOSE RETURNING AFTER THE THANKSGIVING HOLIDAY. TEMPERATURES IN THE
EXTENDED CONTINUE TO BE AT OR ABOVE SEASONAL NORMALS. DETAILS OF THE
IMPACTS EXPECTED FROM NEXT WEEKENDS SYSTEM WILL CONTINUE TO BE
REFINED WITH FUTURE UPDATES. /64
&&
.AVIATION...A BAND OF RAIN ASSOCIATED WITH A WEAKENING FRONTAL
BOUNDARY IS CURRENTLY DRAPED FROM JUST SOUTH OF TILLAMOOK THROUGH
THE NORTHERN AND CENTRAL WILLAMETTE VALLEY. THIS BOUNDARY WILL
PUSH SLOWLY SOUTH AND WEAKEN FURTHER LATER THIS AFTERNOON AND THIS
EVENING. EXPECT PRIMARILY VFR CONDITIONS DURING THIS TIME...WITH
AREAS OF MVFR FROM TIME TO TIME UNDERNEATH THE HEAVIER RAIN BAND.
THERE IS ALSO STILL ISOLATED THUNDER BEING DETECTED ALONG THE
FRONTAL BOUNDARY...BUT THIS THREAT SHOULD END BY EARLY EVENING.
EXPECT SOME CLEARING TO DEVELOP LATER THIS EVENING AND
OVERNIGHT AND THE ATMOSPHERE BEGINS TO STABILIZE. THIS SHOULD
ALLOW SOME PATCHY MVFR OR IFR FOG OR LOW STRATUS TO FORM
OVERNIGHT INTO EARLY MON MORNING. ANOTHER FRONT WILL BEGIN TO
SPREAD LIGHT RAIN AND POSSIBLY MVFR CIGS INTO THE COAST BETWEEN
21Z AND 00Z MON.
KPDX AND APPROACHES...A BAND OF RAIN ASSOCIATED WITH A WEAKENING
FRONT MAY TEMPORARILY REDUCE CIGS INTO MVFR THROUGH 00Z. SOME
CLEARING TONIGHT MAY ALLOW PATCHY FOG OR LOW STRATUS TO FORM
OVERNIGHT OR EARLY MON MORNING. PYLE
&&
.MARINE...A WEAKENING FRONT HAS MOVED SLOWLY FROM NORTH TO SOUTH
THROUGH THE WATERS TODAY...AND IS NOW LOCATED JUST SOUTH OF
TILLAMOOK. THERE IS STILL ISOLATED THUNDER BEING DETECTED ALONG
THE FRONT...BUT EXPECT THIS THREAT TO END BY LATE AFTERNOON OR
EARLY EVENING. WINDS HAVE DROPPED OFF THIS AFTERNOON AS THE FRONT
HAS WEAKENED...AND ARE NOW WESTERLY AT AROUND 10 TO 15 KT.
THUS...WILL ALLOW THE SMALL CRAFT ADVISORY FOR WINDS TO DROP OFF
AT 3 PM. EXPECT THE LULL IN THE WINDS TO LAST INTO EARLY MON. THEN
THE NEXT FRONT IS EXPECTED TO MOVE INTO THE WATERS TOMORROW. THE
LATEST FCST MODELS ARE INDICATING THAT LOW END GALE FORCE WINDS
ARE A POSSIBILITY TOMORROW...MAINLY DURING THE AFTERNOON AND EARLY
EVENING. DECIDED TO ISSUE A GALE WATCH STARTING AT 10 AM.
WINDS MAY STAY A BIT GUSTIER ACROSS THE NORTHERN WATERS THROUGH MID
WEEK BEFORE A SLOW MOVING LOW PRESSURE SYSTEM BEGINS TO IMPACT THE
WATERS MID TO LATE NEXT WEEK. LOW END GALE FORCE WIND GUSTS MIGHT
BE SQUEEZED OUT OF THIS SYSTEM AT SOME POINT...BUT THE SCENARIO
DOES NOT LOOK ALL THAT PROMISING FOR A SOLID GALE FORCE OR HIGHER
WIND EVENT FOR THE WATERS.
SEAS HAVE COME UP JUST A BIT TODAY...AND ARE NOW AROUND 12 TO 14
FT. EXPECT THEM TO REMAIN FAIRLY STEADY THROUGH THIS EVENING
BEFORE GRADUALLY DECREASING OVERNIGHT AND MON. HOWEVER...EXPECT
SEAS TO REMAIN ABOVE 10 FT INTO EARLY WED. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...WINTER WEATHER ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR SOUTH
WASHINGTON CASCADES.
PZ...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM PST
MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
231 PM PST SUN NOV 23 2014
.SYNOPSIS...
The north Idaho mountains will continue to receive snow this
evening, along with the Cascade crest near Stevens Pass. The
breezy winds will taper off overnight, and Monday will be a
relatively quiet and chilly day. More rain and heavy mountain snow
is expected Monday night into Tuesday. A breezy and wet but warm
Thanksgiving Day will give way to a colder weather pattern for the
holiday weekend with the mountains receiving several rounds of
snow. Snow levels will fall to valley floors by the weekend.
&&
.DISCUSSION...
Tonight and Monday: A temporary break in the wet weather can be
expected starting tonight. A moist and progressive cold front will
push south and east of Spokane and through north Idaho early this
evening. Somewhat drier air will move into the region from the
northwest, although enough residual moisture and favorable
orographic flow will keep the threat of mountain showers. This is
especially true along the Cascade crest near Stevens Pass where
hints of a PVCZ may linger and then Central Idaho panhandle
mountains. The only concern for accumulating valley snow would be
north of Bonners Ferry, but the front will quickly exit this area
and allow the threat of snow to taper off. Meanwhile, either the
valley locations will be done with snow for the evening, or have
warmed up and should just experience rain this evening especially
across the central and southern Idaho panhandle. Breezy winds will
continue into the early evening behind the front with gusts to 30
mph. These winds will decrease overnight and become light by
Monday as surface pressure gradients relax. Skies will clear for a
good chunk of eastern Washington. This coupled with lighter winds,
wet ground and radiational cooling will lead to rather chilly
temperatures overnight into the 20s. These sub freezing lows and
frozen ground will also raise the risk of icy roadways by early
Monday morning for the commute. Meanwhile, boundary layer moisture
remains high overnight especially across the Palouse and
Spokane/Coeur d`Alene area. Given the southwest winds and light
precipitation today, there is a good chance of seeing stratus and
patchy fog develop late tonight into Monday morning. This threat
will expand into the northern and Panhandle valleys as well. By
Monday, the low cloud deck will gradually erode but daytime
temperatures will be inhibited by the cloud cover. In addition,
mid and high level clouds will be on the increase as the next
weather system approaches. /rfox.
Monday night through Thursday morning...No major changes for the
mid forecast time frame. High pressure will build in the eastern
Pacific just off the coast. This will put the Inland Northwest in
a northwest flow...before coming around to westerly Wednesday
night. This flow will tap in deep Pacific moisture tap to move
over the ridge and drop through the region through the period. We
are looking at an extended wet and unsettled period through early
Wednesday evening.
* Precipitation: You bet. Precipitable water by Tuesday morning
will approach an inch which is around 270% of normal. Quite wet
indeed. Isentropic up-glide will get established over Pac NW
early Tuesday evening and remain in place through Wednesday
afternoon. A pretty substantial rain shadow will develop in the
lee of the Cascades keeping the lower east slopes and the deep
basin from getting much more than a few hundredths to maybe a
tenth of an inch. Outside of the basin the lower elevations and
northern mountains look to get from .25 to .55 if not slightly
more. The Panhandle mountains from .50 to .80 and the higher
elevation of the Cascades from .50 to well over an inch near the
crest.
* Snow: A much trickier questions. Southerly surface winds and
strong warm advection is what will cause the lifting procees to
squeeze out all the moisture. But this will also raise snow
levels rapidly Tuesday night. For all of the urban areas snow
levels will be high enough for precipitation as all rain. The
tricky parts will be the mountain valleys. By the time the
heaviest precipitation gets into these areas the snow should
turn to rain. At this time snow accumulations for all of the
mountain valleys remain below highlight criteria. An even
trickier snow forecast will be for northeast WA and ID Panhandle
mountains above 3-4k feet where the same processes will be at
work, but it will take a little longer to warm. 24 hour snow
amounts will range from 6-9 inches which would be the low end of
an advisory. I will hold off on any highlights...first because
we already have advisories out for the central Panhandle
mountains and second there is still a little uncertainty on just
how fast temperatures will increase.
* Temperatures and wind: As mentioned above there will be strong
warm air advection and breezy/gusty south-southwest winds.
Temperatures on Tuesday will increase with high from the mid 30s
across the north to the high 40s/lower 50s across the south.
Then add 4-5 more degrees for Wednesday putting highs well into
the 40s and 50s. South-southwest of 10-25 mph with gusts 25-35
mph will be common across the region. /Tobin
Thanksgiving Day through Sunday...Another day, another fight
between medium range models. Why can`t we just get along? The
00Z run of the ECMWF was showing an arctic front dropping south
across the forecast area Thanksgiving Day, leading to a much
colder forecast than the more consistent GFS. Surprise...the 12Z
EC is much closer to the GFS solution. There are still differences
in several of the details but the general consensus is for warmer
temperatures in southerly flow at least through Turkey Day. The
stream of shortwave energy riding over the forecast area will
bring some precipitation to the higher elevations of the Inland
Northwest but valley precip is one of those pesky details that
model are having a hard time deciding on, depending on the
location of the upper jet and associated areas of enhanced lift.
This jet will be directing a fetch of deep moisture into the
region with Pwats approaching 200 percent of normal. At least
there is agreement on liquid precip as snow levels will be quite
high. Breezy southerly winds will keep the atmosphere somewhat
mixed overnight, keeping low temperatures at or above freezing for
most of the valleys. The exceptions will be across the extreme
northern valleys where winds will start to shift to the north and
colder, drier air will infiltrate the valleys. For Friday and into
the weekend, models start to fight again. The general trend will
be a cooldown as an arctic front slides south but timing and
southern extent of the very cold air is still being debated.
/Kelch
&&
.AVIATION...
18Z TAFS: Radar trends and 15z HRRR model show most of the shower
activity today will develop just east of KGEG/KSFF with light
rain and snow showers spanning from extreme northeast Washington,
north Idaho. Strong low level warm advection has raised both temps
and dewpoints, making the precipitation type mainly rain at the
TAF sites. Airports north of the metro like Bonners Ferry and
Colville may see a slushy runway accumulations up to an inch will
be possible. Gusty westerly winds will develop from KEAT to KMWH
this afternoon and evening. Dry/downslope advection from the
west/northwest this evening should disperse stratus in the
evening, but fog and low stratus may crop up toward Monday
morning from KPUW to KGEG and KSFF. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 37 33 42 39 47 / 10 10 50 60 50 50
Coeur d`Alene 28 38 34 40 40 45 / 20 10 60 80 60 70
Pullman 30 41 37 47 44 50 / 20 10 60 90 50 30
Lewiston 34 47 40 52 46 54 / 20 10 60 60 30 20
Colville 23 36 31 39 36 42 / 10 10 50 70 70 50
Sandpoint 28 36 31 38 36 41 / 40 10 70 80 80 80
Kellogg 28 36 33 37 37 40 / 70 10 80 90 80 70
Moses Lake 25 41 33 46 41 52 / 10 0 20 30 10 20
Wenatchee 31 40 35 44 42 49 / 10 10 30 50 30 30
Omak 24 35 30 38 36 43 / 10 10 30 50 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 6 AM PST Monday for Central
Panhandle Mountains.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
1012 AM PST SUN NOV 23 2014
.SYNOPSIS...CONVECTIVE SHOWERS WILL CONTINUE OVER SW WASHINGTON AND
NW OREGON THROUGH THIS MORNING. THESE SHOWERS ARE ASSOCIATED WITH A
SLOW MOVING FRONT THAT WILL STALL OVER NW WASHINGTON BEFORE FALLING
A PART OVER NW OREGON THIS AFTERNOON. RAIN AND MOUNTAIN SNOW IS
EXPECTED FOR WASHINGTON THIS MORNING WITH LESS ACCUMULATIONS FOR
OREGON THIS AFTERNOON. A FLAT UPPER RIDGE WILL BUILD
INTO CALIFORNIA AND OREGON MONDAY AND TUESDAY...BUT SHOULD REMAIN
WEAK ENOUGH FOR SYSTEMS TO CLIP OUR NORTHERN ZONES WITH OCCASIONAL
WET WEATHER. VALLEY INVERSIONS WILL LIKELY BUILD IN THE CENTRAL AND
SOUTH WILLAMETTE VALLEY...WITH FOG POSSIBLY BECOMING MORE PERSISTENT
BY THE MIDDLE OF NEXT WEEK. ANOTHER ORGANIZED FRONT IS EXPECTED FOR
THE THANKSGIVING WEEKEND.
&&
.UPDATE...THE LONE OF CONVECTIVE SHOWERS OVER THE NORTHERN EDGE OF
THE PORTLAND FORECAST AREA IS MOVING SLOWLY SOUTHWARD. A FEW CELLS
ARE SPROUTING UP AHEAD OF THIS LINE. ONE IN PARTICULAR...JUST OFF OF
LONG BEACH WA HAD STRONG ROTATION SIGNATURES INDICATIVE OF A TORNADO
AND A TORNADO WARNING WAS ISSUED AS THE STORM TRACKED INLAND. THE
STORM FINALLY WEAKENED OVER NASELLE WA. WE HAVE RECEIVED NO
OBSERVATIONS NEAR THIS STORM TO VERIFY OR DENY THE PRESENCE OF A
TORNADO. ONE SPOTTER JUST NORTH OF LONG BEACH HAD PEA-SIZE HAIL AND
LIGHTNING AND DID NOT SEE THE ROTATION. HOWEVER...THE BEST VIEWING OF
ANY ROTATION WOULD BE SOUTH OF THE STORM...AND SOUTH OF LONG BEACH.
VERTICAL SHEAR IN THE ATMOSPHERE WILL CONTINUE A THREAT FOR WEAKLY
ORGANIZED STORMS THROUGH NOON TODAY. MOST OF THESE STORMS WILL BE
OVER THE WATERS...BUT THEY MAY OCCASIONAL MOVE ONSHORE. WE WILL BE
MONITORING RADAR CLOSELY THIS MORNING.
THE FRONT HAS PRODUCED .3 TO .5 INCHES OF RAIN IN THE PAST 3 HOURS
NORTH OF OUR AREA. THE HIGHER AMOUNTS ARE MOST LIKELY ASSOCIATED WITH
THE CONVECTIVE BAND. HOWEVER STILL THINK THE SW WASHINGTON CASCADES
WILL SEE SOME SNOW ACCUMULATIONS ABOVE 4000 FEET AND HAVE NOT MADE
ANY CHANGES TO THE WINTER WEATHER ADVISORY WITH THE UPDATE.
ELSEWHERE...EXPECT COOL AND RAINY CONDITIONS THROUGH THIS EVENING.
HIGH PRESSURE BEGINS TO BUILD OVER THE EASTERN PACIFIC LATE TONIGHT
INTO MONDAY...WHICH SHOULD KEEP THE REGION FAIRLY DRY BUT CLOUDY. BUT
THE THREAT FOR VALLEY FOG INCREASES...ESPECIALLY FOR THE CENTRAL AND
SOUTH WILLAMETTE VALLEY AS WELL AS THE CENTRAL COAST. MODELS HAVE
BEEN CONSISTENT IN SHOWING A FEW DISTURBANCES RIDING OVER THE RIDGE
AND BRINGING SOME PRECIP MAINLY TO THE FAR NORTHERN FORECAST ZONES BY
MONDAY EVENING. EXPECT THIS PATTERN OF NORTHERN SHOWERS WITH SOUTHERN
VALLEY AND COASTAL FOG TO CONTINUE THROUGH WEDNESDAY. TJ/27
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...OVERALL MODELS ARE
ATTEMPTING TO FLATTEN THE UPPER LEVEL RIDGE LATE WEDNESDAY. BUT ONCE
WE GET TO THANKSGIVING MORNING...MODEL SOLUTIONS VARY CONCERNING THE
NEXT PACIFIC FRONTAL SYSTEM APPROACHING THE REGION THANKSGIVING DAY.
THE 06Z GFS SHOWS A RATHER WELL-ORGANIZED FRONTAL BAND REACHING THE
SW WASHINGTON/NW OREGON COAST IN THE MORNING...WITH RAIN SPREADING
INLAND BY THE AFTERNOON...RIGHT IN TIME FOR THANKSGIVING DINNER. WILL
HAVE TO SEE WHAT THE 12Z ECMWF DOES WITH THIS SYSTEM...AND WHETHER OR
NOT IT MAINTAINS ITS LIGHTER RAIN/RIDGY SOLUTION. A MUCH
STRONGER AND WETTER SYSTEM LOOKS TO MOVE IN OVER THE WEEKEND WHICH
COULD POSE A THREAT TO TRAVELERS RETURNING AFTER THE THANKSGIVING
HOLIDAY. DETAILS AT THIS POINT ARE STILL UNKNOWN AND WILL BE REFINED
WITH FUTURE UPDATES. THE GOOD NEWS IS THAT TEMPERATURES IN THE
EXTENDED WILL BE AT OR ABOVE SEASONAL NORMALS. /64/27
&&
.AVIATION...CONDITIONS ARE PRIMARILY VFR ACROSS THE REGION THIS
MORNING. A FRONT ALONG THE WASHINGTON COAST AND OVER THE COASTAL
WATERS IS PRODUCING SIGNIFICANT LIGHTNING AND GUSTY WINDS. THE
FRONT IS FCST TO WEAKEN AS IT PUSHES INTO NORTHWEST OREGON LATER
THIS MORNING...BUT IT MAY ALLOW FOR A PERIOD OF MVFR CONDITIONS
AT KAST LATER THIS MORNING AND THE KPDX METRO TAF SITES TOWARDS
MIDDAY. THERE IS A CHANCE MVFR CONDITIONS MAY PERSIST TOWARDS 12Z
MONDAY FOR THE PORTLAND METRO TAF SITES. FARTHER SOUTH WHERE
CLEARING THIS EVENING WILL BE MORE LIKELY TO OCCUR...IFR
CONDITIONS MAY DEVELOP AT KEUG...KSLE AND EVEN KHIO TOWARDS 12Z
MONDAY.
KPDX AND APPROACHES...A POST FRONTAL SHOWERY AIR MASS WILL LEAD
TO PREDOMINANTLY VFR CONDITIONS TODAY. A BAND OF RAIN ASSOCIATED
WITH A DYING FRONT MAY TEMPORARILY REDUCE CIGS INTO MVFR AROUND
MIDDAY. THERE IS A CHANCE THESE CONDITIONS COULD PERSIST WELL
INTO SUNDAY NIGHT...OR PERHAPS DETERIORATE INTO HIGH END IFR
CONDITIONS...BUT CONFIDENCE IN THESE DETAILS IS LOW AT THIS POINT.
PYLE/NEUMAN
&&
.MARINE...A SLOW MOVING FRONT BROUGHT A BAND OF STRONG
THUNDERSTORMS INTO THE W WASHINGTON COASTAL WATERS THIS MORNING.
BASED ON SEVERAL REPORTS OF WINDS IN EXCESS OF 40 MPH WITH SOME OF
THESE STORMS FURTHER NORTH ALONG THE WASHINGTON COAST...DECIDED TO
ISSUE A SPECIAL MARINE WARNING FOR THE WATERS AS FAR SOUTH AS THE
COLUMBIA RIVER BAR. EXPECT PERIODIC GUSTS IN EXCESS OF 34 KT ALONG
WITH FREQUENT LIGHTNING IN SOME OF THE STRONGER STORMS.
OTHERWISE...EXPECT GUSTY WINDS TO CONTINUE OVER THE NORTHERN
COASTAL WATERS INTO EARLY THIS AFTERNOON. THEN WINDS DROP OFF
CONSIDERABLY LATER THIS AFTERNOON AS THE FRONT WEAKENS. SEAS IN
THE 12 TO 13 FT RANGE AT CURRENT WILL LIKELY PEAK IN THE MID TEENS
LATER TODAY BEFORE DECREASING TONIGHT INTO MONDAY.
A WEAK FRONT WILL PUSH INTO THE WATERS LATE MONDAY...BUT ASIDE
FROM SOME SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 KT...NOT
EXPECTING MUCH IMPACT. WINDS MAY STAY A BIT GUSTIER ACROSS THE
NORTHERN WATERS EARLY TO MID WEEK BEFORE A SLOW MOVING LOW PRESSURE
SYSTEM IMPACTS THE WATERS MID TO LATE NEXT WEEK. LOW END GALE FORCE
WIND GUSTS MIGHT BE SQUEEZED OUT OF THIS SYSTEM AT SOME POINT...BUT
THE SCENARIO DOES NOT LOOK ALL THAT PROMISING FOR A SOLID GALE
FORCE OR HIGHER WIND EVENT FOR THE WATERS. PYLE/NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 PM PST THIS AFTERNOON FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 AM PST MONDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM
PST MONDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
938 AM PST SUN NOV 23 2014
.SYNOPSIS...
The mountains will receive another round of accumulating snow
this afternoon and evening. Most of the lower elevations will
experience light rain, but some wet snow is possible in the far
northern valleys. Monday will be a relatively quiet and chilly
day. More rain and heavy mountain snow is expected Monday night
into Tuesday. A breezy and wet weather pattern will persist for
much of the week with the mountains receiving several rounds of
snow.
&&
.DISCUSSION...
Updated the forecast on snow levels and temperatures this morning.
The incoming weather system seems to have slowed slightly,
meanwhile overnight lows were not as cool due to the thicking
clouds. The delayed arrival of the the precipitation has allowed
both temps and dewpoints to rise slightly and makes the
precipitation type a little tricky. But along and south of a line
south of Coeur d`Alene, Spokane, Ephrata and Wenatchee, expect
mostly rain as wetbulbs are above freezing. Expect snow at the
onset north of this line with accumulations of 1 to 2 inches.
Although increased southerly flow will allow valley temperatures
to rise this afternoon and lead to valley rain and mountain snow
across the north. /rfox
&&
.AVIATION...
18Z TAFS: Radar trends and 15z HRRR model show most of the shower
activity today will develop just east of KGEG/KSFF with light
rain and snow showers spanning from extreme northeast Washington,
north Idaho. Strong low level warm advection has raised both temps
and dewpoints, making the precipitation type mainly rain at the
TAF sites. Airports north of the metro like Bonners Ferry and
Colville may see a slushy runway accumulations up to an inch will
be possible. Gusty westerly winds will develop from KEAT to KMWH
this afternoon and evening. Dry/downslope advection from the
west/northwest this evening should disperse stratus in the
evening, but fog and low stratus may crop up toward Monday
morning from KPUW to KGEG and KSFF. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 27 36 32 43 38 / 90 20 10 50 60 40
Coeur d`Alene 38 28 37 33 41 39 / 100 40 10 60 80 60
Pullman 41 29 40 36 46 42 / 80 60 10 60 70 30
Lewiston 50 33 47 39 50 44 / 50 60 10 60 60 20
Colville 36 25 35 30 39 36 / 90 10 10 60 60 50
Sandpoint 36 29 36 30 39 37 / 100 40 10 70 80 80
Kellogg 40 28 36 33 38 38 / 100 80 10 70 90 70
Moses Lake 46 25 40 32 48 40 / 20 10 10 20 20 10
Wenatchee 48 29 37 34 46 41 / 10 10 10 20 30 20
Omak 37 22 33 30 41 36 / 30 10 10 30 40 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 6 AM PST Monday for Central
Panhandle Mountains.
WA...None.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
945 PM CST MON NOV 24 2014
.UPDATED...
945 PM CST MON NOV 24 2014
WITH MOST OF THE ACCUMULATING SNOWS HAVING SHIFTED EAST...HAVE
ELECTED TO CANCEL THE WINTER WEATHER ADVISORY. ANTICIPATE SOME LIGHT
SNOW OR FLURRIES TO LINGER FOR THE NEXT FEW HOURS - MOSTLY EAST OF
THE MISSISSIPPI RIVER. BUT ANY ADDITIONAL ACCUMULATION SHOULD BE
JUST A TRACE TO A COUPLE TENTHS.
TRAVEL WILL REMAIN HAZARDOUS HOWEVER...ESPECIALLY ON UNTREATED AND
SECONDARY ROADS.
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A PROGRESSIVE AND ENERGETIC FLOW PERSISTS OVER THE CONUS THROUGH
THIS WEEK WITH AN EVOLUTION TO MORE OF A ZONAL OR BROAD FLAT RIDGE
IN THE LARGE SCALE. PREDICTABILITY OVER THE PAST WEEKEND HAS BEEN
LOW...AS SEEN BY THE SHORT RANGE VARIABILITY IN HOW THIS CURRENT
SNOW EVENT TRANSPIRED. NOT PRETTY. THIS WILL CONTINUE THROUGH THE
WEEK...AND CONFIDENCE IS LOW IN TIMING AND PLACEMENT OF WEATHER
SYSTEMS.
LATEST SNOW AMOUNTS IN CENTRAL WISCONSIN ARE IN THE 3 TO 5 INCH
RANGE WITH WINDS CAUSING SOME MEASUREMENT DIFFICULTY. RADAR
INDICATING THAT MOST OF THE CENTRAL WI AREA SHOULD CONTINUE TO
DIMINISH IN INTENSITY AS SNOW SHIELD MOVES NORTHEAST. THE LATEST
RAP TRENDS INDICATE A STRENGTHENING 600-700MB WEAK-MODERATE
FRONTOGENESIS BAND WILL DEVELOP N-S OVER CENTRAL WI LATER THIS
AFTERNOON WHICH COULD BUMP THE RATES A BIT ON WEST END OF THE
SHIELD. BUT...THAT RAP FRONTOGENESIS GUIDANCE IN THE MID-LEVELS
HAS NOT PROVIDED MUCH FOR SENSIBLE SNOW INCREASE OR BANDING FOR
THIS ENVIRONMENT. OVERALL...FROM TRENDS AND WHAT HAS FALLEN...SNOW
WILL SLOWLY SHIFT EAST THIS EVENING...DIMINISHING. HAVE LOWER
STORM TOTAL AMOUNTS IN CENTRAL WISCONSIN...MORE AROUND 4.5 TO 5
INCHES...AND AFTER COLLABORATION WITH MKX...HAVE DOWNGRADED THE
WARNING TO ADVISORY.
WINDS WILL CONTINUE THROUGH THE EVENING TO CAUSE ROADS TO BE
COVERED AND SNOW PLOW CAMS IN NORTHEAST IA SUGGEST THE ROADS ARENT
TOO CLEAN YET. SO...HAVE DECIDED TO LET THE ENTIRE ADVISORY
CONTINUE THROUGH MIDNIGHT.
WATER VAPOR IMAGERY SHOWING A SHORTWAVE TROUGH DROPPING THROUGH MN
AND RADAR INDICATES SOME SNOW SHOWERS THERE. THIS SHOULD NOT
AMOUNT TO MUCH BUT A BRIEF SNOW SHOWER PERIOD AND MAYBE A BIT OF
VSBY REDUCTION /1-2SM/...BUT NOT A HAZARD GENERALLY. HOWEVER AN
AREA EXISTS AHEAD OF THE SHORTWAVE TROUGH IN MN AND THE HIGHER
LEVEL CLOUD WITH THE SNOW SHIELD THAT IS PROMOTING SOME FZDZ.
THIS IS FROM SERN MN INTO SWRN WI. SHERIFFS HAVE HAD FZDZ IN GRANT
COUNTY...AND EARLIER IN NERN IA. MOST OF THIS FZDZ SHOULD OCCUR
IN THE ADVISORY AREA AND FOR THE NEXT FEW HOURS AS THE DEEP SNOW
SHOWERS MOVING IN WILL SHIFT THE PRECIPITATION TYPE VIA SEEDER-
FEEDER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A FAIRLY TRANQUIL PERIOD FOR THE WEEK REALLY WITH A COLDER THAN
NORMAL PERIOD UNDER THE DEEP LONG WAVE TROUGH....BUT AS THIS
BECOMES MORE ZONAL...THE AREA WILL SEE CYCLES OF WARM ADVECTION
AND PRECIPITATION CHANCES...CYCLONE PASSAGE...AND COLD AIR PUSHES.
THE FIRST SHORTWAVE TROUGH COMES ON WEDNESDAY...A HEAVIER TRAVEL
DAY. THIS SHORTWAVE IS COMING INTO BRITISH COLUMBIA COAST
CURRENTLY ON THE POLEWARD SIDE OF A 155 KT 250 MB JET PER 12Z
RAOBS. A PRETTY VIGOROUS SYSTEM THAT DIGS SOUTHEAST IN THE
LONGWAVE TROUGH. THIS WILL BE A 1-2 INCH SNOW MAKER BUT THE TRACK
IS THE QUESTION. HAVE GENERALLY KEPT THE SAME FORECAST AS PREVIOUS
WITH MOSTLY A SRN MN AND NERN IA SYSTEM. CONFIDENCE ON THE TRACK
IS NOT HIGH YET WITH COMPLEX SYSTEM OVER GREAT LAKES AND TOTAL
ENERGY OVER THE CONUS RIGHT NOW. NEW GFS PARALLEL RUN INTENSIFIES
THE NWRLY FLOW ENERGY MORE AND BRINGS MORE SNOW TO THE NORTH...BUT
IS AN OUTLIER. BEHIND THIS SYSTEM...COLD AIR COMES IN FOR
THANKSGIVING...BUT A QUITE WEATHER DAY.
ANOTHER SYSTEM MOVES IN FRIDAY AND IF MY CONFIDENCE IS LOW ON THE
TRACK FOR WEDNESDAY...FRIDAYS WARM ADVECTION SWATH OF SNOW OR
WINTER MIX IS LOWER. GOOD MEDIUM RANGE GUIDANCE CONSENSUS ON THE
TRACK RIGHT NOW...BUT THAT DOESNT MEAN IT WILL BE CORRECT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY NIGHT)
ISSUED AT 530 PM CST MON NOV 24 2014
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR THE SNOW/LOW CLOUDS/WINDS
CONTINUE TO PULL OFF TO THE EAST EARLY THIS EVENING. THE BACK-EDGE
OF THE MAIN AREA OF SNOW WAS JUST EAST OF KLSE...BUT THERE WAS A
BAND OF -SHSN SLIDING SOUTHWARD ACROSS SOUTHEAST MN. THIS COULD
BRING A BRIEF RETURN TO MVFR OR LOWER VSBYS FOR AN HOUR OR
TWO...WITH SOME LINGERING FLURRIES FOR THE REST OF THE EVENING.
EXPECTING CIGS TO STAY MVFR THROUGH THE OVERNIGHT. DISTINCT EDGE TO
THE CLOUD SHIELD EVIDENT ON FOG/STRATUS SATELLITE IMAGERY...AND
MODELS FAVORING SLIDING THIS EAST OF THE TAF SITES EARLY TUE
MORNING. WILL CONTINUE THIS TREND...AND THUS SCT SKIES AND VFR
CONDITIONS FOR MOST OF THE DAY ON TUE.
WINDS WILL STAY STRONG THROUGH THROUGH THE EVENING...BUT LOOK FOR AN
DECREASING OVERNIGHT THROUGH TUE AS THE PRESSURE GRADIENT SLACKENS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A PROGRESSIVE AND ENERGETIC FLOW PERSISTS OVER THE CONUS THROUGH
THIS WEEK WITH AN EVOLUTION TO MORE OF A ZONAL OR BROAD FLAT RIDGE
IN THE LARGE SCALE. PREDICTABILITY OVER THE PAST WEEKEND HAS BEEN
LOW...AS SEEN BY THE SHORT RANGE VARIABILITY IN HOW THIS CURRENT
SNOW EVENT TRANSPIRED. NOT PRETTY. THIS WILL CONTINUE THROUGH THE
WEEK...AND CONFIDENCE IS LOW IN TIMING AND PLACEMENT OF WEATHER
SYSTEMS.
LATEST SNOW AMOUNTS IN CENTRAL WISCONSIN ARE IN THE 3 TO 5 INCH
RANGE WITH WINDS CAUSING SOME MEASUREMENT DIFFICULTY. RADAR
INDICATING THAT MOST OF THE CENTRAL WI AREA SHOULD CONTINUE TO
DIMINISH IN INTENSITY AS SNOW SHIELD MOVES NORTHEAST. THE LATEST
RAP TRENDS INDICATE A STRENGTHENING 600-700MB WEAK-MODERATE
FRONTOGENESIS BAND WILL DEVELOP N-S OVER CENTRAL WI LATER THIS
AFTERNOON WHICH COULD BUMP THE RATES A BIT ON WEST END OF THE
SHIELD. BUT...THAT RAP FRONTOGENESIS GUIDANCE IN THE MID-LEVELS
HAS NOT PROVIDED MUCH FOR SENSIBLE SNOW INCREASE OR BANDING FOR
THIS ENVIRONMENT. OVERALL...FROM TRENDS AND WHAT HAS FALLEN...SNOW
WILL SLOWLY SHIFT EAST THIS EVENING...DIMINISHING. HAVE LOWER
STORM TOTAL AMOUNTS IN CENTRAL WISCONSIN...MORE AROUND 4.5 TO 5
INCHES...AND AFTER COLLABORATION WITH MKX...HAVE DOWNGRADED THE
WARNING TO ADVISORY.
WINDS WILL CONTINUE THROUGH THE EVENING TO CAUSE ROADS TO BE
COVERED AND SNOW PLOW CAMS IN NORTHEAST IA SUGGEST THE ROADS ARENT
TOO CLEAN YET. SO...HAVE DECIDED TO LET THE ENTIRE ADVISORY
CONTINUE THROUGH MIDNIGHT.
WATER VAPOR IMAGERY SHOWING A SHORTWAVE TROUGH DROPPING THROUGH MN
AND RADAR INDICATES SOME SNOW SHOWERS THERE. THIS SHOULD NOT
AMOUNT TO MUCH BUT A BRIEF SNOW SHOWER PERIOD AND MAYBE A BIT OF
VSBY REDUCTION /1-2SM/...BUT NOT A HAZARD GENERALLY. HOWEVER AN
AREA EXISTS AHEAD OF THE SHORTWAVE TROUGH IN MN AND THE HIGHER
LEVEL CLOUD WITH THE SNOW SHIELD THAT IS PROMOTING SOME FZDZ.
THIS IS FROM SERN MN INTO SWRN WI. SHERIFFS HAVE HAD FZDZ IN GRANT
COUNTY...AND EARLIER IN NERN IA. MOST OF THIS FZDZ SHOULD OCCUR
IN THE ADVISORY AREA AND FOR THE NEXT FEW HOURS AS THE DEEP SNOW
SHOWERS MOVING IN WILL SHIFT THE PRECIPITATION TYPE VIA SEEDER-
FEEDER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A FAIRLY TRANQUIL PERIOD FOR THE WEEK REALLY WITH A COLDER THAN
NORMAL PERIOD UNDER THE DEEP LONG WAVE TROUGH....BUT AS THIS
BECOMES MORE ZONAL...THE AREA WILL SEE CYCLES OF WARM ADVECTION
AND PRECIPITATION CHANCES...CYCLONE PASSAGE...AND COLD AIR PUSHES.
THE FIRST SHORTWAVE TROUGH COMES ON WEDNESDAY...A HEAVIER TRAVEL
DAY. THIS SHORTWAVE IS COMING INTO BRITISH COLUMBIA COAST
CURRENTLY ON THE POLEWARD SIDE OF A 155 KT 250 MB JET PER 12Z
RAOBS. A PRETTY VIGOROUS SYSTEM THAT DIGS SOUTHEAST IN THE
LONGWAVE TROUGH. THIS WILL BE A 1-2 INCH SNOW MAKER BUT THE TRACK
IS THE QUESTION. HAVE GENERALLY KEPT THE SAME FORECAST AS PREVIOUS
WITH MOSTLY A SRN MN AND NERN IA SYSTEM. CONFIDENCE ON THE TRACK
IS NOT HIGH YET WITH COMPLEX SYSTEM OVER GREAT LAKES AND TOTAL
ENERGY OVER THE CONUS RIGHT NOW. NEW GFS PARALLEL RUN INTENSIFIES
THE NWRLY FLOW ENERGY MORE AND BRINGS MORE SNOW TO THE NORTH...BUT
IS AN OUTLIER. BEHIND THIS SYSTEM...COLD AIR COMES IN FOR
THANKSGIVING...BUT A QUITE WEATHER DAY.
ANOTHER SYSTEM MOVES IN FRIDAY AND IF MY CONFIDENCE IS LOW ON THE
TRACK FOR WEDNESDAY...FRIDAYS WARM ADVECTION SWATH OF SNOW OR
WINTER MIX IS LOWER. GOOD MEDIUM RANGE GUIDANCE CONSENSUS ON THE
TRACK RIGHT NOW...BUT THAT DOESNT MEAN IT WILL BE CORRECT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY NIGHT)
ISSUED AT 530 PM CST MON NOV 24 2014
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR THE SNOW/LOW CLOUDS/WINDS
CONTINUE TO PULL OFF TO THE EAST EARLY THIS EVENING. THE BACK-EDGE
OF THE MAIN AREA OF SNOW WAS JUST EAST OF KLSE...BUT THERE WAS A
BAND OF -SHSN SLIDING SOUTHWARD ACROSS SOUTHEAST MN. THIS COULD
BRING A BRIEF RETURN TO MVFR OR LOWER VSBYS FOR AN HOUR OR
TWO...WITH SOME LINGERING FLURRIES FOR THE REST OF THE EVENING.
EXPECTING CIGS TO STAY MVFR THROUGH THE OVERNIGHT. DISTINCT EDGE TO
THE CLOUD SHIELD EVIDENT ON FOG/STRATUS SATELLITE IMAGERY...AND
MODELS FAVORING SLIDING THIS EAST OF THE TAF SITES EARLY TUE
MORNING. WILL CONTINUE THIS TREND...AND THUS SCT SKIES AND VFR
CONDITIONS FOR MOST OF THE DAY ON TUE.
WINDS WILL STAY STRONG THROUGH THROUGH THE EVENING...BUT LOOK FOR AN
DECREASING OVERNIGHT THROUGH TUE AS THE PRESSURE GRADIENT SLACKENS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ088-
096.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ011-
030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
247 PM CST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CST SUN NOV 23 2014
LIFR /IFR/ CONDITIONS ARE EXPECTED TO CONTINUE AT KRST /KLSE/
THROUGH THE AFTERNOON UNTIL A COLD FRONT PROVIDES A WIND SHIFT AT
KRST LATER THIS AFTERNOON. CURRENTLY THIS FRONT HAS VFR CONDITONS
BEHIND IT...HOWEVER ABUNDANT LOW-LEVEL MOISTURE AND SUNSET SUGGEST
THAT IF THERE IS A BREAK IN THE LIFR CONDITIONS AT THE TAF SITES...IT
WILL BUILD BACK IN FOR THE OVERNIGHT WITH COOLING. A CHANGE FROM
RAIN TO SNOW THEN OCCURS LATER OVERNIGHT...WITH DEEPER MIXING AND
STRONGER WINDS MOVING IN BY DAYBREAK. THIS MIXING WILL HELP
FINALLY REMOVE THE LIFR/IFR CONDITIONS...IF THEY HAVE NOT LIFTED
ACROSS THE AREA. STRONG WINDS ARE EXPECTED MONDAY AND POSSIBLY
FLURRIES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT CST MONDAY
NIGHT FOR WIZ055-061.
DENSE FOG ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1111 PM CST SAT NOV 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POWERFUL TROUGH OVER THE PACIFIC NORTHWEST...NOTED
BY A 155 KT JET NEAR 300MB ON THE 12Z MEDFORD OREGON RAOB. OTHER
FEATURES OF NOTE WERE AN UPPER LOW OVER THE BIG BEND REGION OF TEXAS
AND AN UPPER RIDGE OVER THE DAKOTAS AND MN. BELOW THE UPPER
RIDGE...WEST TO SOUTHWEST WINDS OF 20-30 KT FROM 925-850MB PER
PROFILER/VWP DATA HAS BEEN ADVECTING WARMER AIR INTO THE REGION.
925MB TEMPS HAVE RISEN FROM -1 TO 2C AT 12Z TO 2-6C AT 21Z.
HOWEVER...TAMDAR SOUNDINGS SHOW MUCH OF THIS WARMING HAS BEEN
STRENGTHENING A STRONG LOW LEVEL INVERSION...TRAPPING MOISTURE
ADVECTING NORTHWARD ON SOUTHERLY WINDS. DEWPOINTS PRESENTLY RANGE IN
THE 30S TO LOW 40S ACROSS THE FORECAST AREA...BUT 40S TO MID 50S
WERE LURKING ACROSS CENTRAL AND SOUTHERN IOWA. THE INCREASED
WARMING AND MOISTURE AT THE SURFACE HAS ALSO ALLOWED THE SNOWPACK TO
BEGIN TO WARM AND MELT...ADDING ADDITIONAL MOISTURE. WE HAVE SEEN
DENSE FOG EARLIER IN THE DAY...BUT DAYTIME MIXING PLUS WARMER AIR
COMING UP FROM THE SOUTH HAS HELPED TO RAISE VISIBILITIES FOR NOW.
