Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/24/11
AREA FORECAST DISCUSSION
NWS ALBANY NY
950 PM EST FRI DEC 23 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 945 PM EST...CLOUDS ARE FINALLY SHOWING SIGNS OF BREAKING
UP IN VALLEY REGIONS...WHILE CLOUDS CONTINUE TO HANG ON ACROSS
HIGHER ELEVATIONS WITHIN THE CATSKILLS...WESTERN
ADIRONDACKS...SOUTHERN GREENS AND BERKSHIRES. SOME FLURRIES WILL
REMAIN POSSIBLE FROM THESE CLOUDS OVER THE NEXT FEW HOURS.
AS CLOUDS BEGIN TO BREAK...TEMPERATURES ARE ALSO STARTING TO
FALL...AND HAVE NOT TOUCHED OVERNIGHT MINS FROM CURRENT
PROJECTIONS...ESP GIVEN THE EXPECTATION FOR CONTINUED COLD
ADVECTION FROM THE NORTH.
HIGH/MID LEVEL CLOUDS WILL INCREASE AFTER MIDNIGHT FROM W TO E
AHEAD OF APPROACHING GREAT LAKES SHORTWAVE. THIS MAY INITIATE
ADDITIONAL SNOW FLURRIES OR LIGHT SNOW SHOWERS ACROSS PORTIONS OF
THE CATSKILLS AND ADIRONDACKS LATER TONIGHT AS SEEDER/FEEDER
MECHANISM POTENTIALLY DEVELOPS BETWEEN THICKENING MID LEVEL
CLOUDS...AND LOWER STRATOCU BELOW. IN ADDITION...SOME SNOW
FLURRIES WILL BE POSSIBLE FROM VEERING LOW LEVEL NNE FLOW ACROSS
THE UPPER HUDSON RIVER VALLEY CROSSING LAKE CHAMPLAIN...AND HAVE
KEPT MENTION OF FLURRIES IN THIS REGION AND INTO SW VT OVERNIGHT.
OTHERWISE...SOME ADJUSTMENTS TO WINDS...WHICH HAVE REMAINED BRISK
WITHIN THE MOHAWK RIVER VALLEY/CAPITAL REGION AND NORTHERN
BERKSHIRES...AND TO HOURLY TEMPS/DEWPOINTS ACCORDING TO RECENT OBS.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH AT LEAST 00Z/SUNDAY. VFR CIGS
WITH BASES OF 3500-5000 FT AGL WILL PERSIST THROUGH AT LEAST
06Z/SAT...WITH GRADUAL DECREASE IN LOWER LEVEL CLOUDS EXPECTED
THEREAFTER. THERE IS A SLIGHT CHC FOR MVFR CIGS AT KGFL AND KALB
LATER THIS EVENING BEFORE DRIER AIR ALLOWS CIGS TO BREAK.
SOME FLURRIES WILL BE POSSIBLE THROUGH MIDNIGHT AT KGFL AND
KALB.
EXPECT NORTHWEST TO NORTH WINDS AT 5-10 KT TONIGHT...ALTHOUGH
10-15 KT WITH SOME GUSTS UP TO 20 KT POSSIBLE AT KALB THROUGH THIS
EVENING. WINDS WILL BECOME MAINLY NORTH ON SATURDAY AT 5-10 KT.
OUTLOOK...
SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...NAS
NEAR TERM...KL/NAS
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...KL
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
704 PM EST FRI DEC 23 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH AT LEAST 00Z/SUNDAY. VFR CIGS
WITH BASES OF 3500-5000 FT AGL WILL PERSIST THROUGH AT LEAST
06Z/SAT...WITH GRADUAL DECREASE IN LOWER LEVEL CLOUDS EXPECTED
THEREAFTER. THERE IS A SLIGHT CHC FOR MVFR CIGS AT KGFL AND KALB
LATER THIS EVENING BEFORE DRIER AIR ALLOWS CIGS TO BREAK.
SOME FLURRIES WILL BE POSSIBLE THROUGH MIDNIGHT AT KGFL AND
KALB.
EXPECT NORTHWEST TO NORTH WINDS AT 5-10 KT TONIGHT...ALTHOUGH
10-15 KT WITH SOME GUSTS UP TO 20 KT POSSIBLE AT KALB THROUGH THIS
EVENING. WINDS WILL BECOME MAINLY NORTH ON SATURDAY AT 5-10 KT.
OUTLOOK...
SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...NAS
NEAR TERM...KL/NAS
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...KL/SND
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 PM EST THU DEC 22 2011
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE THROUGH THE ARE LATE TONIGHT
AND EARLY FRIDAY MORNING. THE CHANCE OF SHOWERS WILL DECREASE BY
FRIDAY AFTERNOON. HIGH PRESSURE WILL BUILD IN BRIEFLY FRIDAY NIGHT
AND SATURDAY BEFORE ANOTHER WEATHER SYSTEM APPROACHES LATE
SATURDAY NIGHT AND CHRISTMAS DAY WITH ANOTHER CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK COLD FRONT WILL CONTINUE TO APPROACH FROM THE NORTHWEST
WITH A CHANCE OF SHOWERS. A FEW THUNDERSTORMS ARE POSSIBLE IN THE
CSRA WHERE CONDITIONS ARE BIT MORE UNSTABLE WITH THE RUC MODEL
SHOWING LIS -2/-3 LATE THIS AFTERNOON AND EARLY THIS EVENING.
OTHERWISE...JUST SHOWERS ARE EXPECTED ELSEWHERE. ANOTHER WARM
MUGGY NIGHT IN STORE WITH LOW TEMPERATURES IN THE UPPER 50S TO
NEAR 60 DEGREES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE WEAK SLOW MOVING COLD FRONT MOVES WEST TO EAST DURING THE DAY
FRIDAY AND EXITS TO THE EAST LATE IN THE DAY FRIDAY. THINK JUST A
SLIGHT CHANCE OF SHOWERS WILL COVER THE SITUATION IN MOST
LOCATIONS. ANOTHER WARM DAY FRIDAY BEFORE THE COOLER AIR ARRIVES.
WILL GO WITH HIGHS IN THE UPPER 60S TO NEAR 70. FRIDAY NIGHT AND
SATURDAY...CHRISTMAS EVE WILL SEE A BRIEF PERIOD OF DRY WEATHER AS
HIGH PRESSURE COVERS THE REGION UNTIL A GULF SYSTEM APPROACHES
LATE SATURDAY NIGHT. MORE NORMAL TEMPERATURES BY SATURDAY WITH
HIGHS IN THE LOWER TO MID 60S. LOWS SATURDAY NIGHT SHOULD BE IN
THE LOWER TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT MOVING GULF SYSTEM TO THE
EAST SUNDAY...CHRISTMAS DAY. DECIDED TO DOWN PLAY WEAK GULF SYSTEM
MODELS WERE HINTING AT FOR TUESDAY AND WEDNESDAY WITH UPPER FLOW
MAINLY ZONAL. THINK ANY SYSTEMS WILL MOVE QUICKLY WITH LITTLE
MOISTURE SINCE THERE ARE NO DEEP TROUGHS TO TRANSPORT MUCH
MOISTURE INTO THE REGION. SO EXPECT MAINLY HIGH PRESSURE WITH DRY
CONDITIONS MONDAY ON THROUGH THURSDAY. TEMPERATURES RETURN TO
NORMAL WITH HIGHS IN THE MID TO UPPER 50S MAYBE REACHING 60 BY
THURSDAY. OVERNIGHT LOWS IN THE MID TO UPPER 30S.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A FEW LIGHT SHOWERS ACROSS THE NORTHERN AND CENTRAL MIDLANDS AT THE
TIME. EXPECT GENERALLY VFR WITH OCCASIONAL MVFR CONDITIONS ESPECIALLY
INVOF SHOWERS FOR THE REST OF THE AFTERNOON INTO TONIGHT. SPOTTY
SHOWERS WILL LINGER INTO THE EVENING HOURS. LOW CLOUDS WILL BE MORE
LIKELY DURING THE OVERNIGHT HOURS AS OPPOSED TO FOG DUE TO A
40 KNOT LOW-LEVEL JET ANTICIPATED TO DEVELOP LATE TONIGHT AS
SUGGESTED BY NAM BUFKIT TIME SECTIONS.
CONDITIONS SLOWLY IMPROVE AFTER 14Z AS A COLD FRONT MOVES THROUGH
THE AREA. SHOULD SEE SOME BREAKS IN THE CLOUDS BY LATE MORNING/EARLY
AFTERNOON ON FRIDAY.
EXTENDED AVIATION OUTLOOK...PERIODS OF CIG/VSBY RESTRICTIONS
EXPECTED THROUGH SATURDAY AS A SERIES OF WEATHER SYSTEMS CROSS THE
REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...07
NEAR TERM...07
SHORT TERM...07
LONG TERM...07
AVIATION...22
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
647 AM EST THU DEC 22 2011
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL REMAIN NEAR THE FORECAST AREA
THROUGH THE CHRISTMAS WEEKEND. A SERIES OF LOW PRESSURE SYSTEMS WILL
MOVE NORTHEASTWARD ALONG THE FRONT.
&&
.NEAR TERM /THROUGH TODAY/...
SCATTERED SHOWERS DEVELOPING ACROSS SOUTH GEORGIA THIS MORNING
ASSOCIATED WITH WARM ADVECTION. LATEST RUC SUGGESTS THESE SHOWERS
WILL CONTINUE TO TRACK NORTHEAST INTO THE CSRA LATER THIS MORNING
AND ACROSS THE MIDLANDS. BASED ON 850MB TEMPERATURES EXPECT ANOTHER
WARM DAY WITH TEMPERATURES IN THE LOWER 70S. MAY BE HIGHER IF
BREAKS IN THE CLOUDS THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
WEAK CONVERGENCE AND MOISTURE ASSOCIATED WITH THE SLOW MOVING
FRONT WILL SUPPORT A CONTINUED SHOWER CHANCE...ALTHOUGH WITH LACK
OF UPPER LEVEL SUPPORT...AND LOW SREF POPS...DECREASED POPS FROM
PREVIOUS FORECAST INTO FRIDAY MORNING. THE NAM AND GFS SHOW SOME
DRYING DEVELOPING FRIDAY AS THE FRONT PUSHES A LITTLE FARTHER
SOUTHEASTWARD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONFIDENCE REMAINES LOW HOWEVER WITH THE FORECAST THROUGH THE
EXTENDED PERIOD. LATEST GFS/ECMWF ADVECTING MOISTURE FROM THE
GULF NORTHEAST INTO GEORGIA AND SOUTH CAROLINA FASTER THAN NAM
SATURDAY NIGHT AS NAM CLOSES OFF UPPER LOW IN THE SOUTHERN PLAINS.
POPS THOUGH SHOULD REMAIN LOW SATURDAY NIGHT. UNCERTAINTY
CHRISTMAS DAY WITH MEAN GFS ENSEMBLE POPS LOWER THAN OPERATIONAL
GFS. LITTLE CHANGE MADE TO FORECAST FOR CHRISTMAS...CHANCE POPS
AND TEMPERATURES ABOVE NORMAL SEEMS REASONABLE. DRYING MONDAY WITH
RIDGING BECOMING DOMINATE TUESDAY. TEMPERATURES NEAR NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH TUESDAY/...
REGIONAL RADAR COMPOSITE SHOWS LIGHT RAIN SHOWERS MOVING NORTHEAST
ALONG THE I-95 CORRIDOR AND FROM MACON GA TOWARD THE CSRA.
OBS/SATELLITE INDICATE IFR/MVFR CONDITIONS AT ALL TAF SITES THIS
MORNING.
MODEL SOUNDINGS CONTINUE TO SHOW ABUNDANT LOW LEVEL MOISTURE ACROSS
THE REGION THIS MORNING AND THROUGH THE TAF PERIOD. OBS UPSTREAM
INDICATE THAT CONDITIONS COULD CONTINUE TO DETERIORATE AT ALL TAF
SITES THROUGH MID/LATE MORNING WITH CONTINUED IFR/MVFR CONDITIONS.
WILL ALSO MENTION VCSH FOR ISOLATED LIGHT SHOWERS/SPRINKLES AT BOTH
OGB/AGS THROUGH THE MORNING/AFTERNOON HOURS. CONDITIONS MAY IMPROVE
THIS AFTERNOON TO VFR AT ALL TAF SITES...AND HAVE INDICATED THIS IN
TAFS AFTER 21Z. HOWEVER...THERE IS A CHANCE THAT CONDITIONS WILL
ONLY IMPROVE TO MVFR. TONIGHT...EXPECT CONDITIONS TO ONCE AGAIN
DETERIORATE AS ADDITIONAL MOISTURE STREAMS NORTHEAST AHEAD/ALONG
FRONTAL BOUNDARY AND MVFR CONDITIONS RETURN. POTENTIAL EVEN EXIST
FOR A PERIOD OF IFR FRIDAY MORNING...BUT HAVE DECIDED NOT TO GO THAT
LOW OR MENTION ANY SHOWERS AT THIS TIME. WINDS WILL BE LIGHT FROM
THE SOUTH THIS MORNING...THEN INCREASING TO NEAR 10 KNOTS FROM THE
SOUTH THIS AFTERNOON/TONIGHT.
EXTENDED AVIATION OUTLOOK...PERIODS OF CIG/VSBY RESTRICTIONS
EXPECTED THROUGH SATURDAY AS A SERIES OF WEATHER SYSTEMS CROSS THE
REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
250 AM EST THU DEC 22 2011
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL REMAIN NEAR THE FORECAST AREA
THROUGH THE CHRISTMAS WEEKEND. A SERIES OF LOW PRESSURE SYSTEMS WILL
MOVE NORTHEASTWARD ALONG THE FRONT.
&&
.NEAR TERM /THROUGH TODAY/...
SCATTERED SHOWERS DEVELOPING ACROSS SOUTH GEORGIA THIS MORNING
ASSOCIATED WITH WARM ADVECTION. LATEST RUC SUGGESTS THESE SHOWERS
WILL CONTINUE TO TRACK NORTHEAST INTO THE CSRA LATER THIS MORNING
AND ACROSS THE MIDLANDS. BASED ON 850MB TEMPERATURES EXPECT ANOTHER
WARM DAY WITH TEMPERATURES IN THE LOWER 70S. MAY BE HIGHER IF
BREAKS IN THE CLOUDS THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
WEAK CONVERGENCE AND MOISTURE ASSOCIATED WITH THE SLOW MOVING
FRONT WILL SUPPORT A CONTINUED SHOWER CHANCE...ALTHOUGH WITH LACK
OF UPPER LEVEL SUPPORT...AND LOW SREF POPS...DECREASED POPS FROM
PREVIOUS FORECAST INTO FRIDAY MORNING. THE NAM AND GFS SHOW SOME
DRYING DEVELOPING FRIDAY AS THE FRONT PUSHES A LITTLE FARTHER
SOUTHEASTWARD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CONFIDENCE REMAINES LOW HOWEVER WITH THE FORECAST THROUGH THE
EXTENDED PERIOD. LATEST GFS/ECMWF ADVECTING MOISTURE FROM THE
GULF NORTHEAST INTO GEORGIA AND SOUTH CAROLINA FASTER THAN NAM
SATURDAY NIGHT AS NAM CLOSES OFF UPPER LOW IN THE SOUTHERN PLAINS.
POPS THOUGH SHOULD REMAIN LOW SATURDAY NIGHT. UNCERTAINTY
CHRISTMAS DAY WITH MEAN GFS ENSEMBLE POPS LOWER THAN OPERATIONAL
GFS. LITTLE CHANGE MADE TO FORECAST FOR CHRISTMAS...CHANCE POPS
AND TEMPERATURES ABOVE NORMAL SEEMS REASONABLE. DRYING MONDAY WITH
RIDGING BECOMING DOMINATE TUESDAY. TEMPERATURES NEAR NORMAL.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
MUCH OF THE RAINFALL FROM WEDNESDAY HAS MOVED NORTHEAST OF THE AREA.
ONLY A FEW SPRINKLES WILL MOVE ACROSS THE REGION FOR MUCH OF THE TAF
PERIOD...ESPECIALLY OVERNIGHT INTO THURSDAY MORNING.
MVFR CONDITIONS HAVE ALREADY DEVELOPED AT AGS/DNL AND EXPECT
MVFR/IFR CONDITIONS TO DEVELOP LATER TONIGHT AT THE REMAINDER TAF
SITES. EXPECT AREAS OF LOW CLOUDS AND FOG TO DEVELOP THROUGH THE
MORNING HOURS. BUFKIT CONTINUES WITH HIGH LOW-LEVEL MOISTURE AND
BRINGS IN SOME SLIGHTLY DRIER AIR ALOFT BY MORNING. MODELS ALL
SHOWING POSSIBLE LIFR/IFR CONDITIONS BY MORNING...WITH VISIBILITIES
LESS THAN A HALF A MILE. FOR NOW WILL NOT GO THAT LOW...BUT WILL
DROP VISIBILITIES IN THE MIDLANDS AND CSRA DOWN TO 1SM IN BR. WILL
NEED TO MONITOR OVERNIGHT THROUGH. CLOUDS STILL FORECAST TO DROP
DOWN BELOW 500 FT TOWARDS MORNING. CONDITIONS WILL SLOWLY IMPROVE
AFTER 16Z THURSDAY WITH IFR CIGS AND MVFR VSBYS. VFR CONDITIONS
POSSIBLE AFTER 22Z THURSDAY FOR A PERIOD IN THE AFTERNOON. SURFACE
WINDS WILL BE LIGHT FROM THE SOUTH-SOUTHWEST OVERNIGHT AND BECOME
MORE SOUTHERLY AND INCREASE TO NEAR 10 KNOTS ON THURSDAY.
EXTENDED AVIATION OUTLOOK...PERIODS OF CIG/VSBY RESTRICTIONS
EXPECTED THROUGH SATURDAY AS A SERIES OF WEATHER SYSTEMS CROSS THE
REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
225 PM CST THU DEC 22 2011
.DISCUSSION...
ISSUED 225 PM CST THU DEC 22 2011
19Z SFC MAP INDICATED WEAK FRONT WASHING OUT NEAR I-57 WITH LIGHT
NORTHERLY BEHIND IT. MAIN WEATHER SYSTEM ACROSS THE COUNTRY WAS
LOCATED WELL TO OUR SOUTHEAST...HOWEVER STRATIFORM RAIN SHIELD
REACHED AS FAR NORTH AS THE OHIO VALLEY...AND CLOUDS ASSOCIATED WITH
THIS FEATURE OVERSPREAD THE ENTIRE AREA. BEYOND THIS EVENING...LITTLE IN
THE WAY OF FORECAST CONCERNS WITH A DRY AND MILD PATTERN PERSISTING
THROUGH MUCH OF NEXT WEEK.
SHORT TERM...TONIGHT AND FRIDAY
A COUPLE ITEMS OF INTEREST THIS EVENING. FIRST...NORTHERN FRINGE OF
OH VALLEY RAINS LOOK TO STAY JUST SOUTHEAST OF THE LAWRENCEVILLE
AREA IN REGION OF BETTER LIFT AND MOISTURE...BUT MAY INSERT LOW CHC POPS
IN THE FAR SE BASED ON LATEST RADAR TRENDS. OTHER ITEM IS RIBBON
OF 850-700 MB FRONTOGENESIS SLIDING SE INTO NRN MO/SE IA
CURRENTLY. RADAR MOSAIC INDICATES LIGHT SNOW BAND DEVELOPING FROM
KMCI TO NEAR KIRK IN MO. LATEST RUN OF HRRR AND 12KM NAM STREAK
THIS BAND TO THE EAST...ACROSS PARTS OF CENTRAL ILLINOIS THIS
EVENING. AIRMASS IS FAIRLY DRY...SO BELIEVE MOST PRECIP GENERATION
WILL BE EATEN BY SATURATION PROCESSES. HOWEVER SOME SCATTERED
FLURRIES OR BRIEF PERIODS OF LIGHT SNOW LOOK POSSIBLE FOR ROUGHLY
THE NW HALF BEFORE FRONTOGENESIS WANES AFTER MIDNIGHT. AS THE MAIN
SYNOPTIC WEATHER FEATURES SHIFT FARTHER EAST TOMORROW...HIGH
PRESSURE WILL BEGIN TO NOSE EAST FROM THE CENTRAL PLAINS. THIS
WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST FOR A WELCOME RETURN
TO SUNSHINE.
LONG TERM...SATURDAY THROUGH THURSDAY
AS HAS BEEN THE CASE MUCH OF THIS EARLY WINTER...SPLIT FLOW JET
STREAM PATTERN WILL DOMINATE THE EXTENDED PORTION OF THE FORECAST.
THIS WILL KEEP ANY ARCTIC AIR BOTTLED UP IN CANADA...AND ANY
MOISTURE-RICH SHORTWAVES WELL TO OUR SOUTH. THIS PATTERN IS
CONSISTENT WITH POSITIVE PHASES OF THE AO AND NAO...AND THESE ARE
FORECAST TO STAY POSITIVE FOR THE NEXT COUPLE WEEKS.
THE HOLIDAY WEEKEND WILL FEATURE EXCELLENT TRAVEL
CONDITIONS...WITH THE CLOSEST PRECIPITATION BEING LAKE EFFECT AND
CLIPPER SNOW FOR THE GREAT LAKES...AND RAIN FROM THE LOWER
MISSISSIPPI VALLEY INTO THE DEEP SOUTH. FOR THE LOCAL
AREA...MOSTLY CLEAR SKIES AND TEMPERATURES RUNNING 5-10 DEGREES
ABOVE NORMAL WILL DOMINATE...WITH ANY CLIPPERS STAYING WELL TO OUR
NORTHEAST. THERE IS SOME MODEL DISAGREEMENT MONDAY NIGHT...WHEN A
SOUTHERN STREAM SHORTWAVE LIFTS INTO THE MS VALLEY. PREVIOUS
GUIDANCE AND THE CURRENT GFS KEEP ANY RAIN WITH THIS FEATURE WELL
SOUTH OF THE AREA...WHILE THE LATEST ECMWF AND GEM BRING RAIN OR A
RAIN/SNOW MIX UP TO THE LOWER GREAT LAKES BY TUESDAY MORNING. FOR
NOW WILL BASE THE FORECAST ON THE MORE CONSISTENT/DRY SOLUTION BUT
KEEP AN EYE ON THIS PERIOD FOR POP ADJUSTMENT. BEYOND THIS
POTENTIAL SYSTEM...ZONAL UPPER LEVEL FLOW WILL PRODUCE DRY AND
SEASONABLY WARM WEATHER THROUGH MID-WEEK.
25
&&
.AVIATION...
ISSUED 1155 AM CST THU DEC 22 2011
MVFR VISIBILITIES FROM LIGHT FOG WILL BE VFR AT TIMES THIS AFTERNOON.
EXPECT VISIBILITIES TO LOWER THIS EVENING TO IFR WITH FOG AND CHANCE
OF LIGHT RAIN/SNOW OVER MAINLY PIA AND BMI LATER THIS AFTERNOON
INTO MID EVENING. VFR CEILINGS AT MIDDAY WITH CEILING AT OR ABOVE
12K FT TO DETERORIATE DURING THE AFTERNOON AND EVENING AS IFR
CEILINGS BEHIND A COLD FRONT NW OF THE IL RIVER SPREAD SE ACROSS
CENTRAL IL DURING THE AFTERNOON...REACHING PIA EARLY THIS AFTERNOON.
MODELS HAVE TRENDED SLOWER WITH DECREASING LOW CLOUDS DURING FRI
MORNING AND HAVE PIA SCATTER OUT AROUND 13Z...AND KEEP LOW CLOUDS
AT CMI THROUGH 18Z/FRI THOUGH LIFTING CEILINGS UP TO MVFR. LIGHT
TO CALM WINDS TO BECOME NNW BEHIND A COLD FRONT WHICH IS
APPROACHING I-55 AND TO SPREAD SE THROUGH REST OF CENTRAL IL
DURING EARLY AND MID AFTERNOON. NORTH WINDS TO INCREASE TO 8-13
KTS DURING THE AFTERNOON AND CONTINUE TONIGHT...AND BE MORE NW
AT 4-8 KTS BY FRI MORNING.
1012 MB LOW PRESSURE OVER WEST CENTRAL AL TO DEEPEN NE TO 1010 MB
OVER THE MID ATLANTIC STATES BY MIDNIGHT TONIGHT. THIS WILL KEEP
ITS LIGHT RAIN SHIELD SE OF THE CENTRAL IL AIRPORTS THIS AFTERNOON
AND EVENING. A FEW MODELS SHOW LIGHT QPF APPEARING BEHIND THE COLD
FRONT OVER THE IL RIVER VALLEY LATER THIS AFTERNOON UNTIL MID
EVENING. CONFIDENCE OF THIS OCCURING IS NOT TOO HIGH AND MAINLY
KEPT VSCH WITH TEMPO GROUPS ONLY AT PIA AND BMI FOR LIGHT OR LIGHT
SNOW. 1036 MB HIGH PRESSURE OVER WESTERN NEBRASKA TO NOSE INTO IL
BY 18Z/NOON FRI HELPING TO BRING IN DRIER AIR AND DECREASE THE LOW
CLOUDS FROM THE NW...THOUGH LIKELY LINGERING AT CMI AND POSSIBLY
DEC FRI MORNING.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
553 PM CST FRI DEC 23 2011
.AVIATION...
A DEPARTING UPPER AIR DISTURBANCE MOVING ACROSS WISCONSIN INTO THE
GREAT LAKES WILL EXIT BY 03Z. ANY MID LEVEL CLOUDS WILL MOVE EAST
WITH CLEAR SKIES RETURNING BY 03Z. CLEAR SKIES...VISIBILITIES ABOVE
7 MILES AND LIGHT SW WINDS OF 5-10 MPH WILL CONTINUE THROUGH 25/00Z
AND ON INTO SUNDAY...RESULTING IN VFR CONDITIONS. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 312 PM CST FRI DEC 23 2011/
SYNOPSIS...
A VIGOROUS CLIPPER SYSTEM WAS SEEN ON WATER VAPOR IMAGERY SWEEPING
SOUTHEAST ACROSS MN AND WI THIS AFTERNOON. AT 18Z...ASSOCIATED
SURFACE LOW PRESSURE WAS CENTERED IN SW ONTARIO JUST NORTH OF MN
WITH A TROUGH EXTENDING S-SW ACROSS MN INTO CENTRAL NEB. AHEAD OF
THIS TROUGH...WIDESPREAD LIGHT SNOW AND BRIEF LOCALIZED MODERATE
SNOW WAS FALLING ACROSS SE MN INTO MUCH OF WI. MID AND HIGH LEVEL
CLOUD COVER PRECEDING THE SYSTEM HAS SPREAD SOUTH-SE TO COVER THE
NORTHERN HALF OF THE FORECAST AREA...WHILE STRATUS TO THE SOUTH
THAT PERSISTED OVERNIGHT HAS BEEN DRAWN NORTHWARD IN THE LOW LEVEL
SW FLOW TO COVER THE FAR SOUTHEAST PART OF THE FORECAST AREA. THE
CLOUD COVER...AND SLIGHTLY HIGHER LOW LEVEL MOISTURE LEVELS...HAVE
HELD TEMPERATURES A FEW DEGREES COOLER THAN EXPECTED TODAY WITH
MANY AREAS STRUGGLING TO REACH 32 AS OF 2 PM.
SHORT TERM...TONIGHT AND SATURDAY...
THE MAIN FOCUS IS ON THE NEAR TERM POTENTIAL FOR LIGHT SNOW. 12Z
FORECAST MODELS HAVE GENERALLY BEEN TOO WEAK WITH THE SURFACE
PRESSURE FIELDS...TOO LOW ON LOW LEVEL MOISTURE LEVELS...AND ALSO
AND A BIT TOO FAR NORTH AND TOO WEAK WITH THE UPPER FORCING SO FAR
TODAY. FOLLOWING THE LATEST RUC DEPICTION OF A LOBE OF MID LEVEL
VORTICITY ROTATING AROUND THE BASE OF THE MAIN SHORTWAVE...THE TRACK
OF UPPER LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100 PLUS
KT JET DIVING SOUTH OUT OF MANITOBA...THERE IS SUPPORT THAT LIFT
AND SATURATION MAY PULL FLURRIES OR EVEN LIGHT SNOW FURTHER SOUTH
AND SOUTHWEST THAN PREVIOUSLY EXPECTED. AN IMPRESSIVE AXIS OF
WIDESPREAD 4 MB PRESSURE FALLS ON MSAS SWEEPING INTO EASTERN IA
AND A MOST RECENT 5 MB BULLSEYE CENTERED NEAR VINTON...FURTHER
SUPPORTS THIS POSSIBILITY. HOWEVER...WITH CLOUD BASES STILL WELL
ABOVE 9000 FT OVER MOST OF IA AND A STRONG SW LOW LEVEL FLOW
ADVECTING DRY AIR INTO THIS FAST MOVING SYSTEM...SUFFICIENT
SATURATION WILL BE DIFFICULT OVER MOST OF THE FORECAST AREA. HAVE
ADDED A POTENTIAL FOR FLURRIES ACROSS THE NORTHEAST FOR LATE
AFTERNOON INTO EVENING...WITH LOW CHANCES FOR A DUSTING OF
ACCUMULATION ALONG AND NORTH OF THE HIGHWAY 20 CORRIDOR IN IL.
ONCE THIS SYSTEM PASSES EARLY THIS EVENING...DRIER AIR AND WEAK
SUBSIDENCE SHOULD ALLOW THE WIDESPREAD CLEARING OVER THE PLAINS TO
SPREAD EASTWARD OVER THE FORECAST AREA. HAVE KEPT LOWS IN A RANGE
FROM THE TEENS NORTH TO LOWER 20S SOUTH...BUT WILL HAVE TO WATCH
TRENDS CLOSELY AS TEMPERATURES COULD POSSIBLY PLUNGE LOWER AS WINDS
BECOME LIGHT WESTERLY LATE TONIGHT UNDER MOSTLY CLEAR SKIES.
SATURDAY...TEMPERATURES SHOULD MODERATE AS WARM ADVECTION ALOFT
COMMENCES WHILE A LARGELY DRY AIRMASS FAVORS MOSTLY SUNNY SKIES.
FORECAST SOUNDINGS DEPICT A LOW LEVEL INVERSION HOLDING STRONG WITH
GENERALLY LIGHT SW WINDS AND HAVE THUS HELD HIGHS CLOSE TO GUIDANCE
VALUES IN THE 30S OVER MOST OF THE AREA. ..SHEETS..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
AN OVERALL TREND OF WARMER AND LIKELY DRIER THAN NORMAL SHOULD BE
SEEN THROUGH THE END OF THE MONTH.
A COLD FRONTAL PASSAGE WILL OCCUR SATURDAY NIGHT/EARLY SUNDAY AS
ANOTHER SYSTEM PASSES WELL NORTH OF THE AREA. CONDENSATION PRESSURE
DEFICITS IN THE LOW AND MID LEVELS ARE QUITE HIGH. THUS A DRY FROPA
SHOULD BE SEEN WITH ONLY AN INCREASE IN CLOUDS. BRISK CONDITIONS
WILL BE SEEN ON SUNDAY WITH RESPECTABLE CAA BEHIND THE FRONT.
HIGH PRESSURE WILL QUICKLY MOVE THROUGH THE REGION SUNDAY NIGHT
KEEPING QUIET AND DRY CONDITIONS ACROSS THE AREA. ATTENTION THEN
TURNS TO THE STORM SYSTEM EARLY NEXT WEEK.
THE OVERALL LONGWAVE PATTERN IS DE-AMPLIFYING AND WILL ELIMINATE THE
SPLIT FLOW OVER THE WESTERN CONUS EARLY NEXT WEEK. A STRONG UPPER
LEVEL SYSTEM NEAR 40N/160W WILL MAKE LANDFALL ON THE WA/OR COAST
SUNDAY AND WILL BE THE KEY TO WHAT HAPPENS WITH THE CUT OFF LOW IN
THE SOUTHERN STREAM MONDAY INTO MONDAY NIGHT. THE OVERALL TREND WITH
THE MODELS HAS BEEN TO SLOW DOWN THE EJECTION OF THE CUT OFF LOW.
THUS THERE ARE TWO POSSIBLE OUTCOMES. THE FIRST IS A PARTIAL PHASING
WITH THE NORTHERN STREAM ENERGY WHICH WOULD PULL THE SOUTHERN CUT
OFF LOW FURTHER NORTH. THE OTHER POSSIBILITY IS A CONTINUED SLOWING
OF THE CUT OFF LOW WHICH WOULD RESULT IN NO PHASING OF THE NORTHERN
AND SOUTHERN STREAMS. IF THE SECOND SCENARIO OCCURS...THE SOUTHERN
STREAM SYSTEM WOULD PASS SOUTH OF THE AREA RESULTING IN DRY
CONDITIONS.
SINCE THE MODELS HAVE BECOME SLOWER WITH THE SOUTHERN CUT OFF
LOW...MONDAY WILL BE DRY WITH AN INCREASE IN CLOUDS THROUGH THE DAY.
PRECIPITATION MAY BE NOT FAR AWAY FROM THE SOUTHERN CWFA BY SUNSET
MONDAY.
MONDAY NIGHT ON...
RIGHT NOW THE MODEL CONSENSUS IS FOR A PARTIAL PHASING OF THE
NORTHERN AND SOUTHERN STREAMS. SUCH A SCENARIO WILL BRING A THREAT
OF PRECIPITATION TO MUCH OF THE CWFA MONDAY NIGHT. A RAIN/SNOW MIX
LOOKS TO BE THE MOST LIKELY WITH A POSSIBLE CHANGE OVER TO ALL SNOW
JUST PRIOR TO SUNRISE TUESDAY. ANY SNOWFALL WOULD BE ONE HALF INCH
OR LESS.
MODEL CONSENSUS GIVES QUIET AND DRY CONDITIONS TUESDAY/TUES NIGHT AS
HIGH PRESSURE QUICKLY MOVES THROUGH THE AREA.
BY MID WEEK A NEAR ZONAL OR VERY LOW AMPLITUDE FLOW WILL EXIST
ACROSS THE CONUS AND PACIFIC. THERE ARE DIFFERENCES BETWEEN THE
MODELS BUT THE POTENTIAL EXISTS FOR A NEAR DAILY OCCURRENCE OF
CLIPPER OR HYBRID CLIPPER SYSTEMS FROM WEDNESDAY THROUGH FRIDAY. THE
MODEL DIFFERENCES WITH TIMING AND SMOOTHING ARE CAUSING POPS TO
CANCEL EACH OTHER OUT WHICH PRODUCES A CONSENSUS FCST OF MAINLY DRY
CONDITIONS FOR WEDNESDAY THROUGH FRIDAY.
INTERNALLY...THE MODELS SHOW SOME RESPECTABLE FORCING AND A
LOWERING OF CONDENSATION PRESSURE DEFICITS WITH EACH SYSTEM. THUS
THERE MAY BE A POTENTIAL FOR PRECIPITATION WEDNESDAY THROUGH FRIDAY.
THE SMOOTHING OF FEATURES MAKES IT DIFFICULT TO ASCERTAIN WHERE
PRECIPITATION MAY OCCUR. AREAS NORTH OF HWY 30 ARE CURRENTLY
DEPICTED AS HAVING THE BETTER FORCING AND LOWER CONDENSATION
PRESSURE DEFICITS WHICH IMPLIES A BETTER CHANCE OF PRECIPITATION.
HOWEVER...ANY PRECIPITATION THAT OCCURS WILL BE LIGHT.
THE PROGNOSTIC CHARTS ARE INDICATING THE LONGWAVE PATTERN WILL BEGIN
TO RE-AMPLIFY IN EARLY JANUARY. A WEAK TO MODERATE LA NINA COMBINED
WITH A NEGATIVE PDO AND SST ANOMALIES WOULD FAVOR A LONGWAVE TROF
NEAR THE EAST COAST. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
321 PM CST THU DEC 22 2011
.SYNOPSIS...
SURFACE ANALYSIS AT 18Z SHOWED THE COLD FRONT THAT MOVED THROUGH
OVERNIGHT STRETCHED FROM NE TX ACROSS FAR SOUTHERN IL TO LOWER MI. A
1032 HIGH WAS BUILDING INTO SD AND NE WITH A RESULTING TIGHT
PRESSURE GRADIENT ACROSS IA PRODUCING 15 TO 20 KT NORTHERLY WINDS
OVER MUCH OF THE FORECAST AREA. SATELLITE IMAGES INDICATED THE BACK
EDGE OF THE SOUTHWARD RETREATING STRATUS DECK REACHING FROM KOTM TO
NEAR GALENA. A NARROWER...MORE CONVECTIVE LOOKING CLOUD DECK WITH
MVFR BASES WAS FURTHER NORTH ACROSS NE IA INTO WI...SHOWING SINGS OF
SHRINKING AS IT WAS ADVANCING SLOWLY SOUTHWARD. FURTHER SOUTH...AREA
RADARS SHOWED AN EXPANDING BAND OF REFLECTIVITY FROM KIRKSVILLE TO
THE QUAD CITIES...LIKELY ASSOCIATED WITH A WEAK MID LEVEL VORT
MOVING THROUGH THE AREA AND THE DEPARTING 300 MB JET CORE. 12Z
ANALYSIS REVEALED THIS JET MAX EMBEDDED IN THE UPPER LEVEL SW FLOW
AHEAD OF A NORTHERN STREAM TROUGH FROM HUDSON BAY SE INTO NEB AND A
SEPARATE...MORE CUTOFF...MID AND UPPER LEVEL CIRCULATION OVER
SOUTHERN UT.
&&
.SHORT TERM...TONIGHT AND FRIDAY...
INITIAL CONCERN IS THE POTENTIAL FOR VERY LIGHT SNOW OR FLURRIES
OVER THE NEXT SEVERAL HOURS...THEN FOCUS TURNS TO OVERNIGHT LOW
TEMPERATURES. THE EXPANDING AND INCREASING BAND OF LIGHT SNOW
MENTIONED IN THE SYNOPSIS OVER THE SOUTH HAS RECENTLY BEGUN SHOWING
UP WITH GENERALLY 1 TO 4SM -SN ALONG THE MS RIVER SOUTH OF
MUSCATINE. BASED ON VSBYS AND RADAR TRENDS...COULD SEE A QUICK
DUSTING TO POSSIBLE 1/2 INCH BEFORE THE MID LEVEL FORCING...WHICH
THE LATEST RUC AND NAM12 HAVE A ROUGH HANDLE ON...QUICKLY PUSHES
EAST BEFORE 00Z. HAVE THUS INCREASED A SMALL AREA TO LIKELY POPS FOR
LATE AFTERNOON FOR ALONG AND EAST OF THE MS RIVER SOUTH OF THE QUAD CITIES
INTO IL.
OVERNIGHT...HIGH PRESSURE RIDGE EXTENDING W-NW FROM THE HIGH PLAINS
HIGH...ALONG WITH MID LEVEL SUBSIDENCE BEHIND THE SHORTWAVE PASSING
TO THE NORTH SHOULD PUSH THE LOW CLOUDS SOUTH OF THE AREA BY
MIDNIGHT. CLEARING SKIES AND LIGHT WINDS SHOULD RESULT IN THE
COLDEST NIGHT IN SEVERAL DAYS...AND BASED ON TRAJECTORIES...LOWS
CLOSE TO GUIDANCE BLEND FROM AROUND 15 NORTH TO LOWER 20S SOUTH LOOK
REASONABLE. FRIDAY...SUNSHINE...LACK OF SNOW COVER...AND RETURN FLOW
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO RECOVER WELL INTO THE
30S. ..SHEETS..
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
THE EXTENDED FORECAST REMAINS DOMINATED BY MOSTLY BENIGN NORTHWEST
FLOW FRONTAL PASSAGES. THIS NORMALLY REPRESENTS A BELOW NORMAL
FORECAST FOR TEMPERATURES...BUT WITH SPLIT FLOW...THIS SHOULD KEEP
TEMPERATURES GENERALLY ABOVE NORMAL...AND ALSO WILL KEEP POPS VERY
LOW. THERE REMAINS TWO POTENTIAL POP CHANCES IN THE EXTENDED...BUT
BOTH ARE POORLY SHOWN WITH RESPECT TO CONSISTENCY IN ANY ONE MODEL
RUN. THE FIRST...MONDAY AND MONDAY NIGHT... THE MODEL BLEND KEEPS
THE FORECAST DRY AS THE GFS CONTINUES TO SHOW A CLIPPER PASSING WELL
NORTH OF THE CWA....RESULTING IN DRY WAA DAY. HOWEVER...THE ECMWF
AND CANADIAN BOTH BRING THE CUT OFF LOW FROM THE SOUTHWEST UP OVER
THE CWA MONDAY AND MONDAY NIGHT...RESULTING IN POTENTIAL RAIN OR
SNOW. FOR NOW...HAVE BUMPED UP POPS TO 10 TO 14 PERCENT AND SKY
COVER AS WELL...BUT LEFT DRY.
AFTER SEVERAL MORE DAYS OF BENIGN NORTHWEST FLOW...MODELS SHOW
ANOTHER BROAD TROF MOVING PAST THE REGION AROUND FRIDAY. THIS WAVE
INITIALIZED WITH SLIGHT TO LOW CHANCE POPS FOR SNOW.
TEMPERATURES THROUGHOUT THE FORECAST ARE GENERALLY FROM THE MID 30S
TO MID 40S...WITH LOWS IN THE MID 20S TO LOWER 30S. SUCH
TEMPERATURES ARE VERY MILD FOR THE SHORTEST DAYS OF THE YEAR.
..ERVIN..
&&
.AVIATION...
HIGH PRESSURE BUILDING INTO THE PLAINS WILL CONTINUE TO PUSH
COLDER...DRIER AIR INTO THE AREA LOCAL AREA LATE THIS AFTERNOON INTO
EVENING...DRIVING THE LOW CLOUDS SOUTHWARD. CIGS LIFTED TO VFR EARLY
THIS AFTERNOON AT CID AND DBQ...AND THIS CLEARING TREND IS EXPECTED
REACH MLI AND BRL LATE THIS AFTERNOON INTO EARLY EVENING. A WEAK
UPPER LEVEL DISTURBANCE PRODUCING A BAND OF FLURRIES OVER SE IA AT
MID AFTERNOON MAY AFFECT BRL BEFORE 00Z...AND A TEMPO GROUP FOR MVFR
VSBYS HAS BEEN ADDED IN AN UPDATE. OVERNIGHT INTO FRIDAY...SKIES
WILL BECOME MOSTLY CLEAR WITH NORTH WINDS BACKING TO THE WEST AND
THEN SOUTHWEST BY LATE MORNING. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SHEETS/ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1110 AM CST THU DEC 22 2011
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
LIGHT SNOW AND BLOWING SNOW WILL KEEP KDDC AND KGCK IN IFR CIGS
AND VSBYS THROUGH 22Z TO BE IFR. KHYS WILL HAVE MVFR CIGS WITH 6SM
PLUS VSBY. NORTHEAST WINDS OF 20 TO 25 KNOTS WILL PERSIST THROUGH
22 TO 23Z. AS THE UPPER AIR DISTURBANCE EXITS EAST THIS EVENING,
THE WINDS WILL DIMINISH TO NORTHWEST AT 10 KTS OR LESS AFTER 03Z,
AND BOTH CIGS AND VSBYS WILL IMPROVE TO VFR BY 03Z. CLEAR SKIES ARE
EXPECTED AFTER 09Z TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 539 AM CST THU DEC 22 2011/
SYNOPSIS...
22.00Z 300 HPA JET ANALYSIS SHOWS THAT KANSAS LIES BETWEEN A STRONG
SOUTHERN JET EXTENDING FROM MEXICO TO THE LOWER MISSISSIPPI RIVER VALLEY
AND A NORTHERN JET WAS SLIDING EAST ACROSS THE NORTHERN PLAINS. A 75-85
KT JET WAS MOVING PUSHING SOUTHWARD UPSTREAM OF A 500 HPA LOW PRESSURE
CENTER LOCATED ACROSS EASTERN UTAH. MID ATMOSPHERE ANALYSIS INDICATES
COLD AIR OF -30 TO -37 DEG C AIR FROM WYOMING NORTHWARD TO/ACROSS THE
CANADIAN PRAIRIES. AT 700 AND 850 HPA...COLDER AIR WAS ADVECTING ACROSS
THE NORTHERN AND CENTRAL PLAINS. AT THE SURFACE, A COLD FRONT WAS PUSHING
ACROSS THE STATE OF KANSAS EARLY THIS MORNING. -SUGDEN
DISCUSSION...
DAYS 1-2...
TODAY:
THE AFOREMENTIONED MID ATMOSPHERIC LOW WILL SINK SOUTHWARD FROM UTAH
TO THE 4 CORNERS REGION. THE 80-90 KT JET WRAPPING AROUND THIS LOW WILL
PUT WESTERN KANSAS JUST NORTH OF THE LEFT EXIT REGION WITH DYNAMIC LIFT
AND 700 OMEGA DEVELOPING ACROSS THE REGION. IN ADDITION, UPSLOPE 700/850
HPA FLOW WILL PROVIDE ENOUGH LOW TO MID LEVEL LIFT TO PROVIDE THE REGION
WITH LIGHT SNOW SHOWERS TODAY. THE LATEST HRRR (WHICH ONLY GOES OUT
TIL ABOUT 20Z) WAS USED AS A STARTING FOUNDATION FOR SNOW ACCUMULATION.
MUCH OF THE REGION WILL SEE ABOUT 0.5 TO 1.0 INCHES WITH SLIGHTLY MORE
POSSIBLE ACROSS MY NORTHWEST COUNTIES (FLIRTING TO AROUND 2.0 INCHES).
HAVE ADDED BLOWING SNOW BASED OFF UPSTREAM OBSERVATIONS SHOWING A REDUCTION
IN VISIBILITIES ALREADY. OTHERWISE, TODAY WILL BE CLOUDY WITH NORTH
TO NORTHEASTERLY WINDS RUNNING AROUND 20 KT IN THE WAKE OF A COLD FRONT.
WILL HIGHLIGHT THE LIGHT SNOW ACCUMULATIONS/BLOWING SNOW IN THE HWO
BUT THIS WILL BE BELOW ADVISORY CRITERIA SO AM NOT PLANNING TO ISSUE
A WSW RIGHT NOW. MAXIMUM TEMPERATURES WILL BE IN THE UPPER 20S TO LOWER
30S DEG F.
TONIGHT:
PRECIPITATION WILL END THIS EVENING FROM THE NORTHEAST TO THE SOUTHWEST
AS THE MID LEVEL LOW SINKS FURTHER SOUTH. FORECAST SOUNDINGS SHOW QUITE
A BIT OF DRYING LATE TONIGHT INTO TOMORROW MORNING SO I HAVE RAMPED
CLOUD COVER DOWN. WITH CLEARING SKIES AND A SURFACE HIGH PRESSURE CENTER
SLIDING ACROSS KANSAS, A GOOD NIGHT FOR RADIATIONAL COOLING IS EXPECTED.
MINIMUM TEMPERATURES IN THE SINGLE DIGITS DEG F IS EXPECTED ACROSS FAR
WESTERN KANSAS. SLIGHTLY WARMER TEMPERATURES WITH TEENS DEG F ARE EXPECTED
ACROSS SOUTH CENTRAL KANSAS.
FRIDAY/FRIDAY NIGHT:
I HAVE INCREASED TEMPERATURES FRIDAY AS A LEE TROUGH DEVELOPS ACROSS
THE LEE OF THE ROCKIES AND MOVES EAST IN ASSOCIATION WITH THE PASSAGE
OF A WEAK SHORTWAVE TROUGH TRAVERSING ACROSS THE NORTHERN PLAINS. MAXIMUM
TEMPERATURES SHOULD WARM TO NEAR TO SLIGHTLY ABOVE FREEZING WITH A BIT
OF DOWNSLOPE SOUTHWESTERLY TO WESTERLY SURFACE WINDS. A DRY ATMOSPHERE
WILL LEAD TO FULL INSOLATION ON FRIDAY AS WELL. A BIT OF EROSION OF
THE SNOW FIELD IS POSSIBLE FRIDAY FOR AREAS THAT GET ABOVE FREEZING.
OVERNIGHT LOWS INTO SATURDAY WILL BE SLIGHTLY WARMER WITH THE CONTINUATION
OF A DOWNSLOPE WESTERLY WIND. NO PRECIPITATION IS EXPECTED FRIDAY. -SUGDEN
DAYS 3-7...
THE PERIOD SATURDAY THROUGH WEDNESDAY WILL BE VERY QUIET SENSIBLE WEATHER
WISE WITH NO PRECIPITATION EXPECTED DURING THIS ENTIRE PERIOD. THE PLANETARY
SCALE PATTERN ACROSS THE NORTH PACIFIC INTO NORTH AMERICA WILL BE CHARACTERIZED
BY A LOW WAVE NUMBER/LOW AMPLITUDE WHICH WILL RESULT IN A WARMER-THAN-
AVERAGE PERIOD OF WEATHER ACROSS THE WESTERN PLAINS...IF IT WERE NOT
FOR A FAIRLY HEALTHY SNOW PACK IN PLACE.
THE 19-20 DECEMBER BLIZZARD CAUSED A LARGE SNOWPACK ACROSS SOUTHEASTERN
COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS WHICH WILL TAKE SEVERAL DAYS
TO DWINDLE DOWN. AS A RESULT...HIGH TEMPERATURE FORECASTING WILL BE
DIFFICULT...AND WILL BE DEPENDENT UPON THE DAILY REDUCTION OF THE SNOWPACK.
AN UPPER RIDGE WILL BUILD OVER THE ROCKIES SATURDAY/SATURDAY NIGHT...WHICH
WILL THEN ERODE AS ZONAL JET FLOW MOVES INTO THE NORTHERN ROCKIES SPAWNING
A DEEP LEE TROUGH FROM ALBERTA SOUTH TO EASTERN COLORADO. THIS LOOKS
LIKE A CLASSIC DOWNSLOPE WARMING SETUP AND IT WOULD APPEAR ON PAPER
THAT THIS DAY WILL BE QUITE WARM AND WILL REALLY KNOCK OUT A GOOD CHUNK
OF WHATEVER REMNANT SNOWPACK THERE IS ACROSS WESTERN DDC FORECAST AREA.
