Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/15/13
AREA FORECAST DISCUSSION
NWS ALBANY NY
1135 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM...THE LAKE EFFECT BAND EAST OF LAKE ONTARIO HAS
DIMINISHED TO NOTHING MORE THAN FLURRIES WHILE THE LAST REMNANTS OF
MORE SIGNIFICANT SNOW SHOWERS MOVE DONW THE EASTERN MOHAWK
VALLEY...THROUGH THE CAPITAL DISTRICT AND INTO THE TACONICS AND
BERKSHIRES. CURRENT FORECAST HAS THIS COVERED FAIRLY WELL AND HAVE
ONLY MADE ADJUSTMENTS TO THE TEMP GRIDS.
WITH THE SNOWBAND NEARLY DISIPATED EAST OF LAKE ONTARIO HAVE
CANCELLED THE LAKE EFFECT ADVISORIES AND WARNINGS EARLY (THEY WERE
DUE TO EXPIRE AT 100 PM.
.PREVIOUS DISCUSSION...
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS THIS MORNING WITH SOME
SCT-BKN STRATOCU CLOUDS AROUND 4 KFT AND A BKN-OVC MID LEVEL DECK
AROUND 10 KFT.
DURING THE LATE MORNING TO EARLY AFTN HOURS...AN ARCTIC FRONTAL
BOUNDARY...AIDED BY SOME MOISTURE OFF LAKE ONTARIO...WILL PASS
THROUGH THE REGION FROM NORTH TO SOUTH. CONVERGENCE ALONG THIS
BOUNDARY MAY ALLOW FOR SOME SNOW SHOWERS OR SQUALLS ACROSS THE
REGION. THE BEST CHANCE WILL BE FOR KALB/KPSF...AS THE SNOW SHOWERS
MAY PASS DOWN THE MOHAWK VALLEY AND TOWARDS THE CAPITAL
REGION/BERKSHIRES. WE HAVE INCLUDED A TEMPO TO ACCOUNT FOR THIS
POSSIBILITY FOR A BRIEF PERIOD OF IFR CONDITIONS WITHIN SNOW
SHOWERS/SQUALLS DURING THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW
SHOWERS...CIGS WILL BE BKN AROUND 4 KFT DURING THE LATE MORNING TO
AFTN HOURS. CLOUDS SHOULD START TO CLEAR BY THIS EVENING WITH JUST
FEW-SCT LOW CLOUDS AND SOME PASSING CIRRUS OVERNIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY...BECOMING WESTERLY AT
AROUND 10 KTS THIS MORNING. BEHIND THE BOUNDARY...WINDS WILL BE
W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF...WHERE WINDS MAY GUST AS HIGH AS 25 KTS. WINDS WILL
DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING...AND WILL BE
NW OVERNIGHT AT 10 KTS OR LESS.
OUTLOOK...
SATURDAY-SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE SN.
SUNDAY NIGHT-MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT-TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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 SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...GJM/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
628 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST...
LITTLE CHANGE TO THE ONGOING FORECAST AS LAKE BAND WAS A BIT
DELAYED WITH THE TRACK FURTHER SOUTH BUT WILL DO SO IN A COUPLE OF
HOURS. INLAND EXTENT REMAINS AROUND 60 MILES WHICH IS STILL IN
EXCELLENT AGREEMENT WITH LOCAL EXPERIMENTAL PROGRAM. DID TWEAK
TEMPS AS VALUES HAVE INCREASED A BIT DUE TO THE CLOUD COVER AND
BEFORE THE ARCTIC FRONT FROPA.
AS OF 300 AM EST...
THE INITIAL CONCERN THIS MORNING IS THE ONGOING LAKE EFFECT
ACTIVITY DOWNWIND OF LAKE ONTARIO. KTYX DOPPLER RADAR SUGGESTS THE
INLAND EXTENT OF THE >20DBZ WAS ACROSS NORTH CENTRAL HERKIMER
COUNTY AROUND 60 MILES INLAND FROM THE LAKE. THIS IS IN EXCELLENT
AGREEMENT WITH THE LOCALLY DEVELOPED CSTAR RESEARCH OF LAKE EFFECT
INLAND EXTENT PROGRAM WHICH KEEPS THIS BAND AROUND THAT 60 MILE
INLAND PENETRATION THROUGH THE REMAINDER OF THIS EARLY FRIDAY
MORNING. AFTER SUNRISE...THE ARCTIC FRONTAL BOUNDARY IS EXPECTED
TO SLIDE TOWARD THE I90 CORRIDOR WHICH WILL SHIFT THE BOUNDARY
LAYER WIND TOWARD A WEST-NORTHWEST THEN NORTHWEST WHICH WILL TAKE
THIS BAND SOUTHWARD. MAIN QUESTION WILL BE HOW MUCH THIS FRONT
WILL INTERACT WITH THE MOISTURE AND TRANSPORT IT DOWNSTREAM INTO
THE MOHAWK VALLEY AND THE CAPITAL REGION. LOCALLY DEVELOP HIRESWRF
AND HRRR REFLECTIVITY FORECASTS SUGGEST A FEW SNOW SHOWERS AND
SQUALLS MAY MAKE IT INTO THESE REGIONS AS WE WILL PLACE A LITTLE
HIGHER POPS THROUGH THE MORNING HOURS. AS THE FLOW CONTINUES TO
BACK IN THE WAKE OF THE FROPA...THIS BAND WILL WEAKEN AS FLOW
TRAJECTORY BECOMES LESS THAN FAVORABLE FOR OUR REGION AND LOWERING
SUBSIDENCE INVERSION AS SURFACE HIGH BUILDS NORTH OF THE GREAT
LAKES REGION AND EXTENDS ITS INFLUENCE OVER LAKE ONTARIO.
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS THIS MORNING WITH SOME
SCT-BKN STRATOCU CLOUDS AROUND 4 KFT AND A BKN-OVC MID LEVEL DECK
AROUND 10 KFT.
DURING THE LATE MORNING TO EARLY AFTN HOURS...AN ARCTIC FRONTAL
BOUNDARY...AIDED BY SOME MOISTURE OFF LAKE ONTARIO...WILL PASS
THROUGH THE REGION FROM NORTH TO SOUTH. CONVERGENCE ALONG THIS
BOUNDARY MAY ALLOW FOR SOME SNOW SHOWERS OR SQUALLS ACROSS THE
REGION. THE BEST CHANCE WILL BE FOR KALB/KPSF...AS THE SNOW SHOWERS
MAY PASS DOWN THE MOHAWK VALLEY AND TOWARDS THE CAPITAL
REGION/BERKSHIRES. WE HAVE INCLUDED A TEMPO TO ACCOUNT FOR THIS
POSSIBILITY FOR A BRIEF PERIOD OF IFR CONDITIONS WITHIN SNOW
SHOWERS/SQUALLS DURING THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW
SHOWERS...CIGS WILL BE BKN AROUND 4 KFT DURING THE LATE MORNING TO
AFTN HOURS. CLOUDS SHOULD START TO CLEAR BY THIS EVENING WITH JUST
FEW-SCT LOW CLOUDS AND SOME PASSING CIRRUS OVERNIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY...BECOMING WESTERLY AT
AROUND 10 KTS THIS MORNING. BEHIND THE BOUNDARY...WINDS WILL BE
W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF...WHERE WINDS MAY GUST AS HIGH AS 25 KTS. WINDS WILL
DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING...AND WILL BE
NW OVERNIGHT AT 10 KTS OR LESS.
OUTLOOK...
SATURDAY-SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE SN.
SUNDAY NIGHT-MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT-TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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 SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ033-038.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ032.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
330 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 300 AM EST...
THE INITIAL CONCERN THIS MORNING IS THE ONGOING LAKE EFFECT
ACTIVITY DOWNWIND OF LAKE ONTARIO. KTYX DOPPLER RADAR SUGGESTS THE
INLAND EXTENT OF THE >20DBZ WAS ACROSS NORTH CENTRAL HERKIMER
COUNTY AROUND 60 MILES INLAND FROM THE LAKE. THIS IS IN EXCELLENT
AGREEMENT WITH THE LOCALLY DEVELOPED CSTAR RESEARCH OF LAKE EFFECT
INLAND EXTENT PROGRAM WHICH KEEPS THIS BAND AROUND THAT 60 MILE
INLAND PENETRATION THROUGH THE REMAINDER OF THIS EARLY FRIDAY
MORNING. AFTER SUNRISE...THE ARCTIC FRONTAL BOUNDARY IS EXPECTED
TO SLIDE TOWARD THE I90 CORRIDOR WHICH WILL SHIFT THE BOUNDARY
LAYER WIND TOWARD A WEST-NORTHWEST THEN NORTHWEST WHICH WILL TAKE
THIS BAND SOUTHWARD. MAIN QUESTION WILL BE HOW MUCH THIS FRONT
WILL INTERACT WITH THE MOISTURE AND TRANSPORT IT DOWNSTREAM INTO
THE MOHAWK VALLEY AND THE CAPITAL REGION. LOCALLY DEVELOP HIRESWRF
AND HRRR REFLECTIVITY FORECASTS SUGGEST A FEW SNOW SHOWERS AND
SQUALLS MAY MAKE IT INTO THESE REGIONS AS WE WILL PLACE A LITTLE
HIGHER POPS THROUGH THE MORNING HOURS. AS THE FLOW CONTINUES TO
BACK IN THE WAKE OF THE FROPA...THIS BAND WILL WEAKEN AS FLOW
TRAJECTORY BECOMES LESS THAN FAVORABLE FOR OUR REGION AND LOWERING
SUBSIDENCE INVERSION AS SURFACE HIGH BUILDS NORTH OF THE GREAT
LAKES REGION AND EXTENDS ITS INFLUENCE OVER LAKE ONTARIO.
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
...WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS AND THIS WILL CONTINUE
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS WITH JUST SCT-BKN
STRATOCU CLOUDS AROUND 3500-4000 FT. DURING THE LATE MORNING TO
EARLY AFTN HOURS...AN ARCTIC FRONTAL BOUNDARY...AIDED BY SOME
MOISTURE OFF LAKE ONTARIO...WILL PASS THROUGH THE REGION. THIS MAY
ALLOW FOR SOME SNOW SHOWERS ACROSS THE REGION. THE BEST CHANCE WILL
BE FOR KALB/KPSF...AS THE SNOW SHOWERS MAY PASS DOWN THE MOHAWK
VALLEY AND TOWARDS THE CAPITAL REGION/BERKSHIRES. WE HAVE INCLUDED A
PROB30 TO INCLUDE THE POTENTIAL FOR A BRIEF IFR SNOW SHOWER DURING
THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW SHOWERS...CIGS WILL BE
BKN AROUND 4 KFT DURING THE DAY FRIDAY. CLOUDS SHOULD START TO CLEAR
FOR FOR FRIDAY EVENING/FRIDAY NIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY THROUGH THE REMAINDER OF
THE OVERNIGHT HOURS AROUND 5-10 KTS. DURING THE DAY FRIDAY...WINDS
WILL BECOME W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF. WINDS WILL DIMINISH ON FRIDAY EVENING WITH THE LOSS OF
DAYTIME HEATING.
OUTLOOK...
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY THROUGH SUNDAY: HIGH OPERATIONAL IMPACT. SN.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF -SHSN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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 SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ033-038.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ032.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 AM EST FRI DEC 13 2013
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A CONVERGENT UPPER LEVEL
PATTERN OVER THE EASTERN HALF OF THE NATION BETWEEN THE NORTHERN AND
SOUTHERN STREAM FLOW. TROUGHING THAT PAST THROUGH THE SE CONUS THE
PAST 24 HOURS AND HELPED FINALLY EXIT THE OLD COLD FRONT TO OUR
SOUTH IS NOW WELL OFF TO THE EAST OF THE REGION. THIS FEATURE ALSO
SIGNIFICANTLY DRIED OUT OUR COLUMN OVERHEAD WITH IT ASSOCIATED POST
PASSAGE SUBSIDENCE. TO SHOW THE EXTENT OF DRYING THAT WE SAW DURING
THURSDAY...THE 12/12Z KTBW SOUNDING PROFILE HAD A PW OF 1.4" WHILE
THE 13/00Z PROFILE WAS DOWN TO AROUND 0.6". ELSEWHERE...A CLOSED LOW
FEATURE OVER THE 4-CORNERS REGION IS BEGINNING TO OPEN UP AND BECOME
PROGRESSIVE TO THE EAST THIS MORNING. ALREADY BEGINNING TO SEE UPPER
LEVEL SOUTHERN STREAM MOISTURE STREAM EASTWARD AHEAD OF THIS FEATURE
ALONG THE NORTHERN GULF COAST...AND SOME OF THIS CIRRUS WILL BEGIN
TO INVADE OUR SKIES THIS MORNING.
AT THE SURFACE...FLORIDA PENINSULA RESIDES BETWEEN THE OLD DECAYING
FRONTAL BOUNDARY TO OUR SOUTH...AND 1030MB HIGH PRESSURE CENTERED
NEAR THE TN VALLEY. THE GRADIENT BETWEEN THESE 2 FEATURES IS
PROVIDING A GENERAL E/NE FLOW THIS MORNING. THE BOUNDARY LAYER IS
QUITE DRY EARLY THIS MORNING WITH DEWPOINTS IN THE 30S AND
40S...HOWEVER...WITH THE EASTERLY FLOW OFF THE ATLANTIC AND THE LOSS
OF COOL/DRY AIR ADVECTION...THESE LOW LEVEL MOISTURE LEVELS WILL
BEGIN TO CREEP BACK UP BY TONIGHT. TEMPERATURES ARE ALSO BECOMING
QUITE COOL THIS MORNING...ESPECIALLY COMPARED TO THE PAST WEEK WE
ALL EXPERIENCED. IN CLOSEST PROXIMITY TO THE HIGH AND IN A BETTER
DRAINAGE PATTERN OVER THE FAR NORTHERN NATURE COAST...THE BOUNDARY
LAYER IS HAVING A EASIER TIME DE-COUPLING AND MORE EFFICIENT
RADIATIONAL COOLING IS TAKING PLACE. SEVERAL STATIONS NORTH OF
CRYSTAL RIVER ARE ALREADY IN THE LOWER/MID 30S AND WITH THESE TEMPS
"CRASHING THROUGH THE DEWPOINTS"...ITS A GOOD BET THAT WE WILL SEE
SOME PATCHY FROST BEFORE SUNRISE FOR PARTS OF LEVY COUNTY...AND
INLAND NORTHERN CITRUS COUNTY. ELSEWHERE...ALTHOUGH IT WILL BE A
COOL START TO THE DAY...NO FROST OR FREEZE CONCERNS ARE EXPECTED.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...A FAIR WEATHER AND GENERALLY DRY DAY ON TAP TO END OUT THE
WORK WEEK AFTER THE COOL START TO THE MORNING. ZONAL FLOW ALOFT WILL
REMAIN IN PLACE THROUGH THE EVENING HOURS WHILE THE SURFACE HIGH
SHIFTS EASTWARD OFF THE CAROLINA COAST. THE FAIRLY DRY COLUMN AND
LACK OF ANY SYNOPTIC FORCING SUGGEST VERY LOW RAIN CHANCES FOR THE
REGION. ONLY EXCEPTION THAT ONE COULD SEE IS IN FAR EASTERN
POLK/HIGHLANDS COUNTY WHERE THE EASTERLY ONSHORE FLOW ALONG THE FL
EAST COAST COULD BE ENOUGH TO FORCE A FEW SHALLOW SPEED CONVERGENCE
SHOWERS/SPRINKLES. LOCAL HI-RES MODEL RUNS ARE SHOWING THE POTENTIAL
FOR THESE SHOWERS WITH MOST OF THE ACTIVITY EVAPORATING BEFORE
REACHING OUR ZONES. CAN NOT RULE OUT AN ISOLATED SPRINKLE FOR THESE
AREAS DURING THE AFTERNOON HOURS...BUT NO MEASURABLE RAINFALL IS
EXPECTED. OTHERWISE...SOME HIGH LEVEL CIRRUS AT TIMES AND A
DEVELOPING CUMULUS FIELD ASSOCIATED WITH THE INCREASING LOW LEVEL
ATLANTIC MOISTURE WILL GIVE US A MIX OF SUN AND CLOUDS BY THE
AFTERNOON. TEMPERATURES CLIMB TO THE LOWER 70S NORTH...MIDDLE 70S
ALONG THE I-4 CORRIDOR...AND MID/UPPER 70S DOWN TOWARD FORT MYERS.
TONIGHT...A NOTICEABLY WARMER OVERNIGHT PERIOD IN STORE WITH MANY
SPOTS SEEING LOWS 10+ DEGREES WARMER THAN FRIDAY MORNING. SHORTWAVE
IMPULSE WILL EJECT EASTWARD FROM THE SOUTHERN PLAINS TOWARD THE TN
VALLEY WITH AN ASSOCIATED WEAK SURFACE REFLECTION TRACKING ACROSS
THE LOWER MS VALLEY. A COLD FRONT WILL THEN TRAIL BACK FROM THIS
FEATURE INTO THE WESTERN GULF OF MEXICO. ANY SYNOPTIC FORCING OF
INFLUENCE WILL BE WELL TO OUR NORTH AND NORTHWEST AND THE UPPER JET
IS UNFAVORABLE TO AID IN LARGE SCALE LIFT. NO HEIGHT FALLS ARE
SUGGESTED BY ANY GUIDANCE MEMBER...AND GFS ENSEMBLES ARE ALL TIGHTLY
CLUSTERED FOR SATURDAY MORNING. THEREFORE...FEEL CONFIDENT IN A
RAIN-FREE FORECAST FOR ALL ZONES.
SATURDAY...
IT LOOKS LIKE A PATTERN THAT WILL PROVIDE A VERY DIFFERENT FORECAST
FROM NORTH TO SOUTH ACROSS THE FORECAST AREA BY SATURDAY NIGHT. FOR
THE DAYLIGHT HOURS ON SATURDAY THOUGH...LOOKING AT A MAINLY RAIN
FREE FORECAST. INITIAL SHORTWAVE WILL QUICKLY PIVOT UP THE SPINE OF
THE APPALACHIANS...BUT BE FOLLOWED BY YET ANOTHER IMPULSE EJECTING
EASTWARD IN ITS WAKE FROM THE SOUTHERN PLAINS. THE LARGE SCALE FLOW
BETWEEN THESE TWO SHORTWAVE WILL BE NEARLY PARALLEL TO THE FRONT
ALIGNED FROM THE NORTH-CENTRAL GULF COAST TO AL/GA. THIS PARALLEL
FLOW WILL ONLY ALLOW FOR A LIMITED AMOUNT OF EASTWARD PROGRESSION
DURING THE DAY...AND WE WILL BE WAITING TILL THE VERY LATE
DAY/EVENING HOURS FOR THE NEXT IMPULSE TO FINALLY PUSH THE SYSTEM
ENOUGH TO REALLY INFLUENCE ANY OF OUR ZONES. WILL BRING IN A CHANCE
FOR SHOWERS TO CITRUS/LEVY COUNTY AND THE ADJACENT MARINE ZONES
DURING THE LATE AFTERNOON...BUT FEEL MOST OF THE CONVECTIVE ACTIVITY
WILL HOLD OFF UNTIL ALMOST DARK. SO FOR THE MAJORITY OF THE DAY WILL
SEE INCREASING CLOUDS NORTH AND A MIX OF SUN AND CLOUDS SOUTH.
PRE-FRONTAL THERMAL RIDGE AND DECENT DIURNAL MIXING WILL RESULT IN A
WARM SATURDAY WITH MID 70S TO NEAR 80 NORTH AND INTO THE LOWER/MID
80S FROM I-4 CORRIDOR SOUTHWARD. LOW LEVEL FLOW WILL VEER ONSHORE
DURING THE AFTERNOON AND THIS MAY KNOCK THE TEMPS AT THE BEACHES
BACK INTO THE 70S OFF THE RELATIVELY COOLER SHELF WATERS.
SATURDAY NIGHT...THE FRONT ALIGNS JUST TO OUR NORTHWEST WITH THE
APPROACHING TROUGH PROVIDING A ZONE OF DEEP LAYER QG-FORCING AND
INCREASING FAVORABLE UPPER JET DYNAMICS TO SUPPORT RAINFALL. THIS
SETUP IS BEST TO THE NORTH OF TAMPA BAY...AND DECREASES RAPIDLY FROM
THE I-4 CORRIDOR SOUTHWARD. AT THIS POINT...THE EXCELLENT AGREEMENT
OF THE ENSEMBLE GUIDANCE MAKES THIS FORECAST OF HIGHER CONFIDENCE
THAN USUAL. WILL GO WITH LIKELY POPS FOR THE NORTHERN NATURE COAST
ZONES...DECREASING TO CHANCE POPS THROUGH THE I-4 CORRIDOR AND THEN
DECREASING RAIN CHANCES TO 10% OR LESS DOWN TOWARD CHARLOTTE/LEE
COUNTIES. AS OF NOW...THE SEVERE THREAT FOR THE NATURE COAST LOOKS
MARGINAL AT BEST. A FEW ISOLATED WIND GUST CAN NOT BE RULED OUT...
BUT INSTABILITY IS NOT IMPRESSIVE AND NEITHER IS THE LOW LEVEL JET.
SUNDAY...RAPID CYCLOGENESIS IS PROGGED TO TAKE PLACE LATE SATURDAY
NIGHT AND SUNDAY MORNING OVER MID-ATLANTIC/NEW ENGLAND COAST
BAROCLINIC ZONE. AS THIS OCCURS...WOULD ANTICIPATE THE MAIN ENERGY
TO TRANSLATE AWAY FROM OUR REGION WITH THE SURFACE FRONT BECOME
INCREASINGLY STRETCHED WITH TIME. THEREFORE...IT MAY BE DIFFICULT TO
SUPPORT ANY ORGANIZED BANDS OF CONVECTION ON SUNDAY AS THE FRONT
SLOWLY SAGS THROUGH THE REGION. BEST FORECAST AT THIS TIME WOULD BE
FOR A MOSTLY CLOUDY DAY WITH SCATTERED SHOWER COVERAGE DECREASING
THE LATER INTO THE DAY WE GO.
&&
.LONG TERM (SUNDAY NIGHT THROUGH NEXT THURSDAY)...
A COLD FRONT WILL BE MOVING THROUGH THE AREA TO BEGIN THE PERIOD.
THE FRONT WILL BRING WITH IT A LOW CHANCE FOR SHOWERS...GENERALLY
20-30 PERCENT ACROSS THE AREA. THIS FRONT WILL GRADUALLY CLEAR THE
AREA BY MONDAY AFTERNOON WITH COOLER AND DRIER HIGH PRESSURE FROM
THE NORTHERN GULF REGION BUILDING INTO THE AREA BEHIND THE FRONT.
THIS HIGH PRESSURE CENTER WILL SLOWLY SHIFT TO THE EAST ACROSS THE
SOUTHEASTERN STATES THROUGH WEDNESDAY WITH NEAR ZONAL FLOW
ALOFT...THEN SHIFT ENE TO OVER THE WEST ATLANTIC AND EASTERN US
THROUGH THURSDAY. MODELS ARE IN GOOD AGREEMENT THROUGH WEDNESDAY
ACROSS THE REGION WITH THE RIDGING REMAINING IN PLACE ACROSS THE
AREA AND WINDS SHIFTING FROM THE NORTH TO THE EAST THROUGH THE WEEK
ALLOWING FOR A GRADUAL MODERATION IN TEMPS AND MOISTURE.
TEMPERATURES WILL BEGIN BELOW NORMAL FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...THEN NEAR NORMAL TUESDAY...AND RISING ABOVE NORMAL THROUGH
THE REST OF THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH NE FLOW BECOMING
MORE EASTERLY IN THE LATE MORNING/EARLY AFTERNOON AND INCREASING TO
10-12KTS.
&&
.MARINE...
WINDS OVER THE EASTERN GULF OF MEXICO ARE BEGINNING TO SUBSIDE EARLY
THIS MORNING AND WILL CANCEL THE REMAINING SMALL CRAFT ADVISORIES
WITH THE 430AM MARINE FORECAST ISSUANCE. CAUTIONARY LEVEL WINDS AND
SEAS WILL STILL BE AROUND FOR PART OF THE MORNING AND THEN SUBSIDE
BELOW HEADLINE CRITERIA FOR THE AFTERNOON. ANOTHER BRIEF ROUND OF
CAUTIONARY LEVEL WINDS IS POSSIBLE FRIDAY NIGHT WITH WINDS AGAIN
SUBSIDING BELOW HEADLINE CRITERIA FOR SATURDAY. A COLD FRONT WILL
SLOWLY SAG THROUGH THE FORECAST WATERS LATE SATURDAY NIGHT AND
SUNDAY WITH A WIND SHIFT TO THE NORTHWEST AND NORTH IN ITS WAKE. A
ROUND OF SHOWERS AND STORM WILL ACCOMPANY THIS FRONT LATER SATURDAY
INTO SUNDAY MORNING WITH THE BEST CHANCES FOR STORMS TO THE NORTH OF
TARPON SPRINGS.
&&
.FIRE WEATHER...
HIGH PRESSURE TO OUR NORTH WILL SHIFT OFF THE CAROLINA COAST BY
TONIGHT. THE NEXT SYSTEM TO EFFECT OUR REGION WILL APPROACH FROM THE
WEST ON SATURDAY GIVING GOOD RAIN CHANCES SATURDAY NIGHT AND SUNDAY
MORNING TO AREAS NORTH OF TAMPA BAY. EASTERLY FLOW WILL BEGIN TO
DELIVER INCREASINGLY LOW LEVEL MOISTURE OFF THE ATLANTIC TODAY AND
SHOULD PREVENT ANY CRITICALLY LOW LEVELS OF RELATIVE HUMIDITY. A
FURTHER INCREASE IN LOW LEVEL MOISTURE BY SATURDAY WILL KEEP
RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS. AREAS OF FOG
ARE ANTICIPATED TO DEVELOP AFTER MIDNIGHT FRIDAY NIGHT INTO EARLY
SATURDAY MORNING...ALTHOUGH A WIDESPREAD DENSE FOG EVENT DOES NOT
APPEAR LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 63 79 69 / 0 0 10 40
FMY 80 64 83 68 / 10 0 0 10
GIF 75 59 82 66 / 10 10 10 40
SRQ 78 62 79 69 / 0 0 10 30
BKV 74 57 82 67 / 0 0 20 50
SPG 74 65 79 69 / 0 0 10 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...COLSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CST FRI DEC 13 2013
.DISCUSSION...
319 PM CST
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
NOT MUCH HAS CHANGED WITH THE CURRENT THINKING FOR TONIGHT AND
SATURDAY REGARDING SNOWFALL AMOUNTS AND PLACEMENT. THE CURRENT
WATER VAPOR IMAGERY CONTINUES TO INDICATE A DECENT DISTURBANCE
NEAR THE TEXAS PANHANDLE EARLY THIS AFTERNOON...WITH SEVERAL LEAD
DISTURBANCES ACROSS OK AND INTO WESTERN MO. PROFILER AND VWP DATA
ACROSS THE SOUTHERN PLAINS AND MID MISSISSIPPI VALLEY INDICATES
THAT AROUND 30KT OF SOUTHWESTERLY FLOW AROUND 850 MB HAS DEVELOPED
IN ASSOCIATION WITH THIS SYSTEM. THIS IS ALLOWING FOR SOME DECENT
MOISTURE TRANSPORT AND ISENTROPIC ASCENT ACROSS THE MISSOURI AND
WEST CENTRAL ILLINOIS THIS AFTERNOON. THIS HAS PRODUCED A GOOD
AREA OF PRECIPITATION ACROSS MISSOURI...ESPECIALLY ALONG THE
LEADING EDGE OF THE BETTER MOISTURE TRANSPORT.
I EXPECT THIS AREA OF PRECIP TO CONTINUE TO MOVE NORTHWARD AND TO
OVERSPREAD MOST AREAS ALONG AND SOUTH OF INTERSTATE 80 THROUGH THE
EVENING AS THE BETTER MOISTURE GETS DRAWN NORTHWARD IN ASSOCIATION
WITH THE APPROACHING SOUTHERN STREAM SYSTEM. IT APPEARS LIKELY THAT
A BAND OF MODERATE TO HEAVY SNOW WILL SET UP THIS EVENING ACROSS MY
SOUTHERN COUNTIES...IN ASSOCIATION WITH A DEVELOPING BAND OF
FRONTOGENESIS. THE ENHANCED FORCING FOR ASCENT WITHIN THE
FRONTOGENETIC CIRCULATION WILL ALLOW FOR SOME DECENT ASCENT WITHIN
THE DENDRITIC GROWTH ZONE. THIS ALONG WITH THE FACT THAT STEEP LAPSE
RATES AND -EPV EXITS WITHIN AND ABOVE THIS ZONE ALSO SUGGESTS THAT
THEIR WILL BE SOME FAIRLY EFFICIENT SNOWFALL PRODUCTION WITHIN THIS
BAND OF SNOW. WITH THIS IN MIND...IT APPEARS THAT SNOWFALL RATES
COULD APPROACH 1 INCH PER HOUR FOR A COUPLE HOUR PERIOD THIS
EVENING...ESPECIALLY TO THE SOUTH OF INTERSTATE 80 WITHIN AND NEAR
THE CURRENT WINTER STORM WARNING.
A SECOND AREA OF SNOW WILL BE FAVORED...MAINLY ACROSS SOUTHERN
WISCONSIN THIS EVENING AS A SECONDARY AXIS OF FRONTOGENESIS DEVELOPS
ALONG A BAROCLINIC RIBBON...AND COMBINES WITH INCREASING FLOW AND LOW
LEVEL CONVERGENCE OFF OF LAKE MICHIGAN. HOWEVER...MOST HIGH RES
GUIDANCE CONTINUES TO FAVOR AREAS NORTH OF THE ILLINOIS BOARDER.
THEREFORE...IT APPEARS MOST OF NORTHERN ILLINOIS WILL REMAIN SNOW
FREE...THROUGH AT LEAST MID TO LATE EVENING.
THE SNOW SHOULD BEGIN TO SPREAD NORTHWARD BY LATE THIS EVENING...AND
BEGIN IMPACTING MOST OF NORTHERN ILLINOIS BY OR SHORTLY AFTER
MIDNIGHT AS THE SURFACE INVERTED TROUGH BECOMES ORIENTED NORTH TO
SOUTH ACROSS THE AREA OVERNIGHT. THE SNOW WILL CONTINUE INTO
SATURDAY AS SOME LARGER SCALE SUPPORT FOR ASCENT OVERSPREADS THE
AREA IN ASSOCIATION WITH THE APPROACHING NORTHERN STREAM SHORT WAVE.
THIS COULD EVEN LEAD TO A BIT IN AN UPTICK TO THE SNOWFALL
INTENSITY...PARTICULARLY ACROSS EASTERN ILLINOIS AND NORTHWESTERN
INDIANA...WHERE MID LEVEL DEFORMATION WILL CONTINUE IN ASSOCIATION
WITH THE MID LEVEL CIRCULATION. THE SNOW WILL GRADUALLY END ACROSS
NORTHERN ILLINOIS AS THE FLOW TURNS NORTHWESTERLY. SOME LINGERING
LAKE EFFECT SNOW SHOWERS ARE POSSIBLE ACROSS NORTHWESTERN INDIANA
INTO SATURDAY EVENING.
THERE ARE SOME POSSIBILITIES FOR SOME LAKE ENHANCEMENT FOR AREAS
NEAR THE LAKE LATE TONIGHT AND INTO SATURDAY AS THE FLOW TURNS EAST
NORTHEASTWARD. HOWEVER...THERMODYNAMICS OVER THE LAKE DO NOT APPEAR
TO BE VERY FAVORABLE FOR ANY SIGNIFICANT LAKE ENHANCEMENT POTENTIAL.
DELTA T`S LOOK TO REMAIN AROUND 12 DEGREES CELSIUS AND EQUILIBRIUM
LEVELS NEVER APPEAR TO REACH INTO THE DENDRITIC GROWTH ZONE.
SO...OVERALL...IT STILL APPEARS SNOWFALL AMOUNTS WILL RANGE FROM
ABOUT 5 TO 8 INCHES ACROSS THE WARNING AREA...3 TO 6 INCHES IN THE
ADVISORY AREAS...AND 2 TO 3 INCHES AROUND NORTHEASTERN
ILLINOIS...AND AN INCH OR LESS ACROSS NORTH CENTRAL ILLINOIS.
ONCE THE SNOW ENDS...THE NORTHWESTERLY FLOW WILL ALLOW COLDER AIR
TO SPILL BACK ACROSS THE REGION SETTING UP ANOTHER COLD SUNDAY
MORNING.
KJB
MEDIUM-LONG RANGE...SUNDAY THROUGH NEXT FRIDAY...
HIGHLIGHTS OF THE MEDIUM-LONG RANGE FORECAST PERIOD ARE CONTINUED
NORTHWEST UPPER FLOW WITH A PARADE OF WEAK CLIPPER SYSTEMS INTO
MID-WEEK...THEN A SHIFT TOWARD SOUTHWEST FLOW ALOFT MID/LATE NEXT
WEEK AS UPPER RIDGE BUILDS ACROSS THE EASTERN PACIFIC AND GULF OF
ALASKA AND INDUCES DOWNSTREAM LONG WAVE TROUGH ACROSS WESTERN NORTH
AMERICA. THIS WILL SUPPORT A TRANSITION FROM BELOW NORMAL TEMPS
SUN-WED...WITH THE POTENTIAL FOR A BRIEF WARM-UP THURS-EARLY FRI
AHEAD OF WESTERN TROUGH.
SUNDAY THROUGH WEDNESDAY...
MID-LEVEL SHORT WAVE TROUGH AXIS ASSOCIATED WITH EARLY WEEKEND
WINTER STORM WILL BE WELL EAST OF THE REGION BY SUNDAY MORNING.
MID/UPPER LEVEL LOW OVER DEVELOPS OVER ONTARIO AND THE NORTHERN
LAKES HOWEVER...WITH REGION OF ENHANCED NORTHWEST FLOW ALOFT FROM
THE NORTHERN PLAINS TO THE MIDWEST. SEVERAL MINOR AMPLITUDE RIPPLES
ARE INDICATED IN MODEL GUIDANCE WHICH PROPAGATE ALONG LOW LEVEL
BAROCLINIC ZONE WHICH STRETCHES NORTHWEST-SOUTHEAST ACROSS THE
REGION. SOME TIMING DIFFERENCES WITH THE MORE SUBTLE DISTURBANCES
BETWEEN MODELS...THOUGH IT APPEARS A WEAK WAVE WILL TRAVERSE THE
AREA SUNDAY WITH A SOMEWHAT BETTER DEFINED VORT MOVING OVER THE AREA
SUNDAY NIGHT AND EARLY MONDAY. FORECAST SOUNDINGS AND TIME/HEIGHT
DEPICTIONS INDICATE GENERALLY DRY MOISTURE PROFILES...WITH ONLY A
POCKET OF DEEPER MID-LEVEL MOISTURE SUNDAY NIGHT-EARLY MONDAY WITH
ISENTROPIC FORCING AHEAD OF THE STRONGER WAVE. THUS THE BEST
POTENTIAL FOR A LITTLE LIGHT SNOW APPEARS BE SUNDAY NIGHT...THOUGH
WITH LITTLE ACCUMULATION EXPECTED (A DUSTING TO PERHAPS A HALF INCH)
AS LIFT APPEARS GENERALLY WEAK AND WELL BELOW THE DENDRITIC GROWTH
ZONE. WEAK ASCENT LINGERS INTO MONDAY...ESPECIALLY ACROSS THE
NORTHEAST/EAST PARTS OF THE CWA WITH THE LEFT EXIT REGION OF THE
UPPER JET STREAK HELPING TO MAINTAIN SOME LARGE SCALE SUPPORT DURING
THE DAY. A MORE AMPLIFIED SHORT WAVE IS PROGGED TO DIG ACROSS THE
WESTERN GREAT LAKES REGION ON TUESDAY...THOUGH THE BEST WARM
ADVECTION AND ISENTROPIC UPGLIDE APPEARS TO REMAIN JUST TO THE
NORTH/NORTHEAST OF THE CWA...THOUGH A REINFORCING PUSH OF COLDER AIR
DOES ARRIVE TUESDAY NIGHT WITH A COLD FRONT.
COLDEST CONDITIONS LOOK TO OCCUR SUNDAY BEHIND THE EARLY WEEKEND
WINTER STORM...WITH HIGHS IN THE TEENS AND LOWS IN THE SINGLE DIGITS
TO AROUND 10 ABOVE. SOME MODERATION OCCURS MON-TUE WITH THE WEAK BUT
NEARLY PERSISTENT WARM ADVECTION ASSOCIATED WITH THE AFOREMENTIONED
CLIPPERS. A LITTLE COOLER TUESDAY NIGHT-WEDNESDAY BEHIND TUESDAY
NIGHTS COLD FRONT.
AS INDICATED ABOVE...DEVELOPING UPPER RIDGING OVER THE EAST PACIFIC
AND TROUGH INDUCEMENT OVER THE WESTERN CONUS WEDNESDAY-THURSDAY
RESULTS IN SURFACE LOW PRESSURE DEVELOPMENT OVER THE PLAINS BY EARLY
THURSDAY. FAIRLY DECENT MODEL AGREEMENT IN THIS LOW DEEPENING AND
LIFTING NORTHEAST ACROSS MINNESOTA AND THE NORTHERN GREAT LAKES
THURSDAY AND THURSDAY NIGHT...PLACING WFO LOT CWA IN THE WARM SECTOR
AS WARM FRONT LIFTS NORTH. SHALLOW COLD SURFACE LAYER MAY RESULT IN
A LITTLE MIXED PRECIPITATION THURSDAY MORNING ESPECIALLY NORTH AS
WARMING OCCURS MORE VIGOROUSLY ALOFT...THOUGH GFS/ECMWF RUNS
INDICATE THAT LOW LEVELS WARM ENOUGH TO PRODUCE MAINLY RAIN BY
THURSDAY EVENING/NIGHT. SOME TIMING DIFFERENCES DO ARISE WITH THE
NEW 12Z ECMWF (THE 00Z RUN WAS IN BETTER AGREEMENT WITH THE 00/12Z
GFS AND ENSEMBLE MEMBERS)...WITH THE ECMWF FASTER WITH THE LOW
LIFTING ACROSS THE NORTHERN LAKES EARLY FRIDAY AND BRINGING THE
TRAILING COLD FRONT THROUGH FASTER. CONTINUE TO FAVOR A SLIGHTLY
SLOWER SOLUTION SIMILAR TO THE 00Z EC/12Z GFS AND GEFS RUNS. THIS
WOULD SUPPORT TEMPS POTENTIALLY WARMING INTO THE 35-40 F RANGE
THURSDAY AND POTENTIALLY INTO THE 40S/EVEN 50 ACROSS THE SOUTHEAST
FRIDAY PRIOR TO COLD FRONTAL PASSAGE. PRECIP POTENTIAL APPEARS TO BE
GREATEST ALONG/AHEAD OF THE COLD FRONT INTO FRIDAY. DECREASING
THICKNESSES IN COLDER AIR BEHIND THE FRONT PORTEND A CHANGE BACK TO
SNOW FROM THE WEST FRIDAY.
THINGS LOOK POTENTIALLY INTERESTING JUST BEYOND THE END OF DAY
7...AS SOUTHWEST-NORTHEAST ORIENTED BAROCLINIC ZONE COULD BECOME THE
FOCUS FOR A COUPLE OF ROUNDS OF WINTRY PRECIP SOMEWHERE FROM HERE
INTO THE OHIO VALLEY...WHILE HIGH PRESSURE AND A RETURN TO
SUB-AVERAGE TEMPS BUILD BACK ACROSS THE UPPER MIDWEST.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ONSET TIMING OF SNOW TONIGHT AND PERIOD OF GREATEST INTENSITY
OVERNIGHT ALONG WITH MAGNITUDE OF RESULTING VISIBILITY
RESTRICTION.
* TIMING OF DETERIORATION FROM VFR TO LIFR THIS EVENING AND
IMPROVEMENT BACK TO MVFR SAT AFTERNOON.
* VELOCITY OF E TO NE WIND.
TRS
//DISCUSSION...UPDATED 18Z...
SIGNIFICANT UPPER DISTURBANCE OVER THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS LATE THIS MORNING IS FORECAST TO CONTINUE TO
MOVE E ACROSS THE PLAINS TO THE CENTRAL AND LOWER MO VALLEY BY
12Z SAT...AND THEN ON TO THE UPPER MIDWEST AND MID MS VALLEY BY
15/00Z. ASSOCIATED SURFACE LOW TO TRACK SE FROM KS TO THE LOWER
MS VALLEY BY SAT MORNING AND THEN E ACROSS THE DEEP S DURING THE
DAY. MEANWHILE...A SECOND LOW IS TO DEVELOP IN THE PLAINS AND
REACH THE MID MS VALLEY BY 12Z...CONTINUING UP THE OH VALLEY
DURING THE DAY.
PER 12Z RAOBS A STRONG BAROCLINIC ZONE WAS FROM THE CANADIAN
ROCKIES ESE ACROSS THE FAR NORTHERN PLAINS AND THE UPPER MIDWEST
AND THROUGH THE GREAT LAKES INTO THE NE STATES /850HPA TEMP OF
-23C AT INL AND +7C AT SGF/. MODELS INDICATE THAT AS THE STORM
SYSTEM MOVES E TODAY AND TONIGHT THAT THE BAROCLINIC ZONE WILL
SHIFT S AS COLD AIR ADVECTION CONTINUES OVER THE GREAT LAKES AND
THE NORTHERN PORTION OF THE UPPER MIDWEST WHILE STRONG WARM AIR
ADVECTION SPREADS FROM THE LOWER MO VALLEY TO THE MID MS VALLEY
AND THEN ACROSS THE OH VALLEY AND MIDWEST.
MID LEVEL MOISTURE AS WELL AS LOWER LEVEL MOISTURE /12Z 700HPA
DEW POINT DEPRESSION OF 1 DEG C AT OUN AND FWD...850HPA
DEPRESSION OF 0-1 DEG C AT CRP AND FWD/ IS PROGGED TO RAPIDLY
STREAM N AND NE FROM THE SOUTHERN PLAINS AHEAD OF THE APPROACHING
SYSTEM. MVFR CEILINGS HAD ALREADY SPREAD AS FAR NE AS IRK AND
QUN AT MIDDAY. AS THIS MOISTURE CONTINUES TO MOVE INTO AND
OVERSPREAD THE LOCAL AREA THIS EVENING CEILINGS ARE ANTICIPATED TO
DROP FROM VFR THROUGH MVFR AND IFR TO LIFR DURING THE MID AND LATE
EVENING.
ALONG WITH THE ARRIVAL OF DEEP MOISTURE WILL BE UPWARD MOTION
INCREASING IN BOTH DEPTH AND STRENGTH THROUGH THE COLUMN AS
INS ENTROPIC UPGLIDE/Q-VECTOR CONVERGENCE/FRONTOGENESIS INCREASES
AND EXPECT LIGHT SNOW TO BEGIN LOCALLY AROUND 03Z AND INTENSIFY BY
06Z WITH A PERIOD OF MODERATE SNOWFALL OCCURRING OVERNIGHT CAUSING
INCREASING REDUCTION IN VISIBILITY. WITH THE SURFACE LOW TO TRACK
FROM CENTRAL MO NE TO NORTHERN IN OVERNIGHT AND SAT MORNING THE
LOCAL AREA LOOKS TO BE MORE ON THE NORTHERN EDGE OF THE SNOWFALL
WITH THE BAND OF HEAVIER SNOW ACROSS CENTRAL IL TO CENTRAL AND
NORTHERN IN.
THERE MAY BE SOME LAKE ENHANCEMENT TO THE SNOWFALL OVERNIGHT
TONIGHT INTO EARLY SAT AFTERNOON BUT ANY SIGNIFICANT LAKE EFFECT
SNOW IS EXPECTED TO BE OCCURRING IN NW IN AS THE LOW LEVEL FLOW
VEERS FROM NE TO N.
CONDITIONS TO IMPROVE SAT DURING THE LATER MORNING AND THE
AFTERNOON AS THE SURFACE AND 850HPA LOWS MOVE E TO OH...AND THE
UPPER TROUGH AXIS REACHES LAKE MI AND LOWER OH VALLEY BY 15/00Z.
WINDS LOCALLY DO NOT LOOK TO BE PARTICULARLY STRONG WITH THIS
SYSTEM...GENERALLY IN THE 8-12KT RANGE REST OF TODAY THROUGH THE
DAY SAT WHILE WINDS BACK FROM OUT OF THE E TO THE NE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FCST.
* MEDIUM CONFIDENCE IN TIMING OF ONSET...THE PERIOD OF GREATER
INTENSITY...AND ENDING TIME.
* MEDIUM CONFIDENCE IN TIMING OF DETERIORATION FROM VFR TO LIFR.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...MAINLY VFR. PERIOD OF MVFR CIGS EARLY EVENING
WITH LIGHT SNOW/FLURRIES ENDING.
SUNDAY-MONDAY...SLIGHT CHC OF SNOW AND MVFR.
TUESDAY-WEDNESDAY...MAINLY VFR
THURSDAY...VFR. POSSIBLE PERIOD OF LGT WINTRY MIX.
BEACHLER
&&
.MARINE...
144 PM CST
A LARGE AREA OF HIGH PRESSURE IS SETTLING OVER THE SERN CONUS AS WEAK
LOW PRESSURE MOVING ACROSS NRN NEW ENGLAND DAGS A COLD FRONT DOWN
LAKE MICHIGAN. THE FRONT HAS STALLED OUT OVER THE SOUTHERN TIP OF
THE LAKE LEADING TO LIGHT AND VARIABLE WINDS OVER THE SOUTHERN TIP
OF THE LAKE. NORTH WINDS ARE STRENGTHENING OVER THE NORTHERN
PORTIONS OF THE LAKE AS ANOTHER AREA OF ARCTIC HIGH PRESSURE BUILDS
OUT OF CANADA AND SPREADS ACROSS THE NRN PLAINS AND UPPER GREAT
LAKES. THE FRONT OVER THE SRN PORTIONS OF THE LAKE WILL WASH OUT AS
A DOUBLE BARRELED LOW PRESSURE SYSTEM DEVELOPS OVER THE SRN AND
CNTRL PLAINS. THE COMPLEX LOW PRESSURE SYSTEM WILL TRACK EWD THIS
EVENING WITH ONE CIRCULATION CENTER TRACKING THROUGH CNTRL IL AND
ANOTHER TRACKING THROUGH THE LOWER MISSISSIPPI VALLEY. A WEAK
INVERTED SFC TROUGH AXIS ASSOCIATED WITH THE MORE NORTHERN OF THE
TWO LOWS WILL MOVE ACROSS THE LAKE EARLY TOMORROW. AS THE HIGH
BUILDS ACROSS THE UPPER GREAT LAKES THIS EVENING...WINDS OVER THE
ENTIRE LAKE WILL GRADUALLY TURN EASTERLY...BUT AS THE INVERTED
TROUGH AXIS CROSSES THE LAKE TOMORROW...WINDS OVER THE LAKE WILL
GRADUALLY BACK THROUGH NELY TO NORTHERLY TOMORROW EVENING AND THEN
THEN CONTINUE TO BACK TO NWLY BY LATE SATURDAY NIGHT AND EARLY
SUNDAY MORNING. AS COLDER AIR ASSOCIATED WITH THE ARCTIC HIGH IS
DRAWN OVER THE LAKE...THE STRONG COLD ADVECTION AND STRENGTHENING
PRESSURE GRADIENT WILL LEAD TO WINDS INCREASING TO AROUND 30KT
THROUGH THE DAY ON SUNDAY. WHILE GALES ARE NOT EXPECTED AT THIS
TIME...THE STRONG WINDS AND COLDER AIR WILL LEAD TO A CHANCE FOR
LIGHT TO MODERATE FREEZING SPRAY ON SUNDAY. THE BRISK NWLY WINDS
WILL PERSIST THROUGH SUNDAY NIGHT...AND THEN ANOTHER HIGH WILL BUILD
ACROSS LAKE MICHIGAN ON MONDAY...ALLOWING WINDS TO TEMPORARILY
SUBSIDE. AS THE HIGH MOVES OFF TO THE EAST ON TUESDAY...ANOTHER LOW
WILL TRACK ACROSS SCNTRL CANADA...LEADING TO INCREASING SWLY-WLY
WINDS BY TUESDAY...WHICH SHOULD PERSIST THROUGH THE MIDDLE OF NEXT
WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ033-ILZ039 UNTIL NOON SATURDAY.
WINTER WEATHER ADVISORY...ILZ019-ILZ021-ILZ022-ILZ023-ILZ032
UNTIL NOON SATURDAY.
WINTER WEATHER ADVISORY...ILZ014...10 PM FRIDAY TO 6 PM SATURDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL NOON SATURDAY.
WINTER STORM WARNING...INZ010-INZ011-INZ019 UNTIL NOON SATURDAY.
LM...SMALL CRAFT ADVISORY...LMZ740...MIDNIGHT SATURDAY TO 3 PM
SATURDAY.
SMALL CRAFT ADVISORY...LMZ741-LMZ742-LMZ743...3 AM SATURDAY TO 3
PM SATURDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
216 PM CST Fri Dec 13 2013
.DISCUSSION...
ISSUED 205 PM CST Fri Dec 13 2013
Clouds continue to lower and thicken this afternoon ahead of the winter
storm system expected to affect our area tonight into Saturday. Already
seeing some light rain and sleet pushing into extreme southwest IL early
this afternoon as the upper level wave tracks across the southern Plains.
SHORT TERM...Tonight through Monday
Significant snowfall expected over parts of central through east
central Illinois tonight thru Saturday morning...but not much in
the way of strong winds with this particular storm system.
The main forecast challenge this period will be with snowfall totals
starting tonight thru early Saturday afternoon. Will continue to hold
on to the winter weather advisory with a few locations across central
thru east central Illinois edging close to 6 inches by the time the
snow tapers off to flurries Saturday afternoon. Forecast soundings,
at least for a few hours late this afternoon into early this evening,
continues to suggest a brief period of rain, sleet and possibly some
freezing rain over parts of west central Illinois before we see the
lower layers saturate and cool sufficiently enough to support mostly
snow thru the overnight hours. NAM-WRF time height cross sections
indicate the best forcing coupled with the deeper moisture/and dendritic
growth zone will be mainly tonight thru about 14z Saturday. Using a
13:1 SLR indicates 4 to 6 inches will be common across the area by the
time the snow diminishes on Saturday.
Still a bit concerned about the potential for banding, especially
along the inverted trof, which is expected to push across our area
early Saturday morning. Several of the hi-res models suggest the
threat is there but unfortunately, are not very consistent in depicting
the location. Past few runs of the HRRR have indicated one band to move
north across the area this evening, with a break over parts of central
thru east central IL around midnight, before another band pushes
acrs the area towards morning with the inverted trof. Wouldn`t at all
be surprised to see a few areas with 6 to 8 inches accumulation by late
Saturday morning, but at this time, the threat appears too isolated.
Models are a bit more consistent in showing an increase in snow totals
just to our east as the weak surface low and inverted trof shift off
to our east and we see a better coupled 250mb jet structure and
associated upper level divergence.
The upper level wave and surface reflection should push well off
to our east by late tomorrow afternoon with all of the precip shifting
out of the forecast area. The weather should be on the quiet side for
the rest of the short term period with a brief cool down in the wake
of the winter system Saturday night through Sunday night before we see
milder temperatures move into our area early next week.
LONG TERM...Tuesday through Friday
Medium range models indicate some fast moving waves approaching
our area from the northwest at the start of this forecast period
with little in the way of moisture available to produce much in
the way of precip in our area. The first such wave will move across
the lower Great Lakes on Monday with a hint for some very light
precip during the day, mainly to our north. The next wave moves
quickly southeast along the tight 850 mb baroclinic zone on Tue,
at least according to the latest ECMWF, with again little in the
way of moisture to work with. Will continue to keep the first part
of the week dry but could see some low chance pops added in later
forecasts.
Warmer temperatures expected in the Wed-Fri time frame as a deep
upper level trof drops southeast into the southern Rockies and
brings about a strong southwest flow aloft over our area. This
should result in mild temps, at least compared to what we have
been experiencing, through the end of the week. However, as the
deep upper level trof edges east into the central Plains, a strong
Arctic cold front will approach our area on Friday increasing the
precip chances Thursday night into Friday, followed by much colder
weather for next weekend.
Smith/07
&&
.AVIATION...
ISSUED 1159 AM CST Fri Dec 13 2013
Shield of mixed precipitation moving ne across MO nearing the MS
river at noon and will spread ne to SPI around 20Z/2 pm, DEC by
21Z/3 pm and I-74 TAF sites of PIA, BMI & CMI between 22Z-23Z/4-5 pm.
Precipitation should mainly fall as snow, but will begin as a
period of mixed precipitation with sleet, rain and freezing rain
especially sw TAF sites this afternoon. Moderate to even bands of
heavy snow to set up this evening and continue overnight. VFR
conditions early this afternoon to deteoriate during 2nd half of
afternoon into this evening with LIFR/IFr conditions setting in
with the widespread snow. Snow will diminish from west to east
during 15Z-18Z Sat with MVFR vsbys and IFR-low end MVFR ceilings.
SSE winds 7-10 kts to turn ENE this evening and north Sat morning.
Deepening 1005 mb low pressure along the NM/OK border to weaken to
1010 mb over south central KY by 18Z/noon Sat with an inverted trof
extending into IL/IN.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST Saturday FOR ILZ038-
042>046-051>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY until 6 AM CST Saturday FOR ILZ027>031-
036-037-040-041-047>050.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1244 AM EST FRI DEC 13 2013
.SYNOPSIS...
ISSUED AT 1244 AM EST FRI DEC 13 2013
HIGH PRESSURE WILL BE OVER THE REGION TONIGHT BUT TEMPERATURES
WILL NOT BE AS COLD AS LAST NIGHT. LOWS WILL STILL DROP INTO THE
LOWER AND MIDDLE TEENS...WITH A FEW SINGLE DIGITS POSSIBLE IN
RURAL AREAS. CLOUDS WILL INCREASE FRIDAY AHEAD OF A STRONG LOW
PRESSURE SYSTEM WHICH WILL BRING ACCUMULATING SNOW TO THE REGION
FRIDAY NIGHT AND SATURDAY. CURRENT INDICATIONS ARE THAT
ACCUMULATIONS BETWEEN 2 AND 6 INCHES WILL BE LIKELY.
&&
.UPDATE...
ISSUED AT 844 PM EST THU DEC 12 2013
UPDATED THIS EVE TO ISSUE A WINTER WEATHER ADVISORY FOR TOMORROW
NIGHT AND SATURDAY. NO SGFNT CHANGES TO GRIDS IN THIS TIMEFRAME.
18Z MODEL RUNS IN DECENT AGREEMENT WITH GOOD RUN-RUN CONTINUITY ON
UPR LOW OPENING UP OVER SWRN U.S. THIS EVE TRACKING NE INTO THE
LWR OH VALLEY BY SATURDAY MORNING. SUB-TROPICAL PLUME ALREADY S-SW
OF THE CIRCULATION IS EXPECTED TO BE DRAWN NORTHWARD OVER THE COLD
AIRMASS IN PLACE OVER THE MIDWEST RESULTING IN WIDESPREAD OVER-
RUNNING SNOW MOVG INTO OUR AREA FRIDAY NIGHT AS THE LOW
APPROACHES... FOLLOWED BY DEFORMATION ZONE SNOWS DURING THE DAY
SATURDAY AS THE VORT MAX MOVES UP THE OH VALLEY. GIVEN THE SYSTEM
IS STILL EXPECTED TO BE IN A WKNG TREND WITH NO CLOSING OFF MID
LEVEL LOW... EXPECT SNOWFALL ACCUMS TO REMAIN BLO WARNING
CRITERIA... BUT WITH DEEP MOISTURE/LIFT THROUGH THE DGZ FCST FOR A
SUBSTANTIAL PERIOD... SGFNT SNOW AMOUNTS SHOULD OCCUR OVER MOST IF
NOT THE ENTIRE AREA FRIDAY NIGHT AND SATURDAY. WITH START OF THE
EVENT NOW APPROX 24HRS OUT AND CONFIDENCE FAIRLY HIGH... FELT
HEADLINE WARRANTED ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
FEW CONCERNS THROUGH THE SHORT TERM PERIOD AS SIGNIFICANT WEATHER
AHEAD OF NEXT SYSTEM WILL HOLD OFF UNTIL FRIDAY NIGHT.
SATELLITE SHOWING MID AND HIGH CLOUDS EXITING SOUTHERN AREAS THIS
AFTERNOON WHILE THERMAL TROUGH SAGGING ACROSS LAKE MICHIGAN WAS
AIDING IN STRATOCU DEVELOPMENT ACROSS BERRIEN AND CASS COUNTIES IN
MICHIGAN. THESE LOW CLOUDS AND ANY LAKE EFFECT SNOW SHOWERS WILL BE
MAIN CHALLENGE TONIGHT. SYNOPTIC SCALE THERMAL TROUGH ALREADY MOVING
EAST BUT LAKE INDUCED TROUGHINESS AND THERMAL DISPARITY PROGGED TO
ONLY SLOWLY WARM OVERNIGHT. SATELLITE ALREADY SHOWING LAKE CLOUDS
INTO NORTHERN BERRIEN COUNTY DESPITE WARM AIR ADVECTION. HIRES
GUIDANCE SUGGEST TRAJECTORIES AND WEAK LAKE AGGREGATE TROUGH MAY
ALLOW CLOUDS TO STREAM ACROSS MICHIGAN COUNTIES THIS EVENING AND
INTO OVERNIGHT HOURS. PREVIOUS SKY COVER GRIDS HAD THIS TREND
HANDLED WELL AND GENERALLY STAYED WITH SIMILAR IDEA. LIGHT SNOW
SHOWERS ALREADY NEAR OR INTO EXTREME NORTHERN TIP OF BERRIEN COUNTY
SO WILL CARRY SCT FLURRIES OR LIGHT SNOW SHOWERS THROUGH THE EVENING
UNTIL WARMER AIR ARRIVES AND FLOW WEAKENS WHICH COULD LEAD TO WEAK
MESOLOW FORMATION OVER BOWL REGION OF LAKE. LITTLE OR NO
ACCUMULATION EXPECTED GIVEN SHALLOW MOISTURE DEPTH IN OUR AREA.
OTHERWISE EXPECT MOSTLY CLEAR SKIES TO START THE EVENING WITH SOME
MID AND HIGH CLOUDS INCREASING LATE.
NAM MODEL SOUNDINGS QUITE BULLISH ON LOW LEVEL MOISTURE AND STRATUS
DEVELOPMENT FRIDAY MORNING. NAM12 HAS BEEN RATHER
AGGRESSIVE WITH THIS IDEA THIS WINTER WITH SEVERAL INSTANCES SHOWING
THIS WITH LITTLE TO NO DEVELOPMENT. LATEST HRRR GIVES SOME CREDENCE
TO THIS SOLUTION IN THE NORTH NEAR WEAK SURFACE BOUNDARY WHERE WINDS
BECOME LIGHT. HAVE SLOWLY INCREASED CLOUDS ACROSS THE NORTH
AND NORTHWEST WITH POTENTIAL FOR SOME MID AND HIGH CLOUDS AS WELL.
THIS SHOULD KEEP TEMPS FROM FALLING TOO MUCH OVERNIGHT WITH WARM AIR
ADVECTION WELL UNDERWAY. LOOKING FOR LOWS IN THE 10 TO 15 DEGREE
RANGE LATE EVENING WITH STEADY OR EVEN SLOWLY RISING TEMPS LATE WITH
ANY CLOUD COVER DEVELOPMENT.
COL AREA ASSOCIATED WITH WEAK BOUNDARY WILL LIE ACROSS NW FORECAST
AREA FRIDAY WITH GENERALLY LIGHT WINDS. CLOUD COVER REMAINS TRICKY
DEPENDING ON HOW MUCH SATURATION OCCURS NEAR BOUNDARY WITH INVERSION
ALOFT COURTESY OF WARM AIR ADVECTION. HIGHS WILL REACH MID TO UPPER
20S MOST AREAS WITH LOW 30S POSSIBLE FAR SOUTHWEST AHEAD OF NEXT
STRONG SHORT WAVE. BULK OF PCPN WILL HOLD OFF UNTIL FRIDAY EVENING
BUT DID ALLOW A SLIGHT CHANCE TO RESIDE FAR SOUTHWEST AFTER 21Z WITH
PROXIMITY OF INCREASING MOISTURE AND ISENTROPIC LIFT.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
...ACCUMULATING SNOWFALL FRIDAY NIGHT-SATURDAY...
PATTERN IS STILL SUPPORTIVE OF FAVORABLE SYNOPTIC SCALE SNOW EVENT
FOR THE REGION BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO THE
DAY SATURDAY.
NORTHERN STREAM FLOW WILL KEEP THE BOUNDARY LAYER COLD AIR IN PLACE
AND DEEP ENOUGH TO FAVOR ALL SNOW FOR THE EVENT. THE CHALLENGE WILL
BE TIMING THE PHASING OF THE SOUTHERN STREAM AND NORTHERN STREAM
SHORTWAVES ACROSS THE GREAT LAKES.
12Z RUNS ARE GENERALLY CONSISTENT WITH THE SURFACE LOW DEEPENING IN
THE PANHANDLE REGION DURING THE DAY FRIDAY. CONTINUED DEEPENING AND
OF THE SURFACE LOW OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
RIVER VALLEY DURING THE EVENING FRIDAY INTO SATURDAY WILL USHER IN
COPIOUS MOISTURE AND EXPECT TO SEE A PRONOUNCED WARM LAYER SPREADING
NORTHWARD. THIS WILL FAVOR A MORE DENSE AND WET SNOW ACROSS THE
SOUTH.
TIMING AND PHASING OF THE SOUTHERN AND NORTHERN STREAM WILL
CRITICALLY AFFECT THE DURATION OF THE SNOW AND EXPECT THAT THERE
WILL BE A RAPID CUTOFF OF PRECIPITATION EARLY SATURDAY.
SNOWFALL WILL BE HEAVIEST AND WETTER SOUTH OF THE CWFA AND DRIER
NORTH. REGARDLESS EXPECT TO SEE UPWARDS OF 5 INCHES ACROSS MOST OF
THE AREA.
AS THE SYNOPTIC DRIVEN SNOW ENDS...LAKE EFFECT SHOULD CONTINUE IN
LAPORTE...ST. JOSEPH...BERRIEN AND CASS COUNTIES FOR AN ADDITIONAL 2
TO 4 INCHES BY SATURDAY NIGHT EARLY SUNDAY MORNING.
COLDER AND DRIER AIR WILL SETTLE ACROSS THE PLAINS SUNDAY AND WITH
NEW SNOW AND SOME CLEARING...TEMPERATURES SHOULD BOTTOM OUT AGAIN
SUNDAY NIGHT/MONDAY MORNING. WILL BE MAKING SOME DOWNWARD
ADJUSTMENTS TO THE TEMPERATURES FOR SUN/MON PERIOD.
NEXT CLIPPER SYSTEM FORMS IN THE GREAT LAKES REGION MONDAY/MONDAY
NIGHT/TUESDAY AND THIS WILL BRING AN INCREASE OF CLOUDS AND LAKE
EFFECT TO THE AREA. TIMING AND DURATION OF SNOWFALL IS TOO FAR OUT
TO MAKE DEFINITIVE AMOUNT FORECASTS...BUT IT WILL ADD TO THE SNOW
ALREADY ON THE GROUND. AS THAT SYSTEM EXITS...THE COLD AIR RETURNS
IN ITS WAKE. STARTING TO SEE A DECENT SNOW PACK OVER THE NRN
PLAINS...ADDING TO THE DOUBT THAT ANY SIZABLE WARM UP IS COMING OUR
WAY.
NEXT STORY ON THE HORIZON...ECMWF PREDICTION OF DEEP AND EXPLOSIVE
CYCLOGENESIS ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT
INTO THURSDAY. THERE ARE HINTS IN THE OTHER LONG RANGE MODELS OF A
WAVE EJECTING THROUGH THE ROCKIES. THIS WILL HAVE TO BE WATCHED AS
THE PATTERN EVOLVES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1238 AM EST FRI DEC 13 2013
THE FIRST HALF OF THE TAF PERIOD WILL BE RATHER UNEVENTFUL WITH
VFR CONDITIONS AT BOTH SITES AS WE AWAIT THE ARRIVAL OF LOW
PRESSURE FROM THE SOUTHWEST AND A FRONTAL BOUNDARY FROM THE NORTH.
HAVE BACKED OFF ON ARRIVAL OF MVFR CIGS AT KSBN IN RESPONSE TO
SOUTHWARD MOVING FRONT AS MODELS CONTINUE TO TREND A BIT SLOWER
WITH THIS FEATURE ARRIVING. MAIN FOCUS WILL BE WITH ONSET OF SNOW
TONIGHT WITH RAPID ONSET OF SNOW IN THE 3 TO 6Z WINDOW AND SIMILAR
FLGT CONDITIONS AT BOTH SITES. AFTER 6Z AND WELL INTO THE NEXT
DAY...IFR/POSSIBLE LIFR CIGS/VSBYS WILL ARRIVE WITH MAIN FOCUS
POINTING TOWARDS KFWA WHERE HEAVIEST SNOW MAY OCCUR. FURTHER
DETAILS WILL BE ADDED IN LATER FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 PM EST /6 PM CST/ SATURDAY FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SATURDAY FOR MIZ077>081.
OH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SATURDAY FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
LMZ043.
&&
$$
UPDATE...JT
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...LEWIS
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1204 PM CST Fri Dec 13 2013
...Updated aviation section...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1200 PM CST FRI DEC 13 2013
North winds will continue in the wake of a departing low pressure
system this afternoon through Saturday. Wind speeds will generally
be in the 12 to 15 knot range tonight given a moderately strong
pressure gradient. VFR conditions will be found as subsidence
prevails across western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 21 43 23 54 / 0 0 0 0
GCK 20 46 21 53 / 0 0 0 0
EHA 23 46 24 53 / 0 0 0 0
LBL 22 46 24 54 / 0 0 0 0
HYS 17 39 21 53 / 10 0 0 0
P28 22 40 22 54 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Umscheid
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
508 AM CST Fri Dec 13 2013
...Updated for Aviation...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 503 AM CST FRI DEC 13 2013
VFR conditions will continue into Saturday. An upper level trough
will swing across the Central Plains today pushing a cold front
across western Kansas. Light and variable winds will become north
with the front around 15-18Z at 10-20kt then as the pressure gradient
increases later tonight with cold air advection, north winds increase to
15-25kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 21 43 23 / 0 10 0 0
GCK 50 20 46 21 / 0 0 0 0
EHA 49 23 46 24 / 0 0 0 0
LBL 50 22 46 24 / 0 0 0 0
HYS 42 17 39 21 / 10 10 0 0
P28 49 22 40 22 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Kruse
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
248 AM CST Fri Dec 13 2013
...Updated for Short and Long Term...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1128 PM CST THU DEC 12 2013
There is good agreement between the short term mesoscale models that
any precipitation will be focused across south central Kansas and
have not impact of the local terminals (DDC/GCK/HYS). Beyond this,
the only concerns remain some chance for fog development between 10
and 14 UTC which is not expected to be widespread but patchy at best,
and a wind shift later Friday morning that will bring increasingly
stronger surface winds through Friday night behind the cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 21 43 23 / 0 10 0 0
GCK 50 20 46 21 / 0 0 0 0
EHA 49 23 46 24 / 0 0 0 0
LBL 50 22 46 24 / 0 0 0 0
HYS 42 17 39 21 / 10 10 0 0
P28 49 22 40 22 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1038 PM MST THU DEC 12 2013
.UPDATE...
ISSUED AT 605 PM MST THU DEC 12 2013
JUST COMPLETED AN UPDATE. MODELS HAVING A HARD TIME WITH THE SURFACE
WIND FIELD AND DEWPOINTS. WITH THE EXCEPTION OF THE FAR EAST...LOWER
DEWPOINTS COMBINED WITH THE LIGHT WIND FIELD...AS A SURFACE TROUGH
MOVES ACROSS...HAVE ALLOWED TEMPERATURES FALL RATHER RAPIDLY.
LATEST ADJMAV AND RAP ARE HANDLING THE WINDS...DEWPOINTS AND
TEMPERATURES THE BEST. SO USED THOSE COMBINED WITH REALITY TO MAKE
THOSE ADJUSTMENTS. ALSO A LITTLE MORE CLOUD COVER FROM THE SOUTH
MOVING SO ADJUSTED THAT UP SLIGHTLY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1154 AM MST THU DEC 12 2013
A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE SOUTHERN PLAINS
TONIGHT AND FRIDAY. HOWEVER THE BEST FORCING WILL STAY WELL TO THE
SOUTH AND MOISTURE WILL BE LACKING ANYWAY. THE SURFACE TROUGH IN
EASTERN COLORADO WILL MOVE TO CENTRAL KANSAS BY FRIDAY MORNING
FOLLOWED BY A COLD FRONT AROUND MID DAY. NET RESULT WILL SEE
SURFACE WINDS SHIFTING TO NORTHWEST AND BECOMING BREEZY FRIDAY
AFTERNOON BEHIND THE FRONT. TEMPERATURES WILL BE NEAR
NORMAL...EXCEPT IN THE VERY LIMITED AREAS WHERE LINGERING SNOW
COVER MAY KEEP THEM SLIGHTLY BELOW NORMAL (MAINLY THE OBERLIN TO
MCCOOK AREA).
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 147 PM MST THU DEC 12 2013
FRIDAY NIGHT-MONDAY...SHORTWAVE TROUGH QUICKLY TRANSITIONS EAST
FRIDAY NIGHT AND NORTHWESTERLY FLOW REDEVELOPS OVER THE NORTHERN
PLAINS ALONG WITH RIDGING ACROSS THE SOUTHWESTERN US. OTHER THAN
PASSING MID-HIGH CLOUDS FRIDAY NIGHT AND AGAIN SATURDAY NIGHT WITH
EMBEDDED SHORTWAVE TROUGHS I ANTICIPATE DRY CONDITIONS TO CONTINUE
AS THE STORM TRACK WILL FAVOR LOCATIONS WELL NORTH OF THE CWA AND
A VERY DEEP DRY AIR MASS BELOW 600MB WILL BE SETTLING INTO THE
REGION. A BACKDOOR COLD FRONT WILL KEEP NEAR SEASONAL TEMPS IN
PLACE FRIDAY AND SATURDAY BEFORE TEMPS BEGIN MODERATING ALOFT IN
RESPONSE TO WEST-SOUTHWEST FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE SUNDAY AND MONDAY. IN RESPONSE TO GOOD WAA I WOULD
EXPECT HIGHS BOTH SUNDAY AND MONDAY TO BE IN THE 50S ACROSS THE
REGION WITH MID 50S ALONG THE CO/KS BORDER (IF NOT HIGHER WITH
GOOD MIXING).
MONDAY NIGHT-WEDNESDAY...FORECAST BECOMES TRICKIER IN THESE PERIODS
AS MODELS HAVE SHOWN LESS CONSISTENCY/CONTINUITY ON TIMING/EVOLUTION
OF TWO STRONG UPPER LEVEL TROUGHS MOVING OUT OF CANADA. THE FIRST
TROUGH SHOULD PASS OVER THE GREAT LAKES REGION MONDAY NIGHT/TUESDAY
TIME FRAME AND GFS IS MUCH STRONGER AND PUSHES A COLD FRONT
SOUTH OVER OUR CWA. ECMWF AND GEM ARE FURTHER NORTH WITH THE INITIAL
TRACK AND HAS CONSISTENTLY SHOW RIDGING ACROSS THE WESTERN US...AND
THE COLD FRONT REMAINING NORTH AND EAST OF OUR CWA. WHILE EITHER
SOLUTION SUPPORTS DRY WEATHER FOR OUR AREA...THERE IS A LARGE SPREAD
IN TEMPERATURES THROUGH THESE PERIODS. BASED ON BETTER CONTINUITY I
TRENDED THE FORECAST FROM THE MODEL CONSENSUS MEAN TOWARDS THE
WARMER ECMWF SOLUTION...WHICH KEEPS ABOVE NORMAL TEMPS IN PLACE
THROUGH WEDNESDAY.
THURSDAY...GEFS/GFS/ECMWF SHOW A LARGE CHANGE IN THE PATTERN AS A
STRONG TROUGH MOVES INTO THE CENTRAL PLAINS AND AN ARCTIC FRONT
DROPS SOUTH OVER OUR CWA. THERE ARE TIMING DIFFERENCES WITH THIS
FRONT...HOWEVER THE OVERALL TREND SHOULD BE THE RETURN OF MUCH
COLDER TEMPS AND THE POSSIBILITY OF ACCUMULATING SNOW BY LATE NEXT
WEEK OR NEXT WEEKEND. BASED ON PAST EXPERIENCE I WOULD NOT BE
SURPRISED IF THE FRONT TIMING IS IN LINE WITH THE FASTER END OF
GUIDANCE AS THE MOMENTUM OF THE VERY COLD/DENSE AIR MASS CARRIES
IT SOUTH ACROSS THE PLAINS AHEAD OF THE MAIN TROUGH THURSDAY.
THERE IS TOO MUCH UNCERTAINTY AT THIS RANGE TO PICK ONE
SOLUTION...SO FOR THIS FORECAST PACKAGE I HAVE SEASONAL HIGHS IN
THE LOW-MID 40S WHICH IS CLOSE TO MODEL MEAN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1035 PM MST THU DEC 12 2013
VFR CONDITIONS WITH VARIABLE AMOUNTS OF HIGH CLOUD COVER EXPECTED
THROUGH THE PERIOD. WINDS WILL BE LIGHT AND VARIABLE AS A
PREFRONTAL TROUGH MOVES THROUGH DURING THE OVERNIGHT AND MORNING
HOURS. BY MIDDAY...A COLD FRONT WILL MOVE THROUGH AND BRING GUSTY
WINDS TO BOTH SITES...HIGHER AT KGLD...THROUGH THE AFTERNOON. THE
GUSTS END BY LATE IN THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...024
LONG TERM...DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1210 PM EST FRI DEC 13 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON
ALLOWING A REINFORCING SHOT OF VERY COLD AIR TO FOLLOW FOR TONIGHT
THROUGH SATURDAY. LOW PRESSURE WILL APPROACH FROM THE SOUTH
SATURDAY NIGHT...AND PASS JUST SOUTHEAST OF THE REGION
SUNDAY...POTENTIALLY BRINGING SIGNIFICANT SNOWFALL TO MUCH OF THE
AREA.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 1200L: RADAR SUGGESTS SOME SNOW STREAMERS BEGINNING TO DVLP
ACROSS NRN MAINE W/ THESE ORIENTED WNW-ESE AS CAA BEGINS BEHIND
THIS MORNING/S WEAK CLIPPER WHICH IS NOW WELL E OF THE AREA. FOCUS
FOR THE REMAINDER OF THIS AFTN WILL BE ON THESE W/ BITTER WND
CHILLS THEN THE ISSUE FOR TNGT AS A BITTER COLD REINFORCING SHOT
OF ARCTIC AIR OVERSPREADS THE AREA. MADE A MINOR ADJUSTMENT TO
POPS TO BETTER FIT CURRENT AND EXPECTED CONDS. OTHERWISE...CURRENT
FCST ON TRACK...
UPDATE 0905L: WEAK CLIPPER NOW E OF THE AREA W/ AREA OF VRY LGT
SNW E INTO NB AS WELL... CAA COMMENCING ONCE AGAIN ACROSS THE AREA
ATTM BEHIND THIS SYSTEM AND THIS WILL REINFORCE THE VRY COLD
AIRMASS WHICH HAS SETTLED OVR THE AREA LAST FEW DYS. BRISK NW FLOW
WILL ALSO LIKELY TOUCH OFF A FEW STREAMERS OFF OF THE ST LAWRENCE
THIS AFTN W/ THE HRRR NICELY DEPICTING THIS ACTIVITY ACROSS N
CENTRAL INTO E CENTRAL AREAS FROM ERLY THRU LATE AFTN. HAVE TRIED
TO REPRESENT THIS EXPECTED SCENARIO IN OUR POP AND WX GRIDS BUT
MAY NEED TO ADJUST AS THIS ACTIVITY DVLPS SINCE THESE STREAMERS
CAN BE QUITE LOCALIZED AND DIFFICULT TO PINPOINT IN ADVANCE...
REMAINDER OF THE FCST ON TRACK ATTM...
PREVIOUS DISCUSSION...
THE WEAK CLIPPER LOW WILL CROSS NORTHERN MAINE THIS MORNING AND
REDEVELOP IN THE CANADIAN MARITIMES THIS AFTERNOON. THE CLIPPER
WILL BRING LIGHT SNOW TO NORTHERN ZONES THIS MORNING...MOSTLY
NORTH OF HOULTON. ACCUMULATIONS COULD REACH AN INCH AND POSSIBLY
UP TO 2 INCHES IN HIGHER TERRAIN WITHIN NORTHERN AROOSTOOK COUNTY. AS
THE LOW MOVES EAST OF THE FORECAST AREA...IT WILL DRAG AN ARCTIC
FRONT THROUGH THE AREA. SOME SNOW SQUALLS ARE POSSIBLE. IT APPEARS
THE SQUALL WILL ORGANIZE FROM HOULTON WEST TO THE KATAHDIN REGION
TOWARDS MIDDAY AND THEN SWEEP SOUTH TOWARDS WASHINGTON COUNTY THIS
AFTERNOON AS IT DISSIPATES. SOUTHERN PORTIONS OF THE FORECAST AREA
SUCH AS BANGOR SHOULD ESCAPE THE SNOW OUTSIDE OF A BRIEF SNOW
SHOWER AS THE ARCTIC FRONT CROSSES. WITH SOME SUN...THE
BANGOR/BREWER AREA SHOULD REACH NEAR 20F TODAY. FURTHER
NORTH...ONLY SINGLE DIGITS ARE FORECAST FOR CARIBOU NORTHWARD INTO
THE SAINT JOHN VALLEY. THE ARCTIC FRONT WILL BRING ANOTHER ROUND
OF BITTER COLD AND WINDS FOR LATER THIS AFTERNOON AND TONIGHT.
WIND CHILLS MAY DROP TO LESS THAN MINUS 30 IN NORTHERN AROOSTOOK
AND HAVE ISSUED A WIND CHILL ADVISORY FOR AROOSTOOK...NORTHERN
PISCATAQUIS AND NORTHERN PENOBSCOT COUNTIES FOR TONIGHT. LOWS WILL
DROP TO MINUS 10 TO MINUS 20 IN THESE AREAS WITH WINDS GUSTING TO
OVER 20 MPH. THE WINDS WILL DECREASE LATER IN THE NIGHT AS HIGH
PRESSURE BUILDS. ELSEWHERE...LOWS OF ZERO TO TEN BELOW ARE
EXPECTED.&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
*MAIN ISSUES WILL BE LOW WIND CHILLS SAT MORNING AND A POTENTIAL
SNOWSTORM SUNDAY.
*WINTER STORM WATCHES HAVE BEEN ISSUED FOR THE SOUTHERN HALF OF THE
CWA FOR LATE SAT NIGHT AND SUNDAY.
A COLD HIGH CENTERED JUST WEST OF QUEBEC CITY AT 12Z SAT WILL
GRADUALLY LIFT TO THE NORTH OF THE AREA SAT NIGHT. AS THE CENTER OF
THE HIGH IS WEST OF THE AREA FIRST THING SAT MORNING THERE WILL BE
SOME WIND AND THE POTENTIAL FOR LOW WIND CHILLS SAT MORNING. THE
WIND SPEED LOOKS MARGINAL (AROUND 10 MPH). WIND CHILL ADVISORIES
WERE ISSUED FOR TONIGHT AND EXTENDED INTO SAT MORNING.
LOW PRESSURE ACROSS THE GULF COAST STATES SAT MORNING IS EXPECTED TO
LIFT UP TO NEAR NANTUCKET BY 12Z SUN AND CONTINUE TO DEEPEN AS
THE LOW RACES NE AND PASSES JUST EAST OF NOVA SCOTIA SUN
AFTERNOON AND EVENING. SNOW IS EXPECTED TO DEVELOP FROM THE
SOUTHWEST AFTER MIDNIGHT SAT NIGHT AND SNOW SHOULD BE FALLING
ACROSS MOST IF NOT ALL OF DOWNEAST MAINE BY 12Z SUN. THE SNOW
WILL OVERSPREAD THE REMAINDER OF THE CWA SUN MORNING. GIVEN THE
TRACK OF THE LOW THE HEAVIEST SNOW WILL FALL ACROSS DOWNEAST AREAS
WITH AMOUNTS DROPPING OFF TO THE NORTH OF THE KATAHDIN REGION. AS
THE MODELS HAVE NOW JOGGED BACK A BIT TO THE WEST IT NOW APPEARS
THAT THERE IS A GOOD CHANCE OF 8-14 INCHES OF SNOW ACROSS DOWNEAST
MAINE. THE STORM IS PROGRESSIVE WITH AN INCOMING UPPER TROUGH FROM
THE WEST IT IS UNLIKELY THAT AMOUNTS WILL EXCEED MUCH MORE THAN 14
INCHES. THE LATEST 00Z GFS IS EVEN FURTHER TO THE WEST TAKING THE
LOW RIGHT OVER NOVA SCOTIA AND WOULD BRING WARNING CRITERIA SNOW
ALL THE WAY NORTH AND ACROSS THE CROWN OF MAINE AND MIGHT EVEN
INTRODUCE A BIT OF A MIX ALONG THE IMMEDIATE COAST FOR A BRIEF
TIME SUN AFTERNOON. THE 00Z OPERATIONAL GFS IS FURTHER WEST THAN
ITS ENSEMBLE MEAN AND THERE ARE ONLY A COUPLE OF ENSEMBLE MEMBERS
THAT ARE AS FAR WEST AS THE OPERATIONAL GFS. THE LATEST 00Z ECMWF
IS VERY CONSISTENT WITH ITS PREVIOUS RUN AND IS ALSO VERY CLOSE TO
THE GFS ENSEMBLE MEAN AND CANADIAN GEM. FORECASTER CONFIDENCE IS
HIGH ENOUGH TO ISSUE A WINTER STORM WATCH FOR LATE SAT NIGHT INTO
SUNDAY FOR DOWNEAST AREAS INTO CENTRAL MAINE WITH THE IDEA THAT
LATER SHIFTS CAN REFINE THE AREA AS NEEDED. THE FORECAST AMOUNTS
ARE BASED VERY CLOSELY ON A BLEND OF THE GFS ENSEMBLE
MEAN/OPERATIONAL ECMWF/CANADIAN. THE HEADLINES WERE WELL
COLLABORATED WITH WFO GYX AND DISCUSSED WITH THE WPC.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE SFC LOW PULLS AWAY FROM THE REGION SUN NIGHT AND MON WITH AN
INVERTED TROUGH EXTENDING BACK ACROSS THE AREA. THE MID/UPPER LEVEL
LOW FOLLOWS SUN NIGHT INTO MON MORNING. THIS WILL LIKELY KEEP SOME
LIGHTER SNOW FALLING ACROSS PARTS OF NORTHERN AND EASTERN MAINE
INTO MON MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE REGION MON
NIGHT. AN INTERESTING LOOKING CLIPPER MOVES ACROSS THE AREA
TUE WITH A GOOD CHANCE OF SNOW. THE MODELS ARE HINTING AT A
SECONDARY THAT MAY DEVELOP IN THE GULF OF MAINE AND PRODUCE MORE
SIGNIFICANT SNOWS ACROSS THE AREA TUE NIGHT INTO WED. THU LOOKS
MAINLY DRY AND SEASONABLY COLD AS THE LOW MOVES OUT OF THE AREA
AND IS AT LEAST BRIEFLY REPLACED BY A RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MOSTLY IFR THIS MORNING NORTH OF HUL IN SNOW. VFR IS
EXPECTED THROUGH THE PERIOD FOR BGR AND BHB. SNOW SQUALLS MAY SET
UP WITH AN ARCTIC COLD FRONT CROSSING THE REGION LATER THIS
MORNING AND EARLY AFTERNOON...MOST LIKELY AFFECTING HUL. SOME MVFR
CIGS ARE POSSIBLE AT TIMES FROM PQI NORTHWARD THIS AFTERNOON AND
TONIGHT.
SHORT TERM: VFR SAT INTO THE FIRST HALF OF SAT NIGHT. CONDITIONS
WILL DETERIORATE LATE SAT NIGHT WITH IFR AND EVEN SOME VLIFR IN SNOW
SUNDAY...ESPECIALLY AT THE SOUTHERN TERMINALS. MOSTLY IFR/MVFR IN
AREAS OF LIGHT SNOW THAT WILL LIKELY PERSIST INTO MONDAY. ANOTHER
SYSTEM MAY QUICKLY FOLLOW WITH MORE IFR/MVFR IN SNOW TUE.
&&
.MARINE...
NEAR TERM: HAVE UPGRADED THE SCA TO A GALE WARNING FOR TODAY WITH
THE STRONG PRESSURE GRADIENT AHEAD OF AN ARCTIC FRONT AND STRONG
NW WINDS BEHIND THE FRONT BRINGING BITTER COLD AIR OVER THE
RELATIVELY WARM WATERS. WILL GO WITH A SCA FOR THE INTRACOASTAL
THROUGH TONIGHT. WHEN THE GALE ENDS THIS EVENING...AN SCA WILL BE
NEEDED TO REPLACE IT.
SHORT TERM: A GALE IS POSSIBLE FOR A TIME SUNDAY AS LOW PRESSURE
DEEPENS AS IT PASSES EAST OF THE FORECAST WATERS. A GUSTY WIND ON
THE BACKSIDE OF LOW WILL LIKELY KEEP AT LEAST SCA CONDITIONS GOING
INTO MONDAY. THE WIND WILL DIMINISH AND THE SEAS SUBSIDE MON NIGHT
BELOW SCA LEVELS AS HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
SATURDAY FOR MEZ001>006-010.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY
EVENING FOR MEZ011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ052.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...CB
LONG TERM...CB
AVIATION...KHW/MCW/CB
MARINE...KHW/MCW/CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
913 AM EST FRI DEC 13 2013
.SYNOPSIS...
LOW PRESSURE WILL CROSS NORTHERN MAINE THIS MORNING AND DRAG AN
ARCTIC COLD FRONT ACROSS THE REGION THIS AFTERNOON. COLD HIGH PRESSURE
WILL THEN BUILD INTO THE AREA SATURDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTH SATURDAY NIGHT...AND PASS EAST OF THE REGION
SUNDAY.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 0905L: WEAK CLIPPER NOW E OF THE AREA W/ AREA OF VRY LGT
SNW E INTO NB AS WELL... CAA COMMENCING ONCE AGAIN ACROSS THE AREA
ATTM BEHIND THIS SYSTEM AND THIS WILL REINFORCE THE VRY COLD
AIRMASS WHICH HAS SETTLED OVR THE AREA LAST FEW DYS. BRISK NW FLOW
WILL ALSO LIKELY TOUCH OFF A FEW STREAMERS OFF OF THE ST LAWRENCE
THIS AFTN W/ THE HRRR NICELY DEPICTING THIS ACTIVITY ACROSS N
CENTRAL INTO E CENTRAL AREAS FROM ERLY THRU LATE AFTN. HAVE TRIED
TO REPRESENT THIS EXPECTED SCENARIO IN OUR POP AND WX GRIDS BUT
MAY NEED TO ADJUST AS THIS ACTIVITY DVLPS SINCE THESE STREAMERS
CAN BE QUITE LOCALIZED AND DIFFICULT TO PINPOINT IN ADVANCE...
REMAINDER OF THE FCST ON TRACK ATTM...
PREVIOUS DISCUSSION...
THE WEAK CLIPPER LOW WILL CROSS NORTHERN MAINE THIS MORNING AND
REDEVELOP IN THE CANADIAN MARITIMES THIS AFTERNOON. THE CLIPPER
WILL BRING LIGHT SNOW TO NORTHERN ZONES THIS MORNING...MOSTLY
NORTH OF HOULTON. ACCUMULATIONS COULD REACH AN INCH AND POSSIBLY
UP TO 2 INCHES IN HIGHER TERRAIN WITHIN NORTHERN AROOSTOOK COUNTY. AS
THE LOW MOVES EAST OF THE FORECAST AREA...IT WILL DRAG AN ARCTIC
FRONT THROUGH THE AREA. SOME SNOW SQUALLS ARE POSSIBLE. IT APPEARS
THE SQUALL WILL ORGANIZE FROM HOULTON WEST TO THE KATAHDIN REGION
TOWARDS MIDDAY AND THEN SWEEP SOUTH TOWARDS WASHINGTON COUNTY THIS
AFTERNOON AS IT DISSIPATES. SOUTHERN PORTIONS OF THE FORECAST AREA
SUCH AS BANGOR SHOULD ESCAPE THE SNOW OUTSIDE OF A BRIEF SNOW
SHOWER AS THE ARCTIC FRONT CROSSES. WITH SOME SUN...THE
BANGOR/BREWER AREA SHOULD REACH NEAR 20F TODAY. FURTHER
NORTH...ONLY SINGLE DIGITS ARE FORECAST FOR CARIBOU NORTHWARD INTO
THE SAINT JOHN VALLEY. THE ARCTIC FRONT WILL BRING ANOTHER ROUND
OF BITTER COLD AND WINDS FOR LATER THIS AFTERNOON AND TONIGHT.
WIND CHILLS MAY DROP TO LESS THAN MINUS 30 IN NORTHERN AROOSTOOK
AND HAVE ISSUED A WIND CHILL ADVISORY FOR AROOSTOOK...NORTHERN
PISCATAQUIS AND NORTHERN PENOBSCOT COUNTIES FOR TONIGHT. LOWS WILL
DROP TO MINUS 10 TO MINUS 20 IN THESE AREAS WITH WINDS GUSTING TO
OVER 20 MPH. THE WINDS WILL DECREASE LATER IN THE NIGHT AS HIGH
PRESSURE BUILDS. ELSEWHERE...LOWS OF ZERO TO TEN BELOW ARE
EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
*MAIN ISSUES WILL BE LOW WIND CHILLS SAT MORNING AND A POTENTIAL
SNOWSTORM SUNDAY.
*WINTER STORM WATCHES HAVE BEEN ISSUED FOR THE SOUTHERN HALF OF THE
CWA FOR LATE SAT NIGHT AND SUNDAY.
A COLD HIGH CENTERED JUST WEST OF QUEBEC CITY AT 12Z SAT WILL
GRADUALLY LIFT TO THE NORTH OF THE AREA SAT NIGHT. AS THE CENTER OF
THE HIGH IS WEST OF THE AREA FIRST THING SAT MORNING THERE WILL BE
SOME WIND AND THE POTENTIAL FOR LOW WIND CHILLS SAT MORNING. THE
WIND SPEED LOOKS MARGINAL (AROUND 10 MPH). WIND CHILL ADVISORIES
WERE ISSUED FOR TONIGHT AND EXTENDED INTO SAT MORNING.
LOW PRESSURE ACROSS THE GULF COAST STATES SAT MORNING IS EXPECTED TO
LIFT UP TO NEAR NANTUCKET BY 12Z SUN AND CONTINUE TO DEEPEN AS
THE LOW RACES NE AND PASSES JUST EAST OF NOVA SCOTIA SUN
AFTERNOON AND EVENING. SNOW IS EXPECTED TO DEVELOP FROM THE
SOUTHWEST AFTER MIDNIGHT SAT NIGHT AND SNOW SHOULD BE FALLING
ACROSS MOST IF NOT ALL OF DOWNEAST MAINE BY 12Z SUN. THE SNOW
WILL OVERSPREAD THE REMAINDER OF THE CWA SUN MORNING. GIVEN THE
TRACK OF THE LOW THE HEAVIEST SNOW WILL FALL ACROSS DOWNEAST AREAS
WITH AMOUNTS DROPPING OFF TO THE NORTH OF THE KATAHDIN REGION. AS
THE MODELS HAVE NOW JOGGED BACK A BIT TO THE WEST IT NOW APPEARS
THAT THERE IS A GOOD CHANCE OF 8-14 INCHES OF SNOW ACROSS DOWNEAST
MAINE. THE STORM IS PROGRESSIVE WITH AN INCOMING UPPER TROUGH FROM
THE WEST IT IS UNLIKELY THAT AMOUNTS WILL EXCEED MUCH MORE THAN 14
INCHES. THE LATEST 00Z GFS IS EVEN FURTHER TO THE WEST TAKING THE
LOW RIGHT OVER NOVA SCOTIA AND WOULD BRING WARNING CRITERIA SNOW
ALL THE WAY NORTH AND ACROSS THE CROWN OF MAINE AND MIGHT EVEN
INTRODUCE A BIT OF A MIX ALONG THE IMMEDIATE COAST FOR A BRIEF
TIME SUN AFTERNOON. THE 00Z OPERATIONAL GFS IS FURTHER WEST THAN
ITS ENSEMBLE MEAN AND THERE ARE ONLY A COUPLE OF ENSEMBLE MEMBERS
THAT ARE AS FAR WEST AS THE OPERATIONAL GFS. THE LATEST 00Z ECMWF
IS VERY CONSISTENT WITH ITS PREVIOUS RUN AND IS ALSO VERY CLOSE TO
THE GFS ENSEMBLE MEAN AND CANADIAN GEM. FORECASTER CONFIDENCE IS
HIGH ENOUGH TO ISSUE A WINTER STORM WATCH FOR LATE SAT NIGHT INTO
SUNDAY FOR DOWNEAST AREAS INTO CENTRAL MAINE WITH THE IDEA THAT
LATER SHIFTS CAN REFINE THE AREA AS NEEDED. THE FORECAST AMOUNTS
ARE BASED VERY CLOSELY ON A BLEND OF THE GFS ENSEMBLE
MEAN/OPERATIONAL ECMWF/CANADIAN. THE HEADLINES WERE WELL
COLLABORATED WITH WFO GYX AND DISCUSSED WITH THE WPC.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE SFC LOW PULLS AWAY FROM THE REGION SUN NIGHT AND MON WITH AN
INVERTED TROUGH EXTENDING BACK ACROSS THE AREA. THE MID/UPPER LEVEL
LOW FOLLOWS SUN NIGHT INTO MON MORNING. THIS WILL LIKELY KEEP SOME
LIGHTER SNOW FALLING ACROSS PARTS OF NORTHERN AND EASTERN MAINE
INTO MON MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE REGION MON
NIGHT. AN INTERESTING LOOKING CLIPPER MOVES ACROSS THE AREA
TUE WITH A GOOD CHANCE OF SNOW. THE MODELS ARE HINTING AT A
SECONDARY THAT MAY DEVELOP IN THE GULF OF MAINE AND PRODUCE MORE
SIGNIFICANT SNOWS ACROSS THE AREA TUE NIGHT INTO WED. THU LOOKS
MAINLY DRY AND SEASONABLY COLD AS THE LOW MOVES OUT OF THE AREA
AND IS AT LEAST BRIEFLY REPLACED BY A RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MOSTLY IFR THIS MORNING NORTH OF HUL IN SNOW. VFR IS
EXPECTED THROUGH THE PERIOD FOR BGR AND BHB. SNOW SQUALLS MAY SET
UP WITH AN ARCTIC COLD FRONT CROSSING THE REGION LATER THIS
MORNING AND EARLY AFTERNOON...MOST LIKELY AFFECTING HUL. SOME MVFR
CIGS ARE POSSIBLE AT TIMES FROM PQI NORTHWARD THIS AFTERNOON AND
TONIGHT.
SHORT TERM: VFR SAT INTO THE FIRST HALF OF SAT NIGHT. CONDITIONS
WILL DETERIORATE LATE SAT NIGHT WITH IFR AND EVEN SOME VLIFR IN SNOW
SUNDAY...ESPECIALLY AT THE SOUTHERN TERMINALS. MOSTLY IFR/MVFR IN
AREAS OF LIGHT SNOW THAT WILL LIKELY PERSIST INTO MONDAY. ANOTHER
SYSTEM MAY QUICKLY FOLLOW WITH MORE IFR/MVFR IN SNOW TUE.
&&
.MARINE...
NEAR TERM: HAVE UPGRADED THE SCA TO A GALE WARNING FOR TODAY WITH
THE STRONG PRESSURE GRADIENT AHEAD OF AN ARCTIC FRONT AND STRONG
NW WINDS BEHIND THE FRONT BRINGING BITTER COLD AIR OVER THE
RELATIVELY WARM WATERS. WILL GO WITH A SCA FOR THE INTRACOASTAL
THROUGH TONIGHT. WHEN THE GALE ENDS THIS EVENING...AN SCA WILL BE
NEEDED TO REPLACE IT.
SHORT TERM: A GALE IS POSSIBLE FOR A TIME SUNDAY AS LOW PRESSURE
DEEPENS AS IT PASSES EAST OF THE FORECAST WATERS. A GUSTY WIND ON
THE BACKSIDE OF LOW WILL LIKELY KEEP AT LEAST SCA CONDITIONS GOING
INTO MONDAY. THE WIND WILL DIMINISH AND THE SEAS SUBSIDE MON NIGHT
BELOW SCA LEVELS AS HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
SATURDAY FOR MEZ001>006-010.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY
EVENING FOR MEZ011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ052.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...CB
LONG TERM...CB
AVIATION...KHW/MCW/CB
MARINE...KHW/MCW/CB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 AM EST FRI DEC 13 2013
.UPDATE...
ISSUED AT 942 PM EST THU DEC 12 2013
MAIN FCST CONCERN THIS EVNG HAS BEEN ON TIMING/IMPACT OF INTENSE LES
BAND SHOWN ON MQT 88D OVER SCENTRAL LK SUP EXTENDING INTO FAR ERN
ALGER/NRN LUCE COUNTIES. THIS BAND HAS BEEN NEARLY STNRY THRU MUCH
OF THE EVNG...WITH HIEST REFLECTIVITIES APRCHG 30 DBZ AS HI AS 6-7K
FT...PROMPTING ISSUANCE OF AN SPS EARLIER IN THE EVNG. CALL TO
SPOTTER JUST S OF GRAND MARAIS INDICATED SN FALLING AT THE RATE OF
AN INCH/HR WITH TOTAL ACCUMULATION FM NOON THRU 9 PM ARND 7 INCHES.