FOR TONIGHT...IMPRESSIVE SURFACE TO 925MB WARM AND MOIST AIR
ADVECTION REMAINS PROGGED TO OCCUR ACROSS THE FORECAST AREA...AIDED
BY THE 925MB WINDS INCREASING TO 30-40 KT. 925MB TEMPS AND
DEWPOINTS BY 12Z SUNDAY CLIMB TO 8-10C...WITH MUCH OF THE JUMP
HAPPENING BETWEEN 00-06Z. THESE DEWPOINTS ARE 2-3 STANDARD
DEVIATIONS ABOVE NORMAL. HAD TO DO SOME MAJOR TEMP/DEWPOINT
ADJUSTMENTS TO HANDLE THIS WARM/MOIST AIR ADVECTION...FOLLOWING
MORE OF THE ECMWF/CANADIAN WHICH ARE NOT AFFECTED AS MUCH BY
SNOWPACK LIKE THE NAM IS. WITH ALL OF THIS WARMING AND MOISTURE
COMING ACROSS THE SNOWPACK...ANTICIPATE FAIRLY RAPID MELTING...
THROWING MORE MOISTURE INTO THE BOUNDARY LAYER. GIVEN AN
INVERSION HOLDING IN PLACE BETWEEN 850-900MB THIS EVENING...BELIEVE
WE SHOULD GET MORE FOG TO DEVELOP...POSSIBLY DENSE...SIMILAR TO WHAT
IS GOING ON RIGHT NOW IN SOUTH CENTRAL IA ON I-35 ON THE NOSE OF
THE MOISTURE SURGE. CONSIDERED GOING WITH AN ADVISORY...BUT
AFTERNOON TRENDS HAS REDUCED CONFIDENCE. ADVISORIES ARE STILL
POSSIBLE...THOUGH. OVERNIGHT...ALL THE FOG COULD DISSIPATE AS
THAT INVERSION WEAKENS...AS INDICATED IN RAP/HIRESARW VISIBILITY
FORECASTS. IN FACT...WE SHOULD HAVE THE AIRMASS OVER MISSOURI IN
PLACE WHICH FEATURES NO VISIBILITY RESTRICTION. SINCE THERE STILL
IS SNOWPACK...HAVE KEPT SOME FOG MENTION...BUT WE MAY NOT HAVE
MUCH SNOWPACK EXCEPT IN OUR NORTH BY THE TIME 12Z ROLLS AROUND.
ALONG WITH THE FOG...THE STRONG INCREASE OF LOW LEVEL MOISTURE IS
LIKELY TO LEAD TO AREAS- WIDESPREAD DRIZZLE...ESPECIALLY
OVERNIGHT.
ON SUNDAY...GOOD MODEL CONSENSUS EXISTS FOR DEEP TROUGHING TO FORM
ACROSS THE PLAINS BY 00Z...WHICH HELPS TO PULL NORTHEASTWARD THE
UPPER LOW NEAR TEXAS INTO SOUTHERN ILLINOIS. THE 22.12Z NAM IS THE
ONLY MODEL WHICH DOESNT PULL THE UPPER LOW NORTHEASTWARD...WHICH
APPEARS TO BE AN OUTLIER AND HAS BEEN DISCOUNTED. WITH THE APPROACH
OF BOTH THE UPPER TROUGH AND LOW IN THE AFTERNOON...DPVA FOR
VERTICAL MOTION INCREASES. THIS VERTICAL MOTION COMBINED WITH
PRECIPITABLE WATER CLIMBING TO 0.75-1 INCH...HIGHEST OVER THE
SOUTHEAST HALF OF THE FORECAST AREA...WILL LEAD TO AN INCREASE IN
SHOWER ACTIVITY...ESPECIALLY IN THE AFTERNOON. NOTE THAT THERE ARE
SIGNS FOR A FRONTOGENETIC BAND TO FORM STRETCHING SOUTHWEST TO
NORTHEAST ACROSS THE FORECAST AREA...WHICH MAY LEAD TO LESS
PRECIPITATION OVER THE FAR NORTHWEST SIDE OF THE FORECAST AREA.
OTHERWISE...ANY FOG FROM TONIGHT LOOKS TO DISSIPATE WEST TO EAST
THROUGH THE AFTERNOON...IN RESPONSE TO A COLD FRONT COMING INTO THE
WESTERN FORECAST AREA AND THE RAIN MOVING IN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 313 PM CST SAT NOV 22 2014
SUNDAY NIGHT AND MONDAY...THIS PERIOD IS BECOMING MORE INTERESTING.
THERE ARE SIGNS IN THE 22.12Z GFS AND CANADIAN OF PHASING TAKING
PLACE...BETWEEN THE OVERALL UPPER TROUGH ACROSS THE PLAINS AND THE
CURRENT STRONG JET STREAK AT MEDFORD OREGON LIFTING INTO THE OHIO
VALLEY. THE GFS EVEN TAKES IT ONCE STEP FURTHER AND PHASES IN THE
TEXAS UPPER LOW. THE RESULT OF THE PHASING IS RAPID DEEPENING OF A
SURFACE LOW BETWEEN 00-12Z MONDAY MARCHING FROM MISSOURI TO NORTHERN
LAKE MICHIGAN. PRESSURES FALL FROM THE UPPER 980S TO LOW 970S OR
UPPER 960S MB. THE 22.09Z SREF NMMB MEMBERS AND SOME OF THE
CANADIAN ENSEMBLES ARE ALSO QUITE DEEP...EVEN MORESO THAN THE
GFS/CANADIAN. THESE DEEPER MODELS WOULD RESULT IN A TROWAL
OVER THE FORECAST AREA...LEADING TO A HEAVY SNOW BAND AND STRONG
WINDS. ALTHOUGH THERE HAS BEEN A TREND OF DEEPENING IN THE
AFOREMENTIONED MODELS...THE 22.12Z ECMWF REMAINS CONSISTENT IN A
MORE PROGRESSIVE/LESS PHASED SCENARIO. THE MODEL STILL HAS SNOW FOR
THE FORECAST AREA AFTER SOME EVENING RAIN...BUT THE F-GEN BAND IS
NOT NEARLY AS IMPRESSIVE. GIVEN THE CONSISTENCY IN THE ECMWF
AND THE MODEL BEING GENERALLY ONE OF THE BEST AT SYNOPTIC
VERIFICATION...FEEL IT IS DIFFICULT TO JUMP ON THE DEEP SCENARIOS
YET. THUS...THE FORECAST FOR SUNDAY NIGHT/MONDAY REMAINS LARGELY
UNCHANGED. DID BACK OFF THE BLOWING SNOW A BIT SINCE THE SNOWPACK
WILL BE GONE...ALLOWING ANY FALLING SNOW TO ACCUMULATE IN DITCHES
AND THUS LIMIT BLOWING. TEMPERATURE WISE...EXPECT A CONTINUOUS
FALLING TREND FROM SUNDAY NIGHT THROUGH MONDAY.
SNOW SHOULD GRADUALLY TAPER OFF MONDAY NIGHT AS THE LOW LIFTS
OFF TO THE NORTHEAST...BUT CONTINUED COLD AIR ADVECTION IS
ADVERTISED. 925MB TEMPS PLUNGE TO -10 TO -12C...WHICH SHOULD BRING
TEMPS DOWN INTO THE TEENS. TUESDAY FINALLY LOOKS LIKE A DRY
DAY...ASSOCIATED WITH SURFACE RIDGING COMING ACROSS AND AHEAD OF A
POTENT SHORTWAVE DROPPING INTO THE DAKOTAS. PRECIPITABLE WATER IS
QUITE DRY TOO...AROUND 0.2 OF AN INCH...WHICH SHOULD ALLOW ANY LOW
CLOUDS TO CLEAR TUESDAY MORNING. MORE HIGH CLOUDS ARE LIKELY TO
ARRIVE IN THE AFTERNOON...THOUGH. WITH 925MB TEMPS OF -8 TO -10C AT
18Z...HIGHS ONLY LOOK TO TOP OUT IN THE 20S.
TUESDAY NIGHT AND WEDNESDAY COULD BE INTERESTING AS WELL WITH THE
22.12Z ECMWF REMAINING CONSISTENT IN DRIVING A STORM SYSTEM
FROM THE DAKOTAS THROUGH THE REGION. THE 22.12Z/18Z NAM ARE SIMILAR
TOO...THOUGH THERE REALLY IS NO RESEMBLANCE OF THE SYSTEM IN THE
22.12Z GFS. THE 22.12Z CANADIAN IS LIKE A WEAKER NAM/ECMWF. SHOULD
THE ECMWF/NAM VERIFY...WE COULD BE LOOKING AT A 1-2 INCH
SNOWFALL...WHICH COULD IMPACT THANKSGIVING TRAVEL. FOR NOW HAVE TO
KEEP THE CHANCES LOWER...20-40...UNTIL BETTER MODEL AGREEMENT OCCURS.
HOWEVER WEDNESDAY PANS OUT...GOOD MODEL AGREEMENT EXISTS FOR ANOTHER
COLD SURGE TO DIVE INTO THE REGION FOR THANKSGIVING. 925MB TEMPS OF
-14 TO -16C ARE PROGGED...WHICH WOULD RESULT IN HIGHS ONLY IN THE
MID TEENS TO LOW 20S AT BEST. THIS COLD AIR LOOKS TO LINGER INTO THE
EARLY PART OF THE WEEKEND AS CANADIAN HIGH PRESSURE BUILDS IN.
GENERALLY CONDITIONS SHOULD BE DRY...THOUGH CANNOT RULE OUT A FEW
LIGHT SNOW PERIODS THAT DO NOT ACCUMULATE UP TO MUCH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY TONIGHT)
ISSUED AT 1111 PM CST SAT NOV 22 2014
VSBYS HAVE BEEN VERY CHALLENGING TONIGHT...AND WILL LIKELY STAY THIS
WAY THROUGH SUNDAY. VARIABILITY AND MULTIPLE WEATHER ELEMENTS ARE
KEEPING FORECAST CONFIDENCE SHAKY IN HOW LOW VSBYS WILL GO...AND HOW
LONG THEY WILL STAY THERE. DON/T THINK THEY WILL IMPROVE OUT OF
MVFR...AND LIKELY STAY IFR FOR A BULK OF THE NEXT 24
HOURS...ESPECIALLY AT KRST. LIFR ALSO A GOOD BET THROUGH THE
OVERNIGHT HOURS.
AS FOR DRIZZLE. STILL SIGNALS IN THE MODELS FOR LIFT THROUGH THE
STRATUS LAYER...WHICH SHOULD LEAD TO AREAS OF -DZ. THIS SHOULD HANG
AROUND THROUGH SUNDAY MORNING...WITH AN AREA OF RAIN THEN ADVANCING
NORTHEAST OUT OF IA AS AN AREA OF LOW PRESSURE TAKES AIM ON THE
REGION. LOOKING FOR A WIND SHIFT TO THE NORTHEAST AS THE LOW MOVES
IN/SLIDES EAST...AND A SIGNIFICANT INCREASE IN WIND SPEED FOR SUNDAY
EVENING.
FOR CIGS...GOING TO KEEP THEM UNDER 1KFT FOR NOW. BUFKIT SOUNDINGS
VIA ALL MODELS DON/T BUDGE ON THE LOW LEVEL SATURATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR WIZ017-029-032>034.
MN...DENSE FOG ADVISORY UNTIL 8 AM CST SUNDAY FOR MNZ079.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
244 PM MST SUN NOV 23 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM MST SUN NOV 23 2014
MODELS IN GOOD AGREEMENT THROUGH TUESDAY...WITH WINDS AND HIGH
ELEVATION SNOWS THE PRIMARY FORECAST CONCERN OVER THE NEXT 48 TO
60 HOURS. FOR TONIGHT AND MONDAY...KEPT THE WIND ADVISORY GOING
FOR THE NEXT FEW HOURS WITH WINDS GUSTING TO 50 MPH ACROSS THE
WESTERN NEBRASKA PANHANDLE. THESE WINDS WILL DIMINISH AROUND
SUNSET WITH BREEZY CONDITIONS EXPECTED THROUGH MIDNIGHT. THE
MOUNTAIN SNOWFALL CONTINUING ACROSS THE REGION TODAY...AND SNOTEL
SITES REPORTING OVER ONE FOOT STORM TOTAL SNOW ALREADY...THE
WINTER STORM WARNING LOOKS GOOD AS WELL THROUGH MONDAY. DID ADJUST
SNOW ACCUMULATIONS A BIT ACROSS THE HIGHER RIDGES SINCE A FEW
PLACES MAY SEE CLOSE TO 30 INCHES BY LATE MONDAY. ADDED BLOWING
SNOW TO THE MOUNTAINS AND SURROUNDING VALLEYS INTO MONDAY AS THE
NEXT UPPER LEVEL DISTURBANCE MOVES INTO WYOMING LATE TONIGHT.
AFTER A BRIEF LULL IN THE SNOWFALL RATES THIS EVENING...SNOW
INTENSITY WILL QUICKLY INCREASE AFTER MIDNIGHT WITH AN ADDITIONAL
6 TO 12 INCHES EXPECTED THROUGH MONDAY AFTERNOON.
THE MAIN FORECAST CHALLENGE WILL BE TONIGHT AND THEN AGAIN ON
TUESDAY WITH STRONG WINDS ACROSS PORTIONS OF SOUTHEAST WYOMING.
THE NEXT UPPER LEVEL DISTURBANCE...CURRENTLY PUSHING SOUTHEAST
ACROSS IDAHO AND WESTERN MONTANA...WILL MOVE INTO WYOMING LATE
TONIGHT. LLVL WINDS WILL SHIFT INTO THE WEST BY MIDNIGHT AND
GRADUALLY INCREASE DUE TO A STRENGTHENING PRESSURE GRADIENT ALONG
THE CONTINENTAL DIVIDE AND THE LARAMIE RANGE. WIND GUSTS OVER 58
MPH ARE POSSIBLE OVER THE WIND PRONE AREAS ALONG I80.
THEREFORE...ISSUED A HIGH WIND WATCH FOR THE ARLINGTON AREA AND
THE I80 SUMMIT BETWEEN CHEYENNE AND LARAMIE. DO NOT BELIEVE I25
WILL SEE THE STRONGEST WINDS THIS TIME AROUND SINCE MODELS SHOW
SURFACE PRESSURE REMAINING STEADY OR INCREASING SLIGHTLY ACROSS
THE HIGH PLAINS. MODELS DO INDICATE PRESSURE FALLS FURTHER SOUTH
ACROSS NORTHERN COLORADO...SO EXPECT THE SOUTHERN LARAMIE RANGE TO
RECEIVE THE HIGHER GUSTS THIS TIME AROUND. OTHERWISE...EXPECT
ANOTHER ROUND OF ISOLATED TO SCATTERED SNOW SHOWERS ACROSS THE
VALLEYS AND HIGH PLAINS ON MONDAY AS THIS DISTURBANCE MOVES ACROSS
THE AREA AND INTO COLORADO.
FOR TUESDAY...A MORE WIDESPREAD HIGH WIND EVENT IS POSSIBLE AS A
140 KNOT JET MAX PUSHES ACROSS THE AREA WHILE THE JET STREAM
ITSELF TRANSLATES NORTHEASTWARD INTO TUESDAY NIGHT. MAY NEED A
HIGH WIND WATCH FOR MOST OF SOUTHEAST WYOMING ON TUESDAY ALONG
WITH WIND ADVISORIES ACROSS WESTERN NEBRASKA. THERE IS HIGH
CONFIDENCE THAT THE WIND PRONE AREAS WILL SEE GUSTS OVER 60 MPH BY
EARLY TUESDAY MORNING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM MST SUN NOV 23 2014
WINDS ARE THE PRIMARY FORECAST CHALLENGE IN THE LONG
TERM...FOLLOWED BY TEMPERATURES LATE IN THE EXTENDED. NOT A GOOD
TRAVEL TIME TUESDAY NIGHT THROUGH WEDNESDAY ACROSS SOUTHEAST
WYOMING AHEAD OF THE THANKSGIVING HOLIDAY.
STARTING OFF TUESDAY EVENING...GOING TO BE REALLY WINDY ACROSS
SOUTHEAST WYOMING. GFS 700MB WINDS 75 TO 80KTS ACROSS SOUTHERN
ALBANY COUNTY AND THE SOUTH LARAMIE RANGE. ECMWF 700MB WINDS A
BIT LOWER...BUT STILL IN THE 50 TO 60KT RANGE...SO CHANCES ARE
STILL REALLY GOOD FOR HIGH WIND HIGHLIGHTS AT LEAST FOR OUR WIND
PRONE AREAS CONTINUING INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
LATEST WRKHGT PRODUCT ENDS AT 00Z WEDNESDAY...BUT STILL SHOWS BOTH
850 AND 700MB CRAIG TO CASPER HEIGHT GRADIENTS WELL ABOVE 60MTRS.
ANOTHER UNCERTAINTY IN TUESDAY NIGHTS FORECAST...GFS SETS UP A
FAIRLY ROBUST BAND OF PRECIP OVER THE LARAMIE RANGE. COULD BE DUE
TO UPSLOPING OF NORTHWEST WINDS ON THE WEST SIDE OF THE LARAMIE
RANGE ALONG THE FRONTAL BOUNDARY THATS GOING TO LAY IN THE AREA.
ECMWF MUCH LESS ON QPF AMOUNTS. WE ARE GOING TO NEED TO WATCH THIS
DEVELOPMENT. SHOULD THE GFS SOLUTION COME TRUE...THIS SNOW
COMBINED WITH THE VERY STRONG WINDS WILL CREATE BLIZZARD
CONDITIONS FOR THE SOUTH LARAMIE RANGE OVER TO PROBABLY ARLINGTON
OR SO TUESDAY NIGHT INTO WEDNESDAY. DID ADD AREAS OF BLOWING SNOW
INTO THE FORECAST WEATHER GRIDS FOR THAT TIMEFRAME. LATER SHIFTS
WILL NEED TO DETERMINE WHAT WINTER HEADLINES TO ISSUE.
BOTH THE GFS AND ECMWF LIFT THE FRONTAL BOUNDARY NORTHEAST INTO
THE FAR NORTHERN NEBRASKA PANHANDLE BY WEDNESDAY AFTERNOON. WINDY
CONDITIONS WEST OF THE LARAMIE RANGE TO CONTINUE AS BOTH THE GFS
AND ECMWF SHOW 700MB WINDS WELL ABOVE 50KTS.
FOR THANKSGIVING...IT LOOKS DRY ACROSS SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE. CONTINUED WINDY...BUT NOTHING NEAR WHAT WE
WILL SEE TUESDAY AND WEDNESDAY. WIND PRONE AREAS COULD STILL BE
FLIRTING WITH HIGH WIND CRITERIA...ESPECIALLY OUT BY ARLINGTON ON
INTERSTATE 80. FAIRLY WARM THURSDAY AFTERNOON WITH LOW TO MID 40S
COMMON.
STRONG WINDS LOOK TO RETURN FRIDAY INTO SATURDAY AS ANOTHER
FRONTAL BOUNDARY BEGINS TO SAG SOUTH OUT OF MONTANA. GFS MUCH
FASTER ON THE SOUTHERN MOVEMENT OF THIS BOUNDARY...DRIVING THE
FRONT INTO THE EAST SLOPES OF THE LARAMIE RANGE BY SATURDAY
MORNING. ECMWF HAS FRONT STILL UP OVER NORTHERN WYOMING BY 12Z
SATURDAY. SO WE COULD BE LOOKING AT A 15 TO 20 DEGREE TEMPERATURE
BUST DEPENDING ON WHICH SOLUTION PANS OUT. DID LOWER HIGH
TEMPERATURES SATURDAY SEVERAL DEGREES ACROSS THE PANHANDLE AND
EASTERN SECTIONS OF SOUTHEAST WYOMING AS A HEDGE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 948 AM MST SUN NOV 23 2014
LATEST HRRR FORECAST USED FOR THE 18Z TAFS. SOME CONCERN FOR SOME
CONVECTIVE SNOW SHOWERS FOR KRWL AND KLAR AS SEEN IN THE HRRR
SOLUTION. BUT THESE BANDS ARE VERY NARROW AND IT WOULD BE ALMOST
IMPOSSIBLE TO NAIL DOWN TIMING OF THESE BANDS. DO BELIEVE MOST OF
THE SNOW SHOWERS WILL STAY SOUTH OF KLAR AND KRWL THIS
AFTERNOON...SO KEPT LOWER CONDITIONS OUT OF THE TAFS FOR BOTH
SITES. WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 110 PM MST SUN NOV 23 2014
ALTHOUGH WINDS WILL BE STRONG EARLY THIS WEEK...NO FIRE WEATHER
CONCERNS ARE ANTICIPATED DUE TO COOL TEMPERATURES AND HIGH
RELATIVE HUMIDITIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR WYZ112-114.
HIGH WIND WATCH FROM MIDNIGHT MST TONIGHT THROUGH MONDAY MORNING
FOR WYZ110-116.
NE...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR NEZ002-003-019>021-
054-055-095-096.
&&
$$
SHORT TERM...TJT
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
952 AM MST SUN NOV 23 2014
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 300 PM MST SAT NOV 22 2014
TODAY...MOIST NORTHWEST FLOW ALOFT CONTINUES TODAY WITH A FEW WEAK
SHORTWAVE TROUGHS IN THE FLOW. COLD AIR ADVECTION IN EARNEST TODAY
WITH PLENTY OF LOW AND MID LEVEL MOISTURE BEING ADVECTED ACROSS THE
SNOWY AND SIERRA MADRE RANGES...PRODUCING WIDESPREAD LIGHT
SNOW...AND THUS WE WILL CONTINUE THE WINTER STORM WARNING THERE. FOR
THE WESTERN NEBRASKA PANHANDLE...PROGGED GRADIENTS SUGGEST WIND
ADVISORY CRITERIA FROM LATE THIS MORNING THROUGH THIS AFTERNOON.
TONIGHT...MOIST NORTHWEST FLOW ALOFT CONTINUES PRODUCING OROGRAPHIC
SNOW SHOWERE ACROSS THE MOUNTAINS.
MONDAY...PROGRESSIVE LOW AMPLITUDE POSITIVELY TILTED SHORTWAVE MOVES
ACROSS OUR COUNTIES ON NORTHWEST FLOW ALOFT. MODERATE TO HEAVY
OROGRAPHIC SNOWS WILL CONTINUE ACROSS THE SNOWY AND SIERRA MADRE
RANGES IN FLOW ALOFT...DRY ELSEWHERE...EXCEPT FOR ISOLATED SHOWERS
OVER THE PLAINS.
MONDAY NIGHT...FAST NORTHWEST FLOW ALOFT CONTINUES. DECENT SURFACE
LEE TROUGH EXPECTED TO SCOUR THE COLD AIR OUT TO OUR EAST.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 300 PM MST SAT NOV 22 2014
TUESDAY THROUGH SATURDAY...NORTH/NORTHWEST FLOW EARLY IN THE PERIOD
WILL FLATTEN AND BECOME MORE ZONAL BY THE END OF THE WEEK AND NEXT
WEEKEND. 00Z MEDIUM RANGE SOLUTIONS ARE SIMILAR AT LEAST FOR TUESDAY
AND WEDNESDAY...BUT CONTINUE THEIR MASSIVE DISCREPENCIES THEREAFTER.
MORE ON THAT LATER. LETS TALK ABOUT THE PART OF THE FORECAST THAT
CARRIES THE GREATEST CONFIDENCE...TUESDAY AND WEDNESDAY.
NORTH/NORTHWEST FLOW WILL BE IN PLACE WITH WITH THE NOSE OF AN 160+
KNOT H3 JET MOVING OVERHEAD. TIGHT LLVL PRESSURE/HEIGHT GRADIENT AND
PROGD H7 WINDS OF OF 60-70 KNOTS WILL MAKE TUESDAY ANOTHER WIND DAY.
WILL UNDOUBTEDLY NEED WIND HIGHLIGHTS IN TIME ON TUESDAY ESPECIALLY
IN WIND PRONE AREAS. WIND SPEEDS OUTSIDE OF THESE AREAS WILL DEPEND
ON THE AMOUNT OF LENTICULAR CLOUD COVER AND CORRESPONDING MIXING.
OROGRAPHIC SNOWS WILL BE A NEAR CERTAINTY ON TUESDAY AFTERNOON AS
MOISTURE ADVECTION COMBINES WITH ACCELERATING LLVL FLOW. ANOTHER 4
TO 8 INCHES OF SNOW WILL BE POSSIBLE OVR THE SNOWY AND SIERRA MADRES
TUESDAY AND TUESDAY NIGHT. WILL UNDOUBTEDLY NEED ANOTHER WINTER
HEADLINE OVR THE SNOWY/SIERRA MADRE RANGES TUESDAY AND TUESDAY
NIGHT. TUESDAY WILL BE ABOUT 5 DEGREES MORE MILD AS WELL. FLOW
BECOMES MORE NORTHWEST ON WEDNESDAY...AS THE JET TRANSLATES EAST AND
BEGINS FLATTENING. OROGRAPHIC SNOW WILL DIMINISH ON WEDNESDAY AS
MOISTURE/LIFT DEPART.
AND NOW FOR THE UNCERTAINTY THAT CONTINUES FOR THANKSGIVING. IF YOU
RECALL MODEL SOLUTIONS FROM 24 HOURS SHOWED A COOLER/WETTER GFS
COMPARED TO MILD AND DRY ECMWF. WELL TONIGHTS RUNS HAVE COMPLETELY
FLIP FLOPED. NOW THE ECMWF SHOWS THE ARCTIC AIR MASS BACKING IN
EARLY THURSDAY AND SNOW DEVELOPING THURSDAY NIGHT AND FRIDAY.
COMPARATIVELY...THE GFS IS DRY AND SIGNIFICANTLY WARMER THRU THE
PERIOD. TO ILLUSTRATE THE UNCERTAINTY FURTHER...GFS MOS FORECASTS A
HIGH TEMPERATURE OF 63F FOR THANKSGIVING...WHILE THE ECMWF PROGS
34F. NEEDLESS TO SAY FORECAST CONFIDENCE REMAINS UNUSUALLY LOW FOR
THANKSGIVING AND FRIDAY. FOR NOW HAVE STEERED THE FORECAST TOWARDS A
COMPROMISE OF THE TWO FOR THANKSGIVING AND KEPT THINGS DRY. IN
EITHER CASE...COLD AIR RETREATS FOR THE WEEKEND AS THE PATTERN
BECOMES MORE ZONAL. STAY TUNED OVER THE NEXT FEW DAYS AS THE MODELS
HOPEFULLY GET A BETTER HANDLE ON THE HOLIDAY TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 948 AM MST SUN NOV 23 2014
LATEST HRRR FORECAST USED FOR THE 18Z TAFS. SOME CONCERN FOR SOME
CONVECTIVE SNOW SHOWERS FOR KRWL AND KLAR AS SEEN IN THE HRRR
SOLUTION. BUT THESE BANDS ARE VERY NARROW AND IT WOULD BE ALMOST
IMPOSSIBLE TO NAIL DOWN TIMING OF THESE BANDS. DO BELIEVE MOST OF
THE SNOW SHOWERS WILL STAY SOUTH OF KLAR AND KRWL THIS
AFTERNOON...SO KEPT LOWER CONDITIONS OUT OF THE TAFS FOR BOTH
SITES. WILL CONTINUE TO MONITOR.
&&
.FIRE WEATHER...
ISSUED AT 209 PM MST SAT NOV 22 2014
MINIMAL CONCERNS DUE TO PROJECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR WYZ112-114.
NE...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR NEZ002-003-019>021-
054-055-095-096.
&&
$$
SHORT TERM...RUBIN
LONG TERM...CAH
AVIATION...GCC
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
355 AM EST Tue Nov 25 2014
...Another Day and Night of Rain on Tap for Most Areas Along with
Cooler Temperatures...
.Near Term [Through Today]...
A band of moderate to heavy rain and embedded thunderstorms has
developed across our forecast area early this morning, just along a
surface cold front. The surface cold front will push southeast of
our area today, but rain will be maintained along the sloped frontal
surface to the northwest as a strong shortwave ejects east across
Texas. The response to the ejecting wave will be a strengthening
frontogenetic circulation - especially in the 18-00Z time frame.
Model consensus places the strongest 925-700mb UVV roughly right
where the rain band is already positioned as of 08Z - from Mexico
Beach, to Quincy, to Tifton, and 25-30 miles either side of that.
Rain should initially be quite focused in this narrow band, but will
eventually expand in coverage as 00Z approaches with cyclogenesis
commencing in the eastern Gulf of Mexico. During the daytime hours,
though, we expect a sharp gradient in rain chances due to some dry
low-level air working in behind the cold front. Model forecast cross
sections cut through the front across our area from NW-SE show a
wedge of drier air from roughly ECP-BIJ and to the northwest. This
should limit northwestward progress of measurable rain today,
although even our northwest zones should see some light rain by
tonight. Given the strength of the frontogenetic circulation and
precipitable water values about 1.5 to 2 standard deviations above
normal, it is likely we will see some heavy rain at times today,
particularly in the f-gen band. Heavy rain wording was added to the
forecast with 12-hr QPF of 1.0-1.5" on average in those areas. To
the southeast, scattered showers and thunderstorms should gradually
increase in coverage through the day as low-level ascent becomes
stronger with the developing surface low in the eastern Gulf.
We went with a non-diurnal temperature trend for today. Cooler air
will be working its way southeast across the area in the morning
behind the surface cold front. However, abundant cloud cover and
rain will likely maintain temperatures in the 50s for all but the
eastern Florida Big Bend. By 18-20Z, the coolest temperatures in our
area should be in the low 50s, roughly along the same rain band axis
described earlier (Mexico Beach - Quincy - Tifton). Therefore, highs
for a significant part of our area may occur early in the morning.
The hourly temperatures were a blend of the RAP and 4km NSSL-WRF.
.Short Term [Tonight Through Thursday]...
Isentropic ascent of the 300K surface will be strongest during the
hours centered around 00Z Wednesday as the front remains stalled
over the area under parallel southwesterly flow aloft. DPVA will
also be in play. Therefore, we start out with categorical PoPs
across the board, as high as 100% across roughly the eastern half of
the forecast area. After that, forcing for ascent will drop off
precipitously after midnight with all PoPs ending before 18Z
Wednesday. For additional rainfall totals and any flooding concerns,
see the hydrology section below.
As cyclogenesis jumps to the coastal Carolinas, the colder air will
finally be drawn completely across the forecast area tonight. In
fact, temperatures will be chilly throughout this period. Look for
low temps by dawn Wednesday to range from the upper 30s over
Southeast AL and adjacent portions of the FL Panhandle to the upper
40s across the Southeast FL Big Bend. Highs both Wednesday and
Thursday will generally be closer to what we see in January with
lowers 60s common. A few spots across our northern zones will not
even quite make it to 60. Overnight lows Wednesday night will
generally be in the mid to upper 30s inland with 40s near the coast.
.Long Term [Thursday Night Through Tuesday]...
This period will be dry with surface high pressure in control.
Heights will also rise with zonal flow in place from the weekend
into Monday. However, the chilly air mass will remain in place
through Friday night with temps near or below even normal midwinter
levels. A few spots across the northern fringe of the forecast area
could touch freezing Thursday night and there could be some frost
Friday night. A moderating trend is expected from the weekend into
Monday. Some areas will see lower 70s degrees by Sunday with most
areas getting there on Monday.
&&
.Aviation...
[Through 06Z Wednesday] In general, there was a gradient in
observed conditions as of TAF issuance time from VFR to the
northwest, to IFR to the southeast, across the area. We expect
that trend to continue through the day, although it is likely
model guidance is being too optimistic with CIGS. A steady, cool
rain is forecast at most of the terminals, and that should help
lower cloud bases. In general, we are forecasting CIGS to trend
down into IFR or low-end MVFR at TLH and VLD, and trend down to
MVFR at ECP and ABY. DHN is most likely to stay at VFR for much of
the period. Visibility may be briefly reduced into the IFR range
at times in heavier rain or thunderstorms.
&&
.Marine...
Small craft advisory conditions will first be achieved with offshore
winds speeds this morning. The nearshore legs will not see this
until later in the day. Winds will be strongest overnight and an
occasional gust to gale force will be possible. Conditions will drop
below advisory criteria, even offshore, Wednesday morning. After a
brief lull Wednesday afternoon, a return to cautionary conditions is
expected from Wednesday night into Friday. Winds will then drop
below headline criteria for Friday night and Saturday as they
finally veer to onshore.
&&
.Fire Weather...
Wetting rains are expected today with high RH. Drier air will arrive
on Wednesday and Thursday, but RH values are not currently forecast
to reach critical levels. Additionally, fuel moisture will be quite
high given recent rainfall.
&&
.Hydrology...
Radar estimates that 2.5-3.5 inch rainfall totals have been common
since Saturday across most of our GA zones as well as northern and
western portions of the FL Big Bend and adjacent Panhandle. This is
causing rises on most area rivers. These slow rises will continue
for the next several days. Additional rainfall totals through
tonight will be around 2-2.5 inches for the southeastern 1/2 of
the forecast area. These rains are not expected to cause
significant areal or riverine flooding. However, the Ochlockonee
River could approach minor flood stage in 4-5 days.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 61 43 62 37 64 / 100 100 10 10 0
Panama City 57 44 63 45 63 / 100 90 10 10 0
Dothan 54 40 60 39 60 / 50 90 10 10 0
Albany 56 42 61 37 61 / 80 100 20 10 0
Valdosta 62 46 61 37 62 / 100 100 20 10 0
Cross City 68 49 64 37 65 / 90 100 20 10 0
Apalachicola 62 46 62 44 64 / 100 100 10 10 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...Small Craft Advisory from 4 PM this afternoon to 7 AM EST
Wednesday for Apalachee Bay-Coastal waters From Ochlockonee
River to Apalachicola FL out to 20 NM-Coastal waters from
Suwannee River to Keaton Beach FL out 20 NM-Coastal waters
from Apalachicola to Destin FL out 20 NM.
Small Craft Advisory until 10 AM EST Wednesday for Waters from
Suwannee River to Apalachicola FL from 20 to 60 NM-Waters
from Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1158 PM CST MON NOV 24 2014
.UPDATE...
830 PM CST
MINOR ADDITIONAL TWEAKS TO GOING FORECAST TONIGHT...MAINLY TO
REFINE POPS FOR ADDITIONAL SCATTERED SNOW SHOWERS/FLURRIES
OVERNIGHT AND TO LOWER TEMPS A BIT WITH PERSISTENT COLD ADVECTION.
REPORTS OF FREEZING DRIZZLE HAVE TAPERED OFF AT MID-EVENING AS
ANTICIPATED PER FORECAST SOUNDING TRENDS. A COMPARISON OF ILX/DVN
00Z RAOBS SHOWS THE MINOR DIFFERENCE IN LOW LEVEL SATURATION DEPTH
WITH THE TOP OF THE ILX MOIST LAYER JUST BELOW 700 HPA AND -14C
WHILE AT DVN IT IS AT 650 HPA AND -18C AND THUS MORE LIKELY TO
CONTAIN ICE AND PRODUCE SNOW. RAP SOUNDING AND IR SATELLITE
TRENDS INDICATE THAT FREEZING DRIZZLE SHOULD BE LESS OF AN ISSUE
FOR REMAINDER OF THE EVENING AS THE COLUMN CONTINUES TO COOL AND
MOISTURE DEEPENS AGAIN WITH APPROACH OF SHORT WAVE APPROACHING
FROM NORTHEAST IA. THIS WAVE IS EXPECTED TO CONTINUE TO PRODUCE
SCATTERED SNOW SHOWERS AS IT MOVES INTO THE CWA OVERNIGHT...THOUGH
HRRR/NAM BOTH INDICATE A DECREASE IN COVERAGE AFTER MIDNIGHT OVER
OUR NORTHERN CWA. THUS WHILE FLURRIES/SNOW SHOWERS WILL BE AROUND
THROUGH MUCH OF THE NIGHT...IT APPEARS THAT ANY LIGHT ADDITIONAL
MEASURABLE SNOW (JUST A COUPLE TENTHS PERHAPS) WILL BE LIMITED TO
NORTHERN PARTS OF NORTH CENTRAL IL. SNOW SHOWERS SHOULD TAPER OFF
TO JUST FLURRIES AFTER 07-09Z (2-4 AM CST) WITH PASSAGE OF
NORTHEAST IA VORT...BASED ON EXTRAPOLATION OF RADAR LOOP.
OTHERWISE...HAVE LOWERED MIN TEMPS JUST A BIT OVERNIGHT AS WE WERE
ALREADY WITHIN A COUPLE OF DEGREES OF FORECAST MINS OUT WEST.
BLENDED IN A BIT OF MAV/MET MOS GUIDANCE WHICH LOWERED MINS ABOUT
2 DEGREES IN MANY PLACES. WINDS CONTINUE TO GUST ABOVE 35 MPH IN A
FEW SPOTS...BUT WILL GRADUALLY DIMINISH OVERNIGHT AS GRADIENT
SLOWLY WEAKENS AND SURFACE PRESSURE RISE MAXIMA CONTINUES TO EXIT
TO OUR NORTHEAST.
RATZER
&&
.SHORT TERM...
302 PM CST
THROUGH WEDNESDAY...
TONIGHT...
PRIMARY SNOW BAND/DEFORMATION AXIS HAS SHIFTED NORTH BUT
WILL STILL SEE OCCASIONAL SNOW SHOWERS MOVING INTO NORTHERN ILLINOIS
INTO THE EVENING RUSH. SOME OF THESE COULD DROP VISIBILITY DOWN
UNDER 1 MILE AT TIMES...ESPECIALLY AS WINDS CONTINUE TO GUST CLOSE
TO 45 MPH AT TIMES. GOING TO SHIFT END TIME OF ADVISORY FOR
NORTH/NW CWA TO 00Z...WITH THE WIDESPREAD ACCUMULATING SNOW
ALREADY HAVING ENDED. COULD SEE SOME LINGERING LIGHT
SNOW/FLURRIES LATE EVE/OVERNIGHT AS ADDITIONAL UPPER LEVEL ENERGY
TRAVERSES AREA IN CYCLONIC FLOW ALOFT. STRATUS DECK WILL
COUNTERACT LOW LEVEL CAA TO KEEP TEMP FALL IN CHECK TONIGHT...BUT
STILL ANTICIPATING LOW- MID 20S BY DAYBREAK TUESDAY.
TUESDAY/TUES NIGHT...
OTHER THAN POSSIBLY A FEW FLURRIES IN NORTHEAST
IL/NW IN IN THE AM AS SOME LIFT REMAINS OVER THE AREA...LAKE EFFECT
FOCUS WILL LIKELY BE TO OUR EAST WITH WESTERLY FLOW. QUESTION IS
DOES STRATUS ERODE DURING AFTERNOON INTO EVENING. AS IS
TYPICAL...WRF/NAM GUIDANCE IS MOST BULLISH ON LOW LEVEL
MOISTURE...WHILE REMAINDER OF GUIDANCE DOES ENABLE DRY AIR TO MOVE
IN LATE DAY INTO TUESDAY EVENING. CONFIDENCE IS NOT THE
HIGHEST...BUT HAVE TRENDED A BIT MORE OPTIMISTIC WITH CLOUD COVER.
WARM ADVECTION WILL RAMP UP ALOFT IN ADVANCE OF CLIPPER SYSTEM
TOMORROW NIGHT...BUT WITH A TRANSIENT SURFACE RIDGE OVER THE
AREA...CLEAR/PCLOUDY SKIES COULD ENABLE A MORE SIGNIFICANT
TEMPERATURE FALL FROM HIGHS IN THE UPPER 20S-LOW 30S. THIS IS
PARTICULARLY THE CASE FOR AREAS THAT PUT DOWN SNOW COVER TODAY. HAVE
ADJUSTED LOW TEMPS DOWN A FEW DEGREES...TO UPPER TEENS IN NORTHWEST
TO LOW-MID 20S ELSEWHERE.
WEDNESDAY...
DECIDED TREND ON GUIDANCE AND ENSEMBLES TODAY HAS BEEN TO TRACK
CLIPPER MAINLY SOUTH OF THE CWA...AND HAVE ADJUSTED POPS DOWNWARD
CHANCE SOUTHWEST CWA AND SLIGHT CHANCE ELSEWHERE. UPPER LEVEL ENERGY
ASSOCIATED WITH THIS SYSTEM WAS STILL OFF OF THE BRITISH COLUMBIA
COAST AT RAOB TIME. GIVEN TENDENCY FOR LARGE SHIFTS IN THE SHORT
TERM GUIDANCE WITH THE TRACK OF SUBTLE FEATURES SUCH AS
CLIPPERS...HAVE NOT GONE WITH A COMPLETELY DRY FORECAST YET.
HOWEVER...IF TRENDS CONTINUE...ONLY THE FAR SOUTHWEST CWA WOULD SEE
ANY SENSIBLE WX IMPACTS. TEMPS LOOK TO RISE INTO THE LOW-MID
30S...WITH A FEW DEGREES ABOVE THIS POSSIBLE IF CLIPPER TRACKS
COMPLETELY SOUTH OF THE CWA. THIS WILL BE IN ADVANCE OF NEXT SURGE
OF MODIFIED ARCTIC AIR FOR THANKSGIVING DAY.
RC
&&
.LONG TERM...
WEDNESDAY NIGHT THROUGH TUESDAY...
A SECONDARY TROUGH AXIS WILL CROSS THE REGION WEDNESDAY NIGHT...BUT
OUTSIDE OF BULLISH CANADIAN MODEL...LITTLE SUPPORT FOR ANYTHING MORE
THAN SLIGHT POPS. BIG STORY IS GLANCING BLOW OF ARCTIC AIR SENDING
H85 TEMPS INTO THE LOW-MID MINUS TEENS CELSIUS ON THANKSGIVING
DAY...ONLY SUPPORTING HIGHS FROM THE MID 20S TO LOWER 30S...COLDEST
WHERE THERE WILL STILL BE SOME LEFTOVER SNOW COVER. LAKE EFFECT
FOCUS LOOKS TO BE EAST OF OUR NW IN COUNTIES...BUT WILL STILL NEED
TO MONITOR DUE TO FAVORABLE PARAMETERS.