WITH SOME COLLABORATION HAVE INCREASED THE HIGHS A FEW DEGREES OVER
THE ALLBLEND GUIDANCE FOR MONDAY. THIS IS THE ONLY CHANGE MADE AGAINST
THE ALLBLEND GUIDANCE FOR THE MEDIUM RANGE.
IN THE FAR EXTENDED TIME FRAME...AN EXTENDED NORTH PACIFIC JET WILL
MIGRATE EASTWARD DURING THE 27-30 DECEMBER TIME FRAME WITH A HINT AT
RIDGE BUILDING SOMEWHERE BETWEEN 140W AND 120W...WHICH COULD FAVOR DOWNSTREAM
TROUGH DEVELOPMENT OVER THE WESTERN OR CENTRAL CONUS BY THE 30-31 DECEMBER
TIME FRAME. THIS WOULD BE THE EARLIEST TIME FRAME THAT PRECIPITATION
CHANCES COULD ENTER THE PICTURE...BUT THIS IS IN THE DAY 8-10 TIME FRAME
AND IT REMAINS TO BE SEEN HOW THE SYNOPTIC SCALE EVOLVES AS THE EXTENDED
JET APPROACHES THE NORTHEAST PACIFIC. -UMSCHEID
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 14 33 14 / 50 10 0 0
GCK 31 8 33 12 / 60 20 0 0
EHA 29 10 27 16 / 70 20 0 0
LBL 32 12 31 15 / 60 20 0 0
HYS 32 13 34 14 / 60 10 0 0
P28 33 19 36 21 / 50 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM CST /3 PM MST/ THIS AFTERNOON
FOR KSZ030-031-043>046-061>065-074>078-084>087.
&&
$$
FN12/99/99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
539 AM CST THU DEC 22 2011
.AVIATION...
FOR THE 12Z TAF ISSUANCE...
LIGHT SNOW WILL CONTINUE TO DEVELOP SOUTHWARD THIS MORNING AND
AFFECT GCK, DDC, AND HYS TERMINALS FOR SEVERAL HOURS TODAY. AT
THIS TIME...BELIEVE THAT THE LIGHT SNOW EVENT WILL LAST NO MORE
THAN ABOUT 4 OR 5 HOURS AS THIS WILL NOT BE A VERY SIGNIFICANT
PRECIPITATION EVENT. NEVERTHELESS...STRONG NORTHEAST WINDS
COMBINED WITH EVEN LIGHT SNOW WILL LOWER VISIBILITY DOWN TO THE 1
TO 2 MILE RANGE FOR SOME TIME DURING THE EVENT. IFR CONDITIONS
SHOULD PERSIST THROUGH THE DAY UNTIL ABOUT 21Z AT GCK AND DDC AND
ABOUT 19Z AT HYS. -UMSCHEID
&&
.PREV DISCUSSION... /ISSUED 225 AM CST THU DEC 22 2011/
SYNOPSIS...
22.00Z 300 HPA JET ANALYSIS SHOWS THAT KANSAS LIES BETWEEN A STRONG
SOUTHERN JET EXTENDING FROM MEXICO TO THE LOWER MISSISSIPPI RIVER VALLEY
AND A NORTHERN JET WAS SLIDING EAST ACROSS THE NORTHERN PLAINS. A 75-85
KT JET WAS MOVING PUSHING SOUTHWARD UPSTREAM OF A 500 HPA LOW PRESSURE
CENTER LOCATED ACROSS EASTERN UTAH. MID ATMOSPHERE ANALYSIS INDICATES
COLD AIR OF -30 TO -37 DEG C AIR FROM WYOMING NORTHWARD TO/ACROSS THE
CANADIAN PRAIRIES. AT 700 AND 850 HPA...COLDER AIR WAS ADVECTING ACROSS
THE NORTHERN AND CENTRAL PLAINS. AT THE SURFACE, A COLD FRONT WAS PUSHING
ACROSS THE STATE OF KANSAS EARLY THIS MORNING. -SUGDEN
DISCUSSION...
DAYS 1-2...
TODAY:
THE AFOREMENTIONED MID ATMOSPHERIC LOW WILL SINK SOUTHWARD FROM UTAH
TO THE 4 CORNERS REGION. THE 80-90 KT JET WRAPPING AROUND THIS LOW WILL
PUT WESTERN KANSAS JUST NORTH OF THE LEFT EXIT REGION WITH DYNAMIC LIFT
AND 700 OMEGA DEVELOPING ACROSS THE REGION. IN ADDITION, UPSLOPE 700/850
HPA FLOW WILL PROVIDE ENOUGH LOW TO MID LEVEL LIFT TO PROVIDE THE REGION
WITH LIGHT SNOW SHOWERS TODAY. THE LATEST HRRR (WHICH ONLY GOES OUT
TIL ABOUT 20Z) WAS USED AS A STARTING FOUNDATION FOR SNOW ACCUMULATION.
MUCH OF THE REGION WILL SEE ABOUT 0.5 TO 1.0 INCHES WITH SLIGHTLY MORE
POSSIBLE ACROSS MY NORTHWEST COUNTIES (FLIRTING TO AROUND 2.0 INCHES).
HAVE ADDED BLOWING SNOW BASED OFF UPSTREAM OBSERVATIONS SHOWING A REDUCTION
IN VISIBILITIES ALREADY. OTHERWISE, TODAY WILL BE CLOUDY WITH NORTH
TO NORTHEASTERLY WINDS RUNNING AROUND 20 KT IN THE WAKE OF A COLD FRONT.
WILL HIGHLIGHT THE LIGHT SNOW ACCUMULATIONS/BLOWING SNOW IN THE HWO
BUT THIS WILL BE BELOW ADVISORY CRITERIA SO AM NOT PLANNING TO ISSUE
A WSW RIGHT NOW. MAXIMUM TEMPERATURES WILL BE IN THE UPPER 20S TO LOWER
30S DEG F.
TONIGHT:
PRECIPITATION WILL END THIS EVENING FROM THE NORTHEAST TO THE SOUTHWEST
AS THE MID LEVEL LOW SINKS FURTHER SOUTH. FORECAST SOUNDINGS SHOW QUITE
A BIT OF DRYING LATE TONIGHT INTO TOMORROW MORNING SO I HAVE RAMPED
CLOUD COVER DOWN. WITH CLEARING SKIES AND A SURFACE HIGH PRESSURE CENTER
SLIDING ACROSS KANSAS, A GOOD NIGHT FOR RADIATIONAL COOLING IS EXPECTED.
MINIMUM TEMPERATURES IN THE SINGLE DIGITS DEG F IS EXPECTED ACROSS FAR
WESTERN KANSAS. SLIGHTLY WARMER TEMPERATURES WITH TEENS DEG F ARE EXPECTED
ACROSS SOUTH CENTRAL KANSAS.
FRIDAY/FRIDAY NIGHT:
I HAVE INCREASED TEMPERATURES FRIDAY AS A LEE TROUGH DEVELOPS ACROSS
THE LEE OF THE ROCKIES AND MOVES EAST IN ASSOCIATION WITH THE PASSAGE
OF A WEAK SHORTWAVE TROF TRAVERSING ACROSS THE NORTHERN PLAINS. MAXIMUM
TEMPERATURES SHOULD WARM TO NEAR TO SLIGHTLY ABOVE FREEZING WITH A BIT
OF DOWNSLOPE SOUTHWESTERLY TO WESTERLY SURFACE WINDS. A DRY ATMOSPHERE
WILL LEAD TO FULL INSOLATION ON FRIDAY AS WELL. A BIT OF EROSION OF
THE SNOW FIELD IS POSSIBLE FRIDAY FOR AREAS THAT GET ABOVE FREEZING.
OVERNIGHT LOWS INTO SATURDAY WILL BE SLIGHTLY WARMER WITH THE CONTINUATION
OF A DOWNSLOPE WESTERLY WIND. NO PRECIPITATION IS EXPECTED FRIDAY. -SUGDEN
DAYS 3-7...
THE PERIOD SATURDAY THROUGH WEDNESDAY WILL BE VERY QUIET SENSIBLE WEATHER
WISE WITH NO PRECIPITATION EXPECTED DURING THIS ENTIRE PERIOD. THE PLANETARY
SCALE PATTERN ACROSS THE NORTH PACIFIC INTO NORTH AMERICA WILL BE CHARACTERIZED
BY A LOW WAVE NUMBER/LOW AMPLITUDE WHICH WILL RESULT IN A WARMER-THAN-
AVERAGE PERIOD OF WEATHER ACROSS THE WESTERN PLAINS...IF IT WERE NOT
FOR A FAIRLY HEALTHY SNOW PACK IN PLACE.
THE 19-20 DECEMBER BLIZZARD CAUSED A LARGE SNOWPACK ACROSS SOUTHEASTERN
COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS WHICH WILL TAKE SEVERAL DAYS
TO DWINDLE DOWN. AS A RESULT...HIGH TEMPERATURE FORECASTING WILL BE
DIFFICULT...AND WILL BE DEPENDENT UPON THE DAILY REDUCTION OF THE SNOWPACK.
AN UPPER RIDGE WILL BUILD OVER THE ROCKIES SATURDAY/SATURDAY NIGHT...WHICH
WILL THEN ERODE AS ZONAL JET FLOW MOVES INTO THE NORTHERN ROCKIES SPAWNING
A DEEP LEE TROUGH FROM ALBERTA SOUTH TO EASTERN COLORADO. THIS LOOKS
LIKE A CLASSIC DOWNSLOPE WARMING SETUP AND IT WOULD APPEAR ON PAPER
THAT THIS DAY WILL BE QUITE WARM AND WILL REALLY KNOCK OUT A GOOD CHUNK
OF WHATEVER REMNANT SNOWPACK THERE IS ACROSS WESTERN DDC FORECAST AREA.
WITH SOME COLLABORATION HAVE INCREASED THE HIGHS A FEW DEGREES OVER
THE ALLBLEND GUIDANCE FOR MONDAY. THIS IS THE ONLY CHANGE MADE AGAINST
THE ALLBLEND GUIDANCE FOR THE MEDIUM RANGE.
IN THE FAR EXTENDED TIME FRAME...AN EXTENDED NORTH PACIFIC JET WILL
MIGRATE EASTWARD DURING THE 27-30 DECEMBER TIME FRAME WITH A HINT AT
RIDGE BUILDING SOMEWHERE BETWEEN 140W AND 120W...WHICH COULD FAVOR DOWNSTREAM
TROUGH DEVELOPMENT OVER THE WESTERN OR CENTRAL CONUS BY THE 30-31 DECEMBER
TIME FRAME. THIS WOULD BE THE EARLIEST TIME FRAME THAT PRECIPITATION
CHANCES COULD ENTER THE PICTURE...BUT THIS IS IN THE DAY 8-10 TIME FRAME
AND IT REMAINS TO BE SEEN HOW THE SYNOPTIC SCALE EVOLVES AS THE EXTENDED
JET APPROACHES THE NORTHEAST PACIFIC. -UMSCHEID
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 30 14 33 14 / 50 10 0 0
GCK 32 8 33 12 / 60 20 0 0
EHA 29 10 27 16 / 70 20 0 0
LBL 31 12 31 15 / 60 20 0 0
HYS 32 13 34 14 / 60 10 0 0
P28 34 19 36 21 / 50 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN99/99/25
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
225 AM CST THU DEC 22 2011
.SYNOPSIS...
22.00Z 300 HPA JET ANALYSIS SHOWS THAT KANSAS LIES BETWEEN A STRONG
SOUTHERN JET EXTENDING FROM MEXICO TO THE LOWER MISSISSIPPI RIVER VALLEY
AND A NORTHERN JET WAS SLIDING EAST ACROSS THE NORTHERN PLAINS. A 75-85
KT JET WAS MOVING PUSHING SOUTHWARD UPSTREAM OF A 500 HPA LOW PRESSURE
CENTER LOCATED ACROSS EASTERN UTAH. MID ATMOSPHERE ANALYSIS INDICATES
COLD AIR OF -30 TO -37 DEG C AIR FROM WYOMING NORTHWARD TO/ACROSS THE
CANADIAN PRAIRIES. AT 700 AND 850 HPA...COLDER AIR WAS ADVECTING ACROSS
THE NORTHERN AND CENTRAL PLAINS. AT THE SURFACE, A COLD FRONT WAS PUSHING
ACROSS THE STATE OF KANSAS EARLY THIS MORNING. -SUGDEN
&&
.DISCUSSION...
DAYS 1-2...
TODAY:
THE AFOREMENTIONED MID ATMOSPHERIC LOW WILL SINK SOUTHWARD FROM UTAH
TO THE 4 CORNERS REGION. THE 80-90 KT JET WRAPPING AROUND THIS LOW WILL
PUT WESTERN KANSAS JUST NORTH OF THE LEFT EXIT REGION WITH DYNAMIC LIFT
AND 700 OMEGA DEVELOPING ACROSS THE REGION. IN ADDITION, UPSLOPE 700/850
HPA FLOW WILL PROVIDE ENOUGH LOW TO MID LEVEL LIFT TO PROVIDE THE REGION
WITH LIGHT SNOW SHOWERS TODAY. THE LATEST HRRR (WHICH ONLY GOES OUT
TIL ABOUT 20Z) WAS USED AS A STARTING FOUNDATION FOR SNOW ACCUMULATION.
MUCH OF THE REGION WILL SEE ABOUT 0.5 TO 1.0 INCHES WITH SLIGHTLY MORE
POSSIBLE ACROSS MY NORTHWEST COUNTIES (FLIRTING TO AROUND 2.0 INCHES).
HAVE ADDED BLOWING SNOW BASED OFF UPSTREAM OBSERVATIONS SHOWING A REDUCTION
IN VISIBILITIES ALREADY. OTHERWISE, TODAY WILL BE CLOUDY WITH NORTH
TO NORTHEASTERLY WINDS RUNNING AROUND 20 KT IN THE WAKE OF A COLD FRONT.
WILL HIGHLIGHT THE LIGHT SNOW ACCUMULATIONS/BLOWING SNOW IN THE HWO
BUT THIS WILL BE BELOW ADVISORY CRITERIA SO AM NOT PLANNING TO ISSUE
A WSW RIGHT NOW. MAXIMUM TEMPERATURES WILL BE IN THE UPPER 20S TO LOWER
30S DEG F.
TONIGHT:
PRECIPITATION WILL END THIS EVENING FROM THE NORTHEAST TO THE SOUTHWEST
AS THE MID LEVEL LOW SINKS FURTHER SOUTH. FORECAST SOUNDINGS SHOW QUITE
A BIT OF DRYING LATE TONIGHT INTO TOMORROW MORNING SO I HAVE RAMPED
CLOUD COVER DOWN. WITH CLEARING SKIES AND A SURFACE HIGH PRESSURE CENTER
SLIDING ACROSS KANSAS, A GOOD NIGHT FOR RADIATIONAL COOLING IS EXPECTED.
MINIMUM TEMPERATURES IN THE SINGLE DIGITS DEG F IS EXPECTED ACROSS FAR
WESTERN KANSAS. SLIGHTLY WARMER TEMPERATURES WITH TEENS DEG F ARE EXPECTED
ACROSS SOUTH CENTRAL KANSAS.
FRIDAY/FRIDAY NIGHT:
I HAVE INCREASED TEMPERATURES FRIDAY AS A LEE TROUGH DEVELOPS ACROSS
THE LEE OF THE ROCKIES AND MOVES EAST IN ASSOCIATION WITH THE PASSAGE
OF A WEAK SHORTWAVE TROF TRAVERSING ACROSS THE NORTHERN PLAINS. MAXIMUM
TEMPERATURES SHOULD WARM TO NEAR TO SLIGHTLY ABOVE FREEZING WITH A BIT
OF DOWNSLOPE SOUTHWESTERLY TO WESTERLY SURFACE WINDS. A DRY ATMOSPHERE
WILL LEAD TO FULL INSOLATION ON FRIDAY AS WELL. A BIT OF EROSION OF
THE SNOW FIELD IS POSSIBLE FRIDAY FOR AREAS THAT GET ABOVE FREEZING.
OVERNIGHT LOWS INTO SATURDAY WILL BE SLIGHTLY WARMER WITH THE CONTINUATION
OF A DOWNSLOPE WESTERLY WIND. NO PRECIPITATION IS EXPECTED FRIDAY. -SUGDEN
DAYS 3-7...
THE PERIOD SATURDAY THROUGH WEDNESDAY WILL BE VERY QUIET SENSIBLE WEATHER
WISE WITH NO PRECIPITATION EXPECTED DURING THIS ENTIRE PERIOD. THE PLANETARY
SCALE PATTERN ACROSS THE NORTH PACIFIC INTO NORTH AMERICA WILL BE CHARACTERIZED
BY A LOW WAVE NUMBER/LOW AMPLITUDE WHICH WILL RESULT IN A WARMER-THAN-
AVERAGE PERIOD OF WEATHER ACROSS THE WESTERN PLAINS...IF IT WERE NOT
FOR A FAIRLY HEALTHY SNOW PACK IN PLACE.
THE 19-20 DECEMBER BLIZZARD CAUSED A LARGE SNOWPACK ACROSS SOUTHEASTERN
COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS WHICH WILL TAKE SEVERAL DAYS
TO DWINDLE DOWN. AS A RESULT...HIGH TEMPERATURE FORECASTING WILL BE
DIFFICULT...AND WILL BE DEPENDENT UPON THE DAILY REDUCTION OF THE SNOWPACK.
AN UPPER RIDGE WILL BUILD OVER THE ROCKIES SATURDAY/SATURDAY NIGHT...WHICH
WILL THEN ERODE AS ZONAL JET FLOW MOVES INTO THE NORTHERN ROCKIES SPAWNING
A DEEP LEE TROUGH FROM ALBERTA SOUTH TO EASTERN COLORADO. THIS LOOKS
LIKE A CLASSIC DOWNSLOPE WARMING SETUP AND IT WOULD APPEAR ON PAPER
THAT THIS DAY WILL BE QUITE WARM AND WILL REALLY KNOCK OUT A GOOD CHUNK
OF WHATEVER REMNANT SNOWPACK THERE IS ACROSS WESTERN DDC FORECAST AREA.
WITH SOME COLLABORATION HAVE INCREASED THE HIGHS A FEW DEGREES OVER
THE ALLBLEND GUIDANCE FOR MONDAY. THIS IS THE ONLY CHANGE MADE AGAINST
THE ALLBLEND GUIDANCE FOR THE MEDIUM RANGE.
IN THE FAR EXTENDED TIME FRAME...AN EXTENDED NORTH PACIFIC JET WILL
MIGRATE EASTWARD DURING THE 27-30 DECEMBER TIME FRAME WITH A HINT AT
RIDGE BUILDING SOMEWHERE BETWEEN 140W AND 120W...WHICH COULD FAVOR DOWNSTREAM
TROUGH DEVELOPMENT OVER THE WESTERN OR CENTRAL CONUS BY THE 30-31 DECEMBER
TIME FRAME. THIS WOULD BE THE EARLIEST TIME FRAME THAT PRECIPITATION
CHANCES COULD ENTER THE PICTURE...BUT THIS IS IN THE DAY 8-10 TIME FRAME
AND IT REMAINS TO BE SEEN HOW THE SYNOPTIC SCALE EVOLVES AS THE EXTENDED
JET APPROACHES THE NORTHEAST PACIFIC. -UMSCHEID
&&
.AVIATION...
FOR THE 06Z TAF ISSUANCE...VFR CIGS AT THE TAF SITES WILL DEGRADE INTO
MVFR/IFR CONDITIONS THROUGH THE EARLY MORNING HOURS. LIGHT SNOW WILL
SPREAD SOUTH ACROSS WESTERN KANSAS FROM THE EARLY MORNING HOURS THROUGH
ABOUT MIDDAY BEFORE MOVING SOUTH OF THE AREA THIS AFTERNOON. OCCASIONAL
MVFR VSBYS IN LIGHT SNOW WILL BE POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 14 33 14 / 50 10 0 0
GCK 28 8 33 12 / 60 20 0 0
EHA 27 10 27 16 / 70 20 0 0
LBL 29 12 31 15 / 60 20 0 0
HYS 30 13 34 14 / 60 10 0 0
P28 33 19 36 21 / 50 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN36/25/25
AREA FORECAST DISCUSSION
NWS GRAY ME
508 PM EST THU DEC 22 2011
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL TRACK NORTHEAST FROM THE MID
ATLANTIC STATES TONIGHT THEN CONTINUE TO MOVE TO THE NORTHEAST
JUST BEYOND THE GULF OF MAINE ON FRIDAY. HIGH PRESSURE AND DRY
AIR FOLLOWS FOR LATER SATURDAY INTO CHRISTMAS DAY. A WEAK WARM
FRONT COULD PRODUCE A FEW SNOW SHOWERS ACROSS NORTHERN SECTIONS OF
THE AREA LATE CHRISTMAS DAY. A COLD FRONT WILL CROSS THE AREA
EARLY MONDAY, WHILE AN OCEAN LOW PASSES WELL SOUTH AND EAST OF THE
AREA. HIGH PRESSURE WILL BUILD BY TO OUR SOUTH LATE MONDAY INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATE...
MINOR ADJUSTMENTS MADE TO THE TEMPERATURE AND DEW POINT GRIDS
BASED ON CURRENT CONDITIONS. PRECIPITATION SHIELD CONTINUES TO
MOVE STEADILY NORTHEASTWARD AND WILL ARRIVE QUICKLY AROUND OR
SHORTLY AFTER MIDNIGHT. AWAITING FOR BOUNDARY LAYER TEMPERATURES
TO COOL AS WARM GROUND WILL INHIBIT ACCUMULATIONS AT THE ONSET.
PRECIPITATION RATES INCREASE LATER TONIGHT WHICH WILL AID IN
COOLING THE COLUMN. WILL TAKE A GOOD LOOK AT THE 00Z GYX SOUNDING
FOR LOW LEVEL TRENDS IN THE ATMOS.
MINOR ADJUSTMENT MADE TO OTHER PRODUCTS...BUT ALL IN
ALL...FORECAST APPEARS IN GOOD SHAPE. WILL LIKELY BE ISSUING A
STATEMENT LATER THIS EVENING TO ACCOUNT FOR THE TIMING AND PTYPE
TRENDS...SINCE MUCH OF THIS WILL AFFECT THE MORNING RUSH HOUR.
TIMING OF STEADY PCPN: LATEST HRRR RUN BRINGS THE
HEAVIEST/STEADIEST PCPN TO SOUTHERN NEW HAMPSHIRE AROUND 09Z WHICH
SEAMS REASONABLE AT THIS TIME.
PREV DISC...
A WEAK AND FAST MOVING SFC LOW MOVES NE FROM THE MID ATLANTIC
STATES TNGT THEN TRACKS TO THE NE JUST BEYOND THE GULF OF MAINE
FRIDAY...REACHING E OF THE HAGUE LINE LATE IN THE DAY. THE TRACK
IS ABOUT OVER THE BENCHMARK OF 40N 70W BUT DUE TO ITS RAPID
MOVEMENT AMOUNTS SHOULD REMAIN LIGHT. ALSO THE UPR LVL SUPPORT IS
LIMITED WITH A POSITIVE TILTED TROF AND A WEAK SFC LOW AS A
RESULT. STILL...THE MODELS FCST GENERALLY 2-4 INCHES OF SNOW WITH
THE HIGHEST AMOUNTS OVER SOUTHERN AREAS OF INTERIOR MAINE AND NH.
A FEW HIGHER AMOUNTS OF AROUND 5 INCHES CAN`T BE RULED OUT OVER
SOME AREAS OF HIGHER TERRAIN OVER SOUTHERN INTERIOR PORTIONS. THE
MOUNTAINS WILL SEE THE LEAST AMOUNT OF SNOWFALL WITH THIS SYSTEM
WITH ONLY AN INCH OR TWO EXPECTED.
THE TIMING OF THE PCPN IS FOR IT TO BEGIN OVER SOUTHWEST AREAS
AROUND OR SHORTLY AFTER MIDNIGHT BUT THEN RAPIDLY DEVELOP AND
OVERSPREAD THE REST OF THE REGION BY 10Z.
THE PRCP COULD START AS -RA OR MIXED -RASN OVER MORE SERN AND
COASTAL AREAS TNGT AS BOUNDARY LAYER UP TO 925 MB WILL HAVE TEMPS
AROUND OR JUST ABOVE FREEZING. EVENTUALLY PRCP CHANGES TO SN AS
TEMPS COOL DOWN. ON FRIDAY THE SN MAY MIX BACK TO RA IN THE MRNG OVER
THESE AREAS AS SFC AND BOUNDARY LAYER TEMPS AGAIN BEGIN TO CLIMB
INTO THE MID 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
CANADIAN HIGH PRES BUILDS SLOWLY SOUTH SO SOME CLEARING AND DRY CONDITIONS
EXPECTED WITH A RETURN TO MUCH COLDER TEMPS. USED A 50/50 BLEND
OF THE MAV/MET TEMPS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
QUIET WEATHER FOR THE MOST THROUGH THE PERIOD. PERHAPS A FEW SNOW
SHOWERS XMAS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH. THIS
MAY START AS SOME LIGHT OCEAN ENHANCED SNOW ON THE MID COAST
DURING THE AFTERNOON ON XMAS. OTHERWISE...WE/LL HAVE TO WAIT UNTIL
THE 28TH OR SO FOR THE POSSIBILITY OF ANYTHING DECENT IN THE
PRECIPITATION DEPT...AND EVEN THEN THE MODELS HAVE BEEN
INCONSISTENT.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDS THIS EVENING WILL BECOME MVFR TO IFR AFTER
MIDNIGHT FROM SOUTH TO NORTH AS SNOW DEVELOPS AND SPREADS NORTH.
OVER SOUTHEAST NEW HAMPSHIRE THE PCPN MAY FALL AS A MIX AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FRIDAY AFTERNOON ALTHOUGH
SOME SCATTERED SNOW SHOWERS MAY BRIEFLY REDUCE CIGS/VSBYS TO MVFR.
VFR CONDS ACROSS ALL AREAS FRIDAY NIGHT.
LONG TERM...MAINLY VFR THROUGH TUESDAY. A PERIOD OF MVFR POSSIBLE
XMAS DAY AND NIGHT IN SNOW SHOWERS.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS
TNGT AND FRIDAY AS A WEAK AND FAST MOVING COASTAL LOW PASSES SOUTH
OF NEW ENGLAND. CANADIAN HIGH PRESSURE TO OUR NORTH SLOWLY BUILDS
SOUTH ACROSS THE WATERS FRIDAY NIGHT.
LONG TERM...SCA CONDS POSSIBLE OVER THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
910 PM EST FRI DEC 23 2011
.UPDATE...
ALTHOUGH NO MORE THAN AN INCH OF SN HAS FALLEN SO FAR IN LUCE COUNTY
PER CALLS TO SPOTTERS...LATEST RADAR IMAGERY SHOWS HIER
REFLECTIVITIES SHOWING UP IN NRN LK MI AND MOVING NEWD INTO CHIPPEWA
COUNTY TOWARD ERY. THE 00Z APX RAOB SHOWS DEEP MSTR THRU THE ENTIRE
TROP AND AN H85 TEMP OF -12C...PARAMETERS CONDUCIVE TO LK ENHANCED
SN IN AN AREA OF LARGE SCALE QVECTOR CNVGC ASSOCIATED WITH A FAIRLY
VIGOROUS SHRTWV DIGGING SEWD THRU WI. WITH SSW FLOW...EXPECT THE LK
ENHANCED SHSN NOW PUSHING TOWARD ERY TO IMPACT MAINLY THE SE HALF OF
LUCE COUNTY FOR AT LEAST THE NEXT COUPLE OF HRS. SO OPTED TO KEEP
THE GOING WINTER WX ADVY GOING FOR THAT COUNTY THRU MIDNGT. ALTHOUGH
SOME OF THE MORE RECENT HIER RES MODELS SHOW THE SHSN PERSISTING
EVEN BEYOND 06Z...LATEST RUC SHOWS SGNFT DEEP LYR QVECTOR DVGC/MID
LVL DRYING OVERSPREADING THE AREA FM THE W BY 06Z...CONSISTENT WITH
WARMING CLD TOPS OBSVD TO THE W ON RECENT IR STLT IMAGERY AND TRACK
OF SHRTWV TO THE SE AWAY FM THE AREA OF INTEREST. SO EXPECT SHSN
INTENSITY/COVERAGE TO DIMINISH AFT MIDNGT.
&&
.SHORT TERM /TONIGHT AND SATURDAY/ ISSUED AT 402 PM...
PRIMARY ISSUE IS LAKE ENHANCED SNOW OVER FAR EASTERN CWA THIS
EVENING.
CLIPPER LOW PRESSURE SYSTEM ON ITS WAY ACROSS UPR MI LATE THIS AFTN.
WV LOOP AND RAOBS FM 12Z POINT TO SHARP SHORTWAVE DIGGING ACROSS MN
AND NOW INTO SW WI. IR SATELLITE SHOWS GRADUALLY WARMING CLOUD TOP
TEMPS AS THE SYSTEM SNOW HAS PUSHED INTO CNTRL UPR MI AND EASTERN
WI. MOST CONCENTRATED MODERATE SNOW SHOULD END UP FALLING JUST ALONG
AND SOUTH OF THE WI BORDER ADJACENT TO TRACK OF COMPACT SHORTWAVE.
ELSEWHERE...DEEP LAYER Q-VECTOR CONVERGENCE AND BOUT OF ISENTROPIC
ASCENT ON 280K SFC /H7-H6/ WILL LEAD TO A LIGHT DUSTING OF SNOW WITH
ACCUMS UNDER AN INCH. THIS BOUT OF LGT SYSTEM SNOW EXPECTED TO TAPER
QUICKLY THIS EVENING WEST HALF OF CWA AS SUBSIDENCE SPREADS IN FM
MN.
FORCING FM SYSTEM IN PROCESS OF SPREADING ACROSS EASTERN UPR MI
WHICH BRINGS LAKE ENHANCEMENT OFF OF LK MICHIGAN INTO MIX THROUGH
THIS EVENING WITH H85 TEMPS AROUND -10C AND LK SFC TEMPS ROUGHLY
+6C. VISIBLE SATELLITE LOOP OVER PAST FEW HOURS SHOWS CLOUD ELEMENTS
STREAMING IN OFF LK HURON (SE WINDS) AND LK MICHIGAN (SSW WINDS)
CONVERGING OVR CNTRL MACKINAC COUNTY INTO SOUTHERN LUCE COUNTY.
PRESENCE OF THE LOW-LEVEL CONVERGENT FLOW ALLOWED SNOW TO BEGIN AS
EARLY AS MIDDAY AT KERY WITH REDUCED VSBY THROUGH THIS AFTN.
REGIONAL CANADIAN REALLY WAS ONLY HIGHER RESOLUTION MODEL TO
INDICATE SNOW SO EARLY AT KERY AND WILL CONTINUE TO FOLLOW ITS IDEA
FOR FCST THIS EVENING SHOWING WIND TRAJECTORIES FM 210-230 DIRECTION
FLOWING INTO EASTERN CWA. RESULT IS INCREASING LK ENHANCEMENT
THROUGH AROUND 03Z TONIGHT AS BULK OF STRONGER LARGER SCALE LIFT
SLIDES ACROSS AND INVERSION IS PRETTY MUCH ELIMANATED FOR A TIME.
EXPECT HEAVIEST SNOW /TOTALS UP TO 5 INCHES THROUGH MIDNIGHT/ TO
STAY JUST SOUTH AND SOUTHEAST OF CITY OF NEWBERRY WITH PROBABLY LESS
THAN 1 INCH OF SNOW OCCURRING FARTHER W AND NW AT MCMILLAN AND PINE
STUMP JUNCTION. WHERE THIS BAND OF ENHANCED SNOW SETS UP TRAVEL WILL
LIKELY BECOME QUITE DIFFICULT DUE TO SNOW COVERED ROADS AND POOR
VISIBILITY. HAZARD IS FURTHER HEIGHTENED SINCE TRAVEL VOLUME MAY BE
HIGHER DUE TO THE CHRISTMAS HOLIDAY WEEKEND. LAKE ENHANCED SNOW
HEADS EAST OUT OF THE CWA AFT MIDNIGHT ...LEAVING JUST A FEW LIGHTER
SNOW SHOWERS IN ITS WAKE. ELSEWHERE AFTER MID EVENING...SHOULD BE
FAIRLY QUIET AS LOW PRESSURE TROUGH FILLS OVR THE AREA. IF ENOUGH
LOW-LEVEL MOISTURE LINGERS...PERHAPS COULD SEE SOME FZDZ. BETTER
CHANCE FOR THIS WOULD BE OVER EASTERN CWA WITH MOISTURE FLOWING IN
OFF LK MICHIGAN.
LOOKING QUIET FOR SATURDAY. STILL A LOW RISK OF LINGERING LOW CLOUDS
AND MAYBE SOME FZDZ/FLURRIES EARLY. OTHERWISE...EXPECT INCREASING SW
WINDS AND SCT-BKN MID CLOUDS AHEAD OF ANOTHER LOW PRESSURE TROUGH IN
NW FLOW PATTERN. HIGHS SHOULD BE ABOVE NORMAL WITH READINGS UPR 20S
TO LWR 30S.
.LONG TERM 00Z SUN...
NAM SHOWS A 500 MB TROUGH NEAR LAKE WINNIPEG 00Z SUN THAT DIGS
SOUTHEAST INTO THE UPPER GREAT LAKES ON SUN. THIS TROUGH IS QUICKLY
FOLLOWED BY A 500 MB RIDGE OVER THE NORTHERN PLAINS 00Z MON AND THEN
ANOTHER TROUGH COMES INTO THE NORTHERN PLAINS 00Z TUE. NAM SHOWS
SOME 850-500 MB Q-VECTOR CONVERGENCE SAT NIGHT WITH DEEPER MOISTURE
MOVING THROUGH THE CWA AND BOTH MOVE OUT ON SUN. GFS AND ECMWF SHOW
ABOUT THE SAME THING AS THE NAM DOES. DID NOT MAKE TOO MANY CHANGES
TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER. ONE THING WAS TO
CUT BACK ON POPS FOR SAT NIGHT AS COLD AIR DOES NOT GET IN UNTIL
SUNDAY WHEN LAKE EFFECT SNOW STARTS AS COLDER AIR AT 850 MB
TEMPERATURES DROP TO -10C ON SUNDAY. THIS WILL HAVE AN AFFECT OVER
THE WEST WITH LESS LAKE EFFECT FOR LATE SAT NIGHT. WINDS QUICKLY
BACK TO THE NORTHWEST WITH WARM AIR ADVECTION ON SUNDAY NIGHT INTO
MONDAY...SO DRY WEATHER WILL MOVE IN THEN. WILL GET BREEZY ON MONDAY
WITH THE WARM AIR ADVECTION AND WILL GET WARM WITH HIGHS ABOVE
NORMAL IN THE MID 30S TO LOWER 40S.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB RIDGE OVER THE
UPPER GREAT LAKES 12Z MON WITH A TROUGH IN THE CANADIAN PRAIRIES.
THE ECMWF BRINGS THIS TROUGH INTO THE UPPER GREAT LAKES 12Z TUE.
THIS MOVES OUT AND THE UPPER FLOW STAYS NW TO SE FOR WED INTO THU.
THIS WILL ALLOW A COLD FRONT TO BECOME STATIONARY ACROSS THE AREA
FOR THOSE TWO DAYS BEFORE A 500 MB TROUGH ARRIVES FOR FRI WITH AND
ALBERTA CLIPPER AFFECTING THE UPPER GREAT LAKES. COLD AIR COMES IN
WITH LAKE EFFECT FOR TUE AS THE ECMWF BRINGS IN SOME 850 MB
TEMPERATURES THAT FALL TO -14C TO -16C BY 00Z WED. SOME SLOW
MODIFICATION OCCURS WITH 850 MB TEMPERATURES OFF THE ECMWF WARMING
TO -6C OVER THE WEST AND -10C OVER THE EAST 12Z THU. 850 MB
TEMPERATURES THEN CONTINUE TO WARM AHEAD OF THE ALBERTA CLIPPER FOR
FRI. WITH THE FRONT AND THE COLD 850 MB TEMPERATURES AROUND THE
AREA...LAKE EFFECT AND SOME POPS WILL BE NEEDED FOR THE EXTENDED
PERIOD THROUGH MOST OF IT. TEMPERATURES LOOK TO STAY ABOVE NORMAL
THROUGH THE PERIOD WITH NO REAL COLD AIR IN SIGHT.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
EXPECT SUBSIDENCE/DRYING ALF IN THE WAKE OF DISTURBANCE RESPONSIBLE
FOR SN TODAY TO BRING PREDOMINANT VFR TO MVFR CIGS THRU THE EVNG.
MODEL GUIDANCE INDICATES THAT PERSISTENT SUBSIDENCE/DRYING ALF WILL
FURTHER BREAK UP THIS LO CLD DECK CONCERN IS THAT WITH MOIST LLVLS
AND LGT WINDS...FOG AND ST/IFR CONDITIONS MAY DVLP. CONTINUED TO
SHOW THIS POTENTIAL WITH FCST OF SCT LO CLDS AND MVFR VSBY. IWD HAS
THE BEST CHC TO HOLD ON TO MORE MVFR CIGS WITH WLY FLOW FOLLOWING
WEAK TROF PASSAGE PER UPSTREAM SFC OBS...WHICH WOULD LIMIT THE CHC
OF IFR CONDITIONS AT THAT SITE. PLAN ON VFR CONDITIONS TO DVLP AT
ALL LOCATIONS ON SAT WITH WSW FLOW OF DRIER AIR SAMPLED BY 12Z MPX
RAOB. &&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SOUTHERLY WINDS TO 30 KTS TO DIMINISH THIS EVENING AS LOW
PRESSURE DIMINISHES OVR THE AREA. SW WINDS WILL INCREASE SATURDAY
AHEAD OF THE NEXT TROUGH TO AFFECT LK SUPERIOR. AS WINDS SHIFT NW
ON SUNDAY BEHIND THE TROUGH THERE COULD BE GALE GUSTS OVR CNTRL AND
EASTERN LK SUPERIOR IN THE MORNING. NEXT TROUGH WILL AFFECT LK
SUPERIOR MONDAY INTO MONDAY NIGHT. THIS TROUGH IS EVEN STRONGER AND
THERE SHOULD BE SW GALES TO 35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY
INTO MONDAY EVENING. MORE NW GALES ARE POSSIBLE BEHIND THE TROUGH ON
TUESDAY OVR EASTERN LK SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS
HIGH PRESSURE MOVES ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLA
LONG TERM...07
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
620 AM EST THU DEC 22 2011
.SYNOPSIS.../ISSUED AT 355 AM/
A COLD FRONT WILL SLOWLY MOVE SOUTH ACROSS NORTHERN MICHIGAN TODAY.
THIS WILL BRING LIGHT SNOW...MAINLY THROUGH EARLY AFTERNOON...AND
MAINLY IN NORTHERN LOWER MICHIGAN. SOME LAKE EFFECT WILL DEVELOP
BEHIND THE FRONT THIS AFTERNOON...AND CONTINUE INTO TONIGHT...BEFORE
TAPERING. A FAST MOVING UPPER LEVEL DISTURBANCE WILL BRING ANOTHER
ROUND OF LIGHT SNOW TO MOST OF NORTHERN MICHIGAN FRIDAY EVENING.
AFTER THAT...OUR NEXT FOR SNOW WILL ARRIVE ON CHRISTMAS DAY.
THROUGHOUT ALL OF THIS...TEMPERATURES WILL REMAIN NEAR OR ABOVE
NORMAL.
JZ
&&
.SHORT TERM.../ISSUED AT 556 AM/...TODAY
UPDATE: HAVE THROWN IN A RAIN/SNOW MIX ALONG THE IMMEDIATE
LAKESHORES THIS MORNING PER OBS...WITH RUC FCST SOUNDINGS SUGGESTIVE
OF SFC-BASED MELTING LAYERS UP TO AROUND 1.5KFT. COMBINED WITH SFC
TEMPS INTO THE MIDDLE 30S...SHOULD CONTINUE TO SEE RAIN MIX IN WITH
THE SNOW RIGHT NEAR THE COAST GIVEN A WESTERLY WIND FLOW OFF LAKE
MICHIGAN. HAVE ALSO LOWERED FCST SNOW AMOUNTS A BIT AFTER 12Z...AND
SHIFTED AXIS OF "HEAVIEST" SNOW (STILL WELL UNDER AN INCH) SOUTHWARD
A BIT BETWEEN M-72 AND M-55 PER RADAR EXTRAPOLATION OF BEST FGEN
BANDING.
LAWRENCE
PREVIOUS DISCUSSION BELOW (ISSUED AT 355 AM):
PRIMARY FCST CONCERN THROUGH THE DAY COMES MAINLY THIS MORNING...IN
THE FORM OF TIMING/PLACEMENT OF FGEN-DRIVEN BAND OF MAINLY LIGHT
SNOW SLIDING THROUGH MAINLY NORTHERN LOWER MICHIGAN. EARLY MORNING
ANALYSIS SHOWS BROAD UPPER TROUGHING ACROSS THE UPPER MIDWEST...WITH
A SHARPER SOUTHERN STREAM WAVE LIFTING THROUGH THE SOUTHERN PLAINS.
TIGHTENING CONFLUENCE AXIS BETWEEN THESE TWO SYSTEM IS FORCING AN
INCREASED MID LEVEL FRONTOGENETIC RESPONSE IN A NARROW AXIS FROM
SOUTHERN NEBRASKA INTO NORTHERN MICHIGAN...WITH UPSTREAM OBS AND
RADAR IMAGERY SHOWING A GRADUALLY EXPANDING (ALBEIT RATHER NARROW)
CORRIDOR OF LIGHT SNOW ONGOING. CLOSER TO HOME...QUITE THE DRY WEDGE
TO OVERCOME PER 00Z APX/GRB RAOBS...THOUGH FGEN FORCING AND
ASSOCIATED GRADUAL MOISTENING FROM TOP DOWN IS WINNING THE BATTLE
WITH TIME.
EXPECT TO SEE THIS BAND OF LIGHT SNOW GRADUALLY WORK ITS WAY
SOUTHWARD THROUGH NORTHERN LOWER INTO MIDDAY...THOUGH WEAKENING
RATHER RAPIDLY WITH TIME BY 18Z AS CONFLUENCE/FGEN WANE
CONSIDERABLY. PER RADAR AND SHORT TERM GUIDANCE (RUC/HRRR/NAM)
TRENDS...STILL APPEAR THE "BEST" SNOWFALL WILL FALL BETWEEN ROUGHLY
M-32 AND M-72...WHERE PERHAPS AN INCH OR TWO WILL BE POSSIBLE AS
BEST MID LEVEL OMEGA BRIEFLY BISECTS A RATHER DEEP DGZ (I.E.
SLIGHTLY BETTER RATIOS). PROBABLY NOT LOOKING AT MUCH LEFT OF THIS
SNOW BAND AFTER 18Z...THOUGH THE CHANCES ARE NOT TOTALLY ZERO ACROSS
THE SOUTHERN COUNTIES...WHERE WILL MAINTAIN A SMALL CHANCE FOR SOME
LIGHTER SNOW SHOWERS. OTHERWISE...FOCUS SHIFTS TO LAKE EFFECT
POTENTIAL AS COLDER AIR GRADUALLY SEEPS INTO THE AREA...WITH H85
TEMPS SETTLING IN AROUND -13C ON LAKE SUPERIOR TO -10C OVER LAKE
MICHIGAN. MOISTURE PROFILES NOTHING TERRIBLY IMPRESSIVE IN EITHER
LOCATION...THOUGH OVERLAKE INSTABILITY AND THUS LAKE-INDUCED
BOUNDARY LAYER DEEPER ON LAKE SUPERIOR. HOWEVER...VEERING LOW LEVEL
FLOW PROFILES MORE NORTHERLY SUPPORT BEST CHANCES ONLY ACROSS FAR
NORTHWEST CHIPPEWA COUNTY WHERE WILL CARRY A LIKELY POP (WITH ACCUMS
LESS THAN AN INCH). FARTHER SOUTH...SIMILAR FLOW REGIME WILL GIVEN
AT LEAST A SMALL CHANCE FOR SOME LIGHT SNOW SHOWERS VICINITY OF
GRAND TRAVERSE BAY...THOUGH LESS THAN STELLAR INSTABILITY AND CLOUD
TOP TEMPS ONLY AROUND -10C JUST DON`T DO MUCH TO BOLSTER ANY
CONFIDENCE ABOUT A CHANCE POP. HIGH TEMPS TO REMAIN A FEW DEGREES
ABOVE NORMAL...WITH READINGS SLOWLY FALLING THROUGH THE AFTERNOON
AND EARLY EVENING.
LAWRENCE
&&
.LONG TERM.../ISSUED AT 355 AM/...TONIGHT AND BEYOND
RATHER ACTIVE NORTHERN GREAT LAKES WEATHER REGIME EXPECTED THROUGH
CHRISTMAS DAY...AND PERHAPS BEYOND...THOUGH WITH NO MAJOR WEATHER
SYSTEMS AFFECTING THE AREA. STILL...DOES APPEAR AT LEAST A FEW
CHANCES FOR ACCUMULATING SNOW WILL EXIST HEADING INTO CHRISTMAS DAY.
FOR TONIGHT...COLDEST OF THE AIR ARRIVES...WITH H85 TEMPS DIPPING
TOWARD -15C...ALL WHILE ELONGATED LOW LEVEL RIDGING ATTEMPTS TO
BUILD THROUGH THE REGION. WHILE SETUP FOR LAKE EFFECT FROM A LAKE
INSTABILITY STANDPOINT LOOKS GREAT...LACK OF DEEPER MOISTURE...LOW
INVERSION HEIGHTS...AND RATHER LIGHT (AND THUS MESOSCALE-DOMINATED)
BOUNDARY LAYER FLOW REGIME WILL NOT WORK IN OUR FAVOR. BUBBLE HIGH
SETUP INTO ONTARIO SHOULD SUPPORT A DECENT DRAINAGE FLOW LATER
TONIGHT...ACTING TO FORCE BEST POTENTIAL FOR LAKE SNOWS WEST OF
CHIPPEWA COUNTY...THOUGH PERHAPS SETTING UP A LOCALIZED STRONGER
CONVERGENCE AXIS SOMEWHERE JUST WEST OF WHITEFISH POINT. SAID
DRAINAGE FLOW MAY ALSO ACT TO KICK SOME LAKE SNOW SHOWERS DEEPER
INTO PORTIONS OF NORTHEAST LOWER FOR A TIME. BEST CHANCES FOR SNOW
SHOWERS ACTUALLY APPEAR TO BE IN THE VICINITY OF GRAND TRAVERSE
BAY...WHERE MEAN LOW LEVEL NORTH/NORTHEAST (020 DEGREES) FLOW IN
COMBINATION WITH LONGER FETCH AND POSSIBLY SOME LAKE SUPERIOR
CONNECTION MAY BRING A COUPLE INCHES...MOST LIKELY INTO LEELANAU/
NORTHERN GRAND TRAVERSE COUNTIES. AS FOR LOWS...SHOULD BE A COLD
NIGHT FOR AREAS ALONG AND EAST OF I-75 IN EASTERN UPPER WITH
DRAINAGE FLOW SETUP...AND COULD SEE SOME SINGLE DIGIT READINGS
ACROSS INTERIOR NORTHERN LOWER AS WELL...SHOULD CLOUDS CLEAR UNDER
NORTH FLOW REGIME.
LAKE SNOW SHOWERS SHOULD WIND DOWN FRIDAY MORNING WITH SHARPLY
BACKING LOW LEVEL FLOW AND LOSS OF OVERLAKE INSTABILITY PER QUICK
PUSH OF WARM ADVECTION IN ADVANCE OF SHARPENING UPPER WAVE CROSSING
WESTERN LAKE SUPERIOR. SAID WAVE STILL FCST TO DROP BASICALLY
OVERHEAD FRIDAY EVENING...WITH QUICK SHOT OF DEEP LAYER QG-UPWARD
FORCING AND STRONG ISENTROPIC UPGLIDE ACTING TO ADVANCE AN AXIS OF
SNOW THROUGH ALL OF EASTERN UPPER AND LIKELY MUCH OF NORTHERN LOWER.
WILL PROBABLY SEE A LAKE MICHIGAN CONTRIBUTION AS WELL AS MARGINAL
INSTABILITY REMAINS OUT AHEAD OF THIS FEATURE...AND WILL CONTINUE TO
PAINT A GENERAL 2 TO 3 INCHES FROM THE STRAITS ON NORTH...TAPERING
TO LESS THAN A HALF INCH SOUTH OF AN ALPENA TO CADILLAC LINE WITH
LACK OF LAKE HELP AND WHERE PRONOUNCED DRY WEDGE BELOW 750MB WILL
TAKE SOME TIME TO OVERCOME.
TRANSIENT LOW LEVEL SHORTWAVE RIDGING ARRIVING IN THE WAKE OF THIS
SYSTEM EARLY SATURDAY ALONG WITH STARK WARM ADVECTION OUT AHEAD OF
NEXT APPROACHING UPPER WAVE SHOULD END ANY THREAT FOR LAKE SNOW
SHOWERS BEHIND THE INITIAL DEPARTING SHORTWAVE. THIS UPPER WAVE
SATURDAY AFTERNOON REALLY DOESN`T HAVE MUCH TO WORK WITH IN TERMS OF
MOISTURE...SO PERHAPS JUST A BRIEF INCREASE IN CLOUDS. NEXT...WE SET
OUR EYES ON THE NEXT UPPER WAVE AMPLIFYING INTO THE REGION LATER
SATURDAY NIGHT...WHICH SHOULD BEGIN TO SPREAD SOME LIGHT SNOW ACROSS
THE CENTRAL/EASTERN U.P. UP THROUGH CHRISTMAS MORNING.
LAWRENCE
REST OF THE FORECAST...REASONABLY VIGOROUS SHORTWAVE WILL DIG ACROSS
THE FORECAST AREA ON XMAS MORNING. DELTA T/S OF 12/13C ARE MARGINAL
FOR ANY LAKE ENHANCEMENT FOR THE BULK OF THE EVENT...COLD ADVECTION
DEVELOPS IN THE AFTERNOON JUST ABOUT AS DEEP MOISTURE PULLS OUT.