THE BAND INTENSIFIED DURING THE EVNG WITH SHARPENING LLVL CNVGC
ACCOMPANYING MORE PRONOUNCED LAND BREEZE SW WIND COMPONENT ON THE
SRN FLANK OF THE BAND. CONSIDERED UPGRADING ADVY TO WRNG TO THIS
AREA...BUT RECENT RADAR IMAGERY INDICATES THE BAND IS BEGINNING TO
SHIFT TO THE S IN LINE WITH VEERING LLVL WINDS TO THE NW...WHICH IS
IN AGREEMENT WITH HIER RES MODEL FCSTS. IN FACT...NEARBY SFC OBS/MQD
88D VWP DO SHOW A VEERING TREND. WITH THE STEADY VEERING EXPECTED
THRU THE NGT AND FCST WEAKENING LAND BREEZE CNVGC...EXPECT THE BAND
TO MOVE MORE STEADILY AND DIMINISH A BIT WITH TIME. WITH WEAKER
MULTIPLE BANDED LES EXPECTED TO DOMINATE...WL HOLD ON TO GOING ADVY
FOR ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
OTRW...TENDED TO BUMP UP MIN TEMPS FCST A FEW DEGREES WITH QUITE A
BIT OF CLD COVER AND WSHFT TO A MORE N DIRECTION ALLOWING FOR MORE
LK SUP MODERATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 423 AM EST FRI DEC 13 2013
NAM SHOWS A 500 MB RIDGE OVER THE WESTERN U.S. 12Z SAT WITH A
SHORTWAVE TROUGH OVER THE CENTRAL U.S. A CLOSED 500 MB LOW OVER
NORTHERN MANITOBA DIGS SOUTHEAST ON SAT AND DIGS A DEEPER TROUGH
INTO THE UPPER GREAT LAKES WHICH AFFECTS THE AREA LATE ON SAT INTO
SAT NIGHT. THIS TROUGH MOVES INTO THE LOWER GREAT LAKES ON SUN.
NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND SOME DEEPER
MOISTURE SAT NIGHT AND BOTH LEAVE ON SUN. LOOKS LIKE THERE COULD BE
SOME LAKE ENHANCEMENT WITH EAST FLOW GOING ON OVER THE KEWEENAW AND
ALSO FROM LAKE MICHIGAN ACROSS MENOMINEE AND DELTA COUNTIES ON
SATURDAY WITH A DRY WEDGE OF AIR IN BETWEEN OVER THE CENTRAL AND
EASTERN CWA IN THE MORNING AND TRIED TO REFLECT THE TWO AREAS OF
PCPN IN THE POPS GRIDS. WILL GO CATEGORICAL WITH THE LAKE
ENHANCEMENT OVER SOUTHERN MENOMINEE AND ACROSS THE NORTHERN KEWEENAW
PENINSULA AS LAKE TEMPERATURES ARE AROUND 4C AND GFS AND NAM ARE
SHOWING 850 MB TEMPERATURES OF -16C TO -20C. THESE AREAS MIGHT NEED
ADVISORIES FOR LAKE ENHANCED SNOWFALL AS THERE COULD BE 4-6 INCHES
OF SNOW SAT AND SAT NIGHT WITH THIS NEXT SYSTEM. WILL LET DAY SHIFT
LOOK AT THIS POSSIBILITY AGAIN...BUT RIGHT NOW LOOKS LIKE ADVISORY
SNOWFALL. THIS DRY AIR ERODES IN THE AFTERNOON AND WENT CHANCE POPS
ACROSS THE CENTRAL AND EAST THEN. LAKE EFFECT STARTS SAT NIGHT
ACROSS THE WEST IN NORTHWEST LAKE EFFECT SNOW BELTS AND THIS
CONTINUES INTO SUNDAY EVENING. DID NOT MAKE TOO MANY ADJUSTMENTS TO
GOING TEMPERATURES EXCEPT TO LOWER LOW TEMPERATURES A BIT MORE
DURING THE NIGHTS WITH LIGHTER WINDS.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS
THE U.S. 12Z MON. THIS BROAD TROUGH REMAINS 12Z TUE WITH A STRONGER
SHORTWAVE DIGGING INTO THE UPPER GREAT LAKES. THIS TROUGH MOVES INTO
THE EASTERN U.S. 12Z WED. ECMWF THEN SHOWS A STRONG TROUGH DIGGING
INTO THE ROCKIES 12Z THU WHILE THE GFS IS ZONAL WITH ITS UPPER FLOW
AND SOLUTION IS TOTALLY DIFFERENT. THE GFS HAS A HIGH PRESSURE
SYSTEM OVER THE GREAT LAKES 12Z THU. LOOKING AT THE MANUAL
PROGS...LOOKS LIKE THE ECMWF SOLUTION WAS FOLLOWED ON THU. STILL
LOOKS COLDER THAN NORMAL THIS FORECAST PERIOD. WILL HAVE CHANCE POPS
IN FOR MONDAY WITH PASSAGE OF A SHORTWAVE ACROSS THE AREA AND THEN
MON NIGHT THERE COULD BE SOME LAKE ENHANCEMENT OVER THE EASTERN CWA
OFF OF LAKE MICHIGAN AND WENT LIKELY POPS THERE WITH CHANCE POPS
ELSEWHERE. FOR TUE...LAKE EFFECT SNOW OFF OF LAKE SUPERIOR STARTS UP
AND WENT CHANCE POPS FOR THEN AND THEN THE NEXT SYSTEM COMES IN FOR
THU AND WENT CHANCE POPS THEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1229 AM EST FRI DEC 13 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW EARLY
IN THE FCST PERIOD TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW
WEAKENS AND VEERS TO A MORE UNFVRBL NNE DIRECTION.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS AT IWD EARLY THIS MRNG. SO MVFR
CONDITIONS EARLY IN THE TAF PERIOD SHOULD DETERIORATE TO IFR BY
SUNRISE. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE THEN E
DIRECTION FRI AFTN/EVNG...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR
AND PERHAPS VFR BY EVNG.
SAW...EXPECT VFR CONDITIONS EARLY THIS MRNG TO DETERIORATE TO MVFR
BY SUNRISE AS THE FLOW VEERS TOWARD THE N FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION THIS
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT ENHANCED
SHSN. AS THE FLOW VEERS FURTHER LATER THIS EVNG TOWARD A LESS FVRBL
E DIRECTION...CONDITIONS WL REBOUND TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ263>266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLB
LONG TERM...07
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 AM EST FRI DEC 13 2013
.UPDATE...
ISSUED AT 942 PM EST THU DEC 12 2013
MAIN FCST CONCERN THIS EVNG HAS BEEN ON TIMING/IMPACT OF INTENSE LES
BAND SHOWN ON MQT 88D OVER SCENTRAL LK SUP EXTENDING INTO FAR ERN
ALGER/NRN LUCE COUNTIES. THIS BAND HAS BEEN NEARLY STNRY THRU MUCH
OF THE EVNG...WITH HIEST REFLECTIVITIES APRCHG 30 DBZ AS HI AS 6-7K
FT...PROMPTING ISSUANCE OF AN SPS EARLIER IN THE EVNG. CALL TO
SPOTTER JUST S OF GRAND MARAIS INDICATED SN FALLING AT THE RATE OF
AN INCH/HR WITH TOTAL ACCUMULATION FM NOON THRU 9 PM ARND 7 INCHES.
THE BAND INTENSIFIED DURING THE EVNG WITH SHARPENING LLVL CNVGC
ACCOMPANYING MORE PRONOUNCED LAND BREEZE SW WIND COMPONENT ON THE
SRN FLANK OF THE BAND. CONSIDERED UPGRADING ADVY TO WRNG TO THIS
AREA...BUT RECENT RADAR IMAGERY INDICATES THE BAND IS BEGINNING TO
SHIFT TO THE S IN LINE WITH VEERING LLVL WINDS TO THE NW...WHICH IS
IN AGREEMENT WITH HIER RES MODEL FCSTS. IN FACT...NEARBY SFC OBS/MQD
88D VWP DO SHOW A VEERING TREND. WITH THE STEADY VEERING EXPECTED
THRU THE NGT AND FCST WEAKENING LAND BREEZE CNVGC...EXPECT THE BAND
TO MOVE MORE STEADILY AND DIMINISH A BIT WITH TIME. WITH WEAKER
MULTIPLE BANDED LES EXPECTED TO DOMINATE...WL HOLD ON TO GOING ADVY
FOR ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
OTRW...TENDED TO BUMP UP MIN TEMPS FCST A FEW DEGREES WITH QUITE A
BIT OF CLD COVER AND WSHFT TO A MORE N DIRECTION ALLOWING FOR MORE
LK SUP MODERATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
MODELS TODAY CONTINUE TO INDICATE AN OVERALL COLD PATTERN THRU THE
LONG TERM PORTION OF THE FCST. HOWEVER...WITH CURRENT DEEP EXPANSIVE
POLAR VORTEX CENTERED AROUND HUDSON BAY STILL FCST TO WEAKEN AND
RETREAT N THRU AT LEAST THE MIDDLE OF NEXT WEEK...THE COLD WILL EASE
SOME. A VAST SUPPLY OF COLD AIR WILL REMAIN ACROSS CANADA...SO ANY
SHORTWAVE TRACKING ALONG IN THE RELAXING NW FLOW PATTERN WILL BE
ABLE TO TUG COLDER AIR INTO THE UPPER LAKES. FOR THIS REASON...
MEDIUM RANGE GUIDANCE FOR SEVERAL DAYS HAS BEEN PROGRESSIVELY SLOWER
TO BRING WARMING INTO THE UPPER LAKES AND HAS ALSO BEEN MORE
TEMPERED WITH THE WARMING. AROUND THE MIDDLE OF NEXT WEEK THERE WILL
BE A TEMPORARY SHIFT IN THE PATTERN TOWARD A DEEPENING TROF OVER THE
WRN CONUS AND DOWNSTREAM BUILDING RIDGE OVER THE SE CONUS/WRN
ATLANTIC. THUS THE MIDWEEK PERIOD WILL OFFER THE BEST CHANCE OF A
WARMUP. HOW MUCH WARMING OCCURS WILL DEPEND ON THE AMPLITUDE AND
LONGITUDE OF THE TROF/RIDGE PATTERN. LATEST MODEL TRENDS POINT
TOWARD AN EWD SHIFT IN THE TROF/RIDGE PATTERN WHICH WILL LIMIT
WARMING FOR THE UPPER LAKES. IN ANY CASE...WARMING WILL ONLY BE
BRIEF AS LONGER RANGE GUIDANCE CONTINUES TO POINT TOWARD
REINTENSIFYING ARCTIC AIR ACROSS WRN/NRN CANADA DUMPING BACK INTO
THE AREA SOMETIME AROUND THE WEEKEND BEFORE CHRISTMAS. OUTSIDE OF
AREAS AFFECTED BY LES/LAKE ENHANCEMENT...THERE WON`T BE MUCH MORE
THAN SOME -SN AT TIMES DURING THE LONG TERM. THE RESURGENCE OF
ARCTIC AIR S INTO THE CONUS LATE NEXT WEEK/WEEKEND COULD OFFER THE
POTENTIAL FOR SOMETHING MORE SUBSTANTIAL IN TERMS OF WIDESPREAD
SNOWFALL.
BEGINNING FRI NIGHT...WINDS WILL CONTINUE VEERING TO THE E THEN
SE FRI NIGHT/SAT MORNING AS SFC HIGH PRES CENTER PASSES JUST N OF
LAKE SUPERIOR AND NEXT CLIPPER SHORTWAVE APPROACHES FROM THE NW. LES
THAT WILL BE OCCURRING MAINLY INTO NCNTRL UPPER MI THU AFTN WILL
SLOWLY SHIFT OUT OF NCNTRL UPPER MI AND THEN CROSS THE KEWEENAW
PENINSULA FOR A TIME LATE FRI NIGHT/SAT MORNING. DGZ WILL BE WELL
CENTERED IN THE CONVECTIVE LAYER...SO A FEW INCHES OF FLUFFY SNOW
ARE POSSIBLE IN THIS AREA OF LES THAT WILL BE SHIFTING WITH THE
WINDS. ALSO...WITH WINDS VEERING OVER NRN LAKE MI...LES OFF LAKE MI
WILL LIKELY MOVE INTO MENOMINEE COUNTY AND POSSIBLY DELTA COUNTY...
LEADING TO SOME FLUFFY SNOW ACCUMULATIONS LATE FRI NIGHT/SAT
MORNING.
ATTENTION THEN TURNS TO NEXT CLIPPER SHORTWAVE DROPPING THRU THE
UPPER GREAT LAKES SAT NIGHT/SUN. -SN ASSOCIATED WITH FEATURE SHOULD
SPREAD INTO THE AREA SAT AFTN/EVENING...AND IT LOOKS LIKE THERE WILL
BE A PERIOD OF LAKE ENHANCEMENT OFF LAKE MI IN SOUTHERLY FLOW...
LEADING TO A POTENTIAL ADVY EVENT. A BRIEF SHOT OF ARCTIC AIR
FOLLOWING SYSTEM WILL PROBABLY RESULT IN A SHORT DURATION PERIOD OF
MDT TO POSSIBLY HVY LAKE ENHANCED SNOW FOR NORTHWEST AND NORTHEAST
UPPER MI LATE SAT NIGHT/EARLY SUNDAY AS WIND SHIFTS NW. SINCE DEEP
LAYER FORCING WITH SHORTWAVE IS FAIRLY IMPRESSIVE...WILL NEED TO
WATCH FOR LOCALLY HVY LAKE ENHANCED SNOW OFF LAKE MI AHEAD OF WAVE
AND OFF LAKE SUPERIOR AS THE WAVE PASSES. AS WINDS VEER AROUND TO
THE N OR NE WITH SFC HIGH PRES PASSING ACROSS NRN ONTARIO...LIGHTER
LES WILL AGAIN SHIFT TO AFFECT MORE OF NRN UPPER MI SUN
AFTN/EVENING.
OVER THE LAST FEW DAYS...UNCERTAINTY FOR THE EARLY AND MIDDLE PARTS
OF NEXT WEEK HAS BEEN HIGH WITH REGARD TO TIMING/STRENGTH/TRACK OF
SEVERAL SHORTWAVES IN WNW FLOW. IT APPEARS THERE MAY BE A COUPLE OF
PERIODS OF WIDESPREAD -SN (CONFIDENCE HIGHEST FOR -SN ON MON) AS
WELL AS LAKE ENHANCEMENT OFF LAKE MICHIGAN AND LAKE SUPERIOR
DEPENDING ON WIND DIRECTION IMMEDIATELY PRIOR TO AND AFTER PASSAGE
OF THE WAVES. GIVEN THE SPREAD OF SOLUTIONS IN RECENT DAYS...
CONFIDENCE IN SNOW AND TEMP FCSTS FOR MON-WED ESPECIALLY TUE/WED
WILL BE LOW UNTIL THAT PART OF THE FCST MOVES CLOSER TO THE SHORT
TERM.
THERE ARE SOME INDICATIONS THAT A SOMEWHAT MORE MEANINGFUL LOW PRES
WAVE MAY MOVE TOWARD THE GREAT LAKES THU/FRI AS THE WRN TROF
DEVELOPS/DEEPENS AND BEGINS TO SHIFT E.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1229 AM EST FRI DEC 13 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW EARLY
IN THE FCST PERIOD TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW
WEAKENS AND VEERS TO A MORE UNFVRBL NNE DIRECTION.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS AT IWD EARLY THIS MRNG. SO MVFR
CONDITIONS EARLY IN THE TAF PERIOD SHOULD DETERIORATE TO IFR BY
SUNRISE. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE THEN E
DIRECTION FRI AFTN/EVNG...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR
AND PERHAPS VFR BY EVNG.
SAW...EXPECT VFR CONDITIONS EARLY THIS MRNG TO DETERIORATE TO MVFR
BY SUNRISE AS THE FLOW VEERS TOWARD THE N FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION THIS
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT ENHANCED
SHSN. AS THE FLOW VEERS FURTHER LATER THIS EVNG TOWARD A LESS FVRBL
E DIRECTION...CONDITIONS WL REBOUND TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ006-007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ263>266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
553 PM CST SAT DEC 14 2013
.UPDATE...FOR 00Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 338 PM CST SAT DEC 14 2013
LIGHT SNOW CONTINUED ACROSS THE REGION TODAY AHEAD OF A WEAK
SHORTWAVE THAT WAS EMBEDDED IN THE PERSISTENT NORTHWEST FLOW.
FORECAST SOUNDINGS OFF THE RAP SHOWED A BEAUTIFUL VEERING
PROFILE...WITH DENDRITIC SATURATION FROM THE SURFACE UP TO 650MB.
THE REGION OF ASCENT ROOTED IN THE POSITIVE VORTICITY ADVECTION
ASSOCIATED WITH THE CURVATURE OF THIS WAVE WILL CONTINUE TO SHIFT
EASTWARD OVERNIGHT. MODEST H500 HEIGHT RISES AND AN ASSOCIATED
SURFACE RIDGE OF HIGH PRESSURE WILL BUILD OVER WESTERN MN...WHICH
WILL SET THE STAGE FOR ANOTHER NIGHT OF COLD TEMPERATURES WITH LIGHT
WINDS...ESPECIALLY IF SKIES MANAGE TO CLEAR. HOWEVER...DESPITE THE
SURFACE HIGH...CONFIDENCE IN CLEARING SKIES IS LOW AS AGITATED
NORTHWEST FLOW WILL CONTINUE. THE THERMAL PROFILE FROM FORECAST
SOUNDINGS ARE SUCH THAT ONLY A SMALL AMOUNT OF UPWARD VERTICAL
MOTION IS REQUIRED TO PRODUCE A FEW SNOWFLAKES...LET ALONE MID LEVEL
CLOUDS. IN FACT...THE NEXT UPPER LEVEL WAVE / LOW LEVEL WARM AIR
ADVECTION DUO WILL MOVE ACROSS WESTERN MN ON SUNDAY...SO HAVE
INCREASED POPS CONSIDERABLY SINCE CONFIDENCE IS HIGH IN ANOTHER
ROUND OF LIGHT SNOWFALL ALONG THE MINNESOTA RIVER VALLEY. SUNDAYS
HIGH TEMPERATURES WILL STRUGGLE TO GET OUT OF THE SINGLE DIGITS FOR
MOST LOCATIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 PM CST SAT DEC 14 2013
THE UPPER WAVE BRINGING LIGHT SNOW SUNDAY WILL SLIDE SOUTHEAST
INTO THE OHIO VALLEY SUNDAY NIGHT WHILE ANOTHER WAVE DIVES
SOUTHEAST INTO NORTHERN MINNESOTA EARLY MONDAY MORNING. A QUICK
SHOT OF DECENT ISENTROPIC UPGLIDE AND MODEST MOISTURE ADVECTION
WILL BE ENOUGH TO GENERATE A BAND OF SNOW ACROSS NORTHERN AND
CENTRAL MN WHICH WILL PROPAGATE INTO WESTERN WISCONSIN MONDAY
MORNING. ONE TO TWO INCHES OF SNOW ARE POSSIBLE BEFORE STRONG
ISENTROPIC DOWNGLIDE TAKES OVER AGAIN IN THE AFTERNOON AND MONDAY
NIGHT.
A TROUGH DIGGING INTO THE GREAT LAKES WILL CLIP THE FORECAST
AREA...LEAVING WESTERLY SURFACE FLOW IN PLACE THROUGH MIDWEEK.
MILD TEMPS /COMPARED TO THE REST OF THIS MONTH/ CAN BE
EXPECTED...ALTHOUGH TUESDAY NIGHT WILL BE COLD AS THE RIDGE
AXIS PASSES OVERHEAD.
EYES THEN TURN TO LATE WEEK AS A TROUGH DIGS DOWN THE WEST COAST
AND HIGH PRESSURE BUILDS SOUTHWARD INTO WESTERN AND CENTRAL
CANADA. FAST ZONAL FLOW WILL DEVELOP ALONG THE U.S./CANADIAN
BORDER WEDNESDAY WITH ONE WAVE RAPIDLY PUSHING EAST ACROSS
NORTHERN MINNESOTA. SENSIBLE WEATHER IMPACTS FOR OUR AREA WILL BE
MINIMAL INITIALLY WITH FORCING AND MOISTURE CONVERGENCE REMAINING
WELL NORTH. HOWEVER...THIS WAVE AND HIGH PRESSURE BUILDING TOWARD
THE NORTHERN PLAINS WILL PUSH A COLD FRONT SOUTH WEDNESDAY NIGHT.
AS SOME ENERGY ROUNDS THE BASE OF THE WESTERN TROUGH...A SURFACE
LOW WILL SPAWN OVER COLORADO THURSDAY AND TRACK EAST NORTHEAST
ACROSS THE PLAINS AND INTO THE LOWER GREAT LAKES LATE
THURSDAY/THURSDAY NIGHT. NORMALLY THIS WOULD BE A HIGHLY FAVORABLE
TRACK FOR HEAVY SNOWFALL ACROSS THE CWA. HOWEVER...GIVEN THE FAST
FLOW WITH TIGHTENING BAROCLINICITY LEADING TO A MORE PROGRESSIVE
FEATURE...IN CONJUNCTION WITH SURFACE RIDGING OVER THE GULF WHICH
WILL LIKELY DELAY THE NORTHERLY MOISTURE TRANSPORT UNTIL THE
SURFACE WAVE IS TO THE EAST OF THE AREA...WOULD LIMIT THE
POTENTIAL FOR A BIG SNOWFALL. IF MODELS EVOLVE THE WESTERN TROUGH
DIFFERENTLY...AND THEY MOST LIKELY WILL AT THIS RANGE...THIS
FORECAST CAN CERTAINLY CHANGE. LEFT POPS IN THE MID RANGE FOR NOW
WITH THE MOISTURE UNCERTAINTY AND SOME TIMING DIFFERENCES BETWEEN
THE MEDIUM RANGE MODELS.
THE HIGH WILL BUILD IN FOR FRIDAY AND SATURDAY WITH ANOTHER BLAST
OF ARCTIC AIR ACCOMPANYING IT. HIGHS WILL AGAIN BE IN THE SINGLE
DIGITS WITH LOWS FRIDAY NIGHT IN THE TEENS TO 20S BELOW ZERO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 554 PM CST SAT DEC 14 2013
A SWATH OF SNOW WILL CONTINUE SHIFTING SOUTHEAST ACROSS THE TAF
SITES /KRWF-KMSP-KRNH-KEAU/ DURING THE FIRST COUPLE HOURS OF THE TAF
PERIOD. ATTENDANT MVFR CIGS/VSBYS WILL BE POSSIBLE...WITH
PRIMARILY VFR CONDITIONS EXPECTED AFTER THAT. WILL HAVE SOME
LINGERING 2500FT SCT CLOUDS AND A LOW-END VFR DECK AROUND THROUGH
MOST OF THE PERIOD...BUT THIS EVE WILL BE THE PRIMARY WINDOW FOR
MVFR CONDITIONS. ANOTHER AREA OF SNOW WILL APPROACH WESTERN MN
FROM THE DAKOTAS ON SUNDAY...POSSIBLY AFFECTING KAXN AND KRWF LATE
SUNDAY MORNING AND AFTERNOON...BUT IT/S EXPECTED TO STAY
WEST/SOUTH OF THE REMAINDER OF THE TAF SITES. WINDS WILL BE
NORTHWEST BELOW 10KTS THROUGH MIDDAY SUNDAY.
KMSP...
MVFR VSBYS/CIGS IN SNOW POSSIBLE UNTIL 02Z...THEN IMPROVEMENT TO
VFR EXPECTED FROM 03Z THROUGH THE REMAINDER OF THE PERIOD. WILL
HAVE FEW-SCT CLOUDS AROUND 2000-2500FT THROUGH SUNDAY...WITH A MID
LEVEL DECK FOR MUCH OF THE PERIOD AS WELL. 280-310 DEGREE WINDS
THROUGH SUNDAY AFTERNOON AT SPEEDS AOB 10KTS...BECOMING LIGHT AND
VRB BY 00Z MONDAY.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR WITH IFR/-SN POSSIBLE. WINDS SW AT 10KTS.
TUE...VFR WITH MVFR/-SN POSSIBLE. WINDS W AT 15KTS.
WED...VFR. WINDS VRBL AT 05KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...LS
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1152 PM CST Thu Dec 12 2013
...Update to Aviation Section...
.UPDATE...
Issued at 947 PM CST THU DEC 12 2013
Near term forecast updated to account for rather wild fluctuations
in hourly temperatures. Snow cover, wind and incoming clouds will
continue to play havoc with temperatures the rest of tonight.
Concerning the forecast for tomorrow, incoming NAM and latest
RUC/HRRR suggest that precipitation onset may be delayed a few
hours Friday morning as compared to the going forecast. The very
dry 00 UTC raobs from KSGF/KLZK/KSHV/KOUN do lend credence to a
slightly slower onset. The NAM and RUC continue to be more
aggressive with the warm nose with this system versus its global
model (GFS/Euro/GEM) counterparts. With such a dry airmass in
place will come rather substantial wet bulbing potential, thus am
not buying off on the strength of the warm nose in the NAM/RUC.
Thus, other than a slight delay in onset, precipitation type
expectations have not changed. Snow, sleet and rain/freezing rain
(dependent upon surface temperatures) are all plausible Friday
and Friday night. Surface temperatures will remain very, very
tricky tomorrow. Again, wet bulbing will have a big affect on
readings through at least the morning hours. Most locations will
be a few degrees either side of the freezing mark, with localized
cooler spots in the area terrain. Full forecast update will be
provided when GFS/Euro/GEM are available for investigation.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 245 PM CST THU DEC 12 2013
A complex forecast the next 48 hours as a storm system tracks
across the region bringing a wintry mix.
A shortwave trough now over the Baja California region will track
northeast toward the Ozarks Friday. Clouds will be on the increase
later tonight as the associated moisture plume streams
northeastward.
A jet streak and accompanying lead disturbance will impact the
region beginning Friday morning. The Ozarks will become favorably
positioned within a coupled jet structure to promote strengthening
synoptic scale lift. This will result in a rapid development and
expansion of precipitation as early as day break and more so
during the morning hours Friday.
Progged low level thermal profiles suggest that precipitation
will begin as a wintry mix in the form of freezing rain and sleet.
Existing cold surfaces and potential of moderate precipitation
rates will likely lead to rapid deterioration of road conditions
Friday morning.
Temperatures will slowly rise Friday with readings rising above
the freezing mark from southwest to northeast. Most locations west
of Highway 65 will rise above freezing by midday while freezing
temperatures and wintry mix linger into at least early afternoon
east of Highway 65 into the eastern Ozarks. Just how long
temperatures remain below freezing will have to monitored closely.
The uncertainty on the exact precipitation type and duration lead
to questions on the exact amount of ice accumulation. At this time
generally expect a few hundredths to near one tenth of an inch ice
accretion.
The shortwave trough will push across the region Friday night
bringing a continuation and even an increase in precipitation
Friday evening. Meanwhile temperatures will slowly settle back
down toward freezing. Expect a wintry mix to expand across the
eastern Ozarks and also spread south across the remainder of the
area. Expect precipitation to transition to a mix of snow and sleet
before diminishing later Friday night. Light snow accumulations are
expected Friday night mainly across central Missouri and the
eastern Ozarks where an inch or two of snow accumulation is
expected.
Areas and perhaps widespread freezing drizzle is expected to develop
late Friday night into Saturday morning. This could result
hazardous travel conditions through Saturday morning.
Temperatures will rise little Saturday with all precipitation
ending during the afternoon.
With the expectation of winter precipitation a Winter Weather
Advisory will be issued from Friday morning into Friday night for
most of the Missouri Ozarks generally east of Interstate 49. The
most impacted area from this event will be along and east of the
Highway 65 corridor. Exact ice and snow accumulations remain
somewhat uncertain and the latest weather information should be
monitored.
.LONG TERM...(Saturday Night through Thursday)
Issued at 230 PM CST THU DEC 12 2013
A Canadian surface high pressure will move in for Saturday night
into early Sunday morning. Temperatures will be coldest with lows
down into the middle to upper teens especially over the higher
terrain of the Ozark Plateau and if any snow cover still remains
on the ground by that time.
Southerly to southwesterly winds will begin on Sunday on the
backside of the surface high. Sunday will remain chilly and below
average but sunny. Temperatures will rebound nicely by the early
part of next week back to more seasonable weather. The upper level
flow will try to flatten somewhat for the middle of next week.
Another weak and dry front will pass through early on Tuesday but
no real temperatures differences expected on either side of the
boundary. A dry and seasonable weather looks to stay around for
the early and middle portion of next week with possibly some
significant weather changes just beyond the 7 days toward the end
of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1152 PM CST THU DEC 12 2013
Very messy and complex forecast for the next 24 to 36 hours.
Please refer to the short range discussion aloft for the explicit
details regarding the dynamics of this system and the temperature
profiles that will dictate a variety of precipitation types. The
forecast bottom line is that conditions will remain quiet through
tonight. Precipitation will move in from the southwest during the
daylight hours of Friday morning and continue in an on again/off
again fashion through Friday night. All precipitation types are
possible Friday...starting at a mix of freezing rain/sleet/snow
changing to rain/sleet/snow as surface temperatures rise above
freezing by a few degrees. Any flight restrictions will initially
be tied to visibility (MVFR). As the afternoon progresses,
ceilings will lower to low end MVFR. As the core of the system
passes over the region Friday night, a swath of snow will develop
over a portion of the region, with better chances of affecting
SGF/BBG. Widespread IFR visibility and ceilings are expected (LIFR
is plausible). A transition to freezing drizzle is expected just
beyond the end of the TAF cycle with IFR continuing.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY from 6 AM Friday to 6 AM CST Saturday
FOR MOZ055>058-066>071-077>083-089>092-094>098-102>106.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Griffin
AVIATION...Gagan
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1133 AM MST FRI DEC 13 2013
.AVIATION...
18Z TAF CYCLE
THE UPPER LEVEL LOW WHICH HAS IMPACTED THE STATE OVERNIGHT WILL
PROGRESS EASTWARD. THIS WILL ALLOW CURRENT MVFR CIGS/VIS
RESTRICTIONS TO IMPROVE DRAMATICALLY THIS AFTERNOON. ANOTHER
SYSTEM WILL BE ON THE HEALS OF THE CURRENT ONE AND WILL SPREAD MID
AND HIGH LEVEL CLOUDS OVER NORTHERN AND EASTERN AREAS TONIGHT.
A TRICKY FORECAST LIES AHEAD FOR KFMN...KGUP...AND
KROW BECAUSE BRIEF CLEARING BETWEEN THE SYSTEMS COMBINED WITH LOW
LEVEL RESIDUAL MOISTURE COULD LEAD TO VERY LOW CIGS AND FG
DVLPMENT. HEDGED FORECAST WORDING AT GUP/FMN AND LEFT IT OUT OF
THE FMN FORECAST AT THIS TIME. THE INCREASED MID/HIGH LVL CLOUDS
COULD IMPEDE THIS LOW CIG DVLPMENT TONIGHT. WILL BE MONITORING
OBSERVATION AND MODEL TRENDS CLOSELY. WINDS THROUGH 0Z WILL ALSO
PICKUP TODAY ALONG THE CENTRAL MTNS WITH GUSTS REACHING AS HIGH AS
40 KT ACROSS THE EASTERN PLAINS. BTWN 25 TO 30 KT AT ROW/TCC.
CML/JBW
&&
.PREV DISCUSSION...1025 AM MST FRI DEC 13 2013...
QUICK UPDATE TO REMOVE POPS FOR THE REST OF THE DAY. SOME FLURRIES
AND/OR SPRINKLES MAY OCCUR...BUT GIVEN RADAR TRENDS AND THE FACT
THAT THE SYSTEM IS PULLING AWAY FROM THE AREA...ADDITIONAL
MEASURABLE PRECIPITATION IS NOT EXPECTED. FOG ALSO APPEARS TO BE
LIFTING ALONG THE PECOS RIVER VALLEY AND ACROSS PORTIONS OF THE
LOWER RIO GRANDE VALLEY...THOUGH MUCH SLOWER IN THIS LATTER AREA.
MEANWHILE...UP AT CLAYTON...DOWNSLOPING OFF THE RATON
RIDGE/JOHNSON MESA HAS ALLOWED TEMPS TO CLIMB ABOVE FORECAST HIGHS
ALREADY. THUS...HAVE RAISED CLAYTONS HIGH TEMP A FEW DEGREES.
HOWEVER...A BACK DOOR COLD FRONT SHOULD TAPER THE WARMING THERE
SHORTLY.
WILL ALSO ADD SOUTHWEST CHAVES COUNTY TO THE WIND ADVISORY THIS
AFTERNOON AS 35-40KT H7 FLOW WILL BE OVERHEAD AND THERE COULD BE
SOME MOUNTAIN WAVE ACTIVITY...ESPECIALLY IF CLOUDS JUST EAST OF
THE SANDIA/MANZANO MTNS ARE ANY INDICATION.
UPDATES OUT SHORTLY.
34
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-533-537>540.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1025 AM MST FRI DEC 13 2013
.UPDATE...
QUICK UPDATE TO REMOVE POPS FOR THE REST OF THE DAY. SOME FLURRIES
AND/OR SPRINKLES MAY OCCUR...BUT GIVEN RADAR TRENDS AND THE FACT
THAT THE SYSTEM IS PULLING AWAY FROM THE AREA...ADDITIONAL
MEASURABLE PRECIPITATION IS NOT EXPECTED. FOG ALSO APPEARS TO BE
LIFTING ALONG THE PECOS RIVER VALLEY AND ACROSS PORTIONS OF THE
LOWER RIO GRANDE VALLEY...THOUGH MUCH SLOWER IN THIS LATTER AREA.
MEANWHILE...UP AT CLAYTON...DOWNSLOPING OFF THE RATON
RIDGE/JOHNSON MESA HAS ALLOWED TEMPS TO CLIMB ABOVE FORECAST HIGHS
ALREADY. THUS...HAVE RAISED CLAYTONS HIGH TEMP A FEW DEGREES.
HOWEVER...A BACK DOOR COLD FRONT SHOULD TAPER THE WARMING THERE
SHORTLY.
WILL ALSO ADD SOUTHWEST CHAVES COUNTY TO THE WIND ADVISORY THIS
AFTERNOON AS 35-40KT H7 FLOW WILL BE OVERHEAD AND THERE COULD BE
SOME MOUNTAIN WAVE ACTIVITY...ESPECIALLY IF CLOUDS JUST EAST OF
THE SANDIA/MANZANO MTNS ARE ANY INDICATION.
UPDATES OUT SHORTLY.
34
&&
.PREV DISCUSSION...453 AM MST FRI DEC 13 2013...
.AVIATION...
12Z TAF CYCLE
AN UPPER TROUGH AND SURFACE COLD FRONT CROSSING FROM THE W WILL
CONTINUE TO PRODUCE MVFR AND PATCHY IFR CONDITIONS IN SNOW SHOWERS
OVER CENTRAL AND WESTERN PARTS OF THE FORECAST AREA THROUGH THE
MORNING. MOUNTAIN OBSCURATIONS ARE ALSO EXPECTED. FURTHER...PATCHY
FOG AND LOW CLOUDS WILL CONTINUE TO AFFLICT THE PECOS RIVER
VALLEY UNTIL MID MORNING. WINDS WILL SHIFT OUT OF THE NW AND
BECOME GUSTY AS THE A COLD FRONT CROSSES. THE STRONGEST WINDS
WILL BE FOUND EAST OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS
WHERE GUSTS MAY REACH 45 KT FROM LATE MORNING TO MID AFTN. A
SECONDARY UPPER TROUGH COULD TRIGGER A FEW LIGHT SNOW SHOWERS AND
MOUNTAIN OBSCURATIONS IN THE NORTHERN MOUNTAINS TONIGHT...ESPECIALLY
NEAR THE CO BORDER.
44
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-533-537>540.
&&
$$
34
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
453 AM MST FRI DEC 13 2013
.AVIATION...
12Z TAF CYCLE
AN UPPER TROUGH AND SURFACE COLD FRONT CROSSING FROM THE W WILL
CONTINUE TO PRODUCE MVFR AND PATCHY IFR CONDITIONS IN SNOW SHOWERS
OVER CENTRAL AND WESTERN PARTS OF THE FORECAST AREA THROUGH THE
MORNING. MOUNTAIN OBSCURATIONS ARE ALSO EXPECTED. FURTHER...PATCHY
FOG AND LOW CLOUDS WILL CONTINUE TO AFFLICT THE PECOS RIVER
VALLEY UNTIL MID MORNING. WINDS WILL SHIFT OUT OF THE NW AND
BECOME GUSTY AS THE A COLD FRONT CROSSES. THE STRONGEST WINDS
WILL BE FOUND EAST OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS
WHERE GUSTS MAY REACH 45 KT FROM LATE MORNING TO MID AFTN. A
SECONDARY UPPER TROUGH COULD TRIGGER A FEW LIGHT SNOW SHOWERS AND
MOUNTAIN OBSCURATIONS IN THE NORTHERN MOUNTAINS TONIGHT...ESPECIALLY
NEAR THE CO BORDER.
44
&&
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON
FOR THE FOLLOWING ZONES...NMZ521>524-526-533-537>539.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
259 AM MST FRI DEC 13 2013
.DISCUSSION...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
&&
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.AVIATION...
06Z TAF CYCLE
STORM CENTER OVER CENTRAL ARIZONA MOVING TO SOUTHERN OKLA BY 00Z
FRI AFTERNOON...AS NEXT INBOUND SYSTEM AMPLIFIES OVER THE FOUR
CORNERS BY 06Z FRIDAY EVENING. MT OBSCURATION AND CIGS DOWN TO
MVFR THRESHOLDS IN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
ACROSS MUCH OF WESTERN AND CENTRAL NEW MEXICO. THUNDER WILL BE
MOST LIKELY FROM THE CONTINENTAL DIVIDE TO THE ARIZONA LINE FROM
09Z ONWARD...WITH LESS LIKELY ACTIVITY OVER THE RIO GRANDE VALLEY
BY 10Z THIS EVENING. ACTIVITY WILL TAPER OFF RAPIDLY AFTER FRIDAY
SUNRISE...AND END BY 18Z LATE FRIDAY MORNING AS WEATHER SYSTEM
CROSSES OUT OF EASTERN NEW MEXICO INTO THE TX PANHANDLE. SOME
LINGERING CLOUD NEAR THE ARIZONA LINE FOR MT TOP OBSCURATION AND
CIGS AOA BKN/OVC040 CONTG THROUGH 06Z AND BEYOND...WITH CLEAR
SKIES ELSEWHERE. IN TAFS...SCT GROUPS AT IFR AND MVFR LEVELS
SIGNALING MOST LIKELY WINDOW FOR REDUCED FLIGHT
CATEGORIES...WHILE VCSH SET FOR MOST LIKELY ONSET OF RAIN CHANGING
RAPIDLY TO LIGHT SNOW. HAVE SET VCTS AT GUP TO COVER NEARBY
THUNDER THROUGH 09Z THIS EVENING.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 36 13 35 13 / 5 0 0 0
DULCE........................... 35 4 34 2 / 10 5 0 0
CUBA............................ 38 15 36 14 / 30 5 0 0
GALLUP.......................... 40 11 37 10 / 10 0 0 0
EL MORRO........................ 38 14 37 10 / 30 0 0 0
GRANTS.......................... 43 16 39 13 / 30 0 0 0
QUEMADO......................... 45 20 40 18 / 30 0 0 0
GLENWOOD........................ 54 22 52 19 / 20 0 0 0
CHAMA........................... 34 9 32 9 / 20 10 0 0
LOS ALAMOS...................... 41 18 36 16 / 30 5 0 0
PECOS........................... 38 18 35 20 / 20 5 0 0
CERRO/QUESTA.................... 34 4 30 4 / 30 5 0 0
RED RIVER....................... 34 10 28 8 / 30 10 5 0
ANGEL FIRE...................... 38 9 32 8 / 20 10 5 0
TAOS............................ 37 7 34 5 / 30 5 0 0
MORA............................ 41 16 36 16 / 10 5 0 0
ESPANOLA........................ 43 18 37 16 / 20 0 0 0
SANTA FE........................ 35 19 34 19 / 40 5 0 0
SANTA FE AIRPORT................ 39 17 36 17 / 30 0 0 0
ALBUQUERQUE FOOTHILLS........... 41 24 40 23 / 40 0 0 0
ALBUQUERQUE HEIGHTS............. 43 25 42 22 / 40 0 0 0
ALBUQUERQUE VALLEY.............. 45 23 44 21 / 30 0 0 0
ALBUQUERQUE WEST MESA........... 44 25 44 23 / 40 0 0 0
LOS LUNAS....................... 46 22 44 20 / 40 0 0 0
RIO RANCHO...................... 43 24 43 22 / 30 0 0 0
SOCORRO......................... 55 26 47 23 / 30 0 0 0
SANDIA PARK/CEDAR CREST......... 38 19 38 18 / 50 0 0 0
TIJERAS......................... 40 22 40 21 / 40 0 0 0
MORIARTY/ESTANCIA............... 38 11 37 11 / 20 0 0 0
CLINES CORNERS.................. 36 17 35 18 / 20 0 0 0
GRAN QUIVIRA.................... 44 22 40 21 / 30 0 0 0
CARRIZOZO....................... 47 26 45 22 / 20 0 0 0
RUIDOSO......................... 46 24 41 23 / 20 0 0 0
CAPULIN......................... 42 17 35 17 / 5 5 0 0
RATON........................... 49 18 40 16 / 5 5 0 0
SPRINGER........................ 48 17 41 16 / 5 5 0 0
LAS VEGAS....................... 44 17 37 19 / 10 5 0 0
CLAYTON......................... 52 22 44 26 / 5 5 0 0
ROY............................. 48 22 40 22 / 5 5 0 0
CONCHAS......................... 58 28 47 26 / 0 0 0 0
SANTA ROSA...................... 52 25 47 25 / 5 0 0 0
TUCUMCARI....................... 59 27 49 26 / 0 0 0 0
CLOVIS.......................... 55 25 46 26 / 5 0 0 0
PORTALES........................ 57 26 47 25 / 5 0 0 0
FORT SUMNER..................... 56 27 49 26 / 5 0 0 0
ROSWELL......................... 61 29 50 24 / 5 0 0 0
PICACHO......................... 55 27 45 23 / 5 0 0 0
ELK............................. 52 27 43 25 / 10 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON
FOR THE FOLLOWING ZONES...NMZ521>524-526-533-537>539.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1029 PM EST SAT DEC 14 2013
.SYNOPSIS...
A COASTAL LOW WILL DEEPEN ALONG THE NEW ENGLAND COAST OVERNIGHT AS
LOW PRESSURE TRANSITIONS FROM THE OHIO VALLEY EASTWARD. THIS IS
BRINGING WIDESPREAD ACCUMULATING SNOW TO THE ENTIRE REGION WHICH
WILL TAPER OFF FROM WEST TO EAST EARLY SUNDAY. SOME LINGERING LAKE
EFFECT SNOW WILL CONTINUE LATER SUNDAY AND MONDAY SOUTHEAST OF THE
LAKES. ANOTHER WEAKER LOW PRESSURE WILL BRING ANOTHER ROUND OF SNOW
ON TUESDAY WITH SOME ADDITIONAL LAKE EFFECT SNOW SOUTHEAST OF THE
LAKES WEDNESDAY. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MIDWEEK BEFORE MODERATING BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
DUAL LOW PRESSURE CENTERS ON THE SURFACE MAP LATE THIS EVENING. ONE
IS NOW CROSSING OVER WESTERN PA WITH THE STRONGER LOW NOW LIFTING
NORTH ACROSS THE DELMARVA PENINSULA. THESE TWO LOWS WILL PHASE INTO
A SINGLE NOREASTER OFF THE NEW JERSEY COAST OVERNIGHT IN A MILLER
TYPE-B COASTAL CYCLOGENESIS. THIS ALWAYS PROVES DIFFICULT FROM A SNOW
ACCUMULATION STANDPOINT AS THE TIMING AND DEGREE OF ENERGY TRANSFER
TO THE COAST CAN IMPACT AMOUNTS TO THE WEST OF THE APPALACHIANS.
TYPICALLY WRAP AROUND PRECIPITATION CAN BE MUCH HEAVIER AS MOISTURE
AND LIFT INCREASE ON THE NORTHWESTERN QUADRANT OF THE SYSTEM WITH
TROWEL FORMATION.
REGIONAL RADAR IMAGERY AND SURFACE OBS SHOWING A DRY SLOT NOW
SHIFTING ACROSS THE GENESEE VALLEY AND WESTERN FINGER LAKES TO THE
NORTHEAST AS THE STORM WRAPS IN DRIER AIR FROM THE NORTH AND WEST.
THIS DRY SLOT WILL BRING A SHORT WINDOW WITH A BREAK IN SNOWFALL
FROM THE GENESEE VALLEY NORTHEAST TO THE EASTERN LAKE ONTARIO
REGION. THE LATEST HRRR RUNS SHOW THIS SCENARIO VERY WELL. ACROSS
FAR WESTERN NEW YORK THE WRAP AROUND PRECIP IS NOW SHIFTING BACK
ACROSS THE FORECAST AREA ON THE HEELS OF THE DRY SLOT. THIS AREA
EXHIBITING MORE IN THE WAY OF SYNOPTIC LIFT AND MOISTURE SHOULD
BRING MORE INTENSE SNOWFALL RATES POSSIBLY UP TO AN INCH AN
HOUR.
THE QPF AND SNOW FORECASTS WERE UPDATED EARLIER THIS EVENING BASED
THE DRY SLOT WHICH HAS LIKELY CUT BACK ON SNOW TOTALS SOME. THE NEW
FORECAST IS A LITTLE LIGHTER ON SNOW TOTALS MAINLY ACROSS THE
GENESEE VALLEY AND FINGER LAKES WHERE THE DRY SLOT WILL PERSIST
LONGER. EAST OF LAKE ONTARIO SNOW RATES AFTER MIDNIGHT WILL INCREASE
UP TO AND INCH AN HOUR AS THE NOREASTER TAKES SHAPE OFF THE COAST
AND WRAP AROUND MOISTURE INCREASES.
EXPECT STORM TOTALS OF 5-8 INCHES FROM THE GENESEE VALLEY AND
WESTERN FINGER LAKES WITH THE DRY SLOT CONTRIBUTING TO LOWER SNOW
TOTALS. WITH AN INTENSIFYING NOREASTER OVER NIGHT HIGHER AMOUNTS OF
10-14 INCHES CAN BE EXPECTED ACROSS THE NORTH COUNTRY EAST OF LAKE
ONTARIO. ACROSS THE ADVISORY AREA FROM THE BUFFALO AND NIAGARA
REGION DOWN TO THE SOUTHERN TIER...EXPECT TOTALS OF 4-6 INCHES. IT
APPEARS THE COMMA HEAD AND STRONGEST WARM ADVECTION WILL NOT RESIDE
IN THESE AREAS LONG ENOUGH TO PRODUCE WARNING CRITERIA SNOW...WITH A
SOLID TO HIGH END ADVISORY STILL LOOKING MOST LIKELY.
THE SYNOPTIC SNOW WILL BE OVER BY DAYBREAK FROM THE GENESEE VALLEY
WESTWARD...AND WILL END BY MID MORNING EAST OF LAKE ONTARIO. THIS
WILL LEAVE JUST SCATTERED SNOW SHOWERS IN SOME LIMITED WRAP AROUND
MOISTURE. SOME LIMITED LAKE EFFECT SNOW WILL ALSO DEVELOP ESPECIALLY
DURING THE AFTERNOON AS TEMPERATURES ALOFT BEGIN TO DROP.
OFF LAKE ERIE...LAKE INDUCED EQUILIBRIUM LEVELS RISE TO AROUND 7K
FEET BY MID AFTERNOON. EXPECT A HYBRID LAKE EFFECT/UPSLOPE SNOW TO
DEVELOP MAINLY ALONG THE CHAUTAUQUA RIDGE. THIS MAY PRODUCE 2-3
INCHES DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN INLAND FROM
LAKE ERIE.
OFF LAKE ONTARIO...LAKE INDUCED EQUILIBRIUM LEVELS ALSO RISE TO
AROUND 7K FEET BY MID AFTERNOON. EXPECT A BAND OF LAKE EFFECT SNOW
TO DEVELOP ACROSS MAINLY OSWEGO COUNTY TO THE SOUTHERN TUG HILL
DURING THE AFTERNOON WITH 2 TO 4 INCHES POSSIBLE.
TEMPERATURES WILL SLOWLY CLIMB OVERNIGHT INTO THE LOWER TO MID 20S
WITH ONGOING LOW/MID LEVEL WARM ADVECTION. TEMPS WILL THEN STAY
FAIRLY STEADY THROUGH SUNDAY...PERHAPS ONLY CLIMBING A DEGREE OR TWO
THROUGH THE DAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SUNDAY NIGHT WILL TRANSITION FROM THE DAYS SYNOPTIC SNOW BACK TO
LAKE EFFECT SNOW AS COOLER AIR BEHIND THE DEPARTING STORM SYSTEM
SENDS TEMPERATURES AT 850 HPA BACK DOWN TO -16 TO -18C.
OFF LAKE ERIE...A WEST TO NORTHWEST FLOW WILL ORIENT A BAND OF SNOW
ACROSS SOUTHERN ERIE/CHAUTAUQUA AND POINTS INLAND. MOST FAVORABLE
LAKE PARAMETERS WILL BE FOUND EARLY IN THE NIGHT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 10K FEET AND UPWARD MOTION THROUGH A
SATURATED LOW LEVEL. WITH MOISTURE REMAINING PLENTIFUL THROUGH THE
NIGHT EXPECT A BAND OF SNOW...THAT MIGHT BECOME MORE MULTI BANDED IN
CHARACTERISTICS AS WINDS VEER SOME...TO CONTINUE. ALOFT A CLOSED 500
HPA LOW WILL BEGIN THE PERIOD OVER THE UPPER GREAT LAKES...BUT WILL
QUICKLY SLIDE ACROSS THE EASTERN GREAT LAKES THROUGH THE NIGHT. THIS
FEATURE WILL LIKELY KEEP THE LAKE BAND SHIFTING THROUGH THE NIGHT
AND HOLD ACCUMULATIONS TO ADVISORY RANGE VALUES.
OFF LAKE ONTARIO...A WEST TO NORTHWEST FLOW WILL ALSO BE FOUND WITH
A LAKE BAND FIRST ACROSS THE SOUTHERN TUG HILL...DROPPING SOUTHWARD
TO AREAS SOUTHEAST OF LAKE ONTARIO. WHILE THERE WILL BE SOME
FAVORABLE LAKE PARAMETERS...WITH LAKE INDUCED EQUILIBRIUM LEVELS AND
INVERSION HEIGHTS OVER 10K FEET THE AMOUNT OF MOISTURE IN THE LOWER
LEVELS WILL BE SOMEWHAT LIMITED. NORTHERLY FLOW AROUND THE ATLANTIC
COASTAL LOW WILL DROP SOUTHWARD AND SETTLE TO POINTS AROUND LAKE
ONTARIO...WHICH WILL ALSO PREVENT ANY UPSTREAM LAKE CONNECTION.
EXPECT SNOW TOTALS OFF LAKE ONTARIO TO BE LIGHTER THAN LAKE
ERIE...WITH OVERALL NUMBERS POSSIBLY REMAINING BELOW ADVISORY
LEVELS.
ELSEWHERE MONDAY NIGHT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LIKELY FLY WITH THE PASSAGE OF THE UPPER LEVEL TROUGH. IT WILL
REMAIN COLD SUNDAY NIGHT WITH LOWS DROPPING DOWN INTO THE SINGLE
DIGITS TO LOW DOUBLE DIGITS. THE NORTH COUNTY...IF THEY HAVE SOME
CLEARING STANDS A CHANCE TO BECOME EVEN COLDER THAN FORECASTED.
CURRENT FORECAST MINS JUST BELOW ZERO COULD EASILY REACH -10F OR
COLDER OVER A DEEP AND FRESH SNOW PACK...IF WE GET SOME CLEARING.
FOR NOW BELIEVE THERE MAY BE ENOUGH CLOUDS LINGERING THROUGH THE
NIGHT AHEAD OF THE SHORTWAVE TO PREVENT THESE MUCH COLDER LOWS.
ON MONDAY DRIER AIR BEHIND THE SHORTWAVE WILL BEGIN TO WEAKEN THE
LAKE BANDS. HIGH PRESSURE WILL SCURRY BY TO OUR SOUTH AND INVERSION
HEIGHTS WILL FALL WHICH ALSO WILL PUT A DAMPER ON THE LAKE EFFECT
SNOWS. AS THIS HIGH SLIDES EASTWARD LATER MONDAY AND IN ADVANCE OF
THE NEXT CLIPPER LOW OUR WINDS WILL BACK AROUND TO MORE OF A
SOUTHWESTERLY FLOW. INCREASE WIND SHEAR WILL FURTHER DIMINISH THE
LAKE SNOWS MONDAY NIGHT WHILE SENDING THEM NORTHWARD TOWARDS METRO
BUFFALO OFF LAKE ERIE AND WATERTOWN OFF LAKE ONTARIO.
THERE ARE STILL SOME MODEL TIMING DIFFERENCES WITH THE ARRIVAL OF
THE NEXT AREA OF LOW PRESSURE...ONE THAT WILL DROP ACROSS SOUTHERN
CANADA AND THE UPPER GREAT LAKES...AND THEN NORTH OF LAKE
ONTARIO...BEFORE A COASTAL REDEVELOPMENT TAKES PLACE. THE 12Z ECMWF
AND THE 12Z CMC CONTINUE TO BE FASTER THAN THE GFS MODEL...THOUGH
ALL AGREE THAT A LIGHT GENERAL SNOWFALL ACROSS THE CWA
TUESDAY-TUESDAY NIGHT IS LIKELY. AHEAD OF THE SYSTEM OUR HIGHS WILL
CLIMB INTO THE UPPER 20S...AND MAY EVEN CRACK THE FREEZING MARK FOR
A BRIEF PERIOD OF TIME. WITH THE LINGERING CLOUDS TUESDAY NIGHT WILL
NOT BE AS COLD...WITH LOWS GENERALLY IN THE LOW 20S ACROSS THE CWA.
SNOW WILL TAPER OFF TUESDAY NIGHT BEHIND THE CLIPPER LOW...HOWEVER
AGAIN WE WILL SEE LAKE EFFECT SNOW LINGERING TO THE EAST...AND THEN
SOUTHEAST OF THE LAKES. SHIFTING WINDS AND A RETURN OF HIGH PRESSURE
ON WEDNESDAY WILL LIKELY KEEP SNOW TOTALS ON TUESDAY NIGHT TO
PERHAPS ADVISORY LEVELS OR LOWER.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THROUGH THIS TIME PERIOD OUR FLOW ALOFT WILL GO FROM NORTHWESTERLY
TO A WESTERLY ZONAL FLOW...AND THEN TO A DEEP AMPLIFIED SOUTHWEST
FLOW. THIS WILL ALLOW FROM BELOW NORMAL TEMPERATURES AT THE START OF
THE PERIOD TO WARM TO ABOVE NORMAL AROUND FRIDAY...SOME MODEL
UNCERTAINTY ON THE TIMING OF A COLD FRONT AT THE BEGINNING OF THE
WEEKEND...MAY OR MAY NOT LEAVE SATURDAY ABOVE NORMAL AS WELL.
WILL CONTINUE WITH A CHANCE FOR SOME LIGHT LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF THE LAKES WEDNESDAY AND INTO EARLY WEDNESDAY WITH THE
NORTHWEST FLOW...BUT AS HIGH PRESSURE AT THE SURFACE NUDGES INTO THE
REGION WEDNESDAY NIGHT EXPECT THE LAKE SNOW ACTIVITY TO GREATLY
DIMINISH. THIS MAY LEAVE THURSDAY AS A DRY DAY AS THE FLOW BECOMES
MORE SOUTHWESTERLY IN RESPONSE TO A DIGGING TROUGH ACROSS THE
SOUTHWESTERN US AND BUILDING DOWNSTREAM HEIGHTS ACROSS THE EASTERN
US. WILL BRING A CHANCE FOR RAIN SNOW IN LATER FRIDAY...WITH A COLD
FRONT PASSING ACROSS THE REGION NEXT WEEKEND CHANGING THE RAIN BACK
TO SNOW. THERE IS STILL SOME MODEL UNCERTAINTY TO THE TIMING AND
PLACEMENT OF SURFACE WAVES ALONG THIS COLD FRONT...WHICH WILL IMPACT
THE FRONTAL CROSSING FOR OUR REGION.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
KBUF RADAR SHOWING A DRY SLOT IN THE SNOW SHIFTING NORTHEAST ACROSS
THE GENESEE VALLEY TOWARD THE EASTERN LAKE ONTARIO REGION. WITHIN
THIS DRY SLOT BRIEF VFR CONDITIONS HAVE BEEN OBSERVED. THIS WILL
SHIFT ACROSS THE KART TERMINAL OVER THE NEXT FEW HOURS. BACK TO THE
WEST A SECOND PERIOD OF HEAVY SNOW IS WORKING BACK ACROSS THE WNY
TERMINALS ASSOCIATED WITH WRAP AROUND MOISTURE FROM A DEVELOPING
NOREASTER TAKING SHAPE NEAR THE MID-ATLANTIC COAST. THIS WRAP
AROUND SNOW WILL BRING BACK IFR/LIFR CONDITIONS THROUGH THE 04Z TO
10Z TIME FRAME WITH CONDITIONS IMPROVING TO MVFR CIGS IN MOST PLACES
WITH SCATTERED LIGHT SNOW SHOWERS TOMORROW AFTER DAY BREAK. IFR CIGS
LOOK TO REMAIN ACROSS THE SOUTHERN TIER. SOME LIMITED LAKE EFFECT
SNOW WILL KEEP SPOTTY IFR GOING SOUTHEAST OF THE LAKES. MVFR CIGS
WILL LIKELY LINGER IN MOST AREAS THROUGH AT LEAST THE FIRST HALF OF
SUNDAY...WITH SOME IFR ACROSS HIGHER TERRAIN IN THE MORNING.
OUTLOOK...
MONDAY...LAKE EFFECT SNOW SHOWERS WITH LOCAL IFR SOUTHEAST OF THE
LAKES DIMINISHING.
TUESDAY...SNOW SHOWERS LIKELY WITH AREAS OF MVFR/IFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS...EXCEPT LAKE
EFFECT SNOW SHOWERS LIKELY SOUTHEAST OF THE LAKES WITH LOCAL IFR.
THURSDAY...MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE ALONG THE NY/PA BORDER OVERNIGHT AND GIVE WAY
TO A SECONDARY COASTAL LOW OFF THE MID ATLANTIC COAST. THE PRESSURE
GRADIENT BETWEEN BOTH OF THESE SYSTEMS AND HIGH PRESSURE OVER
SOUTHEAST CANADA WILL MAINTAIN MODERATE NORTHEAST WINDS ON THE LOWER
LAKES. THIS WILL KEEP SMALL CRAFT CONDITIONS GOING ON THE WEST HALF
OF LAKE ONTARIO.
ON SUNDAY AS THE COASTAL LOW DEEPENS WINDS WILL COME AROUND TO THE
NORTHWEST AND EVENTUALLY WEST. THIS WILL BRING SMALL CRAFT ADVISORY
CONDITIONS TO BOTH LAKES ERIE AND ONTARIO...WHICH WILL LAST THROUGH
MONDAY BEFORE HIGH PRESSURE BUILDS OVER THE LOWER LAKES AND ALLOWS
WINDS TO DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 10 AM EST SUNDAY FOR NYZ006>008.
WINTER STORM WARNING UNTIL 9 AM EST SUNDAY FOR NYZ002>005-
011>014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR NYZ001-010-
019>021-085.
MARINE...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 1 PM EST MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR
LOZ042-043.
SMALL CRAFT ADVISORY FROM 5 PM SUNDAY TO 4 PM EST MONDAY
FOR LOZ045.
SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 PM EST MONDAY
FOR LOZ044.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...HITCHCOCK/SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/SMITH
MARINE...HITCHCOCK/SMITH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
934 PM EST SAT DEC 14 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE UP THE OHIO RIVER
VALLEY...BRINGING SIGNIFICANT SNOWFALL AS IT DEVELOPS INTO A
COASTAL LOW NEAR CAPE COD BY SUNDAY MORNING. SNOWFALL WILL BEGIN
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHERN
AREAS...SPREADING NORTHWARD TONIGHT AND CONTINUING THROUGH MUCH
OF SUNDAY WITH TOTAL ACCUMULATIONS OF 6 TO 12 INCHES LIKELY BY
SUNDAY EVENING. COLD TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 933 PM EST SATURDAY...FIRST WIDESPREAD SIGNIFICANT SNOWFALL
OF THE WINTER SEASON HAS BEGIN ACRS THE NORTH COUNTY...WITH CRNT RADAR
SHOWING MODERATE SNOW NOW ENTERING EXTREME SOUTHERN VT. SFC
ANALYSIS PLACES PRIMARY LOW PRES ACRS EASTERN OHIO ATTM...WITH
SECONDARY 1007MB LOW PRES NEAR NORFOLK VA WITH GREATEST 3HR PRE
FALL OF 6MB TWD THE MID ALTANTIC STATES. EXPECT RAPID DEVELOPMENT
OF SFC LOW PRES OVERNIGHT...WITH A GENERAL TRACK TO THE NORTHEAST
TWD NYC ACRS THE CAPE COD CANAL AND INTO THE GULF OF MAINE BY 18Z
SUNDAY. THE LATEST 00Z RAP AND NAM CONTINUE TO SUPPORT THIS IDEA.
THIS WL ALLOW FOR A STRENGHTENING LLVL JET BTWN 925MB AND 850MB TO
DEVELOP...AND ADVECT PLENTY OF ATLANTIC MOISTURE BACK INTO OUR
CWA. ALREADY NOTICING 60 KNOT 85H JET OFF KBGM VAD FROM THE SE.
THE NOSE OF THIS LLVL JET LIFTS FROM EASTERN NY/SOUTHERN NEW
ENGLAND INTO CENTRAL NH/EASTERN VT BY 06Z AND NORTH OF OUR CWA BY
12Z SUNDAY. THIS COMBINED WITH RAP/NAM CONTINUING TO SHOW STRONG
FGEN FORCING/DEEP LAYER UVVS WL PRODUCE A MESO-SCALE BAND OF
MODERATE TO HEAVY SNOW FROM 04Z SOUTHERN VT TO 12Z NORTHERN CWA.
EXPECT VIS BTWN 1/4SM AND 1/2SM IN THIS BAND WITH SNOWFALL RATES
OF 1 TO 2 INCHES PER HOUR. THIS BAND WL CONTINUE TO MOVE AND NOT
BECOMING STATIONARY GIVEN NO CLOSED 5H/7H AND PROGRESSIVE SW TO NE
FLW ALOFT AND FAST MOVEMENT OF SFC LOW PRES. OVERALL...LITTLE
CHANGE IN EXPECTED SNOWFALL WITH A GENERAL 6 TO 12
INCHES...SLIGHTLY HIGHER IN THE FAVORALBE SE UPSLOPE REGIONS AND
SLIGHTLY LESS IN THE DOWNSLOPE REGIONS OF THE NEK/SOUTHERN
CPV...AND PARTS OF THE SLV.
ALSO...EXPECT SFC WIND GUSTS BTWN 30 AND 40 MPH NEAR
RUTLAND/MIDDLEBURY BTWN 04Z-10Z TONIGHT. TEMPS WL SLOWLY RISES
UNDER WAA TO THE MID/UPPER TEENS BY SUNRISE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 331 PM EST SATURDAY...SFC LOW WILL MOVE INTO THE GULF OF
MAINE AND TOWARD THE CANADIAN MARITIMES ON SUNDAY. BULK OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO DEPART MID-
LATE SUNDAY...TRANSITIONING STEADY SNOWFALL TO SNOW SHOWERS.
THESE SHOWERS WILL LIKELY CONTINUE THROUGH SUNDAY NIGHT ACROSS
THE HIGHER TRRN AS THE PARENT UPPER TROUGH TRACKS THROUGH.
STORM TOTAL SNOWFALL AMOUNTS BY SUNDAY EVENING WILL GENERALLY BE
6-12 INCHES WITH LOCALIZED HIGHER AMOUNTS ACROSS ERN SLOPES DUE
TO SE FLOW TONIGHT INTO SUNDAY MORNING.
TEMPS NOTICEABLY WARMER...BUT SNOWFALL...CLOUDS AND WINDS KEEP
CONDITIONS CHILLY WITH MAX TEMPS IN THE TEENS TO M20S. SUNDAY
NIGHT TEMPS SEE SINGLE DIGITS TEMPS ABOVE AND BELOW ZERO.
ON MONDAY...THE UPPER LOW WILL EXIT THE NORTH COUNTRY TO THE
NE...WITH RIDGING DEVELOPING AT THE SFC AND ALOFT LATE IN THE DAY
INTO MONDAY EVENING. SOME UPSLOPE SNOW ON W-NW FLOW NOT OUT OF
THE QUESTION. WITH SKIES SLOW TO CLEAR AND WINDS OUT OF THE W-NW
AT 10-20 KTS...BLUSTERY CONDITIONS WILL CONTINUE WITH MAX TEMPS
RANGING FROM -5 TO +15 DEGREES FROM STRONG CAA.
MONDAY NIGHT WINDS SHIFT TO THE SOUTH AHEAD OF A CLIPPER TYPE
SYSTEM APPROACHING FROM THE NW. THREAT OF SNOW FROM THIS SYSTEM
WILL INCREASE TOWARDS TUESDAY MORNING FROM THE WEST. ANOTHER COLD
NIGHT...WITH MOST AREAS BEING NEAR OR BELOW ZERO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 323 PM EST SATURDAY...SUITE OF GLOBAL DETERMINISTIC AND
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT THROUGH THURSDAY
NIGHT. MODELS THEN BEGIN TO DIVERGE SIGNIFICANTLY ENOUGH TO LIMIT
PREDICTABILITY FOR THE FRIDAY INTO THE EARLY WEEKEND PERIOD.
AMPLIFICATION OF A 500 MB TROUGH OVER THE GREAT LAKES IS
PREDICTED BY TUESDAY WHICH INDUCES SECONDARY CYCLOGENESIS NEAR
CAPE COD BY TUESDAY NIGHT...WITH THE PROGGED COASTAL MOVING INTO
THE CENTRAL GULF OF MAINE BY WEDNESDAY. I OPTED TO INCREASE POPS
TO HIGH CHANCE/LOW LIKELY FOR TUESDAY INTO TUESDAY NIGHT GIVEN
GOOD CONSISTENCY OVER SEVERAL MODEL CYCLES FOR WHAT WILL BE A
LIGHT-QPF STRATIFORM LIGHT SNOW EVENT FROM INITIAL CLIPPER
SYSTEM. I WAS A LITTLE LEERY OF GOING MUCH HIGHER THAN THAT
THOUGH DUE TO UNCERTAINTIES IN ENERGY TRANSFER TO THE DEVELOPING
COASTAL. THOUGH I DO THINK A DOWNWARD TREND IN POPS ON WEDNESDAY
LOOKS GOOD...I`VE KEPT CHANCE POPS FOR THE NORTHEAST KINGDOM AREA
AS THERE IS SOME INDICATION OF AN INVERTED TROUGH/TROWAL FEATURE
WHICH IF PROGGED CORRECTLY MAY HELP KEEP LIGHT SNOWS GOING A
LITTLE LONGER THERE. TEMPERATURES ARE PRETTY SIMILAR TUESDAY AND
WEDNESDAY...HIGHS GENERALLY IN THE 20S WITH LOWS IN THE TEENS.
A PATTERN CHANGE TOWARD A BRIEF PERIOD OF WARMER WEATHER LOOKS TO
BE IN STORE FOR THE MID TO LATE WEEK PERIOD AS 500 MB HEIGHTS
RISE ACROSS THE EASTERN CONUS. HIGHS ON FRIDAY MAY REACH INTO THE
UPPER 30S TO AROUND 40 IN SPOTS. UNCERTAINTY THEN INCREASES
MARKEDLY DUE TO DIFFERENCES IN HANDLING A LOW MOVING OUT OF THE
MIDWEST TO THE NORTHEAST. THESE DIFFERENCES ARE MOSTLY DUE TO
TIMING THE EJECTION OF AN UPPER-LEVEL TROUGH FRIDAY
AFTERNOON...WHICH IN TURN LEADS TO SOME DISCREPANCY AS TO WHEN
THE ASSOCIATED SFC COLD FRONT PUSHES THROUGH THE NORTH COUNTRY.
ONE THING THAT CAN BE SAID ABOUT THE EARLY WEEKEND PERIOD IS THAT
THE BAROCLINIC ZONE TIED TO THE AFOREMENTIONED COLD FRONT GETS
HUNG UP SOMEWHERE IN THE INTERIOR SOUTHEASTERN CONUS WITH THE
IMPLICATION OF ADDITIONAL CHANCES FOR UNSETTLED WEATHER. IT`S NOT
CLEAR HOW ALL THAT UNFOLDS HOWEVER. I`VE STAYED CLOSE TO THE
SUPERBLEND GUIDANCE FOR THE EARLY WEEKEND PERIOD WHICH OFFERS
CHANCE POPS WITH LOWS TRENDING NEAR TO BELOW NORMAL.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...COMPOSITE RADAR LOOP AND SURFACE OBSERVATIONS SHOWING
SNOW HAS OVERSPREAD MOST OF VERMONT AND NORTHERN NEW YORK AS OF
00Z SUNDAY. EXPECTING WIDESPREAD IFR/LIFR CONDITIONS IN SNOW OVERNIGHT.
EXPECTING CONDITIONS TO IMPROVE TO IFR/MVFR IN LIGHT SNOW BY 18Z
SUNDAY. LATEST MODEL GUIDANCE SUGGESTING A PERIOD OF SLEET WILL BE
POSSIBLE ACROSS SOUTHERN VERMONT BETWEEN 10Z-14Z SUNDAY...AS
WARMER AIR ALOFT MOVES INTO THE REGION. THUS...HAVE INDICATED A
PERIOD OF SNOW AND SLEET IN THE TAF FOR KRUT.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...SNOW COMES TO AN END LATE
SUNDAY AFTN AREAWIDE AS SURFACE LOW PULLS NEWD AWAY FROM THE
REGION. TRENDING VFR WITH NWLY WINDS SUNDAY NIGHT. CHANCE OF
FLURRIES SUNDAY NIGHT. MAINLY VFR MONDAY AND MOST OF MONDAY NIGHT
AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. LIGHT SNOW OR
SNOW SHOWERS POSSIBLE TUESDAY NIGHT AND WEDNESDAY. A SLIGHT CHANCE
FOR SOME SNOW SHOWERS ON THURSDAY...BUT MAINLY VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR VTZ001>012-
016>019.
NY...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR NYZ026>031-034-
035-087.
&&
$$
SYNOPSIS...LAHIFF/KGM
NEAR TERM...TABER
SHORT TERM...KGM
LONG TERM...LOCONTO
AVIATION...WGH/LOCONTO
AREA FORECAST DISCUSSION
NWS BUFFALO NY
837 PM EST SAT DEC 14 2013
.SYNOPSIS...
A COASTAL LOW WILL DEEPEN ALONG THE NEW ENGLAND COAST OVERNIGHT AS
LOW PRESSURE TRANSITIONS FROM THE OHIO VALLEY EASTWARD. THIS IS
BRINGING WIDESPREAD ACCUMULATING SNOW TO THE ENTIRE REGION WHICH
WILL TAPER OFF FROM WEST TO EAST EARLY SUNDAY. SOME LINGERING LAKE
EFFECT SNOW WILL CONTINUE LATER SUNDAY AND MONDAY SOUTHEAST OF THE
LAKES. ANOTHER WEAKER LOW PRESSURE WILL BRING ANOTHER ROUND OF SNOW
ON TUESDAY WITH SOME ADDITIONAL LAKE EFFECT SNOW SOUTHEAST OF THE
LAKES WEDNESDAY. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MIDWEEK BEFORE MODERATING BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
UPDATED THE QPF AND SNOW FORECASTS THIS EVENING BASED ON CURRENT
RADAR IMAGERY AND HRRR MODEL GUIDANCE. A DRY SLOT IS WORKING
NORTHEAST ACROSS WESTERN NEW YORK AT 830PM WHICH WILL CUT BACK ON
SNOW TOTALS SOME. THE NEW FORECAST IS A LITTLE LIGHTER ON SNOW
TOTALS MAINLY ACROSS THE GENESEE VALLEY AND FINGER LAKES WHERE THE
DRY SLOT WILL PERSIST LONGER. ACROSS NORTHEAST OHIO WRAP-AROUND SNOW
IS FILLING IN ON THE HEELS OF THE DRY SLOT WHICH WILL BRING BACK A
SECOND BURST OF SNOW LATE THIS EVENING. EAST OF LAKE ONTARIO SNOW
RATES AFTER MIDNIGHT WILL INCREASE UP TO AND INCH AN HOUR AS THE
NOREASTER TAKES SHAPE OFF THE COAST AND WRAP AROUND MOISTURE
INCREASES.
LOW PRESSURE OVER CENTRAL OHIO WILL SHIFT TOWARDS THE NY/PA BORDER
THEN EVENTUALLY GIVE WAY TO A SECONDARY COASTAL STORM/NOREASTER OFF
THE NEW JERSEY COAST AS DPVA AND HEIGHT FALLS INTERACT WITH THE
COASTAL FRONT. THIS MILLER TYPE-B COASTAL CYCLOGENESIS ALWAYS PROVES
DIFFICULT FROM A SNOW ACCUMULATION STANDPOINT AS THE TIMING AND
DEGREE OF ENERGY TRANSFER TO THE COAST CAN IMPACT AMOUNTS TO THE
WEST OF THE APPALACHIANS.
REGIONAL RADAR IMAGERY AND SURFACE OBS SHOWING A DRY SLOT ACROSS
MUCH OF WESTERN NEW YORK WHICH IS LIFTING TO THE NORTHEAST WITH THE
ENTIRE SYSTEM AS IT WRAPS IN DRIER AIR FROM THE NORTH AND WEST. THIS
DRY SLOT WILL BRING A SHORT WINDOW WITH A BREAK IN SNOWFALL THIS
EVENING ACROSS WESTERN NEW YORK BUT EXPECT THAT THIS WILL FILL BACK
IN LATER IN THE EVENING AS THE WRAP-AROUND/COMMA HEAD DRIVEN SNOW ON
THE BACK SIDE OF THE TRANSITIONING LOW SHIFTS ACROSS OUR REGION. THE
LATEST HRRR RUNS SHOW THIS SCENARIO VERY WELL. THE WRAP AROUND
PRECIP EXHIBITING MORE IN THE WAY OF SYNOPTIC LIFT AND MOISTURE
WHICH SHOULD EVEN BRING MORE INTENSE SNOWFALL RATES POSSIBLY UP TO
AN INCH AN HOUR.
EXPECT STORM TOTALS OF 5-8 INCHES FROM THE GENESEE VALLEY AND
WESTERN FINGER LAKES WITH THE DRY SLOT CONTRIBUTING TO LOWER SNOW
TOTALS. WITH AN INTENSIFYING NOREASTER OVER NIGHT HIGHER AMOUNTS OF
10-14 INCHES CAN BE EXPECTED ACROSS THE NORTH COUNTRY EAST OF LAKE
ONTARIO. ACROSS THE ADVISORY AREA FROM THE BUFFALO AND NIAGARA
REGION DOWN TO THE SOUTHERN TIER...EXPECT TOTALS OF 4-6 INCHES. IT
APPEARS THE COMMA HEAD AND STRONGEST WARM ADVECTION WILL NOT RESIDE
IN THESE AREAS LONG ENOUGH TO PRODUCE WARNING CRITERIA SNOW...WITH A
SOLID TO HIGH END ADVISORY STILL LOOKING MOST LIKELY.
THE SYNOPTIC SNOW WILL BE OVER BY DAYBREAK FROM THE GENESEE VALLEY
WESTWARD...AND WILL END BY MID MORNING EAST OF LAKE ONTARIO. THIS
WILL LEAVE JUST SCATTERED SNOW SHOWERS IN SOME LIMITED WRAP AROUND
MOISTURE. SOME LIMITED LAKE EFFECT SNOW WILL ALSO DEVELOP ESPECIALLY
DURING THE AFTERNOON AS TEMPERATURES ALOFT BEGIN TO DROP.
OFF LAKE ERIE...LAKE INDUCED EQUILIBRIUM LEVELS RISE TO AROUND 7K
FEET BY MID AFTERNOON. EXPECT A HYBRID LAKE EFFECT/UPSLOPE SNOW TO
DEVELOP MAINLY ALONG THE CHAUTAUQUA RIDGE. THIS MAY PRODUCE 2-3
INCHES DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN INLAND FROM
LAKE ERIE.
OFF LAKE ONTARIO...LAKE INDUCED EQUILIBRIUM LEVELS ALSO RISE TO
AROUND 7K FEET BY MID AFTERNOON. EXPECT A BAND OF LAKE EFFECT SNOW
TO DEVELOP ACROSS MAINLY OSWEGO COUNTY TO THE SOUTHERN TUG HILL
DURING THE AFTERNOON WITH 2 TO 4 INCHES POSSIBLE.
TEMPERATURES WILL SLOWLY CLIMB OVERNIGHT INTO THE LOWER TO MID 20S
WITH ONGOING LOW/MID LEVEL WARM ADVECTION. TEMPS WILL THEN STAY
FAIRLY STEADY THROUGH SUNDAY...PERHAPS ONLY CLIMBING A DEGREE OR TWO
THROUGH THE DAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SUNDAY NIGHT WILL TRANSITION FROM THE DAYS SYNOPTIC SNOW BACK TO
LAKE EFFECT SNOW AS COOLER AIR BEHIND THE DEPARTING STORM SYSTEM
SENDS TEMPERATURES AT 850 HPA BACK DOWN TO -16 TO -18C.
OFF LAKE ERIE...A WEST TO NORTHWEST FLOW WILL ORIENT A BAND OF SNOW
ACROSS SOUTHERN ERIE/CHAUTAUQUA AND POINTS INLAND. MOST FAVORABLE
LAKE PARAMETERS WILL BE FOUND EARLY IN THE NIGHT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 10K FEET AND UPWARD MOTION THROUGH A
SATURATED LOW LEVEL. WITH MOISTURE REMAINING PLENTIFUL THROUGH THE
NIGHT EXPECT A BAND OF SNOW...THAT MIGHT BECOME MORE MULTI BANDED IN
CHARACTERISTICS AS WINDS VEER SOME...TO CONTINUE. ALOFT A CLOSED 500
HPA LOW WILL BEGIN THE PERIOD OVER THE UPPER GREAT LAKES...BUT WILL
QUICKLY SLIDE ACROSS THE EASTERN GREAT LAKES THROUGH THE NIGHT. THIS
FEATURE WILL LIKELY KEEP THE LAKE BAND SHIFTING THROUGH THE NIGHT
AND HOLD ACCUMULATIONS TO ADVISORY RANGE VALUES.
OFF LAKE ONTARIO...A WEST TO NORTHWEST FLOW WILL ALSO BE FOUND WITH
A LAKE BAND FIRST ACROSS THE SOUTHERN TUG HILL...DROPPING SOUTHWARD
TO AREAS SOUTHEAST OF LAKE ONTARIO. WHILE THERE WILL BE SOME
FAVORABLE LAKE PARAMETERS...WITH LAKE INDUCED EQUILIBRIUM LEVELS AND
INVERSION HEIGHTS OVER 10K FEET THE AMOUNT OF MOISTURE IN THE LOWER
LEVELS WILL BE SOMEWHAT LIMITED. NORTHERLY FLOW AROUND THE ATLANTIC
COASTAL LOW WILL DROP SOUTHWARD AND SETTLE TO POINTS AROUND LAKE
ONTARIO...WHICH WILL ALSO PREVENT ANY UPSTREAM LAKE CONNECTION.
EXPECT SNOW TOTALS OFF LAKE ONTARIO TO BE LIGHTER THAN LAKE
ERIE...WITH OVERALL NUMBERS POSSIBLY REMAINING BELOW ADVISORY
LEVELS.
ELSEWHERE MONDAY NIGHT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LIKELY FLY WITH THE PASSAGE OF THE UPPER LEVEL TROUGH. IT WILL
REMAIN COLD SUNDAY NIGHT WITH LOWS DROPPING DOWN INTO THE SINGLE
DIGITS TO LOW DOUBLE DIGITS. THE NORTH COUNTY...IF THEY HAVE SOME
CLEARING STANDS A CHANCE TO BECOME EVEN COLDER THAN FORECASTED.
CURRENT FORECAST MINS JUST BELOW ZERO COULD EASILY REACH -10F OR
COLDER OVER A DEEP AND FRESH SNOW PACK...IF WE GET SOME CLEARING.
FOR NOW BELIEVE THERE MAY BE ENOUGH CLOUDS LINGERING THROUGH THE
NIGHT AHEAD OF THE SHORTWAVE TO PREVENT THESE MUCH COLDER LOWS.
ON MONDAY DRIER AIR BEHIND THE SHORTWAVE WILL BEGIN TO WEAKEN THE
LAKE BANDS. HIGH PRESSURE WILL SCURRY BY TO OUR SOUTH AND INVERSION
HEIGHTS WILL FALL WHICH ALSO WILL PUT A DAMPER ON THE LAKE EFFECT
SNOWS. AS THIS HIGH SLIDES EASTWARD LATER MONDAY AND IN ADVANCE OF
THE NEXT CLIPPER LOW OUR WINDS WILL BACK AROUND TO MORE OF A
SOUTHWESTERLY FLOW. INCREASE WIND SHEAR WILL FURTHER DIMINISH THE
LAKE SNOWS MONDAY NIGHT WHILE SENDING THEM NORTHWARD TOWARDS METRO
BUFFALO OFF LAKE ERIE AND WATERTOWN OFF LAKE ONTARIO.
THERE ARE STILL SOME MODEL TIMING DIFFERENCES WITH THE ARRIVAL OF
THE NEXT AREA OF LOW PRESSURE...ONE THAT WILL DROP ACROSS SOUTHERN
CANADA AND THE UPPER GREAT LAKES...AND THEN NORTH OF LAKE
ONTARIO...BEFORE A COASTAL REDEVELOPMENT TAKES PLACE. THE 12Z ECMWF
AND THE 12Z CMC CONTINUE TO BE FASTER THAN THE GFS MODEL...THOUGH
ALL AGREE THAT A LIGHT GENERAL SNOWFALL ACROSS THE CWA
TUESDAY-TUESDAY NIGHT IS LIKELY. AHEAD OF THE SYSTEM OUR HIGHS WILL
CLIMB INTO THE UPPER 20S...AND MAY EVEN CRACK THE FREEZING MARK FOR
A BRIEF PERIOD OF TIME. WITH THE LINGERING CLOUDS TUESDAY NIGHT WILL
NOT BE AS COLD...WITH LOWS GENERALLY IN THE LOW 20S ACROSS THE CWA.
SNOW WILL TAPER OFF TUESDAY NIGHT BEHIND THE CLIPPER LOW...HOWEVER
AGAIN WE WILL SEE LAKE EFFECT SNOW LINGERING TO THE EAST...AND THEN
SOUTHEAST OF THE LAKES. SHIFTING WINDS AND A RETURN OF HIGH PRESSURE
ON WEDNESDAY WILL LIKELY KEEP SNOW TOTALS ON TUESDAY NIGHT TO
PERHAPS ADVISORY LEVELS OR LOWER.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THROUGH THIS TIME PERIOD OUR FLOW ALOFT WILL GO FROM NORTHWESTERLY
TO A WESTERLY ZONAL FLOW...AND THEN TO A DEEP AMPLIFIED SOUTHWEST
FLOW. THIS WILL ALLOW FROM BELOW NORMAL TEMPERATURES AT THE START OF
THE PERIOD TO WARM TO ABOVE NORMAL AROUND FRIDAY...SOME MODEL
UNCERTAINTY ON THE TIMING OF A COLD FRONT AT THE BEGINNING OF THE
WEEKEND...MAY OR MAY NOT LEAVE SATURDAY ABOVE NORMAL AS WELL.
WILL CONTINUE WITH A CHANCE FOR SOME LIGHT LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF THE LAKES WEDNESDAY AND INTO EARLY WEDNESDAY WITH THE
NORTHWEST FLOW...BUT AS HIGH PRESSURE AT THE SURFACE NUDGES INTO THE
REGION WEDNESDAY NIGHT EXPECT THE LAKE SNOW ACTIVITY TO GREATLY
DIMINISH. THIS MAY LEAVE THURSDAY AS A DRY DAY AS THE FLOW BECOMES
MORE SOUTHWESTERLY IN RESPONSE TO A DIGGING TROUGH ACROSS THE
SOUTHWESTERN US AND BUILDING DOWNSTREAM HEIGHTS ACROSS THE EASTERN
US. WILL BRING A CHANCE FOR RAIN SNOW IN LATER FRIDAY...WITH A COLD
FRONT PASSING ACROSS THE REGION NEXT WEEKEND CHANGING THE RAIN BACK
TO SNOW. THERE IS STILL SOME MODEL UNCERTAINTY TO THE TIMING AND
PLACEMENT OF SURFACE WAVES ALONG THIS COLD FRONT...WHICH WILL IMPACT
THE FRONTAL CROSSING FOR OUR REGION.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
WIDESPREAD IFR/LIFR SNOW EXTENDING ACROSS MUCH OF NEW YORK THIS
EVENING AS A STORM SYSTEM OVER CENTRAL OHIO APPROACHES FROM THE
WEST. KBUF RADAR SHOWING A DRY SLOT WHERE A BREAK IN IFR SNOW
INTENSITY IS OBSERVED LIFTING NORTH ACROSS NORTHWEST PA INTO WESTERN
NEW YORK. THIS MAY BRING A TEMPORARY BREAK IN IFR CONDITIONS THROUGH
THE EVENING HOURS BUT A PERIOD OF HEAVY SNOW IS EXPECTED TO WRAP
BACK ACROSS THE REGION OVERNIGHT AS THE STORM SYSTEM TRANSITIONS TO
THE EAST COAST.
THE SECOND BURST OF STEADY SNOW WILL QUICKLY TAPER OFF FROM WEST TO
EAST IN THE 09Z TO 15Z TIME FRAME WITH CONDITIONS IMPROVING TO MVFR
CIGS IN MOST PLACES WITH SCATTERED LIGHT SNOW SHOWERS...HOWEVER IFR
CIGS LOOK TO REMAIN ACROSS THE SOUTHERN TIER. SOME LIMITED LAKE
EFFECT SNOW WILL KEEP SPOTTY IFR GOING SOUTHEAST OF THE LAKES. MVFR
CIGS WILL LIKELY LINGER IN MOST AREAS THROUGH AT LEAST THE FIRST
HALF OF SUNDAY...WITH SOME IFR ACROSS HIGHER TERRAIN IN THE MORNING.
OUTLOOK...
MONDAY...LAKE EFFECT SNOW SHOWERS WITH LOCAL IFR SOUTHEAST OF THE
LAKES DIMINISHING.
TUESDAY...SNOW SHOWERS LIKELY WITH AREAS OF MVFR/IFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS...EXCEPT LAKE
EFFECT SNOW SHOWERS LIKELY SOUTHEAST OF THE LAKES WITH LOCAL IFR.
THURSDAY...MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY THIS EVENING ALONG THE
NY/PA BORDER OVERNIGHT AND GIVE WAY TO A SECONDARY COASTAL LOW OFF
THE MID ATLANTIC COAST. THE PRESSURE GRADIENT BETWEEN BOTH OF THESE
SYSTEMS AND HIGH PRESSURE OVER SOUTHEAST CANADA WILL MAINTAIN
MODERATE NORTHEAST WINDS ON THE LOWER LAKES. THIS WILL KEEP SMALL
CRAFT CONDITIONS GOING ON THE WEST HALF OF LAKE ONTARIO.
ON SUNDAY AS THE COASTAL LOW DEEPENS WINDS WILL COME AROUND TO THE
NORTHWEST AND EVENTUALLY WEST. THIS WILL BRING SMALL CRAFT ADVISORY
CONDITIONS TO BOTH LAKES ERIE AND ONTARIO...WHICH WILL LAST THROUGH
MONDAY BEFORE HIGH PRESSURE BUILDS OVER THE LOWER LAKES AND ALLOWS
WINDS TO DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 10 AM EST SUNDAY FOR NYZ006>008.
WINTER STORM WARNING UNTIL 9 AM EST SUNDAY FOR NYZ002>005-
011>014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR NYZ001-010-
019>021-085.
MARINE...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 1 PM EST MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR
LOZ042-043.
SMALL CRAFT ADVISORY FROM 5 PM SUNDAY TO 4 PM EST MONDAY
FOR LOZ045.
SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 PM EST MONDAY
FOR LOZ044.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...HITCHCOCK/SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/SMITH
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
725 PM EST SAT DEC 14 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO THE OHIO VALLEY THIS EVENING
BEFORE GIVING WAY TO A COASTAL LOW ALONG THE NEW ENGLAND COAST LATER
TONIGHT. THIS WILL BRING A WIDESPREAD ACCUMULATING SNOW TO THE
ENTIRE REGION THROUGH TONIGHT BEFORE TAPERING OFF FROM WEST TO EAST
EARLY SUNDAY. SOME LINGERING LAKE EFFECT SNOW WILL CONTINUE LATER
SUNDAY AND MONDAY SOUTHEAST OF THE LAKES. ANOTHER WEAKER LOW
PRESSURE WILL BRING ANOTHER ROUND OF SNOW ON TUESDAY WITH SOME
ADDITIONAL LAKE EFFECT SNOW SOUTHEAST OF THE LAKES WEDNESDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MIDWEEK BEFORE
MODERATING BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
THROUGH TONIGHT LOW PRESSURE OVER CENTRAL OHIO THIS EVENING WILL
SHIFT TOWARDS THE NY/PA BORDER THEN EVENTUALLY GIVE WAY TO A
SECONDARY COASTAL STORM NOW FORMING OVER THE COASTAL CAROLINAS AS
DPVA AND HEIGHT FALLS INTERACT WITH THE COASTAL FRONT. THIS MILLER
TYPE-B COASTAL CYCLOGENESIS ALWAYS PROVES DIFFICULT FROM A SNOW
ACCUMULATION STANDPOINT AS THE TIMING AND DEGREE OF ENERGY TRANSFER
TO THE COAST CAN IMPACT AMOUNTS TO THE WEST OF THE APPALACHIANS.
CURRENT REGIONAL RADAR IMAGERY AND SURFACE OBS SHOWING A WIDE SWATH
OF SNOW EXTENDING FROM NORTHEASTERN OHIO ACROSS PENNSYLVANIA AND
NEW YORK STATE. MODERATE TO AT TIMES HEAVY SNOW IS BEING REPORTED
WITH SNOWFALL RATES RUNNING BETWEEN A QUARTER AND HALF INCH PER
HOUR. A DRY SLOT IS SHOWING UP ON KBUF RADAR ACROSS NORTHWEST PA
INTO THE SOUTHERN TIER WHICH IS LIFTING TO THE NORTHEAST WITH THE
ENTIRE SYSTEM AS IT WRAPS IN DRIER AIR FROM THE NORTH AND WEST. THIS
DRY SLOT WILL BRING A SHORT WINDOW WITH A BREAK IN SNOWFALL THIS
EVENING ACROSS WESTERN NEW YORK BUT EXPECT THAT THIS WILL FILL BACK
IN LATER IN THE EVENING AS WRAP-AROUND/COMMA HEAD DRIVEN SNOW ON THE
BACK SIDE OF THE TRANSITIONING LOW SHIFTS ACROSS OUR REGION. THE
LATEST HRRR RUNS SHOW THIS SCENARIO VERY WELL. THE BREAK IN SNOW MAY
EVEN CUT BACK ON SNOW TOTALS IF THE WRAP AROUND TAKES LONGER TO FILL
BACK IN. THE WRAP AROUND PRECIP EXHIBITING MORE IN THE WAY OF
SYNOPTIC LIFT AND MOISTURE WHICH SHOULD EVEN BRING MORE INTENSE
SNOWFALL RATES POSSIBLY UP TO AN INCH AN HOUR.
EXPECT STORM TOTALS OF 6-10 INCHES FROM THE GENESEE VALLEY AND
WESTERN FINGER LAKES TO THE NORTH COUNTRY...WITH SOME LOCAL 10-12
INCH AMOUNTS POSSIBLE ACROSS THE HIGHER TERRAIN EAST OF LAKE
ONTARIO. ACROSS THE ADVISORY AREA FROM THE BUFFALO AND NIAGARA
REGION DOWN TO THE SOUTHERN TIER...EXPECT TOTALS OF 5-8 INCHES. IT
APPEARS THE COMMA HEAD AND STRONGEST WARM ADVECTION WILL NOT RESIDE
IN THESE AREAS LONG ENOUGH TO PRODUCE WARNING CRITERIA SNOW...WITH A
SOLID TO HIGH END ADVISORY STILL LOOKING MOST LIKELY.
THE SYNOPTIC SNOW WILL BE OVER BY DAYBREAK FROM THE GENESEE VALLEY
WESTWARD...AND WILL END BY MID MORNING EAST OF LAKE ONTARIO. THIS
WILL LEAVE JUST SCATTERED SNOW SHOWERS IN SOME LIMITED WRAP AROUND
MOISTURE. SOME LIMITED LAKE EFFECT SNOW WILL ALSO DEVELOP ESPECIALLY
DURING THE AFTERNOON AS TEMPERATURES ALOFT BEGIN TO DROP.
OFF LAKE ERIE...LAKE INDUCED EQUILIBRIUM LEVELS RISE TO AROUND 7K
FEET BY MID AFTERNOON. EXPECT A HYBRID LAKE EFFECT/UPSLOPE SNOW TO
DEVELOP MAINLY ALONG THE CHAUTAUQUA RIDGE. THIS MAY PRODUCE 2-3
INCHES DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN INLAND FROM
LAKE ERIE.
OFF LAKE ONTARIO...LAKE INDUCED EQUILIBRIUM LEVELS ALSO RISE TO
AROUND 7K FEET BY MID AFTERNOON. EXPECT A BAND OF LAKE EFFECT SNOW
TO DEVELOP ACROSS MAINLY OSWEGO COUNTY TO THE SOUTHERN TUG HILL
DURING THE AFTERNOON WITH 2 TO 4 INCHES POSSIBLE.
TEMPERATURES WILL SLOWLY CLIMB OVERNIGHT INTO THE LOWER TO MID 20S
WITH ONGOING LOW/MID LEVEL WARM ADVECTION. TEMPS WILL THEN STAY
FAIRLY STEADY THROUGH SUNDAY...PERHAPS ONLY CLIMBING A DEGREE OR TWO
THROUGH THE DAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SUNDAY NIGHT WILL TRANSITION FROM THE DAYS SYNOPTIC SNOW BACK TO
LAKE EFFECT SNOW AS COOLER AIR BEHIND THE DEPARTING STORM SYSTEM
SENDS TEMPERATURES AT 850 HPA BACK DOWN TO -16 TO -18C.
OFF LAKE ERIE...A WEST TO NORTHWEST FLOW WILL ORIENT A BAND OF SNOW
ACROSS SOUTHERN ERIE/CHAUTAUQUA AND POINTS INLAND. MOST FAVORABLE
LAKE PARAMETERS WILL BE FOUND EARLY IN THE NIGHT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 10K FEET AND UPWARD MOTION THROUGH A
SATURATED LOW LEVEL. WITH MOISTURE REMAINING PLENTIFUL THROUGH THE
NIGHT EXPECT A BAND OF SNOW...THAT MIGHT BECOME MORE MULTI BANDED IN
CHARACTERISTICS AS WINDS VEER SOME...TO CONTINUE. ALOFT A CLOSED 500
HPA LOW WILL BEGIN THE PERIOD OVER THE UPPER GREAT LAKES...BUT WILL
QUICKLY SLIDE ACROSS THE EASTERN GREAT LAKES THROUGH THE NIGHT. THIS
FEATURE WILL LIKELY KEEP THE LAKE BAND SHIFTING THROUGH THE NIGHT
AND HOLD ACCUMULATIONS TO ADVISORY RANGE VALUES.
OFF LAKE ONTARIO...A WEST TO NORTHWEST FLOW WILL ALSO BE FOUND WITH
A LAKE BAND FIRST ACROSS THE SOUTHERN TUG HILL...DROPPING SOUTHWARD
TO AREAS SOUTHEAST OF LAKE ONTARIO. WHILE THERE WILL BE SOME
FAVORABLE LAKE PARAMETERS...WITH LAKE INDUCED EQUILIBRIUM LEVELS AND
INVERSION HEIGHTS OVER 10K FEET THE AMOUNT OF MOISTURE IN THE LOWER
LEVELS WILL BE SOMEWHAT LIMITED. NORTHERLY FLOW AROUND THE ATLANTIC
COASTAL LOW WILL DROP SOUTHWARD AND SETTLE TO POINTS AROUND LAKE
ONTARIO...WHICH WILL ALSO PREVENT ANY UPSTREAM LAKE CONNECTION.
EXPECT SNOW TOTALS OFF LAKE ONTARIO TO BE LIGHTER THAN LAKE
ERIE...WITH OVERALL NUMBERS POSSIBLY REMAINING BELOW ADVISORY
LEVELS.
ELSEWHERE MONDAY NIGHT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LIKELY FLY WITH THE PASSAGE OF THE UPPER LEVEL TROUGH. IT WILL
REMAIN COLD SUNDAY NIGHT WITH LOWS DROPPING DOWN INTO THE SINGLE
DIGITS TO LOW DOUBLE DIGITS. THE NORTH COUNTY...IF THEY HAVE SOME
CLEARING STANDS A CHANCE TO BECOME EVEN COLDER THAN FORECASTED.
CURRENT FORECAST MINS JUST BELOW ZERO COULD EASILY REACH -10F OR
COLDER OVER A DEEP AND FRESH SNOW PACK...IF WE GET SOME CLEARING.
FOR NOW BELIEVE THERE MAY BE ENOUGH CLOUDS LINGERING THROUGH THE
NIGHT AHEAD OF THE SHORTWAVE TO PREVENT THESE MUCH COLDER LOWS.
ON MONDAY DRIER AIR BEHIND THE SHORTWAVE WILL BEGIN TO WEAKEN THE
LAKE BANDS. HIGH PRESSURE WILL SCURRY BY TO OUR SOUTH AND INVERSION
HEIGHTS WILL FALL WHICH ALSO WILL PUT A DAMPER ON THE LAKE EFFECT
SNOWS. AS THIS HIGH SLIDES EASTWARD LATER MONDAY AND IN ADVANCE OF
THE NEXT CLIPPER LOW OUR WINDS WILL BACK AROUND TO MORE OF A
SOUTHWESTERLY FLOW. INCREASE WIND SHEAR WILL FURTHER DIMINISH THE
LAKE SNOWS MONDAY NIGHT WHILE SENDING THEM NORTHWARD TOWARDS METRO
BUFFALO OFF LAKE ERIE AND WATERTOWN OFF LAKE ONTARIO.
THERE ARE STILL SOME MODEL TIMING DIFFERENCES WITH THE ARRIVAL OF
THE NEXT AREA OF LOW PRESSURE...ONE THAT WILL DROP ACROSS SOUTHERN
CANADA AND THE UPPER GREAT LAKES...AND THEN NORTH OF LAKE
ONTARIO...BEFORE A COASTAL REDEVELOPMENT TAKES PLACE. THE 12Z ECMWF
AND THE 12Z CMC CONTINUE TO BE FASTER THAN THE GFS MODEL...THOUGH
ALL AGREE THAT A LIGHT GENERAL SNOWFALL ACROSS THE CWA
TUESDAY-TUESDAY NIGHT IS LIKELY. AHEAD OF THE SYSTEM OUR HIGHS WILL
CLIMB INTO THE UPPER 20S...AND MAY EVEN CRACK THE FREEZING MARK FOR
A BRIEF PERIOD OF TIME. WITH THE LINGERING CLOUDS TUESDAY NIGHT WILL
NOT BE AS COLD...WITH LOWS GENERALLY IN THE LOW 20S ACROSS THE CWA.