UPPER LEVEL PATTERN CONTINUES TO LOOK TO QUICKLY SHIFT TO MORE ZONAL
ON LATEST GUIDANCE...SUPPORTING A RAPID MODERATING TREND. PRIOR TO
THAT...GUIDANCE DOES BREAK OUT SOME LIGHT WAA PRECIP ON FRIDAY AS AN
UPPER LEVEL WAVE MOVES OVER THE REGION. BETTER FORCING LOOKS TO BE
INTO SOUTHERN WI AT THIS TIME...BUT STILL A WAYS OUT. HAVE INDICATED
SLIGHT POPS FOR LIGHT SNOW...WITH A MIX OR TRANSITION TO RAIN BY
AFTERNOON FOR PARTS OF AREA AS BOUNDARY LAYER WARMS ABOVE FREEZING.
LOW PRESSURE OVER NORTHERN PLAINS LOOKS TO ADVECT IN A MUCH WARMER
AIR MASS ON SOUTHWEST FLOW ON SATURDAY. H85 TEMPS WARMING TO
POSSIBLY UPWARDS OF +10C COULD SPELL READINGS WELL INTO THE 50S (!)
FOR AT LEAST PORTIONS OF AREA IF TRENDS HOLD. DESPITE FLOW REMAINING
ZONAL...SIGNS THAT COLD AIR OVER CANADA AND FAR NORTHERN TIER COULD
TRY TO OOZE SOUTH LATER INTO THE WEEKEND INTO EARLY NEXT WEEK. THIS
WOULD SET UP A BAROCLINIC ZONE AND POSSIBLY LOW PRECIP CHANCES
RETURNING.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERSISTENT SCATTERED LIGHT SNOW SHOWERS...BUT REMAINING VFR.
* POTENTIAL FOR A STRONGER SNOW SHOWER EARLY THIS FORECAST
PERIOD...WITH POSSIBLE IFR VIS.
* MVFR CEILINGS THROUGH LATE MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
LATEST RADAR IMAGERY SHOWING SNOW SHOWERS PERSISTING AROUND THE
TERMINALS THIS HOUR...BUT WITH NO REAL VIS RESTRICTION. THESE SNOW
SHOWERS AND VIS TRENDS WILL CONTINUE EARLY THIS MORNING BUT WITH
THE POSSIBILITY FOR A BRIER HEAVIER SNOW SHOWER EARLY...POSSIBLY
PROVIDING IFR VIS. HAVE MAINTAINED TEMPO GROUP WITH 2SM VIS BUT
DID PUSH IT BACK AN HOUR BASED ON LATEST TRENDS. ANY SNOW WILL
LIKELY COME TO AN END LATER THIS MORNING WHILE MVFR CEILINGS
SLOWLY LIFT TO VFR BY LATE MORNING...WITH VFR CEILINGS THEN
LINGERING INTO THE AFTERNOON. AS HIGH PRESSURE BUILDS ACROSS THE
REGION THIS AFTERNOON SHOULD SEE THESE CLOUDS SCATTER...WITH ONLY
HIGH LEVEL CLOUD THEN ANTICIPATED THROUGH THE REST OF THE FORECAST
PERIOD. THE STRONGER WESTERLY WINDS ARE CURRENTLY
DIMINISHING...WITH THIS TREND CONTINUING THROUGH THE REST OF THE
MORNING BUT WHILE STAYING WESTERLY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH SCATTERED LIGHT SNOW SHOWERS.
* MEDIUM CONFIDENCE WITH ANY STRONGER SNOW SHOWERS EARLY.
* HIGH CONFIDENCE WITH MVFR CEILINGS...LOW MEDIUM CONFIDENCE WITH
DURATION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SOUTH WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
MDB
&&
.MARINE...
235 PM CST
LOW PRESSURE THAT MOVED OVER THE STRAITS THIS MORNING AND DRAGGED A
COLD FRONT ACROSS THE LAKE WILL HAVE LIFTED INTO THE JAMES BAY AREA
LATE THIS EVENING. STRONG WEST GALES ACROSS THE SOUTH HALF OF THE
LAKE WILL PERSIST INTO THE OVERNIGHT HOURS...WITH GUSTY BUT WEAKER
NORTHWEST WINDS ACROSS THE NORTHERN HALF OF THE LAKE. SNOW MOVES
OUT TONIGHT EXCEPT FOR LINGERING LAKE EFFECT ALONG THE MICHIGAN
SHORE.
WINDS REMAIN WESTERLY BUT RELAX DURING THE DAY TUESDAY AND THEN
RELAX FURTHER BY WEDNESDAY IN A WEAK AND DISORGANIZED PRESSURE
GRADIENT. BY WEDNESDAY NIGHT INTO THURSDAY THE PATTERN BECOMES
BETTER ORGANIZED AGAIN AND WINDS PICK UP FROM THE WEST TO NORTH.
WEATHER REMAINS MOSTLY QUIET THIS WEEK AFTER TONIGHT ASIDE FROM A
BRIEF SHOT OF SNOW AGAIN LATE WEDNESDAY AND THE MICHIGAN SIDE LAKE
EFFECT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION...CORRECTED
NWS JACKSON KY
308 AM EST TUE NOV 25 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
SURFACE RIDGING CONTINUES TO BUILD INTO EASTERN KENTUCKY THIS MORNING
WITH SKIES GENERALLY CLEAR TO MOSTLY CLEAR. THIS WILL HOLD THROUGH
THE DAY...PROVIDING A COOLER...BUT STILL RELATIVELY PLEASANT DAY. IN
FACT...WITH THE HELP OF THE SUNSHINE AND TEMPERATURES IN SOME PLACES
ALREADY IN THE 40S THIS MORNING...WE SHOULD HAVE NO PROBLEM
SURPASSING THE 50 DEGREE MARK THIS AFTERNOON. WITH AN ABUNDANCE OF LOW
LEVEL DRY AIR JUST OFF THE SURFACE...RAP AND HRRR ARE SUGGESTING
FAIRLY LOW DEWPOINTS THIS AFTERNOON...ESPECIALLY ACROSS SOUTHEAST
KENTUCKY. IT MIGHT BE A STRETCH TO FALL INTO THE TEENS...BUT
CERTAINLY DEWPOINTS DOWN INTO THE MID 20S WILL BE POSSIBLE. THIS WILL
PUT US CLOSE TO THE 25 PERCENT RH`S THIS AFTERNOON. I WOULDN`T BE
SURPRISED TO SEE A FEW SPOTS ACTUALLY REACH THIS VALUE...ESPECIALLY
IN SOUTHEAST KENTUCKY.
CLOUDS WILL BE ON THE INCREASE THIS EVENING AND ESPECIALLY TONIGHT.
MODELS HAVE AN AREA OF LOW PRESSURE DEVELOPING OVER FLORIDA AND
TRACKING NORTHWARD ALONG THE COAST TONIGHT. NEARLY ALL MODELS ARE IN
SUPPORT OF MOISTURE AND LIFT ASSOCIATED WITH THIS SYSTEM DEVELOPING
ACROSS FAR SOUTHEAST AND EAST KENTUCKY OVERNIGHT INTO WEDNESDAY
MORNING. GIVEN THE ABUNDANCE OF DRY AIR IN PLACE...WET BULB
TEMPERATURES WILL BE FAIRLY LOW. ASSUMING WE GET PRECIP RATES THAT
SUPPORT IT...WE SHOULD SEE PRIMARILY SNOW LATE TONIGHT INTO WEDNESDAY
MORNING...BUT SOME RAIN MAY BE POSSIBLE FARTHER INTO EASTERN KENTUCKY
WHERE PRECIP RATES MAY NOT BE AS HIGH. REGARDLESS...WE SHOULD SEE
TEMPERATURES COOL ENOUGH TO SUPPORT SOME LIGHT SNOW ACCUMULATION
ACROSS SOUTHEAST KENTUCKY. AT THIS TIME...THE HIGHEST AMOUNTS SHOULD
BE ABOVE 2500 FEET...WHERE 2 TO 3 INCHES OF SNOW MAY BE POSSIBLE.
LIGHTER AMOUNTS IN THE LOWER ELEVATIONS UP TO AN INCH WILL BE
POSSIBLE FOR AREAS SOUTHEAST OF A LINE FROM INEZ TO HAZARD...TO
BARBOURVILLE. WHILE SNOW IS EXPECTED ACROSS SOUTHEAST KENTUCKY...THE
REST OF EASTERN KENTUCKY MAY NOT SEE MUCH MORE THAN INCREASED CLOUD
COVER. PLAN TO GO AHEAD AND ISSUE AN SPS FOR OUR SOUTHEAST COUNTIES
TO ADDRESS THE POTENTIAL SNOWFALL. GIVEN THE EXPECTED CLOUD COVER
INTO WEDNESDAY...WENT WITH A PRETTY GOOD GRADIENT IN TEMPERATURES
FROM WEST TO EAST...WITH READINGS AROUND 50 IN THE WEST TO LOW AND
MID 30S IN THE EAST. PRECIPITATION WILL DEPART BY MIDDAY
WEDNESDAY...WITH TEMPORARY BREAK IN PRECIPITATION EXPECTED THROUGH
THE AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
THE MODELS BEGIN THE PERIOD IN PRETTY GOOD AGREEMENT...WITH A LARGE
SCALE UPPER LEVEL TROUGH OF LOW PRESSURE EJECTING OUT OF THE
NORTHERN PLAINS AND ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS
WEDNESDAY NIGHT THROUGH FRIDAY. IT APPEARS THAT THIS INITIAL SYSTEM
WILL BE FAIRLY PROGRESSIVE...SO ANY PRECIPITATION ASSOCIATED WITH IT
SHOULD BE SHORT LIVED AND NOT VERY HEAVY. A SHOT OF COLD AIR WILL
SPILL INTO THE REGION AS THE SYSTEM DEPARTS...WITH HIGHS ON THURSDAY
ONLY TOPPING OUT AROUND 40 DEGREES...AFTER MORNING LOWS IN THE UPPER
20S AND LOWER 30S. A RIDGE OF HIGH PRESSURE IS THEN PROGGED TO
BECOME ESTABLISHED ACROSS THE REGION TO BEGIN THE WEEKEND...WITH
WARMER TEMPERATURES AND PARTLY CLOUDY SKIES ON TAP FOR FRIDAY NIGHT
AND SATURDAY. SATURDAY COULD MARK THE START OF A SIGNIFICANT WARMING
TREND...WITH HIGHS POSSIBLY TOPPING OUT IN THE LOW TO MID 50S. THE
REGION IS EXPECTED TO WARM EVEN MORE ON SUNDAY AND MONDAY...AS THE
MERCURY CLIMBS INTO THE MID TO UPPER 50S FOR MOST LOCATIONS BOTH
DAYS. OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT WILL FEEL ALMOST
BALMY IF THEY IN FACT ONLY DROP INTO THE LOW TO MID 40S EACH NIGHT.
ENOUGH COLD AIR WILL LIKELY SPILL INTO THE REGION TO BEGIN THE
PERIOD TO ALLOW FOR SOME SNOW TO MIX WITH RAIN EARLY WEDNESDAY NIGHT
INTO THURSDAY MORNING ACROSS THE AREA. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THE NEXT ROUND OF PRECIPITATION IS
EXPECTED TO MOVE ACROSS THE AREA BEGINNING SATURDAY NIGHT...AS A
WEAK FRONTAL BOUNDARY MOVES INTO AND STALLS OUT ACROSS THE AREA. THE
MODELS KEEP THE FRONT IN PLACE...AND THEREFORE THE THREAT OF
PRECIPITATION...THROUGH THE END OF THE DAY ON MONDAY. TEMPERATURES
DURING THIS PERIOD WILL REMAIN WARM ENOUGH FOR ANY PRECIPITATION
THAT OCCURS TO REMAIN IN LIQUID FORM. DUE TO SOME SMALL TIMING
DIFFERENCES BETWEEN THE MODELS REGARDING PRECIPITATION
ONSET...DURATION...AND AREAL COVERAGE...DECIDED TO GO WITH ONLY
CHANCE POPS AT THIS TIME. BASED ON THE LATEST MODEL DATA...THE FRONT
COULD EITHER REMAIN STALLED ACROSS THE AREA...ECMWF...OR DRIFT
SLOWLY NORTH AS A WEAK WARM FRONT...GFS...DURING THE MONDAY INTO
MONDAY NIGHT TIME FRAME. ONLY TIME WILL TELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1232 AM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS AS HIGH
PRESSURE SETS UP OVERHEAD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1233 AM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1232 AM EST TUE NOV 25 2014
UPDATED TO SLOW DOWN THE TEMPERATURE FALL OVERNIGHT AS WINDS HAVE
STAYED UP A BIT ALLOWING FOR A SLOWER OVERALL DECREASE. IN
FACT...TEMPERATURES MAY NOT REACH THE EXPECTED LOWS ACROSS MUCH OF
THE AREA GIVEN THE ADDED WIND. THUS...HAVE UPDATED TO INCREASE LOWS A
TAD. ALSO UPDATED SKY COVER TO REFLECT LESS IN THE WEST AND KEEPING
SOME PARTLY CLOUDY CONDITIONS IN THE EAST WITH THE HIGH CLOUDS
STREAMING NORTHWARD. UPDATED FORECAST HAS BEEN SENT.
UPDATE ISSUED AT 944 PM EST MON NOV 24 2014
CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUD COVER
MOVING INTO CENTRAL KENTUCKY. THIS IS ASSOCIATED WITH A NEARLY
STATIONARY LOW OVER THE GREAT LAKES AND A WEAK SURFACE TROUGH IS
BRINGING SOME LOW LEVEL MOISTURE INTO THE AREA. THE BULK OF THIS
CLOUD COVER IS NOT EXPECTED TO MOVE INTO FAR EASTERN KENTUCKY AND
ADJUSTED THE FORECAST TO HAVE THE BULK OF THE CLOUD COVER EXIT THE
AREA TO THE NORTHEAST BY THE MORNING. THE OTHER CONCERN WAS THE
TEMPERATURES ACROSS THE AREA. TEMPS REMAIN QUITE WARM AND THE COOLER
AIR IS SLOW TO FILTER INTO THE AREA. IN FACT SOME GUSTY NORTHWEST
WINDS ARE STILL OCCURRING. HAVE UPDATED THE FORECAST TO HIGHLIGHT
THESE CHANGES. A NEW ZFP HAS BEEN ISSUED.
UPDATE ISSUED AT 651 PM EST MON NOV 24 2014
THE COLD FRONT AND ASSOCIATED LOW PRESSURE SYSTEM CONTINUE TO TRACK
OFF TO THE NORTHEAST THIS EVENING. WITH THIS A LESSENING GRADIENT IS
OCCURRING AND WINDS HAVE REALLY LESSENED ACROSS THE AREA. THOUGH A FEW
20 TO 25 MPH GUSTS ARE STILL POSSIBLE...HAVE DECIDED TO CANCEL THE
WIND ADVISORY AN HOUR EARLY. THIS IS ALSO LINING UP WITH
COLLABORATION WITH NEIGHBORING OFFICES AS WELL. OTHERWISE...DROPPING
TEMPS THIS EVENING WITH COLDER AIR MOVING INTO THE AREA WILL CONTINUE
AND THE CURRENT FORECAST HAS THIS IN CHECK. WILL LET THE OTHER
PARAMETERS OF THE FORECAST RIDE BUT WILL SEND OUT A NEW ZFP TO TAKE
OUT THE NPW.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM EST MON NOV 24 2014
19Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING NORTHEAST
AWAY FROM THE GREAT LAKES. FROM THIS...A STRONG...BUT NOW DRY...COLD
FRONT IS PRESSING THROUGH EAST KENTUCKY. AHEAD OF THIS BOUNDARY...
STRONG SOUTHWEST WINDS ARE GUSTING ROUTINELY INTO THE 35 TO 45 MPH
RANGE WITH A FEW GUSTS EXCEEDING 50 MPH. THE OFFICE HAS RECEIVED
NUMEROUS REPORTS OF TREE DAMAGE AND POWER OUTAGES DUE TO THE WINDS.
THESE WINDS HAVE ALSO SUPPORTED TEMPERATURES IN THE UPPER 60S AND
LOWER 70S WITH DEWPOINTS IN THE MID 40S FOR MUCH OF THE AFTERNOON AND
THEY REMAIN THERE IN FAR EASTERN KENTUCKY. HOWEVER...ON THE OTHER
SIDE OF THE BOUNDARY THE WINDS REMAIN SOUTHWEST BUT ARE NOT QUITE AS
STRONG AND ARE BRINGING IN A DIFFERENT AIR MASS. AS SUCH...
TEMPERATURES DROPPING THROUGH THE 50S ARE NOW REACHING THE WESTERN
EXTENT OF THE CWA ALONG WITH DEWPOINTS HEADED FOR THE 30S. THE WINDS
REMAIN AT ADVISORY LEVEL IN THE EAST BUT ARE NOT QUITE THERE IN THE
WEST. AS THEY FURTHER SETTLE WE WILL LIKELY BE ABLE TO DROP THE
ADVISORY EARLY. FOR NOW...THOUGH...WILL CONTINUE TO LET IT RIDE FOR
THE ENTIRE CWA THROUGH 00Z.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP...AND FULL-
LATITUDE...TROUGH CROSSING THE OHIO VALLEY AND GREAT LAKES TODAY INTO
TUESDAY. HOWEVER...A SOUTHWESTERN EXTENT OF THE LARGER TROUGH WILL
REMAIN STRETCHED INTO SOUTHWESTERN TEXAS AND IT IS THIS SECTION
THAT TIGHTENS UP AND MOVES EAST LATER TUESDAY. THE SOUTHERN
ENERGY...IN CONJUNCTION WITH SOME MOVING THROUGH THE MID MISSISSIPPI
VALLEY WILL SWEEP THROUGH THE DEEP SOUTH AND ACROSS THE TENNESSEE
VALLEY ON TUESDAY NIGHT. OF NOTE ALSO...A CLUSTER OF ENERGY WILL BE
RIDING SOUTHEAST THROUGH THE CENTRAL PLAINS AT DAWN WEDNESDAY. WITH
THE MODEL AGREEMENT HAVE FAVORED THE NAM12 AND HRRR INITIALLY AND
THEN A BLEND OF THE ECMWF AND NAM12 FOR WX DETAILS INTO WEDNESDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE WINDS SETTLING DOWN THIS EVENING FROM
WEST TO EAST AS THE GRADIENT RELAXES. IT WILL ALSO MEAN A COOLER
EVENING...BUT NOWHERE NEAR AS COLD AS IT HAS BEEN OF LATE. TUESDAY
WILL CERTAINLY BE A COOLER DAY BUT A QUIETER ONE AS WE WILL BE
BETWEEN SYSTEMS. A DEVELOPING SFC LOW ALONG THE SOUTHEAST COAST WILL
START TO SPREAD HIGH CLOUDS INTO THE AREA FROM THE SOUTHEAST BY
EVENING. LOOK FOR THESE TO THICKEN AND LOWER WITH TIME THAT NIGHT AS
THE SOUTHEAST PORTION OF THE CWA IS BRUSHED BY THE PCPN SHIELD FROM
THIS NASCENT COASTAL SYSTEM. HAVE CONTINUED THE THREAT OF RAIN OR
SNOW PRIMARILY IN THE COUNTIES BORDERING VIRGINIA...BUT NOT
ANTICIPATING MUCH IN THE WAY OF ACCUMULATIONS EXCEPT PERHAPS A TOUCH
OF IT JUST ON THE PEAK OF BLACK MOUNTAIN.
USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH THE
NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR
TERRAIN BASED ADJUSTMENTS TONIGHT AND TUESDAY NIGHT TO THE LOWS. AS
FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET NUMBERS FOR
TUESDAY NIGHT AND DRY OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM EST MON NOV 24 2014
THERE WILL BE A DEVELOPING SURFACE LOW OFF THE CAROLINA COAST BEGINNING
THE PERIOD AND THE FRONTOGENESIS IS AIDED BY A BROAD TROUGH/EMBEDDED
SHORTWAVE ENERGY SWING THROUGH THE EASTERN U.S. THOROUGH THE PERIOD.
THIS COASTAL LOW IS EXPECTED TO MOVE NE ALONG THE ATLANTIC SEABOARD
WEDNESDAY INTO THURSDAY. ANOTHER EMBEDDED SHORTWAVE WILL EXIT THE
UPPER PLAINS AND DROP SE INTO THE OHIO AND TENNESSEE VALLEYS
WEDNESDAY NIGHT INTO THURSDAY. SURFACE HIGH WILL BUILD EAST LATER
THURSDAY INTO FRIDAY. UPPER LEVELS WILL BEGIN TO BECOME MORE ZONAL
WITH SURFACE FRONT DEVELOPING ACROSS PORTIONS OF THE OHIO VALLEY
GOING INTO SUNDAY INTO MONDAY.
SENSIBLE WEATHER... GIVEN SYNOPTIC SETUP LOW PRESSURE MOVING ALONG
THE ATLANTIC COAST COULD BRING SLIGHT TO CHANCES MAINLY RAIN/SNOW
SHOWERS ACROSS THE EASTERN AND SOUTHEASTERN PORTIONS OF THE REGION
EARLY WEDNESDAY...BEFORE TRANSITIONING TO RAIN SHOWERS THROUGH THE
DAY WEDNESDAY. THIS LOW WILL TRACK NORTH AND EAST WHILE AFOREMENTIONED
DISTURBANCE DROPS SE ACROSS THE REGION WEDNESDAY NIGHT. THERE IS
BETTER AGREEMENT WITH MODELS SO DID OPT TO BRING POPS UP A BIT FOR
THIS SYSTEM. THIS SYSTEM IS EXPECTED TO BRING SLIGHT TO CHANCE
RAIN/SNOW SHOWERS ACROSS EASTERN KY WEDNESDAY NIGHT. THURSDAY MUCH OF
THE REGION WILL WARM UP SO EXPECT MOST OF THE ACTIVITY WILL
TRANSITION TO RAIN SHOWERS BEFORE EXITING THE REGION LATE IN THE DAY
ON THURSDAY. AFTER THIS IT IS EXPECTED TO BE QUIET AND MOSTLY CLEAR
CONDITIONS TIL WE GET TO THE SATURDAY TIME FRAME. DURING THIS TIME
MODELS ARE NOT IN GOOD AGREEMENT ON TIMING/DEVELOPMENT OF NEXT
SYSTEM. RIGHT NOW THINKING WILL ONLY GO WITH SLIGHT CHANCES OF RAIN
SHOWERS SATURDAY...THEN TRANSITION TO SLIGHT/CHANCE RAINS SHOWERS AS
FRONT SLOW PROGRESSES SOUTH ACROSS THE REGION GOING INTO SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1232 AM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS AS HIGH
PRESSURE SETS UP OVERHEAD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 AM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014
...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...
BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.
MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.
INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.
ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.
ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.
BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EST TUE NOV 25 2014
IFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT BEFORE IMPROVING
TO MVFR ON TUESDAY AS DRIER AIR MOVES IN. BY LATE AFTERNOON INTO
EARLY EVENING...VFR CONDITIONS WILL PREVAIL AT ALL SITES AS WINDS
PUSH LAKE EFFECT SNOW BANDS WELL OFFSHORE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ006-007-085.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ004-005.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLA
AVIATION...07
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 PM EST MON NOV 24 2014
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON THE POTENTIAL
FOR AT LEAST SOME MARGINAL ADVY LES TOTALS ON WED INTO EARLY
THANKSGIVING ASSOCIATED WITH A SHRTWV DIGGING SEWD THRU THE UPR LKS.
FORTUNATELY FOR THOSE INTERESTED IN TRAVEL ON THANKSGIVING...MODELS
HAVE CONTINUED TREND TOWARD LESS PHASING BTWN A PAIR OF SHRTWVS THAT
WL LIMIT THE POTENTIAL FOR HEAVIER SN AWAY FM LK SUP. TEMPS WL RUN
BLO TO WELL BLO NORMAL ON TUE NGT INTO FRI WITH AN UPR TROF
DEEPENING OVER ERN NAMERICA. AS THIS TROF GIVES WAY TO A MORE ZONAL
FLOW THIS WEEKEND...A MORE CHANGEABLE PATTERN WL DOMINATE WITH
WARMER AIR IN STORE FOR SAT.
TUE NGT...A WEAK SFC HI PRES UNDER SUBTLE SHRTWV RDGING/AREA OF DEEP
LYR QVECTOR DVGC WL DOMINATE MOST OF THE NGT AND BRING DRY WX TO
MOST OF THE CWA. THE BEST CHC FOR SOME PCPN WL BE OVER THE NW CWA
NEAR A STATIONARY FNT ORIENTED W-E OVER LK SUP. H85 TEMPS ANRD -13C
MAY SUPPORT A LK EFFECT COMPONENT...ESPECIALLY LATE WHEN SOME DPVA/
DEEP LYR QVECTOR CNVGC IN ADVANCE OF A SHRTWV DIGGING SEWD TOWARD
THE CNDN/MN BORDER IS FCST TO ARRIVE. EXPECT THE LOWEST MIN TEMPS
OVER THE INTERIOR SCENTRAL AND E WHERE THE NEGATIVE DYNAMICS SHOULD
LINGER THRU THE NGT IN THE PRESENCE OF PWAT UNDER 0.25 INCH AND
MINIMIZE CLD COVER EXCEPT FOR SOME HIER CLDS SPILLING INTO UPR MI
AHEAD OF THE INCOMING SHRWTV.
WED...SHRTWV APRCHG FM THE NW IS FCST TO MOVE INTO WRN LK SUP BY 00Z
THU...WITH DPVA/DEEP LYR QVECTOR CNVGC INVADING UPR MI. BUT SINCE
THE MODELS HAVE TRENDED TOWARD LESS PHASING BTWN THIS SHRTWV AND
ANOTHER STRONGER DISTURBANCE DIGGING SEWD IN THE MID MS RIVER VALLEY
THAT WL ROB THE AREA OF DEEPER MSTR AND LEAVE PWAT NO HIER THAN
ABOUT 0.25-0.30 INCH...ACCOMPANYING SN OVER THE CWA SHOULD BE
RELATIVELY LGT. THE BEST CHC FOR MORE SN WL BE IN THE N WIND SN
BELTS NEAR LK SUP AS THE H925 FLOW SHIFTS TO THE N COINCIDENT WITH
PASSING NRN SHRTWV AND ALLOWS FOR SOME LES AS H85 TEMPS FALL TO ARND
-15C OVER THE NW BY 00Z WED. SN TOTALS IN THAT AREA MAY ALSO BE
BOOSTED A BIT BY RATHER DEEP DGZ BTWN ABOUT 4-9K FT MSL EVEN THOUGH
MORE SHARPER UVV IS NOT FCST WITHIN THAT LYR. NOT OUT OF THE
QUESTION THE FLOW MAY BACK SUFFICIENTLY TO THE SW IN ADVANCE OF THE
SHRTWV TO ALLOW FOR A PERIOD OF SOME LK EFFECT SN OFF LK MI INTO THE
SE CWA IN THE PRESENCE OF H85 TEMPS NEAR -10C.
WED NGT...STEADY NNW WIND IN THE WAKE OF PASSING SHRTWV IS FCST TO
ADVECT H85 TEMPS AS LO AS -20C OVER THE KEWEENAW BY 12Z THU. THERE
MAY BE SOME ADVY LVL LES IN THE FAVORED SN BELTS AS THERE WL BE A
PERIOD WHERE THE FAVORABLE CAA/CYC NNW FLOW IS COINCIDENT WITH
DEEPER MSTR/SOME DEEP LYR QVECTOR CNVGC THAT WL LIKELY BRING SOME
LIGHTER SN EVEN TO THE SCENTRAL. THE ARRIVAL OF SOME DNVA/DEEP LYR
QVECTOR DVGC LATER AT NGT IS PROGGED TO SHARPLY LOWER INVRN BASE
TOWARD H85...WHICH SHOULD BRING ABOUT A DIMINISHING TREND IN THE LES
OVER AT LEAST THE W HALF. THE 12Z GFS IS FASTEST WITH THIS
DIMINISHING TREND.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN
BELTS E OF MARQUETTE...BUT LO INVRN BASE BLO H85 SHOWN ON THE FCST
SDNGS UNDER THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. AS THE SFC
RDG AXIS SHIFTS TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING
LES WL SHIFT OUT INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN
THE EVNG BEFORE MORE HI CLDS ASSOCIATED WITH DVLPG ISENTROPIC ASCENT
OVERSPREAD THE AREA W-E.
FRI INTO SAT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES THAT WL BE FORCING
THIS CHANGE IN THE UPR PATTERN IS PROGGED BY MOST OF THE MEDIUM
RANGE GUIDANCE IS FCST TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN
ON FRI TO THE NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS
INTO MN. THE LATEST MODEL GUIDANCE HINTS THE HEAVIER PCPN ASSOCIATED
WITH THIS WARM AIR RETURN ON FRI MAY FALL TO THE SW IN WI. EXPECT
THE HIER POPS OVER THE ERN CWA WITH SW FLOW OF COLD AIR OFF LK MI
ALLOWING FOR SOME LES INTO THAT AREA ON FRI. AS A SHRTWV WITHIN THE
ZONAL FLOW SHIFTS EWD NEAR THE CNDN BORDER...A SFC LO PRES WL SHIFT
EWD AND JUST N OF LK SUP ON SAT. MOST OF THE GUIDANCE SHOWS H85
TEMPS RISING TO AOA 0C OVER AT LEAST THE S HALF OF THE CWA ON SAT...
INDICATING THE POTENTIAL FOR SOME MIXED PCPN. GFS FCST SDNGS SHOW AN
ELEVATED WARM LYR...SO INCLUDED A MENTION OF SOME FREEZING RA OVER
THE SCENTRAL WHERE THE WARM WEDGE H85 TEMPS ARE OVER 0C. THE MODELS
SUCH AS THE 12Z GFS AND ESPECIALLY THE 12Z CND THAT SHOW THE DEEPEST
SFC LO/FARTHER N TRACK ACTUALLY INDICATE UPR MI MIGHT SEE SOME DRY
SLOTTING AS THE H85 WARM FNT SHIFTS TO THE N OF THE CWA AND H85
TEMPS RISE AS HI AS 5-6C...SO POPS WL BE LOWEST OVER THE S.
SUN/MON...AS THE SHRTWV/SFC LO SHIFT INTO QUEBEC SAT NGT/SUN...
ATTENDANT COLD FNT WL SWING THRU UPR MI AND BRING A RETURN OF COLDER
AIR AND SOME LES FOR SUN. TRAILING HI PRES WL PASS TRHU THE CENTRAL
GREAT LKS ON SUN NGT...ENDING THIS LES. AS THE HI SHIFTS TOWARD NEW
ENGLAND...EXPECT A RETURN SW FLOW OF WARMER AIR TO DVLP ON MON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EST TUE NOV 25 2014
IFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT BEFORE IMPROVING
TO MVFR ON TUESDAY AS DRIER AIR MOVES IN. BY LATE AFTERNOON INTO
EARLY EVENING...VFR CONDITIONS WILL PREVAIL AT ALL SITES AS WINDS
PUSH LAKE EFFECT SNOW BANDS WELL OFFSHORE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ THIS MORNING
FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST EARLY THIS MORNING FOR
MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR LSZ248>251-
265>267.
GALE WARNING UNTIL 2 AM EST EARLY THIS MORNING FOR LSZ242>245-
263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...KC
AVIATION...07
MARINE...MRD
AREA FORECAST DISCUSSION...CORRECTED
NWS TWIN CITIES/CHANHASSEN MN
1039 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT TROUGH COMING INTO CENTRAL BRITISH COLUMBIA ON TOP
OF EAST PACIFIC RIDGING...AND MORE TROUGHING COVERING MUCH OF
CENTRAL NORTH AMERICA. WITHIN THIS BROAD TROUGH...A SHORTWAVE WAS
PRESENT OVER EASTERN IOWA/NORTHERN IL...WHICH DPVA FROM IT COMBINED
WITH A BAND OF MID LEVEL FRONTOGENESIS HAS ALLOWED A BAND OF SNOW TO
PERSIST FROM WESTERN INTO SOUTHERN WI. ADDITIONAL SNOW SHOWERS HAVE
BEEN TAKING PLACE ACROSS MUCH OF MN INTO IA...MOSTLY ASSOCIATED WITH
INSTABILITY PRODUCED FROM COOL MID LEVEL TEMPS ALOFT AND RELATIVELY
WARMER TEMPS/DEWPOINTS AT THE SURFACE. RAP 700MB TEMPS SHOWED
READING IN THE -12 TO -13C RANGE...MEANWHILE SURFACE TEMPS HAVE
COOLED INTO THE TEENS AND 20S...WARMEST IN WESTERN WI. A TIGHT
PRESSURE GRADIENT IN PLACE...BETWEEN A SURFACE RIDGE OVER THE
WESTERN PLAINS AND A LOW PRESSURE TROUGH IN NORTHERN LOWER MI...HAS
PRODUCED GUSTS OF 30-40 MPH. THE STRONGEST GUSTS HAVE BEEN CONFINED
TO SOUTHWEST AND SOUTH CENTRAL MN WHERE THE DEEPEST MIXING HAS BEEN
TAKING PLACE. FARTHER TO THE WEST...A LARGE EXPANSE OF CLEARING
DOMINATES A LOT OF THE PLAINS...ASSOCIATED WITH THE SURFACE RIDGE
AND VERY DRY AIR. PRECIPITABLE WATER VALUES THERE ARE IN THE 0.1-0.2
INCH RANGE.
THE FOCUS FOR ATTENTION BEGINS TO SHIFT TO THAT POTENT TROUGH OVER
CENTRAL BRITISH COLUMBIA. GOOD MODEL CONSENSUS EXISTS FOR THE TROUGH
TO DIG DOWN INTO THE WESTERN DAKOTAS BY 00Z WEDNESDAY...ALLOWING
WEAK RIDGING TO BUILD OVER THE FORECAST AREA. ADDITIONALLY...THE
NEXT POTENT TROUGH WILL HELP PUSH THE CURRENT SHORTWAVE TROUGH AND
700MB COOL AIR SITUATED OVER THE FORECAST AREA OFF TO THE EAST.
FOR TONIGHT...ANTICIPATING SNOW SHOWERS OVER MINNESOTA TO DIMINISH
QUICKLY THIS EVENING WITH LOSS OF DAYTIME HEATING. FIGURE
SOMEWHERE AROUND 03Z THEY SHOULD HAVE ENDED...IN AGREEMENT WITH A
LOT OF HI RESOLUTION MODEL GUIDANCE. THE SNOW OVER WESTERN WI WILL
TAKE LONGER TO END BEING ASSOCIATED WITH THE MID LEVEL
FRONTOGENESIS BAND THERE...SOMEWHERE AROUND 06Z. CURRENT WINTER
WEATHER ADVISORY END TIME STILL LOOKS GOOD. REGARDING THE WIND
ADVISORY...PRESENT WINDS ARE MARGINAL TO KEEP IT GOING.
HOWEVER...SINCE CONDITIONS REMAIN BRISK FOR THE REST OF THE
AFTERNOON AND WINDS ARE STILL ON TRACK TO DIMINISH THIS
EVENING...PLAN ON LETTING THE WIND ADVISORY EXPIRE AT 6 PM. CLEARING
ACROSS THE PLAINS SHOULD MAKE ITS WAY WEST TO EAST ACROSS A LOT OF
THE FORECAST AREA...PERHAPS EVEN INTO WESTERN WI BY 12Z. THE
CLEARING COMBINED WITH A WEAKENING PRESSURE GRADIENT AND ALREADY
COOL TEMPERATURES SHOULD ALLOW READINGS TO DIP INTO THE SINGLE
DIGITS OVER WEST-CENTRAL MN. TEENS ARE LIKELY ELSEWHERE WITH MORE
CLOUDS AND WIND. IT SHOULD BE NOTED THAT MORE CLOUDS ARE LIKELY TO
COME INTO WESTERN SECTIONS OF THE FORECAST AREA BY 12Z...AHEAD OF
THE APPROACHING POTENT TROUGH.
ON TUESDAY...CLOUDS WILL MARCH THEIR WAY WEST TO EAST ACROSS THE
FORECAST AREA AGAIN AS THE POTENT TROUGH MOVES INTO THE WESTERN
DAKOTAS. ANY PRECIPITATION DOES LOOK TO REMAIN TO THE WEST PRIOR TO
00Z WEDNESDAY...THOUGH. ALTHOUGH THERE MIGHT BE MORE CLOUDS...
INCREASING SOUTHWESTERLY FLOW AHEAD OF THE AFTERNOON SHOULD HELP
GIVE TEMPERATURES A BOOST. IN FACT...925MB READINGS CLIMB FROM
AROUND -10C AT 12Z TO -4 TO -7C BY 00Z...WARMEST NEAR MANKATO AND
NEW ULM. MOST LOCATIONS SHOULD SEE HIGHS IN THE 20S...WITH 30S
POSSIBLE NEAR THE MN RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
MAIN FOCUS STARTING OFF THE PERIOD IS THE POTENT SHORTWAVE TROUGH
CURRENTLY IN CENTRAL BRITISH COLUMBIA. THERE HAS BEEN A MAJOR TREND
OVER THE PAST 2 DAYS TO DIG THIS TROUGH FARTHER SOUTHWEST...
ESPECIALLY IN THE ECMWF. THIS TREND APPEARS TO BE RELATED TO THE
CURRENT CENTRAL NORTH AMERICA TROUGH BEING MORE AMPLIFIED THAN
PREVIOUSLY PROGGED. AS A RESULT OF THIS TREND...THERE IS A CHANCE
SUGGESTED BY THE 24.12Z GFS THAT MUCH OF THE AREA COULD BE MISSED BY
THIS SYSTEM. THIS WOULD BE GOOD NEWS FOR TRAVELERS. IN THE GFS...THE
SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW DIVE DOWN TO NEAR
THE KANSAS CITY AREA BY 12Z...WITH THE ISENTROPIC LIFT/MID LEVEL
FRONTOGENESIS ZONE BRUSHING THE MN RIVER VALLEY WITH SOME SNOW
BETWEEN 06-18Z WEDNESDAY. HAVE TRENDED THE FORECAST DRIER TO ACCOUNT
FOR THE MODEL TREND...BUT QPF AND POPS MAY NEED TO BE REDUCED
FURTHER. TEMPERATURES SHOULD NOT DROP MUCH TUESDAY NIGHT WITH THE
CLOUDS IN PLACE AND EVEN SOME SLIGHT WARM ADVECTION POSSIBLE. FOR
WEDNESDAY...HIGHS ARE LIKELY TO OCCUR BY NOON AS COLD ADVECTION
LOOKS TO COMMENCE IN THE WAKE OF THE TROUGH. THE AMOUNT OF ADVECTION
DEPENDS ON HOW FAR SOUTH THE TROUGH DIGS...THUS THESE READINGS ARE
SUBJECT TO CHANGE.
DRY AND COLDER CONDITIONS REMAIN PROGGED TO AFFECT THE AREA FOR
WEDNESDAY NIGHT AND THANKSGIVING...AS ARCTIC HIGH PRESSURE MOVES IN
FROM THE NORTHWEST. 925MB TEMPS TOPPING OUT IN THE -10 TO -16C RANGE
WILL ONLY ALLOW FOR HIGHS IN THE TEENS.
A PATTERN CHANGE IS IN THE OFFERING FOR THURSDAY NIGHT INTO EARLY
NEXT WEEK WITH MODELS ADVERTISING A SERIES OF TROUGHS MOVING INTO
THE WESTERN U.S.. THIS RESULTS IN A MORE ZONAL FLOW PATTERN
DOWNSTREAM TO EVENTUALLY SOUTHWESTERLY EARLY NEXT WEEK. THE SWITCH
TO ZONAL FLOW RESULTS IN A WARM ADVECTION REGIME THURSDAY NIGHT AND
FRIDAY. ON THE NOSE OF THE WARM ADVECTION...A MID-LEVEL
FRONTOGENESIS SNOWFALL BAND LOOKS TO SETUP FROM THE DAKOTAS THROUGH
MINNESOTA AND WISCONSIN. EXACT PLACEMENT AND AMOUNTS ARE YET TO BE
DETERMINED...BUT THE FOCUS RIGHT NOW GENERALLY APPEARS ALONG/NORTH
OF I-94. THE WARM FRONT LOOKS TO LIFT THROUGH MUCH OF THE FORECAST
AREA FRIDAY NIGHT. THEN FOR SATURDAY...A SHORTWAVE CROSSES THE AREA
IN THE ZONAL FLOW...SENDING A COLD FRONT THROUGH. THIS PERIOD COULD
BE TRICKY FOR HIGHS. IF THE FRONT IS SLOWER...HIGHS COULD EASILY TOP
OUT IN THE 40S. HOWEVER...AT THE CURRENT SPEED...UPPER 20S TO MID
30S SEEM MORE REASONABLE. DESPITE THE ZONAL FLOW...AN ARCTIC LOW
LEVEL INTRUSION LOOKS TO AFFECT THE AREA FOR SATURDAY NIGHT AND
SUNDAY...ACCOMPANIED BY ARCTIC HIGH PRESSURE...NOTED BY 925MB TEMPS
ABOUT 5C COLDER THAN AT 850MB. THOSE 925MB TEMPS ON SUNDAY RANGING
FROM -10 TO -15C MEANS BACK TO HIGHS IN THE TEENS. WE SHOULD BEGIN
TO DISLODGE THE COLD AIR ON MONDAY WITH THE UPPER FLOW TURNING
SOUTHWESTERLY...ALLOWING FOR A REBOUND BACK INTO THE 20S FOR HIGHS.
CONDITIONS LOOK TO REMAIN DRY FOR MONDAY WITH ARCTIC HIGH PRESSURE
IN PLACE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 1039 PM CST MON NOV 24 2014
MVFR CIGS ARE IN PLACE OVER FAR EASTERN MINNESOTA AND WISCONSIN...