BUT...WITH SLIGHTLY BETTER MODEL AGREEMENT IN TIMING THIS FEATURE
IN...WILL GO AHEAD AND BUMP POPS UP JUST A BIT. SYSTEM HAS DECENT
DYNAMICS BUT IS (LIKE ALL WAVES IN THIS TIGHTLY-PACKED WAVE TRAIN)
SOMEWHAT MOISTURE-DEFICIENT. WOULD LEAN TOWARD ACCUMS OF 2 INCHES OR
LESS...THOUGH WITH SOME LOW-END BLOWING-DRIFTING WITH DEVELOPING
GUSTY NW WINDS. ANY SNOW MAY BE ON THE SLOPPY SIDE EARLY NEAR THE
LAKE MI COAST. ANY LINGERING LAKE EFFECT EARLY XMAS NIGHT WILL
QUICKLY GET CRUSHED BY DEEP SUBSIDENCE/DRYING/WARMING.
WX SYSTEMS WILL CONTINUE TO COME FAST AND NOT-AT-ALL-FURIOUS IN
RAPID WNW FLOW ALOFT. HOWEVER...MODEL TIMING DIFFERENCES ARE GROWING
WITH TIME...AND DON/T HAVE MUCH CONFIDENCE IN ANY ONE SOLUTION. BUT
EVEN THE FAST GFS WOULD ALLOW FOR A DRY/MILD MONDAY. GEM/ECMWF HOLD
OFF ON ANY REAL FORCING UNTIL TUESDAY...WHILE THE GFS BRINGS IN A
LEAD IMPULSE MONDAY NIGHT. PREFER THE GREATER RUN-TO-RUN CONSISTENCY
OF THE GEM/ECMWF CAMP...KEEPING MONDAY NIGHT LARGELY DRY...BUT
RETURNING A CHANCE OF SNOW IN SPOTS (MAINLY EASTERN UPPER MI) FOR
TUESDAY. LARGELY DRY FOR WEDNESDAY...AS WE FIND OURSELVES BRIEFLY
BETWEEN SYSTEMS AGAIN.
TEMPS ABOVE CLIMO THROUGHOUT...ESPECIALLY AT NIGHT AFTER SUNDAY
NIGHT. XMAS DAY WILL LIKELY FEATURE A NON-DIURNAL CURVE...WITH AN
EARLY HIGH AND FALLING (BUT NOT CRATERING) TEMPS IN THE AFTERNOON.
JZ
&&
.MARINE.../ISSUED AT 355 AM/
QUITE CHANGEABLE WEATHER CONDITIONS ARE EXPECTED OVER THE NEXT
SEVERAL DAYS...AS NUMEROUS WAVES OF LOW PRESSURE TRACK THROUGH THE
NORTHERN GREAT LAKES. WINDS WILL BY FAR BE THE LIGHTEST TODAY
THROUGH THE FIRST HALF OF FRIDAY...AS HIGH PRESSURE SLOWLY WORKS ITS
WAY THROUGH THE REGION...PROVIDING A MAINLY NORTHERLY FLOW REGIME.
WINDS WILL BACK QUICKLY TO THE SOUTHWEST AND INCREASE FRIDAY
AFTERNOON AND EVENING AS A CLIPPER SYSTEM CROSSES THE WATERS...WITH
SMALL CRAFT CONDITIONS BRIEFLY POSSIBLE. THEREAFTER...WINDS ARE
EXPECTED TO DIMINISH FOR A BRIEF TIME INTO EARLY SATURDAY...BEFORE
STRENGTHENING ONCE AGAIN SATURDAY NIGHT AS THE NEXT WAVE OF LOW
PRESSURE DROPS INTO THE GREAT LAKES. SMALL CRAFT ADVISORY OR EVEN
LOW GALE CONDITIONS ARE POSSIBLE DURING THIS TIME AS WELL.
LOOKING AHEAD...THIS GENERAL PATTERN WILL CONTINUE INTO EARLY NEXT
WEEK...WITH THE POTENTIAL FOR WIDESPREAD GALES LATER MONDAY INTO
TUESDAY AS A STRONG PUSH OF MUCH WARMER AIR ARRIVES.
LAWRENCE
&&
.AVIATION.../ISSUED AT 620 AM/...VALID FOR 12Z TAFS
A BAND OF LIGHT SNOW WILL CONTINUE ACROSS THE APN/TVC/MBL TERMINAL
SITES THROUGH MID MORNING...WITH BRIEF IFR CEILINGS/VISBYS
EXPECTED. A COLD FRONT CROSSING THE AREA WILL AID IN PUSHING THE
SNOW OUT OF THE PICTURE BY 16Z...WITH WIDESPREAD MVFR CEILINGS
EXPECTED IN THE WAKE OF THIS FRONT AS COLDER AIR ARRIVES. WINDS
MAY TURN A BIT GUSTY FROM THE NORTH BEHIND THE FRONT...
PARTICULARLY AT APN/TVC...BUT ANY GUSTS SHOULD REMAIN BELOW 18
KNOTS. A FEW LAKE EFFECT SNOW SHOWERS MAY ALSO WORK INTO THE TVC
TERMINAL THROUGH THE AFTERNOON...AND PERHAPS INTO APN AFTER SUNSET
TONIGHT.
LAWRENCE
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
556 AM EST THU DEC 22 2011
.SYNOPSIS.../ISSUED AT 355 AM/
A COLD FRONT WILL SLOWLY MOVE SOUTH ACROSS NORTHERN MICHIGAN TODAY.
THIS WILL BRING LIGHT SNOW...MAINLY THROUGH EARLY AFTERNOON...AND
MAINLY IN NORTHERN LOWER MICHIGAN. SOME LAKE EFFECT WILL DEVELOP
BEHIND THE FRONT THIS AFTERNOON...AND CONTINUE INTO TONIGHT...BEFORE
TAPERING. A FAST MOVING UPPER LEVEL DISTURBANCE WILL BRING ANOTHER
ROUND OF LIGHT SNOW TO MOST OF NORTHERN MICHIGAN FRIDAY EVENING.
AFTER THAT...OUR NEXT FOR SNOW WILL ARRIVE ON CHRISTMAS DAY.
THROUGHOUT ALL OF THIS...TEMPERATURES WILL REMAIN NEAR OR ABOVE
NORMAL.
JZ
&&
.SHORT TERM.../ISSUED AT 556 AM/...TODAY
UPDATE: HAVE THROWN IN A RAIN/SNOW MIX ALONG THE IMMEDIATE
LAKESHORES THIS MORNING PER OBS...WITH RUC FCST SOUNDINGS SUGGESTIVE
OF SFC-BASED MELTING LAYERS UP TO AROUND 1.5KFT. COMBINED WITH SFC
TEMPS INTO THE MIDDLE 30S...SHOULD CONTINUE TO SEE RAIN MIX IN WITH
THE SNOW RIGHT NEAR THE COAST GIVEN A WESTERLY WIND FLOW OFF LAKE
MICHIGAN. HAVE ALSO LOWERED FCST SNOW AMOUNTS A BIT AFTER 12Z...AND
SHIFTED AXIS OF "HEAVIEST" SNOW (STILL WELL UNDER AN INCH) SOUTHWARD
A BIT BETWEEN M-72 AND M-55 PER RADAR EXTRAPOLATION OF BEST FGEN
BANDING.
LAWRENCE
PREVIOUS DISCUSSION BELOW (ISSUES AT 355 AM):
PRIMARY FCST CONCERN THROUGH THE DAY COMES MAINLY THIS MORNING...IN
THE FORM OF TIMING/PLACEMENT OF FGEN-DRIVEN BAND OF MAINLY LIGHT
SNOW SLIDING THROUGH MAINLY NORTHERN LOWER MICHIGAN. EARLY MORNING
ANALYSIS SHOWS BROAD UPPER TROUGHING ACROSS THE UPPER MIDWEST...WITH
A SHARPER SOUTHERN STREAM WAVE LIFTING THROUGH THE SOUTHERN PLAINS.
TIGHTENING CONFLUENCE AXIS BETWEEN THESE TWO SYSTEM IS FORCING AN
INCREASED MID LEVEL FRONTOGENETIC RESPONSE IN A NARROW AXIS FROM
SOUTHERN NEBRASKA INTO NORTHERN MICHIGAN...WITH UPSTREAM OBS AND
RADAR IMAGERY SHOWING A GRADUALLY EXPANDING (ALBEIT RATHER NARROW)
CORRIDOR OF LIGHT SNOW ONGOING. CLOSER TO HOME...QUITE THE DRY WEDGE
TO OVERCOME PER 00Z APX/GRB RAOBS...THOUGH FGEN FORCING AND
ASSOCIATED GRADUAL MOISTENING FROM TOP DOWN IS WINNING THE BATTLE
WITH TIME.
EXPECT TO SEE THIS BAND OF LIGHT SNOW GRADUALLY WORK ITS WAY
SOUTHWARD THROUGH NORTHERN LOWER INTO MIDDAY...THOUGH WEAKENING
RATHER RAPIDLY WITH TIME BY 18Z AS CONFLUENCE/FGEN WANE
CONSIDERABLY. PER RADAR AND SHORT TERM GUIDANCE (RUC/HRRR/NAM)
TRENDS...STILL APPEAR THE "BEST" SNOWFALL WILL FALL BETWEEN ROUGHLY
M-32 AND M-72...WHERE PERHAPS AN INCH OR TWO WILL BE POSSIBLE AS
BEST MID LEVEL OMEGA BRIEFLY BISECTS A RATHER DEEP DGZ (I.E.
SLIGHTLY BETTER RATIOS). PROBABLY NOT LOOKING AT MUCH LEFT OF THIS
SNOW BAND AFTER 18Z...THOUGH THE CHANCES ARE NOT TOTALLY ZERO ACROSS
THE SOUTHERN COUNTIES...WHERE WILL MAINTAIN A SMALL CHANCE FOR SOME
LIGHTER SNOW SHOWERS. OTHERWISE...FOCUS SHIFTS TO LAKE EFFECT
POTENTIAL AS COLDER AIR GRADUALLY SEEPS INTO THE AREA...WITH H85
TEMPS SETTLING IN AROUND -13C ON LAKE SUPERIOR TO -10C OVER LAKE
MICHIGAN. MOISTURE PROFILES NOTHING TERRIBLY IMPRESSIVE IN EITHER
LOCATION...THOUGH OVERLAKE INSTABILITY AND THUS LAKE-INDUCED
BOUNDARY LAYER DEEPER ON LAKE SUPERIOR. HOWEVER...VEERING LOW LEVEL
FLOW PROFILES MORE NORTHERLY SUPPORT BEST CHANCES ONLY ACROSS FAR
NORTHWEST CHIPPEWA COUNTY WHERE WILL CARRY A LIKELY POP (WITH ACCUMS
LESS THAN AN INCH). FARTHER SOUTH...SIMILAR FLOW REGIME WILL GIVEN
AT LEAST A SMALL CHANCE FOR SOME LIGHT SNOW SHOWERS VICINITY OF
GRAND TRAVERSE BAY...THOUGH LESS THAN STELLAR INSTABILITY AND CLOUD
TOP TEMPS ONLY AROUND -10C JUST DON`T DO MUCH TO BOLSTER ANY
CONFIDENCE ABOUT A CHANCE POP. HIGH TEMPS TO REMAIN A FEW DEGREES
ABOVE NORMAL...WITH READINGS SLOWLY FALLING THROUGH THE AFTERNOON
AND EARLY EVENING.
LAWRENCE
&&
.LONG TERM.../ISSUED AT 355 AM/...TONIGHT AND BEYOND
RATHER ACTIVE NORTHERN GREAT LAKES WEATHER REGIME EXPECTED THROUGH
CHRISTMAS DAY...AND PERHAPS BEYOND...THOUGH WITH NO MAJOR WEATHER
SYSTEMS AFFECTING THE AREA. STILL...DOES APPEAR AT LEAST A FEW
CHANCES FOR ACCUMULATING SNOW WILL EXIST HEADING INTO CHRISTMAS DAY.
FOR TONIGHT...COLDEST OF THE AIR ARRIVES...WITH H85 TEMPS DIPPING
TOWARD -15C...ALL WHILE ELONGATED LOW LEVEL RIDGING ATTEMPTS TO
BUILD THROUGH THE REGION. WHILE SETUP FOR LAKE EFFECT FROM A LAKE
INSTABILITY STANDPOINT LOOKS GREAT...LACK OF DEEPER MOISTURE...LOW
INVERSION HEIGHTS...AND RATHER LIGHT (AND THUS MESOSCALE-DOMINATED)
BOUNDARY LAYER FLOW REGIME WILL NOT WORK IN OUR FAVOR. BUBBLE HIGH
SETUP INTO ONTARIO SHOULD SUPPORT A DECENT DRAINAGE FLOW LATER
TONIGHT...ACTING TO FORCE BEST POTENTIAL FOR LAKE SNOWS WEST OF
CHIPPEWA COUNTY...THOUGH PERHAPS SETTING UP A LOCALIZED STRONGER
CONVERGENCE AXIS SOMEWHERE JUST WEST OF WHITEFISH POINT. SAID
DRAINAGE FLOW MAY ALSO ACT TO KICK SOME LAKE SNOW SHOWERS DEEPER
INTO PORTIONS OF NORTHEAST LOWER FOR A TIME. BEST CHANCES FOR SNOW
SHOWERS ACTUALLY APPEAR TO BE IN THE VICINITY OF GRAND TRAVERSE
BAY...WHERE MEAN LOW LEVEL NORTH/NORTHEAST (020 DEGREES) FLOW IN
COMBINATION WITH LONGER FETCH AND POSSIBLY SOME LAKE SUPERIOR
CONNECTION MAY BRING A COUPLE INCHES...MOST LIKELY INTO LEELANAU/
NORTHERN GRAND TRAVERSE COUNTIES. AS FOR LOWS...SHOULD BE A COLD
NIGHT FOR AREAS ALONG AND EAST OF I-75 IN EASTERN UPPER WITH
DRAINAGE FLOW SETUP...AND COULD SEE SOME SINGLE DIGIT READINGS
ACROSS INTERIOR NORTHERN LOWER AS WELL...SHOULD CLOUDS CLEAR UNDER
NORTH FLOW REGIME.
LAKE SNOW SHOWERS SHOULD WIND DOWN FRIDAY MORNING WITH SHARPLY
BACKING LOW LEVEL FLOW AND LOSS OF OVERLAKE INSTABILITY PER QUICK
PUSH OF WARM ADVECTION IN ADVANCE OF SHARPENING UPPER WAVE CROSSING
WESTERN LAKE SUPERIOR. SAID WAVE STILL FCST TO DROP BASICALLY
OVERHEAD FRIDAY EVENING...WITH QUICK SHOT OF DEEP LAYER QG-UPWARD
FORCING AND STRONG ISENTROPIC UPGLIDE ACTING TO ADVANCE AN AXIS OF
SNOW THROUGH ALL OF EASTERN UPPER AND LIKELY MUCH OF NORTHERN LOWER.
WILL PROBABLY SEE A LAKE MICHIGAN CONTRIBUTION AS WELL AS MARGINAL
INSTABILITY REMAINS OUT AHEAD OF THIS FEATURE...AND WILL CONTINUE TO
PAINT A GENERAL 2 TO 3 INCHES FROM THE STRAITS ON NORTH...TAPERING
TO LESS THAN A HALF INCH SOUTH OF AN ALPENA TO CADILLAC LINE WITH
LACK OF LAKE HELP AND WHERE PRONOUNCED DRY WEDGE BELOW 750MB WILL
TAKE SOME TIME TO OVERCOME.
TRANSIENT LOW LEVEL SHORTWAVE RIDGING ARRIVING IN THE WAKE OF THIS
SYSTEM EARLY SATURDAY ALONG WITH STARK WARM ADVECTION OUT AHEAD OF
NEXT APPROACHING UPPER WAVE SHOULD END ANY THREAT FOR LAKE SNOW
SHOWERS BEHIND THE INITIAL DEPARTING SHORTWAVE. THIS UPPER WAVE
SATURDAY AFTERNOON REALLY DOESN`T HAVE MUCH TO WORK WITH IN TERMS OF
MOISTURE...SO PERHAPS JUST A BRIEF INCREASE IN CLOUDS. NEXT...WE SET
OUR EYES ON THE NEXT UPPER WAVE AMPLIFYING INTO THE REGION LATER
SATURDAY NIGHT...WHICH SHOULD BEGIN TO SPREAD SOME LIGHT SNOW ACROSS
THE CENTRAL/EASTERN U.P. UP THROUGH CHRISTMAS MORNING.
LAWRENCE
REST OF THE FORECAST...REASONABLY VIGOROUS SHORTWAVE WILL DIG ACROSS
THE FORECAST AREA ON XMAS MORNING. DELTA T/S OF 12/13C ARE MARGINAL
FOR ANY LAKE ENHANCEMENT FOR THE BULK OF THE EVENT...COLD ADVECTION
DEVELOPS IN THE AFTERNOON JUST ABOUT AS DEEP MOISTURE PULLS OUT.
BUT...WITH SLIGHTLY BETTER MODEL AGREEMENT IN TIMING THIS FEATURE
IN...WILL GO AHEAD AND BUMP POPS UP JUST A BIT. SYSTEM HAS DECENT
DYNAMICS BUT IS (LIKE ALL WAVES IN THIS TIGHTLY-PACKED WAVE TRAIN)
SOMEWHAT MOISTURE-DEFICIENT. WOULD LEAN TOWARD ACCUMS OF 2 INCHES OR
LESS...THOUGH WITH SOME LOW-END BLOWING-DRIFTING WITH DEVELOPING
GUSTY NW WINDS. ANY SNOW MAY BE ON THE SLOPPY SIDE EARLY NEAR THE
LAKE MI COAST. ANY LINGERING LAKE EFFECT EARLY XMAS NIGHT WILL
QUICKLY GET CRUSHED BY DEEP SUBSIDENCE/DRYING/WARMING.
WX SYSTEMS WILL CONTINUE TO COME FAST AND NOT-AT-ALL-FURIOUS IN
RAPID WNW FLOW ALOFT. HOWEVER...MODEL TIMING DIFFERENCES ARE GROWING
WITH TIME...AND DON/T HAVE MUCH CONFIDENCE IN ANY ONE SOLUTION. BUT
EVEN THE FAST GFS WOULD ALLOW FOR A DRY/MILD MONDAY. GEM/ECMWF HOLD
OFF ON ANY REAL FORCING UNTIL TUESDAY...WHILE THE GFS BRINGS IN A
LEAD IMPULSE MONDAY NIGHT. PREFER THE GREATER RUN-TO-RUN CONSISTENCY
OF THE GEM/ECMWF CAMP...KEEPING MONDAY NIGHT LARGELY DRY...BUT
RETURNING A CHANCE OF SNOW IN SPOTS (MAINLY EASTERN UPPER MI) FOR
TUESDAY. LARGELY DRY FOR WEDNESDAY...AS WE FIND OURSELVES BRIEFLY
BETWEEN SYSTEMS AGAIN.
TEMPS ABOVE CLIMO THROUGHOUT...ESPECIALLY AT NIGHT AFTER SUNDAY
NIGHT. XMAS DAY WILL LIKELY FEATURE A NON-DIURNAL CURVE...WITH AN
EARLY HIGH AND FALLING (BUT NOT CRATERING) TEMPS IN THE AFTERNOON.
JZ
&&
.MARINE.../ISSUED AT 355 AM/
QUITE CHANGEABLE WEATHER CONDITIONS ARE EXPECTED OVER THE NEXT
SEVERAL DAYS...AS NUMEROUS WAVES OF LOW PRESSURE TRACK THROUGH THE
NORTHERN GREAT LAKES. WINDS WILL BY FAR BE THE LIGHTEST TODAY
THROUGH THE FIRST HALF OF FRIDAY...AS HIGH PRESSURE SLOWLY WORKS ITS
WAY THROUGH THE REGION...PROVIDING A MAINLY NORTHERLY FLOW REGIME.
WINDS WILL BACK QUICKLY TO THE SOUTHWEST AND INCREASE FRIDAY
AFTERNOON AND EVENING AS A CLIPPER SYSTEM CROSSES THE WATERS...WITH
SMALL CRAFT CONDITIONS BRIEFLY POSSIBLE. THEREAFTER...WINDS ARE
EXPECTED TO DIMINISH FOR A BRIEF TIME INTO EARLY SATURDAY...BEFORE
STRENGTHENING ONCE AGAIN SATURDAY NIGHT AS THE NEXT WAVE OF LOW
PRESSURE DROPS INTO THE GREAT LAKES. SMALL CRAFT ADVISORY OR EVEN
LOW GALE CONDITIONS ARE POSSIBLE DURING THIS TIME AS WELL.
LOOKING AHEAD...THIS GENERAL PATTERN WILL CONTINUE INTO EARLY NEXT
WEEK...WITH THE POTENTIAL FOR WIDESPREAD GALES LATER MONDAY INTO
TUESDAY AS A STRONG PUSH OF MUCH WARMER AIR ARRIVES.
LAWRENCE
&&
.AVIATION.../ISSUED AT 1158 PM/...VALID FOR 06Z TAFS
NARROW BAND OF SNOWFALL EXPECTED TO EXPAND SOUTHEAST ACROSS THE TAF
SITES THIS MORNING AS MID LEVEL FGEN RESPONSE INTENSIFIES AND COLD
FRONT PASSES THROUGH THE REGION. CIGS AND VIS EXPECTED TO TANK
RATHER QUICKLY WITHIN THIS BAND...WITH TRENDS SUPPORTING STEADIEST
AND "HEAVIEST" SNOWS IMPACTING TVC AND MBL. WILL CONTINUE TO DROP
VIS TO 2 TO 3 MILES ALL LOCATIONS (LOWEST AT AFOREMENTIONED
TERMINALS)...ALTHOUGH LIKELY SHORT DURATION HEAVIER SNOW BURSTS WILL
LOWER THIS EVEN FURTHER. GIVEN UNCERTAINTY...WILL ATTEMPT NO BETTER
TEMPORAL AND SPATIAL RESOLUTION...AND WAIT FOR DEVELOPMENT OF
ANTICIPATED SNOW BAND FOR POSSIBLE HIGHER IMPACT TEMPO INCLUSIONS.
BAND IS EXPECTED TO WEAKEN RATHER QUICKLY THURSDAY MORNING...LEAVING
BEHIND AN MVFR CLOUD DECK...WITH THIS PERSISTING INTO THURSDAY
EVENING.
MSB
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1143 AM CST THU DEC 22 2011
.AVIATION...
CLOUDS CONTINUE TO MOVE SOUTH WITH GENERALLY CLEAR SKIES EXPECTED
INTO TOMORROW. COULD SEE SOME PASSING THIN HIGH CLOUDS BUT WITH
HIGH PRESSURE DOMINATING THE REGION EXPECTED VFR CONDITIONS AND
LIGHT WINDS...LESS THAN 10KTS...THROUGH TOMORROW MORNING.
&&
.PREV DISCUSSION.../ISSUED 358 AM CST THU DEC 22 2011/
DISCUSSION...
NEAR TERM MODEL SOLUTIONS CONTINUE TO INDICATE AN ABRUPT END TO
THE SNOWFALL AS DRIER AIR AND DIMINISHING FORCING WILL
EFFECTIVELY END SNOW PRODUCTION BEFORE SUNRISE FOR MOST OF THE
FORECAST AREA. THE LONE EXCEPTIONS WILL BE THE FAR SOUTHERN
COUNTIES...WHERE MODEL CONSENSUS WOULD SUGGEST -SN OR FLURRIES UP
THROUGH 15Z TODAY. FLURRIES ALSO MAY BE POSSIBLE ACROSS THE SAND
HILLS THROUGH MID MORNING AS THE 22.05Z HRRR INDICATES CSI
BANDING IN THE WAKE OF THE DEPARTING SYSTEM. CROSS SECTIONS DO
REVEAL A SHORT PERIOD WHERE MOMENTUM LINES RUN PARALLEL TO THE
THETA SURFACES...SO WILL NOT RULE OUT A STRAY FLURRY OR SNOW
SHOWER...BUT GIVEN RECENT RADAR TRENDS AND THE DRYING...FEEL THAT
THE THREAT WILL BE MINIMAL AT BEST. OTHERWISE...CAA AND SNOW
PACK...ALBEIT SLIGHT SNOW PACK...WITH HELP KEEP TEMPERATURES
BELOW AVERAGE THIS AFTERNOON...WITH GENERAL MODEL CONSENSUS
SUGGESTING HIGHS IN THE LOWER 30S. DID UNDERCUT GUIDANCE SLIGHTLY
ACROSS THE WEST...WHERE A SLIGHTLY DEEPER SNOW PACK RESIDES...MID
TO UPPER 20S SHOULD BE FINE. FOR TONIGHT..WESTERLY DOWN SLOPING
FLOW DEVELOPS OVERNIGHT AS CANADIAN HIGH PRESSURE SETTLES ACROSS
THE DEEPER SNOW PACK OF EASTERN COLORADO AND WESTERN
KANSAS/OKLAHOMA. GUIDANCE IS SUGGESTING RATHER COLD TEMPERATURES
ACROSS THE CWA...WITH POSSIBLY SUB ZERO READINGS ACROSS THE FAR
WESTERN ZONES. NOT READY TO LOWER MINS THAT MUCH...ESPECIALLY
SINCE WEAK WAA AND DOWN SLOPE FLOW SHOULD PREVAIL. AS OF
NOW...SINGLE DIGIT LOWS LOOK APPROPRIATE ACROSS THE WESTERN HALF
OF THE CWA...WITH LOW TO MID TEENS ACROSS THE EAST. ON
FRIDAY...RISING HEIGHTS ASSOCIATED WITH SHORTWAVE RIDGING WILL
WORK IN CONCERT WITH DOWN SLOPING FLOW TO PUSH TEMPERATURES UP TO
NEAR CLIMO...WITH HIGHS BACK INTO THE UPPER 30S...POSSIBLY IN THE
LOW 40S FOR THE WARM BIASED LOCATIONS.
FOR THE HOLIDAY WEEKEND AND BEYOND. NORTHWESTERLY FLOW WILL
BECOME ESTABLISHED ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS AS
RIDGING BUILDS ACROSS THE WESTERN CONUS. THE NORTHERN STREAM
REMAINS ACTIVE...WITH INDICATIONS OF SEVERAL SHORTWAVES PUSHING
SOUTHEAST FROM THE CANADIAN ROCKIES TOWARD THE GREAT LAKES
REGION...BUT A LACK OF KINEMATIC FORCING WILL KEEP PRECIPITATION
OUT OF THE FORECAST THROUGH MIDWEEK. AS FOR TEMPERATURES...A
GRADUAL WARMING TREND IS EXPECTED THROUGH EARLY NEXT WEEK. HIGHS
SATURDAY AND CHRISTMAS DAY SHOULD CLIMB ABOVE 40F AS INCREASING
THICKNESS BUILDS OVER WESTERN NEBRASKA. MONDAY APPEARS TO BE THE
WARMEST DAY YET...AS H85 TEMPS FLIRT WITH 10C AND DOWN SLOPING
FLOW HELP WARM TEMPS AOA 50F. LOWS THROUGH THE EXTENDED LOOK TO
REMAIN ABOVE SEASONAL NORMS...WITH MID TEENS AND 20S EXPECTED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1128 AM CST THU DEC 22 2011
.DISCUSSION...
UPDATED THE FORECAST FOR TEMPERATURE AND SKY TRENDS. PATCH OF
STRATUS IS IN PLACE BEHIND THE MAIN SYSTEM CLEARING LINE. RUC HAS
A DECENT HANDLE ON THE CLOUDS WITH THE 900MB RH FIELD...AND IT
INDICATES THAT THE STRATUS WILL LINGER THROUGH AROUND 00-03Z. HAVE
INCREASED CLOUDS IN THE NORTHWEST CWA THROUGH THE DAY. HAVE
LOWERED TEMPS IN THE NORTH/NORTHWEST CWA AS WELL...AS TEMPS ARE
STILL HOVERING AROUND 20 AND CLOUDS WILL COMBINE WITH COLD AIR
ADVECTION TO STUNT TEMPERATURE RISE.
MAYES
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE AT KOMA AND
KLNK. AT KOFK...MVFR STRATUS DECK IS PERSISTING...AND WILL THROUGH
MUCH OF THE AFTERNOON...BEFORE BREAKING TO VFR CONDITIONS FOR THE
REST OF THE TAF CYCLE. NORTH WINDS WILL DIMINISH THROUGH THIS
AFTERNOON...WITH LIGHT WINDS OVERNIGHT SWITCHING FROM NORTHWEST TO
SOUTHWEST BEFORE WINDS INCREASE OUT OF THE SOUTHWEST DURING THE
LATE MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 327 AM CST THU DEC 22 2011/
DISCUSSION...TODAY THROUGH TUESDAY.
NARROW BAND OF LIGHT SNOW FROM GREAT LAKES REGION TO ERN KS THIS
MORNING LINING UP WELL ALONG AXIS OF 700-500MB AGEOSTROPHIC
FORCING. THE SNOW ACTIVITY WAS TRACKING SLOWLY TO THE SOUTHEAST AND
WILL CONTINUE TO DO SO WITH THE AID OF SHORTWAVE ENERGY DROPPING
OUT OF CANADA INTO THE UPPER MIDWEST. OTHERWISE DRY CONDITIONS ON
TAP THRU THE WEEKEND AND EARLY PART OF NEXT WEEK. MODELS ARE IN
GREAT AGREEMENT THE CENTRAL PLAINS WILL UNDERGO A GRADUAL WARMING
TREND IN RESPONSE TO UPPER LEVEL POSITIVE TILT LONGWAVE TROF OVER THE
WRN/CNTRL CONUS GETTING KICKED EAST AND INCREASING THICKNESSES
BUILDING IN. THIS LEADING TO MAX TEMPS GOING FROM AROUND 30
TODAY TO THE MID 40S BY MONDAY AND TUESDAY.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
521 AM CST THU DEC 22 2011
.UPDATE...
.AVIATION...
MIXED MVFR/VFR LOCAL IFR CONDITIONS WILL IMPROVE TO VFR FROM
NORTH TO SOUTH THIS MORNING. SATELLITE TIMING TOOLS INDICATE VFR
COULD BE WIDESPREAD BY 15Z AND CERTAINLY BY 18Z AS PACIFIC HIGH
PRESSURE AND DRY AIR AT THE LOWER LEVELS SWEEPS IN.
VFR IS EXPECTED ALL AREAS 18Z THROUGH 12Z FRIDAY AS HIGH PRESSURE
DRIFTS SOUTH ACROSS KS/COLO AND LOW PRESSURE DEEPENS ACROSS SRN
CANADA.
&&
.PREV DISCUSSION... /ISSUED 358 AM CST THU DEC 22 2011/
DISCUSSION...
NEAR TERM MODEL SOLUTIONS CONTINUE TO INDICATE AN
ABRUPT END TO THE SNOWFALL AS DRIER AIR AND DIMINISHING FORCING WILL
EFFECTIVELY END SNOW PRODUCTION BEFORE SUNRISE FOR MOST OF THE
FORECAST AREA. THE LONE EXCEPTIONS WILL BE THE FAR SOUTHERN
COUNTIES...WHERE MODEL CONSENSUS WOULD SUGGEST -SN OR FLURRIES UP
THROUGH 15Z TODAY. FLURRIES ALSO MAY BE POSSIBLE ACROSS THE
SAND HILLS THROUGH MID MORNING AS THE 22.05Z HRRR INDICATES CSI
BANDING IN THE WAKE OF THE DEPARTING SYSTEM. CROSS SECTIONS DO
REVEAL A SHORT PERIOD WHERE MOMENTUM LINES RUN PARALLEL TO THE
THETA SURFACES...SO WILL NOT RULE OUT A STRAY FLURRY OR SNOW
SHOWER...BUT GIVEN RECENT RADAR TRENDS AND THE DRYING...FEEL THAT
THE THREAT WILL BE MINIMAL AT BEST. OTHERWISE...CAA AND
SNOW PACK...ALBEIT SLIGHT SNOW PACK...WITH HELP KEEP TEMPERATURES
BELOW AVERAGE THIS AFTERNOON...WITH GENERAL MODEL CONSENSUS
SUGGESTING HIGHS IN THE LOWER 30S. DID UNDERCUT GUIDANCE SLIGHTLY
ACROSS THE WEST...WHERE A SLIGHTLY DEEPER SNOW PACK RESIDES...MID
TO UPPER 20S SHOULD BE FINE. FOR TONIGHT..WESTERLY DOWN SLOPING
FLOW DEVELOPS OVERNIGHT AS CANADIAN HIGH PRESSURE SETTLES ACROSS
THE DEEPER SNOW PACK OF EASTERN COLORADO AND WESTERN
KANSAS/OKLAHOMA. GUIDANCE IS SUGGESTING RATHER COLD TEMPERATURES
ACROSS THE CWA...WITH POSSIBLY SUB ZERO READINGS ACROSS THE FAR
WESTERN ZONES. NOT READY TO LOWER MINS THAT MUCH...ESPECIALLY
SINCE WEAK WAA AND DOWN SLOPE FLOW SHOULD PREVAIL. AS OF
NOW...SINGLE DIGIT LOWS LOOK APPROPRIATE ACROSS THE WESTERN HALF
OF THE CWA...WITH LOW TO MID TEENS ACROSS THE EAST. ON
FRIDAY...RISING HEIGHTS ASSOCIATED WITH SHORTWAVE RIDGING WILL
WORK IN CONCERT WITH DOWN SLOPING FLOW TO PUSH TEMPERATURES UP TO
NEAR CLIMO...WITH HIGHS BACK INTO THE UPPER 30S...POSSIBLY IN THE
LOW 40S FOR THE WARM BIASED LOCATIONS.
FOR THE HOLIDAY WEEKEND AND BEYOND. NORTHWESTERLY FLOW WILL BECOME
ESTABLISHED ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS AS RIDGING
BUILDS ACROSS THE WESTERN CONUS. THE NORTHERN STREAM REMAINS
ACTIVE...WITH INDICATIONS OF SEVERAL SHORTWAVES PUSHING SOUTHEAST
FROM THE CANADIAN ROCKIES TOWARD THE GREAT LAKES REGION...BUT A LACK
OF KINEMATIC FORCING WILL KEEP PRECIPITATION OUT OF THE FORECAST
THROUGH MIDWEEK. AS FOR TEMPERATURES...A GRADUAL WARMING TREND IS
EXPECTED THROUGH EARLY NEXT WEEK. HIGHS SATURDAY AND CHRISTMAS DAY
SHOULD CLIMB ABOVE 40F AS INCREASING THICKNESS BUILDS OVER WESTERN
NEBRASKA. MONDAY APPEARS TO BE THE WARMEST DAY YET...AS H85 TEMPS
FLIRT WITH 10C AND DOWN SLOPING FLOW HELP WARM TEMPS AOA 50F. LOWS
THROUGH THE EXTENDED LOOK TO REMAIN ABOVE SEASONAL NORMS...WITH MID
TEENS AND 20S EXPECTED.
AVIATION...
MIXED MVFR/VFR LOCAL IFR CONDITIONS WILL RAPIDLY IMPROVE TO VFR FROM
NORTH TO SOUTH THIS MORNING. VFR COULD BE WIDESPREAD BY 12Z AND
CERTAINLY BY 15Z AS PACIFIC HIGH PRESSURE AND DRY AIR AT THE LOWER
LEVELS SWEEPS IN.
VFR IS EXPECTED ALL AREAS 15Z THROUGH 12Z FRIDAY AS HIGH PRESSURE
DRIFTS SOUTH ACROSS KS/COLO AND LOW PRESSURE DEEPENS ACROSS SRN
CANADA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
358 AM CST THU DEC 22 2011
.DISCUSSION...
NEAR TERM MODEL SOLUTIONS CONTINUE TO INDICATE AN
ABRUPT END TO THE SNOWFALL AS DRIER AIR AND DIMINISHING FORCING WILL
EFFECTIVELY END SNOW PRODUCTION BEFORE SUNRISE FOR MOST OF THE
FORECAST AREA. THE LONE EXCEPTIONS WILL BE THE FAR SOUTHERN
COUNTIES...WHERE MODEL CONSENSUS WOULD SUGGEST -SN OR FLURRIES UP
THROUGH 15Z TODAY. FLURRIES ALSO MAY BE POSSIBLE ACROSS THE
SAND HILLS THROUGH MID MORNING AS THE 22.05Z HRRR INDICATES CSI
BANDING IN THE WAKE OF THE DEPARTING SYSTEM. CROSS SECTIONS DO
REVEAL A SHORT PERIOD WHERE MOMENTUM LINES RUN PARALLEL TO THE
THETA SURFACES...SO WILL NOT RULE OUT A STRAY FLURRY OR SNOW
SHOWER...BUT GIVEN RECENT RADAR TRENDS AND THE DRYING...FEEL THAT
THE THREAT WILL BE MINIMAL AT BEST. OTHERWISE...CAA AND
SNOW PACK...ALBEIT SLIGHT SNOW PACK...WITH HELP KEEP TEMPERATURES
BELOW AVERAGE THIS AFTERNOON...WITH GENERAL MODEL CONSENSUS
SUGGESTING HIGHS IN THE LOWER 30S. DID UNDERCUT GUIDANCE SLIGHTLY
ACROSS THE WEST...WHERE A SLIGHTLY DEEPER SNOW PACK RESIDES...MID
TO UPPER 20S SHOULD BE FINE. FOR TONIGHT..WESTERLY DOWN SLOPING
FLOW DEVELOPS OVERNIGHT AS CANADIAN HIGH PRESSURE SETTLES ACROSS
THE DEEPER SNOW PACK OF EASTERN COLORADO AND WESTERN
KANSAS/OKLAHOMA. GUIDANCE IS SUGGESTING RATHER COLD TEMPERATURES
ACROSS THE CWA...WITH POSSIBLY SUB ZERO READINGS ACROSS THE FAR
WESTERN ZONES. NOT READY TO LOWER MINS THAT MUCH...ESPECIALLY
SINCE WEAK WAA AND DOWN SLOPE FLOW SHOULD PREVAIL. AS OF
NOW...SINGLE DIGIT LOWS LOOK APPROPRIATE ACROSS THE WESTERN HALF
OF THE CWA...WITH LOW TO MID TEENS ACROSS THE EAST. ON
FRIDAY...RISING HEIGHTS ASSOCIATED WITH SHORTWAVE RIDGING WILL
WORK IN CONCERT WITH DOWN SLOPING FLOW TO PUSH TEMPERATURES UP TO
NEAR CLIMO...WITH HIGHS BACK INTO THE UPPER 30S...POSSIBLY IN THE
LOW 40S FOR THE WARM BIASED LOCATIONS.
FOR THE HOLIDAY WEEKEND AND BEYOND. NORTHWESTERLY FLOW WILL BECOME
ESTABLISHED ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS AS RIDGING
BUILDS ACROSS THE WESTERN CONUS. THE NORTHERN STREAM REMAINS
ACTIVE...WITH INDICATIONS OF SEVERAL SHORTWAVES PUSHING SOUTHEAST
FROM THE CANADIAN ROCKIES TOWARD THE GREAT LAKES REGION...BUT A LACK
OF KINEMATIC FORCING WILL KEEP PRECIPITATION OUT OF THE FORECAST
THROUGH MIDWEEK. AS FOR TEMPERATURES...A GRADUAL WARMING TREND IS
EXPECTED THROUGH EARLY NEXT WEEK. HIGHS SATURDAY AND CHRISTMAS DAY
SHOULD CLIMB ABOVE 40F AS INCREASING THICKNESS BUILDS OVER WESTERN
NEBRASKA. MONDAY APPEARS TO BE THE WARMEST DAY YET...AS H85 TEMPS
FLIRT WITH 10C AND DOWN SLOPING FLOW HELP WARM TEMPS AOA 50F. LOWS
THROUGH THE EXTENDED LOOK TO REMAIN ABOVE SEASONAL NORMS...WITH MID
TEENS AND 20S EXPECTED.
&&
.AVIATION...
MIXED MVFR/VFR LOCAL IFR CONDITIONS WILL RAPIDLY IMPROVE TO VFR FROM
NORTH TO SOUTH THIS MORNING. VFR COULD BE WIDESPREAD BY 12Z AND
CERTAINLY BY 15Z AS PACIFIC HIGH PRESSURE AND DRY AIR AT THE LOWER
LEVELS SWEEPS IN.
VFR IS EXPECTED ALL AREAS 15Z THROUGH 12Z FRIDAY AS HIGH PRESSURE
DRIFTS SOUTH ACROSS KS/COLO AND LOW PRESSURE DEEPENS ACROSS SRN
CANADA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1004 PM EST FRI DEC 23 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS ARE VERY
LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE REGION.
HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF OF LAKE
ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE NORTHWEST
HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE OF THE
COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO DESPITE THE
SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN LAKE AND
850MB TO INITIATE CONTINUED LAKE EFFECT SNOW SHOWERS/FLURRIES
OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM HRRR OR LOW LEVEL
RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW BANDS OF LIGHT
SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO INCLUDE MORE OF
THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER. IN THE END
THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES WILL
DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED AREA
WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THOUGH A VERY DRY AIR MASS IS MOVING INTO THE REGION...NORTH-
NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE TRAPPED
UNDER INVERSION FOR MAINLY MVFR CIGS /EXCEPT KRME/ FOR MUCH OF THE
NIGHT...AND A FEW FLURRIES FOR SOME TERMINALS. MVFR CIGS BREAK UP
BY 07-08Z...IN FAVOR OF HIGHER CIGS AROUND 120 KFT AS A WEAK UPPER
DISTURBANCE COMES THROUGH. VFR FOR BALANCE OF TAF PERIOD...AS EVEN
THE HIGHER CIGS LEAVE WITH QUICK EXIT OF UPPER DISTURBANCE BY MID
MORNING. BUILDING SURFACE HIGH PRESSURE KEEPS WINDS LIGHT.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW. LATER MONDAY INTO
MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
657 PM EST FRI DEC 23 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
645PM UPDATE...RADAR SHOWS THAT MOST FLURRIES HAVE ENDED BECAUSE
OF THE VERY DRY AIR MASS ADVECTING INTO THE REGION.
HOWEVER...LIGHT RETURNS ON RADAR SHOWS A LINGERING LAKE
INDUCED BAND OF LIGHT SNOW SHOWERS SKIRTING AROUND THE THRUWAY
FROM SYRACUSE TO NORTHERN MADISON/SOUTHERN ONEIDA COUNTIES. HIGH
RESOLUTION MODELS...VIA QPF FROM HRRR OR LOW LEVEL RH FIELDS OF
THE RUC AND WRFNMM...SUGGEST NARROW BANDS OF LIGHT SNOW SHOWERS
AND FLURRIES WILL SHIFT SOUTHWARD TO INCLUDE SOME OF THE SOUTHERN
TIER AS THE FLOW CONTINUES TO VEER. IN THE END THOUGH...DRY AIR
MASS WINS AND WHAT IS LEFT OF ACTIVITY WILL DISSIPATE BEFORE DAWN.
AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THOUGH A VERY DRY AIR MASS IS MOVING INTO THE REGION...NORTH-
NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE TRAPPED
UNDER INVERSION FOR MAINLY MVFR CIGS /EXCEPT KRME/ FOR MUCH OF THE
NIGHT...AND A FEW FLURRIES FOR SOME TERMINALS. MVFR CIGS BREAK UP
BY 07-08Z...IN FAVOR OF HIGHER CIGS AROUND 120 KFT AS A WEAK UPPER
DISTURBANCE COMES THROUGH. VFR FOR BALANCE OF TAF PERIOD...AS EVEN
THE HIGHER CIGS LEAVE WITH QUICK EXIT OF UPPER DISTURBANCE BY MID
MORNING. BUILDING SURFACE HIGH PRESSURE KEEPS WINDS LIGHT.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW. LATER MONDAY INTO
MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
930 AM EST THU DEC 22 2011
.SYNOPSIS...
UNSEASONABLE WARMTH WILL CONTINUE TODAY WITH ONLY A FEW SHOWERS...
ESPECIALLY INLAND. A COLD FRONT WILL MOVE ACROSS THE AREA FRIDAY
BRINGING WITH IT A BETTER CHANCE OF SHOWERS. CHRISTMAS EVE WILL BE
DRY WITH WET WEATHER EXPECTED CHRISTMAS DAY. NEXT WEEK LOOKS TO BE
DRY WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...SO FAR NO ADJUSTMENTS TO THE FORECAST HAVE
BEEN NEEDED AND LOOKING FORWARD NONE ARE ANTICIPATED. EARLY VISIBLE
SATELLITE IMAGE SUGGESTS THAT THE MAIN THING TO BE ON THE LOOK OUT
FOR WILL BE BREAKS IN THE CLOUDS THAT WIND UP LASTING LONG ENOUGH IN
A GIVEN PLACE THAT COULD BUST THE TEMPERATURE FORECAST. ONCE AGAIN
HOWEVER THIS CURRENTLY APPEARS UNLIKELY. PREV DISCUSSION FOLLOWS...
AS OF 630 AM THURSDAY...TODAY IS THE FIRST DAY OF WINTER AND WILL
SEE SOME OF THE LOWEST SUN ANGLES (32-33 DEGREES AT SOLAR NOON)...
THE SHORTEST DAY LENGTH (ABOUT 9 HOURS 52 MINUTES)...AND THE LEAST
POTENTIAL SOLAR ENERGY OF THE ENTIRE YEAR. HOWEVER OUR AIRMASS IS
SUBTROPICAL IN ORIGIN AND WILL YIELD HIGH TEMPERATURES MORE TYPICAL
OF MID-APRIL THAN MID-DECEMBER. SOUTHERLY FLOW BETWEEN HIGH PRESSURE
WELL OFFSHORE AND A COLD FRONT SNAKING FROM COASTAL NEW ENGLAND
THROUGH THE SOUTHERN APPALACHIANS WILL CONTINUE TO BRING THIS WARM
AND HUMID AIR INTO THE CAROLINAS THROUGH TONIGHT.
PLENTY OF STRATOCUMULUS BETWEEN 3000-6000 FT AGL WILL MOVE ACROSS
THE AREA TODAY. EVEN WITH CONSIDERABLE CLOUDINESS ENOUGH SUNSHINE
SHOULD GET THROUGH TO PRODUCE HIGHS IN THE 71-75 RANGE...JUST
SLIGHTLY ABOVE GFS/NAM MOS CONSENSUS. WITH 11Z TEMPERATURES IN THE
LOWER TO MIDDLE 60S IT WON`T TAKE MUCH SUN TO REACH THESE HIGH
TEMPERATURES! THE ONLY PORTION OF OUR FORECAST AREA NOT EXPECTED TO
SHARE THE WARMTH TODAY IS THE IMMEDIATE COASTLINE WHERE A
SOUTH-SOUTHWEST (220 DEGREE) WIND IS BLOWING ONSHORE. THIS INCLUDES
THE BEACHES BETWEEN MYRTLE BEACH AND BALD HEAD ISLAND...PLUS MOST OF
THE PENDER COUNTY BEACHES. HERE COOLER MARINE AIR WILL KEEP
TEMPERATURES IN THE 60S TODAY...ALONG WITH THE POTENTIAL FOR SOME
SEA FOG AS DEWPOINTS RISE IN THE LOWER TO MID 60S THIS AFTERNOON AND
EVENING.
A WEAK UPPER LEVEL DISTURBANCE MOVING NORTH OUT OF GEORGIA WILL HELP
SUSTAIN AN AREA OF SHOWERS ACROSS EAST-CENTRAL SOUTH CAROLINA AND
ADJACENT PORTIONS OF NORTH CAROLINA THIS MORNING. CONVECTIVE
POTENTIAL DUE TO SURFACE HEATING IS VERY LOW GIVEN THE SHALLOW MIXED
LAYER (2000-3000 FT) EXPECTED TO DEVELOP. IF ANY SHOWERS WERE TO
DEVELOP LATER TODAY...THE AREA ALONG AND WEST OF I-95 IS PREFERRED
DUE TO THE RELATIVE PROXIMITY OF AN UPPER DISTURBANCE AFTER 18Z THAT
MOVES THROUGH THE WESTERN CAROLINAS. SHOWER CHANCES WILL INCREASE A
LITTLE MORE LATE THIS EVENING AS A 300 MB JET STREAK MOVES NORTH OF
THE AREA AND CREATES AN AREA OF DIFLUENCE AND INFERRED LIFT ACROSS
THE CENTRAL CAROLINAS. OUR POPS TONIGHT RANGE FROM 20 ALONG THE
COAST TO 40 IN THE LUMBERTON/BENNETTSVILLE AREA...WITH LOWS EXPECTED
TO REMAIN IN THE 59-63 RANGE FOR MOST AREAS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...PROSPECTS FOR AN APPRECIABLE OR AT LEAST A
"WETTING` RAIN EVENT FOR FRIDAY HAVE TAKEN A STEP BACK WITH THE
LATEST MODEL CYCLES THIS MORNING. COLD FRONT MOVING ACROSS THE
AREA REMAINS ON SCHEDULE BUT ANY MID LEVEL FORCING HAS WEAKENED
WITH A BROAD EXIT REGION OF THE 300MB JET. WE WILL PROBABLY SEE
SEVERAL PATCHES OF LIGHT RAIN SIMILAR TO WEDNESDAY BEFORE 1800 UTC
FRIDAY. CHRISTMAS EVE COULD OFFER A LITTLE SUNSHINE ALTHOUGH WITH
THE PERSISTENT MOISTURE LADEN SOUTHWEST FLOW MID LEVEL SCATTERED
TO BROKEN CEILINGS ARE PROBABLE. TAKING A QUE FROM WEDNESDAYS
EVENTS...LEANED TOWARD THE COOLER MET NUMBERS FOR HIGHS FRIDAY AND
A BLEND SATURDAY AS TEMPERATURES REMAIN ELEVATED FROM SEASONAL
NORMS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...THE EXTENDED PACKAGE THIS MORNING IS
ESSENTIALLY AN UPDATE OF THE PREVIOUS FORECAST AS THE MEDIUM RANGE
MODELS CONTINUE TO STRUGGLE WITH THE SCENARIO AND TIMING OF PACIFIC
ENERGY. THIS WILL BE THE IMPETUS THAT KICKS OUT WHAT SHOULD BE A
SHEARING SHORTWAVE FROM THE SEEMINGLY PERSISTENT TROUGH ACROSS THE
SOUTHWEST. THERE IS SOME CONSENSUS BUILDING THAT THE SYSTEM WILL BE
WEAK AND A QUICK MOVER. THE FORECAST FOR CHRISTMAS DAY IS ISNT
LOOKING GREAT. DID INCREMENTALLY INCREASE POPS TO REFLECT A SLIGHT
INCREASE IN CONFIDENCE. OTHERWISE NO OTHER CHANGES. DIDNT WANT TO
GET INTO TRYING TO RESOLVE ANY ISSUES FOR LATE IN THE PERIOD WHEN
THE MODELS CONTINUE TO STRUGGLE WITH EARLIER FEATURES.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...LOW CONFIDENCE EARLY DUE TO POTENTIAL IFR
CIGS...BECOMING MODERATE CONFIDENCE THIS AFTN AS MVFR/VFR DEVELOPS.