SNOW WILL TAPER OFF TUESDAY NIGHT BEHIND THE CLIPPER LOW...HOWEVER
AGAIN WE WILL SEE LAKE EFFECT SNOW LINGERING TO THE EAST...AND THEN
SOUTHEAST OF THE LAKES. SHIFTING WINDS AND A RETURN OF HIGH PRESSURE
ON WEDNESDAY WILL LIKELY KEEP SNOW TOTALS ON TUESDAY NIGHT TO
PERHAPS ADVISORY LEVELS OR LOWER.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THROUGH THIS TIME PERIOD OUR FLOW ALOFT WILL GO FROM NORTHWESTERLY
TO A WESTERLY ZONAL FLOW...AND THEN TO A DEEP AMPLIFIED SOUTHWEST
FLOW. THIS WILL ALLOW FROM BELOW NORMAL TEMPERATURES AT THE START OF
THE PERIOD TO WARM TO ABOVE NORMAL AROUND FRIDAY...SOME MODEL
UNCERTAINTY ON THE TIMING OF A COLD FRONT AT THE BEGINNING OF THE
WEEKEND...MAY OR MAY NOT LEAVE SATURDAY ABOVE NORMAL AS WELL.
WILL CONTINUE WITH A CHANCE FOR SOME LIGHT LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF THE LAKES WEDNESDAY AND INTO EARLY WEDNESDAY WITH THE
NORTHWEST FLOW...BUT AS HIGH PRESSURE AT THE SURFACE NUDGES INTO THE
REGION WEDNESDAY NIGHT EXPECT THE LAKE SNOW ACTIVITY TO GREATLY
DIMINISH. THIS MAY LEAVE THURSDAY AS A DRY DAY AS THE FLOW BECOMES
MORE SOUTHWESTERLY IN RESPONSE TO A DIGGING TROUGH ACROSS THE
SOUTHWESTERN US AND BUILDING DOWNSTREAM HEIGHTS ACROSS THE EASTERN
US. WILL BRING A CHANCE FOR RAIN SNOW IN LATER FRIDAY...WITH A COLD
FRONT PASSING ACROSS THE REGION NEXT WEEKEND CHANGING THE RAIN BACK
TO SNOW. THERE IS STILL SOME MODEL UNCERTAINTY TO THE TIMING AND
PLACEMENT OF SURFACE WAVES ALONG THIS COLD FRONT...WHICH WILL IMPACT
THE FRONTAL CROSSING FOR OUR REGION.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
WIDESPREAD IFR/LIFR SNOW EXTENDING ACROSS MUCH OF NEW YORK THIS
EVENING AS A STORM SYSTEM OVER CENTRAL OHIO APPROACHES FROM THE
WEST. KBUF RADAR SHOWING A DRY SLOT WHERE A BREAK IN IFR SNOW
INTENSITY IS OBSERVED LIFTING NORTH ACROSS NORTHWEST PA INTO WESTERN
NEW YORK. THIS MAY BRING A TEMPORARY BREAK IN IFR CONDITIONS THROUGH
THE EVENING HOURS BUT A PERIOD OF HEAVY SNOW IS EXPECTED TO WRAP
BACK ACROSS THE REGION OVERNIGHT AS THE STORM SYSTEM TRANSITIONS TO
THE EAST COAST.
THE SECOND BURST OF STEADY SNOW WILL QUICKLY TAPER OFF FROM WEST TO
EAST IN THE 09Z TO 15Z TIME FRAME WITH CONDITIONS IMPROVING TO MVFR
CIGS IN MOST PLACES WITH SCATTERED LIGHT SNOW SHOWERS...HOWEVER IFR
CIGS LOOK TO REMAIN ACROSS THE SOUTHERN TIER. SOME LIMITED LAKE
EFFECT SNOW WILL KEEP SPOTTY IFR GOING SOUTHEAST OF THE LAKES. MVFR
CIGS WILL LIKELY LINGER IN MOST AREAS THROUGH AT LEAST THE FIRST
HALF OF SUNDAY...WITH SOME IFR ACROSS HIGHER TERRAIN IN THE MORNING.
OUTLOOK...
MONDAY...LAKE EFFECT SNOW SHOWERS WITH LOCAL IFR SOUTHEAST OF THE
LAKES DIMINISHING.
TUESDAY...SNOW SHOWERS LIKELY WITH AREAS OF MVFR/IFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS...EXCEPT LAKE
EFFECT SNOW SHOWERS LIKELY SOUTHEAST OF THE LAKES WITH LOCAL IFR.
THURSDAY...MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY THIS EVENING ALONG THE
NY/PA BORDER OVERNIGHT AND GIVE WAY TO A SECONDARY COASTAL LOW OFF
THE MID ATLANTIC COAST. THE PRESSURE GRADIENT BETWEEN BOTH OF THESE
SYSTEMS AND HIGH PRESSURE OVER SOUTHEAST CANADA WILL MAINTAIN
MODERATE NORTHEAST WINDS ON THE LOWER LAKES. THIS WILL KEEP SMALL
CRAFT CONDITIONS GOING ON THE WEST HALF OF LAKE ONTARIO.
ON SUNDAY AS THE COASTAL LOW DEEPENS WINDS WILL COME AROUND TO THE
NORTHWEST AND EVENTUALLY WEST. THIS WILL BRING SMALL CRAFT ADVISORY
CONDITIONS TO BOTH LAKES ERIE AND ONTARIO...WHICH WILL LAST THROUGH
MONDAY BEFORE HIGH PRESSURE BUILDS OVER THE LOWER LAKES AND ALLOWS
WINDS TO DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 10 AM EST SUNDAY FOR NYZ006>008.
WINTER STORM WARNING UNTIL 9 AM EST SUNDAY FOR NYZ002>005-
011>014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR NYZ001-010-
019>021-085.
MARINE...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 1 PM EST MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR
LOZ042-043.
SMALL CRAFT ADVISORY FROM 5 PM SUNDAY TO 4 PM EST MONDAY
FOR LOZ045.
SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 PM EST MONDAY
FOR LOZ044.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK/SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/SMITH
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
711 PM EST SAT DEC 14 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE UP THE OHIO RIVER
VALLEY...BRINGING SIGNIFICANT SNOWFALL AS IT DEVELOPS INTO A
COASTAL LOW NEAR CAPE COD BY SUNDAY MORNING. SNOWFALL WILL BEGIN
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHERN
AREAS...SPREADING NORTHWARD TONIGHT AND CONTINUING THROUGH MUCH
OF SUNDAY WITH TOTAL ACCUMULATIONS OF 6 TO 12 INCHES LIKELY BY
SUNDAY EVENING. COLD TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 612 PM EST SATURDAY...MINOR UPDATES TO CRNT FCST TO TIME
ARRIVAL OF SNOW ACRS NORTHERN FA...INCREASE SNOW AMOUNTS SLIGHTLY
ACRS CENTRAL/NORTHERN VT MTNS AND PARTS OF THE DACKS...AND TO
MENTION SLEET ACRS EXTREME SOUTHERN RUTLAND COUNTY.
RADAR/SFC OBS SHOW LIGHT SNOW RAPIDLY DEVELOPING ACRS
CENTRAL/SOUTHERN VT AND ALL OF NORTHERN NY ATTM....WITH BTV
ALREADY DOWN TO 2SM -SN. THIS TREND WL CONTINUE THRU THE EVENING
HOURS.
CRNT WATER VAPOR SHOWS POTENT S/W ENERGY RACING ACRS THE OHIO
VALLEY INTO CENTRAL PA ATTM...WITH WELL DEFINE DRY SLOT DEVELOPING
FROM KY TO SOUTHERN PA. MEANWHILE...SFC ANALYSIS SHOWS A CLASSIC
COLD AIR DAMMING SIGNATURE WITH HIGH PRES OVER NORTHERN MAINE AND
A DUAL AREA OF LOW PRES FROM CENTRAL OHIO INTO EASTERN NORTH
CAROLINA. AS S/W ENERGY ACRS OHIO INTERACTS WITH DEVELOPING LOW
PRES ON THE LEE SIDE OF THE APPALACHIAN MTNS...EXPECT COASTAL LOW
PRES TO QUICKLY DEVELOP AND RACE NORTHEAST OVERNIGHT. LATEST 3HR
PRES TRENDS SHOWS 3 TO 5 MB FALLS ACRS THE EASTERN MID ATLANTIC
STATES ATTM. LATEST TRENDS HAVE BEEN FOR COASTAL SFC LOW PRES TO
TRACK SLIGHTLY FURTHER NORTH...FROM EASTERN DELAWARE BY 03Z TO NYC
BY 06Z...AND ACRS THE CAPE COD CANAL BY 12Z AND INTO THE GULF OF
MAINE BY 15Z SUNDAY.
THIS IS AN EXCELLENT SFC LOW TRACK FOR A MODERATE TO HEAVY SNOW
EVENT ACRS OUR CWA. GIVEN SFC TRACK SLIGHTLY FURTHER NORTH...I
INCREASED SNOW AMOUNTS SLIGHTLY ACRS CENTRAL/NORTHERN VT...AND
MENTIONED JUST A SLIGHT CHANCE OF SLEET IN SOUTHERN RUTLAND
COUNTY. LATEST 18Z NAM AND RAP SHOW WARMING BTWN 4000 FT AND 5000
FT ASSOCIATED WITH POTENT 925MB TO 850MB JET OF 50 TO 70 KNOTS.
BOTH MODEL SOUNDINGS SHOW TEMPS IN WARM LAYER REACHING >0C.
OTHERWISE...NOSE OF STRONG LLVL JET WL HELP ADVECT DEEP LAYER
ATLANTIC MOISTURE INTO OUR REGION AHEAD OF DEVELOPING COASTAL LOW
PRES. IN ADDITION...RAP13 AND LATEST NAM/WRF SHOW A BAND OF VERY
STRONG 850 TO 700MB FGEN FORCING AND DEEP LAYER UVVS LIFTING FROM
SOUTH TO NORTH ACRS OUR CWA BTWN 06Z-15Z SUNDAY. THIS WL RESULT IN
A BAND OF VERY HEAVY SNOWFALL WITH HRLY SNOWFALL RATES OF 1 TO 2
INCHES PER HOUR LIKELY. THIS BAND WL CONT TO MOVE...BEFORE GOING
STATIONARY ACRS OUR NORTHERN CWA NEAR THE INTERNATIONAL BORDER BY
EARLY SUNDAY MORNING...THEN SWING BACK TO THE SOUTHEAST AS SFC LOW
PRES RACES NE INTO THE CANADIAN MARITIMES. INTERESTING THE SREF
SNOWFALL RATE SHOWS 70 TO 90% OF SNOWFALL RATES OF 1" AND 20 TO
30% OF SNOWFALL RATES AS HIGH AS 2 INCHES PER HOUR TONIGHT.
RAP/NAM AND GFS SHOW MID/UPPER LVL DRY SLOT IMPACTING SOUTHERN NEW
ENGLAND...WHILE MOST OF OUR CWA STAYS IN THE FAVORABLE 850 TO
500MB MOISTURE FIELDS THRU 15Z SUNDAY. THIS QUICKLY SHIFTS EAST OF
OUR CWA BY 18Z...AND LOOK FOR A RAPID DECREASE IN SNOWFALL ACRS
OUR CWA.
EXPECT TRRN/ELEVATION TO PLAY AN IMPORTANT ROLE IN STORM TOTAL
SNOWFALL...WITH A GENERAL 8 TO 12 INCHES LIKELY. THINKING AMOUNTS
WL BE NEAR 15 INCHES FROM KILLINGTON/LUDLOW TO
STOWE/MPV/BROOKFIELD TO WALDEN/JAY PEAK...WITH ONLY 4 TO 8 INCHES
IN THE DOWNSLOPE/SHADOWING REGIONS OF THE NEK AND PARTS OF
RUTLAND/ADDISON COUNTIES. IN ADDITION...EXPECT SOME WIND GUSTS
BTWN 30 AND 40 MPH ALONG THE IMMEDIATE WESTERN SLOPES FROM RUTLAND
TO JERICHO.
PREVIOUS DISCUSSION BELOW:
LOW PRESSURE MOVING UP THE OHIO RIVER VALLEY WILL BRING WIDESPREAD
SNOWFALL TO THE AREA. MOST OF THE NORTH COUNTRY IS STILL
DRY...WITH RH VALUES RANGING FROM M40S- L70S. ADKS AND PORTIONS OF
NRN NY WILL SEE SNOW FIRST...MOVING SW- NE GRADUALLY THIS
AFTERNOON AND EVENING. THIS WILL BE FOLLOWED BY SNOW IN SRN
VT...MOVING N/NEWD...ENCOMPASSING THE WHOLE NORTH COUNTRY BEFORE
MIDNIGHT.
SFC LOW TRANSLATES ITS ENERGY TO THE DELMARVA
AREA...STRENGTHENING AS A COASTAL LOW AFTER MIDNIGHT...AND SHIFTS
NEWD TOWARD ERN TIP OF LONG ISLAND BY 12Z. BEST DEFORMATION
STICKS NEAR THE COAST...WITH BEST FGEN OVER THE NORTHEAST
OCCURRING BTWN 06Z AND 15Z WITH BEST MID-UPR LVL QVECTOR
CONVERGENCE ALSO ACCRUING AT THIS TIME. NAM SHOWS HEAVIER BAND OF
SNOW MOVING OVER THE NORTH COUNTRY FROM N TO S DURING THIS TIME.
HAVE INCLUDED MODERATE SNOWFALL DURING THE EARLY MORNING HRS TO
REFLECT THIS BAND.
ALSO...STRONG JET OUT OF THE SE AT 40-60KTS WILL CREATE ENHANCED
SNOWFALL ALONG SE FACING SLOPES OF CENTRAL AND SRN GREENS AND
ADKS. ON THE DOWNSLOPING/WRN SIDE...SHADOWING WILL RESULT IN
LIGHTER AMNTS...MAINLY IN ERN CPV. PORTIONS OF NEK WILL ALSO BE
SOMEWHAT SHADOWED BY THE WHITE MOUNTAINS...BUT TO A LESSER EXTENT
AS THE CORE OF THE LLJ STAYS ACROSS SRN VT AND NH. EXPECT SNOW TO
HAVE HIGHER THAN 15:1 RATIO AS COLD AIR IS FIRMLY IN PLACE. BY
SUNDAY MORNING...MOST AREAS WILL SEE FIVE OR MORE INCHES WITH
SNOWFALL CONTINUING INTO SUNDAY.
TEMPERATURE-WISE...NON-DIURNAL TREND EXPECTED AS WAA GRADUALLY
WARMS TEMPS OVERNIGHT. TEMPS WILL STILL BE IN THE SINGLE DIGITS
TO M/U TEENS COME SUNDAY MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 331 PM EST SATURDAY...SFC LOW WILL MOVE INTO THE GULF OF
MAINE AND TOWARD THE CANADIAN MARITIMES ON SUNDAY. BULK OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO DEPART MID-
LATE SUNDAY...TRANSITIONING STEADY SNOWFALL TO SNOW SHOWERS.
THESE SHOWERS WILL LIKELY CONTINUE THROUGH SUNDAY NIGHT ACROSS
THE HIGHER TRRN AS THE PARENT UPPER TROUGH TRACKS THROUGH.
STORM TOTAL SNOWFALL AMOUNTS BY SUNDAY EVENING WILL GENERALLY BE
6-12 INCHES WITH LOCALIZED HIGHER AMOUNTS ACROSS ERN SLOPES DUE
TO SE FLOW TONIGHT INTO SUNDAY MORNING.
TEMPS NOTICEABLY WARMER...BUT SNOWFALL...CLOUDS AND WINDS KEEP
CONDITIONS CHILLY WITH MAX TEMPS IN THE TEENS TO M20S. SUNDAY
NIGHT TEMPS SEE SINGLE DIGITS TEMPS ABOVE AND BELOW ZERO.
ON MONDAY...THE UPPER LOW WILL EXIT THE NORTH COUNTRY TO THE
NE...WITH RIDGING DEVELOPING AT THE SFC AND ALOFT LATE IN THE DAY
INTO MONDAY EVENING. SOME UPSLOPE SNOW ON W-NW FLOW NOT OUT OF
THE QUESTION. WITH SKIES SLOW TO CLEAR AND WINDS OUT OF THE W-NW
AT 10-20 KTS...BLUSTERY CONDITIONS WILL CONTINUE WITH MAX TEMPS
RANGING FROM -5 TO +15 DEGREES FROM STRONG CAA.
MONDAY NIGHT WINDS SHIFT TO THE SOUTH AHEAD OF A CLIPPER TYPE
SYSTEM APPROACHING FROM THE NW. THREAT OF SNOW FROM THIS SYSTEM
WILL INCREASE TOWARDS TUESDAY MORNING FROM THE WEST. ANOTHER COLD
NIGHT...WITH MOST AREAS BEING NEAR OR BELOW ZERO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 323 PM EST SATURDAY...SUITE OF GLOBAL DETERMINISTIC AND
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT THROUGH THURSDAY
NIGHT. MODELS THEN BEGIN TO DIVERGE SIGNIFICANTLY ENOUGH TO LIMIT
PREDICTABILITY FOR THE FRIDAY INTO THE EARLY WEEKEND PERIOD.
AMPLIFICATION OF A 500 MB TROUGH OVER THE GREAT LAKES IS
PREDICTED BY TUESDAY WHICH INDUCES SECONDARY CYCLOGENESIS NEAR
CAPE COD BY TUESDAY NIGHT...WITH THE PROGGED COASTAL MOVING INTO
THE CENTRAL GULF OF MAINE BY WEDNESDAY. I OPTED TO INCREASE POPS
TO HIGH CHANCE/LOW LIKELY FOR TUESDAY INTO TUESDAY NIGHT GIVEN
GOOD CONSISTENCY OVER SEVERAL MODEL CYCLES FOR WHAT WILL BE A
LIGHT-QPF STRATIFORM LIGHT SNOW EVENT FROM INITIAL CLIPPER
SYSTEM. I WAS A LITTLE LEERY OF GOING MUCH HIGHER THAN THAT
THOUGH DUE TO UNCERTAINTIES IN ENERGY TRANSFER TO THE DEVELOPING
COASTAL. THOUGH I DO THINK A DOWNWARD TREND IN POPS ON WEDNESDAY
LOOKS GOOD...I`VE KEPT CHANCE POPS FOR THE NORTHEAST KINGDOM AREA
AS THERE IS SOME INDICATION OF AN INVERTED TROUGH/TROWAL FEATURE
WHICH IF PROGGED CORRECTLY MAY HELP KEEP LIGHT SNOWS GOING A
LITTLE LONGER THERE. TEMPERATURES ARE PRETTY SIMILAR TUESDAY AND
WEDNESDAY...HIGHS GENERALLY IN THE 20S WITH LOWS IN THE TEENS.
A PATTERN CHANGE TOWARD A BRIEF PERIOD OF WARMER WEATHER LOOKS TO
BE IN STORE FOR THE MID TO LATE WEEK PERIOD AS 500 MB HEIGHTS
RISE ACROSS THE EASTERN CONUS. HIGHS ON FRIDAY MAY REACH INTO THE
UPPER 30S TO AROUND 40 IN SPOTS. UNCERTAINTY THEN INCREASES
MARKEDLY DUE TO DIFFERENCES IN HANDLING A LOW MOVING OUT OF THE
MIDWEST TO THE NORTHEAST. THESE DIFFERENCES ARE MOSTLY DUE TO
TIMING THE EJECTION OF AN UPPER-LEVEL TROUGH FRIDAY
AFTERNOON...WHICH IN TURN LEADS TO SOME DISCREPANCY AS TO WHEN
THE ASSOCIATED SFC COLD FRONT PUSHES THROUGH THE NORTH COUNTRY.
ONE THING THAT CAN BE SAID ABOUT THE EARLY WEEKEND PERIOD IS THAT
THE BAROCLINIC ZONE TIED TO THE AFOREMENTIONED COLD FRONT GETS
HUNG UP SOMEWHERE IN THE INTERIOR SOUTHEASTERN CONUS WITH THE
IMPLICATION OF ADDITIONAL CHANCES FOR UNSETTLED WEATHER. IT`S NOT
CLEAR HOW ALL THAT UNFOLDS HOWEVER. I`VE STAYED CLOSE TO THE
SUPERBLEND GUIDANCE FOR THE EARLY WEEKEND PERIOD WHICH OFFERS
CHANCE POPS WITH LOWS TRENDING NEAR TO BELOW NORMAL.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...COMPOSITE RADAR LOOP AND SURFACE OBSERVATIONS SHOWING
SNOW HAS OVERSPREAD MOST OF VERMONT AND NORTHERN NEW YORK AS OF
00Z SUNDAY. EXPECTING WIDESPREAD IFR/LIFR CONDITIONS IN SNOW OVERNIGHT.
EXPECTING CONDITIONS TO IMPROVE TO IFR/MVFR IN LIGHT SNOW BY 18Z
SUNDAY. LATEST MODEL GUIDANCE SUGGESTING A PERIOD OF SLEET WILL BE
POSSIBLE ACROSS SOUTHERN VERMONT BETWEEN 10Z-14Z SUNDAY...AS
WARMER AIR ALOFT MOVES INTO THE REGION. THUS...HAVE INDICATED A
PERIOD OF SNOW AND SLEET IN THE TAF FOR KRUT.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...SNOW COMES TO AN END LATE
SUNDAY AFTN AREAWIDE AS SURFACE LOW PULLS NEWD AWAY FROM THE
REGION. TRENDING VFR WITH NWLY WINDS SUNDAY NIGHT. CHANCE OF
FLURRIES SUNDAY NIGHT. MAINLY VFR MONDAY AND MOST OF MONDAY NIGHT
AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. LIGHT SNOW OR
SNOW SHOWERS POSSIBLE TUESDAY NIGHT AND WEDNESDAY. A SLIGHT CHANCE
FOR SOME SNOW SHOWERS ON THURSDAY...BUT MAINLY VFR CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR VTZ001>012-
016>019.
NY...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR NYZ026>031-034-
035-087.
&&
$$
SYNOPSIS...LAHIFF/KGM
NEAR TERM...TABER
SHORT TERM...KGM
LONG TERM...LOCONTO
AVIATION...WGH/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
636 PM EST SAT DEC 14 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE UP THE OHIO RIVER
VALLEY...BRINGING SIGNIFICANT SNOWFALL AS IT DEVELOPS INTO A
COASTAL LOW NEAR CAPE COD BY SUNDAY MORNING. SNOWFALL WILL BEGIN
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHERN
AREAS...SPREADING NORTHWARD TONIGHT AND CONTINUING THROUGH MUCH
OF SUNDAY WITH TOTAL ACCUMULATIONS OF 6 TO 12 INCHES LIKELY BY
SUNDAY EVENING. COLD TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 612 PM EST SATURDAY...MINOR UPDATES TO CRNT FCST TO TIME
ARRIVAL OF SNOW ACRS NORTHERN FA...INCREASE SNOW AMOUNTS SLIGHTLY
ACRS CENTRAL/NORTHERN VT MTNS AND PARTS OF THE DACKS...AND TO
MENTION SLEET ACRS EXTREME SOUTHERN RUTLAND COUNTY.
RADAR/SFC OBS SHOW LIGHT SNOW RAPIDLY DEVELOPING ACRS
CENTRAL/SOUTHERN VT AND ALL OF NORTHERN NY ATTM....WITH BTV
ALREADY DOWN TO 2SM -SN. THIS TREND WL CONTINUE THRU THE EVENING
HOURS.
CRNT WATER VAPOR SHOWS POTENT S/W ENERGY RACING ACRS THE OHIO
VALLEY INTO CENTRAL PA ATTM...WITH WELL DEFINE DRY SLOT DEVELOPING
FROM KY TO SOUTHERN PA. MEANWHILE...SFC ANALYSIS SHOWS A CLASSIC
COLD AIR DAMMING SIGNATURE WITH HIGH PRES OVER NORTHERN MAINE AND
A DUAL AREA OF LOW PRES FROM CENTRAL OHIO INTO EASTERN NORTH
CAROLINA. AS S/W ENERGY ACRS OHIO INTERACTS WITH DEVELOPING LOW
PRES ON THE LEE SIDE OF THE APPALACHIAN MTNS...EXPECT COASTAL LOW
PRES TO QUICKLY DEVELOP AND RACE NORTHEAST OVERNIGHT. LATEST 3HR
PRES TRENDS SHOWS 3 TO 5 MB FALLS ACRS THE EASTERN MID ATLANTIC
STATES ATTM. LATEST TRENDS HAVE BEEN FOR COASTAL SFC LOW PRES TO
TRACK SLIGHTLY FURTHER NORTH...FROM EASTERN DELAWARE BY 03Z TO NYC
BY 06Z...AND ACRS THE CAPE COD CANAL BY 12Z AND INTO THE GULF OF
MAINE BY 15Z SUNDAY.
THIS IS AN EXCELLENT SFC LOW TRACK FOR A MODERATE TO HEAVY SNOW
EVENT ACRS OUR CWA. GIVEN SFC TRACK SLIGHTLY FURTHER NORTH...I
INCREASED SNOW AMOUNTS SLIGHTLY ACRS CENTRAL/NORTHERN VT...AND
MENTIONED JUST A SLIGHT CHANCE OF SLEET IN SOUTHERN RUTLAND
COUNTY. LATEST 18Z NAM AND RAP SHOW WARMING BTWN 4000 FT AND 5000
FT ASSOCIATED WITH POTENT 925MB TO 850MB JET OF 50 TO 70 KNOTS.
BOTH MODEL SOUNDINGS SHOW TEMPS IN WARM LAYER REACHING >0C.
OTHERWISE...NOSE OF STRONG LLVL JET WL HELP ADVECT DEEP LAYER
ATLANTIC MOISTURE INTO OUR REGION AHEAD OF DEVELOPING COASTAL LOW
PRES. IN ADDITION...RAP13 AND LATEST NAM/WRF SHOW A BAND OF VERY
STRONG 850 TO 700MB FGEN FORCING AND DEEP LAYER UVVS LIFTING FROM
SOUTH TO NORTH ACRS OUR CWA BTWN 06Z-15Z SUNDAY. THIS WL RESULT IN
A BAND OF VERY HEAVY SNOWFALL WITH HRLY SNOWFALL RATES OF 1 TO 2
INCHES PER HOUR LIKELY. THIS BAND WL CONT TO MOVE...BEFORE GOING
STATIONARY ACRS OUR NORTHERN CWA NEAR THE INTERNATIONAL BORDER BY
EARLY SUNDAY MORNING...THEN SWING BACK TO THE SOUTHEAST AS SFC LOW
PRES RACES NE INTO THE CANADIAN MARITIMES. INTERESTING THE SREF
SNOWFALL RATE SHOWS 70 TO 90% OF SNOWFALL RATES OF 1" AND 20 TO
30% OF SNOWFALL RATES AS HIGH AS 2 INCHES PER HOUR TONIGHT.
RAP/NAM AND GFS SHOW MID/UPPER LVL DRY SLOT IMPACTING SOUTHERN NEW
ENGLAND...WHILE MOST OF OUR CWA STAYS IN THE FAVORABLE 850 TO
500MB MOISTURE FIELDS THRU 15Z SUNDAY. THIS QUICKLY SHIFTS EAST OF
OUR CWA BY 18Z...AND LOOK FOR A RAPID DECREASE IN SNOWFALL ACRS
OUR CWA.
EXPECT TRRN/ELEVATION TO PLAY AN IMPORTANT ROLE IN STORM TOTAL
SNOWFALL...WITH A GENERAL 8 TO 12 INCHES LIKELY. THINKING AMOUNTS
WL BE NEAR 15 INCHES FROM KILLINGTON/LUDLOW TO
STOWE/MPV/BROOKFIELD TO WALDEN/JAY PEAK...WITH ONLY 4 TO 8 INCHES
IN THE DOWNSLOPE/SHADOWING REGIONS OF THE NEK AND PARTS OF
RUTLAND/ADDISON COUNTIES. IN ADDITION...EXPECT SOME WIND GUSTS
BTWN 30 AND 40 MPH ALONG THE IMMEDIATE WESTERN SLOPES FROM RUTLAND
TO JERICHO.
PREVIOUS DISCUSSION BELOW:
LOW PRESSURE MOVING UP THE OHIO RIVER VALLEY WILL BRING WIDESPREAD
SNOWFALL TO THE AREA. MOST OF THE NORTH COUNTRY IS STILL
DRY...WITH RH VALUES RANGING FROM M40S- L70S. ADKS AND PORTIONS OF
NRN NY WILL SEE SNOW FIRST...MOVING SW- NE GRADUALLY THIS
AFTERNOON AND EVENING. THIS WILL BE FOLLOWED BY SNOW IN SRN
VT...MOVING N/NEWD...ENCOMPASSING THE WHOLE NORTH COUNTRY BEFORE
MIDNIGHT.
SFC LOW TRANSLATES ITS ENERGY TO THE DELMARVA
AREA...STRENGTHENING AS A COASTAL LOW AFTER MIDNIGHT...AND SHIFTS
NEWD TOWARD ERN TIP OF LONG ISLAND BY 12Z. BEST DEFORMATION
STICKS NEAR THE COAST...WITH BEST FGEN OVER THE NORTHEAST
OCCURRING BTWN 06Z AND 15Z WITH BEST MID-UPR LVL QVECTOR
CONVERGENCE ALSO ACCRUING AT THIS TIME. NAM SHOWS HEAVIER BAND OF
SNOW MOVING OVER THE NORTH COUNTRY FROM N TO S DURING THIS TIME.
HAVE INCLUDED MODERATE SNOWFALL DURING THE EARLY MORNING HRS TO
REFLECT THIS BAND.
ALSO...STRONG JET OUT OF THE SE AT 40-60KTS WILL CREATE ENHANCED
SNOWFALL ALONG SE FACING SLOPES OF CENTRAL AND SRN GREENS AND
ADKS. ON THE DOWNSLOPING/WRN SIDE...SHADOWING WILL RESULT IN
LIGHTER AMNTS...MAINLY IN ERN CPV. PORTIONS OF NEK WILL ALSO BE
SOMEWHAT SHADOWED BY THE WHITE MOUNTAINS...BUT TO A LESSER EXTENT
AS THE CORE OF THE LLJ STAYS ACROSS SRN VT AND NH. EXPECT SNOW TO
HAVE HIGHER THAN 15:1 RATIO AS COLD AIR IS FIRMLY IN PLACE. BY
SUNDAY MORNING...MOST AREAS WILL SEE FIVE OR MORE INCHES WITH
SNOWFALL CONTINUING INTO SUNDAY.
TEMPERATURE-WISE...NON-DIURNAL TREND EXPECTED AS WAA GRADUALLY
WARMS TEMPS OVERNIGHT. TEMPS WILL STILL BE IN THE SINGLE DIGITS
TO M/U TEENS COME SUNDAY MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 331 PM EST SATURDAY...SFC LOW WILL MOVE INTO THE GULF OF
MAINE AND TOWARD THE CANADIAN MARITIMES ON SUNDAY. BULK OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO DEPART MID-
LATE SUNDAY...TRANSITIONING STEADY SNOWFALL TO SNOW SHOWERS.
THESE SHOWERS WILL LIKELY CONTINUE THROUGH SUNDAY NIGHT ACROSS
THE HIGHER TRRN AS THE PARENT UPPER TROUGH TRACKS THROUGH.
STORM TOTAL SNOWFALL AMOUNTS BY SUNDAY EVENING WILL GENERALLY BE
6-12 INCHES WITH LOCALIZED HIGHER AMOUNTS ACROSS ERN SLOPES DUE
TO SE FLOW TONIGHT INTO SUNDAY MORNING.
TEMPS NOTICEABLY WARMER...BUT SNOWFALL...CLOUDS AND WINDS KEEP
CONDITIONS CHILLY WITH MAX TEMPS IN THE TEENS TO M20S. SUNDAY
NIGHT TEMPS SEE SINGLE DIGITS TEMPS ABOVE AND BELOW ZERO.
ON MONDAY...THE UPPER LOW WILL EXIT THE NORTH COUNTRY TO THE
NE...WITH RIDGING DEVELOPING AT THE SFC AND ALOFT LATE IN THE DAY
INTO MONDAY EVENING. SOME UPSLOPE SNOW ON W-NW FLOW NOT OUT OF
THE QUESTION. WITH SKIES SLOW TO CLEAR AND WINDS OUT OF THE W-NW
AT 10-20 KTS...BLUSTERY CONDITIONS WILL CONTINUE WITH MAX TEMPS
RANGING FROM -5 TO +15 DEGREES FROM STRONG CAA.
MONDAY NIGHT WINDS SHIFT TO THE SOUTH AHEAD OF A CLIPPER TYPE
SYSTEM APPROACHING FROM THE NW. THREAT OF SNOW FROM THIS SYSTEM
WILL INCREASE TOWARDS TUESDAY MORNING FROM THE WEST. ANOTHER COLD
NIGHT...WITH MOST AREAS BEING NEAR OR BELOW ZERO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 323 PM EST SATURDAY...SUITE OF GLOBAL DETERMINISTIC AND
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT THROUGH THURSDAY
NIGHT. MODELS THEN BEGIN TO DIVERGE SIGNIFICANTLY ENOUGH TO LIMIT
PREDICTABILITY FOR THE FRIDAY INTO THE EARLY WEEKEND PERIOD.
AMPLIFICATION OF A 500 MB TROUGH OVER THE GREAT LAKES IS
PREDICTED BY TUESDAY WHICH INDUCES SECONDARY CYCLOGENESIS NEAR
CAPE COD BY TUESDAY NIGHT...WITH THE PROGGED COASTAL MOVING INTO
THE CENTRAL GULF OF MAINE BY WEDNESDAY. I OPTED TO INCREASE POPS
TO HIGH CHANCE/LOW LIKELY FOR TUESDAY INTO TUESDAY NIGHT GIVEN
GOOD CONSISTENCY OVER SEVERAL MODEL CYCLES FOR WHAT WILL BE A
LIGHT-QPF STRATIFORM LIGHT SNOW EVENT FROM INITIAL CLIPPER
SYSTEM. I WAS A LITTLE LEERY OF GOING MUCH HIGHER THAN THAT
THOUGH DUE TO UNCERTAINTIES IN ENERGY TRANSFER TO THE DEVELOPING
COASTAL. THOUGH I DO THINK A DOWNWARD TREND IN POPS ON WEDNESDAY
LOOKS GOOD...I`VE KEPT CHANCE POPS FOR THE NORTHEAST KINGDOM AREA
AS THERE IS SOME INDICATION OF AN INVERTED TROUGH/TROWAL FEATURE
WHICH IF PROGGED CORRECTLY MAY HELP KEEP LIGHT SNOWS GOING A
LITTLE LONGER THERE. TEMPERATURES ARE PRETTY SIMILAR TUESDAY AND
WEDNESDAY...HIGHS GENERALLY IN THE 20S WITH LOWS IN THE TEENS.
A PATTERN CHANGE TOWARD A BRIEF PERIOD OF WARMER WEATHER LOOKS TO
BE IN STORE FOR THE MID TO LATE WEEK PERIOD AS 500 MB HEIGHTS
RISE ACROSS THE EASTERN CONUS. HIGHS ON FRIDAY MAY REACH INTO THE
UPPER 30S TO AROUND 40 IN SPOTS. UNCERTAINTY THEN INCREASES
MARKEDLY DUE TO DIFFERENCES IN HANDLING A LOW MOVING OUT OF THE
MIDWEST TO THE NORTHEAST. THESE DIFFERENCES ARE MOSTLY DUE TO
TIMING THE EJECTION OF AN UPPER-LEVEL TROUGH FRIDAY
AFTERNOON...WHICH IN TURN LEADS TO SOME DISCREPANCY AS TO WHEN
THE ASSOCIATED SFC COLD FRONT PUSHES THROUGH THE NORTH COUNTRY.
ONE THING THAT CAN BE SAID ABOUT THE EARLY WEEKEND PERIOD IS THAT
THE BAROCLINIC ZONE TIED TO THE AFOREMENTIONED COLD FRONT GETS
HUNG UP SOMEWHERE IN THE INTERIOR SOUTHEASTERN CONUS WITH THE
IMPLICATION OF ADDITIONAL CHANCES FOR UNSETTLED WEATHER. IT`S NOT
CLEAR HOW ALL THAT UNFOLDS HOWEVER. I`VE STAYED CLOSE TO THE
SUPERBLEND GUIDANCE FOR THE EARLY WEEKEND PERIOD WHICH OFFERS
CHANCE POPS WITH LOWS TRENDING NEAR TO BELOW NORMAL.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...ASIDE FROM SOME LAKE EFFECT-INDUCED MVFR
CEILINGS AT PBG (EVIDENT ON WEBCAMS OVERLOOKING LAKE
CHAMPLAIN)...REST OF THE TAFS ARE VFR. THIS WILL REMAIN THE CASE
UNTIL THE 21-00Z TIMEFRAME BEFORE CONDITIONS STEADILY
DETERIORATE. IN GENERAL...HAVE STAYED CLOSE TO THE PRIOR TAF
FORECAST THINKING FOR THIS UPDATE WITH A FEW ADJUSTMENTS TO START
TIME. NOTING CURRENT TRENDS IN SFC DEWPOINTS SHOWING THAT THE
RELATIVELY HIGHER LEVELS OF LOW- LEVEL MOISTURE ARE PRESENTLY
ACROSS CENTRAL NEW YORK. IT`S NOTABLY DRIER ACROSS MUCH OF
VERMONT WHERE DEWPOINTS ARE ONLY IN THE SINGLE DIGITS TO TEENS
BELOW ZERO. THE EFFECT THIS HAS ON THE TAFS IS THAT THE ONSET OF
MVFR SNOWS WILL START A LITTLE LATER FOR THE VERMONT TAFS AND
SOONER AT SLK (STARTING AT 21Z). VISIBILITIES WILL THEN PROCEED
TO DROP WITH WIDESPREAD IFR/LIFR ANTICIPATED BY THE EVENING
CONTINUING INTO THE OVERNIGHT. HEAVIEST SNOWS AGAIN APPEAR TO
FALL IN THE 03-12Z TIME PERIOD...THOUGH CONTINUED IFR
VISIBILITIES IN LIGHTER SNOWS EXPECTED AFTER THAT TIME LIGHTEST
AT RUT.
WINDS INITIALLY ARE LIGHT NORTH TO NORTHEAST...THOUGH WILL BEGIN
TO BACK TO SOUTHEAST AND INCREASE IN THE 5-10KT RANGE (EXCEPT MSS
DUE TO FAVORED VALLEY FLOW) BY EVENING. EXPECT WINDS TO THEN
BECOME NORTHEAST BY TOMORROW MORNING AS SFC CYCLONE ENTERS THE
GULF OF MAINE.
OUTLOOK 18Z SUNDAY THROUGH WEDNESDAY...SNOW COMES TO AN END LATE
SUNDAY AFTN AREAWIDE AS SURFACE LOW PULLS NEWD AWAY FROM THE
REGION. TRENDING VFR WITH NWLY WINDS SUNDAY NIGHT. CHANCE OF
FLURRIES SUNDAY NIGHT THRU MONDAY. LIGHT SNOW OR SNOW SHOWERS
POSSIBLE TUESDAY NIGHT AND WEDNESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR VTZ001>012-
016>019.
NY...WINTER STORM WARNING UNTIL 4 PM EST SUNDAY FOR NYZ026>031-034-
035-087.
&&
$$
SYNOPSIS...LAHIFF/KGM
NEAR TERM...TABER
SHORT TERM...KGM
LONG TERM...LOCONTO
AVIATION...BANACOS/LOCONTO
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
137 PM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12 PM UPDATE...LES BAND HAS NOW BEEN STRIPPED OFF THE LONG AXIS OF
LAKE ONTARIO AS WINDS ARE NOW NORTHERLY. ALLOWED WARNING FOR NRN
ONEIDA COUNTY TO EXPIRE WILL CONTINUE WITH ADV UNTIL MID AFTERNOON
FOR AREAS SE OF LAKE.
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISSIPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROWTH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
115 PM UPDATE...
WITH A SNOW EVENT TOMORROW I WENT WITH WPC GUIDANCE FOR THE LONG
TERM PERIOD WITH A FEW MINOR TWEAKS. OVERALL A FAIRLY QUIET
PATTERN WITH NO HUGE STORMS. WE WILL SEE A SERIES OF WEAK
WAVES...ONE COMING MONDAY NIGHT INTO TUESDAY AND AGAIN TUESDAY
NIGHT INTO WEDNESDAY...WHICH WILL KEEP SNOW SHOWERS AROUND. IN
ADDITION SOME PERIODS OF LAKE EFFECT ARE POSSIBLE. TOWARD
THURSDAY HEIGHTS WILL RISE AND DRIER WEATHER IS EXPECTED. ALTHOUGH
BEYOND OUR CURRENT EXTENDED...BOTH THE GFS AND EURO POINT TO OUR
NEXT SYSTEM BEING AN INLAND RUNNER WITH MUCH WARMER AIR AND RAIN
BY THE END OF NEXT WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
115 PM UPDATE...
TWO PERIODS OF CONCERN FOR THE TAFS. THE FIRST WILL BE THROUGH
EARLY EVENING WITH ONGOING LAKE SNOWS...THEN A BREAK...WITH A MORE
WIDESPREAD SNOW DEVELOPING DURING THE DAY SATURDAY.
FOR NOW IFR VSBYS WILL REMAIN POSSIBLE AT KSYR/KITH AND KBGM
THROUGH 21Z IN LAKE EFFECT SNOW. OUTSIDE OF THESE AREAS VFR TO
MVFR CIGS ARE LIKELY THROUGH EARLY EVENING WITH A FEW FLURRIES OR
A BRIEF SNOW SHOWER. AFTER EARLY TONIGHT MOST TERMINALS WILL GO TO
VFR WITH LAKE INFLUENCES NOT BEING AN ISSUE ANYMORE.
TOWARD DAYBREAK SATURDAY SNOW WILL SPREAD FROM SOUTHWEST TO
NORTHEAST ACROSS THE TERMINALS. ONCE THE SNOW ARRIVES IFR VSBYS
WILL BE LIKELY THROUGH THE REST OF THE DAY WITH LOW END MVFR CIGS
TO PERHAPS SOME IFR ESPECIALLY ON THE ELEVATED SITES. ARRIVAL TIME
LOOKS TO BE BETWEEN 12Z AND 15Z SOUTHERN TERMINALS AFTER 17Z UP
NORTH.
OUTLOOK...
SAT NIGHT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES. SOME IMPROVEMENT TOWARD SUNDAY AFTERNOON.
SUN NGT/MON/TUE/WED...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1215 PM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12 PM UPDATE...LES BAND HAS NOW BEEN STRIPPED OFF THE LONG AXIS OF
LAKE ONTARIO AS WINDS ARE NOW NORTHERLY. ALLOWED WARNING FOR NRN
ONEIDA COUNTY TO EXPIRE WILL CONTINUE WITH ADV UNTIL MID AFTERNOON
FOR AREAS SE OF LAKE.
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1004 AM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW WARNING UNTIL NOON EST TODAY FOR NYZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
544 AM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROMM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA DURING SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW WARNING UNTIL NOON EST TODAY FOR NYZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
855 PM EST SAT DEC 14 2013
.SYNOPSIS...
LOW PRESSURE WILL PASS WEST OF THE AREA TONIGHT...BRINGING PERIODS OF
RAIN INTO SUNDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON
SUNDAY...BRINGING COOL AND DRY WEATHER INTO EARLY NEXT WEEK. DRY
AND SEASONABLE WEATHER EXPECTED MUCH OF NEXT WEEK AS SURFACE HIGH
PRESSURE IS REINFORCED OVER THE AREA. A LOW PRESSURE SYSTEM WILL
APPROACH THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 745 PM SATURDAY...TORNADO WATCH IN EFFECT FOR PORTIONS OF
THE ILM CWA THRU 200 AM EST SUNDAY...FOR BASICALLY LOCATIONS EAST
OF THE I-95 CORRIDOR TO THE ATLANTIC WATERS OUT TO 40 NM FROM THE
COAST.
A NE TO SW SFC BOUNDARY EXTENDS ACROSS THE FA...MAINLY ALONG THE
I-95 CORRIDOR WITHIN THE ILM CWA. THIS BOUNDARY IS THE DIVIDING
LINE BETWEEN MILD/WARM MOISTURE LADEN AIRMASS EAST OF THIS
BOUNDARY WITH WIDESPREAD 60 DEGREE TEMPS WHICH OBVIOUSLY IS WELL
ABOVE THE NORM FOR THIS TIME OF THE YEAR. JUST WEST OF THIS
BOUNDARY...LOOKING AT 40S AND 50S FOR TEMPS. ACTIVITY IS RACING TO
THE NE AT 35 TO 50 MPH...WITH THE AREA AS A WHOLE IS SLIDING VERY
SLOWLY TO THE EAST. EAST OF THE INLAND BOUNDARY...LOW CAPE AND
HIGH WIND SHEAR ESPECIALLY IN THE LOW LEVELS WILL PRIMARILY DRIVE
THE INCREASED POTENTIAL FOR SEVERE WX IE. TORNADO THREAT. THE SFC
BASED MARINE LAYER HAS PUSHED PARTIALLY INLAND FROM THE SE-S WINDS
BUT IS APPARENTLY NOT DEEP ENOUGH TO PREVENT THUNDERSTORM
DEVELOPMENT. LOCAL SHELF WATERS SSTS ARE IN THE 50S...BUT SSTS IN
THE 70S LURK JUST BEYOND 20 NM OUT FROM THE COAST. ONCE THE 50S
SSTS EXPAND FURTHER FROM THE CAROLINA COASTS DURING THIS WINTER
SEASON...THE MARINE LAYER WILL BECOME MORE PREVALENT AND A
DETERRENT FOR CONVECTIVE DEVELOPMENT. MINOR TWEAKS FOR PCPN TIMING
AS IT TRACKS ACROSS THE FA HAVE BEEN APPLIED. IN ADDITION...LATEST
SFC OBS INDICATE DEWPOINTS ARE RUNNING HIER THAN WHAT HAS BEEN
FORECAST...AND AS A RESULT WILL TWEAK THEM HIER OVERNIGHT. THE
WEAK INSTABILITY FOR CONVECTION HAS BEEN OVERCOME BY THE POTENT
DYNAMICS FROM A ROBUST MID-LEVEL S/W TROF PUSHING ACROSS THE SE
STATES.
PREVIOUS DISCUSSION...................................
AS OF 230 PM SATURDAY...SWIFT COLUMN WINDS ARE TRANSPORTING
INCREASING MOISTURE INTO THE AREA AS PRECIPITABLE WATERS CLIMB
THIS AFTERNOON ACROSS THE FORECAST AREA. KLTX VAD WIND PROFILE
CLOCKING 40 KNOT BARBS IN THE LOWEST GATES ADVECTING HIGHER
BOUNDARY LAYER DEWPOINTS OFF THE ATLANTIC ONTO LAND...WHILE ALOFT
A 50-70 KT SOUTHWEST TRAJECTORIES WERE STREAMING GULF MOISTURE
INTO THE CAROLINAS. LATEST SATELLITE-SENSED PWAT LOOPS DEPICT PWAT
VALUES IN EXCESS OF 1-INCH CROSSING THE SC/NC BORDER.
A WARM FRONT IS PUSHING NW ACROSS OUR FORECAST AREA PRESENTLY.
GUSTY SE WINDS AND RISING T/TD VALUES CHARACTERIZED CONDITIONS
EAST OF THE BOUNDARY. THIS TREND WILL CONTINUE INTO EARLY EVENING
INCREASING INSTABILITY OVER THE AREA AND MOST NOTABLY ALONG THE
COAST WHERE HIGHER TD VALUES ARE ANTICIPATED.
A NEARLY MOIST ADIABATIC SOUNDING PROFILE TONIGHT WILL LIMIT
OVERALL INSTABILITY BUT MOST OF THE MODELS APPEAR TO GENERATE CAPE
VALUES THIS EVENING SUFFICIENT FOR A FEW UPDRAFTS...AND BESIDES WE
SHOULD HAVE ADEQUATE JET SUPPORT ALOFT. OVERLAYED TEMPORALLY WITH
THIS INSTABILITY MAXIMA MAINLY BETWEEN 0Z/7PM AND 6Z/1AM...ARE
ELEVATED 0-3 KM HELICITY VALUES...AS CYCLOGENESIS PROMPTS A
DEEPENING WAVE OF LOW PRESSURE ALONG THE FRONT THAT TRACKS OVER
THE AREA THIS EVENING. THERE REMAINS ENOUGH INGREDIENTS TO RETAIN
A MENTION OF POTENTIALLY DAMAGING WINDS WITH ANY THUNDERSTORMS
THAT MAY FORM...DUE TO DYNAMIC WIND-FIELDS AND FAVORABLE HELICITY
AND HODOGRAPH PROFILES. THE BEST VERTICAL SHEAR PROFILES CONTINUE
TO REMAIN ALONG THE COAST AND COASTAL INTERIOR ALTHOUGH ANY ONE
LOCATION ACROSS THE FORECAST AREA WOULD POSSESS A SMALL CHANCE OF
WIND-DAMAGE AS THE FRONT TRANSITS.
COOL AIR ADVECTION LATER TONIGHT WILL BRING OUR MILD TEMPERATURES
DOWN EVEN THOUGH WIND DIRECTIONS MAY BE ESSENTIALLY WEST TO EAST
HAVING CRESTED THE APPALACHIANS BEFORE THE LEADING EDGE OF HIGH
PRESSURE ARRIVES. MINIMUMS THEREFOR IN THE MIDDLE TO UPPER 50S
THE COAST AND A CHILLIER MIDDLE UPPER 40S ACROSS OUR FAR INTERIOR.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...THE SHORT TERM FORECAST IS RATHER STRAIGHT FORWARD AS
THE MID LEVEL TROUGH WILL CONTINUE TO MOVE OFFSHORE SUNDAY WITH A
MODEST NORTHWEST FLOW ENSUING THROUGH THE REMAINDER OF THE PERIOD.
AT THE SURFACE...HIGH PRESSURE BUILDS IN FROM THE NORTHWEST THEN THE
SURFACE PATTERN SHOWS A WEAKNESS DEVELOPING LATER MONDAY. ALTHOUGH
THERE ARE WEAK SHORTWAVES IN THE FLOW...NONE ARE STRONG ENOUGH TO
REINFORCE THE MODEST COLD AIR ADVECTION THAT MOVES IN SUNDAY.
OVERALL GUIDANCE REMAINS IN GOOD AGREEMENT WITH HIGHS IN THE 50S AND
LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...ZONAL FLOW ON TUESDAY EVEN AS IMPRESSIVE JET
OF 100KT DIVES ACROSS NRN PLAINS. THE MID LEVEL WAVE WRAPS UP FAIRLY
QUICKLY AND THUS DOES NOT LEAD TO A VERY DEEP TROUGH. EVEN SO IT
WILL MANAGE TO PUSH A RAIN-FREE COLD FRONT THROUGH THE CAROLINAS
TUESDAY NIGHT. HIGH RISES ALREADY UNDERWAY THOUGH WEDNESDAY MORNING
AS THE SYSTEM ALOFT SWINGS NEGATIVE AND LIFTS INTO NEW ENGLAND.
WEDNESDAY IS WHEN SURFACE PRESSURE GRADIENT FINALLY BECOMES LESS
NOISY AS HIGH PRESSURE CONGEALS OVER THE NC SOUNDS WHILE SUBTLE MID
LEVEL HEIGHT RISES CONTINUE. SURFACE RIDGE MOVES CONSIDERABLY TO THE
EAST FOR THE LATE WEEK PERIOD AND MID LEVEL TROUGHINESS DEVELOPS
OVER THE SWRN U.S. BOUNDARY LAYER WARMTH AND MOISTURE WILL BE ON THE
RISE BUT NOT SUFFICIENTLY FOR ANY MEANINGFUL RAIN CHANCES.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...CONVECTION ONGOING WITH BRIEF PERIODS OF 1-2SM
VISIBILITY IN HEAVY SHOWERS...WITH ISOLATED EMBEDDED THUNDER. STRONG
HELICITY COUNTERED BY WEAK CAPE WILL LIKELY PRODUCE ISOLATED SEVERE
WEATHER. MOST OF THE ACTIVITY WILL BE OVER BY 03Z. THE HRRR HAS A
SECONDARY LINE MOVING FROM WEST TO EAST ALONG THE FRONT...BUT THE
AREA IS WEAKER THAN THE EARLIER MAIN LINE. LOOK FOR BRIEF BOUTS OF
IFR STRATUS. OVERNIGHT...CONDITIONS WILL IMPROVE AS THE THE FRONT
MOVES THROUGH. WINDS WILL SHIFT TO THE WEST...REMAINING ELEVATED.
SHOWERS WILL END FROM WEST TO EAST BY 06-08Z. BECOMING VFR TOWARD
MORNING...CONTINUING ON SUNDAY WITH A GUSTY NORTHWEST WIND.
EXTENDED OUTLOOK...SHOWERS LIKELY WITH PERIODS OF MVFR/IFR
CONDITIONS INTO EARLY SUNDAY. VFR DEVELOPING SUNDAY AND
PERSISTING THROUGH MID-WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 830 PM SATURDAY...TORNADO...WATERSPOUT...WATCH CONTINUES
ACROSS THE COASTAL AND OFFSHORE WATERS...AND OUT 40 NM. THE
MARINE LAYER ACROSS THE ILM COASTAL WATERS WHERE SSTS ARE IN THE
50S REMAINS JUST THICK ENOUGH TO PREVENT THE HIER SUSTAINED WINDS
ALOFT FROM WORKING THEIR WAY TO THE OCEAN SFC. THIS WILL RESULT
WITH THE CONTINUATION OF A STRONG SCA...WITH FEW GALE FORCE GUSTS
POSSIBLE. JUST BEYOND 20 NM OUT...SSTS ARE IN THE 60S AND 70S
ALLOWING THE STRONGER WINDS ALOFT TO MIX DOWN TO THE OCEAN SFC.
WITH A SE-S WIND...PRIMARILY AN ONSHORE DIRECTION...THE HIER WIND
DRIVEN WAVES JUST OFFSHORE...IE. LATEST BUOY 41013 IS AT 14 FEET
WITH A S WIND AT 29G41 KT...WILL PUSH INTO THE COASTAL WATERS. AS
A RESULT...HAVE MODIFIED THE SIGNIFICANT SEAS ACROSS THE COASTAL
WATERS BY INCREASING THEM BY 1 TO 3 FT FROM THEIR CURRENT
FORECAST. LOOK FOR THE SFC BOUNDARY EXTENDING NE-SW ACROSS THE
CAROLINAS...TO PUSH ACROSS THE ILM WATERS DURING THE PRE-DAWN SUN
HOURS. THIS WILL VEER THE WINDS TO SW-W BEFORE FINALLY VEERING TO
THE NW-N EARLY IN THE SHORT TERM PERIOD FROM THE PASSAGE OF THE
COLD FRONT.
PREVIOUS DISCUSSION...............................................
AS OF 230 PM SATURDAY...DANGEROUS MARINE CONDITIONS OVERNIGHT AS A
MODERATELY STRONG COLD FRONT CROSSES THE AREA AND JACKS UP SW
WINDS IN ADVANCE THROUGH EARLY SUNDAY...WITH SW 20-30 KT LIKELY
OVER THE WATERS. A FEW GALE GUSTS BEYOND 20 NM IN WARMER WATERS IS
POSSIBLE...SUCH AS THE FRYING PAN SHOALS AREA. SEAS OF 5-9 FT
EXPECTED AND HIGHEST OFFSHORE...COMPOSED MAINLY OF LARGE S WAVES
EVERY 6-8 SECONDS. SEVERAL STRONG TSTMS ARE POSSIBLE ON THE WATERS
TONIGHT...AND WILL BE CAPABLE OF GENERATING GUSTS TO 50KT IN
ISOLATED MARINE LOCATIONS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...INITIALLY A WESTERLY FLOW WILL BE IN PLACE
OVER THE WATERS IN A RANGE OF 15-20 KNOTS. AS SUNDAY
PROGRESSES...WINDS WILL OBTAIN A MORE NORTHWESTERLY COMPONENT AND
DECREASE. THE WINDS WILL VERY GRADUALLY DIMINISH TO 10-15 KNOTS
THROUGH THE REMAINDER OF THE PERIOD. AS FOR SEAS...THE CHANGE IN
FETCH WILL BE WELL UNDERWAY EARLY WITH A FEW SIX FOOTERS REMAINING
ACROSS THE OUTER WATERS WITH A WIDE RANGE OF 2-6 FEET. SEAS WILL
GRADUALLY DIMINISH TO 2-3 FEET BY MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM SATURDAY...WEST TO SOUTHWEST WINDS PICK UP AHEAD OF A
COLD FRONT ON TUESDAY. THE OFFSHORE FLOW DIRECTION BUILDS SEAS AWAY
FROM SHORE TO 3 OR 4 FT WHILE LANDMASS WAVE SHADOWING KEEPS THE
NEARSHORE WAVES CLOSER TO 2 FT. VEERING FLOW BEHIND THE BOUNDARY ON
WEDNESDAY TO SHORTEN THE PERIOD SOMEWHAT AS WAVE FACES STEEPEN BUT
LITTLE OVERALL CHANGE IN SIG WAVE HEIGHT EXPECTED. THURSDAY PUTS US
INTO A SOUTHERLY RETURN FLOW REGIME THAT WILL LAST FOR SEVERAL
DAYS. ANY BUILDING OF SEAS WILL BE GRADUAL AND LIKELY NOT OCCUR
UNTIL AFTER THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
836 PM EST SAT DEC 14 2013
.SYNOPSIS...
LOW PRESSURE WILL PASS WEST OF THE AREA TONIGHT...BRINGING PERIODS OF
RAIN INTO SUNDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON
SUNDAY...BRINGING COOL AND DRY WEATHER INTO EARLY NEXT WEEK. DRY
AND SEASONABLE WEATHER EXPECTED MUCH OF NEXT WEEK AS SURFACE HIGH
PRESSURE IS REINFORCED OVER THE AREA. A LOW PRESSURE SYSTEM WILL
APPROACH THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 745 PM SATURDAY...TORNADO WATCH IN EFFECT FOR PORTIONS OF
THE ILM CWA THRU 200 AM EST SUNDAY...FOR BASICALLY LOCATIONS EAST
OF THE I-95 CORRIDOR TO THE ATLANTIC WATERS OUT TO 40 NM FROM THE
COAST.
A NE TO SW SFC BOUNDARY EXTENDS ACROSS THE FA...MAINLY ALONG THE
I-95 CORRIDOR WITHIN THE ILM CWA. THIS BOUNDARY IS THE DIVIDING
LINE BETWEEN MILD/WARM MOISTURE LADEN AIRMASS EAST OF THIS
BOUNDARY WITH WIDESPREAD 60 DEGREE TEMPS WHICH OBVIOUSLY IS WELL
ABOVE THE NORM FOR THIS TIME OF THE YEAR. JUST WEST OF THIS
BOUNDARY...LOOKING AT 40S AND 50S FOR TEMPS. ACTIVITY IS RACING TO
THE NE AT 35 TO 50 MPH...WITH THE AREA AS A WHOLE IS SLIDING VERY
SLOWLY TO THE EAST. EAST OF THE INLAND BOUNDARY...LOW CAPE AND
HIGH WIND SHEAR ESPECIALLY IN THE LOW LEVELS WILL PRIMARILY DRIVE
THE INCREASED POTENTIAL FOR SEVERE WX IE. TORNADO THREAT. THE SFC
BASED MARINE LAYER HAS PUSHED PARTIALLY INLAND FROM THE SE-S WINDS
BUT IS APPARENTLY NOT DEEP ENOUGH TO PREVENT THUNDERSTORM
DEVELOPMENT. LOCAL SHELF WATERS SSTS ARE IN THE 50S...BUT SSTS IN
THE 70S LURK JUST BEYOND 20 NM OUT FROM THE COAST. ONCE THE 50S
SSTS EXPAND FURTHER FROM THE CAROLINA COASTS DURING THIS WINTER
SEASON...THE MARINE LAYER WILL BECOME MORE PREVALENT AND A
DETERRENT FOR CONVECTIVE DEVELOPMENT. MINOR TWEAKS FOR PCPN TIMING
AS IT TRACKS ACROSS THE FA HAVE BEEN APPLIED. IN ADDITION...LATEST
SFC OBS INDICATE DEWPOINTS ARE RUNNING HIER THAN WHAT HAS BEEN
FORECAST...AND AS A RESULT WILL TWEAK THEM HIER OVERNIGHT. THE
WEAK INSTABILITY FOR CONVECTION HAS BEEN OVERCOME BY THE POTENT
DYNAMICS FROM A ROBUST MID-LEVEL S/W TROF PUSHING ACROSS THE SE
STATES.
PREVIOUS DISCUSSION..............................................
AS OF 230 PM SATURDAY...SWIFT COLUMN WINDS ARE TRANSPORTING
INCREASING MOISTURE INTO THE AREA AS PRECIPITABLE WATERS CLIMB
THIS AFTERNOON ACROSS THE FORECAST AREA. KLTX VAD WIND PROFILE
CLOCKING 40 KNOT BARBS IN THE LOWEST GATES ADVECTING HIGHER
BOUNDARY LAYER DEWPOINTS OFF THE ATLANTIC ONTO LAND...WHILE ALOFT
A 50-70 KT SOUTHWEST TRAJECTORIES WERE STREAMING GULF MOISTURE
INTO THE CAROLINAS. LATEST SATELLITE-SENSED PWAT LOOPS DEPICT PWAT
VALUES IN EXCESS OF 1-INCH CROSSING THE SC/NC BORDER.
A WARM FRONT IS PUSHING NW ACROSS OUR FORECAST AREA PRESENTLY.
GUSTY SE WINDS AND RISING T/TD VALUES CHARACTERIZED CONDITIONS
EAST OF THE BOUNDARY. THIS TREND WILL CONTINUE INTO EARLY EVENING
INCREASING INSTABILITY OVER THE AREA AND MOST NOTABLY ALONG THE
COAST WHERE HIGHER TD VALUES ARE ANTICIPATED.
A NEARLY MOIST ADIABATIC SOUNDING PROFILE TONIGHT WILL LIMIT
OVERALL INSTABILITY BUT MOST OF THE MODELS APPEAR TO GENERATE CAPE
VALUES THIS EVENING SUFFICIENT FOR A FEW UPDRAFTS...AND BESIDES WE
SHOULD HAVE ADEQUATE JET SUPPORT ALOFT. OVERLAYED TEMPORALLY WITH
THIS INSTABILITY MAXIMA MAINLY BETWEEN 0Z/7PM AND 6Z/1AM...ARE
ELEVATED 0-3 KM HELICITY VALUES...AS CYCLOGENESIS PROMPTS A
DEEPENING WAVE OF LOW PRESSURE ALONG THE FRONT THAT TRACKS OVER
THE AREA THIS EVENING. THERE REMAINS ENOUGH INGREDIENTS TO RETAIN
A MENTION OF POTENTIALLY DAMAGING WINDS WITH ANY THUNDERSTORMS
THAT MAY FORM...DUE TO DYNAMIC WIND-FIELDS AND FAVORABLE HELICITY
AND HODOGRAPH PROFILES. THE BEST VERTICAL SHEAR PROFILES CONTINUE
TO REMAIN ALONG THE COAST AND COASTAL INTERIOR ALTHOUGH ANY ONE
LOCATION ACROSS THE FORECAST AREA WOULD POSSESS A SMALL CHANCE OF
WIND-DAMAGE AS THE FRONT TRANSITS.
COOL AIR ADVECTION LATER TONIGHT WILL BRING OUR MILD TEMPERATURES
DOWN EVEN THOUGH WIND DIRECTIONS MAY BE ESSENTIALLY WEST TO EAST
HAVING CRESTED THE APPALACHIANS BEFORE THE LEADING EDGE OF HIGH
PRESSURE ARRIVES. MINIMUMS THEREFOR IN THE MIDDLE TO UPPER 50S
THE COAST AND A CHILLIER MIDDLE UPPER 40S ACROSS OUR FAR INTERIOR.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...THE SHORT TERM FORECAST IS RATHER STRAIGHT FORWARD AS
THE MID LEVEL TROUGH WILL CONTINUE TO MOVE OFFSHORE SUNDAY WITH A
MODEST NORTHWEST FLOW ENSUING THROUGH THE REMAINDER OF THE PERIOD.
AT THE SURFACE...HIGH PRESSURE BUILDS IN FROM THE NORTHWEST THEN THE
SURFACE PATTERN SHOWS A WEAKNESS DEVELOPING LATER MONDAY. ALTHOUGH
THERE ARE WEAK SHORTWAVES IN THE FLOW...NONE ARE STRONG ENOUGH TO
REINFORCE THE MODEST COLD AIR ADVECTION THAT MOVES IN SUNDAY.
OVERALL GUIDANCE REMAINS IN GOOD AGREEMENT WITH HIGHS IN THE 50S AND
LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...ZONAL FLOW ON TUESDAY EVEN AS IMPRESSIVE JET
OF 100KT DIVES ACROSS NRN PLAINS. THE MID LEVEL WAVE WRAPS UP FAIRLY
QUICKLY AND THUS DOES NOT LEAD TO A VERY DEEP TROUGH. EVEN SO IT
WILL MANAGE TO PUSH A RAIN-FREE COLD FRONT THROUGH THE CAROLINAS
TUESDAY NIGHT. HIGH RISES ALREADY UNDERWAY THOUGH WEDNESDAY MORNING
AS THE SYSTEM ALOFT SWINGS NEGATIVE AND LIFTS INTO NEW ENGLAND.
WEDNESDAY IS WHEN SURFACE PRESSURE GRADIENT FINALLY BECOMES LESS
NOISY AS HIGH PRESSURE CONGEALS OVER THE NC SOUNDS WHILE SUBTLE MID
LEVEL HEIGHT RISES CONTINUE. SURFACE RIDGE MOVES CONSIDERABLY TO THE
EAST FOR THE LATE WEEK PERIOD AND MID LEVEL TROUGHINESS DEVELOPS
OVER THE SWRN U.S. BOUNDARY LAYER WARMTH AND MOISTURE WILL BE ON THE
RISE BUT NOT SUFFICIENTLY FOR ANY MEANINGFUL RAIN CHANCES.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...CONVECTION ONGOING WITH BRIEF PERIODS OF 1-2SM
VISIBILITY IN HEAVY SHOWERS...WITH ISOLATED EMBEDDED THUNDER. STRONG
HELICITY COUNTERED BY WEAK CAPE WILL LIKELY PRODUCE ISOLATED SEVERE
WEATHER. MOST OF THE ACTIVITY WILL BE OVER BY 03Z. THE HRRR HAS A
SECONDARY LINE MOVING FROM WEST TO EAST ALONG THE FRONT...BUT THE
AREA IS WEAKER THAN THE EARLIER MAIN LINE. LOOK FOR BRIEF BOUTS OF
IFR STRATUS. OVERNIGHT...CONDITIONS WILL IMPROVE AS THE THE FRONT
MOVES THROUGH. WINDS WILL SHIFT TO THE WEST...REMAINING ELEVATED.
SHOWERS WILL END FROM WEST TO EAST BY 06-08Z. BECOMING VFR TOWARD
MORNING...CONTINUING ON SUNDAY WITH A GUSTY NORTHWEST WIND.
EXTENDED OUTLOOK...SHOWERS LIKELY WITH PERIODS OF MVFR/IFR
CONDITIONS INTO EARLY SUNDAY. VFR DEVELOPING SUNDAY AND
PERSISTING THROUGH MID-WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM SATURDAY...DANGEROUS MARINE CONDITIONS OVERNIGHT AS A
MODERATELY STRONG COLD FRONT CROSSES THE AREA AND JACKS UP SW
WINDS IN ADVANCE THROUGH EARLY SUNDAY...WITH SW 20-30 KT LIKELY
OVER THE WATERS. A FEW GALE GUSTS BEYOND 20 NM IN WARMER WATERS
IS POSSIBLE...SUCH AS THE FRYING PAN SHOALS AREA. SEAS OF 5-9 FT
EXPECTED AND HIGHEST OFFSHORE...COMPOSED MAINLY OF LARGE S WAVES
EVERY 6-8 SECONDS. SEVERAL STRONG TSTMS ARE POSSIBLE ON THE WATERS
TONIGHT...AND WILL BE CAPABLE OF GENERATING GUSTS TO 50KT IN
ISOLATED MARINE LOCATIONS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...INITIALLY A WESTERLY FLOW WILL BE IN PLACE OVER
THE WATERS IN A RANGE OF 15-20 KNOTS. AS SUNDAY PROGRESSES...WINDS
WILL OBTAIN A MORE NORTHWESTERLY COMPONENT AND DECREASE. THE WINDS
WILL VERY GRADUALLY DIMINISH TO 10-15 KNOTS THROUGH THE REMAINDER
OF THE PERIOD. AS FOR SEAS...THE CHANGE IN FETCH WILL BE WELL
UNDERWAY EARLY WITH A FEW SIX FOOTERS REMAINING ACROSS THE OUTER
WATERS WITH A WIDE RANGE OF 2-6 FEET. SEAS WILL GRADUALLY DIMINISH
TO 2-3 FEET BY MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM SATURDAY...WEST TO SOUTHWEST WINDS PICK UP AHEAD OF A
COLD FRONT ON TUESDAY. THE OFFSHORE FLOW DIRECTION BUILDS SEAS AWAY
FROM SHORE TO 3 OR 4 FT WHILE LANDMASS WAVE SHADOWING KEEPS THE
NEARSHORE WAVES CLOSER TO 2 FT. VEERING FLOW BEHIND THE BOUNDARY ON
WEDNESDAY TO SHORTEN THE PERIOD SOMEWHAT AS WAVE FACES STEEPEN BUT
LITTLE OVERALL CHANGE IN SIG WAVE HEIGHT EXPECTED. THURSDAY PUTS US
INTO A SOUTHERLY RETURN FLOW REGIME THAT WILL LAST FOR SEVERAL DAYS.
ANY BUILDING OF SEAS WILL BE GRADUAL AND LIKELY NOT OCCUR UNTIL
AFTER THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL
MARINE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
710 PM EST SAT DEC 14 2013
.SYNOPSIS...LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS THE
REGION TONIGHT. HIGH PRESSURE WILL THEN PROVIDE FAIR WEATHER
ACROSS OUR AREA THROUGH MUCH OF NEXT WEEK.
&&
NEAR TERM /THROUGH TONIGHT/...
AS OF 255 PM SATURDAY...
CURRENT PATTERN FEATURES A POSITIVELY TILTED L/W TROUGH MVG ACROSS
THE MIDDLE OF THE COUNTRY WITH A WELL DEFINED EMBEDDED S/W MOVING NE
ALONG THE OH RIVER VALLEY...AND ANOTHER S/W IN THE BASE OF THE L/W
TROUGH MVG ACROSS THE SRN PLAINS. A CLASSIC MILLER TYPE-B
CYCLOGENESIS PATTERN IS UNFOLDING ACROSS THE REGION ATTM WITH LOW
PRESSURE AND AN ASSOC COLD FRONT MVG ACROSS THE TN VALLEY AND
CYCLOGENESIS NOW OCCURRING OVER THE CAROLINAS WITH SEVERAL RECENT
OBS SHOWING RAPID PRESSURE FALLS FROM NORTHCENTRAL SC NEWD ACROSS
THE NC SANDHILLS AND COASTAL PLAIN. THE WEDGE BOUNDARY CONTINUES
ALONG AND WEST OF THE I-85 CORRIDOR STRENGTHENED BY ONGOING RAIN
ACROSS WESTERN PIEDMONT...WHILE THE COASTAL FRONT HAS BEEN SLOW TO
PUSH INLAND AND STILL LOCATED NEAR THE COAST. MEANWHILE...A LARGE
PRECIP SHIELD ASSOC WITH THE ADVANCING SHORT WAVES AND PREFRONTAL
TROUGH HAS CROSSED THE MOUNTAINS AND IS WELL-DEPICTED BY NEAR-TERM
GUIDANCE AND PROGGED TO CONTINUE MOVING ACROSS OUR CWA THROUGH THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. THE HEAVIEST RAIN IS
EXPECTED TO OCCUR ACROSS OUR WESTERN ZONES AND THE TRIAD REGION
BETWEEN NOW AND 22Z...ACROSS OUR CENTRAL ZONES AND THE TRIANGLE
REGION BETWEEN 21Z AND 00Z...AND ACROSS OUR COASTAL PLAIN ZONES
BETWEEN 23Z AND 03Z.
THE PRIMARY CONCERN FOR THIS EVENING IS THE POTENTIAL FOR THUNDER.
WHILE PRESSURE IS FALLING RAPIDLY ATTM ACROSS THE SANDHILLS AND
COASTAL PLAIN REGION...AND THE SFC LOW IS EXPECTED TO MOVE NE ALONG
OR TO THE EAST OF THE I-95 CORRIDOR...THE AIRMASS WITH THE BEST
BUOYANCY IS STILL S/E OF THE COASTAL FRONT. AS PRESSURES CONTINUE TO
FALL AND THE LOW FURTHER DEVELOPS...WE MAY YET SEE AN INLAND
ADVANCEMENT OF THIS BOUNDARY. HOWEVER...THE CURRENT PRESSURE FALLS
AND SFC TEMP/WIND OBS SUGGEST THAT THE BEST TEMP/DWPT ADVECTION (AND
THUS INSTABILITY) SHOULD REMAIN MOSTLY EAST OF OUR CWA. AS SUCH...
RIGHT NOW THE BEST CHANCE FOR THUNDER IN OUR CWA APPEARS TO BE
ACROSS OUR FAR E/SE ZONES. PRIMARY IMPACTS WITH TSTMS ACROSS OUR
AREA SHOULD BE LIMITED TO SCATTERED HEAVY DOWNPOURS AND PERHAPS A
BRIEF WIND GUST OR TWO BELOW SVR LIMITS. NONETHELESS...THESE
SCATTERED HEAVIER DOWNPOURS MAY RESULT IN BRIEF PERIODS OF LOW
VISIBILITY AND WATER PONDING IN THE TYPICAL POOR DRAINAGE AREAS.
WHILE THE STEADY PRECIP IS EXPECTED TO END ACROSS OUR WESTERN ZONES
BY 02-03Z AND OUR EASTERN ZONES BY 05-06Z...LATEST HRRR SHOWS SOME
LIGHT PRECIP REDEVELOPMENT ASSOC WITH SFC FRONT AFT MIDNIGHT...SO
WILL KEEP A LINGERING 20-40 PERCENT POP GOING OVERNIGHT THROUGH 09Z.
IN ADDITION...FORECAST SOUNDINGS CONTINUE TO SHOW THE SFC NEARLY
SATURATED WITH LIGHT WINDS...THUS LOOK FOR LOW CLOUDS AND SOME FOG
TO PERSIST THROUGH SUNRISE. LOWS TONIGHT WILL RANGE FROM THE MID 30S
NW TO MID 40S SE.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 255 PM SATURDAY...
AFTER SUNRISE SUNDAY...SKIES WILL BEGIN TO CLEAR OUT AS NW LOW LEVEL
FLOW INCREASES BEHIND THE DEPARTING LOW AND BL MIXING HELPS TO DRY
OUT THE AIRMASS. AS MIXING INCREASES THROUGH THE MORNING...WE MAY
SEE A FEW HOURS OF 15-20 MPH WIND GUSTS FROM THE NW. OTHERWISE...
LOOK FOR PLENTY OF SUNSHINE...WITH HIGHS NEAR SEASONAL VALUES IN THE
LOW-MID 50S.
MAINLY CLEAR SKIES AND LIGHT WINDS WILL PROMOTE GOOD RADIATIONAL
COOLING SUNDAY NIGHT. LOWS WILL RANGE FROM THE UPPER 20S NW TO LOWER
30S E...A FEW DEGREES BELOW NORMAL.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 235 PM SATURDAY...
A LOW PRESSURE SYSTEM DIVING OUT OF THE CANADIAN ROCKIES WILL
APPROACH THE GREAT LAKES AND DIVE THROUGH NEW ENGLAND AS AN UPPER
LEVEL TROUGH DIGS DOWN THE EASTERN SEABOARD BUT WILL HAVE A HARD
TIME EXTENDING SOUTHWARD. THIS WILL MAKE UPPER LEVEL FLOW MORE ZONAL
OVER NORTH CAROLINA CAUSING A FAIRLY CONSTANT TEMPERATURE PATTERN
WITH SOME OSCILLATION IN HIGH AND LOW TEMPS FOR THE FIRST TWO THIRDS
OF THE PERIOD. BY THE END OF THE WEEK A FEW SHORTWAVES DEVELOP IN
THE SOUTHERN STREAM AND STRONG WARM AIR ADVECTION TAKES TEMPERATURES
WELL ABOVE SEASONAL NORMALS FOR FRIDAY AND SATURDAY BEFORE A
STRONGER LOW DEVELOPS AND MOVES THROUGH THE OHIO VALLEY ON SUNDAY.
MONDAY AND TUESDAY: WHILE MODELS GENERALLY KEEP THE PATTERN THE SAME
...THE GFS HAS A BROADER SURFACE HIGH OVER THE REGION...THUS
SHUTTING OFF ANY SLIGHT COLD AIR ADVECTION ON THE FRONT SIDE OF THE
HIGH. THE ECMWF HANGS BACK WITH THIS AND THUS ITS TEMPERATURES ARE
COOLER. EITHER WAY A SLIGHT WARMING TREND FROM MONDAY TO TUESDAY
WITH UPPER 40S TO LOW 50S EXPECTED MONDAY AND MID 50S ON TUESDAY.
DRY AND MOSTLY CLEAR WITH VERY LIGHT WINDS OUT OF THE NORTHWEST.
LOWS IN THE LOWER TO MID 30S.
WEDNESDAY AND THURSDAY: A MORE NORTHWESTERLY UPPER LEVEL FLOW AND A
TIGHTER GRADIENT IN THE GFS YIELD SOME LOWER TEMPERATURES FOR
WEDNESDAY BUT THE PATTERN IS MORE RELAXED IN THE LATEST EUROPEAN
WITH MOST OF THE STRONGER DYNAMICS WELL TO THE NORTH. WILL INDICATE
A SMALL REDUCTION IN HIGHS ON WEDNESDAY...LOWER TO MID 50S WITH LOWS
IN THE LOWER 30S THURSDAY MORNING. ON THURSDAY UPPER LEVEL FLOW WILL
BEGIN TO BACK AROUND TO WESTERLY AND THEN SOUTHWESTERLY. AT THE SAME
TIME THE SURFACE HIGH MOVES OFF SHORT. THIS WILL BEGIN A PERIOD OF
SIGNIFICANT WARM AIR ADVECTION WHICH WILL PUT HIGHS ON THURSDAY INTO
THE MID TO UPPER 50S WITH LOWS IN THE LOWER 40S.
FRIDAY AND SATURDAY: AS FLOW BECOMES MORE SOUTHWESTERLY...INCREASED
WARM AIR ADVECTION WILL HELP TEMPERATURES RISE ABOVE SEASONAL
NORMALS. INCREASED MOISTURE AHEAD OF A DEVELOPING FRONTAL ZONE IN
THE TN VALLEY WILL BEGIN TO BRING MORE CLOUDS INTO THE AREA AND A
SLIGHT CHANCE OF SOME DRIZZLE OR LIGHT RAIN FRIDAY AFTERNOON AND
EVENING...INCREASING TO CHANCE OF RAIN BY SATURDAY. HIGHEST
POTENTIAL FOR RAIN WILL BE IN THE NORTHWEST. HIGHS POTENTIALLY
RISING TO THE MID TO UPPER 60S BY SATURDAY...ALMOST 15 DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 710 PM SATURDAY...
AREA OF LOW PRESSURE OVER SOUTHEASTERN NC
THAT FORMED ALONG THE WEDGE FRONT WILL QUICKLY LIFT OFF TO THE NE
BETWEEN 00 TO 03Z. PRIMARY RAIN SHIELD WILL FOLLOW SUITE...HOWEVER
LIGHT RAIN AND/OR DRIZZLE IS POSSIBLE ACROSS EASTERN TERMINALS UNTIL
THE PASSAGE OF THE FRONT OVERNIGHT BETWEEN 09 TO 12Z. UNTIL
THEN...IFR CONDITIONS WITH LOW CLOUDS AND FOG MAY PERSIST FOR THE
REMAINDER OF THE NIGHT DUE TO LINGERING LOW LEVEL MOISTURE.
ADDITIONALLY...KINT...KGSO... AND KRDU WILL SEE ANOTHER 3 TO 4 HOURS
OF LLWS BEFORE THE THREAT ENDS BETWEEN 03 TO 05Z AS THE LLJ WEAKENS
AND SHIFTS EAST OF THE AREA.
AFTER 12Z...LOOK FOR ABRUPT WEST TO EAST CLEARING VIA STRONG DRY
COLD AIR ADVECTION IN THE WAKE OF THE FRONT WITH VFR CONDITIONS
EVERYWHERE BY 15Z WITH OCCASIONAL NWLY WINDS GUSTS INTO THE UPPER
TEENS.
OUTLOOK:
DRY VFR CONDITIONS WILL PERSIST THROUGH MID-WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...NP
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...ELLIS
AVIATION...CBL/NP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1131 PM CST THU DEC 12 2013
.UPDATE...
ISSUED AT 1131 PM CST THU DEC 12 2013
SNOW BAND CONTINUES FROM THE NORTHWEST CWA INTO THE GFK
AREA...WITH VIS AROUND 2 TO 4 MILES. ACCUMULATIONS SHOULD REMAIN
AROUND AN INCH OR MAYBE TWO. COLD AIR CONTINUES TO MOVE DOWN FROM
THE NORTH AND WIND CHILLS IN THE NORTHERN TIER HAVE STARTED TO
DROP TO CRITERIA. WILL MAINTAIN HEADLINE.
UPDATE ISSUED AT 929 PM CST THU DEC 12 2013
SNOW BAND HAS STARTED TO DEVELOP...BUT HAS BEEN A BIT FURTHER
SOUTH THAN ORIGINALLY EXPECTED AND SOME FLAKES HAVE ALREADY BEEN
REPORTED AT COOPERSTOWN AND VALLEY CITY ALTHOUGH NOT CONSISTENTLY.
BROUGHT POPS A BIT FURTHER SOUTH FOR TONIGHT AND MADE SOME FURTHER
ADJUSTMENTS TO QPF AS NOT MUCH WILL ACCUMULATE BEFORE MIDNIGHT.
TEMPS STILL SEEM ON TRACK TO DROP DOWN SIGNIFICANTLY LATER
TONIGHT...AND WINDS WILL STAY NORTH TO NORTHEASTERLY AT AROUND 10
TO 15 MPH. WILL CONTINUE TO KEEP THE WIND CHILL HEADLINE THAT WE
HAVE GOING.
UPDATE ISSUED AT 635 PM CST THU DEC 12 2013
THERE HAS BEEN A BREAK IN THE SNOW EARLY THIS EVENING...BUT
SHORT RANGE MODELS HAVE THE SNOW BAND REDEVELOPING IN THE DEVILS
LAKE BASIN SOON...SO KEPT POPS THAT RAMP UP IN THE NEXT FEW HOURS
GOING. DID CUT AMOUNTS TOWARDS THE SOUTH AND EAST THOUGH. TEMPS
CONTINUE TO BE ON TRACK SO WILL KEEP LOWS IN THE TEENS BELOW ZERO
UP NORTH TO NEAR ZERO IN THE SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM CST THU DEC 12 2013
MAIN FORECAST CONCERNS IN THE SHORT TERM WILL BE EXTENT OF LIGHT
SNOW WITH PASSING UPPER WAVES AND TEMP TRENDS...WITH COLD AIR
REMAINING FIRMLY ENTRENCHED.
A NARROW BAND OF LIGHT SNOW HAS PROGRESSED FROM THE NORTHERN
VALLEY SOUTHEASTWARD INTO NW MINNESOTA THIS AFTERNOON. THIS WILL
CONTINUE TO SHIFT SOUTHEASTWARD THROUGH THE REST OF THE AFTERNOON.
ANOTHER AREA OF LIGHT SNOW WILL SHIFT INTO THE DEVILS LAKE BASIN
THIS EVENING AND SOUTHEASTWARD OVERNIGHT...IN ASSOCIATION WITH AN
AREA OF MID-LEVEL FRONTOGENESIS AND SYNOPTIC FORCING IN THE RIGHT
ENTRANCE REGION OF A BROAD UPPER JET. AS THE FORCING GRADUALLY
WEAKENS...A DECREASING TREND IN THE SNOWFALL IS EXPECTED WITH TIME
AS THE SNOW SHIFTS SOUTHWARD. RIGHT NOW THE BEST CHANCE FOR 1 TO 3
INCHES OF ACCUMULATION LOOKS TO BE FROM THE DEVILS LAKE AREA INTO
PARTS OF THE NORTHERN AND CENTRAL VALLEY TONIGHT INTO FRIDAY.
TEMPS TONIGHT MAY BE TRICKY. ALTHOUGH LOW-LEVEL COLD ADVECTION
WILL CONTINUE THROUGH THE NIGHT...HOW MUCH TEMPS FALL WILL DEPEND
ON CLOUD COVERAGE. THE RAP BRINGS SOME LOW-LEVEL DRYING INTO PARTS
OF NORTHWEST MINNESOTA OVERNIGHT. TEMPS COULD DROP PRETTY QUICKLY
IF ANY CLEARING DOES OCCUR...AND THUS HAVE THE LOWEST TEMPS IN
THIS AREA OF NW MINNESOTA. HIGHS ON FRIDAY LIKELY WILL BE COLDEST
NORTH...WITH TEMPS REMAINING BELOW ZERO...AND SINGLE DIGITS ABOVE
ZERO FARTHER SOUTH.
AS WINDS ARE EXPECTED TO STAY UP AROUND 10 KTS OVERNIGHT...WILL
ALSO ISSUE A WIND CHILL ADVISORY FOR MUCH OF NE ND EASTWARD INTO
NW MN FROM 06Z TONIGHT THROUGH 03Z SATURDAY. WITH WINDS BRISK FROM
THE NORTHEAST ON FRIDAY AHEAD OF THE SFC HIGH...HELD ONTO THE
ADVISORY UNTIL FRIDAY EVENING...ALTHOUGH WIND CHILLS MAY RISE ABOVE
CRITERIA FOR A BIT DURING THE DAY. AS THE SFC RIDGE AXIS
APPROACHES FRIDAY NIGHT...WINDS MAY GO LIGHT...ALLOWING FOR WIND
CHILLS TO RISE ABOVE ADVISORY THRESHOLD. THIS WILL BE MONITORED
DURING FUTURE SHIFTS THOUGH.
A SERIES OF UPPER IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT WILL
CONTINUE TO AFFECT THE AREA FRIDAY NIGHT INTO SATURDAY...BRINGING
CONTINUED CHANCES FOR LIGHT SNOW. ALTHOUGH MODEL QPF IS LOW...WITH
HIGH SNOW RATIOS AND MODEL SOUNDINGS INDICATING A FAIRLY DEEP
SATURATED LAYER...A FLUFFY INCH OR TWO OF SNOW IS
POSSIBLE...DEPENDING ON THE EXACT TRACK OF THE IMPULSES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM CST THU DEC 12 2013
TEMPS ON SATURDAY WILL RISE INTO THE SINGLE DIGITS EITHER SIDE OF
ZERO WITH LIGHT SNOW REMAINING POSSIBLE AS UPPER LEVEL ENERGY
CASCADES THROUGH THE FLOW. A SFC RIDGE WILL SPREAD OVER THE AREA
ON SATURDAY NIGHT. THE MAIN QUESTION WILL BE TEMPS...WHICH WILL BE
DEPENDENT ON CLOUD COVER. THUS...TEMPS COULD BE A BIT COLDER IF
SKIES DO CLEAR.
ANOTHER ROUND OF LIGHT SNOW IS POSSIBLE SUNDAY AS WARM AIR ADVECTION
DEVELOPS AND THE LOW-LEVEL BAROCLINIC ZONE APPROACHES FROM THE WEST
AHEAD OF THE NEXT UPPER WAVE. HOWEVER...TEMPS WILL REMAIN WELL
BELOW NORMAL.
FOR THE SUNDAY NIGHT THROUGH THURSDAY PERIOD...12Z ECMWF/GFS/GEM SO
ENOUGH DISAGREEMENT IN TIMING AND LOCATION OF SEVERAL 500 MB SHORT
WAVES/SURFACE LOW PRESSURE SYSTEMS TO KEEP CONFIDENCE IN FCST A BIT
LOWER THAN NORMAL. IDEA IS FOR ONE SHORT WAVE MONDAY TO EXIT
FOLLOWED BY SOME COLDER AIR MON NIGHT-TUE THEN THE NEXT ONE DUE WED
NIGHT-THU TIME FRAME. EXACT PLACEMENT OF LOWS WILL MEAN POTENTIAL
TEMP DIFFERENCES WITH OVERALL 12Z EURO AND GEM A BIT WARMER THAN 12Z
GFS ESP FOR MID WEEK SYSTEM. WITH THE DIFFERENCES STUCK WITH ALL
BLEND GUIDANCE. THERAFTER AND BEYOND THIS PERIOD IS WHEN THE NEXT
ARCTIC OUBREAK WILL OCCUR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1131 PM CST THU DEC 12 2013
CIGS CONTINUE BETWEEN LOW VFR AND MVFR...WITH THE BAND OF LIGHT
SNOW BRINGING VIS AT KDVL AND KGFK TO 3SM...EVEN 2SM AT TIMES.
THINK THAT THE VIS WILL STAY AT OR ABOVE THESE LEVELS AND
CONDITIONS WILL BE MOSTLY MVFR THROUGH MOST OF THE NIGHT. NORTH TO
NORTHEAST WINDS WILL CONTINUE BETWEEN 10 AND 15 KTS. CONDITIONS
SHOULD IMPROVE TO VFR TOWARDS THE END OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR NDZ006>008-014>016-
024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR MNZ001-002-004>009-
013>017-022-023.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
728 PM EST SAT DEC 14 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST INTO NEW YORK SUNDAY MORNING. COLDER
AIR IN NORTHWEST FLOW SUNDAY/SUNDAY NIGHT WITH LOW LEVEL MOISTURE
LINGERING. CLIPPER PASSES MONDAY/TUESDAY. NEXT SYSTEM SATURDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
WILL CANCEL THE EXISTING WINTER WEATHER ADVISORY FOR THE
SNOW...SLEET AND FREEZING RAIN THAT WAS IN EFFECT SINCE FRIDAY NIGHT
FOR RANDOLPH AND POCAHONTAS COUNTY. WITH THE SOUTHEAST FLOW
BREAKING DOWN...TEMPERATURES WILL CONTINUE TO CREEP A BIT HIGHER.
YET...WITH FREEZING DRIZZLE BACK FOR THE HIGH TERRAIN IN THE COLDER
WEST FLOW...WOULD NOT RULE OUT A NEW ADVISORY FOR LIGHT ICING FOR
SUNDAY MORNING.
IN THE EARLY EVENING UPDATE THIS SATURDAY...AFTER SURVEYING FORECAST
SOUNDINGS...ADDED SOME DRIZZLE FOR LOWLANDS OVERNIGHT AND SOME
DRIZZLE LATER TONIGHT IN THE MOUNTAINS...WITH SOME FREEZING DRIZZLE
IN THE MOUNTAINS FOR SUNDAY MORNING.
PREVIOUS DISCUSSION
NICE DRY AIR INTRUSION ALOFT NOW PUSHING IN FROM THE SOUTHWEST...AND
EASILY SEEN ON THE ENHANCED WATER VAPOR IMAGERY. THIS WILL PUT A
DAMPER ON THE POPS OVER THE NEXT FEW HOURS AND HAVE REDUCED THEM
ACCORDINGLY. MEANWHILE...OVER SOUTHEAST OHIO...PRECIPITATION HAS
BEEN ALL RAIN FOR SEVERAL HOURS AS TEMPERATURES STRUGGLED TO EVEN
GET TOWARDS FREEZING LAST NIGHT. AS A RESULT...ALL OHIO HEADLINES IN
OUR AREA OF RESPONSIBILITY HAVE BEEN CANCELLED.
LOW PRESSURE MOVES NORTHEAST THIS EVENING AND TONIGHT WHICH WILL
PROVIDE A WIND SWITCH AND COLLAPSING COLD AIR TO DIG IN.
TEMPERATURES WILL FALL BEHIND THE COLD FRONT THROUGH THE TONIGHT
PERIOD. NOT A PREFECT DIURNAL CURVE TO THE TEMPERATURE TRENDS
THROUGH EARLY SUNDAY...AND AS A RESULT...MAX TEMPS FOR SUNDAY COULD
OCCUR EARLY IN THE DAY.
LOOKING AT THE LOW LEVEL MOISTURE AND STREAMLINES...IT WILL TAKE
UNTIL AROUND 09Z SUNDAY UNTIL THE BEST NORTHWEST FLOW INTO THE
MOUNTAINS WILL TAKE HOLD. THIS WILL BE SHORT LIVED AS THE FLOW VEERS
TOWARDS A MORE WESTERLY DIRECTION DURING THE DAY. CARRY WANING POPS
INTO THE EVENING HOURS. MAY NEED TO ADD A BRIEF PERIOD OF FREEZING
DRIZZLE IN THE MORNING HOURS OVER THE NORTHEAST MOUNTAINS AS
MOISTURE DEPTH MAY BECOME TOO SHALLOW TO SUPPORT SNOW WITH NO
SATURATION IN THE CRYSTAL GROWTH LAYER.
TEMPERATURES...AS MENTIONED...WILL FALL THROUGH THE NIGHT...AND WILL
NOT RECOVER MUCH DURING THE DAY SUNDAY. AFTERNOON VALUES MAY ONLY
GET TO FREEZING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPSLOPE SNOW SHOWERS WILL BE IN PLACE ACROSS THE NORTHERN MOUNTAINS
TO START THE SHORT TERM PERIOD. PRETTY GOOD NW FLOW...BUT MOISTURE
BECOMING FAIRLY LIMITED SO ONLY HAVE AN ADDITIONAL INCH OR TWO OF
SNOW ACCUMULATION AT HIGHER ELEVATIONS. A COUPLE 500MB SHORTWAVE
TROUGHS ROTATING AROUND UPPER LEVEL LOW NORTH OF THE GREAT LAKES
WILL BRING ADDITIONAL SNOW SHOWERS...ESPECIALLY ACROSS THE NORTH.
HOWEVER...TIMING AND LOCATION OF THESE SHORTWAVES STILL DIFFER
BETWEEN MODELS...SO WILL ONLY GO WITH SLIGHT CHANCE TO LOW CHANCE
POPS MONDAY. ALSO HAVE A COLD FRONT THAT WILL COME THROUGH
TUESDAY...MODELS KEEP MOST OF THE PRECIP NORTH OF CWA...BUT DID
INCREASE BASED ON A GFS/NAM BLEND. THIS LOOKS LIKE ANOTHER SITUATION
WHERE WAA WILL START MONDAY NIGHT...WITH WARM WEDGE TAKING OVER FOR
THE WV LOWLANDS. SO HAVE PRECIP STARTING AS SNOW EARLY TUESDAY
MORNING...TRANSITIONING TO RAIN ACROSS THE LOWLANDS TUESDAY...AND
SNOW REMAINING AT HIGHER ELEVATIONS.
USED BLEND OF MAV/MET FOR LOWS SUNDAY NIGHT RESULTING IN A FEW
DEGREES COOLER. HAVE NON-DIURNAL TREND MONDAY NIGHT AHEAD OF COLD
FRONT. FOR HIGHS...BLENDED ECE AND MAV.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE ON STRONG AMPLIFICATION OF THE UPPER PATTERN THIS
PERIOD. A STRONG UPPER TROUGH IS FORECAST TO DIG INTO THE WEST
CENTRAL U.S. AND AN UPPER RIDGE WILL BUILD OVER THE EASTERN PART OF
THE NATION. THIS WILL BRING DRY CONDITIONS THE REMAINDER OF THE WEEK
WITH A SIGNIFICANT WARMING TREND TO ABOVE NORMAL TEMPERATURES.
THE MAIN FORECAST PROBLEM WILL BE TIMING OF THE NEXT LOW PRESSURE
SYSTEM THAT EJECTS OUT OF THE WESTERN UPPER TROUGH AND DRIVES A
STRONG COLD FRONT EASTWARD. WPC AND MOST MEDIUM MODEL TRENDS ARE
SLOWER WITH THIS SYSTEM. THE EXCEPTION IS THE FASTER GFS...WHICH HAS
A TYPICAL BIAS OF EJECTING SYSTEMS TOO QUICKLY...ESPECIALLY WITH
SUCH AN AMPLIFIED PATTERN. THUS WE WILL BE GOING WITH THE SLOWER
SOLUTIONS...SO WILL WAIT TILL THE WEEKEND TO BRING IN SHOWERS AS THE
SYSTEM APPROACHES. THE EARLY PART OF THE WEEKEND LOOKS WET...BUT
VERY MILD WITH WELL ABOVE NORMAL TEMPERATURES IN A DEEP SOUTHERLY
FLOW.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
THE SOUTHEAST WIND FLOW IS NOW BREAKING DOWN AS LOW CENTER LIFTS
NORTHEAST TOWARD NORTHEASTERN OHIO AT 23Z. THE ASSOCIATED COLD FRONT
AND WIND SHIFT WAS IN EASTERN KENTUCKY NEAR KJKL AT 23Z. HAVE THAT
FRONT REACHING CRW BY AROUND 02Z...THEN PKB TO BKW BY 03Z...THEN
CKB-EKN BY 05Z. CEILINGS IN THE WESTERN LOWLANDS WILL LOWER AS THAT
FRONT APPROACHES.
WITH COLD AIR ADVECTION AND SATURATION LEVELS OF MOISTURE BECOMING
RATHER SHALLOW AFTER 09Z...MAY BE MORE DRIZZLE TRANSITIONING TO
FREEZING DRIZZLE IN THE MOUNTAIN COUNTIES...RATHER THAN LIGHT RAIN
SHOWERS BECOMING LIGHT SNOW SHOWERS. SO WILL ADD DRIZZLE...WITH
SOME FREEZING DRIZZLE FOR PLACES LIKE CKB...EKN...AND BKW FOR SUNDAY
MORNING.