BUT CLEARING IS PUSHING EASTWARD INTO WESTERN MINNESOTA. THIS TREND
WILL CONTINUE THROUGH THE NIGHT WITH VFR CONDITIONS GRADUALLY
RETURNING. THE STEADY SNOW HAS ENDED...BUT A FEW FLURRIES CANNOT BE
RULED OUT ACROSS WI. SOME MVFR CIGS COULD RETURN LATE SATURDAY AS
ANOTHER SYSTEM APPROACHES. WINDS WILL EASE THIS EVENING AND BECOME
LIGHT/VARIABLE TUESDAY AFTERNOON.
KMSP...MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SOME
HIGH/MID LEVEL CLOUDS MAY STICK AROUND TUESDAY MORNING BEFORE LOWER
MVFR CLOUDS RETURN LATE TUESDAY.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CHC -SN EARLY. WINDS NW 10-15KTS.
THU...VFR. WINDS LIGHT/VARIABLE.
FRI...VFR/CHC MVFR AND -SN. WINDS S 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
308 AM CST TUE NOV 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE NOV 25 2014
...BECOMING CLOUDY WITH ANOTHER LIGHT PRECIP EVENT LATE THIS
AFTERNOON/EVE FOLLOWED BY MORE WIND...
ALOFT: THE FLOW WAS HIGHLY AMPLIFIED WITH A LONGWAVE TROF OVER
THE CNTRL USA AND RIDGES JUST OFF BOTH COASTS. WV IMAGERY SHOWED A
SHORTWAVE TROF OVER ALBERTA. THIS TROF WILL DIVE SE INTO THE
DAKOTAS TODAY AND INTO NEB/KS TONIGHT...DEEPENING OVER TIME WITH A
GOOD SHOT OF QG FORCING IN THE EXIT REGION OF A 150 KT UPR-LVL JET.
SURFACE: A CLIPPER LOW WAS ORGANIZING OVER ALBERTA. THIS LOW WILL
RACE INTO THE DAKOTAS TODAY AND BE LOCATED OVER WRN IA BY DAYBREAK
WED. ITS COLD FRONT WILL SWEEP THRU TONIGHT.
EARLY THIS MORNING: WAA WAS UNDERWAY. SATELLITE SHOWS ARE LARGE
EXPANSE OF LOW-MID CLOUDS OVER THE NRN PLAINS AHEAD OF THE CLIPPER
WARM FRONT. THE SRN END OF THESE CLOUDS WAS GRAZING THE FCST AREA.
COULD EVEN SEE A COUPLE FLURRIES N OF NEB HWY 92 BEFORE SUNRISE.
TODAY: WAA WILL CONT IN THE WARM SECTOR OF THE CLIPPER. MORNING
SUN WILL RAPIDLY BE OBSCURED BY INCREASING AND DESCENDING MID-HIGH
CLOUDS. ONE WEAKNESS IN THIS FCST IS THAT CLOUDS MAY COME IN THICK
FASTER THAN CURRENTLY DEPICTED. I.E. WE MAY NOT BE PESSIMISTIC
ENOUGH. THAT IS A DENSE CIRRUS SHIELD ON SATELLITE IMAGERY.
MODEL CONSENSUS INCLUDING HI-RES MODELING INDICATE A SWATH OF
FGEN-ENHANCED LIGHT RAIN AND/OR SPRINKLES WILL DEVELOP AND CROSS
THE FCST AREA FROM 3PM-12AM. SPRINKLES ARE MOST LIKELY ON THE SRN
FRINGE OF THE PRECIP SHIELD. INCLUDED SPRINKLES S AND W OF THE
MODEL CONSENSUS OF .01" QPF AS SOME SREF MEMBERS DO HINT AT THE
POSSIBILITY OF RAIN OUTSIDE OF THE BEST MODEL CLUSTERING.
USED THE 05Z BIAS CORRECTED RAP FOR HIGHS TODAY WHICH SEEMS TO
HAVE A BETTER GRASP ON WHERE THICKER CLOUDS WILL ARRIVE FROM THE
N. DESPITE THE CLOUDS SHOULD BE A MILD DAY WITH TEMPS AT OR
SLIGHTLY ABOVE NORMAL.
THERE IS CONSIDERABLE UNCERTAINTY IN DWPTS/RH TODAY WITH 10F OF
SPREAD BETWEEN THE MAV/MET MOS. USED CONSENSUS OF SHORT-TERM HI-
RES MODELS WHICH WERE NOT THE LOWEST BUT DID FAVOR THE DRIER MAV
MOS. THIS WILL WORK BEST OUTSIDE WHERE IT RAINS...BUT MOISTENING
FROM RAINFALL WILL INCREASE DWPTS LOCALLY.
TONIGHT: SWATH OF RAIN/SPRINKLES EXITS TO THE E BY MIDNIGHT.
STRONG CAA KICKS IN AFTER PASSAGE OF THE COLD FRONT WITH A CORE OF
50 KT WINDS AT 850 MB. OUTPUT FROM THE WIND GUST TOOL SEEMED TOO
LOW SO USED GUSTS FROM A BLEND OF THE 18Z/00Z RAW MODEL GUIDANCE
/CONSRAW/. NW WINDS WILL GUST 30-35 KTS N OF HWY 6 BEGINNING 3 AM.
WITH 40 KTS AS LOW AS 1500 FT...CAN`T RULE OUT ISOLATED HIGHER
GUSTS.
P-TYPE: KEPT IT PRIMARILY RAIN/SPRINKLES EXCEPT ON THE EXTREME
NE/E FRINGES OF THE FCST AREA 07Z-08Z ON THE BACK EDGE OF THE
PRECIP...IF IT`S STILL FALLING BY THEN. NAM P-TYPE ALGORITHM KEEPS
IT ALL RAIN AND FCST SOUNDINGS SUGGEST THE LEFTOVER DAYTIME BL
WILL BE TOO WARM TO SUPPORT SNOW. EVEN WETBULB TEMPS FAVOR RAIN
WITH +2 UP TO 1K FT. CURRENT INDICATIONS ARE THAT THE PRECIP
SHOULD BE OVER BY THE TIME TEMP PROFILES COOL ENOUGH FOR SNOW.
MODEL 2M TEMPS SUGGEST A FAIRLY MILD NIGHT WITH LOWS 27-38F AND
30-31F IN THE TRI-CITIES. EVEN THE MOS 3-HOURLY TEMPS SUGGEST
THIS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE NOV 25 2014
WE ARE CALLING FOR A DRY FORECAST FROM START TO FINISH THIS
HOLIDAY WEEKEND. THE PRIMARY FORECAST CONCERN WILL CENTER AROUND
SEVERAL BIG TEMPERATURE SWINGS. EXPECT TWO COLD AIR OUTBREAKS...
ONE ON WEDNESDAY LASTING INTO THANKSGIVING DAY...AND A SECOND SHOT
OF COLD AIR TO FINISH THE HOLIDAY WEEKEND ON SUNDAY. HOWEVER...
FRIDAY AND SATURDAY CURRENTLY APPEAR TO BE WARM WITH HIGHS WELL
ABOVE NORMAL.
WEDNESDAY...A COLD FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW
COOLER AIR TO FILTER INTO OUR REGION THROUGHOUT THE DAY. THEREFORE
...TEMPERATURES WILL WARM VERY LITTLE IF AT ALL DURING THE DAYTIME
HOURS. WE CAN NOT RULE OUT A FLURRY OR TWO WITH A LITTLE 850/700
MB MOISTURE AND COOLER AIR SETTLING IN. HOWEVER...FORECAST MODELS
CONTINUE TO BE IN GOOD AGREEMENT IN 0.00 QPF AND THE CHANCE OF
FLURRIES IS STILL TOO LOW TO INCLUDE MENTION IN THE FORECAST.
THERE COULD BE A PRETTY GOOD TEMPERATURE CONTRAST ACROSS THE
FORECAST AREA AS THE COLD AIR WILL HANG UP MORE OVER NEBRASKA.
THEREFORE...EXPECT HIGHS ON WEDNESDAY SHOULD RANGE FROM THE 30S
ACROSS SOUTH CENTRAL NEBRASKA TO THE LOWER 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...FORECAST MODELS ARE IN INCREASINGLY GOOD AGREEMENT
THAT WE WILL SLOWLY START TO WARM BACK UP ON THANKSGIVING DAY. AN
UPPER RIDGE WILL BEGIN TO WORK ITS WAY EAST INTO THE FORECAST AREA
BRINGING WARMER AIR ALOFT. AT THE SFC...THE WIND WILL TURN TO
SOUTHERLY AND WILL ALSO RESULT IN WARM AIR ADVECTION. THE WARMING
WILL BE GRADUAL ON THANKSGIVING WITH ONLY A FEW DEGREE RISE
EXPECTED OVER WEDNESDAY HIGHS...BUT THE WARM UP WILL INCREASE AS
WE HEAD INTO FRIDAY. AS FOR THANKSGIVING...EXPECT HIGHS IN THE
UPPER 30S NORTHEASTERN ZONES...TO AROUND 40 IN THE TRI-CITIES...TO
THE MID AND UPPER 40S OVER NORTH CENTRAL KANSAS.
FRIDAY AND SATURDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN PORTIONS OF THE DAKOTAS AND IN
CANADA. THIS WILL ALSO KEEP THE STORM TRACK WELL TO OUR NORTH
RESULTING IN CONTINUED DRY CONDITIONS. THERE IS HIGH CONFIDENCE IN
FRIDAY BEING A VERY NICE DAY WITH WARM AIR ADVECTION BOTH ALOFT
AND AT THE SFC. THE SFC WINDS WILL BE FAIRLY LIGHT BUT SHOULD HAVE
A BIT OF A DOWNSLOPE WARMING COMPONENT TO IT BEING OUT OF THE WEST
TO SOUTHWEST. ALL IN ALL EXPECT A VERY NICE DAY WITH HIGHS IN THE
MID TO UPPER 50S IN THE TRI-CITIES TO THE LOWER 60S OVER PORTIONS
OF NORTH CENTRAL KANSAS. FORECAST MODELS ARE COMING INTO BETTER
AGREEMENT WITH THE COLD FRONTAL PASSAGE TIMING ON SATURDAY.
OVERALL FORECAST MODELS HAVE LARGELY SLOWED DOWN THE COLD FRONT
AND BRING IT THROUGH OUR FORECAST AREA SATURDAY EVENING OR
SATURDAY NIGHT. THIS WILL ALLOW FOR FULL DIURNAL HEATING UNDER A
CONTINUED WARM AIR MASS WHICH SHOULD HELP ALL AREAS GET INTO THE
UPPER 50S TO LOWER 60S. THE 00Z ECMWF EVEN INDICATES A FEW SPOTS
COULD HIT 70 SATURDAY AFTERNOON. EVERYTHING HINGES ON THE TIMING
OF THE COLD FRONT...BUT RIGHT NOW SATURDAY APPEARS TO BE A GREAT
DAY TO GET OUT AND ENJOY BEFORE THE NEXT COLD SNAP HITS.
SUNDAY AND MONDAY...THERE IS CURRENTLY DECENT FORECAST AGREEMENT
BETWEEN THE 00Z GFS AND 00Z ECMWF THAT A PRETTY POTENT COLD AIR
MASS WILL OVERSPREAD THE AREA SATURDAY NIGHT INTO SUNDAY. IT
SHOULD BE A DRY FRONTAL PASSAGE SO WE ARE NOT REALLY WORRIED ABOUT
SNOW...BUT IT DOES APPEAR TO BE COLD. OUR FORECAST HIGHS BASED OFF
THE SUPERBLEND OF MODELS RANGE FROM THE UPPER 20S IN ORD TO THE
30S ELSEWHERE AND THIS MAY BE OPTIMISTICALLY TOO WARM IF YOU
BELIEVE THE DETERMINISTIC 00Z GFS AND ECMWF MODEL RUNS. THERE IS A
HIGH LEVEL OF UNCERTAINTY AS TOO HOW LONG THE COLD AIR WILL LINGER
ACROSS THE AREA AS THE 00Z GFS IS MUCH QUICKER TO PUSH THE COLD
AIR OUT ON MONDAY THAN THE 00Z ECMWF.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUE NIGHT)
ISSUED AT 1131 PM CST MON NOV 24 2014
OVERNIGHT: VFR WITH SCT PATCHES OF 7K ALTOCU DRIFTING THRU. WINDS
WILL BE LIGHT FROM THE W. CONFIDENCE: HIGH
TUE: MULTI-LAYERED VFR CIGS MOVE IN AND GRADUALLY DESCEND DOWN TO
ROUGHLY 9K FT. WINDS BECOME SW 10-15 KTS. CONFIDENCE: HIGH
TUE EVE: VFR CIGS DESCEND TO AROUND 4K FT WITH POTENTIAL FOR A
PERIOD OF MVFR CIGS WITH A BIT OF -RA POSSIBLE. COLD FRONTAL
PASSAGE AND WSHFT EXPECTED AROUND 03Z. CONFIDENCE: MEDIUM
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1112 PM CST MON NOV 24 2014
.UPDATE...
ISSUED AT 933 PM CST MON NOV 24 2014
SO ONLY -SN OR FLURRIES BE REPORTED BY UPSTREAM OBSERVATIONS. NO
ACCUMULATION EXPECTED...AND IF FREEZING DRIZZLE DOES OCCUR (AS THE
DRY LAYER ALOFT MOVES OVER THE REGION) IT SHOULD BE VERY LIGHT AND
PATCHY AND LIKELY WILL NOT CAUSE ANY PROBLEMS (THIS IS FOR THE
DEVILS LAKE BASIN AND SOUTHWARD).
UPDATE ISSUED AT 656 PM CST MON NOV 24 2014
WEAK UPPER SHORTWAVE PRODUCING RADAR RETURNS ACROSS SOUTHWEST
MANITOBA INTO NORTH CENTRAL AND NORTHWEST NORTH DAKOTA. A FEW OB
SITES INDICATING -SN WITH VSBY IN THE 2SM-5SM RANGE. WILL KEEP THE
SCHC POPS FOR LATER THIS EVENING INTO THE OVERNIGHT HOURS FOR THE
FAR WESTERN FA. THE RAP AND HRRR ALSO INDICATE QPF HERE...ALBEIT
VERY LIGHT. THE MAIN CONCERN WITH THIS QPF IS THAT A DRY LAYER
ALOFT WILL BE MOVING INTO THIS REGION AFTER MIDNIGHT...AND WITH
THE LOW-LEVEL MOIST LAYER MEAN TEMPERATURES AROUND -5C TO
-8C...SUPERCOOLED WATER DROPLETS ARE POSSIBLE. INSERTED PATCHY
FREEZING DRIZZLE INTO THE FORECAST FOR THE DEVILS LAKE BASIN AND
SOUTHWARD.
WILL ALSO ISSUE A SPS FOR THE SNOWFALL POTENTIAL TUESDAY
EVENING/OVERNIGHT. WFO BIS HAS A STATEMENT ISSUED...AND IT WOULD
BE BEST TO KEEP THE MESSAGE WITHIN NORTH DAKOTA CONSISTENT.
PLUS...A FEW INDICATIONS FOR MESO-SCALE BANDING (STEEP MID-LEVEL
LAPSE RATE...FRONTOGENESIS...POSSIBLE CONDITIONAL
INSTABILITY)...AND HIGHER RESOLUTION MODELS INDICATING A NARROW
BAND OF QPF UP TO AROUND 0.4 INCHES (SO COULD BE A NARROW BAND OF
3-5 INCHES...BUT LOCATION OF THIS BAND COULD BE ANYWHERE).
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 333 PM CST MON NOV 24 2014
FCST CHALLENGE IS LOW TEMPS TONIGHT AND THEN SNOW THREAT TUESDAY
NIGHT. FOR TONIGHT...SKIES GENERALLY CLEAR OVER MUCH OF ERN/CNTRL
ND WITH LINGERING CLOUDS ROUGHLY ROSEAU TO FARGO TO FORMAN EAST.
CLOUDS IN THE EAST WILL SLOWLY DIMINISH AS LOW PRESSURE MOVES
INTO UPPER MICHIGAN. EXPECT A PERIOD OF CLEAR SKY THIS EVENING IN
ERN ND AND AS WINDS LIGHTEN TEMPS COULD FALL QUICKLY IN SOME
SPOTS. VARIABLE SNOW COVER WILL MAKE LOW TEMPS TOUGH...BUT
GENERALLY EXPECT SINGLE DIGITS. THERE IS A SHORT WAVE IN
SASKATCHEWAN THAT WILL MOVE SOUTHEAST. THERE HAS BEEN SOME VERY
LIGHT WITH THIS ON CANADIAN RADAR BUT MODELS INDICATE PRECIP WILL
DRY OUT MORE AS IT MOVES EAST INTO SFC HIGH. DID KEEP 20 POP FOR
ANY LIGHT SNOW THAT MAY MAKE IT INTO WRN FCST AREA TOWARD MIDNIGHT
OR A BIT AFTER. CLOUDS COMING INTO THE WEST SHOULD MAKE TEMP FALL
STOP AND TEMPS RISE A BIT.
ALBERTA CLIPPER SYSTEM FOR LATER TUESDAY HANDLED A BIT BETTER NOW
WITH CONSENSUS IS TO TAKE SFC LOW THRU SOUTHWESTERN ND INTO
EASTERN SD WITH BAND OF 2-3 INCH SNOWFALL WILLISTON TO CARRINGTON
TO ABOUT WAHPETON-FORMAN AREA. LESSER AMOUNTS EAST OF THIS BUT
STILL EXPECT ENOUGH MOISTURE INTO THE COLDER AIRMASS NORTHEAST OF
THE LOW TO SQUEEZE OUT SOME LIGHT SNOW TUES NIGHT. LOOK FOR A
PERIOD OF WIND (20-25 KTS) SRN VALLEY LATE TUES NIGHT SO WILL NEED
TO WATCH THAT FOR ANY BLOWING SNOW ISSUES IF FORECAST PANS OUT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 PM CST MON NOV 24 2014
BLUSTERY AND COLD WEDNESDAY AS HIGH DROPS SOUTH. NEXT SHORT WAVE
DUE TO MOVE EAST FROM SOUTHERN B.C. INTO MONTANA AND NORTHWESTERN
NORTH DAKOTA THANKSGIVING DAY WITH LIGHT SNOW REACHING DVL BASIN
THURSDAY LATE AFTN. THIS IS A MORE PACIFIC HYBRID TYPE SYSTEM AND
MODELS TYPICALLY HAVE A HARD TIME WITH THESE AND WITH THERMAL
BOUNDARY IN PLACE TRACK OF SYSTEM MAY CHANGE.
THURSDAY NIGHT TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE LONG
HOLIDAY WEEKEND WEATHER. CHC OF SNOW THURSDAY NIGHT THROUGH SATURDAY
NIGHT AS 500MB FLOW BECOMES NEARLY ZONAL AND A BAROCLINIC ZONE SETS
UP ACROSS THE NORTHERN PLAINS. BEST CHC WILL BE THURSDAY NIGHT
ACROSS THE ENTIRE CWFA AS WAA OCCURS AND TEMPS RISE OVERNIGHT.
LESSER CHCS CONTINUING INTO THE WEEKEND ESPECIALLY ACROSS THE
NORTHERN TIER. THE BAROCLINIC ZONE WILL BE PUSHED SOUTH OF THE AREA
AS 1036MB HIGH PRESSURE MOVES INTO THE REGION SUNDAY...ENDING THE
PCPN THREAT. MAX TEMPS WILL BE BLO END OF NOVEMBER NORMALS WITH 20S
FRI FALLING INTO THE TEENS AND SINGLE DIGITS SATURDAY THROUGH
MONDAY WITH SUNDAY BEING THE COLDEST DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON NOV 24 2014
AN AREA OF MVFR CIGS IS APPROACHING THE REGION FROM THE
NORTHWEST...AND SHOULD AFFECT ALL TAF SITES EVENTUALLY. THESE
CIGS WILL LIKELY CONTINUE THROUGH MUCH OF THE DAY ON TUESDAY. -SN
EXPECTED TO AFFECT KDVL/KGFK/KFAR TUESDAY EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
342 AM CST TUE NOV 25 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 AM CST TUE NOV 25 2014
RADAR EARLY THIS MORNING SHOWING FINAL SNOW BAND ON THE BACK SIDE OF
DEPARTING LOW PRESSURE SYSTEM MAKING ITS WAY ACROSS CENTRAL
WISCONSIN. THIS SHOULD CLEAR THE AREA BY 6 AM WITH LITTLE IN THE WAY
OF ADDITIONAL ACCUMULATION EXPECTED. THEN FOR TODAY...A RIDGE OF
HIGH PRESSURE BUILDS OVER THE AREA FOR SOME CLEARING. MODEL
SOUNDINGS SHOWING STRATUS MAY BE A BIT MORE PESKY EAST OF THE
MISSISSIPPI RIVER UNDER THE SUBSIDENCE INVERSION. THINKING THIS
STRATUS WILL CONTINUE TO THIN THROUGH THE DAY...BUT MAY BE A BIT
SLOWER THAN ANTICIPATED. WILL HAVE TO KEEP AN EYE ON THIS.
OTHERWISE...LOOK FOR HIGHS TODAY IN THE 20S WITH NORTHWEST WINDS
THIS MORNING BECOMING SOUTHWEST BY AFTERNOON WITH THE PASSAGE OF THE
HIGH PRESSURE RIDGE AXIS.
FOR TONIGHT THROUGH WEDNESDAY...WILL BE WATCHING A FAIRLY VIGOROUS
MID-LEVEL SHORTWAVE TROUGH AND SURFACE LOW DROP SOUTHEAST ACROSS THE
DAKOTAS...THROUGH IOWA...AND THEN TOWARD THE MID-MISSISSIPPI VALLEY.
MODELS ARE IN VERY GOOD AGREEMENT IN KEEPING BULK OF SNOWFALL
ASSOCIATED WITH THIS FEATURE WEST OF THE AREA...BUT LOOKS LIKE
PORTIONS OF NORTHEAST IA/SOUTHEAST MN WILL LIKELY GET CLIPPED WITH
SOME LIGHT SNOW DURING THE DAY WEDNESDAY. RIGHT NOW IT APPEARS
SNOWFALL OF 1 TO PERHAPS 3 INCHES ON THE HIGHEST END IS LIKELY
MAINLY ALONG AND WEST OF A ROCHESTER MN TO OELWEIN IA LINE.
MEANWHILE ON WEDNESDAY...WILL BE WATCHING AN ARCTIC FRONT DROPPING
THROUGH MN INTO WESTERN WI BY LATE IN THE AFTERNOON. NAM SHOWING
PRETTY DECENT AMOUNT OF 1000-700MB FRONTOGENESIS AND SHOULD PROVIDE
ENOUGH FORCING FOR THE LIKELIHOOD OF SOME SNOW SHOWER ACTIVITY.
LOOK FOR THIS FRONT AND BAND OF SNOW SHOWERS TO SWING THROUGH THE
AREA WEDNESDAY NIGHT...WITH THE BULK OF IT EXITING BEFORE
THANKSGIVING DAYBREAK. THINKING THAT WE COULD SEE UPWARDS OF AN INCH
OF SNOW WITH THE SNOW SHOWERS WITH BEST CHANCES FOR ACCUMULATION
ALONG AND NORTH OF I-94 WHERE BEST FORCING WILL RESIDE.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 342 AM CST TUE NOV 25 2014
DRY/SUNNY/COLD CONDITIONS WILL BE SEEN FOR THANKSGIVING DAY AS
ARCTIC HIGH/MODIFIED ARCTIC AIRMASS DRIFTS ACROSS THE REGION. PLAN
ON HIGHS ONLY IN THE TEENS.
A WARM FRONT WILL THEN LIFT NORTHWARD THROUGH THE REGION THURSDAY
NIGHT THROUGH FRIDAY NIGHT FOR A CHANCE OF LIGHT SNOW. TEMPERATURES
ARE EXPECTED TO SLOWLY RISE THURSDAY NIGHT....THEN TOP OFF IN THE
20S TO LOWER 30S ON FRIDAY. LOOKS LIKE WE WILL BE IN THE WARM SECTOR
OF APPROACHING LOW PRESSURE ACROSS THE PLAINS ON SATURDAY. HIGHS ON
SATURDAY IN THE LOWER 30S FOR AREAS ALONG AND NORTH OF I-94...TO
PERHAPS A FEW 40 DEGREE READINGS ACROSS NORTHEAST IA INTO SOUTHWEST
WISCONSIN.
LOOK FOR A RETURN TO COLDER CONDITIONS SUNDAY AND MONDAY AS ARCTIC
AIR SPILLS BACK INTO THE REGION. PLAN ON HIGHS BOTH DAYS IN THE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1100 PM CST MON NOV 24 2014
THE SNOW HAS EXITED TO THE EAST LATE THIS EVENING...AS THE
RESPONSIBLE AREA OF LOW PRESSURE CONTINUES TO TREK ACROSS THE
EASTERN GREAT LAKES. THE ASSOCIATED CLOUDS LINGER WELL WEST OF THE
LOW THOUGH...WITH CURRENT SATELLITE TRENDS SUGGESTING CLEARING OF
THE MVFR DECK AT KRST AROUND 11Z AND KLSE BY 14Z. SHOULD SEE SCT/VFR
CONDITIONS FOR THE BULK OF THE DAY TUE.
SEE SOME POTENTIAL FOR A RETURN FOR AN MVFR DECK AFTER 00Z WED /TUE
NIGHT/. RAP AND NAM12 RH FIELDS SUGGEST CURRENT STRATUS DECK OVER ND
WILL SINK SOUTHEAST OVERNIGHT THROUGH TUE...AND COULD HOLD TOGETHER
LONG ENOUGH TO IMPACT KRST...POSSIBLY KLSE. WILL ALLUDE TO IT FOR
NOW...ADDING IN A SCATTERED LOW CLOUD IN ADDITION TO BKN HIGH CIGS.
DO EXPECT SOME LOWER CIGS TO RETURN ON WED AS THE NEXT UPPER LEVEL
SHORTWAVE TRACKS ACROSS PARTS OF THE REGION. LIKELY SEE SOME -SN TOO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A PROGRESSIVE AND ENERGETIC FLOW PERSISTS OVER THE CONUS THROUGH
THIS WEEK WITH AN EVOLUTION TO MORE OF A ZONAL OR BROAD FLAT RIDGE
IN THE LARGE SCALE. PREDICTABILITY OVER THE PAST WEEKEND HAS BEEN
LOW...AS SEEN BY THE SHORT RANGE VARIABILITY IN HOW THIS CURRENT
SNOW EVENT TRANSPIRED. NOT PRETTY. THIS WILL CONTINUE THROUGH THE
WEEK...AND CONFIDENCE IS LOW IN TIMING AND PLACEMENT OF WEATHER
SYSTEMS.
LATEST SNOW AMOUNTS IN CENTRAL WISCONSIN ARE IN THE 3 TO 5 INCH
RANGE WITH WINDS CAUSING SOME MEASUREMENT DIFFICULTY. RADAR
INDICATING THAT MOST OF THE CENTRAL WI AREA SHOULD CONTINUE TO
DIMINISH IN INTENSITY AS SNOW SHIELD MOVES NORTHEAST. THE LATEST
RAP TRENDS INDICATE A STRENGTHENING 600-700MB WEAK-MODERATE
FRONTOGENESIS BAND WILL DEVELOP N-S OVER CENTRAL WI LATER THIS
AFTERNOON WHICH COULD BUMP THE RATES A BIT ON WEST END OF THE
SHIELD. BUT...THAT RAP FRONTOGENESIS GUIDANCE IN THE MID-LEVELS
HAS NOT PROVIDED MUCH FOR SENSIBLE SNOW INCREASE OR BANDING FOR
THIS ENVIRONMENT. OVERALL...FROM TRENDS AND WHAT HAS FALLEN...SNOW
WILL SLOWLY SHIFT EAST THIS EVENING...DIMINISHING. HAVE LOWER
STORM TOTAL AMOUNTS IN CENTRAL WISCONSIN...MORE AROUND 4.5 TO 5
INCHES...AND AFTER COLLABORATION WITH MKX...HAVE DOWNGRADED THE
WARNING TO ADVISORY.
WINDS WILL CONTINUE THROUGH THE EVENING TO CAUSE ROADS TO BE
COVERED AND SNOW PLOW CAMS IN NORTHEAST IA SUGGEST THE ROADS ARENT
TOO CLEAN YET. SO...HAVE DECIDED TO LET THE ENTIRE ADVISORY
CONTINUE THROUGH MIDNIGHT.
WATER VAPOR IMAGERY SHOWING A SHORTWAVE TROUGH DROPPING THROUGH MN
AND RADAR INDICATES SOME SNOW SHOWERS THERE. THIS SHOULD NOT
AMOUNT TO MUCH BUT A BRIEF SNOW SHOWER PERIOD AND MAYBE A BIT OF
VSBY REDUCTION /1-2SM/...BUT NOT A HAZARD GENERALLY. HOWEVER AN
AREA EXISTS AHEAD OF THE SHORTWAVE TROUGH IN MN AND THE HIGHER
LEVEL CLOUD WITH THE SNOW SHIELD THAT IS PROMOTING SOME FZDZ.
THIS IS FROM SERN MN INTO SWRN WI. SHERIFFS HAVE HAD FZDZ IN GRANT
COUNTY...AND EARLIER IN NERN IA. MOST OF THIS FZDZ SHOULD OCCUR
IN THE ADVISORY AREA AND FOR THE NEXT FEW HOURS AS THE DEEP SNOW
SHOWERS MOVING IN WILL SHIFT THE PRECIPITATION TYPE VIA SEEDER-
FEEDER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A FAIRLY TRANQUIL PERIOD FOR THE WEEK REALLY WITH A COLDER THAN
NORMAL PERIOD UNDER THE DEEP LONG WAVE TROUGH....BUT AS THIS
BECOMES MORE ZONAL...THE AREA WILL SEE CYCLES OF WARM ADVECTION
AND PRECIPITATION CHANCES...CYCLONE PASSAGE...AND COLD AIR PUSHES.
THE FIRST SHORTWAVE TROUGH COMES ON WEDNESDAY...A HEAVIER TRAVEL
DAY. THIS SHORTWAVE IS COMING INTO BRITISH COLUMBIA COAST
CURRENTLY ON THE POLEWARD SIDE OF A 155 KT 250 MB JET PER 12Z
RAOBS. A PRETTY VIGOROUS SYSTEM THAT DIGS SOUTHEAST IN THE
LONGWAVE TROUGH. THIS WILL BE A 1-2 INCH SNOW MAKER BUT THE TRACK
IS THE QUESTION. HAVE GENERALLY KEPT THE SAME FORECAST AS PREVIOUS
WITH MOSTLY A SRN MN AND NERN IA SYSTEM. CONFIDENCE ON THE TRACK
IS NOT HIGH YET WITH COMPLEX SYSTEM OVER GREAT LAKES AND TOTAL
ENERGY OVER THE CONUS RIGHT NOW. NEW GFS PARALLEL RUN INTENSIFIES
THE NWRLY FLOW ENERGY MORE AND BRINGS MORE SNOW TO THE NORTH...BUT
IS AN OUTLIER. BEHIND THIS SYSTEM...COLD AIR COMES IN FOR
THANKSGIVING...BUT A QUITE WEATHER DAY.
ANOTHER SYSTEM MOVES IN FRIDAY AND IF MY CONFIDENCE IS LOW ON THE
TRACK FOR WEDNESDAY...FRIDAYS WARM ADVECTION SWATH OF SNOW OR
WINTER MIX IS LOWER. GOOD MEDIUM RANGE GUIDANCE CONSENSUS ON THE
TRACK RIGHT NOW...BUT THAT DOESNT MEAN IT WILL BE CORRECT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1100 PM CST MON NOV 24 2014
THE SNOW HAS EXITED TO THE EAST LATE THIS EVENING...AS THE
RESPONSIBLE AREA OF LOW PRESSURE CONTINUES TO TREK ACROSS THE
EASTERN GREAT LAKES. THE ASSOCIATED CLOUDS LINGER WELL WEST OF THE
LOW THOUGH...WITH CURRENT SATELLITE TRENDS SUGGESTING CLEARING OF THE
MVFR DECK AT KRST AROUND 11Z AND KLSE BY 14Z. SHOULD SEE SCT/VFR
CONDITIONS FOR THE BULK OF THE DAY TUE.
SEE SOME POTENTIAL FOR A RETURN FOR AN MVFR DECK AFTER 00Z WED /TUE
NIGHT/. RAP AND NAM12 RH FIELDS SUGGEST CURRENT STRATUS DECK OVER ND
WILL SINK SOUTHEAST OVERNIGHT THROUGH TUE...AND COULD HOLD TOGETHER
LONG ENOUGH TO IMPACT KRST...POSSIBLY KLSE. WILL ALLUDE TO IT FOR
NOW...ADDING IN A SCATTERED LOW CLOUD IN ADDITION TO BKN HIGH CIGS.
DO EXPECT SOME LOWER CIGS TO RETURN ON WED AS THE NEXT UPPER LEVEL
SHORTWAVE TRACKS ACROSS PARTS OF THE REGION. LIKELY SEE SOME -SN TOO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
939 AM CST Tue Nov 25 2014
.UPDATE...
ISSUED AT 938 AM CST TUE NOV 25 2014
Large area of stratocumulus continues to sag southeast across the
forecast area, with the last holdouts near Lawrenceville now
clouding up. A narrow area of clearing from Peoria southeast has
been shifting toward Bloomington and Champaign, although this is
also starting to show a bit of filling in on the latest visible
satellite imagery. At present, the northern edge of the cloud deck
is advancing across northwest Illinois and is approaching
Galesburg from the north. The latest RAP and HRRR guidance shows
some additional development in that area over the next couple
hours, so we will need to keep an eye on that. For now, it looks
like the bulk of the clearing will begin across the southwest CWA
soon and slowly pull northeast.
Have made some adjustments to the high temperatures across the
northern CWA, where it`s still only in the lower 20s, and the
latest sky grids have been sent as well.
&&
.SHORT TERM...(Today)
ISSUED AT 312 AM CST TUE NOV 25 2014
Low pressure that brought widespread rain to central Illinois on
Sunday is now over Quebec, with trailing cold front approaching the
East Coast. Despite the parent low being so far away from the
region, lingering upper troughing is keeping cloud cover locked in
place. 08z/2am IR satellite imagery shows low clouds covering all
of central/northern Illinois and as far west as eastern Iowa.
Timing tools are indicating only a very slow eastward progression of
the clearing line, so have delayed the clearing across the KILX CWA
accordingly. The day will start out overcast across the board, then
a slow west-to-east clearing will occur as the day progresses.
Based on latest satellite loop and 00z forecast soundings, think
locations along/northeast of a Bloomington to Mattoon line will
remain cloudy for the entire day. Further west and south, skies
will become partly to mostly sunny this afternoon. Will be a cold
day with highs only in the 30s, but it will not be nearly as windy
as yesterday with westerly winds generally around 10 mph.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 312 AM CST TUE NOV 25 2014
Main weather challenge in the extended continues to be clipper
system expected to track through the region on Wednesday. 00z Nov
25 models are in excellent agreement with the timing and track of
the system, but display minor differences with their QPF fields.
All models take low pressure currently over Alberta and track it
southeastward into western Iowa by 12z Wed, then into southern
Illinois by 00z Thu. This represents a continued southerly trend
in the track, which means portions of the far N/NE CWA may see
little or no precip with this system. NAM is the most
concentrated with its QPF, keeping it confined very near the low
track. Meanwhile, both the GFS and ECMWF are more generous and
spread light precip further north across the entire area. Have
updated Wednesday precip chances to focus likely PoPs along/south
of a Rushville to Decatur to Robinson line, tapering down to low
chance northeast of I-74. Given the more southerly track, WAA
ahead of the wave will be weaker than previously thought, so high
temps will not be quite as warm. Afternoon readings will range
from the middle 30s far north to the lower 40s south of I-70.
Forecast soundings support snow: however, surface temps will be
warm enough for a rain/snow mix across much of the area and
perhaps mainly rain across the far southeast. Snowfall amounts
will be mitigated by the marginal temps and overall light QPF,
with perhaps a half inch along/southwest of Macomb to Springfield
line where the precip will begin during the morning hours when it
is still cold enough to support all snow reaching the ground.
System will quickly track into the Appalachians Wednesday night,
with just a few lingering snow-showers across the E/SE into the
evening.
Once Wednesday clipper departs, the remainder of the extended
appears to be quiet. A shot of cold air behind the system will drop
high temps into the upper 20s/lower 30s on Thursday: however, a
marked warming trend is still expected for the end of the week as
eastern CONUS upper troughing relaxes and a zonal pattern develops.
As southerly winds develop on the back side of departing high
pressure, high temperatures will soar well into the 50s on Saturday
before a cold front sags southward into the region late in the day.
Still some discrepancies further out concerning how far south front
will make it, with overall consensus taking it into the Ohio River
Valley by Sunday. High pressure initially along the Gulf Coast will
limit northward moisture return, so showers will likely not develop
along/ahead of the boundary until it sinks into the SE CWA Sunday
afternoon/night. All model solutions point to a cool/dry day on
Monday before southerly flow resumes and precip chances slowly begin
to increase by Tuesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 539 AM CST TUE NOV 25 2014
MVFR conditions in place across the central Illinois terminals to
start the day as the low clouds have been slow to depart in the
wake of yesterday`s storm system. The low CIGS will eventually
scatter out by this afternoon, resiting in VFR conditions for the
balance of the 12Z TAF valid time. However, the clearing will be
short lived as mid/high level clouds spill into the area tonight
in advance of a clipper system that will impact the area on
Wednesday. Westerly winds will diminish today as the pressure
gradient relaxes. Then winds will trend variable tonight as a
ridge of high pressure passes by, and shift to the southeast by
morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart/EJL
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1025 AM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1025 AM EST TUE NOV 25 2014
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BRIEFLY BUILDING INTO EAST
KENTUCKY THIS MORNING BRINGING SUNNY SKIES AND A DRIER AIR MASS. THE
EARLIER HIGH CLOUDS HAVE SLID OFF TO THE EAST OF THE STATE AND WINDS
ARE LIGHT AND VARIABLE. TEMPERATURES ARE IN THE LOW TO MID 40S IN
MOST PLACES ACROSS THE CWA NOW THAT THE COLDER VALLEYS ARE STARTING
TO MIX OUT. DEWPOINTS ARE CURRENTLY IN THE LOW 30S...BUT WITH DRIER
AIR OFF THE SFC THESE ARE EXPECTED TO MIX DOWN INTO THE 20S THROUGH
MID AFTERNOON. FIRST GLANCE OF THE LATEST NAM12 SHOWS THE SOUTHEAST
LOW A BIT FURTHER EAST FROM THE MORE AGGRESSIVE 06Z RUN. HOWEVER...IT
STILL HAS A SIGNIFICANT AMOUNT OF PCPN FALLING TONIGHT INTO WEDNESDAY
MORNING IN AND NEAR THE VIRGINIA BORDER COUNTIES WHERE MUCH OF IT
WILL LIKELY WET BULB TO SNOW. SOME ACCUMULATIONS APPEAR LIKELY...
PARTICULARLY IN THE HIGHER ELEVATIONS AND ON GRASSY/ELEVATED SFCS
ELSEWHERE. THE SPS CONTINUES BUT MAY NEED TO BE UPGRADED TO AN
ADVISORY LATER THIS AFTERNOON DEPENDING ON HOW THE OTHER MODELS COME
IN. FOR THIS UPDATE...HAVE MAINLY FINE TUNED T AND TD GRIDS INTO THE
AFTERNOON PER THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 621 AM EST TUE NOV 25 2014
06Z NAM AND GFS ARE NOW IN AND BOTH ARE A LITTLE MORE ROBUST WITH
PRECIPITATION AND BOTH A TAD FARTHER WEST WITH THE EXTENT. IN
FACT...THE NAM SNOWFALL ALGORITHM IS SUGGESTING AS MUCH AS 5 INCHES
OF SNOW COULD FALL OVER FAR SOUTHEAST KENTUCKY. HOWEVER...THIS IS THE
FIRST RUN SUGGESTING THIS HIGH OF QPF AND WILLING TO CONSIDER IT AN
OUTLIER FOR NOW...BUT THE 12Z MODEL GUIDANCE WILL HAVE TO BE WATCHED
FOR POSSIBLE TRENDS TOWARDS THE HIGHER SNOWFALL AMOUNTS TONIGHT.
ALREADY SEEING SOME COOLER CLOUD TOPS DEVELOPING ACROSS EAST
TEXAS...SO AS MENTIONED...MAY NEED TO WATCH FOR A FARTHER WEST EXTENT
TO THE PRECIPITATION.