THE COASTAL CAROLINAS REMAIN IN MOIST SWLY FLOW BETWEEN HIGH
PRESSURE OFFSHORE AND A COLD FRONT APPROACHING FROM THE WEST. THIS
HIGH DEWPOINT AIR IS CREATING HIGHLY VARIABLE BKN CIGS WHICH WILL
PERSIST THROUGH THE VALID PERIOD.
THE INLAND TERMINALS...WHICH ARE CLOSER TO SATURATION IN THE LOWEST
LEVELS...MAY SEE SOME IFR THIS MORNING. ALTHOUGH ONLY THE HRRR IS
DEPICTING IFR CIGS...THIS GUIDANCE HAS DONE WELL RECENTLY AND IFR IS
DEVELOPING UPSTREAM. CONFIDENCE IS RELATIVELY HIGHER AT LBT WHERE
TEMPO IFR HAS BEEN INTRODUCED...BUT IFR MAY REMAIN JUST WEST.
OTRW...BOTH FLO AND LBT WILL REMAIN MVFR THROUGH AT LEAST EARLY
AFTN. THE COASTAL TERMINALS WILL SEE SOME MVFR THIS MORNING BEFORE
CIGS RISE DIURNALLY WITH BKN VFR STRATOCU EXPECTED ALL DAY WITH SW
WINDS AROUND 10 KTS GUSTING TO 15-20 KTS AT THE COAST. THE SW WINDS
AND MOISTURE RICH AIR MAY CREATE SOME SEA FOG AT THE MYRTLES
TODAY...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION ATTM.
CIGS WILL LOWER DIURNALLY OVERNIGHT WITH MVFR AGAIN POSSIBLE.
SHOWERS ALONG THE COLD FRONT WILL APPROACH THE INLAND TERMINALS LATE
IN THIS VALID PERIOD...AND HAVE VCSH AT LBT/FLO AFTER MIDNIGHT.
WINDS WILL PERSIST FROM THE SW AROUND 10 KTS AS GRADIENT REMAINS
TIGHT AHEAD OF THE FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH ASSOCIATED MVFR/IFR
FRIDAY. VFR SATURDAY. MORE RAIN AND IFR POSSIBLE SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...SCEC HEADLINES LOWERED AS ANTICIPATED AS
SEAS EVEN AS FAR OUT AS 41013 NOW SETTLED TO 5.5 FT...PROBABLY
TRANSLATING TO ABOUT 4 FT OUT NEAR 20 NM IN THE COAST-PARALLEL SWRLY
FLOW. A FEW SHOWERS ALONG THE WEST WALL EXPECTED TO GENERALLY REMAIN
EAST OF THE FORECAST AREA. SUSPECT THAT MAIN FORECAST ISSUE FOR THE
PERIOD WILL BE MONITORING VIS SAT IMAGERY AND NEW GUIDANCE FOR SEA
FOG POTENTIAL.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...BIG STORY WILL BE THE WIND SHIFT FOR FRIDAY
AFTERNOON AS THE FRONT MOVES ACROSS THE WATERS. WINDS VEER FROM
SOUTHWEST TO NORTHEAST. WITHOUT ANY SIGNIFICANT COLD AIR
ADVECTION...SPEEDS WILL BE LIMITED TO A MAX OF 15-20 KNOTS MAINLY
FOR A FEW HOURS SATURDAY AFTERNOON. HIGH PRESSURE WEAKENS AND
SETTLES SOUTH BY EARLY SUNDAY ALLOWING FOR A MORE EASTERLY FLOW. THE
LATEST SWAN IS ADVERTISING 3-5 FEET FRIDAY DROPPING OT 2-4 FEET
SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...PRESSURE PATTERN BECOMES VERY DIFFUSE AS A
MID LEVEL SYSTEM ROLLS ACROSS SUNDAY. IN THE WAKE OF THIS SYSTEM A
WEST TO NORTHWEST FLOW DEVELOPS AS HIGH PRESSURE BUILDS IN FROM
THE MISSISSIPPI VALLEY. WIND SPEEDS INCREASE TO NEAR 20 KNOTS EARLY
MONDAY. WITH THE OFFSHORE FLOW EXPECT SEAS OF 2-4 FEET WITH THE
HIGHER VALUES FURTHER ACROSS THE OUTER WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
635 AM EST THU DEC 22 2011
.SYNOPSIS...
UNSEASONABLE WARMTH WILL CONTINUE TODAY WITH ONLY A FEW SHOWERS...
ESPECIALLY INLAND. A COLD FRONT WILL MOVE ACROSS THE AREA FRIDAY
BRINGING WITH IT A BETTER CHANCE OF SHOWERS. CHRISTMAS EVE WILL BE
DRY WITH WET WEATHER EXPECTED CHRISTMAS DAY. NEXT WEEK LOOKS TO BE
DRY WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...TODAY IS THE FIRST DAY OF WINTER AND WILL
SEE SOME OF THE LOWEST SUN ANGLES (32-33 DEGREES AT SOLAR NOON)...
THE SHORTEST DAY LENGTH (ABOUT 9 HOURS 52 MINUTES)...AND THE LEAST
POTENTIAL SOLAR ENERGY OF THE ENTIRE YEAR. HOWEVER OUR AIRMASS IS
SUBTROPICAL IN ORIGIN AND WILL YIELD HIGH TEMPERATURES MORE TYPICAL
OF MID-APRIL THAN MID-DECEMBER. SOUTHERLY FLOW BETWEEN HIGH PRESSURE
WELL OFFSHORE AND A COLD FRONT SNAKING FROM COASTAL NEW ENGLAND
THROUGH THE SOUTHERN APPALACHIANS WILL CONTINUE TO BRING THIS WARM
AND HUMID AIR INTO THE CAROLINAS THROUGH TONIGHT.
PLENTY OF STRATOCUMULUS BETWEEN 3000-6000 FT AGL WILL MOVE ACROSS
THE AREA TODAY. EVEN WITH CONSIDERABLE CLOUDINESS ENOUGH SUNSHINE
SHOULD GET THROUGH TO PRODUCE HIGHS IN THE 71-75 RANGE...JUST
SLIGHTLY ABOVE GFS/NAM MOS CONSENSUS. WITH 11Z TEMPERATURES IN THE
LOWER TO MIDDLE 60S IT WON`T TAKE MUCH SUN TO REACH THESE HIGH
TEMPERATURES! THE ONLY PORTION OF OUR FORECAST AREA NOT EXPECTED TO
SHARE THE WARMTH TODAY IS THE IMMEDIATE COASTLINE WHERE A
SOUTH-SOUTHWEST (220 DEGREE) WIND IS BLOWING ONSHORE. THIS INCLUDES
THE BEACHES BETWEEN MYRTLE BEACH AND BALD HEAD ISLAND...PLUS MOST OF
THE PENDER COUNTY BEACHES. HERE COOLER MARINE AIR WILL KEEP
TEMPERATURES IN THE 60S TODAY...ALONG WITH THE POTENTIAL FOR SOME
SEA FOG AS DEWPOINTS RISE IN THE LOWER TO MID 60S THIS AFTERNOON AND
EVENING.
A WEAK UPPER LEVEL DISTURBANCE MOVING NORTH OUT OF GEORGIA WILL HELP
SUSTAIN AN AREA OF SHOWERS ACROSS EAST-CENTRAL SOUTH CAROLINA AND
ADJACENT PORTIONS OF NORTH CAROLINA THIS MORNING. CONVECTIVE
POTENTIAL DUE TO SURFACE HEATING IS VERY LOW GIVEN THE SHALLOW MIXED
LAYER (2000-3000 FT) EXPECTED TO DEVELOP. IF ANY SHOWERS WERE TO
DEVELOP LATER TODAY...THE AREA ALONG AND WEST OF I-95 IS PREFERRED
DUE TO THE RELATIVE PROXIMITY OF AN UPPER DISTURBANCE AFTER 18Z THAT
MOVES THROUGH THE WESTERN CAROLINAS. SHOWER CHANCES WILL INCREASE A
LITTLE MORE LATE THIS EVENING AS A 300 MB JET STREAK MOVES NORTH OF
THE AREA AND CREATES AN AREA OF DIFLUENCE AND INFERRED LIFT ACROSS
THE CENTRAL CAROLINAS. OUR POPS TONIGHT RANGE FROM 20 ALONG THE
COAST TO 40 IN THE LUMBERTON/BENNETTSVILLE AREA...WITH LOWS EXPECTED
TO REMAIN IN THE 59-63 RANGE FOR MOST AREAS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...PROSPECTS FOR AN APPRECIABLE OR AT LEAST A
"WETTING` RAIN EVENT FOR FRIDAY HAVE TAKEN A STEP BACK WITH THE
LATEST MODEL CYCLES THIS MORNING. COLD FRONT MOVING ACROSS THE
AREA REMAINS ON SCHEDULE BUT ANY MID LEVEL FORCING HAS WEAKENED
WITH A BROAD EXIT REGION OF THE 300MB JET. WE WILL PROBABLY SEE
SEVERAL PATCHES OF LIGHT RAIN SIMILAR TO WEDNESDAY BEFORE 1800 UTC
FRIDAY. CHRISTMAS EVE COULD OFFER A LITTLE SUNSHINE ALTHOUGH WITH
THE PERSISTENT MOISTURE LADEN SOUTHWEST FLOW MID LEVEL SCATTERED
TO BROKEN CEILINGS ARE PROBABLE. TAKING A QUE FROM WEDNESDAYS
EVENTS...LEANED TOWARD THE COOLER MET NUMBERS FOR HIGHS FRIDAY AND
A BLEND SATURDAY AS TEMPERATURES REMAIN ELEVATED FROM SEASONAL
NORMS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...THE EXTENDED PACKAGE THIS MORNING IS
ESSENTIALLY AN UPDATE OF THE PREVIOUS FORECAST AS THE MEDIUM RANGE
MODELS CONTINUE TO STRUGGLE WITH THE SCENARIO AND TIMING OF PACIFIC
ENERGY. THIS WILL BE THE IMPETUS THAT KICKS OUT WHAT SHOULD BE A
SHEARING SHORTWAVE FROM THE SEEMINGLY PERSISTENT TROUGH ACROSS THE
SOUTHWEST. THERE IS SOME CONSENSUS BUILDING THAT THE SYSTEM WILL BE
WEAK AND A QUICK MOVER. THE FORECAST FOR CHRISTMAS DAY IS ISNT
LOOKING GREAT. DID INCREMENTALLY INCREASE POPS TO REFLECT A SLIGHT
INCREASE IN CONFIDENCE. OTHERWISE NO OTHER CHANGES. DIDNT WANT TO
GET INTO TRYING TO RESOLVE ANY ISSUES FOR LATE IN THE PERIOD WHEN
THE MODELS CONTINUE TO STRUGGLE WITH EARLIER FEATURES.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...LOW CONFIDENCE EARLY DUE TO POTENTIAL IFR
CIGS...BECOMING MODERATE CONFIDENCE THIS AFTN AS MVFR/VFR DEVELOPS.
THE COASTAL CAROLINAS REMAIN IN MOIST SWLY FLOW BETWEEN HIGH
PRESSURE OFFSHORE AND A COLD FRONT APPROACHING FROM THE WEST. THIS
HIGH DEWPOINT AIR IS CREATING HIGHLY VARIABLE BKN CIGS WHICH WILL
PERSIST THROUGH THE VALID PERIOD.
THE INLAND TERMINALS...WHICH ARE CLOSER TO SATURATION IN THE LOWEST
LEVELS...MAY SEE SOME IFR THIS MORNING. ALTHOUGH ONLY THE HRRR IS
DEPICTING IFR CIGS...THIS GUIDANCE HAS DONE WELL RECENTLY AND IFR IS
DEVELOPING UPSTREAM. CONFIDENCE IS RELATIVELY HIGHER AT LBT WHERE
TEMPO IFR HAS BEEN INTRODUCED...BUT IFR MAY REMAIN JUST WEST.
OTRW...BOTH FLO AND LBT WILL REMAIN MVFR THROUGH AT LEAST EARLY
AFTN. THE COASTAL TERMINALS WILL SEE SOME MVFR THIS MORNING BEFORE
CIGS RISE DIURNALLY WITH BKN VFR STRATOCU EXPECTED ALL DAY WITH SW
WINDS AROUND 10 KTS GUSTING TO 15-20 KTS AT THE COAST. THE SW WINDS
AND MOISTURE RICH AIR MAY CREATE SOME SEA FOG AT THE MYRTLES
TODAY...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION ATTM.
CIGS WILL LOWER DIURNALLY OVERNIGHT WITH MVFR AGAIN POSSIBLE.
SHOWERS ALONG THE COLD FRONT WILL APPROACH THE INLAND TERMINALS LATE
IN THIS VALID PERIOD...AND HAVE VCSH AT LBT/FLO AFTER MIDNIGHT.
WINDS WILL PERSIST FROM THE SW AROUND 10 KTS AS GRADIENT REMAINS
TIGHT AHEAD OF THE FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH ASSOCIATED MVFR/IFR
FRIDAY. VFR SATURDAY. MORE RAIN AND IFR POSSIBLE SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...HIGH PRESSURE WELL OFFSHORE IS PUMPING A
WARM AND HUMID AIRMASS NORTHWARD ALONG THE CAROLINA COASTLINE. A
COLD FRONT EXTENDING FROM COASTAL NEW ENGLAND SOUTH INTO THE WESTERN
CAROLINAS WILL MOVE SLOWLY EASTWARD THROUGH TONIGHT...REMAINING
INLAND. A PERIOD OF MODERATE SOUTH-SOUTHWESTERLY FLOW YESTERDAY
BUILT SEAS TO AS HIGH AS 6 FT AT THE FRYING PAN SHOALS BUOY...AND 4
FT AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. MODELS SHOW WIND SPEEDS
SHOULD REMAIN 15 KT OR LESS THROUGH THE AFTERNOON...ALLOWING SEA
HEIGHTS TO FALL BELOW 5 FEET ACROSS THE COASTAL WATERS. WINDS ARE
HOWEVER EXPECTED TO PICK BACK UP THIS EVENING WITH THE POTENTIAL OF
A FEW 6 FT SEAS DEVELOPING WITHIN 20 MILES OF SHORE...PARTICULARLY
ACROSS THE NORTH CAROLINA WATERS. CONDITIONS ARE MARGINAL FOR A
SMALL CRAFT ADVISORY ALONG FRYING PAN SHOALS OVERNIGHT...BUT FOR NOW
WE WILL STICK WITH 15-20 KT WINDS AND 4-5 FT SEAS IN THE FORECAST.
AS MOISTURE CONTINUES TO INCREASE THERE IS SOME POTENTIAL FOR SEA
FOG TO DEVELOP THIS AFTERNOON AND TONIGHT ACROSS THE NEARSHORE
WATERS. VISIBILITIES IN ANY SEA FOG COULD BE REDUCED TO LESS THAN
ONE-HALF MILE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...BIG STORY WILL BE THE WIND SHIFT FOR FRIDAY
AFTERNOON AS THE FRONT MOVES ACROSS THE WATERS. WINDS VEER FROM
SOUTHWEST TO NORTHEAST. WITHOUT ANY SIGNIFICANT COLD AIR
ADVECTION...SPEEDS WILL BE LIMITED TO A MAX OF 15-20 KNOTS MAINLY
FOR A FEW HOURS SATURDAY AFTERNOON. HIGH PRESSURE WEAKENS AND
SETTLES SOUTH BY EARLY SUNDAY ALLOWING FOR A MORE EASTERLY FLOW. THE
LATEST SWAN IS ADVERTISING 3-5 FEET FRIDAY DROPPING OT 2-4 FEET
SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...PRESSURE PATTERN BECOMES VERY DIFFUSE AS A
MID LEVEL SYSTEM ROLLS ACROSS SUNDAY. IN THE WAKE OF THIS SYSTEM A
WEST TO NORTHWEST FLOW DEVELOPS AS HIGH PRESSURE BUILDS IN FROM
THE MISSISSIPPI VALLEY. WIND SPEEDS INCREASE TO NEAR 20 KNOTS EARLY
MONDAY. WITH THE OFFSHORE FLOW EXPECT SEAS OF 2-4 FEET WITH THE
HIGHER VALUES FURTHER ACROSS THE OUTER WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
301 AM EST THU DEC 22 2011
.SYNOPSIS...
UNSEASONABLE WARMTH WILL CONTINUE TODAY WITH ONLY A FEW SHOWERS. A
COLD FRONT WILL MOVE ACROSS THE AREA FRIDAY BRINGING WITH IT A
BETTER CHANCE OF SHOWERS. CHRISTMAS EVE WILL BE DRY WITH A WET
CHRISTMAS DAY. NEXT WEEK LOOKS TO BE DRY WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM THURSDAY...TODAY IS THE FIRST DAY OF WINTER AND WILL
SEE SOME OF THE LOWEST SUN ANGLES (32-33 DEGREES AT SOLAR NOON)...
THE SHORTEST DAY LENGTH (ABOUT 9 HOURS 52 MINUTES)...AND THE LEAST
POTENTIAL SOLAR ENERGY OF THE ENTIRE YEAR. HOWEVER OUR AIRMASS IS
SUBTROPICAL IN ORIGIN AND WILL YIELD HIGH TEMPERATURES MORE TYPICAL
OF MID-APRIL THAN MID-DECEMBER. SOUTH FLOW BETWEEN HIGH PRESSURE
WELL OFFSHORE AND A COLD FRONT SNAKING FROM COASTAL NEW ENGLAND
THROUGH THE SOUTHERN APPALACHIANS WILL CONTINUE TO BRING THIS WARM
AND HUMID AIR INTO THE CAROLINAS THROUGH TONIGHT.
PLENTY OF STRATOCUMULUS BETWEEN 3000-6000 FT AGL WILL MOVE ACROSS
THE AREA TODAY. LOW STRATUS BELOW 600 FT SHOULD AFFECT MAINLY THE
AREA WEST OF I-95 THIS MORNING...BUT EVEN HERE CLOUDS SHOULD BURN
OFF BY MID TO LATE MORNING WITH THE FILTERED SUNSHINE ENOUGH TO
PRODUCE HIGHS IN THE 72-75 RANGE...ABOUT 1-2 DEGREES ABOVE GFS/NAM
MOS CONSENSUS. THE ONLY PORTION OF OUR FORECAST AREA NOT EXPECTED TO
SHARE THE WARMTH TODAY IS THE IMMEDIATE COASTLINE WHERE A SOUTH-
SOUTHWEST (220 DEGREE) WIND IS ONSHORE. THIS INCLUDES AREAS BETWEEN
MYRTLE BEACH AND BALD HEAD ISLAND...PLUS MOST OF THE PENDER COUNTY
BEACHES. HERE COOLER MARINE AIR WILL KEEP TEMPERATURES IN THE 60S
TODAY...ALONG WITH THE POTENTIAL FOR SOME SEA FOG AS DEWPOINTS RISE
IN THE LOWER TO MID 60S THIS AFTERNOON AND EVENING.
COMPARED TO YESTERDAY WE SEE COMPARATIVELY LITTLE POTENTIAL FOR
SHOWERS TODAY DUE TO LACK OF ANY UPPER DISTURBANCES TO PRODUCE LIFT.
CONVECTIVE POTENTIAL DUE TO SURFACE HEATING IS VERY LOW GIVEN THE
SHALLOW MIXED LAYER EXPECTED TO DEVELOP. IF ANY SHOWERS WERE TO
DEVELOP LATER TODAY...THE AREA ALONG AND WEST OF I-95 IS PREFERRED
DUE TO THE RELATIVE PROXIMITY OF AN UPPER DISTURBANCE AFTER 18Z THAT
MOVES THROUGH THE WESTERN CAROLINAS. SHOWER CHANCES WILL INCREASE A
LITTLE MORE LATE THIS EVENING AS A 300 MB JET STREAK MOVES NORTH OF
THE AREA AND CREATES AN AREA OF DIFLUENCE AND INFERRED LIFT ACROSS
THE CENTRAL CAROLINAS. OUR POPS TONIGHT RANGE FROM 20 ALONG THE
COAST TO 40 IN THE LUMBERTON/BENNETTSVILLE AREA...WITH LOWS EXPECTED
TO REMAIN IN THE 59-63 RANGE FOR MOST AREAS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...PROSPECTS FOR AN APPRECIABLE OR AT LEAST A
"WETTING` RAIN EVENT FOR FRIDAY HAVE TAKEN A STEP BACK WITH THE
LATEST MODEL CYCLES THIS MORNING. COLD FRONT MOVING ACROSS THE
AREA REMAINS ON SCHEDULE BUT ANY MID LEVEL FORCING HAS WEAKENED
WITH A BROAD EXIT REGION OF THE 300MB JET. WE WILL PROBABLY SEE
SEVERAL PATCHES OF LIGHT RAIN SIMILAR TO WEDNESDAY BEFORE 1800 UTC
FRIDAY. CHRISTMAS EVE COULD OFFER A LITTLE SUNSHINE ALTHOUGH WITH
THE PERSISTENT MOISTURE LADEN SOUTHWEST FLOW MID LEVEL SCATTERED
TO BROKEN CEILINGS ARE PROBABLE. TAKING A QUE FROM WEDNESDAYS
EVENTS...LEANED TOWARD THE COOLER MET NUMBERS FOR HIGHS FRIDAY AND
A BLEND SATURDAY AS TEMPERATURES REMAIN ELEVATED FROM SEASONAL
NORMS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...THE EXTENDED PACKAGE THIS MORNING IS ESSENTIALLY AN
UPDATE OF THE PREVIOUS FORECAST AS THE MEDIUM RANGE MODELS CONTINUE
TO STRUGGLE WITH THE SCENARIO AND TIMING OF PACIFIC ENERGY. THIS
WILL BE THE IMPETUS THAT KICKS OUT WHAT SHOULD BE A SHEARING
SHORTWAVE FROM THE SEEMINGLY PERSISTENT TROUGH ACROSS THE SOUTHWEST.
THERE IS SOME CONSENSUS BUILDING THAT THE SYSTEM WILL BE WEAK AND A
QUICK MOVER. THE FORECAST FOR CHRISTMAS DAY IS ISNT LOOKING GREAT.
DID INCREMENTALLY INCREASE POPS TO REFLECT A SLIGHT INCREASE IN
CONFIDENCE. OTHERWISE NO OTHER CHANGES. DIDNT WANT TO GET INTO
TRYING TO RESOLVE ANY ISSUES FOR LATE IN THE PERIOD WHEN THE MODELS
CONTINUE TO STRUGGLE WITH EARLIER FEATURES.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...HIGH UNCERTAINTY EXISTS WITH REGARDS TO CEILING HEIGHTS
THROUGH DAYBREAK. MOISTURE IS SUFFICIENT ENOUGH TO ALLOW IFR
CEILINGS TO FORM SOMETIME AFTER 09Z...BUT ONLY ACROSS THE FLORENCE
AND LUMBERTON VICINITY WHERE SURFACE WINDS WILL BE LIGHTER AND
TEMPERATURES ARE ALREADY COOLER AND CLOSER TO SATURATION. THIS IS
ALSO WHAT THE LATEST HRRR AVIATION FORECAST FIELDS ARE SHOWING.
PREDOMINANT VISIBILITIES WILL LIKELY REMAIN ABOVE 3SM AS THE WINDS
JUST ABOVE THE SURFACE WILL AVERAGE 15 KTS OR MORE. ANY EARLY IFR
WILL IMPROVE TO MVFR BY MID MORNING...BECOMING VFR IN THE
AFTERNOON...ALTHOUGH A STRATOCUMULUS CEILING WILL LIKELY REMAIN.
CONTINUED SOUTHWEST FLOW...INCREASING TO 10 KTS BY MID MORNING.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH ASSOCIATED RESTRICTIONS
LIKELY FRIDAY. IMPROVING CONDITIONS SATURDAY...WITH ANOTHER WEATHER
SYSTEM ON SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM THURSDAY...HIGH PRESSURE WELL OFFSHORE IS PUMPING A
WARM AND HUMID AIRMASS NORTHWARD ALONG THE CAROLINA COASTLINE. A
COLD FRONT EXTENDING FROM COASTAL NEW ENGLAND SOUTH INTO THE WESTERN
CAROLINAS WILL MOVE SLOWLY EASTWARD THROUGH TONIGHT...REMAINING
INLAND. A PERIOD OF MODERATE SOUTH-SOUTHWESTERLY FLOW EARLY THIS
EVENING HAS BUILT SEAS TO AS HIGH AS 6 FT AT THE FRYING PAN SHOALS
BUOY...AND 4 FT AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. MODELS
SHOW WIND SPEEDS DIMINISHING LATER THIS MORNING WITH SEAS EXPECTED
TO COME DOWN BY ABOUT ONE-QUARTER. WINDS ARE HOWEVER EXPECTED TO
PICK BACK UP THIS EVENING WITH THE POTENTIAL OF A FEW 6 FT SEAS
DEVELOPING WITHIN 20 MILES OF SHORE...PARTICULARLY ACROSS THE NORTH
CAROLINA WATERS. CONDITIONS ARE MARGINAL FOR A SMALL CRAFT ADVISORY
ALONG FRYING PAN SHOALS OVERNIGHT...BUT FOR NOW WE WILL STICK WITH
15-20 KT WINDS AND 4-5 FT SEAS IN THE FORECAST.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...BIG STORY WILL BE THE WIND SHIFT FOR FRIDAY
AFTERNOON AS THE FRONT MOVES ACROSS THE WATERS. WINDS VEER FROM
SOUTHWEST TO NORTHEAST. WITHOUT ANY SIGNIFICANT COLD AIR
ADVECTION...SPEEDS WILL BE LIMITED TO A MAX OF 15-20 KNOTS MAINLY
FOR A FEW HOURS SATURDAY AFTERNOON. HIGH PRESSURE WEAKENS AND
SETTLES SOUTH BY EARLY SUNDAY ALLOWING FOR A MORE EASTERLY FLOW. THE
LATEST SWAN IS ADVERTISING 3-5 FEET FRIDAY DROPPING OT 2-4 FEET
SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...PRESSURE PATTERN BECOMES VERY DIFFUSE AS A
MID LEVEL SYSTEM ROLLS ACROSS SUNDAY. IN THE WAKE OF THIS SYSTEM A
WEST TO NORTHWEST FLOW DEVELOPS AS HIGH PRESSURE BUILDS IN FROM
THE MISSISSIPPI VALLEY. WIND SPEEDS INCREASE TO NEAR 20 KNOTS EARLY
MONDAY. WITH THE OFFSHORE FLOW EXPECT SEAS OF 2-4 FEET WITH THE
HIGHER VALUES FURTHER ACROSS THE OUTER WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1230 AM EST THU DEC 22 2011
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS PASSING WEST AND NORTH OF THE AREA
WILL MAINTAIN A MILD PATTERN WITH SCATTERED SHOWERS THROUGH THE
WEEK. A COLD FRONT IS EXPECTED TO CROSS THE REGION LATE
FRIDAY...WITH COOL HIGH PRESSURE BUILDING FROM THE WEST THIS
WEEKEND. FAIR AND DRY CONDITIONS ARE EXPECTED INTO EARLY NEXT WEEK.
UNSETTLED CONDITIONS MAY RETURN BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM THURSDAY...VERY FEW CHANGES NEEDED ON THIS EARLY
MORNING FORECAST UPDATE. AN ANOMALOUSLY WARM AND HUMID AIRMASS (FOR
THE FIRST DAY OF WINTER) COVERS THE EASTERN CAROLINAS. SCATTERED TO
BROKEN MID AND HIGH LEVEL CLOUD COVER EXISTS ACROSS THE AREA...BUT
ENOUGH BREAKS ARE SHOWING UP ON INFRARED SATELLITE IMAGERY ACROSS
EASTERN SOUTH CAROLINA THAT WE MAY SEE TEMPERATURES FALL DESPITE A
STEADY 5-10 MPH SOUTH WIND. SOME LOWER CLOUDS MAY DEVELOP ESPECIALLY
ACROSS THE PEE DEE AND LUMBERTON AREA BEFORE DAYBREAK DUE TO
RADIATIONAL COOLING WITHIN THE HUMID AIRMASS. SHOWER ACTIVITY HAS
NEARLY DISSIPATED AND WE ARE EXPECTING ONLY A SLIGHT CHANCE OF ANY
ADDITIONAL SHOWER DEVELOPMENT OVERNIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...MOIST AND MILD SW COLUMN WIND FLOW WILL
SUSTAIN A CHANCE OF SHOWERS THROUGH THE SHORT TERM PERIOD...AS A
SERIES OF WEAK IMPULSES ALOFT GENERATE ENOUGH BUOYANCY TO SUSTAIN
LIGHT AND MODERATE SHOWERS THURSDAY AND FRIDAY. TIME-HGT SECTIONS
DEPICT A BIT OF DRYING ALOFT FRIDAY AFTERNOON AS DRIER WESTERLY
WINDS ARRIVE BEHIND A COLD FRONT WHICH PUSHES OFF THE COAST THEN.
RAIN CHANCES HOWEVER WERE CARRIED INTO FRIDAY NIGHT AND OVERNIGHT
INTO EARLY SATURDAY...WITH COOL OVERRUNNING POTENTIAL BEHIND THE
COLD FRONT. CONSENSUS HAS BECOME MORE SOLID AMONG GFS/NAM/EURO MODEL
TIMING...BRINGING THE FRONT THROUGH OUR FORECAST AREA FROM MIDDAY
FRIDAY FAR INTERIOR...BEFORE CHUGGING OFF THE COAST BY OR AROUND
NIGHTFALL FRIDAY LATE AFTERNOON.
CLEARLY WE WILL EXPERIENCE WELL ABOVE NORMAL TEMPERATURES IN THE
BALMY WARM SECTOR REGIME...WITH OVERNIGHT LOWS REPRESENTING WHAT
SHOULD BE NEAR NORMAL TEMPS FOR MAXIMUMS! THURSDAY THE MILDEST DAY
WITH WIDESPREAD READINGS IN THE 70S AWAY FROM THE IMMEDIATE COAST.
TEMPS DAYBREAK THURSDAY WILL HAVE A GOOD HEAD-START...ONLY DIPPING
TO AROUND 60. SOME COOL ADVECTION SHOULD ARRIVE LATE FRIDAY NIGHT
BUT WILL BE TEMPERED BY WINDS AND CLOUDS...BUT WILL SHOOT FOR A
42-51 DEGREE RANGE DAYBREAK SATURDAY...COOLEST NORTH AND WESTERN
ZONES...AND MILDEST ALONG THE SC COAST...WHERE THE FRONT WILL
FINALLY CLEAR OUR WARNING AREA. NO TSTMS INSERTED...AS INSTABILITY
APPEARS MEAGER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...THE 12Z CANADIAN/GFS ALONG WITH THE 00Z ECMWF
WERE SHOWING SOME SIMILARITIES BUT THE 12Z ECMWF HAS INTRODUCED MORE
UNCERTAINTY...ESPECIALLY LATE IN THE PERIOD. COLD FRONT OFF THE
COAST AT THE START OF THE PERIOD IS NOW PUSHED FARTHER SOUTH AND
EAST SAT AS HIGH PRESSURE OVER WESTERN KY EXTENDING EAST. HIGH
CONTINUES TO TRANSLATE EAST SAT NIGHT INTO SUN AS WEAK SHORTWAVE
EMERGES FROM THE WESTERN GULF OF MEXICO. WAVE INDUCES A SURFACE LOW
ALONG THE FRONT...STALLED ALONG THE GULF COAST. THIS LOW PASSES
OVER OR JUST EAST OF THE AREA SUN INTO SUN NIGHT...BRINGING PERHAPS
THE BEST CHANCE OF PRECIP FOR THE PERIOD. THUS HIGHEST POP FORECAST
IS ON SUN. GUIDANCE IS STILL HAVING TROUBLE RESOLVING THIS SHORTWAVE
SO TIMING AND LOCATION OF THE SURFACE FEATURE REMAIN IN QUESTION.
WED AND WED NIGHT THE FORECAST BECOMES MORE COMPLICATED. MEDIUM
RANGE GUIDANCE SHOWS ANOTHER WAVE EMERGING FROM THE GULF OF MEXICO
ON WED. HOWEVER LOCATION AND STRENGTH OF THE FEATURE VARIES
CONSIDERABLY. CONFIDENCE IS QUITE LOW AND FORECAST IS A BLEND OF THE
12Z GFS AND 00Z ECMWF WHICH RESULTS IN ANOTHER WEAK LOW AND
ASSOCIATED SHORTWAVE PASSING OFF THE SOUTHEAST COAST.
TEMPERATURES NEAR TO ABOVE CLIMO THROUGH THE PERIOD. LOWS WILL BE A
LITTLE MORE ABOVE THAN THE HIGHS...ESPECIALLY EARLY IN THE PERIOD.
SAT NIGHT LOWS COULD END UP CLOSE TO 10 DEGREES ABOVE CLIMO.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...HIGH UNCERTAINTY EXISTS WITH REGARDS TO CEILING HEIGHTS
THROUGH DAYBREAK. MOISTURE IS SUFFICIENT ENOUGH TO ALLOW IFR
CEILINGS TO FORM SOMETIME AFTER 09Z...BUT ONLY ACROSS THE FLORENCE
AND LUMBERTON VICINITY WHERE SURFACE WINDS WILL BE LIGHTER AND
TEMPERATURES ARE ALREADY COOLER AND CLOSER TO SATURATION. THIS IS
ALSO WHAT THE LATEST HRRR AVIATION FORECAST FIELDS ARE SHOWING.
PREDOMINANT VISIBILITIES WILL LIKELY REMAIN ABOVE 3SM AS THE WINDS
JUST ABOVE THE SURFACE WILL AVERAGE 15 KTS OR MORE. ANY EARLY IFR
WILL IMPROVE TO MVFR BY MID MORNING...BECOMING VFR IN THE
AFTERNOON...ALTHOUGH A STRATOCUMULUS CEILING WILL LIKELY REMAIN.
CONTINUED SOUTHWEST FLOW...INCREASING TO 10 KTS BY MID MORNING.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH ASSOCIATED RESTRICTIONS
LIKELY FRIDAY. IMPROVING CONDITIONS SATURDAY...WITH ANOTHER WEATHER
SYSTEM ON SUNDAY. VFR MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM THURSDAY...NO CHANGES NEEDED ON THIS EARLY MORNING
UPDATE. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS...
SOMEWHAT PINCHED SFC PRESSURE GRADIENT ACROSS THE WATERS TO RELAX
SOME OVERNIGHT AS AN UPPER S/W TROF DEPARTS TO THE NE THIS EVENING.
THE COLD FRONT TO REMAIN NORTHWEST OF THE AREA OVERNIGHT KEEPING
WINDS FROM THE S-SW. WIND SPEEDS SHOULD DIMINISH BY ATLEAST 5 KT
OVERNIGHT. LATEST BUOY REPORTS INDICATE WINDS AND SEAS WELL BELOW
SCA THRESHOLDS WHERE SSTS ARE IN THE 50S...IN FACT EVEN BELOW SCEC
THRESHOLDS. WILL HOWEVER CONTINUE SCEC CONDITIONS FOR THE ILM NC
WATERS TO ACCOUNT FOR THE OUTER WATERS OFF CAPE FEAR EXHIBITING HIER
WATER TEMPS...RESULTING IN SW-15-20 KT WINDS AND 5 FT SEAS DURING
THIS EVENING. WITH A RATHER DIFFUSE BUOY NETWORK...DIFFICULT TO
JUDGE/GAGE JUST HOW MUCH OF THOSE HIGHER SEAS OFFSHORE ARE BLEEDING
INTO THE COASTAL WATERS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...WE MAY NEED A SMALL CRAFT ADVISORY FOR THU
NIGHT ALTHOUGH IT APPEARS MARGINAL OR LOW-END. BUT 4-6 FOOT SEAS
SHOULD BE EXPECTED LATE THURSDAY AND HIGHEST OFFSHORE. THE PRIMARY
WAVE ENERGY THU AND FRI WILL BE S WAVES WITH INTERVALS OF 6-7
SECONDS. AS WINDS GO NE LATE FRI/EARLY SAT...WE WILL SEE ENE WAVES
ENTER THE PICTURE AS THE S WAVES FADE A BIT. STRONGEST WINDS
THURSDAY NIGHT AND FRIDAY MORNING...AND THIS REPRESENTS THE BEST
CHANCE FOR AN ADVISORY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...NORTH TO NORTHEAST FLOW WILL CONTINUE
THROUGH THE PERIOD. A COLD FRONT OFF THE COAST AT THE START OF THE
PERIOD WILL PUSH FARTHER SOUTH AND EAST SAT AS HIGH PRESSURE BUILDS
EAST. WEAK SURFACE LOW WILL TRACK ALONG THE BOUNDARY SUN WITH FLOW
FIRST BECOMING MORE EASTERLY AND THE BACKING TO NORTHWEST AS THE LOW
PASSES. NORTHWEST FLOW SUN NIGHT INTO MON WILL VEER TO
NORTH-NORTHEAST DURING MON AS HIGH PRESSURE BUILDS BACK IN FROM THE
WEST. GRADIENT WILL REMAIN RELATIVELY SLACK THROUGH THE
PERIOD...KEEPING SPEEDS 10 TO 15 KT EXCEPT AT THE START OF THE
PERIOD WHERE WANING COLD ADVECTION MAY RESULT IN NORTHEAST WINDS OF
15 TO 20 KT. SEAS START OUT 3 TO 5 FT BUT SUBSIDE TO 2 TO 4 FT BY
SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...COLBY
LONG TERM...III
AVIATION...HDL/TRA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
806 PM EST FRI DEC 23 2011
.SYNOPSIS...
NORTHWEST FLOW ALOFT WILL BRING A COUPLE OF WEAK AND RATHER DRY
UPPER DISTURBANCES TONIGHT AND AGAIN SUNDAY NIGHT. BUT HIGH
PRESSURE AT THE SURFACE WILL KEEP SKIES FAIR FOR MOST OF THE AREA
AND TEMPERATURES WILL BE SEASONABLE TO EVEN ABOVE NORMALS FOR LATE
DECEMBER. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION WOULD BE
ON TUESDAY AS A STORM APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BREAKS IN STRATO-CU APPEARING THIS EVENING...ESP DOWNWIND /EAST/
OF THE MTNS...AS SFC RIDGE OVERSPREADS THE AREA AND INVERSION HGTS
FALL. SHALLOW LYR OF MOISTURE ASCENDING THE LAUREL HIGHLANDS THIS
EVENING MAY PRODUCE A BIT OF VERY LIGHT SNOW OR FZDZ OVR
CAMBRIA/SOMERSET COUNTIES. PIT SOUNDING AND RUC MDL SOUNDINGS
INDICATE CLOUD TOP TEMPS ONLY MARGINAL FOR ICE CRYSTALS UNTIL
MIDNIGHT.
FOCUS FOR LATER TONIGHT IS ON COMPACT BUT POTENT SHORT WAVE
DROPPING ACROSS LK MICHIGAN THIS EVENING. THIS FEATURE WILL PASS
OVER CENTRAL PA LATE TONIGHT. HOWEVER...A LOOK AT SATL-DERIVED
PWATS SHOWS MOISTURE IS VERY LIMITED...SO EXPECT NO MORE THAN A
DUSTING OVER THE OROGRAPHICALLY FAVORED LAUREL HIGHLANDS AND NW
MTNS. ELSEWHERE...NO MORE THAN A FEW FLURRIES EXPECTED.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
ANY FLURRIES SHOULD END AROUND DAWN...AS SHORTWAVE PASSES EAST AND
LG SCALE SUBSIDENCE OVERSPREADS THE STATE. WITH SFC RIDGE OVR THE
REGION...SATURDAY SHOULD BE TRANQUIL WITH LIGHT WINDS AND
PT-MOSUNNY SKIES. MODEL 900MB TEMPS SUPPORT HIGHS CLOSE TO
AVERAGE...RANGING FROM THE L30S OVR THE ALLEGHENY MTNS...TO NR 40
ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
CHRISTMAS DAY WILL BE A PLEASANT WINTER DAY. SOUTWESTERLY FLOW
WILL PROVIDE SLIGHTLY ABOVE NORMAL TEMPS AND MOSTLY SUNNY SKIES.
A WEAK SHORTWAVE WILL PASS OVER THE REGION LATE IN THE DAY WITH
SOME SNOW SHOWERS POSSIBLE ACROSS THE NORTHWEST.
HIGH PRESSURE WILL BUILD INTO THE REGION FOR MONDAY WITH CLEAR
SKIES AND SEASONABLE TEMPS.
FOR TUESDAYS STORM SYSTEM...CONFIDENCE IS INCREASING IN A
SOLUTION FAVORING A LOW PRESSURE CENTER MOVING UP THE EAST
COAST...BRINGING A RAIN AND SNOW TO THE MID ATLANTIC AND
NORTHEAST. MOST MEMBERS OF THE GEFS SHOW A WEAK LOW AND MORE
ZONAL UPPER LEVEL PATTERN...RESULTING IN A PROGESSIVE STORM WITH
ONE QUARTER TO THREE QUARTERS OF AN INCH FALLING ACROSS THE
REGION. THE ECMWF IS MUCH MORE AGGRESSIVE WITH THE DEVELOPMENT OF
A LOW ALONG THE NJ COAST. THE UPPER LEVEL TROUGH IS MUCH
DEEPER..BECOMING NEGATIVELY TILTED AS THE STORM MOVES INTO THE
NORTHEAST. THIS SOLUTION BRINGS UP TO AN INCH OF QPF. THE WEAKER
SOLUTION IS ALSO COLDER...AND THE GEFS SHOWS A HIGH PROBABILY OF
SNOW ACROSS THE NORTHERN PORTIONS OF THE STATE.
HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY WITH SEASONABLE TEMPS.
A WEAK SHORTWAVE WILL CROSS THE GREAT LAKES ON THURSDAY AND PASS
JUST NORTH OF THE REGION...RESULTING IN THE CHANCE FOR SNOW
SHOWERS ACROSS THE NORTHWEST. A STORM SYSTEM WILL APPROACH FROM
THE NORTHERN PLAINS FOR THE WEEKEND.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
SFC RIDGE OVER THE REGION WILL GRADUALLY GIVE WAY TO WEAKENING TROUGH
THAT WILL WORK ACROSS THE GREAT LAKES ON SUNDAY.
TONIGHT...NW/W FLOW ACROSS CWA KEEPING CONDITIONS MVFR/IFR IN THE
USUAL UPSLOPE AREAS IN THE WESTERN HIGHER TERRAIN /KBFD-KJST/.
THESE WILL PERSIST THROUGH MUCH OF THE NIGHT...REINFORCED BY A
WEAKENING SHORTWAVE THAT WILL PASS OVERHEAD BEFORE 12Z. CIGS WILL
SLOWLY DECREASE IN THE HIGHER TERRAIN TO IFR AS THE NIGHT WEARS
ON. CENTRAL LOCATIONS OF KAOO-KUNV MAY SEE A BRIEF PERIOD OF MVFR
CIGS...MAINLY BETWEEN 06-12Z. ELSEWHERE...VFR WILL CONTINUE IN
WEAK DOWNSLOPE FLOW.
CONDITIONS IMPROVE QUICKLY MID MORNING SAT...WITH VFR CONDITIONS
DEVELOPING AREAWIDE ALONG WITH LIGHT WESTERLY WINDS. VFR WILL
CONTINUE THROUGH SUNDAY.
OUTLOOK...
SUN NIGHT...MVFR NW/VFR SE.
MON...VFR.
TUE...SHRA/LOW CIGS POSSIBLE...MAINLY W MTNS.
WED...MVFR NW...VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...LA CORTE/KREKELER
AVIATION...RXR
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1050 PM CST WED DEC 21 2011
.DISCUSSION.../ISSUED AT 925 PM CST...
MODEL AND RADAR DATA CONTINUE TO SHOW AN EARLIER AND FASTER DECREASE
IN THE LIGHT SNOW FROM THE NORTH THAN WE HAD BEEN GOING FOR EARLIER.
EVEN IN OUR SOUTHEAST CORNER PRECIPITATION SHOULD MOVE OUT BY 3 AM
IF NOW SOONER. CERTAINLY NOTHING LEFT FOR THURSDAY. EARLIER GFS AND
NEW NAM/NAM12 HAVE A BETTER HANDLE ON THE PRECIPITATION THAN THE
SHORT TERM MODELS RUC AND HRRR. BETTER COOLING STARTING FROM THE
NORTH THIS EVENING SO EARLIER FORECAST LOW TEMPERATURES LOOK OK OR
NOW THOUGH THEY COULD GET A LITTLE COLDER AROUND SUNRISE WITH FASTER
CLEARING. / WILLIAMS
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
LIGHT SNOW AND FLURRIES WILL PERSIST LATE THIS EVENING SOUTH OF A
YANKTON TO SPENCER IA LINE...GRADUALLY SHIFTING SOUTH SOUTHEAST WARD
THROUGH AROUND 12Z. MVFR VISIBILITY AND CEILINGS WILL ACCOMPANY THE
LIGHT SNOWFALL...BUT SHOULD IMPROVE TO VFR SHORTLY AFTER SNOWFALL
ENDS AS DRIER AIR WILL START WORKS INTO THE AREA. FOG PRODUCT
SATELLITE SHOWS A LONG AND NARROW STREAM OF STRATUS TRACKING
SOUTHWARD FROM SOUTHERN MANITOBA INTO NORTHEAST SD. EXPECT LOW END
VFR CEILINGS WITH THIS...BUT A BRIEF DROP INTO MVFR IS POSSIBLE
THROUGH AT LEAST 12Z.
&&
.PREV DISCUSSION.../ISSUED AT 300 PM CST/
UPPER LEVEL LOW PRESSURE CONTINUES TO SAG SOUTH ACROSS THE ROCKIES
THIS AFTERNOON. A DECENT JET STREAK WILL SPREAD ACROSS THE NORTHERN
PLAINS...WHICH WILL INTERACT WITH A WEAK BOUNDARY IN THE MID LEVELS.
REALLY NOT MUCH LOW LEVEL MOISTURE AND INSTABILITY NOT PRESENT SO
ONLY EXPECTING MINOR AMOUNTS OF ACCUMULATION. THE BEST CHANCE TO GET
SOMETHING CLOSER TO A HALF AN INCH OR SO WILL BE ALONG THE MISSOURI
RIVER VALLEY INTO SOUTHERN NORTHWEST IOWA...WITH THE BEST CHANCE
EARLY THIS EVENING. DRIER AND COLDER AIR WILL WORK IN BEHIND THIS
SYSTEM WITH NORTH WINDS EXPECTED TO BE ABOUT 10 TO 20 MPH THROUGH
THE NIGHT INTO THURSDAY. DID LOWER LOWS JUST A TOUCH TONIGHT IN THE
FAR NORTH WHERE SOME CLEARING WILL BE POSSIBLE LATE...BUT REMAINED
CLOSEST TO THE CONSRAW OUTPUT WHICH TENDS TO PERFORM BETTER ON
WIND/CLOUDY NIGHTS.
CLOUDS WILL DECREASE FROM NORTH TO SOUTH THROUGH THE MORNING INTO
THE AFTERNOON ON THURSDAY AS WILL A BREEZY MORNING NORTHWEST WIND.
FAIRLY COLD 925MB TEMPERATURES FROM AROUND -6 TO -8 DEGREES C DO
SUPPORT HIGHS FROM NEAR 32 WEST TO THE UPPER 20S IN THE EAST...AND
WILL GO CLOSE TO THIS IN THE FORECAST. THIS COMES IN A COUPLE OF
DEGREES WARMER THAN THE CONSALL OUTPUT WHICH IS GOOD SINCE THE GEM
AND GFS...BOTH PART OF THE CONSALL...ARE TOO COLD AND HAVE BEEN
RUNNING A 3 TO 6 DEGREE COLD BIAS ON HIGHS FOR THE PAST 20 TO 30
DAYS. /08
FOR THE REST OF THE SHORTER RANGE...A MILD NORTHWEST FLOW ALOFT
REMAINS IN THIS AREA WITH THE SPLIT FLOW JET REGIME CONTINUING. WITH
THE UPPER FLOW COMING OUT OF SOUTHWEST CANADA...IT WILL BE A MILD
FLOW WITH SURFACE WINDS GENERALLY FROM A WESTERLY DIRECTION ALLOWING
FOR PRIME MIXING. GIVEN THE LATEST MODEL CONSENSUS OF 925MB
TEMPERATURES...SEE ABSOLUTELY NO REASON WHY GOING WITH THE WARMEST
GUIDANCE READINGS IS NOT A GOOD IDEA. THE LOW LYING LOCATIONS MAY
BOTTOM OUT A LITTLE THURSDAY NIGHT...BUT OTHERWISE BLENDING THE WARM
BIAS CORRECTED GUIDANCE READINGS WITH THE EVEN WARMER ECMWF NUMBERS
SEEMED PRUDENT.
IN THE EXTENDED SATURDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER WILL
VERY LIKELY CONTINUE WITH THE SAME IDEA CONTINUING. THE 925MB
TEMPERATURES CONTINUE TO BE VERY WARM MEANING THAT GOING WITH THE
WARMEST GUIDANCE READINGS OF BIAS CORRECTED NUMBERS AND ECMWF VALUES
ARE PROBABLY THE BEST WAY TO GO. THE GFS AND GEM VALUES HAVE BEEN
RUNNING VERY COOL LATELY AND SHOULD BE DISCOUNTED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1148 PM CST WED DEC 21 2011
.AVIATION...
UPPER LEVEL DISTURBANCE CURRENTLY CROSSING THE REGION AND SHOULD
MAKE STEADY PROGRESS EAST OVERNIGHT AND INTO EARLY THURSDAY
MORNING. LARGE AREA OF RAIN WITH EMBEDDED THUNDERSTORMS CONTINUES
TO SHIFT TO THE EAST WITH THE PRECIPITATION MOVING NORTHEAST. MVFR
CEILINGS AND VISIBILITIES EXPECTED TO CONTINUE IN AREAS OF RAIN
AND FOG. PRECIPITATION WILL END FROM WEST TO EAST BETWEEN 12Z-14Z.