WITH FORECAST SOUNDINGS ON THE RAP AND NAM SHOWING SATURATION AOB
5 THSD FT MSL...KEEP CEILINGS LOWER LONGER. CONFIDENCE REALLY DROPS
FOR VISIBILITY AFTER 15Z. HELD ONTO SOME IFR OVER THE HIGH
MOUNTAINS...WITH SOME MVFR IN THE WESTERN UPSLOPE AREAS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: VSBY MAY IMPROVE FASTER DURING THE DAY ON
SUNDAY AS SURFACE TEMPERATURE AND DEW POINT SPREAD INCREASES.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY H H H H H H H M M M M L
HTS CONSISTENCY M M H H H M M L L L L L
BKW CONSISTENCY H H L L L H H H L M L M
EKN CONSISTENCY H H M H H L M L M M M M
PKB CONSISTENCY H M M M M M M M M M L L
CKB CONSISTENCY H H H M H L L M M M M M
AFTER 00Z MONDAY...
IFR MAY LINGER IN LOW CEILINGS INTO MONDAY...ESPECIALLY ACROSS WEST
VIRGINA MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ/26
NEAR TERM...KTB/26
SHORT TERM...MZ
LONG TERM...JMV
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
645 PM EST SAT DEC 14 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST INTO NEW YORK SUNDAY MORNING. COLDER
AIR IN NORTHWEST FLOW SUNDAY/SUNDAY NIGHT WITH LOW LEVEL MOISTURE
LINGERING. CLIPPER PASSES MONDAY/TUESDAY. NEXT SYSTEM SATURDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
IN THE EARLY EVENING UPDATE THIS SATURDAY...AFTER SURVEYING FORECAST
SOUNDINGS...ADDED SOME DRIZZLE FOR LOWLANDS OVERNIGHT AND SOME
DRIZZLE LATER TONIGHT IN THE MOUNTAINS...WITH SOME FREEZING DRIZZLE
IN THE MOUNTAINS FOR SUNDAY MORNING.
PREVIOUS DISCUSSION
NICE DRY AIR INTRUSION ALOFT NOW PUSHING IN FROM THE SOUTHWEST...AND
EASILY SEEN ON THE ENHANCED WATER VAPOR IMAGERY. THIS WILL PUT A
DAMPER ON THE POPS OVER THE NEXT FEW HOURS AND HAVE REDUCED THEM
ACCORDINGLY. MEANWHILE...OVER SOUTHEAST OHIO...PRECIPITATION HAS
BEEN ALL RAIN FOR SEVERAL HOURS AS TEMPERATURES STRUGGLED TO EVEN
GET TOWARDS FREEZING LAST NIGHT. AS A RESULT...ALL OHIO HEADLINES IN
OUR AREA OF RESPONSIBILITY HAVE BEEN CANCELLED.
LOW PRESSURE MOVES NORTHEAST THIS EVENING AND TONIGHT WHICH WILL
PROVIDE A WIND SWITCH AND COLLAPSING COLD AIR TO DIG IN.
TEMPERATURES WILL FALL BEHIND THE COLD FRONT THROUGH THE TONIGHT
PERIOD. NOT A PREFECT DIURNAL CURVE TO THE TEMPERATURE TRENDS
THROUGH EARLY SUNDAY...AND AS A RESULT...MAX TEMPS FOR SUNDAY COULD
OCCUR EARLY IN THE DAY.
LOOKING AT THE LOW LEVEL MOISTURE AND STREAMLINES...IT WILL TAKE
UNTIL AROUND 09Z SUNDAY UNTIL THE BEST NORTHWEST FLOW INTO THE
MOUNTAINS WILL TAKE HOLD. THIS WILL BE SHORT LIVED AS THE FLOW VEERS
TOWARDS A MORE WESTERLY DIRECTION DURING THE DAY. CARRY WANING POPS
INTO THE EVENING HOURS. MAY NEED TO ADD A BRIEF PERIOD OF FREEZING
DRIZZLE IN THE MORNING HOURS OVER THE NORTHEAST MOUNTAINS AS
MOISTURE DEPTH MAY BECOME TOO SHALLOW TO SUPPORT SNOW WITH NO
SATURATION IN THE CRYSTAL GROWTH LAYER.
TEMPERATURES...AS MENTIONED...WILL FALL THROUGH THE NIGHT...AND WILL
NOT RECOVER MUCH DURING THE DAY SUNDAY. AFTERNOON VALUES MAY ONLY
GET TO FREEZING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPSLOPE SNOW SHOWERS WILL BE IN PLACE ACROSS THE NORTHERN MOUNTAINS
TO START THE SHORT TERM PERIOD. PRETTY GOOD NW FLOW...BUT MOISTURE
BECOMING FAIRLY LIMITED SO ONLY HAVE AN ADDITIONAL INCH OR TWO OF
SNOW ACCUMULATION AT HIGHER ELEVATIONS. A COUPLE 500MB SHORTWAVE
TROUGHS ROTATING AROUND UPPER LEVEL LOW NORTH OF THE GREAT LAKES
WILL BRING ADDITIONAL SNOW SHOWERS...ESPECIALLY ACROSS THE NORTH.
HOWEVER...TIMING AND LOCATION OF THESE SHORTWAVES STILL DIFFER
BETWEEN MODELS...SO WILL ONLY GO WITH SLIGHT CHANCE TO LOW CHANCE
POPS MONDAY. ALSO HAVE A COLD FRONT THAT WILL COME THROUGH
TUESDAY...MODELS KEEP MOST OF THE PRECIP NORTH OF CWA...BUT DID
INCREASE BASED ON A GFS/NAM BLEND. THIS LOOKS LIKE ANOTHER SITUATION
WHERE WAA WILL START MONDAY NIGHT...WITH WARM WEDGE TAKING OVER FOR
THE WV LOWLANDS. SO HAVE PRECIP STARTING AS SNOW EARLY TUESDAY
MORNING...TRANSITIONING TO RAIN ACROSS THE LOWLANDS TUESDAY...AND
SNOW REMAINING AT HIGHER ELEVATIONS.
USED BLEND OF MAV/MET FOR LOWS SUNDAY NIGHT RESULTING IN A FEW
DEGREES COOLER. HAVE NON-DIURNAL TREND MONDAY NIGHT AHEAD OF COLD
FRONT. FOR HIGHS...BLENDED ECE AND MAV.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE ON STRONG AMPLIFICATION OF THE UPPER PATTERN THIS
PERIOD. A STRONG UPPER TROUGH IS FORECAST TO DIG INTO THE WEST
CENTRAL U.S. AND AN UPPER RIDGE WILL BUILD OVER THE EASTERN PART OF
THE NATION. THIS WILL BRING DRY CONDITIONS THE REMAINDER OF THE WEEK
WITH A SIGNIFICANT WARMING TREND TO ABOVE NORMAL TEMPERATURES.
THE MAIN FORECAST PROBLEM WILL BE TIMING OF THE NEXT LOW PRESSURE
SYSTEM THAT EJECTS OUT OF THE WESTERN UPPER TROUGH AND DRIVES A
STRONG COLD FRONT EASTWARD. WPC AND MOST MEDIUM MODEL TRENDS ARE
SLOWER WITH THIS SYSTEM. THE EXCEPTION IS THE FASTER GFS...WHICH HAS
A TYPICAL BIAS OF EJECTING SYSTEMS TOO QUICKLY...ESPECIALLY WITH
SUCH AN AMPLIFIED PATTERN. THUS WE WILL BE GOING WITH THE SLOWER
SOLUTIONS...SO WILL WAIT TILL THE WEEKEND TO BRING IN SHOWERS AS THE
SYSTEM APPROACHES. THE EARLY PART OF THE WEEKEND LOOKS WET...BUT
VERY MILD WITH WELL ABOVE NORMAL TEMPERATURES IN A DEEP SOUTHERLY
FLOW.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THE SOUTHEAST WIND FLOW IS NOW BREAKING DOWN AS LOW CENTER LIFTS
NORTHEAST TOWARD NORTHEASTERN OHIO AT 23Z. THE ASSOCIATED COLD FRONT
AND WIND SHIFT WAS IN EASTERN KENTUCKY NEAR KJKL AT 23Z. HAVE THAT
FRONT REACHING CRW BY AROUND 02Z...THEN PKB TO BKW BY 03Z...THEN
CKB-EKN BY 05Z. CEILINGS IN THE WESTERN LOWLANDS WILL LOWER AS THAT
FRONT APPROACHES.
WITH COLD AIR ADVECTION AND SATURATION LEVELS OF MOISTURE BECOMING
RATHER SHALLOW AFTER 09Z...MAY BE MORE DRIZZLE TRANSITIONING TO
FREEZING DRIZZLE IN THE MOUNTAIN COUNTIES...RATHER THAN LIGHT RAIN
SHOWERS BECOMING LIGHT SNOW SHOWERS. SO WILL ADD DRIZZLE...WITH
SOME FREEZING DRIZZLE FOR PLACES LIKE CKB...EKN...AND BKW FOR SUNDAY
MORNING.
WITH FORECAST SOUNDINGS ON THE RAP AND NAM SHOWING SATURATION AOB
5 THSD FT MSL...KEEP CEILINGS LOWER LONGER. CONFIDENCE REALLY DROPS
FOR VISIBILITY AFTER 15Z. HELD ONTO SOME IFR OVER THE HIGH
MOUNTAINS...WITH SOME MVFR IN THE WESTERN UPSLOPE AREAS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: VSBY MAY IMPROVE FASTER DURING THE DAY ON
SUNDAY AS SURFACE TEMPERATURE AND DEW POINT SPREAD INCREASES.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY H H H H H H H M M M M L
HTS CONSISTENCY M M H H H M M L L L L L
BKW CONSISTENCY H H L L L H H H L M L M
EKN CONSISTENCY H H M H H L M L M M M M
PKB CONSISTENCY H M M M M M M M M M L L
CKB CONSISTENCY H H H M H L L M M M M M
AFTER 00Z MONDAY...
IFR MAY LINGER IN LOW CEILINGS INTO MONDAY...ESPECIALLY ACROSS WEST
VIRGINA MOUNTAIN COUNTIES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 AM EST SUNDAY FOR WVZ046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ/26
NEAR TERM...KTB/26
SHORT TERM...MZ
LONG TERM...JMV
AVIATION...KTB/26
AREA FORECAST DISCUSSION
NWS TULSA OK
1059 PM CST THU DEC 12 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... LIGHT RAIN WILL MOVE INTO THE AREA BY AS EARLY
AS ABOUT 9Z. TEMPERATURES ARE WARMING OVERNIGHT AND ARE NOW ABOVE
FREEZING AT ALL SITES EXCEPT KXNA AND KFSM. THESE SITES WILL WARM
ABOVE FREEZING BY ABOUT THE TIME RAINFALL BEGINS. WILL NOT INCLUDE
FZRA IN ANY TAFS... BUT IT COULD BE A REMOTE POSSIBILITY FOR A
SHORT TIME AFTER RAINFALL BEGINS. CEILINGS AT ALL SITES ARE
EXPECTED TO GRADUALLY FALL TO MVFR LEVELS DURING THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 935 PM CST THU DEC 12 2013/
..UPDATE...
DISCUSSION...
QUIET WEATHER SO FAR ACROSS THE REGION THIS
EVENING...ALTHOUGH RADAR ECHOES ACROSS SW OK
CONTINUE TO ADVANCE SLOWLY ENE. HRRR OUTPUT HAS
BEEN VERY CONSISTENT OVER THE PAST SEVERAL HOURS
BRINGING LIGHT PRECIP INTO ERN TOWARD 06Z...AND
EVENTUALLY INTO NW AR 09-12Z. BASED ON THIS AND
CURRENT TRENDS...HAVE UPPED POPS SOME LATER TONIGHT
AND BROUGHT PRECIP INTO NW AR A BIT QUICKER THAN
PREVIOUSLY THOUGHT.
SURFACE TEMPS ALREADY RUNNING AT OR JUST A BIT
BELOW FREEZING ACROSS FAR ERN OK/NW AR...SO ONSET
OF PRECIP IN THESE AREAS WILL LIKELY BE LIGHT
FREEZING RAIN. TOUGHER CALL ON PRECIP TYPE TOWARD
12Z-15Z AS SOUTH WINDS CONTINUE TO INCREASE ALONG
WITH SLOWLY RISING SFC TEMPS.
UPDATE PRODUCTS WILL BE OUT SHORTLY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
709 PM EST SAT DEC 14 2013
.SYNOPSIS...
A RELATIVELY COMPLEX LOW PRESSURE SYSTEM WITH ENERGY TRANSFERRING
FROM THE OHIO VALLEY TO THE MID-ATLANTIC COAST WILL CONTINUE TO
BRING WIDESPREAD HEAVY SNOW AND MIXED PRECIPITATION TO THE REGION
THROUGH TONIGHT. WINTER STORM WARNINGS REMAIN IN EFFECT FOR ALL OF
CENTRAL PENNSYLVANIA UNTIL 4 AM SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MODERATE TO HEAVY SNOW CONTINUES THIS EVENING ACROSS MUCH OF THE
AREA...WITH SNOWFALL RATES OF 1 TO LOCALLY 2 INCHES PER HOUR BEING
REPORTED BY SEVERAL SPOTTERS AND OBSERVERS. THE LATEST SNOWFALL
REPORTS HAVE BEEN ISSUED VIA A PUBLIC INFORMATION STATEMENT /PNS/.
WE WILL CONTINUE TO UPDATE THIS AS NEW REPORTS FLOW INTO THE
OFFICE.
REGIONAL RADAR IMAGERY ALONG WITH THE MESO MODEL DATA SHOWS THE
MOST INTENSE SNOWS OVER THE NEXT FEW HOURS SHIFTING INTO THE
N-CNTRL AND NERN ZONES. DRY SLOT VIA WV LOOP PUNCHING INTO SWRN PA
GIVING THE RETURNS A MORE CONVECTIVE APPEARANCE. RUC 925/850MB WET
BULBS SHOW THE CLASSIC WEDGE OF COLD AIR BANKED E OF THE ALLEGHENY
FRONT...AS WARM/ABV FREEZING AIR ALOFT SLOWLY MAKES PROGRESS INTO
THE LAUREL HIGHLANDS AND FAR S-CNTRL/SERN PA. RECENT SPOTTER
REPORTS INDICATE A TRANSITION TO SLEET ALONG/SOUTH OF THE PA
TURNPIKE. ONCE THE TRANSITION OCCURS...THE ACCUMULATING SNOW WILL
ESSENTIALLY BE OVER WITH MIXED PCPN GOING FWD INTO TONIGHT.
THE COMPLEX LOW PRESSURE SYSTEM IS IN THE PROCESS OF SHIFTING ITS
ENERGY TO THE MID-ATLC COAST WITH THE STRONGEST 3HR SFC PRES FALLS
NEAR THE SRN DELMARVA. WILL NEED TO MONITOR THE EXTENT OF THE PCPN
SHIELD ON NW SIDE OF THE DEVELOPING COASTAL LOW FOR POSSIBLE MESO
BANDING IMPACTING PORTIONS OF ERN PA.
THE LATEST CONSENSUS SHORT-RANGE GUIDANCE SHOWS WINTRY PCPN
STARTING TO TAPER OFF ACRS MUCH OF SWRN PA BTWN 00-02Z. IN GENERAL
TREND SEEMS TO BE FOR THINGS TO WIND DOWN A LITTLE SOONER THAN
CURRENTLY FCST AND WILL WORK ON THIS IN FUTURE UPDATES. AS IS
TYPICALLY THE CASE DURING THE TAIL-END OF WINTER STORM
EVENTS...WE SHOULD LOSE THE ICE INTRODUCTION ALOFT AND SEE A
PERIOD OF -FZDZ OR "SNIZZLE" AS THE DRY SLOT OVERSPREADS THE CWA
THRU 06Z.
OVERALL MADE ONLY MINOR CHANGES TO THE GRIDS AND UPDATED/SEGMENTED
THE WSW TO HIGHLIGHT CORRIDORS OF EXPECTED STORM TOTAL SNOWFALL.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE WIND
GETS PRETTY GUSTY OUT OF THE WEST ON SUNDAY AND WILL MAKE IT VERY
BLUSTERY WITH THE NEW SNOW BLOWING AROUND AND TEMPS ONLY IN THE
MID 20S N AND LOW/MID 30S S. LAKE EFFECT AND UPSLOPE SNOW SHOWERS
ARE LIKELY IN THE NW AND WRN MTNS. ADDITIONAL ACCUMS WILL PROBABLY
BE LESS THAN ADVY LEVELS THOUGH. TEMPS WON/T RISE MORE THAN A DEG
OR TWO IN THE WEST AND ONLY 5-6F IN THE EAST ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
IN THE WAKE OF THE EARLY WEEKEND STORM...A MEAN UPPER LEVEL TROF
WILL REMAIN OVER THE EASTERN THIRD OF COUNTRY. SEVERAL SHORTWAVES
ARE FORECAST TO MOVE THROUGH THE FAST WEST NORTHWESTERLY FLOW. THE
FIRST IS FORECAST TO MOVE ACROSS THE REGION SUNDAY AFTERNOON
BRINGING ANOTHER SHOT OF SNOW SHOWERS MAINLY TO THE NORTHERN TIER.
ANOTHER WILL BRING A FRONT ON TUESDAY...WITH LIMITED MOISTURE.
HAVE INCREASED POPS ACCORDINGLY...HOWEVER DUE TO THE LIMITED
MOISTURE HAVE ONLY LIGHT ACCUMULATIONS. TEMPERATURES THROUGH THE
MIDDLE OF THE WEEK WILL REMAIN COLD...AS 850MB TEMPS -10C OR
BELOW. SO LOOK FOR DAYTIME HIGHS TO BE BELOW NORMAL THROUGH MUCH
OF THE PERIOD. GUIDANCE SUGGESTS THAT BY LATE IN THE WEEK ENERGY
WILL DIVE INTO THE ROCKIES IN TURN PUMPING UP HEIGHTS OVER THE
EAST. BRINGING A POSSIBLE WARM UP TO THE REGION LATE NEXT WEEK.
THIS SHOULD ALLOW FOR HIGHS FOR FRIDAY IN THE 40S ACROSS PA.
MOISTURE OUT AHEAD OF THE FRONT COULD ALLOW FOR RAIN
SHOWERS...WITH COLD AIR BEHIND...SO MIXED PRECIPITATION AT AND
BEHIND THE FRONT REMAINS A POSSIBILITY. THE MODELS VARY IN TIMING
BUT ALL AGREE THAT NEXT WEEKEND SHOULD SEE A DEEP TROUGH MOVE
THROUGH THE MID WEST AND INTO THE EAST COAST. THIS WILL END THE
BRIEF WARM UP AND SEE THE RETURN OF COLD AIR.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
BAND OF HEAVIEST SNOW...WITH VISIBILITIES OF 1/2 TO 1/4 MILE...IS
NOW LIFTING ACROSS THE NORTHERN THIRD OF PENNSYLVANIA. PRECIPITATION
MIX HAS REACHED INTO KJST AND APPROACHING KAOO...WITH /UP/ BEING
REPORTED INTERMITTENTLY AT KJST. IN THE SOUTHEAST...REPORTS OF A
CHANGEOVER NOW OCCURRING IN SOUTHERN LANCASTER...YORK AND FRANKLIN
COUNTIES...MIGRATING NORTHWARD.
MODELS CONTINUE TO SUPPORT CHANGEOVER LINE MIGRATING NORTH TO
ABOUT A KAOO TO KMDT LINE THROUGH ABOUT 06Z...THEN BEGINNING TO
SHIFT BACK TO THE SOUTH AND EAST 07Z-09Z AS COASTAL LOW TAKES
OVER.
STRONG SOUTHEAST LLJ NOW IN PLACE...AND HAVE KEPT A PERIOD OF
LLWS IN THE TAFS FOR THE EVENING PERIOD.
OUTLOOK...
SUN...GUSTY WNW WINDS. AM LOW CIGS POSS W MTNS. PM SHSN/REDUCED
VSBYS POSS W MTNS.
MON...LGT SNOW/REDUCED VSBYS POSS MON NITE NW MTNS.
TUE...AM LOW CIGS/LGT SNOW POSS NW MTNS.
WED...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 AM EST SUNDAY FOR PAZ004>006-
010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
652 PM EST SAT DEC 14 2013
.SYNOPSIS...
A RELATIVELY COMPLEX LOW PRESSURE SYSTEM WITH ENERGY TRANSFERRING
FROM THE OHIO VALLEY TO THE MID-ATLANTIC COAST WILL CONTINUE TO
BRING WIDESPREAD HEAVY SNOW AND MIXED PRECIPITATION TO THE REGION
THROUGH TONIGHT. WINTER STORM WARNINGS REMAIN IN EFFECT FOR ALL OF
CENTRAL PENNSYLVANIA UNTIL 4 AM SUNDAY.
&&
.NEAR TERM /UNTIL 4 AM SUNDAY MORNING/...
MODERATE TO HEAVY SNOW CONTINUES THIS EVENING ACROSS MUCH OF THE
AREA...WITH SNOWFALL RATES OF 1 TO LOCALLY 2 INCHES PER HOUR BEING
REPORTED BY SEVERAL SPOTTERS AND OBSERVERS. THE LATEST SNOWFALL
REPORTS HAVE BEEN ISSUED VIA A PUBLIC INFORMATION STATEMENT /PNS/.
WE WILL CONTINUE TO UPDATE THIS AS NEW REPORTS FLOW INTO THE
OFFICE.
REGIONAL RADAR IMAGERY ALONG WITH THE MESO MODEL DATA SHOWS THE
MOST INTENSE SNOWS OVER THE NEXT FEW HOURS SHIFTING INTO THE
N-CNTRL AND NERN ZONES. DRY SLOT VIA WV LOOP PUNCHING INTO SWRN PA
GIVING THE RETURNS A MORE CONVECTIVE APPEARANCE. RUC 925/850MB WET
BULBS SHOW THE CLASSIC WEDGE OF COLD AIR BANKED E OF THE ALLEGHENY
FRONT...AS WARM/ABV FREEZING AIR ALOFT SLOWLY MAKES PROGRESS INTO
THE LAUREL HIGHLANDS AND FAR S-CNTRL/SERN PA. RECENT SPOTTER
REPORTS INDICATE A TRANSITION TO SLEET ALONG/SOUTH OF THE PA
TURNPIKE. ONCE THE TRANSITION OCCURS...THE ACCUMULATING SNOW WILL
ESSENTIALLY BE OVER WITH MIXED PCPN GOING FWD INTO TONIGHT.
THE COMPLEX LOW PRESSURE SYSTEM IS IN THE PROCESS OF SHIFTING ITS
ENERGY TO THE MID-ATLC COAST WITH THE STRONGEST 3HR SFC PRES FALLS
NEAR THE SRN DELMARVA. WILL NEED TO MONITOR THE EXTENT OF THE PCPN
SHIELD ON NW SIDE OF THE DEVELOPING COASTAL LOW FOR POSSIBLE MESO
BANDING IMPACTING PORTIONS OF ERN PA.
THE LATEST CONSENSUS SHORT-RANGE GUIDANCE SHOWS WINTRY PCPN
STARTING TO TAPER OFF ACRS MUCH OF SWRN PA BTWN 00-02Z. IN GENERAL
TREND SEEMS TO BE FOR THINGS TO WIND DOWN A LITTLE SOONER THAN
CURRENTLY FCST AND WILL WORK ON THIS IN FUTURE UPDATES. AS IS
TYPICALLY THE CASE DURING THE TAIL-END OF WINTER STORM
EVENTS...WE SHOULD LOSE THE ICE INTRODUCTION ALOFT AND SEE A
PERIOD OF -FZDZ OR "SNIZZLE" AS THE DRY SLOT OVERSPREADS THE CWA
THRU 06Z.
OVERALL MADE ONLY MINOR CHANGES TO THE GRIDS AND UPDATED/SEGMENTED
THE WSW TO HIGHLIGHT CORRIDORS OF EXPECTED STORM TOTAL SNOWFALL.
&&
.SHORT TERM /4 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... THE WIND
GETS PRETTY GUSTY OUT OF THE WEST ON SUNDAY AND WILL MAKE IT VERY
BLUSTERY WITH THE NEW SNOW BLOWING AROUND AND TEMPS ONLY IN THE
MID 20S N AND LOW/MID 30S S. LAKE EFFECT AND UPSLOPE SNOW SHOWERS
ARE LIKELY IN THE NW AND WRN MTNS. ADDITIONAL ACCUMS WILL PROBABLY
BE LESS THAN ADVY LEVELS THOUGH. TEMPS WON/T RISE MORE THAN A DEG
OR TWO IN THE WEST AND ONLY 5-6F IN THE EAST ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
IN THE WAKE OF THE EARLY WEEKEND STORM...A MEAN UPPER LEVEL TROF
WILL REMAIN OVER THE EASTERN THIRD OF COUNTRY. SEVERAL SHORTWAVES
ARE FORECAST TO MOVE THROUGH THE FAST WEST NORTHWESTERLY FLOW. THE
FIRST IS FORECAST TO MOVE ACROSS THE REGION SUNDAY AFTERNOON
BRINGING ANOTHER SHOT OF SNOW SHOWERS MAINLY TO THE NORTHERN TIER.
ANOTHER WILL BRING A FRONT ON TUESDAY...WITH LIMITED MOISTURE.
HAVE INCREASED POPS ACCORDINGLY...HOWEVER DUE TO THE LIMITED
MOISTURE HAVE ONLY LIGHT ACCUMULATIONS. TEMPERATURES THROUGH THE
MIDDLE OF THE WEEK WILL REMAIN COLD...AS 850MB TEMPS -10C OR
BELOW. SO LOOK FOR DAYTIME HIGHS TO BE BELOW NORMAL THROUGH MUCH
OF THE PERIOD. GUIDANCE SUGGESTS THAT BY LATE IN THE WEEK ENERGY
WILL DIVE INTO THE ROCKIES IN TURN PUMPING UP HEIGHTS OVER THE
EAST. BRINGING A POSSIBLE WARM UP TO THE REGION LATE NEXT WEEK.
THIS SHOULD ALLOW FOR HIGHS FOR FRIDAY IN THE 40S ACROSS PA.
MOISTURE OUT AHEAD OF THE FRONT COULD ALLOW FOR RAIN
SHOWERS...WITH COLD AIR BEHIND...SO MIXED PRECIPITATION AT AND
BEHIND THE FRONT REMAINS A POSSIBILITY. THE MODELS VARY IN TIMING
BUT ALL AGREE THAT NEXT WEEKEND SHOULD SEE A DEEP TROUGH MOVE
THROUGH THE MID WEST AND INTO THE EAST COAST. THIS WILL END THE
BRIEF WARM UP AND SEE THE RETURN OF COLD AIR.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
VSBYS AND CIGS WILL VARY BETWEEN IFR AND VLIFR INTO THE EVENING AS
A MODERATE TO HEAVY AREA OF SNOW ROTATES NORTHWARD ACROSS THE
REGION.
MODELS CONTINUE TO SUPPORT A CHANGE TO SOME FZRA/FZDZ IN
SOUTHWESTERN AND SOUTHEASTERN AREAS AS PRECIPITATION TAPERS OFF
TONIGHT. APPEARS THAT MID/LOW LEVEL WARM AIR INTRUSION MAKES IT
TO KJST DURING THE NEXT SEVERAL HOURS...AND AFTER 02Z IN THE
SOUTHEASTERN AIRFIELDS OF KLNS AND KMDT. THE NORTHWARD PUSH OF
WARM AIR ABRUPTLY ENDS AROUND 07Z-09Z AS COASTAL LOW TAKES OVER.
STRONG LLJ NOW IN PLACE...AND HAVE KEPT THE IDEA OF A PERIOD OF
LLWS IN THE TAFS FOR THE EVENING PERIOD.
OUTLOOK...
SUN...GUSTY WNW WINDS. AM LOW CIGS POSS W MTNS. PM SHSN/REDUCED
VSBYS POSS W MTNS.
MON...LGT SNOW/REDUCED VSBYS POSS MON NITE NW MTNS.
TUE...AM LOW CIGS/LGT SNOW POSS NW MTNS.
WED...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 AM EST SUNDAY FOR PAZ004>006-
010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...JUNG/LAMBERT
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1200 AM CST FRI DEC 13 2013
.AVIATION...
CIGS WILL BE SLIGHTLY LOWER THAN EARLIER FORECASTED DURING PARTS
OF THE 13/06Z TAF PERIOD. VFR CIGS BKN-0VC035-050 WILL SPREAD
ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS IN THE NEXT COUPLE OF
HOURS. MVFR CIGS/VSBYS AND ISOLD SHRA WILL DEVELOP OVER THE HILL
COUNTRY DURING THE OVERNIGHT HOURS AND SPREAD ACROSS THE REMAINDER
OF SOUTH CENTRAL TEXAS FRIDAY MORNING. SHRA WILL BECOME A LITTLE
MORE NUMEROUS EAST OF A KJCT TO KHDO TO KPEZ LINE ON FRIDAY AS AN
UPPER LEVEL TROUGH MOVES ACROSS TEXAS. HAVE MAINTAINED PROB30S FOR
THE I-35 TAF SITES FROM MID MORNING TO MID AFTERNOON. THE TROUGH
ALONG WITH THE SHOWERS AND CLOUDS MOVES OFF TO THE EAST FRIDAY
EVENING LEADING TO VFR SKIES OUT WEST IN LATE AFTERNOON AND IN
THE EAST DURING THE EVENING. S TO SE WINDS 4 TO 10 KTS WILL BECOME
SW FRIDAY EVENING AND W FRIDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 600 PM CST THU DEC 12 2013/
AVIATION...
VFR SKIES WILL PREVAIL THROUGH THE 13/00Z TAF PERIOD. CIGS AT
BKN-OVC035-050 DEVELOPING ACROSS THE AREA THIS EVENING WITH ISOLD
SHRA DEVELOPING MAINLY OVER THE HILL COUNTRY OVERNIGHT N-NW OF TAF
SITES AS AN UPPER LEVEL TROUGH APPROACHES. ISOLD TO SCT SHRA CAN
BE EXPECTED FRIDAY AS THE UPPER LEVEL TROUGH MOVES ACROSS THE AREA
WITH TEMPO MVFR CIGS/VSBYS. WILL MAINTAIN MENTION AT THE I-35 TAF
SITES. UPPER LEVEL TROUGH MOVES EAST LEADING TO CLEARING SKIES
FRIDAY AFTERNOON WEST AND EVENING EAST. WINDS WILL BECOME S-SE AT
4 TO 8 KTS AT TAF SITES TONIGHT...THEN TURN TO SW FRIDAY EVENING.
PREV DISCUSSION... /ISSUED 300 PM CST THU DEC 12 2013/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
MID TO UPPER LEVEL CLOUDS ARE COVERING ALL OF SOUTH CENTRAL TEXAS
THIS AFTERNOON AS SOUTHWEST FLOW ALOFT PUSHES MOISTURE ACROSS THE
AREA. THESE CLOUDS WILL LINGER AROUND THROUGH FRIDAY AS AN UPPER
LEVEL TROUGH TRAVELS FROM THE DESERT SOUTHWEST INTO THE SOUTHERN
PLAINS. AT LOWER LEVELS...VISIBLE SATELLITE IMAGES ARE DEPICTING
BROKEN TO OVERCAST SKIES PUSHING TO THE NORTH-NORTHEAST ACROSS THE RIO
GRANDE VALLEY WHILE SPREADING NORTHEASTWARD TOWARD THE SAN ANTONIO
AREA. LATEST RUC SOLUTION HAS THIS LOW LEVEL CLOUD DECK SPREADING
ACROSS MOST AREAS OF SOUTH CENTRAL TEXAS BY MIDNIGHT. OVERNIGHT
LOWS WILL RANGE FROM THE MID TO UPPER 30S HILL COUNTRY TO LOWER
40S REST OF THE AREA. LATE TONIGHT INTO FRIDAY...CHANCES OF RAIN
WILL BE INCREASING AS THE UPPER LEVEL TROUGH ABOVE MENTIONED NEARS
THE SOUTHERN PLAINS. EXPECT SHOWERS TO AFFECT THE NORTHWEST AND
NORTHERN SECTIONS OF SOUTH CENTRAL TEXAS OVERNIGHT WITH SHOWERS
SPREADING EASTWARD ON FRIDAY. RAIN CHANCES WILL COME TO AN END
LATE FRIDAY AS THE UPPER TROUGH PUSHES TO THE EAST. RAINFALL
AMOUNTS WILL GENERALLY BE FROM A FEW HUNDREDTHS TO ONE QUARTER
INCH...ESPECIALLY ACROSS THE NORTHEAST PART OF THE HILL COUNTRY.
LONG TERM (SATURDAY THROUGH THURSDAY)...
A DRY COLD FRONT IS EXPECTED TO PUSH ACROSS SOUTH CENTRAL TEXAS
ON SATURDAY WITH SKIES CLEARING FROM WEST TO EAST BY THE AFTERNOON.
MODERATE NORTHWESTERLY WINDS ARE EXPECTED IN THE WAKE OF THE FRONT
WITH WIND SPEEDS DECREASING LATE SATURDAY INTO SUNDAY. SEVERAL
COOL NIGHTS ARE EXPECTED IN THE WAKE OF THE FRONTAL PASSAGE WITH
OVERNIGHT LOWS IN THE LOWER 30S OVER THE HILL COUNTRY AND MID 30S
REST OF THE AREA ON SUNDAY WITH SIMILAR LOWS MONDAY MORNING.
A NORTHWEST TO ZONAL FLOW ALOFT IS ANTICIPATED FOR MUCH OF NEXT
WEEK WITH DRY AND WARMING WEATHER CONDITIONS IN STORE THROUGH
THURSDAY OF NEXT WEEK. LATEST GFS AND ECMWF SOLUTIONS CONTINUE TO
SHOW ANOTHER ARCTIC AIRMASS ARRIVING TO THE LOCAL AREA BETWEEN
SATURDAY AND SUNDAY...DECEMBER 21 AND 22.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 56 44 55 33 / 10 40 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 37 58 42 56 32 / 10 40 20 10 -
NEW BRAUNFELS MUNI AIRPORT 40 58 44 57 33 / 10 30 20 10 -
BURNET MUNI AIRPORT 37 56 40 52 30 / 20 40 10 - -
DEL RIO INTL AIRPORT 40 63 41 60 34 / 10 10 - 0 -
GEORGETOWN MUNI AIRPORT 37 56 42 52 31 / 20 40 20 10 -
HONDO MUNI AIRPORT 40 60 43 61 32 / 10 30 10 - -
SAN MARCOS MUNI AIRPORT 39 59 44 57 33 / 10 40 20 10 -
LA GRANGE - FAYETTE REGIONAL 41 60 47 57 33 / 10 40 30 10 -
SAN ANTONIO INTL AIRPORT 41 58 45 59 34 / 10 30 20 - -
STINSON MUNI AIRPORT 43 60 46 61 35 / 10 30 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
205 PM CST FRI DEC 13 2013
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 205 PM CST FRI DEC 13 2013
WATER VAPOR LOOP/LATEST RUC 500MB ANALYSIS SHOWS A BROAD LONG WAVE
TROUGH ENCOMPASSING THE ENTIRE CONUS. WITHIN THIS LONG WAVE TROUGH
THERE ARE TWO MID-LEVEL SHORTWAVE TROUGHS THAT WILL EVENTUALLY
IMPACT THE AREA TONIGHT THROUGH SATURDAY EVENING. TROUGH NUMBER ONE
WAS MOVING EAST OUT OF MT/WY TOWARD THE NORTHERN PLAINS WHILE A MORE
POTENT TROUGH NUMBER TWO WAS MOVING EAST OUT OF CO/NM INTO THE
SOUTHERN PLAINS. AT THE SURFACE...THIS TRANSLATED TO AN AREA OF
CYCLOGENESIS OVER WESTERN KS WITH A WARM FRONT EXTENDING ALONG THE
IA/MO BORDER INTO CENTRAL IL. CURRENTLY...OUR LOCAL FORECAST AREA
WAS IN BETWEEN THE INFLUENCES OF THE SOUTHERN PLAINS LOW AND HIGH
PRESSURE OVER SOUTHERN MANITOBA CANADA WITH EAST WINDS AND MOSTLY
CLOUDY CONDITIONS RESULTING. TEMPERATURES THIS AFTERNOON RANGED FROM
THE TEENS ACROSS NORTH CENTRAL WI...TO THE LOWER AND MIDDLE 20S
ELSEWHERE.
WILL BE WATCHING THE SOUTHERN PLAINS AND NORTHERN PLAINS TROUGHS
CONVERGE ON THE AREA LATE TONIGHT INTO SATURDAY. NOT PARTICULARLY
STRONG DYNAMICS ASSOCIATED WITH THESE WAVES. HOWEVER...THE AREA WILL
BE IN LONG-LIVED RIGHT ENTRANCE REGION OF 300MB JET WHILE THERE IS
SOME WEAK ISENTROPIC UPGLIDE NOTED ON THE NAM 275K SURFACE.
ALSO...THERE IS A DECENT PASSING LOBE OF 700-300 PV-ADVECTION FROM
ABOUT 12Z-18Z SATURDAY. ALL THIS IS EXPECTED TO COME TOGETHER TO
PRODUCE A FAIRLY WIDESPREAD AREA OF LIGHT SNOW WITH THE PEAK
CENTERED FROM ABOUT 09Z-15Z...THEN TAPERING OFF IN THE
AFTERNOON/SATURDAY EVENING AS THE TROUGH AXIS PASSES AND SUBSIDENCE
TAKES OVER. SOME VERY LIGHT SNOW/FLURRIES WILL BE POSSIBLE THROUGH
MIDNIGHT SATURDAY NIGHT BEFORE FULL SUBSIDENCE KICKS IN...DRYING
THINGS OUT. APPEARS AT THIS TIME THERE IS THE POTENTIAL FOR 1/2 UP
TO 2 INCHES OF SNOWFALL OUT OF THIS FROM TONIGHT THROUGH SATURDAY
EVENING. TEMPERATURE-WISE... LOOK FOR LOWS TONIGHT IN THE SINGLE
DIGITS AND TEENS...HIGHS ON SATURDAY IN THE UPPER TEENS TO MIDDLE
20S...AND LOWS SATURDAY NIGHT DROPPING INTO THE SINGLE DIGITS ABOVE
AND BELOW ZERO.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 205 PM CST FRI DEC 13 2013
SUNDAY LOOKS DRY AT THIS TIME BUT CLOUDS WILL BE THICKENING ONCE
AGAIN IN ADVANCE OF THE NEXT MID-LEVEL SHORTWAVE TO IMPACT THE AREA.
FOR SUNDAY NIGHT INTO MONDAY...WARM AIR ADVECTION WING OF THIS WAVE
MOVES IN WITH A GOOD CHANCE FOR LIGHT SNOW TO OVERSPREAD THE AREA.
WILL HAVE TO WATCH CLOSELY AS MODEL BUFKIT SOUNDINGS HINT AT THE
POTENTIAL FOR SOME LOSS OF ICE IN THE COLUMN. THIS COULD LEAD TO
SOME FREEZING DRIZZLE ISSUES. KEPT PRECIPITATION AS ALL SNOW FOR NOW
AFTER COORDINATION/COLLABORATION WITH OTHER OFFICES...BUT WILL
REMAIN LEARY AND KEEP A CLOSE EYE ON LATER MODEL RUNS FOR FREEZING
DRIZZLE POTENTIAL. OTHERWISE...SNOWFALL LOOKS TO BE VERY LIGHT WITH
LESS THAN AN INCH EXPECTED.
TUESDAY THROUGH WEDNESDAY LOOK TO BE DRY FOR NOW AS NORTHWEST FLOW
ALOFT PERSISTS ACROSS THE EASTERN HALF OF THE CONUS.
ECMWF/GFS COMING INTO BETTER AGREEMENT WITH THE LOW PRESSURE SYSTEM
AFFECTING THE AREA ON THURSDAY. APPEARS THERE WILL BE ENOUGH WARM
AIR DRAWN IN WITH THIS SYSTEM TO PRODUCE A RAIN/SNOW MIX FOR
PORTIONS OF THE AREA AS TEMPERATURES WARM INTO THE LOWER/MIDDLE 30S
ALONG AND SOUTH OF I-90. LOOK FOR THE PRECIPITATION TO SWITCH BACK
TO ALL SNOW AS COLD AIR SWEEPS IN BEHIND THE DEPARTING LOW THURSDAY
NIGHT.
THERE WILL BE A LINGERING CHANCE FOR LIGHT SNOW ON FRIDAY AS A
POTENT/COLD MID-LEVEL TROUGH MOVES TOWARD THE UPPER MISSISSIPPI
RIVER FROM THE NORTHERN PLAINS. OTHERWISE...MUCH COLDER TEMPERATURES
LOOK TO INVADE THE AREA WITH HIGHS DROPPING BACK INTO THE TEENS/20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1222 PM CST FRI DEC 13 2013
LOWER CONFIDENCE TAF FORECAST THIS PERIOD. BIG PICTURE BELIEF IS
THAT THERE WILL BE SOME SNOW AT THE TAF SITES FOR A PERIOD OF TIME
FROM 06-18Z...BUT THE QUESTION REMAINS OF HOW LOW THE CIGS/VSBYS
WILL GET WITH THIS SYSTEM MOVING THROUGH.
CURRENTLY AN MVFR CLOUD DECK RESIDES JUST NORTH OF THE TAF SITES AND
THIS IS SLOWLY MOVING SOUTHWEST TOWARD THE AIRFIELDS AND WILL ARRIVE
AS THE AFTERNOON PROGRESSES. THIS IS A STABLE CLOUD FIELD AND LOWER
CONDITIONS THAN MVFR ARE NOT EXPECTED. AT 18Z...THE LEADING EDGE TO
THE CLOUDS WERE ALONG A KCMY-KONA-KSYN LINE.
TWO SYSTEMS WILL AFFECT THE AREA OVERNIGHT AND SATURDAY...ONE COMING
FROM THE NW AND ANOTHER MOVING BY TO THE SOUTH. THE NW SYSTEM SHOULD
BRING SOME LIGHT SNOW INTO THE TAFS BY LATE TONIGHT HOWEVER THE LOW-
LEVEL LIFT IS SOMEWHAT WEAK...WHILE THE MID-UPPER LEVELS ARE A BIT
MORE FAVORABLE. WHILE THE MVFR CLOUD DECK WILL BE IN PLACE...JUST
HOW MUCH SATURATION AND LIFT WILL OCCUR DETERMINES THE VSBY
REDUCTION IN THE TAFS. HAVE PROVIDED A MORE CONSERVATIVE TAF WITH
IFR VSBYS FOR NOW. HOWEVER...CUSTOMERS SHOULD MONITOR LATER
FORECASTS IF FLYING SATURDAY MORNING. IMPROVING TRENDS ARE EXPECTED
FOR SATURDAY AFTERNOON AS THE SYSTEMS SHIFT EAST OF THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....BAUMGARDT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
315 AM EST SUN DEC 15 2013
.DISCUSSION...
...SHOWERS AND ISOLATED LIGHTNING STORMS TODAY BEFORE A COLD FRONT
MOVES THROUGH THE AREA BRINGING COOLER AIR TO START THE WEEK...
TODAY...SFC LOW PRESSURE WILL MOVE NE UP THE EASTERN SEABOARD TODAY
AND PULL A COLD FRONT THROUGH THE AREA THIS AFTERNOON. PRE-FRONTAL
CONVECTIVE BAND WILL MOVE ACROSS THE NRN FORECAST AREA THIS MORNING
WITH ADDITIONAL SHOWERS AND ISOLATED LIGHTNING STORMS AHEAD OF THE
FRONT ACROSS SRN AREAS INTO LATE AFTERNOON. MAIN LIGHTNING STORM
HAZARDS WILL BE GUSTY WINDS TO 45 MPH...LOCALLY HEAVY RAIN AND
OCCASIONAL CLOUD TO GROUND LIGHTNING STRIKES. HRRR MODEL INDICATES
CONVECTIVE LINE ACROSS FAR NRN SECTIONS WILL WEAKEN AS IT PUSHES
SOUTH TOWARD ORLANDO THROUGH MID MORNING AND APPEARS ADDITIONAL
STORMS CURRENTLY OVER THE LOOP CURRENT AND APPROACHING THE SW FL
COAST WILL AFFECT SRN AREAS THIS AFTERNOON BEFORE THE COLD FRONT
MOVES SOUTH OF THE AREA. S-SW WINDS WILL BECOME NW BEHIND THE FRONT
THIS AFTERNOON. HIGHS WILL BE IN THE LOWER 70S FAR NORTH TO THE
LOWER 80S FROM VERO BEACH SOUTH.
TONIGHT...FRONT WILL MOVE TOWARD THE BAHAMAS AND S FL DURING THE
EARLY EVENING SOME MID AND HIGH CLOUDINESS WILL LINGER BEHIND THE
SFC BOUNDARY WITH CLEARING LATE. THINK MOST OF THE SHOWER ACTIVITY
WILL HAVE MOVED OFF INTO THE ATLC BY EARLY EVENING. NW-N WINDS WILL
USHER IN COOLER AIR. LOWS WILL BE IN THE 40S NW OF I-4 CORRIDOR TO
THE LOWER 50S AT MELBOURNE AND VERO BEACH AND AROUND 60 ALONG THE
MARTIN COUNTY COAST.
MON-MON NIGHT...THE COLD FRONT CLEARS SOUTH FLORIDA DURING THE DAY.
HIGH PRESSURE BUILDING EASTWARD ALONG THE NORTHERN GULF COAST WILL
KEEP WINDS OUT OF THE NORTH/NORTHEAST DURING THE DAY MONDAY. THIS
WILL CONTINUE TO TRANSPORT DRIER AND COOLER AIR OVER THE AREA. HIGHS
WILL BE SEVERAL DEGREES BELOW NORMAL EVEN UNDER SUNNY
SKIES...RANGING FROM THE MID TO UPPER 60S NORTH OF MELBOURNE TO
AROUND 70/LOW 70S FARTHER SOUTH. LIGHTER WINDS MONDAY NIGHT AND
CLEAR SKIES WILL GENERATE FAVORABLE RADIATIONAL COOLING CONDITIONS
WITH TEMPS DROPPING TO VALUES NEAR TO PERHAPS EVEN A FEW DEGREES
LOWER THAN EARLY MONDAY MORNING.
TUE-FRI...HIGH PRESSURE OVER THE NRN GULF COAST WILL EXTEND OVER THE
SOUTHEAST U.S. AND EVENTUALLY OFFSHORE LATE IN THE WEEK. AS THE
CENTER OF THE HIGH PRESSURE SYSTEM TRACKS EASTWARD WINDS WILL
INITIALLY BE OUT OF THE NORTH TO NORTHEAST THROUGH MID WEEK THEN
SHIFT TO ONSHORE LATE IN THE WEEK. COOLER MORNING TEMPERATURES EARLY
TUESDAY WILL BEGIN A SLOW MODIFICATION AND WARMING TREND THROUGH THE
REST OF THE WEEK AS THE WINDS BECOME MORE ONSHORE. LOWS MODERATING
IN THE 50S THURSDAY MORNING AND THE MID 50S TO LOW 60S MELBOURNE
COCOA BEACH SOUTH BY FRIDAY SUNRISE.
&&
.AVIATION...MVFR CIGS FROM 015-025 WILL ENCROACH ON NRN TERMINALS
THROUGH THE MID MORNING WITH SHRA AND PSBL ISOLD TSRA EXPECTED NORTH
OF KISM-KTIX LINE TROUGH 15Z. ADDITIONAL SHRA/ISOLD TSRA WILL MOVE E
ACROSS SRN PORTIONS OF E CENTRAL FL LIKELY AFFECT TERMINALS FROM
KMLB-KSUA BY MID DAY INTO THE AFTERNOON. WINDS WILL BECOME NW THIS
AFTERNOON BEHIND THE FRONT WITH VFR MID LVL CIGS INTO THIS EVENING.
&&
.MARINE...SW WINDS TO 20 KNOTS OFFSHORE THIS MORNING WILL BECOME NW
THIS AFTERNOON AS A SFC COLD FRONT MOVES DOWN ACROSS THE WATERS.
WILL EXTEND THE ADVISORY FOR THE OFFSHORE WATERS INTO EARLY
AFTERNOON. NNW/N WINDS TONIGHT TO 15-20 KNOTS OFFSHORE WILL LIKELY
REQUIRE SCEC OR SCA HEADLINES FOR THE GULF STREAM AND OFFSHORE
WATERS. MON-THU...NORTHERLY WINDS UP TO 15 TO 20 KNOTS BEHIND THE
FRONT WILL PRODUCE POOR TO HAZARDOUS BOATING CONDITIONS MONDAY WITH
SEAS UP TO 7 FEET IN THE GULF STREAM. NORTHERLY WINDS WILL THEN
DECREASE AND VEER TO THE NORTH/NORTHEAST TUE/WED BEFORE BECOMING
ONSHORE AND INCREASING ONCE AGAIN LATE IN THE WEEK.
&&
.FIRE WEATHER...TODAY...SW WINDS WILL SWITCH TO THE NW THIS
AFTERNOON AS A COLD FRONT MOVES THROUGH THE AREA. SCATTERED SHOWERS
AND ISOLATED LIGHTNING STORMS EXPECTED INTO THIS AFTERNOON BEFORE
THE FRONT CLEARS THE AREA BY EARLY EVENING. MON...DRIER AIRMASS WILL
BUILD INTO THE AREA BEHIND THE COLD FRONT INTO EARLY THIS WEEK. RH
VALUES FORECAST TO FALL INTO THE LOWER 30S ALONG AND WEST OF THE I-4
CORRIDOR MONDAY AND TUESDAY AFTERNOONS BUT LOWER ERC VALUES AND 20
FT WIND SPEEDS SHOULD PRECLUDE ANY FIRE WEATHER WATCHES/WARNINGS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 46 65 44 / 60 0 0 10
MCO 77 49 67 45 / 50 10 0 10
MLB 79 52 69 50 / 50 10 10 10
VRB 82 56 70 52 / 50 10 10 10
LEE 72 45 65 43 / 60 0 0 10
SFB 75 48 67 45 / 60 10 0 10
ORL 76 50 66 48 / 60 10 0 10
FPR 82 58 71 52 / 50 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60
NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20
TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE
TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...VOLKMER
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
357 AM EST SUN DEC 15 2013
.SHORT TERM...TODAY AND TONIGHT
THE SHORT TERM WILL FEATURE LIGHT SNOW...GUSTY AFTERNOON WINDS...AND
POSSIBLE SINGLE DIGIT TEMPS OVERNIGHT. A NORTHERN STREAM UPPER LEVEL
LOW WILL DROP THROUGH THE NORTHERN GREAT LAKES TODAY WHILE A LAKE
AGGREGATE SURFACE TROUGH LINGERS ACROSS CENTRAL MI. STRONG CAA HAS
BEGUN IN THE WAKE OF SATURDAYS LOW AS BROAD MID LEVEL TROUGHING
SINKS INTO THE GREAT LAKES. THIS WILL USHER IN ANOTHER ARCTIC
AIRMASS TO DEAL WITH THROUGH TONIGHT. MODELS SHOW SOME AIRMASS
MODIFICATION AS IT CROSSES THE LAKES WITH -26C TEMPS AT 850MB
ENTERING LAKE SUPERIOR AND NEGATIVE TEENS ENTERING MI. SOUTHERN MI
WILL FALL NEAR THE BASE OF THE MID LEVEL TROUGH AND ON THE SOUTH
SIDE OF THE SFC TROUGH LEADING TO WESTERLY FLOW. THE WESTERLY FLOW
AND CAA WILL LEAD TO AN ACTIVE SETUP FOR LAKE EFFECT WITH MIXING
LEVELS OVER LAKE MI REACHING 10KFT. EVEN OVER SE MI THE CAA IN THE
LOW LEVELS WILL LEAD TO STRONG LAPSE RATES UP TO ABOUT 6KFT. BOTH
THE NAM AND RUC SHOW THE ENTIRE MIXED LAYER TO BE SATURATED WHICH
EXTENDS THROUGH THE DGZ. IN ADDITION TO THE SFC FEATURES...A MID
LEVEL VORT MAX WILL ROTATE AROUND AND THROUGH MID MI LENDING SOME
ADDITIONAL SYNOPTIC SUPPORT ALOFT. POPS WILL RAMP UP IN THE
AFTERNOON AS THE DIURNAL CYCLE GIVES THE MIXED LAYER A BOOST AND AS
THE SFC TROUGH AND VORT MAX SWING THROUGH. LAKE EFFECT SHOULD MAKE
IT INTO THE CWA WITH THE STEADY WESTERLY FLOW DURING THE DAY. THE
NAM IS ADVERTISING THE LAKE MI CONVERGENT BAND SETTING UP WHICH WILL
NEED TO BE WATCHED IN CASE IT IMPACTS ANY ONE AREA FOR ANY
DURATION...MOST LIKELY NEAR THE I94 CORRIDOR. OVERALL NOT EXPECTING
MUCH SNOW WITH AROUND A HALF INCH FOR MOST LOCATIONS. IF WE CAN GET
SOME ENHANCE MESOSCALE FEATURES TO SET UP OR THE LAKE EFFECT BAND TO
PERSIST...TOTALS WOULD OBVIOUSLY GO UP SOME. THE OTHER CONCERN TODAY
WILL BE THE WINDS. MODEL SOUNDINGS SHOW THE MIXING LEVELS PREVIOUSLY
MENTIONED BRINGING DOWN GUST AROUND 30 MPH IN THE AFTERNOON. THIS
WILL LIKELY LEAD TO ADDITIONAL DRIFTING OF THE SNOW PACK. THE LAST
CONCERN WILL BE LOW TEMPS TONIGHT. WITH THE FRESH SNOW PACK AND
ARCTIC AIR MOVING IN...THE POTENTIAL IS THERE FOR LOW SINGLE DIGIT
TEMPS. A BIG CONCERN WILL BE CLOUD COVER PREVENTING THIS FROM
ACTUALLY OCCURRING...ESPECIALLY ACROSS THE SOUTH WHERE THE LAKE
CLOUD SHOULD PERSIST THE LONGEST. ADJUSTED TEMPS UP A COUPLE DEGREES
ACROSS THE SOUTH WITH THE MORE PESSIMISTIC CLOUD COVER
FORECAST...OTHERWISE CONTINUED THE COOL PLAY IN THE MID SINGLE
DIGITS RESULTING IN WIND CHILL VALUES -5 TO -10F.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
SHORTWAVE RIDGING WILL TRACK THROUGH THE CENTRAL GREAT LAKES MONDAY
MORNING...KEEPING THE WEATHER DRY FOR THE FIRST HALF OF THE DAY.
QUICKLY ON ITS HEELS WILL BE A VIGOROUS MID LEVEL SHORTWAVE DIVING
SOUTH FROM CANADA. THIS ELONGATED MID LEVEL TROUGH...SEEN ON WATER
VAPOR OVER WESTERN CANADA...WILL BRING A PROLONGED PERIOD OF LIGHT
SNOW SHOWERS FROM MONDAY AFTERNOON THROUGH TUESDAY TO SOUTHEAST
MICHIGAN. AS THE TROUGH MOVES THROUGH THE GREAT LAKES...IT WILL HAVE
THE ASSISTANCE OF BEING UNDER THE LEFT EXIT REGION OF A 140 KNOT JET
DIVING INTO THE WESTERN GREAT LAKES REGION. THE BEST TIME FOR SNOW
APPEARS TO BE LATE MONDAY AFTERNOON INTO MONDAY NIGHT WHEN THE LEAD
SHORTWAVE TRACKS THROUGH THE CENTRAL GREAT LAKES...WITH AN INCH OF
TWO OF SNOWFALL ACCUMULATION POSSIBLE. A SUBTLE BUT NOTICEABLE
WARMING IN THE LOW LEVELS SHOULD CAUSE LOW TEMPERATURES TO OCCUR
EARLY MONDAY NIGHT...WITH SLOWLY RISING TEMPERATURES AFTER MIDNIGHT.
ANOTHER SHORTWAVE TRACKING THROUGH THE SOUTHERN GREAT LAKES ON
TUESDAY COULD BRING ADDITIONAL SNOWFALL AMOUNTS OF A FEW TENTHS OF
AN INCH TO SOUTHEAST MICHIGAN.
ONCE THIS SYSTEM MOVES OFF TO THE EAST HEIGHTS WILL INCREASE ACROSS
THE CENTRAL GREAT LAKES WITH TEMPERATURES WARMING INTO THE 30S ON
THURSDAY...WITH 40S POSSIBLE BY FRIDAY AHEAD OF THE NEXT LOW
PRESSURE SYSTEM TRACKING THROUGH THE GREAT LAKES REGION. THIS
SYSTEM...ORIGINATING OVER THE SOUTHERN PLAINS ON THURSDAY...WILL
TRACK NORTHEAST THROUGH MICHIGAN ON FRIDAY. GIVEN THE NORTHERN TRACK
OF THE LOW THE AREA WILL BE IN THE WARM SECTOR OF THE
SYSTEM...MEANING PRECIPITATION MORE IN THE FORM OF LIQUID RATHER
THAN ICE CRYSTALS. THERE ARE STILL TIMING DIFFERENCES BETWEEN THE
LONG RANGE MODELS...NOTABLY THE FASTER ECMWF AND THE SLOWER GFS.
HOWEVER THEY DO AGREE ON A RETURN TO COLDER TEMPERATURES BEHIND THE
LOW BY SATURDAY AS RIDGING BUILDS OVER THE CENTRAL GREAT LAKES.
&&
.MARINE...
WAVES IN THE NEARSHORE ZONES CONTINUE TO SUBSIDE...WITH CONDITIONS
HAVING FALLEN BELOW HEADLINE CRITERIA. HOWEVER...INCREASING WESTERLY
WINDS THIS AFTERNOON ARE EXPECTED AS LOW PRESSURE TRACKS THROUGH THE
CENTRAL GREAT LAKES. THE FETCH WILL BE FAVORABLE FOR WAVES TO BUILD
UP OVER THE NORTHERN TIP OF THE THUMB OVERNIGHT...NECESSITATING A
SMALL CRAFT ADVISORY FOR OUTER SAGINAW BAY AND THE LAKE HURON
NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH. CONDITIONS WILL
REMAIN UNSETTLED INTO EARLY NEXT WEEK AS SOUTHWEST WINDS DEVELOP
AHEAD OF A PASSING SYSTEM MONDAY NIGHT INTO TUESDAY. THERE ARE NO
SIGNIFICANT WIND EVENTS ON THE HORIZON.
&&
.AVIATION...ISSUED 1202 AM EST SUN DEC 15 2013
//DISCUSSION...
CEILINGS WILL VARY SIGNIFICANTLY OVERNIGHT AS POCKETS OF DRY AIR
INFILTRATE THE LOWER REACHES OF THE ATMOSPHERE. WINDS WILL BACK
THROUGH NORTHWESTERLY TO WESTERLY BY SUNDAY AM. AS THE BOUNDARY
DESTABILIZES DURING SUNDAY AFTERNOON WEST WINDS WILL BECOME RATHER
GUSTY.
FOR DTW...CEILINGS BE QUITE VARIABLE AS POCKETS OF DRY AIR WORK IN
FROM THE WEST/SOUTHWEST. GUIDANCE CONTINUES TO SUGGEST A NEAR
SURFACE INVERSION DEVELOPING THAT MAY TRAP SOME RESIDUAL MOISTURE
BELOW 1KFT. OTHERWISE...THE OTHER POINT OF INTEREST IS WESTERLY
GUSTS LIKELY ECLIPSING 25KTS SUNDAY AFTERNOON.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5KFT FT THROUGH THE TAF PERIOD.
* LOW CONFIDENCE IN CEILINGS BELOW 1KFT OVERNIGHT.
* MODERATE CONFIDENCE IN WESTERLY GUSTS EXCEEDING 25KTS SUNDAY
AFTERNOON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE
WATERS FROM PORT AUSTIN TO HARBOR BEACH...FROM 7 PM SUNDAY TO
10 AM MONDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DRK
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
AVIATION.....MANN
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1054 PM CST SAT DEC 14 2013
.UPDATE...FOR 06Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 338 PM CST SAT DEC 14 2013
LIGHT SNOW CONTINUED ACROSS THE REGION TODAY AHEAD OF A WEAK
SHORTWAVE THAT WAS EMBEDDED IN THE PERSISTENT NORTHWEST FLOW.
FORECAST SOUNDINGS OFF THE RAP SHOWED A BEAUTIFUL VEERING
PROFILE...WITH DENDRITIC SATURATION FROM THE SURFACE UP TO 650MB.
THE REGION OF ASCENT ROOTED IN THE POSITIVE VORTICITY ADVECTION
ASSOCIATED WITH THE CURVATURE OF THIS WAVE WILL CONTINUE TO SHIFT
EASTWARD OVERNIGHT. MODEST H500 HEIGHT RISES AND AN ASSOCIATED
SURFACE RIDGE OF HIGH PRESSURE WILL BUILD OVER WESTERN MN...WHICH
WILL SET THE STAGE FOR ANOTHER NIGHT OF COLD TEMPERATURES WITH LIGHT
WINDS...ESPECIALLY IF SKIES MANAGE TO CLEAR. HOWEVER...DESPITE THE
SURFACE HIGH...CONFIDENCE IN CLEARING SKIES IS LOW AS AGITATED
NORTHWEST FLOW WILL CONTINUE. THE THERMAL PROFILE FROM FORECAST
SOUNDINGS ARE SUCH THAT ONLY A SMALL AMOUNT OF UPWARD VERTICAL
MOTION IS REQUIRED TO PRODUCE A FEW SNOWFLAKES...LET ALONE MID LEVEL
CLOUDS. IN FACT...THE NEXT UPPER LEVEL WAVE / LOW LEVEL WARM AIR
ADVECTION DUO WILL MOVE ACROSS WESTERN MN ON SUNDAY...SO HAVE
INCREASED POPS CONSIDERABLY SINCE CONFIDENCE IS HIGH IN ANOTHER
ROUND OF LIGHT SNOWFALL ALONG THE MINNESOTA RIVER VALLEY. SUNDAYS
HIGH TEMPERATURES WILL STRUGGLE TO GET OUT OF THE SINGLE DIGITS FOR
MOST LOCATIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 PM CST SAT DEC 14 2013
THE UPPER WAVE BRINGING LIGHT SNOW SUNDAY WILL SLIDE SOUTHEAST
INTO THE OHIO VALLEY SUNDAY NIGHT WHILE ANOTHER WAVE DIVES
SOUTHEAST INTO NORTHERN MINNESOTA EARLY MONDAY MORNING. A QUICK
SHOT OF DECENT ISENTROPIC UPGLIDE AND MODEST MOISTURE ADVECTION
WILL BE ENOUGH TO GENERATE A BAND OF SNOW ACROSS NORTHERN AND
CENTRAL MN WHICH WILL PROPAGATE INTO WESTERN WISCONSIN MONDAY
MORNING. ONE TO TWO INCHES OF SNOW ARE POSSIBLE BEFORE STRONG
ISENTROPIC DOWNGLIDE TAKES OVER AGAIN IN THE AFTERNOON AND MONDAY
NIGHT.
A TROUGH DIGGING INTO THE GREAT LAKES WILL CLIP THE FORECAST
AREA...LEAVING WESTERLY SURFACE FLOW IN PLACE THROUGH MIDWEEK.
MILD TEMPS /COMPARED TO THE REST OF THIS MONTH/ CAN BE
EXPECTED...ALTHOUGH TUESDAY NIGHT WILL BE COLD AS THE RIDGE
AXIS PASSES OVERHEAD.
EYES THEN TURN TO LATE WEEK AS A TROUGH DIGS DOWN THE WEST COAST
AND HIGH PRESSURE BUILDS SOUTHWARD INTO WESTERN AND CENTRAL
CANADA. FAST ZONAL FLOW WILL DEVELOP ALONG THE U.S./CANADIAN
BORDER WEDNESDAY WITH ONE WAVE RAPIDLY PUSHING EAST ACROSS
NORTHERN MINNESOTA. SENSIBLE WEATHER IMPACTS FOR OUR AREA WILL BE
MINIMAL INITIALLY WITH FORCING AND MOISTURE CONVERGENCE REMAINING
WELL NORTH. HOWEVER...THIS WAVE AND HIGH PRESSURE BUILDING TOWARD
THE NORTHERN PLAINS WILL PUSH A COLD FRONT SOUTH WEDNESDAY NIGHT.
AS SOME ENERGY ROUNDS THE BASE OF THE WESTERN TROUGH...A SURFACE
LOW WILL SPAWN OVER COLORADO THURSDAY AND TRACK EAST NORTHEAST
ACROSS THE PLAINS AND INTO THE LOWER GREAT LAKES LATE
THURSDAY/THURSDAY NIGHT. NORMALLY THIS WOULD BE A HIGHLY FAVORABLE
TRACK FOR HEAVY SNOWFALL ACROSS THE CWA. HOWEVER...GIVEN THE FAST
FLOW WITH TIGHTENING BAROCLINICITY LEADING TO A MORE PROGRESSIVE
FEATURE...IN CONJUNCTION WITH SURFACE RIDGING OVER THE GULF WHICH
WILL LIKELY DELAY THE NORTHERLY MOISTURE TRANSPORT UNTIL THE
SURFACE WAVE IS TO THE EAST OF THE AREA...WOULD LIMIT THE
POTENTIAL FOR A BIG SNOWFALL. IF MODELS EVOLVE THE WESTERN TROUGH
DIFFERENTLY...AND THEY MOST LIKELY WILL AT THIS RANGE...THIS
FORECAST CAN CERTAINLY CHANGE. LEFT POPS IN THE MID RANGE FOR NOW
WITH THE MOISTURE UNCERTAINTY AND SOME TIMING DIFFERENCES BETWEEN
THE MEDIUM RANGE MODELS.
THE HIGH WILL BUILD IN FOR FRIDAY AND SATURDAY WITH ANOTHER BLAST
OF ARCTIC AIR ACCOMPANYING IT. HIGHS WILL AGAIN BE IN THE SINGLE
DIGITS WITH LOWS FRIDAY NIGHT IN THE TEENS TO 20S BELOW ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1055 PM CST SAT DEC 14 2013
MID LEVEL CLOUDS WILL BE ON THE INCREASE OVERNIGHT...WITH BKN-
OVC CIGS BUILDING IN FROM THE DAKOTAS. ANOTHER AREA OF SNOW WILL
APPROACH WESTERN MN FROM THE DAKOTAS ON SUNDAY...POSSIBLY
AFFECTING KAXN AND KRWF LATE SUNDAY MORNING AND AFTERNOON...BUT
IT/S EXPECTED TO STAY WEST/SOUTH OF THE REMAINDER OF THE TAF
SITES. NORTHWEST WINDS BELOW 10KTS THROUGH MIDDAY SUNDAY...BECOME
LIGHT AND VARIABLE OR LIGHT SOUTHERLY AROUND 00Z MONDAY.
KMSP...
A FEW CLOUDS AROUND 2000-2500FT LINGERS THROUGH SUNDAY...WITH A
BKN-OVC MID LEVEL DECK FOR MUCH OF THE PERIOD AS WELL. 300-330
DEGREE WINDS THROUGH SUNDAY AFTERNOON AT SPEEDS AOB
10KTS...BECOMING LIGHT AND VRB BY 00Z MONDAY.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR WITH IFR/-SN POSSIBLE. WINDS SW AT 10KTS.
TUE...VFR WITH MVFR/-SN POSSIBLE. WINDS W AT 15KTS.
WED...VFR. WINDS VRBL AT 05KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...LS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 AM CST SUN DEC 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CST SUN DEC 15 2013
TODAY AND TONIGHT...A POWERFUL THERMAL RIDGE WILL CONTINUE OPERATING
ACROSS THE FORECAST AREA. WINDS AT H850 MB CONTINUE AT 35 TO 45 KT
TODAY AND THEN WEAKEN TO AROUND 30 KTS TONIGHT. THE MID LEVEL CLOUD
DECK CURRENTLY ACROSS THE FCST AREA IS FCST TO SHIFT EAST AND EXIT
THE AREA THIS AFTN. AT THE SAME TIME A BANK OF CIRRUS ACROSS THE NRN
PLAINS WILL DRIFT ACROSS THE FCST AREA. THE TEMPERATURE FCST TODAY
USES THE WARM SIDE OF THE MODEL CONSENSUS PLUS ABOUT 3 DEGREES FOR
HIGHS IN THE UPPER 50S SOUTHWEST TO UPPER 30S NORTHEAST. THIS IS A
FEW DEGREES COOLER THAN THE HRRR MODEL BUT THAT MODEL WAS TOO WARM
SATURDAY.
THE QUESTION TONIGHT IS HOW COOL LOWS WILL GO. PRESUMABLY CIRRUS
WILL CONTINUE ACROSS THE FCST AREA BUT NONE OF THE MODELS SHOW MUCH
MID LEVEL CLOUDINESS WHICH WOULD KEEP MIN TEMPS IN THE 30S. THE FCST
IS FOR LOWER 20S ASSUMING CIRRUS CLOUDS.
OTHERWISE...500M AGL WINDS INCREASE TO 25 TO 30 KTS WHICH SUPPORTS
WINDS IN THE 20 TO 30 MPH RANGE AT THE SFC. THE FCST USES MULTIMODEL
DATA TODAY AND TONIGHT FOR WINDS BUT INCREASES WIND SPEEDS TO NEAR
THE MAV GUIDANCE...THE STRONGEST WIND DATA SET AVAILABLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM CST SUN DEC 15 2013
PRIMARY FORECAST PROBLEMS THROUGH THIS PERIOD ARE TEMPERATURES AS
WELL AS PRECIPITATION CHANCES THURSDAY AND THURSDAY NIGHT.
AMPLIFIED UPPER LEVEL FLOW WITH RIDGING OVER THE EASTERN PACIFIC AND
WESTERN CONUS WITH TROUGHING OVER THE EASTERN HALF OF THE CONUS WILL
GIVE WAY TO A CHANGE BY MID WEEK AS THE UPPER LEVEL LOW CURRENTLY
OVER ONTARIO MOVES EAST DECREASING THE STRENGTH OF THE
TROUGH...WHILE A SERIES OF SHORTWAVE TROUGHS MOVE THROUGH THE
NORTHERN STREAM OUT OF RUSSIA AND ALASKA TO FLATTEN THE FLOW BY
MONDAY AND TUESDAY. SEVERAL WEAK SURFACE FRONTS WILL MOVE THROUGH
THE REGION WITH THE FIRST COMING THROUGH MONDAY MORNING AND ANOTHER
MONDAY NIGHT. EVEN WITH THESE FRONTS MOVING THROUGH...THE AIRMASS
WILL HAVE A PACIFIC INFLUENCE SO NOT EXPECTING TEMPERATURES TO BE
IMPACTED MUCH BY IT. WILL ALSO SEE WESTERLY FLOW IN THE LOW LEVELS
TO HELP WITH MIXING AND RAISING THE TEMPERATURES ON MONDAY. HIGH
PRESSURE WILL BUILD SOUTHEAST ACROSS THE AREA AND BY TUESDAY WILL
MOVE FURTHER SOUTHEAST BRINGING RETURN FLOW BACK INTO THE AREA.
AGAIN EXPECTING TEMPERATURES SIMILAR TO SUNDAY AND MONDAY.
TUESDAY NIGHT INTO WEDNESDAY THE CHANGING UPPER LEVEL PATTERN WILL
START TO BECOME APPARENT AS WHAT WILL BECOME A STRONG UPPER LEVEL
WAVE MOVES DOWN THE BRITISH COLUMBIA COAST AND INTO THE PACIFIC
NORTHWEST. MEANWHILE...THE UPPER LOW CURRENTLY WELL OFF THE
CALIFORNIA COAST WILL MOVE ONSHORE INTO SOUTHERN CALIFORNIA. AS
THESE TWO SYSTEMS BEGIN TO DEEPEN A TROUGH OVER THE WEST
COAST...UPPER LEVEL RIDGING WILL BUILD OVER THE PLAINS.
CONCURRENTLY...LOW PRESSURE AT THE SURFACE WILL DEVELOP OVER EASTERN
WYOMING WHICH WILL STRENGTHEN THE SOUTHERLY FLOW INTO THE LOCAL
AREA. WEDNESDAY SHOULD BE THE WARMEST DAY OF THE WEEK...HOWEVER
THERE ARE SOME DIFFERENCES IN HOW WARM IT WILL GET. THE ECMWF RISES
850MB TEMPERATURES TO NEAR 13C OVER THE SOUTHERN PART OF THE
FORECAST AREA WEDNESDAY AFTERNOON...WHILE THE GFS DOESN/T WARM
THINGS UP AS MUCH. THIS WOULD MEAN A DIFFERENCE IN HIGHS BY 5 TO 10
DEGREES ACROSS THE FORECAST AREA. AT THIS TIME...TRENDED CLOSER TO
THE WARMER SOLUTION...YET NOT AS WARM AS SOME MODEL SOLUTIONS
SUGGESTING.
THE OTHER CONSIDERATION WHEN DEALING WITH THE TEMPERATURES IS THE
IMPACT OF THE SNOWPACK OVER THE NORTHERN PARTS OF THE FORECAST AREA.
SHOULD GET QUITE A BIT OF SNOW TO MELT OVER THE NEXT SEVERAL
DAYS...AND DO HAVE TEMPERATURES ON THE UPWARD TREND THROUGH
WEDNESDAY. BELIEVE WILL STILL SEE SOME INFLUENCE FROM THE SNOW
THROUGH THE WEEK...BUT HOW MUCH REMAINS IN QUESTION. WILL SEE HOW
TEMPERATURES WARM TODAY AND WILL SEE WHAT ADJUSTMENTS WILL NEED TO
BE MADE FOR THE FOLLOWING DAYS OVER THE NEXT SEVERAL FORECAST
CYCLES.
ON WEDNESDAY NIGHT THE UPPER LOW THAT MOVES INTO CALIFORNIA ON
WEDNESDAY WILL EJECT OUT OF THE UPPER TROUGH AND INTO THE CENTRAL
PLAINS. AS THIS OCCURS...THE WYOMING SURFACE LOW WILL MOVE INTO
EASTERN COLORADO...WITH THE ENTIRE SYSTEM WEAKENING. GOING INTO
THURSDAY THE SURFACE LOW WILL MOVE ACROSS KANSAS WITH AN INVERTED
TROUGH PASSING ACROSS THE LOCAL FORECAST AREA. THE MAJORITY OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL REMAIN ACROSS KANSAS AND
SOUTHEAST NEBRASKA SO NOT EXPECTING ANY PRECIPITATION INVOLVED WITH
IT.
FOCUS THEN TURNS TO THE NEXT ARCTIC AIRMASS TO PUSH THROUGH THE
PLAINS. THE ARCTIC FRONT IS NOW BEING TIMED TO MOVE SOUTH ACROSS
NEBRASKA DURING THE DAY THURSDAY WITH PRECIPITATION MOVING IN BEHIND
THE FRONT. THE MUCH COLDER AIR WILL LAG BEHIND THE FRONT...HOWEVER
WITH COLD AIR ADVECTION ONGOING THROUGH THE DAY AM QUESTIONING HOW
WARM IT WILL GET...OR WHAT TIME HIGHS WILL BE REACHED. LOCATIONS
ACROSS THE NORTH MAY SEE HIGHS IN THE MORNING...WHILE THE SOUTHERN
PARTS OF THE AREA MAY HAVE SOME TIME TO WARM UP BEFORE THE BIG PUSH
OF COLD AIR. DID LOWER HIGHS SLIGHTLY FOR THURSDAY...BUT WILL LIKELY
NEED FURTHER ADJUSTMENTS UNTIL A BETTER HANDLE IS ON THE MODELS FOR
THIS SYSTEM. THE PRESSURE GRADIENT WILL TIGHTEN BEHIND THE
FRONT...WITH STRONG NORTHERLY WINDS EXPECTED ON THURSDAY INTO
THURSDAY NIGHT. BY FRIDAY HIGH PRESSURE WILL BUILD IN WITH THE
PRESSURE GRADIENT RELAXING SO WINDS SHOULDN/T BE AS STRONG. COLDER
AND BELOW NORMAL TEMPERATURES WILL THEN CONTINUE INTO THE WEEKEND AS
THE TROUGH AXIS MOVES ACROSS THE CONUS THROUGH THE WEEKEND. CURRENT
MODELS AREN/T QUITE AS COLD WITH THE TEMPERATURES FOR FRIDAY AND
SATURDAY AS PREVIOUS RUNS...BUT STILL BRING 850MB TEMPERATURES OF
-15C TO -17C INTO THE CENTRAL PLAINS.
IN TERMS OF PRECIPITATION...THERE SEEMS TO BE AN ISSUE WITH A POCKET
OF DRY AIR IN THE MID LEVELS BEHIND THE FRONT WHICH MAY CAUSE
PROBLEMS WITH THE DEVELOPMENT OF PRECIPITATION. THERE CONTINUES TO
BE A SLIGHT SIGNAL FOR SOME DRIZZLE ON THURSDAY PRIOR TO THE COLUMN
BECOMING SATURATED THURSDAY NIGHT. HOWEVER...EVEN IN THE LOW
LEVELS...THE AIR WASN/T COMPLETELY SATURATED EITHER SO WILL STILL
NOT MENTION ANY DRIZZLE YET IN THE FORECAST. BESIDES THIS OUTSIDE
CHANCE FOR DRIZZLE...THE POST-FRONTAL PRECIPITATION SHOULD BE QUITE
LIGHT. PRECIPITABLE WATER AMOUNTS AREN/T BAD...HOWEVER THE SIGNALS
FOR ANY FRONTOGENESIS ARE NOT STRONG AND THE MOISTURE DOES NOT STAY
LONG BEFORE MUCH DRIER AIR PUSHES IN TO DRY OUT THE COLUMN SO NOT
EXPECTING ANY HEAVY PRECIPITATION AMOUNTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1025 PM CST SAT DEC 14 2013
CEILINGS MOVING ACROSS CENTRAL AND WESTERN NEBRASKA TONIGHT ARE
FORECAST TO REMAIN 3500 FEET AGL OR HIGHER. THOSE CLOUDS ARE THEN
EXPECTED TO SCATTER OUT LATE MORNING IN SOUTHWEST NEBRASKA AND BY
LATE AFTERNOON IN NORTHERN NEBRASKA.
WIND IS FORECAST TO REMAIN BELOW 10KT TONIGHT AND ARE LIKELY TO
BECOME 280-310 AT 11-14G18-22KT BY ABOUT 18Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
332 AM EST SUN DEC 15 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE UP THE OHIO RIVER
VALLEY...BRINGING SIGNIFICANT SNOWFALL AS IT DEVELOPS INTO A
COASTAL LOW NEAR CAPE COD BY SUNDAY MORNING. SNOWFALL WILL BEGIN
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHERN
AREAS...SPREADING NORTHWARD TONIGHT AND CONTINUING THROUGH MUCH
OF SUNDAY WITH TOTAL ACCUMULATIONS OF 6 TO 12 INCHES LIKELY BY
SUNDAY EVENING. COLD TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 933 PM EST SATURDAY...FIRST WIDESPREAD SIGNIFICANT SNOWFALL
OF THE WINTER SEASON HAS BEGIN ACRS THE NORTH COUNTY...WITH CRNT RADAR
SHOWING MODERATE SNOW NOW ENTERING EXTREME SOUTHERN VT. SFC
ANALYSIS PLACES PRIMARY LOW PRES ACRS EASTERN OHIO ATTM...WITH
SECONDARY 1007MB LOW PRES NEAR NORFOLK VA WITH GREATEST 3HR PRE
FALL OF 6MB TWD THE MID ALTANTIC STATES. EXPECT RAPID DEVELOPMENT
OF SFC LOW PRES OVERNIGHT...WITH A GENERAL TRACK TO THE NORTHEAST
TWD NYC ACRS THE CAPE COD CANAL AND INTO THE GULF OF MAINE BY 18Z
SUNDAY. THE LATEST 00Z RAP AND NAM CONTINUE TO SUPPORT THIS IDEA.
THIS WL ALLOW FOR A STRENGTHENING LLVL JET BTWN 925MB AND 850MB TO
DEVELOP...AND ADVECT PLENTY OF ATLANTIC MOISTURE BACK INTO OUR
CWA. ALREADY NOTICING 60 KNOT 85H JET OFF KBGM VAD FROM THE SE.
THE NOSE OF THIS LLVL JET LIFTS FROM EASTERN NY/SOUTHERN NEW
ENGLAND INTO CENTRAL NH/EASTERN VT BY 06Z AND NORTH OF OUR CWA BY
12Z SUNDAY. THIS COMBINED WITH RAP/NAM CONTINUING TO SHOW STRONG
FGEN FORCING/DEEP LAYER UVVS WL PRODUCE A MESO-SCALE BAND OF
MODERATE TO HEAVY SNOW FROM 04Z SOUTHERN VT TO 12Z NORTHERN CWA.
EXPECT VIS BTWN 1/4SM AND 1/2SM IN THIS BAND WITH SNOWFALL RATES
OF 1 TO 2 INCHES PER HOUR. THIS BAND WL CONTINUE TO MOVE AND NOT
BECOMING STATIONARY GIVEN NO CLOSED 5H/7H AND PROGRESSIVE SW TO NE
FLW ALOFT AND FAST MOVEMENT OF SFC LOW PRES. OVERALL...LITTLE
CHANGE IN EXPECTED SNOWFALL WITH A GENERAL 6 TO 12
INCHES...SLIGHTLY HIGHER IN THE FAVORALBE SE UPSLOPE REGIONS AND
SLIGHTLY LESS IN THE DOWNSLOPE REGIONS OF THE NEK/SOUTHERN
CPV...AND PARTS OF THE SLV.
ALSO...EXPECT SFC WIND GUSTS BTWN 30 AND 40 MPH NEAR
RUTLAND/MIDDLEBURY BTWN 04Z-10Z TONIGHT. TEMPS WL SLOWLY RISES
UNDER WAA TO THE MID/UPPER TEENS BY SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
AS OF 331 PM EST SATURDAY...SFC LOW WILL MOVE INTO THE GULF OF
MAINE AND TOWARD THE CANADIAN MARITIMES ON SUNDAY. BULK OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO DEPART MID-
LATE SUNDAY...TRANSITIONING STEADY SNOWFALL TO SNOW SHOWERS.
THESE SHOWERS WILL LIKELY CONTINUE THROUGH SUNDAY NIGHT ACROSS
THE HIGHER TRRN AS THE PARENT UPPER TROUGH TRACKS THROUGH.
STORM TOTAL SNOWFALL AMOUNTS BY SUNDAY EVENING WILL GENERALLY BE
6-12 INCHES WITH LOCALIZED HIGHER AMOUNTS ACROSS ERN SLOPES DUE
TO SE FLOW TONIGHT INTO SUNDAY MORNING.
TEMPS NOTICEABLY WARMER...BUT SNOWFALL...CLOUDS AND WINDS KEEP
CONDITIONS CHILLY WITH MAX TEMPS IN THE TEENS TO M20S. SUNDAY
NIGHT TEMPS SEE SINGLE DIGITS TEMPS ABOVE AND BELOW ZERO.
ON MONDAY...THE UPPER LOW WILL EXIT THE NORTH COUNTRY TO THE
NE...WITH RIDGING DEVELOPING AT THE SFC AND ALOFT LATE IN THE DAY
INTO MONDAY EVENING. SOME UPSLOPE SNOW ON W-NW FLOW NOT OUT OF
THE QUESTION. WITH SKIES SLOW TO CLEAR AND WINDS OUT OF THE W-NW
AT 10-20 KTS...BLUSTERY CONDITIONS WILL CONTINUE WITH MAX TEMPS
RANGING FROM -5 TO +15 DEGREES FROM STRONG CAA.
MONDAY NIGHT WINDS SHIFT TO THE SOUTH AHEAD OF A CLIPPER TYPE
SYSTEM APPROACHING FROM THE NW. THREAT OF SNOW FROM THIS SYSTEM
WILL INCREASE TOWARDS TUESDAY MORNING FROM THE WEST. ANOTHER COLD
NIGHT...WITH MOST AREAS BEING NEAR OR BELOW ZERO.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 330 AM EST SUNDAY...GOOD MODEL CONSISTENCY SHOWN THRU FRIDAY WITH
MODELS DIVERGING SIGNIFICANTLY THEREAFTER. NO SIGNIFICANT PRECIPITATION
FORECAST WITH TEMPS REMAINING GENERALLY BELOW NORMAL EXCEPT ON
FRIDAY.
A 700-500MB SHORTWAVE TROUGH IS EXPECTED TO TRANSLATE EWD ACROSS THE
NORTHEAST CONUS DURING TUESDAY NIGHT. WEAK SFC LOW WILL REDEVELOP IN
THE GULF OF MAINE BY 12Z WEDNESDAY...BUT IT APPEARS THAT THIS
DEVELOPMENT WILL OCCUR TO LATE/FAR EAST TO HAVE ANY SIGNIFICANT
IMPACT ON THE NORTH COUNTRY. ANTICIPATE CLOUDY CONDITIONS AND
PERIODS OF LIGHT SNOW TUESDAY NIGHT ASSOCIATED WITH UPPER TROUGH AND
DECAYING PRIMARY LOW AS IT SHIFTS EWD ACROSS NRN NY AND VT. LOWS
WILL BE RELATIVELY UNIFORM ACROSS THE FORECAST AREA AND GENERALLY IN
THE TEENS.
LOW AMPLITUDE SHORTWAVE RIDGE AND SFC RIDGE BRING DRY WX CONDITIONS
DURING WEDNESDAY AND WEDNESDAY NIGHT. WINDS WILL BE RELATIVELY
LIGHT. TEMPS WILL REMAIN WELL BELOW SEASONAL LEVELS WITH HIGHS
WEDNESDAY IN THE MID 20S AND LOWS WEDNESDAY NIGHT MAINLY IN THE
TEENS.
PREVAILING MID-TROPOSPHERIC FLOW TRANSITIONS FROM WEST TO SOUTHWEST
WITH WEAK WAVE LOW EXPECTED TO DEVELOP ACROSS THE MID-MS RIVER
VALLEY BEFORE TRACKING TO OUR WEST DURING FRIDAY MORNING. THIS
SHOULD ALLOW FOR SOME MODERATION IN TEMPS THURSDAY AND FRIDAY AS SFC
WINDS BECOME S-SW. HIGHS THURSDAY SHOULD REACH THE UPR 20S AND THEN
MID-UPR 30S ON FRIDAY. LOW PCPN CHANCES UNTIL COLD FRONT SHIFTS
ACROSS THE REGION LATE FRIDAY INTO FRIDAY NIGHT. THIS FEATURE COULD
BRING RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWERS FRIDAY NIGHT.
THE OPERATIONAL 00Z GFS/ECMWF DIVERGE ON SATURDAY. GFS BRINGS STRONG
POLAR HIGH WITH DRY WEATHER FOR SATURDAY AND SUNDAY. ECMWF ALLOWS
THE COLD FRONT FRIDAY NIGHT TO STALL NEAR OR JUST SOUTH OF THE
REGION...WITH POTENTIAL WAVE LOW TRACKING UP ACROSS THE REGION WITH
POSSIBLE WINTRY MIX. PREDICTABILITY IS CONSIDERED LOW ATTM AND
STAYED CLOSER TO THE DRIER 00Z GFS.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...IFR CIGS/VSBY IN SNOW AREAWIDE THRU 18Z WITH
PERIODS OF MODERATE TO BRIEFLY HEAVY SNOW POSSIBLE BTV/PBG/RUT/MPV
THRU ABOUT 13Z SUNDAY. SIGNIFICANT IMPACT TO AVIATION OPERATIONS
EXPECTED THRU 18Z SUNDAY. WIND NOT A MAJOR FACTOR EXCEPT LOCALLY
WITH DOWNSLOPE FLOW AT RUT (SE 20G30KT) AND WITH CHANNELED VALLEY
FLOW AT MSS (NE 12G20KT) THRU 13-14Z SUNDAY. SNOW BECOMES LIGHT
SUNDAY AFTN...BUT ANTICIPATE CONTINUED 2-3SM -SN AT BTV WITH WINDS
TURNING NORTH AND LOCAL TOPOGRAPHIC FORCING THRU 00-02Z MONDAY.
SNOW ENDS DURING SUNDAY NIGHT WITH LINGERING MVFR CEILINGS AND SFC
WINDS GENERALLY NWLY AROUND 10 KTS.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...MAINLY VFR MONDAY AND MOST
OF MONDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE
REGION. LIGHT SNOW OR SNOW SHOWERS POSSIBLE DURING TUESDAY NIGHT
INTO EARLY WEDNESDAY WITH MVFR/BRIEF IFR CONDITIONS POSSIBLE. A
SLIGHT CHANCE FOR SOME SNOW SHOWERS ON THURSDAY...BUT MAINLY VFR
CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
VTZ001>012-016>019.
NY...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ026>031-034-035-087.
&&
$$
SYNOPSIS...LAHIFF/KGM
NEAR TERM...TABER
SHORT TERM...KGM
LONG TERM...BANACOS
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 AM EST SUN DEC 15 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE UP THE OHIO RIVER
VALLEY...BRINGING SIGNIFICANT SNOWFALL AS IT DEVELOPS INTO A
COASTAL LOW NEAR CAPE COD BY SUNDAY MORNING. SNOWFALL WILL BEGIN
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHERN
AREAS...SPREADING NORTHWARD TONIGHT AND CONTINUING THROUGH MUCH
OF SUNDAY WITH TOTAL ACCUMULATIONS OF 6 TO 12 INCHES LIKELY BY
SUNDAY EVENING. COLD TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 933 PM EST SATURDAY...FIRST WIDESPREAD SIGNIFICANT SNOWFALL
OF THE WINTER SEASON HAS BEGIN ACRS THE NORTH COUNTY...WITH CRNT RADAR
SHOWING MODERATE SNOW NOW ENTERING EXTREME SOUTHERN VT. SFC
ANALYSIS PLACES PRIMARY LOW PRES ACRS EASTERN OHIO ATTM...WITH
SECONDARY 1007MB LOW PRES NEAR NORFOLK VA WITH GREATEST 3HR PRE
FALL OF 6MB TWD THE MID ALTANTIC STATES. EXPECT RAPID DEVELOPMENT
OF SFC LOW PRES OVERNIGHT...WITH A GENERAL TRACK TO THE NORTHEAST
TWD NYC ACRS THE CAPE COD CANAL AND INTO THE GULF OF MAINE BY 18Z
SUNDAY. THE LATEST 00Z RAP AND NAM CONTINUE TO SUPPORT THIS IDEA.
THIS WL ALLOW FOR A STRENGTHENING LLVL JET BTWN 925MB AND 850MB TO
DEVELOP...AND ADVECT PLENTY OF ATLANTIC MOISTURE BACK INTO OUR
CWA. ALREADY NOTICING 60 KNOT 85H JET OFF KBGM VAD FROM THE SE.
THE NOSE OF THIS LLVL JET LIFTS FROM EASTERN NY/SOUTHERN NEW
ENGLAND INTO CENTRAL NH/EASTERN VT BY 06Z AND NORTH OF OUR CWA BY
12Z SUNDAY. THIS COMBINED WITH RAP/NAM CONTINUING TO SHOW STRONG
FGEN FORCING/DEEP LAYER UVVS WL PRODUCE A MESO-SCALE BAND OF
MODERATE TO HEAVY SNOW FROM 04Z SOUTHERN VT TO 12Z NORTHERN CWA.
EXPECT VIS BTWN 1/4SM AND 1/2SM IN THIS BAND WITH SNOWFALL RATES
OF 1 TO 2 INCHES PER HOUR. THIS BAND WL CONTINUE TO MOVE AND NOT
BECOMING STATIONARY GIVEN NO CLOSED 5H/7H AND PROGRESSIVE SW TO NE
FLW ALOFT AND FAST MOVEMENT OF SFC LOW PRES. OVERALL...LITTLE
CHANGE IN EXPECTED SNOWFALL WITH A GENERAL 6 TO 12
INCHES...SLIGHTLY HIGHER IN THE FAVORALBE SE UPSLOPE REGIONS AND
SLIGHTLY LESS IN THE DOWNSLOPE REGIONS OF THE NEK/SOUTHERN
CPV...AND PARTS OF THE SLV.
ALSO...EXPECT SFC WIND GUSTS BTWN 30 AND 40 MPH NEAR
RUTLAND/MIDDLEBURY BTWN 04Z-10Z TONIGHT. TEMPS WL SLOWLY RISES
UNDER WAA TO THE MID/UPPER TEENS BY SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 331 PM EST SATURDAY...SFC LOW WILL MOVE INTO THE GULF OF
MAINE AND TOWARD THE CANADIAN MARITIMES ON SUNDAY. BULK OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO DEPART MID-
LATE SUNDAY...TRANSITIONING STEADY SNOWFALL TO SNOW SHOWERS.
THESE SHOWERS WILL LIKELY CONTINUE THROUGH SUNDAY NIGHT ACROSS
THE HIGHER TRRN AS THE PARENT UPPER TROUGH TRACKS THROUGH.
STORM TOTAL SNOWFALL AMOUNTS BY SUNDAY EVENING WILL GENERALLY BE
6-12 INCHES WITH LOCALIZED HIGHER AMOUNTS ACROSS ERN SLOPES DUE
TO SE FLOW TONIGHT INTO SUNDAY MORNING.
TEMPS NOTICEABLY WARMER...BUT SNOWFALL...CLOUDS AND WINDS KEEP
CONDITIONS CHILLY WITH MAX TEMPS IN THE TEENS TO M20S. SUNDAY
NIGHT TEMPS SEE SINGLE DIGITS TEMPS ABOVE AND BELOW ZERO.
ON MONDAY...THE UPPER LOW WILL EXIT THE NORTH COUNTRY TO THE
NE...WITH RIDGING DEVELOPING AT THE SFC AND ALOFT LATE IN THE DAY
INTO MONDAY EVENING. SOME UPSLOPE SNOW ON W-NW FLOW NOT OUT OF
THE QUESTION. WITH SKIES SLOW TO CLEAR AND WINDS OUT OF THE W-NW
AT 10-20 KTS...BLUSTERY CONDITIONS WILL CONTINUE WITH MAX TEMPS
RANGING FROM -5 TO +15 DEGREES FROM STRONG CAA.
MONDAY NIGHT WINDS SHIFT TO THE SOUTH AHEAD OF A CLIPPER TYPE
SYSTEM APPROACHING FROM THE NW. THREAT OF SNOW FROM THIS SYSTEM
WILL INCREASE TOWARDS TUESDAY MORNING FROM THE WEST. ANOTHER COLD
NIGHT...WITH MOST AREAS BEING NEAR OR BELOW ZERO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 323 PM EST SATURDAY...SUITE OF GLOBAL DETERMINISTIC AND
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT THROUGH THURSDAY
NIGHT. MODELS THEN BEGIN TO DIVERGE SIGNIFICANTLY ENOUGH TO LIMIT
PREDICTABILITY FOR THE FRIDAY INTO THE EARLY WEEKEND PERIOD.
AMPLIFICATION OF A 500 MB TROUGH OVER THE GREAT LAKES IS
PREDICTED BY TUESDAY WHICH INDUCES SECONDARY CYCLOGENESIS NEAR
CAPE COD BY TUESDAY NIGHT...WITH THE PROGGED COASTAL MOVING INTO
THE CENTRAL GULF OF MAINE BY WEDNESDAY. I OPTED TO INCREASE POPS
TO HIGH CHANCE/LOW LIKELY FOR TUESDAY INTO TUESDAY NIGHT GIVEN
GOOD CONSISTENCY OVER SEVERAL MODEL CYCLES FOR WHAT WILL BE A
LIGHT-QPF STRATIFORM LIGHT SNOW EVENT FROM INITIAL CLIPPER
SYSTEM. I WAS A LITTLE LEERY OF GOING MUCH HIGHER THAN THAT
THOUGH DUE TO UNCERTAINTIES IN ENERGY TRANSFER TO THE DEVELOPING
COASTAL. THOUGH I DO THINK A DOWNWARD TREND IN POPS ON WEDNESDAY
LOOKS GOOD...I`VE KEPT CHANCE POPS FOR THE NORTHEAST KINGDOM AREA
AS THERE IS SOME INDICATION OF AN INVERTED TROUGH/TROWAL FEATURE
WHICH IF PROGGED CORRECTLY MAY HELP KEEP LIGHT SNOWS GOING A
LITTLE LONGER THERE. TEMPERATURES ARE PRETTY SIMILAR TUESDAY AND
WEDNESDAY...HIGHS GENERALLY IN THE 20S WITH LOWS IN THE TEENS.
A PATTERN CHANGE TOWARD A BRIEF PERIOD OF WARMER WEATHER LOOKS TO
BE IN STORE FOR THE MID TO LATE WEEK PERIOD AS 500 MB HEIGHTS
RISE ACROSS THE EASTERN CONUS. HIGHS ON FRIDAY MAY REACH INTO THE
UPPER 30S TO AROUND 40 IN SPOTS. UNCERTAINTY THEN INCREASES
MARKEDLY DUE TO DIFFERENCES IN HANDLING A LOW MOVING OUT OF THE
MIDWEST TO THE NORTHEAST. THESE DIFFERENCES ARE MOSTLY DUE TO
TIMING THE EJECTION OF AN UPPER-LEVEL TROUGH FRIDAY
AFTERNOON...WHICH IN TURN LEADS TO SOME DISCREPANCY AS TO WHEN
THE ASSOCIATED SFC COLD FRONT PUSHES THROUGH THE NORTH COUNTRY.
ONE THING THAT CAN BE SAID ABOUT THE EARLY WEEKEND PERIOD IS THAT
THE BAROCLINIC ZONE TIED TO THE AFOREMENTIONED COLD FRONT GETS
HUNG UP SOMEWHERE IN THE INTERIOR SOUTHEASTERN CONUS WITH THE
IMPLICATION OF ADDITIONAL CHANCES FOR UNSETTLED WEATHER. IT`S NOT
CLEAR HOW ALL THAT UNFOLDS HOWEVER. I`VE STAYED CLOSE TO THE
SUPERBLEND GUIDANCE FOR THE EARLY WEEKEND PERIOD WHICH OFFERS
CHANCE POPS WITH LOWS TRENDING NEAR TO BELOW NORMAL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...IFR CIGS/VSBY IN SNOW AREAWIDE THRU 18Z WITH
PERIODS OF MODERATE TO BRIEFLY HEAVY SNOW POSSIBLE BTV/PBG/RUT/MPV
THRU ABOUT 13Z SUNDAY. SIGNIFICANT IMPACT TO AVIATION OPERATIONS
EXPECTED THRU 18Z SUNDAY. WIND NOT A MAJOR FACTOR EXCEPT LOCALLY
WITH DOWNSLOPE FLOW AT RUT (SE 20G30KT) AND WITH CHANNELED VALLEY
FLOW AT MSS (NE 12G20KT) THRU 13-14Z SUNDAY. SNOW BECOMES LIGHT
SUNDAY AFTN...BUT ANTICIPATE CONTINUED 2-3SM -SN AT BTV WITH WINDS
TURNING NORTH AND LOCAL TOPOGRAPHIC FORCING THRU 00-02Z MONDAY.
SNOW ENDS DURING SUNDAY NIGHT WITH LINGERING MVFR CEILINGS AND SFC
WINDS GENERALLY NWLY AROUND 10 KTS.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...MAINLY VFR MONDAY AND MOST
OF MONDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE
REGION. LIGHT SNOW OR SNOW SHOWERS POSSIBLE DURING TUESDAY NIGHT
INTO EARLY WEDNESDAY WITH MVFR/BRIEF IFR CONDITIONS POSSIBLE. A
SLIGHT CHANCE FOR SOME SNOW SHOWERS ON THURSDAY...BUT MAINLY VFR
CONDITIONS EXPECTED.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
VTZ001>012-016>019.