ALSO SOMETHING ELSE TO CONSIDER...DRY AIR MIX DOWN ACROSS SOUTHEAST
KENTUCKY THIS AFTERNOON MAY BRING DOWN SOME AWFULLY LOW
DEWPOINTS...WHICH WOULD SET THE STAGE FOR GOOD WET BULB COOLING AS
PRECIPITATION MOVES IN TONIGHT. THUS...IF LOWER DEWPOINTS
MATERIALIZE...THEY MAY HELP DISTINGUISH BETWEEN WHO GETS MORE
SNOW...VERSES MORE RAIN. LOWER DEWPOINTS WOULD ALLOW FOR A FASTER
TRANSITION TO SNOW...AND THUS...MORE SNOWFALL ACCUMULATION. FOR
NOW...WILLING TO SIT ON THIS AND LET DAY-SHIFT RE-EVALUATE THE NEED
FOR ANY CHANGES. IF MODELS CONTINUE TO HOLD COURSE...IT LOOKS LIKE AT
A MINIMUM A WINTER WEATHER ADVISORY WOULD BE NEEDED FOR A PORTION OF
THE AREA.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
SURFACE RIDGING CONTINUES TO BUILD INTO EASTERN KENTUCKY THIS MORNING
WITH SKIES GENERALLY CLEAR TO MOSTLY CLEAR. THIS WILL HOLD THROUGH
THE DAY...PROVIDING A COOLER...BUT STILL RELATIVELY PLEASANT DAY. IN
FACT...WITH THE HELP OF THE SUNSHINE AND TEMPERATURES IN SOME PLACES
ALREADY IN THE 40S THIS MORNING...WE SHOULD HAVE NO PROBLEM
SURPASSING THE 50 DEGREE MARK THIS AFTERNOON. WITH AN ABUNDANCE OF LOW
LEVEL DRY AIR JUST OFF THE SURFACE...RAP AND HRRR ARE SUGGESTING
FAIRLY LOW DEWPOINTS THIS AFTERNOON...ESPECIALLY ACROSS SOUTHEAST
KENTUCKY. IT MIGHT BE A STRETCH TO FALL INTO THE TEENS...BUT
CERTAINLY DEWPOINTS DOWN INTO THE MID 20S WILL BE POSSIBLE. THIS WILL
PUT US CLOSE TO THE 25 PERCENT RH`S THIS AFTERNOON. I WOULDN`T BE
SURPRISED TO SEE A FEW SPOTS ACTUALLY REACH THIS VALUE...ESPECIALLY
IN SOUTHEAST KENTUCKY.
CLOUDS WILL BE ON THE INCREASE THIS EVENING AND ESPECIALLY TONIGHT.
MODELS HAVE AN AREA OF LOW PRESSURE DEVELOPING OVER FLORIDA AND
TRACKING NORTHWARD ALONG THE COAST TONIGHT. NEARLY ALL MODELS ARE IN
SUPPORT OF MOISTURE AND LIFT ASSOCIATED WITH THIS SYSTEM DEVELOPING
ACROSS FAR SOUTHEAST AND EAST KENTUCKY OVERNIGHT INTO WEDNESDAY
MORNING. GIVEN THE ABUNDANCE OF DRY AIR IN PLACE...WET BULB
TEMPERATURES WILL BE FAIRLY LOW. ASSUMING WE GET PRECIP RATES THAT
SUPPORT IT...WE SHOULD SEE PRIMARILY SNOW LATE TONIGHT INTO WEDNESDAY
MORNING...BUT SOME RAIN MAY BE POSSIBLE FARTHER INTO EASTERN KENTUCKY
WHERE PRECIP RATES MAY NOT BE AS HIGH. REGARDLESS...WE SHOULD SEE
TEMPERATURES COOL ENOUGH TO SUPPORT SOME LIGHT SNOW ACCUMULATION
ACROSS SOUTHEAST KENTUCKY. AT THIS TIME...THE HIGHEST AMOUNTS SHOULD
BE ABOVE 2500 FEET...WHERE 2 TO 3 INCHES OF SNOW MAY BE POSSIBLE.
LIGHTER AMOUNTS IN THE LOWER ELEVATIONS UP TO AN INCH WILL BE
POSSIBLE FOR AREAS SOUTHEAST OF A LINE FROM INEZ TO HAZARD...TO
BARBOURVILLE. WHILE SNOW IS EXPECTED ACROSS SOUTHEAST KENTUCKY...THE
REST OF EASTERN KENTUCKY MAY NOT SEE MUCH MORE THAN INCREASED CLOUD
COVER. PLAN TO GO AHEAD AND ISSUE AN SPS FOR OUR SOUTHEAST COUNTIES
TO ADDRESS THE POTENTIAL SNOWFALL. GIVEN THE EXPECTED CLOUD COVER
INTO WEDNESDAY...WENT WITH A PRETTY GOOD GRADIENT IN TEMPERATURES
FROM WEST TO EAST...WITH READINGS AROUND 50 IN THE WEST TO LOW AND
MID 30S IN THE EAST. PRECIPITATION WILL DEPART BY MIDDAY
WEDNESDAY...WITH TEMPORARY BREAK IN PRECIPITATION EXPECTED THROUGH
THE AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
THE MODELS BEGIN THE PERIOD IN PRETTY GOOD AGREEMENT...WITH A LARGE
SCALE UPPER LEVEL TROUGH OF LOW PRESSURE EJECTING OUT OF THE
NORTHERN PLAINS AND ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS
WEDNESDAY NIGHT THROUGH FRIDAY. IT APPEARS THAT THIS INITIAL SYSTEM
WILL BE FAIRLY PROGRESSIVE...SO ANY PRECIPITATION ASSOCIATED WITH IT
SHOULD BE SHORT LIVED AND NOT VERY HEAVY. A SHOT OF COLD AIR WILL
SPILL INTO THE REGION AS THE SYSTEM DEPARTS...WITH HIGHS ON THURSDAY
ONLY TOPPING OUT AROUND 40 DEGREES...AFTER MORNING LOWS IN THE UPPER
20S AND LOWER 30S. A RIDGE OF HIGH PRESSURE IS THEN PROGGED TO
BECOME ESTABLISHED ACROSS THE REGION TO BEGIN THE WEEKEND...WITH
WARMER TEMPERATURES AND PARTLY CLOUDY SKIES ON TAP FOR FRIDAY NIGHT
AND SATURDAY. SATURDAY COULD MARK THE START OF A SIGNIFICANT WARMING
TREND...WITH HIGHS POSSIBLY TOPPING OUT IN THE LOW TO MID 50S. THE
REGION IS EXPECTED TO WARM EVEN MORE ON SUNDAY AND MONDAY...AS THE
MERCURY CLIMBS INTO THE MID TO UPPER 50S FOR MOST LOCATIONS BOTH
DAYS. OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT WILL FEEL ALMOST
BALMY IF THEY IN FACT ONLY DROP INTO THE LOW TO MID 40S EACH NIGHT.
ENOUGH COLD AIR WILL LIKELY SPILL INTO THE REGION TO BEGIN THE
PERIOD TO ALLOW FOR SOME SNOW TO MIX WITH RAIN EARLY WEDNESDAY NIGHT
INTO THURSDAY MORNING ACROSS THE AREA. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THE NEXT ROUND OF PRECIPITATION IS
EXPECTED TO MOVE ACROSS THE AREA BEGINNING SATURDAY NIGHT...AS A
WEAK FRONTAL BOUNDARY MOVES INTO AND STALLS OUT ACROSS THE AREA. THE
MODELS KEEP THE FRONT IN PLACE...AND THEREFORE THE THREAT OF
PRECIPITATION...THROUGH THE END OF THE DAY ON MONDAY. TEMPERATURES
DURING THIS PERIOD WILL REMAIN WARM ENOUGH FOR ANY PRECIPITATION
THAT OCCURS TO REMAIN IN LIQUID FORM. DUE TO SOME SMALL TIMING
DIFFERENCES BETWEEN THE MODELS REGARDING PRECIPITATION
ONSET...DURATION...AND AREAL COVERAGE...DECIDED TO GO WITH ONLY
CHANCE POPS AT THIS TIME. BASED ON THE LATEST MODEL DATA...THE FRONT
COULD EITHER REMAIN STALLED ACROSS THE AREA...ECMWF...OR DRIFT
SLOWLY NORTH AS A WEAK WARM FRONT...GFS...DURING THE MONDAY INTO
MONDAY NIGHT TIME FRAME. ONLY TIME WILL TELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 621 AM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING AS HIGH PRESSURE
PUSHES EAST ACROSS THE AREA. A DEVELOPING LOW PRESSURE SYSTEM WILL
SPREAD MOISTURE BACK INTO EASTERN KENTUCKY LATE TONIGHT...WITH CIGS
LOWERING. AS OF RIGHT NOW...LOOKS LIKE WE SHOULD SEE A GRADIENT IN
THE LOWER CIGS WITH THE LOWEST (IFR/MVFR) IN THE EAST...TRAILING
BACK TO VFR IN THE WEST. WE WILL ALSO SEE PRECIPITATION SPREAD INTO
THE AREA...MAINLY ACROSS SOUTHEASTERN KENTUCKY...WITH A MIX OF RAIN
AND SNOW...LIKELY BECOMING ALL SNOW. THIS WILL RESTRICT VISIBILITIES
BY LATE TONIGHT AS WELL...MAINLY AT KJKL AND KSJS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
621 AM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 621 AM EST TUE NOV 25 2014
O6Z NAM AND GFS ARE NOW IN AND BOTH ARE A LITTLE MORE ROBUST WITH
PRECIPITATION AND BOTH A TAD FARTHER WEST WITH THE EXTENT. IN
FACT...THE NAM SNOWFALL ALGORITHM IS SUGGESTING AS MUCH AS 5 INCHES
OF SNOW COULD FALL OVER FAR SOUTHEAST KENTUCKY. HOWEVER...THIS IS THE
FIRST RUN SUGGESTING THIS HIGH OF QPF AND WILLING TO CONSIDER IT AN
OUTLIER FOR NOW...BUT THE 12Z MODEL GUIDANCE WILL HAVE TO BE WATCHED
FOR POSSIBLE TRENDS TOWARDS THE HIGHER SNOWFALL AMOUNTS TONIGHT.
ALREADY SEEING SOME COOLER CLOUD TOPS DEVELOPING ACROSS EAST
TEXAS...SO AS MENTIONED...MAY NEED TO WATCH FOR A FARTHER WEST EXTENT
TO THE PRECIPITATION.
ALSO SOMETHING ELSE TO CONSIDER...DRY AIR MIX DOWN ACROSS SOUTHEAST
KENTUCKY THIS AFTERNOON MAY BRING DOWN SOME AWFULLY LOW
DEWPOINTS...WHICH WOULD SET THE STAGE FOR GOOD WET BULB COOLING AS
PRECIPITATION MOVES IN TONIGHT. THUS...IF LOWER DEWPOINTS
MATERIALIZE...THEY MAY HELP DISTINGUISH BETWEEN WHO GETS MORE
SNOW...VERSES MORE RAIN. LOWER DEWPOINTS WOULD ALLOW FOR A FASTER
TRANSITION TO SNOW...AND THUS...MORE SNOWFALL ACCUMULATION. FOR
NOW...WILLING TO SIT ON THIS AND LET DAY-SHIFT RE-EVALUATE THE NEED
FOR ANY CHANGES. IF MODELS CONTINUE TO HOLD COURSE...IT LOOKS LIKE AT
A MINIMUM A WINTER WEATHER ADVISORY WOULD BE NEEDED FOR A PORTION OF
THE AREA.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
SURFACE RIDGING CONTINUES TO BUILD INTO EASTERN KENTUCKY THIS MORNING
WITH SKIES GENERALLY CLEAR TO MOSTLY CLEAR. THIS WILL HOLD THROUGH
THE DAY...PROVIDING A COOLER...BUT STILL RELATIVELY PLEASANT DAY. IN
FACT...WITH THE HELP OF THE SUNSHINE AND TEMPERATURES IN SOME PLACES
ALREADY IN THE 40S THIS MORNING...WE SHOULD HAVE NO PROBLEM
SURPASSING THE 50 DEGREE MARK THIS AFTERNOON. WITH AN ABUNDANCE OF LOW
LEVEL DRY AIR JUST OFF THE SURFACE...RAP AND HRRR ARE SUGGESTING
FAIRLY LOW DEWPOINTS THIS AFTERNOON...ESPECIALLY ACROSS SOUTHEAST
KENTUCKY. IT MIGHT BE A STRETCH TO FALL INTO THE TEENS...BUT
CERTAINLY DEWPOINTS DOWN INTO THE MID 20S WILL BE POSSIBLE. THIS WILL
PUT US CLOSE TO THE 25 PERCENT RH`S THIS AFTERNOON. I WOULDN`T BE
SURPRISED TO SEE A FEW SPOTS ACTUALLY REACH THIS VALUE...ESPECIALLY
IN SOUTHEAST KENTUCKY.
CLOUDS WILL BE ON THE INCREASE THIS EVENING AND ESPECIALLY TONIGHT.
MODELS HAVE AN AREA OF LOW PRESSURE DEVELOPING OVER FLORIDA AND
TRACKING NORTHWARD ALONG THE COAST TONIGHT. NEARLY ALL MODELS ARE IN
SUPPORT OF MOISTURE AND LIFT ASSOCIATED WITH THIS SYSTEM DEVELOPING
ACROSS FAR SOUTHEAST AND EAST KENTUCKY OVERNIGHT INTO WEDNESDAY
MORNING. GIVEN THE ABUNDANCE OF DRY AIR IN PLACE...WET BULB
TEMPERATURES WILL BE FAIRLY LOW. ASSUMING WE GET PRECIP RATES THAT
SUPPORT IT...WE SHOULD SEE PRIMARILY SNOW LATE TONIGHT INTO WEDNESDAY
MORNING...BUT SOME RAIN MAY BE POSSIBLE FARTHER INTO EASTERN KENTUCKY
WHERE PRECIP RATES MAY NOT BE AS HIGH. REGARDLESS...WE SHOULD SEE
TEMPERATURES COOL ENOUGH TO SUPPORT SOME LIGHT SNOW ACCUMULATION
ACROSS SOUTHEAST KENTUCKY. AT THIS TIME...THE HIGHEST AMOUNTS SHOULD
BE ABOVE 2500 FEET...WHERE 2 TO 3 INCHES OF SNOW MAY BE POSSIBLE.
LIGHTER AMOUNTS IN THE LOWER ELEVATIONS UP TO AN INCH WILL BE
POSSIBLE FOR AREAS SOUTHEAST OF A LINE FROM INEZ TO HAZARD...TO
BARBOURVILLE. WHILE SNOW IS EXPECTED ACROSS SOUTHEAST KENTUCKY...THE
REST OF EASTERN KENTUCKY MAY NOT SEE MUCH MORE THAN INCREASED CLOUD
COVER. PLAN TO GO AHEAD AND ISSUE AN SPS FOR OUR SOUTHEAST COUNTIES
TO ADDRESS THE POTENTIAL SNOWFALL. GIVEN THE EXPECTED CLOUD COVER
INTO WEDNESDAY...WENT WITH A PRETTY GOOD GRADIENT IN TEMPERATURES
FROM WEST TO EAST...WITH READINGS AROUND 50 IN THE WEST TO LOW AND
MID 30S IN THE EAST. PRECIPITATION WILL DEPART BY MIDDAY
WEDNESDAY...WITH TEMPORARY BREAK IN PRECIPITATION EXPECTED THROUGH
THE AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
THE MODELS BEGIN THE PERIOD IN PRETTY GOOD AGREEMENT...WITH A LARGE
SCALE UPPER LEVEL TROUGH OF LOW PRESSURE EJECTING OUT OF THE
NORTHERN PLAINS AND ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS
WEDNESDAY NIGHT THROUGH FRIDAY. IT APPEARS THAT THIS INITIAL SYSTEM
WILL BE FAIRLY PROGRESSIVE...SO ANY PRECIPITATION ASSOCIATED WITH IT
SHOULD BE SHORT LIVED AND NOT VERY HEAVY. A SHOT OF COLD AIR WILL
SPILL INTO THE REGION AS THE SYSTEM DEPARTS...WITH HIGHS ON THURSDAY
ONLY TOPPING OUT AROUND 40 DEGREES...AFTER MORNING LOWS IN THE UPPER
20S AND LOWER 30S. A RIDGE OF HIGH PRESSURE IS THEN PROGGED TO
BECOME ESTABLISHED ACROSS THE REGION TO BEGIN THE WEEKEND...WITH
WARMER TEMPERATURES AND PARTLY CLOUDY SKIES ON TAP FOR FRIDAY NIGHT
AND SATURDAY. SATURDAY COULD MARK THE START OF A SIGNIFICANT WARMING
TREND...WITH HIGHS POSSIBLY TOPPING OUT IN THE LOW TO MID 50S. THE
REGION IS EXPECTED TO WARM EVEN MORE ON SUNDAY AND MONDAY...AS THE
MERCURY CLIMBS INTO THE MID TO UPPER 50S FOR MOST LOCATIONS BOTH
DAYS. OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT WILL FEEL ALMOST
BALMY IF THEY IN FACT ONLY DROP INTO THE LOW TO MID 40S EACH NIGHT.
ENOUGH COLD AIR WILL LIKELY SPILL INTO THE REGION TO BEGIN THE
PERIOD TO ALLOW FOR SOME SNOW TO MIX WITH RAIN EARLY WEDNESDAY NIGHT
INTO THURSDAY MORNING ACROSS THE AREA. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THE NEXT ROUND OF PRECIPITATION IS
EXPECTED TO MOVE ACROSS THE AREA BEGINNING SATURDAY NIGHT...AS A
WEAK FRONTAL BOUNDARY MOVES INTO AND STALLS OUT ACROSS THE AREA. THE
MODELS KEEP THE FRONT IN PLACE...AND THEREFORE THE THREAT OF
PRECIPITATION...THROUGH THE END OF THE DAY ON MONDAY. TEMPERATURES
DURING THIS PERIOD WILL REMAIN WARM ENOUGH FOR ANY PRECIPITATION
THAT OCCURS TO REMAIN IN LIQUID FORM. DUE TO SOME SMALL TIMING
DIFFERENCES BETWEEN THE MODELS REGARDING PRECIPITATION
ONSET...DURATION...AND AREAL COVERAGE...DECIDED TO GO WITH ONLY
CHANCE POPS AT THIS TIME. BASED ON THE LATEST MODEL DATA...THE FRONT
COULD EITHER REMAIN STALLED ACROSS THE AREA...ECMWF...OR DRIFT
SLOWLY NORTH AS A WEAK WARM FRONT...GFS...DURING THE MONDAY INTO
MONDAY NIGHT TIME FRAME. ONLY TIME WILL TELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 621 AM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING AS HIGH PRESSURE
PUSHES EAST ACROSS THE AREA. A DEVELOPING LOW PRESSURE SYSTEM WILL
SPREAD MOISTURE BACK INTO EASTERN KENTUCKY LATE TONIGHT...WITH CIGS
LOWERING. AS OF RIGHT NOW...LOOKS LIKE WE SHOULD SEE A GRADIENT IN
THE LOWER CIGS WITH THE LOWEST (IFR/MVFR) IN THE EAST...TRAILING
BACK TO VFR IN THE WEST. WE WILL ALSO SEE PRECIPITATION SPREAD INTO
THE AREA...MAINLY ACROSS SOUTHEASTERN KENTUCKY...WITH A MIX OF RAIN
AND SNOW...LIKELY BECOMING ALL SNOW. THIS WILL RESTRICT VISIBILITIES
BY LATE TONIGHT AS WELL...MAINLY AT KJKL AND KSJS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
750 AM EST TUE NOV 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE NOV 25 2014
CONCERNS FOCUS MAINLY ON LES TRENDS AND HEADLINES THIS MORNING.
LATEST WATER VAPOR LOOP AND RUC ANALYSIS SHOWS STRONG SHORTWAVE AND
ASSOC STORM SYSTEM LIFTING RAPIDLY NE THROUGH NRN QUEBEC EARLY THIS
MORNING AS A STRONG PACIFIC SHORTWAVE AND ASSOC 150 KT 3H JET MAX
PLOWS EAST THROUGH SRN BRITISH COLUMBIA AND SRN ALBERTA. SUBSEQUENT
MOVEMENT OF THESE TWO SHORTWAVE FEATURES ALLOWING MID-UPR LVL TROUGH
TO WEAKEN OVER THE UPPER GREAT LAKES THIS MORNING. THE WEAKENING
TROUGH AND MID-LVL DRYING FM THE WEST AS NOTED ON MODEL SNDGS HAS
ALLOWED SNOW AND LAKE ENHANCED SNOW TO DIMINISH FROM THE WEST AND
SOUTHWEST PER LATEST RADAR LOOP AND SFC OBS. AS A RESULT...HAVE
CANCELLED LES ADVISORIES OVER THE WESTERN COUNTIES AND WINTER WX
ADVISORY OVER MNM COUNTY THIS MORNING. LES CONTINUES OVER MUCH OF
THE REST OF THE ERN HALF OF THE FCST AREA WHERE LES ADVISORIES
REMAIN IN PLACE INTO EARLY AFTERNOON.
EXPECT THE LES TO GRADUALLY DIMINISH OVER THE ERN COUNTIES LATE THIS
MORNING INTO EARLY AFTERNOON AS DEEP MOISTURE AND MODERATE Q-VECT
CONVERGENCE PULLS NE WITH MOVEMENT OF QUEBEC SHORTWAVE AND CONTINUED
WEAKENING OF ASSOC MID-LVL/SFC TROUGH INTO THE UPPER LAKES. BEHIND
THE WEAKENED TROUGH...MODELS INDICATE FC RIDGE BUILDING IN FM WEST
WITH BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY
REMAINING LES TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE LATE
THIS AFTERNOON AND TONIGHT. AS SUCH...WILL MAINTAIN CHANCE POPS FOR
MUCH OF TODAY AND INTO TONIGHT ACROSS THE KEWEENAW BUT END THE POPS
ACROSS THE FAR WEST. WILL MAINTAIN HIGHER POPS ALONG LAKE SUPERIOR
SHORELINE FAR EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY.
EXPECT ADDITIONAL SNOW ACCUMULATION OF 2 TO LOCALLY 4 INCHES FOR
AREAS ROUGHLY ALONG AND EAST OF A LINE FM HURON MTNS/BIG BAY THROUGH
MQT TO RAPID RIVER WITH THE HIGHER ACCUMS ALONG HIGHER TERRAIN NEAR
LAKE SUPERIOR. ELSEWHERE SNOW WILL TAPER OFF FM A DUSTING TO HALF AN
INCH.
HIGH TEMPS TODAY WILL RANGE FROM THE LOWER 20S INTERIOR WEST TO
UPPER 20S EAST HALF AND OVER THE TIP OF THE KEWEENAW. POTENTIAL FOR
TEMPS TO PLUMMET NEAR ZERO TONIGHT OVER THE TYPICAL COLD SPOTS OF
THE WEST AND CENTRAL INTERIOR AS RIDGE MOVING OVERHEAD WILL RESULT
IN LIGHT WINDS AND CLEARING SKIES. FAVORED LOWER END OF MODEL TEMP
GUIDANCE USING A BLEND OF BIAS-CORRECTED ECMWF AND GEM-NH TEMPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014
...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...
BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.
MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.
INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.
ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.
ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.
BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 740 AM EST TUE NOV 25 2014
IFR CONDITIONS AT KSAW WILL IMPROVE TO MVFR BY LATE MORNING AND TO
VFR BY LATE AFTERNOON AS DRIER AIR MOVES IN FM THE WEST. MVFR
CONDITIONS AS BOTH KIWD AND KCMX WILL IMPROVE TO VFR LATE
AFTERNOON/EARLY EVENING AS BACKING WINDS PUSH LAKE EFFECT SNOW BANDS
WELL OFFSHORE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EST TUE NOV 25 2014
STRONG LOW PRESSURE CONTINUES TO MOVE NE THROUGH NRN QUEBEC TODAY AS
THE GRADIENT GRADUALLY SLACKENS OVER LAKE SUPERIOR. NORTH WINDS HAVE
SUBSIDED BLO GALES OVER ERN LAKE SUPERIOR SO GALE WARNING HAS BEEN
CANCELLED. N-NW WINDS 25-30 KNOTS WILL QUICKLY DIMINISH BLO 20 KNOTS
BY THIS AFTERNOON. GENERALLY QUIET WEATHER EXPECTED FOR THE
REMAINDER OF THE WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH
OF THE LAKE WED AY ALLOW FOR N-NE WINDS TO BRIEFLY GUST NEAR GALE
FORCE WED NIGHT INTO EARLY THU. HIGH PRESSURE BY THE WEEKEND SHOULD
ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ004-005.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 AM EST TUE NOV 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE NOV 25 2014
CONCERNS FOCUS MAINLY ON LES TRENDS AND HEADLINES THIS MORNING.
LATEST WATER VAPOR LOOP AND RUC ANALYSIS SHOWS STRONG SHORTWAVE AND
ASSOC STORM SYSTEM LIFTING RAPIDLY NE THROUGH NRN QUEBEC EARLY THIS
MORNING AS A STRONG PACIFIC SHORTWAVE AND ASSOC 150 KT 3H JET MAX
PLOWS EAST THROUGH SRN BRITISH COLUMBIA AND SRN ALBERTA. SUBSEQUENT
MOVEMENT OF THESE TWO SHORTWAVE FEATURES ALLOWING MID-UPR LVL TROUGH
TO WEAKEN OVER THE UPPER GREAT LAKES THIS MORNING. THE WEAKENING
TROUGH AND MID-LVL DRYING FM THE WEST AS NOTED ON MODEL SNDGS HAS
ALLOWED SNOW AND LAKE ENHANCED SNOW TO DIMINISH FROM THE WEST AND
SOUTHWEST PER LATEST RADAR LOOP AND SFC OBS. AS A RESULT...HAVE
CANCELLED LES ADVISORIES OVER THE WESTERN COUNTIES AND WINTER WX
ADVISORY OVER MNM COUNTY THIS MORNING. LES CONTINUES OVER MUCH OF
THE REST OF THE ERN HALF OF THE FCST AREA WHERE LES ADVISORIES
REMAIN IN PLACE INTO EARLY AFTERNOON.
EXPECT THE LES TO GRADUALLY DIMINISH OVER THE ERN COUNTIES LATE THIS
MORNING INTO EARLY AFTERNOON AS DEEP MOISTURE AND MODERATE Q-VECT
CONVERGENCE PULLS NE WITH MOVEMENT OF QUEBEC SHORTWAVE AND CONTINUED
WEAKENING OF ASSOC MID-LVL/SFC TROUGH INTO THE UPPER LAKES. BEHIND
THE WEAKENED TROUGH...MODELS INDICATE FC RIDGE BUILDING IN FM WEST
WITH BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY
REMAINING LES TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE LATE
THIS AFTERNOON AND TONIGHT. AS SUCH...WILL MAINTAIN CHANCE POPS FOR
MUCH OF TODAY AND INTO TONIGHT ACROSS THE KEWEENAW BUT END THE POPS
ACROSS THE FAR WEST. WILL MAINTAIN HIGHER POPS ALONG LAKE SUPERIOR
SHORELINE FAR EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY.
EXPECT ADDITIONAL SNOW ACCUMULATION OF 2 TO LOCALLY 4 INCHES FOR
AREAS ROUGHLY ALONG AND EAST OF A LINE FM HURON MTNS/BIG BAY THROUGH
MQT TO RAPID RIVER WITH THE HIGHER ACCUMS ALONG HIGHER TERRAIN NEAR
LAKE SUPERIOR. ELSEWHERE SNOW WILL TAPER OFF FM A DUSTING TO HALF AN
INCH.
HIGH TEMPS TODAY WILL RANGE FROM THE LOWER 20S INTERIOR WEST TO
UPPER 20S EAST HALF AND OVER THE TIP OF THE KEWEENAW. POTENTIAL FOR
TEMPS TO PLUMMET NEAR ZERO TONIGHT OVER THE TYPICAL COLD SPOTS OF
THE WEST AND CENTRAL INTERIOR AS RIDGE MOVING OVERHEAD WILL RESULT
IN LIGHT WINDS AND CLEARING SKIES. FAVORED LOWER END OF MODEL TEMP
GUIDANCE USING A BLEND OF BIAS-CORRECTED ECMWF AND GEM-NH TEMPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014
...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...
BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.
MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.
INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.
ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.
ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.
BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EST TUE NOV 25 2014
IFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT BEFORE IMPROVING
TO MVFR ON TUESDAY AS DRIER AIR MOVES IN. BY LATE AFTERNOON INTO
EARLY EVENING...VFR CONDITIONS WILL PREVAIL AT ALL SITES AS WINDS
PUSH LAKE EFFECT SNOW BANDS WELL OFFSHORE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EST TUE NOV 25 2014
STRONG LOW PRESSURE CONTINUES TO MOVE NE THROUGH NRN QUEBEC TODAY AS
THE GRADIENT GRADUALLY SLACKENS OVER LAKE SUPERIOR. NORTH WINDS HAVE
SUBSIDED BLO GALES OVER ERN LAKE SUPERIOR SO GALE WARNING HAS BEEN
CANCELLED. N-NW WINDS 25-30 KNOTS WILL QUICKLY DIMINISH BLO 20 KNOTS
BY THIS AFTERNOON. GENERALLY QUIET WEATHER EXPECTED FOR THE
REMAINDER OF THE WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH
OF THE LAKE WED AY ALLOW FOR N-NE WINDS TO BRIEFLY GUST NEAR GALE
FORCE WED NIGHT INTO EARLY THU. HIGH PRESSURE BY THE WEEKEND SHOULD
ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ004-005.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
545 AM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 545 AM CST TUE NOV 25 2014
FURTHER MONITORING OF SATELLITE TRENDS NECESSITATES INCREASING
CLOUD COVER FASTER THAN IN THE 3 AM FCST ISSUANCE. THERE IS A LOT
OF THICK CIRROSTRATUS/ALTOSTRATUS/ALTOCU UPSTREAM AND IT IS NOT
SHOWING ANY SIGNS OF THINNING. SO SKY COVER WAS INCREASED FURTHER.
BASED ON THIS...HIGH TEMPS WERE ALSO LOWERED 2-4F AND THAT MAY NOT
BE ENOUGH GIVEN HOW COLD TEMPS ARE RIGHT NOW. WHILE WAA WILL BE IN
PROGRESS...IT`S ALWAYS HARD TO FIGHT THE EFFECTS OF THICK CLOUD
COVER. WE NOW HAVE 43-50F WITH MID 40S IN THE TRI-CITIES VS.
45-53F WITH UPR 40S IN THE TRI-CITIES.
THE CANADIAN GEM DOES WELL IN THESE "SURPRISE" TEMP REGIMES AND IT
MAY WELL BE ONTO THIS. IT HAS 40-47F WITH 42-44F TRI-CITIES.
SUFFICE TO SAY FURTHER DOWNWARD REFINEMENTS MAY BE FORTHCOMING BY
THE DAY SHIFT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 545 AM CST TUE NOV 25 2014
...BECOMING CLOUDY WITH ANOTHER LIGHT PRECIP EVENT LATE THIS
AFTERNOON/EVE FOLLOWED BY MORE WIND...
ALOFT: THE FLOW WAS HIGHLY AMPLIFIED WITH A LONGWAVE TROF OVER
THE CNTRL USA AND RIDGES JUST OFF BOTH COASTS. WV IMAGERY SHOWED A
SHORTWAVE TROF OVER ALBERTA. THIS TROF WILL DIVE SE INTO THE
DAKOTAS TODAY AND INTO NEB/KS TONIGHT...DEEPENING OVER TIME WITH A
GOOD SHOT OF QG FORCING IN THE EXIT REGION OF A 150 KT UPR-LVL JET.
SURFACE: A CLIPPER LOW WAS ORGANIZING OVER ALBERTA. THIS LOW WILL
RACE INTO THE DAKOTAS TODAY AND BE LOCATED OVER WRN IA BY DAYBREAK
WED. ITS COLD FRONT WILL SWEEP THRU TONIGHT.
TODAY: WAA WILL CONT IN THE WARM SECTOR OF THE CLIPPER. MORNING
SUN WILL RAPIDLY BE OBSCURED BY INCREASING AND DESCENDING MID-HIGH
CLOUDS. ONE WEAKNESS IN THIS FCST IS THAT CLOUDS MAY COME IN THICK
FASTER THAN CURRENTLY DEPICTED. I.E. WE MAY NOT BE PESSIMISTIC
ENOUGH. THAT IS A DENSE CIRRUS SHIELD ON SATELLITE IMAGERY.
MODEL CONSENSUS INCLUDING HI-RES MODELING INDICATE A SWATH OF
FGEN-ENHANCED LIGHT RAIN AND/OR SPRINKLES WILL DEVELOP AND CROSS
THE FCST AREA FROM 3PM-12AM. SPRINKLES ARE MOST LIKELY ON THE SRN
FRINGE OF THE PRECIP SHIELD. INCLUDED SPRINKLES S AND W OF THE
MODEL CONSENSUS OF .01" QPF AS SOME SREF MEMBERS DO HINT AT THE
POSSIBILITY OF RAIN OUTSIDE OF THE BEST MODEL CLUSTERING.
USED THE 05Z BIAS CORRECTED RAP FOR HIGHS TODAY WHICH SEEMS TO
HAVE A BETTER GRASP ON WHERE THICKER CLOUDS WILL ARRIVE FROM THE
N. DESPITE THE CLOUDS SHOULD BE A MILD DAY WITH TEMPS AT OR
SLIGHTLY ABOVE NORMAL.
THERE IS CONSIDERABLE UNCERTAINTY IN DWPTS/RH TODAY WITH 10F OF
SPREAD BETWEEN THE MAV/MET MOS. USED CONSENSUS OF SHORT-TERM HI-
RES MODELS WHICH WERE NOT THE LOWEST BUT DID FAVOR THE DRIER MAV
MOS. THIS WILL WORK BEST OUTSIDE WHERE IT RAINS...BUT MOISTENING
FROM RAINFALL WILL INCREASE DWPTS LOCALLY.
TONIGHT: SWATH OF RAIN/SPRINKLES EXITS TO THE E BY MIDNIGHT.
STRONG CAA KICKS IN AFTER PASSAGE OF THE COLD FRONT WITH A CORE OF
50 KT WINDS AT 850 MB. OUTPUT FROM THE WIND GUST TOOL SEEMED TOO
LOW SO USED GUSTS FROM A BLEND OF THE 18Z/00Z RAW MODEL GUIDANCE
/CONSRAW/. NW WINDS WILL GUST 30-35 KTS N OF HWY 6 BEGINNING 3 AM.
WITH 40 KTS AS LOW AS 1500 FT...CAN`T RULE OUT ISOLATED HIGHER
GUSTS.
P-TYPE: KEPT IT PRIMARILY RAIN/SPRINKLES EXCEPT ON THE EXTREME
NE/E FRINGES OF THE FCST AREA 07Z-08Z ON THE BACK EDGE OF THE
PRECIP...IF IT`S STILL FALLING BY THEN. NAM P-TYPE ALGORITHM KEEPS
IT ALL RAIN AND FCST SOUNDINGS SUGGEST THE LEFTOVER DAYTIME BL
WILL BE TOO WARM TO SUPPORT SNOW. EVEN WETBULB TEMPS FAVOR RAIN
WITH +2 UP TO 1K FT. CURRENT INDICATIONS ARE THAT THE PRECIP
SHOULD BE OVER BY THE TIME TEMP PROFILES COOL ENOUGH FOR SNOW.
MODEL 2M TEMPS SUGGEST A FAIRLY MILD NIGHT WITH LOWS 27-38F AND
30-31F IN THE TRI-CITIES. EVEN THE MOS 3-HOURLY TEMPS SUGGEST
THIS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE NOV 25 2014
WE ARE CALLING FOR A DRY FORECAST FROM START TO FINISH THIS
HOLIDAY WEEKEND. THE PRIMARY FORECAST CONCERN WILL CENTER AROUND
SEVERAL BIG TEMPERATURE SWINGS. EXPECT TWO COLD AIR OUTBREAKS...
ONE ON WEDNESDAY LASTING INTO THANKSGIVING DAY...AND A SECOND SHOT
OF COLD AIR TO FINISH THE HOLIDAY WEEKEND ON SUNDAY. HOWEVER...
FRIDAY AND SATURDAY CURRENTLY APPEAR TO BE WARM WITH HIGHS WELL
ABOVE NORMAL.
WEDNESDAY...A COLD FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW
COOLER AIR TO FILTER INTO OUR REGION THROUGHOUT THE DAY. THEREFORE
...TEMPERATURES WILL WARM VERY LITTLE IF AT ALL DURING THE DAYTIME
HOURS. WE CAN NOT RULE OUT A FLURRY OR TWO WITH A LITTLE 850/700
MB MOISTURE AND COOLER AIR SETTLING IN. HOWEVER...FORECAST MODELS
CONTINUE TO BE IN GOOD AGREEMENT IN 0.00 QPF AND THE CHANCE OF
FLURRIES IS STILL TOO LOW TO INCLUDE MENTION IN THE FORECAST.
THERE COULD BE A PRETTY GOOD TEMPERATURE CONTRAST ACROSS THE
FORECAST AREA AS THE COLD AIR WILL HANG UP MORE OVER NEBRASKA.
THEREFORE...EXPECT HIGHS ON WEDNESDAY SHOULD RANGE FROM THE 30S
ACROSS SOUTH CENTRAL NEBRASKA TO THE LOWER 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...FORECAST MODELS ARE IN INCREASINGLY GOOD AGREEMENT
THAT WE WILL SLOWLY START TO WARM BACK UP ON THANKSGIVING DAY. AN
UPPER RIDGE WILL BEGIN TO WORK ITS WAY EAST INTO THE FORECAST AREA
BRINGING WARMER AIR ALOFT. AT THE SFC...THE WIND WILL TURN TO
SOUTHERLY AND WILL ALSO RESULT IN WARM AIR ADVECTION. THE WARMING
WILL BE GRADUAL ON THANKSGIVING WITH ONLY A FEW DEGREE RISE
EXPECTED OVER WEDNESDAY HIGHS...BUT THE WARM UP WILL INCREASE AS
WE HEAD INTO FRIDAY. AS FOR THANKSGIVING...EXPECT HIGHS IN THE
UPPER 30S NORTHEASTERN ZONES...TO AROUND 40 IN THE TRI-CITIES...TO
THE MID AND UPPER 40S OVER NORTH CENTRAL KANSAS.
FRIDAY AND SATURDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN PORTIONS OF THE DAKOTAS AND IN
CANADA. THIS WILL ALSO KEEP THE STORM TRACK WELL TO OUR NORTH
RESULTING IN CONTINUED DRY CONDITIONS. THERE IS HIGH CONFIDENCE IN
FRIDAY BEING A VERY NICE DAY WITH WARM AIR ADVECTION BOTH ALOFT
AND AT THE SFC. THE SFC WINDS WILL BE FAIRLY LIGHT BUT SHOULD HAVE
A BIT OF A DOWNSLOPE WARMING COMPONENT TO IT BEING OUT OF THE WEST
TO SOUTHWEST. ALL IN ALL EXPECT A VERY NICE DAY WITH HIGHS IN THE
MID TO UPPER 50S IN THE TRI-CITIES TO THE LOWER 60S OVER PORTIONS
OF NORTH CENTRAL KANSAS. FORECAST MODELS ARE COMING INTO BETTER
AGREEMENT WITH THE COLD FRONTAL PASSAGE TIMING ON SATURDAY.
OVERALL FORECAST MODELS HAVE LARGELY SLOWED DOWN THE COLD FRONT
AND BRING IT THROUGH OUR FORECAST AREA SATURDAY EVENING OR
SATURDAY NIGHT. THIS WILL ALLOW FOR FULL DIURNAL HEATING UNDER A
CONTINUED WARM AIR MASS WHICH SHOULD HELP ALL AREAS GET INTO THE
UPPER 50S TO LOWER 60S. THE 00Z ECMWF EVEN INDICATES A FEW SPOTS
COULD HIT 70 SATURDAY AFTERNOON. EVERYTHING HINGES ON THE TIMING
OF THE COLD FRONT...BUT RIGHT NOW SATURDAY APPEARS TO BE A GREAT
DAY TO GET OUT AND ENJOY BEFORE THE NEXT COLD SNAP HITS.
SUNDAY AND MONDAY...THERE IS CURRENTLY DECENT FORECAST AGREEMENT
BETWEEN THE 00Z GFS AND 00Z ECMWF THAT A PRETTY POTENT COLD AIR
MASS WILL OVERSPREAD THE AREA SATURDAY NIGHT INTO SUNDAY. IT
SHOULD BE A DRY FRONTAL PASSAGE SO WE ARE NOT REALLY WORRIED ABOUT
SNOW...BUT IT DOES APPEAR TO BE COLD. OUR FORECAST HIGHS BASED OFF
THE SUPERBLEND OF MODELS RANGE FROM THE UPPER 20S IN ORD TO THE
30S ELSEWHERE AND THIS MAY BE OPTIMISTICALLY TOO WARM IF YOU
BELIEVE THE DETERMINISTIC 00Z GFS AND ECMWF MODEL RUNS. THERE IS A
HIGH LEVEL OF UNCERTAINTY AS TOO HOW LONG THE COLD AIR WILL LINGER
ACROSS THE AREA AS THE 00Z GFS IS MUCH QUICKER TO PUSH THE COLD
AIR OUT ON MONDAY THAN THE 00Z ECMWF.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WED MORNING)
ISSUED AT 545 AM CST TUE NOV 25 2014
TODAY: THICK MULTI-LAYERED VFR CIGS INVADE AROUND 18K FT AND
CASCADE DOWNWARD THRU THE DAY TO AROUND 6K FT BY SUNSET. LIGHT
SW-W WINDS WILL BECOME SW AND INCREASE...GUSTING 20-23 KTS AT
TIMES PRIMARILY AFTER 18Z. CONFIDENCE: HIGH
TONIGHT: VFR CIGS WITH A BRIEF VFR SHWR POSSIBLE 00Z-03Z. THEN A
COLD FRONTAL PASSAGE 03Z-05Z. MVFR CIGS APPEAR PROBABLE...BUT NOT
ALL GUIDANCE IS ON BOARD YET. NW WINDS WILL GUST 25-33 KTS.
CONFIDENCE: MEDIUM DUE TO UNCERTAINTY ON POSSIBLE MVFR CIGS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
925 AM EST TUE NOV 25 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE BY MID-MORNING. LOW PRESSURE WILL
FORM ON THE FRONT AND MOVE NORTH ALONG THE NORTH CAROLINA COAST ON
WEDNESDAY. A WEAK BOUNDARY WILL MOVE THROUGH THE AREA ON THURSDAY.
HIGH PRESSURE WILL BUILD INTO THE AREA FRIDAY AND REMAIN THROUGH
THE WEEKEND. A COLD FRONT WILL DROP THROUGH THE AREA MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 921 AM TUE...FRONT OVER THE CENTRAL PART OF NORTH CAROLINA
WILL MOVE SLOWLY EASTWARD AND AS PER HRRR WILL CROSS EASTERN NORTH
CAROLINA DURING THE EARLY AFTERNOON HOURS. LINE OF SHOWERS OVER
EASTERN NORTH CAROLINA WILL ONLY SLOWLY MOVE EASTWARD IN DEEP
LAYERED SOUTHWEST FLOW. BLENDED PRECIPITABLE WATER VALUES AVERAGE
ABOUT 1.5 INCHES. HEAVIER SHOWERS PRODUCING UP TO AN INCH OF RAIN IN
AN HOUR. ISOLATED THUNDERSTORMS ARE ALSO SEEN ON RADAR. UPPER LEVEL
ENERGY WILL REMAIN OVER THE AREA THROUGH THE DAY AND AS SURFACE
FRONT APPROACHES...EXPECT AN INCREASE IN PRECIPITATION COVERAGE.
TEMPERATURES ARE CURRENTLY IN THE 60S. WITH CLOUD COVER...
PRECIPITATION...AND PASSAGE OF COLD FRONT...AM NOT EXPECTING MUCH OF
AN INCREASE IN TEMPERATURES THROUGH THE DAY. WE MAY HAVE ALREADY
REACHED OUR HIGH TEMPERATURES.
&&
.SHORT TERM / WEDNESDAY THROUGH 6 AM WEDNESDAY/...
AS OF 335 AM TUESDAY...MAIN WAVE OF LOW PRESSURE DEVELOPS AND
RAPIDLY STRENGTHENS EAST OF THE NORTH CAROLINA COAST BY LATE
TONIGHT AND EARLY WEDNESDAY MORNING. EXPECT WIDESPREAD RAIN WITH
GUSTY NORTHERLY WINDS DEVELOPING AFTER MIDNIGHT. TEMPERATURES WILL
BE COOLER WITH CANADIAN AIR FILTERING IN BEHIND THE DEPARTING LOW.
EXPECT MINIMUM TEMPERATURES TONIGHT IN THE MID 40S INLAND TO MID
50S OUTER BANKS. POPS ARE CATEGORICAL AND SOME AREAS...ESPECIALLY
NEAR THE COAST COULD RECEIVE 1 TO 2 INCHES OF RAINFALL.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ACTIVE WEATHER AT THE BEGINNING OF THE LONG TERM FORECAST PERIOD
THEN SETTLING IN TO A MORE BENIGN WEATHER PATTERN STARTING LATE IN
THE WEEK AND THROUGH THE WEEKEND. A DEEP UPPER TROUGH MOVES THROUGH
THE EASTERN STATES WED/THU THEN THE UPPER FLOW TRANSITIONS TO A MORE
ZONAL FLOW THROUGH EARLY NEXT WEEK.
DEEPENING SFC LOW PRESSURE WILL BE SKIRTING THE NC COAST WEDNESDAY
BEFORE LIFTING NORTHEAST OF THE OUTER BANKS LATE IN THE DAY. A SOLID
AREA OF MODERATE RAIN IN THE BAROCLINIC ZONE OVER EASTERN NORTHERN
WILL SWEEP THROUGH THE AREA THROUGH MIDDAY THEN RAIN CHANCES WILL
BEGIN TO TAPER OFF FROM SW TO NE DURING THE AFTERNOON. AN ADDITIONAL
1-3 INCHES OF RAIN IS LIKELY THROUGH WEDNESDAY AND THIS MAY LEAD TO
MINOR/LOCALIZED FLOODING DURING THIS BUSY TRAVEL PERIOD BUT
WIDESPREAD FLOOD PROBLEMS NOT EXPECTED. OTHER THAN FOR COASTAL
AREAS, THERE WONT BE MUCH OF A DIURNAL TEMPERATURE RISE WITH
READINGS STUCK IN THE MID AND UPPER 40S AWAY FROM THE COAST WED.
DEPENDING ON THE EXACT TRACK OF THE LOW, WARM SECTOR TEMPS MAY RISE
INTO THE 60S ALONG THE COAST.
LOW LEVEL DRIER AIR WILL FILTER INTO THE AREA ON NW WINDS AS THE SFC
LOW MOVES WELL TO THE NE WED NIGHT INTO THURSDAY. THE PASSAGE OF A
MID LEVEL TROUGH JUST TO THE NORTH MAY PROVIDE SOME MID LEVEL
CLOUDINESS BUT EXPECT ANY PRECIP TO REMAIN NORTH OF THE FORECAST
AREA LATE WED NIGHT THRU THURSDAY. COLD AIR ADVECTION WILL DROP
TEMPS INTO THE MID 30S INLAND AND LOW 40S COAST WED NIGHT WITH HIGHS
ON THURSDAY MAINLY IN THE LOW 50S. ALSO A SECONDARY SURGE OF CAA
WILL ACCOMPANY THE PASSAGE OF THE MID LEVEL TROF WITH TEMPS
REMAINING WELL BLO NORMAL THURSDAY NIGHT THRU FRIDAY NIGHT.
A GRADUAL WARMING TREND AND A CONTINUATION OF DRY WEATHER WILL
HIGHLIGHT WEATHER DURING THE WEEKEND AND INTO EARLY NEXT WEEK AS SFC
HIGH PRESSURE TRANSITS THROUGH THE AREA. TEMPERATURES RETURN TO NEAR
OR EVEN A LITTLE ABOVE NORMAL SUNDAY AND POSSIBLY INTO MONDAY. MODEL
CONCENSUS FAVORS A WEAK/DRY COLD FRONT PASSAGE LATE MONDAY WHICH MAY
KNOCK TEMPS BACK A FEW DEGS MON NIGHT INTO TUESDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 640 AM TUESDAY...GENERALLY VFR CONDITIONS CONTINUES AT THE TAF
SITES. AS RAIN COVERAGE INCREASES WITH APPROACH OF COLD
FRONT...EXPECT CEILINGS AND VSBYS TO LOWER BY MID MORNING TO MVFR
WITH WIDESPREAD IFR BY LATE AFTERNOON INTO TONIGHT. A STEADY
RAINFALL SHOULD KEEP CONDITIONS IN IFR RANGE INTO WEDNESDAY MORNING.
GUSTY NORTH TO NORTHWEST WINDS ARE LIKELY BY LATE TONIGHT.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A SOLID AREA OF RAIN WILL BRING LIKELY IFR CONDITIONS AT LEAST THRU
MIDDAY WEDNESDAY. MAY BEING TO SEE IMPROVING CONDITIONS AS THE SFC
LOW MOVES NE OF THE AREA WED AFTERNOON BUT MAY NOT SEE VFR
CONDITIONS RETURNING UNTIL LATE IN THE DAY. THEREAFTER EXPECT A
PROLONGED PERIOD OF MAINLY VFR CONDITIONS AS SFC HIGH PRESSURE
GRADUALLY APPROACHES DURING THE LATTER PART OF THE WEEK THEN
TRANSITS THE AREA DURING THE WEEKEND. MAY SEE PERIODS OF LATE NIGHT
PATCHY FOG OVER THE WEEKEND.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 924 AM TUE...GENERALLY SOUTHWESTERLY FLOW OVER THE NORTH
CAROLINA COASTAL WATERS THIS MORNING AHEAD OF APPROACHING COLD
FRONT. SPEEDS ARE 10 KNOTS OR LESS AND SEAS 4 TO 6 FEET. SMALL CRAFT
ADVISORY IS IN EFFECT. WINDS WILL INCREASE ASSOCIATED WITH THE COLD
FRONTAL PASSAGE IN THE EARLY AFTERNOON HOURS. WIND WIND SHIFT TO
NORTHERLY BEHIND THE FRONT.
STILL APPEARS THAT THERE WILL BE SEVERAL HOURS LATER THIS
EVENING/TONIGHT WHERE SEAS DROP TO BELOW 6 FEET...BUT WILL CONTINUE
SMALL CRAFT ADVISORY INTO LATE WEEK...AS GUSTY N/NW WINDS WILL
DEVELOP ON THE BACKSIDE OF THE STRENGTHENING LOW OFF THE NC COAST
LATER TONIGHT WITH SEAS...PER LATEST LOCAL NWPS/SWAN
MODEL...BUILDING TO 6 TO 9 FEET OVER THE NORTHERN WATERS AND AROUND
6 FEET SOUTHERN WATERS AFTER MIDNIGHT.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ACTIVE MARINE WEATHER EARLY THIS FORECAST PERIOD AS DEEPENING SFC
LOW PRES SKIRTS THE COAST. MAY SEE SOME GALE FORCE WINDS, MAINLY IN
GUSTS OVER THE NORTHERN AND CENTRAL COASTAL WATERS AS THE
INTENSIFYING LOW MOVES NE OF THE AREA WEDNESDAY. SOLID SMALL CRAFT
ADVISORY LEVEL WINDS LIKELY CONTINUE WED NIGHT THRU THURSDAY BEFORE
BEGINNING TO DIMINISH AS HIGH PRESSURE BUILDS EAST ON FRIDAY. SEAS
PEAK 10-12 FT WEDNESDAY THEN SLOWLY SUBSIDE BUT MAY REMAIN ABV 6 FT
OVER THE OUTER COASTAL WATERS THRU FRIDAY.
WINDS SHIFT W/SW AND GRADUALLY INCREASE AGAIN AS HIGH PRESSURE MOVES
OFFSHORE DURING THE WEEKEND. SW WINDS MAY AGAIN BEGIN TO APPROACH
SMALL CRAFT ADVISORY LEVELS ON SUNDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST WEDNESDAY FOR
AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR AMZ150-152-
154-156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CGG
SHORT TERM...CTC
LONG TERM...BTC
AVIATION...CTC/BTC
MARINE...CGG/CTC/BTC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
941 AM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 928 AM CST TUE NOV 25 2014
IR SATELLITE LOOPS SHOW VORT MAX JUST NORTHWEST OF WILLISTON MOVING
SOUTHEAST AS RUC13 MODEL SHOWS. TRACK OF THIS VORT SHOULD DEFINE
THE HEAVIEST SNOW BAND FOR THE REMAINING MORNING HOURS FROM
WILLISTON TO GARRISON AND NORTH. LIGHTER SNOW SOUTHWEST OF THIS
LINE. WILLISTON SHOWING ONE HALF MILE VSBY IN MODERATE SNOW AT 9
AM CST. SNOW RATES SHOULD BEGIN TO LIGHTEN NORTHWEST ND AS THE
VORT LOBE MOVES PAST LATE THIS AM.
UPDATE ISSUED AT 630 AM CST TUE NOV 25 2014
FORECAST IS ON TRACK. REGIONAL RADARS SHOWS AREA OF SNOW MOVING
INTO EASTERN MONTANA WITH THE MOST RECENT BAKER OB REPORTING SNOW.
CEILINGS CONTINUE TO LOWER ACROSS WESTERN ND LOCATIONS AND
MARMARTH ND DOT WEB CAM NOW SHOWS SNOWFALL OCCURRING. BOWMAN RADAR
ALSO SHOWS STRONGER ECHOES ACROSS THE SOUTHWEST. ONLY CHANGES WERE
TO BLEND FORECAST TO MOST RECENT OBSERVATIONS...OTHERWISE EXPECT
SNOW TO CONTINUE EXPANDING EASTWARD THROUGH THE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CST TUE NOV 25 2014
HIGHLIGHTS INCLUDE A WINTER WEATHER ADVISORY TO BE ISSUED FOR SNOW
AMOUNTS TODAY AND TONIGHT AND GUSTY WINDS TONIGHT.
THE FORECAST CHALLENGE IN THE SHORT TERM WILL BE SNOW AMOUNTS TODAY
AND TONIGHT.
CURRENTLY A SURFACE LOW PRESSURE CENTER WAS OVER SOUTHERN ALBERTA.
AT UPPER LEVELS A FAST-MOVING SHORTWAVE IN THE NORTHWEST FLOW ALOFT
WAS COINCIDENT WITH THE SURFACE LOW. AS THE SHORTWAVE DIVES
SOUTHEAST ACROSS THE DAKOTAS TODAY AND INTO THIS EVENING...THE
SURFACE LOW/CLIPPER WILL ALSO TRACK SOUTHEAST QUICKLY ACROSS THE
REGION. THIS SCENARIO WILL CREATE A STRONG BAROCLINIC ZONE ORIENTED
NORTHWEST-TO-SOUTHEAST ACROSS NORTH DAKOTA. AS THE SYSTEM TRACKS
ACROSS THE STATE...THE BEST LIFT/INSTABILITY WILL BE ALONG AND
NORTHEAST OF THE SURFACE LOW TRACK. MEANWHILE SOUTHWEST OF THE LOW
TRACK (SOUTHWESTERN QUARTER OF ND) WILL BE IN THE WARM SECTOR OF THE
SYSTEM...AND SURFACE TEMPERATURES SHOULD REACH INTO THE LOWER 30S
THERE TODAY. THUS THE SOUTHWEST WILL SEE A RAIN/SNOW MIX...WHILE
LIGHT TO MODERATE SNOW WILL OCCUR ACROSS NORTHWESTERN AND CENTRAL
NORTH DAKOTA.
THE SNOW IS EXPECTED TO BEGIN BEFORE DAYBREAK IN THE FAR
WEST...BECOME MORE INTENSE WITH TIME AS THE FAVORED SNOW BANDS
APPROACH CENTRAL NORTH DAKOTA CLOSER TO NOON...AND CONTINUE THIS
EVENING OVER CENTRAL/EASTERN NORTH DAKOTA. CURRENT MODEL RUNS ARE IN
BETTER AGREEMENT FOR PLACEMENT AND TIMING. THUS EXPECTING 3-4 INCHES
OF SNOW IN AN ARC/LINE FROM CROSBY IN THE FAR NORTHWEST...TO
STANLEY/MINOT/BOTTINEAU TO BISMARCK/JAMESTOWN AND LINTON/OAKES.
AROUND 1.5 TO 2.5 INCHES OF SNOW IS FORECAST FOR MAINLY SOUTH AND
WEST OF THE MISSOURI RIVER...AND IN THE TURTLE MOUNTAINS AREA.
IN ADDITION TO THE SNOW...NORTHWEST WINDS ARE FORECAST TO INCREASE
TO 20 TO 25 MPH THIS AFTERNOON AND EVENING IN THE SOUTHWEST AND INTO
CENTRAL NORTH DAKOTA. ALTHOUGH BLOWING SNOW IS NOT EXPECTED BECAUSE
OF THE FAIRLY WET NATURE OF THE FALLING SNOW...DRIFTING SNOW ACROSS
ROADWAYS COMBINED WITH SNOW-COVERED AND ICY ROADS WILL MAKE FOR
HAZARDOUS TRAVEL.
DECIDED TO ISSUE A WINTER WEATHER ADVISORY FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA. BEGAN THE ADVISORY IN THE WESTERN QUARTER OF
THE STATE THIS MORNING AND ENDED IT THERE AROUND MIDNIGHT TONIGHT.
BEGAN THE ADVISORY FOR CENTRAL NORTH DAKOTA THIS AFTERNOON AND WILL
HAVE IT VALID UNTIL JUST BEFORE SUNRISE WEDNESDAY MORNING...WHEN
WINDS SHOULD BE DECREASING AND SNOW TAPERING TO FLURRIES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 346 AM CST TUE NOV 25 2014
MAIN FORECAST CHALLENGES INVOLVE PERIODIC CHANCES OF PRECIPITATION
AS ACTIVE PATTERN CONTINUES. ON WEDNESDAY...THE STORM SYSTEM WILL
DEPART TO THE SOUTHEAST WITH 1038MB SURFACE HIGH DROPPING
SOUTHWARD ACROSS THE NORTHERN PLAINS. WILL MAINTAIN LOW CHANCE
POPS FOR SNOW ACROSS SOUTHWEST PORTION OF STATE CLOSEST TO SURFACE
LOW/FRONTAL BOUNDARY IN MONTANA. NEXT SYSTEM AFFECTS OUR AREA ON
THURSDAY WITH SURFACE LOW SUPPORTED BY 120KT 300MB JET STREAK
NUDGING IN FROM MONTANA. SNOW TOTALS WITH THIS SYSTEM SHOULD BE IN
THE 1 TO 3 INCH RANGE WITH HIGHEST AMOUNTS EXPECTED ACROSS THE
NORTH NEAR CANADIAN BORDER AND ABOUT 1 TO 2 INCHES ALONG THE I-94
CORRIDOR. MODELS CONTINUE TO INDICATE WARM POCKET ALOFT BEHIND
MAIN BAND OF PRECIP...SO WILL HAVE TO CONTINUE TO MONITOR FOR
POSSIBILITY OF MIX PRECIP TYPE DEVELOPING. ANOTHER SYSTEM MOVES
THROUGH THE AREA FRIDAY/FRIDAY NIGHT WITH A CONTINUED CHANCE OF
LIGHT SNOW...MAINLY NORTH. THIS SYSTEM WILL ALSO PULL ANOTHER SHOT
OF ARCTIC AIR SOUTHWARD RESULTING IN WIND CHILLS IN THE -25 TO
-30F RANGE ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY MORNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY AFTERNOON)
ISSUED AT 928 AM CST TUE NOV 25 2014
SURFACE LOW PRESSURE WILL TRACK FROM NORTHEAST MONTANA THROUGH
WESTERN NORTH DAKOTA TODAY. THE LOW WILL BE THE FOCUS FOR SNOW AND
IFR CONDITIONS SPREADING THROUGH WEST AND CENTRAL NORTH DAKOTA
TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ WEDNESDAY FOR
NDZ003>005-011>013-019>023-025-034>037-042-045>048-050-051.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT
FOR NDZ001-002-009-010-017-018-031>033-040-041-043-044.
&&
$$
UPDATE...WAA
SHORT TERM...JV
LONG TERM...JNS
AVIATION...WAA
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1005 AM CST TUE NOV 25 2014
.UPDATE...
THERE ARE STILL A FEW POCKETS OF SUNSHINE OUT THERE...BUT CLOUDS
CONTINUE TO FILL IN THIS MORNING. LATEST RAP SOUNDINGS INDICATE
MOSTLY CLOUDY SKIES INTO THIS EVENING...SO WILL LIKELY HAVE TO
BUMP UP CLOUD COVER. TEMPERATURES ARE ALREADY WITHIN A FEW DEGREES
OF FORECAST HIGHS...SO NO MAJOR CHANGES EXPECTED WITH TEMPS FOR
THE REMAINDER OF THE DAY.
&&
.AVIATION/18Z TAFS/...
LATEST SOUNDINGS INDICATE LOWER CLOUDS MAY STICK AROUND INTO THE
EVENING...OR POSSIBLY LATER. WILL CONTINUE TO EVALUATE NEW MODEL
DATA AS IT COMES IN AND ADJUST TAFS AS NEED BE. OTHERWISE...IT
LOOKS FAIRLY QUIET THROUGH WEDNESDAY...WITH A LITTLE LIGHT SNOW
APPROACHING BY WEDNESDAY EVENING. COULD THEN SEE A DUSTING OR
COUPLE TENTHS OF AN INCH OF SNOW WEDNESDAY NIGHT AS A WEAK WAVE
PUSHES THROUGH.
&&
.PREV DISCUSSION... /ISSUED 340 AM CST TUE NOV 25 2014/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
ANY LINGERING LIGHT SNOW/FLURRIES WILL END BY MID MORNING AS THE
REMNANTS OF THE SURFACE TROUGH PULLS OFF TO THE NORTHEAST AND WE
FINALLY GET INTO SOME RIDGING. THAT RIDGE WILL PROTECT US THROUGH
TONIGHT AS ANOTHER LOW PRESSURE SYSTEM IS ALREADY APPROACHING FROM
THE WEST. THE CLOUDS SHOULD DIMINISH SLOWLY FROM WEST TO EAST
TODAY. A CHILLY DAY IS ON TAP WITH HIGHS IN THE MID TO UPPER 20S AND
LOW DROPPING DOWN IN THE TEENS TONIGHT. TEMPS TONIGHT ARE A BIT
TRICKY. WE SHOULD SEE SOME HIGH CLOUDS SPREAD IN...BUT IF WE STAY
MOSTLY CLEAR TOO LONG TEMPS COULD DROP A BIT MORE DUE TO THE LIGHT
WINDS UNDER THE RIDGE.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
ONE MORE SHORTWAVE TROUGH WILL TRACK ACROSS THE MIDWEST WEDNESDAY
INTO THURSDAY. THE STRONGER PORTION OF IT ROUNDING THE BASE OF THE
UPPER TROUGH WILL MISS US TO THE SOUTH WED AFTERNOON/EVENING. A
WEAKER SHORTWAVE WILL CROSS WI WED NIGHT... AND THIS IS THE ONE THAT
WILL BRING SOUTHERN WI THE NEXT CHANCE FOR SNOW. IT WILL BE A LIGHT
EVENT... WITH UP TO AN INCH OF DRY SNOW THROUGH THURSDAY MORNING.
FLURRIES COULD LINGER THROUGH MUCH OF THANKSGIVING DAY DUE TO LOW
LEVEL MOISTURE AND CYCLONIC FLOW ALOFT. EXPECT CLOUDY SKIES AND
STEADY TEMPERATURES IN THE LOWER 20S WITH A NORTHWEST BREEZE.
THURSDAY NIGHT...FORECAST CONFIDENCE HIGH.
TEMPERATURES WILL DROP QUICKLY IN THE EVENING AS SKIES CLEAR AND
HIGH PRESSURE SPREADS IN. LOWS WILL BE AROUND 10 INLAND WITH LIGHT
WINDS. TEMPERATURES WILL BEGIN TO WARM LATE THURSDAY NIGHT WITH
INCREASING CLOUDS.
LONG TERM...
FRIDAY... FORECAST CONFIDENCE HIGH.
THE UPPER LEVEL FLOW WILL BECOME MORE ZONALLY ORIENTED FOR THE
LATTER HALF OF THE WEEK. A PAIR OF WEAK SHORTWAVES DUE TO A
STRENGTHENING UPPER JET OVER THE NORTHERN PLAINS WILL MAKE THEIR WAY
INTO THE UPPER MIDWEST LATE THURSDAY NIGHT THROUGH FRIDAY. THE BEST
CHANCE FOR SNOW IN SOUTHERN WI WILL BE FRIDAY MORNING WITH ANOTHER
INCH POSSIBLE... LOWEST AMOUNTS NEAR THE ILLINOIS BORDER.
WARMER AIR ALOFT WILL LIFT INTO SOUTHERN WI FRIDAY AFTERNOON. AT
THIS TIME... IT LOOKS LIKE JUST SOUTHWEST AND PORTIONS OF SOUTH
CENTRAL WI WILL GET INTO AN AREA WHERE TEMPERATURES ALOFT WILL BE
WARMER THAN THE SURFACE TEMPS SUGGESTING FREEZING RAIN. MODEL
SOUNDINGS SHOW THE MAJORITY OF THE MOISTURE MOVING OUT OF SOUTHERN
WI BY THE TIME THE TEMPS ALOFT WARM ABOVE FREEZING. THE GFS PROFILE
ACTUALLY SUGGESTS FREEZING DRIZZLE SINCE THE UPPER LEVELS DRY OUT
EARLIER THAN THE LOWER LEVELS.
FRIDAY NIGHT THROUGH SATURDAY... FORECAST CONFIDENCE MEDIUM.
WE WILL FINALLY GET INTO A PERIOD OF QUIET WEATHER WITH MILD
TEMPERATURES. THE GFS HAS A MORE SHEARED VORT MAX OVER SOUTHERN
CANADA THAN THE SLIGHTLY MORE-AMPLIFIED ECMWF. THUS... THERE ARE
TIMING DIFFERENCES BETWEEN THE MODELS ABOUT WHEN THE WARMEST TEMPS
WILL BE OVER SOUTHERN WI. THE ECMWF IS WARMEST DURING THE DAY
SATURDAY WHILE THE GFS GIVES US A SHORTER WARM PERIOD FRIDAY NIGHT
AND SHOWS SOME LIGHT QPF FOR SATURDAY AFTERNOON. I KEPT THE FORECAST
DRY FOR NOW AND USED A MODEL CONSENSUS FOR HIGHS IN THE UPPER
30S/LOWER 40S ON SATURDAY. THIS IS A CONSERVATIVE FORECAST AS WE
COULD SEE EVEN WARMER TEMPS IF THE ECMWF VERIFIES.
SUNDAY AND BEYOND... FORECAST CONFIDENCE MEDIUM.
A COLD FRONT WILL DROP DOWN THROUGH WI SUNDAY MORNING AND BRING US A
QUICK-HITTING COLD SNAP. EXPECT TEMPERATURES TO WARM ONCE AGAIN
TUESDAY AND WEDNESDAY NEXT WEEK THOUGH.
AVIATION/12Z TAFS/...LOOK FOR MVFR CONDITIONS DUE TO CIGS THIS
MORNING...IMPROVING TO VFR AS HIGH PRESSURE GRADUALLY BUILDS BACK
INTO THE REGION. ANY LINGERING LIGHT SNOW OR FLURRIES ACROSS THE
SOUTHEAST WILL END BY MID MORNING AS A TROF OF LOW PRESSURE FINALLY
EXITS TO THE NORTHEAST. ONCE CIGS LIFT TO VFR LEVELS...LOOK FOR THIS
TO CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD.
MARINE...THE SMALL CRAFT ADVISORY WILL BE CANCELED EARLY DUE TO
WESTERLY WINDS DIMINISHING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS BOISE ID
956 AM MST TUE NOV 25 2014
.DISCUSSION...WARM FRONTAL SNOW CHANGING TO RAIN TODAY WILL EXIT
THE AREA FROM SW TO NE AS THE DAY WEARS ON. NE VALLEY COUNTY WILL
BE THE LAST TO IMPROVE. LATEST HRRR HOLD ON TO LIGHT RAIN THERE
THROUGH AROUND 3Z AND MID LEVEL CLOUDS ACROSS THE EAST PORTIONS OF
THE WEST CENTRAL AND BOISE MOUNTAINS BEYOND 6Z. NO CHANGES FOR THE
MORNING UPDATE. WILL REVIEW TIMING WITH AFTERNOON PACKAGE.
&&
.AVIATION....MVFR-IFR RAIN AND SNOW SHOWERS NORTHEAST OF A LINE FROM
KBKE-KONO-KMUO-KSUN. OTHERWISE...VFR. RAIN AND SNOW SHOWERS ENDING
BY 21Z. SURFACE WINDS...SE 5-15 KTS THIS MORNING...EXCEPT BECOMING
SOUTHWESTERLY 15-25KT IN SE OR AND MAGIC VALLEY DURING
AFTERNOON...WITH GUSTS TO 35KT POSSIBLE IN MAGIC VALLEY. WINDS ALOFT
NEAR 10K FEET MSL...NW 35-50KT SOUTHWEST OF KBNO-KTWF LINE...NW 55-
75KT NORTHEAST OF KBNO-KTWF LINE...SUBSIDING TO NW 25-40KT BY 15Z
WED.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH WEDNESDAY...SNOW CONTINUES TO PILE UP
IN THE BOISE MOUNTAINS AND WEST CENTRAL MOUNTAINS THIS MORNING.
WEBCAMS SHOW THAT THE ROADS ARE SNOW-COVERED AS SEVERAL INCHES OF
SNOW HAVE ALREADY ACCUMULATED...WITH 5 INCHES SO FAR OVERNIGHT IN
MCCALL. A MOIST PACIFIC PLUME RESIDES OVER THE AREA...WITH THE
TREASURE VALLEY ON THE SOUTHERN EDGE OF THE PLUME. AREAS TO THE
SOUTH AND EAST OF THE TREASURE VALLEY WILL EXPERIENCE OCCASIONAL
RAIN SHOWERS AND HIGH ELEVATION SNOW SHOWERS THIS MORNING BEFORE
TAPERING OFF THIS AFTERNOON. MEANWHILE...THE BOISE/WEST CENTRAL
MOUNTAINS WILL SEE ADDITIONAL SNOW ACCUMULATIONS THIS MORNING
WHICH WILL THEN TAPER OFF THIS AFTERNOON. A WINTER WEATHER
ADVISORY IS IN EFFECT. SNOW LEVELS NEAR VALLEY FLOORS IN THE
NORTHERN MTNS WILL RISE TO ABOVE 5000 FEET THIS AFTERNOON AS A
WARM FRONT MOVES FROM SE OREGON INTO SW IDAHO. TEMPERATURES WILL
BE WARMER THIS AFTERNOON AS WARMER AIR ACCOMPANIES THE BUILDING
UPPER RIDGE. PRECIP WILL LINGER IN THE FAR NORTH TONIGHT...ENDING
ON WEDNESDAY AS THE CREST OF THE UPPER RIDGE REACHES OUR AREA.
TEMPERATURES TODAY AND WEDNESDAY WILL BE ABOVE NORMAL...WITH HIGHS
IN THE 40S ACROSS THE NORTH AND 50S ACROSS THE SOUTH - INCLUDING
THE TREASURE VALLEY AND WESTERN MAGIC VALLEY. STRONG W-NW WINDS
ALOFT WILL MIX DOWN TO THE SURFACE IN SOME AREAS BY THIS
AFTERNOON. NEAR ADVISORY SPEEDS AND GUSTS ARE EXPECTED IN THE
OWYHEE MOUNTAINS AND IN THE WESTERN MAGIC VALLEY. WINDS WILL BE
LIGHTER ON WEDNESDAY AS THE W-NW WINDS ALOFT WEAKEN.
LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY...A TROUGH NOW NEAR
40N AND 150W WILL SLOWLY MEANDER TOWARDS THE WEST COAST THROUGH
THE EXTENDED PERIOD CREATING AN UPPER LEVEL RIDGE THAT WILL SLOWLY
BREAK DOWN BY FRIDAY MORNING. MOISTURE FROM THIS SYSTEM WILL STAY
NORTH OF THE RIDGE ALONG AN ARCTIC BOUNDARY. TEMPERATURES WILL BE
WELL ABOVE NORMAL THROUGH FRIDAY. SOUTHEAST WINDS IN BOISE WILL
AID IN MIXING THE WARM TEMPERATURES ALOFT AND TEMPERATURES NEAR 60
ARE POSSIBLE ON THURSDAY AFTERNOON. MODELS DO NOT HAVE A GOOD
HANDLE ON THE SNOW COVER AROUND THE AREA...THUS HAVE IGNORED THE
COLDER GUIDANCE AS THESE MODELS HAVE TOO MUCH SNOW COVER AND THUS
ARE MUCH COOLER. BY FRIDAY THE RIDGE BREAKS DOWN AND THE ARCTIC
BOUNDARY MOVES SOUTHWARD TOWARDS THE COLUMBIA BASIN. DO NOT THINK
THE COLD AIR WILL REACH THE FORECAST AREA AS THE ARCTIC FRONT
STALLS ALONG THE BLUE MOUNTAINS NORTH OF THE REGION. THE TROUGH
OFF THE COAST IS OVERTAKEN BY A STRONG TROUGH DIVING SOUTH OUT OF
THE GULF OF ALASKA BY SATURDAY. SOUTHERLY FLOW WILL DEVELOP AHEAD
OF THIS TROUGH OVER THE GREAT BASIN ALLOWING FOR WEAK RIDGING
AHEAD OF THE SYSTEM MONDAY INTO TUESDAY BEFORE THE SYSTEM MOVES
INLAND.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON IDZ011-013.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....JS
PREV SHORT TERM...BW
PREV LONG TERM....KA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1139 AM CST TUE NOV 25 2014
.SHORT TERM...
303 AM CST
THROUGH WEDNESDAY...
PRIMARY FORECAST CHALLENGE TODAY IS CLOUD COVER. GUIDANCE IS ALL
FAIRLY AGGRESSIVE IS CLEARING THINGS OUT THIS AFTERNOON SAVE FOR THE
WRF-NAM. MODELS ARE OFTEN TOO QUICK TO CLEAR STRATUS OUT IN THE
WINTER...THOUGH IN THIS CASE IT IS A FAIRLY TRANSIENT PATTERN SO
STRATUS MAY BE A BIT QUICKER TO CLEAR THAN IS TYPICAL. MOS GUIDANCE
KEEPS SKIES FAIRLY CLOUDY AND HAVE MAINTAINED CLOUDINESS LONGER THAN
GUIDANCE SUGGESTS BUT DO PARTIALLY CLEAR SKIES OUT TONIGHT FOR A
TIME BEFORE CLOUDS ROLL BACK IN AHEAD OF THE NEXT SYSTEM.
SPEAKING OF THE NEXT SYSTEM...GUIDANCE CONTINUES TO TAKE THE CLIPPER
ON THE SOUTHERN ROUTE WITH ITS PRECIP LARGELY MISSING OUR CWA. HAVE
MAINTAINED SOME SLIGHT CHANCE POPS IN OUR SOUTHWESTERN MOST CWA
WEDNESDAY BUT OTHERWISE CONTINUED THE TREND FROM THE DAY SHIFT OF
LOWERING POPS...COMPLETELY REMOVING THEM FROM MUCH OF THE CWA.
IZZI
&&
.LONG TERM...
303 AM CST
WEDNESDAY NIGHT ONWARD...
IN THE LONGER TERM GUIDANCE IS STILL BRINGS IN A TRANSIENT BUT
MODERATELY POTENT SHOT OF COLD AIR THANKSGIVING DAY WHEN HIGHS
SHOULD ONCE AGAIN HOLD IN THE 20S. LARGE SCALE PATTERN WILL BEGIN TO
TRANSITION TO MORE OF A ZONAL FLOW BY FRIDAY WITH WARM AIR ADVECTION
BEGINNING AND POSSIBLY PRODUCING A BIT OF LIGHT PRECIP...BUT IF
ANYTHING DOES FALL AMOUNTS LOOK TO BE VERY LIGHT. BY SATURDAY STRONG
LOW PRESSURE IS PROGGED TO TRACK EAST INTO THE UPPER GREAT LAKES
ALLOWING FOR A BRISK BUT MILD SOUTHERLY FLOW TO DEVELOP OVER THE
AREA. FORECAST 850MB TEMPS WOULD SUPPORT HIGHS WELL INTO THE 50S AND
PERHAPS NEAR 60...THOUGH 925MB TEMPS ARE NOT QUITE AS MILD AND THAT
COULD PARTIALLY BE A RESULT OF A BIT MORE SNOW COVER. HAVE RAISED
HIGHS A BIT OVER THE BLENDED INITIALIZATION BUT THINKING CURRENT
FORECAST IS STILL TOO COOL...ESPECIALLY IN AREAS WITH LITTLE OR NO
SNOW COVER WHICH SHOULD BE A LARGE PORTION OF THE CWA BY SATURDAY.
COLD FRONT LOOKS TO MOVE THROUGH SAT NIGHT OR SUNDAY BRINGING COOLER
WEATHER FOR A COUPLE DAYS BUT IN THE TRANSIENT RATHER ZONAL FLOW GFS
AND ECMWF BOTH HINT AT ANOTHER HEALTHY WARM UP TOWARD MIDDLE OF NEXT
WEEK. PRECIP CHANCES THROUGH THE PERIOD LOOK LOW AND LARGELY
INCONSEQUENTIAL IF ANYTHING DOES FALL.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE.
RC
//DISCUSSION...UPDATED 18Z...
QUIET AVIATION WEATHER FOR NEXT 30 HOURS...AS SNOW ASSOCIATED WITH
WEAK LOW PRESSURE PASSING TO SOUTHWEST ON WEDNESDAY WILL REMAIN TO
THE SOUTHWEST OF THE TERMINALS. MID MVFR CIGS AT GYY SHOULD
SCATTER WITHIN NEXT HOUR OR SO AND MVFR OVER WISCONSIN EXPECTED TO
STAY TO THE NORTH THIS AFTERNOON...THOUGH COULD SEE FEW TO SCT
CLOUDS AT 020 FILL BACK IN A BIT. WIND SPEEDS WILL REMAIN
GENERALLY LIGHT THROUGHOUT THE TAF PERIOD...WITH DIRECTIONS
SHIFTING TO SOUTHERLY OVERNIGHT...SOUTHEAST WEDNESDAY MORNING AND
EAST-NORTHEAST BY MID TO LATE WEDNESDAY AFTERNOON.
RC
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH IN ALL ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...SLIGHT CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...SLIGHT CHANCE OF LIGHT RAIN OR SNOW.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
436 AM CST
AS LOW PRESSURE OVER NORTHERN QUEBEC CONTINUES TO LIFT NORTH
TODAY...A TROUGH OF LOW PRESSURE AND FRONTAL BOUNDARY EXTENDING
FROM THIS LOW SOUTHWEST THROUGH THE CENTRAL GREAT LAKES WILL SHIFT
TO THE EASTERN GREAT LAKES AND SOUTHERN QUEBEC. WHILE THIS IS
OCCURRING...EXPECT THE ONGOING DIMINISHING TREND WITH THE
NORTHWEST AND WEST WINDS IN PLACE TO CONTINUE. WINDS ARE CURRENTLY
TO 30 KT ACROSS THE LAKE EARLY THIS MORNING BUT DO EXPECT THEM TO
DIMINISH TO 15 TO 25 KT THIS MORNING...AND THEN TO 10 TO 20 KT IN
THE AFTERNOON. BUILDING HIGH PRESSURE ACROSS THE REGION WILL
PROVIDE A PERIOD OF LIGHTER WINDS OVER THE LAKE TONIGHT INTO
WEDNESDAY AND PART OF WEDNESDAY NIGHT. DEPARTING LOW PRESSURE TO
THE SOUTH OF THE LAKE AND ANOTHER HIGH BUILDING ACROSS THE PLAINS
WILL HELP PROVIDE A TIGHTER PRESSURE GRADIENT OVER THE
LAKE...HELPING RETURN STRONGER WINDS BACK OVER THE LAKE THURSDAY
INTO THURSDAY NIGHT.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1128 AM CST Tue Nov 25 2014
.UPDATE...
ISSUED AT 938 AM CST TUE NOV 25 2014
Large area of stratocumulus continues to sag southeast across the
forecast area, with the last holdouts near Lawrenceville now
clouding up. A narrow area of clearing from Peoria southeast has
been shifting toward Bloomington and Champaign, although this is
also starting to show a bit of filling in on the latest visible
satellite imagery. At present, the northern edge of the cloud deck
is advancing across northwest Illinois and is approaching
Galesburg from the north. The latest RAP and HRRR guidance shows
some additional development in that area over the next couple
hours, so we will need to keep an eye on that. For now, it looks
like the bulk of the clearing will begin across the southwest CWA
soon and slowly pull northeast.
Have made some adjustments to the high temperatures across the
northern CWA, where it`s still only in the lower 20s, and the
latest sky grids have been sent as well.
&&
.SHORT TERM...(Today)
ISSUED AT 312 AM CST TUE NOV 25 2014
Low pressure that brought widespread rain to central Illinois on
Sunday is now over Quebec, with trailing cold front approaching the
East Coast. Despite the parent low being so far away from the
region, lingering upper troughing is keeping cloud cover locked in
place. 08z/2am IR satellite imagery shows low clouds covering all
of central/northern Illinois and as far west as eastern Iowa.
Timing tools are indicating only a very slow eastward progression of
the clearing line, so have delayed the clearing across the KILX CWA
accordingly. The day will start out overcast across the board, then
a slow west-to-east clearing will occur as the day progresses.
Based on latest satellite loop and 00z forecast soundings, think
locations along/northeast of a Bloomington to Mattoon line will
remain cloudy for the entire day. Further west and south, skies
will become partly to mostly sunny this afternoon. Will be a cold
day with highs only in the 30s, but it will not be nearly as windy
as yesterday with westerly winds generally around 10 mph.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 312 AM CST TUE NOV 25 2014
Main weather challenge in the extended continues to be clipper
system expected to track through the region on Wednesday. 00z Nov
25 models are in excellent agreement with the timing and track of
the system, but display minor differences with their QPF fields.
All models take low pressure currently over Alberta and track it
southeastward into western Iowa by 12z Wed, then into southern
Illinois by 00z Thu. This represents a continued southerly trend
in the track, which means portions of the far N/NE CWA may see
little or no precip with this system. NAM is the most
concentrated with its QPF, keeping it confined very near the low
track. Meanwhile, both the GFS and ECMWF are more generous and
spread light precip further north across the entire area. Have
updated Wednesday precip chances to focus likely PoPs along/south
of a Rushville to Decatur to Robinson line, tapering down to low
chance northeast of I-74. Given the more southerly track, WAA
ahead of the wave will be weaker than previously thought, so high
temps will not be quite as warm. Afternoon readings will range
from the middle 30s far north to the lower 40s south of I-70.
Forecast soundings support snow: however, surface temps will be
warm enough for a rain/snow mix across much of the area and
perhaps mainly rain across the far southeast. Snowfall amounts
will be mitigated by the marginal temps and overall light QPF,
with perhaps a half inch along/southwest of Macomb to Springfield
line where the precip will begin during the morning hours when it
is still cold enough to support all snow reaching the ground.
System will quickly track into the Appalachians Wednesday night,
with just a few lingering snow-showers across the E/SE into the
evening.
Once Wednesday clipper departs, the remainder of the extended
appears to be quiet. A shot of cold air behind the system will drop
high temps into the upper 20s/lower 30s on Thursday: however, a
marked warming trend is still expected for the end of the week as
eastern CONUS upper troughing relaxes and a zonal pattern develops.
As southerly winds develop on the back side of departing high
pressure, high temperatures will soar well into the 50s on Saturday
before a cold front sags southward into the region late in the day.
Still some discrepancies further out concerning how far south front
will make it, with overall consensus taking it into the Ohio River
Valley by Sunday. High pressure initially along the Gulf Coast will
limit northward moisture return, so showers will likely not develop
along/ahead of the boundary until it sinks into the SE CWA Sunday
afternoon/night. All model solutions point to a cool/dry day on
Monday before southerly flow resumes and precip chances slowly begin
to increase by Tuesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1124 AM CST TUE NOV 25 2014
Main forecast concern is with the timing of the MVFR conditions
this afternoon. All TAF sites currently with ceilings at or below
2000 feet. Clearing line advancing eastward from far western
Illinois, with AWIPS timing tool showing it reaching KSPI around
20Z, but not reaching KCMI until toward 00-01Z. Once skies clear,
VFR conditions are on tap the remainder of the forecast period.
There will be lowering ceilings late Wednesday morning ahead of a
fast moving storm system, but any MVFR conditions would likely be
after 18Z. Westerly winds this afternoon will become light and
variable for a time early this evening, before a southeast flow
sets up and persists the remainder of the forecast period.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart/EJL
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart/EJL
AREA FORECAST DISCUSSION
NWS JACKSON KY
356 PM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EST TUE NOV 25 2014
...ACCUMULATING SNOW EXPECTED OVER FAR EASTERN KENTUCKY TONIGHT INTO
WEDNESDAY MORNING...
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL INFLUENCING THE WEATHER OF
EASTERN KENTUCKY. THIS HAS PROVIDED PLENTY OF SUNSHINE AND GENERALLY
SOUTHWEST WINDS OF 5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS. THESE
CONDITIONS...ALONG WITH GOOD DRYING THROUGH EARLY AFTERNOON HAS SENT
TEMPERATURES WELL UP INTO THE 50S FOR MOST OF THE AREA...THOUGH
LOCATIONS NORTHWEST OF INTERSTATE 64 ARE LAGGING IN THE UPPER 40S. OF
NOTE ON THE SFC CHART IS AN AREA OF DEVELOPING LOW PRESSURE CROSSING
NORTHERN FLORIDA ON ITS WAY TO THE SOUTHEAST U.S. SEABOARD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE FIRST PART
OF THE SHORT TERM FORECAST. THEY ALL TAKE A STRONG SHORTWAVE
CURRENTLY BOTTOMING OUT OVER THE CENTRAL GULF COAST NORTHEAST INTO
THE SOUTHERN APPALACHIANS BY WEDNESDAY MORNING. IN ADDITION...A
COMPACT WAVE WILL BE DROPPING SOUTHEAST FROM THE NORTHERN PLAINS INTO
THE MID MISSISSIPPI VALLEY AND EVENTUALLY THROUGH THE TENNESSEE
VALLEY LATER WEDNESDAY NIGHT. THE MODELS ARE CLOSE ON THE TIMING OF
THIS BUT THE CORE OF THE ENERGY IS FURTHER SOUTH IN THE NAM...
ECMWF...AND GEM WHEN COMPARED TO THE GFS. WILL FAVOR THIS MORE
SOUTHERN TRACK AS SEEN IN THE CONSENSUS. IN GENERAL HAVE LEANED MOST
CLOSELY TO THE HIGHER RESOLUTION MODELS OF THE NAM12 AND HRRR...
THOUGH THE HRRR PCPN FIELDS SEEM TOO FAR SOUTHEAST AND SLOW LATER
TONIGHT.
SENSIBLE WEATHER WILL FEATURE A QUICK INCREASE IN CLOUD COVER FROM
THE SOUTHEAST AS THE COASTAL LOW STARTS TO TAKE SHAPE LATER THIS
EVENING. LOWER CLOUDS AND PCPN WILL START TO SPILL OVER THE SPINE OF
THE APPALACHIANS AND MOVE INTO OUR FAR EASTERN COUNTIES AROUND
MIDNIGHT. EXPECT TEMPERATURES TO WET BULB DOWN WHEN THE PCPN MOVES IN
AND TRANSITION THE RAIN TO SNOW IN THE HIGHER ELEVATIONS FIRST BUT
EVENTUALLY DOWN IN THE VALLEYS...AS WELL. THE HEAVIEST SNOW WILL FALL
IN THE HIGHER TERRAIN ALONG THE VIRGINIA BORDER WHERE AS MUCH AS A
QUARTER TO A THIRD OF AN INCH OF LIQUID WILL LIKELY OCCUR. THIS WILL
PROBABLY AMOUNT TO BETWEEN TWO AND THREE INCHES OF WET SNOW IN THE
HIGHER TERRAIN...ABOVE 2000 FEET AND AROUND AN INCH OR LESS
ELSEWHERE. HIGHER RIDGES BELOW 2000 FEET CAN EXPECT TO PICK UP
BETWEEN ONE AND TWO INCHES BY MIDDAY WEDNESDAY. HAVE SET UP THIS AREA
WITH A WINTER WEATHER ADVISORY FROM MIDNIGHT THROUGH NOON WEDNESDAY
FOR THIS PASSING EVENT. WITH THE POTENTIAL FOR LIGHT ACCUMULATIONS
IN THE COUNTIES IMMEDIATELY WEST OF THE ADVISORY WILL ALSO ISSUE AN
SPS ADDRESSING THIS MARGINAL CONCERN. OTHERWISE...THE COASTAL PULLS
OUT LATER WEDNESDAY WITH A BRIEF VISIT BY HIGH PRESSURE FOR EAST
KENTUCKY IN ITS WAKE. HOWEVER...THE NEXT DEVELOPING LOW WORKS IN FROM
THE NORTHWEST LATER THAT NIGHT CARVING ITS WAY THROUGH OUR SOUTHERN
COUNTIES INTO DAWN THURSDAY. THIS TOO WILL BRING SOME RAIN OR SNOW
TO PARTS OF THE AREA WITH SOME SLUSHY LIGHT SNOW ACCUMULATIONS
POSSIBLE MAINLY ON RIDGES AND GRASSY/ELEVATED SURFACES.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH
THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME
MORE SIGNIFICANT TERRAIN BASED ADJUSTMENTS TONIGHT INTO WEDNESDAY IN
THE EXPECTED SNOW AREAS OF THE FAR EAST. AS FOR POPS...ENDED UP
CLOSE TO A BLEND OF THE MAV AND MET NUMBERS THROUGH THE PERIOD.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 354 PM EST TUE NOV 25 2014
SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH AND ASSOCIATED LOW
PRESSURE WILL BE MOVING EAST OF THE REGION WITH BEST POP CHANCES
ACROSS THE SE PORTIONS OF THE CWA. THIS WILL GENERALLY BE LIGHT
RAIN/SNOW SHOWERS AND DO NOT EXPECT MUCH QPF THROUGH THE DAY THURSDAY
AT THIS POINT. THIS SYSTEM SLIDES EAST ALLOWING FOR NW/W FLOW TO
SETUP ACROSS THE REGION AND THEREFORE HELD SLIGHT CHANCE IN FAR SE
INTO THE AFTERNOON.
SURFACE HIGH PRESSURE WILL SLOWLY SLIDE EAST THROUGH THE NIGHT
THURSDAY AND GENERALLY CRESTING ACROSS THE REGION EARLY FRIDAY. THIS
HIGH PRESSURE BUILDS EAST BRINGING RETURN SOUTHERLY FLOW TO EASTERN
KY WITH TEMPERATURES RISING INTO THE LOWER 50S SATURDAY. SATURDAY
AFTERNOON WE DO PRESENT SOME SLIGHT CHANCE SHOWERS ESPECIALLY ACROSS
THE FAR NORTH AS FRONTAL BOUNDARY GENERALLY STALLS ACROSS THE NORTH.
THIS QUASI-STATIONARY FRONT WILL KEEP THE WEATHER UNSETTLED THROUGH
THE PERIOD. THE QUESTION REALLY BECOMES HOW QUICKLY DOES THIS
BOUNDARY MOVE SOUTH...THAT SAID THE 12Z ECMWF IS MORE PROGRESSIVE
MOVING THIS FRONT SOUTH THAN THE 12Z GFS. RIGHT NOW WITH MODEL
DISCREPANCIES WILL KEEP BLEND POPS FOR THE MOST PART BUT WOULD THINK
THESE POPS WILL CONTINUE TO TREND UP ONCE MODELS COME INTO BETTER
ALIGNMENT. SATURDAY HIGHS ARE EXPECTED TO WARM INTO THE LOW TO MID
50S WITH TEMPERATURES MODIFYING INTO THE UPPER 50S TO LOWER 60S
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 100 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING AS HIGH PRESSURE
HOLD ON OVER THE AREA. A DEVELOPING LOW PRESSURE SYSTEM WILL SPREAD
MOISTURE AND LOWERING CLOUDS BACK INTO EASTERN KENTUCKY LATE
TONIGHT...WITH CIGS FALLING INTO THE MVFR RANGE IN THE EAST BY 08Z.
AS OF RIGHT NOW...LOOKS LIKE WE SHOULD SEE A GRADIENT IN THE LOWER
CIGS WITH THE LOWEST (IFR/MVFR) IN THE EAST...TRAILING BACK TO VFR IN
THE WEST...THROUGH MID MORNING WEDNESDAY. WE WILL ALSO SEE
PRECIPITATION SPREAD INTO THE AREA...MAINLY ACROSS SOUTHEASTERN
KENTUCKY...AS A MIX OF RAIN AND SNOW...LIKELY BECOMING ALL IN THE
PRE-DAWN HOURS. THIS SNOW WILL RESTRICT VISIBILITIES LATER TONIGHT
AS WELL...MAINLY AT KJKL AND KSJS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
WEDNESDAY FOR KYZ087-088-110-113-115-117>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
325 PM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EST TUE NOV 25 2014
...ACCUMULATING SNOW EXPECTED OVER FAR EASTERN KENTUCKY TONIGHT INTO
WEDNESDAY MORNING...
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL INFLUENCING THE WEATHER OF
EASTERN KENTUCKY. THIS HAS PROVIDED PLENTY OF SUNSHINE AND GENERALLY
SOUTHWEST WINDS OF 5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS. THESE
CONDITIONS...ALONG WITH GOOD DRYING THROUGH EARLY AFTERNOON HAS SENT
TEMPERATURES WELL UP INTO THE 50S FOR MOST OF THE AREA...THOUGH
LOCATIONS NORTHWEST OF INTERSTATE 64 ARE LAGGING IN THE UPPER 40S. OF
NOTE ON THE SFC CHART IS AN AREA OF DEVELOPING LOW PRESSURE CROSSING
NORTHERN FLORIDA ON ITS WAY TO THE SOUTHEAST U.S. SEABOARD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE FIRST PART
OF THE SHORT TERM FORECAST. THEY ALL TAKE A STRONG SHORTWAVE
CURRENTLY BOTTOMING OUT OVER THE CENTRAL GULF COAST NORTHEAST INTO
THE SOUTHERN APPALACHIANS BY WEDNESDAY MORNING. IN ADDITION...A
COMPACT WAVE WILL BE DROPPING SOUTHEAST FROM THE NORTHERN PLAINS INTO
THE MID MISSISSIPPI VALLEY AND EVENTUALLY THROUGH THE TENNESSEE
VALLEY LATER WEDNESDAY NIGHT. THE MODELS ARE CLOSE ON THE TIMING OF
THIS BUT THE CORE OF THE ENERGY IS FURTHER SOUTH IN THE NAM...
ECMWF...AND GEM WHEN COMPARED TO THE GFS. WILL FAVOR THIS MORE
SOUTHERN TRACK AS SEEN IN THE CONSENSUS. IN GENERAL HAVE LEANED MOST
CLOSELY TO THE HIGHER RESOLUTION MODELS OF THE NAM12 AND HRRR...
THOUGH THE HRRR PCPN FIELDS SEEM TOO FAR SOUTHEAST AND SLOW LATER
TONIGHT.
SENSIBLE WEATHER WILL FEATURE A QUICK INCREASE IN CLOUD COVER FROM
THE SOUTHEAST AS THE COASTAL LOW STARTS TO TAKE SHAPE LATER THIS
EVENING. LOWER CLOUDS AND PCPN WILL START TO SPILL OVER THE SPINE OF
THE APPALACHIANS AND MOVE INTO OUR FAR EASTERN COUNTIES AROUND
MIDNIGHT. EXPECT TEMPERATURES TO WET BULB DOWN WHEN THE PCPN MOVES IN
AND TRANSITION THE RAIN TO SNOW IN THE HIGHER ELEVATIONS FIRST BUT
EVENTUALLY DOWN IN THE VALLEYS...AS WELL. THE HEAVIEST SNOW WILL FALL
IN THE HIGHER TERRAIN ALONG THE VIRGINIA BORDER WHERE AS MUCH AS A
QUARTER TO A THIRD OF AN INCH OF LIQUID WILL LIKELY OCCUR. THIS WILL
PROBABLY AMOUNT TO BETWEEN TWO AND THREE INCHES OF WET SNOW IN THE
HIGHER TERRAIN...ABOVE 2000 FEET AND AROUND AN INCH OR LESS
ELSEWHERE. HIGHER RIDGES BELOW 2000 FEET CAN EXPECT TO PICK UP
BETWEEN ONE AND TWO INCHES BY MIDDAY WEDNESDAY. HAVE SET UP THIS AREA
WITH A WINTER WEATHER ADVISORY FROM MIDNIGHT THROUGH NOON WEDNESDAY
FOR THIS PASSING EVENT. WITH THE POTENTIAL FOR LIGHT ACCUMULATIONS
IN THE COUNTIES IMMEDIATELY WEST OF THE ADVISORY WILL ALSO ISSUE AN
SPS ADDRESSING THIS MARGINAL CONCERN. OTHERWISE...THE COASTAL PULLS
OUT LATER WEDNESDAY WITH A BRIEF VISIT BY HIGH PRESSURE FOR EAST
KENTUCKY IN ITS WAKE. HOWEVER...THE NEXT DEVELOPING LOW WORKS IN FROM
THE NORTHWEST LATER THAT NIGHT CARVING ITS WAY THROUGH OUR SOUTHERN
COUNTIES INTO DAWN THURSDAY. THIS TOO WILL BRING SOME RAIN OR SNOW
TO PARTS OF THE AREA WITH SOME SLUSHY LIGHT SNOW ACCUMULATIONS
POSSIBLE MAINLY ON RIDGES AND GRASSY/ELEVATED SURFACES.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH
THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME
MORE SIGNIFICANT TERRAIN BASED ADJUSTMENTS TONIGHT INTO WEDNESDAY IN
THE EXPECTED SNOW AREAS OF THE FAR EAST. AS FOR POPS...ENDED UP
CLOSE TO A BLEND OF THE MAV AND MET NUMBERS THROUGH THE PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
THE MODELS BEGIN THE PERIOD IN PRETTY GOOD AGREEMENT...WITH A LARGE
SCALE UPPER LEVEL TROUGH OF LOW PRESSURE EJECTING OUT OF THE
NORTHERN PLAINS AND ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS
WEDNESDAY NIGHT THROUGH FRIDAY. IT APPEARS THAT THIS INITIAL SYSTEM
WILL BE FAIRLY PROGRESSIVE...SO ANY PRECIPITATION ASSOCIATED WITH IT
SHOULD BE SHORT LIVED AND NOT VERY HEAVY. A SHOT OF COLD AIR WILL
SPILL INTO THE REGION AS THE SYSTEM DEPARTS...WITH HIGHS ON THURSDAY
ONLY TOPPING OUT AROUND 40 DEGREES...AFTER MORNING LOWS IN THE UPPER
20S AND LOWER 30S. A RIDGE OF HIGH PRESSURE IS THEN PROGGED TO
BECOME ESTABLISHED ACROSS THE REGION TO BEGIN THE WEEKEND...WITH
WARMER TEMPERATURES AND PARTLY CLOUDY SKIES ON TAP FOR FRIDAY NIGHT
AND SATURDAY. SATURDAY COULD MARK THE START OF A SIGNIFICANT WARMING
TREND...WITH HIGHS POSSIBLY TOPPING OUT IN THE LOW TO MID 50S. THE
REGION IS EXPECTED TO WARM EVEN MORE ON SUNDAY AND MONDAY...AS THE
MERCURY CLIMBS INTO THE MID TO UPPER 50S FOR MOST LOCATIONS BOTH
DAYS. OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT WILL FEEL ALMOST
BALMY IF THEY IN FACT ONLY DROP INTO THE LOW TO MID 40S EACH NIGHT.
ENOUGH COLD AIR WILL LIKELY SPILL INTO THE REGION TO BEGIN THE
PERIOD TO ALLOW FOR SOME SNOW TO MIX WITH RAIN EARLY WEDNESDAY NIGHT
INTO THURSDAY MORNING ACROSS THE AREA. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THE NEXT ROUND OF PRECIPITATION IS
EXPECTED TO MOVE ACROSS THE AREA BEGINNING SATURDAY NIGHT...AS A
WEAK FRONTAL BOUNDARY MOVES INTO AND STALLS OUT ACROSS THE AREA. THE
MODELS KEEP THE FRONT IN PLACE...AND THEREFORE THE THREAT OF
PRECIPITATION...THROUGH THE END OF THE DAY ON MONDAY. TEMPERATURES
DURING THIS PERIOD WILL REMAIN WARM ENOUGH FOR ANY PRECIPITATION
THAT OCCURS TO REMAIN IN LIQUID FORM. DUE TO SOME SMALL TIMING
DIFFERENCES BETWEEN THE MODELS REGARDING PRECIPITATION
ONSET...DURATION...AND AREAL COVERAGE...DECIDED TO GO WITH ONLY
CHANCE POPS AT THIS TIME. BASED ON THE LATEST MODEL DATA...THE FRONT
COULD EITHER REMAIN STALLED ACROSS THE AREA...ECMWF...OR DRIFT
SLOWLY NORTH AS A WEAK WARM FRONT...GFS...DURING THE MONDAY INTO
MONDAY NIGHT TIME FRAME. ONLY TIME WILL TELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 100 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING AS HIGH PRESSURE
HOLD ON OVER THE AREA. A DEVELOPING LOW PRESSURE SYSTEM WILL SPREAD
MOISTURE AND LOWERING CLOUDS BACK INTO EASTERN KENTUCKY LATE
TONIGHT...WITH CIGS FALLING INTO THE MVFR RANGE IN THE EAST BY 08Z.
AS OF RIGHT NOW...LOOKS LIKE WE SHOULD SEE A GRADIENT IN THE LOWER
CIGS WITH THE LOWEST (IFR/MVFR) IN THE EAST...TRAILING BACK TO VFR IN
THE WEST...THROUGH MID MORNING WEDNESDAY. WE WILL ALSO SEE
PRECIPITATION SPREAD INTO THE AREA...MAINLY ACROSS SOUTHEASTERN
KENTUCKY...AS A MIX OF RAIN AND SNOW...LIKELY BECOMING ALL IN THE
PRE-DAWN HOURS. THIS SNOW WILL RESTRICT VISIBILITIES LATER TONIGHT
AS WELL...MAINLY AT KJKL AND KSJS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
WEDNESDAY FOR KYZ087-088-110-113-115-117>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
120 PM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 120 PM EST TUE NOV 25 2014
DID A QUICK PRIMARILY TO BUMP UP TEMPERATURES GIVEN THE SUNNY SKIES
AND DRIER AIR IN PLACE. ALSO TWEAKED THE HOURLY TEMPS AND DEWPOINTS
PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
UPDATE ISSUED AT 1025 AM EST TUE NOV 25 2014
14Z SFC ANALYSIS SHOWS HIGH PRESSURE BRIEFLY BUILDING INTO EAST
KENTUCKY THIS MORNING BRINGING SUNNY SKIES AND A DRIER AIR MASS. THE
EARLIER HIGH CLOUDS HAVE SLID OFF TO THE EAST OF THE STATE AND WINDS
ARE LIGHT AND VARIABLE. TEMPERATURES ARE IN THE LOW TO MID 40S IN
MOST PLACES ACROSS THE CWA NOW THAT THE COLDER VALLEYS ARE STARTING
TO MIX OUT. DEWPOINTS ARE CURRENTLY IN THE LOW 30S...BUT WITH DRIER
AIR OFF THE SFC THESE ARE EXPECTED TO MIX DOWN INTO THE 20S THROUGH
MID AFTERNOON. FIRST GLANCE OF THE LATEST NAM12 SHOWS THE SOUTHEAST
LOW A BIT FURTHER EAST FROM THE MORE AGGRESSIVE 06Z RUN. HOWEVER...IT
STILL HAS A SIGNIFICANT AMOUNT OF PCPN FALLING TONIGHT INTO WEDNESDAY
MORNING IN AND NEAR THE VIRGINIA BORDER COUNTIES WHERE MUCH OF IT
WILL LIKELY WET BULB TO SNOW. SOME ACCUMULATIONS APPEAR LIKELY...
PARTICULARLY IN THE HIGHER ELEVATIONS AND ON GRASSY/ELEVATED SFCS
ELSEWHERE. THE SPS CONTINUES BUT MAY NEED TO BE UPGRADED TO AN
ADVISORY LATER THIS AFTERNOON DEPENDING ON HOW THE OTHER MODELS COME
IN. FOR THIS UPDATE...HAVE MAINLY FINE TUNED T AND TD GRIDS INTO THE
AFTERNOON PER THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 621 AM EST TUE NOV 25 2014
06Z NAM AND GFS ARE NOW IN AND BOTH ARE A LITTLE MORE ROBUST WITH
PRECIPITATION AND BOTH A TAD FARTHER WEST WITH THE EXTENT. IN
FACT...THE NAM SNOWFALL ALGORITHM IS SUGGESTING AS MUCH AS 5 INCHES
OF SNOW COULD FALL OVER FAR SOUTHEAST KENTUCKY. HOWEVER...THIS IS THE
FIRST RUN SUGGESTING THIS HIGH OF QPF AND WILLING TO CONSIDER IT AN
OUTLIER FOR NOW...BUT THE 12Z MODEL GUIDANCE WILL HAVE TO BE WATCHED
FOR POSSIBLE TRENDS TOWARDS THE HIGHER SNOWFALL AMOUNTS TONIGHT.
ALREADY SEEING SOME COOLER CLOUD TOPS DEVELOPING ACROSS EAST
TEXAS...SO AS MENTIONED...MAY NEED TO WATCH FOR A FARTHER WEST EXTENT
TO THE PRECIPITATION.
ALSO SOMETHING ELSE TO CONSIDER...DRY AIR MIX DOWN ACROSS SOUTHEAST
KENTUCKY THIS AFTERNOON MAY BRING DOWN SOME AWFULLY LOW
DEWPOINTS...WHICH WOULD SET THE STAGE FOR GOOD WET BULB COOLING AS
PRECIPITATION MOVES IN TONIGHT. THUS...IF LOWER DEWPOINTS
MATERIALIZE...THEY MAY HELP DISTINGUISH BETWEEN WHO GETS MORE
SNOW...VERSES MORE RAIN. LOWER DEWPOINTS WOULD ALLOW FOR A FASTER
TRANSITION TO SNOW...AND THUS...MORE SNOWFALL ACCUMULATION. FOR
NOW...WILLING TO SIT ON THIS AND LET DAY-SHIFT RE-EVALUATE THE NEED
FOR ANY CHANGES. IF MODELS CONTINUE TO HOLD COURSE...IT LOOKS LIKE AT
A MINIMUM A WINTER WEATHER ADVISORY WOULD BE NEEDED FOR A PORTION OF
THE AREA.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
SURFACE RIDGING CONTINUES TO BUILD INTO EASTERN KENTUCKY THIS MORNING
WITH SKIES GENERALLY CLEAR TO MOSTLY CLEAR. THIS WILL HOLD THROUGH
THE DAY...PROVIDING A COOLER...BUT STILL RELATIVELY PLEASANT DAY. IN
FACT...WITH THE HELP OF THE SUNSHINE AND TEMPERATURES IN SOME PLACES
ALREADY IN THE 40S THIS MORNING...WE SHOULD HAVE NO PROBLEM
SURPASSING THE 50 DEGREE MARK THIS AFTERNOON. WITH AN ABUNDANCE OF LOW
LEVEL DRY AIR JUST OFF THE SURFACE...RAP AND HRRR ARE SUGGESTING
FAIRLY LOW DEWPOINTS THIS AFTERNOON...ESPECIALLY ACROSS SOUTHEAST
KENTUCKY. IT MIGHT BE A STRETCH TO FALL INTO THE TEENS...BUT
CERTAINLY DEWPOINTS DOWN INTO THE MID 20S WILL BE POSSIBLE. THIS WILL
PUT US CLOSE TO THE 25 PERCENT RH`S THIS AFTERNOON. I WOULDN`T BE
SURPRISED TO SEE A FEW SPOTS ACTUALLY REACH THIS VALUE...ESPECIALLY
IN SOUTHEAST KENTUCKY.
CLOUDS WILL BE ON THE INCREASE THIS EVENING AND ESPECIALLY TONIGHT.
MODELS HAVE AN AREA OF LOW PRESSURE DEVELOPING OVER FLORIDA AND
TRACKING NORTHWARD ALONG THE COAST TONIGHT. NEARLY ALL MODELS ARE IN
SUPPORT OF MOISTURE AND LIFT ASSOCIATED WITH THIS SYSTEM DEVELOPING
ACROSS FAR SOUTHEAST AND EAST KENTUCKY OVERNIGHT INTO WEDNESDAY
MORNING. GIVEN THE ABUNDANCE OF DRY AIR IN PLACE...WET BULB
TEMPERATURES WILL BE FAIRLY LOW. ASSUMING WE GET PRECIP RATES THAT
SUPPORT IT...WE SHOULD SEE PRIMARILY SNOW LATE TONIGHT INTO WEDNESDAY
MORNING...BUT SOME RAIN MAY BE POSSIBLE FARTHER INTO EASTERN KENTUCKY
WHERE PRECIP RATES MAY NOT BE AS HIGH. REGARDLESS...WE SHOULD SEE
TEMPERATURES COOL ENOUGH TO SUPPORT SOME LIGHT SNOW ACCUMULATION
ACROSS SOUTHEAST KENTUCKY. AT THIS TIME...THE HIGHEST AMOUNTS SHOULD
BE ABOVE 2500 FEET...WHERE 2 TO 3 INCHES OF SNOW MAY BE POSSIBLE.
LIGHTER AMOUNTS IN THE LOWER ELEVATIONS UP TO AN INCH WILL BE
POSSIBLE FOR AREAS SOUTHEAST OF A LINE FROM INEZ TO HAZARD...TO
BARBOURVILLE. WHILE SNOW IS EXPECTED ACROSS SOUTHEAST KENTUCKY...THE
REST OF EASTERN KENTUCKY MAY NOT SEE MUCH MORE THAN INCREASED CLOUD
COVER. PLAN TO GO AHEAD AND ISSUE AN SPS FOR OUR SOUTHEAST COUNTIES
TO ADDRESS THE POTENTIAL SNOWFALL. GIVEN THE EXPECTED CLOUD COVER
INTO WEDNESDAY...WENT WITH A PRETTY GOOD GRADIENT IN TEMPERATURES
FROM WEST TO EAST...WITH READINGS AROUND 50 IN THE WEST TO LOW AND
MID 30S IN THE EAST. PRECIPITATION WILL DEPART BY MIDDAY
WEDNESDAY...WITH TEMPORARY BREAK IN PRECIPITATION EXPECTED THROUGH
THE AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 AM EST TUE NOV 25 2014
THE MODELS BEGIN THE PERIOD IN PRETTY GOOD AGREEMENT...WITH A LARGE
SCALE UPPER LEVEL TROUGH OF LOW PRESSURE EJECTING OUT OF THE
NORTHERN PLAINS AND ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS
WEDNESDAY NIGHT THROUGH FRIDAY. IT APPEARS THAT THIS INITIAL SYSTEM
WILL BE FAIRLY PROGRESSIVE...SO ANY PRECIPITATION ASSOCIATED WITH IT
SHOULD BE SHORT LIVED AND NOT VERY HEAVY. A SHOT OF COLD AIR WILL
SPILL INTO THE REGION AS THE SYSTEM DEPARTS...WITH HIGHS ON THURSDAY
ONLY TOPPING OUT AROUND 40 DEGREES...AFTER MORNING LOWS IN THE UPPER
20S AND LOWER 30S. A RIDGE OF HIGH PRESSURE IS THEN PROGGED TO
BECOME ESTABLISHED ACROSS THE REGION TO BEGIN THE WEEKEND...WITH
WARMER TEMPERATURES AND PARTLY CLOUDY SKIES ON TAP FOR FRIDAY NIGHT
AND SATURDAY. SATURDAY COULD MARK THE START OF A SIGNIFICANT WARMING
TREND...WITH HIGHS POSSIBLY TOPPING OUT IN THE LOW TO MID 50S. THE
REGION IS EXPECTED TO WARM EVEN MORE ON SUNDAY AND MONDAY...AS THE
MERCURY CLIMBS INTO THE MID TO UPPER 50S FOR MOST LOCATIONS BOTH
DAYS. OVERNIGHT LOWS SATURDAY AND SUNDAY NIGHT WILL FEEL ALMOST
BALMY IF THEY IN FACT ONLY DROP INTO THE LOW TO MID 40S EACH NIGHT.
ENOUGH COLD AIR WILL LIKELY SPILL INTO THE REGION TO BEGIN THE
PERIOD TO ALLOW FOR SOME SNOW TO MIX WITH RAIN EARLY WEDNESDAY NIGHT
INTO THURSDAY MORNING ACROSS THE AREA. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THE NEXT ROUND OF PRECIPITATION IS
EXPECTED TO MOVE ACROSS THE AREA BEGINNING SATURDAY NIGHT...AS A
WEAK FRONTAL BOUNDARY MOVES INTO AND STALLS OUT ACROSS THE AREA. THE
MODELS KEEP THE FRONT IN PLACE...AND THEREFORE THE THREAT OF
PRECIPITATION...THROUGH THE END OF THE DAY ON MONDAY. TEMPERATURES
DURING THIS PERIOD WILL REMAIN WARM ENOUGH FOR ANY PRECIPITATION
THAT OCCURS TO REMAIN IN LIQUID FORM. DUE TO SOME SMALL TIMING
DIFFERENCES BETWEEN THE MODELS REGARDING PRECIPITATION
ONSET...DURATION...AND AREAL COVERAGE...DECIDED TO GO WITH ONLY
CHANCE POPS AT THIS TIME. BASED ON THE LATEST MODEL DATA...THE FRONT
COULD EITHER REMAIN STALLED ACROSS THE AREA...ECMWF...OR DRIFT
SLOWLY NORTH AS A WEAK WARM FRONT...GFS...DURING THE MONDAY INTO
MONDAY NIGHT TIME FRAME. ONLY TIME WILL TELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 100 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING AS HIGH PRESSURE
HOLD ON OVER THE AREA. A DEVELOPING LOW PRESSURE SYSTEM WILL SPREAD
MOISTURE AND LOWERING CLOUDS BACK INTO EASTERN KENTUCKY LATE
TONIGHT...WITH CIGS FALLING INTO THE MVFR RANGE IN THE EAST BY 08Z.
AS OF RIGHT NOW...LOOKS LIKE WE SHOULD SEE A GRADIENT IN THE LOWER
CIGS WITH THE LOWEST (IFR/MVFR) IN THE EAST...TRAILING BACK TO VFR IN
THE WEST...THROUGH MID MORNING WEDNESDAY. WE WILL ALSO SEE
PRECIPITATION SPREAD INTO THE AREA...MAINLY ACROSS SOUTHEASTERN
KENTUCKY...AS A MIX OF RAIN AND SNOW...LIKELY BECOMING ALL IN THE
PRE-DAWN HOURS. THIS SNOW WILL RESTRICT VISIBILITIES LATER TONIGHT
AS WELL...MAINLY AT KJKL AND KSJS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 PM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.
TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.
SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 457 PM EST TUE NOV 25 2014
MAIN FCST CONCERNS IN THE LONG TERM WL FOCUS ON LES POTENTIAL FOR
WED NIGHT INTO THANKSGIVING AND NEED FOR HEADLINES AT SENSITIVE
TRAVEL TIME. ANOTHER ROUND OF SN WL BE POSSIBLE ON FRI/FRI NIGHT
WITH DVLPG ISENTROPIC ASCENT UNDER AN UPPER AIR PATTERN THAT WL
SHIFT TO A PROGRESSIVE...ZONAL FLOW BY THE WEEKEND. WELL BLO NORMAL
TEMPS WITH SOME RECORD LO MAX TEMPS ON THANKSGIVING WL GIVE WAY TO
MUCH WARMER WX ON SAT. ALTHOUGH SOME COLDER AIR WL RETURN FOR SUN
INTO MON...A WARMER SW FLOW ON THE WRN FLANK OF HI PRES SHIFTING TO
THE E WILL DVLP ON TUE UNDER THIS PROGRESSIVE PATTERN.
WED NGT...STEADY N BACKING NNW WIND IN THE WAKE OF PASSING NRN
STREAM SHRTWV IS FCST TO ADVECT COLDER AIR INTO THE UPR LKS WITH H85
TEMPS FALLING AS LO AS -18C OVER THE KEWEENAW BY 12Z THU...A FVRBL
SETUP FOR LES. EXPECT A PERIOD OF SOME HEAVIER LK ENHANCED SN IN THE
FAVORED SN BELTS WHEN AREA OF DPVA/DEEP LYR QVECTOR CNVGC/UVV/DEEP
MSTR ASSOCIATED WITH THE PASSING DISTURBANCE COINCIDES WITH FVRBL
UPSLOPE...WEAKLY CYC N FLOW. AREAS OVER ONTONAGON/GOGEBIC IN THE
EVNG AND MARQUETTE/ALGER COUNTIES IN THE LATER EVNG/EARLY OVERNGT
APPEAR TO BE MOST FAVORED TO SEE HEAVIER SN. ENHANCEMENT FACTOR FOR
HEAVIER SN TOTALS INCLUDE FAIRLY DEEP DGZ UP TO 4K FT. ALTHOUGH THE
SHARPEST UVV IS FCST TO BE JUST BLO THE DGZ MUCH OF THE TIME...THERE
WL BE SOME UVV IN THIS ZONE THAT SHOULD ALLOW SN/WATER RATIOS UP TO
20-25:1. ONE NEGATIVE APPEARS TO BE THE ABSENCE OF SHARP CYC FLOW/
PERSISTENT LLVL CNVGC. ALTHOUGH THE LK ENHANCEMENT WL NOT BE A
PLAYER WELL INLAND FM LK SUP...DYNAMIC FORCING SHOULD ALLOW FOR SOME
LIGHT SN EVEN OVER THE SCENTRAL. BUT ABSENCE OF HIER ABSOLUTE MSTR..
.WITH PWAT NO MORE THAN ABOUT 0.3 INCH AND H7 SPECIFIC HUMIDITY
ABOUT 1G/KG...WL LIMIT SN TOTALS TO NO MORE THAN AN INCH OR SO AWAY
FM LK ENHANCEMENT/UPSLOPE WINDS. LATER AT NGT...EXPECT THE SN TO
DIMINISH NW-SE WITH THE ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/
SUBSIDENCE/MID LVL DRYING IN THE WAKE OF THE PASSING SHRTWV THAT IS
FCST TO STRENGTHEN INVRN AS LO AS H875-9 AS SHOWN ON NAM FCST SDNGS.
ALTHOUGH IT IS NOT COMMON PRACTICE TO ISSUE AN ADVY FOR PRIMARLIY A
3RD PERIOD EVENT...SENSITIVE TRAVEL TIME JUST BEFORE THANKSGIVING
HOLIDAY AS WELL AS FAVORABLE UPSLOPE FLOW/FAIRLY EFFICIENT SN GROWTH
PARAMETERS WARRANTS EARLY ISSUANCE OF AN LES ADVY IN THE FAVORED
AREAS OVER THE W/NCENTRAL DESPITE THE RATHER FLUFFY NATURE OF THE SN
THAT IS EXPECTED TO FALL. THE LES ADVY WL INCLUDE GOGEBIC/
ONTONAGON/MARQUETTE AND ALGER COUNTIES. AS MUCH AS 7 TO 8 INCHES OF
SN WL FALL IN THESE AREAS THRU THE ADVY PERIOD. N WINDS GUSTING UP
TO 25-30 MPH WL CAUSE SOME BLSN NEAR LK SUP WED NIGHT INTO THU MRNG.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD SW WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE SN SHOWERS SHOULD END COMPLETELY AT IWD LATE IN
THE AFTN. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN BELTS E OF
MARQUETTE WITH H85 THERMAL TROF/TEMPS ARND -18C REACHING THAT AREA
LATE IN THE DAY...BUT INCRSG ACYC FLOW AND ABSENCE OF SGNFT LLVL
CNVGC/LOWERING INVRN BASE TO H875-9 SHOWN ON THE FCST SDNGS UNDER
THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. THANKSGIVING WL BE QUITE
CHILLY WITH H85 THERMAL TROF PASSING OVHD AND COULD FEATURE SOME
RECORD LO MAX TEMPS. EXPECT THE LOWEST TEMPS OVER THE W HALF WHERE
BACKING FLOW WL LIMIT LK SUP MODERATION. AS THE SFC RDG AXIS SHIFTS
TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING LES WL SHIFT OUT
INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN THE EVNG TOWARD
THE LO END OF GUIDANCE BEFORE MORE HI CLDS OVERSPREAD THE AREA W-E
ASSOCIATED WITH DVLPG ISENTROPIC ASCENT IN THE SW FLOW ON THE NW
FLANK OF PRES SHIFTING INTO THE OH RIVER VALLEY AND IN ADVANCE OF
SHRTWV STREAKING EWD TOWARD MN. SOME OF THE FASTER MODELS SHOW SN
ASSOCIATED WITH THIS WAA/SHRTWV REACHING THE FAR W BY 12Z FRI...SO
WL MAINTAIN SOME LO CHC POPS IN THIS AREA LATE THU NGT.
FRI/FRI NGT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES AND IN ADVANCE OF
SHRTWV TRACKING EWD THRU MN IS PROGGED BY MOST OF THE MEDIUM RANGE
GUIDANCE TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN ON FRI TO THE
NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS INTO MN AND WI.
ALTHOUGH INITIAL SHOT OF SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE
280-290K SFCS/H85-7 FGEN AXIS/DEEP LYR QVECTOR CNVGC IS FCST TO
IMPACT NRN WI ON FRI MRNG...THIS WAA/FORCING MAY SHIFT FARTHER N
INTO UPR MI DURING THE DAY. H7 SPECIFIC HUMIDITY IS FCST AS HI AS 3
G/KG...SO NOT OUT OF THE QUESTION THERE COULD BE SOME MODERATE SN
AMOUNTS APRCHG ADVY CRITERIA OVER THE SRN CWA. AS THE H925 WINDS
BECOME MORE S IN THE PRESENCE OF H85 TEMPS IN THE -8 TO -10C
RANGE...LES OFF LK MI WL IMPACT THE ERN CWA. WL MAINTAIN THE HIER
POPS/QPF IN THIS AREA. ON FRI NGT...MORE NOTABLE MODEL DIFFERENCES
ARE SHOWING UP WITH THE 12Z GFS SHOWING A MORE WNW VS W FLOW ALOFT
AND A STRONGER SHRTWV/SFC LO TRACKING FASTER E ACROSS LK SUP ON FRI
NGT...WITH CYC NW FLOW OF COLDER AIR DVLPG OVER THE CWA LATE FRI
NGT. THIS SOLUTION IS VERY MUCH AN OUTLIER EVEN AMONG THE MOST
RECENT GFS ENSEMBLE GUIDANCE... SO TENDED TO FOLLOW THE MORE
CONSISTENT 12Z CNDN/00Z AND 12Z ECMWF MODELS. THIS GUIDANCE SHOWS A
SLOWER SFC LO AND MORE AGGRESSIVE PUSH TO THE NE OF H85 WARM
FNT...WITH H85 TEMPS RISING ABOVE 0C OVER THE SCENTRAL CWA BY 12Z
SAT ACCOMPANYING DRY SLOTTING/LOWERING POPS OVER THE SRN TIER. WITH
ECWMF SDNGS SHOWING LINGERING LLVL MSTR BLO THE WARMING/DRYING WARM
NOSE ARND H85...ADDED A MENTION OF SOME FREEZING DZ OVER THE SW CWA.
SAT/SAT NGT...SHRTWV EMBEDDED IN ZONAL FLOW OVER SRN CANADA WL
STREAM E...WITH ACCOMPANYING SFC LO STREAKING ENEWD THRU ONTARIO AND
THEN DRAGGING A COLD FNT ACRS THE CWA SAT NGT. AHEAD OF THIS FNT...
MORE CONSISTENT...FAVORED 12Z ECMWF/CNDN MODELS SHOW WARM SURGE INTO
THE UPR LKS WITH H85 TEMPS RISING AS HI AS 8-10C OVER THE SRN TIER
ON SAT UNDER SOME MID LVL DRYING. TENDED TO CUT POPS OVER THE SRN
TIER...WHERE THE ECMWF AND CNDN MODELS SHOW MORE AGGRESSIVE MID LVL
DRYING FARTHER FM THE LO TRACK. CONTINUED TO MENTION SOME RA OR
FREEZING DZ IN THESE AREAS AS WELL. FARTHER TO THE N CLOSER TO THE
LO TRACK AND SOMEWHAT HIER CHC POPS...INCLUDED MENTION OF FREEZING
RA AND RA IN ADDITION TO SN IN CASE THE AIRMASS IS A BIT COLDER. IF
SFC TEMPS END UP HIER THAN CURRENTLY FCST...LATER SHIFTS MAY BE ABLE
TO CUT BACK ON THE FREEZING DZ/RA AND GO WITH PLAIN RA. RIGHT NOW...
LOOKS LIKE ANY ICE ACCUMULATION WL BE MINOR.
EXTENDED...MUCH COLDER AIR...WITH H85 TEMPS FCST AS LO AS -18C BY
00Z MON...AND SOME LK EFFECT SN WL FOLLOW ON SUN UNDER NW FLOW BTWN
DEPARTING COLD FNT AND CNDN HI PRES BLDG E THRU THE NRN PLAINS. BUT
SINCE THE UPR FLOW WL REMAIN FAIRLY PROGRESSIVE...THE SFC HI PRES WL
SHIFT THRU THE GREAT LKS ON MON AND INTO NEW ENGLAND TUE AS UPR RDG
BLDS INTO THE UPR LKS ON TUE. THE RESULT SHOULD BE DIMINISHING LES
ON MON WITH DRY WX LINGERING INTO TUE. WARMER SW FLOW ON THE WRN
FLANK OF DEPARTING SFC HI PRES MAY DRAW ENUF MSTR TO THE N ON TUE TO
BRING A RETURN OF SOME SN OR A RA/SN MIX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1248 PM EST TUE NOV 25 2014
DRIER AIR AND BACKING WINDS TO THE SW WITH APPROACHING WEAK SFC HIGH
PRES RIDGE WILL RESULT IN LAKE EFFECT -SHSN ENDING AND MVFR
CONDITIONS IMPROVING TO VFR AT KIWD DURING THE MID AFTN AND AT KSAW
LATE THIS AFTN. MAY YET SEE SOME BRIEF IFR CONDITIONS AT KSAW BASED
ON RADAR IMAGERY SHOWING HEAVIER SNOW SHOWERS IN NCNTRL UPPER MI.
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT. NEXT APPROACHING
DISTURBANCE MAY BRING SOME -SN/MVFR CONDITIONS TO KIWD LATE WED
MORNING. AT KCMX...WINDS WILL PROBABLY RETAIN ENOUGH OVERWATER
COMPONENT TO MAINTAIN MVFR CONDITIONS THRU THE NIGHT EVEN THOUGH
-SHSN SHOULD END. BEFORE THE -SHSN END...THERE MAY BE A PERIOD OF
SOMEWHAT HEAVIER SNOW SHOWERS AT KCMX THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014
PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM WEDNESDAY TO 10 AM EST
THURSDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY FROM 3 PM EST /2 PM CST/ WEDNESDAY TO
10 AM EST /9 AM CST/ THURSDAY FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
452 PM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.
TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.
SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014
...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...
BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.
MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.
INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.
ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.
ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.
BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1248 PM EST TUE NOV 25 2014
DRIER AIR AND BACKING WINDS TO THE SW WITH APPROACHING WEAK SFC HIGH
PRES RIDGE WILL RESULT IN LAKE EFFECT -SHSN ENDING AND MVFR
CONDITIONS IMPROVING TO VFR AT KIWD DURING THE MID AFTN AND AT KSAW
LATE THIS AFTN. MAY YET SEE SOME BRIEF IFR CONDITIONS AT KSAW BASED
ON RADAR IMAGERY SHOWING HEAVIER SNOW SHOWERS IN NCNTRL UPPER MI.
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT. NEXT APPROACHING
DISTURBANCE MAY BRING SOME -SN/MVFR CONDITIONS TO KIWD LATE WED
MORNING. AT KCMX...WINDS WILL PROBABLY RETAIN ENOUGH OVERWATER
COMPONENT TO MAINTAIN MVFR CONDITIONS THRU THE NIGHT EVEN THOUGH
-SHSN SHOULD END. BEFORE THE -SHSN END...THERE MAY BE A PERIOD OF
SOMEWHAT HEAVIER SNOW SHOWERS AT KCMX THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014
PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM WEDNESDAY TO 10 AM EST
THURSDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY FROM 3 PM EST /2 PM CST/ WEDNESDAY TO
10 AM EST /9 AM CST/ THURSDAY FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1249 PM EST TUE NOV 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE NOV 25 2014
CONCERNS FOCUS MAINLY ON LES TRENDS AND HEADLINES THIS MORNING.
LATEST WATER VAPOR LOOP AND RUC ANALYSIS SHOWS STRONG SHORTWAVE AND
ASSOC STORM SYSTEM LIFTING RAPIDLY NE THROUGH NRN QUEBEC EARLY THIS
MORNING AS A STRONG PACIFIC SHORTWAVE AND ASSOC 150 KT 3H JET MAX
PLOWS EAST THROUGH SRN BRITISH COLUMBIA AND SRN ALBERTA. SUBSEQUENT
MOVEMENT OF THESE TWO SHORTWAVE FEATURES ALLOWING MID-UPR LVL TROUGH
TO WEAKEN OVER THE UPPER GREAT LAKES THIS MORNING. THE WEAKENING
TROUGH AND MID-LVL DRYING FM THE WEST AS NOTED ON MODEL SNDGS HAS
ALLOWED SNOW AND LAKE ENHANCED SNOW TO DIMINISH FROM THE WEST AND
SOUTHWEST PER LATEST RADAR LOOP AND SFC OBS. AS A RESULT...HAVE
CANCELLED LES ADVISORIES OVER THE WESTERN COUNTIES AND WINTER WX
ADVISORY OVER MNM COUNTY THIS MORNING. LES CONTINUES OVER MUCH OF
THE REST OF THE ERN HALF OF THE FCST AREA WHERE LES ADVISORIES
REMAIN IN PLACE INTO EARLY AFTERNOON.
EXPECT THE LES TO GRADUALLY DIMINISH OVER THE ERN COUNTIES LATE THIS
MORNING INTO EARLY AFTERNOON AS DEEP MOISTURE AND MODERATE Q-VECT
CONVERGENCE PULLS NE WITH MOVEMENT OF QUEBEC SHORTWAVE AND CONTINUED
WEAKENING OF ASSOC MID-LVL/SFC TROUGH INTO THE UPPER LAKES. BEHIND
THE WEAKENED TROUGH...MODELS INDICATE FC RIDGE BUILDING IN FM WEST
WITH BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY
REMAINING LES TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE LATE
THIS AFTERNOON AND TONIGHT. AS SUCH...WILL MAINTAIN CHANCE POPS FOR
MUCH OF TODAY AND INTO TONIGHT ACROSS THE KEWEENAW BUT END THE POPS
ACROSS THE FAR WEST. WILL MAINTAIN HIGHER POPS ALONG LAKE SUPERIOR
SHORELINE FAR EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY.
EXPECT ADDITIONAL SNOW ACCUMULATION OF 2 TO LOCALLY 4 INCHES FOR
AREAS ROUGHLY ALONG AND EAST OF A LINE FM HURON MTNS/BIG BAY THROUGH
MQT TO RAPID RIVER WITH THE HIGHER ACCUMS ALONG HIGHER TERRAIN NEAR
LAKE SUPERIOR. ELSEWHERE SNOW WILL TAPER OFF FM A DUSTING TO HALF AN
INCH.
HIGH TEMPS TODAY WILL RANGE FROM THE LOWER 20S INTERIOR WEST TO
UPPER 20S EAST HALF AND OVER THE TIP OF THE KEWEENAW. POTENTIAL FOR
TEMPS TO PLUMMET NEAR ZERO TONIGHT OVER THE TYPICAL COLD SPOTS OF
THE WEST AND CENTRAL INTERIOR AS RIDGE MOVING OVERHEAD WILL RESULT
IN LIGHT WINDS AND CLEARING SKIES. FAVORED LOWER END OF MODEL TEMP
GUIDANCE USING A BLEND OF BIAS-CORRECTED ECMWF AND GEM-NH TEMPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM EST TUE NOV 25 2014
...ACTIVE WITH FREQUENT CHANCES OF LAKE EFFECT OFF BOTH SUPERIOR AND
MICHIGAN...
BROAD TROUGHING ALOFT OVER EASTERN TWO THIRDS OF NORTH AMERICA TO
START THE LONG TERM PERIOD ON WEDNESDAY. PRIMARY SHORTWAVE AND SFC
LOW WITH SWATH OF SNOW OVER THE MID CONUS SHOULD STAY WELL TO THE
SOUTH OVER THE MIDDLE MISSISSIPPI RIVER VALLEY. SHORTWAVE IN THE
NORTHERN STREAM SLIDES FROM SOUTHERN MANITOBA TOWARD UPPER GREAT
LAKES REGION ON WEDNESDAY AFTN. EVEN THOUGH SFC LOW WILL BE WELL TO
SOUTH...TROUGHING SFC-925MB DEVELOPS VCNTY OF LK SUPERIOR AND UPR
MICHIGAN IN RESPONSE THE NORTHERN STREAM SHORTWAVE AND SHARP TEMP
GRADIENT FM NORTHERN ONTARIO TO THE UPPER GREAT LAKES. SE/S WINDS
AHEAD OF THE SFC TROUGH AND MOISTURE TO H85 WITH H85 TEMPS OF -10C
SHOULD SUPPORT SOME LAKE EFFECT OFF NORTHERN LK MICHIGAN INTO THE
EASTERN CWA. MARGINAL INSTABILITY AND LACK OF ENHANCEMENT FACTORS
SHOULD LIMIT LES INTENSITY OVER EAST CWA MOST OF WEDNESDAY. COULD
SEE INCREASE ON WEDNESDAY EVENING WITH LITTLE CHANGE IN LOW-LEVEL
WINDS AND TEMPS BUT INCREASING MOISTURE/LIFT AS THE SHORTWAVE AND
DEEP LAYER Q-VECTOR CONVERGENCE MOVES THROUGH. LATER ON WEDNESDAY
NIGHT...WINDS BECOME W-WNW BLO H85 WHICH WILL DIMINISH THE LES FOR
THE EASTERN CWA.
MEANWHILE...EXPECT LES ON THE KEWEENAW IN WESTERLY LOW-LEVEL FLOW
ON WEDNESDAY MORNING TO SHIFT TO THE AREAS OF WESTERN UPR MICHIGAN
AND EVENTUALLY NORTH CENTRAL UPR MICHIGAN ON WEDNESDAY AFTN INTO
WEDNESDAY EVENING AS WINDS TURN NORTHERLY IN WAKE OF THE SFC TROUGH
PASSAGE. NNE WINDS H95-H85 WITH NORTH WINDS AT SFC AND TEMPS AT H85
OF -15C LEADING TO DELTA T/S NEARING 20C SUPPLEMENTED WITH LARGER
SCALE FORCING FM THE SHORTWAVE COULD RESULT IN HEAVY LES FOR FAR
WEST UPR MICHIGAN...VCNTY OF GOGEBIC COUNTY...LATE WEDNESDAY AFTN
THROUGH MUCH OF WEDNESDAY NIGHT. SIMILAR POTENTIAL FOR HIGHER
TERRAIN OF BARAGA AND MARQUETTE COUNTY WEDNESDAY NIGHT THROUGH
AROUND DAYBREAK ON THANKSGIVING MORNING. SHORTWAVE LIKELY WILL
PRODUCE WIDESPREAD LGT SNOW FOR MOST OF THE CWA AWAY FM THE LAKE
EFFECT AREAS. MOISTURE LACKING WITH H7 MIXING RATIOS AROUND 1G/KG.
THROUGH AND NAM/GFS SOUNDINGS POINT TO MAYBE 6 HOURS OF SNOW AT
IMT/ESC...SO PROBABLY LOOKING AT UP TO AN INCH OF FLUFFY SNOW FOR
AREAS AWAY FM LK SUPERIOR. WINDS UP TO 30 KTS WITHIN THE MIXED LAYER
BUT DOES NOT APPEAR TO BE ESPECIALLY WINDY...SO ALTHOUGH THERE WILL
BE SOME BLSN DOES NOT SEEM THAT WILL BE WIDESPREAD.
INTO THANKSGIVING...WILL BE IMPROVING TREND TO WEATHER AWAY FM LK
SUPERIOR...BUT EXPECT LAKE EFFECT TO PERSIST THROUGH MOST OF THE DAY
ALONG LK SUPERIOR. SOUNDINGS SHOW A CHILLY AIRMASS WITH GRADUALLY
LOWERING INVERSIONS BLO 5KFT BY 00Z FRIDAY. MAX TEMPS ONLY IN THE
LOWER TEENS WEST HALF AND AROUND 20 DEGREES EAST HALF...WELL BLO
NORMAL FOR LATE NOVEMBER AND LIKELY NEAR A RECORD LOW MAX TEMP FOR
THIS DAY. TEMPS AT TOP OF INVERSION HOVER AROUND -18C THROUGH THE
DAY WHICH WILL BE PLENTY GOOD ENOUGH FOR LAKE EFFECT WITH LK
SUPERIOR WATER TEMPS NOW AROUND 3-4C. SNOW SHOULD BE FAIRLY FLUFFY
AS MAJORITY OF CLOUD BEARING LAYER WILL BE WITHIN THE DGZ. SLR/S
COULD BE PUSHING 30:1...SO THAT FLUFF COULD ADD UP QUICKLY.
CONFIDENCE INCREASING THAT WILL NEED ANOTHER ROUND OF LAKE EFFECT
SNOW HEADLINES FOR AREAS ALONG LK SUPERIOR WEDNESDAY AFTN INTO EARLY
THURSDAY. ISOLD WARNING AMOUNTS MAY OCCUR FOR HIGHER TERRAIN AREAS
FAVORED BY NNE WINDS... BUT MOSTLY EXPECT ADVY TYPE SNOWS. NO
HEADLINES THOUGH NOW WITH CURRENT LAKE EFFECT EVENT STILL RUNNING
ITS COURSE. WILL HIGHLIGHT IN THE HWO AND WITHIN THE EWHO GRAPHICS.
ONCE THE SHORTWAVE ON THANKSGIVING CLEARS THE AREA...UPPER LEVEL
FLOW FLATTENS OUT SOME...BUT STAYS WNW COMPARED TO THE WESTERLY FLOW
MODELS INDICATED 24 HR AGO. RESULT IS TIGHT BAROCLINIC ZONE AT
925-850MB STAYS TO THE WEST AND SOUTH OF UPR MICHIGAN. THUS WHEN THE
NEXT SERIES OF SHORTWAVES AND UPPER LEVEL JET PUSH ACROSS THE
NORTHERN PLAINS...MODELS NOW SHOW BAND OF MODERATE SNOW WILL STAY
MOSTLY ALONG THE BAROCLINIC ZONE TO THE SOUTH OF UPR MICHIGAN. H7
MIXING RATIOS 3-4G/KG SUGGEST WHEREVERE THAT BAND OF SNOW DEVELOPS
IT COULD BE AT LEAST MODERATE. MAIN ISSUE OVER UPR MICHIGAN FM THAT
SYSTEM MAY BE LAKE ENHANCED SNOW OVER EASTERN CWA OFF LK MICHIGAN
DUE TO FORCING FM THE SYSTEM GLANCING THE AREA...SSW WINDS
SFC-H85...AND H85 TEMPS -10C OR LOWER. MOST IDEAL LAKE ENHANCEMENT
PERIOD FRIDAY AFTN THROUGH FRIDAY EVENING OVER SOUTHERN SCHOOLCRAFT
INTO LUCE COUNTIES. INCREASED QPF/SNOW AMOUNTS MARKEDLY. LIKELY A
HEADLINE WILL BE NEEDED FOR THOSE AREAS AT LEAST FRIDAY/FRIDAY NIGHT.
ANOTHER SHORTWAVES QUICKLY FOLLOWS FOR SATURDAY. AT THIS POINT
BETTER FORCING AND THUS QPF STAYS ALONG AND NORTH OF LK SUPERIOR.
SOME INDICATION OF AT LEAST LGT PRECIP OVER THE CWA THOUGH. WARM
LAYER H8-H9 BECOMES MORE OF AN ISSUE. ECMWF WARMER THAN GFS AND
WOULD SUGGEST MOSTLY RAIN AS PTYPE OVER MUCH OF CWA BY SATURDAY
AFTN. GFS HAS MAINLY SNOW WITH A LITTLE RAIN WORKING IN OVER SCNTRL.
COULD BE FZRA IF WARMING AT SFC IS DELAYED. BLENDED TWO SOLUTIONS
FOR NOW AND CAME UP WITH HIGHER POPS NORTH AND MOSTLY SNOW IN
MORNING TRENDING TOWARD MORE RAIN/FZRA IN AFTN. FZRA MAY BE NOT AS
LONG LASTING THOUGH...ESPECIALLY IF THE WARMER ECMWF IDEA IS CORRECT
AS SFC WARMING WOULD BE MORE THAN IS SHOWN IN THIS FORECAST. EITHER
WAY...IF THE PRECIP OCCURS...COULD BE KIND OF A MESSY DEAL.
BECOMES COLDER AGAIN /H85 TEMPS -16C TO -20C/ BEHIND THAT SYSTEM TO
CLOSE THE WEEKEND. MORE LES EXPECTED FOR NW FLOW AREAS ALONG LK
SUPERIOR INTO MONDAY. CYCLONIC FLOW LACKING THOUGH AS BROAD HIGH
PRESSURE RIDGE OVER 1035MB EXPANDS FM THE NORTHERN PLAINS TO THE
GREAT LAKES. ANTICYCLONIC FLOW SHOULD LIMIT THE LES COVERAGE AND
INTENSITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1248 PM EST TUE NOV 25 2014
DRIER AIR AND BACKING WINDS TO THE SW WITH APPROACHING WEAK SFC HIGH
PRES RIDGE WILL RESULT IN LAKE EFFECT -SHSN ENDING AND MVFR
CONDITIONS IMPROVING TO VFR AT KIWD DURING THE MID AFTN AND AT KSAW
LATE THIS AFTN. MAY YET SEE SOME BRIEF IFR CONDITIONS AT KSAW BASED
ON RADAR IMAGERY SHOWING HEAVIER SNOW SHOWERS IN NCNTRL UPPER MI.
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT. NEXT APPROACHING
DISTURBANCE MAY BRING SOME -SN/MVFR CONDITIONS TO KIWD LATE WED
MORNING. AT KCMX...WINDS WILL PROBABLY RETAIN ENOUGH OVERWATER
COMPONENT TO MAINTAIN MVFR CONDITIONS THRU THE NIGHT EVEN THOUGH
-SHSN SHOULD END. BEFORE THE -SHSN END...THERE MAY BE A PERIOD OF
SOMEWHAT HEAVIER SNOW SHOWERS AT KCMX THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EST TUE NOV 25 2014
STRONG LOW PRESSURE CONTINUES TO MOVE NE THROUGH NRN QUEBEC TODAY AS
THE GRADIENT GRADUALLY SLACKENS OVER LAKE SUPERIOR. NORTH WINDS HAVE
SUBSIDED BLO GALES OVER ERN LAKE SUPERIOR SO GALE WARNING HAS BEEN
CANCELLED. N-NW WINDS 25-30 KNOTS WILL QUICKLY DIMINISH BLO 20 KNOTS
BY THIS AFTERNOON. GENERALLY QUIET WEATHER EXPECTED FOR THE
REMAINDER OF THE WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH
OF THE LAKE WED AY ALLOW FOR N-NE WINDS TO BRIEFLY GUST NEAR GALE
FORCE WED NIGHT INTO EARLY THU. HIGH PRESSURE BY THE WEEKEND SHOULD
ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ007-013-014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1149 AM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 545 AM CST TUE NOV 25 2014
FURTHER MONITORING OF SATELLITE TRENDS NECESSITATES INCREASING
CLOUD COVER FASTER THAN IN THE 3 AM FCST ISSUANCE. THERE IS A LOT
OF THICK CIRROSTRATUS/ALTOSTRATUS/ALTOCU UPSTREAM AND IT IS NOT
SHOWING ANY SIGNS OF THINNING. SO SKY COVER WAS INCREASED FURTHER.
BASED ON THIS...HIGH TEMPS WERE ALSO LOWERED 2-4F AND THAT MAY NOT
BE ENOUGH GIVEN HOW COLD TEMPS ARE RIGHT NOW. WHILE WAA WILL BE IN
PROGRESS...IT`S ALWAYS HARD TO FIGHT THE EFFECTS OF THICK CLOUD
COVER. WE NOW HAVE 43-50F WITH MID 40S IN THE TRI-CITIES VS.
45-53F WITH UPR 40S IN THE TRI-CITIES.
THE CANADIAN GEM DOES WELL IN THESE "SURPRISE" TEMP REGIMES AND IT
MAY WELL BE ONTO THIS. IT HAS 40-47F WITH 42-44F TRI-CITIES.
SUFFICE TO SAY FURTHER DOWNWARD REFINEMENTS MAY BE FORTHCOMING BY
THE DAY SHIFT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 545 AM CST TUE NOV 25 2014
...BECOMING CLOUDY WITH ANOTHER LIGHT PRECIP EVENT LATE THIS
AFTERNOON/EVE FOLLOWED BY MORE WIND...
ALOFT: THE FLOW WAS HIGHLY AMPLIFIED WITH A LONGWAVE TROF OVER
THE CNTRL USA AND RIDGES JUST OFF BOTH COASTS. WV IMAGERY SHOWED A
SHORTWAVE TROF OVER ALBERTA. THIS TROF WILL DIVE SE INTO THE
DAKOTAS TODAY AND INTO NEB/KS TONIGHT...DEEPENING OVER TIME WITH A
GOOD SHOT OF QG FORCING IN THE EXIT REGION OF A 150 KT UPR-LVL JET.
SURFACE: A CLIPPER LOW WAS ORGANIZING OVER ALBERTA. THIS LOW WILL
RACE INTO THE DAKOTAS TODAY AND BE LOCATED OVER WRN IA BY DAYBREAK
WED. ITS COLD FRONT WILL SWEEP THRU TONIGHT.
TODAY: WAA WILL CONT IN THE WARM SECTOR OF THE CLIPPER. MORNING
SUN WILL RAPIDLY BE OBSCURED BY INCREASING AND DESCENDING MID-HIGH
CLOUDS. ONE WEAKNESS IN THIS FCST IS THAT CLOUDS MAY COME IN THICK
FASTER THAN CURRENTLY DEPICTED. I.E. WE MAY NOT BE PESSIMISTIC
ENOUGH. THAT IS A DENSE CIRRUS SHIELD ON SATELLITE IMAGERY.
MODEL CONSENSUS INCLUDING HI-RES MODELING INDICATE A SWATH OF
FGEN-ENHANCED LIGHT RAIN AND/OR SPRINKLES WILL DEVELOP AND CROSS
THE FCST AREA FROM 3PM-12AM. SPRINKLES ARE MOST LIKELY ON THE SRN
FRINGE OF THE PRECIP SHIELD. INCLUDED SPRINKLES S AND W OF THE
MODEL CONSENSUS OF .01" QPF AS SOME SREF MEMBERS DO HINT AT THE
POSSIBILITY OF RAIN OUTSIDE OF THE BEST MODEL CLUSTERING.
USED THE 05Z BIAS CORRECTED RAP FOR HIGHS TODAY WHICH SEEMS TO
HAVE A BETTER GRASP ON WHERE THICKER CLOUDS WILL ARRIVE FROM THE
N. DESPITE THE CLOUDS SHOULD BE A MILD DAY WITH TEMPS AT OR
SLIGHTLY ABOVE NORMAL.
THERE IS CONSIDERABLE UNCERTAINTY IN DWPTS/RH TODAY WITH 10F OF
SPREAD BETWEEN THE MAV/MET MOS. USED CONSENSUS OF SHORT-TERM HI-
RES MODELS WHICH WERE NOT THE LOWEST BUT DID FAVOR THE DRIER MAV
MOS. THIS WILL WORK BEST OUTSIDE WHERE IT RAINS...BUT MOISTENING
FROM RAINFALL WILL INCREASE DWPTS LOCALLY.
TONIGHT: SWATH OF RAIN/SPRINKLES EXITS TO THE E BY MIDNIGHT.
STRONG CAA KICKS IN AFTER PASSAGE OF THE COLD FRONT WITH A CORE OF
50 KT WINDS AT 850 MB. OUTPUT FROM THE WIND GUST TOOL SEEMED TOO
LOW SO USED GUSTS FROM A BLEND OF THE 18Z/00Z RAW MODEL GUIDANCE
/CONSRAW/. NW WINDS WILL GUST 30-35 KTS N OF HWY 6 BEGINNING 3 AM.
WITH 40 KTS AS LOW AS 1500 FT...CAN`T RULE OUT ISOLATED HIGHER
GUSTS.
P-TYPE: KEPT IT PRIMARILY RAIN/SPRINKLES EXCEPT ON THE EXTREME
NE/E FRINGES OF THE FCST AREA 07Z-08Z ON THE BACK EDGE OF THE
PRECIP...IF IT`S STILL FALLING BY THEN. NAM P-TYPE ALGORITHM KEEPS
IT ALL RAIN AND FCST SOUNDINGS SUGGEST THE LEFTOVER DAYTIME BL
WILL BE TOO WARM TO SUPPORT SNOW. EVEN WETBULB TEMPS FAVOR RAIN
WITH +2 UP TO 1K FT. CURRENT INDICATIONS ARE THAT THE PRECIP
SHOULD BE OVER BY THE TIME TEMP PROFILES COOL ENOUGH FOR SNOW.
MODEL 2M TEMPS SUGGEST A FAIRLY MILD NIGHT WITH LOWS 27-38F AND
30-31F IN THE TRI-CITIES. EVEN THE MOS 3-HOURLY TEMPS SUGGEST
THIS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE NOV 25 2014
WE ARE CALLING FOR A DRY FORECAST FROM START TO FINISH THIS
HOLIDAY WEEKEND. THE PRIMARY FORECAST CONCERN WILL CENTER AROUND
SEVERAL BIG TEMPERATURE SWINGS. EXPECT TWO COLD AIR OUTBREAKS...
ONE ON WEDNESDAY LASTING INTO THANKSGIVING DAY...AND A SECOND SHOT
OF COLD AIR TO FINISH THE HOLIDAY WEEKEND ON SUNDAY. HOWEVER...
FRIDAY AND SATURDAY CURRENTLY APPEAR TO BE WARM WITH HIGHS WELL
ABOVE NORMAL.
WEDNESDAY...A COLD FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW
COOLER AIR TO FILTER INTO OUR REGION THROUGHOUT THE DAY. THEREFORE
...TEMPERATURES WILL WARM VERY LITTLE IF AT ALL DURING THE DAYTIME
HOURS. WE CAN NOT RULE OUT A FLURRY OR TWO WITH A LITTLE 850/700
MB MOISTURE AND COOLER AIR SETTLING IN. HOWEVER...FORECAST MODELS
CONTINUE TO BE IN GOOD AGREEMENT IN 0.00 QPF AND THE CHANCE OF
FLURRIES IS STILL TOO LOW TO INCLUDE MENTION IN THE FORECAST.
THERE COULD BE A PRETTY GOOD TEMPERATURE CONTRAST ACROSS THE
FORECAST AREA AS THE COLD AIR WILL HANG UP MORE OVER NEBRASKA.
THEREFORE...EXPECT HIGHS ON WEDNESDAY SHOULD RANGE FROM THE 30S
ACROSS SOUTH CENTRAL NEBRASKA TO THE LOWER 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...FORECAST MODELS ARE IN INCREASINGLY GOOD AGREEMENT
THAT WE WILL SLOWLY START TO WARM BACK UP ON THANKSGIVING DAY. AN
UPPER RIDGE WILL BEGIN TO WORK ITS WAY EAST INTO THE FORECAST AREA
BRINGING WARMER AIR ALOFT. AT THE SFC...THE WIND WILL TURN TO
SOUTHERLY AND WILL ALSO RESULT IN WARM AIR ADVECTION. THE WARMING
WILL BE GRADUAL ON THANKSGIVING WITH ONLY A FEW DEGREE RISE
EXPECTED OVER WEDNESDAY HIGHS...BUT THE WARM UP WILL INCREASE AS
WE HEAD INTO FRIDAY. AS FOR THANKSGIVING...EXPECT HIGHS IN THE
UPPER 30S NORTHEASTERN ZONES...TO AROUND 40 IN THE TRI-CITIES...TO
THE MID AND UPPER 40S OVER NORTH CENTRAL KANSAS.
FRIDAY AND SATURDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN PORTIONS OF THE DAKOTAS AND IN
CANADA. THIS WILL ALSO KEEP THE STORM TRACK WELL TO OUR NORTH
RESULTING IN CONTINUED DRY CONDITIONS. THERE IS HIGH CONFIDENCE IN
FRIDAY BEING A VERY NICE DAY WITH WARM AIR ADVECTION BOTH ALOFT
AND AT THE SFC. THE SFC WINDS WILL BE FAIRLY LIGHT BUT SHOULD HAVE
A BIT OF A DOWNSLOPE WARMING COMPONENT TO IT BEING OUT OF THE WEST
TO SOUTHWEST. ALL IN ALL EXPECT A VERY NICE DAY WITH HIGHS IN THE
MID TO UPPER 50S IN THE TRI-CITIES TO THE LOWER 60S OVER PORTIONS
OF NORTH CENTRAL KANSAS. FORECAST MODELS ARE COMING INTO BETTER
AGREEMENT WITH THE COLD FRONTAL PASSAGE TIMING ON SATURDAY.
OVERALL FORECAST MODELS HAVE LARGELY SLOWED DOWN THE COLD FRONT
AND BRING IT THROUGH OUR FORECAST AREA SATURDAY EVENING OR
SATURDAY NIGHT. THIS WILL ALLOW FOR FULL DIURNAL HEATING UNDER A
CONTINUED WARM AIR MASS WHICH SHOULD HELP ALL AREAS GET INTO THE
UPPER 50S TO LOWER 60S. THE 00Z ECMWF EVEN INDICATES A FEW SPOTS
COULD HIT 70 SATURDAY AFTERNOON. EVERYTHING HINGES ON THE TIMING
OF THE COLD FRONT...BUT RIGHT NOW SATURDAY APPEARS TO BE A GREAT
DAY TO GET OUT AND ENJOY BEFORE THE NEXT COLD SNAP HITS.
SUNDAY AND MONDAY...THERE IS CURRENTLY DECENT FORECAST AGREEMENT
BETWEEN THE 00Z GFS AND 00Z ECMWF THAT A PRETTY POTENT COLD AIR
MASS WILL OVERSPREAD THE AREA SATURDAY NIGHT INTO SUNDAY. IT
SHOULD BE A DRY FRONTAL PASSAGE SO WE ARE NOT REALLY WORRIED ABOUT
SNOW...BUT IT DOES APPEAR TO BE COLD. OUR FORECAST HIGHS BASED OFF
THE SUPERBLEND OF MODELS RANGE FROM THE UPPER 20S IN ORD TO THE
30S ELSEWHERE AND THIS MAY BE OPTIMISTICALLY TOO WARM IF YOU
BELIEVE THE DETERMINISTIC 00Z GFS AND ECMWF MODEL RUNS. THERE IS A
HIGH LEVEL OF UNCERTAINTY AS TOO HOW LONG THE COLD AIR WILL LINGER
ACROSS THE AREA AS THE 00Z GFS IS MUCH QUICKER TO PUSH THE COLD
AIR OUT ON MONDAY THAN THE 00Z ECMWF.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1135 AM CST TUE NOV 25 2014
THE WEATHER WILL UNDERGO CHANGES DURING THE TAF PERIOD WITH A
PASSAGE OF A COLD FRONTAL BOUNDARY AND AN UPPER LEVEL DISTURBANCE.
CLOUD COVER WILL INCREASE AND THICKEN TODAY/TONIGHT AND CHCS FOR
RAIN SHOWERS INCREASE FOR THE EVENING HOURS. NW WINDS INCREASE AND
WILL BE STRONG/GUSTY BEHIND THE COLD FRONT WITH GUSTS OVER 30KT
EXPECTED. THE STRONG WINDS WILL INCREASE DURING THE OVERNIGHT
HOURS AND REMAIN STRONG/GUSTY ON WEDNESDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 PM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1233 PM CST TUE NOV 25 2014
AT 12 NOON CST IR SAT AND RUC MODEL SHOW THE VORT CENTER PAST
WILLISTON AND MOVING SOUTHEAST. SNOW SHOULD BE QUIT A BIT LIGHTER
ACROSS THE NORTHWEST NOW. THE FOCUS FOR MODERATE SNOW FOR THE NEXT
2 TO 3 HOURS WILL BE FROM STANLEY SOUTHEAST TO BISMARCK. STARTING
TO SEE GUSTY WINDS ACROSS EASTERN MONTANA. WITH TEMPERATURES IN
THE MID 30S SOUTHWEST FOR HIGHS TODAY MAY BE A PROBLEM GETTING
MUCH BLOWING SNOW INITIALLY. AS TEMPERATURES FALL ROADS WILL
BECOME SLICK THERE. WILL CONTINUE THE ADVISORY UNTIL THE BLOWING
SNOW ISSUES ARE RESOLVED.
UPDATE ISSUED AT 928 AM CST TUE NOV 25 2014
IR SATELLITE LOOPS SHOW VORT MAX JUST NORTHWEST OF WILLISTON MOVING
SOUTHEAST AS RUC13 MODEL SHOWS. TRACK OF THIS VORT SHOULD DEFINE
THE HEAVIEST SNOW BAND FOR THE REMAINING MORNING HOURS FROM
WILLISTON TO GARRISON AND NORTH. LIGHTER SNOW SOUTHWEST OF THIS
LINE. WILLISTON SHOWING ONE HALF MILE VSBY IN MODERATE SNOW AT 9
AM CST. SNOW RATES SHOULD BEGIN TO LIGHTEN NORTHWEST ND AS THE
VORT LOBE MOVES PAST LATE THIS AM.
UPDATE ISSUED AT 630 AM CST TUE NOV 25 2014
FORECAST IS ON TRACK. REGIONAL RADARS SHOWS AREA OF SNOW MOVING
INTO EASTERN MONTANA WITH THE MOST RECENT BAKER OB REPORTING SNOW.
CEILINGS CONTINUE TO LOWER ACROSS WESTERN ND LOCATIONS AND
MARMARTH ND DOT WEB CAM NOW SHOWS SNOWFALL OCCURRING. BOWMAN RADAR
ALSO SHOWS STRONGER ECHOES ACROSS THE SOUTHWEST. ONLY CHANGES WERE
TO BLEND FORECAST TO MOST RECENT OBSERVATIONS...OTHERWISE EXPECT
SNOW TO CONTINUE EXPANDING EASTWARD THROUGH THE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CST TUE NOV 25 2014
HIGHLIGHTS INCLUDE A WINTER WEATHER ADVISORY TO BE ISSUED FOR SNOW
AMOUNTS TODAY AND TONIGHT AND GUSTY WINDS TONIGHT.
THE FORECAST CHALLENGE IN THE SHORT TERM WILL BE SNOW AMOUNTS TODAY
AND TONIGHT.
CURRENTLY A SURFACE LOW PRESSURE CENTER WAS OVER SOUTHERN ALBERTA.
AT UPPER LEVELS A FAST-MOVING SHORTWAVE IN THE NORTHWEST FLOW ALOFT
WAS COINCIDENT WITH THE SURFACE LOW. AS THE SHORTWAVE DIVES
SOUTHEAST ACROSS THE DAKOTAS TODAY AND INTO THIS EVENING...THE
SURFACE LOW/CLIPPER WILL ALSO TRACK SOUTHEAST QUICKLY ACROSS THE
REGION. THIS SCENARIO WILL CREATE A STRONG BAROCLINIC ZONE ORIENTED
NORTHWEST-TO-SOUTHEAST ACROSS NORTH DAKOTA. AS THE SYSTEM TRACKS
ACROSS THE STATE...THE BEST LIFT/INSTABILITY WILL BE ALONG AND
NORTHEAST OF THE SURFACE LOW TRACK. MEANWHILE SOUTHWEST OF THE LOW
TRACK (SOUTHWESTERN QUARTER OF ND) WILL BE IN THE WARM SECTOR OF THE
SYSTEM...AND SURFACE TEMPERATURES SHOULD REACH INTO THE LOWER 30S
THERE TODAY. THUS THE SOUTHWEST WILL SEE A RAIN/SNOW MIX...WHILE
LIGHT TO MODERATE SNOW WILL OCCUR ACROSS NORTHWESTERN AND CENTRAL
NORTH DAKOTA.
THE SNOW IS EXPECTED TO BEGIN BEFORE DAYBREAK IN THE FAR
WEST...BECOME MORE INTENSE WITH TIME AS THE FAVORED SNOW BANDS
APPROACH CENTRAL NORTH DAKOTA CLOSER TO NOON...AND CONTINUE THIS
EVENING OVER CENTRAL/EASTERN NORTH DAKOTA. CURRENT MODEL RUNS ARE IN
BETTER AGREEMENT FOR PLACEMENT AND TIMING. THUS EXPECTING 3-4 INCHES
OF SNOW IN AN ARC/LINE FROM CROSBY IN THE FAR NORTHWEST...TO
STANLEY/MINOT/BOTTINEAU TO BISMARCK/JAMESTOWN AND LINTON/OAKES.
AROUND 1.5 TO 2.5 INCHES OF SNOW IS FORECAST FOR MAINLY SOUTH AND
WEST OF THE MISSOURI RIVER...AND IN THE TURTLE MOUNTAINS AREA.
IN ADDITION TO THE SNOW...NORTHWEST WINDS ARE FORECAST TO INCREASE
TO 20 TO 25 MPH THIS AFTERNOON AND EVENING IN THE SOUTHWEST AND INTO
CENTRAL NORTH DAKOTA. ALTHOUGH BLOWING SNOW IS NOT EXPECTED BECAUSE
OF THE FAIRLY WET NATURE OF THE FALLING SNOW...DRIFTING SNOW ACROSS
ROADWAYS COMBINED WITH SNOW-COVERED AND ICY ROADS WILL MAKE FOR
HAZARDOUS TRAVEL.
DECIDED TO ISSUE A WINTER WEATHER ADVISORY FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA. BEGAN THE ADVISORY IN THE WESTERN QUARTER OF
THE STATE THIS MORNING AND ENDED IT THERE AROUND MIDNIGHT TONIGHT.
BEGAN THE ADVISORY FOR CENTRAL NORTH DAKOTA THIS AFTERNOON AND WILL
HAVE IT VALID UNTIL JUST BEFORE SUNRISE WEDNESDAY MORNING...WHEN
WINDS SHOULD BE DECREASING AND SNOW TAPERING TO FLURRIES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 346 AM CST TUE NOV 25 2014
MAIN FORECAST CHALLENGES INVOLVE PERIODIC CHANCES OF PRECIPITATION
AS ACTIVE PATTERN CONTINUES. ON WEDNESDAY...THE STORM SYSTEM WILL
DEPART TO THE SOUTHEAST WITH 1038MB SURFACE HIGH DROPPING
SOUTHWARD ACROSS THE NORTHERN PLAINS. WILL MAINTAIN LOW CHANCE
POPS FOR SNOW ACROSS SOUTHWEST PORTION OF STATE CLOSEST TO SURFACE
LOW/FRONTAL BOUNDARY IN MONTANA. NEXT SYSTEM AFFECTS OUR AREA ON
THURSDAY WITH SURFACE LOW SUPPORTED BY 120KT 300MB JET STREAK
NUDGING IN FROM MONTANA. SNOW TOTALS WITH THIS SYSTEM SHOULD BE IN
THE 1 TO 3 INCH RANGE WITH HIGHEST AMOUNTS EXPECTED ACROSS THE
NORTH NEAR CANADIAN BORDER AND ABOUT 1 TO 2 INCHES ALONG THE I-94
CORRIDOR. MODELS CONTINUE TO INDICATE WARM POCKET ALOFT BEHIND
MAIN BAND OF PRECIP...SO WILL HAVE TO CONTINUE TO MONITOR FOR
POSSIBILITY OF MIX PRECIP TYPE DEVELOPING. ANOTHER SYSTEM MOVES
THROUGH THE AREA FRIDAY/FRIDAY NIGHT WITH A CONTINUED CHANCE OF
LIGHT SNOW...MAINLY NORTH. THIS SYSTEM WILL ALSO PULL ANOTHER SHOT
OF ARCTIC AIR SOUTHWARD RESULTING IN WIND CHILLS IN THE -25 TO
-30F RANGE ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1233 PM CST TUE NOV 25 2014
SURFACE LOW PRESSURE WILL TRACK FROM NORTHWEST NORTH DAKOTA
SOUTHEAST INTO SOUTH DAKOTA TONIGHT. THE LOW WILL BE THE FOCUS
FOR SNOW AND IFR CONDITIONS SPREADING THROUGH WEST AND CENTRAL
NORTH DAKOTA TODAY. GUSTY WINDS TO 35 KTS POSSIBLE SOUTHWEST THIS
AFTERNOON AND EVENING. CONDITIONS IMPROVING TO MVFR WESTERN ND
TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ WEDNESDAY FOR
NDZ003>005-011>013-019>023-025-034>037-042-045>048-050-051.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT
FOR NDZ001-002-009-010-017-018-031>033-040-041-043-044.
&&
$$
UPDATE...WAA
SHORT TERM...JV
LONG TERM...JNS
AVIATION...WAA
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
208 PM MST TUE NOV 25 2014
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014
THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.
THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.
ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014
SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.
THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.
WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014
SNOW AND A RAIN/SNOW MIX WILL CONTINUE ACROSS MUCH OF THE
REGION...BRINGING WIDESPREAD MVFR/IFR CONDITIONS INTO TONIGHT.
SOME LIFR CONDITIONS EXPECTED AROUND THE NRN BLKHLS. LOW CLOUDS
WILL HANG AROUND THROUGH WEDNESDAY MORNING. NORTHWEST WINDS WILL
BE GUSTY THIS AFTERNOON AND INTO TONIGHT...GRADUALLY DIMINISHING
AFTER MIDNIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 7 PM THIS EVENING TO 5 AM MST WEDNESDAY FOR
SDZ014-025-026-031-032-043-072-073.
WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...POJORLIE