AFTER 14Z VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
WINDS OVERNIGHT WILL BE N-NE AT SPEEDS LESS THAN 10 KTS. KDRT WILL
SEE VFR CONDITIONS WITH EAST WIND LESS THAN 10 KTS BECOMING W-NW
AFTER 12Z. COLD FRONT WILL BEGIN TO IMPACT THE REGION THURSDAY
EVENING. CURRENT THINKING IS FOR A WIND SHIFT TO THE N AT KDRT AND
KAUS AROUND 01Z-03Z AND KSAT AND KSSF 04Z-06Z.
.PREV DISCUSSION... /ISSUED 913 PM CST WED DEC 21 2011/
UPDATE...
RADAR SHOWS BACK EDGE OF PRECIPITATION GENERALLY ALONG A TELEGRAPH
TO QUEMADO LINE MOVING LITTLE. A WIDESPREAD AREA OF MOSTLY LIGHT
RAIN EXTENDS FROM THE MIDDLE RIO GRANDE PLAINS NORTHEAST TO
ENCOMPASS MUCH OF THE HILL COUNTRY AND ADJACENT PORTIONS OF SOUTH
CENTRAL TEXAS LATE THIS EVENING. THE NEW RUC SHORT TERM MODEL RUN
THIS EVENING SHOWS THE UPPER TROUGH PUSHING INTO FAR WESTERN
PORTIONS OF THE CWA (VAL VERDE COUNTY) SHORTLY AFTER MIDNIGHT...
THEN ACCELERATING EASTWARD OVERNIGHT AS IT WEAKENS. THE CURRENT
WIDESPREAD AREA OF LIGHT RAIN WILL CONTINUE TO SPREAD EAST AND BY
3 AM SHOULD ENCOMPASS ALL OF THE EASTERN HALF OF SOUTH CENTRAL
TEXAS WITH RAINS ENDING OVER THE HILL COUNTRY. RAINS SHOULD BE
ENDING OVER ALL OF THE AREA FROM THE WEST BY LATE MORNING. IT
SHOULD REMAIN LIGHT AND DUE TO THE WIDESPREAD AREA...ISOLATED
THUNDERSTORMS AT BEST ARE EXPECTED. GRIDS WERE READJUSTED ACCORDING
TO CURRENT RADAR AND SATELLITE TRENDS.
PREV DISCUSSION... /ISSUED 545 PM CST WED DEC 21 2011/
AVIATION...
VFR CONDITIONS WILL DETERIORATE QUICKLY AS UPPER LEVEL LOW IS
CURRENTLY GENERATING LIGHT RAIN...SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS MEXICO AND ALONG THE RIO GRANDE. THIS PRECIPITATION WILL
SPREAD EAST AND NORTHEAST QUICKLY THROUGH 06Z. MVFR CEILINGS AND
RAIN WILL DEVELOP FROM WEST TO EAST THROUGH 05Z. THUNDERSTORMS ARE
POSSIBLE...MAINLY ALONG AND EAST OF I-35 BETWEEN 05Z-12Z. SMALL
HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS...BUT COVERAGE AND
PROBABILITIES ARE BOTH LOW...SO NOT MENTIONED IN THE TERMINAL
FORECAST. EXPECTED IMPROVEMENTS TO VFR CONDITIONS AFTER 13Z-15Z.
KDRT EXPECTED TO REMAIN VFR WITH LIGHT RAIN AND SHOWERS. WINDS ARE
EXPECTED TO BE VARIABLE IN DIRECTION...BUT LESS THAN 10 KNOTS
THROUGH THE FORECAST. FOR THE 30 HOUR TAF SITE...NEXT COLD FRONT
WILL CAUSE A WIND SHIFT TOWARDS THE END OF THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 323 PM CST WED DEC 21 2011/
DISCUSSION...
A 500 HPA LOW NEAR THE BIG BEND CONTINUES TO DEVELOP AS IT MOVES
TO THE EAST. INCREASING CLOUDS CONTINUE OVER SOUTH CENTRAL TEXAS
EAST OF THIS WEATHER SYSTEM...AND THIS WILL CONTINUE THROUGH
TONIGHT. PATCHY AREAS OF LIGHT RAIN AND SHOWERS ARE DEVELOPING
FROM THE WEST...AND WILL MOVE OVER SOUTH CENTRAL TEXAS TONIGHT.
EXPECT OCCASIONAL RAIN OVER SOUTH CENTRAL TEXAS TONIGHT. RAINFALL
AMOUNTS NEAR A TENTH OF AN INCH ARE EXPECTED OVER THE WEST PART OF
THE AREA AND NEAR ONE HALF TO ONE INCH OVER THE EAST PART OF
SOUTH CENTRAL TEXAS TONIGHT. SHOWERS AND ISOLATED THUNDERSTORMS
ARE EXPECTED WITH THE RAIN TONIGHT. WINTER 2011/2012 WILL
OFFICIALLY BEGIN TONIGHT AT 1130 PM CST...AND WILL END AT 1214 AM
CDT ON TUESDAY...MARCH 20...2012...WHEN THE SPRING OF 2012
OFFICIALLY BEGINS.
ON THURSDAY...DECREASING CLOUDS AND RAIN CHANCES ARE STILL EXPECTED
FROM THE WEST IN THE MORNING...WITH A MOSTLY SUNNY TO PARTLY
CLOUDY CONDITIONS EXPECTED TO DEVELOP ON THURSDAY. WILL SHOW HIGHS
IN THE 60S OVER THE HILL COUNTRY AND IN THE UPPER 60S TO NEAR 70
OVER ADJACENT PARTS OF SOUTH CENTRAL TEXAS.
INCREASING CLOUDS ARE EXPECTED THURSDAY NIGHT AND FRIDAY...WITH
A CHANCE OF RAIN OR SHOWERS POSSIBLE FRIDAY NIGHT AND SATURDAY.
COLD CONDITIONS ARE EXPECTED WITH MOSTLY CLOUDY SKIES SATURDAY
AND SATURDAY NIGHT. RAIN CHANCES ARE EXPECTED TO DECREASE FROM THE
WEST SATURDAY NIGHT...FOLLOWED BY PARTLY CLOUDY CONDITIONS ON
SUNDAY...WITH DAYTIME HIGHS IN THE 50S.
A FAST MOVING DISTURBANCE WILL COME ACROSS SOUTH CENTRAL TEXAS
MONDAY...YET EXPECT SCATTERED CLOUDS WITH THIS WEATHER SYSTEM...
FOLLOWED BY MOSTLY SUNNY TO PARTLY CLOUDY CONDITIONS IN THE
DAY AND MOSTLY CLEAR NIGHTS ON TUESDAY AND WEDNESDAY OF NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 42 67 42 52 36 / 80 20 - 10 20
AUSTIN BERGSTROM INTL AIRPORT 42 67 39 52 35 / 80 20 - 10 20
NEW BRAUNFELS MUNI AIRPORT 44 68 40 54 35 / 80 20 - 10 20
BURNET MUNI AIRPORT 41 65 38 49 34 / 60 10 - 10 10
DEL RIO INTL AIRPORT 39 66 38 51 35 / 50 - 0 - 20
GEORGETOWN MUNI AIRPORT 42 64 39 50 34 / 80 20 - 10 10
HONDO MUNI AIRPORT 44 70 39 55 36 / 70 10 - 10 30
SAN MARCOS MUNI AIRPORT 44 67 40 54 36 / 80 20 - 10 20
LA GRANGE - FAYETTE REGIONAL 47 66 45 56 39 / 80 40 10 10 20
SAN ANTONIO INTL AIRPORT 45 70 42 55 36 / 80 20 - 10 30
STINSON MUNI AIRPORT 46 70 44 56 38 / 80 20 - 10 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...02
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1157 PM EST WED DEC 21 2011
.SYNOPSIS...
LOW PRESSURE WILL TRACK EASTWARD ACROSS NEW ENGLAND...DRAGGING A
WEAK COLD FRONT THROUGH THE AREA TONIGHT. THE FRONT WILL THEN
STALL ACROSS NORTHERN NORTH CAROLINA THURSDAY MORNING. A SERIES OF
LOW PRESSURE SYSTEMS WILL TRACK UP ALONG THE FRONT THURSDAY AND
AGAIN ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 1000 PM EDT WEDNESDAY...
SFC FRONT GETTING CLOSE TO WRN SLOPES OF APPALACHIANS BUT DRIER
LOW LEVEL AIR HAS MOVED INTO THE MTNS AND LIGHT SW WINDS HAVE KEPT
FOG AND DRIZZLE FROM DEVELOPING. ALL PRECIP HAS MOVED EAST OF FCST
AREA AS WELL. SOME LIGHT SOUTHEAST SFC FLOW ON EAST SIDE OF BLUE
RIDGE IS KEEPING LOW CLOUDS AND FOG BANKED UP AGAINST BLUE RIDGE
IN FAR NW NC INCLUDING FANCY GAP...BUT AS FLOW BEGINS TO TURN MORE
SW AND THEN WEST BEHIND FRONT LATER TONIGHT THIS SHOULD LIFT. AT
THE SAME TIME...COOLER AIR BEHIND FRONT AND LIONGERING LOW LEVEL
MSTR ON GROUND...AND WITH POTENTIAL FOR THINNING OUT OF HIGH
CLOUDS...COULD RESULT IN SOME PATCHY VALLEY FOG. ENDED UP REMOVING
MUCH OF THE PATCHY DRIZZLE FROM PREVIOUS UPDATE...AND REDUCING
AREAS OF FOG...EXCEPT FOR MTN VALLEYS AND CLOSER TO WHERE SFC
FRONTAL POSITION IS EXPECTED TO STALL TOWARD MORNING ACROSS FAR
SOUTHEAST. LEFT A SLIGHT CHC OF A SHOWER DOWN THERE AS WELL.
OVERNIGHT TEMPS ARE TRICKY AS AIR BEHIND FRONT IS COOLER BUT NOT
THAT COOL...AND OVERALL THIS HAS BEEN SLOWING DOWN. ENDED UP
BOOSTING OVERNIGHT MINS A COUPLE DEG BECAUSE OF SLOWER
MOVEMENT...AND NOT DROPPING DEW PTS OFF QUITE AS FAST...BUT STILL
FALLING. ALSO MADE SOME MINOR CHANGES INTO THURSDAY MORNING PER
SLOWER MODEL SOLUTIONS FOR NEXT WAVE MOVING UP ALONG FRONT. RAIN
MAY NOT REACH FAR SW UNTIL MIDDAY...AND THEN PERHAPS NOT UNTIL LATE
AFTERNOON OR EARLY EVENING ACROSS THE NORTHEAST. MID SHIFT MAY
NEED TO SLOW THIS DOWN EVEN MORE.
AS OF 710 PM EST WEDNESDAY...
LIGHT SHOWERS AHEAD OF WEAK FRONT HAVE FADED QUICKLY THIS EVENING
AND ONLY A FEW SPOTTY SHOWERS REMAIN...PRIMARILY EAST OF THE BLUE
RIDGE. HAVE UPDATED POPS ACCORDINGLY. LINGERING LOW LEVEL MSTR
WITH STEADY WINDS ALONG THE RIDGES MAY STILL RESULT IN ENOUGH
SHALLOW LIFT FOR SOME DRIZZLE AS WELL AS PATCHY FOG...SUCH AS
ALONG AND NEAR THE BLUE RIDGE AND HOT SPRINGS VCNTY. MID CLOUDS
THINNING OUT AND WITH PARTIAL CLEARING...COULD BEGIN TO SEE SOME
PATCHY FOG IN VALLEYS AS WELL AS WINDS REMAIN DECOUPLED THERE...SO
HAVE INCLUDED A FAIRLY WIDESPREAD AREA OF PATCHY FOG...WITH AREAS
OF FOG ALONG THE BLUE RIDGE. REMOVED MENTION OF ANY DRIZZLE AFTER
MIDNIGHT AS SHALLOW MOISTURE BEGINS TO DRY OUT SLIGHTLY...BUT WILL
KEEP FOG IN THROUGH OVERNIGHT FOR NOW. ALSO WILL KEEP SLIGHT CHC
SHWRS NEAR WEAK FRONTAL BOUNDARY POSITION LATE TONIGHT OUT IN FAR
SOUTHEAT PIEDMONT...AS SUGGESTED BY LOCAL WRF AND HRRR MODELS.
PREV DISCUSSION AS OF 318 PM EST WEDNESDAY...
A WEAK COLD FRONT WILL PIVOT OVER THE AREA TONIGHT...THEN STALL
ACROSS NORTHERN NORTH CAROLINA. THE RAIN WILL END WEST TO EAST THIS
EVENING. AREAS OF DRIZZLE POSSIBLE ON WESTERN FACING SLOPES AND NEAR
THE FRONT THROUGH EARLY MORNING. CLOUD COVER SHOULD ALSO LINGER WITH
THE FRONT STALLED IN THE VICINITY. SOME CLEARING IS POSSIBLE OVER
THE GREENBRIER VALLEY AND ALLEGHANY HIGHLANDS TONIGHT AS HIGH
PRESSURE TRACKS EASTWARD. IF CLEARING IS PRONOUNCED ENOUGH...PATCHY
DENSE FOG COULD DEVELOP TOWARD SUNRISE.
MARITIME AIR BEHIND THE FRONT WILL KEEP TEMPERATURES MILD AND ABOVE
NORMAL.
WINTER SOLSTICE TO BEGIN TONIGHT AT 530Z/1230 AM.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
AS OF 320 PM EST WEDNESDAY...
NEXT IN SERIES OF SOUTHERN STREAM SHORT WAVES EXPECTED TO LIFT
NORTHEAST OUT OF THE SOUTHERN PLAINS AND GULF COAST STATES INTO THE
MID APPALACHIAN AND MID ATLANTIC STATES THURSDAY INTO THURSDAY
NIGHT...TO BE FOLLOWED BY SLIGHTLY COOLER AND DRIER AIR ON THE
BACKSIDE OF THE SYSTEM LATER THURSDAY NIGHT INTO SATURDAY.
ABUNDANT MID AND HIGH LEVEL CLOUDS STREAMING NORTHEAST IN ADVANCE OF
THE SYSTEM SHOULD ASSURE A MOSTLY CLOUDY TO CLOUDY START IN MOST
LOCATIONS ON THURSDAY...WITH THREAT OF PRECIPITATION INCREASING AS
THE DAY PROGRESSES FROM SOUTH TO NORTH AS BROAD UPWARD VERTICAL
MOTIONS FIELDS FROM STRONG MOISTURE TRANSPORT AND INCREASING
ISENTROPIC LIFT IN 850-600 MILLIBAR LAYER COMBINE WITH DIFFERENTIAL
POSITIVE VORTICITY ADVECTION AND UPPER DILUENT FIELD WITH APPROACH
OF RIGHT ENTRANCE REGION OF UPPER JET MAX. EXPECT TO SEE A GOOD
DRENCHING RAIN THROUGHOUT THE ENTIRE BLACKSBURG FORECAST AREA BY
DAYS END...CONTINUING THROUGH THE EVENING HOURS BEFORE BEGINNING TO
TAPER OFF FROM WITH WEST DURING THE EARNING MORNING HOURS ON FRIDAY
WITH PASSAGE OF COOL FRONT. AT THE PRESENT TIME...TOTAL RAINFALL
AMOUNTS FROM THIS SYSTEM ARE NOT EXPECTED TO BE EXCESSIVE...
GENERALLY IN THE ONE-HALF TO ONE-INCH RANGE.
DOWNSLOPING WINDS EAST OF THE BLUE RIDGE SHOULD ALLOW FOR DRY AND
MILD WEATHER ACROSS THE PIEDMONT FRIDAY INTO SATURDAY...ALTHOUGH
SOUTHWESTERLY FLOW ALOFT WILL MAINTAIN AT LEAST SOME PARTIAL MID AND
HIGH LEVEL CLOUD COVER. WEST OF THE BLUE RIDGE...COOL ADVECTION
UPSLOPING WINDS SHOULD MAINTAIN LOWER LEVEL CLOUDS FOR MUCH OF THE
PERIOD...WITH PERHAPS EVEN SOME SPOTTY SHOWERS OR FLURRIES ACROSS
THE PREFERRED HIGHER WEST FACING SLOPES INTO FRIDAY NIGHT.
MOS GUIDANCE THROUGH THE PERIOD QUITE CONSISTENT AND GENERALLY
ACCEPTED EXCLUDING NEED TO SUBTLY TWEAK SOME TEMPERATURES TO REFLECT
LOCAL CLIMATOLOGICAL INFLUENCES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 PM EST WEDNESDAY...
COMPLICATED WEATHER PATTERN IN THE LONG TERM. FORECAST IS HEAVILY
DEPENDENT ON THE EVOLUTION OF A CLOSED UPPER LEVEL LOW THAT IS
CURRENTLY DROPPING INTO THE SOUTHWESTERN PART OF THE COUNTRY. HOW
QUICKLY AND HOW MUCH OF THIS ENERGY EJECTS NORTHEAST WILL PLAY A
MAJOR FACTOR IN OUR WEATHER CHRISTMAS DAY INTO EARLY NEXT WEEK. THE
STRENGTH OF A NORTHERN STREAM WAVE FORECAST TO MOVE INTO THE
NORTHEAST WILL ALSO PLAY A BIG ROLE.
ECMWF AND GFS CONTINUE TO EJECT SOME OF THE ENERGY OVER THE
SOUTHWESTERN STATES INTO OUR REGION CHRISTMAS DAY. HOWEVER THE
AMOUNT OF ENERGY EJECTED CONTINUES TO TREND DOWN...AND THE 12Z GFS
ENSEMBLES HAVE ALSO TRENDED DRY ON CHRISTMAS DAY. MODELS ARE ALSO
TRENDING STRONGER WITH THE NORTHERN STREAM ENERGY...WHICH WOULD
EFFECTIVELY PUSH ANY WAVE FURTHER SOUTH ON CHRISTMAS DAY. BUT JUST
HOW MUCH THIS NORTHERN STREAM CAN SUPPRESS THE SOUTHEAST RIDGE IS
STILL IN QUESTION. GIVEN THE PERSISTENCE OF THE SOUTHEAST RIDGE THIS
MONTH...NOT READY TO GO COMPLETELY WITH THE SOUTHERN SOLUTION. BUT
GIVEN LATEST ECMWF TREND OF PUSHING THE WAVE SOUTH...AND 12Z GFS
ENSEMBLE MEAN KEEPING US DRY...HAVE TRENDED TOWARD THE SOUTHERN
SOLUTION. THIS WOULD KEEP THE BEST CHANCE OF RAIN NEAR THE NC/VA
BORDER AND POINTS SOUTH...WITH DECREASING CHANCES TO THE NORTH.
ENOUGH COLD AIR MAY BE PRESENT FOR SOME SNOW ON THE FAR NORTHERN
FRINGE OF THE PRECIP SHIELD NORTH OF ROUTE 460...HOWEVER THIS IS
STILL A LOW PROBABILITY EVENT AND NO ACCUMULATIONS EXPECTED AT THIS
TIME.
EXPECT A BRIEF DRY PERIOD AND SHOT OF COLD AIR BEHIND THIS SYSTEM ON
MONDAY. HOWEVER MODEL DIFFERENCES BEGIN TO INCREASE AGAIN BY
TUESDAY. THE REST OF THE ENERGY ASSOCIATED WITH THE CLOSED SOUTHWEST
LOW SHOULD FINALLY EJECT NORTHEASTWARD MONDAY NIGHT INTO TUESDAY.
LAST 2 RUNS OF THE ECMWF AND ABOUT HALF THE GFS ENSEMBLES PUSH THIS
WAVE TO OUR NORTH TUESDAY AND TUESDAY NIGHT BRINGING MORE RAIN TO
THE REGION. GIVEN THE CONSISTENCY OF THE ECMWF SOLUTION...AND THE GFS
ENSEMBLES COMING ON BOARD...HAVE TRENDED THE FORECAST TOWARDS THIS
SOLUTION. ECMWF HAS SOME LOW LEVEL COLD AIR LOCKED IN AHEAD OF THIS
SYSTEM...SO VERBATIM IT WOULD HAVE SOME SLEET OR FREEZING RAIN IN
THE ALLEGHANY HIGHLANDS. HOWEVER THIS IS A LOW PROBABILITY
EVENT...BUT WILL BE MONITORED IN THE COMING DAYS.
WENT CLOSE TO HPC GUIDANCE...TRENDED A BIT TOWARD THE ECMWF...FOR
TEMPERATURES THIS PERIOD. THIS RESULTS IN TEMPERATURES AROUND
AVERAGE...HIGHS GENERALLY IN THE 40S WEST AND AROUND 50 EAST...AND
LOWS IN THE 20S TO AROUND 30. COLDEST DAYS LOOK TO BE MONDAY BEHIND
THE FIRST SYSTEM...AND THEN AGAIN ON WEDNESDAY BEHIND THE POTENTIAL
SECOND SYSTEM.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1155 PM EST WEDNESDAY...
CIGS HAVE LIFTED TO VFR IN WEST WITH DRYING CONDITIONS AND SW FLOW
AS WEAK FRONT IS IN THE PROCESS OF JUMPING ACROSS THE APPALACHIANS
INTO THE PIEDMONT...WHERE SOME MVFR CIGS STILL EXIST. BREAKS IN
CLOUDS IN THE WEST COULD STILL RESULT IN SOME VALLEY FOG LATE
TONIGHT BUT AS DEW PTS CONTINUE TO DRY CURRENT THINKING IS WILL
BARELY GET TO IFR VSBYS BRIEFLY...IF AT ALL. BEST CHC WOULD BE AT
LWB. NEAR FRONTAL BOUNDARY IN PIEDMONT...MVFR CIGS LIKELY TO LAST
THROUGHOUT THE NIGHT BUT NOT EXPECTING IFR FOG THERE EITHER
ANYMORE. A SPRINKLE AT DAN NOT OUT OF THE QUESTION THOUGH THROUGH
EARLY MORNING HOURS.
GENERALLY VFR FOR MOST OF THE DAY THURSDAY AHEAD OF THE NEXT WAVE
THAT WILL BE MOVING UP THE STALLED FRONT FROM THE SOUTHWEST.
MOISTURE WILL QUICKLY DEEPEN AGAIN BY LATE IN THE DAY FROM
SOUTHWEST TO NORTHEAST...WITH MORE WIDEPSREAD RAIN EXPECTED IN THE
WEST BY EVENING AND OVERNIGHT COMPARED TO THIS PAST SYSTEM...MORE
SHOWERY EAST OF THE BLUE RIDGE. EXPECTING BETTER CHANCE OF IFR
CONDITIONS BY DARK MOST TAF SITES. SMALL THREAT FOR THUNDER IN FAR
SW...MAYBE GETTING TO BLF OR BCB...BUT NOT LIKELY. WINDS AT RIDGE
TOP STRONG AGAIN FROM SW JUST AHEAD OF FRONT...WHICH WILL BE SWUNG
BACK THROUGH FROM WEST BEHIND DEVELOPING SFC LOW PRESSURE BY LATE
EVENING...AND THESE COULD BE MIXED DWON TO SFC IN HEAVIER
SHOWERS...BEST CHANCES AT BLF...BCB...AND MAYBE ROA. GUSTS TO 40
MPH POSSIBLE BUT NOT CONFIDENT ENOUGH TO PUT IN TAFS YET.
THIS SYSTEM CLEARS OUT BY FRIDAY...WITH VFR CONDITIONS EXPECTED
IN THE EAST...AND POSSIBLY MVFR UPSLOPE CLOUDS IN THE MOUNTAINS
WITH A FEW SHWRS POSSIBLE AT BLF ESPECIALLY. EVERYONE SHOULD BECOME
VFR BY SATURDAY AS HIGH PRESSURE BUILDS IN. A STORM MAY BRING
ANOTHER ROUND OF RAIN SUNDAY...ALTHOUGH MODELS HAVE BEEN TRENDING
FURTHER SOUTH WITH THIS STORM. THUS BEST CHANCE OF RAIN AND
REDUCED CEILINGS APPEARS TO BE CLOSER TO THE NC/VA BORDER IF
ANYWHERE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RCS/SK
NEAR TERM...RCS/SK
SHORT TERM...WERT
LONG TERM...MC
AVIATION...MC/RCS/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 AM CST THU DEC 22 2011
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
305 AM CST THU DEC 22 2011
MAIN CONCERNS WILL BE LINGERING SNOW ACROSS SOUTHERN WI INTO
NORTHEAST IA EARLY THIS MORNING...THEN SLIGHT SNOW CHANCES ACROSS
NORTHERN WISCONSIN ON FRIDAY.
RADAR AND SURFACE OBSERVATIONS SHOWING A BAND OF LIGHT SNOW
EXTENDING FROM EAST CENTRAL WISCONSIN...THROUGH SOUTHWEST WI AND
CENTRAL IA. AT THE NWS OFFICE HERE AROUND A HALF INCH HAS FALLEN SO
FAR. SHORTWAVE TROUGH PRODUCING LIFT FOR THIS SNOW WAS INDICATED ON
WATER VAPOR IMAGERY ACROSS SD/NEB. AIDING IN THE BANDING OF THIS
SNOW WAS CONFLUENT 850-700MB FLOW/WEAK FRONTOGENESIS INDICATED BY
THE RUC MODEL FROM NORTHEAST IA INTO SOUTHERN WI. LOWEST VISIBILITY
UNDER THE HIGHEST REFLECTIVITY BAND ON RADAR AROUND 1SM AT BOSCOBEL
AND MINERAL POINT WI. OTHERWISE...UNDER MOSTLY CLOUDY SKIES ACROSS
THE FORECAST AREA...TEMPERATURES AT 3 AM RANGED FROM THE MID 20S
ACROSS NORTH CENTRAL WI TO THE LOWER 30S SOUTH OF I-90.
22.00Z NCEP MODEL SUITE/29.03Z SREF IN GOOD AGREEMENT THROUGH THE
SHORT TERM.
FOR TODAY...MAIN CONFLUENT 850-700MB FLOW/FRONTOGENESIS SHIFTS
SOUTHEAST OF THE AREA BY 9 AM...BRINGING AN END TO SNOW CHANCES FOR
THE AREA. OTHERWISE...IR IMAGERY SHOWS A DECENT FIELD OF
STRATOCUMULUS ACROSS MN INTO WI...AND THIS WILL LIKELY HOLD THROUGH
MUCH OF THE MORNING...THEN START TO SCOUR OUT THROUGH THE AFTERNOON
HOURS AS A RIDGE OF HIGH PRESSURE/INCREASING SUBSIDENCE BUILDS IN
FROM THE PLAINS.
NORTHWEST FLOW ALOFT WILL BRING A FAIRLY VIGOROUS MID-LEVEL
SHORTWAVE TROUGH AND SURFACE LOW ACROSS SOUTHERN ONTARIO/LAKE
SUPERIOR REGION ON FRIDAY. NAM/GFS SHOW BEST FORCING AND CHANCES FOR
SNOW WILL BE CONFINED CLOSE TO THE TROUGH/LOW. HOWEVER...THE 29.00Z
ECMWF/GEM SHOW LIGHT QPF ALL THE WAY DOWN TO I-94. WENT WITH A
COMPROMISE AND KEPT A SMALL/SLIGHT CHANCE POP IN FOR TAYLOR COUNTY.
THE FORECAST AREA WILL THEN BE IN THE WARM SECTOR OF A LOW PRESSURE
SYSTEM PASSING THROUGH CANADA ON SATURDAY. SOUTHWEST SURFACE FLOW
AND AMPLE SUNSHINE SHOULD WARM HIGHS WELL INTO THE 30S WITH PERHAPS
A FEW READINGS AROUND THE 40 DEGREE MARK ACROSS FAR SOUTHWEST
WI/NORTHEAST IA.
.LONG TERM...CHRISTMAS DAY THROUGH WEDNESDAY
305 AM CST THU DEC 22 2011
22.00Z GFS/ECMWF IN DECENT AGREEMENT THROUGH THE LONG TERM.
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA CHRISTMAS DAY...BUT
APPEARS THE BULK OF THE COLD AIR ADVECTION WILL BE ALONG/NORTHEAST
OF I-94. AS A RESULT...COULD SEE HIGHS AROUND THE 40 DEGREE MARK
AGAIN SOUTHWEST OF I-94...ESPECIALLY FROM FAR SOUTHWEST WI INTO
NORTHEAST IA. OTHERWISE...WILL PROBABLY SEE SOME BLUSTERY CONDITIONS
WITH GOOD MIXING/FAIRLY TIGHT PRESSURE GRADIENT.
FAIRLY ACTIVE ZONAL FLOW REMAINS IN PLACE WITH STORM SYSTEMS STAYING
MAINLY NORTH OF THE U.S./CANADIAN BORDER. THIS KEEPS PRECIPITATION
CHANCES NORTH OF THE AREA AND WILL CONTINUE TO PRODUCE ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION...THROUGH 18Z FRIDAY
1136 AM CST THU DEC 22 2011
THE MAIN FOCUS OF THE TAFS IS WITH THE TIMING OF WHEN THE 2KFT TO
4KFT STRATUS CLEARS THE TAF SITES. THIS STRATUS CURRENTLY EXTENDS
ACROSS MUCH OF WISCONSIN AND A SMALL PORTION OF SOUTHEAST
MINNESOTA AND IS SLOWLY DROPPING TO THE SOUTH. CURRENT INDICATIONS
ARE THAT THE BACK EDGE OF THIS STRATUS WILL GET INTO LSE AROUND
21Z AND RST AROUND 22Z. AFTER THESE CLOUDS SHIFT TO THE SOUTHEAST
A RIDGE AXIS OF HIGH PRESSURE WILL SWING THROUGH THE REGION
TONIGHT AND BRING LIGHT AND VARIABLE WINDS ALONG WITH IT. SOME SCT
TO BKN MID LEVEL CLOUDS WILL SKIRT THE TAF SITES OVERNIGHT AS
WELL. WINDS WILL THEN SHIFT TO THE SOUTHWEST TOMORROW MORNING AND
BECOME GUSTY BY LATE MORNING WITH SOME GUSTS UP ABOVE 20KT
POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 AM CST THU DEC 22 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 AM CST THU DEC 22 2011
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
305 AM CST THU DEC 22 2011
MAIN CONCERNS WILL BE LINGERING SNOW ACROSS SOUTHERN WI INTO
NORTHEAST IA EARLY THIS MORNING...THEN SLIGHT SNOW CHANCES ACROSS
NORTHERN WISCONSIN ON FRIDAY.
RADAR AND SURFACE OBSERVATIONS SHOWING A BAND OF LIGHT SNOW
EXTENDING FROM EAST CENTRAL WISCONSIN...THROUGH SOUTHWEST WI AND
CENTRAL IA. AT THE NWS OFFICE HERE AROUND A HALF INCH HAS FALLEN SO
FAR. SHORTWAVE TROUGH PRODUCING LIFT FOR THIS SNOW WAS INDICATED ON
WATER VAPOR IMAGERY ACROSS SD/NEB. AIDING IN THE BANDING OF THIS
SNOW WAS CONFLUENT 850-700MB FLOW/WEAK FRONTOGENESIS INDICATED BY
THE RUC MODEL FROM NORTHEAST IA INTO SOUTHERN WI. LOWEST VISIBILITY
UNDER THE HIGHEST REFLECTIVITY BAND ON RADAR AROUND 1SM AT BOSCOBEL
AND MINERAL POINT WI. OTHERWISE...UNDER MOSTLY CLOUDY SKIES ACROSS
THE FORECAST AREA...TEMPERATURES AT 3 AM RANGED FROM THE MID 20S
ACROSS NORTH CENTRAL WI TO THE LOWER 30S SOUTH OF I-90.
22.00Z NCEP MODEL SUITE/29.03Z SREF IN GOOD AGREEMENT THROUGH THE
SHORT TERM.
FOR TODAY...MAIN CONFLUENT 850-700MB FLOW/FRONTOGENESIS SHIFTS
SOUTHEAST OF THE AREA BY 9 AM...BRINGING AN END TO SNOW CHANCES FOR
THE AREA. OTHERWISE...IR IMAGERY SHOWS A DECENT FIELD OF
STRATOCUMULUS ACROSS MN INTO WI...AND THIS WILL LIKELY HOLD THROUGH
MUCH OF THE MORNING...THEN START TO SCOUR OUT THROUGH THE AFTERNOON
HOURS AS A RIDGE OF HIGH PRESSURE/INCREASING SUBSIDENCE BUILDS IN
FROM THE PLAINS.
NORTHWEST FLOW ALOFT WILL BRING A FAIRLY VIGOROUS MID-LEVEL
SHORTWAVE TROUGH AND SURFACE LOW ACROSS SOUTHERN ONTARIO/LAKE
SUPERIOR REGION ON FRIDAY. NAM/GFS SHOW BEST FORCING AND CHANCES FOR
SNOW WILL BE CONFINED CLOSE TO THE TROUGH/LOW. HOWEVER...THE 29.00Z
ECMWF/GEM SHOW LIGHT QPF ALL THE WAY DOWN TO I-94. WENT WITH A
COMPROMISE AND KEPT A SMALL/SLIGHT CHANCE POP IN FOR TAYLOR COUNTY.
THE FORECAST AREA WILL THEN BE IN THE WARM SECTOR OF A LOW PRESSURE
SYSTEM PASSING THROUGH CANADA ON SATURDAY. SOUTHWEST SURFACE FLOW
AND AMPLE SUNSHINE SHOULD WARM HIGHS WELL INTO THE 30S WITH PERHAPS
A FEW READINGS AROUND THE 40 DEGREE MARK ACROSS FAR SOUTHWEST
WI/NORTHEAST IA.
.LONG TERM...CHRISTMAS DAY THROUGH WEDNESDAY
305 AM CST THU DEC 22 2011
22.00Z GFS/ECMWF IN DECENT AGREEMENT THROUGH THE LONG TERM.
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA CHRISTMAS DAY...BUT
APPEARS THE BULK OF THE COLD AIR ADVECTION WILL BE ALONG/NORTHEAST
OF I-94. AS A RESULT...COULD SEE HIGHS AROUND THE 40 DEGREE MARK
AGAIN SOUTHWEST OF I-94...ESPECIALLY FROM FAR SOUTHWEST WI INTO
NORTHEAST IA. OTHERWISE...WILL PROBABLY SEE SOME BLUSTERY CONDITIONS
WITH GOOD MIXING/FAIRLY TIGHT PRESSURE GRADIENT.
FAIRLY ACTIVE ZONAL FLOW REMAINS IN PLACE WITH STORM SYSTEMS STAYING
MAINLY NORTH OF THE U.S./CANADIAN BORDER. THIS KEEPS PRECIPITATION
CHANCES NORTH OF THE AREA AND WILL CONTINUE TO PRODUCE ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION...
515 AM CST THU DEC 22 2011
LATEST FOG/STRATUS SATELLITE IMAGERY POINTS TO AN AREA OF 2500-3000
FT CIGS SINKING SOUTH TOWARD KRST/KLSE...AND EXPECT THESE TO MOVE
ACROSS KRST/KLSE AROUND 12Z. RUC13/NAM12 X-SECTIONS AND BUFKIT
SOUNDINGS THEN SUGGEST THE LOW STRATUS SHOULD GRADUALLY MOVE
EAST/ERODE LATER THIS MORNING...NEAR 18Z. TRENDS LOOK ALRIGHT
COMPARED TO SATELLITE IMAGERY AND WILL KEEP TAFS TAILORED THIS WAY.
EXPECT MOSTLY VFR CONDITIONS THEN THROUGH MUCH OF THE HOLIDAY
WEEKEND AS A SPLIT UPPER LEVEL FLOW USHERS VARIOUS WEATHER SYSTEMS
NORTH AND SOUTH. WHILE PCPN IS NOT EXPECTED...THESE SYSTEMS WILL
BRINGING SOME WINDS AND PERIODS OF HIGH CLOUDINESS. THE STRONGEST
WINDS LOOK TO COME CHRISTMAS EVE-CHRISTMAS MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 AM CST THU DEC 22 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION..... RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 AM CST THU DEC 22 2011
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
305 AM CST THU DEC 22 2011
MAIN CONCERNS WILL BE LINGERING SNOW ACROSS SOUTHERN WI INTO
NORTHEAST IA EARLY THIS MORNING...THEN SLIGHT SNOW CHANCES ACROSS
NORTHERN WISCONSIN ON FRIDAY.
RADAR AND SURFACE OBSERVATIONS SHOWING A BAND OF LIGHT SNOW
EXTENDING FROM EAST CENTRAL WISCONSIN...THROUGH SOUTHWEST WI AND
CENTRAL IA. AT THE NWS OFFICE HERE AROUND A HALF INCH HAS FALLEN SO
FAR. SHORTWAVE TROUGH PRODUCING LIFT FOR THIS SNOW WAS INDICATED ON
WATER VAPOR IMAGERY ACROSS SD/NEB. AIDING IN THE BANDING OF THIS
SNOW WAS CONFLUENT 850-700MB FLOW/WEAK FRONTOGENESIS INDICATED BY
THE RUC MODEL FROM NORTHEAST IA INTO SOUTHERN WI. LOWEST VISIBILITY
UNDER THE HIGHEST REFLECTIVITY BAND ON RADAR AROUND 1SM AT BOSCOBEL
AND MINERAL POINT WI. OTHERWISE...UNDER MOSTLY CLOUDY SKIES ACROSS
THE FORECAST AREA...TEMPERATURES AT 3 AM RANGED FROM THE MID 20S
ACROSS NORTH CENTRAL WI TO THE LOWER 30S SOUTH OF I-90.
22.00Z NCEP MODEL SUITE/29.03Z SREF IN GOOD AGREEMENT THROUGH THE
SHORT TERM.
FOR TODAY...MAIN CONFLUENT 850-700MB FLOW/FRONTOGENESIS SHIFTS
SOUTHEAST OF THE AREA BY 9 AM...BRINGING AN END TO SNOW CHANCES FOR
THE AREA. OTHERWISE...IR IMAGERY SHOWS A DECENT FIELD OF
STRATOCUMULUS ACROSS MN INTO WI...AND THIS WILL LIKELY HOLD THROUGH
MUCH OF THE MORNING...THEN START TO SCOUR OUT THROUGH THE AFTERNOON
HOURS AS A RIDGE OF HIGH PRESSURE/INCREASING SUBSIDENCE BUILDS IN
FROM THE PLAINS.
NORTHWEST FLOW ALOFT WILL BRING A FAIRLY VIGOROUS MID-LEVEL
SHORTWAVE TROUGH AND SURFACE LOW ACROSS SOUTHERN ONTARIO/LAKE
SUPERIOR REGION ON FRIDAY. NAM/GFS SHOW BEST FORCING AND CHANCES FOR
SNOW WILL BE CONFINED CLOSE TO THE TROUGH/LOW. HOWEVER...THE 29.00Z
ECMWF/GEM SHOW LIGHT QPF ALL THE WAY DOWN TO I-94. WENT WITH A
COMPROMISE AND KEPT A SMALL/SLIGHT CHANCE POP IN FOR TAYLOR COUNTY.
THE FORECAST AREA WILL THEN BE IN THE WARM SECTOR OF A LOW PRESSURE
SYSTEM PASSING THROUGH CANADA ON SATURDAY. SOUTHWEST SURFACE FLOW
AND AMPLE SUNSHINE SHOULD WARM HIGHS WELL INTO THE 30S WITH PERHAPS
A FEW READINGS AROUND THE 40 DEGREE MARK ACROSS FAR SOUTHWEST
WI/NORTHEAST IA.
.LONG TERM...CHRISTMAS DAY THROUGH WEDNESDAY
305 AM CST THU DEC 22 2011
22.00Z GFS/ECMWF IN DECENT AGREEMENT THROUGH THE LONG TERM.
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA CHRISTMAS DAY...BUT
APPEARS THE BULK OF THE COLD AIR ADVECTION WILL BE ALONG/NORTHEAST
OF I-94. AS A RESULT...COULD SEE HIGHS AROUND THE 40 DEGREE MARK
AGAIN SOUTHWEST OF I-94...ESPECIALLY FROM FAR SOUTHWEST WI INTO
NORTHEAST IA. OTHERWISE...WILL PROBABLY SEE SOME BLUSTERY CONDITIONS
WITH GOOD MIXING/FAIRLY TIGHT PRESSURE GRADIENT.
FAIRLY ACTIVE ZONAL FLOW REMAINS IN PLACE WITH STORM SYSTEMS STAYING
MAINLY NORTH OF THE U.S./CANADIAN BORDER. THIS KEEPS PRECIPITATION
CHANCES NORTH OF THE AREA AND WILL CONTINUE TO PRODUCE ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION...THROUGH 06Z FRIDAY
1134 PM CST WED DEC 21 2011
BAND OF VERY LIGHT SNOW OVER BOTH KLSE AND KRST TAF SITES AS OF
05Z THURSDAY IS SLOWLY DRIFTING TO THE SOUTH...SUCH THAT THE SNOW
SHOULD BE OUT OF KRST BY 07Z AND KLSE BY 09Z. MVFR VISIBILITIES
ARE THE LOWEST FORECAST AT THIS TIME...THOUGH CANNOT RULE OUT A
VERY BRIEF PERIOD OF IFR AT KLSE. VFR VISIBILITIES SHOULD THEN BE
THE RULE THROUGH THE REST OF THE PERIOD AS DRIER SURFACE AIR MOVES
IN ON A 5 TO 15 KT NORTHWEST WIND. CEILING HEIGHTS ARE A LITTLE
MORE PROBLEMATIC. VFR CEILINGS OVER KRST SHOULD LOWER TO MVFR
AROUND 09Z AS MVFR STRATUS FROM MINNEAPOLIS AND RED WING MOVES
IN. KLSE MAY BOUNCE BETWEEN MVFR AND VFR...MOSTLY DUE TO THE
SNOW...UNTIL THE STRATUS MOVES IN THERE AROUND 09Z. ANTICIPATING
THE STRATUS TO SCATTER OUT AROUND 18Z...DUE TO DAYTIME HEATING AND
DRIER AIR MOVING IN. THIS DRIER AIR CAN CURRENTLY BE SEEN OVER
NORTHWEST MINNESOTA WHERE CLOUDS HAVE BEEN SCOURING OUT. LOOK FOR
THE VFR CEILINGS TO THEN PERSIST THROUGH 06Z FRIDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 AM CST THU DEC 22 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1055 PM CST WED DEC 21 2011
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATED...LOWERED THE PROBABILITY OF SNOW IN THE FORECAST OVER
MOST OF THE AREA NORTH OF A WAUSAU TO GREEN BAY LINE. INITIAL SNOW
OVER NORTHCENTRAL WISCONSIN DURING THE LATE AFTERNOON AND EARLY
EVENING HAD THE BENEFIT OF LOW LEVEL WARM ADVECTION AND
CONVERGENCE IN ADDITION TO THE UPPER JET DYNAMICS. THE LOW LEVEL
FORCING HAS SINCE DIMINISHED AND SO HAS THE SNOW.
AS OF 830 PM THERE WERE ECHOES OVER THE CENTRAL PART OF THE
FORECAST AREA BUT LITTLE OR NOTHING REACHING THE GROUND DUE TO
VERY DRY AIR INITIALLY ACROSS THE AREA. THE PRECIPITABLE WATER OF
THE 00Z GREEN BAY SOUNDING WAS ONLY .22 INCHES. THE MINNEAPOLIS
SOUNDING STARTED OFF SIMILARLY AT 12Z AND MOISTENED UP TO ABOUT
.40 INCHES BUT ONLY MANAGED A TRACE OF SNOW. ALL IS NOT LOST FOR
THOSE WISHING FOR SNOW AS SOME BETTER RADAR REFLECTIVITIES OVER
IOWA ARE MOVING TO THE NORTHEAST. THESE CORRELATE WELL WITH THE
500MB DIVERGENCE OF THE 00Z RUC WHICH WOULD TAKE THIS SNOW
GENERALLY TO THE AREA SOUTH OF A KEWAUNEE TO WAUPACA.
THINK THAT THE ATMOSPHERE WILL MANAGE TO PRODUCE SOME LIGHT SNOW
OR AT LEAST FLURRIES IN THE FOX VALLEY...LAKESHORE AND WAUSHARA
AND WAUPACA COUNTIES LATE TONIGHT OR EARLY THURSDAY BUT PROBABLY
JUST A DUSTING TO A HALF INCH DUE TO THE DRY AIR CURRENTLY IN
PLACE.
RDM
&&
.PREV DISCUSSION...ISSUED AT 624 PM CST WED DEC 21 2011...
SHORT TERM...TONIGHT AND THURSDAY...SNOW TRENDS AND ACCUMULATIONS
ARE THE MAIN FCST CONCERNS.
A COLD FRONT WAS MOVG THROUGH THE NW HALF OF THE CWA THIS AFTERNOON.
MID-LEVEL FRONTOGENETIC FORCING SITUATED JUST NW OF THE FRONT WAS
GENERATING A BAND OF LIGHT SNOW FROM CENTRAL MN INTO NC WI...WITH
OCNL VSBYS OF 1-2SM. MODELS ARE IN GENERAL AGREEMENT THAT THIS
BAND OF SNOW WILL GRADUALLY WEAKEN DURING THE LATE AFT/EARLY EVG...
WITH ANOTHER MORE SIGNIFICANT BAND SETTING UP OVER PARTS OF C/EC WI
LATE TONIGHT. HAVE KEPT CHC POPS ACROSS THE NW TWO-THIRDS OF THE CWA
THIS EVG...THEN LIKELY POPS MAINLY SOUTH OF A MFI-SUE LINE AFTER
MIDNIGHT. THE SNOW WILL CONTINUE TO SAG SOUTH THROUGH OUR SOUTHERN
COUNTIES ON THURSDAY MORNING...AND SHOULD BE OUT OF THE FA BY
MIDDAY. DON`T THINK THAT SNOWFALL TOTALS WILL GET OUT OF HAND...
AS THE INITIAL AIR MASS IS QUITE DRY...AND THERE IS LITTLE
EVIDENCE OF ANY INSTABILITY THAT MIGHT ENHANCE/FOCUS THE FGEN
FORCING. REGARDLESS...IT APPEARS THAT PARTS OF C/EC WI WILL SEE
AROUND AN INCH OF SNOW...WHICH COULD MAKE FOR A SLIPPERY COMMUTE
ON THURSDAY MORNING.
COLDER NNW FLOW WILL BRING A CHC OF LAKE-EFFECT SNOW SHOWERS TO
NC WI LATE TONIGHT INTO THURSDAY. WITH LIGHT WINDS (10-15 KTS)
IN THE 925-850 MB LAYER...WOULD NOT EXPECT THE SNOW SHOWERS TO
MOVE VERY FAR INLAND...SO WILL MAINLY CONFINE POPS TO VILAS
COUNTY FOR NOW.
LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY.
STILL NO SIGNIFICANT CHANGES IN SPLIT FLOW PATTERN THRU FIRST
PART OF NEXT WEEK. SOME HINT OF MORE ZONAL/WNW FLOW PATTERN LATER
NEXT WEEK. OVERALL...WEATHER QUIET FOR THIS TIME OF YEAR.
SERIES OF NW PACIFIC SYSTEMS MOVE ACROSS THE REGION DURING THIS
PERIOD IN NORTHERN STREAM...BUT LITTLE IN THE WAY OF WEATHER
OUTSIDE OF CLOUDS AND FLURRIES...AS THESE SYSTEMS ARE MOISTURE-
STARVED DUE TO SPLIT FLOW. BOTH 21/12Z GFS AND ECMWF INDICATE
SYSTEM ON FRIDAY HAS ENOUGH UPPER LEVEL DYNAMICS TO OVERCOME
INITIALLY DRY COLUMN AND PRODUCE A PERIOD OF SNOW SHOWERS ACROSS
THE NORTH THIRD.
TEMPERATURES WILL BE ABOVE NORMAL FOR MUCH OF PERIOD AS ARCTIC
AIR REMAINS GENERALLY BOTTLED UP N OF 50 N.
&&
.AVIATION...MVFR CIGS ACROSS MOST OF THE REGION OVERNIGHT. A BAND
OF LIGHT SNOW WILL MOVE ACROSS CENTRAL AND EAST CENTRAL WISCONSIN
WITH MVFR VSBYS AND LOCAL BRIEF IFR POSSIBLE. VFR EXPECTED OVER
MOST OF THE AREA BY EARLY AFTERNOON THURSDAY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
500 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COSAT
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSLTY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
430 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COMING SOON.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
410 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COMING SOON.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
345 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING. LOWS
IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER IMPULSE
WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH CLOUDS. SOUTH
WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE LOWER 30S TO AROUND
40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST SAT DEC 24 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM...CLOUDS (MAINLY OF THE HIGH VARIETY) CONTINUE TO
SLOWLY WORK INTO OUR REGION. LOWER CLOUDS...CONTINUE TO HANG ACROSS
THE CATSKILLS...SOUTHERN GREENS AND NORTHERN BERKSHIRES. THESE ARE
LAKE EFFECT CLOUDS...DOWN WIND OF ONTARIO BUT THE INVERSION IS TOO
LOW FOR ANY SNOW TO FALL OUT OF THEM (OTHER THAN FLURRIES).
HIGH CLOUDS MOVING INTO THE REGION MIGHT SEEDER FEED THESE CLOUDS
AND BRING A LITTLE MORE IN THE WAY OF FLURRIES (AS WELL AS A
NORTHERLY WIND FLOW) OFF LAKE CHAMPLAIN. HOWEVER...MOISTURE IS
EXTREMELY LIMITED AND THUS FAR...NO RETURNS ON THE RADARS. SO WILL
KEEP FLURRIES IN BUT NO MORE.
REPOPULATED THE HOURLY GRIDS WHICH LOOKED PRETTY MUCH ON TRACK
COMPARED TO THE PREVIOUS FORECAST. DECIDED NOT TO RERUN THE ACTUAL
ZONES AS THE WORDING WILL CHANGE LITTLE IF AT ALL.
OTHERWISE NO CHANGES TO THE OVERNIGHT PERIODS. DESPITE THE
CLOUDS...TEMPERATURES WILL SLOWLY DROP...BOTTOMING OUT AROUND 20
LOCALLY IN THE TRI-CITY AREA...20S FURTHER SOUTH IN THE MID HUDSON
VALLEY AND LOWER LITCHFIELD...TEENS MOST OTHER PLACES.