NY...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ026>031-034-035-087.
&&
$$
SYNOPSIS...LAHIFF/KGM
NEAR TERM...TABER
SHORT TERM...KGM
LONG TERM...LOCONTO
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1204 AM EST SUN DEC 15 2013
.SYNOPSIS...
A COASTAL LOW WILL DEEPEN ALONG THE NEW ENGLAND COAST OVERNIGHT AS
LOW PRESSURE TRANSITIONS FROM THE OHIO VALLEY EASTWARD. THIS IS
BRINGING WIDESPREAD ACCUMULATING SNOW TO THE ENTIRE REGION WHICH
WILL TAPER OFF FROM WEST TO EAST EARLY SUNDAY. SOME LINGERING LAKE
EFFECT SNOW WILL CONTINUE LATER SUNDAY AND MONDAY SOUTHEAST OF THE
LAKES. ANOTHER WEAKER LOW PRESSURE WILL BRING ANOTHER ROUND OF SNOW
ON TUESDAY WITH SOME ADDITIONAL LAKE EFFECT SNOW SOUTHEAST OF THE
LAKES WEDNESDAY. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MIDWEEK BEFORE MODERATING BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
DUAL LOW PRESSURE CENTERS ON THE SURFACE MAP LATE THIS EVENING. ONE
IS NOW CROSSING OVER WESTERN PA WITH THE STRONGER LOW NOW LIFTING
NORTH ACROSS THE DELMARVA PENINSULA. THESE TWO LOWS WILL PHASE INTO
A SINGLE NOREASTER OFF THE NEW JERSEY COAST OVERNIGHT IN A MILLER
TYPE-B COASTAL CYCLOGENESIS. THIS ALWAYS PROVES DIFFICULT FROM A SNOW
ACCUMULATION STANDPOINT AS THE TIMING AND DEGREE OF ENERGY TRANSFER
TO THE COAST CAN IMPACT AMOUNTS TO THE WEST OF THE APPALACHIANS.
TYPICALLY WRAP AROUND PRECIPITATION CAN BE MUCH HEAVIER AS MOISTURE
AND LIFT INCREASE ON THE NORTHWESTERN QUADRANT OF THE SYSTEM WITH
TROWEL FORMATION.
REGIONAL RADAR IMAGERY AND SURFACE OBS SHOWING A DRY SLOT NOW
SHIFTING ACROSS THE FINGER LAKES TOWARD THE EAST AS THE STORM
WRAPS IN DRIER AIR FROM THE SOUTHWEST. THIS DRY SLOT WILL BRING A
SHORT WINDOW WITH A BREAK IN SNOWFALL FROM THE FINGER LAKES TO
CENTRAL NEW YORK. THE LATEST HRRR RUNS SHOW THIS SCENARIO VERY WELL.
ACROSS FAR WESTERN NEW YORK THE WRAP AROUND PRECIP IS NOW SHIFTING
BACK ACROSS THE FORECAST AREA ON THE HEELS OF THE DRY SLOT. THIS
AREA EXHIBITING MORE IN THE WAY OF SYNOPTIC LIFT AND MOISTURE SHOULD
BRING MORE INTENSE SNOWFALL RATES POSSIBLY UP TO AN INCH AN HOUR.
THE QPF AND SNOW FORECASTS WERE UPDATED EARLIER THIS EVENING BASED
THE DRY SLOT WHICH HAS LIKELY CUT BACK ON SNOW TOTALS SOME. THE NEW
FORECAST IS A LITTLE LIGHTER ON SNOW TOTALS MAINLY ACROSS THE
GENESEE VALLEY AND FINGER LAKES WHERE THE DRY SLOT WILL PERSIST
LONGER. EAST OF LAKE ONTARIO SNOW RATES AFTER MIDNIGHT WILL INCREASE
UP TO AND INCH AN HOUR AS THE NOREASTER TAKES SHAPE OFF THE COAST
AND WRAP AROUND MOISTURE INCREASES.
EXPECT STORM TOTALS OF 5-8 INCHES FROM THE GENESEE VALLEY AND
WESTERN FINGER LAKES WITH THE DRY SLOT CONTRIBUTING TO LOWER SNOW
TOTALS. WITH AN INTENSIFYING NOREASTER OVER NIGHT HIGHER AMOUNTS OF
10-14 INCHES CAN BE EXPECTED ACROSS THE NORTH COUNTRY EAST OF LAKE
ONTARIO. ACROSS THE ADVISORY AREA FROM THE BUFFALO AND NIAGARA
REGION DOWN TO THE SOUTHERN TIER...EXPECT TOTALS OF 4-6 INCHES. IT
APPEARS THE COMMA HEAD AND STRONGEST WARM ADVECTION WILL NOT RESIDE
IN THESE AREAS LONG ENOUGH TO PRODUCE WARNING CRITERIA SNOW...WITH A
SOLID TO HIGH END ADVISORY STILL LOOKING MOST LIKELY.
THE SYNOPTIC SNOW WILL BE OVER BY DAYBREAK FROM THE GENESEE VALLEY
WESTWARD...AND WILL END BY MID MORNING EAST OF LAKE ONTARIO. THIS
WILL LEAVE JUST SCATTERED SNOW SHOWERS IN SOME LIMITED WRAP AROUND
MOISTURE. SOME LIMITED LAKE EFFECT SNOW WILL ALSO DEVELOP ESPECIALLY
DURING THE AFTERNOON AS TEMPERATURES ALOFT BEGIN TO DROP.
OFF LAKE ERIE...LAKE INDUCED EQUILIBRIUM LEVELS RISE TO AROUND 7K
FEET BY MID AFTERNOON. EXPECT A HYBRID LAKE EFFECT/UPSLOPE SNOW TO
DEVELOP MAINLY ALONG THE CHAUTAUQUA RIDGE. THIS MAY PRODUCE 2-3
INCHES DURING THE AFTERNOON ACROSS THE HIGHER TERRAIN INLAND FROM
LAKE ERIE.
OFF LAKE ONTARIO...LAKE INDUCED EQUILIBRIUM LEVELS ALSO RISE TO
AROUND 7K FEET BY MID AFTERNOON. EXPECT A BAND OF LAKE EFFECT SNOW
TO DEVELOP ACROSS MAINLY OSWEGO COUNTY TO THE SOUTHERN TUG HILL
DURING THE AFTERNOON WITH 2 TO 4 INCHES POSSIBLE.
TEMPERATURES WILL SLOWLY CLIMB OVERNIGHT INTO THE LOWER TO MID 20S
WITH ONGOING LOW/MID LEVEL WARM ADVECTION. TEMPS WILL THEN STAY
FAIRLY STEADY THROUGH SUNDAY...PERHAPS ONLY CLIMBING A DEGREE OR TWO
THROUGH THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
SUNDAY NIGHT WILL TRANSITION FROM THE DAYS SYNOPTIC SNOW BACK TO
LAKE EFFECT SNOW AS COOLER AIR BEHIND THE DEPARTING STORM SYSTEM
SENDS TEMPERATURES AT 850 HPA BACK DOWN TO -16 TO -18C.
OFF LAKE ERIE...A WEST TO NORTHWEST FLOW WILL ORIENT A BAND OF SNOW
ACROSS SOUTHERN ERIE/CHAUTAUQUA AND POINTS INLAND. MOST FAVORABLE
LAKE PARAMETERS WILL BE FOUND EARLY IN THE NIGHT WITH LAKE INDUCED
EQUILIBRIUM LEVELS AROUND 10K FEET AND UPWARD MOTION THROUGH A
SATURATED LOW LEVEL. WITH MOISTURE REMAINING PLENTIFUL THROUGH THE
NIGHT EXPECT A BAND OF SNOW...THAT MIGHT BECOME MORE MULTI BANDED IN
CHARACTERISTICS AS WINDS VEER SOME...TO CONTINUE. ALOFT A CLOSED 500
HPA LOW WILL BEGIN THE PERIOD OVER THE UPPER GREAT LAKES...BUT WILL
QUICKLY SLIDE ACROSS THE EASTERN GREAT LAKES THROUGH THE NIGHT. THIS
FEATURE WILL LIKELY KEEP THE LAKE BAND SHIFTING THROUGH THE NIGHT
AND HOLD ACCUMULATIONS TO ADVISORY RANGE VALUES.
OFF LAKE ONTARIO...A WEST TO NORTHWEST FLOW WILL ALSO BE FOUND WITH
A LAKE BAND FIRST ACROSS THE SOUTHERN TUG HILL...DROPPING SOUTHWARD
TO AREAS SOUTHEAST OF LAKE ONTARIO. WHILE THERE WILL BE SOME
FAVORABLE LAKE PARAMETERS...WITH LAKE INDUCED EQUILIBRIUM LEVELS AND
INVERSION HEIGHTS OVER 10K FEET THE AMOUNT OF MOISTURE IN THE LOWER
LEVELS WILL BE SOMEWHAT LIMITED. NORTHERLY FLOW AROUND THE ATLANTIC
COASTAL LOW WILL DROP SOUTHWARD AND SETTLE TO POINTS AROUND LAKE
ONTARIO...WHICH WILL ALSO PREVENT ANY UPSTREAM LAKE CONNECTION.
EXPECT SNOW TOTALS OFF LAKE ONTARIO TO BE LIGHTER THAN LAKE
ERIE...WITH OVERALL NUMBERS POSSIBLY REMAINING BELOW ADVISORY
LEVELS.
ELSEWHERE MONDAY NIGHT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LIKELY FLY WITH THE PASSAGE OF THE UPPER LEVEL TROUGH. IT WILL
REMAIN COLD SUNDAY NIGHT WITH LOWS DROPPING DOWN INTO THE SINGLE
DIGITS TO LOW DOUBLE DIGITS. THE NORTH COUNTY...IF THEY HAVE SOME
CLEARING STANDS A CHANCE TO BECOME EVEN COLDER THAN FORECASTED.
CURRENT FORECAST MINS JUST BELOW ZERO COULD EASILY REACH -10F OR
COLDER OVER A DEEP AND FRESH SNOW PACK...IF WE GET SOME CLEARING.
FOR NOW BELIEVE THERE MAY BE ENOUGH CLOUDS LINGERING THROUGH THE
NIGHT AHEAD OF THE SHORTWAVE TO PREVENT THESE MUCH COLDER LOWS.
ON MONDAY DRIER AIR BEHIND THE SHORTWAVE WILL BEGIN TO WEAKEN THE
LAKE BANDS. HIGH PRESSURE WILL SCURRY BY TO OUR SOUTH AND INVERSION
HEIGHTS WILL FALL WHICH ALSO WILL PUT A DAMPER ON THE LAKE EFFECT
SNOWS. AS THIS HIGH SLIDES EASTWARD LATER MONDAY AND IN ADVANCE OF
THE NEXT CLIPPER LOW OUR WINDS WILL BACK AROUND TO MORE OF A
SOUTHWESTERLY FLOW. INCREASE WIND SHEAR WILL FURTHER DIMINISH THE
LAKE SNOWS MONDAY NIGHT WHILE SENDING THEM NORTHWARD TOWARDS METRO
BUFFALO OFF LAKE ERIE AND WATERTOWN OFF LAKE ONTARIO.
THERE ARE STILL SOME MODEL TIMING DIFFERENCES WITH THE ARRIVAL OF
THE NEXT AREA OF LOW PRESSURE...ONE THAT WILL DROP ACROSS SOUTHERN
CANADA AND THE UPPER GREAT LAKES...AND THEN NORTH OF LAKE
ONTARIO...BEFORE A COASTAL REDEVELOPMENT TAKES PLACE. THE 12Z ECMWF
AND THE 12Z CMC CONTINUE TO BE FASTER THAN THE GFS MODEL...THOUGH
ALL AGREE THAT A LIGHT GENERAL SNOWFALL ACROSS THE CWA
TUESDAY-TUESDAY NIGHT IS LIKELY. AHEAD OF THE SYSTEM OUR HIGHS WILL
CLIMB INTO THE UPPER 20S...AND MAY EVEN CRACK THE FREEZING MARK FOR
A BRIEF PERIOD OF TIME. WITH THE LINGERING CLOUDS TUESDAY NIGHT WILL
NOT BE AS COLD...WITH LOWS GENERALLY IN THE LOW 20S ACROSS THE CWA.
SNOW WILL TAPER OFF TUESDAY NIGHT BEHIND THE CLIPPER LOW...HOWEVER
AGAIN WE WILL SEE LAKE EFFECT SNOW LINGERING TO THE EAST...AND THEN
SOUTHEAST OF THE LAKES. SHIFTING WINDS AND A RETURN OF HIGH PRESSURE
ON WEDNESDAY WILL LIKELY KEEP SNOW TOTALS ON TUESDAY NIGHT TO
PERHAPS ADVISORY LEVELS OR LOWER.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THROUGH THIS TIME PERIOD OUR FLOW ALOFT WILL GO FROM NORTHWESTERLY
TO A WESTERLY ZONAL FLOW...AND THEN TO A DEEP AMPLIFIED SOUTHWEST
FLOW. THIS WILL ALLOW FROM BELOW NORMAL TEMPERATURES AT THE START OF
THE PERIOD TO WARM TO ABOVE NORMAL AROUND FRIDAY...SOME MODEL
UNCERTAINTY ON THE TIMING OF A COLD FRONT AT THE BEGINNING OF THE
WEEKEND...MAY OR MAY NOT LEAVE SATURDAY ABOVE NORMAL AS WELL.
WILL CONTINUE WITH A CHANCE FOR SOME LIGHT LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF THE LAKES WEDNESDAY AND INTO EARLY WEDNESDAY WITH THE
NORTHWEST FLOW...BUT AS HIGH PRESSURE AT THE SURFACE NUDGES INTO THE
REGION WEDNESDAY NIGHT EXPECT THE LAKE SNOW ACTIVITY TO GREATLY
DIMINISH. THIS MAY LEAVE THURSDAY AS A DRY DAY AS THE FLOW BECOMES
MORE SOUTHWESTERLY IN RESPONSE TO A DIGGING TROUGH ACROSS THE
SOUTHWESTERN US AND BUILDING DOWNSTREAM HEIGHTS ACROSS THE EASTERN
US. WILL BRING A CHANCE FOR RAIN SNOW IN LATER FRIDAY...WITH A COLD
FRONT PASSING ACROSS THE REGION NEXT WEEKEND CHANGING THE RAIN BACK
TO SNOW. THERE IS STILL SOME MODEL UNCERTAINTY TO THE TIMING AND
PLACEMENT OF SURFACE WAVES ALONG THIS COLD FRONT...WHICH WILL IMPACT
THE FRONTAL CROSSING FOR OUR REGION.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
KBUF RADAR SHOWING A DRY SLOT IN THE SNOW SHIFTING EAST ACROSS
THE FINGER LAKES TOWARD CENTRAL NEW YORK. WITHIN THIS DRY SLOT BRIEF
VFR CONDITIONS HAVE BEEN OBSERVED. BACK TO THE WEST A SECOND
PERIOD OF HEAVY SNOW IS WORKING BACK ACROSS THE WNY TERMINALS
ASSOCIATED WITH WRAP AROUND MOISTURE FROM A DEVELOPING NOREASTER
TAKING SHAPE NEAR THE MID-ATLANTIC COAST. THIS WRAP AROUND SNOW WILL
BRING BACK IFR/LIFR CONDITIONS THROUGH THE 04Z TO 10Z TIME FRAME
WITH CONDITIONS IMPROVING TO MVFR CIGS IN MOST PLACES WITH SCATTERED
LIGHT SNOW SHOWERS TOMORROW AFTER DAY BREAK. IFR CIGS LOOK TO REMAIN
ACROSS THE SOUTHERN TIER. SOME LIMITED LAKE EFFECT SNOW WILL KEEP
SPOTTY IFR GOING SOUTHEAST OF THE LAKES. MVFR CIGS WILL LIKELY
LINGER IN MOST AREAS THROUGH AT LEAST THE FIRST HALF OF
SUNDAY...WITH SOME IFR ACROSS HIGHER TERRAIN IN THE MORNING.
SUNDAY EVENING INTO THE OVERNIGHT WESTERLY FLOW OVER THE LAKES WILL
DEVELOP SOME LAKE EFFECT SNOW BANDS EAST OF THE GREAT LAKES. THESE
MAY BRING IFR/MVFR TO KJHW AND KART SUNDAY AFTERNOON/EVENING.
OUTLOOK...
MONDAY...LAKE EFFECT SNOW SHOWERS WITH LOCAL IFR SOUTHEAST OF THE
LAKES DIMINISHING.
TUESDAY...SNOW SHOWERS LIKELY WITH AREAS OF MVFR/IFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS...EXCEPT LAKE
EFFECT SNOW SHOWERS LIKELY SOUTHEAST OF THE LAKES WITH LOCAL IFR.
THURSDAY...MAINLY VFR.
&&
.MARINE...
LOW PRESSURE WILL MOVE ALONG THE NY/PA BORDER OVERNIGHT AND GIVE WAY
TO A SECONDARY COASTAL LOW OFF THE MID ATLANTIC COAST. THE PRESSURE
GRADIENT BETWEEN BOTH OF THESE SYSTEMS AND HIGH PRESSURE OVER
SOUTHEAST CANADA WILL MAINTAIN MODERATE NORTHEAST WINDS ON THE LOWER
LAKES. THIS WILL KEEP SMALL CRAFT CONDITIONS GOING ON THE WEST HALF
OF LAKE ONTARIO.
ON SUNDAY AS THE COASTAL LOW DEEPENS WINDS WILL COME AROUND TO THE
NORTHWEST AND EVENTUALLY WEST. THIS WILL BRING SMALL CRAFT ADVISORY
CONDITIONS TO BOTH LAKES ERIE AND ONTARIO...WHICH WILL LAST THROUGH
MONDAY BEFORE HIGH PRESSURE BUILDS OVER THE LOWER LAKES AND ALLOWS
WINDS TO DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR
NYZ006>008.
WINTER STORM WARNING UNTIL 9 AM EST THIS MORNING FOR
NYZ002>005-011>014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NYZ001-010-019>021-085.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 1 PM EST MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR
LOZ042-043.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 4 PM EST
MONDAY FOR LOZ045.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 4 PM EST
MONDAY FOR LOZ044.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...HITCHCOCK/SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...HITCHCOCK/SMITH
MARINE...HITCHCOCK/SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
322 AM EST SUN DEC 15 2013
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE CAROLINAS
EARLY THIS MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
FROM THE SOUTHWEST LATE TODAY THROUGH MID WEEK... PROVIDING FAIR AND
DRY WEATHER. THIS HIGH WILL SHIFT OFF THE COAST LATE WEDNESDAY...
BRINGING A WARMING TREND THROUGH LATE WEEK.
&&
NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 215 AM SUNDAY...
THROUGH TODAY: GREATLY IMPROVING WEATHER IS EXPECTED THIS MORNING.
THE LATEST SURFACE MAP SHOWS THE WEDGE FRONT HAVING MOVED JUST EAST
OF THE CWA... WHILE THE PRIMARY OCCLUDED FRONT HAS MOVED INTO THE NC
MOUNTAINS. WE REMAIN ON THE EAST SIDE OF THE APPROACHING BROAD
TROUGH... AND WHILE THE HEAVIEST RAIN HAS SHIFTED OFF THE COAST... A
POCKET OF MID LEVEL VORTICITY SHEARING OUT OF THE TROUGH BASE ACROSS
THE CENTRAL CAROLINAS IS RESPONSIBLE FOR A BATCH OF MOSTLY LIGHT
RAIN STREAMING OVER THE AREA. THE LATEST HRRR GUIDANCE DEPICTS THIS
PRECIP WELL AND SHOWS THIS LIGHT RAIN AREA PUSHING EASTWARD OUT OF
THE CWA BETWEEN 8 AM AND 10 AM AS THE MID LEVEL TROUGH AXIS CROSSES
THE AREA. THICK LOW CLOUDS WILL PERSIST UNTIL THEN... AS WE`RE
SEEING COOLING AT THE SURFACE BUT THE 925 MB/850 MB TROUGH AXES ARE
STILL TO OUR WEST... YIELDING A VERTICAL THERMAL DIFFERENTIAL AND
FOSTERING LOW LEVEL STABILIZATION (EXACERBATED BY A LOOSE MSLP
GRADIENT AND LIGHT SURFACE WINDS)... HINDERING MIXING. AFTER THE
OCCLUDED FRONT PASSES THROUGH BY MID TO LATE MORNING... THE ENSUING
DOWNSLOPE LOW LEVEL FLOW WILL HELP DRY OUT THE LOWER TROPOSPHERE...
WHILE INCREASING DEEP LAYER SUBSIDENCE IN THE WAKE OF THE DEPARTING
BROAD TROUGH AXIS HELPS DRY AND STABILIZE THE MID-UPPER LEVELS.
EXPECT PLENTY OF SUNSHINE BY THE AFTERNOON HOURS. THICKNESSES DO
FALL DURING THE DAY (MUCH OF WHICH IS A FUNCTION OF COOLING AT 925-
850 MB WITH GOOD DRYING BUT NOT A LOT OF COOLING BELOW 925 MB)...
BUT THE INCOMING AIR MASS IS MODIFIED AND SOURCED FROM OUR WSW...
AND LATE-DAY THICKNESSES ARE STILL JUST SLIGHTLY BELOW NORMAL. HIGHS
49-57... NEAR TO SLIGHTLY UNDER SEASONAL NORMALS. EXPECT BREEZY WNW
WINDS WITH OCCASIONAL GUSTS AS THE COOLER AND MORE DENSE AIR ARRIVES
WITH SHALLOW BUT PRONOUNCED MIXING.
FOR TONIGHT: AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST... A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW... ENSURING
CONTINUED DRY AND STABLE LOW LEVELS... WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 250 AM SUNDAY...
EXPECT DRY AND GENERALLY QUIET WEATHER... ALTHOUGH IT MAY NOT BE
QUITE AS SUN-FILLED AS ONCE THOUGHT ACROSS NRN NC. A WEAK MID LEVEL
WAVE NOW OVER ALBERTA/MT WILL DIVE SE THEN EAST ACROSS THE
MIDATLANTIC/NC MONDAY... WITH A 100+ KT UPPER JET STREAKING INTO THE
REGION. MODEL FORECAST SOUNDINGS SHOW A SOMEWHAT MOIST LAYER BETWEEN
800 MB AND 600 MB OVER THE NRN HALF OF THE CWA... AND GIVEN THAT THE
EXPECTED VERTICAL THERMAL AND MOISTURE STRUCTURE WILL BE SUPPORTIVE
OF OROGRAPHIC ENHANCEMENT OF MID-HIGH CLOUDS IN THIS AREA... WILL
HAVE A FORECAST OF SKIES BECOMING PARTLY CLOUDY ROUGHLY ALONG/NORTH
OF HIGHWAY 64 FOR THE AFTERNOON THROUGH MID EVENING... FOLLOWED BY
CLEARING OVERNIGHT AS THE VORTICITY MAX MOVES TO OUR EAST.
THICKNESSES WILL BE ABOUT 15-20 M BELOW NORMAL... SUGGESTING HIGHS
FROM 47 NORTH TO 53 SOUTH WHEN FACTORING IN THE CLOUDS OVER THE
NORTH. LOWS 28-35 WITH SKIES BECOMING MOSTLY CLEAR. -GIH
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
TUESDAY-WEDNESDAY NIGHT: DRY CONDITIONS AND NEAR NORMAL TEMPS.
EXPECT SOME DEGREE OF WARMING ON TUE (HIGHS MID/UPPER 50S) VIA
SOUTHWEST LOW-LEVEL FLOW AND WARM ADVECTION ASSOC/W A TIGHTENING
MSLP/HEIGHT GRADIENT IN ADVANCE OF A POTENT SHORTWAVE AND ATTENDANT
CLIPPER LOW DIGGING INTO THE GREAT LAKES. THE AFOREMENTIONED
SHORTWAVE ENERGY WILL PROGRESS INTO THE NORTHERN MID-ATLANTIC AND
NEW ENGLAND TUE NIGHT BEFORE MOVING OFFSHORE EARLY WED. THE
GFS/ECMWF GUIDANCE ARE ROUGHLY IN GOOD AGREEMENT ON THE EVOLUTION OF
THE AFOREMENTIONED SHORTWAVE ENERGY/CLIPPER SYSTEM...INDICATING A
WEAK/DRY COLD FRONTAL PASSAGE TUE EVE/NIGHT FOLLOWED BY WEAK HIGH
PRESSURE BUILDING INTO THE REGION ON WED. EXPECT LOWS IN THE LOWER
TO MID 30S WED MORNING (COOLEST N/NW)...WITH HIGHS ON WED SEVERAL
DEGREES COOLER THAN TUE IN THE LOWER 50S FAR NORTH TO MID/UPPER 50S
FAR SOUTH. WITH CLEAR SKIES...LIGHT/CALM WINDS AND A DRY AIRMASS IN
PLACE...EXPECT GOOD RADIATIONAL COOLING WITH LOWS IN THE UPPER 20S
TO LOWER 30S WED NIGHT.
THURSDAY-FRIDAY...EXPECT A WARMING TREND WITH INCREASING CLOUD
COVER. SHORTWAVE ENERGY IS EXPECTED TO DIG SOUTHEAST THROUGH THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST THU/THU NIGHT... WITH AN
ATTENDANT SFC LOW TRACKING NE FROM THE CENTRAL PLAINS TO THE GREAT
LAKES AND AN ASSOCIATED COLD FRONT PROGRESSING EAST ACROSS THE MS
RIVER VALLEY. HIGH PRESSURE WILL MOVE OFFSHORE THE CAROLINA COAST IN
ADVANCE OF THE AFOREMENTIONED FRONT ON THU...RESULTING IN THE ONSET
OF SOUTHERLY RETURN FLOW /WARM ADVECTION/. WARM ADVECTION AND LOW-
LEVEL MOISTURE TRANSPORT WILL STRENGTHEN ON FRIDAY AS THE
AFOREMENTIONED FRONT PROGRESSES INTO THE TN/OH VALLEY AND THE
MSLP/HEIGHT GRADIENT TIGHTENS OVER THE CAROLINAS. EXPECT HIGHS IN
THE UPPER 50S TO NEAR 60F (S) ON THU...AND IN THE MID/UPPER 60S TO
NEAR 70F ON FRIDAY DEPENDING ON CLOUD COVER...WARMEST S/SE. THOUGH
LOW-LEVEL WARM ADVECTION (ALONE OR) IN THE PRESENCE OF ANY SMALL
AMPLITUDE DISTURBANCES IN WSW FLOW ALOFT COULD CONCEIVABLY RESULT IN
A LOW CHANCE FOR SPRINKLES OR LIGHT RAIN THU NIGHT/FRI MORNING...
WILL KEEP THE FCST DRY AT THIS TIME.
FRIDAY NIGHT-SATURDAY: UNCERTAINTY IN THE FORECAST INCREASES
DRAMATICALLY THIS WEEKEND WITH REGARD TO THE EVOLUTION OF A COMPLEX
UPPER LEVEL PATTERN CHARACTERIZED BY SPLIT FLOW. REGARDLESS...THE
OVERALL PATTERN WOULD SUGGEST AN ABOVE AVERAGE CHANCE FOR RAIN
ASSOC/W AN INCREASINGLY WARM/MOIST AIRMASS AND THE FRONTAL ZONE
APPROACHING FROM THE WEST. WILL INDICATE MOSTLY CLOUDY/OVERCAST
SKIES AND A 30% CHANCE OF RAIN ON SAT/SUN. -VINCENT
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM SUNDAY...
SUB-VFR AVIATION CONDITIONS WILL HOLD UNTIL NEAR OR SHORTLY AFTER
SUNRISE... WHEN IMPROVEMENT TO VFR IS EXPECTED BETWEEN 12Z AND 16Z.
A COMPLEX OF SURFACE LOW PRESSURE CENTERS CROSSING THE AREA IS
BRINGING UNSETTLED WEATHER IN THE FORM OF IFR/LIFR CIGS AND MVFR TO
IFR VSBYS EARLY THIS MORNING. THESE CLOUDS WILL PERSIST FOR SEVERAL
MORE HOURS...ALONG WITH PATCHY LIGHT RAIN THAT WILL CROSS CENTRAL
NC. THIS RAIN IS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE THAT
WILL SWEEP THROUGH THE AREA EARLY THIS MORNING. ONCE THIS
DISTURBANCE PASSES TO OUR EAST NEAR OR SOON AFTER SUNRISE...LOW
LEVEL WINDS WILL BECOME FROM THE WNW OR NW (FROM 270-320 DEGREES)
AND WILL INCREASE IN SPEED TO 8-12 KTS OCCASIONALLY GUSTING TO 18-22
KTS MID-LATE MORNING THROUGH AFTERNOON. THIS DOWNSLOPE DRYING FLOW
WILL SCOUR OUT THE LOW CLOUDS BETWEEN 12Z (WRN TAFS) AND 16Z (ERN
TAFS). THUS...CONFIDENCE IS HIGH IN VFR CONDITIONS AT ALL SITES BY
MID TO LATE AFTERNOON. WINDS WILL DIMINISH TO 8 KTS OR LESS AROUND
SUNSET. CLEAR SKIES AND VFR VSBYS ARE EXPECTED TONIGHT AS HIGH
PRESSURE NOSES INTO THE AREA.
LOOKING BEYOND 06Z TONIGHT...HIGH CONFIDENCE IN VFR CONDITIONS LATE
TONIGHT THROUGH THURSDAY...AS SURFACE HIGH PRESSURE DOMINATES WITH
DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...VINCENT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EST SUN DEC 14 2013
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE CAROLINAS
EARLY THIS MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
FROM THE SOUTHWEST LATE TODAY THROUGH MID WEEK... PROVIDING FAIR AND
DRY WEATHER. THIS HIGH WILL SHIFT OFF THE COAST LATE WEDNESDAY...
BRINGING A WARMING TREND THROUGH LATE WEEK.
&&
NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 215 AM SUNDAY...
THROUGH TODAY: GREATLY IMPROVING WEATHER IS EXPECTED THIS MORNING.
THE LATEST SURFACE MAP SHOWS THE WEDGE FRONT HAVING MOVED JUST EAST
OF THE CWA... WHILE THE PRIMARY OCCLUDED FRONT HAS MOVED INTO THE NC
MOUNTAINS. WE REMAIN ON THE EAST SIDE OF THE APPROACHING BROAD
TROUGH... AND WHILE THE HEAVIEST RAIN HAS SHIFTED OFF THE COAST... A
POCKET OF MID LEVEL VORTICITY SHEARING OUT OF THE TROUGH BASE ACROSS
THE CENTRAL CAROLINAS IS RESPONSIBLE FOR A BATCH OF MOSTLY LIGHT
RAIN STREAMING OVER THE AREA. THE LATEST HRRR GUIDANCE DEPICTS THIS
PRECIP WELL AND SHOWS THIS LIGHT RAIN AREA PUSHING EASTWARD OUT OF
THE CWA BETWEEN 8 AM AND 10 AM AS THE MID LEVEL TROUGH AXIS CROSSES
THE AREA. THICK LOW CLOUDS WILL PERSIST UNTIL THEN... AS WE`RE
SEEING COOLING AT THE SURFACE BUT THE 925 MB/850 MB TROUGH AXES ARE
STILL TO OUR WEST... YIELDING A VERTICAL THERMAL DIFFERENTIAL AND
FOSTERING LOW LEVEL STABILIZATION (EXACERBATED BY A LOOSE MSLP
GRADIENT AND LIGHT SURFACE WINDS)... HINDERING MIXING. AFTER THE
OCCLUDED FRONT PASSES THROUGH BY MID TO LATE MORNING... THE ENSUING
DOWNSLOPE LOW LEVEL FLOW WILL HELP DRY OUT THE LOWER TROPOSPHERE...
WHILE INCREASING DEEP LAYER SUBSIDENCE IN THE WAKE OF THE DEPARTING
BROAD TROUGH AXIS HELPS DRY AND STABILIZE THE MID-UPPER LEVELS.
EXPECT PLENTY OF SUNSHINE BY THE AFTERNOON HOURS. THICKNESSES DO
FALL DURING THE DAY (MUCH OF WHICH IS A FUNCTION OF COOLING AT 925-
850 MB WITH GOOD DRYING BUT NOT A LOT OF COOLING BELOW 925 MB)...
BUT THE INCOMING AIR MASS IS MODIFIED AND SOURCED FROM OUR WSW...
AND LATE-DAY THICKNESSES ARE STILL JUST SLIGHTLY BELOW NORMAL. HIGHS
49-57... NEAR TO SLIGHTLY UNDER SEASONAL NORMALS. EXPECT BREEZY WNW
WINDS WITH OCCASIONAL GUSTS AS THE COOLER AND MORE DENSE AIR ARRIVES
WITH SHALLOW BUT PRONOUNCED MIXING.
FOR TONIGHT: AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST... A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW... ENSURING
CONTINUED DRY AND STABLE LOW LEVELS... WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 250 AM SUNDAY...
EXPECT DRY AND GENERALLY QUIET WEATHER... ALTHOUGH IT MAY NOT BE
QUITE AS SUN-FILLED AS ONCE THOUGHT ACROSS NRN NC. A WEAK MID LEVEL
WAVE NOW OVER ALBERTA/MT WILL DIVE SE THEN EAST ACROSS THE
MIDATLANTIC/NC MONDAY... WITH A 100+ KT UPPER JET STREAKING INTO THE
REGION. MODEL FORECAST SOUNDINGS SHOW A SOMEWHAT MOIST LAYER BETWEEN
800 MB AND 600 MB OVER THE NRN HALF OF THE CWA... AND GIVEN THAT THE
EXPECTED VERTICAL THERMAL AND MOISTURE STRUCTURE WILL BE SUPPORTIVE
OF OROGRAPHIC ENHANCEMENT OF MID-HIGH CLOUDS IN THIS AREA... WILL
HAVE A FORECAST OF SKIES BECOMING PARTLY CLOUDY ROUGHLY ALONG/NORTH
OF HIGHWAY 64 FOR THE AFTERNOON THROUGH MID EVENING... FOLLOWED BY
CLEARING OVERNIGHT AS THE VORTICITY MAX MOVES TO OUR EAST.
THICKNESSES WILL BE ABOUT 15-20 M BELOW NORMAL... SUGGESTING HIGHS
FROM 47 NORTH TO 53 SOUTH WHEN FACTORING IN THE CLOUDS OVER THE
NORTH. LOWS 28-35 WITH SKIES BECOMING MOSTLY CLEAR. -GIH
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 PM SATURDAY...
A LOW PRESSURE SYSTEM DIVING OUT OF THE CANADIAN ROCKIES WILL
APPROACH THE GREAT LAKES AND DIVE THROUGH NEW ENGLAND AS AN UPPER
LEVEL TROUGH DIGS DOWN THE EASTERN SEABOARD BUT WILL HAVE A HARD
TIME EXTENDING SOUTHWARD. THIS WILL MAKE UPPER LEVEL FLOW MORE ZONAL
OVER NORTH CAROLINA CAUSING A FAIRLY CONSTANT TEMPERATURE PATTERN
WITH SOME OSCILLATION IN HIGH AND LOW TEMPS FOR THE FIRST TWO THIRDS
OF THE PERIOD. BY THE END OF THE WEEK A FEW SHORTWAVES DEVELOP IN
THE SOUTHERN STREAM AND STRONG WARM AIR ADVECTION TAKES TEMPERATURES
WELL ABOVE SEASONAL NORMALS FOR FRIDAY AND SATURDAY BEFORE A
STRONGER LOW DEVELOPS AND MOVES THROUGH THE OHIO VALLEY ON SUNDAY.
TUESDAY: WHILE MODELS GENERALLY KEEP THE PATTERN THE SAME
...THE GFS HAS A BROADER SURFACE HIGH OVER THE REGION...THUS
SHUTTING OFF ANY SLIGHT COLD AIR ADVECTION ON THE FRONT SIDE OF THE
HIGH. THE ECMWF HANGS BACK WITH THIS AND THUS ITS TEMPERATURES ARE
COOLER. EITHER WAY A SLIGHT WARMING TREND FROM MONDAY TO TUESDAY
WITH UPPER 40S TO LOW 50S EXPECTED MONDAY AND MID 50S ON TUESDAY.
DRY AND MOSTLY CLEAR WITH VERY LIGHT WINDS OUT OF THE NORTHWEST.
LOWS IN THE LOWER TO MID 30S.
WEDNESDAY AND THURSDAY: A MORE NORTHWESTERLY UPPER LEVEL FLOW AND A
TIGHTER GRADIENT IN THE GFS YIELD SOME LOWER TEMPERATURES FOR
WEDNESDAY BUT THE PATTERN IS MORE RELAXED IN THE LATEST EUROPEAN
WITH MOST OF THE STRONGER DYNAMICS WELL TO THE NORTH. WILL INDICATE
A SMALL REDUCTION IN HIGHS ON WEDNESDAY...LOWER TO MID 50S WITH LOWS
IN THE LOWER 30S THURSDAY MORNING. ON THURSDAY UPPER LEVEL FLOW WILL
BEGIN TO BACK AROUND TO WESTERLY AND THEN SOUTHWESTERLY. AT THE SAME
TIME THE SURFACE HIGH MOVES OFF SHORT. THIS WILL BEGIN A PERIOD OF
SIGNIFICANT WARM AIR ADVECTION WHICH WILL PUT HIGHS ON THURSDAY INTO
THE MID TO UPPER 50S WITH LOWS IN THE LOWER 40S.
FRIDAY AND SATURDAY: AS FLOW BECOMES MORE SOUTHWESTERLY...INCREASED
WARM AIR ADVECTION WILL HELP TEMPERATURES RISE ABOVE SEASONAL
NORMALS. INCREASED MOISTURE AHEAD OF A DEVELOPING FRONTAL ZONE IN
THE TN VALLEY WILL BEGIN TO BRING MORE CLOUDS INTO THE AREA AND A
SLIGHT CHANCE OF SOME DRIZZLE OR LIGHT RAIN FRIDAY AFTERNOON AND
EVENING...INCREASING TO CHANCE OF RAIN BY SATURDAY. HIGHEST
POTENTIAL FOR RAIN WILL BE IN THE NORTHWEST. HIGHS POTENTIALLY
RISING TO THE MID TO UPPER 60S BY SATURDAY...ALMOST 15 DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM SUNDAY...
SUB-VFR AVIATION CONDITIONS WILL HOLD UNTIL NEAR OR SHORTLY AFTER
SUNRISE... WHEN IMPROVEMENT TO VFR IS EXPECTED BETWEEN 12Z AND 16Z.
A COMPLEX OF SURFACE LOW PRESSURE CENTERS CROSSING THE AREA IS
BRINGING UNSETTLED WEATHER IN THE FORM OF IFR/LIFR CIGS AND MVFR TO
IFR VSBYS EARLY THIS MORNING. THESE CLOUDS WILL PERSIST FOR SEVERAL
MORE HOURS... ALONG WITH PATCHY LIGHT RAIN THAT WILL CROSS CENTRAL
NC. THIS RAIN IS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE THAT
WILL SWEEP THROUGH THE AREA EARLY THIS MORNING. ONCE THIS
DISTURBANCE PASSES TO OUR EAST NEAR OR SOON AFTER SUNRISE... LOW
LEVEL WINDS WILL BECOME FROM THE WNW OR NW (FROM 270-320 DEGREES)
AND WILL INCREASE IN SPEED TO 8-12 KTS OCCASIONALLY GUSTING TO 18-22
KTS MID-LATE MORNING THROUGH AFTERNOON. THIS DOWNSLOPE DRYING FLOW
WILL SCOUR OUT THE LOW CLOUDS BETWEEN 12Z (WRN TAFS) AND 16Z (ERN
TAFS). THUS... CONFIDENCE IS HIGH IN VFR CONDITIONS AT ALL SITES BY
MID TO LATE AFTERNOON. WINDS WILL DIMINISH TO 8 KTS OR LESS AROUND
SUNSET. CLEAR SKIES AND VFR VSBYS ARE EXPECTED TONIGHT AS HIGH
PRESSURE NOSES INTO THE AREA.
LOOKING BEYOND 06Z TONIGHT... HIGH CONFIDENCE IN VFR CONDITIONS LATE
TONIGHT THROUGH THURSDAY... AS SURFACE HIGH PRESSURE DOMINATES WITH
DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 AM EST SUN DEC 14 2013
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE CAROLINAS
EARLY THIS MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
FROM THE SOUTHWEST LATE TODAY THROUGH MID WEEK... PROVIDING FAIR AND
DRY WEATHER. THIS HIGH WILL SHIFT OFF THE COAST LATE WEDNESDAY...
BRINGING A WARMING TREND THROUGH LATE WEEK.
&&
NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 215 AM SUNDAY...
THROUGH TODAY: GREATLY IMPROVING WEATHER IS EXPECTED THIS MORNING.
THE LATEST SURFACE MAP SHOWS THE WEDGE FRONT HAVING MOVED JUST EAST
OF THE CWA... WHILE THE PRIMARY OCCLUDED FRONT HAS MOVED INTO THE NC
MOUNTAINS. WE REMAIN ON THE EAST SIDE OF THE APPROACHING BROAD
TROUGH... AND WHILE THE HEAVIEST RAIN HAS SHIFTED OFF THE COAST... A
POCKET OF MID LEVEL VORTICITY SHEARING OUT OF THE TROUGH BASE ACROSS
THE CENTRAL CAROLINAS IS RESPONSIBLE FOR A BATCH OF MOSTLY LIGHT
RAIN STREAMING OVER THE AREA. THE LATEST HRRR GUIDANCE DEPICTS THIS
PRECIP WELL AND SHOWS THIS LIGHT RAIN AREA PUSHING EASTWARD OUT OF
THE CWA BETWEEN 8 AM AND 10 AM AS THE MID LEVEL TROUGH AXIS CROSSES
THE AREA. THICK LOW CLOUDS WILL PERSIST UNTIL THEN... AS WE`RE
SEEING COOLING AT THE SURFACE BUT THE 925 MB/850 MB TROUGH AXES ARE
STILL TO OUR WEST... YIELDING A VERTICAL THERMAL DIFFERENTIAL AND
FOSTERING LOW LEVEL STABILIZATION (EXACERBATED BY A LOOSE MSLP
GRADIENT AND LIGHT SURFACE WINDS)... HINDERING MIXING. AFTER THE
OCCLUDED FRONT PASSES THROUGH BY MID TO LATE MORNING... THE ENSUING
DOWNSLOPE LOW LEVEL FLOW WILL HELP DRY OUT THE LOWER TROPOSPHERE...
WHILE INCREASING DEEP LAYER SUBSIDENCE IN THE WAKE OF THE DEPARTING
BROAD TROUGH AXIS HELPS DRY AND STABILIZE THE MID-UPPER LEVELS.
EXPECT PLENTY OF SUNSHINE BY THE AFTERNOON HOURS. THICKNESSES DO
FALL DURING THE DAY (MUCH OF WHICH IS A FUNCTION OF COOLING AT 925-
850 MB WITH GOOD DRYING BUT NOT A LOT OF COOLING BELOW 925 MB)...
BUT THE INCOMING AIR MASS IS MODIFIED AND SOURCED FROM OUR WSW...
AND LATE-DAY THICKNESSES ARE STILL JUST SLIGHTLY BELOW NORMAL. HIGHS
49-57... NEAR TO SLIGHTLY UNDER SEASONAL NORMALS. EXPECT BREEZY WNW
WINDS WITH OCCASIONAL GUSTS AS THE COOLER AND MORE DENSE AIR ARRIVES
WITH SHALLOW BUT PRONOUNCED MIXING.
FOR TONIGHT: AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST... A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW... ENSURING
CONTINUED DRY AND STABLE LOW LEVELS... WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 255 PM SATURDAY...
TO BE UPDATED.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 235 PM SATURDAY...
A LOW PRESSURE SYSTEM DIVING OUT OF THE CANADIAN ROCKIES WILL
APPROACH THE GREAT LAKES AND DIVE THROUGH NEW ENGLAND AS AN UPPER
LEVEL TROUGH DIGS DOWN THE EASTERN SEABOARD BUT WILL HAVE A HARD
TIME EXTENDING SOUTHWARD. THIS WILL MAKE UPPER LEVEL FLOW MORE ZONAL
OVER NORTH CAROLINA CAUSING A FAIRLY CONSTANT TEMPERATURE PATTERN
WITH SOME OSCILLATION IN HIGH AND LOW TEMPS FOR THE FIRST TWO THIRDS
OF THE PERIOD. BY THE END OF THE WEEK A FEW SHORTWAVES DEVELOP IN
THE SOUTHERN STREAM AND STRONG WARM AIR ADVECTION TAKES TEMPERATURES
WELL ABOVE SEASONAL NORMALS FOR FRIDAY AND SATURDAY BEFORE A
STRONGER LOW DEVELOPS AND MOVES THROUGH THE OHIO VALLEY ON SUNDAY.
TUESDAY: WHILE MODELS GENERALLY KEEP THE PATTERN THE SAME
...THE GFS HAS A BROADER SURFACE HIGH OVER THE REGION...THUS
SHUTTING OFF ANY SLIGHT COLD AIR ADVECTION ON THE FRONT SIDE OF THE
HIGH. THE ECMWF HANGS BACK WITH THIS AND THUS ITS TEMPERATURES ARE
COOLER. EITHER WAY A SLIGHT WARMING TREND FROM MONDAY TO TUESDAY
WITH UPPER 40S TO LOW 50S EXPECTED MONDAY AND MID 50S ON TUESDAY.
DRY AND MOSTLY CLEAR WITH VERY LIGHT WINDS OUT OF THE NORTHWEST.
LOWS IN THE LOWER TO MID 30S.
WEDNESDAY AND THURSDAY: A MORE NORTHWESTERLY UPPER LEVEL FLOW AND A
TIGHTER GRADIENT IN THE GFS YIELD SOME LOWER TEMPERATURES FOR
WEDNESDAY BUT THE PATTERN IS MORE RELAXED IN THE LATEST EUROPEAN
WITH MOST OF THE STRONGER DYNAMICS WELL TO THE NORTH. WILL INDICATE
A SMALL REDUCTION IN HIGHS ON WEDNESDAY...LOWER TO MID 50S WITH LOWS
IN THE LOWER 30S THURSDAY MORNING. ON THURSDAY UPPER LEVEL FLOW WILL
BEGIN TO BACK AROUND TO WESTERLY AND THEN SOUTHWESTERLY. AT THE SAME
TIME THE SURFACE HIGH MOVES OFF SHORT. THIS WILL BEGIN A PERIOD OF
SIGNIFICANT WARM AIR ADVECTION WHICH WILL PUT HIGHS ON THURSDAY INTO
THE MID TO UPPER 50S WITH LOWS IN THE LOWER 40S.
FRIDAY AND SATURDAY: AS FLOW BECOMES MORE SOUTHWESTERLY...INCREASED
WARM AIR ADVECTION WILL HELP TEMPERATURES RISE ABOVE SEASONAL
NORMALS. INCREASED MOISTURE AHEAD OF A DEVELOPING FRONTAL ZONE IN
THE TN VALLEY WILL BEGIN TO BRING MORE CLOUDS INTO THE AREA AND A
SLIGHT CHANCE OF SOME DRIZZLE OR LIGHT RAIN FRIDAY AFTERNOON AND
EVENING...INCREASING TO CHANCE OF RAIN BY SATURDAY. HIGHEST
POTENTIAL FOR RAIN WILL BE IN THE NORTHWEST. HIGHS POTENTIALLY
RISING TO THE MID TO UPPER 60S BY SATURDAY...ALMOST 15 DEGREES ABOVE
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM SUNDAY...
SUB-VFR AVIATION CONDITIONS WILL HOLD UNTIL NEAR OR SHORTLY AFTER
SUNRISE... WHEN IMPROVEMENT TO VFR IS EXPECTED BETWEEN 12Z AND 16Z.
A COMPLEX OF SURFACE LOW PRESSURE CENTERS CROSSING THE AREA IS
BRINGING UNSETTLED WEATHER IN THE FORM OF IFR/LIFR CIGS AND MVFR TO
IFR VSBYS EARLY THIS MORNING. THESE CLOUDS WILL PERSIST FOR SEVERAL
MORE HOURS... ALONG WITH PATCHY LIGHT RAIN THAT WILL CROSS CENTRAL
NC. THIS RAIN IS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE THAT
WILL SWEEP THROUGH THE AREA EARLY THIS MORNING. ONCE THIS
DISTURBANCE PASSES TO OUR EAST NEAR OR SOON AFTER SUNRISE... LOW
LEVEL WINDS WILL BECOME FROM THE WNW OR NW (FROM 270-320 DEGREES)
AND WILL INCREASE IN SPEED TO 8-12 KTS OCCASIONALLY GUSTING TO 18-22
KTS MID-LATE MORNING THROUGH AFTERNOON. THIS DOWNSLOPE DRYING FLOW
WILL SCOUR OUT THE LOW CLOUDS BETWEEN 12Z (WRN TAFS) AND 16Z (ERN
TAFS). THUS... CONFIDENCE IS HIGH IN VFR CONDITIONS AT ALL SITES BY
MID TO LATE AFTERNOON. WINDS WILL DIMINISH TO 8 KTS OR LESS AROUND
SUNSET. CLEAR SKIES AND VFR VSBYS ARE EXPECTED TONIGHT AS HIGH
PRESSURE NOSES INTO THE AREA.
LOOKING BEYOND 06Z TONIGHT... HIGH CONFIDENCE IN VFR CONDITIONS LATE
TONIGHT THROUGH THURSDAY... AS SURFACE HIGH PRESSURE DOMINATES WITH
DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...NP
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1227 AM EST SUN DEC 15 2013
.SYNOPSIS...
LOW PRESSURE WILL PASS WEST OF THE AREA TONIGHT...BRINGING PERIODS OF
RAIN INTO SUNDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON
SUNDAY...BRINGING COOL AND DRY WEATHER INTO EARLY NEXT WEEK. DRY
AND SEASONABLE WEATHER EXPECTED MUCH OF NEXT WEEK AS SURFACE HIGH
PRESSURE IS REINFORCED OVER THE AREA. A LOW PRESSURE SYSTEM WILL
APPROACH THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1200 AM SUNDAY...TORNADO WATCH HAS BEEN CANCELLED FOR THE
REMAINING ILM NC CWA. WINDS THRU THE ATM COLUMN HAVE BECOME MORE
UNIDIRECTIONAL...DIMINISHING THE TORNADO THREAT SOMEWHAT...
EVENTHOUGH SOME SPEED SHEAR REMAINS. INSTABILITY IS NO LONGER
EVIDENT AND PLENTIFUL LIKE EARLIER THIS EVENING RELATIVELY
SPEAKING.
A NE TO SW SFC BOUNDARY EXTENDS ACROSS THE FA...IE. COULD CALL IT
A PRE-FRONTAL BOUNDARY...HAS PUSHED EASTWARD ACROSS THE ILM CWA
RESULTING WITH SFC WINDS VEERING TO THE SW-W. THE SFC COLD FRONT
IS LAGGING BEHIND BUT SHOULD PUSH THROUGH EITHER OVERNIGHT OR
DURING SUNDAY. AFTER THE CFP...LOOK FOR A TREND OF DECREASING
TEMPS/DEWPTS AND WINDS VEERING TO THE NW-N. COULD OBSERVE POST
FRONTAL LIGHT PCPN. THE MAJORITY OF THE PCPN ACTIVITY HAS PUSHED
AWAY FROM THE ILM NC CWA AND ADJACENT WATERS. AND NO LONGER POSES
A SVR THREAT FOR THE ILM CWA.
THE SFC BASED MARINE LAYER HAD PUSHED PARTIALLY INLAND FROM THE
SE-S WINDS EARLIER TODAY BUT IS APPARENTLY NOT DEEP ENOUGH TO
PREVENT THUNDERSTORM DEVELOPMENT. LOCAL SHELF WATER SSTS ARE IN
THE 50S...BUT SSTS IN THE 70S LURK JUST BEYOND 20 NM OUT FROM THE
COAST. ONCE THE 50S SSTS EXPAND FURTHER FROM THE CAROLINA COASTS
DURING THIS WINTER SEASON...THE MARINE LAYER WILL BECOME MORE
PREVALENT AND A DETERRENT FOR CONVECTIVE DEVELOPMENT. MINOR TWEAKS
FOR PCPN TIMING AS IT TRACKS ACROSS THE FA HAVE BEEN APPLIED. THE
WEAK INSTABILITY FOR CONVECTION HAS BEEN OVERCOME BY THE POTENT
DYNAMICS FROM A ROBUST MID-LEVEL S/W TROF PUSHING ACROSS THE SE
STATES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...THE SHORT TERM FORECAST IS RATHER STRAIGHT
FORWARD AS THE MID LEVEL TROUGH WILL CONTINUE TO MOVE OFFSHORE
SUNDAY WITH A MODEST NORTHWEST FLOW ENSUING THROUGH THE REMAINDER
OF THE PERIOD.
AT THE SURFACE...HIGH PRESSURE BUILDS IN FROM THE NORTHWEST THEN THE
SURFACE PATTERN SHOWS A WEAKNESS DEVELOPING LATER MONDAY. ALTHOUGH
THERE ARE WEAK SHORTWAVES IN THE FLOW...NONE ARE STRONG ENOUGH TO
REINFORCE THE MODEST COLD AIR ADVECTION THAT MOVES IN SUNDAY.
OVERALL GUIDANCE REMAINS IN GOOD AGREEMENT WITH HIGHS IN THE 50S AND
LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...ZONAL FLOW ON TUESDAY EVEN AS IMPRESSIVE JET
OF 100KT DIVES ACROSS NRN PLAINS. THE MID LEVEL WAVE WRAPS UP FAIRLY
QUICKLY AND THUS DOES NOT LEAD TO A VERY DEEP TROUGH. EVEN SO IT
WILL MANAGE TO PUSH A RAIN-FREE COLD FRONT THROUGH THE CAROLINAS
TUESDAY NIGHT. HIGH RISES ALREADY UNDERWAY THOUGH WEDNESDAY MORNING
AS THE SYSTEM ALOFT SWINGS NEGATIVE AND LIFTS INTO NEW ENGLAND.
WEDNESDAY IS WHEN SURFACE PRESSURE GRADIENT FINALLY BECOMES LESS
NOISY AS HIGH PRESSURE CONGEALS OVER THE NC SOUNDS WHILE SUBTLE MID
LEVEL HEIGHT RISES CONTINUE. SURFACE RIDGE MOVES CONSIDERABLY TO THE
EAST FOR THE LATE WEEK PERIOD AND MID LEVEL TROUGHINESS DEVELOPS
OVER THE SWRN U.S. BOUNDARY LAYER WARMTH AND MOISTURE WILL BE ON THE
RISE BUT NOT SUFFICIENTLY FOR ANY MEANINGFUL RAIN CHANCES.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...CONVECTION ONGOING WITH BRIEF PERIODS OF 1-2SM
VISIBILITY IN HEAVY SHOWERS...WITH ISOLATED EMBEDDED THUNDER. STRONG
HELICITY COUNTERED BY WEAK CAPE WILL LIKELY PRODUCE ISOLATED SEVERE
WEATHER. MOST OF THE ACTIVITY WILL BE OVER BY 03Z. THE HRRR HAS A
SECONDARY LINE MOVING FROM WEST TO EAST ALONG THE FRONT...BUT THE
AREA IS WEAKER THAN THE EARLIER MAIN LINE. LOOK FOR BRIEF BOUTS OF
IFR STRATUS. OVERNIGHT...CONDITIONS WILL IMPROVE AS THE THE FRONT
MOVES THROUGH. WINDS WILL SHIFT TO THE WEST...REMAINING ELEVATED.
SHOWERS WILL END FROM WEST TO EAST BY 06-08Z. BECOMING VFR TOWARD
MORNING...CONTINUING ON SUNDAY WITH A GUSTY NORTHWEST WIND.
EXTENDED OUTLOOK...SHOWERS LIKELY WITH PERIODS OF MVFR/IFR
CONDITIONS INTO EARLY SUNDAY. VFR DEVELOPING SUNDAY AND
PERSISTING THROUGH MID-WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1210 AM SUNDAY...REMAINING TORNADO-WATERSPOUT WATCH HAS BEEN
CANCELLED. THE MARINE LAYER ACROSS THE ILM COASTAL WATERS WHERE
SSTS IN THE 50S...REMAINS JUST THICK ENOUGH TO PREVENT THE HIER
SUSTAINED WINDS ALOFT FROM WORKING THEIR WAY TO THE OCEAN SFC.
THIS WILL RESULT IN THE CONTINUATION OF A STRONG SCA ACROSS ALL
WATERS...WITH A FEW GALE FORCE GUSTS POSSIBLE ACROSS THE OUTER
WATERS OFF CAPE FEAR. JUST BEYOND 20 NM OUT...SSTS ARE IN THE 60S
AND 70S ALLOWING THE STRONGER WINDS ALOFT TO MIX DOWN TO THE OCEAN
SFC. WITH A SW WIND...AN ONSHORE TO PARALLEL TRAJECTORY...THE HIER
WIND DRIVEN WAVES PRODUCED JUST OFFSHORE...IE. LATEST BUOY 41013
AT 15 FEET...WILL PUSH INTO THE COASTAL WATERS. AS A RESULT...
HAVE MODIFIED THE SIGNIFICANT SEAS ACROSS THE COASTAL WATERS BY
TWEAKING THEM TO MESH THE CURRENT CONDITIONS WITH THE FORECAST.
THE SFC BOUNDARY EXTENDING NE-SW HAS PARTIALLY PUSHED THROUGH THE
COASTAL WATERS...WITH WINDS VEERING TO THE SW-W. THE NEXT VEERING
OF THE WINDS TO NW-N WILL OCCUR WITH THE CFP EITHER DURING THE
PRE- DAWN SUNDAY HRS OR SOON THERE-AFTER.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...INITIALLY A WESTERLY FLOW WILL BE IN PLACE
OVER THE WATERS IN A RANGE OF 15-20 KNOTS. AS SUNDAY
PROGRESSES...WINDS WILL OBTAIN A MORE NORTHWESTERLY COMPONENT AND
DECREASE. THE WINDS WILL VERY GRADUALLY DIMINISH TO 10-15 KNOTS
THROUGH THE REMAINDER OF THE PERIOD. AS FOR SEAS...THE CHANGE IN
FETCH WILL BE WELL UNDERWAY EARLY WITH A FEW SIX FOOTERS REMAINING
ACROSS THE OUTER WATERS WITH A WIDE RANGE OF 2-6 FEET. SEAS WILL
GRADUALLY DIMINISH TO 2-3 FEET BY MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM SATURDAY...WEST TO SOUTHWEST WINDS PICK UP AHEAD OF A
COLD FRONT ON TUESDAY. THE OFFSHORE FLOW DIRECTION BUILDS SEAS AWAY
FROM SHORE TO 3 OR 4 FT WHILE LANDMASS WAVE SHADOWING KEEPS THE
NEARSHORE WAVES CLOSER TO 2 FT. VEERING FLOW BEHIND THE BOUNDARY ON
WEDNESDAY TO SHORTEN THE PERIOD SOMEWHAT AS WAVE FACES STEEPEN BUT
LITTLE OVERALL CHANGE IN SIG WAVE HEIGHT EXPECTED. THURSDAY PUTS US
INTO A SOUTHERLY RETURN FLOW REGIME THAT WILL LAST FOR SEVERAL
DAYS. ANY BUILDING OF SEAS WILL BE GRADUAL AND LIKELY NOT OCCUR
UNTIL AFTER THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1145 PM EST SAT DEC 14 2013
.SYNOPSIS...
LOW PRESSURE WILL PASS WEST OF THE AREA TONIGHT...BRINGING PERIODS OF
RAIN INTO SUNDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON
SUNDAY...BRINGING COOL AND DRY WEATHER INTO EARLY NEXT WEEK. DRY
AND SEASONABLE WEATHER EXPECTED MUCH OF NEXT WEEK AS SURFACE HIGH
PRESSURE IS REINFORCED OVER THE AREA. A LOW PRESSURE SYSTEM WILL
APPROACH THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1100 PM SATURDAY...TORNADO WATCH IN EFFECT FOR PORTIONS OF
THE ILM CWA THRU 200 AM EST SUNDAY. BASICALLY IT INCLUDES ALL OF
THE ILM NC CWA...WITH THE ILM SC CWA HAVING BEEN CANCELED. WINDS
THRU THE ATM COLUMN ESPECIALLY ACROSS THE ILM SC CWA HAS BECOME
MORE UNIDIRECTIONAL...DIMINISHING THE TORNADO THREAT
SOMEWHAT...WITH DECENT SPEED SHEAR REMAINING
A NE TO SW SFC BOUNDARY EXTENDS ACROSS THE FA...IE. COULD CALL IT
A PRE-FRONTAL BOUNDARY...HAS PUSHED EASTWARD ACROSS THE MAJORITY
OF THE ILM CWA RESULTING WITH SFC WINDS VEERING TO THE SW-W. THE
SFC COLD FRONT LAGGING BEHIND BUT SHOULD PUSH THROUGH EITHER
OVERNIGHT OR DURING SUNDAY. AFTER THE CFP...LOOK FOR A TREND OF
DECREASING TEMPS/DEWPTS AND WINDS VEERING TO THE NW-N. COULD
OBSERVE POST FRONTAL LIGHT PCPN BUT THE MAJORITY OF THE STRONGER
PCPN ACTIVITY IS PASSING ACROSS THE ILM NC CWA AND ADJACENT
WATERS. AND EVEN THIS AREA OF ISOLATED CONVECTION HAS BECOME LESS
POTENT COMPARED TO EARLIER THIS EVENING.
THE SFC BASED MARINE LAYER HAD PUSHED PARTIALLY INLAND FROM THE
SE-S WINDS BUT IS APPARENTLY NOT DEEP ENOUGH TO PREVENT
THUNDERSTORM DEVELOPMENT. LOCAL SHELF WATERS SSTS ARE IN THE
50S...BUT SSTS IN THE 70S LURK JUST BEYOND 20 NM OUT FROM THE
COAST. ONCE THE 50S SSTS EXPAND FURTHER FROM THE CAROLINA COASTS
DURING THIS WINTER SEASON...THE MARINE LAYER WILL BECOME MORE
PREVALENT AND A DETERRENT FOR CONVECTIVE DEVELOPMENT. MINOR TWEAKS
FOR PCPN TIMING AS IT TRACKS ACROSS THE FA HAVE BEEN APPLIED. THE
WEAK INSTABILITY FOR CONVECTION HAS BEEN OVERCOME BY THE POTENT
DYNAMICS FROM A ROBUST MID-LEVEL S/W TROF PUSHING ACROSS THE SE
STATES.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...THE SHORT TERM FORECAST IS RATHER STRAIGHT
FORWARD AS THE MID LEVEL TROUGH WILL CONTINUE TO MOVE OFFSHORE
SUNDAY WITH A MODEST NORTHWEST FLOW ENSUING THROUGH THE REMAINDER
OF THE PERIOD.
AT THE SURFACE...HIGH PRESSURE BUILDS IN FROM THE NORTHWEST THEN THE
SURFACE PATTERN SHOWS A WEAKNESS DEVELOPING LATER MONDAY. ALTHOUGH
THERE ARE WEAK SHORTWAVES IN THE FLOW...NONE ARE STRONG ENOUGH TO
REINFORCE THE MODEST COLD AIR ADVECTION THAT MOVES IN SUNDAY.
OVERALL GUIDANCE REMAINS IN GOOD AGREEMENT WITH HIGHS IN THE 50S AND
LOWS IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...ZONAL FLOW ON TUESDAY EVEN AS IMPRESSIVE JET
OF 100KT DIVES ACROSS NRN PLAINS. THE MID LEVEL WAVE WRAPS UP FAIRLY
QUICKLY AND THUS DOES NOT LEAD TO A VERY DEEP TROUGH. EVEN SO IT
WILL MANAGE TO PUSH A RAIN-FREE COLD FRONT THROUGH THE CAROLINAS
TUESDAY NIGHT. HIGH RISES ALREADY UNDERWAY THOUGH WEDNESDAY MORNING
AS THE SYSTEM ALOFT SWINGS NEGATIVE AND LIFTS INTO NEW ENGLAND.
WEDNESDAY IS WHEN SURFACE PRESSURE GRADIENT FINALLY BECOMES LESS
NOISY AS HIGH PRESSURE CONGEALS OVER THE NC SOUNDS WHILE SUBTLE MID
LEVEL HEIGHT RISES CONTINUE. SURFACE RIDGE MOVES CONSIDERABLY TO THE
EAST FOR THE LATE WEEK PERIOD AND MID LEVEL TROUGHINESS DEVELOPS
OVER THE SWRN U.S. BOUNDARY LAYER WARMTH AND MOISTURE WILL BE ON THE
RISE BUT NOT SUFFICIENTLY FOR ANY MEANINGFUL RAIN CHANCES.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...CONVECTION ONGOING WITH BRIEF PERIODS OF 1-2SM
VISIBILITY IN HEAVY SHOWERS...WITH ISOLATED EMBEDDED THUNDER. STRONG
HELICITY COUNTERED BY WEAK CAPE WILL LIKELY PRODUCE ISOLATED SEVERE
WEATHER. MOST OF THE ACTIVITY WILL BE OVER BY 03Z. THE HRRR HAS A
SECONDARY LINE MOVING FROM WEST TO EAST ALONG THE FRONT...BUT THE
AREA IS WEAKER THAN THE EARLIER MAIN LINE. LOOK FOR BRIEF BOUTS OF
IFR STRATUS. OVERNIGHT...CONDITIONS WILL IMPROVE AS THE THE FRONT
MOVES THROUGH. WINDS WILL SHIFT TO THE WEST...REMAINING ELEVATED.
SHOWERS WILL END FROM WEST TO EAST BY 06-08Z. BECOMING VFR TOWARD
MORNING...CONTINUING ON SUNDAY WITH A GUSTY NORTHWEST WIND.
EXTENDED OUTLOOK...SHOWERS LIKELY WITH PERIODS OF MVFR/IFR
CONDITIONS INTO EARLY SUNDAY. VFR DEVELOPING SUNDAY AND
PERSISTING THROUGH MID-WEEK.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM SATURDAY...WATERSPOUT WATCH REMAINS IN EFFECT FOR
THE ILM NC COASTAL WATERS THROUGH 2 AM. THE MARINE LAYER ACROSS
THE ILM COASTAL WATERS WHERE SSTS ARE IN THE 50S...REMAINS JUST
THICK ENOUGH TO PREVENT THE HIER SUSTAINED WINDS ALOFT FROM
WORKING THEIR WAY TO THE OCEAN SFC. THIS WILL RESULT IN THE
CONTINUATION OF A STRONG SCA ACROSS ALL WATERS...WITH A FEW GALE
FORCE GUSTS POSSIBLE ACROSS THE OUTER WATERS OFF CAPE FEAR. JUST
BEYOND 20 NM OUT...SSTS ARE IN THE 60S AND 70S ALLOWING THE
STRONGER WINDS ALOFT TO MIX DOWN TO THE OCEAN SFC. WITH A S-SW
WIND...AN ONSHORE TO PARALLEL TRAJECTORY...THE HIER WIND DRIVEN
WAVES PRODUCED JUST OFFSHORE...IE. LATEST BUOY 41013 AT 15 FEET
...WILL PUSH INTO THE COASTAL WATERS. AS A RESULT...HAVE
MODIFIED THE SIGNIFICANT SEAS ACROSS THE COASTAL WATERS BY
TWEAKING THEM TO MESH WITH THE CURRENT CONDITIONS AND FORECAST.
THE SFC BOUNDARY EXTENDING NE-SW HAS PARTIALLY PUSHED INTO THE
COASTAL WATERS...WITH WINDS VEERING TO THE S-SW. THE NEXT VEERING
OF THE WINDS TO NW-N WILL OCCUR WITH THE CFP EITHER DURING THE
PRE-DAWN SUNDAY HRS OR SOON THERE-AFTER.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...INITIALLY A WESTERLY FLOW WILL BE IN PLACE
OVER THE WATERS IN A RANGE OF 15-20 KNOTS. AS SUNDAY
PROGRESSES...WINDS WILL OBTAIN A MORE NORTHWESTERLY COMPONENT AND
DECREASE. THE WINDS WILL VERY GRADUALLY DIMINISH TO 10-15 KNOTS
THROUGH THE REMAINDER OF THE PERIOD. AS FOR SEAS...THE CHANGE IN
FETCH WILL BE WELL UNDERWAY EARLY WITH A FEW SIX FOOTERS REMAINING
ACROSS THE OUTER WATERS WITH A WIDE RANGE OF 2-6 FEET. SEAS WILL
GRADUALLY DIMINISH TO 2-3 FEET BY MONDAY.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM SATURDAY...WEST TO SOUTHWEST WINDS PICK UP AHEAD OF A
COLD FRONT ON TUESDAY. THE OFFSHORE FLOW DIRECTION BUILDS SEAS AWAY
FROM SHORE TO 3 OR 4 FT WHILE LANDMASS WAVE SHADOWING KEEPS THE
NEARSHORE WAVES CLOSER TO 2 FT. VEERING FLOW BEHIND THE BOUNDARY ON
WEDNESDAY TO SHORTEN THE PERIOD SOMEWHAT AS WAVE FACES STEEPEN BUT
LITTLE OVERALL CHANGE IN SIG WAVE HEIGHT EXPECTED. THURSDAY PUTS US
INTO A SOUTHERLY RETURN FLOW REGIME THAT WILL LAST FOR SEVERAL
DAYS. ANY BUILDING OF SEAS WILL BE GRADUAL AND LIKELY NOT OCCUR
UNTIL AFTER THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS PORTLAND OR
950 PM PST SAT DEC 14 2013
.SYNOPSIS...TODAY WAS A CHILLY...CLAMMY DECEMBER DAY FOR MUCH OF
SOUTHWEST WASHINGTON AND NORTHWEST OREGON...AS ABUNDANT LOW CLOUDS
AND FOG LINGER UNDER INCREASING HIGH CLOUDINESS ALOFT. AREAS OF
DRIZZLE OR LIGHT RAIN WILL INCREASE FROM THE NORTH LATER TONIGHT AND
SUNDAY AS A WEAK COLD FRONT MOVES ONSHORE. MONDAY AND TUESDAY SHOULD
BE DRIER AS HIGH PRESSURE MOVES IN OVER THE PACIFIC NORTHWEST...
THOUGH VALLEY FOG WILL PROBABLY LINGER NEAR EUGENE. A COLDER SYSTEM
IS EXPECTED TO BRING RAIN AND MOUNTAIN SNOW WEDNESDAY AND
THURSDAY...WITH MORE UNSETTLED WEATHER POSSIBLE FRIDAY.
&&
.UPDATE...HAVE ADDED A DENSE FOG ADVISORY FOR THE CENTRAL AND SOUTH VALLEY
FOR NOW...AS ENOUGH LOCATIONS CLOSE TO MAJOR ROADWAYS HAVE ONE QUARTER MILE
VISIBILITY OR LESS. /KMD
LOW CLOUDS AND FOG HANGING ON STRONG THIS EVENING...THOUGH
VISIBILITIES ARE ALL OVER THE BOARD... FROM ONE QUARTER MILE OR LESS
TO 6-8 MILES. EXPECT THAT THERE WILL BE SOME DENSE FOG AS THE LOW
LEVELS ARE FAIRLY STABLE AND IT IS CERTAINLY VERY MOIST...BUT WITH
THE INCOMING FRONT WE MAY HAVE JUST ENOUGH WIND TO PREVENT WIDESPREAD
DENSE FOG. THIS IS ESPECIALLY TRUE LATER TONIGHT AS THE FRONT GETS
CLOSER...AND THE HRRR SUGGESTS SOME IMPROVEMENT. THE MOST WIND IS
AROUND THE NORTH VALLEY. THE MESSAGE IS STILL THE SAME...QUITE A BIT
OF FOG...LOCALLY DENSE. FAVORED SPOTS FOR DENSE FOG WILL BE THOSE
THAT HAVE BEEN SEEING IT TO THIS POINT...EUGENE AIRPORT...
MCMINNVILLE...AURORA...AND HILLSBORO...AND ANY HIGHER HILLS THAT ARE
UP INTO THE VERY LOW STRATUS DECK. /KMD
.SHORT TERM...TONIGHT THROUGH TUESDAY...TODAY HAS BEEN A FAIRLY
TYPICAL DECEMBER DAY ACROSS SOUTHWEST WASHINGTON AND NORTHWEST
OREGON...WITH PATCHY FOG LINGERING WELL INTO THE AFTERNOON HOURS...
CHILLY TEMPERATURES AND HIGH RELATIVE HUMIDITY. THE LOW SUN ANGLE
COMBINED WITH INCREASING HIGH CLOUD COVER HAS DONE LITTLE TO BREAK UP
THE LOW CLOUDS WHICH FORMED IN THE VALLEYS OVERNIGHT. THEREFORE
TEMPERATURES HAVE STRUGGLED TO GET MUCH ABOVE 40 DEGREES FOR MOST
LOCATIONS...THOUGH A FEW FOOTHILL LOCATIONS ABOVE THE FOG/LOW CLOUDS
HAVE WARMED UP A LITTLE BETTER...INTO THE UPPER 40S AND LOWER 50S.
AS A SIDE NOTE...AS WE NEAR THE WINTER SOLSTICE...THE SUN ANGLE FOR
PORTLAND AT ITS PEAK OF SOLAR NOON IS ONLY ABOUT 22 DEGREES ABOVE THE
SOUTH HORIZON THIS TIME OF YEAR. HENCE THE LONG SHADOWS WHEN THE SUN
IS ACTUALLY OUT...AND THE LACK OF EFFECTIVENESS OF THE SUN AT WARMING
US UP AND DRYING US OUT THIS TIME OF YEAR.
ANYWAY...PATCHY DRIZZLE CONTINUES TO CAUSE SPOTTY ACCUMULATIONS OF
0.01 INCH HERE AND THERE IN THE COAST RANGE AND CASCADE FOOTHILLS...
NOT TO BE CONFUSED WITH SNOW MELTING INTO THE UNHEATED RAIN GAGES AT
THE HIGHER ELEVATIONS. DRIZZLE AND LIGHT RAIN SHOULD INCREASE FROM
THE NORTH LATER TONIGHT AND SUNDAY...ESPECIALLY IN THE COAST RANGE.
ONLY MINIMAL PRECIPITATION IF ANY IS EXPECTED FOR THE INLAND
VALLEYS...WITH THE BEST CHANCE NORTH. WITH MORE MOISTURE AND WEAK
FLOW...THERE SHOULD BE PLENTY OF LOW CLOUDS AND FOG AROUND AGAIN
SUNDAY. TEMPERATURES SUNDAY SHOULD BE A LOT LIKE TODAY...PERHAPS A
TOUCH WARMER DUE TO THE HIGHER DEWPOINT SUBTROPICAL AIR MOVING IN.
SNOW LEVELS WILL BE HIGH...SO SNOW IS NOT A CONCERN FOR THE CASCADE
PASSES.
MORE FOG SHOULD SETTLE IN SUN NIGHT/MON MORNING...BUT HIGH PRESSURE
IS EXPECTED TO BUILD INTO WASHINGTON BY MONDAY AFTERNOON. THIS IS
EXPECTED TO RESULT IN INCREASING NORTHERLY AND EVENTUALLY
NORTHEASTERLY FLOW MONDAY...POSSIBLY LEADING TO SOME DRYING AND
SUNBREAKS MOST AREAS BY AFTERNOON. THE NORTHERLY FLOW SHOULD CAUSE
THE LOW CLOUDS TO BANK UP AGAINST THE SOUTH END OF THE WILLAMETTE
VALLEY...LEADING TO ANOTHER CHILLY AND CLAMMY DAY AT EUGENE WITH
HIGHS AROUND 40 MONDAY WHILE MOST OTHER AREAS AIM FOR 50 DEGREES OR
A LITTLE HIGHER.
FOG AND LOW CLOUDS SHOULD BE A LITTLE LESS WIDESPREAD MON NIGHT/TUE
MORNING DUE TO THE OFFSHORE FLOW...EXCEPT IN THE SOUTH WILLAMETTE
VALLEY. HOWEVER INCREASING MID-HIGH LEVEL CLOUDS SHOULD KEEP
TEMPERATURES NEAR NORMAL...MAINLY IN THE 40S AND LOWER 50S...TUE
AFTERNOON. WEAGLE
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY. THE EXTENDED PERIOD
BEGINS WITH AN UPPER LEVEL TROUGH DROPPING DOWN THROUGH THE REGION
ALONG THE COAST. AN ASSOCIATED COLD FRONT WILL MOVE ACROSS THE AREA
ON WEDNESDAY ALONG WITH PRECIPITATION IN THE FORM OF WIDESPREAD RAIN
AND CASCADE SNOW. SNOW LEVELS WILL LOWER BEHIND THE FRONT WEDNESDAY
NIGHT AND SOME SHOWERS WILL LINGER INTO THURSDAY UNDER NORTHWEST
FLOW ALOFT. IT IS POSSIBLE THAT THE CASCADE FOOTHILLS AND COAST
RANGE MAY ALSO SEE SOME ACCUMULATING SNOW...THOUGH THIS WILL DEPEND
ON THE FROPA TIMING AND MOISTURE EXTENT.
BY THE END OF THE WEEK...THE RIDGE OF HIGH PRESSURE IN THE PACIFIC
IS CENTERED NEAR 140W KEEPING THE REGION UNDER NORTHWEST FLOW ALOFT.
LATE THURSDAY AFTERNOON AND NIGHT MAY BE DRY AHEAD OF THE NEXT
DISTURBANCE THAT WILL MOVE INTO THE AREA FROM THE NORTH ON FRIDAY OR
FRIDAY NIGHT. FORECAST MODEL AGREEMENT DECREASES AT THIS TIME...WITH
THE 12Z GFS KEEPING THE BULK OF THE MOISTURE TO THE NORTH WHILE THE
12Z ECMWF MOVES THE SYSTEM INTO THE AREA FASTER AND WITH A MORE
WIDESPREAD AREA OF PRECIPITATION. WHILE THE DETAILS REMAIN A BIT
UNCERTAIN...THE EXTENDED PERIOD GENERALLY WILL BE COOL AND WET
ACROSS THE FORECAST AREA. CULLEN
&&
.AVIATION...WIDESPREAD IFR TO LIFR THROUGHOUT THE COAST...COASTAL
VALLEYS AND INLAND VALLEYS. EXPECT THESE FLIGHT CONDITIONS TO
PREVAIL THROUGH TONIGHT AND SUNDAY MORNING. A WEAK FRONTAL SYSTEM
IS EXPECTED TO REACH THE S WA AND N OREGON COAST BETWEEN 09Z AND
12Z. THE FRONT WILL NOT BE STRONG ENOUGH TO CREATE SOME MIXING OF
THE LOW-LEVEL AIR MASS. EXPECT CONDITIONS TO AT LEAST IMPROVE TO
MVFR AFTER 18Z SUN. COAST RANGE AND CASCADES WILL REMAIN OBSCURED
THROUGH AT LEAST MID-AFTERNOON SUNDAY. SURFACE HIGH PRES AND
MOIST LOW-LEVEL AIR MASS SUN EVENING WILL RESULT IN WIDESPREAD
LOW-ELEVATION IFR TO MVFR BY 06Z MON.
KPDX AND APPROACHES...IFR AT THE TERMINAL AS OF 04Z AND CONDITIONS
SHOULD REMAIN THAT WAY THROUGH AT LEAST 12Z. LIGHT PRECIP EXPECTED
TO DEVELOP AROUND 12Z WHICH COULD REDUCE CONDITIONS TO LIFR...
POSSIBLY TO AIRPORT LANDING MINIMUMS. A GRADUAL IMPROVEMENT TO AT
LEAST MVFR TO OCCUR AROUND 18Z SUN. WEISHAAR
&&
.MARINE...WEAK FRONTAL SYSTEM MOVING INTO THE NRN COASTAL WATERS
AS OF 04Z WITH THE TRAILING COLD FRONT EXTENDING TO AROUND 44N
130W. WOULD HAVE EXPECTED 20-25 KT WIND AT BUOY 089 BY NOW...BUT
ONLY 10-15 KT. GUSTS TO 20 KT AT BUOY 029 AS OF 04Z. WILL MAINTAIN
THE CURRENT SMALL CRAFT ADVISORY FOR WIND...BUT A LITTLE LESS
CONFIDENT WIDESPREAD AND/OR FREQUENT GUSTS TO 25 KT WILL OCCUR
OVER THE NRN WATERS. WIND SPEEDS DROP OFF FAIRLY QUICKLY SUN
MORNING BEHIND THE FRONT AS SURFACE HIGH PRESSURE REBUILDS OVER
THE WATERS. A STORM SYSTEM DURING THE MIDDLE PART OF NEXT WEEK
WILL LIKELY NECESSITATE A SMALL CRAFT ADVISORY.
LATEST MODEL GUIDANCE STILL SHOWING SEAS REACHING 10 FT BY 18Z SUN
AS A LONGER-PERIOD SWELL TRAIN MOVES INTO THE WATERS. SPECTRAL
GUIDANCE FOR BUOY 029 SHOWS WAVE HEIGHTS PEAKING AT 13 FT LATE SUN
AFTERNOON AND CONTINUING THROUGH 06Z MON...THEN SLOWLY SUBSIDING.
HOWEVER...SEAS TO REMAIN AT OR ABOVE 10 FT THROUGH MON. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY FOR THE CENTRAL WILLAMETTE VALLEY UNTIL 7 AM SUNDAY
DENSE FOG ADVISORY FOR THE SOUTH WILLAMETTE VALLEY UNTIL 10 AM SUNDAY.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SUNDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 AM SUNDAY TO
4 AM PST MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON
TO 8 PM PST SUNDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
NWS PORTLAND OR
841 PM PST SAT DEC 14 2013
.SYNOPSIS...TODAY WAS A CHILLY...CLAMMY DECEMBER DAY FOR MUCH OF
SOUTHWEST WASHINGTON AND NORTHWEST OREGON...AS ABUNDANT LOW CLOUDS
AND FOG LINGER UNDER INCREASING HIGH CLOUDINESS ALOFT. AREAS OF
DRIZZLE OR LIGHT RAIN WILL INCREASE FROM THE NORTH LATER TONIGHT AND
SUNDAY AS A WEAK COLD FRONT MOVES ONSHORE. MONDAY AND TUESDAY SHOULD
BE DRIER AS HIGH PRESSURE MOVES IN OVER THE PACIFIC NORTHWEST...
THOUGH VALLEY FOG WILL PROBABLY LINGER NEAR EUGENE. A COLDER SYSTEM
IS EXPECTED TO BRING RAIN AND MOUNTAIN SNOW WEDNESDAY AND
THURSDAY...WITH MORE UNSETTLED WEATHER POSSIBLE FRIDAY.
&&
.UPDATE...LOW CLOUDS AND FOG HANGING ON STRONG THIS EVENING...THOUGH
VISIBILITIES ARE ALL OVER THE BOARD... FROM ONE QUARTER MILE OR LESS
TO 6-8 MILES. EXPECT THAT THERE WILL BE SOME DENSE FOG AS THE LOW
LEVELS ARE FAIRLY STABLE AND IT IS CERTAINLY VERY MOIST...BUT WITH
THE INCOMING FRONT WE MAY HAVE JUST ENOUGH WIND TO PREVENT WIDESPREAD
DENSE FOG. THIS IS ESPECIALLY TRUE LATER TONIGHT AS THE FRONT GETS
CLOSER...AND THE HRRR SUGGESTS SOME IMPROVEMENT. THE MOST WIND IS
AROUND THE NORTH VALLEY. THE MESSAGE IS STILL THE SAME...QUITE A BIT
OF FOG...LOCALLY DENSE. FAVORED SPOTS FOR DENSE FOG WILL BE THOSE
THAT HAVE BEEN SEEING IT TO THIS POINT...EUGENE AIRPORT...
MCMINNVILLE...AURORA...AND HILLSBORO...AND ANY HIGHER HILLS THAT ARE
UP INTO THE VERY LOW STRATUS DECK. /KMD
.SHORT TERM...TONIGHT THROUGH TUESDAY...TODAY HAS BEEN A FAIRLY
TYPICAL DECEMBER DAY ACROSS SOUTHWEST WASHINGTON AND NORTHWEST
OREGON...WITH PATCHY FOG LINGERING WELL INTO THE AFTERNOON HOURS...
CHILLY TEMPERATURES AND HIGH RELATIVE HUMIDITY. THE LOW SUN ANGLE
COMBINED WITH INCREASING HIGH CLOUD COVER HAS DONE LITTLE TO BREAK UP
THE LOW CLOUDS WHICH FORMED IN THE VALLEYS OVERNIGHT. THEREFORE
TEMPERATURES HAVE STRUGGLED TO GET MUCH ABOVE 40 DEGREES FOR MOST
LOCATIONS...THOUGH A FEW FOOTHILL LOCATIONS ABOVE THE FOG/LOW CLOUDS
HAVE WARMED UP A LITTLE BETTER...INTO THE UPPER 40S AND LOWER 50S.
AS A SIDE NOTE...AS WE NEAR THE WINTER SOLSTICE...THE SUN ANGLE FOR
PORTLAND AT ITS PEAK OF SOLAR NOON IS ONLY ABOUT 22 DEGREES ABOVE THE
SOUTH HORIZON THIS TIME OF YEAR. HENCE THE LONG SHADOWS WHEN THE SUN
IS ACTUALLY OUT...AND THE LACK OF EFFECTIVENESS OF THE SUN AT WARMING
US UP AND DRYING US OUT THIS TIME OF YEAR.
ANYWAY...PATCHY DRIZZLE CONTINUES TO CAUSE SPOTTY ACCUMULATIONS OF
0.01 INCH HERE AND THERE IN THE COAST RANGE AND CASCADE FOOTHILLS...
NOT TO BE CONFUSED WITH SNOW MELTING INTO THE UNHEATED RAIN GAGES AT
THE HIGHER ELEVATIONS. DRIZZLE AND LIGHT RAIN SHOULD INCREASE FROM
THE NORTH LATER TONIGHT AND SUNDAY...ESPECIALLY IN THE COAST RANGE.
ONLY MINIMAL PRECIPITATION IF ANY IS EXPECTED FOR THE INLAND
VALLEYS...WITH THE BEST CHANCE NORTH. WITH MORE MOISTURE AND WEAK
FLOW...THERE SHOULD BE PLENTY OF LOW CLOUDS AND FOG AROUND AGAIN
SUNDAY. TEMPERATURES SUNDAY SHOULD BE A LOT LIKE TODAY...PERHAPS A
TOUCH WARMER DUE TO THE HIGHER DEWPOINT SUBTROPICAL AIR MOVING IN.
SNOW LEVELS WILL BE HIGH...SO SNOW IS NOT A CONCERN FOR THE CASCADE
PASSES.
MORE FOG SHOULD SETTLE IN SUN NIGHT/MON MORNING...BUT HIGH PRESSURE
IS EXPECTED TO BUILD INTO WASHINGTON BY MONDAY AFTERNOON. THIS IS
EXPECTED TO RESULT IN INCREASING NORTHERLY AND EVENTUALLY
NORTHEASTERLY FLOW MONDAY...POSSIBLY LEADING TO SOME DRYING AND
SUNBREAKS MOST AREAS BY AFTERNOON. THE NORTHERLY FLOW SHOULD CAUSE
THE LOW CLOUDS TO BANK UP AGAINST THE SOUTH END OF THE WILLAMETTE
VALLEY...LEADING TO ANOTHER CHILLY AND CLAMMY DAY AT EUGENE WITH
HIGHS AROUND 40 MONDAY WHILE MOST OTHER AREAS AIM FOR 50 DEGREES OR
A LITTLE HIGHER.
FOG AND LOW CLOUDS SHOULD BE A LITTLE LESS WIDESPREAD MON NIGHT/TUE
MORNING DUE TO THE OFFSHORE FLOW...EXCEPT IN THE SOUTH WILLAMETTE
VALLEY. HOWEVER INCREASING MID-HIGH LEVEL CLOUDS SHOULD KEEP
TEMPERATURES NEAR NORMAL...MAINLY IN THE 40S AND LOWER 50S...TUE
AFTERNOON. WEAGLE
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY. THE EXTENDED PERIOD
BEGINS WITH AN UPPER LEVEL TROUGH DROPPING DOWN THROUGH THE REGION
ALONG THE COAST. AN ASSOCIATED COLD FRONT WILL MOVE ACROSS THE AREA
ON WEDNESDAY ALONG WITH PRECIPITATION IN THE FORM OF WIDESPREAD RAIN
AND CASCADE SNOW. SNOW LEVELS WILL LOWER BEHIND THE FRONT WEDNESDAY
NIGHT AND SOME SHOWERS WILL LINGER INTO THURSDAY UNDER NORTHWEST
FLOW ALOFT. IT IS POSSIBLE THAT THE CASCADE FOOTHILLS AND COAST
RANGE MAY ALSO SEE SOME ACCUMULATING SNOW...THOUGH THIS WILL DEPEND
ON THE FROPA TIMING AND MOISTURE EXTENT.
BY THE END OF THE WEEK...THE RIDGE OF HIGH PRESSURE IN THE PACIFIC
IS CENTERED NEAR 140W KEEPING THE REGION UNDER NORTHWEST FLOW ALOFT.
LATE THURSDAY AFTERNOON AND NIGHT MAY BE DRY AHEAD OF THE NEXT
DISTURBANCE THAT WILL MOVE INTO THE AREA FROM THE NORTH ON FRIDAY OR
FRIDAY NIGHT. FORECAST MODEL AGREEMENT DECREASES AT THIS TIME...WITH
THE 12Z GFS KEEPING THE BULK OF THE MOISTURE TO THE NORTH WHILE THE
12Z ECMWF MOVES THE SYSTEM INTO THE AREA FASTER AND WITH A MORE
WIDESPREAD AREA OF PRECIPITATION. WHILE THE DETAILS REMAIN A BIT
UNCERTAIN...THE EXTENDED PERIOD GENERALLY WILL BE COOL AND WET
ACROSS THE FORECAST AREA. CULLEN
&&
.AVIATION...WIDESPREAD IFR TO LIFR THROUGHOUT THE COAST...COASTAL
VALLEYS AND INLAND VALLEYS. EXPECT THESE FLIGHT CONDITIONS TO
PREVAIL THROUGH TONIGHT AND SUNDAY MORNING. A WEAK FRONTAL SYSTEM
IS EXPECTED TO REACH THE S WA AND N OREGON COAST BETWEEN 09Z AND
12Z. THE FRONT WILL NOT BE STRONG ENOUGH TO CREATE SOME MIXING OF
THE LOW-LEVEL AIR MASS. EXPECT CONDITIONS TO AT LEAST IMPROVE TO
MVFR AFTER 18Z SUN. COAST RANGE AND CASCADES WILL REMAIN OBSCURED
THROUGH AT LEAST MID-AFTERNOON SUNDAY. SURFACE HIGH PRES AND
MOIST LOW-LEVEL AIR MASS SUN EVENING WILL RESULT IN WIDESPREAD
LOW-ELEVATION IFR TO MVFR BY 06Z MON.
KPDX AND APPROACHES...IFR AT THE TERMINAL AS OF 04Z AND CONDITIONS
SHOULD REMAIN THAT WAY THROUGH AT LEAST 12Z. LIGHT PRECIP EXPECTED
TO DEVELOP AROUND 12Z WHICH COULD REDUCE CONDITIONS TO LIFR...
POSSIBLY TO AIRPORT LANDING MINIMUMS. A GRADUAL IMPROVEMENT TO AT
LEAST MVFR TO OCCUR AROUND 18Z SUN. WEISHAAR
&&
.MARINE...WEAK FRONTAL SYSTEM MOVING INTO THE NRN COASTAL WATERS
AS OF 04Z WITH THE TRAILING COLD FRONT EXTENDING TO AROUND 44N
130W. WOULD HAVE EXPECTED 20-25 KT WIND AT BUOY 089 BY NOW...BUT
ONLY 10-15 KT. GUSTS TO 20 KT AT BUOY 029 AS OF 04Z. WILL MAINTAIN
THE CURRENT SMALL CRAFT ADVISORY FOR WIND...BUT A LITTLE LESS
CONFIDENT WIDESPREAD AND/OR FREQUENT GUSTS TO 25 KT WILL OCCUR
OVER THE NRN WATERS. WIND SPEEDS DROP OFF FAIRLY QUICKLY SUN
MORNING BEHIND THE FRONT AS SURFACE HIGH PRESSURE REBUILDS OVER
THE WATERS. A STORM SYSTEM DURING THE MIDDLE PART OF NEXT WEEK
WILL LIKELY NECESSITATE A SMALL CRAFT ADVISORY.
LATEST MODEL GUIDANCE STILL SHOWING SEAS REACHING 10 FT BY 18Z SUN
AS A LONGER-PERIOD SWELL TRAIN MOVES INTO THE WATERS. SPECTRAL
GUIDANCE FOR BUOY 029 SHOWS WAVE HEIGHTS PEAKING AT 13 FT LATE SUN
AFTERNOON AND CONTINUING THROUGH 06Z MON...THEN SLOWLY SUBSIDING.
HOWEVER...SEAS TO REMAIN AT OR ABOVE 10 FT THROUGH MON. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST SUNDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 AM SUNDAY TO
4 AM PST MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON
TO 8 PM PST SUNDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
NWS STATE COLLEGE PA
257 AM EST SUN DEC 15 2013
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WITH ENERGY TRANSFERRING FROM THE
UPPER OHIO VALLEY TO THE MID-ATLANTIC COAST WILL CONTINUE TO BRING
WINTRY PRECIPITATION TO THE REGION THROUGH TONIGHT. WINTER STORM
WARNINGS REMAIN IN EFFECT FOR ALL OF CENTRAL PENNSYLVANIA UNTIL 4
AM SUNDAY. A MEAN LONG WAVE TROUGH IS EXPECTED TO PERSIST ACROSS
THE GREAT LAKES AND NORTHEAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
THE HEAVIER PRECIPITATION IS NOW TO OUR EAST. BUT AN ELEVATED WARM
LAYER NOW COVERS MOST OF THE EASTERN THIRD OF OUR AREA TO INCLUDE
SULLIVAN COUNTY AND OUR EXTREME NORTHEAST. THUS FREEZING RAIN AND
ICE PELLETS ARE FALLING IN THE NORTHERN AREAS. THE LACK OF HIGH
CLOUDS IS MAKING THE TRANSITION TO FREEZING DRIZZLE IN SOME
CENTRAL AND SOUTHEASTERN AREAS.
COLDER DRIER AIR TO THE WEST IS ALREADY WORKING IN AND SHOULD TURN
ANY PRECIPITATION BACK TO LIGHT SNOW OR SNOW SHOWERS. THE RUC
APPEARS TO THINK THE 0C ISOTHERM WILL CLEAR STATE COLLEGE BETWEEN
1-2 AM AND LANCASTER COUNTY BETWEEN 7 AND 8 AM.
RADAR SHOWS MOST OF THE STEADIER PRECIPITATION IS NOW NORTH OF
STATE COLLEGE AND LIFTING TO THE NORTH AND EAST. THIS IMPLIES THE
LACK OF SEEDER FEEDER EFFECT THAT MOST AREAS WILL HAVE FREEZING
DRIZZLE UNTIL THE COLDER AIR MOVE INTO THE REGION OVER THE NEXT 6 HOURS.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM MONDAY/...
CONDITIONS SHOULD IMPROVE DURING THE DAY SUNDAY. WITH MAINLY SNOW
SHOWERS AND FLURRIES OVER THE REGION. THE GRADIENT PICKS UP AND IT
WILL SHOULD BE SOME GUSTY WINDS BY LATER MORNING AND INTO THE AFTERNOON.
THE 13KM RAP AND 4KM NAM SHOW A GOOD LAKE EFFECT SNOW (LES) BAND
GETTING WOUND UP...MOST OF THE SIMULATE INTENSE REFLECTIVITY STAYS
IN NEW YORK BUT IT COULD DRIFT SOUTH SO WE KEPT SNOW SHOWERS UP IN
NW PA THROUGH SUNDAY NIGHT. THERE WILL LIKELY BE SOME UPSLOPE SNOW
SHOWERS IN THE SOUTHWESTERN MOUNTAINS FROM SOUTHERN CLEARFIELD TO
SOMERSET COUNTIES.
MOST ACCUMULATING SNOWS SUNDAY WILL BE CONFINED TO LES AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
IN THE WAKE OF THE EARLY WEEKEND STORM...A MEAN UPPER LEVEL TROF
WILL REMAIN OVER THE EASTERN THIRD OF COUNTRY. SEVERAL SHORTWAVES
ARE FORECAST TO MOVE THROUGH THE FAST WEST NORTHWESTERLY FLOW. THE
FIRST IS FORECAST TO MOVE ACROSS THE REGION SUNDAY AFTERNOON
BRINGING ANOTHER SHOT OF SNOW SHOWERS MAINLY TO THE NORTHERN TIER.
ANOTHER WILL BRING A FRONT ON TUESDAY...WITH LIMITED MOISTURE.
HAVE INCREASED POPS ACCORDINGLY...HOWEVER DUE TO THE LIMITED
MOISTURE HAVE ONLY LIGHT ACCUMULATIONS. TEMPERATURES THROUGH THE
MIDDLE OF THE WEEK WILL REMAIN COLD...AS 850MB TEMPS -10C OR
BELOW. SO LOOK FOR DAYTIME HIGHS TO BE BELOW NORMAL THROUGH MUCH
OF THE PERIOD. GUIDANCE SUGGESTS THAT BY LATE IN THE WEEK ENERGY
WILL DIVE INTO THE ROCKIES IN TURN PUMPING UP HEIGHTS OVER THE
EAST. BRINGING A POSSIBLE WARM UP TO THE REGION LATE NEXT WEEK.
THIS SHOULD ALLOW FOR HIGHS FOR FRIDAY IN THE 40S ACROSS PA.
MOISTURE OUT AHEAD OF THE FRONT COULD ALLOW FOR RAIN
SHOWERS...WITH COLD AIR BEHIND...SO MIXED PRECIPITATION AT AND
BEHIND THE FRONT REMAINS A POSSIBILITY. THE MODELS VARY IN TIMING
BUT ALL AGREE THAT NEXT WEEKEND SHOULD SEE A DEEP TROUGH MOVE
THROUGH THE MID WEST AND INTO THE EAST COAST. THIS WILL END THE
BRIEF WARM UP AND SEE THE RETURN OF COLD AIR.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FREEZING DRIZZLE COVERS MOST OF THE AREA AS THE HIGH SEEDER CLOUDS
HAVE PRETTY MUCH MOVED AWAY. BUT THE PRECIP IS TURNING TO SNOW
AGAIN AS THE LOWER CLOUDS TO THE WEST OF THE PRIMARY LOW LOCATED
OVER KBFD MOVES TOWARD NY STATE AND THE COLDEST AIR WRAPS BACK
IN FROM THE WEST. LOW CIGS DOMINATE...BUT SOME RISE IN CLOUD BASES
IS STARTING IN THE EAST...AND THE SERN TERMINALS MAY IMPROVE TO A
HIGH-END MVFR OR EVEN VFR AROUND SUNRISE.
SFC LOWS BATTLING IT OUT WITH MOST OF CENTRAL PA IN A BIT OF A COL
AT THE MOMENT...BUT THE STRONGER COASTAL LOW SHOULD TAKE OVER BY
SUNRISE. EXPECT WESTERN PRECIPITATION TO CONTINUE TO LIGHTEN
OVERNIGHT AS THE WESTERN LOW FILLS. EXPECT WIND SHIFT TO THE WEST
SHORTLY AT ALL SITES. THEN WINDS SHIFT NORTHWEST AS THE COASTAL
LOW STRENGTHENS AND PULLS NORTH.
WNWRLY FLOW WITH IT/S TYPICAL POST-FRONTAL UPSLOPE SHSN AND LAKE
ENHANCEMENT WILL PROVIDE EQUAL AMOUNTS OF MVFR AND IFR THROUGH THE
DAYLIGHT HOURS. LOTS OF MECHANICAL TURBULENCE EXPECTED AS THE WIND
WILL GET STRONGER AS THE MORNING CONTINUES. SUSTAINED 12-15KTS
WITH GUSTS INTO THE 30S ARE EXPECTED AT JST/BFD THIS AFTN. ONLY
SLIGHTLY LOWER SPEEDS ARE IN STORE FOR THE OTHER TERMINALS. THE
GAP WIND AT AOO AND DOWNSLOPE AT MDT/LNS WILL KEEP THEM ON THE
HIGHER-END OF WIND SPEEDS TODAY.
FAST FLOW BRINGS AN ALMOST NEVER-ENDING TRAIN OF WEAK NRN STREAM
IMPULSES TO MAKE SHSN FOR THE WRN TERMINALS. THE STRONGEST CLIPPER
WILL BE ON TUE AM. WARM AIR TRIES TO RETURN BY FRI.
OUTLOOK...
MON...MAINLY VFR WITH MVFR IN SHSN AT BFD.
MON NITE-TUE...LGT SNOW/REDUCED VSBYS.
WED-THU...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...JUNG/DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1228 AM EST SUN DEC 15 2013
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WITH ENERGY TRANSFERRING FROM THE
UPPER OHIO VALLEY TO THE MID-ATLANTIC COAST WILL CONTINUE TO BRING
WINTRY PRECIPITATION TO THE REGION THROUGH TONIGHT. WINTER STORM
WARNINGS REMAIN IN EFFECT FOR ALL OF CENTRAL PENNSYLVANIA UNTIL 4
AM SUNDAY. A MEAN LONGWAVE TROUGH IS EXPECTED TO PERSIST ACROSS
THE GREAT LAKES AND NORTHEAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
THE HEAVIER PRECIPITATION IS NOW TO OUR EAST. BUT AN ELEVATED WARM
LAYER NOW COVERS MOST OF THE EASTERN THIRD OF OUR AREA TO INCLUDE
SULLIVAN COUNTY AND OUR EXTREME NORTHEAST. THUS FREEZING RAIN AND
ICE PELLETS ARE FALLING IN THE NORTHERN AREAS. THE LACK OF HIGH
CLOUDS IS MAKING THE TRANSITION TO FREEZING DRIZZLE IN SOME
CENTRAL AND SOUTHEASTERN AREAS.
COLDER DRIER AIR TO THE WEST IS ALREADY WORKING IN AND SHOULD TURN
ANY PRECIPITATION BACK TO LIGHT SNOW OR SNOW SHOWERS. THE RUC
APPEARS TO THINK THE 0C ISOTHERM WILL CLEAR STATE COLLEGE BETWEEN
1-2 AM AND LANCASTER COUNTY BETWEEN 7 AND 8 AM.
RADAR SHOWS MOST OF THE STEADIER PRECIPITATION IS NOW NORTH OF
STATE COLLEGE AND LIFTING TO THE NORTH AND EAST. THIS IMPLIES THE
LACK OF SEEDER FEEDER EFFECT THAT MOST AREAS WILL HAVE FREEZING
DRIZZLE UNTIL THE COLDER AIR MOVE INTO THE REGION OVER THE NEXT 6 HOURS.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM MONDAY/...
CONDITIONS SHOULD IMPROVE DURING THE DAY SUNDAY. WITH MAINLY SNOW
SHOWERS AND FLURRIES OVER THE REGION. THE GRADIENT PICKS UP AND IT
WILL SHOULD BE SOME GUSTY WINDS BY LATER MORNING AND INTO THE AFTERNOON.
THE 13KM RAP AND 4KM NAM SHOW A GOOD LAKE EFFECT SNOW (LES) BAND
GETTING WOUND UP...MOST OF THE SIMULATE INTENSE REFLECTIVITY STAYS
IN NEW YORK BUT IT COULD DRIFT SOUTH SO WE KEPT SNOW SHOWERS UP IN
NW PA THROUGH SUNDAY NIGHT. THERE WILL LIKELY BE SOME UPSLOPE SNOW
SHOWERS IN THE SOUTHWESTERN MOUNTAINS FROM SOUTHERN CLEARFIELD TO
SOMERSET COUNTIES.
MOST ACCUMULATING SNOWS SUNDAY WILL BE CONFINED TO LES AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
IN THE WAKE OF THE EARLY WEEKEND STORM...A MEAN UPPER LEVEL TROF
WILL REMAIN OVER THE EASTERN THIRD OF COUNTRY. SEVERAL SHORTWAVES
ARE FORECAST TO MOVE THROUGH THE FAST WEST NORTHWESTERLY FLOW. THE
FIRST IS FORECAST TO MOVE ACROSS THE REGION SUNDAY AFTERNOON
BRINGING ANOTHER SHOT OF SNOW SHOWERS MAINLY TO THE NORTHERN TIER.
ANOTHER WILL BRING A FRONT ON TUESDAY...WITH LIMITED MOISTURE.
HAVE INCREASED POPS ACCORDINGLY...HOWEVER DUE TO THE LIMITED
MOISTURE HAVE ONLY LIGHT ACCUMULATIONS. TEMPERATURES THROUGH THE
MIDDLE OF THE WEEK WILL REMAIN COLD...AS 850MB TEMPS -10C OR
BELOW. SO LOOK FOR DAYTIME HIGHS TO BE BELOW NORMAL THROUGH MUCH
OF THE PERIOD. GUIDANCE SUGGESTS THAT BY LATE IN THE WEEK ENERGY
WILL DIVE INTO THE ROCKIES IN TURN PUMPING UP HEIGHTS OVER THE
EAST. BRINGING A POSSIBLE WARM UP TO THE REGION LATE NEXT WEEK.
THIS SHOULD ALLOW FOR HIGHS FOR FRIDAY IN THE 40S ACROSS PA.
MOISTURE OUT AHEAD OF THE FRONT COULD ALLOW FOR RAIN
SHOWERS...WITH COLD AIR BEHIND...SO MIXED PRECIPITATION AT AND
BEHIND THE FRONT REMAINS A POSSIBILITY. THE MODELS VARY IN TIMING
BUT ALL AGREE THAT NEXT WEEKEND SHOULD SEE A DEEP TROUGH MOVE
THROUGH THE MID WEST AND INTO THE EAST COAST. THIS WILL END THE
BRIEF WARM UP AND SEE THE RETURN OF COLD AIR.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
SIGNIFICANT PRECIPITATION NOW GENERALLY ALONG AND NORTH OF I-80.
FREEZING RAIN AND SLEET LINE HAS MADE IT INTO CENTRAL AREAS...WITH
KAOO...KUNV...KMDT ALL REPORTING SOME MIX OF FZRA AND PL. NORTH
OF THIS LINE...STILL LIGHT TO OCCASIONAL MODERATE SNOW FALLING.
IN THE FAR SOUTHEAST...LIGHT TO MODERATE FREEZING RAIN FALLING. IT
IS CLEAR THAT THE COASTAL LOW IS TAKING OVER IN THIS AREA...AND
DRIVING THE PRECIPITATION. SURFACE WINDS HAVE NOW BACKED TO THE
NORTHEAST AT KMDT AND KLNS...ALSO INDICATING THAT REGION IS FULLY
UNDER THE INFLUENCE OF THE DEVELOPING COASTAL LOW.
EXPECT WESTERN PRECIPITATION TO CONTINUE TO LIGHTEN OVERNIGHT AS
THE WESTERN LOW FILLS. EXPECT WIND SHIFT TO THE WEST AROUND 06Z IN
KJST...07-09Z IN KAOO AND KUNV. THEN WINDS SHIFT NORTHWEST AS THE
COASTAL LOW STRENGTHENS AND PULLS NORTH.
EVEN WITH PRECIPITATION ENDING...IFR CIGS WILL LINGER
OVERNIGHT...WITH SOME IMPROVEMENT TOWARDS 12Z IN THE FAVORED
DOWNSLOPING AREAS IN CENTRAL AND SOUTHEAST PA.
OUTLOOK...
SUN...GUSTY WNW WINDS. AM LOW CIGS POSS W MTNS. PM SHSN/REDUCED
VSBYS POSS W MTNS.
MON...LGT SNOW/REDUCED VSBYS POSS MON NITE NW MTNS.
TUE...AM LOW CIGS/LGT SNOW POSS NW MTNS.
WED...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
334 AM CST SUN DEC 15 2013
.SHORT TERM...TODAY THROUGH TUESDAY
LOCATION OF SHARP WARM FRONT A NO-BRAINER EARLY THIS MORNING AS IT
IS EASILY NOTICEABLE ON SFC OBS. FAITH AND PHILIP ARE 36 AND 37
DEGREES RESPECTIVELY WITH A NORTHWEST WIND...WHILE MOBRIDGE AND
PIERRE ARE STILL IN THE LOWER TEENS WITH A SOUTHEAST WIND. THIS
FRONT CONTINUES NORTHWEST INTO SOUTHWEST NORTH DAKOTA. AS
ADVERTISED...LIGHT SNOW IS ONGOING AHEAD OF THE FRONT WITHIN ZONE
OF LIFT AND FORCING...MAINLY FROM NORTHWEST NORTH DAKOTA AND JUST
NOW INTO NORTH CENTRAL SOUTH DAKOTA. MODELS SEEM TO BE A FEW HOURS
QUICKER WITH THE ONSET OF LIGHT SNOW SO HAVE MADE THE APPROPRIATE
ADJUSTMENTS IN WX/POP GRIDS. MODELS STILL IN RATHER GOOD AGREEMENT
AS WELL...BRINGING A SWATH OF LIGHT SNOW RIGHT DOWN THROUGH THE
NORTHEAST QUARTER OF SOUTH DAKOTA INTO WEST CENTRAL MINNESOTA. A
BIT HARDER TO NAIL DOWN WITH MORE SPECIFICITY THE ACTUAL AREA OF
SLIGHTLY ENHANCED SNOWFALL...BUT INDICATIONS IN MODELS ARE THAT IT
ACTUALLY MIGHT BE RIGHT DOWN THROUGH ABERDEEN TO NEAR
WATERTOWN...SO HAVE SLIGHTLY HIGHER SNOWFALL TOTALS IN THIS
AREA...AROUND AN INCH OR SLIGHTLY HIGHER. SOME OF THE HI RES
MODELS SHOWING THE SNOW MIGHT BE ENDING A BIT QUICKER AS
WELL...DUE TO THE EARLIER ONSET. LATEST RUN OF THE HRRR ACTUALLY
SHOWING MOST SNOW OUT OF THE AREA BY 20Z OR 21Z. A TREND TO WATCH
THROUGH THE DAY.
AFTER THE BULK OF THE SNOWFALL ENDS BY LATE AFTERNOON...ATTENTION
THEN TURNS TO THE EASTWARD PROGRESSION OF THE WARM FRONT AND
DETERMINING JUST HOW WARM TEMPS WILL GET ON MONDAY. MODELS DO NOT
SHOW MUCH MOVEMENT OF THE FRONT AT ALL TODAY...STILL HUNG UP NEAR
THE MISSOURI RIVER BY 00Z THIS EVENING. BUT OVERNIGHT...THERE IS
FINALLY A PUSH TO THE EAST WHICH SHOULD TAKE IT THROUGH MOST IF
NOT ALL THE CWA BY 12Z MONDAY MORNING. THUS...WILL SEE SLOWLY
RISING TEMPS THROUGH THE NIGHT FOR EASTERN AREAS AS THIS FRONT
MOVES THROUGH. DID NOT STRAY MUCH AT ALL FROM PREVIOUS FORECAST
FOR HIGHS ON MONDAY...THEY STILL SEEM IN GOOD SHAPE AT THIS TIME.
MOST AREAS WILL RISE INTO THE 30S AND LOW 40S...EVEN WITH THE SNOW
COVER. WARMEST TEMPS WILL BE OVER THE SOUTHWEST CWA. TUESDAY
SHAPING UP TO NOT BE THAT BAD OF A DAY EITHER. TEMPS ALOFT COOL
SLIGHTLY AND MIXING WILL BE LESS...BUT SHOULD STILL MANAGE UPPER
20S TO MID 30S FOR MOST AREAS.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
NEARLY ZONAL UPPER LEVEL FLOW ON WEDNESDAY WITH NEAR NORMAL SFC
TEMPS GIVES WAY TO AN ARCTIC FRONT INTRUDING FROM THE NORTHWEST
AND A SFC LOW MOVING THROUGH THE CENTRAL PLAINS ON THURSDAY. THE
GFS IS A LITTLE SLOWER TO PROGRESS THE PRECIP SOUTH WITH THE FRONT
AND HANGS IT AROUND A LITTLE LONGER. WITH SFC HIGH PRESSURE
SETTLING OVER THE REGION ON FRIDAY BELIEVE THE ECMWF AND THE
ALLBLEND ARE A BETTER BET WITH ALL PRECIP EXITING THU NIGHT.
SIGNIFICANTLY COOLER TEMPS AND DRIER CONDITIONS WILL THEN PERSIST
THROUGH THE WEEKEND AS NORTHWEST FLOW ALOFT TAKES HOLD ONCE AGAIN.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CIGS AND VISBY ARE EXPECTED FOR THE AREA...THOUGH KABR MAY SEE
WIDELY INTERMITTENT VISBY REDUCTIONS TO 5SM. WINDS WILL PRIMARILY
REMAIN OUT OF THE EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
455 AM EST SUN DEC 15 2013
.SYNOPSIS...
LOW PRESSURE WAS DEEPENING OFF THE NEW JERSEY COAST THIS MORNING
AND WILL MOVE ALONG THE NEW ENGLAND COAST TONIGHT. A SERIES OF
WEAK LOW PRESSURE SYSTEMS WILL TRACK FROM THE NORTHERN PLAINS
THROUGH THE EASTERN UNITED STATES TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 AM EST SUNDAY...
LOCAL WRF AND HRRR HAD EDGE OF SHORT WAVE IN THE SOUTHERN
APPALACHIANS CLEARING THE EASTERN COUNTY WARNING AREA BY 10Z/5AM.
THE NEXT SHORT WAVE COMES OUT OF THE OHIO VALLEY AND ACROSS THE AREA
THIS MORNING.
FOLLOWING THE SHORT WAVES TODAY...REGION STAYS UNDER PERSISTENT LONG
WAVE TROF AND NORTHWEST FLOW ALOFT. EXPECT A BRIEF RISE IN
TEMPERATURE JUST BEHIND THE SHORT WAVE THEN FALLING TEMPERATURES
AROUND SUNRISE. WITH COLD AIR ADVECTION AND LITTLE SUNSHINE
TODAY....MOST LOCATIONS WEST OF THE BLUE RIDGE WILL HAVE A MINIMAL
RISE IN TEMPERATURES. STAYED CLOSER TO THE COOLER BIAS CORRECTED
MAV GUIDANCE FOE TEMPERATURES THROUGH THE EVENING.
MSAS ANALYSIS SHOWS LARGE PRESSURE FALLS NEAR LONG ISLAND WHERE
THE SURFACE LOW IS DEEPENING. PRESSURE RISES AND COLD AIR
ADVECTION OVER OUR FORECAST AREA WILL LEAD TO GUSTY WET WINDS. THE
DOWNSLOPE WINDS AND EXIT OF DEEPER MOISTURE WILL RESULT IN
CLEARING EAST OF THE BLUE RIDGE BY THIS AFTERNOON. PERSISTENT LOW
LEVEL MOISTURE AND UPSLOPE WINDS WILL HOLD CLOUDS IN THE WESTERN
MOUNTAINS OF THE FORECAST AREA THROUGH TONIGHT.
ANOTHER SHORT WAVE COMES THROUGH THE NORTHWEST FLOW ALOFT TONIGHT...
ADDING SOME LIFT TO THE UPSLOPE WINDS AND PROLONGING THE PROBABILITY
OF SNOW SHOWERS THROUGH MONDAY MORNING. MODELS SHOW A SUBTLE
INCREASE IN PRECIPITABLE WATER AND DEPTH OF MOISTURE AS THIS FEATURE
COMES THROUGH. WILL MAINTAIN SNOW SHOWERS ON THE FAR WESTERN
SLOPES FROM GREENBRIER TO TAZEWELL COUNTY LATE TONIGHT.
850 MB TEMPERATURES DROP TODAY BUT BEST PUSH OF COLDER
AIR...ESPECIALLY INTO THE EASTERN COUNTY WARNING AREA WILL BE
TONIGHT. LOW LEVEL JET IN THE 40 TO 50 KNOT RANGE WILL SUPPORT
SURFACE WIND GUSTS OF 25 TO 35 KNOTS/28-40 MPH TODAY WITH ANOTHER
SURGE OF STRONGER WINDS BEHIND THE SHORT WAVE TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM EST SUNDAY...
DURING MOST OF THIS SEGMENT OF THE FORECAST PERIOD THE REGION WILL
REMAIN IN NORTHWEST FLOW THANKS TO A OVERALL LONGWAVE TROUGH PATTERN
OVER SOUTH CENTRAL AND SOUTHEAST CANADA. WITHIN THE PARENT LONGWAVE
PATTERN...A SERIES OF SHORTWAVE TROUGHS ARE PROGGED TO PROGRESS
THROUGH THE GREAT LAKES AND THEN NEW ENGLAND REGIONS OF THE U.S.
EACH OF THESE WILL HAVE A COMPARABLE IMPACT ON THE WEATHER ACROSS
OUR PART OF THE COUNTRY.
THE BULK OF THE UPPER LEVEL DYNAMICS AND ASSOCIATED MOISTURE WILL
REMAIN NORTH OF THE FORECAST AREA. THE SOUTHERN TAIL END OF EACH
SYSTEM WILL CLIP AREAS SOUTH TO ROUGHLY THE I-64 CORRIDOR
WEST OF COVINGTON VA...AND THE I-77 CORRIDOR SOUTH TO ROUGHLY
BLUEFIELD WV.
THE FIRST...AND WEAKEST OF THESE IMPULSES...WILL CROSS THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY. THE SECOND...AND NEXT
STRONGEST...MONDAY NIGHT INTO EARLY TUESDAY. THE FINAL AND STRONGEST
ONE...TUESDAY AFTERNOON INTO TUESDAY EVENING.
WHILE THERE WILL BE SOME LEVEL GUSTINESS WITH THE FIRST
IMPULSE...WINDS WILL INCREASE SIGNIFICANTLY WITH THE PASSAGE OF THE
SECOND SHORTWAVE TROUGH...AND EVEN MORE SO IN THE WAKE OF THE THIRD.
SOLUTIONS AMONG THE VARIOUS MODELS PLACE NORTHWEST 850 MB WINDS
ACROSS THE AREA TUESDAY EVENING THROUGH EARLY WEDNESDAY MORNING IN
THE 45 TO 55 KT RANGE WITH GOOD CROSS BARRIER FLOW. IF THIS PATTERN
HOLDS...THIS SCENARIO WOULD BE FAVORABLE FOR AT LEAST WIND ADVISORY
GUSTS ACROSS THE MOUNTAINS. WILL HIGHLIGHT THIS POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
WE ARE EXPECTING A PATTERN SHIFT WEDNESDAY INTO WEDNESDAY NIGHT. THE
UPPER LEVEL FLOW BECOMES MORE ZONAL TO SLIGHTLY SOUTHWEST. ANY
IMPULSES IN THE NORTHERN STREAM WILL REMAIN WELL NORTH OF THE AREA.
WITH THE NORTHWEST FLOW BACKING MORE WEST TO SOUTHWEST...WE EXPECT
LESS CLOUD COVER ACROSS THE MOUNTAINS.
DURING THIS ENTIRE PORTION OF THE FORECAST PERIOD...LOCATIONS ACROSS
THE PIEDMONT...ESPECIALLY NEAR THE NC/VA BORDER...ARE EXPECTED TO
SEE LIMITED CLOUD COVER. WINDS WILL ALSO BECOME GUSTY...BUT NOT AS
STRONG AS THOSE ANTICIPATED ACROSS THE MOUNTAINS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 302 PM EST SATURDAY...
BOTH THE 12Z GFS/ECM AGREE THAT A SURFACE RIDGE WILL PASS OVER THE
REGION WEDNESDAY...THEN MOVE OFF THE COAST THURSDAY. THIS RIDGE WILL
KEEP THE AREA CHILLY WITH COLDER THAN NORMAL TEMPERATURES FOR
WEDNESDAY. AS THIS RIDGE MOVES EAST THURSDAY...SOUTHWESTERLY FLOW
WILL PREVAIL. TEMPERATURES WILL MODERATE TO NORMAL ON THURSDAY WITH
WARM THAN NORMAL TEMPERATURES ON FRIDAY...POSSIBLY CONTINUING INTO
SATURDAY. THE AREA SHOULD SEE WIDESPREAD 50S ON FRIDAY...AND MID TO
UPPER 50S WEST AND LOW TO MID 60S EAST ON SATURDAY. OF
COURSE...THESE TEMPERATURES WILL BE DEPENDENT ON WHEN THE NEXT COLD
FRONT INFLUENCES OUR WEATHER. THIS PART OF THE FORECAST IS WHERE THE
MODELS DIFFER.
THE 12Z GFS DEVELOPS A SURFACE LOW ALONG A COLD FRONT IN THE CENTRAL
PLAINS THURSDAY NIGHT. THIS LOW IS EXPECTED TO TRACK NORTHEAST TO
NEW ENGLAND BY FRIDAY EVENING. THE TRAILING COLD FRONT WILL BE
SLOWLY MOVING ACROSS THE OHIO-TENN VALLEYS FRIDAY...STALLING ALONG
THE WESTERN APPALACHIANS FRIDAY NIGHT. ANOTHER SURFACE LOW DEVELOPS
ON THE LEE SIDE OF THE SOUTHERN APPALACHIANS...DRAGGING THE FRONT AND
ASSOCIATED RAIN SHOWERS ACROSS THE REGION ON SATURDAY. IF THIS
VERIFIES...SATURDAYS TEMPERATURES WILL NOT BE AS WARM AS FORECASTED.
THE 12Z ECM DEVELOPS A SURFACE LOW ALONG THE FRONT AND TRACKS IT
NORTHEAST BUT OVER QUEBEC. THIS FRONT WILL THEN STALL OVER THE OHIO-
TENN VALLEY ON FRIDAY. A WAVE OF LOW PRESSURE IS EXPECTED TO TRACK
ALONG THIS FRONT FRIDAY NIGHT INTO SATURDAY. ANOTHER WAVE IS
FORECASTED TO TRACK ALONG THE FRONT...STILL OVER THE OHIO
VALLEY...SATURDAY NIGHT INTO SUNDAY. THE 12Z ECM WOULD KEEP THE
FORECAST AREA IN THE WARM SECTOR INTO SATURDAY...POSSIBLY SUNDAY.
THE ECM ALSO KEEPS BULK OF THE RAIN NORTH OF THE AREA WITH A
POSSIBLE PASSING MOUNTAIN SHOWER FRIDAY AND SATURDAY.
FOR THIS FORECAST PACKAGE...FAVORING THE ECM OVER THE GFS (70/30)
ESPECIALLY ON TEMPERATURES. FOR POPS...ADDED LOW CHANCE POPS (30
PERCENT) IN THE WEST FRIDAY NIGHT...THEN ACROSS THE ENTIRE AREA ON
SATURDAY (30 PERCENT).
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
AS OF 130 AM EST SUNDAY...
POOR FLYING CONDITIONS EXPECTED FOR THE FIRST 6-10 HOURS OF THE
PERIOD WITH LOW CEILINGS/FOG/DRIZZLE. OUTSIDE OF WESTERN
SLOPES...CONDITIONS WILL BEGIN TO IMPROVE FROM WEST TO EAST AS
WINDS TURN TO THE WEST. FIRST TO GO WILL BE THE DRIZZLE AND
FOG...THEN CEILINGS LIFT FROM IFR TO VFR BY EARLY SUNDAY MORNING.
WESTERN SLOPES WILL KEEP IFR RESTRICTIONS THROUGH SUNDAY MORNING
WITH A MOIST WEST WIND AND UPSLOPE SNOW SHOWERS. SNOW SHOWERS WILL
TAPER TO FLURRIES DURING THE AFTERNOON WITH CEILINGS LIFTING TO
MVFR.
WINDS SPEED WILL INCREASE THROUGH THE MORNING AND SUBSIDE IN THE
EVENING WITH THE EXCEPTION OF AREAS ALONG THE BLUE RIDGE
(ROA/BCB). WEST WINDS OF 10-20 KNOTS GUSTING TO 20-30 KNOTS ARE
POSSIBLE ACROSS THE ENTIRE FORECAST AREA DURING THE DAY SUNDAY.
THE HIGHER SPEEDS ARE RESERVED FOR LOCATION ALONG THE BLUE RIDGE.
CONFIDENCE IS FAIRLY HIGH WITH IFR CONDITIONS REMAINING THROUGH
THE FIRST 3-6 HOURS OF THE TAF PERIOD. MEDIUM CONFIDENCE ON TIMING
OF IMPROVING CONDITIONS THROUGH 12Z SUN. HIGH CONFIDENCE IN WIND
DIRECTION AND SPEED DURING THE PERIOD.
HIGH PRESSURE EXPECTED TO BUILD INTO THE REGION FROM THE WEST
MONDAY...ALLOWING UPSLOPING CLOUDS TO GRADUALLY ERODE OVER THE
MOUNTAINS...BRINGING A RETURN TO VFR WEATHER WITH UNRESTRICTED
CONDITIONS...EVEN IN THE UPSLOPE AREAS...BY MIDDAY MONDAY. DRY
WEATHER WITH MAINLY VFR WEATHER IS THEN EXPECTED IN MOST AREAS
INTO MID WEEK...WITH PERHAPS THE EXCEPTION OF A PERIOD OF SOME
UPSLOPING CLOUDS WITH MVFR CEILINGS ACROSS THE WESTERN FLANKS OF
THE APPALACHIANS LATER TUESDAY INTO WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...DS
LONG TERM...RCS
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1015 AM EST Sun Dec 15 2013
Updated near term and aviation discussions.
.NEAR TERM [Rest of Today]...
Post-frontal rain showers are quickly coming to an end over the
eastern Florida Big Bend and should be out of the forecast area
completely by 16z. Behind the scattered showers, an expansive area
of low stratus still exists well back to the northeast. The 12z
BMX sounding in central Alabama showed a saturated layer beneath a
pronounced frontal inversion. The depth of the saturated layer was
about 2500 feet, so it should take some time to scour out the
stratus behind the front today, although drier air mixing from
aloft should eventually scatter things out. Also working against a
more rapid decrease in stratus is a large arc of cirrostratus
along the upper level jet axis. This interceding cloud layer will
limit the amount of insolation for now.
Thus, with expected cloudy conditions into the afternoon, the
temperature forecast was nudged down a bit. Most areas will have
already seen their highs for the day or are experiencing them
right about now. We followed a blend of our local CAM ensemble and
the HRRR for hourly temperatures for the rest of the day. Much of
the afternoon should see fairly steady temperatures around 50 in
most parts of the area.
&&
.SHORT TERM [Tonight through Tuesday]...
The large scale regional pattern commences tonight with closed low
over Nrn Great Lakes with broad trough over Ern states with
decreasing amplitude N-S leaving only weak cyclonic flow over NE
Gulf region. Upstream ridge with NW steering flow and strong
subsidence overspreading Gulf region from W-E. At surface,
Saturday`s cold front in FL Straits with high building over E/S TX
with cooler and drier air overspreading local area. This reflected
in model soundings which show NW flow surface to H8 then WSW flow
above with PWATS around 0.3 inches.
During the rest of the period, several shortwaves dig across Nrn
Great Lakes keeping trough anchored over Ern states thru Mon before
another low moves Ewd across Great Lakes pushing initial low
Ewd of Canadian Maritimes with trough nudged into Atlc. Surface high
shifts Ewd to over N/Cntrl Gulf Mon and to NE Gulf on Tues allowing
local winds to progressively decouple. With high still to our NW
tonight, pressure gradient just tight enough for non-ideal
radiational cooling. However with high very close to local area Mon
night and near calm winds...min temps will drop another degree or
two especially east of Apalachicola River. Airmass remains bone dry
with PWATS hovering around 0.30 thru period.
Will go with lows tonight from around 32 NW AL counties to mid-upper
30s SE Big Bend or around 5 degrees below normal. Expect lows Mon
night in low 30s everywhere. A brief light freeze is possible
tonight NW most AL counties and Mon night mainly FL Big Bend. Local
confidence tool with 50-90% chance of light freeze NW AL tonight but
freeze area very small and for at best two hours so will hold off on
issuing any product. Wind chills 28 to 31 degrees tonight and 31 to
33 Mon night. Sheltered areas...especially Ern counties...likely to
see patchy frost both nights, predawn into sunrise. Highs Mon around
60 increasing Tues to at or above normal...upper 60s. Expect cloud
free period.
&&
.LONG TERM [Tuesday Night through Saturday]...
High pressure will dominate for most of the extended period with
drier air and moderating temperatures. Once the high moves off to
the northeast Friday, onshore flow will return resulting in a
slight chance of showers.
&&
.AVIATION...
[through 18z Monday] The latest model guidance suggests that
stratus layer may be more persistent than earlier thought, with
MVFR restrictions possible into the early-mid afternoon before the
clouds scatter out. Will amend the TAFs to reflect this change.
Generally VFR expected at all terminals by 21z.
&&
.MARINE...
Northwest winds will continue to increase into this morning
behind the cold front, reaching advisory levels west of
Apalachicola. A Small Craft Advisory remains in effect for those
areas, and a SCEC headline will be maintained east. Winds will
continue to veer to the north later today and remain at SCEC
levels everywhere into Monday before gradually diminishing as
high pressure builds in.
&&
.FIRE WEATHER...
Dry conditions will prevail for the next several days, with relative
humidity levels remaining above critical thresholds. Dispersions
will likely remain within acceptable ranges as well, thus, hazardous
fire weather conditions are not expected.
&&
.HYDROLOGY...
Despite yesterday`s rainfall, gauges have only detected slight rises
on area rivers which still remain well below action stage at most
sites. Significant rainfall is not expected until perhaps next
weekend, so further decline or steady river levels can be expected
through the week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 60 33 62 32 69 / 20 0 0 0 0
Panama City 54 39 60 39 66 / 10 0 0 0 0
Dothan 49 33 60 34 67 / 0 0 0 0 0
Albany 54 33 60 32 67 / 0 0 0 0 0
Valdosta 62 34 61 33 68 / 20 0 0 0 0
Cross City 61 35 64 33 68 / 50 0 0 0 0
Apalachicola 61 41 60 40 65 / 50 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...SMALL CRAFT ADVISORY until 3 PM EST this afternoon for Coastal
waters from Apalachicola to Destin FL out 60 NM.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Block
LONG TERM...Weston
AVIATION...Lamers
MARINE...Block
FIRE WEATHER...Camp
HYDROLOGY...Evans
AREA FORECAST DISCUSSION
NWS MIAMI FL
930 AM EST SUN DEC 15 2013
.UPDATE...
SHOWERS AND A COUPLE OF THUNDERSTORMS ARE MOVING INTO THE
NORTHWESTERN PORTION OF SOUTH FLORIDA THIS MORNING. HAVE BOOSTED
POPS TO REFLECT THIS AND TRANSLATED THE LINE TO THE SOUTH EAST.
THIS IS A PRE-FRONTAL TROUGH, AHEAD OF THE APPROACHING COLD FRONT,
WHICH IS CURRENTLY OVER CENTRAL FLORIDA. THE SHOWERS DO APPEAR AS
THOUGH THEY ARE HAVING TROUBLE KEEPING TOGETHER ACROSS THE
MAINLAND, AND ALMOST FALLING APART ON THE EAST COAST. HOWEVER,
GIVEN DAYTIME HEATING WILL HELP INSTABILITY, HAVE BUMPED UP POPS
FURTHER SOUTH AS WELL. THE QUESTION IS, THIS AFTERNOON, AND IF
THE LINE WILL HOLD TOGETHER ENOUGH TO CONTINUE SHOWERS AND
THUNDERSTORMS.
AS FAR A THUNDERSTORMS ACROSS THE AREA, THIS MORNINGS SOUNDING
DOES SHOW ALMOST 3000 JOULES OF CAPE OVER MIAMI. HOWEVER, THIS
HIGHER CAPE WILL BE PUSHED OUT OF THE AREA AS THE TROUGH CONTINUES
TO APPROACH. HOWEVER, THE FRONT DOES LOOK AS THOUGH IT MAY CATCH
UP TO THE LARGER LINE OF SHOWERS, HELPING TO PUSH IT THROUGH
QUICKER THAN IT CURRENTLY IS. THIS COULD HELP TO PROVIDE THE
TRIGGER FOR SOME ISOLATED STORMS THIS AFTERNOON.
THE HRRR DOES SHOW THE LINE WEAKENING AS IT APPROACHES THE MIAMI
METRO AREA, ALTHOUGH STILL SHOWS IT BRINGING A LINE OF SHOWERS
THROUGH. TIMING IS CURRENTLY INTO THE WEST PALM BEACH METRO AREA
AROUND 16Z, THE BROWARD METRO AREAS AROUND 18 OR 19Z, AND THE
MIAMI METRO AREA BETWEEN 19 AND 20Z. OF COURSE GIVE OR TAKE SOME A
LITTLE TIME, SO HAVE CHANCE POPS FROM 18Z THROUGH 00Z, ALTHOUGH
MOST LIKELY WILL HAVE TO ADJUST IN A FEW HOURS.
&&
.PREV DISCUSSION... /ISSUED 650 AM EST SUN DEC 15 2013/
AVIATION...
SOUTHWESTERLY WINDS ARE EXPECTED AT ALL TAF SITES TODAY. WITH THE
COLD FRONT MOVING SOUTHWARD ACROSS THE FLORIDA PENINSULA THERE IS
A CHANCE OF SHOWERS THIS AFTERNOON AND EVENING AT ALL TAF SITES.
THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS. THE CONFIDENCE OF
THUNDERSTORMS IS LOW SINCE IT IS NOT CLEAR WITH THE LACK OF STRONG
FORCING AND WEAK LAPSE RATES IF THE THUNDERSTORMS WILL SURVIVE AS
THEY CONTINUE TO MOVE SOUTHWARD OR MOVE FROM THE GULF TO THE LAND. FOR
NOW, INCLUDED VCSH FOR ALL TAF SITES AFTER 17Z. THE CEILING AND
VIS SHOULD MOSTLY STAY IN THE VFR CONDITIONS FOR THE DAYTIME HOURS
TODAY...BUT COULD FALL DOWN INTO THE MVFR CONDITIONS WITH ANY
PASSING SHOWERS.
PREV DISCUSSION... /ISSUED 244 AM EST SUN DEC 15 2013/
SHORT TERM (TODAY-TUESDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD LONG WAVE TROUGH
PROGRESSING EASTWARD TOWARD THE EAST COAST AND PLENTY OF MID/UPPER
MOISTURE SPREADING ENE AHEAD OF IT ACROSS THE REGION. THE EARLY
MORNING SURFACE ANALYSIS SHOWED A COLD FRONT ASSOCIATED WITH THIS
UPPER FEATURE EXTENDING SOUTHWEST ACROSS THE FLORIDA PANHANDLE TO
THE CENTRAL GULF OF MEXICO WITH LIGHT TO MODERATE SOUTHERLY FLOW
ACROSS MUCH OF THE STATE. DEW POINTS ALONG AND AHEAD OF THIS BOUNDARY
RANGED FROM THE UPPER 60S ACROSS CENTRAL FLORIDA TO THE LOWER 70S
ACROSS THE SOUTHERN EXTENT OF THE PENINSULA. THE LATEST SHORT-RANGE
NUMERICAL GUIDANCE REMAINS IN GOOD AGREEMENT AND INDICATES THIS
FRONTAL BOUNDARY CONTINUING ESE THROUGH THE LOCAL AREA LATER THIS
EVENING THROUGH TONIGHT. RAIN CHANCES WILL STEADILY INCREASE ACROSS
THE AREA THROUGH THE DAY...MAINLY ALONG AND AHEAD OF THIS
APPROACHING BOUNDARY. DESPITE THE AMPLE MOISTURE IN PLACE ALONG WITH
THE APPROACHING BOUNDARY...LIMITED FORCING AND POOR LAPSE RATES WILL
LIMIT THUNDERSTORM PROBABILITIES TODAY ACROSS THE LOCAL AREA. FOR
NOW...WE WILL CONTINUE TO INCLUDE ISOLATED TSTMS IN THIS GRIDDED
PACKAGE AND UPDATE AS CONDITIONS EVOLVE TODAY. MODEL RAINFALL
ACCUMULATIONS THROUGH TONIGHT REMAIN LIGHT WITH VALUES RANGING FROM
A TENTH TO A HALF OF AN INCH ACROSS THE AREA. AS TYPICALLY
OBSERVED...LOCALIZED HIGHER AMOUNTS WILL REMAIN POSSIBLE IN ANY
HEAVIER ACTIVITY THAT DEVELOPS OR BECOMES CONCENTRATED.
MONDAY THROUGH TUESDAY...THE DEEP LAYER MOISTURE AXIS ASSOCIATED
WITH THE FRONTAL BOUNDARY EXTENDING SOUTHWEST ACROSS SRN FLORIDA
PENINSULA WILL KEEP A SLIGHT CHANCE OF SHOWERS IN THE FORECAST
THROUGH THE DAY MONDAY. MONDAY NIGHT THROUGH TUESDAY...DRIER AND
COOLER AIR WILL BEGIN TO OVERSPREAD THE LOCAL AREA IN THE WAKE OF
THE BOUNDARY AS HIGH PRESSURE BUILDS EASTWARD ALONG THE NORTHERN
GULF COAST STATES. THE SHORT-RANGE TEMPERATURE GUIDANCE INDICATES
OVERNIGHT LOWS RANGING FROM THE MID 40S ACROSS GLADES COUNTY TO THE
LOWER 60S ALONG THE SOUTHEAST FLORIDA COAST BY DAYBREAK TUESDAY
MORNING.
LONG TERM (WEDNESDAY-SUNDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THE
SECOND HALF OF THE WEEK AND INDICATES WARM AND HUMID CONDITIONS
RETURNING AS HIGH PRESSURE NORTH OF THE AREA QUICKLY TRANSLATES
EASTWARD OVER THE WESTERN ATLANTIC AND UPPER HEIGHTS BEGIN TO RISE.
TEMPERATURES WILL RESPOND AND QUICKLY RETURN TO WELL ABOVE NORMAL
EACH DAY (10-15 DEG ABOVE NORMAL FRIDAY THROUGH WEEKEND).
MARINE...
A COLD FRONT WILL APPROACH AND MOVE INTO THE LOCAL AREA LATER THIS
EVENING THROUGH MONDAY BEFORE MOVING THROUGH. RAIN CHANCES ALONG
WITH A FEW THUNDERSTORMS CAN BE ANTICIPATED THROUGH THIS TIME ACROSS
THE MARINE AREAS. WINDS AND SEAS MAY APPROACH ADVISORY LEVELS
THROUGH THE FIRST PORTION OF THE WEEK IN THE WAKE OF THE BOUNDARY
AS HIGH PRESSURE BUILDS EASTWARD ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 62 74 58 / 70 30 20 10
FORT LAUDERDALE 84 66 75 63 / 60 30 20 10
MIAMI 85 67 75 62 / 60 20 20 20
NAPLES 82 58 72 51 / 90 20 - 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
740 AM MST SUN DEC 15 2013
.UPDATE...
ISSUED AT 740 AM MST SUN DEC 15 2013
COMBINATION OF 850 TEMPERATURES...RUC AND HRRR SFC TEMPS SUPPORT
RAISING HIGH TEMPERATURES TODAY INTO THE MID 50S WITH LOW
60S...WARMEST READINGS ACROSS THE EAST/SOUTHEAST. WEST/NORTHWEST
WINDS WILL BECOME BREEZY PERHAPS LATE MORNING THROUGH THE REST OF
THE DAY. CLOUDINESS CURRENTLY OVER THE AREA EXPECTED TO MOVE OUT
OF THE AREA WITHIN THE NEXT FEW HOURS LEAVING SUNNY/MOSTLY SUNNY
CONDITIONS FOR THE REST OF THE DAY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 154 AM MST SUN DEC 15 2013
DRY AND MILD CONDITIONS WILL REMAIN IN PLACE ACROSS THE FORECAST
AREA THROUGH THE SHORT TERM PERIOD.
MODELS KEEP THE UPPER RIDGE OVER THE WEST COAST THROUGH MONDAY
WITH NORTHWEST FLOW ALOFT ACROSS THE CENTRAL HIGH PLAINS REGION.
DURING THIS TIME...A SURFACE TROUGH MOVES ACROSS THE NORTHERN
PLAINS TOWARDS THE GREAT LAKES REGION WITH THE TAIL END OF THE
TROUGH EXTENDING BACK INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION. THIS WILL KEEP GENERALLY WEST TO NORTHWEST SURFACE FLOW IN
PLACE ACROSS THE FORECAST AREA WITH DOWNSLOPING WINDS AND WARM AND
DRY CONDITIONS.
SURFACE HIGH PRESSURE MOVES INTO THE REGION AS THE TROUGH EXITS
WITH ANOTHER SURFACE TROUGH DEEPENING ALONG THE FRONT RANGE BY
TUESDAY NIGHT AS THE UPPER FLOW ACROSS THE UNITED STATES FLATTENS
WITH THE APPROACH OF THE NEXT UPPER TROUGH.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 154 AM MST
SUN DEC 15 2013
FOR WEDNESDAY THROUGH SATURDAY MAIN INTEREST WILL CONTINUE TO BE THE
ARCTIC FRONTAL PASSAGE THURSDAY WITH CHANCES FOR SNOW THE FOLLOWING
NIGHT. MODELS HAVE COME INTO BETTER AGREEMENT WITH THE UPPER LEVEL
WEATHER PATTERN FOR THE END OF THE WEEK...AND HAVE SPED UP THE
FRONTAL PASSAGE TO THE AFTERNOON HOURS. MODELS CONTINUE TO SHOW A
SPLIT 500MB JET BEHIND THE FRONT. AS A RESULT THE BEST SHOT FOR
SNOWFALL WILL BE THURSDAY EVENING OVER THE NORTHWEST WHERE MID LEVEL
FRONTOGENESIS WILL DEVELOP. FRIDAY THE NORTHERN HALF OF THE 500MB
JET WILL MOVE AN UPPER LEVEL SHORT WAVE TROUGH AXIS OVER THE AREA
WITH SUBSIDENCE MOVING IN BEHIND THE TROUGH AXIS. MODEL SOUNDINGS
INDICATE THE ENVIRONMENT SHOULD SATURATE FAIRLY QUICKLY BEHIND THE
FRONT...ALTHOUGH THERE MAY STILL BE A BRIEF PERIOD OF FREEZING
DRIZZLE.
HIGH TEMPERATURES FOR PERIOD WILL BE NEARLY 20 DEGREES ABOVE NORMAL
WEDNESDAY THEN FALL TO 10-20 DEGREES BELOW NORMAL BY FRIDAY AND
SATURDAY. LOWS WILL BE 10 DEGREES ABOVE NORMAL WEDNESDAY NIGHT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 405 AM MST SUN DEC 15 2013
CONDITIONS AT MCK AND GLD WILL REMAIN VFR THROUGH THE TAF PERIOD
WITH SCATTERED MID TO HIGH LEVEL CLOUDS EXPECTED TO MOVE ACROSS
THE SITES THROUGH EARLY AFTERNOON. LIGHT WEST WINDS WILL TURN
NORTHWEST AND BECOME GUSTY BY 17Z WITH A SURFACE TROUGH IN PLACE
ACROSS THE CENTRAL HIGH PLAINS. WINDS WILL TURN WESTERLY AND
BECOME LIGHT AGAIN AFTER 23Z AS SKIES REMAIN MOSTLY CLEAR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...LOCKHART
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
855 AM EST SUN DEC 15 2013
.UPDATE...
QUICK UPDATE TO CARRY WIDESPREAD SNOW SHOWERS...AS FLAKE SIZE IS
PRETTY GOOD WITH SURFACE OBS REPORTING VSBYS 1-3 SM WITHIN THE
HEAVIER ACTIVITY. 12Z DTX SOUNDING DOES SHOW STEEP LAPSE RATE IN
THE 875-825 MB LAYER...WHICH IS EMBEDDED IN THE DENDRITIC SNOW
GROWTH REGION. SURFACE TROUGH IS PROVIDING SUFFICIENT LOW LEVEL
CONVERGENCE AS WELL. WITH GOOD FLUFF FACTOR...ACCUMULATIONS
AROUND 1 INCH ARE EXPECTED.
&&
.AVIATION...ISSUED 559 AM EST SUN DEC 15 2013
//DISCUSSION...
CONDITIONS SHOULD STAY MVFR THROUGH THE DAY FOR CIGS WITH POTENTIAL
FOR NON VFR VSBYS THIS AFTERNOON AS COVERAGE OF SNOW SHOWERS
INCREASES. WESTERLY WINDS WILL INCREASE AS DEEPER MIXING OCCURS THIS
AFTERNOON WITH GUSTS UP TO 25 KNOTS POSSIBLE. MODELS STILL TRYING TO
SCATTER OUT CLOUDS...AND POSSIBLY BECOME CLEAR OVERNIGHT.
FOR DTW...LIGHT SNOW SHOWERS WILL POSSIBLY OCCUR THIS AFTERNOON AS
LAKE EFFECT SNOW EXTENDS EASTWARD ACROSS LOWER MI. WESTERLY WINDS
WILL INCREASE THROUGH THE MORNING WITH GUSTS LIKELY ECLIPSING 25KTS
THIS AFTERNOON OUT OF ABOUT 270-280 DEGREES.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5KFT FT THROUGH THIS EVENING.
* MODERATE CONFIDENCE IN WESTERLY GUSTS EXCEEDING 25KTS SUNDAY
AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 357 AM EST SUN DEC 15 2013
SHORT TERM...TODAY AND TONIGHT
THE SHORT TERM WILL FEATURE LIGHT SNOW...GUSTY AFTERNOON WINDS...AND
POSSIBLE SINGLE DIGIT TEMPS OVERNIGHT. A NORTHERN STREAM UPPER LEVEL
LOW WILL DROP THROUGH THE NORTHERN GREAT LAKES TODAY WHILE A LAKE
AGGREGATE SURFACE TROUGH LINGERS ACROSS CENTRAL MI. STRONG CAA HAS
BEGUN IN THE WAKE OF SATURDAYS LOW AS BROAD MID LEVEL TROUGHING
SINKS INTO THE GREAT LAKES. THIS WILL USHER IN ANOTHER ARCTIC
AIRMASS TO DEAL WITH THROUGH TONIGHT. MODELS SHOW SOME AIRMASS
MODIFICATION AS IT CROSSES THE LAKES WITH -26C TEMPS AT 850MB
ENTERING LAKE SUPERIOR AND NEGATIVE TEENS ENTERING MI. SOUTHERN MI
WILL FALL NEAR THE BASE OF THE MID LEVEL TROUGH AND ON THE SOUTH
SIDE OF THE SFC TROUGH LEADING TO WESTERLY FLOW. THE WESTERLY FLOW
AND CAA WILL LEAD TO AN ACTIVE SETUP FOR LAKE EFFECT WITH MIXING
LEVELS OVER LAKE MI REACHING 10KFT. EVEN OVER SE MI THE CAA IN THE
LOW LEVELS WILL LEAD TO STRONG LAPSE RATES UP TO ABOUT 6KFT. BOTH
THE NAM AND RUC SHOW THE ENTIRE MIXED LAYER TO BE SATURATED WHICH
EXTENDS THROUGH THE DGZ. IN ADDITION TO THE SFC FEATURES...A MID
LEVEL VORT MAX WILL ROTATE AROUND AND THROUGH MID MI LENDING SOME
ADDITIONAL SYNOPTIC SUPPORT ALOFT. POPS WILL RAMP UP IN THE
AFTERNOON AS THE DIURNAL CYCLE GIVES THE MIXED LAYER A BOOST AND AS
THE SFC TROUGH AND VORT MAX SWING THROUGH. LAKE EFFECT SHOULD MAKE
IT INTO THE CWA WITH THE STEADY WESTERLY FLOW DURING THE DAY. THE
NAM IS ADVERTISING THE LAKE MI CONVERGENT BAND SETTING UP WHICH WILL
NEED TO BE WATCHED IN CASE IT IMPACTS ANY ONE AREA FOR ANY
DURATION...MOST LIKELY NEAR THE I94 CORRIDOR. OVERALL NOT EXPECTING
MUCH SNOW WITH AROUND A HALF INCH FOR MOST LOCATIONS. IF WE CAN GET
SOME ENHANCE MESOSCALE FEATURES TO SET UP OR THE LAKE EFFECT BAND TO
PERSIST...TOTALS WOULD OBVIOUSLY GO UP SOME. THE OTHER CONCERN TODAY
WILL BE THE WINDS. MODEL SOUNDINGS SHOW THE MIXING LEVELS PREVIOUSLY
MENTIONED BRINGING DOWN GUST AROUND 30 MPH IN THE AFTERNOON. THIS
WILL LIKELY LEAD TO ADDITIONAL DRIFTING OF THE SNOW PACK. THE LAST
CONCERN WILL BE LOW TEMPS TONIGHT. WITH THE FRESH SNOW PACK AND
ARCTIC AIR MOVING IN...THE POTENTIAL IS THERE FOR LOW SINGLE DIGIT
TEMPS. A BIG CONCERN WILL BE CLOUD COVER PREVENTING THIS FROM
ACTUALLY OCCURRING...ESPECIALLY ACROSS THE SOUTH WHERE THE LAKE
CLOUD SHOULD PERSIST THE LONGEST. ADJUSTED TEMPS UP A COUPLE DEGREES
ACROSS THE SOUTH WITH THE MORE PESSIMISTIC CLOUD COVER
FORECAST...OTHERWISE CONTINUED THE COOL PLAY IN THE MID SINGLE
DIGITS RESULTING IN WIND CHILL VALUES -5 TO -10F.
LONG TERM...MONDAY THROUGH SATURDAY
SHORTWAVE RIDGING WILL TRACK THROUGH THE CENTRAL GREAT LAKES MONDAY
MORNING...KEEPING THE WEATHER DRY FOR THE FIRST HALF OF THE DAY.
QUICKLY ON ITS HEELS WILL BE A VIGOROUS MID LEVEL SHORTWAVE DIVING
SOUTH FROM CANADA. THIS ELONGATED MID LEVEL TROUGH...SEEN ON WATER
VAPOR OVER WESTERN CANADA...WILL BRING A PROLONGED PERIOD OF LIGHT
SNOW SHOWERS FROM MONDAY AFTERNOON THROUGH TUESDAY TO SOUTHEAST
MICHIGAN. AS THE TROUGH MOVES THROUGH THE GREAT LAKES...IT WILL HAVE
THE ASSISTANCE OF BEING UNDER THE LEFT EXIT REGION OF A 140 KNOT JET
DIVING INTO THE WESTERN GREAT LAKES REGION. THE BEST TIME FOR SNOW
APPEARS TO BE LATE MONDAY AFTERNOON INTO MONDAY NIGHT WHEN THE LEAD
SHORTWAVE TRACKS THROUGH THE CENTRAL GREAT LAKES...WITH AN INCH OF
TWO OF SNOWFALL ACCUMULATION POSSIBLE. A SUBTLE BUT NOTICEABLE
WARMING IN THE LOW LEVELS SHOULD CAUSE LOW TEMPERATURES TO OCCUR
EARLY MONDAY NIGHT...WITH SLOWLY RISING TEMPERATURES AFTER MIDNIGHT.
ANOTHER SHORTWAVE TRACKING THROUGH THE SOUTHERN GREAT LAKES ON
TUESDAY COULD BRING ADDITIONAL SNOWFALL AMOUNTS OF A FEW TENTHS OF
AN INCH TO SOUTHEAST MICHIGAN.
ONCE THIS SYSTEM MOVES OFF TO THE EAST HEIGHTS WILL INCREASE ACROSS
THE CENTRAL GREAT LAKES WITH TEMPERATURES WARMING INTO THE 30S ON
THURSDAY...WITH 40S POSSIBLE BY FRIDAY AHEAD OF THE NEXT LOW
PRESSURE SYSTEM TRACKING THROUGH THE GREAT LAKES REGION. THIS
SYSTEM...ORIGINATING OVER THE SOUTHERN PLAINS ON THURSDAY...WILL
TRACK NORTHEAST THROUGH MICHIGAN ON FRIDAY. GIVEN THE NORTHERN TRACK
OF THE LOW THE AREA WILL BE IN THE WARM SECTOR OF THE
SYSTEM...MEANING PRECIPITATION MORE IN THE FORM OF LIQUID RATHER
THAN ICE CRYSTALS. THERE ARE STILL TIMING DIFFERENCES BETWEEN THE
LONG RANGE MODELS...NOTABLY THE FASTER ECMWF AND THE SLOWER GFS.
HOWEVER THEY DO AGREE ON A RETURN TO COLDER TEMPERATURES BEHIND THE
LOW BY SATURDAY AS RIDGING BUILDS OVER THE CENTRAL GREAT LAKES.
MARINE...
WAVES IN THE NEARSHORE ZONES CONTINUE TO SUBSIDE...WITH CONDITIONS
HAVING FALLEN BELOW HEADLINE CRITERIA. HOWEVER...INCREASING WESTERLY
WINDS THIS AFTERNOON ARE EXPECTED AS LOW PRESSURE TRACKS THROUGH THE
CENTRAL GREAT LAKES. THE FETCH WILL BE FAVORABLE FOR WAVES TO BUILD
UP OVER THE NORTHERN TIP OF THE THUMB OVERNIGHT...NECESSITATING A
SMALL CRAFT ADVISORY FOR OUTER SAGINAW BAY AND THE LAKE HURON
NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH. CONDITIONS WILL
REMAIN UNSETTLED INTO EARLY NEXT WEEK AS SOUTHWEST WINDS DEVELOP
AHEAD OF A PASSING SYSTEM MONDAY NIGHT INTO TUESDAY. THERE ARE NO
SIGNIFICANT WIND EVENTS ON THE HORIZON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
FROM PORT AUSTIN TO HARBOR BEACH...FROM 7 PM SUNDAY TO 10 AM
MONDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SF
AVIATION.....DRK
SHORT TERM...DRK
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
559 AM EST SUN DEC 15 2013
.AVIATION...
//DISCUSSION...
CONDITIONS SHOULD STAY MVFR THROUGH THE DAY FOR CIGS WITH POTENTIAL
FOR NON VFR VSBYS THIS AFTERNOON AS COVERAGE OF SNOW SHOWERS
INCREASES. WESTERLY WINDS WILL INCREASE AS DEEPER MIXING OCCURS THIS
AFTERNOON WITH GUSTS UP TO 25 KNOTS POSSIBLE. MODELS STILL TRYING TO
SCATTER OUT CLOUDS...AND POSSIBLY BECOME CLEAR OVERNIGHT.
FOR DTW...LIGHT SNOW SHOWERS WILL POSSIBLY OCCUR THIS AFTERNOON AS
LAKE EFFECT SNOW EXTENDS EASTWARD ACROSS LOWER MI. WESTERLY WINDS
WILL INCREASE THROUGH THE MORNING WITH GUSTS LIKELY ECLIPSING 25KTS
THIS AFTERNOON OUT OF ABOUT 270-280 DEGREES.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5KFT FT THROUGH THIS EVENING.
* MODERATE CONFIDENCE IN WESTERLY GUSTS EXCEEDING 25KTS SUNDAY
AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 357 AM EST SUN DEC 15 2013
SHORT TERM...TODAY AND TONIGHT
THE SHORT TERM WILL FEATURE LIGHT SNOW...GUSTY AFTERNOON WINDS...AND
POSSIBLE SINGLE DIGIT TEMPS OVERNIGHT. A NORTHERN STREAM UPPER LEVEL
LOW WILL DROP THROUGH THE NORTHERN GREAT LAKES TODAY WHILE A LAKE
AGGREGATE SURFACE TROUGH LINGERS ACROSS CENTRAL MI. STRONG CAA HAS
BEGUN IN THE WAKE OF SATURDAYS LOW AS BROAD MID LEVEL TROUGHING
SINKS INTO THE GREAT LAKES. THIS WILL USHER IN ANOTHER ARCTIC
AIRMASS TO DEAL WITH THROUGH TONIGHT. MODELS SHOW SOME AIRMASS
MODIFICATION AS IT CROSSES THE LAKES WITH -26C TEMPS AT 850MB
ENTERING LAKE SUPERIOR AND NEGATIVE TEENS ENTERING MI. SOUTHERN MI
WILL FALL NEAR THE BASE OF THE MID LEVEL TROUGH AND ON THE SOUTH
SIDE OF THE SFC TROUGH LEADING TO WESTERLY FLOW. THE WESTERLY FLOW
AND CAA WILL LEAD TO AN ACTIVE SETUP FOR LAKE EFFECT WITH MIXING
LEVELS OVER LAKE MI REACHING 10KFT. EVEN OVER SE MI THE CAA IN THE
LOW LEVELS WILL LEAD TO STRONG LAPSE RATES UP TO ABOUT 6KFT. BOTH
THE NAM AND RUC SHOW THE ENTIRE MIXED LAYER TO BE SATURATED WHICH
EXTENDS THROUGH THE DGZ. IN ADDITION TO THE SFC FEATURES...A MID
LEVEL VORT MAX WILL ROTATE AROUND AND THROUGH MID MI LENDING SOME
ADDITIONAL SYNOPTIC SUPPORT ALOFT. POPS WILL RAMP UP IN THE
AFTERNOON AS THE DIURNAL CYCLE GIVES THE MIXED LAYER A BOOST AND AS
THE SFC TROUGH AND VORT MAX SWING THROUGH. LAKE EFFECT SHOULD MAKE
IT INTO THE CWA WITH THE STEADY WESTERLY FLOW DURING THE DAY. THE
NAM IS ADVERTISING THE LAKE MI CONVERGENT BAND SETTING UP WHICH WILL
NEED TO BE WATCHED IN CASE IT IMPACTS ANY ONE AREA FOR ANY
DURATION...MOST LIKELY NEAR THE I94 CORRIDOR. OVERALL NOT EXPECTING
MUCH SNOW WITH AROUND A HALF INCH FOR MOST LOCATIONS. IF WE CAN GET
SOME ENHANCE MESOSCALE FEATURES TO SET UP OR THE LAKE EFFECT BAND TO
PERSIST...TOTALS WOULD OBVIOUSLY GO UP SOME. THE OTHER CONCERN TODAY
WILL BE THE WINDS. MODEL SOUNDINGS SHOW THE MIXING LEVELS PREVIOUSLY
MENTIONED BRINGING DOWN GUST AROUND 30 MPH IN THE AFTERNOON. THIS
WILL LIKELY LEAD TO ADDITIONAL DRIFTING OF THE SNOW PACK. THE LAST
CONCERN WILL BE LOW TEMPS TONIGHT. WITH THE FRESH SNOW PACK AND
ARCTIC AIR MOVING IN...THE POTENTIAL IS THERE FOR LOW SINGLE DIGIT
TEMPS. A BIG CONCERN WILL BE CLOUD COVER PREVENTING THIS FROM
ACTUALLY OCCURRING...ESPECIALLY ACROSS THE SOUTH WHERE THE LAKE
CLOUD SHOULD PERSIST THE LONGEST. ADJUSTED TEMPS UP A COUPLE DEGREES
ACROSS THE SOUTH WITH THE MORE PESSIMISTIC CLOUD COVER
FORECAST...OTHERWISE CONTINUED THE COOL PLAY IN THE MID SINGLE
DIGITS RESULTING IN WIND CHILL VALUES -5 TO -10F.
LONG TERM...MONDAY THROUGH SATURDAY
SHORTWAVE RIDGING WILL TRACK THROUGH THE CENTRAL GREAT LAKES MONDAY
MORNING...KEEPING THE WEATHER DRY FOR THE FIRST HALF OF THE DAY.
QUICKLY ON ITS HEELS WILL BE A VIGOROUS MID LEVEL SHORTWAVE DIVING
SOUTH FROM CANADA. THIS ELONGATED MID LEVEL TROUGH...SEEN ON WATER
VAPOR OVER WESTERN CANADA...WILL BRING A PROLONGED PERIOD OF LIGHT
SNOW SHOWERS FROM MONDAY AFTERNOON THROUGH TUESDAY TO SOUTHEAST
MICHIGAN. AS THE TROUGH MOVES THROUGH THE GREAT LAKES...IT WILL HAVE
THE ASSISTANCE OF BEING UNDER THE LEFT EXIT REGION OF A 140 KNOT JET
DIVING INTO THE WESTERN GREAT LAKES REGION. THE BEST TIME FOR SNOW
APPEARS TO BE LATE MONDAY AFTERNOON INTO MONDAY NIGHT WHEN THE LEAD
SHORTWAVE TRACKS THROUGH THE CENTRAL GREAT LAKES...WITH AN INCH OF
TWO OF SNOWFALL ACCUMULATION POSSIBLE. A SUBTLE BUT NOTICEABLE
WARMING IN THE LOW LEVELS SHOULD CAUSE LOW TEMPERATURES TO OCCUR
EARLY MONDAY NIGHT...WITH SLOWLY RISING TEMPERATURES AFTER MIDNIGHT.
ANOTHER SHORTWAVE TRACKING THROUGH THE SOUTHERN GREAT LAKES ON
TUESDAY COULD BRING ADDITIONAL SNOWFALL AMOUNTS OF A FEW TENTHS OF
AN INCH TO SOUTHEAST MICHIGAN.
ONCE THIS SYSTEM MOVES OFF TO THE EAST HEIGHTS WILL INCREASE ACROSS
THE CENTRAL GREAT LAKES WITH TEMPERATURES WARMING INTO THE 30S ON
THURSDAY...WITH 40S POSSIBLE BY FRIDAY AHEAD OF THE NEXT LOW
PRESSURE SYSTEM TRACKING THROUGH THE GREAT LAKES REGION. THIS
SYSTEM...ORIGINATING OVER THE SOUTHERN PLAINS ON THURSDAY...WILL
TRACK NORTHEAST THROUGH MICHIGAN ON FRIDAY. GIVEN THE NORTHERN TRACK
OF THE LOW THE AREA WILL BE IN THE WARM SECTOR OF THE
SYSTEM...MEANING PRECIPITATION MORE IN THE FORM OF LIQUID RATHER
THAN ICE CRYSTALS. THERE ARE STILL TIMING DIFFERENCES BETWEEN THE
LONG RANGE MODELS...NOTABLY THE FASTER ECMWF AND THE SLOWER GFS.
HOWEVER THEY DO AGREE ON A RETURN TO COLDER TEMPERATURES BEHIND THE
LOW BY SATURDAY AS RIDGING BUILDS OVER THE CENTRAL GREAT LAKES.
MARINE...
WAVES IN THE NEARSHORE ZONES CONTINUE TO SUBSIDE...WITH CONDITIONS
HAVING FALLEN BELOW HEADLINE CRITERIA. HOWEVER...INCREASING WESTERLY
WINDS THIS AFTERNOON ARE EXPECTED AS LOW PRESSURE TRACKS THROUGH THE
CENTRAL GREAT LAKES. THE FETCH WILL BE FAVORABLE FOR WAVES TO BUILD
UP OVER THE NORTHERN TIP OF THE THUMB OVERNIGHT...NECESSITATING A
SMALL CRAFT ADVISORY FOR OUTER SAGINAW BAY AND THE LAKE HURON
NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH. CONDITIONS WILL
REMAIN UNSETTLED INTO EARLY NEXT WEEK AS SOUTHWEST WINDS DEVELOP
AHEAD OF A PASSING SYSTEM MONDAY NIGHT INTO TUESDAY. THERE ARE NO
SIGNIFICANT WIND EVENTS ON THE HORIZON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
FROM PORT AUSTIN TO HARBOR BEACH...FROM 7 PM SUNDAY TO 10 AM
MONDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
SHORT TERM...DRK
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS HASTINGS NE
533 AM CST SUN DEC 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CST SUN DEC 15 2013
THE BIGGEST CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES TODAY.
AT UPPER LEVELS...A RIDGE WILL BE IN THE PACIFIC WHILE A TROUGH IN
THE EASTERN UNITED STATES WILL EXIST. WE WILL BE IN NORTHWEST FLOW
IN BETWEEN WITH WARM AIR ADVECTION BEING ADVERTISED AT 850 MB AS THE
RIDGE NUDGES EAST. A SMALL PERTURBATION UPSTREAM WILL PASS ACROSS
THE CWA THIS MORNING...AND FOR TONIGHT...AN UPPER JET WILL APPROACH
AS THE LEFT FRONT QUADRANT WILL PROBABLY BE NEAR OUR AREA BY THE END
OF THE OVERNIGHT.
AT THE SURFACE...A WARM FRONT HAS NEARLY PASSED THROUGH THE ENTIRE
CWA...EXCEPT FOR THE FAR NORTHEASTERN CORNER. THIS FRONT SHOULD
CONTINUE TO EDGE FARTHER EAST THIS MORNING AND WE SHOULD BE
COMPLETELY IN THE WARM SECTOR FOR TODAY AND TONIGHT...ALTHOUGH THE
COLDER AIR WILL NOT BE TOO FAR TO THE EAST. GOING ABOVE GUIDANCE AS
RECENT BIAS CORRECTED MODEL VERIFICATION SUGGESTS THIS WOULD BE A
GOOD IDEA...AS WELL AS THE FACT THAT OUR SNOW PACK OVER THE CENTRAL
PART OF THE CWA IS FAST DWINDLING. A FLY IN THE OINTMENT COULD BE THE
MID TO UPPER LEVEL CLOUDINESS ASSOCIATED WITH THE PERTURBATION
MOVING ACROSS THE AREA DURING THE LATE MORNING INTO POSSIBLY THE
EARLY AFTERNOON...BUT THE HRRR SUGGESTS THAT WE SHOULD BE WELL CLEAR
OF MOST OF THIS SKY COVER BEFORE THE PEAK HEATING OF THE DAY OCCURS.
ANY PRECIPITATION SHOULD REMAIN WELL OFF THE NORTHEAST AND EAST OF
THE CWA WITH A PASSING WAVE AND NO MODEL IS ADVERTISING MEASURABLE
PRECIPITATION...ALTHOUGH THE WRF IS INDICATING PERHAPS SOME VERY
LIGHT NON-MEASURABLE PRECIPITATION IN OUR FAR NORTHEAST...BUT THIS
IS CLEARLY AN OUTLIER AND NOT CONSIDERED IN THIS FORECAST. THERE
COULD BE A BIT OF PATCHY FOG IN OUR EAST TONIGHT AS THE SREF IS
PICKING UP ON THIS. WITH WIND IN THE EAST NEAR CALM FOR PART OF THE
NIGHT AND DEWPOINT DEPRESSIONS PREDICTED TO BE LOW...WITH A LITTLE
BIT OF FRESHLY MELTED SNOW. THIS SHOULD NOT AMOUNT TO MUCH...AND BY
LATE OVERNIGHT...WIND WILL PROBABLY PICK UP A BIT TO DECREASE FOG
POTENTIAL. WITH THE APPROACHING LEFT FRONT QUADRANT OF AN UPPER
LEVEL JET...WE COULD ALSO HAVE SOME INCREASED CIRRUS BY LATE
OVERNIGHT AS WELL. GOING CLOSE TO GUIDANCE NUMBERS FOR LOWS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CST SUN DEC 15 2013
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM PERIOD LIE WITH A
CHANGE IN TEMPERATURES LATE IN THE WEEK...AND PRECIPITATION CHANCES.
THERE REALLY HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS
THROUGH THE PERIOD...SHOWING IT STARTING OUT MONDAY MORNING WITH
NORTHWESTERLY FLOW CONTINUING IN THE UPPER LEVELS...SET UP BETWEEN
AN AREA OF LOW PRESSURE OVER THE NERN CONUS...AND A RIDGE AXIS
EXTENDING ALONG WRN PORTIONS OF MEXICO UP INTO THE WEST COAST OF THE
CONUS. AT THE SURFACE...EXPECTING THE CWA TO BE BETWEEN HIGH
PRESSURE OVER THE SRN PLAINS AND LOW PRESSURE OVER CENTRAL
CANADA...WITH A WEAK FRONTAL BOUNDARY SLIDING TO THE EAST...BUT
HAVING LITTLE IMPACT. NOT EXPECTING A LOT OF CHANGE IN THE OVERALL
PATTERN MON/TUESDAY...THE FORECAST REMAINS DRY WITH ANY NOTABLE
DISTURBANCES REMAINING TO THE NORTH...AND ABOVE AVERAGE TEMPS ALSO
REMAIN. WINDS THROUGH BOTH DAYS WILL HAVE THE DOWNSLOPING W/NWRLY
WINDS...AIDING IN THE MILD TEMPS. FORECAST HIGHS ON MONDAY ARE IN
THE MID 40S/MID 50S...BUT MONDAY NIGHT/TUESDAY...MODELS ARE SHOWING
A STRONGER DISTURBANCE SLIDING SOUTHEAST INTO THE GREAT LAKES
REGION...WHICH MAY USHER IN SOME SLIGHTLY COOLER AIR AIR...BUT HIGHS
ON TUESDAY ARE JUST A COUPLE DEGREES COOLER.
AS WE GET INTO TUESDAY NIGHT AND WEDNESDAY...LITTLE HAS CHANGED WITH
THE STORY SHOWING THE UPPER LEVEL PATTERN BECOMING MORE ZONAL IN
NATURE...AS A DISTURBANCE BEGINS TO MOVE ONTO THE PAC NW/WEST
COAST. STARTING TO SEE SOME DIFFERENCES BETWEEN MODELS ARISE...WITH
THE SFC PATTERN/WINDS AND THE MAGNITUDE OF WARM AIR ALOFT. CURRENT
HAVE HIGHS ON WED NOT SIGNIFICANTLY DIFFERENT THAN MON/TUES...BUT
CONFIDENCE IS NOT HIGH...AS THE POTENTIAL FOR INCREASING UPPER LEVEL
CLOUDS WILL BE A CONCERN.
CERTAINLY THE MORE INTERESTING TIME FRAME OF THE LONG TERM LIES
THURSDAY THROUGH SATURDAY...WITH IT STILL LOOKING TO BRING AN END TO
THE ABOVE AVERAGE TEMPS. BY 12Z THURSDAY...EXPECTING TO SEE A
TROUGH AXIS EXTENDING FROM NRN CANADA SW TOWARD THE WEST
COAST...WITH MORE SOUTHWESTERLY FLOW IN PLACE ACROSS THE PLAINS. BY
THE END OF THE DAY...MODELS SHOW THIS TROUGH DIGGING SOUTH TOWARD
THE SRN HALF OF CA...BECOMING CLOSED OFF...WITH THE WEAKER NRN
ENERGY EXPECTED TO GRADUALLY CONTINUE WORKING EAST. THE TIMING OF
THE ACCOMPANYING COLD FRONT...AND WHETHER THERE WILL BE ANY
PRECIP...ARE THE MAIN CONCERNS FOR THURSDAY. WILL CONTINUE TO KEEP
THE FORECAST DRY...BUT PRECIP MAY NOT BE FAR OUTSIDE THE NRN AND ERN
PORTIONS OF THE CWA. COOLED HIGHS A BIT FOR THURSDAY INTO THE LOWER
30S NORTH TO LOWER/MID 40S SOUTH...STILL SOME TIMING DIFFERENCES OF
THE COLDER AIR WORKING IN...BUT LATEST MODELS HAVE TRENDED QUICKER.
THURSDAY NIGHT AND FRIDAY...CONFIDENCE IN POPS IS NOT HIGH...AND
THEY REMAIN LOW. THE MAIN UPPER LEVEL LOW CONTINUES ITS SWING
SOUTH...BY 12Z LOOKS TO BE OVER THE NRN BAJA OF MEX...WHILE THE NRN
ENERGY HAS SHIFTED FURTHER EAST...AND THE LATEST EC/GFS/GEM ARE ALL
SHOWING THE CWA GETTING NO MORE THAN A GLANCING BLOW OF SOME LIGHT
SNOW...SET UP IN BETWEEN THE TWO MAIN DISTURBANCES. AT THIS POINT
FRIDAY CONTINUES TO LOOK LIKE THE COLDEST DAY OF THE FORECAST
PERIOD...AS THE COLDER AIR MASS/CENTER OF HIGH PRESSURE SETTLES IN
OVER THE REGION BEHIND THE FRONT...AND FORECAST HIGHS REMAIN IN THE
TEENS TO MID 20S.
FRIDAY NIGHT AND SATURDAY...THE MAIN CHANGE WAS TO REMOVE POPS
FRIDAY NIGHT...SOMETHING THAT MAY NEED TO BE CONSIDERED FOR SATURDAY
AS WELL...BUT AT THIS POINT KEPT SOME LOW POPS IN. THE SPREAD
BETWEEN MODELS WITH THE EVOLUTION OF THAT UPPER LEVEL LOW TO THE SW
IS SIZABLE...WITH THE GFS KEEPING IT CLOSED OFF AND WELL TO THE
SOUTH...SUGGESTING SAT WOULD BE DRY. THE ECMWF FILLS THE
LOW...BECOMING AN OPEN WAVE AND SLIDING PRIMARILY ACROSS THE SRN
PLAINS...BUT PERHAPS CLIPPING THE SERN CORNER OF THE CWA WITH SOME
PRECIP. TEMPS FOR SAT DO LOOK TO REBOUND A BIT AS THE COLDER AIR
MASS STARTS TO SLIDE EAST...BUT STILL LOOKING AT JUST MID/UPPER 20S.
PLENTY OF THINGS MAY SHIFT BETWEEN NOW AND THEN.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z MONDAY MORNING)
ISSUED AT 530 AM CST SUN DEC 15 2013
VFR CONDITIONS ARE FORECAST. MID TO HIGH LEVEL SKY COVER SHOULD
DECREASE BY AFTERNOON ONCE AN UPPER LEVEL PERTURBATION PASSES TO
THE SOUTHEAST OF THE TERMINAL. WIND SHOULD REMAIN RELATIVELY
LIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
525 AM CST SUN DEC 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CST SUN DEC 15 2013
TODAY AND TONIGHT...A POWERFUL THERMAL RIDGE WILL CONTINUE OPERATING
ACROSS THE FORECAST AREA. WINDS AT H850 MB CONTINUE AT 35 TO 45 KT
TODAY AND THEN WEAKEN TO AROUND 30 KTS TONIGHT. THE MID LEVEL CLOUD
DECK CURRENTLY ACROSS THE FCST AREA IS FCST TO SHIFT EAST AND EXIT
THE AREA THIS AFTN. AT THE SAME TIME A BANK OF CIRRUS ACROSS THE NRN
PLAINS WILL DRIFT ACROSS THE FCST AREA. THE TEMPERATURE FCST TODAY
USES THE WARM SIDE OF THE MODEL CONSENSUS PLUS ABOUT 3 DEGREES FOR
HIGHS IN THE UPPER 50S SOUTHWEST TO UPPER 30S NORTHEAST. THIS IS A
FEW DEGREES COOLER THAN THE HRRR MODEL BUT THAT MODEL WAS TOO WARM
SATURDAY.
THE QUESTION TONIGHT IS HOW COOL LOWS WILL GO. PRESUMABLY CIRRUS
WILL CONTINUE ACROSS THE FCST AREA BUT NONE OF THE MODELS SHOW MUCH
MID LEVEL CLOUDINESS WHICH WOULD KEEP MIN TEMPS IN THE 30S. THE FCST
IS FOR LOWER 20S ASSUMING CIRRUS CLOUDS.
OTHERWISE...500M AGL WINDS INCREASE TO 25 TO 30 KTS WHICH SUPPORTS
WINDS IN THE 20 TO 30 MPH RANGE AT THE SFC. THE FCST USES MULTIMODEL
DATA TODAY AND TONIGHT FOR WINDS BUT INCREASES WIND SPEEDS TO NEAR
THE MAV GUIDANCE...THE STRONGEST WIND DATA SET AVAILABLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM CST SUN DEC 15 2013
PRIMARY FORECAST PROBLEMS THROUGH THIS PERIOD ARE TEMPERATURES AS
WELL AS PRECIPITATION CHANCES THURSDAY AND THURSDAY NIGHT.
AMPLIFIED UPPER LEVEL FLOW WITH RIDGING OVER THE EASTERN PACIFIC AND
WESTERN CONUS WITH TROUGHING OVER THE EASTERN HALF OF THE CONUS WILL
GIVE WAY TO A CHANGE BY MID WEEK AS THE UPPER LEVEL LOW CURRENTLY
OVER ONTARIO MOVES EAST DECREASING THE STRENGTH OF THE
TROUGH...WHILE A SERIES OF SHORTWAVE TROUGHS MOVE THROUGH THE
NORTHERN STREAM OUT OF RUSSIA AND ALASKA TO FLATTEN THE FLOW BY
MONDAY AND TUESDAY. SEVERAL WEAK SURFACE FRONTS WILL MOVE THROUGH
THE REGION WITH THE FIRST COMING THROUGH MONDAY MORNING AND ANOTHER
MONDAY NIGHT. EVEN WITH THESE FRONTS MOVING THROUGH...THE AIRMASS
WILL HAVE A PACIFIC INFLUENCE SO NOT EXPECTING TEMPERATURES TO BE
IMPACTED MUCH BY IT. WILL ALSO SEE WESTERLY FLOW IN THE LOW LEVELS
TO HELP WITH MIXING AND RAISING THE TEMPERATURES ON MONDAY. HIGH
PRESSURE WILL BUILD SOUTHEAST ACROSS THE AREA AND BY TUESDAY WILL
MOVE FURTHER SOUTHEAST BRINGING RETURN FLOW BACK INTO THE AREA.
AGAIN EXPECTING TEMPERATURES SIMILAR TO SUNDAY AND MONDAY.
TUESDAY NIGHT INTO WEDNESDAY THE CHANGING UPPER LEVEL PATTERN WILL
START TO BECOME APPARENT AS WHAT WILL BECOME A STRONG UPPER LEVEL
WAVE MOVES DOWN THE BRITISH COLUMBIA COAST AND INTO THE PACIFIC
NORTHWEST. MEANWHILE...THE UPPER LOW CURRENTLY WELL OFF THE
CALIFORNIA COAST WILL MOVE ONSHORE INTO SOUTHERN CALIFORNIA. AS
THESE TWO SYSTEMS BEGIN TO DEEPEN A TROUGH OVER THE WEST
COAST...UPPER LEVEL RIDGING WILL BUILD OVER THE PLAINS.
CONCURRENTLY...LOW PRESSURE AT THE SURFACE WILL DEVELOP OVER EASTERN
WYOMING WHICH WILL STRENGTHEN THE SOUTHERLY FLOW INTO THE LOCAL
AREA. WEDNESDAY SHOULD BE THE WARMEST DAY OF THE WEEK...HOWEVER
THERE ARE SOME DIFFERENCES IN HOW WARM IT WILL GET. THE ECMWF RISES
850MB TEMPERATURES TO NEAR 13C OVER THE SOUTHERN PART OF THE
FORECAST AREA WEDNESDAY AFTERNOON...WHILE THE GFS DOESN/T WARM
THINGS UP AS MUCH. THIS WOULD MEAN A DIFFERENCE IN HIGHS BY 5 TO 10
DEGREES ACROSS THE FORECAST AREA. AT THIS TIME...TRENDED CLOSER TO
THE WARMER SOLUTION...YET NOT AS WARM AS SOME MODEL SOLUTIONS
SUGGESTING.
THE OTHER CONSIDERATION WHEN DEALING WITH THE TEMPERATURES IS THE
IMPACT OF THE SNOWPACK OVER THE NORTHERN PARTS OF THE FORECAST AREA.
SHOULD GET QUITE A BIT OF SNOW TO MELT OVER THE NEXT SEVERAL
DAYS...AND DO HAVE TEMPERATURES ON THE UPWARD TREND THROUGH
WEDNESDAY. BELIEVE WILL STILL SEE SOME INFLUENCE FROM THE SNOW
THROUGH THE WEEK...BUT HOW MUCH REMAINS IN QUESTION. WILL SEE HOW
TEMPERATURES WARM TODAY AND WILL SEE WHAT ADJUSTMENTS WILL NEED TO
BE MADE FOR THE FOLLOWING DAYS OVER THE NEXT SEVERAL FORECAST
CYCLES.
ON WEDNESDAY NIGHT THE UPPER LOW THAT MOVES INTO CALIFORNIA ON
WEDNESDAY WILL EJECT OUT OF THE UPPER TROUGH AND INTO THE CENTRAL
PLAINS. AS THIS OCCURS...THE WYOMING SURFACE LOW WILL MOVE INTO
EASTERN COLORADO...WITH THE ENTIRE SYSTEM WEAKENING. GOING INTO
THURSDAY THE SURFACE LOW WILL MOVE ACROSS KANSAS WITH AN INVERTED
TROUGH PASSING ACROSS THE LOCAL FORECAST AREA. THE MAJORITY OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL REMAIN ACROSS KANSAS AND
SOUTHEAST NEBRASKA SO NOT EXPECTING ANY PRECIPITATION INVOLVED WITH
IT.
FOCUS THEN TURNS TO THE NEXT ARCTIC AIRMASS TO PUSH THROUGH THE
PLAINS. THE ARCTIC FRONT IS NOW BEING TIMED TO MOVE SOUTH ACROSS
NEBRASKA DURING THE DAY THURSDAY WITH PRECIPITATION MOVING IN BEHIND
THE FRONT. THE MUCH COLDER AIR WILL LAG BEHIND THE FRONT...HOWEVER
WITH COLD AIR ADVECTION ONGOING THROUGH THE DAY AM QUESTIONING HOW
WARM IT WILL GET...OR WHAT TIME HIGHS WILL BE REACHED. LOCATIONS
ACROSS THE NORTH MAY SEE HIGHS IN THE MORNING...WHILE THE SOUTHERN
PARTS OF THE AREA MAY HAVE SOME TIME TO WARM UP BEFORE THE BIG PUSH
OF COLD AIR. DID LOWER HIGHS SLIGHTLY FOR THURSDAY...BUT WILL LIKELY
NEED FURTHER ADJUSTMENTS UNTIL A BETTER HANDLE IS ON THE MODELS FOR
THIS SYSTEM. THE PRESSURE GRADIENT WILL TIGHTEN BEHIND THE
FRONT...WITH STRONG NORTHERLY WINDS EXPECTED ON THURSDAY INTO
THURSDAY NIGHT. BY FRIDAY HIGH PRESSURE WILL BUILD IN WITH THE
PRESSURE GRADIENT RELAXING SO WINDS SHOULDN/T BE AS STRONG. COLDER
AND BELOW NORMAL TEMPERATURES WILL THEN CONTINUE INTO THE WEEKEND AS
THE TROUGH AXIS MOVES ACROSS THE CONUS THROUGH THE WEEKEND. CURRENT
MODELS AREN/T QUITE AS COLD WITH THE TEMPERATURES FOR FRIDAY AND
SATURDAY AS PREVIOUS RUNS...BUT STILL BRING 850MB TEMPERATURES OF
-15C TO -17C INTO THE CENTRAL PLAINS.
IN TERMS OF PRECIPITATION...THERE SEEMS TO BE AN ISSUE WITH A POCKET
OF DRY AIR IN THE MID LEVELS BEHIND THE FRONT WHICH MAY CAUSE
PROBLEMS WITH THE DEVELOPMENT OF PRECIPITATION. THERE CONTINUES TO
BE A SLIGHT SIGNAL FOR SOME DRIZZLE ON THURSDAY PRIOR TO THE COLUMN
BECOMING SATURATED THURSDAY NIGHT. HOWEVER...EVEN IN THE LOW
LEVELS...THE AIR WASN/T COMPLETELY SATURATED EITHER SO WILL STILL
NOT MENTION ANY DRIZZLE YET IN THE FORECAST. BESIDES THIS OUTSIDE
CHANCE FOR DRIZZLE...THE POST-FRONTAL PRECIPITATION SHOULD BE QUITE
LIGHT. PRECIPITABLE WATER AMOUNTS AREN/T BAD...HOWEVER THE SIGNALS
FOR ANY FRONTOGENESIS ARE NOT STRONG AND THE MOISTURE DOES NOT STAY
LONG BEFORE MUCH DRIER AIR PUSHES IN TO DRY OUT THE COLUMN SO NOT
EXPECTING ANY HEAVY PRECIPITATION AMOUNTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 522 AM CST SUN DEC 15 2013
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT.
NORTHWEST FLOW WILL CONTINUE AT ALL LEVELS. THE BANK OF MID LEVEL
CLOUDS WILL MOVE EAST TODAY AND BE REPLACED BY BROKEN HIGH CLOUDS
LATE THIS AFTERNOON AND TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
440 AM CST SUN DEC 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CST SUN DEC 15 2013
THE BIGGEST CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES TODAY.
AT UPPER LEVELS...A RIDGE WILL BE IN THE PACIFIC WHILE A TROUGH IN
THE EASTERN UNITED STATES WILL EXIST. WE WILL BE IN NORTHWEST FLOW
IN BETWEEN WITH WARM AIR ADVECTION BEING ADVERTISED AT 850 MB AS THE
RIDGE NUDGES EAST. A SMALL PERTURBATION UPSTREAM WILL PASS ACROSS
THE CWA THIS MORNING...AND FOR TONIGHT...AN UPPER JET WILL APPROACH
AS THE LEFT FRONT QUADRANT WILL PROBABLY BE NEAR OUR AREA BY THE END
OF THE OVERNIGHT.
AT THE SURFACE...A WARM FRONT HAS NEARLY PASSED THROUGH THE ENTIRE
CWA...EXCEPT FOR THE FAR NORTHEASTERN CORNER. THIS FRONT SHOULD
CONTINUE TO EDGE FARTHER EAST THIS MORNING AND WE SHOULD BE
COMPLETELY IN THE WARM SECTOR FOR TODAY AND TONIGHT...ALTHOUGH THE
COLDER AIR WILL NOT BE TOO FAR TO THE EAST. GOING ABOVE GUIDANCE AS
RECENT BIAS CORRECTED MODEL VERIFICATION SUGGESTS THIS WOULD BE A
GOOD IDEA...AS WELL AS THE FACT THAT OUR SNOW PACK OVER THE CENTRAL
PART OF THE CWA IS FAST DWINDLING. A FLY IN THE OINTMENT COULD BE THE
MID TO UPPER LEVEL CLOUDINESS ASSOCIATED WITH THE PERTURBATION
MOVING ACROSS THE AREA DURING THE LATE MORNING INTO POSSIBLY THE
EARLY AFTERNOON...BUT THE HRRR SUGGESTS THAT WE SHOULD BE WELL CLEAR
OF MOST OF THIS SKY COVER BEFORE THE PEAK HEATING OF THE DAY OCCURS.
ANY PRECIPITATION SHOULD REMAIN WELL OFF THE NORTHEAST AND EAST OF
THE CWA WITH A PASSING WAVE AND NO MODEL IS ADVERTISING MEASURABLE
PRECIPITATION...ALTHOUGH THE WRF IS INDICATING PERHAPS SOME VERY
LIGHT NON-MEASURABLE PRECIPITATION IN OUR FAR NORTHEAST...BUT THIS
IS CLEARLY AN OUTLIER AND NOT CONSIDERED IN THIS FORECAST. THERE
COULD BE A BIT OF PATCHY FOG IN OUR EAST TONIGHT AS THE SREF IS
PICKING UP ON THIS. WITH WIND IN THE EAST NEAR CALM FOR PART OF THE
NIGHT AND DEWPOINT DEPRESSIONS PREDICTED TO BE LOW...WITH A LITTLE
BIT OF FRESHLY MELTED SNOW. THIS SHOULD NOT AMOUNT TO MUCH...AND BY
LATE OVERNIGHT...WIND WILL PROBABLY PICK UP A BIT TO DECREASE FOG
POTENTIAL. WITH THE APPROACHING LEFT FRONT QUADRANT OF AN UPPER
LEVEL JET...WE COULD ALSO HAVE SOME INCREASED CIRRUS BY LATE
OVERNIGHT AS WELL. GOING CLOSE TO GUIDANCE NUMBERS FOR LOWS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CST SUN DEC 15 2013
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM PERIOD LIE WITH A
CHANGE IN TEMPERATURES LATE IN THE WEEK...AND PRECIPITATION CHANCES.
THERE REALLY HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS
THROUGH THE PERIOD...SHOWING IT STARTING OUT MONDAY MORNING WITH
NORTHWESTERLY FLOW CONTINUING IN THE UPPER LEVELS...SET UP BETWEEN
AN AREA OF LOW PRESSURE OVER THE NERN CONUS...AND A RIDGE AXIS
EXTENDING ALONG WRN PORTIONS OF MEXICO UP INTO THE WEST COAST OF THE
CONUS. AT THE SURFACE...EXPECTING THE CWA TO BE BETWEEN HIGH
PRESSURE OVER THE SRN PLAINS AND LOW PRESSURE OVER CENTRAL
CANADA...WITH A WEAK FRONTAL BOUNDARY SLIDING TO THE EAST...BUT
HAVING LITTLE IMPACT. NOT EXPECTING A LOT OF CHANGE IN THE OVERALL
PATTERN MON/TUESDAY...THE FORECAST REMAINS DRY WITH ANY NOTABLE
DISTURBANCES REMAINING TO THE NORTH...AND ABOVE AVERAGE TEMPS ALSO
REMAIN. WINDS THROUGH BOTH DAYS WILL HAVE THE DOWNSLOPING W/NWRLY
WINDS...AIDING IN THE MILD TEMPS. FORECAST HIGHS ON MONDAY ARE IN
THE MID 40S/MID 50S...BUT MONDAY NIGHT/TUESDAY...MODELS ARE SHOWING
A STRONGER DISTURBANCE SLIDING SOUTHEAST INTO THE GREAT LAKES
REGION...WHICH MAY USHER IN SOME SLIGHTLY COOLER AIR AIR...BUT HIGHS
ON TUESDAY ARE JUST A COUPLE DEGREES COOLER.
AS WE GET INTO TUESDAY NIGHT AND WEDNESDAY...LITTLE HAS CHANGED WITH
THE STORY SHOWING THE UPPER LEVEL PATTERN BECOMING MORE ZONAL IN
NATURE...AS A DISTURBANCE BEGINS TO MOVE ONTO THE PAC NW/WEST
COAST. STARTING TO SEE SOME DIFFERENCES BETWEEN MODELS ARISE...WITH
THE SFC PATTERN/WINDS AND THE MAGNITUDE OF WARM AIR ALOFT. CURRENT
HAVE HIGHS ON WED NOT SIGNIFICANTLY DIFFERENT THAN MON/TUES...BUT
CONFIDENCE IS NOT HIGH...AS THE POTENTIAL FOR INCREASING UPPER LEVEL
CLOUDS WILL BE A CONCERN.
CERTAINLY THE MORE INTERESTING TIME FRAME OF THE LONG TERM LIES
THURSDAY THROUGH SATURDAY...WITH IT STILL LOOKING TO BRING AN END TO
THE ABOVE AVERAGE TEMPS. BY 12Z THURSDAY...EXPECTING TO SEE A
TROUGH AXIS EXTENDING FROM NRN CANADA SW TOWARD THE WEST
COAST...WITH MORE SOUTHWESTERLY FLOW IN PLACE ACROSS THE PLAINS. BY
THE END OF THE DAY...MODELS SHOW THIS TROUGH DIGGING SOUTH TOWARD
THE SRN HALF OF CA...BECOMING CLOSED OFF...WITH THE WEAKER NRN
ENERGY EXPECTED TO GRADUALLY CONTINUE WORKING EAST. THE TIMING OF
THE ACCOMPANYING COLD FRONT...AND WHETHER THERE WILL BE ANY
PRECIP...ARE THE MAIN CONCERNS FOR THURSDAY. WILL CONTINUE TO KEEP
THE FORECAST DRY...BUT PRECIP MAY NOT BE FAR OUTSIDE THE NRN AND ERN
PORTIONS OF THE CWA. COOLED HIGHS A BIT FOR THURSDAY INTO THE LOWER
30S NORTH TO LOWER/MID 40S SOUTH...STILL SOME TIMING DIFFERENCES OF
THE COLDER AIR WORKING IN...BUT LATEST MODELS HAVE TRENDED QUICKER.
THURSDAY NIGHT AND FRIDAY...CONFIDENCE IN POPS IS NOT HIGH...AND
THEY REMAIN LOW. THE MAIN UPPER LEVEL LOW CONTINUES ITS SWING
SOUTH...BY 12Z LOOKS TO BE OVER THE NRN BAJA OF MEX...WHILE THE NRN
ENERGY HAS SHIFTED FURTHER EAST...AND THE LATEST EC/GFS/GEM ARE ALL
SHOWING THE CWA GETTING NO MORE THAN A GLANCING BLOW OF SOME LIGHT
SNOW...SET UP IN BETWEEN THE TWO MAIN DISTURBANCES. AT THIS POINT
FRIDAY CONTINUES TO LOOK LIKE THE COLDEST DAY OF THE FORECAST
PERIOD...AS THE COLDER AIR MASS/CENTER OF HIGH PRESSURE SETTLES IN
OVER THE REGION BEHIND THE FRONT...AND FORECAST HIGHS REMAIN IN THE
TEENS TO MID 20S.
FRIDAY NIGHT AND SATURDAY...THE MAIN CHANGE WAS TO REMOVE POPS
FRIDAY NIGHT...SOMETHING THAT MAY NEED TO BE CONSIDERED FOR SATURDAY
AS WELL...BUT AT THIS POINT KEPT SOME LOW POPS IN. THE SPREAD
BETWEEN MODELS WITH THE EVOLUTION OF THAT UPPER LEVEL LOW TO THE SW
IS SIZABLE...WITH THE GFS KEEPING IT CLOSED OFF AND WELL TO THE
SOUTH...SUGGESTING SAT WOULD BE DRY. THE ECMWF FILLS THE
LOW...BECOMING AN OPEN WAVE AND SLIDING PRIMARILY ACROSS THE SRN
PLAINS...BUT PERHAPS CLIPPING THE SERN CORNER OF THE CWA WITH SOME
PRECIP. TEMPS FOR SAT DO LOOK TO REBOUND A BIT AS THE COLDER AIR
MASS STARTS TO SLIDE EAST...BUT STILL LOOKING AT JUST MID/UPPER 20S.
PLENTY OF THINGS MAY SHIFT BETWEEN NOW AND THEN.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CST SAT DEC 14 2013
MAINLY MID-LEVEL SKY COVER IS EXPECTED AS A WARM FRONT MOVES EAST.
WIND SHOULD BE LIGHT FROM THE WEST BEHIND THE FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EST SUN DEC 15 2013
.SYNOPSIS...HIGH PRESSURE BUILDS OVER THE REGION TODAY INTO MONDAY.
A MOSTLY DRY COLD FRONT MOVES THROUGH THE REGION TUESDAY. HIGH
PRESSURE RETURNS FOR WEDNESDAY AND THURSDAY ALONG WITH A WARMING
TREND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 940 AM SUNDAY...
CLOUDS HAVE BEEN A LITTLE SLOW TO ERODE THIS MORNING...WITH THE
LATEST SATELLITE IMAGES SHOWING CLEARING BEGINNING ALONG AND WEST OF
U.S. 1...AND ONLY A FEW THIN PATCHES TO THE EAST OF THERE. THE 06Z
GFS WAS LIKELY A LITTLE TOO AGGRESSIVE WITH DRYING AND CLEARING ON
ITS MODEL SOUNDINGS...AND THE LATEST RAP IN COMBINATION WITH THE
HRRR WRF AND THE LAV SEEMS TO BE DOING FAIRLY WELL WITH THE TREND OF
THE CLEARING. WITH THE FAST SOUTHWEST FLOW ALOFT DELAYING THE MID-
LEVEL DRYING AND BETTER MIXING AS THE 850MB FRONT PASSES...IT MAY BE
EARLY AFTERNOON BEFORE BETTER SUNSHINE STARTS TO BE NOTED TOWARD THE
FAR SOUTHEAST AREAS PARTICULARLY TOWARD KCTZ. EVEN WITH THE DELAY IN
CLEARING...THOUGH...WITH TEMPERATURES IN THE FAR SOUTHEAST ALREADY
CLOSE TO 50 DEGREES IT SHOULD NOT TAKE MUCH SUNSHINE TO REALIZE
FORECAST MAXIMUMS. THERE SHOULD BE A FEW WIND GUSTS OF 20 TO 25 MPH
ESPECIALLY AS MIXING DEVELOPS IN THE NORTHWEST PIEDMONT...LESSER
GUSTS FARTHER SOUTHEAST DUE TO LATER ARRIVAL OF CLEARING AND THE
TIMING OF DIMINISHING 925MB WINDS...TO 15 TO 20KT BY EARLY
AFTERNOON. -DJF
FOR TONIGHT...AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST...A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW...ENSURING
CONTINUED DRY AND STABLE LOW LEVELS...WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 250 AM SUNDAY...
EXPECT DRY AND GENERALLY QUIET WEATHER... ALTHOUGH IT MAY NOT BE
QUITE AS SUN-FILLED AS ONCE THOUGHT ACROSS NRN NC. A WEAK MID LEVEL
WAVE NOW OVER ALBERTA/MT WILL DIVE SE THEN EAST ACROSS THE
MIDATLANTIC/NC MONDAY... WITH A 100+ KT UPPER JET STREAKING INTO THE
REGION. MODEL FORECAST SOUNDINGS SHOW A SOMEWHAT MOIST LAYER BETWEEN
800 MB AND 600 MB OVER THE NRN HALF OF THE CWA... AND GIVEN THAT THE
EXPECTED VERTICAL THERMAL AND MOISTURE STRUCTURE WILL BE SUPPORTIVE
OF OROGRAPHIC ENHANCEMENT OF MID-HIGH CLOUDS IN THIS AREA... WILL
HAVE A FORECAST OF SKIES BECOMING PARTLY CLOUDY ROUGHLY ALONG/NORTH
OF HIGHWAY 64 FOR THE AFTERNOON THROUGH MID EVENING... FOLLOWED BY
CLEARING OVERNIGHT AS THE VORTICITY MAX MOVES TO OUR EAST.