*********PREVIOUS NEAR TERM FORECAST*******
AS OF 945 PM EST...CLOUDS ARE FINALLY SHOWING SIGNS OF BREAKING
UP IN VALLEY REGIONS...WHILE CLOUDS CONTINUE TO HANG ON ACROSS
HIGHER ELEVATIONS WITHIN THE CATSKILLS...WESTERN
ADIRONDACKS...SOUTHERN GREENS AND BERKSHIRES. SOME FLURRIES WILL
REMAIN POSSIBLE FROM THESE CLOUDS OVER THE NEXT FEW HOURS.
AS CLOUDS BEGIN TO BREAK...TEMPERATURES ARE ALSO STARTING TO
FALL...AND HAVE NOT TOUCHED OVERNIGHT MINS FROM CURRENT
PROJECTIONS...ESP GIVEN THE EXPECTATION FOR CONTINUED COLD
ADVECTION FROM THE NORTH.
HIGH/MID LEVEL CLOUDS WILL INCREASE AFTER MIDNIGHT FROM W TO E
AHEAD OF APPROACHING GREAT LAKES SHORTWAVE. THIS MAY INITIATE
ADDITIONAL SNOW FLURRIES OR LIGHT SNOW SHOWERS ACROSS PORTIONS OF
THE CATSKILLS AND ADIRONDACKS LATER TONIGHT AS SEEDER/FEEDER
MECHANISM POTENTIALLY DEVELOPS BETWEEN THICKENING MID LEVEL
CLOUDS...AND LOWER STRATOCU BELOW. IN ADDITION...SOME SNOW
FLURRIES WILL BE POSSIBLE FROM VEERING LOW LEVEL NNE FLOW ACROSS
THE UPPER HUDSON RIVER VALLEY CROSSING LAKE CHAMPLAIN...AND HAVE
KEPT MENTION OF FLURRIES IN THIS REGION AND INTO SW VT OVERNIGHT.
OTHERWISE...SOME ADJUSTMENTS TO WINDS...WHICH HAVE REMAINED BRISK
WITHIN THE MOHAWK RIVER VALLEY/CAPITAL REGION AND NORTHERN
BERKSHIRES...AND TO HOURLY TEMPS/DEWPOINTS ACCORDING TO RECENT OBS.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...GJM
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
1240 AM EST SAT DEC 24 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM...CLOUDS (MAINLY OF THE HIGH VARIETY) CONTINUE TO
SLOWLY WORK INTO OUR REGION. LOWER CLOUDS...CONTINUE TO HANG ACROSS
THE CATSKILLS...SOUTHERN GREENS AND NORTHERN BERKSHIRES. THESE ARE
LAKE EFFECT CLOUDS...DOWN WIND OF ONTARIO BUT THE INVERSION IS TOO
LOW FOR ANY SNOW TO FALL OUT OF THEM (OTHER THAN FLURRIES).
HIGH CLOUDS MOVING INTO THE REGION MIGHT SEEDER FEED THESE CLOUDS
AND BRING A LITTLE MORE IN THE WAY OF FLURRIES (AS WELL AS A
NORTHERLY WIND FLOW) OFF LAKE CHAMPLAIN. HOWEVER...MOISTURE IS
EXTREMELY LIMITED AND THUS FAR...NO RETURNS ON THE RADARS. SO WILL
KEEP FLURRIES IN BUT NO MORE.
REPOPULATED THE HOURLY GRIDS WHICH LOOKED PRETTY MUCH ON TRACK
COMPARED TO THE PREVIOUS FORECAST. DECIDED NOT TO RERUN THE ACTUAL
ZONES AS THE WORDING WILL CHANGE LITTLE IF AT ALL.
OTHERWISE NO CHANGES TO THE OVERNIGHT PERIODS. DESPITE THE
CLOUDS...TEMPERATURES WILL SLOWLY DROP...BOTTOMING OUT AROUND 20
LOCALLY IN THE TRI-CITY AREA...20S FURTHER SOUTH IN THE MID HUDSON
VALLEY AND LOWER LITCHFIELD...TEENS MOST OTHER PLACES.
*********PREVIOUS NEAR TERM FORECAST*******
AS OF 945 PM EST...CLOUDS ARE FINALLY SHOWING SIGNS OF BREAKING
UP IN VALLEY REGIONS...WHILE CLOUDS CONTINUE TO HANG ON ACROSS
HIGHER ELEVATIONS WITHIN THE CATSKILLS...WESTERN
ADIRONDACKS...SOUTHERN GREENS AND BERKSHIRES. SOME FLURRIES WILL
REMAIN POSSIBLE FROM THESE CLOUDS OVER THE NEXT FEW HOURS.
AS CLOUDS BEGIN TO BREAK...TEMPERATURES ARE ALSO STARTING TO
FALL...AND HAVE NOT TOUCHED OVERNIGHT MINS FROM CURRENT
PROJECTIONS...ESP GIVEN THE EXPECTATION FOR CONTINUED COLD
ADVECTION FROM THE NORTH.
HIGH/MID LEVEL CLOUDS WILL INCREASE AFTER MIDNIGHT FROM W TO E
AHEAD OF APPROACHING GREAT LAKES SHORTWAVE. THIS MAY INITIATE
ADDITIONAL SNOW FLURRIES OR LIGHT SNOW SHOWERS ACROSS PORTIONS OF
THE CATSKILLS AND ADIRONDACKS LATER TONIGHT AS SEEDER/FEEDER
MECHANISM POTENTIALLY DEVELOPS BETWEEN THICKENING MID LEVEL
CLOUDS...AND LOWER STRATOCU BELOW. IN ADDITION...SOME SNOW
FLURRIES WILL BE POSSIBLE FROM VEERING LOW LEVEL NNE FLOW ACROSS
THE UPPER HUDSON RIVER VALLEY CROSSING LAKE CHAMPLAIN...AND HAVE
KEPT MENTION OF FLURRIES IN THIS REGION AND INTO SW VT OVERNIGHT.
OTHERWISE...SOME ADJUSTMENTS TO WINDS...WHICH HAVE REMAINED BRISK
WITHIN THE MOHAWK RIVER VALLEY/CAPITAL REGION AND NORTHERN
BERKSHIRES...AND TO HOURLY TEMPS/DEWPOINTS ACCORDING TO RECENT OBS.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH AT LEAST 00Z/SUNDAY. VFR CIGS
WITH BASES OF 3500-5000 FT AGL WILL PERSIST THROUGH AT LEAST
06Z/SAT...WITH GRADUAL DECREASE IN LOWER LEVEL CLOUDS EXPECTED
THEREAFTER. THERE IS A SLIGHT CHC FOR MVFR CIGS AT KGFL AND KALB
LATER THIS EVENING BEFORE DRIER AIR ALLOWS CIGS TO BREAK.
SOME FLURRIES WILL BE POSSIBLE THROUGH MIDNIGHT AT KGFL AND
KALB.
EXPECT NORTHWEST TO NORTH WINDS AT 5-10 KT TONIGHT...ALTHOUGH
10-15 KT WITH SOME GUSTS UP TO 20 KT POSSIBLE AT KALB THROUGH THIS
EVENING. WINDS WILL BECOME MAINLY NORTH ON SATURDAY AT 5-10 KT.
OUTLOOK...
SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...KL
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CST FRI DEC 23 2011
.AVIATION...
WEST TO NORTHWEST FLOW WITH UPPER RIDGING WILL BRING QUIET WEATHER
TO THE REGION THE NEXT FEW DAYS. SKIES WILL BE CLEAR TO MOSTLY
CLEAR WITH SOME PASSING HIGH CLOUDS PERIODICALLY. LIGHT WEST TO
SOUTHWEST WINDS CAN BE EXPECTED OF 5-10 MPH WITH VISIBILITIES AOA
7 MILES...RESULTING IN VFR CONDITIONS. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 312 PM CST FRI DEC 23 2011/
SYNOPSIS...
A VIGOROUS CLIPPER SYSTEM WAS SEEN ON WATER VAPOR IMAGERY
SWEEPING SOUTHEAST ACROSS MN AND WI THIS AFTERNOON. AT
18Z...ASSOCIATED SURFACE LOW PRESSURE WAS CENTERED IN SW ONTARIO
JUST NORTH OF MN WITH A TROUGH EXTENDING S-SW ACROSS MN INTO
CENTRAL NEB. AHEAD OF THIS TROUGH...WIDESPREAD LIGHT SNOW AND
BRIEF LOCALIZED MODERATE SNOW WAS FALLING ACROSS SE MN INTO MUCH
OF WI. MID AND HIGH LEVEL CLOUD COVER PRECEDING THE SYSTEM HAS
SPREAD SOUTH-SE TO COVER THE NORTHERN HALF OF THE FORECAST
AREA...WHILE STRATUS TO THE SOUTH THAT PERSISTED OVERNIGHT HAS
BEEN DRAWN NORTHWARD IN THE LOW LEVEL SW FLOW TO COVER THE FAR
SOUTHEAST PART OF THE FORECAST AREA. THE CLOUD COVER...AND
SLIGHTLY HIGHER LOW LEVEL MOISTURE LEVELS...HAVE HELD TEMPERATURES
A FEW DEGREES COOLER THAN EXPECTED TODAY WITH MANY AREAS
STRUGGLING TO REACH 32 AS OF 2 PM.
SHORT TERM...TONIGHT AND SATURDAY...
THE MAIN FOCUS IS ON THE NEAR TERM POTENTIAL FOR LIGHT SNOW. 12Z
FORECAST MODELS HAVE GENERALLY BEEN TOO WEAK WITH THE SURFACE
PRESSURE FIELDS...TOO LOW ON LOW LEVEL MOISTURE LEVELS...AND ALSO
AND A BIT TOO FAR NORTH AND TOO WEAK WITH THE UPPER FORCING SO FAR
TODAY. FOLLOWING THE LATEST RUC DEPICTION OF A LOBE OF MID LEVEL
VORTICITY ROTATING AROUND THE BASE OF THE MAIN SHORTWAVE...THE TRACK
OF UPPER LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100 PLUS
KT JET DIVING SOUTH OUT OF MANITOBA...THERE IS SUPPORT THAT LIFT
AND SATURATION MAY PULL FLURRIES OR EVEN LIGHT SNOW FURTHER SOUTH
AND SOUTHWEST THAN PREVIOUSLY EXPECTED. AN IMPRESSIVE AXIS OF
WIDESPREAD 4 MB PRESSURE FALLS ON MSAS SWEEPING INTO EASTERN IA
AND A MOST RECENT 5 MB BULLSEYE CENTERED NEAR VINTON...FURTHER
SUPPORTS THIS POSSIBILITY. HOWEVER...WITH CLOUD BASES STILL WELL
ABOVE 9000 FT OVER MOST OF IA AND A STRONG SW LOW LEVEL FLOW
ADVECTING DRY AIR INTO THIS FAST MOVING SYSTEM...SUFFICIENT
SATURATION WILL BE DIFFICULT OVER MOST OF THE FORECAST AREA. HAVE
ADDED A POTENTIAL FOR FLURRIES ACROSS THE NORTHEAST FOR LATE
AFTERNOON INTO EVENING...WITH LOW CHANCES FOR A DUSTING OF
ACCUMULATION ALONG AND NORTH OF THE HIGHWAY 20 CORRIDOR IN IL.
ONCE THIS SYSTEM PASSES EARLY THIS EVENING...DRIER AIR AND WEAK
SUBSIDENCE SHOULD ALLOW THE WIDESPREAD CLEARING OVER THE PLAINS TO
SPREAD EASTWARD OVER THE FORECAST AREA. HAVE KEPT LOWS IN A RANGE
FROM THE TEENS NORTH TO LOWER 20S SOUTH...BUT WILL HAVE TO WATCH
TRENDS CLOSELY AS TEMPERATURES COULD POSSIBLY PLUNGE LOWER AS WINDS
BECOME LIGHT WESTERLY LATE TONIGHT UNDER MOSTLY CLEAR SKIES.
SATURDAY...TEMPERATURES SHOULD MODERATE AS WARM ADVECTION ALOFT
COMMENCES WHILE A LARGELY DRY AIRMASS FAVORS MOSTLY SUNNY SKIES.
FORECAST SOUNDINGS DEPICT A LOW LEVEL INVERSION HOLDING STRONG WITH
GENERALLY LIGHT SW WINDS AND HAVE THUS HELD HIGHS CLOSE TO GUIDANCE
VALUES IN THE 30S OVER MOST OF THE AREA. ..SHEETS..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
AN OVERALL TREND OF WARMER AND LIKELY DRIER THAN NORMAL SHOULD BE
SEEN THROUGH THE END OF THE MONTH.
A COLD FRONTAL PASSAGE WILL OCCUR SATURDAY NIGHT/EARLY SUNDAY AS
ANOTHER SYSTEM PASSES WELL NORTH OF THE AREA. CONDENSATION PRESSURE
DEFICITS IN THE LOW AND MID LEVELS ARE QUITE HIGH. THUS A DRY FROPA
SHOULD BE SEEN WITH ONLY AN INCREASE IN CLOUDS. BRISK CONDITIONS
WILL BE SEEN ON SUNDAY WITH RESPECTABLE CAA BEHIND THE FRONT.
HIGH PRESSURE WILL QUICKLY MOVE THROUGH THE REGION SUNDAY NIGHT
KEEPING QUIET AND DRY CONDITIONS ACROSS THE AREA. ATTENTION THEN
TURNS TO THE STORM SYSTEM EARLY NEXT WEEK.
THE OVERALL LONGWAVE PATTERN IS DE-AMPLIFYING AND WILL ELIMINATE THE
SPLIT FLOW OVER THE WESTERN CONUS EARLY NEXT WEEK. A STRONG UPPER
LEVEL SYSTEM NEAR 40N/160W WILL MAKE LANDFALL ON THE WA/OR COAST
SUNDAY AND WILL BE THE KEY TO WHAT HAPPENS WITH THE CUT OFF LOW IN
THE SOUTHERN STREAM MONDAY INTO MONDAY NIGHT. THE OVERALL TREND WITH
THE MODELS HAS BEEN TO SLOW DOWN THE EJECTION OF THE CUT OFF LOW.
THUS THERE ARE TWO POSSIBLE OUTCOMES. THE FIRST IS A PARTIAL PHASING
WITH THE NORTHERN STREAM ENERGY WHICH WOULD PULL THE SOUTHERN CUT
OFF LOW FURTHER NORTH. THE OTHER POSSIBILITY IS A CONTINUED SLOWING
OF THE CUT OFF LOW WHICH WOULD RESULT IN NO PHASING OF THE NORTHERN
AND SOUTHERN STREAMS. IF THE SECOND SCENARIO OCCURS...THE SOUTHERN
STREAM SYSTEM WOULD PASS SOUTH OF THE AREA RESULTING IN DRY
CONDITIONS.
SINCE THE MODELS HAVE BECOME SLOWER WITH THE SOUTHERN CUT OFF
LOW...MONDAY WILL BE DRY WITH AN INCREASE IN CLOUDS THROUGH THE DAY.
PRECIPITATION MAY BE NOT FAR AWAY FROM THE SOUTHERN CWFA BY SUNSET
MONDAY.
MONDAY NIGHT ON...
RIGHT NOW THE MODEL CONSENSUS IS FOR A PARTIAL PHASING OF THE
NORTHERN AND SOUTHERN STREAMS. SUCH A SCENARIO WILL BRING A THREAT
OF PRECIPITATION TO MUCH OF THE CWFA MONDAY NIGHT. A RAIN/SNOW MIX
LOOKS TO BE THE MOST LIKELY WITH A POSSIBLE CHANGE OVER TO ALL SNOW
JUST PRIOR TO SUNRISE TUESDAY. ANY SNOWFALL WOULD BE ONE HALF INCH
OR LESS.
MODEL CONSENSUS GIVES QUIET AND DRY CONDITIONS TUESDAY/TUES NIGHT AS
HIGH PRESSURE QUICKLY MOVES THROUGH THE AREA.
BY MID WEEK A NEAR ZONAL OR VERY LOW AMPLITUDE FLOW WILL EXIST
ACROSS THE CONUS AND PACIFIC. THERE ARE DIFFERENCES BETWEEN THE
MODELS BUT THE POTENTIAL EXISTS FOR A NEAR DAILY OCCURRENCE OF
CLIPPER OR HYBRID CLIPPER SYSTEMS FROM WEDNESDAY THROUGH FRIDAY. THE
MODEL DIFFERENCES WITH TIMING AND SMOOTHING ARE CAUSING POPS TO
CANCEL EACH OTHER OUT WHICH PRODUCES A CONSENSUS FCST OF MAINLY DRY
CONDITIONS FOR WEDNESDAY THROUGH FRIDAY.
INTERNALLY...THE MODELS SHOW SOME RESPECTABLE FORCING AND A
LOWERING OF CONDENSATION PRESSURE DEFICITS WITH EACH SYSTEM. THUS
THERE MAY BE A POTENTIAL FOR PRECIPITATION WEDNESDAY THROUGH FRIDAY.
THE SMOOTHING OF FEATURES MAKES IT DIFFICULT TO ASCERTAIN WHERE
PRECIPITATION MAY OCCUR. AREAS NORTH OF HWY 30 ARE CURRENTLY
DEPICTED AS HAVING THE BETTER FORCING AND LOWER CONDENSATION
PRESSURE DEFICITS WHICH IMPLIES A BETTER CHANCE OF PRECIPITATION.
HOWEVER...ANY PRECIPITATION THAT OCCURS WILL BE LIGHT.
THE PROGNOSTIC CHARTS ARE INDICATING THE LONGWAVE PATTERN WILL BEGIN
TO RE-AMPLIFY IN EARLY JANUARY. A WEAK TO MODERATE LA NINA COMBINED
WITH A NEGATIVE PDO AND SST ANOMALIES WOULD FAVOR A LONGWAVE TROF
NEAR THE EAST COAST. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
402 PM MST FRI DEC 23 2011
VFR CONDS EXPECTED NEXT 24 HOURS AT BOTH TERMINALS AS HIGH PRESSURE
WILL BE IN CONTROL OF THE WEATHER PATTERN.
BAS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 AM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.UPDATE...
ALTHOUGH NO MORE THAN AN INCH OF SN HAS FALLEN SO FAR IN LUCE COUNTY
PER CALLS TO SPOTTERS...LATEST RADAR IMAGERY SHOWS HIER
REFLECTIVITIES SHOWING UP IN NRN LK MI AND MOVING NEWD INTO CHIPPEWA
COUNTY TOWARD ERY. THE 00Z APX RAOB SHOWS DEEP MSTR THRU THE ENTIRE
TROP AND AN H85 TEMP OF -12C...PARAMETERS CONDUCIVE TO LK ENHANCED
SN IN AN AREA OF LARGE SCALE QVECTOR CNVGC ASSOCIATED WITH A FAIRLY
VIGOROUS SHRTWV DIGGING SEWD THRU WI. WITH SSW FLOW...EXPECT THE LK
ENHANCED SHSN NOW PUSHING TOWARD ERY TO IMPACT MAINLY THE SE HALF OF
LUCE COUNTY FOR AT LEAST THE NEXT COUPLE OF HRS. SO OPTED TO KEEP
THE GOING WINTER WX ADVY GOING FOR THAT COUNTY THRU MIDNGT. ALTHOUGH
SOME OF THE MORE RECENT HIER RES MODELS SHOW THE SHSN PERSISTING
EVEN BEYOND 06Z...LATEST RUC SHOWS SGNFT DEEP LYR QVECTOR DVGC/MID
LVL DRYING OVERSPREADING THE AREA FM THE W BY 06Z...CONSISTENT WITH
WARMING CLD TOPS OBSVD TO THE W ON RECENT IR STLT IMAGERY AND TRACK
OF SHRTWV TO THE SE AWAY FM THE AREA OF INTEREST. SO EXPECT SHSN
INTENSITY/COVERAGE TO DIMINISH AFT MIDNGT.
&&
.SHORT TERM /TONIGHT AND SATURDAY/ ISSUED AT 402 PM...
PRIMARY ISSUE IS LAKE ENHANCED SNOW OVER FAR EASTERN CWA THIS
EVENING.
CLIPPER LOW PRESSURE SYSTEM ON ITS WAY ACROSS UPR MI LATE THIS AFTN.
WV LOOP AND RAOBS FM 12Z POINT TO SHARP SHORTWAVE DIGGING ACROSS MN
AND NOW INTO SW WI. IR SATELLITE SHOWS GRADUALLY WARMING CLOUD TOP
TEMPS AS THE SYSTEM SNOW HAS PUSHED INTO CNTRL UPR MI AND EASTERN
WI. MOST CONCENTRATED MODERATE SNOW SHOULD END UP FALLING JUST ALONG
AND SOUTH OF THE WI BORDER ADJACENT TO TRACK OF COMPACT SHORTWAVE.
ELSEWHERE...DEEP LAYER Q-VECTOR CONVERGENCE AND BOUT OF ISENTROPIC
ASCENT ON 280K SFC /H7-H6/ WILL LEAD TO A LIGHT DUSTING OF SNOW WITH
ACCUMS UNDER AN INCH. THIS BOUT OF LGT SYSTEM SNOW EXPECTED TO TAPER
QUICKLY THIS EVENING WEST HALF OF CWA AS SUBSIDENCE SPREADS IN FM
MN.
FORCING FM SYSTEM IN PROCESS OF SPREADING ACROSS EASTERN UPR MI
WHICH BRINGS LAKE ENHANCEMENT OFF OF LK MICHIGAN INTO MIX THROUGH
THIS EVENING WITH H85 TEMPS AROUND -10C AND LK SFC TEMPS ROUGHLY
+6C. VISIBLE SATELLITE LOOP OVER PAST FEW HOURS SHOWS CLOUD ELEMENTS
STREAMING IN OFF LK HURON (SE WINDS) AND LK MICHIGAN (SSW WINDS)
CONVERGING OVR CNTRL MACKINAC COUNTY INTO SOUTHERN LUCE COUNTY.
PRESENCE OF THE LOW-LEVEL CONVERGENT FLOW ALLOWED SNOW TO BEGIN AS
EARLY AS MIDDAY AT KERY WITH REDUCED VSBY THROUGH THIS AFTN.
REGIONAL CANADIAN REALLY WAS ONLY HIGHER RESOLUTION MODEL TO
INDICATE SNOW SO EARLY AT KERY AND WILL CONTINUE TO FOLLOW ITS IDEA
FOR FCST THIS EVENING SHOWING WIND TRAJECTORIES FM 210-230 DIRECTION
FLOWING INTO EASTERN CWA. RESULT IS INCREASING LK ENHANCEMENT
THROUGH AROUND 03Z TONIGHT AS BULK OF STRONGER LARGER SCALE LIFT
SLIDES ACROSS AND INVERSION IS PRETTY MUCH ELIMANATED FOR A TIME.
EXPECT HEAVIEST SNOW /TOTALS UP TO 5 INCHES THROUGH MIDNIGHT/ TO
STAY JUST SOUTH AND SOUTHEAST OF CITY OF NEWBERRY WITH PROBABLY LESS
THAN 1 INCH OF SNOW OCCURRING FARTHER W AND NW AT MCMILLAN AND PINE
STUMP JUNCTION. WHERE THIS BAND OF ENHANCED SNOW SETS UP TRAVEL WILL
LIKELY BECOME QUITE DIFFICULT DUE TO SNOW COVERED ROADS AND POOR
VISIBILITY. HAZARD IS FURTHER HEIGHTENED SINCE TRAVEL VOLUME MAY BE
HIGHER DUE TO THE CHRISTMAS HOLIDAY WEEKEND. LAKE ENHANCED SNOW
HEADS EAST OUT OF THE CWA AFT MIDNIGHT ...LEAVING JUST A FEW LIGHTER
SNOW SHOWERS IN ITS WAKE. ELSEWHERE AFTER MID EVENING...SHOULD BE
FAIRLY QUIET AS LOW PRESSURE TROUGH FILLS OVR THE AREA. IF ENOUGH
LOW-LEVEL MOISTURE LINGERS...PERHAPS COULD SEE SOME FZDZ. BETTER
CHANCE FOR THIS WOULD BE OVER EASTERN CWA WITH MOISTURE FLOWING IN
OFF LK MICHIGAN.
LOOKING QUIET FOR SATURDAY. STILL A LOW RISK OF LINGERING LOW CLOUDS
AND MAYBE SOME FZDZ/FLURRIES EARLY. OTHERWISE...EXPECT INCREASING SW
WINDS AND SCT-BKN MID CLOUDS AHEAD OF ANOTHER LOW PRESSURE TROUGH IN
NW FLOW PATTERN. HIGHS SHOULD BE ABOVE NORMAL WITH READINGS UPR 20S
TO LWR 30S.
.LONG TERM 00Z SUN...
NAM SHOWS A 500 MB TROUGH NEAR LAKE WINNIPEG 00Z SUN THAT DIGS
SOUTHEAST INTO THE UPPER GREAT LAKES ON SUN. THIS TROUGH IS QUICKLY
FOLLOWED BY A 500 MB RIDGE OVER THE NORTHERN PLAINS 00Z MON AND THEN
ANOTHER TROUGH COMES INTO THE NORTHERN PLAINS 00Z TUE. NAM SHOWS
SOME 850-500 MB Q-VECTOR CONVERGENCE SAT NIGHT WITH DEEPER MOISTURE
MOVING THROUGH THE CWA AND BOTH MOVE OUT ON SUN. GFS AND ECMWF SHOW
ABOUT THE SAME THING AS THE NAM DOES. DID NOT MAKE TOO MANY CHANGES
TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER. ONE THING WAS TO
CUT BACK ON POPS FOR SAT NIGHT AS COLD AIR DOES NOT GET IN UNTIL
SUNDAY WHEN LAKE EFFECT SNOW STARTS AS COLDER AIR AT 850 MB
TEMPERATURES DROP TO -10C ON SUNDAY. THIS WILL HAVE AN AFFECT OVER
THE WEST WITH LESS LAKE EFFECT FOR LATE SAT NIGHT. WINDS QUICKLY
BACK TO THE NORTHWEST WITH WARM AIR ADVECTION ON SUNDAY NIGHT INTO
MONDAY...SO DRY WEATHER WILL MOVE IN THEN. WILL GET BREEZY ON MONDAY
WITH THE WARM AIR ADVECTION AND WILL GET WARM WITH HIGHS ABOVE
NORMAL IN THE MID 30S TO LOWER 40S.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB RIDGE OVER THE
UPPER GREAT LAKES 12Z MON WITH A TROUGH IN THE CANADIAN PRAIRIES.
THE ECMWF BRINGS THIS TROUGH INTO THE UPPER GREAT LAKES 12Z TUE.
THIS MOVES OUT AND THE UPPER FLOW STAYS NW TO SE FOR WED INTO THU.
THIS WILL ALLOW A COLD FRONT TO BECOME STATIONARY ACROSS THE AREA
FOR THOSE TWO DAYS BEFORE A 500 MB TROUGH ARRIVES FOR FRI WITH AND
ALBERTA CLIPPER AFFECTING THE UPPER GREAT LAKES. COLD AIR COMES IN
WITH LAKE EFFECT FOR TUE AS THE ECMWF BRINGS IN SOME 850 MB
TEMPERATURES THAT FALL TO -14C TO -16C BY 00Z WED. SOME SLOW
MODIFICATION OCCURS WITH 850 MB TEMPERATURES OFF THE ECMWF WARMING
TO -6C OVER THE WEST AND -10C OVER THE EAST 12Z THU. 850 MB
TEMPERATURES THEN CONTINUE TO WARM AHEAD OF THE ALBERTA CLIPPER FOR
FRI. WITH THE FRONT AND THE COLD 850 MB TEMPERATURES AROUND THE
AREA...LAKE EFFECT AND SOME POPS WILL BE NEEDED FOR THE EXTENDED
PERIOD THROUGH MOST OF IT. TEMPERATURES LOOK TO STAY ABOVE NORMAL
THROUGH THE PERIOD WITH NO REAL COLD AIR IN SIGHT.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS THIS MRNG AT CMX AND IWD WITH LLVL DRY AIR
DOMINATING. FARTHER TO THE E...THE LLVLS ARE MOIST ENUF IN THE
PRESENCE OF LIGHT UPSLOPE SLY FLOW TO MAINTAIN SC/MVFR CIGS AT SAW
THRU SUNRISE. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WL OVERSPREAD UPR MI AND BRING VFR CONDITIONS. LOOK FOR
THE APRCHG DISTURBANCE TO DRAG A LO PRES TROF ACROSS THE U.P. THIS
EVNG. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY PER THE 00Z
BISMARCK RAOB/OBSERVATIONS NEAR THE TROF...VFR CONDITIONS ARE MOST
LIKELY WITH THE TROF PASSAGE. THE ONLY EXCEPTION MAY BE CMX...WITH
FAVORABLE UPSLOPE W WIND COMPONENT. LOOK FOR W WIND GUSTS AT THIS
EXPOSED LOCATION TO REACH 25-30 KTS.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SOUTHERLY WINDS TO 30 KTS TO DIMINISH THIS EVENING AS LOW
PRESSURE DIMINISHES OVR THE AREA. SW WINDS WILL INCREASE SATURDAY
AHEAD OF THE NEXT TROUGH TO AFFECT LK SUPERIOR. AS WINDS SHIFT NW
ON SUNDAY BEHIND THE TROUGH THERE COULD BE GALE GUSTS OVR CNTRL AND
EASTERN LK SUPERIOR IN THE MORNING. NEXT TROUGH WILL AFFECT LK
SUPERIOR MONDAY INTO MONDAY NIGHT. THIS TROUGH IS EVEN STRONGER AND
THERE SHOULD BE SW GALES TO 35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY
INTO MONDAY EVENING. MORE NW GALES ARE POSSIBLE BEHIND THE TROUGH ON
TUESDAY OVR EASTERN LK SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS
HIGH PRESSURE MOVES ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLA
LONG TERM...07
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
338 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
330 AM UPDATE...
FAST FLOW AND LOW UPPER LEVEL AMPLITUDE WILL KEEP IT ACTIVE AND
WET...BUT AGAIN WITH NO SIGNIFICANT SNOW EXPECTED. FOLLOWED HPC
GUIDANCE...WHICH FAVORS THE EURO AND CANADIAN. GFS LOOKS TOO FAST
AGAIN. TUESDAY A STORM MOVES NE THROUGH US WITH MIXED PRECIP. THE
SFC LOW QUICKLY INTENSIFIES IN EASTERN NEW ENGLAND AND EASTERN
CANADA TUESDAY NIGHT AND WED. THIS WILL PULL IN SOME COLDER AIR SO
CHANGE TO ALL SNOW WITH LAKE EFFECT. THIS DOES NOT LAST LONG WITH
HIGH PRESSURE THURSDAY AND FRIDAY. MILD AIR AGAIN WITH A WEAK
UPPER LEVEL RIDGE. SATURDAY WILL BE THE NEXT COLD FRONT BUT ONCE
AGAIN MIXED RAIN AND SNOW.
PREVIOUS DISCUSSION...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
1230 AM UPDATE...
NORTH NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE
TRAPPED UNDER INVERSION FOR MAINLY MVFR CIGS THROUGH AROUND 9Z
BEFORE A UPPER LEVEL DISTURBANCE SHIFTS THE WIND AND HIGH PRESSURE
BUILDS IN TOWARD 12Z. SYR AND ITH COULD HAVE MVFR IN LIGHT SNOW
SHOWERS THE FIRST FEW HOURS.
FOR THE DAYTIME HOURS SKIES WILL CLEAR EXCEPT MAYBE CLOSE TO LAKE
ONTARIO AND LAKE CAYUGA FOR SCT LOW CLOUDS.
NW TO N WINDS AT 5 KTS SHIFTING TO NW AROUND 12Z. THIS EVENING SE
WINDS AT 5 KTS.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1246 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
1230 AM UPDATE...
NORTH NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE
TRAPPED UNDER INVERSION FOR MAINLY MVFR CIGS THROUGH AROUND 9Z
BEFORE A UPPER LEVEL DISTURBANCE SHIFTS THE WIND AND HIGH PRESSURE
BUILDS IN TOWARD 12Z. SYR AND ITH COULD HAVE MVFR IN LIGHT SNOW
SHOWERS THE FIRST FEW HOURS.
FOR THE DAYTIME HOURS SKIES WILL CLEAR EXCEPT MAYBE CLOSE TO LAKE
ONTARIO AND LAKE CAYUGA FOR SCT LOW CLOUDS.
NW TO N WINDS AT 5 KTS SHIFTING TO NW AROUND 12Z. THIS EVENING SE
WINDS AT 5 KTS.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1231 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THOUGH A VERY DRY AIR MASS IS MOVING INTO THE REGION...NORTH-
NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE TRAPPED
UNDER INVERSION FOR MAINLY MVFR CIGS /EXCEPT KRME/ FOR MUCH OF THE
NIGHT...AND A FEW FLURRIES FOR SOME TERMINALS. MVFR CIGS BREAK UP
BY 07-08Z...IN FAVOR OF HIGHER CIGS AROUND 120 KFT AS A WEAK UPPER
DISTURBANCE COMES THROUGH. VFR FOR BALANCE OF TAF PERIOD...AS EVEN
THE HIGHER CIGS LEAVE WITH QUICK EXIT OF UPPER DISTURBANCE BY MID
MORNING. BUILDING SURFACE HIGH PRESSURE KEEPS WINDS LIGHT.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW. LATER MONDAY INTO
MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
347 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO PA/NY, AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST WITH
SLIGHTLY STRONGER WINDS SPEEDS. LOW CLOUDS STILL COVERED MUCH OF
THE AREA WEST OF THE BLUE RIDGE WITH CLEARING ON THE WESTERN EDGE
OF THE CLOUDS IN KENTUCKY AND WEST VIRGINIA WITH THE PASSAGE OF
THE UPPER SHORT WAVE. RADAR CONTINUED TO DETECT SCATTERED RAIN AND
SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER
VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1205 AM EST SATURDAY...
MOIST UPSLOPING FLOW WILL CONTINUE TO RESULT IN ABUNDANT STRATOCUMULUS
LAYER ALONG AND WEST OF THE BLUE RIDGE FOR THE REST OF THE NIGHT WITH
CEILINGS MAINLY IN THE 25-35 HUNDRED FOOT RANGE...BUT WITH SOME
LOCALIZED CEILINGS OF 10-20 HUNDRED FEET IN PREFERRED UPSLOPING
AREAS...SUCH AS NEAR KBLF.
NO CEILING RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN AS
DEPTH OF LOW LEVEL MOISTURE GRADUALLY LESSENS WITH APPROACH OF
SURFACE RIDGE.
WEAKENING UPSLOPING WINDS AND INTRUSION OF DRIER AIR IN LOWER
TROPOSPHERE WITH ARRIVAL OF SURFACE RIDGE SHOULD ALLOW FOR RETURN
TO UNRESTRICTED CEILINGS WEST OF THE BLUE RIDGE BY MID TO LATE
MORNING...ALTHOUGH FAVORED UPSLOPE AREAS SUCH AS AT/NEAR KBLF MAY
HAVE TO WAIT UNTIL EARLY AFTERNOON BEFORE LOW LEVEL CLOUDS FINALLY
BECOME CLEAR TO SCATTERED.
VFR WEATHER WITH UNRESTRICTED CONDITIONS IS EXPECTED ACROSS THE
ENTIRE TERMINAL FORECAST AREA INTO SUNDAY BEFORE NEXT SHORT WAVE
SCOOTS RAPIDLY EAST TO THE NORTH OF THE AREA...DRIVING A COLD FRONT
SOUTHEAST THROUGH THE REGION. THERE IS A POSSIBILITY OF A BRIEF
RETURN TO UPSLOPING CLOUDS ACROSS THE WESTERN FLANKS OF THE
APPALACHIANS (KBLF AND KLWB) ON SUNDAY NIGHT.
SURFACE RIDGE WILL QUICKLY BUILD IN BEHIND THIS SYSTEM ON
MONDAY...ALONG WITH VFR CONDITIONS UNTIL NEXT SOUTHERN STREAM
WAVE RESULTS IN AN INCREASING THREAT FOR RAIN AND ASSOCIATED
FLIGHT RESTRICTIONS DOWN INTO THE MVFR OR IFR RANGE MONDAY NIGHT
INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS/WERT
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CST SAT DEC 24 2011
.TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
CLOUDS ASSOCIATED WITH THE VORT MAX CROSSING THE GREAT LAKES REGION
ARE EXITING THE EASTERN FCST AREA EARLY THIS MORNING. WARM AIR
ADVECTION UNDERWAY...AS YESTERDAY/S MAX TEMPS WERE REACHED AT
MIDNIGHT. NEXT SHORTWAVE/VORT MAX APPARENT ON WATER VAPOR IMAGERY
OVER THE DAKOTAS AT 0330Z. NO CLOUDS ASSOCIATED WITH THIS
DISTURBANCE PER IR SATELLITE...SO FEEL COMFORTABLE WITH NO CHANCES
FOR FLURRIES OR EVEN CLOUDS THIS AFTERNOON AS THE WAVE PASSES
THROUGH.
MODEL SNDGS SHOW POTENTIAL FOR MIXING UP TO 950 OR EVEN 925MB THIS
AFTERNOON...SO LOWERED DEWPOINT TEMPS ACCORDINGLY. RUC AND GFS SHOW
WINDS UP TO AROUND 20 KT MIXING DOWN TO THE SFC AS WELL...WITH THE
NAM A BIT LIGHTER. BUMPED UP WIND GUSTS TO THE 18-20 KNOT RANGE THIS
AFTERNOON.
PRESSURE GRADIENT WILL CONTINUE TO INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM TRACKS INTO ONTARIO CANADA. DESPITE SFC
INVERSION...WINDS SHOULD BE ELEVATED THROUGH THE NIGHT. TEMPS NOT
EXPECTED TO DROP MUCH SINCE THERE IS NO SNOW COVER AND CONTINUOUS
WARM AIR ADVECTION AND SOME SHALLOW MIXING. THE EXCEPTION MAY BE
LONE ROCK IF THEY DECOUPLE IN THE RIVER VALLEY.
.CHRISTMAS DAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
MODELS DROP A DECENT SHORTWAVE THROUGH SOUTHERN WISCONSIN CHRISTMAS
MORNING. STILL KEEPING AN EYE ON THIS SYSTEM...AS THERE IS SOME
FORCING...BUT MODELS ACTUALLY TRENDING DRIER OVER THE LAST 24 HOURS.
CONCERN HAS BEEN THAT THIS MAY END UP LIKE A COUPLE OF THE PREVIOUS
WAVES THAT MOVED THROUGH...WHERE MODELS ARE DRY FOR DAYS LEADING UP
TO THE ARRIVAL OF THE SYSTEM...THEN SATURATE THINGS LATE IN THE
GAME. SEEMING LIKE THIS ONE WILL ACTUALLY STAY DRY AS ADVERTISED
THOUGH WITH NO SIGNS OF MODELS TRENDING WETTER.
STILL EXPECTING BREEZY WEST TO NORTHWEST WINDS CHRISTMAS AFTERNOON.
COLD ADVECTION ENSUES BEHIND THE WAVE...WITH THE WINDS PICKING UP
LATE MORNING INTO THE AFTERNOON. COULD SEE GUSTS OF 30-35 MPH IF
THINGS STAY ON TRACK. HIGHS EXPECTED TO BE IN THE MID TO UPPER 30S
AGAIN...THE COLDER TEMPS IN THE NORTH WHERE THE THIN SNOWPACK WILL
PROBABLY STILL LINGER.
.MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
WINDS QUICKLY RETURN TO OUT OF THE SOUTHWEST FOR MONDAY...BECOMING
BREEZY AGAIN LATE MORNING INTO THE AFTERNOON...THOUGH MAYBE A BIT
LIGHTER THAN ON CHRISTMAS. WITH THESE WINDS...A DECENT AMOUNT OF
SUN...AND WARMING ALOFT...SHOULD HIT 40 PRETTY EASILY...ESPECIALLY
IN LOCATIONS WITH NO SNOW COVER.
KEPT SOME LOW POPS IN THE FORECAST MONDAY NIGHT...AS MODELS BRING
ANOTHER SHORTWAVE THROUGH THE AREA. THE WILL WAVE DRAW UP A
DEEPENING SFC LOW...BUT THAT IS EXPECTED TO PASS BY WELL TO THE
SOUTHEAST. MAIN THREAT FOR PRECIP ASSOCIATED WITH A BAND OF MID
LEVEL FRONTOGENESIS AND THETA-E ADVECTION IN THE EVENING...AND SOME
ISENTROPIC LIFT WITH THE NORTHWEST FRINGE OF THE DEFORMATION PRECIP
AS THE LOW SLIDES BY LATER IN THE NIGHT. DEEP MOISTURE DEFINITELY AN
ISSUE...SO JUST KEPT POPS ON THE LIGHT SIDE. NEWEST ECMWF SUGGESTING
PRECIP WILL GENERALLY MISS SOUTHERN WISCONSIN COMPLETELY TO THE
SOUTH AND EAST.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING THE WAVE TRAIN WILL CONTINUE THROUGH THE LATTER HALF
OF THE WORK WEEK. ENOUGH OVERLAP OF DECENT MOISTURE/LIFT IN MODELS
FOR SLIGHT CHANCE POPS THURSDAY AND FRIDAY. THE GFS AND ECMWF
DIVERGE BY FRIDAY THOUGH...WITH THE ECMWF MAINTAINING A STRONG SFC
LOW MOVING ACROSS NORTHERN MINNESOTA...WHILE THE GFS SLIDES THE LOW
SOUTHEAST TOWARD WISCONSIN. MAIN DIFFERENCE IS THAT THE ECMWF IS
MUCH WARMER...SUGGESTING MID 40S TO NEAR 50 FRIDAY...WHILE THE GFS
WOULD BE MAINLY 30S. GFS ALSO BRINGS A BIT MORE PRECIP...WITH BETTER
MOISTURE AND DYNAMICS TOWARD THE CENTER OF THE SYSTEM PUSHING INTO
THE FORECAST AREA. OVERALL...GENERALLY SPLIT THE DIFFERENCE BETWEEN
THE GFS AND ECMWF FOR NOW...WITH NO GOOD REASON TO GO ONE WAY OR THE
OTHER. EITHER WAY...LOOKS LIKE ABOVE NORMAL TEMPERATURES WILL
PROBABLY CONTINUE.
&&
.AVIATION/12Z TAFS/...WIND GUST POTENTIAL IN THE 20 KNOT RANGE THIS
AFTERNOON WITH SOME DAYTIME MIXING. VFR THROUGH THE PERIOD. CLEAR
SKIES EXPECTED TODAY...THEN INCREASING HIGH/MID CLOUDS TONIGHT.
WINDS WILL ALSO INCREASE OVER THE PERIOD AND BECOME GUSTY ONCE AGAIN
ON SUNDAY WITH A PASSING UPPER LEVEL DISTURBANCE.
&&
.MARINE...THERE IS A POSSIBILITY OF SOME WIND GUSTS UP TO 22 KNOTS
THIS AFTERNOON WITH DAYTIME MIXING...BUT CONFIDENCE IS LOW...SO NO
SMALL CRAFT ADVY ISSUED FOR THIS TIME PERIOD. HOWEVER...A LOW
PRESSURE SYSTEM CROSSING SOUTHERN CANADA THROUGH SUNDAY WILL BRING
INCREASING WINDS TO SOUTHERN LAKE MICHIGAN. SOUTHWESTERLY WIND GUSTS
EXPECTED TO REACH SMALL CRAFT ADVY CRITERIA OVERNIGHT SATURDAY NIGHT
THROUGH SUNDAY AFTERNOON. SMALL CRAFT ADVY ISSUED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST SUNDAY
FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MRC
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS ALBANY NY
952 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH TODAY. CANADIAN HIGH PRESSURE
WILL BRIEFLY BUILD IN LATE BRINGING INCREASING SUNSHINE BUT
SEASONABLY COLD TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE
TONIGHT INTO SUNDAY. A CLIPPER TYPE STORM WILL BRING SOME LIGHT SNOW
TO MAINLY THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 950 AM...A BAND OF CLOUDS ASSOCIATED WITH A MID/UPPER LEVEL
TROF AXIS AS WELL AS A MOISTURE CONTRIBUTION FROM LAKE CHAMPLAIN
IN NORTHEAST FLOW REGIME IN PLACE FROM AROUND THE GLENS FALLS AREA
SOUTHWARD THROUGH THE CAPITAL DISTRICT AND BERKSHIRES. SCATTERED
FLURRIES HAVE BEEN COMMON THIS MORNING...SO WILL ADD MENTION TO
FORECAST. A FEW SNOW SHOWERS BRINGING DOWN VISIBILITIES TO AROUND
2-3 MILES AROUND GLENS FALLS SO WILL MENTION 20 POPS FOR ISOLATED
SNOW SHOWERS THERE. THE TROF AXIS SHOULD MOVE EAST OF THE REGION
RATHER QUICKLY BY EARLY AFTERNOON...SO FLURRIES AND CLOUD COVER
SHOULD GRADUALLY DIMINISH LEAVING MAINLY CLEAR SKIES BY LATE IN
THE DAY.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/JPV
NEAR TERM...HWJIV/JPV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
645 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
*************PREVIOUS NEAR TERM FORECAST***********
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
631 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
*************PREVIOUS NEAR TERM FORECAST***********
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
420 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
420 AM MST SAT DEC 24 2011
VFR CONDS EXPECTED NEXT 24 HOURS AT BOTH TERMINALS AS HIGH PRESSURE
WILL BE IN CONTROL OF THE WEATHER PATTERN.
BAS/024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...
/TODAY THROUGH MONDAY/
EARLY THIS MORNING...AN UPPER LEVEL SHORTWAVE WAS PASSING NORTHEAST OF
THE AREA THROUGH THE EASTERN GREAT LAKES REGION. MEANWHILE RIDGING
WAS CENTERED TO THE SOUTH AND EAST OF BERMUDA OFF OF THE SOUTHEASTERN
US COAST WITH SOME SHORTWAVE RIDGING OVER THE SOUTHEASTERN STATES. AN
UPPER LEVEL LOW WAS CENTERED NOT FAR FROM KELP WITH A FEW RATHER WEAK
SOUTHERN STREAM SHORTWAVES ROTATING AROUND THIS UPPER LOW. ANOTHER
SHORTWAVE TROUGH WAS ENTERING THE UPPER MIDWEST AND NORTHERN MS
VALLEY. AT THE SFC...HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH RIDGING EXTENDING EAST INTO THE LOWER OH AND TN VALLEYS.
THE COLD FRONT ASSOCIATED WITH THE SYSTEM THAT BROUGHT RAIN ON THU WAS
SOUTH OF THE AREA STALLED OUT OVER THE GULF OF MEXICO. A RATHER WEAK
SFC SYSTEM WAS MOVING THROUGH THE CANADIAN PLAINS ASSOCIATED WITH THE
SHORTWAVE ENTERING THE UPPER MS VALLEY.
THROUGH SUNDAY THE CLOSED LOW NOW NEAR KELP WILL MEANDER INTO THE TX
PANHANDLE BY 0Z MON. AT THE SAME TIME...THE SHORTWAVE NOW ENTERING
THE UPPER MS VALLEY REGION WILL MOVE RATHER QUICKLY ACROSS THE
NORTHERN GREAT LAKES AND ACROSS ONTARIO AND INTO QUEBEC AND DAMPEN BY
THE END OF THE PERIOD...WITH ANOTHER UPSTREAM SHORTWAVE TROUGH
DIGGING SOUTHEAST ACROSS THE GREAT LAKES AND REACH THE EASTERN GREAT
LAKES BY SUN EVENING. THIS WILL LEAD TO WESTERLY FLOW ALOFT TODAY AND
THEN GRADUALLY BECOMING MORE NW WITH SHORTWAVES PASSING NORTH OF THE
REGION. SHORTWAVE RIDING IS PROGGED TO BRIEFLY BUILD INTO THE REGION
ON SUN NIGHT BEFORE SHIFTING EAST BY THE END OF THE PERIOD. THE
UPPER LEVEL LOW WILL MOVE TOWARD THE ARKLATEX REGION AND LEAD TO SFC
LOW PRESSURE DEVELOPING ALONG THE OLD BOUNDARY OVER THE GULF COAST
STATES. SOUTHERLY FLOW WILL INCREASE BY LATE MON BETWEEN A DEPARTING
SFC HIGH AND THE DEVELOPING SYSTEM...LEADING TO THE POTENTIAL FOR
PRECIP LATE OVER THE SW CWA.
THE MAIN WEATHER CONCERNS DURING THE NEAR TERM PERIOD ARE THE TIMING
OF THE CLEARING TOWARD DAWN OR EARLY ON SAT AND THE POTENTIAL FOR
VALLEY FOG TONIGHT AND HOW EXTENSIVE IT MIGHT BE. OTHERWISE...UNTIL
LATE IN THE PERIOD...SFC HIGH PRESSURE WILL GENERALLY REMAIN IN
CONTROL OF THE WEATHER WITH SYSTEMS PASSING BY TO THE NORTH AND SOUTH
OF THE REGION. THIS PATTERN SHOULD LEAD TO NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS THROUGH THE PERIOD. MAX T SHOULD END UP A COUPLE OF
DEGREES ABOVE NORMAL TODAY...ON THE ORDER OF 5 TO 10 DEGREE ABOVE
NORMAL ON SUN AND AROUND 5 DEGREES ABOVE NORMAL ON MON. THE MODEL
GUIDANCE OVERALL POINTED TO A SLIGHTLY LARGER RIDGE/VALLEY TEMP SPLIT
FOR TONIGHT AND SUN NIGHT. THIS CORRESPONDS TO LESS IN THE WAY OF
CLOUD COVER AND JUST CIRRUS ON SAT NIGHT AND SUN ON THE FRINGES OF
WEAK WAVES PASSING TO OUR SOUTH. LESS CLOUD COVER ON SUN SHOULD LEAD
TO WARMER MAX T THAN THE PREVIOUS FORECAST. WE OPTED TO TREND UPWARD
TOWARD THE LOWER END OF GUIDANCE FOR MAX T ON SUN AND ALSO FOLLOWED
THE UPWARD TREND IN GUIDANCE ON MON IN WARM ADVECTIVE PATTERN/DOWNSLOPING
PATTERN IN ADVANCE OF THE DEVELOPING SYSTEM TO OUR SOUTHWEST.
.LONG TERM.../MONDAY NIGHT THROUGH FRIDAY/
CONFIDENCE CONTINUES TO GROW IN ANOTHER ROUND OF WIDESPREAD RAINFALL
MONDAY NIGHT THROUGH EARLY TUESDAY MORNING FOR EASTERN KENTUCKY...AS
AN UPPER LEVEL LOW TRACKS FROM THE ARKLATEX REGION THROUGH THE
TENNESSEE VALLEY...WHILE A NORTHERN STREAM TROUGH SWINGS BY IN
TANDEM FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES. THE GFS AND
ECMWF ARE CURRENTLY IN VERY GOOD AGREEMENT WITH THE TRACK AND
MAGNITUDE OF THESE FEATURES. THIS ALSO TRANSLATES TO THE SURFACE AS
WELL...AS LOW PRESSURE TRACKS NORTHEAST AND INTENSIFIES AS IT MOVES
ACROSS APPALACHIANS AND EVENTUALLY INTO THE MID-ATLANTIC.
RAIN WILL TAPER OFF FROM WEST TO EAST TUESDAY MORNING...WITH COLDER
AIR FILTERING IN. THE AIR MASS WILL BECOME MARGINAL FOR SOME
SNOW...HOWEVER IT LOOKS AS THOUGH THE DEEPER MOISTURE SUPPORTIVE OF
ICE CRYSTALS MAY EXIT A BIT TOO QUICKLY...SO WILL LEAVE OUT THIS
MENTION FOR NOW.
ONCE THIS SYSTEM EXITS...THE FLOW PATTERN WILL BECOME MORE
ZONAL...WITH MAINLY SOME NORTHERN STREAM PASSING SHORT WAVE TROUGHS
TO CONTEND WITH FROM TIME TO TIME. THE GFS HAS PLAYED UP THE
MOISTURE WITH ONE OF THESE FEATURES ON THURSDAY...WHILE THE ECMWF
HAS KEPT THINGS DRY. HAVE LEANED CLOSER TO THE DRIER SOLUTION FOR
NOW...AS THIS FOLLOWS CONTINUITY WELL FROM PREVIOUS MODEL RUNS. THE
NEXT SYSTEM OF INTEREST IN THE FORM OF A COLD FRONT WILL APPROACH BY
EARLY NEXT WEEKEND.
TEMPERATURES WILL CONTINUE TO RUN OVERALL NEAR OR JUST SLIGHTLY
ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION.../12Z TO 12Z/
LINGERING STRATOCU SHOULD DISSIPATE THROUGH 15Z. A FEW VALLEY LOCATIONS
WHERE SKIES HAVE CLEARED WILL EXPERIENCE MVFR TO IFR FOG DISSIPATING
THROUGH 13Z OR 14Z. HOWEVER...THIS WILL NOT AFFECT THE TAF SITES.
RECENT OBS AND SAT TRENDS INDICATE THAT LOZ AND JKL HAVE GONE VFR
WHILE A PATCH OF MVFR STRATOCU LINGERS GENERALLY WEST OF I 75...AND IS
AFFECTING SME. SME SHOULD IMPROVE TO MVFR BY 14Z OR SO. HIGH PRESSURE
SHOULD BRING GENERALLY VFR CONDITIONS THROUGH THE END OF THE
PERIOD...WITH PERHAPS SOME IFR OR LOWER VALLEY FOG NOT AFFECTING THE
TAF SITES FORMING LATE IN THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JP/SBH
LONG TERM....GEOGERIAN
AVIATION...JP
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1025 AM EST SAT DEC 24 2011
.SYNOPSIS...
STRAY FLURRIES WILL END EARLY TODAY AS A WEAK DISTURBANCE
COMPLETES A CROSSING OF THE UPPER OHIO VALLEY. THE NEXT CHANCE FOR
SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR AREAS NORTH AND
EAST OF PITTSBURGH AS ANOTHER TROUGH OF LOW PRESSURE MOVES ACROSS
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO LINGER
FLURRIES NORTH OF PITTSBURGH INTO THE EARLY AFTERNOON AND TO
ACCOUNT FOR THE LATEST SKY AND TEMP TRENDS.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE HIGH IN QUEBEC IS DICTATING A NORTHWESTERLY LOW-LEVEL
FLOW OFF OF LAKE ERIE. THIS TRAJECTORY WITH 850MB TEMPS NEAR -10C
CONTINUES TO PRODUCE SCATTERED FLURRIES FOR AREAS NORTH OF
PITTSBURGH. OTHERWISE, DEEP SUBSIDENCE ALOFT HAS ALLOWED FOR DRY
WEATHER.
THIS AFTERNOON...THE 850MB FLOW WILL BECOME MORE WESTERLY TODAY,
WITH SCATTERED FLURRIES DIMINISHING NORTH OF PITTSBURGH. AFTER THIS
POINT, ASIDE FROM A FEW STRATOCUMULUS POCKETS, SKIES WILL BECOME
MOSTLY SUNNY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR
ALOFT. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, WITH
HIGHS RANGING FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE
EASTERN RIDGES TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-
CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
CUTTING OFF THE MOIST FLOW OFF LAKE ERIE AND ALLOWING DRIER AIR TO
ADVECT INTO THE AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE
SOUTHWEST. THIS WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT
LOWS ARE CLOSEST TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
20S ACROSS THE AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GENERAL VFR FORECAST THROUGH THE AFTERNOON WITH ISOLATED MVFR AS
LAST OF STRATUS EXITS.
MID-LEVEL WAA WILL ALLOW 85H WINDS TO SLOWLY VEER TO THE WEST AND
THEN TO THE SOUTHWEST LATER THIS AFTERNOON. THIS WILL DECAY THE VFR
CLOUD DECK AND SCT CLOUDS OUT BY LATE THIS AFT.
EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
A COLD FRONT WILL BRING POSSIBLE RESTRICTIONS SUNDAY AFTERNOON INTO
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM MOVING
NORTHEAST FROM THE SOUTHERN PLAINS WILL PROVIDE RESTRICTIONS TUESDAY
FOLLOWED BY GENERAL VFR WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
628 AM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN GREAT LAKES
LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN ALBERTA. LOW LEVEL
CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO NRN LAKE MI ALONG
WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND -10C...CONTINUED TO
SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS FROM NEAR BEAVER ISLAND
TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED OVERNIGHT WITH ONLY OCNL
VSBY INTO THE 1-3SM RANGE. AN UPSTREAM TROUGH WAS MOVING THROUGH THE
ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR. OTHERWISE...DRY
WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC ASCENT WITH THE
WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE CWA. WAA WILL
BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA WITH
STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING IN ON TUE
WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF LES FOR
NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN SINCE THE
GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED TO NEAR
-11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE OUT
QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT MVFR CONDITIONS THIS MORNING AT CMX AND IWD AS LOW LEVEL
MOISTURE SITS OVER THE AREA. FARTHER TO THE E...LOW LEVEL MOISTURE
IS MORE PREVALENT...AND IS MOIST ENOUGH IN THE PRESENCE OF LIGHT
UPSLOPE SLY FLOW TO CAUSE IFR TO BRIEFLY LIFT CIGS AT SAW THROUGH
MID MORNING. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FROM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WILL OVERSPREAD UPPER MI AND BRING VFR CONDITIONS. LOOK
FOR THE APPROACHING DISTURBANCE TO DRAG A LOW PRESSURE TROUGH ACROSS
THE U.P. THIS EVENING. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY
PER THE 00Z BISMARCK RAOB/OBSERVATIONS NEAR THE TROUGH...VFR TO HIGH
END MVFR CONDITIONS ARE MOST LIKELY WITH THE TROF PASSAGE.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
533 AM EST SAT DEC 24 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN GREAT LAKES
LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN ALBERTA. LOW LEVEL
CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO NRN LAKE MI ALONG
WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND -10C...CONTINUED TO
SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS FROM NEAR BEAVER ISLAND
TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED OVERNIGHT WITH ONLY OCNL
VSBY INTO THE 1-3SM RANGE. AN UPSTREAM TROUGH WAS MOVING THROUGH THE
ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR. OTHERWISE...DRY
WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC ASCENT WITH THE
WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE CWA. WAA WILL
BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA WITH
STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING IN ON TUE
WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF LES FOR
NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN SINCE THE
GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED TO NEAR
-11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE OUT
QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS THIS MRNG AT CMX AND IWD WITH LLVL DRY AIR
DOMINATING. FARTHER TO THE E...THE LLVLS ARE MOIST ENUF IN THE
PRESENCE OF LIGHT UPSLOPE SLY FLOW TO MAINTAIN SC/MVFR CIGS AT SAW
THRU SUNRISE. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WL OVERSPREAD UPR MI AND BRING VFR CONDITIONS. LOOK FOR
THE APRCHG DISTURBANCE TO DRAG A LO PRES TROF ACROSS THE U.P. THIS
EVNG. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY PER THE 00Z
BISMARCK RAOB/OBSERVATIONS NEAR THE TROF...VFR CONDITIONS ARE MOST
LIKELY WITH THE TROF PASSAGE. THE ONLY EXCEPTION MAY BE CMX...WITH
FAVORABLE UPSLOPE W WIND COMPONENT. LOOK FOR W WIND GUSTS AT THIS
EXPOSED LOCATION TO REACH 25-30 KTS.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION...UDPATED
NWS JACKSON MS
945 AM CST SAT DEC 24 2011
...WET CHRISTMAS EXPECTED AND CONTINUING INTO MONDAY...
.UPDATE...SIGNIFICANT CHANGES REQUIRED TO THE FORECAST FOR TODAY.
MODELS ARE DOING THEIR TYPICAL POOR JOB OF HANDLING RESIDUAL
MOISTURE TRAPPED BELOW A BUILDING SUBSIDENCE INVERSION. IN SPITE OF
MODELS SHOWING LOW CLOUDS CLEARING OUT...REAL ATMOSPHERE SHOWING NO
SIGNS OF THIS HAPPENING ACROSS OUR FORECAST AREA. PUSH OF CLEARING
IN LOW CLOUDS INTO EXTREME NW ZONES HAS PRETTY WELL STOPPED AS AREA
PROFILERS AND VAD WIND PROFILES SHOW LOW LEVEL FLOW VEERING AROUND
TO MORE OF AN EASTERLY DIRECTION. LATEST RUC MODEL GUIDANCE SHOWS
FLOW CONTINUING TO VEER AROUND TO MORE OF ESE DIRECTION TODAY...AND
THIS WILL LIKELY RESULT IN LOW CLOUDS BEGINNING TO BUILD BACK TO
WNW. EVEN IF LOW CLOUDS DO MANAGE TO ERODE SOME...SATELLITE SHOWS
MID/HIGH CLOUDS RAPIDLY THICKENING ACROSS THE AREA IN BUILDING
ASCENT IN RIGHT ENTRANCE REGION OF INCREASING JETSTREAK FROM
MID-SOUTH INTO THE MID-ATLANTIC. HENCE HAVE INCREASED SKY COVER
GRIDS TO SHOW PRETTY MUCH OVERCAST CONDITIONS THROUGH THE DAY TODAY.
BEST CHANCE FOR SOME SUN WOULD APPEAR TO BE IN THE E/SE WHERE SOME
EROSION MAY OCCUR AS SOME DRIER AIR TRIES TO MIX IN FROM THE E.
GUIDANCE TEMPERATURES WERE BASED ON THE IDEA OF A FAIR AMOUNT OF
SUNSHINE TODAY...AND WITH MUCH LESS CHANCE OF THIS HAPPENING...
SIGNIFICANT REDUCTIONS IN MAX TEMPS ARE REQUIRED. AREA SOUNDINGS
SHOW THAT EVEN WITH DECENT SUNSHINE TEMPS WOULD LIKELY STRUGGLE TO
GET OUT OF THE 40S GIVEN SHALLOW RESIDUAL COLD AIR BELOW INCREASING
WARM AIR ADVECTION IN THE 850 TO 700 MB LAYER. HENCE HAVE KNOCKED
6-7 DEGS OFF OF PREVIOUS FORECAST MAXES FOR TODAY. IF LOW CLOUDS
HOLD TOUGH ALL DAY...EVEN THIS MAY NOT BE ENOUGH OF A REDUCTION AS
VERY LITTLE DIURNAL RISE IN TEMPS IS LIKELY WITH RECENT OBSERVATIONS
SHOWING TEMPS PRETTY MUCH HOLDING STEADY SO FAR.
FINALLY...REGIONAL RADAR SHOWS LARGE SHIELD OF RAIN CONTINUING TO
EXPAND OVER E TX AND STREAM RAPIDLY ENE TOWARD THE AREA.
EXTRAPOLATION BRINGS THIS ACTIVITY INTO FAR WESTERN ZONES BY MID
AFTERNOON. WHILE THERE WILL LIKELY BE SOME EROSION ALONG THE LEADING
EDGE...00Z ECMWF DID SUGGEST MEASURABLE QPF INTO WESTERN ZONES BY
00Z. HENCE HAVE UPPED POPS SLIGHTLY TO CHC CATEGORY IN FAR WESTERN
AREAS FOR MID/LATER AFTERNOON...AND EXPANDED SLIGHT CHANCE TO THE MS
RIVER.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST A VERY WET PERIOD COMING
UP EARLY NEXT WEEK. ECMWF/GFS/SREF ENSEMBLE GUIDANCE SUGGESTS THAT
HEAVIEST QPF MAY BE SHIFTED A BIT NW OF WHERE OPERATIONAL RUNS SHOW
IT...PERHAPS MORE OVER THE ARKLAMISS REGION. LATEST 12Z NAM IS
SHOWING SOME 5" TOTALS OVER THE DELTA BY THE TIME EVENT WINDS UP
LATE MONDAY. WILL OBVIOUSLY LOOK AT ALL OF THIS MORE CLOSELY AS 12Z
GUIDANCE CONTINUES TO ARRIVE. /08/
&&
.AVIATION...WIDESPREAD MVFR CEILINGS WITH STUBBORN IFR CLOUD LAYERS
CONTINUE ACROSS THE REGION AS LOW STRATUS CLOUDS HOVER AROUND 1K FT.
A SECOND LAYER OF INCREASING CLOUDS 9-11K FEET WILL MAKE IT
DIFFICULT FOR MUCH SUNSHINE TO BREAK THROUGH TO THESE LOW LEVEL
CLOUDS SO EXPECT ONLY SLIGHT IMPROVEMENTS THROUGH EARLY AFTERNOON
WITH MOST AREAS HOLDING BROKEN MVFR LAYERS 1-2K FEET AT BEST.
CONDITIONS WILL START DETERIORATING LATER THIS EVENING AS RAINS
OVERSPREAD THE REGION FROM SW TO NE...EMBEDDED TSRA SHOULD HOLD OFF
UNTIL AFTER 12Z SUNDAY MORNING BUT BEGIN INCREASING ESPECIALLY
SUNDAY NIGHT THROUGH MONDAY. WIDESPREAD IFR SHOULD PREVAIL AFTER 15Z
SUNDAY. SURFACE WINDS WILL PERSIST NELY AT 5 TO 10 KTS THROUGH THIS
FORECAST PERIOD. /40/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
08/40
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
732 AM CST SAT DEC 24 2011
.DISCUSSION...UPDATED WINDS AND TEMPS TO REFLECT CURRENT TRENDS.
SOLID CLOUD COVER AND NORTH WINDS...ALONG WITH CONTINUED PERIODS
OF RAIN...WILL KEEP TEMPS LOWER TODAY. UPDATED WITH RUC WINDS AS
THEY INITIALIZED BEST. RUC NOT AS BULLISH ON LOW PRESSURE CENTER
OFFSHORE...PREFERRING CONTINUED TROUGHING.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST SAT DEC 24 2011/
DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR THE DISCUSSION OF
THE 06Z TAF ISSUANCE.
AVIATION...LIFR AND IFR CONDITIONS WILL CONTINUE THROUGH THE DAY
AS A SURFACE COASTAL TROUGH INTERACTS WITH SOUTHWEST FLOW ALOFT.
EXPECT LIGHT RAIN SHOWERS...DRIZZLE AND FOG THROUGH OUT THE DAY AS
IN EACH SITE ESPECIALLY IN THE AFTERNOON HOUR. VISIBILITY MAY BE
REDUCED AT TIMES DUE TO PATCHY FOG AND LIGHT RAIN. NORTH WINDS
WILL INCREASE THROUGH OUT THE DAY AS WELL WITH GUSTS UP TO 30 KTS.
PREV DISCUSSION... /ISSUED 445 AM CST SAT DEC 24 2011/
SHORT TERM /TODAY THROUGH SUNDAY/...LIGHT RAIN SHOWERS OR DRIZZLE WILL
CONTINUE TO IMPACT THE RIO GRANDE VALLEY TODAY AS AN AREA OF LOW
PRESSURE CONTINUES TO MOVE EASTWARD OVER CENTRAL TEXAS AND
INTERACTS WITH A COASTAL TROUGH OVER THE REGION TODAY. EXPECT
REDUCED VISIBILITIES AND POSSIBLE AREAS OF PATCHY FOG ACROSS THE
RIO GRANDE VALLEY THROUGH THE DAY. MOST OF THE SHOWER ACTIVITY
WILL BE STRATIFORM TYPE AND WITH LITTLE ACCUMULATION EXPECTED. THE
HIGHER CHANCE OF SOME WIDESPREAD SHOWER ACTIVITY WILL BE SATURDAY
MORNING OVER THE LOWER PART OF THE RIO GRANDE VALLEY AND SHIFT TO
THE NORTHERN PART OF THE FORECAST AREA INTO THE AFTERNOON HOURS.
PRECIPITATION WILL BEGIN TO DIMINISH SATURDAY EVENING AS THE
COASTAL SURFACE TROUGH SHIFTS FURTHER EAST AND NORTHEAST.
NORTHERLY WINDS WILL BEGIN TO SHIFT TO THE NORTHWEST AS THE LOW
PRESSURE SYSTEM OVER CENTRAL TEXAS MIGRATES EASTWARD. THIS WILL
SHIFT MOST OF THE PRECIPITATION ACTIVITY OVER THE WESTERN GULF
WATERS. HIGH TEMPERATURES WILL REMAIN IN THE MID 50S ACROSS THE
RIO GRANDE VALLEY TODAY AND INTO SUNDAY. CHRISTMAS MORNING WILL
START OFF FAIRLY COOL WITH LOW TEMPERATURES IN THE MID 40S FOR
MOST OF THE RIO GRANDE VALLEY. HIGH TEMPERATURES ON CHRISTMAS
WILL NOT REBOUND MUCH LATER IN THE DAY DUE TO LINGERING CLD COVER
AND CONTINUED CAA FROM THE NW SURFACE FLOW PREVAILS.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...UPPER LOW OVER THE
TEXAS PANHANDLE SUNDAY NIGHT WILL MOVE EAST TO THE ARKLATEX REGION
LATE MONDAY AFTERNOON. CLOUDS WILL SLOWLY ERODE MONDAY MORNING AS
THE WAVE FINALLY MOVES EAST AND VERY DRY AIR FILTERS INTO DEEP
SOUTH TEXAS. THE UPPER VALLEY AND RANCHLANDS WILL BEGIN TO CLEAR
MONDAY MORNING AND THE LOWER VALLEY IN THE AFTERNOON. HIGH
TEMPERATURES MONDAY WILL BE IN THE LOW TO MID 60S. A COLD NIGHT IS
EXPECTED MONDAY NIGHT WITH TEMPERATURES IN THE UPPER 30S NORTHERN
AREAS TO THE LOWER/MID 40S NEAR THE COAST. NICE WEATHER IS
EXPECTED ACROSS THE RIO GRANDE VALLEY TUESDAY THROUGH THURSDAY AS
NORTHWEST FLOW ALOFT COMBINES WITH WEAK SURFACE FLOW AND GENERAL
WEAK HIGH PRESSURE AT THE SURFACE. SEASONAL TEMPERATURES
TUESDAY...LOWER 70S...WILL CLIMB INTO THE MID TO UPPER 70S
WEDNESDAY...AND NEAR 80 THURSDAY AND FRIDAY AS WEAK SOUTHERLY FLOW
RETURNS. DRY CONDITIONS WILL PERSIST THROUGH MOST OF THE WEEK BUT
RAIN CHANCES INCREASE LATE IN THE WEEK AS A WEAK COASTAL TROUGH
DEVELOPS OFF THE LOWER TEXAS COAST.
MARINE...
TODAY THROUGH SUNDAY...STRONG NORTH TO NORTHEAST WINDS WILL IMPACT
THE COASTAL WATERS TODAY AS AN UPPER LEVEL SYSTEM OVER CENTRAL TEXAS
MOVES SLOWLY EASTWARD TODAY AND INTERACTS WITH A COASTAL TROUGH OVER
THE REGION. THIS WILL INCREASE WAVE HEIGHTS UP TO 10 FOOT ESPECIALLY
OVER THE OFFSHORE WATERS OF THE GULF SATURDAY AFTERNOON. EXPECT SCA
CONDITIONS FOR THE NEXT 12 TO 24 HOURS INCLUDING THE BAY AREA. SHOWERS
AND PATCHY FOG WILL CONTINUE THROUGH THE DAY AND INTO SUNDAY AS THE
COASTAL TROUGH MOVES TO THE NORTHEAST. HIGH SEAS IN ADDITION TO A
HIGH TIDE THIS EVENING WILL INCREASE THE WAVE HEIGHTS EVEN MORE.
THEREFORE WILL BE ISSUING A COASTAL FLOOD ADVISORY TODAY FOR THE BAY
AREA. THESE HIGH WAVE HEIGHTS WILL CONTINUE INTO SUNDAY BUT WILL
BEGIN TO DIMINISH LATER SUNDAY EVENING AND IMPROVE INTO THE WEEK AS
THE PRESSURE GRADIENT WEAKENS SOME.
SUNDAY NIGHT THROUGH WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEED
SUNDAY NIGHT THROUGH MONDAY AFTERNOON AS THE TIGHT PRESSURE GRADIENT
OVER THE GULF OF MEXICO WILL RESULT IN ELEVATED WINDS AND SEAS
THROUGH MONDAY AFTERNOON. THE PRESSURE GRADIENT BEGINS TO RELAX
MONDAY AFTERNOON AND MARINE CONDITIONS STEADILY IMPROVE BY MONDAY
NIGHT. SURFACE HIGH PRESSURE SETTLES OVER THE NORTHERN GULF TUESDAY
AND WEDNESDAY RESULTING IN LIGHT WINDS AND LOW SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...COASTAL FLOOD ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
54/52/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
939 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST SATURDAY...
FROM THIS MORNINGS RNK SOUNDING...MOISTURE IS CONFIDED TO A LAYER
BETWEEN 5-6KFT. AS DRIER AIR ENTERS THE AREA THIS
AFTERNOON...THIS MOISTURE/CLOUD DECK WILL WITHER AWAY. COLD HIGH
PRESSURE WILL SKIRT ACROSS THE REGION THIS AFTERNOON AND TONIGHT.
85H TEMPERATURES WARM A FEW DEGREES BUT NOT ENOUGH TO TAKE THE
CHILL OUT OF THE AIR. MOUNTAIN TEMPERATURES WILL RANGE FROM THE
M/U 40S AND L/M 50S EAST. THESE TEMPERATURES ARE AROUND 5F ABOVE
NORMAL...WESTERN SLOPES NEAR NORMAL.
PREVIOUS DISCUSSION...AS OF 635 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO NY. AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST. LOW
CLOUDS STILL COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE WITH
WITH SOME BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT WAVE.
RADAR CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 635 AM EST SATURDAY...
MVFR CEILINGS IN THE WESTERN UPSLOPE AREAS...BLF/LWB...WERE
STARING TO ERODE. WEAKENING UPSLOPE WILL RESULT IN CEILINGS
BECOMING SCATTERED AND LIFTING TO VFR BY 18Z. NO CEILING
RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN. MODERATE
CONFIDENCE ON THE TIMING OF THE IMPROVING CONDITIONS AT BLF AND
LWB.
VFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE TERMINAL FORECAST
AREA TONIGHT INTO SUNDAY. HIGH CLOUDS ARE EXPECTED ACROSS SOUTHERN
VIRGINIA AND NORTH CAROLINA THIS AFTERNOON AND TONIGHT.
THERE IS A POSSIBILITY OF A BRIEF RETURN TO UPSLOPING CLOUDS
ACROSS THE WESTERN FLANKS OF THE APPALACHIANS (KBLF AND KLWB) ON
SUNDAY NIGHT.
A SURFACE RIDGE WILL BUILD IN ON MONDAY...ALONG WITH VFR
CONDITIONS UNTIL NEXT SOUTHERN STREAM WAVE RESULTS IN AN
INCREASING THREAT FOR RAIN AND ASSOCIATED FLIGHT RESTRICTIONS DOWN
INTO THE MVFR OR IFR RANGE MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
639 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO NY. AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST.
LOW CLOUDS STILL COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE
WITH WITH SOME BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT
WAVE. RADAR CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW
SHOWERS ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 635 AM EST SATURDAY...
MVFR CEILINGS IN THE WESTERN UPSLOPE AREAS...BLF/LWB...WERE
STARING TO ERODE. WEAKENING UPSLOPE WILL RESULT IN CEILINGS
BECOMING SCATTERED AND LIFTING TO VFR BY 18Z. NO CEILING
RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN. MODERATE
CONFIDENCE ON THE TIMING OF THE IMPROVING CONDITIONS AT BLF AND
LWB.
VFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE TERMINAL FORECAST
AREA TONIGHT INTO SUNDAY. HIGH CLOUDS ARE EXPECTED ACROSS SOUTHERN
VIRGINIA AND NORTH CAROLINA THIS AFTERNOON AND TONIGHT.
THERE IS A POSSIBILITY OF A BRIEF RETURN TO UPSLOPING CLOUDS
ACROSS THE WESTERN FLANKS OF THE APPALACHIANS (KBLF AND KLWB) ON
SUNDAY NIGHT.
A SURFACE RIDGE WILL BUILD IN ON MONDAY...ALONG WITH VFR
CONDITIONS UNTIL NEXT SOUTHERN STREAM WAVE RESULTS IN AN
INCREASING THREAT FOR RAIN AND ASSOCIATED FLIGHT RESTRICTIONS DOWN
INTO THE MVFR OR IFR RANGE MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS SPOKANE WA
500 AM PST Sat Dec 24 2011
.SYNOPSIS...A weak storm system Saturday will bring the potential
for light wintry precipitation to the region...mainly north of
Interstate 90. Stronger and wetter storms will begin to impact the
region Sunday and continue through next week. The storm on Monday
night and Tuesday will bring snow to the lower elevations. The
remainder of the week should see mountain snow and valley rain
with occasionally windy conditions.
&&
.DISCUSSION...
Update to today: Radar showing a broad area of light snow over the
Panhandle this morning. This is confirmed by airport observations at
Sandpoint and Bonners Ferry as well as web cameras. Updated
forecast to show light snow this morning in this area as well as
northeast Washington.
Meanwhile, temperatures continue to warm in the Cascade mountains.
Observations at Stevens Pass as well as surrounding mountains show
above freezing air moving in from the Pacific. Valley temperatures
in the Methow, Entiat, and Wenatchee valleys are currently in the
teens and will take a long time to warm. So the idea of light
freezing rain in these valleys still looks valid.
New 10Z HRRR model continues to show an area of freezing rain
developing over the western basin (i.e. Moses Lake and Ephrata) by
8am this morning and then moving northeastward to Spokane area
before noon. No evidence of this yet on satellite or radar so will
continue to monitor and will update/refine forecast if needed. RJ
...Areas of light freezing rain and snow possible today mainly
north of Interstate 90...
Today through Sunday night: The main focus over the holiday
weekend will be on potential for light freezing rain and snow
today, then potential for mountain snow showers Sunday with a mix
of rain and snow possible in the valleys. Overall, neither storm
system is very strong but may cause localized travel problems
related to icy or snow covered roadways.
For today`s storm system, satellite imagery this evening indicates
a stubborn flat ridge continuing to dominate the Inland NW with a
narrow fetch of subtropical moisture riding up the western spine
of the ridge and spilling into the Pac NW. Meanwhile, a potent
shortwave pivoting within the base of the mean Gulf of Alaska low
is deepening a midlevel low well off the coast. An elongated warm
front extended from this low will lift through the region today
and tonight bringing increasing warm advection ascending air
within the 285-290K isentropic surfaces. This will lead to an
increasing threat for light wintry precipitation with very little
in the way of accumulation. Needless to say, there is a great deal
of midlevel warming already taken place and as this wedge of
warmer air slides across the Cascades this morning, we will be
dealt a mix of wintry precipitation, with the most dominate types
likely to be snow or freezing rain, perhaps ice pellets. Model
initialization appears plausible compared to the 00Z satellite
imagery regarding the moisture plume and PV fields with the main
differences noted on the degree of boundary layer dryness overdone
by the 00Z GFS per surface obs and sfc-800mb raob comparison from
each KOTX and KUIL. Consequently, the forecast has included some
weight from the previously ignored NAM/SREF. Anyone who has been
following these models know that the QPF has been well overdone
the last few days, but has since backed off with the 00/06Z runs
and with a blend of the ECMWF/GFS, gives most locations along and
north of highway 2 some very light precipitation. The challenge
then becomes, what will the p-type be.
Observations from the Cascades already confirm that temperatures
at elevations roughly 3500-4000 feet and higher south of Lake
Chelan are warming near to slightly above freezing. The valleys
and deep basin remain in the teens to twenties and will likely
struggle to reach the freezing mark throughout the day with light
easterly flow and very little pcpn expected. This will keep the
dominate p-type snow or freezing rain with liquid equivalent
amounts generally near 0.02" or less. The SREF/NAM suggest the
highest probability for a few hours of light freezing rain will be
from along the highway 2 corridor from Spokane to Wenatchee and
valleys tucked within the East Slopes of the Cascades, including
the Methow Valley, Lake Chelan, and Wenatchee River Valley. Snow
will be dominate p-type from Omak to Bonners Ferry with little to
no accumulations expected. As the day wears on, the weak forcing
responsible light pcpn and warmer air will continue to nudge
northward eventually ending this evening as the midlevel warm
front lifts through. The only caveat is that very dry midlevel air
associated with the warm front suggest any threat for measurable
pcpn will end, but due to a lack of deep mixing to the surface,
residual boundary layer moisture will continue to lift into the
northern mountains with the potential for areas of drizzle or
freezing drizzle into the night.
Overall, much of the region will dry out Christmas Eve with the
next shortwave and associated cold front expected to race through
the region during the day Sunday. This will renew our chance for
rain and snow showers with most snow focusing over the Cascades,
northeastern Mtns of WA, and northern Idaho Panhandle. Strong
westerly flow in the 800-700mb layer will bring a great deal of
shadowing across the Basin but also aid the orographic pcpn
machine for the Cascades and Idaho Panhandle. A combination of
steepening lapse rates, differential PVA, orographics, and
potential for narrow CAPE within the -10 to -20C layer, suggest
isolated heavy snow showers will be possible over the higher
terrain from the Northern Cascades, east toward the Northern Idaho
Panhandle and travel across the Cascade, Northern Mtn, and Idaho
Panhandle mountain passes may be challenging at times if such
convective snow showers are able to materialize. SB
...Major weather pattern shift for next week...
Monday through Saturday: The predominant weather pattern of the
last month appears to finally be changing. Long range models in
good agreement on replacing the strong high pressure ridge over
the west coast with a strong zonal jet (about 160 kts) across the
Pacific. While not exactly typical of La Nina, the pattern is more
what we`re used to seeing in the winter. This pattern will yield
heavy precipitation for the Cascades and Panhandle mountains, with
mostly rain and wind for the lower elevations. Models typically
are too slow with the timing of weather systems with this pattern,
so forecast timing is likely to change a bit.
The first system of this pattern is currently out in the central
Pacific. MIMIC data show a subtropical moisture plume originating
near the Philippines that is already nearing the dateline. This
wave will reach the west coast on Monday, spreading precipitation
over the Inland Northwest Monday night and Tuesday. Atmosphere
ahead of this system will be cold and dry so dominant precip type
will be snow except for the Lewiston area. With the strong zonal
flow this system will move through the area quickly. The
prefrontal westerly flow will prevent much if any precipitation
for the Wenatchee/Moses Lake area. East of there decent snow
accumulations (2-4") are possible by Tuesday morning.
The next Pacific system will be quickly on the heels of the first,
arriving Tuesday night. There is a brief period of decent 700mb
warm air advection that will overcome the downslope off the
Cascades. Even so precip amounts for the basin will be light. Snow
levels will also rise with this system so most low land locations
will see rain instead of snow.
The rest of the week will finish out with 2 to 3 more Pacific
storms similar to their predecessors. Mild and occasionally windy
in the low lands with snow for the mountains. There could be
enough of a break Thursday night to allow the low lands to cool
enough to start as snow on Friday. But even if this happens the
precip will quickly change back to rain. RJ
&&
.AVIATION...
12Z TAFs: A weak Pacific storm will move onshore today bringing
light precipitation, mainly north of I-90. Precipitation will
start in the Cascades and western Basin this morning. Freezing
rain is possible in this area. The threat of light freezing rain
will move to the Spokane area in the afternoon. Any freezing rain
that occurs will be very light. Due to the low probability for
FZRA I left it out of the TAFs for now. MVFR conditions are likely
with this area of precipitation, and IFR is possible, mainly north
of KGEG in the afternoon. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 32 26 34 26 34 29 / 30 10 30 20 10 80
Coeur d`Alene 33 27 35 26 37 29 / 30 10 40 40 10 80
Pullman 37 30 39 29 38 32 / 20 0 20 40 10 70
Lewiston 40 32 44 30 43 36 / 10 0 10 20 10 30
Colville 29 25 34 21 34 28 / 50 10 40 30 20 90
Sandpoint 32 25 35 25 34 29 / 40 10 40 40 20 80
Kellogg 34 30 36 27 34 28 / 10 10 40 60 30 80
Moses Lake 32 24 35 23 35 27 / 20 0 20 10 10 40
Wenatchee 31 27 37 25 32 27 / 20 10 20 10 10 50
Omak 30 25 33 21 32 25 / 30 10 30 10 10 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER CO
150 PM MST SAT DEC 24 2011
.SHORT TERM...A WIDE BAND OF CIRRUS CLOUDS ON THE LEADING SIDE OF A
SOUTHWEST-NORTHEAST ORIENTED UPPER LEVEL RIDGE ADVANCING SLOWLY
SOUTHWARD OUT OF WYOMING MARKS LEADING EDGE OF WARMER AIR ALOFT.
BENEATH THESE CLOUDS SWLY SFC WINDS WERE GUSTING 20-30KTS ACROSS
SERN WYOMING WHILE WINDS ALOFT WERE NELY 70-90 KTS ACCORDING TO
MEDICINE BOW PROFILER. DURING THE NEXT SEVERAL HOURS THIS
ENVIRONMENT SHIFTS SOUTHWARD OVER THE FORECAST AREA. RUC INDICATING
PRESSURE FALLS ACROSS THE AREA CENTERED ALONG THE MOSQUITO RANGE IN
PARK COUNTY. SHOULD BE JUST A MATTER OF TIME BEFORE THE NRN FRONT
RANGE FOOTHILLS SEE THE DEVELOPMENT OF GUSTY WEST-SOUTHWEST WINDS...
WITH GUSTS OF 30-35KTS POSSIBLE THIS EVENING. SHOULD SEE THESE GUSTY
DOWNSLOPE WINDS MIGRATING SOUTHWARD ALONG THE FOOTHILLS THIS
EVENING...BUT SPEEDS PROBABLY NOT AS STRONG THOSE EXPECTED UP NEAR
THE WYOMING BORDER. GUSTY WLY WINDS ALSO A POSSIBILITY THIS EVENING
ALONG LEE SLOPES OF THE GORE RANGE IN JACKSON COUNTY AND MOSQUITO
RANGE IN PARK COUNTY.
OTHERWISE...SCT-BKN CIRRUS CLOUDS BLOW SOUTH OF THE AREA LATER THIS
EVENING WHICH ALLOWS FOR ANOTHER NIGHT OF CHILLY TEMPERATURES ESPLY
IN THE MTN VALLEYS WHERE STRONG NIGHTTIME INVERSIONS WILL FORM WITH
DARKNESS. AS USUAL WILL SEE COLDEST READINGS ON THE PLAINS IN LOW
LYING AREAS SUCH AS ALONG THE SOUTH PLATTE AND THE AREA AROUND
LIMON. WHEREAS A STEADY DOWNSLOPE FLOW OFF THE FOOTHILLS WILL KEEP
OVERNIGHT TEMPERATURES ON THE MILD SIDE ALONG THE BASE OF THE
FOOTHILLS.
ON CHRISTMAS DAY...WINDS BOTH SFC AND ALOFT EASE AS THE UPPER RIDGE
PASSES OVERHEAD. SEE FEW IF ANY CLOUDS AND SLIGHTLY WARMER
TEMPERATURES AS WARMING CONTINUES ALOFT. WARMEST TEMPS EXPECTED
ALONG THE BASE OF THE FOOTHILLS AND OUT ACROSS THE NERN CORNER OF
THE STATE WHERE THERE/S LITTLE IF ANY SNOW COVER. COULD SEE THE
MERCURY NUDGING THE 50 DEG MARK IN THESE AREAS. MOS TEMPERATURE
GUIDANCE STILL LOOKS A BIT TOO WARM FOR THOSE AREAS INCLUDING THE
DENVER AREA WITH OUR DEEP SNOW COVER. SO WILL SHAVE MOS TEMPS
BACK A FEW DEGS.
.LONG TERM...FOR THE UPCOMING WEEK ACROSS COLORADO THE FLOW WILL BE
A RATHER STRONG NORTHWEST FLOW PATTERN. THIS WILL RESULT IN A DRY
PATTERN ACROSS THE PLAINS...BUT PERIODS OF GUSTY WINDS AND CHANCES
OF SNOW IN THE MOUNTAINS. MOISTURE WILL BE INCREASING ACROSS THE
MOUNTAINS BY MID WEEK WITH SEVERAL JET SEGMENTS TRAVERSING THE STATE.
TO START THE WEEK ON MONDAY...THE TRANSITION TO THE NORTHWEST FLOW
PATTERN WILL BEGIN AS A WEAK WAVE AND FRONTAL SYSTEM MOVES ACROSS
THE NORTHERN HIGH PLAINS. A WEAK SURGE WILL MOVE ACROSS NORTHEAST
COLORADO RESULTING IN COOLER TEMPERATURES BY MONDAY AFTERNOON. CROSS
SECTIONS SHOWING SOME INCREASING DOWNSLOPE WINDS OVER EAST SLOPES
ESPECIALLY BY MONDAY NIGHT AND CONTINUING TUESDAY. GIVEN STRONG
CROSS BARRIER FLOW MAY SEE SOME GUSTS IN THE 40-50KT RANGE OVER
HIGHER EAST SLOPES. SOME SHALLOW MOISTURE WILL RESULT IN SOME
SCATTERED SNOW SHOWERS OVER HIGHER WEST SLOPES OF THE MOUNTAINS. A
STRONGER SYSTEM WITH DEEPER MOISTURE WILL MOVE INTO THE MOUNTAINS ON
WEDNESDAY WITH A BETTER CHANCE OF SNOW AS STRONGER 110KT JET CORE
MOVES INTO CENTRAL COLORADO. ACROSS NORTHEAST COLORADO...THE
DOWNSLOPE FLOW WILL ALLOW TEMPERATURES TO WARM TO SLIGHTLY ABOVE
NORMAL TEMPERATURES FOR THIS TIME OF YEAR.
CONTINUED MODERATE TO STRONG NORTHWEST FLOW THROUGH SATURDAY WILL
RESULT IN A SLIGHT CHANCE OF SNOW FOR THE MOUNTAINS THROUGH THE
PERIOD AND GUSTY WINDS.
&&
.AVIATION...VFR CONDITIONS EXPECTED THROUGH CHRISTMAS DAY WITH A
TYPICAL DRAINAGE WIND PATTERN PREVAILING AREAWIDE. ALTHOUGH BJC
COULD SEE W-SWLY WINDS OF 10-15KTS FOR A TIME THIS EVENING. HERE TOO
WINDS SHOULD WEAKEN AND GO DRAINAGE BY 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
BAKER/ENTREKIN
AREA FORECAST DISCUSSION
NWS ALBANY NY
1222 PM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH TODAY. CANADIAN HIGH PRESSURE
WILL BRIEFLY BUILD IN LATE BRINGING INCREASING SUNSHINE BUT
SEASONABLY COLD TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE
TONIGHT INTO SUNDAY. A CLIPPER TYPE STORM WILL BRING SOME LIGHT SNOW
TO MAINLY THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS HAVE DIMINISHED...BUT COLD AIRMASS STILL IN PLACE WITH
RELATIVELY LIGHT WINDS. JUST A FEW MINOR CHANGES TO FORECAST
THROUGH THIS AFTERNOON.
PREV AFD BELOW...
AS OF 950 AM...A BAND OF CLOUDS ASSOCIATED WITH A MID/UPPER LEVEL
TROF AXIS AS WELL AS A MOISTURE CONTRIBUTION FROM LAKE CHAMPLAIN
IN NORTHEAST FLOW REGIME IN PLACE FROM AROUND THE GLENS FALLS AREA
SOUTHWARD THROUGH THE CAPITAL DISTRICT AND BERKSHIRES. SCATTERED
FLURRIES HAVE BEEN COMMON THIS MORNING...SO WILL ADD MENTION TO
FORECAST. A FEW SNOW SHOWERS BRINGING DOWN VISIBILITIES TO AROUND
2-3 MILES AROUND GLENS FALLS SO WILL MENTION 20 POPS FOR ISOLATED
SNOW SHOWERS THERE. THE TROF AXIS SHOULD MOVE EAST OF THE REGION
RATHER QUICKLY BY EARLY AFTERNOON...SO FLURRIES AND CLOUD COVER
SHOULD GRADUALLY DIMINISH LEAVING MAINLY CLEAR SKIES BY LATE IN
THE DAY.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...NAS
NEAR TERM...NAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1101 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
1056 AM MST SAT DEC 24 2011
WEAK NORTHWEST NEAR SURFACE FLOW REMAINS IN PLACE AS DOES THE AREA
OF GENERALLY HIGHER PRESSURE OVER THE ROCKIES AND HIGH PLAINS. VFR
CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF
SATURDAY...CHRISTMAS EVE...AND CHRISTMAS DAY.
LOCKHART
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
306 PM EST SAT DEC 24 2011
.SYNOPSIS...
A BROAD AREA OF HIGH PRESSURE WITH SHIFT EASTWARD ACROSS THE AREA
FOR A MOSTLY DRY CHRISTMAS WEEKEND. ON SUNDAY NIGHT, A WEAK
DISTURBANCE WILL PASS NORTHEAST OF THE AREA, BRINGING THE CHANCE
OF SNOW SHOWERS NORTHEAST OF PITTSBURGH. HIGH PRESSURE WILL THEN
BUILD IN AND BRING A DRY START TO NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE MOISTURE TRAJECTORY. DEEP SUBSIDENCE ALOFT IS
ALLOWING FOR DRY WEATHER.
TONIGHT THROUGH EARLY SUNDAY...850MB FLOW WILL SHIFT FROM WESTERLY
TO SOUTHWESTERLY, ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS
TO ADVECT INTO THE AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE
SOUTHWEST. THIS WILL ALLOW FOR CLEAR SKIES OVERNIGHT AND ABUNDANT
SUNSHINE EARLY ON CHRISTMAS.
LATE ON CHRISTMAS DAY...GFS/NAM SOLUTIONS INDICATE A MID-LEVEL
TROUGH PASSING FROM THE NORTHERN GREAT LAKES INTO WESTERN NY. AREAS
NORTHEAST OF PITTSBURGH WILL BE ON THE SOUTHWESTERN EDGE OF MOISTURE
WITH THIS SYSTEM, WITH SNOW SHOWERS POSSIBLE THERE BEGINNING SUNDAY
EVENING. TEMPERATURES WILL BE ABOVE 5 DEGREES ABOVE NORMAL THROUGH
THIS PERIOD.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THERE IS STRONG MODEL AGREEMENT THAT THE 500MB TROUGH AXIS WILL
SHIFT FROM THE EASTERN GREAT LAKES INTO NEW ENGLAND ON SUNDAY NIGHT
AND THE LOW AND MID-LEVEL FLOW WILL BECOME NORTHWESTERLY. ALTHOUGH
MOST MODELS TAKE THE BULK OF PRECIPITATION NORTHEAST OF THE AREA
WITH THIS FEATURE, THE 4KM NAM AND CANADIAN SOLUTIONS ARE
CONSIDERED, BRINGING SCHC POPS INTO SOUTHWEST PA AND CHC POPS
NORTHEAST OF PITTSBURGH. 1000-500MB 5400M LINE WILL BE WELL SOUTH OF
THE AREA, WITH ANY PRECIPITATION ALL IN THE FORM OF SNOW SHOWERS.
ANY ACCUMULATION WILL BE LESS THAN AN INCH, AS BEST FORCING REMAINS
NORTHEAST OF THE AREA WITH THIS SYSTEM.
MONDAY...ANY LINGERING SNOW SHOWERS ACROSS THE NORTHEAST OF
PITTSBURGH WILL QUICKLY DIMINISH BY THE AFTERNOON AS A 850MB
RIDGE ALLOWS THE FLOW TO BECOME MORE WESTERLY, HIGH PRESSURE
CROSSES THE AREA, AND DRIER AIR FILTERS INTO THE AREA.
CYCLOGENESIS ACROSS THE MS VALLEY WILL BEGIN LATE IN THE DAY AS A
CLOSED LOW SWINGS ACROSS THE SOUTHERN PLAINS. A SOUTHWESTERLY FLOW
ALOFT AHEAD OF THIS FEATURE WILL ALLOW FOR WARM AIR ADVECTION TO
ENSUE. THIS WILL ALSO CONTRIBUTE TO DECREASED CLOUD COVERAGE. THIS
HAS ALSO BEEN ACCOUNTED FOR IN THE FORECAST TEMPS, WITH HIGHS A
FEW DEGREES ABOVE A MAV/MET BLEND.
MONDAY NIGHT AND TUESDAY...THE CLOSED LOW WILL OPEN INTO A TROUGH AS
IT SWINGS INTO THE OHIO VALLEY, WITH THE SURFACE LOW TRACKING ACROSS
THE TENNESSEE VALLEY. THIS WILL ALLOW FOR STRONG WARM AIR ADVECTION
WITH TEMPS WARMING TO THE LOWER TO MID 40S BY DAWN TUESDAY. RAIN
WILL MOVE INTO EASTERN OHIO AFTER MIDNIGHT WILL ALL OPERATIONAL
MODELS SHOWING A SIMILAR SOLUTION, WITH THE LOW PASSING SOUTHEAST
OF THE AREA ON TUESDAY. WITH THIS IN MIND, LIKELY POPS ARE FORECAST
THROUGHOUT THE DAY. A HALF OF AN INCH TO AN INCH OF PRECIPITATION
WILL BE POSSIBLE WITH THIS SYSTEM.
THERE IS STILL SOME UNCERTAINTY WITH PRECIP TYPE WITH THIS SYSTEM,
AS SURFACE TEMPS MAY BE COLD ENOUGH FOR FREEZING RAIN NORTH OF
PITTSBURGH AT THE ONSET MONDAY NIGHT TO NEAR DAWN ON TUESDAY. 850
TEMPS WILL BE WARM ENOUGH THAT PRECIP SHOULD FALL AS ALL LIQUID,
SO WILL NEED TO MONITOR THIS IN FUTURE FORECAST RUNS. FOR NOW,
MIXED PRECIP IS FORECAST TO EXPRESS UNCERTAINTY. AS THE LOW
SHIFTS EAST OF THE AREA, COLD AIR WILL WRAP INTO THE BACK EDGE OF
THE SYSTEM, WITH THICKNESSES DECREASING AND A CHANGEOVER TO SNOW
LATE ON MONDAY. TEMPS WILL BE AROUND 10 DEGREES ABOVE NORMAL
DURING THE DAY TUESDAY, UNTIL COLD AIR ADVECTION ALLOWS WITH TEMPS
TO DROP INTO THE MID 30S BY EVENING ON THE BACK SIDE OF THE
SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MIXED RAIN AND SNOW SHOWERS WILL CHANGE OVER TO SNOW BEFORE
DIMINISHING TUESDAY NIGHT. SURFACE RIDGE SHOULD BRING A GENERALLY
DRY FORECAST FOR WEDNESDAY. FAST MOVING SYSTEMS IN WAVY ZONAL FLOW
WILL BRING ABOVE NORMAL TEMPERATURES AND A CHANCE OF RAIN OR SNOW
SHOWERS THURSDAY INTO SATURDAY. CLOSE TO HPC PROGS WHICH TREND
TOWARD ECMWF.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
PATCHES OF MVFR STRATUS WILL EXIT NORTHEAST THIS EVENING WITH
GENERAL VFR THROUGH TAF PERIOD AS NEXT CLIPPER TYPE SYSTEM HEADS
ACROSS NORTHERN GREAT LAKES CHRISTMAS DAY. THIS WILL ALLOW SKIES TO
CLEAR OVERNIGHT AS FLOW BECOMES SOUTHWEST AHEAD OF SYSTEM.
INCREASING PRESSURE GRADIENT BY MID MORNING SATURDAY WILL ALLOW FOR
SOUTHWEST WINDS TO GUST TO 25KTS. A MID DECK WILL BEGIN TO
OVERSPREAD THE REGION DURING THE DAY.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...A COLD FRONT ON BACKSIDE
OF SYSTEM EXITING EASTERN GREAT LAKES MAY BRING BRIEF RESTRICTIONS
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM
MOVING NORTHEAST FROM THE SOUTHERN PLAINS WILL BRING RESTRICTIONS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT. GENERAL VFR WEDNESDAY WITH
RESTRICTIONS POSSIBLE THURSDAY AHEAD OF A WEAK COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1244 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR A MOSTLY DRY HOLIDAY WEEKEND. THE
NEXT CHANCE FOR SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR
AREAS NORTH AND EAST OF PITTSBURGH AS A DISTURBANCE MOVES ACROSS
THE NORTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO INCREASE SKY GRIDS TO ACCOUNT FOR DIURNAL CUMULUS WHICH
HAS DEVELOPED.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE TRAJECTORY. THUS, SCATTERED FLURRIES HAVE
DIMINISHED AND DEEP SUBSIDENCE ALOFT IS ALLOWING FOR DRY WEATHER.
THIS AFTERNOON...CLOUD COVERAGE WILL BEGIN TO DECREASE LATE IN
THE DAY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR ALOFT IN
PLACE. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING
FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE EASTERN RIDGES
TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS TO ADVECT INTO THE
AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST. THIS
WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT LOWS ARE CLOSEST
TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 20S ACROSS THE
AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
PATCHES OF MVFR STRATUS WILL EXIT NORTHEAST THIS AFTERNOON WITH GENERAL
VFR THROUGH TAF PERIOD AS NEXT CLIPPER TYPE SYSTEM HEADS ACROSS
NORTHERN GREAT LAKES CHRISTMAS DAY. THIS WILL ALLOW SKIES TO CLEAR
OVERNIGHT AS FLOW BECOMES SOUTHWEST AHEAD OF SYSTEM. INCREASING
PRESSURE GRADIENT BY MID MORNING SATURDAY WILL ALLOW FOR
SOUTHWEST WINDS TO GUST TO 25KTS. A MID DECK WILL BEGIN TO
OVERSPREAD THE REGION DURING THE DAY.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...A COLD FRONT ON BACKSIDE
OF SYSTEM EXITING EASTERN GREAT LAKES MAY BRING BRIEF RESTRICTIONS
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM
MOVING NORTHEAST FROM THE SOUTHERN PLAINS WILL BRING RESTRICTIONS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT. GENERAL VFR THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1212 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR A MOSTLY DRY HOLIDAY WEEKEND. THE
NEXT CHANCE FOR SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR
AREAS NORTH AND EAST OF PITTSBURGH AS A DISTURBANCE MOVES ACROSS
THE NORTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO INCREASE SKY GRIDS TO ACCOUNT FOR DIURNAL CUMULUS WHICH
HAS DEVELOPED.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE TRAJECTORY. THUS, SCATTERED FLURRIES HAVE
DIMINISHED AND DEEP SUBSIDENCE ALOFT IS ALLOWING FOR DRY WEATHER.
THIS AFTERNOON...CLOUD COVERAGE WILL BEGIN TO DECREASE LATE IN
THE DAY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR ALOFT IN
PLACE. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING
FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE EASTERN RIDGES
TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS TO ADVECT INTO THE
AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST. THIS
WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT LOWS ARE CLOSEST
TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 20S ACROSS THE
AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
GENERAL VFR FORECAST THROUGH THE AFTERNOON WITH ISOLATED MVFR AS
LAST OF STRATUS EXITS.
MID-LEVEL WAA WILL ALLOW 85H WINDS TO SLOWLY VEER TO THE WEST AND
THEN TO THE SOUTHWEST LATER THIS AFTERNOON. THIS WILL DECAY THE VFR
CLOUD DECK AND SCT CLOUDS OUT BY LATE THIS AFT.
EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
A COLD FRONT WILL BRING POSSIBLE RESTRICTIONS SUNDAY AFTERNOON INTO
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM MOVING
NORTHEAST FROM THE SOUTHERN PLAINS WILL PROVIDE RESTRICTIONS TUESDAY
FOLLOWED BY GENERAL VFR WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1215 PM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN
GREAT LAKES LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN
ALBERTA. LOW LEVEL CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO
NRN LAKE MI ALONG WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND
-10C...CONTINUED TO SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS
FROM NEAR BEAVER ISLAND TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED
OVERNIGHT WITH ONLY OCNL VSBY INTO THE 1-3SM RANGE. AN UPSTREAM
TROUGH WAS MOVING THROUGH THE ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR.
OTHERWISE...DRY WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC
ASCENT WITH THE WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF
THE CWA. WAA WILL BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S
AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA
WITH STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO
THE MID TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING
IN ON TUE WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF
LES FOR NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN
SINCE THE GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED
TO NEAR -11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE
OUT QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
VFR CONDIITONS ARE EXPECTED AT ALL 3 TAF SITES THROUGH THIS
AFTERNOON. TROUGH WILL APPROACH AND CROSS UPPER MICHIGAN LATE
TONIGHT AND CHRISTMAS MORNING. MOISTURE IS LIMITED BUT EXPECT A
RETURN OF MVFR CIGS WITH ITS PASSAGE. VSBYS MAY EVEN LOWER INTO IFR
RANGE...ESPECIALLY AT CMX DURING THE MORNING WITH SOME LIGHT LAKE
EFFECT SNOW SHRAS AND BLOWING SNOW WITH GUSTY NORTHWEST WINDS.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...MZ
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
339 PM EST SAT DEC 24 2011
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST ACROSS THE REGION TONIGHT AND BRING
TEMPERATURES ABOVE AVERAGE ONCE AGAIN FOR CHRISTMAS DAY. A COLD
FRONT AND UPPER LEVEL DISTURBANCE WILL THEN SWEEP ACROSS THE REGION
CHRISTMAS AFTERNOON AND EVENING WITH A FEW RAIN SHOWERS CHANGING
OVER TO SNOW SHOWERS. DRY WEATHER WILL RETURN FOR MONDAY AS HIGH
PRESSURE BUILDS INTO THE OHIO VALLEY AND GREAT LAKES.
&&
.NEAR TERM /THROUGH SUNDAY/...
THROUGH THIS EVENING...LINGERING CLOUDS SOUTHEAST OF LAKE ONTARIO
WILL CONTINUE TO DISSIPATE AS WINDS SHIFT AND PUSH WHATS LEFT OF THE
CLOUDS NORTHWARD. MEANWHILE...AN A WARM FRONT WILL LIFT TOWARD THE
REGION FROM THE SOUTHWEST THIS EVENING...WITH AN ASSOCIATED AREA OF
CLOUDS FORECAST TO LIFT ACROSS SOUTHWESTERN NEW YORK THIS
EVENING...AND THE EASTERN LAKE ONTARIO REGION OVERNIGHT.
THIS FRONT IS RELATIVELY WEAK...WITH THE NAM/RGEM/GFS SHOWING NO
QPF...AND THE HRRR SHOWING ONLY A COUPLE HUNDREDTHS...MAINLY
CONFINED TO THE NORTH SHORES OF EACH OF THE LAKES. WITH NO
PRECIPITATION UPSTREAM...IT DOES NOT APPEAR THE FRONT ALONE HAS
AMPLE LIFT TO GENERATE ANY PRECIPITATION. WITH 850 MB TEMPERATURES
STILL -7 TO -10C AHEAD OF THE FRONT...IT MAY BE ABLE TO TAP INTO A
LITTLE LAKE INSTABILITY...HOWEVER THE S TO SSW FLOW SHOULD LARGELY
KEEP WHATEVER IS GENERATED TO THE NORTH AND WEST OF NEW YORK STATE.
WE MAY SEE A STRAY FLURRY ON THE NIAGARA FRONTIER...BUT AT THIS
POINT...IF THERE IS NOT ALREADY SNOW ON THE GROUND AT YOUR
LOCATION...IT IS VERY UNLIKELY THAT IT WILL BE A WHITE CHRISTMAS
MORNING.
OTHERWISE...THE OVERNIGHT PERIOD WILL BE SEASONABLY COOL.
TEMPERATURES WILL PROBABLY BOTTOM OUT DURING THE EVENING
HOURS...THEN START TO RAISE AS WINDS INCREASE LATE TONIGHT...AND AS
WARMER AIR BUILDS IN BEHIND THE FRONT. LOWS WILL BE COLDEST EAST OF
LAKE ONTARIO...WHERE A SNOW PACK IS LARGELY IN PLACE...AND WHERE IT
WILL BE CLEAR AND CALM FOR PART OF THE EVENING.
CHRISTMAS DAY SHOULD START OFF DRY...BUT WITH FAIRLY WINDY
CONDITIONS. THE NAM/GFS BOTH ARE FORECASTING A 40 KT LOW LEVEL JET
DOWN TO 2000 FEET ON SUNDAY. WHILE THIS SHOULD NOT MIX
COMPLETELY...EXPECT SOME GUSTS IN THE 35 MPH RANGE INLAND...WITH
PEAK GUSTS AROUND 40 MPH ALONG THE NIAGARA FRONTIER...WHERE
FUNNELING...AND RELATIVELY WARMER TEMPERATURES ON LAKE ERIE WILL
AID MIXING. MEANWHILE...TEMPERATURES WILL BE COOL...BUT ABOVE NORMAL
FOR THE DATE...WITH HIGHS IN THE UPPER 30S TO AROUND 40 ACROSS
WESTERN NEW YORK.
A FAIRLY VIGOROUS SHORTWAVE WILL APPROACH FROM THE UPPER LAKES
SUNDAY AFTERNOON. WHILE THIS WILL LIKELY SPARK SOME SHOWERS...THESE
SHOULD LARGELY HOLD OFF UNTIL SUNSET OR SHORTLY THEREAFTER.
CONSENSUS QPF AMONG THE NAM/RGEM/GFS ALL PRETTY MUCH FOCUS ON THE
21Z TO 03Z SUNDAY TIMEFRAME. WHILE QPFS ARE GENERALLY A TENTH OF AN
INCH OR LESS...THERE IS GOOD MODEL CONSISTENCY. NAM BUFKIT FOR
JAMESTOWN SHOWS A FEW HOURS OF A THIN AND NARROW CAPE...SUGGESTING A
PERIOD OF LAKE ENHANCED PRECIPITATION WITH THE PASSAGE OF THE
SHORTWAVE.
ALONG THE I-90 CORRIDOR FROM BUFFALO TO ROCHESTER...EXPECT SCATTERED
RAIN OR SNOW SHOWERS TOWARD SUNSET...WITH LITTLE IF ANY SNOW
ACCUMULATION. EAST OF THE LAKES...BOTH IN WESTERN PORTIONS OF THE
SOUTHERN TIER...AND THE EASTERN LAKE ONTARIO REGION...PRECIPITATION
WILL LIKELY START AS A MIX TOWARD SUNSET...BUT SHOULD TREND TOWARD SNOW
AFTER SUNSET. THERE MAY BE SOME MODEST ACCUMULATIONS IN THESE
LOCATIONS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER TROUGH AND COLD FRONT DROPS SOUTH ACROSS THE REGION SUNDAY
NIGHT WITH PRECIP CHANGING OVER TO SNOW SHOWERS. BREEZY TO WINDY
CONDITIONS WILL ACCOMPANY THE COLD FRONT DURING THE EVENING AND
EARLY NIGHT. EXPECT SOUTHWEST WIND AVERAGING 20 TO 25 MPH GUSTS TO
30..SHIFTING TO WESTERLY. THE RAIN SHOWERS WILL TRANSITION TO SNOW
SHOWERS AS THE WINDS SHIFT. SNOW ACCUMS DURING THE NIGHT WILL BE
ONLY IN THE FRACTIONS OF AN INCH FOR MOST LOCATIONS...THE TUG HILL
PLATEAU MAY SEE AS MUCH AS 2 INCHES WITH THE OROGRAPHIC ENHANCEMENT
OF LIFT AND COLDER 850MB TEMPS NEAR -8C.
HIGH PRESSURE AND UPPER RIDGING DOMINATE MONDAY AND MONDAY NIGHT.
THERE WILL BE A RETURN OF SUNSHINE BUT DAYTIME TEMPS WILL BE LIMITED
TO THE 30S...MID 20S FOR THE EASTERN LAKE ONTARIO REGION.
A DEEPENING TROUGH ACROSS THE CONTINENT`S MIDSECTION WILL TAP AN
INCREASINGLY MOIST SOUTHERLY FLOW WHICH WILL BRING CLOUDS AND WARMER
CONDITIONS TO THE REGION ON TUESDAY. TEMPS WILL BE ON THE RISE
THROUGH MONDAY NIGHT...TOPPING OUT IN THE UPPER 30S TO LOW 40S ON
TUESDAY. WITH THE STRONG WARM ADVECTION LATE MONDAY NIGHT THROUGH
THE DAY ON TUESDAY...EXPECT THE PRECIP TO BE AS RAIN DURING THE
DAY...TRANSITIONING TO A RAIN/SNOW MIX LATE...THEN TO ALL SNOW TUES
EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TIMING DIFFERENCES BETWEEN GFS AND ECMWF BECOME SIGNIFICANT ON
TUESDAY NIGHT. GFS IS SLOWER IN LIFTING SURFACE AND CLOSED UPPER LOW
FROM THE MIDDLE MISSISSIPPI VALLEY TUESDAY MORNING TO THE CENTRAL
APPALACHIANS TUESDAY EVENING. ECMWF IS FASTER AND FARTHER EAST WITH
THE SURFACE LOW AND HAS THE ADDITIONAL FEATURE OF PHASING THE
NORTHERN BRANCH TROUGH ACROSS THE GREAT LAKES WITH THE MORE OPEN
SOUTHERN BRANCH WAVE. THIS ALLOWS A SOUTHWARD DRAW OF MUCH COLDER
AIR TO THE WEST OF THE SURFACE LOW.
WILL CONCUR WITH THE EXTENDED HPC DISCUSSION AND CONTINUE TO USE THE
ECMWF FOR TUESDAY NIGHT`S PATTERN. THE WET WEATHER OF LATE TUESDAY
WILL CHANGE OVER TO SNOW TUESDAY NIGHT AS 850MB TEMPS RANGING FROM
-2C TO -5C ARE ACROSS THE REGION...WITH MUCH COLDER AIR ON TAP. WILL
HAVE CHANCE POPS FOR LIGHT SNOW...AND DO EXPECT TO SEE AN
ACCUMULATION WITH THIS SYSTEM.
850MB TEMPS DROP TO -14C AS PER ECMWF...THUS WILL KEEP LIGHT SNOW IN
LAKE EFFECT ACROSS MUCH OF THE FORECAST AREA. UPPER MOISTURE SHOULD
LIMIT THE INTENSITY OF LAKE SNOW...BUT THIS WILL BEAR WATCHING OVER
THE NEXT SEVERAL MODEL RUNS TO SEE IF THE -14C TEMPS PERSIST. HIGH
PRESSURE ACROSS THE AREA ON THURSDAY WILL BE FOLLOWED BY A WARM
FRONT THURSDAY NIGHT WITH SCATTERED SNOW SHOWERS FRIDAY AND
SATURDAY. ECMWF AND GFS NOT EXACTLY IN AGREEMENT BUT CLOSE ENOUGH TO
CARRY LOW CHANCE POPS FOR THE END OF THE PERIOD.
TEMPS WILL CLOSE TO SEASONAL NORMS DURING MIDWEEK...THEN A SLIGHT
WARMING TOWARD THE END OF THE WEEK.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THROUGH 20Z...EXPECT LARGELY VFR CONDITIONS THROUGH THE TAF PERIOD.
THERE MAY BE SOME LINGERING MVFR CIGS NEAR JHW. AFTER THIS...AN AREA
OF WARM AIR ADVECTION IN THE LOWER AND MID LEVELS WILL RESULT IN A
BAND OF CLOUDS WILL WILL LIFT ACROSS THE REGION FROM SW-NE THIS
EVENING AND OVERNIGHT. THESE WILL LIKELY BE ABOVE 3000 FT.
OTHERWISE...WINDS WILL INCREASE MARKEDLY SUNDAY MORNING...ESPECIALLY
AT BUF AND IAG...WHERE GUSTS TO 35 KTS ARE EXPECTED. MODEST WIND
SHEAR WILL DEVELOP LATE TONIGHT...BUT WITH A WINDS ALOFT ONLY IN THE
30 TO 35 KT RANGE JUST PRIOR TO MIXING...SO SHEAR MAY FALL SHY OF
CRITERIA FOR INCLUSION IN THE TAFS.
AN APPROACHING SHORTWAVE WILL SPARK RAIN AND SNOW SHOWERS LATE
SUNDAY AFTERNOON...POSSIBLY LOWERING CONDITIONS TO MVFR OR LOWER
TOWARD 00Z MONDAY.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR WITH SNOW SHOWERS...MOST WIDESPREAD EAST OF
THE LAKES.
MONDAY...VFR/MVFR WITH WITH MORNING SNOW SHOWERS...THEN VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN OR SNOW SHOWERS.
WEDNESDAY...MAINLY VFR.
&&
.MARINE...
A WARM FRONT WILL CROSS THE LOWER LAKES FROM SOUTHWEST TO NORTHEAST
OVERNIGHT AND THE PRESSURE GRADIENT QUICKLY INCREASES. WINDS ALOFT
WILL BE ABOUT 40 KTS AT 2000 FT. WHILE A WARM AIR ADVECTION
PATTERN...THE AIR IN PLACE IS QUITE COOL...GENERALLY IN THE 30S.
THIS SHOULD ALLOW FAIRLY GOOD MIXING...WITH THE LAKE TEMPERATURES
RUNNING IN THE LOWER 40S. EXPECT WINDS TO REALLY PICK UP SUNDAY
MORNING...WITH SUSTAINED WINDS EXPECTED TO PEAK NEAR 30 KTS DURING
THE DAY SUNDAY. EXPECT A FEW GALE FORCE GUSTS...BUT BY LARGE EXPECT
CONDITIONS TO PEAK AT HIGH END SMALL CRAFT...BEFORE DIMINISHING
SUNDAY NIGHT AS HIGH PRESSURE BUILDS IN.
HIGH PRESSURE WILL BRIEFLY BUILD ACROSS ON TUESDAY...WITH AN
INCREASING NE FLOW TUESDAY NIGHT AND WEDNESDAY AS LOW PRESSURE
PASSES TO THE SOUTH.
&&
.CLIMATE...
WITH NO MEASURABLE SNOW EXPECTED OVERNIGHT...BOTH BUFFALO AND
ROCHESTER APPEAR VIRTUALLY ASSURED OF A GREEN CHRISTMAS THIS YEAR.
THE ONLY AREAS THAT MAY STILL HAVE WHITE GROUND CHRISTMAS MORNING
ARE THE HILLTOPS OF THE SOUTHERN TIER AND THE HIGHER TERRAIN EAST
OF LAKE ONTARIO...BUT EVEN IN THESE AREAS JUST A MINOR COATING MAY
REMAIN.
THE WINTER OF 2011-12 HAS STARTED AT A RECORD SLOW PACE IN THE
SNOWFALL CATEGORY ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH
DECEMBER 23RD...THE CURRENT SNOW THIS SEASON OF 3.0 INCHES
(BUFFALO) AND 2.5 INCHES (ROCHESTER) ARE WELL BELOW NORMAL THUS
FAR. THERE HAVE BEEN SEVERAL YEARS THAT HAVE HAD SIMILAR STARTS
THOUGH. BELOW IS A LIST OF THE LEAST AMOUNT OF SNOW IN BOTH CITIES
IN PREVIOUS YEARS ON RECORD...MEASURED AT THE RESPECTIVE
AIRPORTS...THROUGH AND INCLUDING CHRISTMAS EVE.
BUFFALO
1 3.0 2011
2 3.1 1998
3 3.3 1931
4 3.6 1896
5 4.3 1918
...
10 6.5 1888
...
15 7.8 1891
***NORMAL THROUGH DECEMBER 24TH 29.1***
ROCHESTER
1 2.5 2011
2 2.6 1939
3 3.7 2001
4 3.8 1877
5 4.2 2006
...
10 6.2 1998
...
15 7.8 1940
***NORMAL THROUGH DECEMBER 24TH 23.5***
SNOWFALL RECORDS GO BACK TO THE WINTER OF 1884-85.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 AM EST MONDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 1 AM SUNDAY TO 4 AM EST MONDAY
FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 AM EST
MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY FROM 7 AM SUNDAY TO 4 AM EST MONDAY
FOR LOZ042>044.
SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 4 AM EST MONDAY
FOR LOZ045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/WCH
CLIMATE...THOMAS/HITCHCOCK/JJR
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1130 AM CST SAT DEC 24 2011
.DISCUSSION...UPDATED FOR 18Z TAFS.
&&
.AVIATION...IFR CEILINGS WILL BE ON TAP THROUGH SUNDAY MORNING...
ALONG WITH BREEZY NORTHWEST WINDS AS HIGH PRESSURE CONTINUES TO
FILTER INTO THE REGION. ALTHOUGH PERIODS OF LIGHT RAIN WILL STILL
BE POSSIBLE AT THE TAF SITES...CHANCES WILL MAINLY BE CONFINED TO
A COASTAL TROUGH AND LOW PRESSURE AREA OFFSHORE. THE FORECAST
CALLS FOR A GRADUAL WEAKENING OF THE TROUGH OFFSHORE ON SUNDAY AS
HIGH PRESSURE KEEPS ON COMING IN FROM THE NORTH. NORTHWEST WINDS
WILL DECREASE TO MODERATE ON SUNDAY AS RAIN CHANCES ALSO DWINDLE.
CEILINGS WILL BEGIN TO RISE TO MVFR CRITERIA SUNDAY DURING THE
DAY.
&&
.PREV DISCUSSION... /ISSUED 732 AM CST SAT DEC 24 2011/
DISCUSSION...UPDATED WINDS AND TEMPS TO REFLECT CURRENT TRENDS.
SOLID CLOUD COVER AND NORTH WINDS...ALONG WITH CONTINUED PERIODS
OF RAIN...WILL KEEP TEMPS LOWER TODAY. UPDATED WITH RUC WINDS AS
THEY INITIALIZED BEST. RUC NOT AS BULLISH ON LOW PRESSURE CENTER
OFFSHORE...PREFERRING CONTINUED TROUGHING.
PREV DISCUSSION... /ISSUED 547 AM CST SAT DEC 24 2011/
DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR THE DISCUSSION OF
THE 06Z TAF ISSUANCE.
AVIATION...LIFR AND IFR CONDITIONS WILL CONTINUE THROUGH THE DAY
AS A SURFACE COASTAL TROUGH INTERACTS WITH SOUTHWEST FLOW ALOFT.
EXPECT LIGHT RAIN SHOWERS...DRIZZLE AND FOG THROUGH OUT THE DAY AS
IN EACH SITE ESPECIALLY IN THE AFTERNOON HOUR. VISIBILITY MAY BE
REDUCED AT TIMES DUE TO PATCHY FOG AND LIGHT RAIN. NORTH WINDS
WILL INCREASE THROUGH OUT THE DAY AS WELL WITH GUSTS UP TO 30 KTS.
PREV DISCUSSION... /ISSUED 445 AM CST SAT DEC 24 2011/
SHORT TERM /TODAY THROUGH SUNDAY/...LIGHT RAIN SHOWERS OR DRIZZLE WILL
CONTINUE TO IMPACT THE RIO GRANDE VALLEY TODAY AS AN AREA OF LOW
PRESSURE CONTINUES TO MOVE EASTWARD OVER CENTRAL TEXAS AND
INTERACTS WITH A COASTAL TROUGH OVER THE REGION TODAY. EXPECT
REDUCED VISIBILITIES AND POSSIBLE AREAS OF PATCHY FOG ACROSS THE
RIO GRANDE VALLEY THROUGH THE DAY. MOST OF THE SHOWER ACTIVITY
WILL BE STRATIFORM TYPE AND WITH LITTLE ACCUMULATION EXPECTED. THE
HIGHER CHANCE OF SOME WIDESPREAD SHOWER ACTIVITY WILL BE SATURDAY
MORNING OVER THE LOWER PART OF THE RIO GRANDE VALLEY AND SHIFT TO
THE NORTHERN PART OF THE FORECAST AREA INTO THE AFTERNOON HOURS.
PRECIPITATION WILL BEGIN TO DIMINISH SATURDAY EVENING AS THE
COASTAL SURFACE TROUGH SHIFTS FURTHER EAST AND NORTHEAST.
NORTHERLY WINDS WILL BEGIN TO SHIFT TO THE NORTHWEST AS THE LOW
PRESSURE SYSTEM OVER CENTRAL TEXAS MIGRATES EASTWARD. THIS WILL
SHIFT MOST OF THE PRECIPITATION ACTIVITY OVER THE WESTERN GULF
WATERS. HIGH TEMPERATURES WILL REMAIN IN THE MID 50S ACROSS THE
RIO GRANDE VALLEY TODAY AND INTO SUNDAY. CHRISTMAS MORNING WILL
START OFF FAIRLY COOL WITH LOW TEMPERATURES IN THE MID 40S FOR
MOST OF THE RIO GRANDE VALLEY. HIGH TEMPERATURES ON CHRISTMAS
WILL NOT REBOUND MUCH LATER IN THE DAY DUE TO LINGERING CLD COVER
AND CONTINUED CAA FROM THE NW SURFACE FLOW PREVAILS.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...UPPER LOW OVER THE
TEXAS PANHANDLE SUNDAY NIGHT WILL MOVE EAST TO THE ARKLATEX REGION
LATE MONDAY AFTERNOON. CLOUDS WILL SLOWLY ERODE MONDAY MORNING AS
THE WAVE FINALLY MOVES EAST AND VERY DRY AIR FILTERS INTO DEEP
SOUTH TEXAS. THE UPPER VALLEY AND RANCHLANDS WILL BEGIN TO CLEAR
MONDAY MORNING AND THE LOWER VALLEY IN THE AFTERNOON. HIGH
TEMPERATURES MONDAY WILL BE IN THE LOW TO MID 60S. A COLD NIGHT IS
EXPECTED MONDAY NIGHT WITH TEMPERATURES IN THE UPPER 30S NORTHERN
AREAS TO THE LOWER/MID 40S NEAR THE COAST. NICE WEATHER IS
EXPECTED ACROSS THE RIO GRANDE VALLEY TUESDAY THROUGH THURSDAY AS
NORTHWEST FLOW ALOFT COMBINES WITH WEAK SURFACE FLOW AND GENERAL
WEAK HIGH PRESSURE AT THE SURFACE. SEASONAL TEMPERATURES
TUESDAY...LOWER 70S...WILL CLIMB INTO THE MID TO UPPER 70S
WEDNESDAY...AND NEAR 80 THURSDAY AND FRIDAY AS WEAK SOUTHERLY FLOW
RETURNS. DRY CONDITIONS WILL PERSIST THROUGH MOST OF THE WEEK BUT
RAIN CHANCES INCREASE LATE IN THE WEEK AS A WEAK COASTAL TROUGH
DEVELOPS OFF THE LOWER TEXAS COAST.
MARINE...
TODAY THROUGH SUNDAY...STRONG NORTH TO NORTHEAST WINDS WILL IMPACT
THE COASTAL WATERS TODAY AS AN UPPER LEVEL SYSTEM OVER CENTRAL TEXAS
MOVES SLOWLY EASTWARD TODAY AND INTERACTS WITH A COASTAL TROUGH OVER
THE REGION. THIS WILL INCREASE WAVE HEIGHTS UP TO 10 FOOT ESPECIALLY
OVER THE OFFSHORE WATERS OF THE GULF SATURDAY AFTERNOON. EXPECT SCA
CONDITIONS FOR THE NEXT 12 TO 24 HOURS INCLUDING THE BAY AREA. SHOWERS
AND PATCHY FOG WILL CONTINUE THROUGH THE DAY AND INTO SUNDAY AS THE
COASTAL TROUGH MOVES TO THE NORTHEAST. HIGH SEAS IN ADDITION TO A
HIGH TIDE THIS EVENING WILL INCREASE THE WAVE HEIGHTS EVEN MORE.
THEREFORE WILL BE ISSUING A COASTAL FLOOD ADVISORY TODAY FOR THE BAY
AREA. THESE HIGH WAVE HEIGHTS WILL CONTINUE INTO SUNDAY BUT WILL
BEGIN TO DIMINISH LATER SUNDAY EVENING AND IMPROVE INTO THE WEEK AS
THE PRESSURE GRADIENT WEAKENS SOME.
SUNDAY NIGHT THROUGH WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEED
SUNDAY NIGHT THROUGH MONDAY AFTERNOON AS THE TIGHT PRESSURE GRADIENT
OVER THE GULF OF MEXICO WILL RESULT IN ELEVATED WINDS AND SEAS
THROUGH MONDAY AFTERNOON. THE PRESSURE GRADIENT BEGINS TO RELAX
MONDAY AFTERNOON AND MARINE CONDITIONS STEADILY IMPROVE BY MONDAY
NIGHT. SURFACE HIGH PRESSURE SETTLES OVER THE NORTHERN GULF TUESDAY
AND WEDNESDAY RESULTING IN LIGHT WINDS AND LOW SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TXZ251-256-
257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
54/52
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1255 PM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EST SATURDAY...
HIGH PRESSURE WILL MOVE ACROSS THE REGION THIS AFTERNOON AND
TONIGHT. THIS HIGH WILL KEEP THE AIR CHILLY WHILE ADVECTING IN DRIER
AIR. MID DECK CLOUDS IN SOUTHEASTERN WEST VIRGINIA WITHERING AWAY
WHILE THIN CIRRUS ENTERS THE SOUTH IN ZONAL FLOW.
LINGERING CLOUD DECK ON WESTERN SLOPES KEEPING TEMPERATURES COOLER
THAN PREVIOUSLY FORECASTED. LOWERED SOME MOUNTAIN TEMPERATURES
DOWN INTO THE UPPER 30S.
PREVIOUS DISCUSSION...AS OF 935 AM EST SATURDAY...FROM THIS
MORNINGS RNK SOUNDING...MOISTURE IS CONFIDED TO A LAYER BETWEEN
5-6KFT. AS DRIER AIR ENTERS THE AREA THIS AFTERNOON...THIS
MOISTURE/CLOUD DECK WILL WITHER AWAY. COLD HIGH PRESSURE WILL
SKIRT ACROSS THE REGION THIS AFTERNOON AND TONIGHT. 85H
TEMPERATURES WARM A FEW DEGREES BUT NOT ENOUGH TO TAKE THE CHILL
OUT OF THE AIR. MOUNTAIN TEMPERATURES WILL RANGE FROM THE M/U 40S
AND L/M 50S EAST. THESE TEMPERATURES ARE AROUND 5F ABOVE
NORMAL...WESTERN SLOPES NEAR NORMAL.
PREVIOUS DISCUSSION...AS OF 635 AM EST SATURDAY...SHORT WAVE WAS
CROSSING INTO NY. AT THE SURFACE WINDS IN THE WESTERN COUNTY
WARNING AREA HAVE COME AROUND TO THE NORTHWEST. LOW CLOUDS STILL
COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE WITH WITH SOME
BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT WAVE. RADAR
CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW SHOWERS ACROSS
SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1235 PM EST SATURDAY...
A FEW WESTERN SLOPE OBSERVATION SITES HANGING ON TO MVFR CEILING
LATE THIS MORNING PARTICULARLY BLF. DRY HIGH PRESSURE WILL CONTINUE
TO ERODE THESE CLOUDS THROUGH THE AFTERNOON. ALL SITES WILL HAVE VFR
CONDITIONS TONIGHT INTO SUNDAY. ALONG THE VA/NC BORDER SOUTH...SOME
HIGH CLOUDS MAY INVADE THE AREA IN ZONAL FLOW.
FOLLOWING A DRY FRONTAL PASSAGE SUNDAY NIGHT...A SURFACE RIDGE
WILL BUILD IN ON MONDAY. VFR CONDITIONS EXPECTED INTO MONDAY
NIGHT...THEN LOWER AS A DISTURBANCE TRACKS WEST OF THE AREA AND INTO
THE OHIO VALLEY TUESDAY. VFR CONDITIONS WILL RETURN TO THE AREA
WEDNESDAY AND MAY LAST FOR THE REST OF THE YEAR.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS/RCS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS SPOKANE WA
953 AM PST Sat Dec 24 2011
.SYNOPSIS...A weak storm system Saturday will bring the potential
for light wintry precipitation to the region. Stronger and wetter
storms will begin to impact the region Sunday and continue through
next week. The storm on Monday night and Tuesday will bring snow
to the lower elevations. The remainder of the week should see
mountain snow and valley rain with occasionally windy conditions.
&&
.DISCUSSION...
Update for today: Radar imagery across the area is fairly
impressive with 25-30 dBz echoes extending from near Odessa to
almost Cheney this morning as well as a more stratiform band of
precipitation sinking southward from the Canadian border with
widespread light snow from Sandpoint to Republic and all points
northward. The first set of activity is expected to wane through
the day, while the second precipitation band is likely to meander
through the northern zones of the forecast area for most of the
day. The result will be periods of flurries and snow pellets from
Lincoln County toward Kootenai County through the early afternoon,
while the northern zones see accumulating snowfall.
The models continue to struggle with precipitation across the
heart of the CWA. Previous versions of the NAM and HRRR indicated
widespread threats of light freezing rain and drizzle from Moses
Lake across the Waterville Plateau and toward the Spokane area.
Early indications are that this was overdone, with no locations
reporting any freezing precipitation as of this time and only snow
pellets really being noticed around Spokane. The 12z KOTX sounding
did show a very limited and weak warm layer aloft, however the wet
bulb profile on the sounding was well below freezing.
Additionally, time height sections from the NAM across the valleys
from the east slopes all the way to Spokane do indicate the best
lift generally in the -5 to -10C layer, which generally should not
be supportive of snowfall. However, with a dry layer below the
lifted layer, these time height sections would also fail to be
indicative of freezing drizzle. Given the convective elements on
radar and that the main overcast deck is still relatively high, it
seems that rimed snow pellets or even a few sleet pellets may be
the preferred precipitation mode for the activity that is moving
from Lincoln into Spokane County this morning. This activity
should lift northeast and likely dissipate as the mid levels
continue to dry through the day.
Farther north, model 295-305K layer isentropic ascent continues
through the day with decent, albeit decreasing, saturation of the
lifted layer by late in the day. A dichotomy of QPF values exists
with the NAM being significantly heavier than the GFS. Inspection
of radar trends favors the values of the NAM and the SREF was used
to smooth out the heavier bullseyes of the NAM across the northern
zones. The result was generally an inch or two of snowfall in many
spots across the northern half of Stevens and Pend Oreille
Counties as well as most of Bonner and Boundary Counties in Idaho.
/Fries
&&
.AVIATION...
18z TAFs: Any area of snow pellets is likely to affect KGEG
through KCOE this morning into early afternoon with CIGs falling a
bit as it translates through the area. Otherwise, CIGs by late
afternoon should be improving at most locations with a period of
VFR conditions likely by evening. Depending on clearing, fog may
redevelop overnight into Sunday morning, with the most likely
locations being KGEG, KSFF, and KCOE. This would result in
deteriorated conditions through the morning hours. Confidence is
not high in the development of fog overnight. /Fries
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 32 26 34 26 34 29 / 10 10 30 20 10 80
Coeur d`Alene 33 27 35 26 37 29 / 20 10 40 40 10 80
Pullman 37 30 39 29 38 32 / 10 0 20 40 10 70
Lewiston 40 32 44 30 43 36 / 0 0 10 20 10 30
Colville 29 25 34 21 34 28 / 60 10 40 30 20 90
Sandpoint 32 25 35 25 34 29 / 70 10 40 40 20 80
Kellogg 34 30 36 27 34 28 / 30 10 40 60 30 80
Moses Lake 32 24 35 23 35 27 / 10 0 20 10 10 40
Wenatchee 31 27 37 25 32 27 / 10 10 20 10 10 50
Omak 30 25 33 21 32 25 / 20 10 30 10 10 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
247 PM CST SAT DEC 24 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
247 PM CST SAT DEC 24 2011
TWAS THE NIGHT BEFORE CHRISTMAS WHEN ALL THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY...A TROUGH WAS STIRRING THAT WILL BRING
CLOUDS TO COVER THE GALLEY.
SPLIT UPPER LEVEL FLOW WILL KEEP THE REGION DRY THROUGH THE
HOLIDAY WEEKEND INTO EARLY NEXT WEEK WITH ABOVE NORMAL
TEMPERATURES ON TAP.
SUNNY SKIES AND LOW LEVEL WARM AIR ADVECTION BROUGHT TEMPERATURES
INTO THE LOW 40S ACROSS MUCH OF THE REGION AND IN TURN MELTED AWAY
THE LITTLE SNOW THAT WAS LEFT FROM THIS PAST WEEK. A MID LEVEL
TROUGH CURRENTLY IN THE CANADIAN ROCKIES WILL DIVE DOWN THROUGH
THE NORTHWESTERLY FLOW TOWARD THE NORTHERN GREAT LAKES TONIGHT.
THE SOUTHERN EXTENT OF THIS TROUGH WILL PROVIDE A QUICK SHOT OF
MID LEVEL QG FORCING TO THE REGION...BUT DOES NOT APPEAR TO BE
DEEP ENOUGH...BASED ON 24.12Z NAM/GFS AND 24.18Z RUC
SOUNDINGS...TO OVERCOME THE SURFACE TO 700MB DRY LAYER TO PRODUCE
ANY PRECIPITATION. THE 24.18Z RUC SHOWS 600-400MB RH TO BE ON THE
INCREASE TOWARD ROCHESTER THIS EVENING WITH THESE HIGH CLOUDS
LINGERING THROUGH OUT THE REGION OVERNIGHT. WITH CONTINUED LOW
LEVEL WARM AIR ADVECTION GOING AND THE HIGH LEVEL CLOUD COVER
TONIGHT...LOW TEMPERATURES WILL NOT DROP OFF MUCH BELOW FREEZING.
AS THIS FEATURE PASSES THROUGH...A LOW LEVEL COLD FRONT WILL MOVE
THROUGH TOWARD DAYBREAK CHRISTMAS MORNING WITH 850MB TEMPERATURES
DROPPING FROM AROUND 1C DOWN TO -3C. THUS...HIGHS FOR CHRISTMAS
WILL BE A LITTLE LOWER THAN WHAT THEY WERE TODAY BUT STILL WELL
ABOVE NORMAL. OVERALL...IT WILL BE AN IDEAL TRAVEL DAY FOR THE
HOLIDAY WITH SUNNY SKIES AND NORTHWEST WINDS AROUND 10KTS.
A RIDGE AXIS WILL THEN MOVE THROUGH THE REGION ON SUNDAY NIGHT
WITH WARMER LOW LEVEL AIR ADVECTING BACK IN ON MONDAY ON THE BACK
SIDE OF THE RIDGE. THIS WILL LIKELY BE THE WARMEST DAY OVER THE
NEXT 7 DAYS WITH HIGHS JUMPING BACK INTO THE LOW 40S WITH NO SNOW
COVER LEFT TO RESTRICT THESE TEMPERATURES. WINDS WILL BE FAIRLY
GUSTY AHEAD OF A COLD FRONT WITH A TIGHTENING PRESSURE GRADIENT
SETTING UP. SUSTAINED WINDS OF AROUND 20KTS LOOK
POSSIBLE...PARTICULARLY AT ROCHESTER...WITH 24.12Z NAM AND GFS
SUGGESTING THAT MOMENTUM TRANSFER WILL BRING SOME 30KT GUSTS DOWN
TO THE SURFACE.
GOING INTO MONDAY NIGHT...THE 24.12Z NAM IS AN OUTLIER WITH ITS
SOLUTION OF BRINGING SOME PRECIPITATION CLOSE TO THE REGION INTO
NORTHERN ILLINOIS AND SOUTHERN WISCONSIN. IT BRINGS THE CUT OFF
LOW IN SOUTHERN NEW MEXICO UP TOWARD THE GREAT LAKES WHILE THE
OTHER MODELS SHOW THE LOW STAYING OFF TO THE SOUTH. THE PREFERRED
SOLUTIONS FROM HPC ON THIS FEATURE ARE WITH THE 24.12Z
UKMET/ECMWF/GEM WHICH ALL KEEP THE LOW WELL TO THE SOUTH AND DRY
HERE.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
247 PM CST SAT DEC 24 2011
CONFIDENCE DROPS OFF QUITE A BIT GOING INTO THE EXTENDED PERIOD
WITH AN ACTIVE NORTHWESTERLY FLOW SETTING UP ALOFT. THE 24.12Z GEM
IS THE FIRST TO INTRODUCE SOME PRECIPITATION ON WEDNESDAY WITH A
TROUGH AND SURFACE LOW COMING THROUGH DURING THE DAY. THIS
SOLUTION WOULD BRING A LIGHT ACCUMULATING SNOW ON WEDNESDAY...BUT
THE 24.12Z GFS AND ECMWF ARE SLOWER AND DEEPER WITH THIS TROUGH
AND BRING IT IN WEDNESDAY NIGHT INTO THURSDAY. HAVE GONE WITH THE
GFS/ECMWF TIMING AT THIS POINT. AFTER A BRIEF BREAK AS A RIDGE
AXIS COMES THROUGH...ANOTHER TROUGH WILL DROP DOWN INTO THE REGION
WITH A SURFACE LOW FORMING OVER THE DAKOTAS AND TRACKING EAST. THE
24.12Z ECMWF IS FURTHER NORTH WITH THIS TRACK WHILE THE 24.12Z GFS
IS MUCH MORE AMPLIFIED AND DROPS IT FURTHER SOUTH. HAVE KEPT SOME
SMALL CHANCES FOR PRECIPITATION IN THERE GOING INTO NEXT WEEKEND.
TEMPERATURE WISE IT LOOKS FAIRLY SEASONAL WITH NO BIG WARM UPS OR
COLD SPELLS DESPITE BEING IN THE NORTHWESTERLY FLOW.
&&
.AVIATION...THROUGH 18Z SUNDAY
1138 AM CST SAT DEC 24 2011
A TROUGH OF LOW PRESSURE WILL MOVE RAPIDLY SOUTHWEST THROUGH THE
FORECAST AREA TONIGHT. THIS SYSTEM WILL PRODUCE MID AND HIGH
CLOUDS ACROSS THE AREA TONIGHT. AN 8-12K DECK OF CLOUDS WILL MOVE
INTO KRST AROUND 25.02Z AND KLSE AROUND 25.03Z. THESE CLOUDS WILL
THEN MOVE OUT OF THE AREA BETWEEN 25.10Z AND 25.13Z. THE WINDS
WILL SHIFT FROM SOUTHWEST TO WEST AT 25.10Z AT KRST AND 25.11Z AT
KLSE...AND THEN SHIFT TO NORTHWEST AROUND 25.15Z. SUSTAINED WINDS
WILL BE IN THE 15 TO 20 KNOT RANGE TONIGHT AND CHRISTMAS MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CST SAT DEC 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1107 AM CST SAT DEC 24 2011
.AVIATION/18Z TAFS/...VFR SKC INTO THIS EVENING. MID/HIGH CLOUDS
STREAMING SE FROM THE DAKOTAS WITH UPPER JET CORE AND 18 UNIT
VORTICITY MAXIMUM. BUFKIT SOUNDINGS AND MOS SHOW MID LEVEL
MOISTURE INCREASING TONIGHT INTO EARLY SUNDAY MORNING THOUGH LOW
LEVELS REMAIN PARCHED. GUSTY NW WINDS WITH STRONG SUBSIDENCE BY
SUN AFTERNOON AS SHORTWAVE SHIFTS TO THE EAST.
PC
&&
.PREV DISCUSSION... /ISSUED 338 AM CST SAT DEC 24 2011/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
CLOUDS ASSOCIATED WITH THE VORT MAX CROSSING THE GREAT LAKES REGION
ARE EXITING THE EASTERN FCST AREA EARLY THIS MORNING. WARM AIR
ADVECTION UNDERWAY...AS YESTERDAY/S MAX TEMPS WERE REACHED AT
MIDNIGHT. NEXT SHORTWAVE/VORT MAX APPARENT ON WATER VAPOR IMAGERY
OVER THE DAKOTAS AT 0330Z. NO CLOUDS ASSOCIATED WITH THIS
DISTURBANCE PER IR SATELLITE...SO FEEL COMFORTABLE WITH NO CHANCES
FOR FLURRIES OR EVEN CLOUDS THIS AFTERNOON AS THE WAVE PASSES
THROUGH.
MODEL SNDGS SHOW POTENTIAL FOR MIXING UP TO 950 OR EVEN 925MB THIS
AFTERNOON...SO LOWERED DEWPOINT TEMPS ACCORDINGLY. RUC AND GFS SHOW
WINDS UP TO AROUND 20 KT MIXING DOWN TO THE SFC AS WELL...WITH THE
NAM A BIT LIGHTER. BUMPED UP WIND GUSTS TO THE 18-20 KNOT RANGE THIS
AFTERNOON.
PRESSURE GRADIENT WILL CONTINUE TO INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM TRACKS INTO ONTARIO CANADA. DESPITE SFC
INVERSION...WINDS SHOULD BE ELEVATED THROUGH THE NIGHT. TEMPS NOT
EXPECTED TO DROP MUCH SINCE THERE IS NO SNOW COVER AND CONTINUOUS
WARM AIR ADVECTION AND SOME SHALLOW MIXING. THE EXCEPTION MAY BE
LONE ROCK IF THEY DECOUPLE IN THE RIVER VALLEY.
CHRISTMAS DAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
MODELS DROP A DECENT SHORTWAVE THROUGH SOUTHERN WISCONSIN CHRISTMAS
MORNING. STILL KEEPING AN EYE ON THIS SYSTEM...AS THERE IS SOME
FORCING...BUT MODELS ACTUALLY TRENDING DRIER OVER THE LAST 24 HOURS.
CONCERN HAS BEEN THAT THIS MAY END UP LIKE A COUPLE OF THE PREVIOUS
WAVES THAT MOVED THROUGH...WHERE MODELS ARE DRY FOR DAYS LEADING UP
TO THE ARRIVAL OF THE SYSTEM...THEN SATURATE THINGS LATE IN THE
GAME. SEEMING LIKE THIS ONE WILL ACTUALLY STAY DRY AS ADVERTISED
THOUGH WITH NO SIGNS OF MODELS TRENDING WETTER.
STILL EXPECTING BREEZY WEST TO NORTHWEST WINDS CHRISTMAS AFTERNOON.
COLD ADVECTION ENSUES BEHIND THE WAVE...WITH THE WINDS PICKING UP
LATE MORNING INTO THE AFTERNOON. COULD SEE GUSTS OF 30-35 MPH IF
THINGS STAY ON TRACK. HIGHS EXPECTED TO BE IN THE MID TO UPPER 30S
AGAIN...THE COLDER TEMPS IN THE NORTH WHERE THE THIN SNOWPACK WILL
PROBABLY STILL LINGER.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
WINDS QUICKLY RETURN TO OUT OF THE SOUTHWEST FOR MONDAY...BECOMING
BREEZY AGAIN LATE MORNING INTO THE AFTERNOON...THOUGH MAYBE A BIT
LIGHTER THAN ON CHRISTMAS. WITH THESE WINDS...A DECENT AMOUNT OF
SUN...AND WARMING ALOFT...SHOULD HIT 40 PRETTY EASILY...ESPECIALLY
IN LOCATIONS WITH NO SNOW COVER.
KEPT SOME LOW POPS IN THE FORECAST MONDAY NIGHT...AS MODELS BRING
ANOTHER SHORTWAVE THROUGH THE AREA. THE WILL WAVE DRAW UP A
DEEPENING SFC LOW...BUT THAT IS EXPECTED TO PASS BY WELL TO THE
SOUTHEAST. MAIN THREAT FOR PRECIP ASSOCIATED WITH A BAND OF MID
LEVEL FRONTOGENESIS AND THETA-E ADVECTION IN THE EVENING...AND SOME
ISENTROPIC LIFT WITH THE NORTHWEST FRINGE OF THE DEFORMATION PRECIP
AS THE LOW SLIDES BY LATER IN THE NIGHT. DEEP MOISTURE DEFINITELY AN
ISSUE...SO JUST KEPT POPS ON THE LIGHT SIDE. NEWEST ECMWF SUGGESTING
PRECIP WILL GENERALLY MISS SOUTHERN WISCONSIN COMPLETELY TO THE
SOUTH AND EAST.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING THE WAVE TRAIN WILL CONTINUE THROUGH THE LATTER HALF
OF THE WORK WEEK. ENOUGH OVERLAP OF DECENT MOISTURE/LIFT IN MODELS
FOR SLIGHT CHANCE POPS THURSDAY AND FRIDAY. THE GFS AND ECMWF
DIVERGE BY FRIDAY THOUGH...WITH THE ECMWF MAINTAINING A STRONG SFC
LOW MOVING ACROSS NORTHERN MINNESOTA...WHILE THE GFS SLIDES THE LOW
SOUTHEAST TOWARD WISCONSIN. MAIN DIFFERENCE IS THAT THE ECMWF IS
MUCH WARMER...SUGGESTING MID 40S TO NEAR 50 FRIDAY...WHILE THE GFS
WOULD BE MAINLY 30S. GFS ALSO BRINGS A BIT MORE PRECIP...WITH BETTER
MOISTURE AND DYNAMICS TOWARD THE CENTER OF THE SYSTEM PUSHING INTO
THE FORECAST AREA. OVERALL...GENERALLY SPLIT THE DIFFERENCE BETWEEN
THE GFS AND ECMWF FOR NOW...WITH NO GOOD REASON TO GO ONE WAY OR THE
OTHER. EITHER WAY...LOOKS LIKE ABOVE NORMAL TEMPERATURES WILL
PROBABLY CONTINUE.
AVIATION/12Z TAFS/...WIND GUST POTENTIAL IN THE 20 KNOT RANGE THIS
AFTERNOON WITH SOME DAYTIME MIXING. VFR THROUGH THE PERIOD. CLEAR
SKIES EXPECTED TODAY...THEN INCREASING HIGH/MID CLOUDS TONIGHT.
WINDS WILL ALSO INCREASE OVER THE PERIOD AND BECOME GUSTY ONCE AGAIN
ON SUNDAY WITH A PASSING UPPER LEVEL DISTURBANCE.
MARINE...THERE IS A POSSIBILITY OF SOME WIND GUSTS UP TO 22 KNOTS
THIS AFTERNOON WITH DAYTIME MIXING...BUT CONFIDENCE IS LOW...SO NO
SMALL CRAFT ADVY ISSUED FOR THIS TIME PERIOD. HOWEVER...A LOW
PRESSURE SYSTEM CROSSING SOUTHERN CANADA THROUGH SUNDAY WILL BRING
INCREASING WINDS TO SOUTHERN LAKE MICHIGAN. SOUTHWESTERLY WIND GUSTS
EXPECTED TO REACH SMALL CRAFT ADVY CRITERIA OVERNIGHT SATURDAY NIGHT
THROUGH SUNDAY AFTERNOON. SMALL CRAFT ADVY ISSUED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST SUNDAY
FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MRC
SUNDAY THROUGH FRIDAY...DDV