THICKNESSES WILL BE ABOUT 15-20 M BELOW NORMAL... SUGGESTING HIGHS
FROM 47 NORTH TO 53 SOUTH WHEN FACTORING IN THE CLOUDS OVER THE
NORTH. LOWS 28-35 WITH SKIES BECOMING MOSTLY CLEAR. -GIH
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
TUESDAY-WEDNESDAY NIGHT: DRY CONDITIONS AND NEAR NORMAL TEMPS.
EXPECT SOME DEGREE OF WARMING ON TUE (HIGHS MID/UPPER 50S) VIA
SOUTHWEST LOW-LEVEL FLOW AND WARM ADVECTION ASSOC/W A TIGHTENING
MSLP/HEIGHT GRADIENT IN ADVANCE OF A POTENT SHORTWAVE AND ATTENDANT
CLIPPER LOW DIGGING INTO THE GREAT LAKES. THE AFOREMENTIONED
SHORTWAVE ENERGY WILL PROGRESS INTO THE NORTHERN MID-ATLANTIC AND
NEW ENGLAND TUE NIGHT BEFORE MOVING OFFSHORE EARLY WED. THE
GFS/ECMWF GUIDANCE ARE ROUGHLY IN GOOD AGREEMENT ON THE EVOLUTION OF
THE AFOREMENTIONED SHORTWAVE ENERGY/CLIPPER SYSTEM...INDICATING A
WEAK/DRY COLD FRONTAL PASSAGE TUE EVE/NIGHT FOLLOWED BY WEAK HIGH
PRESSURE BUILDING INTO THE REGION ON WED. EXPECT LOWS IN THE LOWER
TO MID 30S WED MORNING (COOLEST N/NW)...WITH HIGHS ON WED SEVERAL
DEGREES COOLER THAN TUE IN THE LOWER 50S FAR NORTH TO MID/UPPER 50S
FAR SOUTH. WITH CLEAR SKIES...LIGHT/CALM WINDS AND A DRY AIRMASS IN
PLACE...EXPECT GOOD RADIATIONAL COOLING WITH LOWS IN THE UPPER 20S
TO LOWER 30S WED NIGHT.
THURSDAY-FRIDAY...EXPECT A WARMING TREND WITH INCREASING CLOUD
COVER. SHORTWAVE ENERGY IS EXPECTED TO DIG SOUTHEAST THROUGH THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST THU/THU NIGHT... WITH AN
ATTENDANT SFC LOW TRACKING NE FROM THE CENTRAL PLAINS TO THE GREAT
LAKES AND AN ASSOCIATED COLD FRONT PROGRESSING EAST ACROSS THE MS
RIVER VALLEY. HIGH PRESSURE WILL MOVE OFFSHORE THE CAROLINA COAST IN
ADVANCE OF THE AFOREMENTIONED FRONT ON THU...RESULTING IN THE ONSET
OF SOUTHERLY RETURN FLOW /WARM ADVECTION/. WARM ADVECTION AND LOW-
LEVEL MOISTURE TRANSPORT WILL STRENGTHEN ON FRIDAY AS THE
AFOREMENTIONED FRONT PROGRESSES INTO THE TN/OH VALLEY AND THE
MSLP/HEIGHT GRADIENT TIGHTENS OVER THE CAROLINAS. EXPECT HIGHS IN
THE UPPER 50S TO NEAR 60F (S) ON THU...AND IN THE MID/UPPER 60S TO
NEAR 70F ON FRIDAY DEPENDING ON CLOUD COVER...WARMEST S/SE. THOUGH
LOW-LEVEL WARM ADVECTION (ALONE OR) IN THE PRESENCE OF ANY SMALL
AMPLITUDE DISTURBANCES IN WSW FLOW ALOFT COULD CONCEIVABLY RESULT IN
A LOW CHANCE FOR SPRINKLES OR LIGHT RAIN THU NIGHT/FRI MORNING...
WILL KEEP THE FCST DRY AT THIS TIME.
FRIDAY NIGHT-SATURDAY: UNCERTAINTY IN THE FORECAST INCREASES
DRAMATICALLY THIS WEEKEND WITH REGARD TO THE EVOLUTION OF A COMPLEX
UPPER LEVEL PATTERN CHARACTERIZED BY SPLIT FLOW. REGARDLESS...THE
OVERALL PATTERN WOULD SUGGEST AN ABOVE AVERAGE CHANCE FOR RAIN
ASSOC/W AN INCREASINGLY WARM/MOIST AIRMASS AND THE FRONTAL ZONE
APPROACHING FROM THE WEST. WILL INDICATE MOSTLY CLOUDY/OVERCAST
SKIES AND A 30% CHANCE OF RAIN ON SAT/SUN. -VINCENT
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AS OF 940 AM SUNDAY...
CONDITIONS WILL SLOWLY IMPROVE FROM NORTHWEST TO SOUTHEAST TO
VFR...WITH THE LATEST IMPROVEMENT TOWARD KFAY BY EARLY AFTERNOON.
LOW LEVEL WINDS WILL BECOME FROM THE WNW OR NW (FROM 270-320
DEGREES) AND WILL INCREASE IN SPEED TO 8-12 KTS OCCASIONALLY GUSTING
TO 18-22 KTS LATE MORNING THROUGH AFTERNOON...HIGHEST GUSTS TOWARD
THE TRIAD. THIS DOWNSLOPE DRYING FLOW WILL SCOUR OUT THE LOW
CLOUDS...THUS...CONFIDENCE IS HIGH IN VFR CONDITIONS AT ALL
SITES...EVEN KFAY...BY MID AFTERNOON. WINDS WILL DIMINISH TO 8 KTS
OR LESS AROUND SUNSET. CLEAR SKIES AND VFR VSBYS ARE EXPECTED
TONIGHT AS HIGH PRESSURE NOSES INTO THE AREA.
LOOKING BEYOND 12Z MONDAY MORNING...HIGH CONFIDENCE IN VFR
CONDITIONS MONDAY THROUGH THURSDAY...AS SURFACE HIGH PRESSURE
DOMINATES WITH DRY WEATHER.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...VINCENT
AVIATION...DJF/HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
622 AM EST SUN DEC 15 2013
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL CROSS THE CAROLINAS THIS
MORNING. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE SOUTHWEST
THIS AFTERNOON THROUGH MID WEEK... PROVIDING FAIR AND DRY WEATHER.
THIS HIGH WILL SHIFT OFF THE COAST WEDNESDAY... BRINGING A WARMING
TREND THROUGH LATE WEEK.
&&
NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 215 AM SUNDAY...
THROUGH TODAY: GREATLY IMPROVING WEATHER IS EXPECTED THIS MORNING.
THE LATEST SURFACE MAP SHOWS THE WEDGE FRONT HAVING MOVED JUST EAST
OF THE CWA... WHILE THE PRIMARY OCCLUDED FRONT HAS MOVED INTO THE NC
MOUNTAINS. WE REMAIN ON THE EAST SIDE OF THE APPROACHING BROAD
TROUGH... AND WHILE THE HEAVIEST RAIN HAS SHIFTED OFF THE COAST... A
POCKET OF MID LEVEL VORTICITY SHEARING OUT OF THE TROUGH BASE ACROSS
THE CENTRAL CAROLINAS IS RESPONSIBLE FOR A BATCH OF MOSTLY LIGHT
RAIN STREAMING OVER THE AREA. THE LATEST HRRR GUIDANCE DEPICTS THIS
PRECIP WELL AND SHOWS THIS LIGHT RAIN AREA PUSHING EASTWARD OUT OF
THE CWA BETWEEN 8 AM AND 10 AM AS THE MID LEVEL TROUGH AXIS CROSSES
THE AREA. THICK LOW CLOUDS WILL PERSIST UNTIL THEN... AS WE`RE
SEEING COOLING AT THE SURFACE BUT THE 925 MB/850 MB TROUGH AXES ARE
STILL TO OUR WEST... YIELDING A VERTICAL THERMAL DIFFERENTIAL AND
FOSTERING LOW LEVEL STABILIZATION (EXACERBATED BY A LOOSE MSLP
GRADIENT AND LIGHT SURFACE WINDS)... HINDERING MIXING. AFTER THE
OCCLUDED FRONT PASSES THROUGH BY MID TO LATE MORNING... THE ENSUING
DOWNSLOPE LOW LEVEL FLOW WILL HELP DRY OUT THE LOWER TROPOSPHERE...
WHILE INCREASING DEEP LAYER SUBSIDENCE IN THE WAKE OF THE DEPARTING
BROAD TROUGH AXIS HELPS DRY AND STABILIZE THE MID-UPPER LEVELS.
EXPECT PLENTY OF SUNSHINE BY THE AFTERNOON HOURS. THICKNESSES DO
FALL DURING THE DAY (MUCH OF WHICH IS A FUNCTION OF COOLING AT 925-
850 MB WITH GOOD DRYING BUT NOT A LOT OF COOLING BELOW 925 MB)...
BUT THE INCOMING AIR MASS IS MODIFIED AND SOURCED FROM OUR WSW...
AND LATE-DAY THICKNESSES ARE STILL JUST SLIGHTLY BELOW NORMAL. HIGHS
49-57... NEAR TO SLIGHTLY UNDER SEASONAL NORMALS. EXPECT BREEZY WNW
WINDS WITH OCCASIONAL GUSTS AS THE COOLER AND MORE DENSE AIR ARRIVES
WITH SHALLOW BUT PRONOUNCED MIXING.
FOR TONIGHT: AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST... A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW... ENSURING
CONTINUED DRY AND STABLE LOW LEVELS... WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 250 AM SUNDAY...
EXPECT DRY AND GENERALLY QUIET WEATHER... ALTHOUGH IT MAY NOT BE
QUITE AS SUN-FILLED AS ONCE THOUGHT ACROSS NRN NC. A WEAK MID LEVEL
WAVE NOW OVER ALBERTA/MT WILL DIVE SE THEN EAST ACROSS THE
MIDATLANTIC/NC MONDAY... WITH A 100+ KT UPPER JET STREAKING INTO THE
REGION. MODEL FORECAST SOUNDINGS SHOW A SOMEWHAT MOIST LAYER BETWEEN
800 MB AND 600 MB OVER THE NRN HALF OF THE CWA... AND GIVEN THAT THE
EXPECTED VERTICAL THERMAL AND MOISTURE STRUCTURE WILL BE SUPPORTIVE
OF OROGRAPHIC ENHANCEMENT OF MID-HIGH CLOUDS IN THIS AREA... WILL
HAVE A FORECAST OF SKIES BECOMING PARTLY CLOUDY ROUGHLY ALONG/NORTH
OF HIGHWAY 64 FOR THE AFTERNOON THROUGH MID EVENING... FOLLOWED BY
CLEARING OVERNIGHT AS THE VORTICITY MAX MOVES TO OUR EAST.
THICKNESSES WILL BE ABOUT 15-20 M BELOW NORMAL... SUGGESTING HIGHS
FROM 47 NORTH TO 53 SOUTH WHEN FACTORING IN THE CLOUDS OVER THE
NORTH. LOWS 28-35 WITH SKIES BECOMING MOSTLY CLEAR. -GIH
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
TUESDAY-WEDNESDAY NIGHT: DRY CONDITIONS AND NEAR NORMAL TEMPS.
EXPECT SOME DEGREE OF WARMING ON TUE (HIGHS MID/UPPER 50S) VIA
SOUTHWEST LOW-LEVEL FLOW AND WARM ADVECTION ASSOC/W A TIGHTENING
MSLP/HEIGHT GRADIENT IN ADVANCE OF A POTENT SHORTWAVE AND ATTENDANT
CLIPPER LOW DIGGING INTO THE GREAT LAKES. THE AFOREMENTIONED
SHORTWAVE ENERGY WILL PROGRESS INTO THE NORTHERN MID-ATLANTIC AND
NEW ENGLAND TUE NIGHT BEFORE MOVING OFFSHORE EARLY WED. THE
GFS/ECMWF GUIDANCE ARE ROUGHLY IN GOOD AGREEMENT ON THE EVOLUTION OF
THE AFOREMENTIONED SHORTWAVE ENERGY/CLIPPER SYSTEM...INDICATING A
WEAK/DRY COLD FRONTAL PASSAGE TUE EVE/NIGHT FOLLOWED BY WEAK HIGH
PRESSURE BUILDING INTO THE REGION ON WED. EXPECT LOWS IN THE LOWER
TO MID 30S WED MORNING (COOLEST N/NW)...WITH HIGHS ON WED SEVERAL
DEGREES COOLER THAN TUE IN THE LOWER 50S FAR NORTH TO MID/UPPER 50S
FAR SOUTH. WITH CLEAR SKIES...LIGHT/CALM WINDS AND A DRY AIRMASS IN
PLACE...EXPECT GOOD RADIATIONAL COOLING WITH LOWS IN THE UPPER 20S
TO LOWER 30S WED NIGHT.
THURSDAY-FRIDAY...EXPECT A WARMING TREND WITH INCREASING CLOUD
COVER. SHORTWAVE ENERGY IS EXPECTED TO DIG SOUTHEAST THROUGH THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST THU/THU NIGHT... WITH AN
ATTENDANT SFC LOW TRACKING NE FROM THE CENTRAL PLAINS TO THE GREAT
LAKES AND AN ASSOCIATED COLD FRONT PROGRESSING EAST ACROSS THE MS
RIVER VALLEY. HIGH PRESSURE WILL MOVE OFFSHORE THE CAROLINA COAST IN
ADVANCE OF THE AFOREMENTIONED FRONT ON THU...RESULTING IN THE ONSET
OF SOUTHERLY RETURN FLOW /WARM ADVECTION/. WARM ADVECTION AND LOW-
LEVEL MOISTURE TRANSPORT WILL STRENGTHEN ON FRIDAY AS THE
AFOREMENTIONED FRONT PROGRESSES INTO THE TN/OH VALLEY AND THE
MSLP/HEIGHT GRADIENT TIGHTENS OVER THE CAROLINAS. EXPECT HIGHS IN
THE UPPER 50S TO NEAR 60F (S) ON THU...AND IN THE MID/UPPER 60S TO
NEAR 70F ON FRIDAY DEPENDING ON CLOUD COVER...WARMEST S/SE. THOUGH
LOW-LEVEL WARM ADVECTION (ALONE OR) IN THE PRESENCE OF ANY SMALL
AMPLITUDE DISTURBANCES IN WSW FLOW ALOFT COULD CONCEIVABLY RESULT IN
A LOW CHANCE FOR SPRINKLES OR LIGHT RAIN THU NIGHT/FRI MORNING...
WILL KEEP THE FCST DRY AT THIS TIME.
FRIDAY NIGHT-SATURDAY: UNCERTAINTY IN THE FORECAST INCREASES
DRAMATICALLY THIS WEEKEND WITH REGARD TO THE EVOLUTION OF A COMPLEX
UPPER LEVEL PATTERN CHARACTERIZED BY SPLIT FLOW. REGARDLESS...THE
OVERALL PATTERN WOULD SUGGEST AN ABOVE AVERAGE CHANCE FOR RAIN
ASSOC/W AN INCREASINGLY WARM/MOIST AIRMASS AND THE FRONTAL ZONE
APPROACHING FROM THE WEST. WILL INDICATE MOSTLY CLOUDY/OVERCAST
SKIES AND A 30% CHANCE OF RAIN ON SAT/SUN. -VINCENT
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 620 AM SUNDAY...
SUB-VFR AVIATION CONDITIONS WILL HOLD UNTIL SHORTLY AFTER
SUNRISE... WHEN IMPROVEMENT TO VFR IS EXPECTED BETWEEN 13Z AND 16Z.
A COMPLEX OF SURFACE LOW PRESSURE CENTERS CROSSING THE AREA IS
BRINGING UNSETTLED WEATHER IN THE FORM OF IFR/LIFR CIGS AND MVFR TO
IFR VSBYS EARLY THIS MORNING. THESE CLOUDS WILL PERSIST FOR A FEW
MORE HOURS... ALONG WITH PATCHY LIGHT RAIN THAT WILL CROSS CENTRAL
NC. THIS RAIN IS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE THAT
WILL SWEEP THROUGH THE AREA EARLY THIS MORNING. ONCE THIS
DISTURBANCE PASSES TO OUR EAST NEAR OR SOON AFTER SUNRISE...LOW
LEVEL WINDS WILL BECOME FROM THE WNW OR NW (FROM 270-320 DEGREES)
AND WILL INCREASE IN SPEED TO 8-12 KTS OCCASIONALLY GUSTING TO 18-22
KTS MID-LATE MORNING THROUGH AFTERNOON. THIS DOWNSLOPE DRYING FLOW
WILL SCOUR OUT THE LOW CLOUDS BETWEEN 13Z (WRN TAFS) AND 16Z (ERN
TAFS). THUS...CONFIDENCE IS HIGH IN VFR CONDITIONS AT ALL SITES BY
MID AFTERNOON. WINDS WILL DIMINISH TO 8 KTS OR LESS AROUND SUNSET.
CLEAR SKIES AND VFR VSBYS ARE EXPECTED TONIGHT AS HIGH PRESSURE
NOSES INTO THE AREA.
LOOKING BEYOND 12Z MONDAY MORNING...HIGH CONFIDENCE IN VFR
CONDITIONS MONDAY THROUGH THURSDAY...AS SURFACE HIGH PRESSURE
DOMINATES WITH DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...VINCENT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EST SUN DEC 15 2013
.SYNOPSIS...
THE SURFACE LOW ALONG THE COAST IS NOW THE MAIN LOW TAKING THE
PRECIPITATION WITH IT. COLD AIR IS MOVING DOWN FROM THE NORTHWEST
AND WILL TRIGGER MOUNTAIN SNOW SHOWERS. A TROUGH WILL DOMINATE
OUR WEATHER THROUGH MOST OF THE NEXT 4 DAYS. A CLIPPER WILL PASS
TO OUR NORTH AND SHOULD PRODUCE LIGHT SNOW TUESDAY. HEIGHTS RISE
THURSDAY INTO EARLY SATURDAY AND THERE SHOULD BE A PERIOD OF
RELATIVELY WARM WEATHER LATER THIS WEEK. AFTER THAT...A
DEVELOPING TROUGH SHOULD PUSH COLD AIR BACK INTO PENNSYLVANIA
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SECONDARY SURFACE LOW WAS SOUTH OF LI AT 6 AM AND A COLD FRONT
WAS MOVING ACROSS WESTERN PENNSYLVANIA. THE PRECIPITATION OVER THE
REGION HAS OR WILL CHANGE TO ALL SNOW AS THE COLDER AIR FILTERS
INTO THE REGION. MOSTLY VERY LIGHT SNOW. BEHIND THE COLD FRONT
WINDS WILL BECOME GUSTY FROM THE WEST NORTHWEST LATER THIS MORNING
AND THIS AFTERNOON.
THE COLD AIR MOVING OVER THE LAKES BEHIND THIS FRONT WILL KICK OFF
LAKE EFFECT SNOW SHOWERS AND SNOW BANDS. THE RAP AND 4KM NAM EACH
SHOW THIS EVOLUTION LATER THIS AFTERNOON AND OVERNIGHT. BY LATE
THIS AFTERNOON THE NAM IMPLIES SOME LES SNOW AFFECTING WARREN
COUNTY.
SOME SNOW MAINLY IN MORNING OVER CENTRAL PA AS INDICATED ON
RADAR...VERY LIGHT WITH MINOR ACCUMULATION POSSIBLE IN SPOTS.
MOST LOCATIONS WILL BE WINDY AND COLD. THE MESOSCALE MODELS CLEAR
OUT SOUTHEASTERN PA THIS MORNING. AT THIS TIME ONLY INDICATIONS OF
CLEAR SKIES ARE IN THE DRY SLOT IN THE WV OVER CENTRAL AND
VIRGINIA. THE 11-3.9 MICRON DATA DOES NOT SHOW THIS YET. SUSPECT
WHEN WE SEE THIS VISIBLE IMAGES...CLOUD FORECASTS IN SOUTHEAST
WILL BE LOWERED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE LES AND COLD ARE THE TWO FORECAST ISSUES.
THE HIGH RESOLUTION MODELS IMPLY A SINGLE WEST-EAST SNOW BAND
WHICH AT TIMES COULD DRIFT INTO WARREN COUNTY AND PERHAPS MCKEAN
COUNTY. THE SNOW AMOUNTS IN WARREN USING A BLEND OF HIGH
RESOLUTION MODELS WAS IN THE 3-6 INCH RANGE. MUCH LOWER TO THE
SOUTH AND EAST. THE SREF WAS A BIT MORE ROBUST WITH THE POPS AND
QPF AREA WHICH WAS TRIMMED BACK MORE LIKE THE 4KM NAM.
THE NAM IMPLIES THE LES BAND COULD DRIFT OVER NORTHERN WARREN
COUNTY THIS EVENING AND THROUGH ABOUT 4 AM. THIS SIMULATION AND
THE RAP MAKE IT CLEAR BOTH FORECAST SYSTEMS THINK THERE SHOULD BE
A GOOD LES BAND IN SOUTHERN NY AND NW PA OVERNIGHT TONIGHT. THE
DETAILS WILL OF COURSE ELUDE US.
OUTSIDE THE LES AND UPSLOPE SNOW AREAS...WILL BE A VERY COLD
EVENING AND OVERNIGHT WITH SLOWLY ABATING WINDS.
COLD MONDAY WITH RESIDUAL SNOWS MAINLY CONFINED TO
NORTHWESTERNMOST AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE GEFS-CMCEPS-SREF ALL SHOWS A CLIPPER PASSING TO OUR NORTH
TUESDAY. TIMING VARIES AND TRACK IS TO OUR NORTH THUS ANY
PRECIPITATION SHOULD BE LIGHT. TRIED TO SHOW THE POTENTIAL FOR
LIGHT SNOW TUESDAY. KEPT SNOW GENERALLY LOWER THAN 1 INCH AND
MAINLY CENTRAL AND NORTHERN AREAS.
THE NW FLOW WEAKENS AS A 500 HPA LOW DEVELOPS IN SW US LATER IN
THE WEEK. THIS ALLOWS FOR SOUTHWESTERLY FLOW AND A GRADUAL WARM UP
LIKELY THURSDAY INTO FRIDAY. MODELS IMPLY WARMEST DAY WOULD BE
FRIDAY. THIS WILL NOT LAST AS MODELS SHOWS DEEPENING TROUGH TO OUR
NORTH AND WEST AND A POOL OF ARCTIC AIR MOVING INTO THE LAKES
FRIDAY INTO SATURDAY. THUS SURFACE COLD FRONT SHOULD PUSH COLD AIR
BACK INTO OUR REGION SOMETIME NEXT WEEKEND.
BIAS CORRECT GEFS AND NAEFS SUGGEST TROUGH AND GENERALLY COLD
WEATHER SETTLE BACK IN THIS COMING WEEKEND AND INTO THE CHRISTMAS
WEEK.
AT THIS TIME NO BIG STORMS IN THE ENSEMBLES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE AIR IS GETTING COLDER AS THE WIND HAS TURNED TO THE WNW OVER
THE WRN TERMINALS. THEY SHOULD TURN IN THE EAST VERY SHORTLY AS
THE SFC LOW DEEPENS EVEN MORE ON THE COAST. THE COOLING AIR HAS
TURNED ANY LINGERING PRECIP BACK TO SNOW...AND THE UPSLOPE FLOW
INTO THE WRN MTS IS FORCING LIGHT SNOW THERE. LOW CIGS
DOMINATE...BUT SOME RISE IN CLOUD BASES HAS ALREADY HAPPENED AT
MDT. THE CIGS SHOULD RISE AND CLOUDS BREAK UP SOME IN THE SE. THE
WIND WILL BE THE BIG STORY FOR MOST AIRFIELDS TODAY. SUSTAINED
12-17KTS WITH GUSTS INTO THE 30S IN THE WEST. THE GAP WIND AT AOO
AND ELEVATION AT JST WILL KEEP THEM ON THE HIGHER-END OF WIND
SPEEDS TODAY. LAKE EFFECT SHSN GO INTO HIGH GEAR LATER THIS
EVENING...AND BFD COULD BE IN FOR A LONG NIGHT OF IFR SNOW AND
CIGS.
FAST FLOW WILL BRING AN ALMOST NEVER-ENDING TRAIN OF WEAK NRN
STREAM IMPULSES TO MAKE SHSN FOR THE WRN TERMINALS FOR THE BULK OF
THE WEEK. THE STRONGEST CLIPPER WILL BE ON MON PM-TUE AM. WARM AIR
TRIES TO RETURN BY FRI.
OUTLOOK...
MON...MAINLY VFR WITH MVFR IN SHSN AT BFD.
MON NITE-TUE...LGT SNOW/REDUCED VSBYS.
WED-THU...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST MONDAY FOR PAZ004.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DANGELO
LONG TERM...GRUMM
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
640 AM EST SUN DEC 15 2013
.SYNOPSIS...
THE SURFACE LOW ALONG THE COAST IS NOW THE MAIN LOW TAKING THE
PRECIPITATION WITH IT. A COLD FRONT WILL MOVE OVER THE STATE
TODAY TRIGGERING MOUNTAIN SNOW SHOWERS. A TROUGH WILL DOMINATE
OUR WEATHER THROUGH MOST OF THE NEXT 4 DAYS. A CLIPPER WILL PASS
TO OUR NORTH AND SHOULD PRODUCE LIGHT SNOW TUESDAY. HEIGHTS RISE
THURSDAY INTO EARLY SATURDAY AND THERE SHOULD BE A PERIOD OF
RELATIVELY WARM WEATHER LATER THIS WEEK...DEVELOPING TROUGH SHOULD
PUSH COLD AIR BACK INTO PENNSYLVANIA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SECONDARY SURFACE LOW WAS SOUTH OF LI AT 6 AM AND A COLD FRONT
WAS MOVING ACROSS WESTERN PENNSYLVANIA. THE PRECIPITATION OVER THE
REGION HAS OR WILL CHANGE TO ALL SNOW AS THE COLDER AIR FILTERS
INTO THE REGION. MOSTLY VERY LIGHT SNOW. BEHIND THE COLD FRONT
WINDS WILL BECOME GUSTY FROM THE WEST NORTHWEST LATER THIS MORNING
AND THIS AFTERNOON.
THE COLD AIR MOVING OVER THE LAKES BEHIND THIS FRONT WILL KICK OFF
LAKE EFFECT SNOW SHOWERS AND SNOW BANDS. THE RAP AND 4KM NAM EACH
SHOW THIS EVOLUTION LATER THIS AFTERNOON AND OVERNIGHT. BY LATE
THIS AFTERNOON THE NAM IMPLIES SOME LES SNOW AFFECTING WARREN
COUNTY.
SOME SNOW MAINLY IN MORNING OVER CENTRAL PA AS INDICATED ON
RADAR...VERY LIGHT WITH MINOR ACCUMULATION POSSIBLE IN SPOTS.
MOST LOCATIONS WILL BE WINDY AND COLD. THE MESOSCALE MODELS CLEAR
OUT SOUTHEASTERN PA THIS MORNING. AT THIS TIME ONLY INDICATIONS OF
CLEAR SKIES ARE IN THE DRY SLOT IN THE WV OVER CENTRAL AND
VIRGINIA. THE 11-3.9 MICRON DATA DOES NOT SHOW THIS YET. SUSPECT
WHEN WE SEE THIS VISIBLE IMAGES...CLOUD FORECASTS IN SOUTHEAST
WILL BE LOWERED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE LES AND COLD ARE THE TWO FORECAST ISSUES.
THE HIGH RESOLUTION MODELS IMPLY A SINGLE WEST-EAST SNOW BAND
WHICH AT TIMES COULD DRIFT INTO WARREN COUNTY AND PERHAPS MCKEAN
COUNTY. THE SNOW AMOUNTS IN WARREN USING A BLEND OF HIGH
RESOLUTION MODELS WAS IN THE 3-6 INCH RANGE. MUCH LOWER TO THE
SOUTH AND EAST. THE SREF WAS A BIT MORE ROBUST WITH THE POPS AND
QPF AREA WHICH WAS TRIMMED BACK MORE LIKE THE 4KM NAM.
THE NAM IMPLIES THE LES BAND COULD DRIFT OVER NORTHERN WARREN
COUNTY THIS EVENING AND THROUGH ABOUT 4 AM. THIS SIMULATION AND
THE RAP MAKE IT CLEAR BOTH FORECAST SYSTEMS THINK THERE SHOULD BE
A GOOD LES BAND IN SOUTHERN NY AND NW PA OVERNIGHT TONIGHT. THE
DETAILS WILL OF COURSE ELUDE US.
OUTSIDE THE LES AND UPSLOPE SNOW AREAS...WILL BE A VERY COLD
EVENING AND OVERNIGHT WITH SLOWLY ABATING WINDS.
COLD MONDAY WITH RESIDUAL SNOWS MAINLY CONFINED TO
NORTHWESTERNMOST AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE GEFS-CMCEPS-SREF ALL SHOWS A CLIPPER PASSING TO OUR NORTH
TUESDAY. TIMING VARIES AND TRACK IS TO OUR NORTH THUS ANY
PRECIPITATION SHOULD BE LIGHT. TRIED TO SHOW THE POTENTIAL FOR
LIGHT SNOW TUESDAY. KEPT SNOW GENERALLY LOWER THAN 1 INCH AND
MAINLY CENTRAL AND NORTHERN AREAS.
THE NW FLOW WEAKENS AS A 500 HPA LOW DEVELOPS IN SW US LATER IN
THE WEEK. THIS ALLOWS FOR SOUTHWESTERLY FLOW AND A GRADUAL WARM UP
LIKELY THURSDAY INTO FRIDAY. MODELS IMPLY WARMEST DAY WOULD BE
FRIDAY. THIS WILL NOT LAST AS MODELS SHOWS DEEPENING TROUGH TO OUR
NORTH AND WEST AND A POOL OF ARCTIC AIR MOVING INTO THE LAKES
FRIDAY INTO SATURDAY. THUS SURFACE COLD FRONT SHOULD PUSH COLD AIR
BACK INTO OUR REGION SOMETIME NEXT WEEKEND.
BIAS CORRECT GEFS AND NAEFS SUGGEST TROUGH AND GENERALLY COLD
WEATHER SETTLE BACK IN THIS COMING WEEKEND AND INTO THE CHRISTMAS
WEEK.
AT THIS TIME NO BIG STORMS IN THE ENSEMBLES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
FREEZING DRIZZLE COVERS MOST OF THE AREA AS THE HIGH SEEDER CLOUDS
HAVE PRETTY MUCH MOVED AWAY. BUT THE PRECIP IS TURNING TO SNOW
AGAIN AS THE LOWER CLOUDS TO THE WEST OF THE PRIMARY LOW LOCATED
OVER KBFD MOVES TOWARD NY STATE AND THE COLDEST AIR WRAPS BACK
IN FROM THE WEST. LOW CIGS DOMINATE...BUT SOME RISE IN CLOUD BASES
IS STARTING IN THE EAST...AND THE SERN TERMINALS MAY IMPROVE TO A
HIGH-END MVFR OR EVEN VFR AROUND SUNRISE.
SFC LOWS BATTLING IT OUT WITH MOST OF CENTRAL PA IN A BIT OF A COL
AT THE MOMENT...BUT THE STRONGER COASTAL LOW SHOULD TAKE OVER BY
SUNRISE. EXPECT WESTERN PRECIPITATION TO CONTINUE TO LIGHTEN
OVERNIGHT AS THE WESTERN LOW FILLS. EXPECT WIND SHIFT TO THE WEST
SHORTLY AT ALL SITES. THEN WINDS SHIFT NORTHWEST AS THE COASTAL
LOW STRENGTHENS AND PULLS NORTH.
WNWRLY FLOW WITH IT/S TYPICAL POST-FRONTAL UPSLOPE SHSN AND LAKE
ENHANCEMENT WILL PROVIDE EQUAL AMOUNTS OF MVFR AND IFR THROUGH THE
DAYLIGHT HOURS. LOTS OF MECHANICAL TURBULENCE EXPECTED AS THE WIND
WILL GET STRONGER AS THE MORNING CONTINUES. SUSTAINED 12-15KTS
WITH GUSTS INTO THE 30S ARE EXPECTED AT JST/BFD THIS AFTN. ONLY
SLIGHTLY LOWER SPEEDS ARE IN STORE FOR THE OTHER TERMINALS. THE
GAP WIND AT AOO AND DOWNSLOPE AT MDT/LNS WILL KEEP THEM ON THE
HIGHER-END OF WIND SPEEDS TODAY.
FAST FLOW BRINGS AN ALMOST NEVER-ENDING TRAIN OF WEAK NRN STREAM
IMPULSES TO MAKE SHSN FOR THE WRN TERMINALS. THE STRONGEST CLIPPER
WILL BE ON TUE AM. WARM AIR TRIES TO RETURN BY FRI.
OUTLOOK...
MON...MAINLY VFR WITH MVFR IN SHSN AT BFD.
MON NITE-TUE...LGT SNOW/REDUCED VSBYS.
WED-THU...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST MONDAY FOR PAZ004.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DANGELO
LONG TERM...GRUMM
AVIATION...JUNG/DANGELO
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
652 AM EST SUN DEC 15 2013
.SYNOPSIS...
LOW PRESSURE WAS DEEPENING OFF THE NEW JERSEY COAST THIS MORNING
AND WILL MOVE ALONG THE NEW ENGLAND COAST TONIGHT. A SERIES OF
WEAK LOW PRESSURE SYSTEMS WILL TRACK FROM THE NORTHERN PLAINS
THROUGH THE EASTERN UNITED STATES TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST SUNDAY...
JUST STARTING TO SEE SOME CLEARING ON SATELLITE PICTURES ALONG
AND EAST OF THE BLUE RIDGE BEHIND THE SHORT WAVE OVER MARYLAND.
THE WET GROUND FROM THE RAIN SATURDAY COMBINED WITH THE CLEARING
SKY WILL LEAD TO MORE FOG THROUGH 9AM. VISIBILITIES WERE DOWN TO
ONE QUARTER MILE AT MOUNT AIRY AND NORTH WILKESBORO. IN
COORDINATION WITH NWSFO GSP HAVE ISSUED A DENSE FOG ADVISORY FOR
THE FOOTHILLS UP THROUGH FRANKLIN COUNTY. WINDS WERE GUSTING OUT
OF THE WEST BUT WILL INCREASE ENOUGH AFTER 10AM/14Z FOR
DOWNSLOPING AND DRYING TO HELP ERODE THE FOG.
LOCAL WRF AND HRRR HAD EDGE OF SHORT WAVE IN THE SOUTHERN
APPALACHIANS CLEARING THE EASTERN COUNTY WARNING AREA BY 10Z/5AM.
THE NEXT SHORT WAVE COMES OUT OF THE OHIO VALLEY AND ACROSS THE AREA
THIS MORNING.
FOLLOWING THE SHORT WAVES TODAY...REGION STAYS UNDER PERSISTENT LONG
WAVE TROF AND NORTHWEST FLOW ALOFT. EXPECT A BRIEF RISE IN
TEMPERATURE JUST BEHIND THE SHORT WAVE THEN FALLING TEMPERATURES
AROUND SUNRISE. WITH COLD AIR ADVECTION AND LITTLE SUNSHINE
TODAY....MOST LOCATIONS WEST OF THE BLUE RIDGE WILL HAVE A MINIMAL
RISE IN TEMPERATURES. STAYED CLOSER TO THE COOLER BIAS CORRECTED
MAV GUIDANCE FOE TEMPERATURES THROUGH THE EVENING.
MSAS ANALYSIS SHOWS LARGE PRESSURE FALLS NEAR LONG ISLAND WHERE
THE SURFACE LOW IS DEEPENING. PRESSURE RISES AND COLD AIR
ADVECTION OVER OUR FORECAST AREA WILL LEAD TO GUSTY WET WINDS. THE
DOWNSLOPE WINDS AND EXIT OF DEEPER MOISTURE WILL RESULT IN
CLEARING EAST OF THE BLUE RIDGE BY THIS AFTERNOON. PERSISTENT LOW
LEVEL MOISTURE AND UPSLOPE WINDS WILL HOLD CLOUDS IN THE WESTERN
MOUNTAINS OF THE FORECAST AREA THROUGH TONIGHT.
ANOTHER SHORT WAVE COMES THROUGH THE NORTHWEST FLOW ALOFT TONIGHT...
ADDING SOME LIFT TO THE UPSLOPE WINDS AND PROLONGING THE PROBABILITY
OF SNOW SHOWERS THROUGH MONDAY MORNING. MODELS SHOW A SUBTLE
INCREASE IN PRECIPITABLE WATER AND DEPTH OF MOISTURE AS THIS FEATURE
COMES THROUGH. WILL MAINTAIN SNOW SHOWERS ON THE FAR WESTERN
SLOPES FROM GREENBRIER TO TAZEWELL COUNTY LATE TONIGHT.
850 MB TEMPERATURES DROP TODAY BUT BEST PUSH OF COLDER
AIR...ESPECIALLY INTO THE EASTERN COUNTY WARNING AREA WILL BE
TONIGHT. LOW LEVEL JET IN THE 40 TO 50 KNOT RANGE WILL SUPPORT
SURFACE WIND GUSTS OF 25 TO 35 KNOTS/28-40 MPH TODAY WITH ANOTHER
SURGE OF STRONGER WINDS BEHIND THE SHORT WAVE TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM EST SUNDAY...
DURING MOST OF THIS SEGMENT OF THE FORECAST PERIOD THE REGION WILL
REMAIN IN NORTHWEST FLOW THANKS TO A OVERALL LONGWAVE TROUGH PATTERN
OVER SOUTH CENTRAL AND SOUTHEAST CANADA. WITHIN THE PARENT LONGWAVE
PATTERN...A SERIES OF SHORTWAVE TROUGHS ARE PROGGED TO PROGRESS
THROUGH THE GREAT LAKES AND THEN NEW ENGLAND REGIONS OF THE U.S.
EACH OF THESE WILL HAVE A COMPARABLE IMPACT ON THE WEATHER ACROSS
OUR PART OF THE COUNTRY.
THE BULK OF THE UPPER LEVEL DYNAMICS AND ASSOCIATED MOISTURE WILL
REMAIN NORTH OF THE FORECAST AREA. THE SOUTHERN TAIL END OF EACH
SYSTEM WILL CLIP AREAS SOUTH TO ROUGHLY THE I-64 CORRIDOR
WEST OF COVINGTON VA...AND THE I-77 CORRIDOR SOUTH TO ROUGHLY
BLUEFIELD WV.
THE FIRST...AND WEAKEST OF THESE IMPULSES...WILL CROSS THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY. THE SECOND...AND NEXT
STRONGEST...MONDAY NIGHT INTO EARLY TUESDAY. THE FINAL AND STRONGEST
ONE...TUESDAY AFTERNOON INTO TUESDAY EVENING.
WHILE THERE WILL BE SOME LEVEL GUSTINESS WITH THE FIRST
IMPULSE...WINDS WILL INCREASE SIGNIFICANTLY WITH THE PASSAGE OF THE
SECOND SHORTWAVE TROUGH...AND EVEN MORE SO IN THE WAKE OF THE THIRD.
SOLUTIONS AMONG THE VARIOUS MODELS PLACE NORTHWEST 850 MB WINDS
ACROSS THE AREA TUESDAY EVENING THROUGH EARLY WEDNESDAY MORNING IN
THE 45 TO 55 KT RANGE WITH GOOD CROSS BARRIER FLOW. IF THIS PATTERN
HOLDS...THIS SCENARIO WOULD BE FAVORABLE FOR AT LEAST WIND ADVISORY
GUSTS ACROSS THE MOUNTAINS. WILL HIGHLIGHT THIS POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
WE ARE EXPECTING A PATTERN SHIFT WEDNESDAY INTO WEDNESDAY NIGHT. THE
UPPER LEVEL FLOW BECOMES MORE ZONAL TO SLIGHTLY SOUTHWEST. ANY
IMPULSES IN THE NORTHERN STREAM WILL REMAIN WELL NORTH OF THE AREA.
WITH THE NORTHWEST FLOW BACKING MORE WEST TO SOUTHWEST...WE EXPECT
LESS CLOUD COVER ACROSS THE MOUNTAINS.
DURING THIS ENTIRE PORTION OF THE FORECAST PERIOD...LOCATIONS ACROSS
THE PIEDMONT...ESPECIALLY NEAR THE NC/VA BORDER...ARE EXPECTED TO
SEE LIMITED CLOUD COVER. WINDS WILL ALSO BECOME GUSTY...BUT NOT AS
STRONG AS THOSE ANTICIPATED ACROSS THE MOUNTAINS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 302 PM EST SATURDAY...
BOTH THE 12Z GFS/ECM AGREE THAT A SURFACE RIDGE WILL PASS OVER THE
REGION WEDNESDAY...THEN MOVE OFF THE COAST THURSDAY. THIS RIDGE WILL
KEEP THE AREA CHILLY WITH COLDER THAN NORMAL TEMPERATURES FOR
WEDNESDAY. AS THIS RIDGE MOVES EAST THURSDAY...SOUTHWESTERLY FLOW
WILL PREVAIL. TEMPERATURES WILL MODERATE TO NORMAL ON THURSDAY WITH
WARM THAN NORMAL TEMPERATURES ON FRIDAY...POSSIBLY CONTINUING INTO
SATURDAY. THE AREA SHOULD SEE WIDESPREAD 50S ON FRIDAY...AND MID TO
UPPER 50S WEST AND LOW TO MID 60S EAST ON SATURDAY. OF
COURSE...THESE TEMPERATURES WILL BE DEPENDENT ON WHEN THE NEXT COLD
FRONT INFLUENCES OUR WEATHER. THIS PART OF THE FORECAST IS WHERE THE
MODELS DIFFER.
THE 12Z GFS DEVELOPS A SURFACE LOW ALONG A COLD FRONT IN THE CENTRAL
PLAINS THURSDAY NIGHT. THIS LOW IS EXPECTED TO TRACK NORTHEAST TO
NEW ENGLAND BY FRIDAY EVENING. THE TRAILING COLD FRONT WILL BE
SLOWLY MOVING ACROSS THE OHIO-TENN VALLEYS FRIDAY...STALLING ALONG
THE WESTERN APPALACHIANS FRIDAY NIGHT. ANOTHER SURFACE LOW DEVELOPS
ON THE LEE SIDE OF THE SOUTHERN APPALACHIANS...DRAGGING THE FRONT AND
ASSOCIATED RAIN SHOWERS ACROSS THE REGION ON SATURDAY. IF THIS
VERIFIES...SATURDAYS TEMPERATURES WILL NOT BE AS WARM AS FORECASTED.
THE 12Z ECM DEVELOPS A SURFACE LOW ALONG THE FRONT AND TRACKS IT
NORTHEAST BUT OVER QUEBEC. THIS FRONT WILL THEN STALL OVER THE OHIO-
TENN VALLEY ON FRIDAY. A WAVE OF LOW PRESSURE IS EXPECTED TO TRACK
ALONG THIS FRONT FRIDAY NIGHT INTO SATURDAY. ANOTHER WAVE IS
FORECASTED TO TRACK ALONG THE FRONT...STILL OVER THE OHIO
VALLEY...SATURDAY NIGHT INTO SUNDAY. THE 12Z ECM WOULD KEEP THE
FORECAST AREA IN THE WARM SECTOR INTO SATURDAY...POSSIBLY SUNDAY.
THE ECM ALSO KEEPS BULK OF THE RAIN NORTH OF THE AREA WITH A
POSSIBLE PASSING MOUNTAIN SHOWER FRIDAY AND SATURDAY.
FOR THIS FORECAST PACKAGE...FAVORING THE ECM OVER THE GFS (70/30)
ESPECIALLY ON TEMPERATURES. FOR POPS...ADDED LOW CHANCE POPS (30
PERCENT) IN THE WEST FRIDAY NIGHT...THEN ACROSS THE ENTIRE AREA ON
SATURDAY (30 PERCENT).
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM EST SUNDAY...
LOW PRESSURE DEEPENING OFF THE NEW JERSEY COAST AND THE
ASSOCIATED SHORT WAVE TROF OVER VIRGINIA AND NORTH CAROLINA WERE
PRODUCING GUSTY WEST WINDS ACROSS THE REGION. ON THE EAST SIDE OF
THE BLUE RIDGE DOWNSLOPING WILL CLEAR OUT THE CLOUDS AT KLYH AND
KDAN BY 15Z/10AM. UNTIL THEN PERIODS OF LIFR FOG AND CLOUDS ARE
EXPECTED.
IN THE MOUNTAINS CEILINGS FOR MUCH OF THE DAY WILL BE MVFR WITH
SCATTERED RAIN AND SNOW SHOWERS. WIND GUSTS FROM THE WEST AND
NORTHWEST WILL REACH 25 TO 35 KNOTS...ESPECIALLY AT HIGHER
ELEVATIONS. WINDS SPEED WILL SUBSIDE IN THE EVENING WITH THE
EXCEPTION OF AREAS ALONG THE BLUE RIDGE...KROA AND KBCB.
ANOTHER SHORT WAVE WILL APPROACH THE REGION FROM THE NORTHWEST
TONIGHT. THIS WILL PROLONG THE MVFR CLOUDS AT KBLF AND KLWB AND
WILL BRING SNOW SHOWERS TO THE WESTERN UPSLOPE AREAS. CONDITIONS
ARE EXPECTED TO REMAIN VFR EAST OF THE BLUE RIDGE ALTHOUGH WIND
WILL INCREASE BEHIND THE WAVE.
HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST MONDAY...ALLOWING
UPSLOPING CLOUDS TO GRADUALLY ERODE OVER THE MOUNTAINS...BRINGING
A RETURN TO VFR WEATHER WITH UNRESTRICTED CONDITIONS...EVEN IN THE
UPSLOPE AREAS...BY MIDDAY MONDAY. DRY WEATHER WITH MAINLY VFR
WEATHER IS THEN EXPECTED IN MOST AREAS INTO MID WEEK. THERE WILL
BE A PERIOD OF STRONG GUSTY WINDS IN THE MOUNTAINS TUESDAY INTO
WEDNESDAY...ALONG WITH UPSLOPE CLOUDS WITH MVFR CEILINGS.
HIGH CONFIDENCE ON THE CLEARING TODAY EAST OF THE BLUE RIDGE AND
THE CONTINUATION OF VFR CONDITIONS THROUGH MONDAY. MEDIUM
CONFIDENCE ON THE EXTENT OF SNOW SHOWERS TONIGHT IN SOUTHEAST WEST
VIRGINIA WITH THE NEXT SHORT WAVE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR VAZ032-033-
043.
NC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ003>005-
019-020.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...DS
LONG TERM...RCS
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
605 AM EST SUN DEC 15 2013
.SYNOPSIS...
LOW PRESSURE WAS DEEPENING OFF THE NEW JERSEY COAST THIS MORNING
AND WILL MOVE ALONG THE NEW ENGLAND COAST TONIGHT. A SERIES OF
WEAK LOW PRESSURE SYSTEMS WILL TRACK FROM THE NORTHERN PLAINS
THROUGH THE EASTERN UNITED STATES TONIGHT THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST SUNDAY...
JUST STARTING TO SEE SOME CLEARING ON SATELLITE PICTURES ALONG
AND EAST OF THE BLUE RIDGE BEHIND THE SHORT WAVE OVER MARYLAND.
THE WET GROUND FROM THE RAIN SATURDAY COMBINED WITH THE CLEARING
SKY WILL LEAD TO MORE FOG THROUGH 9AM. VISIBILITIES WERE DOWN TO
ONE QUARTER MILE AT MOUNT AIRY AND NORTH WILKESBORO. IN
COORDINATION WITH NWSFO GSP HAVE ISSUED A DENSE FOG ADVISORY FOR
THE FOOTHILLS UP THROUGH FRANKLIN COUNTY. WINDS WERE GUSTING OUT
OF THE WEST BUT WILL INCREASE ENOUGH AFTER 10AM/14Z FOR
DOWNSLOPING AND DRYING TO HELP ERODE THE FOG.
LOCAL WRF AND HRRR HAD EDGE OF SHORT WAVE IN THE SOUTHERN
APPALACHIANS CLEARING THE EASTERN COUNTY WARNING AREA BY 10Z/5AM.
THE NEXT SHORT WAVE COMES OUT OF THE OHIO VALLEY AND ACROSS THE AREA
THIS MORNING.
FOLLOWING THE SHORT WAVES TODAY...REGION STAYS UNDER PERSISTENT LONG
WAVE TROF AND NORTHWEST FLOW ALOFT. EXPECT A BRIEF RISE IN
TEMPERATURE JUST BEHIND THE SHORT WAVE THEN FALLING TEMPERATURES
AROUND SUNRISE. WITH COLD AIR ADVECTION AND LITTLE SUNSHINE
TODAY....MOST LOCATIONS WEST OF THE BLUE RIDGE WILL HAVE A MINIMAL
RISE IN TEMPERATURES. STAYED CLOSER TO THE COOLER BIAS CORRECTED
MAV GUIDANCE FOE TEMPERATURES THROUGH THE EVENING.
MSAS ANALYSIS SHOWS LARGE PRESSURE FALLS NEAR LONG ISLAND WHERE
THE SURFACE LOW IS DEEPENING. PRESSURE RISES AND COLD AIR
ADVECTION OVER OUR FORECAST AREA WILL LEAD TO GUSTY WET WINDS. THE
DOWNSLOPE WINDS AND EXIT OF DEEPER MOISTURE WILL RESULT IN
CLEARING EAST OF THE BLUE RIDGE BY THIS AFTERNOON. PERSISTENT LOW
LEVEL MOISTURE AND UPSLOPE WINDS WILL HOLD CLOUDS IN THE WESTERN
MOUNTAINS OF THE FORECAST AREA THROUGH TONIGHT.
ANOTHER SHORT WAVE COMES THROUGH THE NORTHWEST FLOW ALOFT TONIGHT...
ADDING SOME LIFT TO THE UPSLOPE WINDS AND PROLONGING THE PROBABILITY
OF SNOW SHOWERS THROUGH MONDAY MORNING. MODELS SHOW A SUBTLE
INCREASE IN PRECIPITABLE WATER AND DEPTH OF MOISTURE AS THIS FEATURE
COMES THROUGH. WILL MAINTAIN SNOW SHOWERS ON THE FAR WESTERN
SLOPES FROM GREENBRIER TO TAZEWELL COUNTY LATE TONIGHT.
850 MB TEMPERATURES DROP TODAY BUT BEST PUSH OF COLDER
AIR...ESPECIALLY INTO THE EASTERN COUNTY WARNING AREA WILL BE
TONIGHT. LOW LEVEL JET IN THE 40 TO 50 KNOT RANGE WILL SUPPORT
SURFACE WIND GUSTS OF 25 TO 35 KNOTS/28-40 MPH TODAY WITH ANOTHER
SURGE OF STRONGER WINDS BEHIND THE SHORT WAVE TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM EST SUNDAY...
DURING MOST OF THIS SEGMENT OF THE FORECAST PERIOD THE REGION WILL
REMAIN IN NORTHWEST FLOW THANKS TO A OVERALL LONGWAVE TROUGH PATTERN
OVER SOUTH CENTRAL AND SOUTHEAST CANADA. WITHIN THE PARENT LONGWAVE
PATTERN...A SERIES OF SHORTWAVE TROUGHS ARE PROGGED TO PROGRESS
THROUGH THE GREAT LAKES AND THEN NEW ENGLAND REGIONS OF THE U.S.
EACH OF THESE WILL HAVE A COMPARABLE IMPACT ON THE WEATHER ACROSS
OUR PART OF THE COUNTRY.
THE BULK OF THE UPPER LEVEL DYNAMICS AND ASSOCIATED MOISTURE WILL
REMAIN NORTH OF THE FORECAST AREA. THE SOUTHERN TAIL END OF EACH
SYSTEM WILL CLIP AREAS SOUTH TO ROUGHLY THE I-64 CORRIDOR
WEST OF COVINGTON VA...AND THE I-77 CORRIDOR SOUTH TO ROUGHLY
BLUEFIELD WV.
THE FIRST...AND WEAKEST OF THESE IMPULSES...WILL CROSS THE AREA LATE
SUNDAY NIGHT INTO EARLY MONDAY. THE SECOND...AND NEXT
STRONGEST...MONDAY NIGHT INTO EARLY TUESDAY. THE FINAL AND STRONGEST
ONE...TUESDAY AFTERNOON INTO TUESDAY EVENING.
WHILE THERE WILL BE SOME LEVEL GUSTINESS WITH THE FIRST
IMPULSE...WINDS WILL INCREASE SIGNIFICANTLY WITH THE PASSAGE OF THE
SECOND SHORTWAVE TROUGH...AND EVEN MORE SO IN THE WAKE OF THE THIRD.
SOLUTIONS AMONG THE VARIOUS MODELS PLACE NORTHWEST 850 MB WINDS
ACROSS THE AREA TUESDAY EVENING THROUGH EARLY WEDNESDAY MORNING IN
THE 45 TO 55 KT RANGE WITH GOOD CROSS BARRIER FLOW. IF THIS PATTERN
HOLDS...THIS SCENARIO WOULD BE FAVORABLE FOR AT LEAST WIND ADVISORY
GUSTS ACROSS THE MOUNTAINS. WILL HIGHLIGHT THIS POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.
WE ARE EXPECTING A PATTERN SHIFT WEDNESDAY INTO WEDNESDAY NIGHT. THE
UPPER LEVEL FLOW BECOMES MORE ZONAL TO SLIGHTLY SOUTHWEST. ANY
IMPULSES IN THE NORTHERN STREAM WILL REMAIN WELL NORTH OF THE AREA.
WITH THE NORTHWEST FLOW BACKING MORE WEST TO SOUTHWEST...WE EXPECT
LESS CLOUD COVER ACROSS THE MOUNTAINS.
DURING THIS ENTIRE PORTION OF THE FORECAST PERIOD...LOCATIONS ACROSS
THE PIEDMONT...ESPECIALLY NEAR THE NC/VA BORDER...ARE EXPECTED TO
SEE LIMITED CLOUD COVER. WINDS WILL ALSO BECOME GUSTY...BUT NOT AS
STRONG AS THOSE ANTICIPATED ACROSS THE MOUNTAINS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 302 PM EST SATURDAY...
BOTH THE 12Z GFS/ECM AGREE THAT A SURFACE RIDGE WILL PASS OVER THE
REGION WEDNESDAY...THEN MOVE OFF THE COAST THURSDAY. THIS RIDGE WILL
KEEP THE AREA CHILLY WITH COLDER THAN NORMAL TEMPERATURES FOR
WEDNESDAY. AS THIS RIDGE MOVES EAST THURSDAY...SOUTHWESTERLY FLOW
WILL PREVAIL. TEMPERATURES WILL MODERATE TO NORMAL ON THURSDAY WITH
WARM THAN NORMAL TEMPERATURES ON FRIDAY...POSSIBLY CONTINUING INTO
SATURDAY. THE AREA SHOULD SEE WIDESPREAD 50S ON FRIDAY...AND MID TO
UPPER 50S WEST AND LOW TO MID 60S EAST ON SATURDAY. OF
COURSE...THESE TEMPERATURES WILL BE DEPENDENT ON WHEN THE NEXT COLD
FRONT INFLUENCES OUR WEATHER. THIS PART OF THE FORECAST IS WHERE THE
MODELS DIFFER.
THE 12Z GFS DEVELOPS A SURFACE LOW ALONG A COLD FRONT IN THE CENTRAL
PLAINS THURSDAY NIGHT. THIS LOW IS EXPECTED TO TRACK NORTHEAST TO
NEW ENGLAND BY FRIDAY EVENING. THE TRAILING COLD FRONT WILL BE
SLOWLY MOVING ACROSS THE OHIO-TENN VALLEYS FRIDAY...STALLING ALONG
THE WESTERN APPALACHIANS FRIDAY NIGHT. ANOTHER SURFACE LOW DEVELOPS
ON THE LEE SIDE OF THE SOUTHERN APPALACHIANS...DRAGGING THE FRONT AND
ASSOCIATED RAIN SHOWERS ACROSS THE REGION ON SATURDAY. IF THIS
VERIFIES...SATURDAYS TEMPERATURES WILL NOT BE AS WARM AS FORECASTED.
THE 12Z ECM DEVELOPS A SURFACE LOW ALONG THE FRONT AND TRACKS IT
NORTHEAST BUT OVER QUEBEC. THIS FRONT WILL THEN STALL OVER THE OHIO-
TENN VALLEY ON FRIDAY. A WAVE OF LOW PRESSURE IS EXPECTED TO TRACK
ALONG THIS FRONT FRIDAY NIGHT INTO SATURDAY. ANOTHER WAVE IS
FORECASTED TO TRACK ALONG THE FRONT...STILL OVER THE OHIO
VALLEY...SATURDAY NIGHT INTO SUNDAY. THE 12Z ECM WOULD KEEP THE
FORECAST AREA IN THE WARM SECTOR INTO SATURDAY...POSSIBLY SUNDAY.
THE ECM ALSO KEEPS BULK OF THE RAIN NORTH OF THE AREA WITH A
POSSIBLE PASSING MOUNTAIN SHOWER FRIDAY AND SATURDAY.
FOR THIS FORECAST PACKAGE...FAVORING THE ECM OVER THE GFS (70/30)
ESPECIALLY ON TEMPERATURES. FOR POPS...ADDED LOW CHANCE POPS (30
PERCENT) IN THE WEST FRIDAY NIGHT...THEN ACROSS THE ENTIRE AREA ON
SATURDAY (30 PERCENT).
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AS OF 130 AM EST SUNDAY...
POOR FLYING CONDITIONS EXPECTED FOR THE FIRST 6-10 HOURS OF THE
PERIOD WITH LOW CEILINGS/FOG/DRIZZLE. OUTSIDE OF WESTERN
SLOPES...CONDITIONS WILL BEGIN TO IMPROVE FROM WEST TO EAST AS
WINDS TURN TO THE WEST. FIRST TO GO WILL BE THE DRIZZLE AND
FOG...THEN CEILINGS LIFT FROM IFR TO VFR BY EARLY SUNDAY MORNING.
WESTERN SLOPES WILL KEEP IFR RESTRICTIONS THROUGH SUNDAY MORNING
WITH A MOIST WEST WIND AND UPSLOPE SNOW SHOWERS. SNOW SHOWERS WILL
TAPER TO FLURRIES DURING THE AFTERNOON WITH CEILINGS LIFTING TO
MVFR.
WINDS SPEED WILL INCREASE THROUGH THE MORNING AND SUBSIDE IN THE
EVENING WITH THE EXCEPTION OF AREAS ALONG THE BLUE RIDGE
(ROA/BCB). WEST WINDS OF 10-20 KNOTS GUSTING TO 20-30 KNOTS ARE
POSSIBLE ACROSS THE ENTIRE FORECAST AREA DURING THE DAY SUNDAY.
THE HIGHER SPEEDS ARE RESERVED FOR LOCATION ALONG THE BLUE RIDGE.
CONFIDENCE IS FAIRLY HIGH WITH IFR CONDITIONS REMAINING THROUGH
THE FIRST 3-6 HOURS OF THE TAF PERIOD. MEDIUM CONFIDENCE ON TIMING
OF IMPROVING CONDITIONS THROUGH 12Z SUN. HIGH CONFIDENCE IN WIND
DIRECTION AND SPEED DURING THE PERIOD.
HIGH PRESSURE EXPECTED TO BUILD INTO THE REGION FROM THE WEST
MONDAY...ALLOWING UPSLOPING CLOUDS TO GRADUALLY ERODE OVER THE
MOUNTAINS...BRINGING A RETURN TO VFR WEATHER WITH UNRESTRICTED
CONDITIONS...EVEN IN THE UPSLOPE AREAS...BY MIDDAY MONDAY. DRY
WEATHER WITH MAINLY VFR WEATHER IS THEN EXPECTED IN MOST AREAS
INTO MID WEEK...WITH PERHAPS THE EXCEPTION OF A PERIOD OF SOME
UPSLOPING CLOUDS WITH MVFR CEILINGS ACROSS THE WESTERN FLANKS OF
THE APPALACHIANS LATER TUESDAY INTO WEDNESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR VAZ032-033-
043.
NC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ003>005-
019-020.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...DS
LONG TERM...RCS
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS MIAMI FL
1254 PM EST SUN DEC 15 2013
.AVIATION...
MAINLY VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING
ESPECIALLY AHEAD OF THE FRONT. THE MAIN LINE OF SHOWERS ASSOCIATED
WITH THE FRONT WILL REACH PBI FIRST AND THEN MOVE SOUTHWARD.
HOWEVER, A FEW SHOWERS COULD ALSO DEVELOP AHEAD OF THE FRONT NEAR
THE EAST COAST TERMINALS THIS AFTERNOON AND EVENING. WE BELIEVE
THAT MINIMUM THUNDER ACTIVITY WILL BE OBSERVED WITH THIS FRONT DUE
TO ABUNDANT MID LEVEL DRY AIR AND WEAK FORCING. THE STRONGEST
SHOWERS COULD SEE BRIEF MVFR CONDITIONS THIS AFTERNOON AND
EVENING. THE ATMOSPHERE IS FORECAST TO BE MORE MOIST BEHIND THE
FRONT. THIS COULD LEAD TO BKN MVFR CEILINGS IN SOME SPOTS BEFORE
O0Z TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 1150 AM EST SUN DEC 15 2013/
UPDATE...
THE SHOWERS CONTINUE TO HAVE DIFFICULTY MAKING IT INTO THE EASTERN
PORTION OF THE CWA. MODEL SOUNDINGS ARE SHOWING DRY MID LEVELS,
WHICH MAY BE HAMPERING THEIR PROGRESSION. SO, HAVE ADJUSTED POPS
ACCORDINGLY FOR THE NEXT COUPLE OF HOURS TO ACCOUNT FOR THIS.
FOR THIS AFTERNOON, NEW HRRR RUN SHOWS THE LINE NOW FALLING APART
THIS AFTERNOON BEFORE IT MAKES IT INTO THE FT LAUDERDALE METRO
AREA. THIS IS A POSSIBLE SCENARIO, GIVEN THE CLOUD COVER NOW IN
PLACE OVER ALL OF SOUTH FLORIDA AND THE DIFFICULTIES MENTIONED
ABOVE. HOWEVER, GIVEN THERE WAS ONLY CHANCE POPS IN ANYWAYS, HAVE
OPTED TO LET THEM RIDE FOR NOW.
PREV DISCUSSION... /ISSUED 930 AM EST SUN DEC 15 2013/
UPDATE...
SHOWERS AND A COUPLE OF THUNDERSTORMS ARE MOVING INTO THE
NORTHWESTERN PORTION OF SOUTH FLORIDA THIS MORNING. HAVE BOOSTED
POPS TO REFLECT THIS AND TRANSLATED THE LINE TO THE SOUTH EAST.
THIS IS A PRE-FRONTAL TROUGH, AHEAD OF THE APPROACHING COLD FRONT,
WHICH IS CURRENTLY OVER CENTRAL FLORIDA. THE SHOWERS DO APPEAR AS
THOUGH THEY ARE HAVING TROUBLE KEEPING TOGETHER ACROSS THE
MAINLAND, AND ALMOST FALLING APART ON THE EAST COAST. HOWEVER,
GIVEN DAYTIME HEATING WILL HELP INSTABILITY, HAVE BUMPED UP POPS
FURTHER SOUTH AS WELL. THE QUESTION IS, THIS AFTERNOON, AND IF
THE LINE WILL HOLD TOGETHER ENOUGH TO CONTINUE SHOWERS AND
THUNDERSTORMS.
AS FAR A THUNDERSTORMS ACROSS THE AREA, THIS MORNINGS SOUNDING
DOES SHOW ALMOST 3000 JOULES OF CAPE OVER MIAMI. HOWEVER, THIS
HIGHER CAPE WILL BE PUSHED OUT OF THE AREA AS THE TROUGH CONTINUES
TO APPROACH. HOWEVER, THE FRONT DOES LOOK AS THOUGH IT MAY CATCH
UP TO THE LARGER LINE OF SHOWERS, HELPING TO PUSH IT THROUGH
QUICKER THAN IT CURRENTLY IS. THIS COULD HELP TO PROVIDE THE
TRIGGER FOR SOME ISOLATED STORMS THIS AFTERNOON.
THE HRRR DOES SHOW THE LINE WEAKENING AS IT APPROACHES THE MIAMI
METRO AREA, ALTHOUGH STILL SHOWS IT BRINGING A LINE OF SHOWERS
THROUGH. TIMING IS CURRENTLY INTO THE WEST PALM BEACH METRO AREA
AROUND 16Z, THE BROWARD METRO AREAS AROUND 18 OR 19Z, AND THE
MIAMI METRO AREA BETWEEN 19 AND 20Z. OF COURSE GIVE OR TAKE SOME A
LITTLE TIME, SO HAVE CHANCE POPS FROM 18Z THROUGH 00Z, ALTHOUGH
MOST LIKELY WILL HAVE TO ADJUST IN A FEW HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 74 58 75 / 30 20 10 10
FORT LAUDERDALE 66 75 63 77 / 30 20 10 10
MIAMI 67 75 62 77 / 20 20 20 10
NAPLES 58 72 51 76 / 20 - 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
1150 AM EST SUN DEC 15 2013
.UPDATE...
THE SHOWERS CONTINUE TO HAVE DIFFICULTY MAKING IT INTO THE EASTERN
PORTION OF THE CWA. MODEL SOUNDINGS ARE SHOWING DRY MID LEVELS,
WHICH MAY BE HAMPERING THEIR PROGRESSION. SO, HAVE ADJUSTED POPS
ACCORDINGLY FOR THE NEXT COUPLE OF HOURS TO ACCOUNT FOR THIS.
FOR THIS AFTERNOON, NEW HRRR RUN SHOWS THE LINE NOW FALLING APART
THIS AFTERNOON BEFORE IT MAKES IT INTO THE FT LAUDERDALE METRO
AREA. THIS IS A POSSIBLE SCENARIO, GIVEN THE CLOUD COVER NOW IN
PLACE OVER ALL OF SOUTH FLORIDA AND THE DIFFICULTIES MENTIONED
ABOVE. HOWEVER, GIVEN THERE WAS ONLY CHANCE POPS IN ANYWAYS, HAVE
OPTED TO LET THEM RIDE FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 930 AM EST SUN DEC 15 2013/
UPDATE...
SHOWERS AND A COUPLE OF THUNDERSTORMS ARE MOVING INTO THE
NORTHWESTERN PORTION OF SOUTH FLORIDA THIS MORNING. HAVE BOOSTED
POPS TO REFLECT THIS AND TRANSLATED THE LINE TO THE SOUTH EAST.
THIS IS A PRE-FRONTAL TROUGH, AHEAD OF THE APPROACHING COLD FRONT,
WHICH IS CURRENTLY OVER CENTRAL FLORIDA. THE SHOWERS DO APPEAR AS
THOUGH THEY ARE HAVING TROUBLE KEEPING TOGETHER ACROSS THE
MAINLAND, AND ALMOST FALLING APART ON THE EAST COAST. HOWEVER,
GIVEN DAYTIME HEATING WILL HELP INSTABILITY, HAVE BUMPED UP POPS
FURTHER SOUTH AS WELL. THE QUESTION IS, THIS AFTERNOON, AND IF
THE LINE WILL HOLD TOGETHER ENOUGH TO CONTINUE SHOWERS AND
THUNDERSTORMS.
AS FAR A THUNDERSTORMS ACROSS THE AREA, THIS MORNINGS SOUNDING
DOES SHOW ALMOST 3000 JOULES OF CAPE OVER MIAMI. HOWEVER, THIS
HIGHER CAPE WILL BE PUSHED OUT OF THE AREA AS THE TROUGH CONTINUES
TO APPROACH. HOWEVER, THE FRONT DOES LOOK AS THOUGH IT MAY CATCH
UP TO THE LARGER LINE OF SHOWERS, HELPING TO PUSH IT THROUGH
QUICKER THAN IT CURRENTLY IS. THIS COULD HELP TO PROVIDE THE
TRIGGER FOR SOME ISOLATED STORMS THIS AFTERNOON.
THE HRRR DOES SHOW THE LINE WEAKENING AS IT APPROACHES THE MIAMI
METRO AREA, ALTHOUGH STILL SHOWS IT BRINGING A LINE OF SHOWERS
THROUGH. TIMING IS CURRENTLY INTO THE WEST PALM BEACH METRO AREA
AROUND 16Z, THE BROWARD METRO AREAS AROUND 18 OR 19Z, AND THE
MIAMI METRO AREA BETWEEN 19 AND 20Z. OF COURSE GIVE OR TAKE SOME A
LITTLE TIME, SO HAVE CHANCE POPS FROM 18Z THROUGH 00Z, ALTHOUGH
MOST LIKELY WILL HAVE TO ADJUST IN A FEW HOURS.
PREV DISCUSSION... /ISSUED 650 AM EST SUN DEC 15 2013/
AVIATION...
SOUTHWESTERLY WINDS ARE EXPECTED AT ALL TAF SITES TODAY. WITH THE
COLD FRONT MOVING SOUTHWARD ACROSS THE FLORIDA PENINSULA THERE IS
A CHANCE OF SHOWERS THIS AFTERNOON AND EVENING AT ALL TAF SITES.
THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS. THE CONFIDENCE OF
THUNDERSTORMS IS LOW SINCE IT IS NOT CLEAR WITH THE LACK OF STRONG
FORCING AND WEAK LAPSE RATES IF THE THUNDERSTORMS WILL SURVIVE AS
THEY CONTINUE TO MOVE SOUTHWARD OR MOVE FROM THE GULF TO THE LAND. FOR
NOW, INCLUDED VCSH FOR ALL TAF SITES AFTER 17Z. THE CEILING AND
VIS SHOULD MOSTLY STAY IN THE VFR CONDITIONS FOR THE DAYTIME HOURS
TODAY...BUT COULD FALL DOWN INTO THE MVFR CONDITIONS WITH ANY
PASSING SHOWERS.
PREV DISCUSSION... /ISSUED 244 AM EST SUN DEC 15 2013/
SHORT TERM (TODAY-TUESDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD LONG WAVE TROUGH
PROGRESSING EASTWARD TOWARD THE EAST COAST AND PLENTY OF MID/UPPER
MOISTURE SPREADING ENE AHEAD OF IT ACROSS THE REGION. THE EARLY
MORNING SURFACE ANALYSIS SHOWED A COLD FRONT ASSOCIATED WITH THIS
UPPER FEATURE EXTENDING SOUTHWEST ACROSS THE FLORIDA PANHANDLE TO
THE CENTRAL GULF OF MEXICO WITH LIGHT TO MODERATE SOUTHERLY FLOW
ACROSS MUCH OF THE STATE. DEW POINTS ALONG AND AHEAD OF THIS BOUNDARY
RANGED FROM THE UPPER 60S ACROSS CENTRAL FLORIDA TO THE LOWER 70S
ACROSS THE SOUTHERN EXTENT OF THE PENINSULA. THE LATEST SHORT-RANGE
NUMERICAL GUIDANCE REMAINS IN GOOD AGREEMENT AND INDICATES THIS
FRONTAL BOUNDARY CONTINUING ESE THROUGH THE LOCAL AREA LATER THIS
EVENING THROUGH TONIGHT. RAIN CHANCES WILL STEADILY INCREASE ACROSS
THE AREA THROUGH THE DAY...MAINLY ALONG AND AHEAD OF THIS
APPROACHING BOUNDARY. DESPITE THE AMPLE MOISTURE IN PLACE ALONG WITH
THE APPROACHING BOUNDARY...LIMITED FORCING AND POOR LAPSE RATES WILL
LIMIT THUNDERSTORM PROBABILITIES TODAY ACROSS THE LOCAL AREA. FOR
NOW...WE WILL CONTINUE TO INCLUDE ISOLATED TSTMS IN THIS GRIDDED
PACKAGE AND UPDATE AS CONDITIONS EVOLVE TODAY. MODEL RAINFALL
ACCUMULATIONS THROUGH TONIGHT REMAIN LIGHT WITH VALUES RANGING FROM
A TENTH TO A HALF OF AN INCH ACROSS THE AREA. AS TYPICALLY
OBSERVED...LOCALIZED HIGHER AMOUNTS WILL REMAIN POSSIBLE IN ANY
HEAVIER ACTIVITY THAT DEVELOPS OR BECOMES CONCENTRATED.
MONDAY THROUGH TUESDAY...THE DEEP LAYER MOISTURE AXIS ASSOCIATED
WITH THE FRONTAL BOUNDARY EXTENDING SOUTHWEST ACROSS SRN FLORIDA
PENINSULA WILL KEEP A SLIGHT CHANCE OF SHOWERS IN THE FORECAST
THROUGH THE DAY MONDAY. MONDAY NIGHT THROUGH TUESDAY...DRIER AND
COOLER AIR WILL BEGIN TO OVERSPREAD THE LOCAL AREA IN THE WAKE OF
THE BOUNDARY AS HIGH PRESSURE BUILDS EASTWARD ALONG THE NORTHERN
GULF COAST STATES. THE SHORT-RANGE TEMPERATURE GUIDANCE INDICATES
OVERNIGHT LOWS RANGING FROM THE MID 40S ACROSS GLADES COUNTY TO THE
LOWER 60S ALONG THE SOUTHEAST FLORIDA COAST BY DAYBREAK TUESDAY
MORNING.
LONG TERM (WEDNESDAY-SUNDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THE
SECOND HALF OF THE WEEK AND INDICATES WARM AND HUMID CONDITIONS
RETURNING AS HIGH PRESSURE NORTH OF THE AREA QUICKLY TRANSLATES
EASTWARD OVER THE WESTERN ATLANTIC AND UPPER HEIGHTS BEGIN TO RISE.
TEMPERATURES WILL RESPOND AND QUICKLY RETURN TO WELL ABOVE NORMAL
EACH DAY (10-15 DEG ABOVE NORMAL FRIDAY THROUGH WEEKEND).
MARINE...
A COLD FRONT WILL APPROACH AND MOVE INTO THE LOCAL AREA LATER THIS
EVENING THROUGH MONDAY BEFORE MOVING THROUGH. RAIN CHANCES ALONG
WITH A FEW THUNDERSTORMS CAN BE ANTICIPATED THROUGH THIS TIME ACROSS
THE MARINE AREAS. WINDS AND SEAS MAY APPROACH ADVISORY LEVELS
THROUGH THE FIRST PORTION OF THE WEEK IN THE WAKE OF THE BOUNDARY
AS HIGH PRESSURE BUILDS EASTWARD ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 62 74 58 / 40 30 20 10
FORT LAUDERDALE 84 66 75 63 / 40 30 20 10
MIAMI 85 67 75 62 / 40 20 20 20
NAPLES 82 58 72 51 / 90 20 - 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 AM MST SUN DEC 15 2013
.UPDATE...
ISSUED AT 740 AM MST SUN DEC 15 2013
COMBINATION OF 850 TEMPERATURES...RUC AND HRRR SFC TEMPS SUPPORT
RAISING HIGH TEMPERATURES TODAY INTO THE MID 50S WITH LOW
60S...WARMEST READINGS ACROSS THE EAST/SOUTHEAST. WEST/NORTHWEST
WINDS WILL BECOME BREEZY PERHAPS LATE MORNING THROUGH THE REST OF
THE DAY. CLOUDINESS CURRENTLY OVER THE AREA EXPECTED TO MOVE OUT
OF THE AREA WITHIN THE NEXT FEW HOURS LEAVING SUNNY/MOSTLY SUNNY
CONDITIONS FOR THE REST OF THE DAY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 154 AM MST SUN DEC 15 2013
DRY AND MILD CONDITIONS WILL REMAIN IN PLACE ACROSS THE FORECAST
AREA THROUGH THE SHORT TERM PERIOD.
MODELS KEEP THE UPPER RIDGE OVER THE WEST COAST THROUGH MONDAY
WITH NORTHWEST FLOW ALOFT ACROSS THE CENTRAL HIGH PLAINS REGION.
DURING THIS TIME...A SURFACE TROUGH MOVES ACROSS THE NORTHERN
PLAINS TOWARDS THE GREAT LAKES REGION WITH THE TAIL END OF THE
TROUGH EXTENDING BACK INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION. THIS WILL KEEP GENERALLY WEST TO NORTHWEST SURFACE FLOW IN
PLACE ACROSS THE FORECAST AREA WITH DOWNSLOPING WINDS AND WARM AND
DRY CONDITIONS.
SURFACE HIGH PRESSURE MOVES INTO THE REGION AS THE TROUGH EXITS
WITH ANOTHER SURFACE TROUGH DEEPENING ALONG THE FRONT RANGE BY
TUESDAY NIGHT AS THE UPPER FLOW ACROSS THE UNITED STATES FLATTENS
WITH THE APPROACH OF THE NEXT UPPER TROUGH.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 154 AM MST
SUN DEC 15 2013
FOR WEDNESDAY THROUGH SATURDAY MAIN INTEREST WILL CONTINUE TO BE THE
ARCTIC FRONTAL PASSAGE THURSDAY WITH CHANCES FOR SNOW THE FOLLOWING
NIGHT. MODELS HAVE COME INTO BETTER AGREEMENT WITH THE UPPER LEVEL
WEATHER PATTERN FOR THE END OF THE WEEK...AND HAVE SPED UP THE
FRONTAL PASSAGE TO THE AFTERNOON HOURS. MODELS CONTINUE TO SHOW A
SPLIT 500MB JET BEHIND THE FRONT. AS A RESULT THE BEST SHOT FOR
SNOWFALL WILL BE THURSDAY EVENING OVER THE NORTHWEST WHERE MID LEVEL
FRONTOGENESIS WILL DEVELOP. FRIDAY THE NORTHERN HALF OF THE 500MB
JET WILL MOVE AN UPPER LEVEL SHORT WAVE TROUGH AXIS OVER THE AREA
WITH SUBSIDENCE MOVING IN BEHIND THE TROUGH AXIS. MODEL SOUNDINGS
INDICATE THE ENVIRONMENT SHOULD SATURATE FAIRLY QUICKLY BEHIND THE
FRONT...ALTHOUGH THERE MAY STILL BE A BRIEF PERIOD OF FREEZING
DRIZZLE.
HIGH TEMPERATURES FOR PERIOD WILL BE NEARLY 20 DEGREES ABOVE NORMAL
WEDNESDAY THEN FALL TO 10-20 DEGREES BELOW NORMAL BY FRIDAY AND
SATURDAY. LOWS WILL BE 10 DEGREES ABOVE NORMAL WEDNESDAY NIGHT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1000 AM MST SUN DEC 15 2013
FOR KGLD AND KMCK VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
WEST/NORTHWEST WINDS 15-20KTS WITH HIGHER GUSTS AT BOTH TERMINALS
EXPECTED THROUGH 23Z-00Z THEN BECOMING W/NW AT 10KTS THROUGH THE
REST OF THE TAF PERIOD. SOME MID AND/OR HIGH LEVEL CLOUDS EXPECTED
TO MOVE THROUGH FROM THE NORTHWEST...MAINLY LATE TONIGHT INTO
MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...LOCKHART
LONG TERM...JTL
AVIATION...99
AREA FORECAST DISCUSSION
NWS PADUCAH KY
215 PM CST Sun Dec 15 2013
.SHORT TERM...(This Evening through Tuesday Night)
ISSUED AT 213 PM CST SUN DEC 15 2013
The short term forecast will continue to be a sky and temperature
challenge, as no measureable precipitation is forecast with
northwest flow aloft continuing.
Plenty of remnant low level moisture has resulted in a prolonged
period of cloudy skies early today. However, by mid morning,
progress was being made in clearing skies in parts of southeast MO.
The RAP model seemed to be doing the best with regards to the low
level moisture departing that area. It indicates that the clearing
will continue across southeast MO and maybe a bit further east into
southwest IL/KY However, upstream cloudiness from disturbances aloft
will likely keep most of southern IL, southwest IN and a good chunk
of western KY in the clouds through tonight into Monday.
Weak warm air advection will start up in southeast MO later today
and into tonight. As this weak warm advection develops over top a
cold moist snow covered ground, we could be looking at fog
potential, as noted by the previous shift. Fog will be most
prevalent in areas where the clouds have cleared and stay clear.
Therefore, we expect the greatest fog potential in southeast MO. It
will be tricky though because there is quite a bit of low level
moisture upstream yet to travel down this way so pinpointing what
areas might stay partly cloudy vs cloudy will be difficult,
especially when mid clouds are expected later tonight as well.
Interestingly enough, the 12Z SREF indicates the best chance for fog
development, especially after 06Z tonight, in SEMO/far southwest IL.
However, numerical guidance is not as hot on the idea. Will opt for
patchy fog wording in SEMO for now and let the evening shift adjust
as need be.
Although no precipitation is forecast for tonight, weak disturbances
in the flow are going to bring some mid level moisture. Northern
neighboring WFOs have flurries/light snow forecast for tonight.
Looking at soundings/mid level moisture plots in our area, there does
appear to be enough moisture aloft (especially around 06Z)to produce
snowflakes but the atmosphere is very dry below 750mb. But in our
extreme northern counties, the 18Z NAM indicates there just might be
enough moisture and we could wet bulb enough to produce a few
flurries up north of the I-64 corridor but most of the activity
should stay to our north, where the better moisture will be.
Monday through Tuesday, below normal temperatures will persist as
the region remains in northwest flow aloft on the back side of a
longwave trough over the east. Minor disturbances traveling through
this NW flow will likely bring us intermittent clouds but no
precipitation is currently forecast...with the cloudiest areas
being southern IL, southwest IN and parts of west KY. Finally, we
start to get rid of this low level moisture Monday night into
Tuesday across a good part of the area. We will also see robust warm
air advection take place Tuesday night, which will start our big
warm up.
.LONG TERM...(Wednesday through Sunday)
ISSUED AT 213 PM CST SUN DEC 15 2013
Will continue the forecast for an active weather regime late this
week possibly extending into the weekend.
Surface high pressure`s dominance on our FA will quickly fade as the
high moves east toward the south Atlantic Coast by Wednesday
evening. This will set the stage for southerly winds and a
pronounced warm up Wednesday with the FA remaining in the warm
sector until a cold front moves across the FA Friday. Both the ECMWF
and GFS now bring this front through the FA Friday with the ECMWF
now even a bit faster than the GFS. Will maintain small POPS across
the west/NW part of the FA for Thursday and increase POPS slightly
for Thursday night and Friday given the fairly consistent signal
with the synoptic pattern through Friday. Will also keep a chance of
thunderstorms for Thu night and Fri with K indices consistently AOA
30 for the last several model runs.
Confidence with the post frontal part of the forecast remains more
uncertain given major model changes with the GFS in particular. This
is due to forecasting the movement of the southwest U.S. upper
low/trough which is much slower with the latest GFS run and
therefore the significant change/lesser precip chances for the
weekend as a result of the southeast progression of the surface cold
front and subsequent post frontal drying. Will tend to lean more
toward the ECMWF position of maintaining... including with the 12Z
model run...ample moisture across our FA given its NE progression of
the upper low.
Precip type will once again be borderline with the often
generalization of the N part of the FA having the best chance for
wintry precip and areas near the MO/AR and KY/TN border having a
greater likelihood of rain as supported by a blend of several
thickness parameters. This is particularly valid of the late weekend
precip ahead of the upper low...assuming this even materializes
given the aforementioned model differences.
Warm air advection will occur Wed-Fri until the cold front moves
through the FA Friday. The trend has been even warmer temps for
Thursday which is now forecast to be as warm as Friday with the
exception of the southeast/Pennyrile area where a later passage of
the cold front should result in Friday temps AOA 60. Back to more
typical temps thereafter.
&&
.AVIATION...
ISSUED AT 213 PM CST SUN DEC 15 2013
Mid afternoon satellite imagery and surface observations indicated
clearing pushing steadily east and nearing the Mississippi River.
MVFR cigs at CGI and KPAH should become scattered through the late
afternoon. KEVV and KOWB will likely remain under MVFR cigs until
this evening when clouds should become scattered to broken at KEVV
and KOWB. A band of moisture/broken ceilings about 6-9K feet is
projected southeast across the TAF sites tonight with a few flurries
possible around KEVV and KOWB. Winds will increasingly become
southwest at 5 to 10 knots with lighter winds at KEVV and KOWB
tonight. Will have to watch for potential fog tonight there.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
CW/RS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
415 PM EST SUN DEC 15 2013
.SYNOPSIS...
STRONG LOW PRESSURE WILL CONTINUE MOVING EAST OVERNIGHT THROUGH
THE SOUTHERN MARITIMES INTO THE OPEN ATLANTIC. HIGH PRESSURE WILL
APPROACH ON MONDAY AND CREST OVER THE REGION MONDAY NIGHT. LOW
PRESSURE WILL FORM NEAR SOUTHERN NEW ENGLAND ON TUESDAY. THIS LOW
WILL TRACK SOUTH OF THE GULF OF MAINE TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
410 PM UPDATE: WITH SIG ACCUMULATING SNFL MOVING OUT OF PORTIONS
OF DOWNEAST AND EAST CENTRAL ME...WE HAVE BEGUN CANX WNTR STRM
WRNGS AS PER THE PREV NEAR TERM DISC. REST OF NEAR TERM FCST
ELEMENTS REMAIN THE SAME.
ORGNL DISC: LATEST HOURLY HRRR MODEL OUTPUT SHOWS HEAVIER SN BAND
ORGANIZATION BREAKING DOWN OVR ERN PTNS OF THE FA AND THEN MOVG
INTO NEW BRUNSWICK OVR THE NEXT FEW HRS...LEAVING LGT SNFL MAINLY
OVR THE N HLF OF THE FA INTO THE OVRNGT. WILL HOLD ON TO WNTR STRM
WRNGS FOR NOW...BUT ENVISION THEM BEING DROPPED FROM SW TO NE
BEGINNING WITHIN THE NEXT FEW HRS...WITH EVEN NRN ZONES BEING
DROPPED...SINCE SN RATES AND ACCUMULATIONS WILL BE TO LOW TO
SUSTAIN IMPACT...AND NEARLY ALL...IF NOT ALL OF THE CURRENT WRNGS
HAVE ALREADY BEEN VERIFIED WITH SNFL THAT HAS FALLEN TO THIS
POINT.
OTHERWISE...SFC TEMPS WILL BE FALLING W AND DOWNEAST INTO THE EVE
AND SLOWLY RISING ACROSS THE N AND E DUE TO DIFFERENTIAL THERMAL`
ADVCN ACROSS THE FA. TEMPS MAY COOL OVR THE NE BY DAYBREAK...BUT
NOT BY MUCH AS A LLVL THERMAL RIDGE HANGS ON AND LLVL COLD ADVCN
BEGINS TO PUNCH EWRD ACROSS WRN AND DOWNEAST AREAS. WINDS SHOULD
DIMINISH THROUGH THE EVENING AND OVRNGT AS THE LLVL PRES GRAD
SLACKENS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
A TROUGH OF LOWER PRESSURE EXTENDS ACROSS NORTHERN MAINE AND HIGH
PRESSURE RIDGE BUILDS INTO WESTERN MAINE AT THE START OF THE
PERIOD. A FEW LINGERING SNOW SHOWERS EARLY...THEN CLEARING. THE
HIGH PRESSURE WILL MOVE EAST OF THE AREA LATE TUESDAY AS THE NEXT
LOW MOVES INTO THE GULF OF MAINE. THE MODELS ARE AT A BIT OF
DISAGREEMENT ON THE POSITION AND MOVEMENT OF THE LOW AS IT EXITS
INTO THE NORTH ATLANTIC. THE ECMWF...NAM...GEM KEEP THE LOW IN THE
NORTHERN PORTIONS OF THE GULF OF MAINE. WITH THE ECMWF AND GEM THE
FARTHEST NORTH. THE GFS MOVES THE LOW OFF THE COAST SOUTH OF CAPE
COD AND MOVES IT EAST WELL SOUTH OF NOVA SCOTIA. A CONSENSUS
FORECAST OF THE ECMWF...NAM...AND GEM BRINGS THE HIGHEST POPS AND
QPF INTO THE SOUTHEASTERN AND EASTERN PORTIONS OF THE AREA. THE
CONSENSUS BLEND FOR QPF GIVES ABOUT THREE TENTHS OF AN INCH IN THE
HOULTON AREA...ABOUT SIX TENTHS OF AN INCH INTO THE ELSWORTH AREA.
THE BULK OF THE SNOW WILL FALL OVERNIGHT TUESDAY INTO WEDNESDAY.
THE SNOW WILL RAPIDLY DIMINISH WEDNESDAY MORNING.
USED THE NAM FOR MAX/MIN AND HRLY TEMPS...BLENDED GFS/ECMWF/NAM
FOR WNDS. LOADED RFC/HPC FOR QPF THRU 00Z WED. LOADED A CONSENSUS
BLEND FOR QPF 00Z WED TO 00Z THURS. LOADED BLENDED GFS/ECMWF/NAM
FOR POPS THRU 00Z WED. LOADED POP FROM QPF FOR POPS 00Z WED TO 00Z
THURS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A LOW PRESSURE AREA WILL BE EAST OF THE AREA MOVING TOWARD THE
CANADIAN MARITIMES. HIGHER PRESSURE WILL BE BUILDING INTO THE AREA
AT THE START OF THE PERIOD. THE RIDGE WILL DOMINATE THE WEATHER
THROUGH EARLY FRIDAY. A LOW PRESSURE AREA MOVING ACROSS THE GREAT
LAKE WILL MOVE INTO EARLY QUEBEC MIDDAY FRI AND THROUGH NRN MAINE
BY EARLY SAT MRNG. A WEAK RIDGE OF HIGHER PRESSURE WILL MOVE
THROUGH THE AREA AND WILL BE EAST OF THE AREA SUN MRNG. THE ECMWF
AND GFS ARE AT ODDS ON THE NEXT SYSTEM TO MOVE INTO THE AREA
TOWARDS THE END OF THE PERIOD. THE GFS INDICATES A BROAD AREA OF
LOWER PRESSURE WITH TWO CENTERS ON SOUTHEAST OF CAPE COD...THE
SECOND CENTER OVER LAKE ONTARIO. THE ECMWF SHOWS A LOW OVER NEW
BRUNSWICK A SECOND LOW OVER VERMONT WITH A FRONTAL BOUNDARY THAT
EXTENDS SW TO THE GULF OF MEXICO. BOTH MODELS INDICATE THAT THEIR
RESPECTIVE SYSTEMS WILL MOVE EAST OF THE AREA BY THE END OF THE
PERIOD.
LOADED THE SUPER BLEND FOR THE EXTENDED PERIOD. SLIT OUT THE POP
GRIDS TO 6 HRLY GRIDS...OTHERWISE JUST MINOR ADJUSTMENTS.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR XPCTD TO CONT LONGEST TNGT ACROSS NRN TAF SITES...
WITH DOWNEAST SITES SLOWLY RECOVERING TO MVFR THIS EVE AND THEN
VFR LATE TNGT.
SHORT TERM: A FEW SCT SNOW SHOWERS ACROSS NRN ME AFFECTING FVE AND
CAR EARLY IN THE PERIOD...OTHERWISE VFR COND ALL SITES 12Z MON
THROUGH 18Z TUES. CIGS WILL BEGIN TO DECREASE SOUTH TO NORTH
AROUND 18Z TUES. VFR COND BHB AND BGR BY 21Z TUE. IFR CONDITIONS
BHB...BGR MVFR HUL BY AROUND 00Z WED IN SNOW. IFR HUL...MVFR
PQI...CAR BY AROUND 03Z. BY AROUND 12Z CONDITIONS WILL BEGIN TO
IMPROVE SW TO E ACROSS THE AREA. BHB AND BGR WILL BEGIN TO BREAK
UP WITH CONTINUOUS SNOW CHANGING OVER TO SHOWERS...CIG AND VSBY
IMPROVING TO MVFR. BY ABOUT 18Z MVFR HUL...VFR BHB AND BGR. ALL
SITES BY THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: WILL DOWNGRADE THE CURRENT STORM WRNG TO A SHORT GALE
WRNG INTO THE MID EVE HRS TO ALLOW THE STRONGER WIND GRAD TO MOVE
OF THE WATERS. WOULD THEN XPCT AN SCA FOR LATE THIS EVE INTO THE
OVRNGT MSLY FOR THE OUTER WATERS FOR SEAS AND PERHAPS MARGINAL
WINDS.
SHORT TERM: A GALE WARNING WILL BE NEEDED EARLY IN THE
PERIOD...AN SCA MAYBE REQUIRED LATE IN THE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 6 AM EST MONDAY FOR MEZ001-002.
WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR
MEZ003>006-010.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MEZ017-
032.
MARINE...GALE WARNING UNTIL 8 PM EST THIS EVENING FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...VJN/NORTON
MARINE...VJN/NORTON
AREA FORECAST DISCUSSION
NWS CARIBOU ME
225 PM EST SUN DEC 15 2013
.SYNOPSIS...
STRONG LOW PRESSURE WILL CONTINUE MOVING EAST OVERNIGHT THROUGH
THE SOUTHERN MARITIMES INTO THE OPEN ATLANTIC. HIGH PRESSURE WILL
APPROACH ON MONDAY AND CREST OVER THE REGION MONDAY NIGHT. LOW
PRESSURE WILL FORM NEAR SOUTHERN NEW ENGLAND ON TUESDAY. THIS LOW
WILL TRACK SOUTH OF THE GULF OF MAINE TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST HOURLY HRRR MODEL OUTPUT SHOWS HEAVIER SN BAND ORGANIZATION
BREAKING DOWN OVR ERN PTNS OF THE FA AND THEN MOVG INTO NEW
BRUNSWICK OVR THE NEXT FEW HRS...LEAVING LGT SNFL MAINLY OVR THE N
HLF OF THE FA INTO THE OVRNGT. WILL HOLD ON TO WNTR STRM WRNGS FOR
NOW...BUT ENVISION THEM BEING DROPPED FROM SW TO NE BEGINNING
WITHIN THE NEXT FEW HRS...WITH EVEN NRN ZONES BEING DROPPED...SINCE
SN RATES AND ACCUMULATIONS WILL BE TO LOW TO SUSTAIN IMPACT...AND
NEARLY ALL...IF NOT ALL OF THE CURRENT WRNGS HAVE ALREADY BEEN
VERIFIED WITH SNFL THAT HAS FALLEN TO THIS POINT.
OTHERWISE...SFC TEMPS WILL BE FALLING W AND DOWNEAST INTO THE EVE
AND SLOWLY RISING ACROSS THE N AND E DUE TO DIFFERENTIAL THERMAL`
ADVCN ACROSS THE FA. TEMPS MAY COOL OVR THE NE BY DAYBREAK...BUT
NOT BY MUCH AS A LLVL THERMAL RIDGE HANGS ON AND LLVL COLD ADVCN
BEGINS TO PUNCH EWRD ACROSS WRN AND DOWNEAST AREAS. WINDS SHOULD
DIMINISH THROUGH THE EVENING AND OVRNGT AS THE LLVL PRES GRAD
SLACKENS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
A TROUGH OF LOWER PRESSURE EXTENDS ACROSS NORTHERN MAINE AND HIGH
PRESSURE RIDGE BUILDS INTO WESTERN MAINE AT THE START OF THE
PERIOD. A FEW LINGERING SNOW SHOWERS EARLY...THEN CLEARING. THE
HIGH PRESSURE WILL MOVE EAST OF THE AREA LATE TUESDAY AS THE NEXT
LOW MOVES INTO THE GULF OF MAINE. THE MODELS ARE AT A BIT OF
DISAGREEMENT ON THE POSITION AND MOVEMENT OF THE LOW AS IT EXITS
INTO THE NORTH ATLANTIC. THE ECMWF...NAM...GEM KEEP THE LOW IN THE
NORTHERN PORTIONS OF THE GULF OF MAINE. WITH THE ECMWF AND GEM THE
FARTHEST NORTH. THE GFS MOVES THE LOW OFF THE COAST SOUTH OF CAPE
COD AND MOVES IT EAST WELL SOUTH OF NOVA SCOTIA. A CONSENSUS
FORECAST OF THE ECMWF...NAM...AND GEM BRINGS THE HIGHEST POPS AND
QPF INTO THE SOUTHEASTERN AND EASTERN PORTIONS OF THE AREA. THE
CONSENSUS BLEND FOR QPF GIVES ABOUT THREE TENTHS OF AN INCH IN THE
HOULTON AREA...ABOUT SIX TENTHS OF AN INCH INTO THE ELSWORTH AREA.
THE BULK OF THE SNOW WILL FALL OVERNIGHT TUESDAY INTO WEDNESDAY.
THE SNOW WILL RAPIDLY DIMINISH WEDNESDAY MORNING.
USED THE NAM FOR MAX/MIN AND HRLY TEMPS...BLENDED GFS/ECMWF/NAM
FOR WNDS. LOADED RFC/HPC FOR QPF THRU 00Z WED. LOADED A CONSENSUS
BLEND FOR QPF 00Z WED TO 00Z THURS. LOADED BLENDED GFS/ECMWF/NAM
FOR POPS THRU 00Z WED. LOADED POP FROM QPF FOR POPS 00Z WED TO 00Z
THURS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A LOW PRESSURE AREA WILL BE EAST OF THE AREA MOVING TOWARD THE
CANADIAN MARITIMES. HIGHER PRESSURE WILL BE BUILDING INTO THE AREA
AT THE START OF THE PERIOD. THE RIDGE WILL DOMINATE THE WEATHER
THROUGH EARLY FRIDAY. A LOW PRESSURE AREA MOVING ACROSS THE GREAT
LAKE WILL MOVE INTO EARLY QUEBEC MIDDAY FRI AND THROUGH NRN MAINE
BY EARLY SAT MRNG. A WEAK RIDGE OF HIGHER PRESSURE WILL MOVE
THROUGH THE AREA AND WILL BE EAST OF THE AREA SUN MRNG. THE ECMWF
AND GFS ARE AT ODDS ON THE NEXT SYSTEM TO MOVE INTO THE AREA
TOWARDS THE END OF THE PERIOD. THE GFS INDICATES A BROAD AREA OF
LOWER PRESSURE WITH TWO CENTERS ON SOUTHEAST OF CAPE COD...THE
SECOND CENTER OVER LAKE ONTARIO. THE ECMWF SHOWS A LOW OVER NEW
BRUNSWICK A SECOND LOW OVER VERMONT WITH A FRONTAL BOUNDARY THAT
EXTENDS SW TO THE GULF OF MEXICO. BOTH MODELS INDICATE THAT THEIR
RESPECTIVE SYSTEMS WILL MOVE EAST OF THE AREA BY THE END OF THE
PERIOD.
LOADED THE SUPER BLEND FOR THE EXTENDED PERIOD. SLIT OUT THE POP
GRIDS TO 6 HRLY GRIDS...OTHERWISE JUST MINOR ADJUSTMENTS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR XPCTD TO CONT LONGEST TNGT ACROSS NRN TAF SITES...
WITH DOWNEAST SITES SLOWLY RECOVERING TO MVFR THIS EVE AND THEN
VFR LATE TNGT.
SHORT TERM: A FEW SCT SNOW SHOWERS ACROSS NRN ME AFFECTING FVE AND
CAR EARLY IN THE PERIOD...OTHERWISE VFR COND ALL SITES 12Z MON
THROUGH 18Z TUES. CIGS WILL BEGIN TO DECREASE SOUTH TO NORTH
AROUND 18Z TUES. VFR COND BHB AND BGR BY 21Z TUE. IFR CONDITIONS
BHB...BGR MVFR HUL BY AROUND 00Z WED IN SNOW. IFR HUL...MVFR
PQI...CAR BY AROUND 03Z. BY AROUND 12Z CONDITIONS WILL BEGIN TO
IMPROVE SW TO E ACROSS THE AREA. BHB AND BGR WILL BEGIN TO BREAK
UP WITH CONTINUOUS SNOW CHANGING OVER TO SHOWERS...CIG AND VSBY
IMPROVING TO MVFR. BY ABOUT 18Z MVFR HUL...VFR BHB AND BGR. ALL
SITES BY THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: WILL DOWNGRADE THE CURRENT STORM WRNG TO A SHORT GALE
WRNG INTO THE MID EVE HRS TO ALLOW THE STRONGER WIND GRAD TO MOVE
OF THE WATERS. WOULD THEN XPCT AN SCA FOR LATE THIS EVE INTO THE
OVRNGT MSLY FOR THE OUTER WATERS FOR SEAS AND PERHAPS MARGINAL
WINDS.
SHORT TERM: A GALE WARNING WILL BE NEEDED EARLY IN THE
PERIOD...AN SCA MAYBE REQUIRED LATE IN THE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 6 AM EST MONDAY FOR MEZ001-002.
WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR
MEZ003>006-010.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MEZ011-
015>017-029>032.
MARINE...GALE WARNING UNTIL 8 PM EST THIS EVENING FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...VJN/NORTON
MARINE...VJN/NORTON
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1228 PM EST SUN DEC 15 2013
.AVIATION...
//DISCUSSION...
A SURFACE TROUGH IS JUST ABOUT THROUGH SOUTHEAST MICHIGAN...AND
WESTERLY WINDS WILL BE GUSTING TO AROUND 25 KNOTS EARLY THIS
AFTERNOON BEHIND THE TROUGH PASSAGE. FLURRIES AND LIGHT SNOW
SHOWERS WILL PROBABLY PERSIST SEVERAL MORE HOURS...BUT DRIER AIR
(MID LEVELS) WILL SHRINK CLOUD DEPTHS. THIS EVENING AND TONIGHT IS
TOUGH CALL FOR CLOUD COVER...AND BANKING ON THE COLD WESTERLY FLOW
OFF LAKE MICHIGAN TO PROVIDE JUST ENOUGH MOISTURE TO MAINTAIN HIGH
MVFR/LOW VFR CEILINGS. IN ADDITION...THE VERY COLD AIRMASS WILL
SUPPORT THE CHANCE OF FLURRIES JUST ABOUT ANYTIME...BUT ESPECIALLY
TOMORROW MORNING AS SOME MID LEVEL MOISTURE ALSO RETURNS TO THE
AREA.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5 KFT FT THROUGH THIS
EVENING...MEDIUM CONFIDENCE OVERNIGHT INTO TOMORROW MORNING
* MODERATE CONFIDENCE IN WESTERLY GUSTS REACHING 25KTS THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 855 AM EST SUN DEC 15 2013
UPDATE...
QUICK UPDATE TO CARRY WIDESPREAD SNOW SHOWERS...AS FLAKE SIZE IS
PRETTY GOOD WITH SURFACE OBS REPORTING VSBYS 1-3 SM WITHIN THE
HEAVIER ACTIVITY. 12Z DTX SOUNDING DOES SHOW STEEP LAPSE RATE IN
THE 875-825 MB LAYER...WHICH IS EMBEDDED IN THE DENDRITIC SNOW
GROWTH REGION. SURFACE TROUGH IS PROVIDING SUFFICIENT LOW LEVEL
CONVERGENCE AS WELL. WITH GOOD FLUFF FACTOR...ACCUMULATIONS
AROUND 1 INCH ARE EXPECTED.
PREV DISCUSSION...ISSUED 357 AM EST SUN DEC 15 2013
SHORT TERM...TODAY AND TONIGHT
THE SHORT TERM WILL FEATURE LIGHT SNOW...GUSTY AFTERNOON WINDS...AND
POSSIBLE SINGLE DIGIT TEMPS OVERNIGHT. A NORTHERN STREAM UPPER LEVEL
LOW WILL DROP THROUGH THE NORTHERN GREAT LAKES TODAY WHILE A LAKE
AGGREGATE SURFACE TROUGH LINGERS ACROSS CENTRAL MI. STRONG CAA HAS
BEGUN IN THE WAKE OF SATURDAYS LOW AS BROAD MID LEVEL TROUGHING
SINKS INTO THE GREAT LAKES. THIS WILL USHER IN ANOTHER ARCTIC
AIRMASS TO DEAL WITH THROUGH TONIGHT. MODELS SHOW SOME AIRMASS
MODIFICATION AS IT CROSSES THE LAKES WITH -26C TEMPS AT 850MB
ENTERING LAKE SUPERIOR AND NEGATIVE TEENS ENTERING MI. SOUTHERN MI
WILL FALL NEAR THE BASE OF THE MID LEVEL TROUGH AND ON THE SOUTH
SIDE OF THE SFC TROUGH LEADING TO WESTERLY FLOW. THE WESTERLY FLOW
AND CAA WILL LEAD TO AN ACTIVE SETUP FOR LAKE EFFECT WITH MIXING
LEVELS OVER LAKE MI REACHING 10KFT. EVEN OVER SE MI THE CAA IN THE
LOW LEVELS WILL LEAD TO STRONG LAPSE RATES UP TO ABOUT 6KFT. BOTH
THE NAM AND RUC SHOW THE ENTIRE MIXED LAYER TO BE SATURATED WHICH
EXTENDS THROUGH THE DGZ. IN ADDITION TO THE SFC FEATURES...A MID
LEVEL VORT MAX WILL ROTATE AROUND AND THROUGH MID MI LENDING SOME
ADDITIONAL SYNOPTIC SUPPORT ALOFT. POPS WILL RAMP UP IN THE
AFTERNOON AS THE DIURNAL CYCLE GIVES THE MIXED LAYER A BOOST AND AS
THE SFC TROUGH AND VORT MAX SWING THROUGH. LAKE EFFECT SHOULD MAKE
IT INTO THE CWA WITH THE STEADY WESTERLY FLOW DURING THE DAY. THE
NAM IS ADVERTISING THE LAKE MI CONVERGENT BAND SETTING UP WHICH WILL
NEED TO BE WATCHED IN CASE IT IMPACTS ANY ONE AREA FOR ANY
DURATION...MOST LIKELY NEAR THE I94 CORRIDOR. OVERALL NOT EXPECTING
MUCH SNOW WITH AROUND A HALF INCH FOR MOST LOCATIONS. IF WE CAN GET
SOME ENHANCE MESOSCALE FEATURES TO SET UP OR THE LAKE EFFECT BAND TO
PERSIST...TOTALS WOULD OBVIOUSLY GO UP SOME. THE OTHER CONCERN TODAY
WILL BE THE WINDS. MODEL SOUNDINGS SHOW THE MIXING LEVELS PREVIOUSLY
MENTIONED BRINGING DOWN GUST AROUND 30 MPH IN THE AFTERNOON. THIS
WILL LIKELY LEAD TO ADDITIONAL DRIFTING OF THE SNOW PACK. THE LAST
CONCERN WILL BE LOW TEMPS TONIGHT. WITH THE FRESH SNOW PACK AND
ARCTIC AIR MOVING IN...THE POTENTIAL IS THERE FOR LOW SINGLE DIGIT
TEMPS. A BIG CONCERN WILL BE CLOUD COVER PREVENTING THIS FROM
ACTUALLY OCCURRING...ESPECIALLY ACROSS THE SOUTH WHERE THE LAKE
CLOUD SHOULD PERSIST THE LONGEST. ADJUSTED TEMPS UP A COUPLE DEGREES
ACROSS THE SOUTH WITH THE MORE PESSIMISTIC CLOUD COVER
FORECAST...OTHERWISE CONTINUED THE COOL PLAY IN THE MID SINGLE
DIGITS RESULTING IN WIND CHILL VALUES -5 TO -10F.
LONG TERM...MONDAY THROUGH SATURDAY
SHORTWAVE RIDGING WILL TRACK THROUGH THE CENTRAL GREAT LAKES MONDAY
MORNING...KEEPING THE WEATHER DRY FOR THE FIRST HALF OF THE DAY.
QUICKLY ON ITS HEELS WILL BE A VIGOROUS MID LEVEL SHORTWAVE DIVING
SOUTH FROM CANADA. THIS ELONGATED MID LEVEL TROUGH...SEEN ON WATER
VAPOR OVER WESTERN CANADA...WILL BRING A PROLONGED PERIOD OF LIGHT
SNOW SHOWERS FROM MONDAY AFTERNOON THROUGH TUESDAY TO SOUTHEAST
MICHIGAN. AS THE TROUGH MOVES THROUGH THE GREAT LAKES...IT WILL HAVE
THE ASSISTANCE OF BEING UNDER THE LEFT EXIT REGION OF A 140 KNOT JET
DIVING INTO THE WESTERN GREAT LAKES REGION. THE BEST TIME FOR SNOW
APPEARS TO BE LATE MONDAY AFTERNOON INTO MONDAY NIGHT WHEN THE LEAD
SHORTWAVE TRACKS THROUGH THE CENTRAL GREAT LAKES...WITH AN INCH OF
TWO OF SNOWFALL ACCUMULATION POSSIBLE. A SUBTLE BUT NOTICEABLE
WARMING IN THE LOW LEVELS SHOULD CAUSE LOW TEMPERATURES TO OCCUR
EARLY MONDAY NIGHT...WITH SLOWLY RISING TEMPERATURES AFTER MIDNIGHT.
ANOTHER SHORTWAVE TRACKING THROUGH THE SOUTHERN GREAT LAKES ON
TUESDAY COULD BRING ADDITIONAL SNOWFALL AMOUNTS OF A FEW TENTHS OF
AN INCH TO SOUTHEAST MICHIGAN.
ONCE THIS SYSTEM MOVES OFF TO THE EAST HEIGHTS WILL INCREASE ACROSS
THE CENTRAL GREAT LAKES WITH TEMPERATURES WARMING INTO THE 30S ON
THURSDAY...WITH 40S POSSIBLE BY FRIDAY AHEAD OF THE NEXT LOW
PRESSURE SYSTEM TRACKING THROUGH THE GREAT LAKES REGION. THIS
SYSTEM...ORIGINATING OVER THE SOUTHERN PLAINS ON THURSDAY...WILL
TRACK NORTHEAST THROUGH MICHIGAN ON FRIDAY. GIVEN THE NORTHERN TRACK
OF THE LOW THE AREA WILL BE IN THE WARM SECTOR OF THE
SYSTEM...MEANING PRECIPITATION MORE IN THE FORM OF LIQUID RATHER
THAN ICE CRYSTALS. THERE ARE STILL TIMING DIFFERENCES BETWEEN THE
LONG RANGE MODELS...NOTABLY THE FASTER ECMWF AND THE SLOWER GFS.
HOWEVER THEY DO AGREE ON A RETURN TO COLDER TEMPERATURES BEHIND THE
LOW BY SATURDAY AS RIDGING BUILDS OVER THE CENTRAL GREAT LAKES.
MARINE...
WAVES IN THE NEARSHORE ZONES CONTINUE TO SUBSIDE...WITH CONDITIONS
HAVING FALLEN BELOW HEADLINE CRITERIA. HOWEVER...INCREASING WESTERLY
WINDS THIS AFTERNOON ARE EXPECTED AS LOW PRESSURE TRACKS THROUGH THE
CENTRAL GREAT LAKES. THE FETCH WILL BE FAVORABLE FOR WAVES TO BUILD
UP OVER THE NORTHERN TIP OF THE THUMB OVERNIGHT...NECESSITATING A
SMALL CRAFT ADVISORY FOR OUTER SAGINAW BAY AND THE LAKE HURON
NEARSHORE WATERS FROM PORT AUSTIN TO HARBOR BEACH. CONDITIONS WILL
REMAIN UNSETTLED INTO EARLY NEXT WEEK AS SOUTHWEST WINDS DEVELOP
AHEAD OF A PASSING SYSTEM MONDAY NIGHT INTO TUESDAY. THERE ARE NO
SIGNIFICANT WIND EVENTS ON THE HORIZON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......SF
SHORT TERM...DRK
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
308 PM CST Sun Dec 15 2013
.SHORT TERM: (Tonight through Monday)
Issued at 259 PM CST Sun Dec 15 2013
Lots of caveats to the forecast for tonight leading to low confidence
in some of the details. A strong surface front currently extends
from western SD through central NE and northeast KS across northern
MO into west central IL. The models are in decent agreement that a
surface low pressure wave will track southeastward along the front
from the central Plains into southern IL tonight with the front
sagging southward in its wake. This surface low will be in response
to a weak elongated short wave/vort max migrating southeastward
within the NW flow aloft. The large scale forcing and strongest
low level baroclinity/frontogenesis will reside to the north of
the forecast area from Iowa thru north central IL into southeast
IN and this is where the greatest threat of snow should reside.
Along the far southern periphery of this zone which encompasses a
zone from around Edina to Quincy to White Hall to Nokomis, the RAP
suggests there could be a brief shot of decent ascent. It also has
some very light QPF within this zone and the last few available
runs of the HRRR showed some spotty precipitation. The overall low
level flow regime is characterized south of the aforementioned
front and above the boundary layer by warm air advection. This WAA
while also contributing to lift has warmed the atmosphere and
soundings suggest any precipitation could teeter between light
freezing rain or light snow. I have added some low pops to account
for this probability and it will bear close watching on the
evening shift. Further south snow melt has contributed to low
level moistening and some of the guidance suggests fog and stratus
will develop. The 12z run of the NAM even went as far as developing
freezing drizzle. The boundary layer is where all the models have
the poorest time resolving, thus my confidence is limited, but
given the current surface dew points are now close to the forecast
mins I have opted to included a mention of fog in the forecast. If
stratus and fog are widespread on Monday morning, then the trend
should be for this to erode/dissipate as the morning progresses
and weak low level WAA kicks in. If the stratus/fog or clouds are
at a minimum then my forecast highs are likely to cool.
Glass
.LONG TERM: (Monday Night through Next Sunday)
Issued at 259 PM CST Sun Dec 15 2013
Despite another weak and ill-defined cold front passing though the
area on Tuesday, the temperatures should moderate some. The real
moderation however will begin to unfold on Tuesday night as the
surface high retreats and low level WAA gets underway. Strong WAA
will be in full swing on Wednesday as low level flow becomes
south/southwesterly and the upper flow transitions to quasi-zonal.
This should be a big snow melter with highs in the upper 40s-middle
50s.
The extended portion of the forecast, especially towards the
weekend, is marked by considerable uncertainty. A big pattern change
will continue to evolve with considerable amplification from the
central Pacific across the CONUS. The main feature will be the
development of a split flow regime with a deep long wave positively
tilted trof in the western U.S. and upper low in the southwest. This trof
develops in response to the absorption of an upper low currently in
the southeast Pacific near 27N/134W and short waves digging
southward out of the Gulf of AK along the west coast. The northern
stream will serve to bring a cold front through the area Thursday
night/early Friday accompanied by a chance of rain and possibly some
rain/snow mix in the wake. However the northern stream is sharper on
the GFS and it also leaves the upper low spinning in the vicinity of
northern Baja CA. This solution would suggest limited post-frontal
precipitation with high pressure building into the Mid MS Valley
late Friday and then additional waves in the northern stream
reinforcing the high pressure and essentially keeping precipitation
south of the area. Alternatively the ECMWF develops an overunning
scenario Saturday into Sunday and potential for a winter mess.
There is no scientific basis at this point in time to suggest one
solution is vastly better than another and the models will continue
to change multiple times in the details in the coming week. Given
the forecast large scale pattern changes and vastly differing model
solutions and resultant low confidence, the best approach at this
time is more of an ensemblistic approach with some mixed flavor.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1221 PM CST Sun Dec 15 2013
Surface ridge to continue weakening as shortwaves slide southeast
through region. Will mainly just see an increase in clouds with
each shortwave, though could have some light snow/flurries for
tafs along Mississippi river valley. For now only mention light
snow in KUIN after 02z Monday as they are closer to better dynamics.
Otherwise, will see mvfr cigs sliding into region late this
afternoon and early this evening. The low cigs to persist through
remainder of forecast period. Some question as to how low cigs
will go as well as fog development due to some melting of the snow
pack today. For now keep mvfr vsbys at KCOU and metro area tafs
tonight until we get a better grasp possible fog situation. Winds
to become light and variable as clipper system moves through, then
winds pick back up from the west to northwest on Monday morning.
Specifics for KSTL:
Surface ridge to continue weakening as shortwaves slide southeast
through region. Will mainly just see an increase in clouds with
each shortwave, though could have some light snow/flurries for
tafs along Mississippi river valley. For now kept mention out of
KSTL taf. Otherwise, will see mvfr cigs sliding into metro area
after 03z Monday and persist through remainder of forecast period.
Some question as to how low cigs will go as well as fog
development due to some melting of the snow pack today. For now
keep mvfr vsbys at KSTL tonight until we get a better grasp
possible fog situation. Winds to become light and variable as
clipper system moves through, then winds pick back up from the
west by 17z Monday.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 AM CST SUN DEC 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM CST SUN DEC 15 2013
TODAY AND TONIGHT...A POWERFUL THERMAL RIDGE WILL CONTINUE OPERATING
ACROSS THE FORECAST AREA. WINDS AT H850 MB CONTINUE AT 35 TO 45 KT
TODAY AND THEN WEAKEN TO AROUND 30 KTS TONIGHT. THE MID LEVEL CLOUD
DECK CURRENTLY ACROSS THE FCST AREA IS FCST TO SHIFT EAST AND EXIT
THE AREA THIS AFTN. AT THE SAME TIME A BANK OF CIRRUS ACROSS THE NRN
PLAINS WILL DRIFT ACROSS THE FCST AREA. THE TEMPERATURE FCST TODAY
USES THE WARM SIDE OF THE MODEL CONSENSUS PLUS ABOUT 3 DEGREES FOR
HIGHS IN THE UPPER 50S SOUTHWEST TO UPPER 30S NORTHEAST. THIS IS A
FEW DEGREES COOLER THAN THE HRRR MODEL BUT THAT MODEL WAS TOO WARM
SATURDAY.
THE QUESTION TONIGHT IS HOW COOL LOWS WILL GO. PRESUMABLY CIRRUS
WILL CONTINUE ACROSS THE FCST AREA BUT NONE OF THE MODELS SHOW MUCH
MID LEVEL CLOUDINESS WHICH WOULD KEEP MIN TEMPS IN THE 30S. THE FCST
IS FOR LOWER 20S ASSUMING CIRRUS CLOUDS.
OTHERWISE...500M AGL WINDS INCREASE TO 25 TO 30 KTS WHICH SUPPORTS
WINDS IN THE 20 TO 30 MPH RANGE AT THE SFC. THE FCST USES MULTIMODEL
DATA TODAY AND TONIGHT FOR WINDS BUT INCREASES WIND SPEEDS TO NEAR
THE MAV GUIDANCE...THE STRONGEST WIND DATA SET AVAILABLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM CST SUN DEC 15 2013
PRIMARY FORECAST PROBLEMS THROUGH THIS PERIOD ARE TEMPERATURES AS
WELL AS PRECIPITATION CHANCES THURSDAY AND THURSDAY NIGHT.
AMPLIFIED UPPER LEVEL FLOW WITH RIDGING OVER THE EASTERN PACIFIC AND
WESTERN CONUS WITH TROUGHING OVER THE EASTERN HALF OF THE CONUS WILL
GIVE WAY TO A CHANGE BY MID WEEK AS THE UPPER LEVEL LOW CURRENTLY
OVER ONTARIO MOVES EAST DECREASING THE STRENGTH OF THE
TROUGH...WHILE A SERIES OF SHORTWAVE TROUGHS MOVE THROUGH THE
NORTHERN STREAM OUT OF RUSSIA AND ALASKA TO FLATTEN THE FLOW BY
MONDAY AND TUESDAY. SEVERAL WEAK SURFACE FRONTS WILL MOVE THROUGH
THE REGION WITH THE FIRST COMING THROUGH MONDAY MORNING AND ANOTHER
MONDAY NIGHT. EVEN WITH THESE FRONTS MOVING THROUGH...THE AIRMASS
WILL HAVE A PACIFIC INFLUENCE SO NOT EXPECTING TEMPERATURES TO BE
IMPACTED MUCH BY IT. WILL ALSO SEE WESTERLY FLOW IN THE LOW LEVELS
TO HELP WITH MIXING AND RAISING THE TEMPERATURES ON MONDAY. HIGH
PRESSURE WILL BUILD SOUTHEAST ACROSS THE AREA AND BY TUESDAY WILL
MOVE FURTHER SOUTHEAST BRINGING RETURN FLOW BACK INTO THE AREA.
AGAIN EXPECTING TEMPERATURES SIMILAR TO SUNDAY AND MONDAY.
TUESDAY NIGHT INTO WEDNESDAY THE CHANGING UPPER LEVEL PATTERN WILL
START TO BECOME APPARENT AS WHAT WILL BECOME A STRONG UPPER LEVEL
WAVE MOVES DOWN THE BRITISH COLUMBIA COAST AND INTO THE PACIFIC
NORTHWEST. MEANWHILE...THE UPPER LOW CURRENTLY WELL OFF THE
CALIFORNIA COAST WILL MOVE ONSHORE INTO SOUTHERN CALIFORNIA. AS
THESE TWO SYSTEMS BEGIN TO DEEPEN A TROUGH OVER THE WEST
COAST...UPPER LEVEL RIDGING WILL BUILD OVER THE PLAINS.
CONCURRENTLY...LOW PRESSURE AT THE SURFACE WILL DEVELOP OVER EASTERN
WYOMING WHICH WILL STRENGTHEN THE SOUTHERLY FLOW INTO THE LOCAL
AREA. WEDNESDAY SHOULD BE THE WARMEST DAY OF THE WEEK...HOWEVER
THERE ARE SOME DIFFERENCES IN HOW WARM IT WILL GET. THE ECMWF RISES
850MB TEMPERATURES TO NEAR 13C OVER THE SOUTHERN PART OF THE
FORECAST AREA WEDNESDAY AFTERNOON...WHILE THE GFS DOESN/T WARM
THINGS UP AS MUCH. THIS WOULD MEAN A DIFFERENCE IN HIGHS BY 5 TO 10
DEGREES ACROSS THE FORECAST AREA. AT THIS TIME...TRENDED CLOSER TO
THE WARMER SOLUTION...YET NOT AS WARM AS SOME MODEL SOLUTIONS
SUGGESTING.
THE OTHER CONSIDERATION WHEN DEALING WITH THE TEMPERATURES IS THE
IMPACT OF THE SNOWPACK OVER THE NORTHERN PARTS OF THE FORECAST AREA.
SHOULD GET QUITE A BIT OF SNOW TO MELT OVER THE NEXT SEVERAL
DAYS...AND DO HAVE TEMPERATURES ON THE UPWARD TREND THROUGH
WEDNESDAY. BELIEVE WILL STILL SEE SOME INFLUENCE FROM THE SNOW
THROUGH THE WEEK...BUT HOW MUCH REMAINS IN QUESTION. WILL SEE HOW
TEMPERATURES WARM TODAY AND WILL SEE WHAT ADJUSTMENTS WILL NEED TO
BE MADE FOR THE FOLLOWING DAYS OVER THE NEXT SEVERAL FORECAST
CYCLES.
ON WEDNESDAY NIGHT THE UPPER LOW THAT MOVES INTO CALIFORNIA ON
WEDNESDAY WILL EJECT OUT OF THE UPPER TROUGH AND INTO THE CENTRAL
PLAINS. AS THIS OCCURS...THE WYOMING SURFACE LOW WILL MOVE INTO
EASTERN COLORADO...WITH THE ENTIRE SYSTEM WEAKENING. GOING INTO
THURSDAY THE SURFACE LOW WILL MOVE ACROSS KANSAS WITH AN INVERTED
TROUGH PASSING ACROSS THE LOCAL FORECAST AREA. THE MAJORITY OF
MOISTURE ASSOCIATED WITH THIS SYSTEM WILL REMAIN ACROSS KANSAS AND
SOUTHEAST NEBRASKA SO NOT EXPECTING ANY PRECIPITATION INVOLVED WITH
IT.
FOCUS THEN TURNS TO THE NEXT ARCTIC AIRMASS TO PUSH THROUGH THE
PLAINS. THE ARCTIC FRONT IS NOW BEING TIMED TO MOVE SOUTH ACROSS
NEBRASKA DURING THE DAY THURSDAY WITH PRECIPITATION MOVING IN BEHIND
THE FRONT. THE MUCH COLDER AIR WILL LAG BEHIND THE FRONT...HOWEVER
WITH COLD AIR ADVECTION ONGOING THROUGH THE DAY AM QUESTIONING HOW
WARM IT WILL GET...OR WHAT TIME HIGHS WILL BE REACHED. LOCATIONS
ACROSS THE NORTH MAY SEE HIGHS IN THE MORNING...WHILE THE SOUTHERN
PARTS OF THE AREA MAY HAVE SOME TIME TO WARM UP BEFORE THE BIG PUSH
OF COLD AIR. DID LOWER HIGHS SLIGHTLY FOR THURSDAY...BUT WILL LIKELY
NEED FURTHER ADJUSTMENTS UNTIL A BETTER HANDLE IS ON THE MODELS FOR
THIS SYSTEM. THE PRESSURE GRADIENT WILL TIGHTEN BEHIND THE
FRONT...WITH STRONG NORTHERLY WINDS EXPECTED ON THURSDAY INTO
THURSDAY NIGHT. BY FRIDAY HIGH PRESSURE WILL BUILD IN WITH THE
PRESSURE GRADIENT RELAXING SO WINDS SHOULDN/T BE AS STRONG. COLDER
AND BELOW NORMAL TEMPERATURES WILL THEN CONTINUE INTO THE WEEKEND AS
THE TROUGH AXIS MOVES ACROSS THE CONUS THROUGH THE WEEKEND. CURRENT
MODELS AREN/T QUITE AS COLD WITH THE TEMPERATURES FOR FRIDAY AND
SATURDAY AS PREVIOUS RUNS...BUT STILL BRING 850MB TEMPERATURES OF
-15C TO -17C INTO THE CENTRAL PLAINS.
IN TERMS OF PRECIPITATION...THERE SEEMS TO BE AN ISSUE WITH A POCKET
OF DRY AIR IN THE MID LEVELS BEHIND THE FRONT WHICH MAY CAUSE
PROBLEMS WITH THE DEVELOPMENT OF PRECIPITATION. THERE CONTINUES TO
BE A SLIGHT SIGNAL FOR SOME DRIZZLE ON THURSDAY PRIOR TO THE COLUMN
BECOMING SATURATED THURSDAY NIGHT. HOWEVER...EVEN IN THE LOW
LEVELS...THE AIR WASN/T COMPLETELY SATURATED EITHER SO WILL STILL
NOT MENTION ANY DRIZZLE YET IN THE FORECAST. BESIDES THIS OUTSIDE
CHANCE FOR DRIZZLE...THE POST-FRONTAL PRECIPITATION SHOULD BE QUITE
LIGHT. PRECIPITABLE WATER AMOUNTS AREN/T BAD...HOWEVER THE SIGNALS
FOR ANY FRONTOGENESIS ARE NOT STRONG AND THE MOISTURE DOES NOT STAY
LONG BEFORE MUCH DRIER AIR PUSHES IN TO DRY OUT THE COLUMN SO NOT
EXPECTING ANY HEAVY PRECIPITATION AMOUNTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1154 AM CST SUN DEC 15 2013
GENERAL VFR EXPECTED ACROSS ALL WESTERN AND NORTH CENTRAL NEBRASKA
AVIATION TERMINALS TODAY/TONIGHT. THERE IS A CONTINUED STREAM OF
MID/HIGH LEVEL CLOUDS THAT HAVE BROUGHT PERIODIC OVC SKIES TO BOTH
KVTN AND KLBF...THIS TREND SHOULD CONTINUE THROUGH THE FORECAST
PERIOD. OTHERWISE WESTERLY SFC WIND WILL BECOME GUSTY THIS
AFTERNOON...ESPECIALLY ACROSS AND SOUTH OF THE CENTRAL
SANDHILLS. PEAK WIND GUSTS OF 24KTS ARE EXPECTED THIS AFTERNOON AT
KLBF....BUT WINDS WILL WEAKEN CONSIDERABLY OVERNIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1123 AM CST SUN DEC 15 2013
.UPDATE...
ISSUED AT 1123 AM CST SUN DEC 15 2013
ANOTHER DAY...ANOTHER TRICKY TEMPERATURE FORECAST. DESPITE QUITE
A BIT OF PASSING MID/HIGH LEVEL CLOUDS SO FAR THIS MORNING...HAVE
BEEN IMPRESSED WITH TEMP RISES...AS ALL BUT THE FAR NORTHEAST CWA
IS ALREADY WELL INTO THE 40S. HOWEVER...THE FAR NORTHEAST IS RIGHT
WITHIN A SHARP GRADIENT ALONG A NORTHWEST-SOUTHEAST ORIENTED QUASI-
STATIONARY FRONT...AS COLUMBUS AIRPORT IS SITTING AT ONLY 25...12
DEGREES COOLER THAN NEARBY YORK. ALTHOUGH NOT QUITE READY TO BUY
WHOLE- SALE INTO THE RAW HOURLY RAP13 TEMPS FOR THIS
AFTERNOON...HAVE RAISED HIGHS AT LEAST 3 DEGREES FROM ORIGINAL
MORNING FORECAST IN ALL AREAS...AND VERY POSSIBLY NOT ENOUGH. AS
IT CURRENTLY STANDS...NOW HAVE THE MAJORITY OF THE CWA TOPPING OUT
50-55...WITH SEVERAL FAR WESTERN/SOUTHERN AREAS MORE SO 56-59. THE
FAR NORTHEAST...ESPECIALLY THE POLK/EASTERN NANCE AREA STANDS THE
BIGGEST ROOM FOR A 5+ DEGREE BUST DEPENDING ON WHETHER OR NOT THE
WARMER AIR CAN SHOVE A LITTLE FARTHER EAST OR NOT. WILL NOT GET
TOO CARRIED AWAY IN THIS AREA...BUT WILL LEAN TOWARD THE
OPTIMISTIC SIDE OF THINGS WITH LOW-MID 40S EVENTUALLY WORKING IN.
OTHERWISE...A FEW ELEVATED RADAR RETURNS ARE SKIRTING FAIRLY CLOSE
TO THE FAR NORTHERN EDGE OF THE CWA...BUT HAVE DOUBTS THAT EVEN A
ROGUE SPRINKLE IS REACHING THE GROUND SO WILL KEEP IT PRECIP-FREE
THIS AFTERNOON UNDER VARIABLE SKY COVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CST SUN DEC 15 2013
THE BIGGEST CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES TODAY.
AT UPPER LEVELS...A RIDGE WILL BE IN THE PACIFIC WHILE A TROUGH IN
THE EASTERN UNITED STATES WILL EXIST. WE WILL BE IN NORTHWEST FLOW
IN BETWEEN WITH WARM AIR ADVECTION BEING ADVERTISED AT 850 MB AS THE
RIDGE NUDGES EAST. A SMALL PERTURBATION UPSTREAM WILL PASS ACROSS
THE CWA THIS MORNING...AND FOR TONIGHT...AN UPPER JET WILL APPROACH
AS THE LEFT FRONT QUADRANT WILL PROBABLY BE NEAR OUR AREA BY THE END
OF THE OVERNIGHT.
AT THE SURFACE...A WARM FRONT HAS NEARLY PASSED THROUGH THE ENTIRE
CWA...EXCEPT FOR THE FAR NORTHEASTERN CORNER. THIS FRONT SHOULD
CONTINUE TO EDGE FARTHER EAST THIS MORNING AND WE SHOULD BE
COMPLETELY IN THE WARM SECTOR FOR TODAY AND TONIGHT...ALTHOUGH THE
COLDER AIR WILL NOT BE TOO FAR TO THE EAST. GOING ABOVE GUIDANCE AS
RECENT BIAS CORRECTED MODEL VERIFICATION SUGGESTS THIS WOULD BE A
GOOD IDEA...AS WELL AS THE FACT THAT OUR SNOW PACK OVER THE CENTRAL
PART OF THE CWA IS FAST DWINDLING. A FLY IN THE OINTMENT COULD BE THE
MID TO UPPER LEVEL CLOUDINESS ASSOCIATED WITH THE PERTURBATION
MOVING ACROSS THE AREA DURING THE LATE MORNING INTO POSSIBLY THE
EARLY AFTERNOON...BUT THE HRRR SUGGESTS THAT WE SHOULD BE WELL CLEAR
OF MOST OF THIS SKY COVER BEFORE THE PEAK HEATING OF THE DAY OCCURS.
ANY PRECIPITATION SHOULD REMAIN WELL OFF THE NORTHEAST AND EAST OF
THE CWA WITH A PASSING WAVE AND NO MODEL IS ADVERTISING MEASURABLE
PRECIPITATION...ALTHOUGH THE WRF IS INDICATING PERHAPS SOME VERY
LIGHT NON-MEASURABLE PRECIPITATION IN OUR FAR NORTHEAST...BUT THIS
IS CLEARLY AN OUTLIER AND NOT CONSIDERED IN THIS FORECAST. THERE
COULD BE A BIT OF PATCHY FOG IN OUR EAST TONIGHT AS THE SREF IS
PICKING UP ON THIS. WITH WIND IN THE EAST NEAR CALM FOR PART OF THE
NIGHT AND DEWPOINT DEPRESSIONS PREDICTED TO BE LOW...WITH A LITTLE
BIT OF FRESHLY MELTED SNOW. THIS SHOULD NOT AMOUNT TO MUCH...AND BY
LATE OVERNIGHT...WIND WILL PROBABLY PICK UP A BIT TO DECREASE FOG
POTENTIAL. WITH THE APPROACHING LEFT FRONT QUADRANT OF AN UPPER
LEVEL JET...WE COULD ALSO HAVE SOME INCREASED CIRRUS BY LATE
OVERNIGHT AS WELL. GOING CLOSE TO GUIDANCE NUMBERS FOR LOWS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CST SUN DEC 15 2013
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM PERIOD LIE WITH A
CHANGE IN TEMPERATURES LATE IN THE WEEK...AND PRECIPITATION CHANCES.
THERE REALLY HASNT BEEN ANY SIGNIFICANT CHANGES IN THE MODELS
THROUGH THE PERIOD...SHOWING IT STARTING OUT MONDAY MORNING WITH
NORTHWESTERLY FLOW CONTINUING IN THE UPPER LEVELS...SET UP BETWEEN
AN AREA OF LOW PRESSURE OVER THE NERN CONUS...AND A RIDGE AXIS
EXTENDING ALONG WRN PORTIONS OF MEXICO UP INTO THE WEST COAST OF THE
CONUS. AT THE SURFACE...EXPECTING THE CWA TO BE BETWEEN HIGH
PRESSURE OVER THE SRN PLAINS AND LOW PRESSURE OVER CENTRAL
CANADA...WITH A WEAK FRONTAL BOUNDARY SLIDING TO THE EAST...BUT
HAVING LITTLE IMPACT. NOT EXPECTING A LOT OF CHANGE IN THE OVERALL
PATTERN MON/TUESDAY...THE FORECAST REMAINS DRY WITH ANY NOTABLE
DISTURBANCES REMAINING TO THE NORTH...AND ABOVE AVERAGE TEMPS ALSO
REMAIN. WINDS THROUGH BOTH DAYS WILL HAVE THE DOWNSLOPING W/NWRLY
WINDS...AIDING IN THE MILD TEMPS. FORECAST HIGHS ON MONDAY ARE IN
THE MID 40S/MID 50S...BUT MONDAY NIGHT/TUESDAY...MODELS ARE SHOWING
A STRONGER DISTURBANCE SLIDING SOUTHEAST INTO THE GREAT LAKES
REGION...WHICH MAY USHER IN SOME SLIGHTLY COOLER AIR AIR...BUT HIGHS
ON TUESDAY ARE JUST A COUPLE DEGREES COOLER.
AS WE GET INTO TUESDAY NIGHT AND WEDNESDAY...LITTLE HAS CHANGED WITH
THE STORY SHOWING THE UPPER LEVEL PATTERN BECOMING MORE ZONAL IN
NATURE...AS A DISTURBANCE BEGINS TO MOVE ONTO THE PAC NW/WEST
COAST. STARTING TO SEE SOME DIFFERENCES BETWEEN MODELS ARISE...WITH
THE SFC PATTERN/WINDS AND THE MAGNITUDE OF WARM AIR ALOFT. CURRENT
HAVE HIGHS ON WED NOT SIGNIFICANTLY DIFFERENT THAN MON/TUES...BUT
CONFIDENCE IS NOT HIGH...AS THE POTENTIAL FOR INCREASING UPPER LEVEL
CLOUDS WILL BE A CONCERN.
CERTAINLY THE MORE INTERESTING TIME FRAME OF THE LONG TERM LIES
THURSDAY THROUGH SATURDAY...WITH IT STILL LOOKING TO BRING AN END TO
THE ABOVE AVERAGE TEMPS. BY 12Z THURSDAY...EXPECTING TO SEE A
TROUGH AXIS EXTENDING FROM NRN CANADA SW TOWARD THE WEST
COAST...WITH MORE SOUTHWESTERLY FLOW IN PLACE ACROSS THE PLAINS. BY
THE END OF THE DAY...MODELS SHOW THIS TROUGH DIGGING SOUTH TOWARD
THE SRN HALF OF CA...BECOMING CLOSED OFF...WITH THE WEAKER NRN
ENERGY EXPECTED TO GRADUALLY CONTINUE WORKING EAST. THE TIMING OF
THE ACCOMPANYING COLD FRONT...AND WHETHER THERE WILL BE ANY
PRECIP...ARE THE MAIN CONCERNS FOR THURSDAY. WILL CONTINUE TO KEEP
THE FORECAST DRY...BUT PRECIP MAY NOT BE FAR OUTSIDE THE NRN AND ERN
PORTIONS OF THE CWA. COOLED HIGHS A BIT FOR THURSDAY INTO THE LOWER
30S NORTH TO LOWER/MID 40S SOUTH...STILL SOME TIMING DIFFERENCES OF
THE COLDER AIR WORKING IN...BUT LATEST MODELS HAVE TRENDED QUICKER.
THURSDAY NIGHT AND FRIDAY...CONFIDENCE IN POPS IS NOT HIGH...AND
THEY REMAIN LOW. THE MAIN UPPER LEVEL LOW CONTINUES ITS SWING
SOUTH...BY 12Z LOOKS TO BE OVER THE NRN BAJA OF MEX...WHILE THE NRN
ENERGY HAS SHIFTED FURTHER EAST...AND THE LATEST EC/GFS/GEM ARE ALL
SHOWING THE CWA GETTING NO MORE THAN A GLANCING BLOW OF SOME LIGHT
SNOW...SET UP IN BETWEEN THE TWO MAIN DISTURBANCES. AT THIS POINT
FRIDAY CONTINUES TO LOOK LIKE THE COLDEST DAY OF THE FORECAST
PERIOD...AS THE COLDER AIR MASS/CENTER OF HIGH PRESSURE SETTLES IN
OVER THE REGION BEHIND THE FRONT...AND FORECAST HIGHS REMAIN IN THE
TEENS TO MID 20S.
FRIDAY NIGHT AND SATURDAY...THE MAIN CHANGE WAS TO REMOVE POPS
FRIDAY NIGHT...SOMETHING THAT MAY NEED TO BE CONSIDERED FOR SATURDAY
AS WELL...BUT AT THIS POINT KEPT SOME LOW POPS IN. THE SPREAD
BETWEEN MODELS WITH THE EVOLUTION OF THAT UPPER LEVEL LOW TO THE SW
IS SIZABLE...WITH THE GFS KEEPING IT CLOSED OFF AND WELL TO THE
SOUTH...SUGGESTING SAT WOULD BE DRY. THE ECMWF FILLS THE
LOW...BECOMING AN OPEN WAVE AND SLIDING PRIMARILY ACROSS THE SRN
PLAINS...BUT PERHAPS CLIPPING THE SERN CORNER OF THE CWA WITH SOME
PRECIP. TEMPS FOR SAT DO LOOK TO REBOUND A BIT AS THE COLDER AIR
MASS STARTS TO SLIDE EAST...BUT STILL LOOKING AT JUST MID/UPPER 20S.
PLENTY OF THINGS MAY SHIFT BETWEEN NOW AND THEN.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1123 AM CST SUN DEC 15 2013
CONFIDENCE IS QUITE HIGH IN VFR CEILING/VISIBILITY THROUGH THE
PERIOD...AS DESPITE PLENTY OF CLOUD COVER AT TIMES...ANY CEILING
IS EXPECTED TO REMAIN NEAR/ABOVE 10KT FT. SURFACE WIND
SPEED/DIRECTION WILL REMAIN FAIRLY CONSISTENT THROUGH THE PERIOD
AS WELL...GENERALLY FROM THE WEST TO WEST-NORTHWEST...SUSTAINED AT
SPEEDS NEAR/BELOW 12KT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1245 PM EST SUN DEC 15 2013
.SYNOPSIS...HIGH PRESSURE BUILDS OVER THE REGION INTO MONDAY. A
COLD FRONT MOVES THROUGH THE REGION TUESDAY. HIGH PRESSURE RETURNS
FOR WEDNESDAY AND THURSDAY ALONG WITH A WARMING TREND.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 940 AM SUNDAY...
CLOUDS HAVE BEEN A LITTLE SLOW TO ERODE THIS MORNING...WITH THE
LATEST SATELLITE IMAGES SHOWING CLEARING BEGINNING ALONG AND WEST OF
U.S. 1...AND ONLY A FEW THIN PATCHES TO THE EAST OF THERE. THE 06Z
GFS WAS LIKELY A LITTLE TOO AGGRESSIVE WITH DRYING AND CLEARING ON
ITS MODEL SOUNDINGS...AND THE LATEST RAP IN COMBINATION WITH THE
HRRR WRF AND THE LAV SEEMS TO BE DOING FAIRLY WELL WITH THE TREND OF
THE CLEARING. WITH THE FAST SOUTHWEST FLOW ALOFT DELAYING THE MID-
LEVEL DRYING AND BETTER MIXING AS THE 850MB FRONT PASSES...IT MAY BE
EARLY AFTERNOON BEFORE BETTER SUNSHINE STARTS TO BE NOTED TOWARD THE
FAR SOUTHEAST AREAS PARTICULARLY TOWARD KCTZ. EVEN WITH THE DELAY IN
CLEARING...THOUGH...WITH TEMPERATURES IN THE FAR SOUTHEAST ALREADY
CLOSE TO 50 DEGREES IT SHOULD NOT TAKE MUCH SUNSHINE TO REALIZE
FORECAST MAXIMUMS. THERE SHOULD BE A FEW WIND GUSTS OF 20 TO 25 MPH
ESPECIALLY AS MIXING DEVELOPS IN THE NORTHWEST PIEDMONT...LESSER
GUSTS FARTHER SOUTHEAST DUE TO LATER ARRIVAL OF CLEARING AND THE
TIMING OF DIMINISHING 925MB WINDS...TO 15 TO 20KT BY EARLY
AFTERNOON. -DJF
FOR TONIGHT...AS THE MID LEVEL TROUGH AXIS MOVES TO OUR EAST...A
PORTION OF THE SURFACE HIGH NOSES IN FROM THE SW...ENSURING
CONTINUED DRY AND STABLE LOW LEVELS...WHILE SUBSIDENCE CONTINUES
ALOFT. THESE LIGHT SURFACE WINDS ALONG WITH MOSTLY CLEAR SKIES AND
COLD AIR ADVECTION WILL FACILITATE RADIATIONAL COOLING. LOWS 26-32.
-GIH
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 250 AM SUNDAY...
EXPECT DRY AND GENERALLY QUIET WEATHER... ALTHOUGH IT MAY NOT BE
QUITE AS SUN-FILLED AS ONCE THOUGHT ACROSS NRN NC. A WEAK MID LEVEL
WAVE NOW OVER ALBERTA/MT WILL DIVE SE THEN EAST ACROSS THE
MIDATLANTIC/NC MONDAY... WITH A 100+ KT UPPER JET STREAKING INTO THE
REGION. MODEL FORECAST SOUNDINGS SHOW A SOMEWHAT MOIST LAYER BETWEEN
800 MB AND 600 MB OVER THE NRN HALF OF THE CWA... ANDHIGH PRESSURE
BUILDS OVER THE REGION TODAY INTO MONDAY. A MOSTLY DRY COLD FRONT
MOVES THROUGH THE REGION TUESDAY. HIGH PRESSURE RETURNS FOR
WEDNESDAY AND THURSDAY ALONG WITH A WARMING TREND. GIVEN THAT THE
EXPECTED VERTICAL THERMAL AND MOISTURE STRUCTURE WILL BE SUPPORTIVE
OF OROGRAPHIC ENHANCEMENT OF MID-HIGH CLOUDS IN THIS AREA... WILL
HAVE A FORECAST OF SKIES BECOMING PARTLY CLOUDY ROUGHLY ALONG/NORTH
OF HIGHWAY 64 FOR THE AFTERNOON THROUGH MID EVENING... FOLLOWED BY
CLEARING OVERNIGHT AS THE VORTICITY MAX MOVES TO OUR EAST.
THICKNESSES WILL BE ABOUT 15-20 M BELOW NORMAL... SUGGESTING HIGHS
FROM 47 NORTH TO 53 SOUTH WHEN FACTORING IN THE CLOUDS OVER THE
NORTH. LOWS 28-35 WITH SKIES BECOMING MOSTLY CLEAR. -GIH
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 320 AM SUNDAY...
TUESDAY-WEDNESDAY NIGHT: DRY CONDITIONS AND NEAR NORMAL TEMPS.
EXPECT SOME DEGREE OF WARMING ON TUE (HIGHS MID/UPPER 50S) VIA
SOUTHWEST LOW-LEVEL FLOW AND WARM ADVECTION ASSOC/W A TIGHTENING
MSLP/HEIGHT GRADIENT IN ADVANCE OF A POTENT SHORTWAVE AND ATTENDANT
CLIPPER LOW DIGGING INTO THE GREAT LAKES. THE AFOREMENTIONED
SHORTWAVE ENERGY WILL PROGRESS INTO THE NORTHERN MID-ATLANTIC AND
NEW ENGLAND TUE NIGHT BEFORE MOVING OFFSHORE EARLY WED. THE
GFS/ECMWF GUIDANCE ARE ROUGHLY IN GOOD AGREEMENT ON THE EVOLUTION OF
THE AFOREMENTIONED SHORTWAVE ENERGY/CLIPPER SYSTEM...INDICATING A
WEAK/DRY COLD FRONTAL PASSAGE TUE EVE/NIGHT FOLLOWED BY WEAK HIGH
PRESSURE BUILDING INTO THE REGION ON WED. EXPECT LOWS IN THE LOWER
TO MID 30S WED MORNING (COOLEST N/NW)...WITH HIGHS ON WED SEVERAL
DEGREES COOLER THAN TUE IN THE LOWER 50S FAR NORTH TO MID/UPPER 50S
FAR SOUTH. WITH CLEAR SKIES...LIGHT/CALM WINDS AND A DRY AIRMASS IN
PLACE...EXPECT GOOD RADIATIONAL COOLING WITH LOWS IN THE UPPER 20S
TO LOWER 30S WED NIGHT.
THURSDAY-FRIDAY...EXPECT A WARMING TREND WITH INCREASING CLOUD
COVER. SHORTWAVE ENERGY IS EXPECTED TO DIG SOUTHEAST THROUGH THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST THU/THU NIGHT... WITH AN
ATTENDANT SFC LOW TRACKING NE FROM THE CENTRAL PLAINS TO THE GREAT
LAKES AND AN ASSOCIATED COLD FRONT PROGRESSING EAST ACROSS THE MS
RIVER VALLEY. HIGH PRESSURE WILL MOVE OFFSHORE THE CAROLINA COAST IN
ADVANCE OF THE AFOREMENTIONED FRONT ON THU...RESULTING IN THE ONSET
OF SOUTHERLY RETURN FLOW /WARM ADVECTION/. WARM ADVECTION AND LOW-
LEVEL MOISTURE TRANSPORT WILL STRENGTHEN ON FRIDAY AS THE
AFOREMENTIONED FRONT PROGRESSES INTO THE TN/OH VALLEY AND THE
MSLP/HEIGHT GRADIENT TIGHTENS OVER THE CAROLINAS. EXPECT HIGHS IN
THE UPPER 50S TO NEAR 60F (S) ON THU...AND IN THE MID/UPPER 60S TO
NEAR 70F ON FRIDAY DEPENDING ON CLOUD COVER...WARMEST S/SE. THOUGH
LOW-LEVEL WARM ADVECTION (ALONE OR) IN THE PRESENCE OF ANY SMALL
AMPLITUDE DISTURBANCES IN WSW FLOW ALOFT COULD CONCEIVABLY RESULT IN
A LOW CHANCE FOR SPRINKLES OR LIGHT RAIN THU NIGHT/FRI MORNING...
WILL KEEP THE FCST DRY AT THIS TIME.
FRIDAY NIGHT-SATURDAY: UNCERTAINTY IN THE FORECAST INCREASES
DRAMATICALLY THIS WEEKEND WITH REGARD TO THE EVOLUTION OF A COMPLEX
UPPER LEVEL PATTERN CHARACTERIZED BY SPLIT FLOW. REGARDLESS...THE
OVERALL PATTERN WOULD SUGGEST AN ABOVE AVERAGE CHANCE FOR RAIN
ASSOC/W AN INCREASINGLY WARM/MOIST AIRMASS AND THE FRONTAL ZONE
APPROACHING FROM THE WEST. WILL INDICATE MOSTLY CLOUDY/OVERCAST
SKIES AND A 30% CHANCE OF RAIN ON SAT/SUN. -VINCENT
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 1245 PM SUNDAY...
VFR CONDITIONS ARE ANTICIPATED THROUGH THE 18Z VALID TAF PERIOD.
AFTER THE RAIN OF SATURDAY INTO SATURDAY NIGHT...SOME CONCERN ABOUT
THE POTENTIAL FOR MVFR FOG GIVEN THE LOW-LEVEL MOISTURE AND THE SLOW-
TO-FALL DEW POINTS DURING THE DAY ESPECIALLY TOWARD KFAY AND KRWI.
HOWEVER...THE SREF PROBABILITIES OF NEAR IFR VISIBILITIES BARELY
REGISTER...AND IT WOULD APPEAR DRIER AIR IS ON ITS WAY WITH DEW
POINTS FALLING OVER THE NORTHWEST PIEDMONT. LEFT ANY MVFR
VISIBILITIES OUT OF THE TAF FOR THE 18Z ISSUANCE...THINKING MOISTURE
WITH FALLING DEW POINTS MAY TRANSLATE MORE INTO DEW/FROST ON THE
GRASSY SURFACES AS OPPOSED TO LIGHT FOG. WINDS GRADUALLY BACK DURING
MONDAY MORNING UNDER 10KT...WITH A FEW MID-LEVEL CLOUDS MOVING INTO
THE NORTHWEST PIEDMONT THEN.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS ARE EXPECTED
THROUGH THE MIDDLE OF THE WEEK. LATE IN THE WEEK...AS THE SOUTHERLY
FLOW INCREASES OVER THE SOUTHEAST STATES...THE BOUNDARY LAYER
MOISTURE SHOULD GRADUALLY INCREASE. THIS COULD HELP LEAD TO SOME
LATE NIGHT AND EARLY MORNING LOW CLOUDS POSSIBLY AS EARLY AS
FRIDAY...MAYBE MORE LIKELY JUST BEYOND THIS DISCUSSION PERIOD INTO
SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...VINCENT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
546 PM EST SUN DEC 15 2013
.SYNOPSIS...
A CHILLY...AND GUSTY WESTERLY FLOW WILL KEEP PLENTY OF CLOUDS ACROSS
MUCH OF CENTRAL AND NORTHERN PENNSYLVANIA THIS AFTERNOON...WITH
OCCASIONAL LIGHT SNOW SHOWERS CONTINUING ACROSS THE NORTHERN AND
WESTERN MOUNTAINS. A DISTURBANCE AT UPPER LEVEL WILL MOVE SOUTHEAST
ACROSS THE GREAT LAKES TONIGHT INTO MONDAY BRINGING SOME LOCALIZED
LAKE EFFECT SNOWS TO THE SNOWBELT OF NORTHWESTERN PA. A STRONGER
DISTURBANCE WILL TRACK ACROSS THE LATE MONDAY NIGHT AND TUESDAY
BRINGING A WIDESPREAD LIGHT SNOWFALL TO AT LEAST CENTRAL AND
NORTHERN PENNSYLVANIA. HEIGHTS RISE THURSDAY INTO EARLY SATURDAY AND
THERE SHOULD BE A PERIOD OF RELATIVELY WARM WEATHER LATER THIS WEEK.
AFTER THAT...A DEVELOPING TROUGH SHOULD BRING A PERIOD OF RAIN OR
MIXED PRECIPITATION LATE NEXT WEEKEND INTO EARLY THE FOLLOWING
WEEK...FOLLOWED BY ANOTHER PUSH COLD AIR
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A WELL-DEFINED UPPER LEVEL SHORTWAVE WAS LOCATED OVER THE U.P.
OF MICHIGAN...AND HEADED SE. 1004MB SFC LOW OVER NRN LAKE HURON HAS
A SWD TRAILING COLD FRONT. THE SFC FLOW WILL BACK PERHAPS ANOTHER
10-20 DEG /TO THE WSW/ LATE TDY AND THIS EVENING AHEAD OF THE
CFRONT. MDTLY STRONG WESTERLY FLOW AND WEAK ISENTROPIC LIFT /FOCUSED
IN THE 275-285K THETA LAYER/ AHEAD OF THESE FEATURES WILL HELP TO
MAINTAIN A SEVERAL DEG C INVERSION BETWEEN 4-7 KFT AGL...RESULTING
IN EXTENSIVE/WIDESPREAD THICK STRATOCU ACROSS MOST OF THE REGION
/EXCEPT FOR THE LOWER SUSQ VALLEY WHERE SOME FLEETING BREAKS OF SUN
WILL OCCUR LATE THIS AFTERNOON/.
THE FAIRLY STEADY LIGHT SNOW THAT/S BEEN PREVALENT TODAY ACROSS THE
NRN AND WRN MTNS OF THE STATE SHOULD AMOUNT TO BETWEEN A COATING AND
1.5 INCHES WITH SFC VSBYS MAINLY IN THE 1-2SM RANGE NEAR AND JUST TO
THE EAST OF THE ROUTE 219 CORRIDOR FROM KBFD TO KJST. OCCASIONAL
VERY LIGHT SNOW WITH VSBYS OF 4-5SM WILL CONTINUE SPILL OVER INTO
THE CENTRAL RIDGE AND VALLEY REGION AS THIS AREA OF WEAK ISENTROPIC
LIFT SPREADS EWD...BRINGING A DUSTING OF SNOW TO SOME AREAS.
THE COLD AIR MOVING OVER THE LAKES BEHIND THIS FRONT AND A
WELL-ALIGNED 270-280 DEG BLYR FLOW WILL KICK OFF LAKE EFFECT SNOW
SHOWERS AND A FEW LOCALIZED HEAVY SNOW BANDS /FIRST ALONG THE I-90
CORRIDOR...THEN SHIFTING SLOWLY SEWRD LATE TODAY AND TONIGHT/. THE
HIGH RESOLUTION RAP AND 4KM NAM/ARW EACH SHOW THIS EVOLUTION LATER
THIS AFTERNOON AND OVERNIGHT.
MID TO LATE AFTERNOON TEMPS WILL VARY FROM MAINLY THE MID 20S ACROSS
THE MTNS TO THE MID 30S THROUGHOUT THE MIDDLE AND LOWER SUSQ VALLEY.
LAKE EFFECT AND COLD WILL BE THE TWO PRIMARY FORECAST ISSUES WITH A
BRISK WEST TO NORTHWEST WIND IN THE MORNING.
THE HIGH RESOLUTION MODELS IMPLY A SINGLE LAKE SHORE PARALLEL SNOW
BAND WHICH SHOULD BECOME MORE EAST-WEST WITH TIME THIS EVENING AS IT
DRIFTS INTO WARREN COUNTY AND LIKELY THE NW HALF MCKEAN COUNTY A FEW
HOURS AFTERWARD.
EXPANDED THE WINTER WEATHER ADVISORY TO MCKEAN COUNTY FOR LATE THIS
EVENING THROUGH 15Z MONDAY...AS THE MODERATELY STRONG MEAN BLYR FLOW
VEERS ABOUT 20-30 DEG...BACK TO A 270-280 DIRECTION. THIS TYPE OF
STEADY STATE WNW FLOW TYPICALLY SUPPORTS A LONGER DURATION/SINGLE
LES BAND THAT CAN PENETRATE FAIRLY FAR INLAND. A LIGHT COATING OF
SNOW IS POSSIBLE LATER TONIGHT AND MONDAY MORNING IN THE KIPT AREA
WITH SOME PTS TO THE NORTH AND EAST SEEING A QUICK HALF INCH TO
ONE-INCH.
THE FCST SNOW AMOUNTS EMPLOY A BLEND OF HIGH RESOLUTION MODELS AND
ANTICIPATED SNOWFALL RATES AND RESIDENCE TIME OF THE SNOWBANDS USING
MEAN SFC-875MB WIND OFF THE RAP AND NAM BUFKIT PROFILES.
MEAN SNOWFALL FOR WARREN CTY IS IN THE 3-6 INCH RANGE...WHILE 2-4
INCHES IS LIKELY ACROSS THE NW HALF OF MCKEAN COUNTY/.
THE NAM IMPLIES AN EXTENSIVE QUASI-SINGLE BAND STRUCTURE PENETRATING
FAR INLAND ACROSS THE NRN TIER COUNTIES...AND PERHAPS THROUGH
SULLIVAN CTY ON TWD THE POCONOS.
THIS SIMULATION AND THE RAP MAKE IT CLEAR BOTH FORECAST SYSTEMS
THINK THERE SHOULD BE A GOOD LES BAND IN SOUTHERN NY AND NW PA
OVERNIGHT TONIGHT.
OUTSIDE THE LES AND UPSLOPE SNOW AREAS...IT WILL BE A VERY COLD
EVENING AND OVERNIGHT WITH GUSTY WINDS...TO AROUND 30 MPH AT TIMES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
WEAK RIDGING SLIDES OVER THE AREA BENEATH THE FAST WESTERLY FLOW
ALOFT. LAKE EFFECT SNOW SHOWERS WILL DECREASE IN INTENSITY AND
BECOME MORE MULTI-BANDED ACROSS THE NW MTNS IN THE MORNING...BEFORE
LIFTING NORTH AND DIMINISHING DURING THE AFTERNOON.
IT/LL BE QUITE COLD MONDAY WITH MAX TEMPS ONLY IN THE UPPER TEENS TO
LOWER 20S ACROSS THE MTNS...AND MID TO UPPER 20S IN THE SUSQ VALLEY.
THESE TEMPS WILL BE ABOUT 15F BELOW NORMAL.
SIGNIFICANT BREAKS IN THE STRATO CU WILL DEVELOP ACROSS THE CENTRAL
AND SE ZONES MONDAY WHILE SKY COVER STAYS BKN-OVC ACROSS THE LAURELS
AND NW MTNS DUE TO LLVL UPSLOPE FLOW AND THICKER MID/HIGH CLOUDS
SPREADING IN LATE AHEAD OF A POTENT CLIPPER.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE GEFS-CMCEPS-SREF ALL SHOWS A CLIPPER PASSING TO OUR NORTH
TUESDAY. TIMING VARIES AND TRACK IS TO OUR NORTH THUS ANY
PRECIPITATION SHOULD BE LIGHT. TRIED TO SHOW THE POTENTIAL FOR
LIGHT SNOW TUESDAY. KEPT SNOW GENERALLY LOWER THAN 1 INCH AND
MAINLY CENTRAL AND NORTHERN AREAS.
THE NW FLOW WEAKENS AS A 500 HPA LOW DEVELOPS IN SW US LATER IN
THE WEEK. THIS ALLOWS FOR SOUTHWESTERLY FLOW AND A GRADUAL WARM UP
LIKELY THURSDAY INTO FRIDAY. MODELS IMPLY WARMEST DAY WOULD BE
FRIDAY. THIS WILL NOT LAST AS MODELS SHOWS DEEPENING TROUGH TO OUR
NORTH AND WEST AND A POOL OF ARCTIC AIR MOVING INTO THE LAKES
FRIDAY INTO SATURDAY. THUS SURFACE COLD FRONT SHOULD PUSH COLD AIR
BACK INTO OUR REGION SOMETIME NEXT WEEKEND.
BIAS CORRECT GEFS AND NAEFS SUGGEST TROUGH AND GENERALLY COLD
WEATHER SETTLE BACK IN THIS COMING WEEKEND AND INTO THE CHRISTMAS
WEEK.
AT THIS TIME NO BIG STORMS IN THE ENSEMBLES.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
15/21Z...A FAST AND PERSISTENT WEST-NORTHWEST FLOW ALOFT WITH
A SERIES OF EMBEDDED CLIPPER SYSTEMS WILL RESULT IN WIDESPREAD
MVFR CIGS AND MVFR-IFR VISBYS AT BFD/JST...WITH OCNL MVFR-IFR
CONDS FURTHER EAST ACRS THE CENTRAL AND EASTERN AIRFIELDS. MUCH
OF THE AIRSPACE COULD SEE -SN AND ASSOCD MVFR TO IFR VIS MON NGT-
TUE NGT. IMPROVING CONDS SHOULD ARRIVE LATER WED INTO THUR AS HIGH
PRESSURE EXPANDS OVER THE REGION. ANOTHER FRONTAL SYSTEM SHOULD
ARRIVE BY FRIDAY WITH TEMPERATURES INITIALLY WARM ENOUGH FOR
RAIN.
OUTLOOK...
MON...MAINLY VFR CENTRAL/EAST. MVFR-IFR IN SHSN AT BFD/JST.
MON NITE-TUE NGT...WDSPRD LGT SNOW/REDUCED VSBYS POSSIBLE.
WED-THU...SHSN/REDUCED VSBYS WEST BCMG VFR. VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
MONDAY FOR PAZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR PAZ004.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...GRUMM/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
255 PM EST SUN DEC 15 2013
.SYNOPSIS...
A CHILLY...AND GUSTY WESTERLY FLOW WILL KEEP PLENTY OF CLOUDS ACROSS
MUCH OF CENTRAL AND NORTHERN PENNSYLVANIA THIS AFTERNOON...WITH
OCCASIONAL LIGHT SNOW SHOWERS CONTINUING ACROSS THE NORTHERN AND
WESTERN MOUNTAINS. A DISTURBANCE AT UPPER LEVEL WILL MOVE SOUTHEAST
ACROSS THE GREAT LAKES TONIGHT INTO MONDAY BRINGING SOME LOCALIZED
LAKE EFFECT SNOWS TO THE SNOWBELT OF NORTHWESTERN PA. A STRONGER
DISTURBANCE WILL TRACK ACROSS THE LATE MONDAY NIGHT AND TUESDAY
BRINGING A WIDESPREAD LIGHT SNOWFALL TO AT LEAST CENTRAL AND
NORTHERN PENNSYLVANIA. HEIGHTS RISE THURSDAY INTO EARLY SATURDAY AND
THERE SHOULD BE A PERIOD OF RELATIVELY WARM WEATHER LATER THIS WEEK.
AFTER THAT...A DEVELOPING TROUGH SHOULD BRING A PERIOD OF RAIN OR
MIXED PRECIPITATION LATE NEXT WEEKEND INTO EARLY THE FOLLOWING
WEEK...FOLLOWED BY ANOTHER PUSH COLD AIR
&&
.NEAR TERM /THROUGH TONIGHT/...
A WELL-DEFINED UPPER LEVEL SHORTWAVE WAS LOCATED OVER THE U.P.
OF MICHIGAN...AND HEADED SE. 1004MB SFC LOW OVER NRN LAKE HURON HAS
A SWD TRAILING COLD FRONT. THE SFC FLOW WILL BACK PERHAPS ANOTHER
10-20 DEG /TO THE WSW/ LATE TDY AND THIS EVENING AHEAD OF THE
CFRONT. MDTLY STRONG WESTERLY FLOW AND WEAK ISENTROPIC LIFT /FOCUSED
IN THE 275-285K THETA LAYER/ AHEAD OF THESE FEATURES WILL HELP TO
MAINTAIN A SEVERAL DEG C INVERSION BETWEEN 4-7 KFT AGL...RESULTING
IN EXTENSIVE/WIDESPREAD THICK STRATOCU ACROSS MOST OF THE REGION
/EXCEPT FOR THE LOWER SUSQ VALLEY WHERE SOME FLEETING BREAKS OF SUN
WILL OCCUR LATE THIS AFTERNOON/.
THE FAIRLY STEADY LIGHT SNOW THAT/S BEEN PREVALENT TODAY ACROSS THE
NRN AND WRN MTNS OF THE STATE SHOULD AMOUNT TO BETWEEN A COATING AND
1.5 INCHES WITH SFC VSBYS MAINLY IN THE 1-2SM RANGE NEAR AND JUST TO
THE EAST OF THE ROUTE 219 CORRIDOR FROM KBFD TO KJST. OCCASIONAL
VERY LIGHT SNOW WITH VSBYS OF 4-5SM WILL CONTINUE SPILL OVER INTO
THE CENTRAL RIDGE AND VALLEY REGION AS THIS AREA OF WEAK ISENTROPIC
LIFT SPREADS EWD...BRINGING A DUSTING OF SNOW TO SOME AREAS.
THE COLD AIR MOVING OVER THE LAKES BEHIND THIS FRONT AND A
WELL-ALIGNED 270-280 DEG BLYR FLOW WILL KICK OFF LAKE EFFECT SNOW
SHOWERS AND A FEW LOCALIZED HEAVY SNOW BANDS /FIRST ALONG THE I-90
CORRIDOR...THEN SHIFTING SLOWLY SEWRD LATE TODAY AND TONIGHT/. THE
HIGH RESOLUTION RAP AND 4KM NAM/ARW EACH SHOW THIS EVOLUTION LATER
THIS AFTERNOON AND OVERNIGHT.
MID TO LATE AFTERNOON TEMPS WILL VARY FROM MAINLY THE MID 20S ACROSS
THE MTNS TO THE MID 30S THROUGHOUT THE MIDDLE AND LOWER SUSQ VALLEY.
LAKE EFFECT AND COLD WILL BE THE TWO PRIMARY FORECAST ISSUES WITH A
BRISK WEST TO NORTHWEST WIND IN THE MORNING.
THE HIGH RESOLUTION MODELS IMPLY A SINGLE LAKE SHORE PARALLEL SNOW
BAND WHICH SHOULD BECOME MORE EAST-WEST WITH TIME THIS EVENING AS IT
DRIFTS INTO WARREN COUNTY AND LIKELY THE NW HALF MCKEAN COUNTY A FEW
HOURS AFTERWARD.
EXPANDED THE WINTER WEATHER ADVISORY TO MCKEAN COUNTY FOR LATE THIS
EVENING THROUGH 15Z MONDAY...AS THE MODERATELY STRONG MEAN BLYR FLOW
VEERS ABOUT 20-30 DEG...BACK TO A 270-280 DIRECTION. THIS TYPE OF
STEADY STATE WNW FLOW TYPICALLY SUPPORTS A LONGER DURATION/SINGLE
LES BAND THAT CAN PENETRATE FAIRLY FAR INLAND. A LIGHT COATING OF
SNOW IS POSSIBLE LATER TONIGHT AND MONDAY MORNING IN THE KIPT AREA
WITH SOME PTS TO THE NORTH AND EAST SEEING A QUICK HALF INCH TO
ONE-INCH.
THE FCST SNOW AMOUNTS EMPLOY A BLEND OF HIGH RESOLUTION MODELS AND
ANTICIPATED SNOWFALL RATES AND RESIDENCE TIME OF THE SNOWBANDS USING
MEAN SFC-875MB WIND OFF THE RAP AND NAM BUFKIT PROFILES.
MEAN SNOWFALL FOR WARREN CTY IS IN THE 3-6 INCH RANGE...WHILE 2-4
INCHES IS LIKELY ACROSS THE NW HALF OF MCKEAN COUNTY/.
THE NAM IMPLIES AN EXTENSIVE QUASI-SINGLE BAND STRUCTURE PENETRATING
FAR INLAND ACROSS THE NRN TIER COUNTIES...AND PERHAPS THROUGH
SULLIVAN CTY ON TWD THE POCONOS.
THIS SIMULATION AND THE RAP MAKE IT CLEAR BOTH FORECAST SYSTEMS
THINK THERE SHOULD BE A GOOD LES BAND IN SOUTHERN NY AND NW PA
OVERNIGHT TONIGHT.
OUTSIDE THE LES AND UPSLOPE SNOW AREAS...IT WILL BE A VERY COLD
EVENING AND OVERNIGHT WITH GUSTY WINDS...TO AROUND 30 MPH AT TIMES.
&&
.SHORT TERM /MONDAY/...
WEAK RIDGING SLIDES OVER THE AREA BENEATH THE FAST WESTERLY FLOW
ALOFT. LAKE EFFECT SNOW SHOWERS WILL DECREASE IN INTENSITY AND
BECOME MORE MULTI-BANDED ACROSS THE NW MTNS IN THE MORNING...BEFORE
LIFTING NORTH AND DIMINISHING DURING THE AFTERNOON.
IT/LL BE QUITE COLD MONDAY WITH MAX TEMPS ONLY IN THE UPPER TEENS TO
LOWER 20S ACROSS THE MTNS...AND MID TO UPPER 20S IN THE SUSQ VALLEY.
THESE TEMPS WILL BE ABOUT 15F BELOW NORMAL.
SIGNIFICANT BREAKS IN THE STRATO CU WILL DEVELOP ACROSS THE CENTRAL
AND SE ZONES MONDAY WHILE SKY COVER STAYS BKN-OVC ACROSS THE LAURELS
AND NW MTNS DUE TO LLVL UPSLOPE FLOW AND THICKER MID/HIGH CLOUDS
SPREADING IN LATE AHEAD OF A POTENT CLIPPER.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE GEFS-CMCEPS-SREF ALL SHOWS A CLIPPER PASSING TO OUR NORTH
TUESDAY. TIMING VARIES AND TRACK IS TO OUR NORTH THUS ANY
PRECIPITATION SHOULD BE LIGHT. TRIED TO SHOW THE POTENTIAL FOR
LIGHT SNOW TUESDAY. KEPT SNOW GENERALLY LOWER THAN 1 INCH AND
MAINLY CENTRAL AND NORTHERN AREAS.
THE NW FLOW WEAKENS AS A 500 HPA LOW DEVELOPS IN SW US LATER IN
THE WEEK. THIS ALLOWS FOR SOUTHWESTERLY FLOW AND A GRADUAL WARM UP
LIKELY THURSDAY INTO FRIDAY. MODELS IMPLY WARMEST DAY WOULD BE
FRIDAY. THIS WILL NOT LAST AS MODELS SHOWS DEEPENING TROUGH TO OUR
NORTH AND WEST AND A POOL OF ARCTIC AIR MOVING INTO THE LAKES
FRIDAY INTO SATURDAY. THUS SURFACE COLD FRONT SHOULD PUSH COLD AIR
BACK INTO OUR REGION SOMETIME NEXT WEEKEND.
BIAS CORRECT GEFS AND NAEFS SUGGEST TROUGH AND GENERALLY COLD
WEATHER SETTLE BACK IN THIS COMING WEEKEND AND INTO THE CHRISTMAS
WEEK.
AT THIS TIME NO BIG STORMS IN THE ENSEMBLES.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
DEEP WESTERLY FLOW AND EXTENSIVE BUT GENERALLY VERY WEAK UPWARD
MOTION IN THE LOW-MID LEVELS WILL MAINTAIN WIDESPREAD MVFR TO OCNL
IFR CIGS AND VSBYS IN LIGHT SNOW ACROSS THE CENTRAL AND NW
MTNS.
MAINLY VFR BKN-OVC CIGS WILL CONTINUE THROUGHOUT THE LOWER SUSQ
VALLEY THIS AFTERNOON. THE WIND WILL BE THE MAIN STORY FOR MOST
CENTRAL AND WESTERN PENN AIRFIELDS TODAY. SUSTAINED 12-17KTS WITH
GUSTS INTO THE MID/UPPER 20KT RANGE. THE ELEVATION AT JST WILL KEEP
THEM ON THE HIGHER-END OF WIND SPEEDS TODAY. LAKE EFFECT SHSN GO
INTO HIGH GEAR LATER THIS EVENING...AND BFD COULD BE IN FOR A LONG
NIGHT OF IFR SNOW AND CIGS.
WINDS /AND GUSTS/ WILL BE SEVERAL TO 10KTS LOWER AT KIPT AND KMDT
BEFORE INCREASING BY LATE THIS EVENING AS THE LLVL PRESSURE GRADIENT
TIGHTENS UP.
FAST FLOW WILL BRING A SERIES OF NRN STREAM IMPULSES OVER THE NEXT
SEVERAL DAYS...AND HELP TO MAINTAIN FREQUENT SHSN FOR THE WRN
TERMINALS FOR THE BULK OF THE WEEK. THE STRONGEST CLIPPER WILL BE ON
MON PM-TUE AM...WITH A SEVERAL HOUR PERIOD OF MVFR TO OCNL IFR
POSSIBLE IN STEADY LIGHT 3/4-1 1/2SM SNOW AT MANY CENTRAL AND NRN
PA TAF SITES. SOMEWHAT WARMER AIR AN IMPROVING FLYING CONDITION
ATTEMPT TO RETURN FOR THURSDAY...BEFORE A FRONTAL BOUNDARY AND
DOWNTREND IMPLYING CONDITIONS OCCURS HEADING INTO NEXT WEEKEND.
OUTLOOK...
MON...MAINLY VFR WITH MVFR TO IFR IN SHSN AT BFD. MVFR ALSO LIKELY
AT KJST.
MON NITE-TUE...LGT SNOW/REDUCED VSBYS. POSSIBLE BRIEF PERIODS OF
MDTLY HEAVY SNOW/SQUALLS ACCOMPANIED BY LIFR-VLIFR.
WED-THU...SHSN/REDUCED VSBYS POSS NW MTNS. MAINLY VFR ELSEWHERE
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
MONDAY FOR PAZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST MONDAY FOR PAZ004.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...GRUMM/CERU
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1151 AM EST SUN DEC 15 2013
.SYNOPSIS...
A CHILLY...AND GUSTY WESTERLY FLOW WILL KEEP PLENTY OF CLOUDS ACROSS
MUCH OF CENTRAL AND NORTHERN PENNSYLVANIA THIS AFTERNOON...WITH
OCCASIONAL LIGHT SNOW SHOWERS CONTINUING ACROSS THE NORTHERN AND
WESTERN MOUNTAINS. A DISTURBANCE AT UPPER LEVEL WILL MOVE SOUTHEAST
ACROSS THE GREAT LAKES TONIGHT INTO MONDAY BRINGING SOME LOCALIZED
LAKE EFFECT SNOWS TO THE SNOWBELT OF NORTHWESTERN PA. A STRONGER
DISTURBANCE WILL TRACK ACROSS THE LATE MONDAY NIGHT AND TUESDAY
BRINGING A WIDESPREAD LIGHT SNOWFALL TO AT LEAST CENTRAL AND
NORTHERN PENNSYLVANIA. HEIGHTS RISE THURSDAY INTO EARLY SATURDAY AND
THERE SHOULD BE A PERIOD OF RELATIVELY WARM WEATHER LATER THIS WEEK.
AFTER THAT...A DEVELOPING TROUGH SHOULD BRING A PERIOD OF RAIN OR
MIXED PRECIPITATION LATE NEXT WEEKEND INTO EARLY THE FOLLOWING
WEEK...FOLLOWED BY ANOTHER PUSH COLD AIR
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASINGLY WEST TO NWRLY FLOW /IN THE WAKE OF THE DEPARTING STORM
THAT BROUGHT WIDESPREAD SNOW THEN SOME ICE SATURDAY AND SATURDAY
NIGHT/ WILL PREVAIL TODAY...LEADING TO PERSISTENT LIGHT SNOW OR SNOW
SHOWERS ACROSS THE WESTERN HIGH TERRAIN THROUGH TODAY.
THE MEAN LLVL FLOW WILL BACK BY ABOUT 20-30 DEGREES THIS AFTERNOON
WELL IN ADVANCE OF A SHORTWAVE HEADED SE FROM THE NRN GLAKES REGION.
THE WEAK WSW LLVL ISENTROPIC LIFT AHEAD OF THIS FEATURE WILL HELP TO
STRENGTHEN THE INVERSION BETWEEN 4-7 KFT AGL KEEPING
EXTENSIVE/WIDESPREAD THICK STRATOCU LOCKED IN ACROSS MOST OF THE
REGION /EXCEPT FOR THE LOWER SUSQ VALLEY WHERE AT LEAST PARTLY SUNNY
SKIES WILL OCCUR THIS AFTERNOON.
THE FAIRLY STEADY LIGHT SNOW TODAY ACROSS THE NRN AND WRN MTNS OF
THE STATE SHOULD AMOUNT TO BETWEEN A COATING AND 1.5 INCHES WITH SFC
VSBYS MAINLY IN THE 1-3SM RANGE NEAR AND JUST TO THE EAST OF THE
ROUTE 219 CORRIDOR FROM KBFD TO KJST. OCCASIONAL VERY LIGHT SNOW
WITH VSBYS OF 3-5SM WILL SPILL OVER INTO THE CENTRAL RIDGE AND
VALLEY REGION AS THIS AREA OF WEAK..ALBEIT DEEPENING ISENTROPIC LIFT
SPREADS EWD THIS AFTERNOON...BRINGING A GOOD DUSTING OF
SNOW.
THE COLD AIR MOVING OVER THE LAKES BEHIND THIS FRONT WILL KICK OFF
LAKE EFFECT SNOW SHOWERS AND SNOW BANDS /FIRST ALONG THE I-90
CORRIDOR...THEN SHIFTING SLOWLY SEWRD LATE TODAY AND TONIGHT/. THE
HIGH RESOLUTION RAP AND 4KM NAM/ARW EACH SHOW THIS EVOLUTION LATER
THIS AFTERNOON AND OVERNIGHT. BY LATE THIS AFTERNOON THE NAM IMPLIES
SOME LES SNOWBANDS AFFECTING NW WARREN COUNTY.
HIGH TEMPS TODAY WILL VARY FROM THE U20S ACROSS THE MTNS TO THE MID
30S IN THE SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE LES AND COLD ARE THE TWO FORECAST ISSUES.
THE HIGH RESOLUTION MODELS IMPLY A SINGLE WEST-EAST SNOW BAND WHICH
WILL DRIFT INTO WARREN COUNTY AND LIKELY THE NW HALF MCKEAN COUNTY.
EXPANDED THE WINTER WEATHER ADVISORY TO MCKEAN COUNTY FOR LATE THIS
EVENING THROUGH 15Z MONDAY...AS THE MODERATELY STRONG MEAN BLYR FLOW
VEERS ABOUT 20-30 DEG...BACK TO A 270-280 DIRECTION. THIS TYPE OF
STEADY STATE WNW FLOW TYPICALLY SUPPORTS A LONGER DURATION/SINGLE
LES BAND THAT CAN PENETRATE FAIRLY FAR INLAND. A LIGHT COATING OF
SNOW IS POSSIBLE LATER TONIGHT AND MONDAY MORNING IN THE KIPT
AREA.
THE SNOW AMOUNTS IN WARREN USING A BLEND OF HIGH RESOLUTION MODELS
WAS IN THE 3-6 INCH RANGE...WHILE 2-4 INCHES IS LIKELY ACROSS THE NW
HALF OF MCKEAN COUNTY/ THE SREF WAS A BIT MORE ROBUST WITH THE POPS
AND QPF AREA WHICH WAS TRIMMED BACK MORE LIKE THE 4KM NAM.
THE NAM IMPLIES THE LES BAND COULD DRIFT OVER NORTHERN WARREN
COUNTY THIS EVENING AND THROUGH ABOUT 4 AM. THIS SIMULATION AND
THE RAP MAKE IT CLEAR BOTH FORECAST SYSTEMS THINK THERE SHOULD BE A
GOOD LES BAND IN SOUTHERN NY AND NW PA OVERNIGHT TONIGHT.
OUTSIDE THE LES AND UPSLOPE SNOW AREAS...IT WILL BE A VERY COLD
EVENING AND OVERNIGHT WITH SLOWLY ABATING WINDS.
COLD MONDAY WITH RESIDUAL SNOWS MAINLY CONFINED TO NORTHWESTERNMOST
AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE GEFS-CMCEPS-SREF ALL SHOWS A CLIPPER PASSING TO OUR NORTH
TUESDAY. TIMING VARIES AND TRACK IS TO OUR NORTH THUS ANY
PRECIPITATION SHOULD BE LIGHT. TRIED TO SHOW THE POTENTIAL FOR
LIGHT SNOW TUESDAY. KEPT SNOW GENERALLY LOWER THAN 1 INCH AND
MAINLY CENTRAL AND NORTHERN AREAS.
THE NW FLOW WEAKENS AS A 500 HPA LOW DEVELOPS IN SW US LATER IN
THE WEEK. THIS ALLOWS FOR SOUTHWESTERLY FLOW AND A GRADUAL WARM UP
LIKELY THURSDAY INTO FRIDAY. MODELS IMPLY WARMEST DAY WOULD BE
FRIDAY. THIS WILL NOT LAST AS MODELS SHOWS DEEPENING TROUGH TO OUR
NORTH AND WEST AND A POOL OF ARCTIC AIR MOVING INTO THE LAKES
FRIDAY INTO SATURDAY. THUS SURFACE COLD FRONT SHOULD PUSH COLD AIR
BACK INTO OUR REGION SOMETIME NEXT WEEKEND.
BIAS CORRECT GEFS AND NAEFS SUGGEST TROUGH AND GENERALLY COLD
WEATHER SETTLE BACK IN THIS COMING WEEKEND AND INTO THE CHRISTMAS
WEEK.
AT THIS TIME NO BIG STORMS IN THE ENSEMBLES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
DEEP WESTERLY FLOW AND EXTENSIVE BUT GENERALLY VERY WEAK UPWARD
MOTION IN THE LOW-MID LEVELS WILL MAINTAIN WIDESPREAD MVFR TO OCNL
IFR CIGS AND VSBYS IN LIGHT SNOW ACROSS THE CENTRAL AND NW
MTNS.
MAINLY VFR BKN CIGS WILL CONTINUE THROUGHOUT THE LOWER SUSQ VALLEY
THIS AFTERNOON. THE WIND WILL BE THE MAIN STORY FOR MOST CENTRAL AND
SUSQ REGION AIRFIELDS TODAY. SUSTAINED 12-17KTS WITH GUSTS INTO THE
MID/UPPER 20KT RANGE. THE ELEVATION AT JST WILL KEEP THEM ON THE
HIGHER-END OF WIND SPEEDS TODAY. LAKE EFFECT SHSN GO INTO HIGH GEAR
LATER THIS EVENING...AND BFD COULD BE IN FOR A LONG NIGHT OF IFR
SNOW AND CIGS.
FAST FLOW WILL BRING AN ALMOST NEVER-ENDING TRAIN OF WEAK NRN
STREAM IMPULSES TO MAKE SHSN FOR THE WRN TERMINALS FOR THE BULK OF
THE WEEK. THE STRONGEST CLIPPER WILL BE ON MON PM-TUE AM...WITH A
SEVERAL HOUR PERIOD OF MVFR TO OCNL IFR POSSIBLE IN STEADY LIGHT
SNOW AT MANY CENTRAL AND NRN PA TAF SITES. WARMER AIR TRIES TO
RETURN BY FRI.
OUTLOOK...
MON...MAINLY VFR WITH MVFR TO IFR IN SHSN AT BFD. MVFR ALSO LIKELY
AT KJST.
MON NITE-TUE...LGT SNOW/REDUCED VSBYS.
WED-THU...SHSN/REDUCED VSBYS POSS NW MTNS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
MONDAY FOR PAZ005.
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST MONDAY FOR PAZ004.
&&
$$
SYNOPSIS...LAMBERT/GRUMM
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/DANGELO
LONG TERM...GRUMM
AVIATION...LAMBERT/DANGELO
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1144 AM CST SUN DEC 15 2013
.UPDATE...
BAND OF ISENTROPIC/WAA DRIVEN SNOW CONTINUES TO DEVELOP OVER THE
FORECAST AREA AS OF 10AM. RIGHT NOW THE MOST PERSISTENT SNOW IS
OCCURRING FROM JUST EAST OF MOBRIDGE AND FAULKTON...TO ABERDEEN
AND REDFIELD. VSBYS IN THIS BAND WILL LIKELY DROP TO BELOW ONE
MILE AT TIMES. DECENT AGREEMENT AMONGST THE HI-RES MODELS ON SHIFTING
THIS NW/SE BAND OF SNOW TO THE EAST THE REMAINDER OF THE
AFTERNOON. SNOW ACCUMULATION THROUGH EVENING IS STILL EXPECTED TO
BE AROUND 1 INCH ACROSS N-CENTRAL AND NERN SD AND WRN MN...WITH ISOLATED
AREAS PICKING UP AS MUCH AS 2 INCHES.
BIG CONTRAST IN TEMPERATURES ACROSS SOUTH DAKOTA. RAPID CITY AREA IS
CURRENTLY BASKING IN THE 40S...WITH AREAS IN THE EAST REMAINING
NEAR ZERO. WILL BE CHALLENGING TO DETERMINE JUST HOW FAR EAST THIS
WARMER AIRMASS WILL BE ABLE TO ADVECT TODAY. LATEST GUIDANCE HAS
IT PUSHING AS FAR EAST AS STANLEY/JONES/DEWEY COUNTIES BY
EVENING...WHICH SEEMS REASONABLE.
BIGGER PUSH OF WARM AIR WILL OCCUR TONIGHT...MORE ON THAT THIS
AFTERNOON. UPDATES ALREADY OUT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
LOCATION OF SHARP WARM FRONT A NO-BRAINER EARLY THIS MORNING AS IT
IS EASILY NOTICEABLE ON SFC OBS. FAITH AND PHILIP ARE 36 AND 37
DEGREES RESPECTIVELY WITH A NORTHWEST WIND...WHILE MOBRIDGE AND
PIERRE ARE STILL IN THE LOWER TEENS WITH A SOUTHEAST WIND. THIS
FRONT CONTINUES NORTHWEST INTO SOUTHWEST NORTH DAKOTA. AS
ADVERTISED...LIGHT SNOW IS ONGOING AHEAD OF THE FRONT WITHIN ZONE
OF LIFT AND FORCING...MAINLY FROM NORTHWEST NORTH DAKOTA AND JUST
NOW INTO NORTH CENTRAL SOUTH DAKOTA. MODELS SEEM TO BE A FEW HOURS
QUICKER WITH THE ONSET OF LIGHT SNOW SO HAVE MADE THE APPROPRIATE
ADJUSTMENTS IN WX/POP GRIDS. MODELS STILL IN RATHER GOOD AGREEMENT
AS WELL...BRINGING A SWATH OF LIGHT SNOW RIGHT DOWN THROUGH THE
NORTHEAST QUARTER OF SOUTH DAKOTA INTO WEST CENTRAL MINNESOTA. A
BIT HARDER TO NAIL DOWN WITH MORE SPECIFICITY THE ACTUAL AREA OF
SLIGHTLY ENHANCED SNOWFALL...BUT INDICATIONS IN MODELS ARE THAT IT
ACTUALLY MIGHT BE RIGHT DOWN THROUGH ABERDEEN TO NEAR
WATERTOWN...SO HAVE SLIGHTLY HIGHER SNOWFALL TOTALS IN THIS
AREA...AROUND AN INCH OR SLIGHTLY HIGHER. SOME OF THE HI RES
MODELS SHOWING THE SNOW MIGHT BE ENDING A BIT QUICKER AS
WELL...DUE TO THE EARLIER ONSET. LATEST RUN OF THE HRRR ACTUALLY
SHOWING MOST SNOW OUT OF THE AREA BY 20Z OR 21Z. A TREND TO WATCH
THROUGH THE DAY.
AFTER THE BULK OF THE SNOWFALL ENDS BY LATE AFTERNOON...ATTENTION
THEN TURNS TO THE EASTWARD PROGRESSION OF THE WARM FRONT AND
DETERMINING JUST HOW WARM TEMPS WILL GET ON MONDAY. MODELS DO NOT
SHOW MUCH MOVEMENT OF THE FRONT AT ALL TODAY...STILL HUNG UP NEAR
THE MISSOURI RIVER BY 00Z THIS EVENING. BUT OVERNIGHT...THERE IS
FINALLY A PUSH TO THE EAST WHICH SHOULD TAKE IT THROUGH MOST IF
NOT ALL THE CWA BY 12Z MONDAY MORNING. THUS...WILL SEE SLOWLY
RISING TEMPS THROUGH THE NIGHT FOR EASTERN AREAS AS THIS FRONT
MOVES THROUGH. DID NOT STRAY MUCH AT ALL FROM PREVIOUS FORECAST
FOR HIGHS ON MONDAY...THEY STILL SEEM IN GOOD SHAPE AT THIS TIME.
MOST AREAS WILL RISE INTO THE 30S AND LOW 40S...EVEN WITH THE SNOW
COVER. WARMEST TEMPS WILL BE OVER THE SOUTHWEST CWA. TUESDAY
SHAPING UP TO NOT BE THAT BAD OF A DAY EITHER. TEMPS ALOFT COOL
SLIGHTLY AND MIXING WILL BE LESS...BUT SHOULD STILL MANAGE UPPER
20S TO MID 30S FOR MOST AREAS.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
NEARLY ZONAL UPPER LEVEL FLOW ON WEDNESDAY WITH NEAR NORMAL SFC
TEMPS GIVES WAY TO AN ARCTIC FRONT INTRUDING FROM THE NORTHWEST
AND A SFC LOW MOVING THROUGH THE CENTRAL PLAINS ON THURSDAY. THE
GFS IS A LITTLE SLOWER TO PROGRESS THE PRECIP SOUTH WITH THE FRONT
AND HANGS IT AROUND A LITTLE LONGER. WITH SFC HIGH PRESSURE
SETTLING OVER THE REGION ON FRIDAY BELIEVE THE ECMWF AND THE
ALLBLEND ARE A BETTER BET WITH ALL PRECIP EXITING THU NIGHT.
SIGNIFICANTLY COOLER TEMPS AND DRIER CONDITIONS WILL THEN PERSIST
THROUGH THE WEEKEND AS NORTHWEST FLOW ALOFT TAKES HOLD ONCE AGAIN.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A WARM FRONT IS CURRENTLY TRACKING INTO WESTERN SOUTH DAKOTA. A
BAND OF LIGHT SNOWFALL HAS DEVELOPED AHEAD OF THE FRONT...WITH
MAINLY MVFR CONDITIONS...ALTHOUGH VFR VSBYS AND CIGS CAN BE
EXPECTED UNDER THE HEAVIEST SNOWFALL. THIS HEAVIEST BAND WILL
MAINLY AFFECT KABR THIS AFTERNOON...BUT COULD SHIFT AS FAR EAST AS
KATY. THE AREA OF SNOWFALL WILL GRADUALLY SLIDE SOUTHEAST AND
DISSIPATE LATER THIS AFTERNOON AND EVENING. WINDS WILL SHIFT TO
THE WEST BEHIND THE FRONT.
EQUIPMENT FAILURE AT THE KATY ASOS HAS CAUSED MISSING
OBSERVATIONS. MAINTENANCE IS BEING PERFORMED...BUT UNTIL THE
OBSERVATIONS RETURN...THE KATY TAF WILL BE NIL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...FOWLE
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1036 AM CST SUN DEC 15 2013
.UPDATE...
BAND OF ISENTROPIC/WAA DRIVEN LIGHT SNOW CONTINUES TO DEVELOP
OVER THE FORECAST AREA AS OF 10AM. RIGHT NOW THE MOST PERSISTENT
SNOW IS OCCURRING FROM JUST EAST OF MOBRIDGE AND FAULKTON...TO
ABERDEEN AND REDFIELD. VSBYS IN THIS BAND WILL LIKELY DROP TO
BELOW ONE MILE AT TIMES. DECENT AGREEMENT AMONGST THE HI-RES
MODELS ON SHIFTING THIS NW/SE BAND OF SNOW TO THE EAST THE
REMAINDER OF THE AFTERNOON. SNOW ACCUMULATION THROUGH EVENING IS
STILL EXPECTED TO BE AROUND 1 INCH ACROSS N-CENTRAL AND NERN SD
AND WRN MN...WITH ISOLATED AREAS PICKING UP AS MUCH AS 2 INCHES.
BIG CONTRAST IN TEMPERATURES ACROSS SOUTH DAKOTA. RAPID CITY AREA IS
CURRENTLY BASKING IN THE 40S...WITH AREAS IN THE EAST REMAINING
NEAR ZERO. WILL BE CHALLENGING TO DETERMINE JUST HOW FAR EAST THIS
WARMER AIRMASS WILL BE ABLE TO ADVECT TODAY. LATEST GUIDANCE HAS
IT PUSHING AS FAR EAST AS STANLEY/JONES/DEWEY COUNTIES BY
EVENING...WHICH SEEMS REASONABLE.
BIGGER PUSH OF WARM AIR WILL OCCUR TONIGHT...MORE ON THAT THIS
AFTERNOON. UPDATES ALREADY OUT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
LOCATION OF SHARP WARM FRONT A NO-BRAINER EARLY THIS MORNING AS IT
IS EASILY NOTICEABLE ON SFC OBS. FAITH AND PHILIP ARE 36 AND 37
DEGREES RESPECTIVELY WITH A NORTHWEST WIND...WHILE MOBRIDGE AND
PIERRE ARE STILL IN THE LOWER TEENS WITH A SOUTHEAST WIND. THIS
FRONT CONTINUES NORTHWEST INTO SOUTHWEST NORTH DAKOTA. AS
ADVERTISED...LIGHT SNOW IS ONGOING AHEAD OF THE FRONT WITHIN ZONE
OF LIFT AND FORCING...MAINLY FROM NORTHWEST NORTH DAKOTA AND JUST
NOW INTO NORTH CENTRAL SOUTH DAKOTA. MODELS SEEM TO BE A FEW HOURS
QUICKER WITH THE ONSET OF LIGHT SNOW SO HAVE MADE THE APPROPRIATE
ADJUSTMENTS IN WX/POP GRIDS. MODELS STILL IN RATHER GOOD AGREEMENT
AS WELL...BRINGING A SWATH OF LIGHT SNOW RIGHT DOWN THROUGH THE
NORTHEAST QUARTER OF SOUTH DAKOTA INTO WEST CENTRAL MINNESOTA. A
BIT HARDER TO NAIL DOWN WITH MORE SPECIFICITY THE ACTUAL AREA OF
SLIGHTLY ENHANCED SNOWFALL...BUT INDICATIONS IN MODELS ARE THAT IT
ACTUALLY MIGHT BE RIGHT DOWN THROUGH ABERDEEN TO NEAR
WATERTOWN...SO HAVE SLIGHTLY HIGHER SNOWFALL TOTALS IN THIS
AREA...AROUND AN INCH OR SLIGHTLY HIGHER. SOME OF THE HI RES
MODELS SHOWING THE SNOW MIGHT BE ENDING A BIT QUICKER AS
WELL...DUE TO THE EARLIER ONSET. LATEST RUN OF THE HRRR ACTUALLY
SHOWING MOST SNOW OUT OF THE AREA BY 20Z OR 21Z. A TREND TO WATCH
THROUGH THE DAY.
AFTER THE BULK OF THE SNOWFALL ENDS BY LATE AFTERNOON...ATTENTION
THEN TURNS TO THE EASTWARD PROGRESSION OF THE WARM FRONT AND
DETERMINING JUST HOW WARM TEMPS WILL GET ON MONDAY. MODELS DO NOT
SHOW MUCH MOVEMENT OF THE FRONT AT ALL TODAY...STILL HUNG UP NEAR
THE MISSOURI RIVER BY 00Z THIS EVENING. BUT OVERNIGHT...THERE IS
FINALLY A PUSH TO THE EAST WHICH SHOULD TAKE IT THROUGH MOST IF
NOT ALL THE CWA BY 12Z MONDAY MORNING. THUS...WILL SEE SLOWLY
RISING TEMPS THROUGH THE NIGHT FOR EASTERN AREAS AS THIS FRONT
MOVES THROUGH. DID NOT STRAY MUCH AT ALL FROM PREVIOUS FORECAST
FOR HIGHS ON MONDAY...THEY STILL SEEM IN GOOD SHAPE AT THIS TIME.
MOST AREAS WILL RISE INTO THE 30S AND LOW 40S...EVEN WITH THE SNOW
COVER. WARMEST TEMPS WILL BE OVER THE SOUTHWEST CWA. TUESDAY
SHAPING UP TO NOT BE THAT BAD OF A DAY EITHER. TEMPS ALOFT COOL
SLIGHTLY AND MIXING WILL BE LESS...BUT SHOULD STILL MANAGE UPPER
20S TO MID 30S FOR MOST AREAS.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
NEARLY ZONAL UPPER LEVEL FLOW ON WEDNESDAY WITH NEAR NORMAL SFC
TEMPS GIVES WAY TO AN ARCTIC FRONT INTRUDING FROM THE NORTHWEST
AND A SFC LOW MOVING THROUGH THE CENTRAL PLAINS ON THURSDAY. THE
GFS IS A LITTLE SLOWER TO PROGRESS THE PRECIP SOUTH WITH THE FRONT
AND HANGS IT AROUND A LITTLE LONGER. WITH SFC HIGH PRESSURE
SETTLING OVER THE REGION ON FRIDAY BELIEVE THE ECMWF AND THE
ALLBLEND ARE A BETTER BET WITH ALL PRECIP EXITING THU NIGHT.
SIGNIFICANTLY COOLER TEMPS AND DRIER CONDITIONS WILL THEN PERSIST
THROUGH THE WEEKEND AS NORTHWEST FLOW ALOFT TAKES HOLD ONCE AGAIN.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
AN AREA OF WAA LIGHT SNOW IS BEGINNING ACROSS THE REGION AND
CURRENTLY AFFECTING KABR. THIS SNOW WILL ALSO MOVE INTO KMBG LATER
THIS MORNING. WHILE VSBY RESTRICTIONS WILL BE LIMITED CIGS WILL
FALL INTO THE MVFR RANGE FOR MUCH OF THE DAY BEFORE LIFTING BY
THIS EVENING. KPIR IS EXPECTED TO REMAIN VFR.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...FOWLE
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN