Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/17/11
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
952 PM EST FRI DEC 16 2011
.SYNOPSIS...
HIGH PRESSURE BUILDING OVER THE AREA HAS PUSHED A FRONTAL SYSTEM
WELL TO OUR SOUTH. A WAVE OF LOW PRESSURE WILL MOVE EAST ALONG THE
FRONT OVERNIGHT AND LIKELY BRING SOME LIGHT RAIN OR SNOW TO DELMARVA
AND FAR SOUTHERN NEW JERSEY. HIGH PRESSURE WILL THEN BRING FAIR
WEATHER FOR THE WEEKEND AND EARLY NEXT WEEK WITH A WARMING TREND
AFTER SUNDAY. LOW PRESSURE APPROACHING FROM THE SOUTHWEST COULD
BRING MORE RAIN AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...MADE SOME ADJUSTMENTS ACROSS THE SOUTHERN ZONES THIS
EVENING WITH BOTH THE 18Z MODELS AND RADAR SHOWING LESS PRECIP.
THAT SAID, SOME LIKELY POPS REMAIN, DOWN FROM CATEGORICAL.
SOUNDINGS STILL SHOW THE POSSIBLY OF AND RAIN MIXING WITH SOME
SNOW, BUT THIS TOO IS LOOKING LESS LIKELY WITH MAINLY LIGHT
PRECIPITATION.
EARLIER DISCUSSION...HIGH POPS FOR MID LVL FGEN GENERATED SNOW
MELTING IN THE BL OVER S DE TO CAPE MAP NJ BETWEEN 23Z-08Z. THE
12Z/16 EC WHICH IS RELATIVELY DRY AT 950 AND 850 MB IS STILL
OFFERING QPF WHERE WE HAVE IT IN THE GRIDS FOR 3 SUCCESSIVE 6 HR
PERIODS. THIS PLUS THE QPF EVALUATION BELOW SUPPORT THE HIGH PROB
LOW QPF EVENT FAR S EDGE OF THE FA FOR A TIME TONIGHT.
18Z 6 HR PCPN EVALUATION FROM 12Z/16 MODELS: THE UKMET APPEARS
TO BE TOO SLOW AND TOO FAR SOUTH AT 18Z WITH ITS MASS FIELDS OF RH.
THEREFORE IT WAS NOT A SIGNIFICANT CONSIDERATION IN THE AFTERNOON
FCST. NAM WAS TOO SLOW AND TOO FAR SOUTH AS WELL. 18Z NAM LOOKS
BETTER AND CONTINUES THE QPF TREND OF ITS PREDECESSOR TO VCNTY
KDOV-KWWD LINE TONIGHT.
15Z SREF HAS COME AROUND TO THE FURTHER N SOLN...USUALLY HANGING ON
THE COATTAILS OF ITS 12Z NAM RUN. SO...THE 12Z GFS OP AND 12Z/16 EC
COMBO LOOK BEST FOR RAPID EXTRAPOLATION ENEWD WITH CONTD SUPPORT
FROM THE 18Z NAM AND 15Z SREF. THE 12Z GEFS PROB FOR .05 WAS VERY
GOOD AT 18Z AND THE 98 PCT PROB FOR .05 IN S DE ENDING AT 06Z LOOKS
LIKE A VERY GOOD FCST ATTM. 15Z SREF .01 PROB NOW UP TO 70 PCT IN S
DE.
SO WHILE A COUPLE OF 12Z/16 NON NCEP MODELS APPEAR TOO SLOW AND
TOO FAR SOUTH ... CONFIDENCE FOR A CATEGORICAL EVENT IS A LITTLE
LESS THAN IDEAL BUT STILL ABOVE AVG FOR S DE AND POSSIBLY CAPE MAY
NJ.
MESOSCALE MODELS: 12Z SPC WRF IS A DECENT FIT FOR REALITY AT 18Z AND
A FCST WHICH IS FASTER AND FURTHER N THAN ITS 00Z VSN. STILL LOOKS A
LITTLE SLOW AT 20Z! 17Z HRRR LOOKS SLOW AND LIGHT IN SW VA BUT EVEN
IT SPREADS QPF INTO S DE BY 03Z!
FGEN ON THE 12Z GFS LOOKS DECENT IN MID ATLC STATES S AND SE OF PHL
TONIGHT.
INITIALLY RAIN ONSET LATE THIS AFTN IN FAR SW DEL BUT COLUMN WET
BULBING DURING HEAVIER PCPN TONIGHT SHOULD PERMIT A CHG TO MIXED OR
ALL SNOW FOR A TIME WHERE IT HEAVIEST...ESP FAR S DE. EXCT DENDRITIC
GROWTH EARLY ON WITH UP TO 20MB LIFT IN THE SATURATED IDEAL DENDRITE
GROWTH ZONE BUT ALAS...BL TOO WARM IN S DE ON THE EARLY SIDE OF THE
PCPN EVENT.
STILL WONT BE SURPRISED AT ISOLATED .5 INCH SNOW ACC IN S DE BETWEEN
03Z-08Z. SNOW TOOLS OFFER .2.
BASED ON HOW DRY THE AIRMASS LOOKS TO BE...NORTH OF A KILG-KACY LINE
THE FORECAST WILL STILL BE DRY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SATURDAY...MIXED SUN AND CLOUDS WITH AN INCREASINGLY GUSTY NW WIND
TO 20 OR 25 MPH SEASONABLY COOL TEMPS AS HIGH PRES SLOWLY EDGES INTO
THE REGION. DECENT LOW LVL LAPSE RATES FOR MOMENTUM TRANSFER...NOT
THAT MUCH WIND IN THE COLUMN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THIS FCST PERIOD STARTS OUT WITH AN UPPER TROF OVER THE EASTERN US
BUT THE TROF AXIS SHIFTS OFFSHORE BY SUNDAY NIGHT. A SHRTWV DIGGING
SEWD FROM THE WERN GRTLKS ON SUNDAY WILL BRING SOME CLOUDINESS BUT
DOESN`T HAVE ENOUGH MOISTURE TO WORK WITH TO CAUSE ANY SGFNT PRECIP.
THE COLDEST TEMPS...JUST SLIGHTLY BELOW NORMAL...WILL BE ON SUNDAY.
THEN WARMER AIR ADVECTS IN FROM WEST FOR MONDAY.
CONDITIONS SHOULD BE DRY FOR EARLY NEXT WEEK, BUT THEN POPS INCREASE
TOWARD MID-WEEK AS THE UPPER LOW NOW OVER SOCAL IS KICKED OUT AND
THE ASSOCD TROF MOVES INTO THE ERN U.S. THE 12Z RUNS OF THE GFS AND
ECMWF ARE ACTUALLY IN RATHER GOOD AGREEMENT ON THE TIMING OF THIS
SYSTEM MOVG ACROSS THE MID-ATLANTIC ON WED. WE HAVE SLGT CHC POPS
FOR TUES AS A COLD FRONT PUSHES S ACROSS THE ARRE AND THEN STALL.
HWVR...THE BEST LIKELIHOOD IS TUES NIGHT INTO WED AS SFC LOW PRES
TRACKS FROM THE MID MISS VLY NEWD INTO THE LOWER GRTLKS. TEMPS
SHOULD BE WARM ENOUGH DURG THIS TIME FOR ALL RAIN...EXCEPT PERHAPS
SOME MIXED PRECIP AT THE BEGINNING OR END OVER NEPA/NWNJ.
THE GFS AND ECMWF DIFFER CONSIDERABLE ON THE SYSTEM WHICH COULD
AFFECT US LATE NEXT WEEK...WITH THE ECMWF KEEPING MOST PRECIP AWAY
TO OUR SOUTH. WE FOLLOW THE HPC GUIDANCE FOR FRIDAY WHICH HAS CHC
POPS OVER OUR AREA. TEMPS AGAIN LOOK TOO WARM FOR SNOW WITH A
CONTINUING PATTERN OF ABOVE NORMAL WARMTH.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
FOR TONIGHT...VFR CIGS AOA 4000 FT. LIGHT WEST TO NORTHWEST WIND.
NO PRECIPITATION FORECAST AT THE TERMINALS, BUT SOUTHERN DELAWARE SHOULD
SEE SNOW ALOFT CHANGE TO RAIN OR MIXED SNOW/RAIN AT THE SURFACE. NOT
IMPOSSIBLE TO SEE AN HOUR OF 1 MILE WET SNOW VCNTY KGED?
SATURDAY...VFR. SCT-BKN CLDS AOA 5000 FT EXPECTED. NW WIND SHOULD
GRADUALLY INCREASE WITH GUSTS IN THE 15 TO 20 KT RANGE.
OUTLOOK...
MAINLY VFR FLYING CONDITIONS EXPECTED SATUDAY NIGHT THROUGH
TUESDAY. CONDS WILL LIKELY BECOME WORSE TUESDAY NIGHT INTO
WEDNESDAY AS A LOW PRESSURE SYSTEM BRINGS RAIN INTO THE AREA.
&&
.MARINE...
A WEAK SURFACE LOW WILL PASS WELL SOUTH OF THE WATERS TONIGHT.
THE GRADIENT BEHIND THE LOW WILL NOT INCREASE UNTIL LATE TONIGHT.
NW WINDS ON SATURDAY MAY INCREASE TO SCA CRITERIA...ESP DE WATERS
AND ESP SAT AFTN...BUT FOR NOW MULTI MODEL TOOLS DO NOT OFFER MUCH
SUPPORT FOR AN SCA.
OUTLOOK...
NW WINDS SATURDAY NIGHT WILL DIMINISH AS HIGH PRES MOVES OVER THE
AREA...THEN WILL BECOME SW AND INCREASE ON MONDAY AS THE HIGH
MOVES OFFSHORE. SCA CONDS ARE POSSIBLE AROUND DTHIS TIME.
A FRONTAL SYSTEM WILL CROSS THE AREA TUESDAY BUT ASSOCD WINDS
SHOULD BE RELATIVELY LIGHT. WINDS SHOULD INCR AGAIN FROM THE SW
AND THEN SHIFT TO NW WED NIGHT AS LOW PRES AND ASSOCD CDFNT MOVE
ACROSS THE AERA. SCA CONDS ARE AGAIN POSSIBLE AT THIS TIME.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AMC
NEAR TERM...DRAG/KRUZDLO
SHORT TERM...DRAG
LONG TERM...AMC
AVIATION...DRAG/KRUZDLO
MARINE...AMC/DRAG/KRUZDLO
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
624 PM EST FRI DEC 16 2011
.SYNOPSIS...
HIGH PRESSURE BUILDING OVER THE AREA HAS PUSHED A FRONTAL SYSTEM
WELL TO OUR SOUTH. A WAVE OF LOW PRESSURE WILL MOVE EAST ALONG THE
FRONT OVERNIGHT AND LIKELY BRING SOME LIGHT RAIN OR SNOW TO DELMARVA
AND FAR SOUTHERN NEW JERSEY. HIGH PRESSURE WILL THEN BRING FAIR
WEATHER FOR THE WEEKEND AND EARLY NEXT WEEK WITH A WARMING TREND
AFTER SUNDAY. LOW PRESSURE APPROACHING FROM THE SOUTHWEST COULD
BRING MORE RAIN AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIGH POPS FOR MID LVL FGEN GENERATED SNOW MELTING IN THE BL OVER S
DE TO CAPE MAP NJ BETWEEN 23Z-08Z. THE 12Z/16 EC WHICH IS RELATIVELY
DRY AT 950 AND 850 MB IS STILL OFFERING QPF WHERE WE HAVE IT IN THE
GRIDS FOR 3 SUCCESSIVE 6 HR PERIODS. THIS PLUS THE QPF EVALUATION
BELOW SUPPORT THE HIGH PROB LOW QPF EVENT FAR S EDGE OF THE FA FOR A
TIME TONIGHT.
18Z 6 HR PCPN EVALUATION FROM 12Z/16 MODELS: THE UKMET APPEARS
TO BE TOO SLOW AND TOO FAR SOUTH AT 18Z WITH ITS MASS FIELDS OF RH.
THEREFORE IT WAS NOT A SIGNIFICANT CONSIDERATION IN THE AFTERNOON
FCST. NAM WAS TOO SLOW AND TOO FAR SOUTH AS WELL. 18Z NAM LOOKS
BETTER AND CONTINUES THE QPF TREND OF ITS PREDECESSOR TO VCNTY
KDOV-KWWD LINE TONIGHT.
15Z SREF HAS COME AROUND TO THE FURTHER N SOLN...USUALLY HANGING ON
THE COATTAILS OF ITS 12Z NAM RUN. SO...THE 12Z GFS OP AND 12Z/16 EC
COMBO LOOK BEST FOR RAPID EXTRAPOLATION ENEWD WITH CONTD SUPPORT
FROM THE 18Z NAM AND 15Z SREF. THE 12Z GEFS PROB FOR .05 WAS VERY
GOOD AT 18Z AND THE 98 PCT PROB FOR .05 IN S DE ENDING AT 06Z LOOKS
LIKE A VERY GOOD FCST ATTM. 15Z SREF .01 PROB NOW UP TO 70 PCT IN S
DE.
SO WHILE A COUPLE OF 12Z/16 NON NCEP MODELS APPEAR TOO SLOW AND
TOO FAR SOUTH ... CONFIDENCE FOR A CATEGORICAL EVENT IS A LITTLE
LESS THAN IDEAL BUT STILL ABOVE AVG FOR S DE AND POSSIBLY CAPE MAY
NJ.
MESOSCALE MODELS: 12Z SPC WRF IS A DECENT FIT FOR REALITY AT 18Z AND
A FCST WHICH IS FASTER AND FURTHER N THAN ITS 00Z VSN. STILL LOOKS A
LITTLE SLOW AT 20Z! 17Z HRRR LOOKS SLOW AND LIGHT IN SW VA BUT EVEN
IT SPREADS QPF INTO S DE BY 03Z!
FGEN ON THE 12Z GFS LOOKS DECENT IN MID ATLC STATES S AND SE OF PHL
TONIGHT.
INITIALLY RAIN ONSET LATE THIS AFTN IN FAR SW DEL BUT COLUMN WET
BULBING DURING HEAVIER PCPN TONIGHT SHOULD PERMIT A CHG TO MIXED OR
ALL SNOW FOR A TIME WHERE IT HEAVIEST...ESP FAR S DE. EXCT DENDRITIC
GROWTH EARLY ON WITH UP TO 20MB LIFT IN THE SATURATED IDEAL DENDRITE
GROWTH ZONE BUT ALAS...BL TOO WARM IN S DE ON THE EARLY SIDE OF THE
PCPN EVENT.
STILL WONT BE SURPRISED AT ISOLATED .5 INCH SNOW ACC IN S DE BETWEEN
03Z-08Z. SNOW TOOLS OFFER .2.
BASED ON HOW DRY THE AIRMASS LOOKS TO BE...NORTH OF A KILG-KACY LINE
THE FORECAST WILL STILL BE DRY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SATURDAY...MIXED SUN AND CLOUDS WITH AN INCREASINGLY GUSTY NW WIND
TO 20 OR 25 MPH SEASONABLY COOL TEMPS AS HIGH PRES SLOWLY EDGES INTO
THE REGION. DECENT LOW LVL LAPSE RATES FOR MOMENTUM TRANSFER...NOT
THAT MUCH WIND IN THE COLUMN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THIS FCST PERIOD STARTS OUT WITH AN UPPER TROF OVER THE EASTERN US
BUT THE TROF AXIS SHIFTS OFFSHORE BY SUNDAY NIGHT. A SHRTWV DIGGING
SEWD FROM THE WERN GRTLKS ON SUNDAY WILL BRING SOME CLOUDINESS BUT
DOESN`T HAVE ENOUGH MOISTURE TO WORK WITH TO CAUSE ANY SGFNT PRECIP.
THE COLDEST TEMPS...JUST SLIGHTLY BELOW NORMAL...WILL BE ON SUNDAY.
THEN WARMER AIR ADVECTS IN FROM WEST FOR MONDAY.
CONDITIONS SHOULD BE DRY FOR EARLY NEXT WEEK, BUT THEN POPS INCREASE
TOWARD MID-WEEK AS THE UPPER LOW NOW OVER SOCAL IS KICKED OUT AND
THE ASSOCD TROF MOVES INTO THE ERN U.S. THE 12Z RUNS OF THE GFS AND
ECMWF ARE ACTUALLY IN RATHER GOOD AGREEMENT ON THE TIMING OF THIS
SYSTEM MOVG ACROSS THE MID-ATLANTIC ON WED. WE HAVE SLGT CHC POPS
FOR TUES AS A COLD FRONT PUSHES S ACROSS THE ARRE AND THEN STALL.
HWVR...THE BEST LIKELIHOOD IS TUES NIGHT INTO WED AS SFC LOW PRES
TRACKS FROM THE MID MISS VLY NEWD INTO THE LOWER GRTLKS. TEMPS
SHOULD BE WARM ENOUGH DURG THIS TIME FOR ALL RAIN...EXCEPT PERHAPS
SOME MIXED PRECIP AT THE BEGINNING OR END OVER NEPA/NWNJ.
THE GFS AND ECMWF DIFFER CONSIDERABLE ON THE SYSTEM WHICH COULD
AFFECT US LATE NEXT WEEK...WITH THE ECMWF KEEPING MOST PRECIP AWAY
TO OUR SOUTH. WE FOLLOW THE HPC GUIDANCE FOR FRIDAY WHICH HAS CHC
POPS OVER OUR AREA. TEMPS AGAIN LOOK TOO WARM FOR SNOW WITH A
CONTINUING PATTERN OF ABOVE NORMAL WARMTH.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
FOR TONIGHT...VFR CIGS AOA 4000 FT. LIGHT WEST TO NORTHWEST WIND.
NO PRECIPITATION FORECAST AT THE TERMINALS, BUT SOUTHERN DELAWARE SHOULD
SEE SNOW ALOFT CHANGE TO RAIN OR MIXED SNOW/RAIN AT THE SURFACE. NOT
IMPOSSIBLE TO SEE AN HOUR OF 1 MILE WET SNOW VCNTY KGED?
SATURDAY...VFR. SCT-BKN CLDS AOA 5000 FT EXPECTED. NW WIND SHOULD
GRADUALLY INCREASE WITH GUSTS IN THE 15 TO 20 KT RANGE.
OUTLOOK...
MAINLY VFR FLYING CONDITIONS EXPECTED SATUDAY NIGHT THROUGH
TUESDAY. CONDS WILL LIKELY BECOME WORSE TUESDAY NIGHT INTO
WEDNESDAY AS A LOW PRESSURE SYSTEM BRINGS RAIN INTO THE AREA.
&&
.MARINE...
A WEAK SURFACE LOW WILL PASS WELL SOUTH OF THE WATERS TONIGHT.
THE GRADIENT BEHIND THE LOW WILL NOT INCREASE UNTIL LATE TONIGHT.
NW WINDS ON SATURDAY MAY INCREASE TO SCA CRITERIA...ESP DE WATERS
AND ESP SAT AFTN...BUT FOR NOW MULTI MODEL TOOLS DO NOT OFFER MUCH
SUPPORT FOR AN SCA.
OUTLOOK...
NW WINDS SATURDAY NIGHT WILL DIMINISH AS HIGH PRES MOVES OVER THE
AREA...THEN WILL BECOME SW AND INCREASE ON MONDAY AS THE HIGH
MOVES OFFSHORE. SCA CONDS ARE POSSIBLE AROUND DTHIS TIME.
A FRONTAL SYSTEM WILL CROSS THE AREA TUESDAY BUT ASSOCD WINDS
SHOULD BE RELATIVELY LIGHT. WINDS SHOULD INCR AGAIN FROM THE SW
AND THEN SHIFT TO NW WED NIGHT AS LOW PRES AND ASSOCD CDFNT MOVE
ACROSS THE AERA. SCA CONDS ARE AGAIN POSSIBLE AT THIS TIME.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AMC
NEAR TERM...DRAG/KRUZDLO
SHORT TERM...DRAG
LONG TERM...AMC
AVIATION...DRAG/KRUZDLO
MARINE...AMC/DRAG/KRUZDLO
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
915 PM EST FRI Dec 16 2011
.UPDATE...
02Z Water vapor and H4 RUC analysis shows an upper level pattern
consisting of broad troughing over the eastern 2/3rds of the nation.
The base of this trough drops down into northern portions of
MS/AL/GA, with the flow becoming more zonal in nature along the
northern Gulf Coast. Despite the zonal flow aloft, a weak shortwave
moving through the base of the trough will give enough push
overnight to allow a weak cold front to pass through the region.
Looking at MSLP analysis and surface obs upstream, it appears that
as of 02Z, the surface position of this front is getting close to
Dothan, AL and Albany, GA.
Guidance is in good agreement in the timing of this front, which
will slowly proceed south and east across the area during the
remainder of the overnight, and then pass off to our south during
the morning hours of Saturday. 00Z KTLH sounding profile still
showed a considerable degree of dry air in the mid levels. This dry
air combined with very little in the way of synoptic forcing will
make this a generally dry and uneventful frontal passage overnight.
Really just looking for a windshift to the northwest and a slow
advection of a drier airmass into the region. There has been just
enough low level focus along the frontal boundary itself during this
evening to support a few isolated sprinkles across central/southern
AL. Hi-res guidance suite all suggest that this focus will weaken
into the early morning hours, with the few sprinkles that are being
observed dissipating. Will be a comfortable night for mid December
with low temperatures generally in the low/mid 50s. A few locations
north and west of Dothan and Albany may drop down into the upper 40s
by sunrise, but not anticipating much lower than that.
Should see some lingering post-frontal clouds hanging around during
the morning hours of Saturday, especially over the southern/SE half
of the forecast area. However, during the afternoon hours a very dry
atmospheric column will descend over the area with skies clearing by
the end of the day for all zones.
&&
.AVIATION (thru 00Z Sun)...
VFR conditions will continue into the early overnight hours except
at ECP where occasional IFR/LIFR CIGS/VSBYS will persist. As the
frontal boundary approaches, expect MVFR to brief IFR cigs with a
few sprinkles to overspread all sites, with the potential for IFR
cigs at TLH/VLD before sunrise, For other terminals, Winds should
remain just high enough to preclude IFR vsbys issues. Thereafter,
should see cigs lift and move out of the area by mid afternoon with
NW winds increasing to around 10 mph as drier air moves into the
region. VFR is expected for the rest of the period.
&&
.MARINE...Light winds will shift offshore Saturday morning as a
cold front moves through the marine area. Winds will increase
Saturday evening as the gradient tightens, resulting in cautionary
conditions across the entire marine area. Expect winds to remain
elevated throughout much of the upcoming week as high pressure
remains located across the Mid Atlantic States.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 54 71 36 64 38 / 10 0 0 0 0
Panama City 57 69 42 63 46 / 10 0 0 0 0
Dothan 50 64 36 63 40 / 10 0 0 0 0
Albany 50 68 35 63 38 / 10 0 0 0 0
Valdosta 53 70 36 63 38 / 10 0 0 0 0
Cross City 52 73 39 66 38 / 10 0 0 0 0
Apalachicola 57 70 43 62 48 / 10 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...BLOCK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
859 PM CST FRI DEC 16 2011
.DISCUSSION...
ISSUED 852 PM CST FRI DEC 16 2011
WEAK WEATHER SYSTEM ACRS MINNESOTA AND NORTHERN IOWA TRACKING SE
WITH SOME LIGHT SNOW AND FLURRIES BEING REPORTED OVER PARTS OF
NORTH CENTRAL THRU NE IOWA THIS EVENING. LOOKS AS IF THE BULK OF
THE LIGHT SNOW SHOULD SKIRT JUST NORTH OF THE AREA LATE TONIGHT
THRU SATURDAY MORNING...BUT WILL INCLUDE SOME FLURRIES ROUGHLY
FROM WYOMING SE TO NEAR CHAMPAIGN AND DANVILLE. HI-RES MODELS AND
LATEST RUC SUGGESTS A LITTLE FURTHER SOUTHWARD SHIFT IN THE VORT
TRACK AND MID LEVEL LIFT...RESULTING IN THE ADJUSTMENT TO THE
PRECIP CHANCES LATE TONIGHT THRU SAT MORNING...MAINLY FROM 2 AM
THRU 10 AM ACROSS THE FAR NORTH. ELSEWHERE...FORECAST SEEMS TO
BE IN GOOD SHAPE AS THE INCREASE IN CLOUD COVER SHOULD KEEP TEMPS
FROM FALLING OFF MUCH FURTHER THIS EVENING. SHOULD HAVE THE UPDATED
ZONE FORECAST OUT BY 915 PM.
SMITH
&&
.AVIATION...
ISSUED 530 PM CST FRI DEC 16 2011
VFR CONDITIONS ARE EXPECTED THRU THIS FORECAST PERIOD. NEXT WEATHER
SYSTEM OVER THE DAKOTAS WILL SWEEP SOUTHEAST INTO THE LOWER GREAT
LAKES BY TOMORROW MORNING. THIS WILL BRING AN INCREASE IN MID LEVEL
CLOUDINESS LATER TONIGHT WHICH SHOULD HOLD ACRS THE AREA THRU AT
LEAST TOMORROW MORNING. A FEW FLURRIES WILL BE POSSIBLE AT PIA AND
BMI AFTR 06Z BUT COVERAGE WILL BE TOO LIMITED TO INCLUDE IN THE
TAFS AT THIS TIME. LIGHT AND VARIABLE WINDS TONIGHT WILL BECOME
SOUTH BY SATURDAY MORNING AND THEN VEER INTO A WESTERLY DIRECTION
BY AFTERNOON...WITH SPEEDS RANGING 10 TO 15 KTS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 300 PM CST FRI DEC 16 2011
SHORT TERM...TONIGHT THROUGH MONDAY...
WEAK UPPER SHORTWAVE MOVING INTO MN AND NORTHWESTERN IA IS PRODUCING
A LITTLE LIGHT SNOW/FLURRIES THIS AFTERNOON. THE MAIN ENERGY WITH
THE WAVE...ALONG WITH THE SNOW...WILL BE STAYING NORTH OF THE
FORECAST AREA AS IT PASSES BY TONIGHT. 18Z NAM REFLECTIVITY
SIMULATIONS ALSO KEEP PRECIPITATION TO THE NORTH...BUT NOT BY MUCH.
A FEW FLURRIES CAN BE ADDED IN THE NORTH LATER IF THE CURRENT RADAR
ECHOES TAKE AN UNEXPECTED SOUTHEAST TURN.
OTHERWISE...DRY WEATHER WITH A SLOW WARMING TREND IS EXPECTED
THROUGH THE WEEKEND AS AN AREA OF HIGH PRESSURE MOVES TO THE SOUTH
OF IL AND RESULTS IN WARM ADVECTION WITH INCREASING WEST TO
SOUTHWEST WINDS. INITIAL 850 MB TEMPERATURES AROUND -4C SHOULD RISE
TO 5 ABOVE BY THE END OF THE DAY SUNDAY.
SPLIT UPPER FLOW WILL CONTINUE OVER THE CONUS FOR MUCH OF THIS
PERIOD. A SHORTWAVE IN THE NORTHERN BRANCH WILL MOVE ACROSS SOUTHERN
CANADA WITH AN ATTENDING COLD FRONT COMING SOUTHWARD INTO IL ON
MONDAY. BY THEN...THE SOUTHERN SURFACE HIGH WILL HAVE MOVED EAST
WHICH WILL ALLOW MOISTURE FROM THE GULF TO COME NORTHWARD INTO THE
MIDWEST. BY MONDAY AFTERNOON...THIS MOISTURE WILL BE LIFTED BY THE
APPROACHING COLD FRONT AND RESULT IN AN INCREASED CHANCE OF RAIN.
WILL START OUT WITH CHANCE POPS IN THE MORNING...THEN LIKELY IN THE
AFTERNOON AS THE MOISTURE DEEPENS OVER THE AREA. AT THIS TIME IT
LOOKS LIKE THERE WILL BE SUFFICIENT WARM ADVECTION AHEAD OF THE COLD
FRONT TO PRECLUDE SNOW INTO AT LEAST MONDAY EVENING.
LONG TERM...TUESDAY THROUGH FRIDAY...
AS THE COLD FRONT STALLS OUT OVER THE MIDWEST...PRECIPITATION
CHANCES WILL INCREASE AS AN UPPER LOW NOW OVER BAHA CA COMES
NORTHEASTWARD AND INTERACTS WITH THE FRONT. WILL CONTINUE LIKELY
POPS OVER THE SOUTHERN HALF OF THE AREA CLOSER TO THE FRONT...WHICH
WILL PROVIDE A LOW LEVEL FOCUS. AT THE SAME TIME...COLD AIR WILL
BEGIN COMING INTO NORTH-CENTRAL IL NORTH OF THE FRONT AND GRADUALLY
CHANGE THE RAIN TO SNOW. IT IS STILL UNCLEAR HOW FAR SOUTH THE COLD
AIR WILL COME OR HOW DEEP IT WILL BE AS THE APPROACH OF THE
SOUTHWESTERN LOW WILL CAUSE WARM ADVECTION AT LEAST ALOFT. IF THE
COMBINATION OF CLOUDS/PRECIP KEEPS SURFACE TEMPERATURES COOL
ENOUGH...THEN AN ELEVATED WARM LAYER COULD CAUSE SOME MIXED
PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY. ALTHOUGH THE OVERALL
LONG-RANGE MODEL SOLUTIONS ARE BEGINNING TO COME INTO BETTER
AGREEMENT IN THE OVERALL SYNOPTIC FEATURES... SIGNIFICANT
DIFFERENCES IN THE LOW LEVEL THERMAL STRUCTURE STILL EXIST WHICH
WILL PLAY A SIGNIFICANT ROLE IN PRECIPITATION TYPES. FOR NOW WILL
INDICATE A RATHER SMOOTH TRANSITION FROM RAIN TO SNOW NORTHWEST TO
SOUTHEAST TUESDAY INTO TUESDAY NIGHT AS THE COLD AIR DEEPENS. BY
TUESDAY NIGHT MOST OF THE PRECIPITATION WILL BE MOVING EAST...AND
WEDNESDAY THROUGH THURSDAY LOOK PRETTY MUCH DRY SO FAR. ANOTHER RAIN
OR RAIN/SNOW CHANCE WILL RETURN ON THURSDAY NIGHT/FRIDAY AS SOME OF
THE MODELS INDICATE A SOUTHERN STORM SYSTEM PASSING JUST TO OUR
SOUTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1104 PM CST WED DEC 14 2011
.DISCUSSION...
ISSUED 830 PM CST WED DEC 14 2011
RATHER IMPRESSIVE UPPER LEVEL WAVE AND SPEED MAX SEEN ON WATER
VAPOR LOOP THIS EVENING ACRS OKLAHOMA...WHICH IS TRACKING
NE AND BRINGING IN ANOTHER ROUND OF RAIN AND THUNDERSTORMS...
THIS TIME TO THE SOUTHERN HALF OF THE FORECAST AREA. FURTHER
NORTH AND WEST...STILL SEEING SOME PRECIP...BUT MORE LIGHT
RAIN AND DRIZZLE THAN THE STEADIER RAINS THAT OCCURRED IN THIS
AREA THRU MOST OF THE DAY. RAINFALL TOTALS RANGED FROM 2 TO 3
INCHES ROUGHLY ALONG AND NORTH OF A RUSHVILLE TO BLOOMINGTON
LINE...WITH TOTALS DROPPING OFF DRAMATICALLY TO THE SOUTH.
HIGHEST POPS WILL CONTINUE ACRS THE SOUTHEAST HALF OF THE FORECAST
AREA FOR THE REST OF THIS EVENING AND INTO THE EARLY MORNING HOURS.
THE COMBINATION OF THE CLOUD COVER AND GUSTY SOUTH WINDS WILL KEEP
TEMPS STEADY THRU THE NIGHT...AND SOME 10 TO 15 DEGREES ABOVE NORMAL
HIGH TEMPERATURES FOR THIS TIME OF YEAR! THE COLD FRONT WHICH IS
SLATED TO MOVE THRU PIA AROUND 3 OR 4 AM WAS JUST EAST OF DES MOINES
THIS EVENING...WITH SURFACE DEW POINTS IN THE MID TO UPPER 50S
STREAMING NORTH JUST AHEAD OF THE BOUNDARY. PRECIP WILL END LAST
ACRS THE FAR SOUTHEAST EITHER LATE TOMORROW MORNING OR EARLY
AFTERNOON AS THE SURFACE LOW DEEPENS OVER THE UPPER GREAT LAKES
DRAWING DOWN COLDER AIR FOR THE REST OF THE WORK WEEK. HAVE ADJUSTED
POPS OUT A BIT LATER INTO THE OVERNIGHT HOURS ACRS MAINLY OUR EAST
AND SOUTHERN AREAS...BASED ON THE BAND OF RAIN AND ISOLD THUNDERSTORMS
OCCURRING FROM EAST CENTRAL IL SOUTHWEST THRU SOUTH CENTRAL MISSOURI.
SHOULD HAVE THE UPDATED ZONES OUT BY 900 PM.
SMITH
&&
.AVIATION...
ISSUED 1100 PM CST WED DEC 14 2011
TIMING OF COLD FRONT ACROSS THE TAF SITES AND DURATION OF IFR/MVFR
CIGS THE MAIN FORECAST CHALLENGES THIS PERIOD. COLD FRONT WAS TRACKING
INTO EAST CENTRAL IOWA AND IT APPEARS IT SHOULD BE PUSHING INTO WEST
CENTRAL IL BETWEEN 08Z AND 10Z. EXTENSIVE MVFR AND IFR CIGS WERE
PRESENT ACRS THE REGION LATE THIS EVENING WITH SOME CLEARING TAKING
PLACE OVER PARTS OF NW MISSOURI...WHICH WAS BEING REPLACED BY MORE
MVFR AND IFR CIGS BEHIND THE COLD FRONT. THE STEADIER RAINS HAVE
SHIFTED OFF TO THE EAST...WITH MORE LIGHT RAIN AND DRIZZLE OCCURRING
ACRS THE AREA AND EXPECTED TO HOLD THRU MOST OF THE NIGHT. REALLY
DON`T SEE ANY SIGNIFICANT CHANGES TO THE CIGS/VSBYS FOR ANY LENGTH OF
TIME TONIGHT INTO THU MRNG. WE MAY SEE A TEMPORARY BREAK IN THE CIGS
IMMEDIATELY BEHIND THE COLD FRONT...WHICH WILL BE FOLLOWED BY AN
INCREASE IN STRATUS AND STRATOCU CLOUDS AS THE LOW LEVEL COLD ADVECTION
RAMPS UP IN THE WAKE OF LOW PRESSURE AREA WHICH SHOULD BE DEEPENING
UP ACRS THE NORTHERN GREAT LAKES TOMORROW MORNING.
STRONG CYCLONIC FLOW AND LOW LEVEL COLD ADVECTION SHOULD BRING MOST
IF NOT ALL OF THE MVFR/IFR CIGS NOW PRESENT ACRS NRN IOWA INTO OUR
AREA TOMORROW ALONG WITH GUSTY WEST TO NORTHWEST WINDS. FORECAST
SOUNDINGS CONTINUE TO SHOW A RATHER SIGNIFICANT SUBSIDENCE INVERSION
DEVELOPING TOMORROW WHICH WILL TRAP THE LOW LEVEL MOISTURE/LOW CLOUDS
IN OUR AREA THRU AT LEAST THE EARLY AFTERNOON HOURS BEFORE WE SEE A
GRADUAL DECREASE IN CLOUDS LATER IN THE DAY. SFC WINDS WILL CONTINUE
FROM A SOUTHERLY DIRECTION FOR THE NEXT FEW HOURS AND THEN VEER INTO
A SOUTHWEST DIRECTION JUST AHEAD OF THE COLD FRONT. WINDS WILL SHIFT
INTO A WEST TO NORTHWEST DIRECTION JUST AFTER FROPA WITH SPEEDS AVERAGING
FROM 15 TO 20 KTS...WITH A FEW GUSTS APPROACHING 30 KTS AT TIMES. WINDS
SHOULD GRADUALLY DIMINISH TOMORROW NIGHT AS THE STORM SYSTEM PULLS AWAY.
SMITH
&&
.PREV DISCUSSION...
ISSUED 238 PM CST WED DEC 14 2011
SPRING-LIKE STORM SYSTEM BRINGING SHOWERS AND SCATTERED
THUNDERSTORMS TO THE CENTRAL/NORTHERN CWA TODAY IN BROAD...WARM
SOUTHWEST FLOW. HEAVIEST RAINS OF 1.5-2.5 INCHES HAVE FALLEN NORTH
OF A BEARDSTOWN TO BLOOMINGTON LINE. MODERATE RAINFALL RATES AND
UNFROZEN GROUND HAVE PRODUCED LITTLE IN THE WAY OF WATER PROBLEMS.
UPPER LEVEL DYNAMICS HELPING DRIVE THIS ACTIVITY AS SFC LOW AND
FRONT ANALYZED AT 19Z ACROSS EASTERN NEB/NRN KS. EVEN WITH THICK
CLOUDS AND RAIN...EARLY AFTERNOON TEMPS WERE RUNNING 15-20 DEGREES
ABOVE NORMAL. SHORT TERM FORECAST ISSUE IS ENDING OF RAIN WITH
COLD FRONTAL PASSAGE LATE TONIGHT AND RETURN TO SEASONABLE TEMPS.
BEYOND...NEXT MAJOR SYSTEM LOOKS TO IMPACT REGION EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH THURSDAY
UNSEASONABLY HIGH P/W VALUES AROUND 1.25 INCHES AND STRONG FORCING
ALOFT WILL CONTINUE TO DRIVE MODERATE RAIN AND EMBEDDED
THUNDERSTORMS THIS EVENING. LATEST HIGH RES NAM AND HRRR RUNS SHOW
ROUNDS OF CONVECTION TRANSLATING EAST ACROSS THE CWA THROUGH LATE
EVENING. PLENTY OF ELEVATED INSTABILITY FOR THUNDER...AND VERY
STRONG LLJ OVERHEAD /1 KM AGL WINDS 50 KTS/ BUT DUE TO STRONG LOW
LEVEL INVERSION DO NOT EXPECT ANY OF THIS TO MAKE IT DOWN TO THE
SURFACE. MAIN BATCH OF RAIN ASSOCIATED WITH PRE-FRONTAL TROUGH
LOOKS TO PUSH INTO INDIANA AFTER MIDNIGHT...WHEN THE ACTUAL COLD
FRONT ENTERS THE NW CWA. EXPECT A LINE OF SCATTERED SHOWERS
ALONG/AHEAD OF THE FRONT...WHICH WILL EXIT THE SE CWA AROUND 15Z
THU. BRISK WEST WINDS GUSTING TO 20-25 MPH WILL MOVE IN BEHIND THE
FRONT...BRINGING IN COOLER AND DRIER AIR.
CLOUD FORECAST FOR THURSDAY IS PROBLEMATIC WITH DRY AIR ADVECTING
IN...BUT FCST SOUNDINGS SHOW A SHALLOW LAYER OF MOISTURE TRAPPED
BENEATH A SHARP SUBSIDENCE INVERSION AROUND 925 MB. THIS COMBINED
WITH CYCLONIC FLOW ALOFT AND WEAK SUN ANGLE MAKES A LOW STRATUS
DECK LOOK LIKELY TO HOLD AT LEAST INTO MID AFTERNOON. TEMPERATURES
MAY HOLD STEADY FOR A FEW HOURS IN THE MORNING...THEN SLOWLY FALL
THROUGH THE AFTERNOON WHEN STRONGER CAA KICKS IN.
LONG TERM...FRIDAY THROUGH WEDNESDAY
QUIET AND SEASONABLE WEATHER IS ON TAP FOR THE FRIDAY INTO SUNDAY
PERIOD. ZONAL/WNW FLOW ALOFT AND HIGH PRESSURE AT THE SURFACE WILL
BE RESPONSIBLE FOR THE TRANQUIL CONDITIONS. AS THE HIGH SHIFTS OFF
TO THE SOUTHEAST LATE IN THE WEEKEND SOUTHERLY FLOW DEVELOPS AHEAD
OF THE NEXT SYSTEM IN THE SW.
CURRENT INDICATIONS SHOW THIS EVENT MAY BE SIMILAR TO THE STORM
THAT IS CURRENTLY IMPACTING THE AREA. THE 12Z ECMWF AND CANADIAN GEM
ARE SIMILAR IN TRACKING A STRONG LOW FROM THE TX PANHANDLE REGION
MONDAY MORNING...INTO THE LOWER GREAT LAKES BY TUESDAY EVENING.
12Z GFS IS MUCH SLOWER AND FARTHER SOUTH AND WAS NOT FOLLOWED FOR
THIS FORECAST. EVENTUAL LOW TRACK WILL DETERMINE EXACT PRECIP TYPE
AND AMOUNTS...BUT CURRENT SOLUTION WOULD POINT TO PRIMARILY
ANOTHER MODERATE RAIN EVENT FOR THE CWA FOR SUNDAY NIGHT INTO TUESDAY.
LATER MODEL RUNS WILL NEED TO BE MONITORED...AS ECMWF DIGS A
NORTHERN STREAM WAVE INTO THE MIDWEST FOR A MORE PHASED SYSTEM AND
POTENTIAL SNOW BAND ON THE NW SIDE OF THE STORM. AFTER A BRIEF
SHOT OF COLDER AIR BEHIND THIS LOW...ZONAL FLOW LOOKS TO MODERATE
TEMPS FOR MID WEEK.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
953 PM EST FRI DEC 16 2011
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE LOWER
GREAT LAKES ON SATURDAY...AND MAY BRING A FEW FLURRIES TO NORTHERN
PORTIONS OF THE FORECAST AREA. OTHERWISE...EXPECT DRY WEATHER AS HIGH
PRESSURE ACROSS THE PLAINS SETTLES INTO THE SOUTHERN STATES AND OHIO
VALLEY BY LATE WEEKEND. THEN...A COLD FRONT IS EXPECTED TO DROP
SOUTHEAST ACROSS CENTRAL INDIANA ON MONDAY BEFORE STALLING NEAR
THE OHIO RIVER AS A WAVE DEVELOPS ALONG THE SOUTHERN EDGE OF THE
FRONT ACROSS THE SOUTHERN PLAINS. THIS WAVE WILL THEN LIFT
NORTHEAST ALONG THE FRONT AND ACROSS THE OHIO VALLEY TUESDAY
NIGHT. THIS WILL RESULT IN A RAINY PERIOD STARTING MONDAY AND
ENDING EARLY WEDNESDAY. THEN...HIGH PRESSURE WILL ALLOW FOR A DRY
WEDNESDAY NIGHT AND THURSDAY BEFORE A SOUTHERN PLAINS SYSTEM
BRINGS A CHANCE OF RAIN OR SNOW ON THURSDAY NIGHT AND FRIDAY.
TEMPERATURES SHOULD REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL
THROUGH NEXT WEEK.
&&
.NEAR TERM /OVERNIGHT/...
STRATOCU CONTINUES TO BE RATHER STUBBORN IN DEPARTING EASTERN
PORTIONS OF THE FORECAST AREA. WITH LOW LEVEL FLOW LARGELY OUT OF
THE N/NW...AM BECOMING LESS OPTIMISTIC THAT THESE CLOUDS WILL
COMPLETELY SCOUR OUT OF THE FORECAST AREA BEFORE RAPIDLY
APPROACHING MID AND HIGH LEVEL CLOUDS EXPAND INTO THE REGION FROM
THE WEST AFTER MIDNIGHT. HAVE THEREFORE BEEFED UP CLOUD COVERAGE
QUITE A BIT FOR MUCH OF THE REST OF THE NIGHT...WITH MANY
LOCATIONS NORTH AND EAST OF THE INDY METRO REMAINING MOSTLY
CLOUDY. MADE MINOR TWEAKS TO TEMPS OVERNIGHT BUT WITH CURRENT
TEMPS ALREADY IN THE UPPER 20S AND LOWER 30S...FORECAST LOWS IN
THE MID 20S LOOK TO BE ON TRACK EVEN WITH THE INCREASE IN CLOUD
COVER.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUD COVER...TEMPERATURES
AND TIMING OF RAIN BACK INTO CENTRAL INDIANA.
MODELS HAVE SOME DIFFERENCES BUT NOTHING REAL DRAMATIC REGARDING
MAJOR SYNOPTIC FEATURES IN THE SHORT TERM. SATURDAY WILL START OFF
WITH SOME MID AND HIGH CLOUDS AROUND ESPECIALLY NORTHEAST SECTIONS
AS A SHORT WAVE AND ASSOCIATED MOISTURE DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES IN THE FAST NORTHWEST FLOW ALOFT. MODEL RUNS
THIS EVENING SHOWING A BIT MORE IN THE WAY OF ISENTROPIC LIFT
PASSING THROUGH NORTHERN FORECAST AREA AND MOST RECENT HRRR DATA
INDICATING MAY SEE A PERIOD WITH FLURRIES OR VERY LIGHT SNOW
SHOWERS GRAZE FAR NORTHERN FORECAST AREA THROUGH 18Z SATURDAY.
IN THE WAKE OF THE SHORT WAVE...SKIES SHOULD BECOME MOSTLY CLEAR
SATURDAY NIGHT AND SUNDAY IN SUBSIDENCE IN PERSISTENT FAST
NORTHWEST FLOW ALOFT AND WITH SURFACE HIGH PRESSURE SLIDING EAST
ACROSS THE SOUTHERN STATES AND OHIO VALLEY. FINALLY...A COLD FRONT
WILL SLIDE SOUTHEAST ACROSS NORTHERN INDIANA ON MONDAY WHICH
SHOULD BRING A CHANCE FOR RAIN ESPECIALLY ACROSS OUR NORTHERN
COUNTIES CLOSER TO THE FRONT.
BASED ON LOW LEVEL THERMAL PROGS WITH 850 MILLIBAR TEMPERATURES
CLIMBING TO 2 TO 4 DEGREES CELSIUS BY LATE SUNDAY AND CLOUD
COVER...GOING WITH THE WARMER NAM MOS FOR TEMPERATURES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT WITH EJECTION OF SYSTEM FROM
THE SOUTHWEST USA EARLY IN THE EXTENDED...BUT CONTINUE TO DIFFER
SOME LATER IN THE EXTENDED LIKE THEY HAVE BEEN DOING. GIVEN THIS THE
ALL-BLEND INITIALIZATION LOOKS GOOD ENOUGH FOR THE MOST PART
THROUGHOUT THE EXTENDED.
TEMPERATURES WILL RUN NEAR OR ABOVE AVERAGE FOR THE MOST PART. 00Z
ECMWF AND 12Z GFS BOTH AGREE THAT TUESDAY NIGHT SHOULD REMAIN AT
LEAST JUST WARM ENOUGH FOR ALL RAIN. WILL REMOVE SNOW MENTION
TUESDAY NIGHT AND WEDNESDAY.
WITH THE UNCERTAINTY WITH POPS FOR THURSDAY NIGHT INTO FRIDAY KEPT
POPS LOW AND MENTIONED CHANCE OF RAIN OR SNOW WITH MARGINAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 17/03Z TAF UPDATE/...
UPDATE...
LOW LEVEL CLOUDS HAVE BEEN SLOW TO MOVE OUT OF KIND AND KBMG...SO
WILL HANG ONTO THEM IN TAFS FOR A FEW MORE HOURS. AFTER THAT...
SCATTERED MID AND HIGH LEVEL CLOUDS WILL DRIFT ACROSS TAF SITES
FOR MOST OF THE NIGHT BEFORE LOW AND MID LEVEL CLOUDS INCREASE ONCE
AGAIN TOMORROW MORNING.
PREVIOUS DISCUSSION...
MID LEVEL CLOUD LAYER CONTINUES TO MOVE EASTWARD OUT OF THE AREA
WITH ONLY SOME LINGERING HIGH CLOUDS EXPECTED OVERNIGHT. AN UPPER
LEVEL SYSTEM WILL PASS THROUGH THE NORTHERN PORTION OF THE
FORECAST AREA ON SATURDAY BRINGING ANOTHER ROUND OF MID LEVEL
CLOUDS TO ALL TAF SITES. CEILINGS SHOULD REMAIN VFR EXCEPT FOR THE
POSSIBILITY OF A BRIEF PERIOD OF MVFR AT KLAF. THEREFORE...WILL
INSERT BKN050 CEILINGS AT KLAF FOR THE 12-18Z TIME FRAME.
NORTHWESTERLY WINDS WILL GRADUALLY SHIFT TO THE WEST/SOUTHWEST AS THE
UPPER LEVEL SYSTEM PASSES BUT WILL REMAIN LIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK/RYAN
NEAR TERM...RYAN
SHORT TERM...MK/RYAN
LONG TERM....CS
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
655 PM EST FRI DEC 16 2011
.AVIATION...
MVFR CLOUDS STILL HOLDING FIRM AS COOLING WITH LOSS OF SUN STOPPED
EROSION OF SOUTHERN EDGE. AS NEXT SYSTEM APPROACHES FLOW WILL BACK
SOME WHICH MAY HELP WESTERN EDGE OF CLOUD DECK PUSH EAST.
HOWEVER...925-850MB FLOW REMAINS NORTHWEST OFF THE LAKE WITH DELTA T
VALUES IN MID TEENS. THIS SHOULD KEEP A CLOUD PLUME OFF THE LAKE
THROUGH THE NIGHT AND RUC13 AND NAM12 LOWER LAYER RH SUGGEST THIS AS
WELL. TRAJECTORIES WOULD SUGGEST KSBN AND KFWA MAY HOVER ALONG CLOUD
EDGE SO HAVE REMAINED OPTIMISTIC WITH SCATTERING OUT OF LOWER CLOUDS
AS FLOW BACKS SLIGHTLY. THIS MAY NEED AMENDED IF NO SIGNS OF CLOUDS
MOVING EAST. NEXT PROBLEM IS APPROACHING SHORT WAVE AND SNOW
POTENTIAL ON SATURDAY. FEEL A WINDOW WILL EXIST IN THE MORNING WITH
LAKE ENHANCEMENT WHICH COULD PRODUCE AN AREA OF LAKE ENHANCED SNOW
WITH SHORT WAVE. THIS WOULD MAINLY AFFECT KSBN WITH KFWA ON SOUTHERN
EXTENT OF TRAJECTORIES OFF OF LAKE. HAVE INTRODUCED AN MVFR CIG AND
VIS AT KSBN FOR SNOW SHOWERS WITH MVFR CIG AT KFWA. THERE IS A
POSSIBILITY OF BRIEF PERIOD OF LOWER VIS AT KSBN IF LAKE ENHANCEMENT
INDEED OCCURS WHICH WOULD BE BETWEEN 12 AND 18Z SATURDAY.
.UPDATE...
18Z MODEL DATA ALONG WITH LATEST RUC ANALYSIS SUGGEST SOME CHANGES
IN ORDER FOR FORECAST. MODELS CONTINUE TO TREND TOWARD A STRONGER
SHORT WAVE WITH POTENT 120 KNOT JET MAX DIGGING INTO THE REGION
SATURDAY MORNING. ISENTROPIC LIFT AND SYNOPTIC MOISTURE LACKING SO
ONLY EXPECTING FLURRIES OR VERY LIGHT SNOW SHOWERS AWAY FROM LAKE
MICHIGAN. HOWEVER...PER LATEST MODEL DATA...A WINDOW EXISTS SATURDAY
MORNING FOR SOME LAKE ENHANCEMENT ACROSS NORTHERN INDIANA AND
SOUTHERN LOWER MICHIGAN AND MODELS SEEM TO BE PICKING UP ON THIS.
NAM12 SHOWING LAKE PLUME DEVELOPING TOWARD 12Z WITH 925-850MB OMEGA
INCREASING FROM 12-18Z WITH DELTA T VALUES IN MID TEENS COINCIDENT
WITH SYNOPTIC SHORT WAVE AND DEEPENING MOISTURE COLUMN. DGZ LOOKS TO
BE SATURATED WITH STRONGEST LIFT JUST REACHING THIS LEVEL BRIEFLY.
COULD PRODUCE A QUICK PERIOD OF LAKE ENHANCED SNOW. WILL BE
INCREASING POPS TO AT LEAST HIGH CHANCE IN THE NORTH WITH THIS
UPDATE. 18Z MODEL DATA SOMETIMES BECOMES OVERALLY AGGRESSIVE SO
WOULD LIKE TO ALLOW LOOK AT 00Z DATA BEFORE INCREASING ANY FURTHER
ESPECIALLY GIVEN LACK OF GOOD SYNOPTIC SCALE LIFT AND MOISTURE WITH
DRY LOWER LEVELS TO OVERCOME INITIALLY. ACCUMS WOULD LIKELY BE AN
INCH
TO POSSIBLY TWO IN LAKE EFFECT AREAS WHERE ENHANCEMENT POTENTIAL
WOULD OBVIOUSLY BE GREATEST. OUTSIDE OF THIS AREA LIKELY JUST A
DUSTING OR LESS. UPDATE OUT SHORTLY.
&&
.PREV FORECAST...
SHORT TERM... / TONIGHT THROUGH SATURDAY NIGHT /
LATEST VIS SAT SHOWING LAKE INDUCED CLOUD DECK HANGING TOUGH OVER
THE NORTHERN HALF OF THE CWA THIS AFTERNOON. SOUTHERN EDGE
GRADUALLY ERODING AND EXPECT THIS TREND TO CONTINUE. SFC HIGH
PRESSURE RIDGE EXTENDING DOWN THE NORTHERN PLAINS AND INTO THE MID
MISSISSIPPI VALLEY WILL MAKE A LITTLE EASTWARD PROGRESS THIS
EVENING...BUT MID LEVEL NW FLOW PATTERN WILL BE MAIN FOCUS IN THE
SHORT TERM. MODELS ARE NOW TRENDING TO A BIT MORE POTENT SHORT
WAVE DROPPING DOWN INTO THE REGION...WITH ADDITIONAL UPPER LEVEL
SUPPORT FROM FAVORABLE JET DYNAMICS. AS USUAL IN NW FLOW...MODELS
SHOWING DIFFERENCES IN TIMING/PLACEMENT/INTENSITY...SO FOR NOW
WILL NOT STRAY TOO FAR FROM GOING FORECAST. WILL KEEP HIGH CHANCE
POPS WITH LIGHT ACCUMS GOING IN THE NORTH AND EXPAND TO 12 HOUR
TIME PERIOD FROM 18Z SAT TO 06Z SUN TO ACCOUNT FOR TIMING
DISCREPANCIES. TEMPS EXPECTED TO BE NEAR CLIMO WITH M30S
HIGHS/M20S LOWS.
LONG TERM... / SUNDAY THROUGH FRIDAY /
PROGRESSIVE/ACTIVE PATTERN WILL CONTINUE IN ABSENCE OF ANY TRUE HIGH
LATITUDE BLOCKING AS POS AO/NAO REGIME CONTINUES THIS PERIOD. THIS
SHOULD RESULT IN A CONTINUATION OF ABOVE NORMAL TEMPS AND
PRECIPITATION NEXT SEVERAL WEEKS.
SUNDAY STILL LOOKS LIKE A DRY DAY WITH TEMPS A LITTLE ABOVE NORMAL
PER HEIGHT RISES AND DEVELOPING LOW LVL ANTICYCLONIC FLOW. 12Z
MODELS CONTINUED TO SHOW A RATHER POTENT NORTHERN STREAM SHORTWAVE
TRAVERSING SOUTH-CENTRAL AND SOUTHEAST CANADA SUNDAY INTO
MONDAY...FORCING A FRONTAL BOUNDARY SEWD INTO THE SRN GREAT LAKES OR
OH VALLEY BY LATE MONDAY/TUESDAY. THIS WILL BE COINCIDENT WITH A SRN
STREAM CLOSED LOW (NOW OVER NRN BAJA PER AFTN WATER VAPOR) FINALLY
GETTING KICKED OUT TOWARDS THE CENTRAL PLAINS AND MID MS VALLEY BY
EARLY NEXT WEEK. THIS APPROACHING POSITIVE PV ANOMALY WILL SUPPORT
BACKING WINDS AND INCREASING ISENTROPIC LIFT...WHICH WHEN COMBINED
WITH INCREASING DIFFLUENCE ALOFT WILL ALLOW THE BAROCLINIC ZONE TO
STALL AND DEEPEN EITHER OVER OR JUST SOUTH OF THE FA DURING THIS
TIME. THE RESULT SHOULD BE AN EXPANDING AREA OF LGT/MOD PRECIP INVOF
THIS FRONTAL CIRCULATION. AS EXPECTED MODELS DO DIFFER WITH TIMING
AND PLACEMENT THIS FAR IN ADVANCE WITH SOME GUIDANCE SETTING UP THIS
BAROCLINIC ZONE AND RESULTING PRECIP WELL SOUTH OF THE FA MONDAY
NIGHT INTO TUESDAY MORNING. GIVEN THIS UNCERTAINTY AND SPREAD WITHIN
GUIDANCE WILL RETAIN CHC POPS...HIGHEST SOUTH. PRECIP SHOULD MAINLY
BE IN THE FORM OF RAIN...WITH SOME WET SNOW POSSIBLE ON THE FAR NRN
FRINGE OF THE PRECIP SHIELD LATE MONDAY NIGHT INTO TUESDAY.
A MODEL CONSENSUS FINALLY EDGES THE FILLING/WEAKENING SRN STREAM
WAVE THROUGH THE AREA LATE TUESDAY AFTN INTO TUESDAY NIGHT...WHEN
LIGHT PRECIPITATION MAY LINGER ACROSS THE AREA AS MID LVL
DEFORMATION FORCING SWINGS THROUGH. THERE COULD BE A NARROW BAND OF
SNOW ON THE NW FRINGE OF THIS SYSTEM...BEST CHANCES ACROSS OUR
NORTHWEST ZONES. ATTM NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATION. THE FA WILL DRY OUT BEHIND THIS SHORTWAVE WEDNESDAY
INTO THURSDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...STEINWEDEL
AVIATION...LASHLEY
UPDATE...LASHLEY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
139 AM EST THU DEC 15 2011
.AVIATION/UPDATE...
HEAVIER RAIN HAD SHIFTED WELL SOUTHEAST OF FWA...BUT AREAS OF RAIN
CONTINUE TO DEVELOP AHEAD OF A COLD FRONT EXTENDING FROM NORTH
CENTRAL IL TO WEST CENTRAL IL. THIS FRONT WILL MOVE ACROSS NRN
INDIANA LATER THIS MORNING...WITH WINDS SHIFTING TO THE WEST AND
INCREASING BEHIND THE FRONT. HAVE UPDATED GRIDS FOR MAINLY MINOR
UPDATED AND TO GET RID OF EVENING WORDING. IFR CONDITIONS SHOULD
IMPROVE ONCE THE FRONT PASSES.
&&
.PREV DISCUSSION... /ISSUED 754 PM EST WED DEC 14 2011/
SHORT TERM... TONIGHT THROUGH THURSDAY NIGHT... KIWX RADAR
DEPICTING BAND OF MOD/HVY RAIN ALONG/AHEAD OF WARM FRONT LIFTING
NORTH THROUGH THE AREA THIS AFTERNOON. THIS IS IN ASSOCIATION WITH
DEVELOPING SFC LOW IN CENTRAL PLAINS. WATER VAPOR IMAGERY AND
LATEST RUC ANALYSIS SHOWING LEAD SHORT WAVE EJECTING OUT OF FOUR
CORNERS AND WILL COMBINE WITH COUPLED JET STRUCTURE FROM NORTHERN
GREAT LAKES DOWN INTO THE CENTRAL PLAINS TO DEEPEN SFC LOW AND
DRIVE IT INTO WESTERN GREAT LAKES THIS EVENING. THIS WILL PLACE
THE FCST AREA IN ENHANCED MOIST SOUTHERLY FLOW IN THE WARM SECTOR
AND SUPPORT ANOTHER ROUND OF PRECIPITATION TONIGHT. COLD FRONT
WILL MOVE THROUGH THE AREA ON THURSDAY AND BRING AN END TO RAIN BY
18Z. SIGNIFICANT DRYING BEHIND THE FRONT ALONG WITH MARGINAL DELTA
T WILL PROVIDE LITTLE SUPPORT FOR LES IN THE WAKE OF THIS SYSTEM
SO FAVOR CURRENT GRIDS IN KEEPING JUST A MENTION OF FLURRIES ATTM.
FIRST TWO PERIODS OF FCST WILL FEATURE NON-DIURNAL TEMP PATTERN AS
WARM FRONT LIFTING NORTH OF THE AREA TONIGHT WILL KEEP TEMPS
STEADY/SLOWLY RISING...THEN CAA BEHIND PASSAGE OF COLD FRONT
THURSDAY WILL SEE HIGHS REACHED IN THE MORNING FOLLOWED BY FALLING
TEMPS IN THE AFTERNOON. COOLER BUT SEASONABLE TEMPS THURSDAY NIGHT
WITH LOWS IN THE MID-UPPER 20S.
LONG TERM...
FRIDAY THROUGH WEDNESDAY
ACTIVE NORTHERN STREAM WILL INFLUENCE LOWER HEIGHTS INTO THE REGION
THIS WEEKEND WITH COLDER/DRIER AIR PUSHING INTO THE GREAT LAKES...AS
PERIPHERY DISTURBANCES ADVECT THROUGH THE FLOW. A SERIES OF THESE
WEAK INFLUENCES MAY INFLUENCE ENOUGH LIFT AND COLUMN SATURATION TO
SUPPORT LIGHT SNOW OR FLURRIES ACROSS THE NORTH...ALONG WITH A WEAK
LAKE RESPONSE. OTHERWISE...MODELS AND ENSEMBLES CONTINUE TO SUPPORT
THE EJECTION OF A SW CONUS DISTURBANCE INTO THE REGION BY EARLY NEXT
WEEK...WITH SOME RATHER SIG DISCREPANCIES AMONG DETERMINISTIC
SOLUTIONS. WILL STAY THE COURSE WITH PERSISTENCE...FAVORING THE
WARMER ECMWF AND GEM. THIS WILL ESP BE TRUE IF FLOW PHASING IS
REALIZED...WHICH IS CERTAINLY POSSIBLE GIVEN THE PATTERN. SMALL
ADJUSTMENT MADE TO THE PREVIOUS FORECAST...GENERALLY TO POPS/WX.
FRI-SUN...OVERALL DRY/SLIGHTLY DISTURBED FLOW WILL REMAIN IN THE
GREAT LAKES REGION. CONTINUED TO OPT NOT TO INCLUDE A LAKE EFFECT
SNOW SHOWER MENTION FRI-SAT FAR NW GIVEN MARGINAL SUPPORT FOR LAKE
INDUCE CONVECTION...WITH ONLY A FLURRY MENTION ATTM...SPREAD OVER
THE ENTIRE NORTH TO COVER THE POTENTIAL FOR LIGHT SNOW WITH ANY OF
THE WEAK DISTURBANCES. PROFILES INDICATE SIG DRYING IN THE SFC TO H8
LAYER WITH MARGINAL DELTA T/S PRESENT. CANNOT RULE OUT A FEW
FLURRIES OR LIGHT LAKE EFFECT SNOW SHOWERS IF COLDER PROFILES
VERIFY...COUPLED WITH A WEAK NORTHERN STREAM DISTURBANCE PROGGED
INTO THE REGION...WHICH COULD GENERATE ENOUGH INVERSION HEIGHT
UNDULATION TO SUPPORT PERHAPS A FEW SNOW SHOWERS/FLURRIES IN SHORT
FETCH WESTERLY FLOW. OTHERWISE...TEMPS ARE EXPECTED TO REMAIN AROUND
NORMAL TO SLIGHTLY ABOVE IN THE PERIOD...WITH LAKE EFFECT CLOUDS
ACROSS NORTHERN AREAS LINGERING THROUGH SAT.
MON-WED...CHANCES FOR A DECENT STORM SYSTEM CONTINUE...AS AN ACTIVE
NORTHERN STREAM IMPULSE LIKELY INTERACTS WITH ANOTHER SW CONUS
UPPER LOW. ADVECTION TIMING/THERMAL FIELDS/AND HEIGHT FALL DEPTH
INTO THE REGION IS STILL MUCH UNCERTAIN...BUT GIVEN THE GFS/S
TENDENCY TOWARD PROGRESSIVE FLOW...LIKELY BIASING THE NAEFS
SOLUTIONS...HAVE CONTINUED TO SIDE TOWARD THE MORE RELIABLE ECMWF. A
TREND TO A DEEPER H5 SOLUTION WOULD CERTAINLY BE NEEDED...ESP IF
WAVE PHASING RESULTS...WITH COUPLED JET DYNAMICS LIKELY SHIFTING THE
SFC LOW TRACK NW OF THE FA...AS SEEN IN THE GEM. RETAINED A
RAIN/SNOW MENTION IN MOST PERIODS...MAINLY TO COVER
UNCERTAINTY...BUT IT CERTAINLY LOOKS LIKE RAIN WILL BE THE DOMINATE
WEATHER TYPE IN THE PERIOD...ESP SE HALF. CONTINUE TO EXPECT MORE
ADJUSTMENT IN THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...JC
AVIATION/UPDATE...SKIPPER
AREA FORECAST DISCUSSION...CORRECTED
NWS QUAD CITIES IA IL
602 PM CST FRI DEC 16 2011
.AVIATION...
AN APPROACHING CLIPPER SYSTEM IS SPREADING VFR CLOUDS INTO
EASTERN IOWA EARLY THIS EVENING. CEILINGS ARE FORECAST TO LOWER TO
MVFR AND VSBYS TO IFR IN SNOW SHOWERS MAINLY AT KDBQ AFTER
04Z. AFTER THE SYSTEM EXITS TO THE EAST AFTER 12Z SATURDAY
CEILINGS WILL GRADUALLY LIFT WITH VFR CONDITIONS THROUGH THE
REMAINDER OF THE TAF PERIOD.
DC/LE
&&
.PREV DISCUSSION... /ISSUED 314 PM CST FRI DEC 16 2011/
SYNOPSIS...
12Z UA ANALYSIS HAS A SHORTWAVE ACROSS THE DAKOTAS WITH AN 850MB
ARCTIC FRONT FROM CENTRAL MINNESOTA INTO UPPER MICHIGAN. A RIDGE
EXTENDED FROM MINNESOTA INTO WEST TEXAS. SATELLITE AND RADAR TRENDS
THROUGH MID AFTERNOON SHOW LOW CLOUDS ACROSS PARTS OF THE DAKOTAS
INTO MINNESOTA WITH MID AND HIGH CLOUDS FROM NEBRASKA INTO
WISCONSIN. SOME LIGHT SNOW WAS OCCURRING IN WESTERN MINNESOTA WHERE
THE STRONGEST WAA WAS OCCURRING.
18Z SFC ANALYSIS HAS A WEAK CLIPPER SYSTEM LOW AT KMHE WITH A WARM
FRONT INTO NORTHWEST IOWA. A COLD FRONT EXTENDED FROM THE LOW IN
CENTRAL AND WESTERN NEBRASKA WHILE A TROF RAN FROM THE LOW INTO
SOUTHEAST COLORADO. DEW POINTS WERE IN THE TEENS AND 20S ACROSS MUCH
OF THE MIDWEST WITH 30 AND HIGHER DEW POINTS FROM THE SOUTHERN
PLAINS INTO THE DEEP SOUTH.
SHORT TERM...TONIGHT AND SATURDAY...
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS THE AREA TONIGHT AND VERY
EARLY SATURDAY. THIS SYSTEM WILL BRING SOME SNOW TO ROUGHLY THE
NORTHERN QUARTER OF THE CWFA.
BASED ON THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS THIS
SNOW EVENT WILL ONLY LAST ABOUT 6 TO POSSIBLY 8 HOURS ONCE IT BEGINS.
NOW...ALL MODELS INITIALIZED TOO MOIST WITH MOISTURE IN THE NORTHERN
PLAINS THIS MORNING. THAT COMBINED WITH THE VERY DRY ATMOSPHERE OVER
THE AREA WILL RESULT IN LOWER SNOW AMOUNTS. THE RUC HAS BEEN VERY
USEFUL SO FAR TODAY DEPICTING WHAT HAS BEEN HAPPENING ON THE 280K
CONDENSATION PRESSURE DEFICIT LAYER WHEN COMBINED WITH
FRONTOGENETICAL FORCING AND F VECTOR CONVERGENCE.
USING THE RUC AS A TREND...THE EARLY EVENING HOURS SHOULD REMAIN
DRY. BETWEEN 03Z AND 06Z FLURRIES OR POSSIBLY SOME VERY LIGHT SNOW
SHOULD MOVE IN OR DEVELOP NORTH OF A KVTI TO KSQI LINE. THE MOST
FAVORED AREA WOULD BE RIGHT ALONG AND NORTH OF HWY 20. HOWEVER...
FCST SOUNDINGS FROM THE RUC AT KDBQ STILL SHOW CONSIDERABLE AMOUNTS
OF DRY AIR BELOW 800MB SO PRECIPITATION CHANCES ARE STILL IN
QUESTION PRIOR TO MIDNIGHT.
AFTER MIDNIGHT THE MAIN VORT MAX MOVES THROUGH THE AREA. FROM JUST
BEFORE MIDNIGHT TO ROUGHLY 10Z WILL BE THE MOST LIKELY TIME FOR SNOW
TO OCCUR. AREAS NORTH OF A KALO TO KRPJ LINE SHOULD SEE -SN WITH
AREAS NORTH OF A KIIB TO KDKB LINE...OR EAST OF MANCHESTER ON THE
HIGHWAY 20 CORRIDOR...HAVING THE BEST CHANCE AT ANY ACCUMULATION.
AMOUNTS WILL BE LIGHT AND SHOULD BE NO MORE THAN 0.5 INCHES. AREAS
IMMEDIATELY NORTH OF THE CWFA MAY SEE AMOUNTS APPROACHING AN INCH.
SATURDAY...SOME LINGERING FLURRIES MAY OCCUR THROUGH SUNRISE IN THE
FAR NORTHEAST PART OF THE CWFA. OTHERWISE...DRY CONDITIONS WITH A
DECREASE IN CLOUDS SHOULD BE SEEN THROUGH THE DAY. TEMPERATURES
SHOULD BE AROUND OR A LITTLE ABOVE NORMAL.
.08..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
SATURDAY NIGHT THROUGH MONDAY...OUR CWA WILL SPEND ANOTHER FEW DAYS
WELL ABOVE NORMAL...WITH TEMPERATURES MUCH MORE REPRESENTATIVE OF
LATE FALL VS MID DECEMBER. HIGHS SUNDAY AND MONDAY IN THE LOWER TO
UPPER 40S LOOK TO BE A STRONG BET...WHILE OVERNIGHT LIGHTS SATURDAY
NIGHT ONLY DIPS TO THE MID 20S AND SUNDAY NIGHT MAY HOLD IN THE
UPPER 30S TO LOWER 40S PENDING CLOUD COVER. WE WILL GO WITH LOWER TO
MID 30S BANKING ON SOME POTENTIAL CLEAR SKIES FOR NOW.
AFTER THE QUIET MILD WEATHER...OUR ATTENTION TURNS TO THE FORECAST
PROBLEMATIC STORM SYSTEM FOR MONDAY AND TUESDAY. MODELS ARE SHIFTING
THIS LOW FARTHER NORTH AGAIN. THIS IS NOT DUE TO SOME SORT OF
CONVECTIVE FEEDBACK OR ANYTHING...BUT RATHER THE INITIALIZATION OF A
STRONG SHORT WAVE OVER THE CENTRAL PACIFIC OCEAN. THE LATITUDE OF
THIS SHORT WAVE AS SEEN ON WATER VAPOR IMAGERY...IS ABOUT 30 TO 35
NORTH...LONGITUDE 155 WEST. THIS PLACEMENT IS A BIT SOUTH OF GLOBAL
MODELS AS OF 18Z. THE IMPACT WILL BE HUGE ON WHETHER THEY HANDLE
THIS WAVE CORRECTLY. OVER TOPPING THE WESTERN RIDGE WOULD RESULT IN
A SOUTHERN LOW TRACK...AND LITTLE OR NO QPF FROM THE STORM MONDAY
AND TUESDAY. A PHASED TRACK IS LIKELY IF THE LOW MAKES A ENTRY INTO
THE CANADIAN AND CONUS NEAR OR SOUTH OF 50 NORTH. THIS COULD BRING
THE SURFACE LOW AS FAR NORTH AS OVERHEAD...PRODUCING A SIGNIFICANT
RAIN EVENT. OUR POPS ARE IN THE CHANCE RANGE FOR MONDAY THROUGH
TUESDAY...WITH THE HIGHEST SOUTH. A TRANSITION FROM RAIN TO SNOW IS
FORECAST FOR MONDAY EVENING NORTH...TO TUESDAY MORNING SOUTH. WHILE
ACCUMULATION ARE POSSIBLE...THE COLD AIR IS LACKING TO THE STORM IN
A PHASED LOW FORECAST. THUS...WE WILL REMAIN VERY VAGUE ON
ACCUMULATION POTENTIAL AT THIS TIME ON PURPOSE.
WEDNESDAY THROUGH FRIDAY REMAINS NEAR OUR BLENDED MODEL FORECAST.
OVER ALL...ANOTHER LARGE TROUGH SHOULD APPROACH THE MIDWEST
THURSDAY...RESULTING IN A CHANCE FOR SNOW...AND POSSIBLY RAIN SNOW
MIX.
.ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
600 PM CST FRI DEC 16 2011
.AVIATION...
AN APPROACHING CLIPPER SYSTEM IS SPREADING VFR CLOUDS INTO
EASTERN IOWA EARLY THIS EVENING. CEILINGS ARE FORECAST TO LOWER TO
MVFR IN SNOW SHOWERS MAINLY AT KDBQ AFTER 04Z. AFTER THE SYSTEM
EXITS TO THE EAST AFTER 12Z SATURDAY CEILINGS WILL GRADUALLY
LIFT WITH VFR CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD.
DC/LE
&&
.PREV DISCUSSION... /ISSUED 314 PM CST FRI DEC 16 2011/
SYNOPSIS...
12Z UA ANALYSIS HAS A SHORTWAVE ACROSS THE DAKOTAS WITH AN 850MB
ARCTIC FRONT FROM CENTRAL MINNESOTA INTO UPPER MICHIGAN. A RIDGE
EXTENDED FROM MINNESOTA INTO WEST TEXAS. SATELLITE AND RADAR TRENDS
THROUGH MID AFTERNOON SHOW LOW CLOUDS ACROSS PARTS OF THE DAKOTAS
INTO MINNESOTA WITH MID AND HIGH CLOUDS FROM NEBRASKA INTO
WISCONSIN. SOME LIGHT SNOW WAS OCCURRING IN WESTERN MINNESOTA WHERE
THE STRONGEST WAA WAS OCCURRING.
18Z SFC ANALYSIS HAS A WEAK CLIPPER SYSTEM LOW AT KMHE WITH A WARM
FRONT INTO NORTHWEST IOWA. A COLD FRONT EXTENDED FROM THE LOW IN
CENTRAL AND WESTERN NEBRASKA WHILE A TROF RAN FROM THE LOW INTO
SOUTHEAST COLORADO. DEW POINTS WERE IN THE TEENS AND 20S ACROSS MUCH
OF THE MIDWEST WITH 30 AND HIGHER DEW POINTS FROM THE SOUTHERN
PLAINS INTO THE DEEP SOUTH.
SHORT TERM...TONIGHT AND SATURDAY...
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS THE AREA TONIGHT AND VERY
EARLY SATURDAY. THIS SYSTEM WILL BRING SOME SNOW TO ROUGHLY THE
NORTHERN QUARTER OF THE CWFA.
BASED ON THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS THIS
SNOW EVENT WILL ONLY LAST ABOUT 6 TO POSSIBLY 8 HOURS ONCE IT BEGINS.
NOW...ALL MODELS INITIALIZED TOO MOIST WITH MOISTURE IN THE NORTHERN
PLAINS THIS MORNING. THAT COMBINED WITH THE VERY DRY ATMOSPHERE OVER
THE AREA WILL RESULT IN LOWER SNOW AMOUNTS. THE RUC HAS BEEN VERY
USEFUL SO FAR TODAY DEPICTING WHAT HAS BEEN HAPPENING ON THE 280K
CONDENSATION PRESSURE DEFICIT LAYER WHEN COMBINED WITH
FRONTOGENETICAL FORCING AND F VECTOR CONVERGENCE.
USING THE RUC AS A TREND...THE EARLY EVENING HOURS SHOULD REMAIN
DRY. BETWEEN 03Z AND 06Z FLURRIES OR POSSIBLY SOME VERY LIGHT SNOW
SHOULD MOVE IN OR DEVELOP NORTH OF A KVTI TO KSQI LINE. THE MOST
FAVORED AREA WOULD BE RIGHT ALONG AND NORTH OF HWY 20. HOWEVER...
FCST SOUNDINGS FROM THE RUC AT KDBQ STILL SHOW CONSIDERABLE AMOUNTS
OF DRY AIR BELOW 800MB SO PRECIPITATION CHANCES ARE STILL IN
QUESTION PRIOR TO MIDNIGHT.
AFTER MIDNIGHT THE MAIN VORT MAX MOVES THROUGH THE AREA. FROM JUST
BEFORE MIDNIGHT TO ROUGHLY 10Z WILL BE THE MOST LIKELY TIME FOR SNOW
TO OCCUR. AREAS NORTH OF A KALO TO KRPJ LINE SHOULD SEE -SN WITH
AREAS NORTH OF A KIIB TO KDKB LINE...OR EAST OF MANCHESTER ON THE
HIGHWAY 20 CORRIDOR...HAVING THE BEST CHANCE AT ANY ACCUMULATION.
AMOUNTS WILL BE LIGHT AND SHOULD BE NO MORE THAN 0.5 INCHES. AREAS
IMMEDIATELY NORTH OF THE CWFA MAY SEE AMOUNTS APPROACHING AN INCH.
SATURDAY...SOME LINGERING FLURRIES MAY OCCUR THROUGH SUNRISE IN THE
FAR NORTHEAST PART OF THE CWFA. OTHERWISE...DRY CONDITIONS WITH A
DECREASE IN CLOUDS SHOULD BE SEEN THROUGH THE DAY. TEMPERATURES
SHOULD BE AROUND OR A LITTLE ABOVE NORMAL.
.08..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
SATURDAY NIGHT THROUGH MONDAY...OUR CWA WILL SPEND ANOTHER FEW DAYS
WELL ABOVE NORMAL...WITH TEMPERATURES MUCH MORE REPRESENTATIVE OF
LATE FALL VS MID DECEMBER. HIGHS SUNDAY AND MONDAY IN THE LOWER TO
UPPER 40S LOOK TO BE A STRONG BET...WHILE OVERNIGHT LIGHTS SATURDAY
NIGHT ONLY DIPS TO THE MID 20S AND SUNDAY NIGHT MAY HOLD IN THE
UPPER 30S TO LOWER 40S PENDING CLOUD COVER. WE WILL GO WITH LOWER TO
MID 30S BANKING ON SOME POTENTIAL CLEAR SKIES FOR NOW.
AFTER THE QUIET MILD WEATHER...OUR ATTENTION TURNS TO THE FORECAST
PROBLEMATIC STORM SYSTEM FOR MONDAY AND TUESDAY. MODELS ARE SHIFTING
THIS LOW FARTHER NORTH AGAIN. THIS IS NOT DUE TO SOME SORT OF
CONVECTIVE FEEDBACK OR ANYTHING...BUT RATHER THE INITIALIZATION OF A
STRONG SHORT WAVE OVER THE CENTRAL PACIFIC OCEAN. THE LATITUDE OF
THIS SHORT WAVE AS SEEN ON WATER VAPOR IMAGERY...IS ABOUT 30 TO 35
NORTH...LONGITUDE 155 WEST. THIS PLACEMENT IS A BIT SOUTH OF GLOBAL
MODELS AS OF 18Z. THE IMPACT WILL BE HUGE ON WHETHER THEY HANDLE
THIS WAVE CORRECTLY. OVER TOPPING THE WESTERN RIDGE WOULD RESULT IN
A SOUTHERN LOW TRACK...AND LITTLE OR NO QPF FROM THE STORM MONDAY
AND TUESDAY. A PHASED TRACK IS LIKELY IF THE LOW MAKES A ENTRY INTO
THE CANADIAN AND CONUS NEAR OR SOUTH OF 50 NORTH. THIS COULD BRING
THE SURFACE LOW AS FAR NORTH AS OVERHEAD...PRODUCING A SIGNIFICANT
RAIN EVENT. OUR POPS ARE IN THE CHANCE RANGE FOR MONDAY THROUGH
TUESDAY...WITH THE HIGHEST SOUTH. A TRANSITION FROM RAIN TO SNOW IS
FORECAST FOR MONDAY EVENING NORTH...TO TUESDAY MORNING SOUTH. WHILE
ACCUMULATION ARE POSSIBLE...THE COLD AIR IS LACKING TO THE STORM IN
A PHASED LOW FORECAST. THUS...WE WILL REMAIN VERY VAGUE ON
ACCUMULATION POTENTIAL AT THIS TIME ON PURPOSE.
WEDNESDAY THROUGH FRIDAY REMAINS NEAR OUR BLENDED MODEL FORECAST.
OVER ALL...ANOTHER LARGE TROUGH SHOULD APPROACH THE MIDWEST
THURSDAY...RESULTING IN A CHANCE FOR SNOW...AND POSSIBLY RAIN SNOW
MIX.
.ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
244 PM CST THU DEC 15 2011
.SYNOPSIS...
12Z UA ANALYSIS HAS A LLJ RUNNING FROM OKLAHOMA INTO NEW ENGLAND.
SEVERAL TROFS RAN FROM THE WESTERN GREAT LAKES INTO THE NORTHERN
PLAINS WHERE ANOTHER LLJ WAS LOCATED. SATELLITE TRENDS THROUGH EARLY
AFTERNOON SHOW THE CLOUDS BEGINNING TO BREAK UP AS STRONG SUBSIDENCE
DEVELOPS ACROSS THE PLAINS AND UPPER MISSISSIPPI VALLEY.
18Z SFC ANALYSIS HAS THE COLD FRONT FROM LAKE HURON INTO EASTERN
TEXAS WITH HIGH PRESSURE IN THE PLAINS. SEVERAL TROFS RAN FROM THE
WESTERN LAKES INTO THE UPPER MISSISSIPPI VALLEY. DEW POINTS AHEAD OF
THE FRONT WERE IN THE 50S AND 60S WITH 30S AND 40S IMMEDIATELY
BEHIND THE FRONT. DEW POINTS IN THE TEENS AND 20S WERE IN THE PLAINS
AND PARTS OF THE MIDWEST.
&&
.SHORT TERM...TONIGHT AND FRIDAY...
QUIET WX WITH SEASONABLE TEMPERATURES WILL BE SEEN TONIGHT AND
FRIDAY. WINDS WILL CONTINUE TO DECREASE LATE THIS AFTERNOON AND
EVENING AS THE STRONGEST ISALLOBARIC CHANGE CONTINUES TO MOVE EAST
OF THE AREA. RUC TRENDS INDICATE THAT STRONG SUBSIDENCE IS
DEVELOPING BEHIND THE DEPARTING SHORTWAVE AND SATELLITE DOES SHOW
MORE BREAKS BEGINNING TO DEVELOP IN THE CLOUD SHIELD.
BASED ON CURRENT SATELLITE AND RUC TRENDS...CLOUDS WILL CONTINUE TO
SLOWLY BREAK UP FOR THE REMAINDER OF THE AFTERNOON WITH CLEARING
DEVELOPING ACROSS THE CWFA LATE THIS AFTERNOON OR EVENING.
..08..
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
A WEAK CLIPPER SHOULD SLIDE SOUTHEAST FRIDAY EVENING...BRINGING SOME
MID CLOUDS TO THE CWA...AND AN OUTSIDE CHANCE FOR A SNOW
SHOWER...BUT MORE LIKELY FLURRIES IN THE NORTH. THIS VERY MINOR
EVENT PASSES QUICKLY FRIDAY NIGHT AND LEAVES SATURDAY AND SUNDAY
WITH VERY PLEASANT LATE FALL WEATHER. HIGHS IN THE MID TO UPPER 30S
SATURDAY AND LOWER TO MID 40S SUNDAY. THIS ENDS THE PERIOD OF HIGH
CONFIDENCE IN THE EXTENDED.
THE MODELS ARE IN TWO CAMPS NOW WITH RESPECT TO THE MONDAY THROUGH
WEDNESDAY STORM. THE GEM...UKMET...AND GFS RUNS SINCE 00Z LAST NIGHT
HAVE GONE FARTHER NORTH...AND BRING A SIMILAR STORM TO THE MIDWEST
THAN WAS SEEN IN THE PAST 2 DAYS. HOWEVER...THE ECMWF HAS TRENDED
SOUTH...AND CLIPS THE CWA WITH LIGHT SNOW ON TUESDAY/TUESDAY NIGHT.
THE MAJOR DIFFERENCE BETWEEN THESE MODELS BOILS DOWN TO HOW THEY
HANDLE A SEPARATE SHORT WAVE THAT ENTERS THE PACIFIC NORTHWEST
SATURDAY. THE GEM/UK/GFS ALL BRING THAT STORM INTO THE WA/OR
COAST...AND PHASE THAT WAVE/KICK THE CLOSED LOW NORTHEASTWARD AND
THEREFORE DEVELOP A SIGNIFICANT MIDWEST STORM. THE ECMWF BRINGS THIS
WAVE INTO CENTRAL BRITISH COLUMBIA...AND AS IT MOVES IT EAST...IT
OVER TOPS THE RIDGE ON THE WEST COAST VS KICKING THE LOW OUT WITH
IT. AFTER OVERTOPPING...IT SWEEPS HIGH PRESSURE AND COLD AIR DOWN
INTO THE MIDWEST FOR EARLY WEEK AND THEREFORE SUPPRESSES THE STORM
SYSTEM SOUTH. SUCH A SMALL DIFFERENCE...RESULTS IN A MAJOR
DIFFERENCES IN OUR WEATHER. THIS WAVE IN QUESTION IS REAL...BUT
FOUND OVER THE NORTH CENTRAL PACIFIC OCEAN AS OF NOW...AND IS WITHIN
A FAST BAND OF WESTERLY FLOW SOUTH OF A MAJOR ALEUTIAN LOW.
THUS...GLOBAL MODELS WILL NO LIKELY LOCK CORRECTLY ONTO ITS POSITION
AND STRENGTH FOR SOME DAYS. PREDICTING THE WEATHER IS A
CHALLENGE...BUT THIS ONE WILL TAKE TIME TO BE WORKED OUT. UNTIL WE
KNOW FOR SURE WHAT LATITUDE THIS WAVE MAKES LANDFALL IN THE PAC
NORTHWEST...WE WILL NO KNOW WHETHER IT OVERTOPS OR PHASES/KICKS OUT
OUR CLOSED LOW IN THE SOUTHWEST. TIME WILL CERTAINLY TELL.
OUR FORECAST REMAINS WET TO START...AND SNOWY TO END THIS
STORM...POPS ARE LOW...BUT SHOULD THE NORTHERN TRACK BY CORRECT...WE
NEED MUCH HIGHER POPS FOR THIS EVENT.
WEDNESDAY AND THURSDAY...ALL GLOBAL MODELS SHOW THE PATTERN
RELOADING FOR ANOTHER CUT OFF LOW IN THE SOUTHWEST. THIS SHOULD
PROVIDE ANOTHER DAY OR TWO OF QUIET WEATHER BEFORE ANOTHER POTENTIAL
EVENT.
..ERVIN..
&&
.AVIATION...
CIGS CONTINUE TO LIFT AND MOST LOCATIONS ARE GENERALLY 3KFT OR 4KFT
AGL. WINDS WILL DIMINISH THROUGH 06Z/16 WITH CLEARING TAKING PLACE.
HIGH PRESSURE BUILDING INTO THE MIDWEST WILL RESULT IN VFR
CONDITIONS THROUGH 00Z/17.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1130 AM CST THU DEC 15 2011
.AVIATION...
MVFR CONDITIONS WILL CONTINUE UNTIL CLOSE TO 00Z/16 WHEN VFR
CONDITIONS ARE EXPECTED TO DEVELOP. THE STRONGEST WINDS WILL BE
SEEN THROUGH 20Z/15 IN RESPONSE TO THE FALL/RISE PRESSURE COUPLET.
WINDS WILL BEGIN TO DECREASE AFT 21Z/15 AS HIGH PRESSURE BUILDS
INTO THE MIDWEST.
..08..
&&
.PREV DISCUSSION... /ISSUED 1036 AM CST THU DEC 15 2011/
UPDATE...
12Z UA DATA HAS A NICE TROF MOVING ACROSS IOWA WHICH IS AIDING IN
GENERATING THE DZ AND SOME VERY LIGHT RAIN. RUC TRENDS HAVE THE
SUPPORT FOR THE DZ MOVING EAST OF THE CWFA EARLY THIS AFTERNOON
AND RADAR EXTRAPOLATION SUPPORTS THIS AS WELL.
AS FOR THE WINDS...THE MAXIMUM ISALLOBARIC CHANGE IS CURRENTLY
MOVING ACROSS THE CWFA. SO THE STRONGEST WINDS WILL BE SEEN OVER
THE NEXT 4 HOURS BEFORE DECREASING. THERE ARE NO PLANS FOR ANY
HEADLINES FOR THE WIND BUT GUSTS TO 35 MPH WILL BE VERY LIKELY
INTO EARLY AFTERNOON.
BREAKS HAVE DEVELOPED IN THE CLOUD COVER BUT SATELLITE TRENDS ARE
INDICATING THESE ARE FILLING IN. AS THE STRONGER SUBSIDENCE
DEVELOPS BEHIND THE DEPARTING SHORTWAVE THIS AFTERNOON CLOUDS
SHOULD BEGIN TO BREAK UP WITH CLEARING OCCURRING ACROSS MUCH OF
THE AREA BY OR SHORTLY AFTER SUNSET.
TEMPERATURES WILL CONTINUE TO SLOWLY FALL THROUGH THE AFTERNOON.
ANY PEEKS OF SUN MAY RESULT IN A BRIEF RISE IN SOME AREAS.
AN UPDATE REFLECTING ALL THIS WILL BE AVAILABLE SHORTLY.
.08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1036 AM CST THU DEC 15 2011
.UPDATE...
12Z UA DATA HAS A NICE TROF MOVING ACROSS IOWA WHICH IS AIDING IN
GENERATING THE DZ AND SOME VERY LIGHT RAIN. RUC TRENDS HAVE THE
SUPPORT FOR THE DZ MOVING EAST OF THE CWFA EARLY THIS AFTERNOON
AND RADAR EXTRAPOLATION SUPPORTS THIS AS WELL.
AS FOR THE WINDS...THE MAXIMUM ISALLOBARIC CHANGE IS CURRENTLY
MOVING ACROSS THE CWFA. SO THE STRONGEST WINDS WILL BE SEEN OVER
THE NEXT 4 HOURS BEFORE DECREASING. THERE ARE NO PLANS FOR ANY
HEADLINES FOR THE WIND BUT GUSTS TO 35 MPH WILL BE VERY LIKELY
INTO EARLY AFTERNOON.
BREAKS HAVE DEVELOPED IN THE CLOUD COVER BUT SATELLITE TRENDS ARE
INDICATING THESE ARE FILLING IN. AS THE STRONGER SUBSIDENCE
DEVELOPS BEHIND THE DEPARTING SHORTWAVE THIS AFTERNOON CLOUDS
SHOULD BEGIN TO BREAK UP WITH CLEARING OCCURRING ACROSS MUCH OF
THE AREA BY OR SHORTLY AFTER SUNSET.
TEMPERATURES WILL CONTINUE TO SLOWLY FALL THROUGH THE AFTERNOON.
ANY PEEKS OF SUN MAY RESULT IN A BRIEF RISE IN SOME AREAS.
AN UPDATE REFLECTING ALL THIS WILL BE AVAILABLE SHORTLY.
..08..
&&
.PREV DISCUSSION... /ISSUED 535 AM CST THU DEC 15 2011/
AVIATION...
LOW CLOUDS WITH BASES OF 800-2500 FEET TO PERSIST AT ALL TERMINALS
THROUGH 17Z OR 11 AM RESULTING IN MVFR TO BRIEFLY IFR CONDITIONS
AT DBQ AND CID TERMINALS. LOW CLOUDS TO GRADUALLY BREAK UP BETWEEN
17-23Z OR 11 AM AND 5 PM RESULTING IN VFR CONDITIONS. WEST TO
NORTHWEST WINDS OF 15 TO 30+ MPH TO DIMINISH TOWARD SUNSET TO 5-10
MPH BY 9 PM. CLEAR SKIES WITH LIGHT NW WINDS TO CONTINUE THROUGH
AT LEAST 16/18Z. ..NICHOLS..
PREV DISCUSSION... /ISSUED 330 AM CST THU DEC 15 2011/
SYNOPSIS...
SURFACE ANALYSIS SHOWS STRONG COLD AIR ADVECTION UNDERWAY ACROSS THE
FORECAST AREA FROM WEST TO NORTHWEST WINDS OF 15 TO 25 MPH.
ISALLOBARIC PRESSURE RISES SUPPORT WINDS TO INCREASE TO 20 TO 30+ MPH
WITH ISOLATED GUSTS AROUND 35 MPH UNTIL MID AFTERNOON. LOW CLOUDS TO
COMBINE WITH COLD AIR ARRIVING TO KEEP TEMPERATURES STEADY OR SLOWLY
FALLING ALL DAY. ISOLATED VERY LIGHT DRIZZLE MAY BE POSSIBLE INTO THE
MID MORNING HOURS. UPPER AIR ANALYSIS SUPPORTS SEASONALLY COLD AND
QUIET NEXT SEVERAL DAYS UNDER NORTHWEST FLOW REGIME. ..NICHOLS..
SHORT TERM...TODAY AND TONIGHT...
TODAY...AS DISCUSSED ABOVE...WINDY AND COLD WITH NEAR STEADY TO
SLOWLY FALLING TEMPERATURE ALL DAY FROM W-NW WINDS OF 20 TO 30+ MPH
WITH ISOLATED HIGHER GUSTS TO AROUND 35 MPH ALONG AND NORTH OF I-80
CORRIDOR UNTIL LATE AFTERNOON. LOW CLOUDS TO PERSIST ACROSS THE
REGION INTO EARLY TO MID AFTERNOON WITH RAPID CLEARING OCCURRING IN
LATE AFTERNOON HOURS FROM SUBSIDENCE AND LOSS OF HEATING AS THE SUN
SETS. TEMPERATURES TO HOVER IN THE MID TO UPPER 30S ALL BUT FAR SE
SECTIONS WHICH WILL STAY IN THE LOWER 40S INTO EARLY AFTERNOON AND
THEN FALL INTO THE 30S.
TONIGHT...CLEAR AND COLD WITH NW WINDS DECREASING TO 5 TO 10 MPH TO
ALLOW ENOUGH BL DECOUPLING FOR LOWS OF 20 TO 25 DEGREES WITH LOCAL
TECHNIQUES SUGGESTING UPPER TEENS IN MANY LOCATIONS ACROSS THE NW
SECTIONS FOR LATER SHIFTS TO CONSIDER. ..NICHOLS..
LONG TERM...FRIDAY THROUGH WEDNESDAY...
PERIOD OF NW FLOW ALOFT AND MORE SEASONABLE TEMPERATURES ARE IN
STORE FOR FRIDAY THROUGH SUNDAY. FOCUS THEN TURNS TO A STORM SYSTEM
LIFTING OUT OF THE SOUTHWEST THAT MAY BRING PRECIPITATION TO THE
AREA EARLY NEXT WEEK.
MODELS CONTINUE TO DEPICT A WEAK CLIPPER SYSTEM FOR FRIDAY
NIGHT...WITH LATEST RUNS DEVELOPING A WEAK CIRCULATION AT THE
SURFACE AND VERY LIGHT QPF. THIS WEAK CIRCULATION AND AXIS OF
STRONGEST LIFT PASSES THROUGH THE NORTHERN HALF OF THE FORECAST
THROUGH AROUND 06Z...AND HAVE GONE WITH SLIGHT CHANCES FOR LIGHT
SNOW ACCUMULATION. NON-ACCUMULATING FLURRIES ARE MORE LIKELY...AND
HAVE EXTENDED MENTION OF OVERNIGHT FLURRIES OVER ALL BUT THE
SOUTHWEST.
A STRONGER SHORTWAVE IS SHOWN PASSING TO THE NORTH ON SATURDAY...
WITH ASSOCIATED FLURRIES AND SNOW CHANCES TRENDING WELL TO THE NORTH
AND NOT INCLUDED IN THE FORECAST. TEMPERATURES BOTH FRIDAY AND
SATURDAY SHOULD BE LIMITED TO THE 30S OVER MOST OF THE REGION...WITH
OVERNIGHT LOWS IN THE 20S.
THE LATEST MODEL RUNS HAVE COME INTO BETTER AGREEMENT SHOWING
ANOTHER SHORTWAVE IN THE NORTHERN STREAM PASSING TO THE NORTH SUNDAY
NIGHT THAT SENDS A COLD FRONT THROUGH THE FORECAST AREA SUNDAY NIGHT
OR MONDAY. THIS IS FOLLOWED BY A SURFACE SYSTEM AND UPPER LOW
LIFTING OUT OF THE SOUTHWEST U.S. ALONG THIS COLD FRONT. THE LATEST
GFS AND ECMWF HAVE LATCHED ONTO A TRACK THAT WOULD THIS SYSTEM
MAINLY WELL TO THE SOUTH...SUGGESTING A DRY PERIOD UNDER HIGH
PRESSURE. THE UKMET AND GEM OFFER A MORE NWRLY TRACK THAT WOULD
IMPACT THE AREA. OVERALL...CONFIDENCE REMAINS LOW IN ANY
DETERMINISTIC FORECAST IN THESE PERIODS AS DIFFERENCES IN PHASING OF
SHORTWAVES IN THE NORTHERN STREAM AND THE UPPER LOW EJECTING FROM THE
SOUTHWEST CONTINUE BETWEEN MEDIUM RANGE MODELS WITH POOR RUN TO RUN
CONSISTENCY. THE GFS HAS REMAINED THE MOST CONSISTENT...HOLDING A
TRACK THAT WOULD KEEP THE SYSTEM WELL TO THE SOUTH. FOR NOW...THE
FORECAST HAS BEEN NUDGED TOWARD MORE SOUTHERLY AND SLOWER
SOLUTIONS...RESULTING IN A SLIGHT LOWERING OF POPS FROM SUNDAY NIGHT
THROUGH TUESDAY. PRECIPITATION TYPE IS ALSO A CHALLENGE...AND KEPT
AS A MIX FOR NOW WITH BETTER CHANCES FOR SNOW IN THE NORTH AND RAIN
IN THE SOUTHEAST. WEDNESDAY IS KEPT WITH TEMPERATURES NEAR CLIMO...
BUT IF THE SLOWER TIMING OF THE 00Z ECMWF HOLDS TRUE...PRECIPITATION
CHANCES MAY NEED TO BE EXTENDED TO THIS PERIOD AS WELL. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1153 PM CST WED DEC 14 2011
.AVIATION...
A COLD FRONT SLOWLY MOVING THROUGH THE AREA THIS EVENING. IT IS
PRECEDED BY A NARROW BAND OF SHOWERS THAT HAS NOW MOVED THROUGH
THE FOUR TERMINAL LOCATIONS. WINDS HAVE NOW ALSO SWITCHED TO
SOUTHWEST OR WEST. THE COLD FRONT HAS LIFTED CIGS AND VSBYS TO
MVFR OR EVEN VFR AS IT HAS MOVED THROUGH EACH OF THE TERMINALS.
STRATUS TO SPREAD BACK INTO THE TERMINALS BEHIND THE COLD
FRONT...AND AT LEAST TEMPORARILY WILL DROP CIG HEIGHTS TO IFR.
THIS IS NOT EXPECTED TO PERSIST...AND SHOULD RISE TO MVFR BEFORE
MID MORNING. CLEARING OF THE STRATUS IS UNCLEAR. INDICATIONS SHOW
AFTERNOON CLEARING AND THEN A CLEAR OVERNIGHT. HOWEVER...THIS TIME
OF YEAR IT IS MORE DIFFICULT TO CLEAR THIS STRATUS AND IT MAY
LINGER OVERNIGHT TONIGHT AS WELL. ..LE..
&&
.PREV DISCUSSION... /ISSUED 319 PM CST WED DEC 14 2011/
SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB WARM FRONT FROM SOUTH DAKOTA INTO
SOUTHERN WISCONSIN. A LLJ RAN FROM THE WESTERN GREAT LAKES TO NORTH
TEXAS WITH THE STRONG CORE OF 50-55 KNOTS FROM EASTERN KANSAS INTO
NORTH TEXAS. A STRONG MOISTURE FEED RAN FROM THE GULF COAST INTO THE
WESTERN GREAT LAKES. RADAR TRENDS SHOW THE CONVECTION AND
THUNDERSTORMS HAVE SHIFTED INTO EASTERN ILLINOIS WITH PRECIPITATION
INTENSITY DECREASING ACROSS IOWA AND MISSOURI.
18Z SFC ANALYSIS HAD A WEAK LOW NEAR KLNK WITH A WARM FRONT ALONG
THE IA/MO BORDER INTO CENTRAL ILLINOIS. A COLD FRONT RAN FROM THE
LOW BACK INTO SOUTHEAST COLORADO. DEW POINTS SOUTH OF THE WARM FRONT
WERE IN THE 50S AND 60S.
SHORT TERM...TONIGHT AND THURSDAY...
THE RUC HAS BEEN DOING A REASONABLE JOB OF HANDLING THE IMMEDIATE
SHORT TERM AND THE TRENDS OF THE RUC WERE FOLLOWED FOR INPUT TONIGHT.
THE LIFT TOOL INDICATES THE THREAT OF THUNDER IS NOW OVER WITH THE
PASSAGE OF A STRONG VORT MAX. OVERALL PRECIPITATION INTENSITY WILL
NOW BE LIGHT DURING THE EVENING HOURS WITH EVERYTHING TRANSITIONING
TO MORE DRIZZLE WITH TIME. THUS DRIZZLE WITH SOME RAIN WILL BE SEEN
DURING THE EVENING HOURS ALONG WITH PATCHY FOG. AFTER MIDNIGHT...
CONDENSATION PRESSURE DEFICITS SLOWLY RISE IN THE WEST WITH THE
BETTER FORCING SHIFTING EAST OF THE MISSISSIPPI. THE RUC DOES SHOW
ANOTHER ROUND OF FORCING ARRIVING AROUND MIDNIGHT IN THE WESTERN
CWFA. THUS WILL CONTINUE THE DRIZZLE WITH OVERALL LOWER CHANCES OF
RAIN. PATCHY FOG WILL STILL BE AN ISSUE AFTER MIDNIGHT.
THE OVERALL DENSE FOG IS PATCHY IN NATURE AND GENERALLY CONFINED TO
THE HWY 20 CORRIDOR. THE MORE WIDESPREAD AND LIKELY DENSE FOG SHOULD
BE SEEN ACROSS WISCONSIN AND MINNESOTA WHERE THE SFC LOW TRACKS.
THE COLD FRONT WILL MOVE THROUGH THE CWFA AFTER MIDNIGHT. WINDS
SHOULD REMAIN UP WHICH WILL KEEP THE FOG FROM GETTING TOO DENSE AS
THE OVERALL ATMOSPHERIC COLUMN COOLS. LOW TEMPERATURES SHOULD OCCUR
BETWEEN 7 AND 9 AM THURSDAY MORNING.
THURSDAY...THERE MAY OR MAY NOT BE SOME LINGERING DRIZZLE ACROSS THE
EASTERN CWFA EARLY IN THE MORNING. CONDENSATION PRESSURE DEFICITS
CONTINUE TO RISE AND NO FORCING IS PRESENT. HOWEVER...FORECAST
SOUNDINGS DO SHOW CONSIDERABLE DRYING ABOVE THE LOW CLOUDS SO SOME
DRIZZLE MAY BE POSSIBLE. CLEARING WILL BE SLOW TO OCCUR DURING THE
MORNING. AS HIGH PRESSURE BEGINS BUILDING IN BY MID DAY A GENERAL
CLEARING OF SKIES SHOULD BE SEEN FROM WEST TO EAST DURING THE
AFTERNOON. MAX TEMPERATURES WILL OCCUR BETWEEN 7 AND 9 AM THURSDAY
MORNING WITH TEMPERATURES SLOWLY FALLING THROUGH THE DAY.
..08..
LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...THE LONG TERM
BEGINS WITH A BRIEF COOL DOWN IN THE WAKE OF OUR CURRENT
STORM...THEN AFTER ABOUT 48 HOURS OF NORTHWEST FLOW...WE BEGIN TO
TREND TOWARD ANOTHER POTENTIAL SIGNIFICANT STORM SYSTEM FOR SUNDAY
NIGHT THROUGH TUESDAY.
MOISTURE WILL BE STARVED...BUT SOME POSSIBLE FLURRIES OR BRIEF LIGHT
SNOW COULD OCCUR SATURDAY AFTERNOON IN THE FAR NORTH AS SHEARED OUT
SHORT WAVE ARRIVES FROM THE NORTHWEST. THIS LOOKS TO MAIN PRODUCE
MID CLOUDS DURING THE AFTERNOON AND EVENING HOURS SATURDAY.
TEMPERATURES WILL BE COOL...BUT NOT COLD. WITH LOWS IN THE LOWER TO
MID 20S...AND HIGHS GENERALLY IN THE LOWER TO UPPER 30S.
SUNDAY...THERE BEGINS TO BE ANOTHER CHANGE TOWARD AN ACTIVE STORM
SYSTEM. THERE ARE MAJOR DIFFERENCES IN THE POSITION OF A NORTHWEST
FLOW WAVE THAT MAKES LANDFALL ON EITHER THE SOUTHWEST CANADIAN
COAST/BRITISH COLUMBIA...OR NORTHWESTERN CONUS. THIS SMALL
DIFFERENCE IN MODELS GREATLY INFLUENCED THE AMOUNT OF PHASING OF THE
UPPER LOW WHICH SHOULD BE CUT OFF IN THE SOUTHWEST CONUS AT THAT
TIME. THE UKMET...GEM...AND ECMWF CONTINUE TO SHOW THE NORTHWEST
FLOW WAVE HITTING THE WA/OR COASTLINE THEN DRAWING THE CUT OFF LOW
NORTHEAST SUNDAY NIGHT. THE GFS MAKES A MORE NORTHERLY ENTRY INTO
CENTRAL BRITISH COLUMBIA WITH THE NORTHWESTERN SHORT
WAVE...THUS...IT IS DELAYED BY 24 HOURS ON PHASING WITH THE LOW IN
THE SOUTHWEST...AND LESS SO AT THAT. THUS...FOR THAT REASON
ALONE...THE GFS REMAINS FAR SOUTH OF OTHER GLOBAL MODELS...AS WELL
AS SLOWER. THE CURRENT STORM OVERHEAD WAS ALSO FORECAST BY THE GFS
TO BE FARTHER SOUTH WHEN IT WAS OUT IN THIS DAY 6 PERIOD FOR SIMILAR
REASONS...AND THEREFORE WHEN COMBINED WITH THE FACT THAT THERE IS
LITTLE OR NO SNOW COVER IN THE MIDWEST AND THERE IS NO ARCTIC AIR IN
PLACE TO KEEP A SYSTEM SOUTH...I BELIEVE IN A MORE PHASED NORTHERLY
SOLUTION. THIS POTENTIAL STORM LOOKS TO HAVE ANOTHER OPEN GULF...AND
MODEST TO STRONG UPPER FORCING. THUS...SHOULD IT OCCUR...ANOTHER
ROUND OF MODERATE RAIN IS LIKELY.
SNOW MAY OCCUR ON THE BACKSIDE PENDING THE SPEED OF THE SYSTEM AND
ABILITY TO DYNAMICALLY COOL THE ATMOSPHERE. THERE IS LITTLE
CONFIDENCE IN THAT PROCESS AT THIS TIME...BUT ENOUGH TO WARRANT
INCLUDING A RAIN OR SNOW FORECAST FOR THE NORTHWEST HALF MONDAY
NIGHT. TUESDAY MAY SEE SNOW...BUT THAT WILL DEPEND GREATLY ON THIS
SYSTEM REMAINING CLOSED AT MID LEVELS. WEDNESDAY OF NEXT WEEK
APPEARS DRY AND SEASONALLY COOL.
..ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
430 PM MST FRI DEC 16 2011
.DISCUSSION...
227 PM MST FRI DEC 16 2011
MAIN FORECAST PROBLEM WILL BE STORM FOR THE BEGINNING OF NEXT WEEK
WITH SECONDARY PROBLEMS OF HOW MUCH TO WARM IT UP BEFORE THIS NEXT
UPPER LOW FOLLOWED BY WHAT KIND OF WEATHER THE NEXT COMPLICATED UPPER
TROUGH/S WILL BRING TO THE AREA THE END OF NEXT WEEK. SATELLITE
SHOWING AN AMPLIFIED/AMPLIFYING PATTERN FROM THE PACIFIC INTO NORTH
AMERICA. DUE TO DEEPENING TROUGH OVER THE WESTERN PACIFIC...SOUTHERN
END OF EASTERN PACIFIC TROUGH IS DEEPENING AND CAUSING THE WESTERN
RIDGE TO BUILD. THIS AND HEIGHT FALL ANALYSIS SHOWS UPPER LOW OVER
BAJA SINKING SOUTH AND WEST. THIS IS PART OF SPLIT FLOW/MEAN TROUGH
THAT EXISTS OVER MOST OF THE REST OF THE COUNTRY.
IN REGARDS TO THE JET OVER THE NORTHEAST PACIFIC AND ROUNDING OVER
THE TOP OF THE RIDGE...THE MODELS LOOK UNDERDONE ON SPEEDS. ON THE
SEGMENT THAT EXTENDS FROM MONTANA TO THE NORTHWEST OF THE UPPER LOW
THE MODELS TENDED TO BE SLIGHTLY UNDERDONE AND TOO FAR EAST AND
SOUTH WITH THE SEGMENT. THE NAM WAS DOING THE BEST FOLLOWED BY THE
UKMET AND THE CANADIAN. SAME THING AT MID LEVELS WITH THE NAM DOING
SLIGHTLY BETTER THAN THE CANADIAN AND UKMET. AT THE SURFACE...THE
ECMWF WAS DOING SLIGHTLY BETTER THAN THE NAM. ON THE LOW LEVEL
THERMAL FIELD THE NAM AND GFS WERE DOING SLIGHTLY BETTER THAN THE
REMAINING OUTPUT.
TONIGHT...CURRENT SURFACE OBSERVATIONS SHOW A SURFACE TROUGH MOVING
EAST ACROSS THE TRI-STATE AREA. WINDS HAVE REMAINED LIGHT TO
BREEZY...BUT A FEW GUSTS HAVE APPROACHED 25 MPH AHEAD AND BEHIND THE
TROUGH. RUC UPPER AIR ANALYSIS SHOWS AN UPPER LEVEL TROUGH
FOLLOWING THE SURFACE FEATURE...AND SATELLITE IMAGERY CONTINUES TO
SHOW A FEW MID AND HIGH CLOUDS ON EITHER SIDE OF THE UPPER LEVEL
TROUGH. FURTHER WEST THE CLOSED LOW REMAINS POSITIONED OVER THE
BAJA PENINSULA AND HAS BEEN SLOWLY RETROGRADING TO THE WEST THROUGH
THE DAY.
NORTHWEST WINDS WILL GRADUALLY TURN TO THE WEST DURING THE EVENING...
AS A SURFACE RIDGE OF HIGH PRESSURE MOVES ACROSS THE TRI-STATE AREA
BEHIND THE SURFACE TROUGH. RELATIVE HUMIDITY VALUES WILL BE NEAR 100
PERCENT OVER THE SNOW FIELD FOR THE MCCOOK AND OBERLIN AREA. HOWEVER
THE LIGHT WEST WINDS AND DRY AIR ABOVE THE SURFACE WOULD SUPPORT NO
FOG FORMING. OTHERWISE LOWS WILL BE SIMILAR TO LAST NIGHT.
SATURDAY/SATURDAY NIGHT...AREA REMAINS UNDER SUBSIDENCE AND
INFLUENCE FROM THE MID/UPPER RIDGE. WILL BE DOWNSLOPE WINDS BUT
MOSTLY LIGHT. DID WARM UP TEMPERATURES BUT POTENTIAL IS THERE TO BE
WARMER THAN WHAT I HAVE. DURING THE NIGHT DOWNSLOPE WINDS ARE IN
PLACE AND CLOUDS DO INCREASE A LITTLE.
SUNDAY...MAIN JET IS STILL FAR AWAY FROM THE AREA. DUE TO THE UPPER
LOW STILL BEING VERY FAR AWAY...MID LEVEL RIDGING AND DRYING WILL
BE IN PLACE. BY THIS TIME...WHATEVER SNOW IS HERE NOW SHOULD NOT BE
A FACTOR IN MAXES. MODELS DIFFER ON THE AMOUNT OF WARMUP WITH THE
ECMWF SHOWING THE MOST. THERE IS WEAK DOWNSLOPING OF THE WINDS WITH
THE MODELS SHOWING LITTLE IF ANY MIXING. ALSO BECAUSE OF THE
MID/UPPER LEVEL RIDGING IN PLACE...IT LOOKS LIKE THERE WILL BE A LOT
OF SUNSHINE. SO IT LOOKS LIKE MODELS ARE UNDERDOING THE WARMING AT
THIS TIME. RAISED MAXES BUT TEMPERED IT SOMEWHAT BASED ON
COLLABORATION AND THRESHOLDS. HOWEVER...THE POTENTIAL FOR BEING
MUCH WARMER THAN WHAT IS CURRENTLY IN THERE IS PRETTY HIGH. IF THE
MIXING GETS CLOSER TO 700 MB...TEMPERATURES COULD SORE INTO THE 60S
BUT I DEFINITELY DID NOT GO THAT FAR.
SUNDAY NIGHT/MONDAY...WEAKER LEFT FRONT QUADRANT OF THE SOUTHERN JET
LOOKS TO START AFFECT THE SOUTHEAST PORTION OF THE AREA LATE IN THE
NIGHT. OF NOTE HIGHER JET SPEEDS ARE STILL BEHIND INCOMING SYSTEM
AS OF 12Z MONDAY. MOST OF THE DETERMINISTIC AND ENSEMBLE DATA SHOW
THE NEXT SYSTEM COMING FURTHER SOUTH AND SLOWER WITH STILL SOMEWHAT
OF A SPREAD. THE NAM AND GEFS MEAN ARE THE FASTEST AND FURTHEST
NORTH WITH THE CANADIAN AND ECMWF FURTHEST SOUTH. IT IS STARTING TO
LOOK LIKE FURTHER SOUTH IS APPEARING MORE LIKELY. THAT SAID WITH
LITTLE IF ANY LIFT AND SOUNDINGS SHOWING AIR MASS STILL DRY...THE
DRY FORECAST FOR SUNDAY NIGHT STILL LOOKS GOOD.
LEFT FRONT QUADRANT OF THE JET AFFECTS MAINLY SOUTHEAST HALF OF THE
AREA EARLY IN THE DAY. MOST OF THE FORCING STILL LOOKS TO BE OVER
TH SOUTHERN PORTION OF THE AREA. IF NAM/GEFS RIGHT...PRECIPITATION
CHANCE WILL BE GREATER. IF ECMWF AND ESPECIALLY THE CANADIAN IS
RIGHT...PRECIPITATION WILL BE LOWER. SINCE THERE IS STILL A LOT OF
MODEL SPREAD AND CURRENT MODEL DATA SUPPORTS THE ONGOING FORECAST...
DID NOT CHANGE MONDAYS PRECIPITATION FORECAST. IT WILL DEFINITELY
WILL BE WINDY AND COLDER ON MONDAY. IF CURRENT TRENDS CONTINUE IT IS
POSSIBLE THAT MAXES WILL NEED TO BE LOWERED MORE.
MONDAY NIGHT THROUGH FRIDAY...SPREAD ON THE DETERMINISTIC AND
ENSEMBLE OUTPUT EARLY ON THROUGH TUESDAY IS PRETTY LARGE. THINKING
THAT THE SYSTEM IS LOOKING TO BE FURTHER SOUTH...PRECIPITATION
SHOULD BE DONE OR MOSTLY DONE BY 12Z TUESDAY. MODERATION OF
TEMPERATURES THEN OCCUR AS THE WESTERN TROUGH RELOADS AND MODELS TRY
TO DECIDE WHAT TO DO WITH THE NEXT SYSTEM. SPREAD IN DETERMINISTIC
AND ENSEMBLE OUTPUT CONTINUES WITH THIS NEXT SET OF STORM SYSTEMS AS
WELL.
ON THURSDAY ALL THE MODELS DO BRING A MID LEVEL TROUGH THROUGH
BUT DIFFER ON THE STRENGTH AND SPEED. IF ECMWF WERE TO VERIFY THEN
PRECIPITATION MAY NEED TO BE EXPANDED FROM WHERE IT IS AT NOW. MODELS
SHOW A FRONT MOVE THROUGH LATE WEDNESDAY NIGHT INTO THURSDAY BUT
DIFFER ON TIME. DUE TO ITS HANDLING OF THE SYSTEM AT MID LEVELS...
THE ECMWF IS MORE AGGRESSIVE WITH THE COOLING...AND LOOKS LIKE IT
IS THE BEST SOLUTION...TEMPERATURES WILL BE COOLED MORE FROM THEY
ARE AT NOW. FRIDAY LOOKS DRY AT THIS TIME BUT WITH MODEL SPREAD
THAT COULD CHANGE. COLDER WORKS ITS WAY INTO THE AREA...COLD MAXES
IN GRIDS LOOK GOOD.
THANKS TO ALL THAT COLLABORATED.
BULLER
&&
.AVIATION...
429 PM MST FRI DEC 16 2011
FOR THE 00Z TAFS...VFR CONDITIONS WITH A GENERAL LIGHT WESTERLY WIND
WILL PREVAIL THROUGH THE VALID PERIOD AS UPPER LEVEL HIGH PRESSURE
CONTINUES TO BUILD INTO THE REGION WITH SURFACE HIGH PRESSURE CENTERED
TO THE SOUTH.
050
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1223 PM MST THU DEC 15 2011
.UPDATE...
1222 PM MST THU DEC 15 2011
JUST COMPLETED AN UPDATE. TEMPERATURES HAVE JUST RISEN TO NEAR
FORECAST MAXES. SO RAISED HIGH TEMPERATURES 2 TO 3 DEGREES ACROSS
THE BOARD.
BULLER
&&
.SHORT TERM (TODAY-SATURDAY)...
230 AM MST THU DEC 15 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE POSITIVELY
TILTED TROUGH ACROSS THE CENTRAL US...WITH MEAN AXIS EXTENDING
FROM MINNESOTA ACROSS WESTERN KANSAS TO THE BAJA PENINSULA.
EARLY THIS MORNING...RUC H7 ANALYSIS SHOWS AXIS OF POSITIVE
FRONTOGENESIS EXTENDING ACROSS EXTREME SW PART OF CWA...WHICH
COULD ACT AS A FOCUS FOR DEVELOPMENT OF FLURRIES BEFORE 12Z. WHILE
RADAR SHOWING LIGHT RETURNS SW OF THIS AREA THERE HAVE BEEN NO
REPORTS OF FLURRIES...AND CONSIDERING DRY LAYER IN PLACE BELOW
5000-7000FT WILL LEAVE MENTION OUT OF FORECAST FOR NOW AND
CONTINUE TO MONITOR.
TODAY-SATURDAY...SHORTWAVE RIDGING DEVELOPS OVER WESTERN KANSAS
IN REPOSE TO CUTOFF LOW DEEPENING OVER THE SW US. EXPECTING DRY
CONDITIONS AND A GRADUAL WARMING TREND THROUGH THIS WEEKEND.
SEASONAL TEMPS TODAY AND FRIDAY WILL BE FOLLOWED BY MILDER TEMPS
SATURDAY WHEN AFTERNOON TEMPS AROUND 50 ARE EXPECTED. WARMEST END
OF GUIDANCE FOR SAT WOULD SUPPORT TEMPS IN THE MID 50S.
DR
.LONG TERM (SUNDAY-WEDNESDAY)...
230 AM MST THU DEC 15 2011
A CUTOFF LOW PRESSURE SYSTEM SPINNING OVER BAJA ON SUNDAY WILL
BEGIN TO MOVE INLAND ALONG THE UNITED STATES MEXICO BORDER. THE
GFS KEEPS THE LOW CENTER NEAR THE BORDER AS IT MOVES EAST OF THE
ROCKIES WHILE THE ECMWF TAKES A SLIGHTLY MORE NORTHERLY
TRACK...PUTTING THE UPPER LOW IN THE NORTHERN TEXAS PANHANDLE BY
MONDAY EVENING WHILE THE GFS HAS IT IN THE SOUTHERN PANHANDLE
REGION. THIS DIFFERENCE IN TRACK AS THE LOW MOVES EAST OF THE
ROCKIES WILL MAKE THE DIFFERENCE BETWEEN THE FORECAST AREA
RECEIVING PRECIPITATION OR KEEPING THE FORECAST DRY FOR THE
BEGINNING OF NEXT WEEK. AS THE MODEL SOLUTIONS EVOLVE FROM CUTTING
OFF THE UPPER LOW OVER THE FAR SOUTHWEST UNITED STATES TO
REINCORPORATING IT INTO THE UPPER FLOW THROUGH THE FORECAST
PERIOD...CONFIDENCE IN EITHER PARTICULAR SOLUTION ARE LOW. THE
GENERAL CONSENSUS IS TO GO WITH A SLOWER SOLUTION THAT FAVORS
DELAYING PRECIPITATION ACROSS THE FORECAST AREA UNTIL MONDAY, AND
THEN KEEPING A RAIN SNOW MIX ON MONDAY THAT TRANSITIONS TO LIGHT
SNOW MONDAY NIGHT AND POSSIBLY INTO TUESDAY MORNING AS THE LOW
CONTINUES ACROSS THE SOUTHERN PLAINS AND INTO THE MISSISSIPPI
VALLEY REGION BY LATE TUESDAY.
LOCKHART
&&
.AVIATION...
1040 AM MST THU DEC 15 2011
FOR THE 18Z TAFS...VFR CONDITIONS CONTINUE THROUGH THE EVENING AND
THEN THINGS GET A LITTLE MORE INTERESTING. TO SOME DEGREE ALL THE
MODEL OUTPUT IS SHOWING RETURN FLOW DURING THE NIGHT BRINGING UP
SOME STRATUS...STILL IN VFR...AFTER 06Z. IT IS ALSO POSSIBLE THAT
SOME FOG COULD RESULT AS WELL. CONSIDERING THAT DEWPOINTS ARE
RUNNING A LITTLE HIGHER THAN PROGGED AND MORE IN LINE WITH THE
NAM...PROBABLY DUE TO THE CONTINUED SNOW MELT...ESPECIALLY TO OUR
SOUTH SOUTHWEST...THINKING THAT THIS MAY NOT BE OUT OF THE REALM
OF POSSIBILITY. RIGHT NOW THE FAVORED AREA WOULD BE MORE NEAR
KGLD THAN KMCK. SO AT THIS TIME PUT A LITTLE LOWER CONDITIONS AT
KGLD AND WILL CONTINUE TO MONITOR THE LATEST OBSERVATIONS AND
MODEL TRENDS. WHATEVER OCCURS DOES NOT LAST TOO LONG AFTER 12Z AS
SURFACE TROUGH MOVES AND BRINGS IN STRONGER WEST TO NORTHWEST
WINDS.
BULLER
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1048 AM MST THU DEC 15 2011
.SHORT TERM (TODAY-SATURDAY)...
230 AM MST THU DEC 15 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE POSITIVELY
TILTED TROUGH ACROSS THE CENTRAL US...WITH MEAN AXIS EXTENDING
FROM MINNESOTA ACROSS WESTERN KANSAS TO THE BAJA PENINSULA.
EARLY THIS MORNING...RUC H7 ANALYSIS SHOWS AXIS OF POSITIVE
FRONTOGENESIS EXTENDING ACROSS EXTREME SW PART OF CWA...WHICH
COULD ACT AS A FOCUS FOR DEVELOPMENT OF FLURRIES BEFORE 12Z. WHILE
RADAR SHOWING LIGHT RETURNS SW OF THIS AREA THERE HAVE BEEN NO
REPORTS OF FLURRIES...AND CONSIDERING DRY LAYER IN PLACE BELOW
5000-7000FT WILL LEAVE MENTION OUT OF FORECAST FOR NOW AND
CONTINUE TO MONITOR.
TODAY-SATURDAY...SHORTWAVE RIDGING DEVELOPS OVER WESTERN KANSAS
IN REPOSE TO CUTOFF LOW DEEPENING OVER THE SW US. EXPECTING DRY
CONDITIONS AND A GRADUAL WARMING TREND THROUGH THIS WEEKEND.
SEASONAL TEMPS TODAY AND FRIDAY WILL BE FOLLOWED BY MILDER TEMPS
SATURDAY WHEN AFTERNOON TEMPS AROUND 50 ARE EXPECTED. WARMEST END
OF GUIDANCE FOR SAT WOULD SUPPORT TEMPS IN THE MID 50S.
DR
.LONG TERM (SUNDAY-WEDNESDAY)...
230 AM MST THU DEC 15 2011
A CUTOFF LOW PRESSURE SYSTEM SPINNING OVER BAJA ON SUNDAY WILL
BEGIN TO MOVE INLAND ALONG THE UNITED STATES MEXICO BORDER. THE
GFS KEEPS THE LOW CENTER NEAR THE BORDER AS IT MOVES EAST OF THE
ROCKIES WHILE THE ECMWF TAKES A SLIGHTLY MORE NORTHERLY
TRACK...PUTTING THE UPPER LOW IN THE NORTHERN TEXAS PANHANDLE BY
MONDAY EVENING WHILE THE GFS HAS IT IN THE SOUTHERN PANHANDLE
REGION. THIS DIFFERENCE IN TRACK AS THE LOW MOVES EAST OF THE
ROCKIES WILL MAKE THE DIFFERENCE BETWEEN THE FORECAST AREA
RECEIVING PRECIPITATION OR KEEPING THE FORECAST DRY FOR THE
BEGINNING OF NEXT WEEK. AS THE MODEL SOLUTIONS EVOLVE FROM CUTTING
OFF THE UPPER LOW OVER THE FAR SOUTHWEST UNITED STATES TO
REINCORPORATING IT INTO THE UPPER FLOW THROUGH THE FORECAST
PERIOD...CONFIDENCE IN EITHER PARTICULAR SOLUTION ARE LOW. THE
GENERAL CONSENSUS IS TO GO WITH A SLOWER SOLUTION THAT FAVORS
DELAYING PRECIPITATION ACROSS THE FORECAST AREA UNTIL MONDAY, AND
THEN KEEPING A RAIN SNOW MIX ON MONDAY THAT TRANSITIONS TO LIGHT
SNOW MONDAY NIGHT AND POSSIBLY INTO TUESDAY MORNING AS THE LOW
CONTINUES ACROSS THE SOUTHERN PLAINS AND INTO THE MISSISSIPPI
VALLEY REGION BY LATE TUESDAY.
LOCKHART
&&
.AVIATION...
1040 AM MST THU DEC 15 2011
FOR THE 18Z TAFS...VFR CONDITIONS CONTINUE THROUGH THE EVENING AND
THEN THINGS GET A LITTLE MORE INTERESTING. TO SOME DEGREE ALL THE
MODEL OUTPUT IS SHOWING RETURN FLOW DURING THE NIGHT BRINGING UP
SOME STRATUS...STILL IN VFR...AFTER 06Z. IT IS ALSO POSSIBLE THAT
SOME FOG COULD RESULT AS WELL. CONSIDERING THAT DEWPOINTS ARE
RUNNING A LITTLE HIGHER THAN PROGGED AND MORE IN LINE WITH THE
NAM...PROBABLY DUE TO THE CONTINUED SNOW MELT...ESPECIALLY TO OUR
SOUTH SOUTHWEST...THINKING THAT THIS MAY NOT BE OUT OF THE REALM
OF POSSIBILITY. RIGHT NOW THE FAVORED AREA WOULD BE MORE NEAR
KGLD THAN KMCK. SO AT THIS TIME PUT A LITTLE LOWER CONDITIONS AT
KGLD AND WILL CONTINUE TO MONITOR THE LATEST OBSERVATIONS AND
MODEL TRENDS. WHATEVER OCCURS DOES NOT LAST TOO LONG AFTER 12Z AS
SURFACE TROUGH MOVES AND BRINGS IN STRONGER WEST TO NORTHWEST
WINDS.
BULLER
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
231 AM MST THU DEC 15 2011
.SHORT TERM (TODAY-SATURDAY)...
230 AM MST THU DEC 15 2011
EARLY MORNING WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE POSITIVELY
TILTED TROUGH ACROSS THE CENTRAL US...WITH MEAN AXIS EXTENDING
FROM MINNESOTA ACROSS WESTERN KANSAS TO THE BAJA PENINSULA.
EARLY THIS MORNING...RUC H7 ANALYSIS SHOWS AXIS OF POSITIVE
FRONTOGENESIS EXTENDING ACROSS EXTREME SW PART OF CWA...WHICH
COULD ACT AS A FOCUS FOR DEVELOPMENT OF FLURRIES BEFORE 12Z. WHILE
RADAR SHOWING LIGHT RETURNS SW OF THIS AREA THERE HAVE BEEN NO
REPORTS OF FLURRIES...AND CONSIDERING DRY LAYER IN PLACE BELOW
5000-7000FT WILL LEAVE MENTION OUT OF FORECAST FOR NOW AND
CONTINUE TO MONITOR.
TODAY-SATURDAY...SHORTWAVE RIDGING DEVELOPS OVER WESTERN KANSAS
IN REPOSE TO CUTOFF LOW DEEPENING OVER THE SW US. EXPECTING DRY
CONDITIONS AND A GRADUAL WARMING TREND THROUGH THIS WEEKEND.
SEASONAL TEMPS TODAY AND FRIDAY WILL BE FOLLOWED BY MILDER TEMPS
SATURDAY WHEN AFTERNOON TEMPS AROUND 50 ARE EXPECTED. WARMEST END
OF GUIDANCE FOR SAT WOULD SUPPORT TEMPS IN THE MID 50S.
DR
.LONG TERM (SUNDAY-WEDNESDAY)...
230 AM MST THU DEC 15 2011
A CUTOFF LOW PRESSURE SYSTEM SPINNING OVER BAJA ON SUNDAY WILL
BEGIN TO MOVE INLAND ALONG THE UNITED STATES MEXICO BORDER. THE
GFS KEEPS THE LOW CENTER NEAR THE BORDER AS IT MOVES EAST OF THE
ROCKIES WHILE THE ECMWF TAKES A SLIGHTLY MORE NORTHERLY
TRACK...PUTTING THE UPPER LOW IN THE NORTHERN TEXAS PANHANDLE BY
MONDAY EVENING WHILE THE GFS HAS IT IN THE SOUTHERN PANHANDLE
REGION. THIS DIFFERENCE IN TRACK AS THE LOW MOVES EAST OF THE
ROCKIES WILL MAKE THE DIFFERENCE BETWEEN THE FORECAST AREA
RECEIVING PRECIPITATION OR KEEPING THE FORECAST DRY FOR THE
BEGINNING OF NEXT WEEK. AS THE MODEL SOLUTIONS EVOLVE FROM CUTTING
OFF THE UPPER LOW OVER THE FAR SOUTHWEST UNITED STATES TO
REINCORPORATING IT INTO THE UPPER FLOW THROUGH THE FORECAST
PERIOD...CONFIDENCE IN EITHER PARTICULAR SOLUTION ARE LOW. THE
GENERAL CONSENSUS IS TO GO WITH A SLOWER SOLUTION THAT FAVORS
DELAYING PRECIPITATION ACROSS THE FORECAST AREA UNTIL MONDAY, AND
THEN KEEPING A RAIN SNOW MIX ON MONDAY THAT TRANSITIONS TO LIGHT
SNOW MONDAY NIGHT AND POSSIBLY INTO TUESDAY MORNING AS THE LOW
CONTINUES ACROSS THE SOUTHERN PLAINS AND INTO THE MISSISSIPPI
VALLEY REGION BY LATE TUESDAY.
LOCKHART
&&
.AVIATION...
951 PM MST WED DEC 14 2011
FOR THE 06Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE
PERIOD WITH ONLY A SCATTERED MID-LEVEL CLOUD DECK OVERNIGHT. SURFACE
HIGH PRESSURE WILL CONTINUE PUSHING SOUTHEAST ACROSS THE REGION WHICH
WILL RESULT IN INITIAL NORTHWEST WINDS OVERNIGHT BECOMING LIGHT AND
VARIABLE DURING MUCH OF THE DAY THURSDAY BEFORE FINALLY SETTING UP
FROM THE SOUTH/SOUTHEAST DURING THE EVENING HOURS.
050
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
ISSUED BY NATIONAL WEATHER SERVICE CARIBOU ME
1225 PM EST THU DEC 15 2011
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH OF THE REGION THIS AFTERNOON DRAWING A WARM
FRONT ACROSS THE AREA. A STRONG COLD FRONT WILL APPROACH THE REGION
FROM THE NORTHWEST TONIGHT AND CROSS THE AREA ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
TEMPERATURES ARE WARMING NICELY THROUGH THE 30S INTO THE LOWER
40S. VALLEY AREAS IN WESTERN AREAS OF MAINE STILL HOVERING IN THE
LOWER 30S BUT PRECIP IS IN LIQUID FORM. SNOW/SLEET HAVE ENDED. THE
WSW FOR WESTERN MAINE HAS BEEN ALLOWED TO EXPIRE. LATEST LAPS SOUNDINGS
INDICATE WARMING DOWN TO THE SFC NOW WILL RAIN.ADJUSTED THE POPS
THROUGH THE REST OF THE AFTERNOON USING THE GFS AND RUC AS A START
AND THEN MANUALLY ADJUSTED W/SOME DRY SLOTTING ATTM. ANOTHER BATCH
OF RAIN MOVING THROUGH SOUTHERN QUEBEC WILL MOVE ACROSS THE REGION
LATER THIS AFTERNOON INTO THE EVENING. WINDS HAVE BEEN GUSTING TO
35 MPH AT PWM AND PSM.
.PREVIOUS DISCUSSION...
MODELS IN VERY GOOD AGREEMENT WITH WARM FRONT CROSSING THE REGION
TODAY. SOUTHERLY FLOW HAS ALLOWED TEMPERATURES TO WARM THROUGH THE
NIGHT WITH READINGS ABOVE FREEZING ACROSS MOST OF SOUTHERN AND
CENTRAL NEW HAMPSHIRE SO HAVE DECIDED TO DROP THE ADVISORY THERE
FOR THIS MORNING. CRITICAL THICKNESS INDICATES MAINLY SLEET AND
FREEZING RAIN ACROSS THE REMINDER OF THE ADVISORY AREA THIS
MORNING BEFORE PRECIP CHANGES TO ALL RAIN BEFORE NOONTIME. AT THIS
TIME, EXPECT ANY SNOW/SLEET ACCUMULATION TO BE LESS THAN AN INCH
AND ANY ICING A TENTH OF AN INCH OR LESS. EXPECT MAIN AREA OF
PRECIP TO MOVE EAST OF THE AREA DURING THIS AFTERNOON WITH ONLY
SCATTERED RAIN SHOWERS FOR TONIGHT. STRONG LOW LEVEL JET WILL MOVE
ACROSS COASTAL SECTIONS ESPECIALLY OVER LINCOLN, KNOX AND WALDO COUNTIES
WHERE WINDS WILL GUSTS UP TO 40 MPH LATER THIS AFTERNOON INTO
EARLY THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
STRONG COLD FRONT WILL CROSS THE REGION FRIDAY UNDER A STRONG
NORTHWEST WIND. STRONG COLD AIR ADVECTION ALONG WITH UPSLOPE WILL
PRODUCE SNOW SHOWERS ACROSS THE MOUNTAINS OF NEW HAMPSHIRE AND
MAINE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BUILD ACROSS THE REGION SATURDAY AND
SUNDAY AND CREST THE AREA SUNDAY EVENING. QUICK MOVING LOW
PRESSURE MAY PROVIDE SOME LIGHT SNOW ACROSS NORTHERN NH AND MAINE
ON MONDAY WITH HIGH PRESSURE BUILDING ACROSS THE REGION ON
TUESDAY. STILL A LOT OF UNCERTAINTY FOR THE END OF THE WEEK AS LOW
PRESSURE AFFECTS THE REGION.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...MVFR/IFR CONDITIONS INTO TONIGHT.
LONG TERM... VFR CONDITIONS FRIDAY THROUGH SATURDAY. GUSTY NORTHWEST
WINDS ON FRIDAY AS STRONG COLD FRONT CROSSES THE REGION.
&&
.MARINE...
SHORT TERM...STRONG LOW LEVEL JET WILL MOVE ACROSS THE GULF OF
MAINE TODAY PRODUCING GALE FORCE WINDS FOR THE EASTERN HALF OF OUR
WATERS. WINDS NOT AS STRONG OVER WESTERN SECTIONS WHERE SCA
CONDITIONS WILL PREVAIL.
LONG TERM...AS STRONG COLD FRONT CROSSES THE WATER, GALE CONDITIONS
POSSIBLE AGAIN ON FRIDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ153-154.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ150>152.
&&
$$
SYNOPSIS...HEWITT
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1015 PM EST FRI DEC 16 2011
.SYNOPSIS...
WEAK LOW PRESSURE, MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES
SATURDAY NIGHT, WILL BRING COLDER TEMPERATURES AND SOME LIGHT SNOW
ACCUMULATIONS THIS WEEKEND. A MORE DEVELOPED LOW PRESSURE SYSTEM,
COMING NORTHEAST FROM TEXAS, WILL BRING MILDER TEMPERATURES AND
SHOWERS MONDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
PER MOST RECENT SATELLITE DATA AND NAM MODEL OUTPUT, MAINTAINED
FORECAST OF CLOUDY SKIES THIS PERIOD. WITH A COLD WESTERLY LOW
LEVEL AIR FLOW OFF LAKE ERIE, THERE IS THE POTENTIAL OF LIGHT SNOW
SHOWERS DEVELOPING WITHIN THE I-80 CORRIDOR OVERNIGHT. THE CHANCES
OF MEASURABLE SNOWFALL WILL BE SLIGHT AS NAM MODEL PROFILES SHOW
THE INSTABILITY TO BE WEAK AND INVERSION-CAPPED NEAR 6 KFT AGL.
SNOW SHOWER CHANCES WILL INCREASE, NORTH TO SOUTH, ACROSS THE
UPPER OHIO VALLEY SATURDAY AFTERNOON, AS AN UPPER LEVEL SHORT-WAVE TROUGH
PASSES SOUTHEASTWARD THROUGH THE GREAT LAKES. SNOW ACCUMULATIONS
SHOULD BE NO MORE THAN A THIN COAT, MAINLY NORTH, THROUGH 5 PM.
FORECASTED TEMPERATURES TO BE SEASONABLY COLD OVERNIGHT AND HIGHS
SATURDAY ABOUT 3-6 DEGREES COLDER THAN NORMAL PER RECENT HRRR AND
NAM AND GFS MOS OUTPUT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
NAM MODEL OUTPUT, INCLUDING NAM MODEL PROFILES, SHOW THE PASSING
SHORT-WAVE TROUGH MAY DEVELOP LIFT WITHIN THE DENDRITIC GROWTH
ZONE/ TEMPERATURES -12C TO -18C/ SATURDAY NIGHT. HOWEVER, SYSTEM-
MOISTURE INGESTION APPEARS LIMITED, SO CONCUR WITH HPC THAT MOST
SNOW ACCUMULATIONS SHOULD BE NO MORE THAN AN INCH.
WITH POST-SYSTEM SURFACE LAYER WINDS REMAINING FAIRLY WEAK AND
LAKE-ENHANCED INSTABILITY CAPPED BY A STABLE LAYER NEAR 7 KFT AGL,
SNOW SHOWERS SUNDAY MORNING WILL BE LIGHT, AND MAINLY CONFINED TO
UPSLOPE LOCATIONS NEAR THE MOUNTAINS.
SURFACE HIGH PRESSURE PASSING TO THE SOUTH WILL PRODUCE DRY
CONDITIONS AREAWIDE SUNDAY AFTERNOON INTO AT LEAST MIDDAY MONDAY.
AS THE WEAK FLOW TURNS INTO THE SOUTHWEST SUNDAY AFTERNOON,
TEMPERATURES CAN BEGIN TO MODERATE, WITH VALUES UP TO 5 DEGREES
WARMER THAN NORMAL MONDAY AFTERNOON.
A COLD FRONT WILL BRING A CHANCE OF RAIN SHOWERS ACROSS EASTERN
OHIO AND NORTHWEST PENNSYLVANIA LATE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
NAEFS/GFSE/ECMWF ARE IN REASONABLE AGREEMENT THAT THE UPPER OHIO
VALLEY WILL BE IN A ZONAL FLOW MONDAY NIGHT WITH A CLOSED MID-LEVEL
LOW ACROSS THE SOUTHERN PLAINS. THE LOW WILL OPEN INTO A TROUGH AS
IT PUSHES ACROSS THE MISSOURI VALLEY INTO THE OHIO VALLEY TUESDAY
INTO WEDNESDAY.
FORECAST OF THE TROUGH PASSAGE ACROSS THE AREA IS CLOSEST TO A
GFS/ECMWF BLEND. WITH THIS IN MIND, CHC POPS ARE FORECAST AHEAD OF
THE LOW AND WITH THE TROUGH PASSAGE MONDAY NIGHT THROUGH
WEDNESDAY. FOR PRECIP TYPE, THICKNESSES ARE WARM ENOUGH TO ALLOW
FOR MOSTLY RAIN THROUGH WEDNESDAY WITH SNOW SHOWERS MIXING IN
ACROSS THE HIGHER ELEVATIONS. IN THE WAKE OF THE TROUGH, A FEW
LINGERING RAIN AND SNOW SHOWERS WILL BE POSSIBLE ACROSS THE AREA
WEDNESDAY NIGHT.
BEHIND THE TROUGH PASSAGE, GFS/ECMWF ARE IN AGREEMENT THAT HIGH
PRESSURE WILL BUILD INTO THE AREA FOR A DRY FORECAST THURSDAY INTO
EARLY FRIDAY. STILL QUITE A BIT OF UNCERTAINTY, ALTHOUGH THERE IS
SOME MODEL AGREEMENT HINTING THAT A SOUTHERN STREAM LOW MAY CLIP THE
AREA ON FRIDAY AND RETURN THE CHANCE OF RAIN SHOWERS.
TEMPERATURES THROUGHOUT THE EXTENDED PERIOD WILL BE AROUND 5
DEGREES ABOVE SEASONAL NORMALS.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
BASED OFF OF THE MOST CURRENT OBS LOCALLY AND UPSTREAM, CLOUD DECK
SHOULD IMPROVE TO VFR ALMOST EVERYWHERE THROUGH THE OVERNIGHT. THE
ONLY EXCEPTION TO THIS BEING FKL AND DUJ, SINCE THEY ARE CLOSER TO
THE LAKE AND WITH THE NORTHWEST FLOW, MAY REMAIN MVFR THROUGH THE
ENTIRE TAF PERIOD.
ALL DETERMINISTIC MODELS HINT TO THE POSSIBILITY OF A FEW LAKE
ENHANCED SNOW SHOWERS DEVELOPING OVERNIGHT THAT COULD IMPACT
KFKL/KDUJ WITH RESTRICTIONS. HOWEVER THINK THE BETTER CHANCE OF
RESTRICTIONS WILL OCCUR TOWARDS DAYBREAK AS A STRONGER SHORTWAVE
DIGS SOUTHWARD OVER THE GREAT LAKES. GENERALLY KEPT THE TIMING OF
THE PREVIOUS TAF ISSUANCE WITH SNOW SHOWERS AND MVFR RESTRICTIONS
STARTING AT KFKL/KDUJ AFTER 15Z SAT AND KPIT AFTER 21Z SAT.
OUTLOOK... SATURDAY NIGHT THROUGH WEDNESDAY...
A DISTURBANCE MOVING ACROSS THE GREAT LAKES WILL BRING SCATTERED
SNOW SHOWERS AND THE POTENTIAL FOR IFR VISIBILITIES AND MVFR
CEILINGS INTO SUNDAY. HIGH PRESSURE WILL RETURN VFR CONDITIONS
SUNDAY NIGHT INTO MONDAY. THE NEXT LOW PRESSURE SYSTEM WILL APPROACH
FROM THE SOUTHWEST MONDAY NIGHT, RETURNING THE CHANCE OF SHOWERS
WITH RESTRICTIONS THROUGH THE MID-WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
730 PM EST FRI DEC 16 2011
.SYNOPSIS...
WEAK LOW PRESSURE, MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES
SATURDAY NIGHT, WILL BRING COLDER TEMPERATURES AND SOME LIGHT SNOW
ACCUMULATIONS THIS WEEKEND. A MORE DEVELOPED LOW PRESSURE SYSTEM,
COMING NORTHEAST FROM TEXAS, WILL BRING MILDER TEMPERATURES AND
SHOWERS MONDAY NIGHT INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
PER RECENT SATELLITE DATA AND NAM MODEL OUTPUT, MAINTAINED FORECAST OF
CLOUDY SKIES THIS PERIOD. WITH A COLD WESTERLY LOW LEVEL AIR FLOW
OFF LAKE ERIE, THERE IS THE POTENTIAL OF LIGHT SNOW SHOWERS
DEVELOPING WITHIN THE I-80 CORRIDOR OVERNIGHT. THE CHANCES OF
MEASURABLE SNOWFALL WILL BE SLIGHT AS NAM MODEL PROFILES SHOW THE
INSTABILITY TO BE WEAK AND INVERSION-CAPPED NEAR 6 KFT AGL.
SNOW SHOWER CHANCES WILL INCREASE, NORTH TO SOUTH, ACROSS THE
UPPER OHIO VALLEY SATURDAY AFTERNOON, AS AN UPPER LEVEL SHORT-WAVE TROUGH
PASSES SOUTHEASTWARD THROUGH THE GREAT LAKES. SNOW ACCUMULATIONS
SHOULD BE NO MORE THAN A THIN COAT IN SPOTS THROUGH 5 PM.
FORECASTED TEMPERATURES TO BE SEASONABLY COLD OVERNIGHT AND HIGHS
SATURDAY ABOUT 3-6 DEGREES COLDER THAN NORMAL PER RECENT HRRR AND
NAM AND GFS MOS OUTPUT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
NAM MODEL OUTPUT, INCLUDING NAM MODEL PROFILES, SHOW THE PASSING
SHORT-WAVE TROUGH MAY DEVELOP LIFT WITHIN THE DENDRITIC GROWTH
ZONE/ TEMPERATURES -12C TO -18C/ SATURDAY NIGHT. HOWEVER, SYSTEM-
MOISTURE INGESTION APPEARS LIMITED, SO MOST SNOW ACCUMULATIONS
SHOULD BE NO MORE THAN AN INCH.
WITH POST-SYSTEM SURFACE LAYER WINDS REMAINING FAIRLY WEAK AND
LAKE-ENHANCED INSTABILITY CAPPED BY A STABLE LAYER NEAR 7 KFT AGL,
SNOW SHOWERS SUNDAY MORNING WILL BE LIGHT, AND MAINLY CONFINED TO
UPSLOPE LOCATIONS NEAR THE MOUNTAINS.
SURFACE HIGH PRESSURE PASSING TO THE SOUTH WILL PRODUCE DRY
CONDITIONS AREAWIDE SUNDAY AFTERNOON INTO AT LEAST MIDDAY MONDAY.
AS THE WEAK FLOW TURNS INTO THE SOUTHWEST SUNDAY AFTERNOON,
TEMPERATURES CAN BEGIN TO MODERATE, WITH VALUES UP TO 5 DEGREES
WARMER THAN NORMAL MONDAY AFTERNOON.
A COLD FRONT WILL BRING A CHANCE OF RAIN SHOWERS ACROSS EASTERN
OHIO AND NORTHWEST PENNSYLVANIA LATE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
NAEFS/GFSE/ECMWF ARE IN REASONABLE AGREEMENT THAT THE UPPER OHIO
VALLEY WILL BE IN A ZONAL FLOW MONDAY NIGHT WITH A CLOSED MID-LEVEL
LOW ACROSS THE SOUTHERN PLAINS. THE LOW WILL OPEN INTO A TROUGH AS
IT PUSHES ACROSS THE MISSOURI VALLEY INTO THE OHIO VALLEY TUESDAY
INTO WEDNESDAY.
FORECAST OF THE TROUGH PASSAGE ACROSS THE AREA IS CLOSEST TO A
GFS/ECMWF BLEND. WITH THIS IN MIND, CHC POPS ARE FORECAST AHEAD OF
THE LOW AND WITH THE TROUGH PASSAGE MONDAY NIGHT THROUGH
WEDNESDAY. FOR PRECIP TYPE, THICKNESSES ARE WARM ENOUGH TO ALLOW
FOR MOSTLY RAIN THROUGH WEDNESDAY WITH SNOW SHOWERS MIXING IN
ACROSS THE HIGHER ELEVATIONS. IN THE WAKE OF THE TROUGH, A FEW
LINGERING RAIN AND SNOW SHOWERS WILL BE POSSIBLE ACROSS THE AREA
WEDNESDAY NIGHT.
BEHIND THE TROUGH PASSAGE, GFS/ECMWF ARE IN AGREEMENT THAT HIGH
PRESSURE WILL BUILD INTO THE AREA FOR A DRY FORECAST THURSDAY INTO
EARLY FRIDAY. STILL QUITE A BIT OF UNCERTAINTY, ALTHOUGH THERE IS
SOME MODEL AGREEMENT HINTING THAT A SOUTHERN STREAM LOW MAY CLIP THE
AREA ON FRIDAY AND RETURN THE CHANCE OF RAIN SHOWERS.
TEMPERATURES THROUGHOUT THE EXTENDED PERIOD WILL BE AROUND 5
DEGREES ABOVE SEASONAL NORMALS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
BASED OFF OF THE MOST CURRENT OBS LOCALLY AND UPSTREAM, CLOUD DECK
SHOULD IMPROVE TO VFR ALMOST EVERYWHERE THROUGH THE OVERNIGHT. THE
ONLY EXCEPTION TO THIS BEING FKL AND DUJ, SINCE THEY ARE CLOSER TO
THE LAKE AND WITH THE NORTHWEST FLOW, MAY REMAIN MVFR THROUGH THE
ENTIRE TAF PERIOD.
ALL DETERMINISTIC MODELS HINT TO THE POSSIBILITY OF A FEW LAKE
ENHANCED SNOW SHOWERS DEVELOPING OVERNIGHT THAT COULD IMPACT
KFKL/KDUJ WITH RESTRICTIONS. HOWEVER THINK THE BETTER CHANCE OF
RESTRICTIONS WILL OCCUR TOWARDS DAYBREAK AS A STRONGER SHORTWAVE
DIGS SOUTHWARD OVER THE GREAT LAKES. GENERALLY KEPT THE TIMING OF
THE PREVIOUS TAF ISSUANCE WITH SNOW SHOWERS AND MVFR RESTRICTIONS
STARTING AT KFKL/KDUJ AFTER 15Z SAT AND KPIT AFTER 21Z SAT.
OUTLOOK... SATURDAY NIGHT THROUGH WEDNESDAY...
A DISTURBANCE MOVING ACROSS THE GREAT LAKES WILL BRING SCATTERED
SNOW SHOWERS AND THE POTENTIAL FOR IFR VISIBILITIES AND MVFR
CEILINGS INTO SUNDAY. HIGH PRESSURE WILL RETURN VFR CONDITIONS
SUNDAY NIGHT INTO MONDAY. THE NEXT LOW PRESSURE SYSTEM WILL APPROACH
FROM THE SOUTHWEST MONDAY NIGHT, RETURNING THE CHANCE OF SHOWERS
WITH RESTRICTIONS THROUGH THE MID-WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
525 PM EST THU DEC 15 2011
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS EVENING WITH SHOWERS AND
GUSTY WIND. COLDER AIR BEHIND THE FRONT WILL BRING A FEW SNOW SHOWERS
TO THE RIDGES AND NORTHWEST PENNSYLVANIA LATER TONIGHT. DRY AND
SEASONABLE FRIDAY FOLLOWED BY SCATTERED SNOW SHOWERS SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
UPDATE WAS MADE EARLIER TO UP WIND GUSTS TO 30-35 MPH WITH COLD
FRONTAL PASSAGE.
COLD FRONT CHUGGING ALONG INTO CENTRAL OHIO BY 20Z WITH A BAND OF
SHOWERS ALONG FRONT AND SCATTERED SHOWERS AHEAD OF IT. AFTER FRONT
PASSES TEMPERATURES WILL GRADUALLY FALL OVERNIGHT WITH NORTHWEST
FLOW ACROSS LAKES BRINGING A BRIEF PERIOD OF SNOW SHOWERS LATER
TONIGHT INTO EARLY FRIDAY. WHILE 850MB TEMPERATURES WILL BE NEAR
-8 C BY DAYBREAK INVERSION HEIGHTS WILL BE LOW AND LOWERING WITH A
LACK OF DEEP MOISTURE. SO LITTLE IF ANY ACCUMULATION.
AS DAY GOES ON FRIDAY, HIGH PRESSURE WILL WORK INTO REGION WITH
NEAR NORMAL TEMPS AND A MIX OF CLOUDS AND SUNSHINE. TIGHT SFC
PRESS GRADIENT WILL KEEP WINDS GUSTY FIRST HAVE OF TONIGHT WITH
FROPA THEN DIMINISHING AFTER MIDNIGHT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A FAST MOVING SHORTWAVE AND LOW PRESSURE CENTER MOVING ALONG MID
ATLANTIC FRIDAY NIGHT INTO EARLY SATURDAY WILL SPREAD CLOUDS INTO
THE SOUTHEAST RIDGES BUT APPEARS PRECIP WILL REMAIN SOUTH.
AS FOR THE REST OF THE AREA, HIGH PRESSURE WILL ALLOW FOR DRY
WEATHER FRIDAY NIGHT BEFORE A SHORT WAVE TROUGH WILL BEGIN TO DIVE
FROM THE GREAT LAKES SOUTHEASTWARD INTO THE AREA. THIS WILL RETURN
THE CHANCE OF SNOW SHOWERS, ESPECIALLY NORTH OF PITTSBURGH
SATURDAY MORNING, SPREADING SOUTH ACROSS THE REGION BY THE
EVENING. 850MB TEMPERATURES PROGGED TO FALL TO -10 C DURING DAY
AND THIS WILL COMBINE WITH SHORTWAVE TO BRING LIGHT ACCUMULATIONS
TO THE RIDGES AND I-80 CORRIDOR SATURDAY NIGHT TO EARLY SUNDAY.
TEMPERATURES WILL BE NEAR NORMAL TO A BIT BELOW.
ON SUNDAY LOWER AND MID LEVEL FLOW WILL BEGIN TO TURN WESTERLY
AND SNOW SHOWERS WILL DIMINISH WITH TEMPERATURES AGAIN AROUND
NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE MODELS SHOW CLOSED UPPER LOW OVER THE SOUTHERN PLAINS
MONDAY...GRADUALLY WEAKENING AS IT TRACKS NORTHEAST THROUGH MIDWEEK.
ASSOCIATED SURFACE LOW IS FORECAST TO TRACK FROM THE SOUTHERN PLAINS
INTO THE MID MS VALLEY BY WEDNESDAY...AND OFF THE MID ATLANTIC COAST
THURSDAY.
WENT CLOSE TO HPC GUIDANCE KEEPING THE FORECAST AREA DRY (POPS LESS
THAN 25 PERCENT) THROUGH LATE MONDAY...THEN CHANCE POPS TUESDAY AND
WEDNESDAY. LIMITED SCATTERED SHOWERS TO EASTERN SECTIONS THURSDAY AS
SYSTEM EXITS.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
PER RECENT SURFACE AND RADAR DATA PLUS HRRR AND NAM MODEL OUTPUT,
EXPECT COLD FRONTAL BAND OF SHOWERS TO PRODUCE BRIEF IFR CONDITIONS
AND WIND GUSTS TO ABOUT 30 KTS.
FRONTAL SHOWERS WILL MOVE PAST KMGW AND KLBE BY 00Z. POST FRONTAL
DRYING WILL PROMOTE MAINLY MVFR STRATOCUMULUS OVERNIGHT INTO MIDDAY
FRIDAY. NAM MODEL PROFILES SUGGEST WESTERLY WINDS CAN STILL GUST TO
30 KTS AT TIMES UNTIL 08Z-12Z.
OUTLOOK... FRIDAY NIGHT THROUGH TUESDAY...
SURFACE RIDGE SHOULD PROVIDE GENERALLY VFR CONDITIONS FRIDAY NIGHT
INTO EARLY SATURDAY. A SHORT WAVE TROUGH AND ASSOCIATED WEAK SURFACE
FRONT MOVING ACROSS THE GREAT LAKES WILL BRING SCATTERED SNOW
SHOWERS AND THE POTENTIAL FOR RESTRICTIONS SATURDAY AFTERNOON INTO
SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
340 PM EST THU DEC 15 2011
LATEST UPDATE...ALL EXCEPT AVIATION...
.SYNOPSIS...(340 PM EST THU DEC 15 2011)
A COLDER AIRMASS CONTINUES TO FILTER INTO SOUTHWEST LOWER MICHIGAN
IN THE WAKE OF A THURSDAY MORNING COLD FRONTAL PASSAGE. WEST TO
NORTHWEST WINDS WILL DROP LOWS INTO THE 20S IN MOST LOCATIONS
TONIGHT. IT WILL BE WINDY THIS EVENING BEFORE WINDS SUBSIDE
CONSIDERABLY OVERNIGHT. LAKE EFFECT SNOW SHOWERS ARE EXPECTED THIS
EVENING AND AGAIN FRIDAY NIGHT INTO SATURDAY. ACCUMULATIONS WILL BE
LIGHT TONIGHT ON THE ORDER OF A DUSTING TO POSSIBLY A HALF INCH IN A
FEW SPOTS. LOCALIZED ACCUMULATIONS FRIDAY NIGHT INTO SATURDAY MAY
REACH AN INCH OR TWO...BUT MOST LOCATIONS WILL SEE VERY LITTLE
ACCUMULATION. EVEN WITH THE COOL DOWN...TEMPERATURES WILL REMAIN
SLIGHTLY ABOVE NORMAL INTO THE WEEKEND.
&&
.SHORT TERM...(340 PM EST THU DEC 15 2011)
(TONIGHT THROUGH SATURDAY NIGHT)
MAIN FOCUS OF THE SHORT TERM REVOLVES AROUND THE WIND THIS EVENING
AND THEN CHANCES FOR LAKE EFFECT SNOW THROUGH THE PERIOD.
MAINTAINED THE WIND ADVISORY WITH THE CORE OF THE WIND STILL SET TO
COME THROUGH. MAIN CONCERN ARE A FEW GUSTS INTO THE 45 TO 50 MPH
RANGE BETWEEN 400 PM AND 1000 PM OR SO. LOCATIONS NEAR LAKE MICHIGAN
STAND THE BEST CHANCE OF SEEING GUSTS TO THIS SPEED. THE WIND SHOULD
GRADUALLY SUBSIDE FROM MIDNIGHT INTO FRIDAY MORNING.
AS FOR LAKE EFFECT SNOW CHANCES...THERE ARE TWO TIME FRAMES OF
POTENTIAL. THE FIRST BEING THIS EVENING...WHERE DEEPER MOISTURE
INTERACTS WITH INCREASING INSTABILITY. THE DEEPER MOISTURE IS ONLY
IN PLACE THROUGH THE 03Z TO 06Z TIME FRAME THOUGH AFTER WHICH TIME
IT DWINDLES TO 4000-5000FT OR LESS. THIS EVENING...EXPECT SNOW
SHOWER ACTIVITY WITH LIGHT ACCUMULATIONS (INCH OR LESS) ACROSS
CENTRAL LOWER MICHIGAN AND POSSIBLY ALONG THE HIGHWAY 131 CORRIDOR
(GIVEN THE STIFF WESTERLY WINDS DISPLACING BANDS INLAND A BIT). A
WET WARM GROUND WILL COUNTERACT THE SNOW SHOWERS SOME.
RELATIVE HUMIDITY IS QUITE LACKING IN THE OVERNIGHT THROUGH FRIDAY
EVENING TIME FRAME AND THEREFORE NOT EXPECTING MUCH IN THE WAY OF
SNOW SHOWERS DESPITE DELTA T/S IN THE MIDDLE TEENS C.
A COUPLE OF SHORTWAVE TROUGHS ROTATE THROUGH THE REGION FRIDAY NIGHT
INTO SATURDAY WHICH SHOULD GIVE A BOOST TO LAKE EFFECT CLOUDS AND
SNOW SHOWERS. SOME MINOR ACCUMULATIONS ARE POSSIBLE ALONG AND WEST
OF HIGHWAY 131. ENVISION DUSTING TO HALF INCH ACCUMS IN MOST
AREAS...BUT SOME LOCALIZED ACCUMS OF AN INCH OR TWO WILL BE
POSSIBLE.
&&
.LONG TERM...(340 PM EST THU DEC 15 2011)
(SUNDAY THROUGH THURSDAY)
SUNDAY LOOKS DRY AS A SFC HIGH AND NW FLOW ALOFT PRODUCES SOME
SUNSHINE ACROSS THE GREAT LAKES.
MODELS CONTINUE TO BE ON DIFFERENT PAGES WRT THE SRN STREAM LOW
MONDAY AND TUESDAY. BOTH THE ECMWF/GFS SHOW A SRN STREAM SHORT WAVE
BEING KICKED NEWD BY A NRN STREAM WAVE. THE ECMWF HOWEVER TAKES THE
LOW MORE EWD THROUGH THE OHIO VALLEY VS THE GFS THAT TAKES THE LOW
OVER LWR MI. BASED ON THE UPPER WAVE TRACK I TEND TO BUY THE GFS
TRACK MORE. THIS TRACK WOULD ALSO BRING WARMER AIR INTO THE CWA.
THUS WE/LL KEEP THE RAIN/SNOW MIX MON-TUE NIGHT. LIGHT SNOW POSSIBLE
ON THE BACK SIDE OF THE SYSTEM WEDNESDAY AS H8 TEMPS FALL TO -5C IN
NW FLOW. TEMPS WILL CONTINUE TO BE A FEW DEGREES WARMER THAN NORMAL
THROUGH THE PERIOD.
&&
.AVIATION...(106 PM EST THU DEC 15 2011)
MVFR CIGS COVER A LARGE PORTION OF THE GREAT LAKES. THE EXCEPTION IS
THE FAR SW LAKE SHORE SOUTH OF SOUTH HAVEN WHERE VFR CIGS ARE
OBSERVED. IT/S POSSIBLE THAT SOME VFR COULD SNEAK INTO
KAZO...HOWEVER MVFR CIGS EXPECTED THROUGH THE AFTERNOON/EVE.
&&
.MARINE...(340 PM EST THU DEC 15 2011)
WILL MAINTAIN THE GALE WARNING THROUGH THIS EVENING AS THE CORE OF
THE WIND LOOKS TO COME THROUGH BETWEEN 400PM AND 1000PM. WE WILL
EXTEND THE GALE SLIGHTLY TO GIVE A LITTLE BIT OF A BUFFER ON THE
BACK END...THROUGH 100 AM. RUC OVERVIEW/S ALONG THE
COAST ARE SHOWING 40 KNOTS OF WIND DOWN TO AROUND 1000FT...WHICH
SHOULD TRANSLATE INTO FREQUENT GALE FORCE GUSTS AT THE COASTAL
SITES. WINDS WILL DROP BELOW GALE FORCE AFTER MIDNIGHT AND WE WILL
NEED A SMALL CRAFT ADVISORY THAT WILL STRETCH INTO THE DAYLIGHT
HOURS OF FRIDAY. SUB SMALL CRAFT ADVISORIES CONDITIONS ARE EXPECTED
FROM FRIDAY EVENING INTO SUNDAY.
&&
.HYDROLOGY...(340 PM EST THU DEC 15 2011)
ONE RIVER FLOOD WARNING (VICKSBURG) AND THREE RIVER FLOOD ADVISORIES
(IONIA...BURLINGTON AND HOLT) ARE CURRENTLY IN EFFECT. WE ARE NOT
EXPECTING MUCH IN THE WAY OF CHANGES TO RIVER HEADLINES AT THIS
POINT GIVEN THE RAINFALL HAS OCCURRED AND IS MAKING IT/S WAY INTO
THE RIVERS. RAINFALL TOTALS RANGED FROM A HALF INCH TO SLIGHTLY OVER
ONE INCH FOR THE LAST 24 HOURS OR SO. COLDER AIR IS NOW SURGING INTO
THE AREA AND THIS WILL ACT TO SLIGHTLY SUPPRESS RUN OFF SLIGHTLY.
SO...BOTTOM LINE RISES WILL CONTINUE THE NEXT COUPLE OF DAYS WITH
MOST SITES IN THE AREA REMAINING UNDER BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY LAKESHORE COUNTIES THROUGH 1100 PM.
LM...GALE WARNING ENTIRE NEARSHORE AREA THROUGH 100 AM.
&&
$$
SYNOPSIS: DUKE
SHORT TERM: DUKE
LONG TERM: 93
AVIATION: 93
MARINE: DUKE
HYDROLOGY: DUKE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1159 AM CST THU DEC 15 2011
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
STILL PLENTY OF WEATHER GOING ON. COLD ADVECTION TAKING SOME TIME
GETTING INTO EASTERN MN AND WESTERN WISCONSIN WITH THE FREEZING
LEVEL STILL IN THE 1500-2000 RANGE BUT DROPPING. WILL STILL NEED TO
KEEP THE POSSIBILITY OF DRIZZLE IN WI AND FREEZING DRIZZLE A
LITTLE FARTHER WEST. THE WAVE BRINGING IN THE COLDER AIR IS OVER
WESTERN LAKE SUPERIOR BUT A STRONGER WAVE IS DROPPING SOUTHEAST
TOWARD LAKE OF THE WOODS. THIS WILL BRING SCATTERED SNOW SHOWERS
TO MAINLY THE EASTERN PARTS OF OF THE CWA INTO THE AFTERNOON...BUT
SOME FLURRIES FOR WESTERN AREA AS WELL THIS MORNING. OF COURSE
LOTS OF CLOUD COVER UPSTREAM IN THE COLD ADVECTION PATTERN AND
THE RUC AND THE LOCAL 4KM MODEL HAVE A BETTER HANDLE ON KEEPING
CLOUDS IN MOST OF THE DAY. SINKING BEHIND THE STRONGER WAVE
ENTERING NORTHERN MN MAY PUNCH SOME HOLES IN THE CLOUD DECK OVER
EASTERN ND AND WESTERN MN LATE AFTERNOON BUT STILL MOSTLY CLOUDY
OVERALL. TEMPS WILL BE FALLING OVER EASTERN AREAS THIS MORNING
AND THEN STEADY OR JUST UP A FEW DEGREES IN THE WEST TODAY.
SEEM TO BE DECENT CONTINUITY WITH THE CLIPPER TYPE SYSTEM IN THE
NORTHERN BRANCH FOR FRIDAY. THE GFS AND NAM SIMILAR WITH SOME
DECENT LIFT IN THE -15C AREA AS THE WAVE MOVES INTO THE AREA. THE
SREF HAS BEEN TRENDING HIGHER IN DEPICTING A DENDRITIC GROWTH
ZONES AS WELL. WILL RAISE POPS MORE INTO THE CHANCE CATEGORY
ACROSS A NW TO SE CORRIDOR THROUGH THE CWA.
THE MILDER TREND IS STILL ON TRACK FOR THE WEEKEND BUT A BIT
DELAYED FOR SATURDAY. MORE OF A SOUTHWEST FLOW SETTING UP FOR
SUNDAY. THE SUNDAY TIME FRAME IS ALSO SIMILAR TO THE TIMING OF THE
THE MAX 850 MB TEMP ANOMALY SHOWN BY THE GEFS. IT IS AMAZING THAT
THE NAEFS FORECAST HAS BEEN SHOWING ABOVE NORMAL TEMPERATURES FOR
WELL OVER A MONTH ACROSS CANADA..THE UPPER MIDWEST...AND GREAT
LAKES...AND CONTINUES WITH THIS TREND WITH THE LATEST RUN OUT TO
DEC 28.
MOST OF THE PRECIP ACTION LOOKS TO BE MAINLY SOUTH OF US IN THE
SPLIT FLOW INTO THE EARLY PART OF THE WEEK..BUT STILL SOMETHING TO
WATCH.
&&
.AVIATION.../18Z TAF ISSUANCE/
CAA AND CYCLONIC FLOW CONSPIRING TO KEEP 020-040 STRATUS LOCKED IN
ACROSS THE AREA. HOWEVER...A NICE DRYING PUSH IS BEGINNING TO WORK
IN FROM THE RED RIVER VALLEY. IN ADDITION STARTING TO SEE MORE
NUMEROUS/LARGER HOLES GETTING PUNCHED IN TO THE STRATUS DECK...SO
GENERALLY KEPT EXISTING TIMING TREND GOING IN TAFS...AS THIS
MATCHES UP WELL WITH CURRENT 925-850MB RH FORECASTS FROM THE
RUC/NAM/GFS. WILL GET A SHORT-LIVED BREAK FROM CLOUDS THIS
EVENING...BEFORE CLOUDS THICKEN/LOWER AGAIN TONIGHT AHEAD OF A
WEAK CLIPPER. SREF PROBS ALONG WITH GFSLAMP FORECASTS BRING MVFR
CIGS BACK TO MOST LOCATIONS BY LATE MORNING/EARLY AFTERNOON
FRIDAY...BUT KEPT THINGS VFR FOR NOW UNTIL WE SEE HOW CIGS START
PLAYING OUT TONIGHT OVER ERN MT. THERE WILL ALSO BE THE POSSIBILITY
OF SNOW...BUT WITH SFC PRESSURE VALUES AROUND 1030MB...WILL
PROBABLY BE TOUGH TO GET MUCH MORE THAN FLURRIES OUT OF ANY
ACTIVITY FRIDAY. FINAL ISSUE THIS TAF ARE THE WINDS. CAA ALONG
WITH SINKING MOTION BEHIND UPPER WAVE MOVING INTO WI HAS RESULTED
IN NUMEROUS AIRPORTS WEST OF I-35 GUSTING UP OVER 30 KTS. SHOULD
CONTINUE TO SEE GUSTY WINDS THROUGH ABOUT 00Z...BUT AFTER THAT
GRADIENT SLACKENS CONSIDERABLY...WITH MOST OF FRIDAY LIKELY TO
HAVE LGT AND VRB WINDS.
KMSP...STARTING TO SEE BREAKS SHOW UP IN THE OVERCAST THE LAST
COUPLE OF HOURS...SO STUCK WITH A SCATTERING OUT AT 23Z...THOUGH
THE VFR CIGS COULD HANG AROUND UNTIL CLOSER TO 03Z. ALSO EXPECT
WINDS TO DIE DOWN QUICKLY AROUND 00Z AS GRADIENT SLACKENS. TOYED
AROUND WITH THE IDEA OF ADDING SOME -SN 20Z-00Z FRIDAY...BUT GIVEN
DRY STATE OF ATMO AND WEAK/BRIEF FORCING...OPTED OUT OF DOING THAT
FOR NOW. IN ADDITION...SREF PROBS FOR MVFR CIGS FRIDAY AFTERNOON
UP AROUND 90 PERCENT...SO CURRENT SCT020 MAY END UP BEING A
CIG...BUT WE HAVE PLENTY OF TIME TO SEE HOW THINGS PLAY OUT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
520 AM CST THU DEC 15 2011
UPDATED FOR 12Z TAF DISCUSSION BELOW...
.DISCUSSION...
STILL PLENTY OF WEATHER GOING ON. COLD ADVECTION TAKING SOME TIME
GETTING INTO EASTERN MN AND WESTERN WISCONSIN WITH THE FREEZING
LEVEL STILL IN THE 1500-2000 RANGE BUT DROPPING. WILL STILL NEED TO
KEEP THE POSSIBILITY OF DRIZZLE IN WI AND FREEZING DRIZZLE A
LITTLE FARTHER WEST. THE WAVE BRINGING IN THE COLDER AIR IS OVER
WESTERN LAKE SUPERIOR BUT A STRONGER WAVE DROPPING SOUTHEAST
TOWARD LAKE OF THE WOODS. THIS WILL BRING SCATTERED SNOW SHOWERS
TO MAINLY THE EASTERN PARTS OF OF THE CWA INTO THE AFTERNOON...BUT
SOME FLURRIES FOR WESTERN AREA AS WELL THIS MORNING. OF COURSE
LOTS OF CLOUD COVER UPSTREAM IN THE COLD ADVECTION PATTERN AND
THE RUC AND THE LOCAL 4KM MODEL HAVE A BETTER HANDLE ON KEEPING
CLOUDS IN MOST OF THE DAY. SINKING BEHIND THE STRONGER WAVE
ENTERING NORTHERN MN MAY PUNCH SOME HOLES IN THE CLOUD DECK OVER
EASTERN ND AND WESTERN MN LATE AFTERNOON BUT STILL MOSTLY CLOUDY
OVERALL. TEMPS WILL BE FALLING OVER EASTERN AREAS THIS MORNING
AND THEN STEADY OR JUST UP A FEW DEGREES IN THE WEST TODAY.
SEEM TO BE DECENT CONTINUITY WITH THE CLIPPER TYPE SYSTEM IN THE
NORTHERN BRANCH FOR FRIDAY. THE GFS AND NAM SIMILAR WITH SOME
DECENT LIFT IN THE -15C AREA AS THE WAVE MOVES INTO THE AREA. THE
SREF HAS BEEN TRENDING HIGHER IN DEPICTING A DENDRITIC GROWTH
ZONES AS WELL. WILL RAISE POPS MORE INTO THE CHANCE CATEGORY
ACROSS A NW TO SE CORRIDOR THROUGH THE CWA.
THE MILDER TREND IS STILL ON TRACK FOR THE WEEKEND BUT A BIT
DELAYED FOR SATURDAY. MORE OF A SOUTHWEST FLOW SETTING UP FOR
SUNDAY. THE SUNDAY TIME FRAME IS ALSO SIMILAR TO THE TIMING OF THE
THE MAX 850 MB TEMP ANOMALY SHOWN BY THE GEFS. IT IS AMAZING THAT
THE NAEFS FORECAST HAS BEEN SHOWING ABOVE NORMAL TEMPERATURES FOR
WELL OVER A MONTH ACROSS CANADA..THE UPPER MIDWEST...AND GREAT
LAKES...AND CONTINUES WITH THIS TREND WITH THE LATEST RUN OUT TO
DEC 28.
MOST OF THE PRECIP ACTION LOOKS TO BE MAINLY SOUTH OF US IN THE
SPLIT FLOW INTO THE EARLY PART OF THE WEEK..BUT STILL SOMETHING TO
WATCH.
&&
.AVIATION.../12Z TAF ISSUANCE/
MVFR/IFR CONDITIONS WILL CONTINUE THROUGH MIDDAY TODAY UNDER
MODERATE COLD AIR ADVECTION. A NORTHWESTERLY FETCH OF COLD AIR WILL
CONTINUE TO BRING WAVES OF LOW CLOUDS OVER MUCH OF THE AREA INTO
EARLY PART OF THE EVENING. AS DRIER AIR BEGIN TO FILTER OVER THE
AREA FROM NORTHWEST TO SOUTHEAST...CLOUDS SHOULD BEGIN TO ERODE AND
THIN OUT ACROSS THE AREA. SCATTERED SNOW FLURRIES WILL LINGER INTO
THE AFTERNOON. NORTHWEST WINDS 15 TO 25 KNOTS...WITH HIGHER GUSTS
AT TIMES THEN DIMINISHING TO UNDER 10 KNOTS OVERNIGHT TONIGHT. VFR
WEATHER CONDITIONS EXPECTED TONIGHT AS A HIGH PRESSURE RIDGE BUILDS
OVER THE AREA.
KMSP...MVFR WITH PATCHY IFR CONDITIONS WILL PREVAIL THROUGH LATE
AFTERNOON TODAY. CONDITIONS WILL IMPROVE TO SCATTERED CLOUDS AT OR
ABOVE 3500 FEET AGL THIS EVENING. NORTHWEST WINDS 15-25 KNOTS.
AFTER 800 PM...NORTHWEST AROUND 10 KNOTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/JM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
409 AM CST THU DEC 15 2011
.DISCUSSION...
STILL PLENTY OF WEATHER GOING ON. COLD ADVECTION TAKING SOME TIME
GETTING INTO EASTERN MN AND WESTERN WISCONSIN WITH THE FREEZING
LEVEL STILL IN THE 1500-2000 RANGE BUT DROPPING. WILL STILL NEED TO
KEEP THE POSSIBILITY OF DRIZZLE IN WI AND FREEZING DRIZZLE A
LITTLE FARTHER WEST. THE WAVE BRINGING IN THE COLDER AIR IS OVER
WESTERN LAKE SUPERIOR BUT A STRONGER WAVE DROPPING SOUTHEAST
TOWARD LAKE OF THE WOODS. THIS WILL BRING SCATTERED SNOW SHOWERS
TO MAINLY THE EASTERN PARTS OF OF THE CWA INTO THE AFTERNOON...BUT
SOME FLURRIES FOR WESTERN AREA AS WELL THIS MORNING. OF COURSE
LOTS OF CLOUD COVER UPSTREAM IN THE COLD ADVECTION PATTERN AND
THE RUC AND THE LOCAL 4KM MODEL HAVE A BETTER HANDLE ON KEEPING
CLOUDS IN MOST OF THE DAY. SINKING BEHIND THE STRONGER WAVE
ENTERING NORTHERN MN MAY PUNCH SOME HOLES IN THE CLOUD DECK OVER
EASTERN ND AND WESTERN MN LATE AFTERNOON BUT STILL MOSTLY CLOUDY
OVERALL. TEMPS WILL BE FALLING OVER EASTERN AREAS THIS MORNING
AND THEN STEADY OR JUST UP A FEW DEGREES IN THE WEST TODAY.
SEEM TO BE DECENT CONTINUITY WITH THE CLIPPER TYPE SYSTEM IN THE
NORTHERN BRANCH FOR FRIDAY. THE GFS AND NAM SIMILAR WITH SOME
DECENT LIFT IN THE -15C AREA AS THE WAVE MOVES INTO THE AREA. THE
SREF HAS BEEN TRENDING HIGHER IN DEPICTING A DENDRITIC GROWTH
ZONES AS WELL. WILL RAISE POPS MORE INTO THE CHANCE CATEGORY
ACROSS A NW TO SE CORRIDOR THROUGH THE CWA.
THE MILDER TREND IS STILL ON TRACK FOR THE WEEKEND BUT A BIT
DELAYED FOR SATURDAY. MORE OF A SOUTHWEST FLOW SETTING UP FOR
SUNDAY. THE SUNDAY TIME FRAME IS ALSO SIMILAR TO THE TIMING OF THE
THE MAX 850 MB TEMP ANOMALY SHOWN BY THE GEFS. IT IS AMAZING THAT
THE NAEFS FORECAST HAS BEEN SHOWING ABOVE NORMAL TEMPERATURES FOR
WELL OVER A MONTH ACROSS CANADA..THE UPPER MIDWEST...AND GREAT
LAKES...AND CONTINUES WITH THIS TREND WITH THE LATEST RUN OUT TO
DEC 28.
MOST OF THE PRECIP ACTION LOOKS TO BE MAINLY SOUTH OF US IN THE
SPLIT FLOW INTO THE EARLY PART OF THE WEEK..BUT STILL SOMETHING TO
WATCH.
&&
.AVIATION.../06Z TAF ISSUANCE/
FORCING WITH UPPER TROUGH NOW EXITING TO THE EAST. LEFTOVER
IFR/LIFR CONDITIONS WITH AREAS OF DRIZZLE/LIGHT RAIN REMAIN. COLDER
AIR IS MOVING INTO WESTERN AREAS AND THIS TREND WILL CONTINUE THE
REMAINDER OF THE NIGHT. SOME FLURRIES POSSIBLE OVER THE WEST...AND
MOVING EAST DURING THE REMAINDER OF THE NIGHT. PATCHY -FZDZ POSSIBLE
AS WELL...BUT WILL LIKELY REMAIN SPOTTY AND NOT LAST VERY LONG.
CLOUDS TO GRADUALLY LIFT TO MVFR THU MORNING AND BREAK OUT FROM WEST
TO EAST ACROSS MN PORTION OF THE AREA. LATEST SREF AND MODEL
GUIDANCE SUGGEST THIS TREND AS WELL. PREVIOUS FORECAST PRETTY GOOD
OVERALL...SCATTERING OUT OVER ALL THE TAF SITES THROUGH 03Z FRI.
INCREASING NORTHWEST WIND...GUSTS TO NEAR 30 KNOTS OVER THE WESTERN
AREAS...NOT QUITE AS STRONG EAST AS SURFACE LOW LIFTS NORTHEAST.
EXPECT WIND TO DIMINISH DURING WED EVENING.
KMSP...LIFR CONDITIONS FOR A FEW HOURS YET WITH PATCHY DRIZZLE
AROUND THE AREA. MAY EVEN SEE A STRAY SNOWFLAKE LATE OR PATCHY
FREEZING DRIZZLE IF TEMPERATURES COOL DOWN QUICK ENOUGH. WILL
MENTION THE -DZ FOR A FEW HOURS AND THEN CONTINUE TREND OF LIFTING
CEILING TO MVFR THROUGH 14Z. SHOULD SEE CLOUDS SCATTER OUT THROUGH
LATE AFTERNOON. NORTHWEST WINDS WILL INCREASE AND REMAIN GUSTY
THROUGH THE DAY...TAPERING OFF THROUGH SUNSET.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/DWE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
542 AM CST THU DEC 15 2011
.AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
LOW CLOUDS MAINLY BETWEEN 1500-3000 FEET ABOVE GROUND LEVEL MOVED
DOWN ACROSS EASTERN NEBRASKA DURING THE EARLY MORNING HOURS WITH
GUSTY NORTHWEST WINDS. AS HIGH PRESSURE TO THE WEST BUILDS EASTWARD
INTO THE AREA...CLOUDS WILL CLEAR OUT THIS MORNING WITH VFR
CONDITIONS THE REST OF THE DAY. WINDS WILL ALSO BE ON THE DECREASE
AS THE HIGH BUILDS EAST...ESPECIALLY BY MID TO LATE AFTERNOON. DID
NOT MENTION ANY FOG FOR TONIGHT...BUT WITH CLEAR SKIES AND LIGHT
WINDS...BUT IT IS POSSIBLE. LATER SHIFTS WILL NEED TO EVALUATE THAT.
MILLER
&&
.PREV DISCUSSION... /ISSUED 336 AM CST THU DEC 15 2011/
DISCUSSION...
WEATHER WILL SETTLE DOWN FOR A FEW DAYS AS THE CENTRAL US REMAINS IN
BETWEEN SYSTEMS. SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROAD
UPPER-LEVEL TROUGH EXTENDING FROM THE HUDSON BAY THROUGH THE
DAKOTAS/WY/AZ...WITH SHORTWAVE AHEAD OF THE TROUGH IN CO/NM.
UPPER-LEVEL JET STREAK EXTENDED FROM THE TX PANHANDLE THROUGH
WESTERN IA. HIGHER DEWPOINTS AT 850MB WERE WELL EAST...ASSOCIATED
WITH BAND OF RAIN FROM GREAT LAKES THROUGH MO/AR/TX...BUT 850MB
SATURATION WAS EVIDENT FROM THE EASTERN DAKOTAS INTO NEB/KS. AFTER
DRY SLOT HAD INITIALLY CLEARED THE CWA...NOSE OF STRATUS DECK WAS
PUSHING SOUTH OUT OF SD AND INTO EASTERN NEB/WESTERN IA THIS
MORNING...ALONG WITH GUSTY WINDS AND EVEN A STRAY FLURRY REPORT ON
THE NOSE OF THE CLOUDS.
MAIN FORECAST CONCERN WILL BE EVOLUTION OF STRATUS TODAY...THEN
WEATHER SYSTEM THAT MAY CLIP THE AREA MONDAY/TUESDAY. RUC 900MB RH
HAS A PRETTY GOOD HANDLE ON THE CURRENT STRATUS DECK...AND HAVE
FOLLOWED IT PRETTY CLOSELY FOR CLOUDS THROUGH TODAY. RUC WOULD
INDICATE CLOUDS OVERSPREADING THE AREA BY 12Z...THEN CLEARING FROM
SOUTHWEST TO NORTHEAST FROM AROUND 15-21Z. IN OTHER WORDS...STRATUS
COULD HANG ON FOR MOST OF THE DAY...ESPECIALLY IN WESTERN IA.
CLOUDS MAY PREVENT TEMPS FROM FALLING OFF MUCH BEFORE DAWN...BUT
ALSO HINDER RECOVERY TODAY...AND HAVE STAYED ON THE COOL SIDE FOR
TODAY. SKIES SHOULD CLEAR AND WINDS SHOULD DIMINISH BY SUNSET
THOUGH...JUST IN TIME FOR TEMPS TO FALL OFF INTO THE TEENS TONIGHT.
WEAK WAVE MOVING THROUGH THE NORTHWEST FLOW WILL BRING A BRIEF SHOT
OF CLOUDS ON FRIDAY...BUT OTHERWISE WILL HAVE LITTLE IMPACT ON
SENSIBLE WEATHER. WARM AIR ADVECTION WILL PICK UP ON SATURDAY AS AN
UPPER-LEVEL LOW DIGS INTO THE SOUTHWEST AND SPINS...ALLOWING
TEMPERATURES TO MODERATE THROUGH AT LEAST SUNDAY.
UPPER LOW WILL EVENTUALLY EJECT OUT OF THE SOUTHWEST...BUT MODELS
ARE STILL STRUGGLING WITH ITS EVOLUTION ACROSS THE PLAINS.
COMPLICATING THE SCENARIO IS A NORTHERN STREAM WAVE MOVING ACROSS
THE US/CANADA BORDER THAT WILL PROVIDE A PUSH OF COLD AIR AND SET UP
A BOUNDARY ACROSS THE CENTRAL PLAINS. RESULTING SPLIT FLOW SCENARIO
MAKES THE FORECAST MONDAY AND ONWARD QUITE UNCERTAIN. DID REMOVE
ALL BUT A TINY STRIP OF CONSOLATION SLIGHT CHANCE POPS IN THE
SOUTHEAST CWA FOR SUNDAY NIGHT...AS MODEL SOLUTIONS HAVE TRENDED
TOWARD SLOWER AND FURTHER SOUTH SCENARIO FOR THE EJECTING SOUTHERN
STREAM LOW. CHANCE FOR PRECIPITATION INCREASES ON MONDAY...THOUGH
THIS IS NO SLAM DUNK EITHER AS THE 00Z ECMWF CAME IN DRY AND GFS
ALSO IS DRY. CURRENTLY...TEMPERATURE PROFILES LOOK LIKE THEY WOULD
REMAIN WARM ENOUGH FOR RAIN SHOULD ANY PRECIPITATION FALL. ANY
PRECIPITATION ON MONDAY NIGHT WOULD LIKELY CHANGE TO SNOW AS COLD
AIR FILTERS IN BEHIND THE NORTHERN STREAM WAVE...THOUGH AGAIN
CONFIDENCE IS VERY LOW. 00Z ECMWF ACTUALLY HAD THE BEST CHANCE FOR
PRECIP ON TUESDAY...WHILE GFS KEEPS PRECIP CWA DRY THROUGHOUT THE
EVENT. PRECIP TYPE ON TUESDAY WOULD BE MORE QUESTIONABLE...BUT FOR
NOW...GRIDS ARE DRY. KEPT FORECAST DRY FOR THE REST OF THE LONG
TERM FORECAST...ALONG WITH TEMPS THAT ARE NEAR TO SLIGHTLY ABOVE
CLIMATOLOGY /WHICH MAKES SENSE GIVEN THE LACK OF SNOW NOW ACROSS THE
AREA/.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
336 AM CST THU DEC 15 2011
.DISCUSSION...
WEATHER WILL SETTLE DOWN FOR A FEW DAYS AS THE CENTRAL US REMAINS IN
BETWEEN SYSTEMS. SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES BROAD
UPPER-LEVEL TROUGH EXTENDING FROM THE HUDSON BAY THROUGH THE
DAKOTAS/WY/AZ...WITH SHORTWAVE AHEAD OF THE TROUGH IN CO/NM.
UPPER-LEVEL JET STREAK EXTENDED FROM THE TX PANHANDLE THROUGH
WESTERN IA. HIGHER DEWPOINTS AT 850MB WERE WELL EAST...ASSOCIATED
WITH BAND OF RAIN FROM GREAT LAKES THROUGH MO/AR/TX...BUT 850MB
SATURATION WAS EVIDENT FROM THE EASTERN DAKOTAS INTO NEB/KS. AFTER
DRY SLOT HAD INITIALLY CLEARED THE CWA...NOSE OF STRATUS DECK WAS
PUSHING SOUTH OUT OF SD AND INTO EASTERN NEB/WESTERN IA THIS
MORNING...ALONG WITH GUSTY WINDS AND EVEN A STRAY FLURRY REPORT ON
THE NOSE OF THE CLOUDS.
MAIN FORECAST CONCERN WILL BE EVOLUTION OF STRATUS TODAY...THEN
WEATHER SYSTEM THAT MAY CLIP THE AREA MONDAY/TUESDAY. RUC 900MB RH
HAS A PRETTY GOOD HANDLE ON THE CURRENT STRATUS DECK...AND HAVE
FOLLOWED IT PRETTY CLOSELY FOR CLOUDS THROUGH TODAY. RUC WOULD
INDICATE CLOUDS OVERSPREADING THE AREA BY 12Z...THEN CLEARING FROM
SOUTHWEST TO NORTHEAST FROM AROUND 15-21Z. IN OTHER WORDS...STRATUS
COULD HANG ON FOR MOST OF THE DAY...ESPECIALLY IN WESTERN IA.
CLOUDS MAY PREVENT TEMPS FROM FALLING OFF MUCH BEFORE DAWN...BUT
ALSO HINDER RECOVERY TODAY...AND HAVE STAYED ON THE COOL SIDE FOR
TODAY. SKIES SHOULD CLEAR AND WINDS SHOULD DIMINISH BY SUNSET
THOUGH...JUST IN TIME FOR TEMPS TO FALL OFF INTO THE TEENS TONIGHT.
WEAK WAVE MOVING THROUGH THE NORTHWEST FLOW WILL BRING A BRIEF SHOT
OF CLOUDS ON FRIDAY...BUT OTHERWISE WILL HAVE LITTLE IMPACT ON
SENSIBLE WEATHER. WARM AIR ADVECTION WILL PICK UP ON SATURDAY AS AN
UPPER-LEVEL LOW DIGS INTO THE SOUTHWEST AND SPINS...ALLOWING
TEMPERATURES TO MODERATE THROUGH AT LEAST SUNDAY.
UPPER LOW WILL EVENTUALLY EJECT OUT OF THE SOUTHWEST...BUT MODELS
ARE STILL STRUGGLING WITH ITS EVOLUTION ACROSS THE PLAINS.
COMPLICATING THE SCENARIO IS A NORTHERN STREAM WAVE MOVING ACROSS
THE US/CANADA BORDER THAT WILL PROVIDE A PUSH OF COLD AIR AND SET UP
A BOUNDARY ACROSS THE CENTRAL PLAINS. RESULTING SPLIT FLOW SCENARIO
MAKES THE FORECAST MONDAY AND ONWARD QUITE UNCERTAIN. DID REMOVE
ALL BUT A TINY STRIP OF CONSOLATION SLIGHT CHANCE POPS IN THE
SOUTHEAST CWA FOR SUNDAY NIGHT...AS MODEL SOLUTIONS HAVE TRENDED
TOWARD SLOWER AND FURTHER SOUTH SCENARIO FOR THE EJECTING SOUTHERN
STREAM LOW. CHANCE FOR PRECIPITATION INCREASES ON MONDAY...THOUGH
THIS IS NO SLAM DUNK EITHER AS THE 00Z ECMWF CAME IN DRY AND GFS
ALSO IS DRY. CURRENTLY...TEMPERATURE PROFILES LOOK LIKE THEY WOULD
REMAIN WARM ENOUGH FOR RAIN SHOULD ANY PRECIPITATION FALL. ANY
PRECIPITATION ON MONDAY NIGHT WOULD LIKELY CHANGE TO SNOW AS COLD
AIR FILTERS IN BEHIND THE NORTHERN STREAM WAVE...THOUGH AGAIN
CONFIDENCE IS VERY LOW. 00Z ECMWF ACTUALLY HAD THE BEST CHANCE FOR
PRECIP ON TUESDAY...WHILE GFS KEEPS PRECIP CWA DRY THROUGHOUT THE
EVENT. PRECIP TYPE ON TUESDAY WOULD BE MORE QUESTIONABLE...BUT FOR
NOW...GRIDS ARE DRY. KEPT FORECAST DRY FOR THE REST OF THE LONG
TERM FORECAST...ALONG WITH TEMPS THAT ARE NEAR TO SLIGHTLY ABOVE
CLIMATOLOGY /WHICH MAKES SENSE GIVEN THE LACK OF SNOW NOW ACROSS THE
AREA/.
MAYES
&&
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDS HAVE RETURNED TO OFK/LNK AND WILL SOON GET TO OMA AS THE
BACK EDGE OF THE CU DECK SHIFTS EWD OF THE TAF SITES. SOME SCT SC
WILL BE POSSIBLE OVERNIGHT AT OFK AND THE DECK OVER SE SD WILL HAVE
TO BE WATCHED. GUSTY NW WINDS ARE EXPECTED AT OFK/LNK DIMINISHING
BY MID AFTN THU WITH LIGHT AND VARIABLE WINDS EXPECTED BY EVENING.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
425 AM EST THU DEC 15 2011
.SYNOPSIS...
LOW PRESSURE TRACKING ACROSS SOUTHERN CANADA WILL BRING RAINY AND
BREEZY CONDITIONS TO WESTERN NEW YORK TODAY. AN ASSOCIATED COLD
FRONT WILL SWEEP ACROSS THE REGION THIS EVENING. THIS WILL BRING
COOLER AND MORE SEASONABLE TEMPERATURES...AND POSSIBLY A RAIN OR
SNOW SHOWER TONIGHT. AFTER THIS...HIGH PRESSURE WILL RIDGE TOWARD
THE EASTERN LAKES THROUGH SATURDAY...WITH JUST A CHANCE OF A
LINGERING SNOW SHOWER.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 400 AM...RADAR SHOWS A LARGE AREA OF RAIN ACROSS
NORTHEASTERN OHIO AND NORTHWESTERN PENNSYLVANIAN...WHICH IS
TRACKING INTO WESTERN NEW YORK. THIS AREA HAS GENERALLY BEEN SHOWN
BY THE PAST COUPLE RUNS OF THE RGEM/NAM12...WITH THE HRRR ALSO
KEYING ON IT QUITE WELL. WITH MODEL AGREEMENT SUPPORTING
RADAR...THINGS LOOK FAIRLY STRAIGHTFORWARD THROUGH
MID-MORNING...WITH THIS AREA OF RAIN TO MOVE ACROSS WESTERN NEW YORK
DURING THIS TIME. IT SHOULD BRING A GENERAL QUARTER TO HALF INCH OF
RAIN...AND WHILE UPSTREAM LIGHTNING HAS DIMINISHED...WILL MAINTAIN
AN ISOLATED CHANCE OF THUNDER WITH THIS...DUE TO THE INSTABILITY
ABOVE 600 MB.
STEADY RAIN WILL MOVE EAST OF LAKE ONTARIO MID-MORNING...LINGERING
THERE WELL INTO THE AFTERNOON. FOR THE REMAINDER OF WESTERN NEW
YORK...THINGS SHOULD BE MORE SHOWERY FROM MID-MORNING ON...BOTH FROM
LINGERING SHOWERS AND WITH SHOWERS GENERATED BY THE APPROACHING COLD
FRONT.
OUTSIDE OF THE RAIN...IT WILL BE NOTABLY WARM AND BREEZY TODAY.
TEMPERATURES WILL BE ON THE WARM SIDE...WITH HIGHS RANGING FROM
AROUND 50 IN THE SOUTHERN TIER...TO THE MID 50S IN DOWNSLOPE REGIONS
NORTH OF THE THRUWAY FROM THE NY/PA LINE TO ROCHESTER. WHILE 925 MB
WINDS WILL RUN 50 TO 60 KTS THROUGH THIS MORNING...THE SSW FLOW WILL
STRUGGLE TO MIX DOWN IN THE WARM AIR ADVECTION PATTERN. THROUGH
MID-MORNING...THIS SHOULD LIMIT GUSTS TO AROUND 35 MPH...PERHAPS
HIGHER ACROSS HIGHER TERRAIN IN BOTH THE SOUTHERN TIER AND THE TUG
HILL. AS WINDS VEER MORE SW LATE MORNING INTO THIS
AFTERNOON...EXPECT BETTER MIXING ON THE NIAGARA FRONTIER AS WINDS
FUNNEL ALONG THE CHAUTAUQUA RIDGE. BY THIS TIME...WINDS ALOFT WILL
HAVE DIMINISHED...BUT STILL EXPECT GUSTS IN THE 40 TO 45 MPH RANGE
FROM LATE MORNING THROUGH MID-AFTERNOON ON THE NIAGARA
FRONTIER...INCLUDING THE BUFFALO METRO REGION.
FOR TONIGHT...THE MOST SIGNIFICANT WEATHER FEATURE WILL BE AN UPPER
LEVEL TROF WHICH WILL CROSS THE REGION OVERNIGHT...EVENTUALLY
PUSHING A REINFORCING SHOT OF COLD AIR ACROSS THE REGION. EVEN
THOUGH COOLER TEMPERATURES ALOFT WILL BE IN PLACE OVERNIGHT...850 MB
TEMPS WILL RUN -3 TO -6C AHEAD OF THE SECONDARY COLD FRONT. THIS
MODEST INSTABILITY COMBINED WITH STRONG WINDS WHICH WILL LIMIT
RESIDENCE TIME ON THE LAKES SHOULD PREVENT ANY PURE LAKE EFFECT
PRECIPITATION FROM DEVELOPING. HOWEVER...THE SHORTWAVE ITSELF IS
FAIRLY POTENT...LIKELY ENOUGH SO TO SPARK SOME SHOWERS WITH ANY
MOISTURE IT CAN GRAB FROM THE LAKES. BY LARGE...RGEM/NAM12 QPF
FIELDS LOOK TO BE OVERDONE...ESPECIALLY IN UPSLOPE REGIONS. EXPECT
THERE WILL BE SOME SHOWERS WITH THE SHORTWAVE...BUT OTHERWISE
MOISTURE IS NOT DEEP ENOUGH TO GENERATE MUCH IN THE WAY OF
PRECIPITATION.
ONLY SEE A CHANCE OF SHOWERS SOUTH OF THE THRUWAY TONIGHT...WHERE IT
IS FURTHER FROM THE SHORTWAVE. THESE SHOULD MOSTLY BE IN THE FORM OF
RAIN...BUT MAY MIX WITH SNOW IN SPOTS. EXPECT SHOWERS EAST OF LAKE
ONTARIO AFTER MIDNIGHT AS THIS SHORTWAVE CROSSES. INITIALLY IT
SHOULD BE TO WARM FOR SNOW...BUT AS AIR ALOFT COOLS WITH THE
SHORTWAVE...EXPECT RAIN SHOWERS TO MIX WITH SNOW ACROSS HIGHER
TERRAIN EAST OF LAKE ONTARIO. MIXING SHOULD LIMIT ACCUMULATION
THROUGH DAYBREAK...BUT PERHAPS A WET INCH OR SO IS POSSIBLE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE END OF THE WORKWEEK AND THE FIRST HALF OF THE WEEKEND WILL
FEATURE A TREND TOWARDS COOLER...MORE SEASONABLE TEMPERATURES WITH
THE POTENTIAL FOR A COMBINATION OF SYNOPTIC SCALE AND LAKE EFFECT
SNOW.
LOW PRESSURE CENTERED NEAR LAKE SUPERIOR EARLY THIS THURSDAY MORNING
WILL BE DRIFTING ACROSS THE CANADIAN MARITIMES ON FRIDAY. A
SECONDARY COLD FRONT TRAILING WEST OF THIS LOW WILL SETTLE SOUTH
ACROSS THE CWA FRIDAY MORNING...FOLLOWED BY A NORTHWEST FLOW OF
COLDER AIR. THIS WILL RESULT IN A CHANCE FOR SOME LAKE EFFECT SNOW
DURING THE MORNING WHEN THERE WILL BE SUFFICIENT LOW LEVEL MOISTURE
AND SOMEWHAT FAVORABLE SNOW GROWTH. WILL MAINTAIN HIGHER LIKELY POPS
EAST OF LAKE ONTARIO WHERE THERE WILL BE ADDITIONAL LIFT FROM A WELL
DEFINED SHORT WAVE THAT WILL BE PUSHING THROUGH NORTHERN NEW YORK
STATE. DRIER AIR AND INCREASING LOW LEVEL SHEAR WILL CAUSE ANY
LINGERING SNOW SHOWERS TO END DURING THE AFTERNOON.
A COUPLE INCHES OF SNOW IS POSSIBLE OVER THE HIGHER ELEVATIONS EAST
OF LAKE ONTARIO ON FRIDAY...BUT GENERALLY UNDER AN INCH IS EXPECTED
EAST OF LAKE ERIE.
A MUCH COOLER DAY IS ON TAP FOR FRIDAY AS 850MB TEMPS DROP FROM -8C
SOUTH TO AROUND -10C ACROSS THE NORTH COUNTRY. CORRESPONDING SURFACE
TEMPERATURES WILL RANGE THROUGH THE 30S...WITH THE COOLEST READINGS
EXPECTED EAST OF LAKE ONTARIO. A WEAK AREA OF HIGH PRESSURE BUILDING
SOUTH FROM SOUTHERN ONTARIO WILL BRING DRY WEATHER FRIDAY NIGHT.
LOOK FOR MORE SNOW SHOWERS TO DEVELOP ACROSS WESTERN NEW YORK
SATURDAY THROUGH SATURDAY NIGHT AS SEVERAL MORE SHORT WAVES CROSS
THE LOWER GREAT LAKES. WHILE SYNOPTIC SCALE FEATURES WILL BE THE
PRIMARY MECHANISM DRIVING THE SNOW SHOWERS...SOME LAKE ENHANCEMENT
IS POSSIBLE AT THOSE TIMES WHEN THE BOUNDARY LAYER WINDS BECOME
BETTER ALIGNED. THE BIGGEST DETRIMENT FOR ORGANIZED LAKE SNOWS IS
THAT THERE MAY BE TOO MUCH SHEAR GENERATED BY THE
PASSING SHORT WAVES. RIGHT NOW IT LOOKS LIKE THE BEST POTENTIAL FOR
LAKE SNOWS MAY BE OFF LAKE ERIE SATURDAY AFTERNOON INTO PART OF
SATURDAY NIGHT WHEN THE GFS SHOWS THE WINDS LINING UP FROM THE WEST.
THE NAM SHOWS QUITE A BIT MORE SHEAR DURING THIS TIME.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ANY LAKE SNOWS THAT LINGER INTO SUNDAY MORNING SHOULD WIND DOWN
DURING THE AFTERNOON AS HIGH PRESSURE OVER THE SOUTHEAST U.S.
ADVECTS WARMER AIR ACROSS THE LOWER LAKES.
FROM SUNDAY EVENING ONWARDS...TIMING DIFFERENCES STILL EXIST BETWEEN
THE MODELS REGARDING THE TIMING OF HOW QUICKLY THE CUTOFF LOW OVER
THE DESERT SOUTHWEST EJECTS INTO THE MIDWEST. THE GFS IS SLOWER ON
BRINGING THE LOW INTO THE PLAINS THAN EITHER THE GEM OR ECMWF WHILE
MAINTAINING A STRONGER ZONAL FLOW ACROSS THE GREAT LAKES WHILE THE
LATTER MODELS ARE FASTER AND AS A RESULT AMPLIFY A SHORTWAVE RIDGE
OVER THE REGION WITH RESULTING WARMER TEMPERATURES THAN THE GFS FOR
THE BEGINNING OF THE WEEK. THIS ALSO AFFECTS THE TIMING OF A
DEVELOPING SURFACE LOW OVER THE MIDWEST. IT IS TOUGH TO TIME THE
EJECTION OF THESE CUTOFF FEATURES...SO CONFIDENCE IN ANY PARTICULAR
SOLUTION IS LOW. FOR NOW WILL MAKE JUST MINOR CHANGES TO THE GOING
FORECAST WITH CHANCE POPS RUNNING NEAR CLIMATOLOGY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
WIDESPREAD RAIN ACROSS FAR WESTERN AREAS AT 09Z WILL SPREAD TO THE
NORTHEAST. THIS SHOULD BRING A MIX OF MVF/IFR CONDITIONS...WHICH
WILL PREVAIL FOR MUCH OF THE DAY.
THE PERIOD OF STEADIEST AND HEAVIEST RAIN WILL MOVE IN DURING THE
10Z-14Z TIME FRAME...A FEW HOURS LATER EAST OF LAKE ONTARIO. THERE
IS STILL A SMALL CHANCE OF ISOLATED CONVECTION DURING THIS TIME
FRAME...AND IT APPEARS THE BEST CHANCE WILL BE ACROSS THE SOUTHERN
TIER. GIVEN THE SPARSE COVERAGE OF THIS...WILL CONTINUE WITH JUST CB
QUALIFIER.
RAIN WILL EVENTUALLY TAPER OFF FROM WEST TO EAST THURSDAY AFTERNOON
WITH MVFR CIGS LINGERING INTO TOMORROW NIGHT. SOME LIMITED LAKE
EFFECT SNOW MAY DEVELOP EAST OF THE LAKES BUT THIS WILL BE VERY
MINOR WITH JUST LOCAL MVFR IN LIGHT SNOW SHOWERS.
LOW LEVEL WIND SHEAR WILL BE WIDESPREAD TONIGHT THROUGH THE FIRST
HALF OF THURSDAY AS A STRONG 60+ KNOT LOW LEVEL JET CROSSES THE
LOWER LAKES REGION. PILOTS SHOULD BE AWARE OF RAPID LOSS OF HEADWIND
ON FINAL APPROACH.
OUTLOOK...
FRIDAY...VFR/MVFR. A CHANCE OF RAIN OR SNOW SHOWERS.
SATURDAY...AREAS OF MVFR WITH A CHANCE OF SNOW SHOWERS.
SUNDAY...VFR.
MONDAY...AREAS OF MVFR WITH A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
00Z BUFKIT SOUNDINGS FROM THE NAM/GFS...AS WELL AS AVAILABLE RGEM
DATA ALL POINT TOWARD GALE CONDITIONS DEVELOPING TONIGHT. FOR LAKE
ONTARIO...HAVE HIGH CONFIDENCE IN GALES...WHERE COOLING TEMPERATURES
SHOULD ENHANCE MIXING OF 925 MB WINDS TO 45 KTS TONIGHT. ON LAKE
ONTARIO...EXPECT WINDS TO INCREASE TO GALE LATE EVENING...WITH GUSTS
LIKELY TO REACH THE PREVAILING 925 MB WINDS OF 45 KTS.
ON LAKE ERIE...WINDS MAY NOT BE QUITE AS STRONG...BUT IN THE SW FLOW
IT LOOKS LIKE WINDS WILL COME UP CONSIDERABLY EARLIER. THROUGH EARLY
AFTERNOON...A 50 KT FLOW AT 925 MB WILL BE IN PLACE ACROSS THE
REGION. WARM AIR ALOFT WILL RESULT IN AN INVERSION WHICH SHOULD KEEP
MUCH OF THIS FROM MIXING...BUT AS THIS VEERS TO THE WSW
MID-AFTERNOON...THE CHAUTAUQUA RIDGE MAY LOCALLY ENHANCE MIXING ON
LAKE ERIE...RESULTING IN MARGINAL GALES LATE AFTERNOON INTO THIS
EVENING. AS COOLER AIR MOVES IN...CONFIDENCE IMPROVES...WITH GALES
LIKELY UNTIL THE SHORTWAVE EXITS TOWARD DAYBREAK FRIDAY.
AFTER THIS...WINDS WILL DIMINISH FRIDAY AND FRIDAY EVENING...WITH
THE HIGH LIKELY TO KEEP WINDS ON THE LIGHT SIDE FOR THIS WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST FRIDAY FOR
LEZ020-040-041.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST
FRIDAY FOR LOZ030.
GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY
FOR LOZ042>045-062>065.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR SLZ022-
024.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP/WOOD
LONG TERM...TJP/WOOD
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
919 PM EST FRI DEC 16 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...BRINGING ONLY A
SMALL CHANCE OF LIGHT RAIN. MUCH COLDER AIR WILL BUILD IN FOR THE
WEEKEND AS ARCTIC HIGH PRESSURE APPROACHES FROM THE WEST.
TEMPERATURES WILL RETURN TO ABOVE NORMAL LEVELS NEXT WEEK AS THE
HIGH MOVES OFFSHORE LATE MONDAY AND TUESDAY. ANOTHER COLD FRONT WILL
MOVE INTO THE AREA ON WEDNESDAY AND MAY STALL. RAIN CHANCES WILL
INCREASE DURING THE LATTER PORTION OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM FRIDAY...THE COLD FRONT IS NOW ALONG A LINE FROM
LAURINBURG TO LUMBERTON TO ELIZABETHTOWN TO JUST NORTH OF
BURGAW...MOVING STEADILY SOUTHWARD. IN ADDITION TO A NEARLY-180
DEGREE WIND SHIFT AND A RAPID CHANGE IN TEMPERATURE AND DEWPOINT...
THE FRONT IS EASY TO PICK OUT ON RADAR IMAGERY NOW FROM THE KLTX
WSR-88D. SHORT-TERM MODELS ARE IN GOOD AGREEMENT WITH THE SOUTHWARD
MOVEMENT OF THE FRONT ACROSS OUR FORECAST AREA LATE THIS EVENING AND
OVERNIGHT...WITH THE BOUNDARY PUSHING AS FAR SOUTH AS GEORGETOWN SC
A FEW HOURS BEFORE DAYBREAK SATURDAY.
RAIN CHANCES ARE THE BIGGEST FORECAST CONCERN OVERNIGHT. CURRENT
RADAR COMPOSITES SHOW A RATHER EXPANSIVE AREA OF LIGHT RAIN
EXTENDING FROM THE CHARLOTTE METRO AREA INTO NORTHEASTERN NORTH
CAROLINA. VERY LITTLE RAIN EXTENDS SOUTH OF THIS BATCH TO IMPACT OUR
FORECAST AREA OVERNIGHT. SHALLOW LIFT OVER THE FRONTAL SURFACE
WITHIN A ZONE OF MOISTURE EXTENDING UP TO 775 MB COULD CAUSE SOME
PATCHES OF LIGHT RAIN TO DEVELOP AS FAR SOUTH AS FLORENCE...
MARION...CONWAY...AND SOUTHPORT...ALTHOUGH THE CHANCES OF RECEIVING
A MEASURABLE 0.01" IS PRETTY SLIM. WE WILL MAINTAIN A 20 (SLIGHT
CHANCE) POP FOR THE AFOREMENTIONED AREAS...WITH SOME OF THE LATEST
HRRR RUNS STILL SHOWING VERY LIGHT PRECIPITATION DEVELOPING AFTER
06Z ACROSS SOUTHEASTERN NORTH CAROLINA AND ADJACENT PORTIONS OF
SOUTH CAROLINA.
AS THE FRONT PASSES BY OVERNIGHT TEMPERATURES WILL FALL INTO THE MID
TO UPPER 40S ACROSS INTERIOR SECTIONS OF THE CAROLINAS...WITH TEMPS
~5 DEGREES WARMER AT THE IMMEDIATE COAST DUE TO SOME WEAK MARINE
INFLUENCE ON THE NORTH-NORTHEAST POST-FRONTAL WIND. AHEAD OF THE
FRONT CURRENT (9 PM) TEMPERATURES RANGE FROM THE MID TO UPPER 50S
WHERE SKIES ARE CLEAR...TO THE LOWER 60S WHERE SKIES ARE CURRENTLY
CLOUDY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A SURFACE COLD FRONT WILL BE SOUTH OF THE
SOUTH SANTEE RIVER SAT MORNING AND WILL CONTINUE TO MOVE TO THE
SOUTH. AN UPPER TROUGH WILL BOTTOM OUT ACROSS THE EAST COAST SAT
AND SAT NIGHT. THIS TROUGH WILL BE VERY PROGRESSIVE...MOVING
OFFSHORE DURING SUN. UPPER RIDGE WILL THEN BUILD ACROSS THE AREA
SUN NIGHT AND MON. FORECAST PERIOD WILL START WITH BKN TO OVC LOW
CLOUDS AND PERHAPS SOME SPRINKLES AS LOW LEVEL MOISTURE REMAINS
LOCKED BENEATH A FRONTAL INVERSION. A SHORTWAVE TROUGH WILL MOVE
ACROSS THE AREA SAT AFTERNOON AND EVE AND THIS WILL SCOUR OUT
REMAINING LOW LEVEL MOISTURE.
CLOUDINESS WILL EVENTUALLY ERODE DURING SAT WITH SKIES CLEAR OR
CLEARING BY EVE. H8 TEMPS WILL DROP FROM AROUND 7 DEG C TO 3 DEG C
SAT. H8 TEMPS WILL BOTTOM OUT AROUND ZERO DEG C ON SUN. THIS INFLUX
OF COLD AIR WILL DELAY ANY SIGNIFICANT UPWARD TREND IN TEMPS SAT.
TEMPS SHOULD STILL BE DROPPING SAT MORNING...BUT AFTERNOON TEMPS
SHOULD BE ABLE TO RECOVER TO THE MID 50S MOST PLACES AND CLOSER TO
60 DEG AS YOU NEAR THE SOUTH SANTEE RIVER. AS SURFACE HIGH
PRESSURE...CENTERED ACROSS THE MID SOUTH AND GULF COAST GROWS
CLOSER...WINDS SHOULD FULLY DECOUPLE DURING SAT NIGHT. CLEAR SKIES
AND LIGHT N WINDS SHOULD ALLOW RADIATIONAL COOLING TO GAIN A STRONG
FOOT HOLD OVERNIGHT. READINGS SUN MORNING WILL BE IN THE LOWER TO
MID 30S WITH SOME OF OUR NORMALLY COLD SPOTS DROPPING INTO THE UPPER
20S. BRIGHT SUNSHINE ON SUN WILL ONLY BE ABLE TO PROPEL TEMPS INTO
THE MID AND UPPER 50S. SUN NIGHT SHOULD BE COLDER THAN THE PREVIOUS
NIGHT. HIGH PRESSURE WILL BE CENTERED VIRTUALLY OVERHEAD SUN NIGHT
WITH SOME THIN CIRRUS INCREASING LATE. TEMPS MON MORNING WILL BE IN
THE UPPER 20S TO LOWER 30S WITH SOME MID 20S IN THE COLDEST
LOCATIONS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...THE EXTENDED FORECAST WARRANTS FEW CHANGES
THIS AFTERNOON AS MOST OF THE ACTION WILL BE CONCENTRATED ON THE
MIDDLE AND LATTER PART OF THE PERIOD. A WEAKENING SHORTWAVE WILL
MOVE ACROSS THE MISSISSIPPI VALLEY LATE TUESDAY AND WEDNESDAY WITH
A WEAK FRONT MOVING ACROSS THE SOUTH. AS HAS BEEN THE CASE THE
PAST FEW WEEKS...THE BEST FORCING WITH THIS SYSTEM MOVES OFF TO
THE NORTHEAST. TWEAKED THE TIMING WITH THE LATEST FORECAST TO
DELAY THE TIMING OTHERWISE I MAINTAINED THE CHANCE POPS FOR LATE
TUESDAY INTO WEDNESDAY FOR OUR AREA. ANOTHER SYSTEM IN THE
SOUTHERN BRANCH QUICKLY FOLLOWS FOR LATE THURSDAY INTO FRIDAY WITH
A BRIEF REPRIEVE EARLY THURSDAY. TEMPERATURES LOOK TO REMAIN ABOVE
NORMAL WITH THE EXCEPTION OF MONDAY WHEN HIGH PRESSURE WILL BE
ESSENTIALLY OVERHEAD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MODERATE CONFIDENCE OVERNIGHT AS COLD FRONT BRINGS A
CHANCE OF SOME VERY LIGHT RAIN AND MVFR. VFR WILL DEVELOP SATURDAY
AFTN.
COLD FRONT DRIFTING SOUTH APPEARS TO BE ALIGNED JUST NORTH OF THE
CWA BORDER BASED OFF WIND SHIFT EVIDENT ON CURRENT OBS. THIS FRONT
WILL VERY SLOWLY DRIFT SOUTHWARD BRINGING A WIND SHIFT FROM SW TO
N/NE. WINDS WILL REMAIN ONLY AROUND 10 KTS HOWEVER SINCE CAA BEHIND
THE FRONT IS RATHER WEAK. BIGGER CONCERN IS HOW PRECIP AND CLOUD
COVER WILL EVOLVE WITH THE FROPA. HRRR AND 4KM WRF BOTH SUGGEST
RAINFALL ERODING AS FRONT DROPS SOUTH...AND THIS IS AGREED UPON BY
MODEL SOUNDINGS WHICH DEPICT ONLY SHALLOW COLUMN SATURATION. FOR
THIS REASON HAVE CARRIED 6SM WITH -DZ AT ILM/FLO...AND 5SM -DZ AT
LBT WHICH IS CLOSEST TO THE FRONT AND HAS THE BEST CHANCE OF SEEING
ANY RAINFALL. POST FRONTAL STRATUS WILL BE SIGNIFICANT...BUT HAVE
OPTED NOT TO INCLUDE ANY IFR BASED OFF UPSTREAM OBS...WHERE IFR IS
ONLY OCCURRING IN SIGNIFICANT RAIN. EXPECT WIDESPREAD MVFR OVERNIGHT
HOWEVER.
S/W WILL PUSH OFF TO THE EAST EARLY SATURDAY BRINGING DRIER AIR TO
THE REGION. THIS WILL HELP ERODE CLOUD COVER AND VFR WILL DEVELOP BY
LATE MORNING OR EARLY AFTN. WINDS WILL PERSIST FROM THE NORTH
THROUGH SATURDAY AROUND 10 KTS...WITH SKY CONDITIONS IMPROVING TO
NEARLY CLEAR BY NIGHTFALL.
EXTENDED OUTLOOK...VFR SUNDAY AND MONDAY. MORNING FOG POSSIBLE
TUESDAY. SHOWERS ASSOCIATED WITH A COLD FRONT MAY IMPACT THE AREA
WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM FRIDAY...A COLD FRONT ACROSS EASTERN NORTH CAROLINA HAS
MOVED THROUGH MOREHEAD CITY AND JACKSONVILLE...AND WILL BE IN SURF
CITY WITHIN THE NEXT HOUR. THIS FRONT SHOULD CONTINUE MOVING SOUTH
TONIGHT...MOVING ACROSS CAPE FEAR BETWEEN MIDNIGHT AND 2 AM...MYRTLE
BEACH BETWEEN 1-3 AM...AND THROUGH GEORGETOWN AN HOUR OR TWO BEFORE
DAYBREAK SATURDAY. SOUTHWEST WINDS WILL TURN WESTERLY AHEAD OF THE
FRONT LATER THIS EVENING...THEN WILL ABRUPTLY SHIFT TO THE NORTH
BEHIND THE FRONT. WITH QUICKLY FALLING TEMPERATURES BEHIND THE FRONT
WINDS WILL BECOME GUSTY WITH GUSTS OVER 20 KNOTS POSSIBLE FOR A FEW
HOURS. ANY LIGHT RAIN ASSOCIATED WITH THE FRONT SHOULD REMAIN MAINLY
NORTH OF CAPE FEAR...BUT THE LATEST MODEL PROJECTIONS ARE THAT VERY
LITTLE RAIN WILL FALL EVEN HERE.
SEAS RANGE FROM 2.5 TO 4 FT AT THE BUOYS THIS EVENING...AND THE
SPECTRAL WAVE PLOT FROM FRYING PAN SHOALS SHOWS THE WAVES ARE ALMOST
EXCLUSIVELY AN 11-14 SECOND SOUTHEAST SWELL. VERY LITTLE WIND CHOP
EXISTS ACROSS THE WATERS CURRENTLY...BUT THIS SHOULD CHANGE LATE
TONIGHT BEHIND THE FRONT WITH THE INCREASING COLD NORTHERLY WINDS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A MODEST NORTHERLY SURGE WILL BE UNDERWAY
AT THE START OF THE PERIOD. INITIAL SURGE WILL WANE SAT AFTERNOON
WITH ANOTHER SURGE EXPECTED SAT NIGHT AND THEN AGAIN DURING SUN. N
WINDS WILL VEER TO NE SUN NIGHT AS WINDS DIMINISH. WINDS WILL
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. SEAS
SHOULD PEAK IN 3 TO 5 FT RANGE ACROSS THE WATERS OFF OF CAPE FEAR
DURING SAT AND 3 TO 4 FT ACROSS THE OUTER FRINGES OF THE SOUTHERN
WATERS. SIX FT SEAS ARE POSSIBLE AROUND FRYING PAN SHOALS BUOY ON
SAT. SUBSEQUENT SURGES ARE NOT EXPECTED TO PRODUCE WAVE HEIGHTS
ECLIPSING THESE VALUES.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 230 PM FRIDAY...LIGHT WINDS WILL GREET MARINERS MONDAY AS
HIGH PRESSURE RESIDES OVERHEAD. A SOUTHERLY FLOW WILL DEVELOP
LATER MONDAY AND PREVAIL TUESDAY AS THE HIGH MOVES OFFSHORE. WINDS
WILL TURN MORE TO THE SOUTHWEST WEDNESDAY AS LOW PRESSURE MOVES
THROUGH THE OHIO VALLEY. THIS STRONGEST WINDS WILL PREVAIL
WEDNESDAY AS WELL WITH 20-25 KNOTS. WAVEWATCH SEAS LOOK REASONABLE
WITH 2-4 FEET EARLY INCREASING TO 4-6 FEET WEDNESDAY. FINALLY
THERE IS THE POSSIBILITY FOR SEA FOG TUESDAY BEFORE WINDS TURN
MORE SOUTHWEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
639 PM EST FRI DEC 16 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...BRINGING ONLY A
SMALL CHANCE OF LIGHT RAIN. MUCH COLDER AIR WILL BUILD IN FOR THE
WEEKEND AS ARCTIC HIGH PRESSURE APPROACHES FROM THE WEST.
TEMPERATURES WILL RETURN TO ABOVE NORMAL LEVELS NEXT WEEK AS THE
HIGH MOVES OFFSHORE LATE MONDAY AND TUESDAY. ANOTHER COLD FRONT WILL
MOVE INTO THE AREA ON WEDNESDAY AND MAY STALL. RAIN CHANCES WILL
INCREASE DURING THE LATTER PORTION OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM FRIDAY...AFTER ANOTHER BEAUTIFULLY WARM DAY ACROSS THE
EASTERN CAROLINAS...THE COLD FRONT THAT WILL BRING A RETURN TO
WINTER-LIKE WEATHER HAS MOVED AS FAR SOUTH AS NEW BERN...
KENANSVILLE...CLINTON AND FAYETTEVILLE. THE FRONT IS EASY TO PICK
OUT ON THE MAP WITH A NEARLY-180 DEGREE WIND SHIFT AND A RAPID
CHANGE IN TEMPERATURE AND DEWPOINT. SHORT-TERM MODELS ARE IN GOOD
AGREEMENT WITH THE SOUTHWARD MOVEMENT OF THE FRONT ACROSS OUR
FORECAST AREA LATE THIS EVENING AND OVERNIGHT...WITH THE BOUNDARY
PUSHING SOUTH THROUGH GEORGETOWN SC A FEW HOURS BEFORE DAYBREAK
SATURDAY.
RAIN CHANCES ARE THE BIGGEST FORECAST CONCERN OVERNIGHT. CURRENT
RADAR COMPOSITES SHOW ONE BAND OF RAIN MOVING EAST FROM THE
CHARLOTTE METRO AREA THROUGH CENTRAL NORTH CAROLINA. VERY LITTLE
RAIN EXTENDS SOUTH OF THIS TO IMPACT OUR AREA OVERNIGHT. SHALLOW
LIFT OVER THE FRONT WITHIN A ZONE OF MOISTURE EXTENDING UP AS HIGH
AS 775 MB COULD CAUSE SOME PATCHES OF LIGHT RAIN TO DEVELOP AS FAR
SOUTH AS FLORENCE...MARION...CONWAY...AND SOUTHPORT...ALTHOUGH THE
CHANCES OF RECEIVING A MEASURABLE 0.01" IS PRETTY SLIM.
TEMPERATURES WILL REMAIN STEADY IN THE 60-65 DEGREE RANGE UNTIL THE
FRONT ARRIVES...THEN TEMPERATURES WILL FALL INTO THE MID TO UPPER
40S ACROSS INTERIOR SECTIONS OF THE CAROLINAS...WITH TEMPS ~5
DEGREES WARMER AT THE IMMEDIATE COAST DUE TO SOME WEAK MARINE
INFLUENCE ON THE NORTH-NORTHEAST POST-FRONTAL WIND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A SURFACE COLD FRONT WILL BE SOUTH OF THE
SOUTH SANTEE RIVER SAT MORNING AND WILL CONTINUE TO MOVE TO THE
SOUTH. AN UPPER TROUGH WILL BOTTOM OUT ACROSS THE EAST COAST SAT
AND SAT NIGHT. THIS TROUGH WILL BE VERY PROGRESSIVE...MOVING
OFFSHORE DURING SUN. UPPER RIDGE WILL THEN BUILD ACROSS THE AREA
SUN NIGHT AND MON. FORECAST PERIOD WILL START WITH BKN TO OVC LOW
CLOUDS AND PERHAPS SOME SPRINKLES AS LOW LEVEL MOISTURE REMAINS
LOCKED BENEATH A FRONTAL INVERSION. A SHORTWAVE TROUGH WILL MOVE
ACROSS THE AREA SAT AFTERNOON AND EVE AND THIS WILL SCOUR OUT
REMAINING LOW LEVEL MOISTURE.
CLOUDINESS WILL EVENTUALLY ERODE DURING SAT WITH SKIES CLEAR OR
CLEARING BY EVE. H8 TEMPS WILL DROP FROM AROUND 7 DEG C TO 3 DEG C
SAT. H8 TEMPS WILL BOTTOM OUT AROUND ZERO DEG C ON SUN. THIS INFLUX
OF COLD AIR WILL DELAY ANY SIGNIFICANT UPWARD TREND IN TEMPS SAT.
TEMPS SHOULD STILL BE DROPPING SAT MORNING...BUT AFTERNOON TEMPS
SHOULD BE ABLE TO RECOVER TO THE MID 50S MOST PLACES AND CLOSER TO
60 DEG AS YOU NEAR THE SOUTH SANTEE RIVER. AS SURFACE HIGH
PRESSURE...CENTERED ACROSS THE MID SOUTH AND GULF COAST GROWS
CLOSER...WINDS SHOULD FULLY DECOUPLE DURING SAT NIGHT. CLEAR SKIES
AND LIGHT N WINDS SHOULD ALLOW RADIATIONAL COOLING TO GAIN A STRONG
FOOT HOLD OVERNIGHT. READINGS SUN MORNING WILL BE IN THE LOWER TO
MID 30S WITH SOME OF OUR NORMALLY COLD SPOTS DROPPING INTO THE UPPER
20S. BRIGHT SUNSHINE ON SUN WILL ONLY BE ABLE TO PROPEL TEMPS INTO
THE MID AND UPPER 50S. SUN NIGHT SHOULD BE COLDER THAN THE PREVIOUS
NIGHT. HIGH PRESSURE WILL BE CENTERED VIRTUALLY OVERHEAD SUN NIGHT
WITH SOME THIN CIRRUS INCREASING LATE. TEMPS MON MORNING WILL BE IN
THE UPPER 20S TO LOWER 30S WITH SOME MID 20S IN THE COLDEST
LOCATIONS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...THE EXTENDED FORECAST WARRANTS FEW CHANGES
THIS AFTERNOON AS MOST OF THE ACTION WILL BE CONCENTRATED ON THE
MIDDLE AND LATTER PART OF THE PERIOD. A WEAKENING SHORTWAVE WILL
MOVE ACROSS THE MISSISSIPPI VALLEY LATE TUESDAY AND WEDNESDAY WITH
A WEAK FRONT MOVING ACROSS THE SOUTH. AS HAS BEEN THE CASE THE
PAST FEW WEEKS...THE BEST FORCING WITH THIS SYSTEM MOVES OFF TO
THE NORTHEAST. TWEAKED THE TIMING WITH THE LATEST FORECAST TO
DELAY THE TIMING OTHERWISE I MAINTAINED THE CHANCE POPS FOR LATE
TUESDAY INTO WEDNESDAY FOR OUR AREA. ANOTHER SYSTEM IN THE
SOUTHERN BRANCH QUICKLY FOLLOWS FOR LATE THURSDAY INTO FRIDAY WITH
A BRIEF REPRIEVE EARLY THURSDAY. TEMPERATURES LOOK TO REMAIN ABOVE
NORMAL WITH THE EXCEPTION OF MONDAY WHEN HIGH PRESSURE WILL BE
ESSENTIALLY OVERHEAD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MODERATE CONFIDENCE OVERNIGHT AS COLD FRONT BRINGS A
CHANCE OF SOME VERY LIGHT RAIN AND MVFR. VFR WILL DEVELOP SATURDAY
AFTN.
COLD FRONT DRIFTING SOUTH APPEARS TO BE ALIGNED JUST NORTH OF THE
CWA BORDER BASED OFF WIND SHIFT EVIDENT ON CURRENT OBS. THIS FRONT
WILL VERY SLOWLY DRIFT SOUTHWARD BRINGING A WIND SHIFT FROM SW TO
N/NE. WINDS WILL REMAIN ONLY AROUND 10 KTS HOWEVER SINCE CAA BEHIND
THE FRONT IS RATHER WEAK. BIGGER CONCERN IS HOW PRECIP AND CLOUD
COVER WILL EVOLVE WITH THE FROPA. HRRR AND 4KM WRF BOTH SUGGEST
RAINFALL ERODING AS FRONT DROPS SOUTH...AND THIS IS AGREED UPON BY
MODEL SOUNDINGS WHICH DEPICT ONLY SHALLOW COLUMN SATURATION. FOR
THIS REASON HAVE CARRIED 6SM WITH -DZ AT ILM/FLO...AND 5SM -DZ AT
LBT WHICH IS CLOSEST TO THE FRONT AND HAS THE BEST CHANCE OF SEEING
ANY RAINFALL. POST FRONTAL STRATUS WILL BE SIGNIFICANT...BUT HAVE
OPTED NOT TO INCLUDE ANY IFR BASED OFF UPSTREAM OBS...WHERE IFR IS
ONLY OCCURRING IN SIGNIFICANT RAIN. EXPECT WIDESPREAD MVFR OVERNIGHT
HOWEVER.
S/W WILL PUSH OFF TO THE EAST EARLY SATURDAY BRINGING DRIER AIR TO
THE REGION. THIS WILL HELP ERODE CLOUD COVER AND VFR WILL DEVELOP BY
LATE MORNING OR EARLY AFTN. WINDS WILL PERSIST FROM THE NORTH
THROUGH SATURDAY AROUND 10 KTS...WITH SKY CONDITIONS IMPROVING TO
NEARLY CLEAR BY NIGHTFALL.
EXTENDED OUTLOOK...VFR SUNDAY AND MONDAY. MORNING FOG POSSIBLE
TUESDAY. SHOWERS ASSOCIATED WITH A COLD FRONT MAY IMPACT THE AREA
WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM FRIDAY...A COLD FRONT ACROSS EASTERN NORTH CAROLINA HAS
DROPPED THROUGH NEW BERN AND WILL APPROACHING MOREHEAD CITY FROM THE
NORTH. THIS FRONT SHOULD CONTINUE MOVING SOUTH TONIGHT...MOVING
ACROSS CAPE FEAR BETWEEN MIDNIGHT AND 2 AM...MYRTLE BEACH BETWEEN
1-3 AM...AND THROUGH GEORGETOWN AN HOUR OR TWO BEFORE DAYBREAK
SATURDAY. SOUTHWEST WINDS WILL TURN WESTERLY AHEAD OF THE FRONT LATE
THIS EVENING...THEN WILL ABRUPTLY SHIFT TO THE NORTH BEHIND THE
FRONT AFTER MIDNIGHT. WITH QUICKLY FALLING TEMPERATURES BEHIND THE
FRONT WINDS WILL BECOME GUSTY WITH GUSTS OVER 20 KNOTS POSSIBLE FOR
A FEW HOURS. ANY LIGHT RAIN ASSOCIATED WITH THE FRONT SHOULD REMAIN
MAINLY NORTH OF CAPE FEAR...BUT THE LATEST MODEL PROJECTIONS ARE
THAT VERY LITTLE RAIN WILL FALL EVEN HERE.
SEAS RANGE FROM 2-3 FT AT THE BUOYS THIS EVENING...AND THE SPECTRAL
WAVE PLOT FROM FRYING PAN SHOALS SHOWS THE WAVES ARE ALMOST
EXCLUSIVELY AN 11-14 SECOND SOUTHEAST SWELL. VERY LITTLE WIND CHOP
EXISTS ACROSS THE WATERS CURRENTLY...BUT THIS SHOULD CHANGE LATE
TONIGHT BEHIND THE FRONT WITH THE INCREASING COLD NORTHERLY WINDS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A MODEST NORTHERLY SURGE WILL BE UNDERWAY
AT THE START OF THE PERIOD. INITIAL SURGE WILL WANE SAT AFTERNOON
WITH ANOTHER SURGE EXPECTED SAT NIGHT AND THEN AGAIN DURING SUN. N
WINDS WILL VEER TO NE SUN NIGHT AS WINDS DIMINISH. WINDS WILL
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. SEAS
SHOULD PEAK IN 3 TO 5 FT RANGE ACROSS THE WATERS OFF OF CAPE FEAR
DURING SAT AND 3 TO 4 FT ACROSS THE OUTER FRINGES OF THE SOUTHERN
WATERS. SIX FT SEAS ARE POSSIBLE AROUND FRYING PAN SHOALS BUOY ON
SAT. SUBSEQUENT SURGES ARE NOT EXPECTED TO PRODUCE WAVE HEIGHTS
ECLIPSING THESE VALUES.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 230 PM FRIDAY...LIGHT WINDS WILL GREET MARINERS MONDAY AS
HIGH PRESSURE RESIDES OVERHEAD. A SOUTHERLY FLOW WILL DEVELOP
LATER MONDAY AND PREVAIL TUESDAY AS THE HIGH MOVES OFFSHORE. WINDS
WILL TURN MORE TO THE SOUTHWEST WEDNESDAY AS LOW PRESSURE MOVES
THROUGH THE OHIO VALLEY. THIS STRONGEST WINDS WILL PREVAIL
WEDNESDAY AS WELL WITH 20-25 KNOTS. WAVEWATCH SEAS LOOK REASONABLE
WITH 2-4 FEET EARLY INCREASING TO 4-6 FEET WEDNESDAY. FINALLY
THERE IS THE POSSIBILITY FOR SEA FOG TUESDAY BEFORE WINDS TURN
MORE SOUTHWEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
937 AM CST THU DEC 15 2011
.DISCUSSION...WIND SPEEDS AND TEMPERATURES THE MAIN CONCERN TODAY.
AREA OF CONCERN FOR WIND SPEEDS IS THE NORTHERN VALLEY WHERE
CURRENT (1530Z) SPEEDS ARE 30 TO 45 MPH. STRONG 925MB COLD AIR
ADVECTION WITH 925MB WINDS SPEEDS AROUND 40 KNOTS. 5MB/3HR SFC
PRESSURE RISE ACROSS THIS AREA. THESE STRONGER WINDS SHOULD OCCUR
FOR LESS THAN AN HOUR...MAINLY ASSOCIATED WITH 925MB COLD AIR
ADVECTION. 12Z RUC INDICATES THESE CONDITIONS WILL BE BRIEF AND
THUS NO WIND ADVISORY WILL BE REQUIRED...BUT DID ISSUE A NOWCAST.
STRONGEST FORCING FOR THESE STRONGER WINDS INDICATED TO REMAIN
ACROSS THE NE FA. FOR THE MOST PART...WITH WEAK COLD AIR
ADVECTION...EXPECT WIND SPEEDS 20 TO 30 MPH GRADUALLY DECREASING
AS SFC HIGH MOVES IN FROM THE WEST.
STRONGEST COLD AIR ADVECTION ACROSS THE NE FA...AND EXPECT TEMPS
TO FALL THROUGH THE DAY...WITH STEADY TEMPS LIKELY ACROSS THE SW
FA WHERE COLD AIR TEMP ADVECTION IS WEAKER.
ADJUSTED FORECAST TO ABOVE THINKING...LEADING TO SOME MINOR
CHANGES.
&&
.AVIATION...CIGS HAVE GENERALLY BEEN RISING FROM THE NORTHWEST AS
WINDS ALSO INCREASE. EXPECT RISING CIGS TO CONTINUE FROM NORTHWEST
TO SOUTHEAST ACROSS THE FORECAST AREA. SOME FLURRIES/SNOW SHOWERS
WILL MOVE ACROSS THE AREA TODAY. GUSTY WINDS FROM THE NORTHWEST
ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 428 AM CST THU DEC 15 2011/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
ECMWF WAS THE FASTER SOLUTION COMPARED TO THE NAM, GFS AND GEM. GEM
WAS THE SLOWEST AND THE GFS AND NAM A COMPROMISE THROUGH 48 HOURS.
WILL USE THE NAM AND GFS. QUITE PROGRESSIVE UPPER AIR PATTERN OVER
THE NORTHERN PLAINS. WATER VAPOR LOOP INDICATED SEVERAL SHORT WAVES
UPSTREAM AND WILL MOE ACROSS THE AREA NEARLY EACH DAY THIS PERIOD.
WATER VAPOR LOOP INDICATED A SHORT WAVE OVER SOUTHERN MAN AND WAS
MOVING SOUTHEAST ABOUT 40 KNOTS. FEW LIGHT SNOW SHOWERS ON
RADAR. SO WILL ADD LOW POPS NORTHEAST AND FLURRIES/SNOW SHOWERS
ELSEWHERE TODAY AND SHIFT EAST THROUGH THE DAY.
ANOTHER SHORT WAVE OVER THE BC COAST WILL MOVE INTO THE FORECAST
AREA LATE TONIGHT. MODELS ARE A LITTLE FASTER. SO WILL ADD LOW POPS
FOR LATE TONIGHT IN SOUTH AND WEST AND UP POPS SOUTH FRI.
ANOTHER SHORT WAVE SOUTH OF THE ALEUTIAN CHAIN WILL MOVE THROUGH SAT
AND IS EXPECTED TO AFFECT THE NORTH AND EAST ZONES.
LONG TERM (SUN-WED)...
NO HINTS AT CHANGES TO THE OVERALL PATTERN. SFC LOW TO MOVE JUST
NORTH OF THE INTERNATIONAL BORDER ON SUNDAY WITH FCST AREA IN WARM
SECTOR WITH 850 MB TEMPS RANGING FROM ZERO IN THE FAR NORTHEAST TO
+7 IN THE FAR SOUTHWEST. WINDS ALSO TURN SOUTHWEST OVER SE ND AND
FEEL THIS AREA COULD EASILY REACH 40+ DEGREES SUN AFTN. SO COORD
WITH SURROUNDING OFFICES AND UPPED MODELED HIGH TEMPS FOR SUNDAY FOR
SOUTHEAST-EAST CENTRAL ND. COLD FRONT WILL SWEEP THROUGH SUN EVE
WITH COLD ADVECTION FOLLOWED BY WARMER TEMPS ON TUESDAY. ANOTHER
WEAK SYSTEM TO PASS ALONG THE INTERNATIONAL BORDER REGION WED OR THU
AS MODEL DIFFERENCES EXIST BTWN ECMWF/GFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1135 AM CST THU DEC 15 2011
.UPDATE...
SEE AVIATION DISCUSSION BELOW FOR 18Z TAFS.
SATELLITE STARTING TO SHOW SOME BREAKS IN THE STRATUS CLOUD DECK
ACROSS THE CWA THIS MORNING. THUS...ADJUSTED CLOUD COVER A LITTLE
THROUGH THE AFTERNOON. BREEZY/WINDY CONDITIONS WILL CONTINUE INTO
THE AFTERNOON ESPECIALLY EAST IN THE CWA. ADJUSTED TEMPERATURES
AND WINDS A LITTLE FOR THE REST OF THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
AN ABUNDANCE OF STRATUS CLOUDS CONTINUE TO MOVE SOUTHEAST ACROSS
THE DAKOTAS...WITH THE EXTENT OF IT PUSHING WELL NORTH BACK INTO
SOUTHERN CANADA. WESTERN EDGE OF CLOUDS ACROSS SOUTH DAKOTA LIES
ALONG THE MISSOURI RIVER. ALTHOUGH...WITH A SOUTHEAST MOVEMENT TO
THE CLOUDS AND PLENTY LEFT UPSTREAM...EXPECTING THE EASTERN CWA TO
REMAIN IN CLOUDS MOST OF THE DAY. THE WESTERN CWA WILL LIKELY SEE
A BIT MORE SUNSHINE TODAY. MOST MODELS HAVING A HARD TIME PICKING
UP ON THE CLOUD COVER BUT THE RUC13 850 RH SEEMS TO HAVE A BETTER
HANDLE ON THINGS. IT WOULD SUGGEST CLOUD COVER THROUGH THE
AFTERNOON ACROSS THE EASTERN CWA...WITH THE WESTERN CWA IN MORE
SUNSHINE...AS PREVIOUSLY STATED. HAVE ALSO BEEN SEEING SCT
FLURRIES WITH THE STRATUS CLOUDS. PLENTY OF THAT UPSTREAM AS WELL
WITH KBIS AND KMBX RADARS SHOWING FLURRIES. EVEN OBS IN SOUTHERN
CANADA SHOWING -SN FROM TIME TO TIME. HAVE THEREFORE ADDED SCT
FLURRIES TO FORECAST THROUGH 18Z AND COULD BE A SITUATION WHERE IT
MAY NEED TO BE EXTENDED FURTHER INTO THE AFTERNOON ACROSS THE
EASTERN CWA WHEREVER STRATUS CLOUDS HANG ON THE LONGEST.
AGAIN...PLENTY OF ACTIVITY NOTED WELL UPSTREAM INTO SOUTHERN
CANADA. NORTHWEST WINDS WILL REMAIN BREEZY TODAY AS THE PRESSURE
GRADIENT REMAINS FAIRLY TIGHT WITH HIGH PRESSURE BUILDING IN.
HIGHEST SPEEDS WILL BE ACROSS THE EASTERN CWA WITH A DROP OFF IN
WINDS ACROSS THE WESTERN COUNTIES BY THIS AFTERNOON.
SFC HIGH WILL SETTLE IN OVER THE AREA TONIGHT BRINGING LIGHT
WINDS. NEXT ITEM TO WATCH WILL BE THE WEAK SHORTWAVE CROSSING THE
DAKOTAS LATE TONIGHT AND FRIDAY. MODELS STILL PEGGING MOST OF
THE LIGHT SNOWFALL ACROSS ND BUT THERE HAS BEEN A SLIGHT SHIFT
FURTHER SOUTH INTO NORTHERN SD. COUPLE MODELS BRINGING LIGHT QPF
INTO THE NORTHEASTERN COUNTIES AND SREF PROBS FOR .01 SHOWING
DECENT CHANCES ACROSS THE NORTHEASTERN CWA AS WELL. HAVE THEREFORE
INCREASED POPS SLIGHTLY FOR FRIDAY.
FOCUS WILL THEN SHIFT TO THE DEGREE OF WARMTH ON SATURDAY AS MILD
PACIFIC AIR BEGINS TO STREAM ACROSS THE NORTHERN PLAINS. WARM
FRONT CROSSES THE AREA DURING THE DAY SATURDAY WITH WINDS TURNING
WESTERLY. 850 MB TEMPS RISE TO JUST ABOVE ZERO C. WITH THE WIND
SHIFT AND A DECENT AMOUNT OF SUN...WILL SEE TEMPS RISE INTO THE
30S AND 40S.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
NOT MUCH TO TALK ABOUT IN THE EXTENDED FORECAST. CONSENSUS MODELS
ARE STILL GOING WITH CONTINUED DRY CONDITIONS. INTERESTINGLY THE
GFS IS STARTING TO HINT AT THE POSSIBILITY OF SOME PRECIP AT THE
END OF THE FORECAST PERIOD ASSOCIATED WITH THE NEXT UPPER TROF
THAT DIGS INTO THE PLAINS SO WILL NEED TO KEEP AN EYE ON HOW THAT
SYSTEM DEVELOPS. FOR NOW THOUGH LEFT THE FORECAST PRECIP FREE.
WITH THE LACK OF SNOW ON THE GROUND TEMPERATURES WILL ALSO
CONTINUE THE ABOVE NORMAL TREND WITH HIGHS STAYING NEAR 30 OR EVEN
CLIMBING INTO THE 40S THROUGH THE PERIOD.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
BAND OF STRATUS HAS BEEN PERSISTENT...ESPECIALLY ACROSS THE ABR
AND ATY TERMINALS HOWEVER THE WESTERN CLOUD EDGE HAS ERODED NICELY
TOWARDS PIR. STRATUS HAS BEEN PERSISTENT NEAR MBG TERMINAL BUT
BELIEVE CEILINGS WILL BEGIN TO LIFT FURTHER AS THE DAY PROGRESSES.
WINDS WILL GRADUALLY DIMINISH FROM WEST TO EAST TODAY AS A
SHORTWAVE RIDGE PROGRESSES ACROSS THE UPPER MIDWEST. EXPECT WINDS
TO GO LIGHT AND VARIABLE FOR A FEW HOURS AS THE SURFACE RIDGE
PASSES OVER THE REGION THIS EVENING INTO TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...TVT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1037 AM CST THU DEC 15 2011
.DISCUSSION.../ISSUED AT 1037 AM CST/
JUST SENT OUT A FRESHENED UP ZFP AND GRIDS. CLOUD COVER IS THE MOST
PROBLEMATIC ELEMENT FOR THIS AFTERNOON. NAM...RUC AND ECMWF LOW
LEVEL MOISTURE FIELDS HAVE NO CLUE THAT STRATUS EXISTS IN OUR
FORECAST AREA. THE GFS...SLIGHTLY BETTER ON CURRENT CONDITIONS...
LIKELY ERODES THE CLOUDS TOO FAST IN OUR EASTERN ZONES. SO STRATUS
EROSION IS REALLY A CHALLENGE. LATEST SATELLITE DOES FINALLY SHOW
SOME EROSION OF STRATUS ON THE WESTERN EDGE NEAR MITCHELL SD. THERE
ARE ALSO SOME AREAS OF CLEARING NOTED IN EASTERN ND. THE STRATUS IS
FAIRLY THIN...SO IT IS POSSIBLE THAT SUBSIDENCE MAY RIP IT APART AS
THE DAY PROGRESSES. IF IT DOES NOT...THEN THE STRATUS WILL LIKELY
HANG TOUGH THROUGH THE DAY EAST OF THE JAMES RIVER. FOR NOW...OPTED
FOR A GRADUAL CLEARING WEST OF I 29...BUT MOSTLY CLOUDY THROUGHOUT
OUR EASTERN ZONES. THE WINDS OFF THE SURFACE SHIFT MORE TO A SW
DIRECTION TONIGHT SO THEY SHOULD EVENTUALLY MOVE OUT OF HERE. CLOUDS
OR NOT...TEMPERATURES WILL NOT MOVE MUCH TODAY OFF OF CURRENT
READINGS DUE TO PLENTY OF COLD AIR ADVECTION. WENT AHEAD AND LET THE
FLURRIES EXPIRE IN OUR NORTHEAST ZONES AS IT LOOKS LIKE MOST OF THE
ACTIVITY SHOULD STAY TO OUR NORTH ALONG THE LEFT EXIT REGION OF A
WEST TO EAST MOVING JET STREAK. PLENTY OF MID LEVEL PV EXISTS
THROUGH 18Z...BUT THEN QUICKLY EXITS THIS AREA. /MJF
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
THERE WILL LIKELY BE A VERY SLOW EROSION OF LOWER VFR TO UPPER END
MVFR CEILINGS THROUGH THE DAY. THAT SAID...IT MAY TAKE QUITE A WHILE
TO GET RID OF THE CLOUD COVER ALONG AND EAST OF I 29. THE TOTAL
EROSION OF LOW CLOUD COVER MAY HAVE TO WAIT UNTIL TONIGHT WHEN THE
WINDS OFF THE SURFACE SHIFT FROM A NW...TO MORE OF A SW DIRECTION
WHERE IT IS CLEAR IN CENTRAL AND WESTERN NEBRASKA. OVERALL...WE
SHOULD HAVE VFR CONDITIONS ACROSS THIS FORECAST AREA FROM 06Z
TONIGHT THROUGH FRIDAY MORNING. SURFACE WIND GUSTS AVERAGING 25 TO
32 KNOTS WILL BE PREVALENT EAST OF THE JAMES RIVER VALLEY UNTIL
ABOUT 22Z THIS AFTERNOON. /MJF
&&
.PREV DISCUSSION...
STRONG NORTHERN STREAM WAVE WILL DELIVER AT LEAST A TEMPORARY RETURN
TOWARD MORE TYPICAL MID DECEMBER WEATHER ACROSS THE AREA TODAY.
MASSIVE STRATUS FIELD IN WAKE OF LEADING WAVE LIFTING TOWARD
NORTHERN WISCONSIN...AS WELL AS GOOD DOSE OF 25 TO 35 MPH NORTHWEST
WINDS. WITH CLOUDS...TEMPERATURES HAVE BEEN MORE SLUGGISH TO FALL
AS HAVE BEEN EQUALIZING WITH MIXING...BUT COLD AIR ADVECTION WILL
SOON BEGIN TO GET THE UPPER HAND...LIKELY KEEPING A DOWNWARD TREND
GOING WELL INTO THE MORNING BEFORE SOME DIURNAL RECOVERY. CLOUDS
WILL HAVE A LOT TO SAY ABOUT THIS...AND HAVE LITTLE OPTION THAN TO
BE EVEN MORE PESSIMISTIC GIVEN TRAJECTORY OF LOW LEVEL FLOW AND
THE CURRENT STRATUS FIELD. FOLLOWED CLOSER TO THE RUC AND FRIENDS
RELATIVE HUMIDITY FIELDS WHICH SEEMED TO HAVE AT LEAST A CLUE WHERE
STRATUS FIELD CURRENTLY RESIDES. OTHER ISSUE THAT HAS BEEN OCCURRING
OVERNIGHT HAS BEEN A FEW FLURRIES. THESE SEEM TO BE MOST CONCENTRATED
IN SMALLER AREAS WITHIN STRATUS FIELD WHERE CLOUD TOPS ARE JUST A
BIT COOLER THAN THE SURROUNDINGS...VERY EVIDENT WITH INITIAL AREA
MOVING THROUGH NORTHWEST IOWA AT 09Z...AND THEN SECONDARY AREA
UP ACROSS NORTHEAST SOUTH DAKOTA. WITH CLOUDS LAYER SNEAKING INTO
THE WARMER END OF THE DENDRITIC LAYER...WOULD NOT BE SURPRISED TO
GET CONTINUATION OF FLURRIES AT TIMES THROUGH AT LEAST MID TO LATE
MORNING WHEN SOME LIFT SUPPORT FROM NORTHERN STREAM UPPER WAVE.
MAY FINALLY GET TO SEE A MORE RAPID EROSION/ADVECTION OF THE CLOUD
BOUNDARY BY THE AFTERNOON AS CONTINUED DRIER LOW LEVEL AIR WORKS ON
CLOUDS FROM BOTTOM UP...AND SUBSIDENCE TO THE SOUTHWEST FLANK OF
UPPER WAVE WORKS FROM THE TOP. WINDS STRONGEST THROUGH THE EARLY
AFTERNOON HOURS...DIMINISHING FROM WEST WITH APPROACH OF RIDGE
AXIS...BUT HANGING ON A BIT STRONGER THROUGH ELEVATED SOUTHWEST
MINNESOTA AREAS WITH DEEPENING SYSTEM TO EAST AND MORE PERSISTENT
COLD AIR ADVECTION.
TONIGHT...CHILLY RIDGE WILL DRIFT EAST ACROSS THE AREA. WILL START
TO GET SOME RETURN FLOW STRENGTHENING A TOUCH FROM THE JAMES VALLEY
WESTWARD...AND THAT ALONG WITH THE THICKENING MID AND HIGH CLOUDS
WILL LIKELY BRING A NON DIURNAL TREND TO LOWS WEST...WITH MORE
TYPICAL FALLS UNDER LINGERING RIDGE THROUGH SOUTHEASTERN AREAS.
NORTHERN PORTION OF TROUGH DIGGING INTO THE SOUTHWEST WILL DETACH
AND MOVE THROUGH THE NORTHERN STREAM...RACING THROUGH THE NORTHERN
PLAINS ON FRIDAY. WEAK SURFACE LOW/TROUGH WILL PUSH QUICKLY ACROSS
SOUTH DAKOTA AND LIKELY TO REACH NORTHWEST IOWA BY EVENING. WHILE
MOISTURE WILL BE LIMITED...AND SPEED OF SYSTEM REDUCING POTENTIAL
EFFICIENCY OF LIFT...TEMPERATURES ARE FAIRLY FAVORABLE FOR ICE
CRYSTAL GROWTH. USED LOWER TO MID LEVEL WARM AIR ADVECTION/QG
FORCING TO TIME OUT A SMALL THREAT FOR SNOWFALL FROM MIDDAY THROUGH
THE AFTERNOON GLANCING THE NORTHEASTERN 1/3 OF THE AREA. LITTLE
WINDOW FOR MIXING BEHIND THE WEAK SURFACE WAVE ACROSS THE SOUTHWEST
CWA BEFORE COLD AIR ADVECTION TAKES TOLL ON TEMPERATURES LATER IN
THE AFTERNOON. /CHAPMAN
FRIDAY NIGHT INTO SATURDAY WILL SEE A RIDGE OF HIGH PRESSURE PASS
THROUGH WITH RETURN FLOW ALOFT DEVELOPING...POSSIBLY SETTING UP A
BIT OF AN INVERSION. BUT...AS IS THE STORY EARLY THIS WINTER...NO
SNOW COVER SHOULD ALLOW A FAVORABLE WIND FOR MIXING TO DEVELOP AND
TEMPERATURES WILL LIKELY CLIMB AT LEAST INTO THE UPPER 30S TO LOWER
40S IN MOST SPOTS. EVEN PLANNING ON SOME MID TO UPPER 40S IN SOUTH
CENTRAL SOUTH DAKOTA. A FAIRLY WEAK PRESSURE GRADIENT ON SATURDAY
NIGHT WILL AID IN SOME DROP OFF IN TEMPERATURES...BUT STILL LOOKING
WELL ABOVE NORMAL.
IN THE LATTER PERIODS(SUN/WED)...A MARGINALLY AGREED UPON JET STREAK
WILL TRAVERSE THE NORTHERN PLAINS EARLY IN THE PERIOD...DROPPING A
COLD FRONT THROUGH ON MONDAY. A SOUTHERN STREAM CUT OFF LOW WILL
MOVE THROUGH KANSAS INTO MISSOURI AND SHOULD NOT REALLY AFFECT THE
AREA. SPLIT FLOW INTENSIFIES DURING THE SECOND HALF OF THE
PERIOD...ALTHOUGH THE MODELS DO INDICATE A DEEPER TROUGH TRYING TO
CARVE OUT OVER THE WESTERN UNITED STATES. HOWEVER...WITH A FAIRLY
STRONG NORTHERN STREAM IT APPEARS THAT IT WILL EJECT POSITIVELY
TILTED THUS NOT CREATING MUCH OF A PROBLEM FOR THE AREA. SO...WILL
GO ABOVE OR AT THE WARMEST GUIDANCE ON SUNDAY WITH A VERY FAVORABLE
FLOW AND ABSOLUTELY NO SNOW COVER ANYWHERE TO SPEAK OF. WILL
INCREASE LOWS A BIT ON SUNDAY NIGHT/MONDAY MORNING CLOSER TO THE RAW
OUTPUT WHICH GENERALLY HANDLES NIGHTS WITH WIND BETTER. COLDER AIR
IN ON MONDAY BUT WILL STILL LEAN TOWARDS MILDER GUIDANCE NUMBERS
WITH NO SNOW ON GROUND. MONDAY NIGHT A LITTLE TRICKY WITH A RIDGE OF
HIGH PRESSURE SLIPPING THROUGH...SO LOWERED LOWS JUST A BIT TO
COMPENSATE FOR THE POTENTIAL FOR A RADIATIONAL DROP OFF...ESPECIALLY
IN THE SOUTHERN CWA. NO BIG CHANGES FOR TUESDAY AND WEDNESDAY THIS
TIME AROUND...JUST A BIT WARMER ON TUESDAY WITH DECENT POTENTIAL LOW
LEVEL WIND FIELD. /08
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1026 AM CST THU DEC 15 2011
.UPDATE...
SATELLITE STARTING TO SHOW SOME BREAKS IN THE STRATUS CLOUD DECK
ACROSS THE CWA THIS MORNING. THUS...ADJUSTED CLOUD COVER A LITTLE
THROUGH THE AFTERNOON. BREEZY/WINDY CONDITIONS WILL CONTINUE INTO
THE AFTERNOON ESPECIALLY EAST IN THE CWA. ADJUSTED TEMPERATURES
AND WINDS A LITTLE FOR THE REST OF THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
AN ABUNDANCE OF STRATUS CLOUDS CONTINUE TO MOVE SOUTHEAST ACROSS
THE DAKOTAS...WITH THE EXTENT OF IT PUSHING WELL NORTH BACK INTO
SOUTHERN CANADA. WESTERN EDGE OF CLOUDS ACROSS SOUTH DAKOTA LIES
ALONG THE MISSOURI RIVER. ALTHOUGH...WITH A SOUTHEAST MOVEMENT TO
THE CLOUDS AND PLENTY LEFT UPSTREAM...EXPECTING THE EASTERN CWA TO
REMAIN IN CLOUDS MOST OF THE DAY. THE WESTERN CWA WILL LIKELY SEE
A BIT MORE SUNSHINE TODAY. MOST MODELS HAVING A HARD TIME PICKING
UP ON THE CLOUD COVER BUT THE RUC13 850 RH SEEMS TO HAVE A BETTER
HANDLE ON THINGS. IT WOULD SUGGEST CLOUD COVER THROUGH THE
AFTERNOON ACROSS THE EASTERN CWA...WITH THE WESTERN CWA IN MORE
SUNSHINE...AS PREVIOUSLY STATED. HAVE ALSO BEEN SEEING SCT
FLURRIES WITH THE STRATUS CLOUDS. PLENTY OF THAT UPSTREAM AS WELL
WITH KBIS AND KMBX RADARS SHOWING FLURRIES. EVEN OBS IN SOUTHERN
CANADA SHOWING -SN FROM TIME TO TIME. HAVE THEREFORE ADDED SCT
FLURRIES TO FORECAST THROUGH 18Z AND COULD BE A SITUATION WHERE IT
MAY NEED TO BE EXTENDED FURTHER INTO THE AFTERNOON ACROSS THE
EASTERN CWA WHEREVER STRATUS CLOUDS HANG ON THE LONGEST.
AGAIN...PLENTY OF ACTIVITY NOTED WELL UPSTREAM INTO SOUTHERN
CANADA. NORTHWEST WINDS WILL REMAIN BREEZY TODAY AS THE PRESSURE
GRADIENT REMAINS FAIRLY TIGHT WITH HIGH PRESSURE BUILDING IN.
HIGHEST SPEEDS WILL BE ACROSS THE EASTERN CWA WITH A DROP OFF IN
WINDS ACROSS THE WESTERN COUNTIES BY THIS AFTERNOON.
SFC HIGH WILL SETTLE IN OVER THE AREA TONIGHT BRINGING LIGHT
WINDS. NEXT ITEM TO WATCH WILL BE THE WEAK SHORTWAVE CROSSING THE
DAKOTAS LATE TONIGHT AND FRIDAY. MODELS STILL PEGGING MOST OF
THE LIGHT SNOWFALL ACROSS ND BUT THERE HAS BEEN A SLIGHT SHIFT
FURTHER SOUTH INTO NORTHERN SD. COUPLE MODELS BRINGING LIGHT QPF
INTO THE NORTHEASTERN COUNTIES AND SREF PROBS FOR .01 SHOWING
DECENT CHANCES ACROSS THE NORTHEASTERN CWA AS WELL. HAVE THEREFORE
INCREASED POPS SLIGHTLY FOR FRIDAY.
FOCUS WILL THEN SHIFT TO THE DEGREE OF WARMTH ON SATURDAY AS MILD
PACIFIC AIR BEGINS TO STREAM ACROSS THE NORTHERN PLAINS. WARM
FRONT CROSSES THE AREA DURING THE DAY SATURDAY WITH WINDS TURNING
WESTERLY. 850 MB TEMPS RISE TO JUST ABOVE ZERO C. WITH THE WIND
SHIFT AND A DECENT AMOUNT OF SUN...WILL SEE TEMPS RISE INTO THE
30S AND 40S.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
NOT MUCH TO TALK ABOUT IN THE EXTENDED FORECAST. CONSENSUS MODELS
ARE STILL GOING WITH CONTINUED DRY CONDITIONS. INTERESTINGLY THE
GFS IS STARTING TO HINT AT THE POSSIBILITY OF SOME PRECIP AT THE
END OF THE FORECAST PERIOD ASSOCIATED WITH THE NEXT UPPER TROF
THAT DIGS INTO THE PLAINS SO WILL NEED TO KEEP AN EYE ON HOW THAT
SYSTEM DEVELOPS. FOR NOW THOUGH LEFT THE FORECAST PRECIP FREE.
WITH THE LACK OF SNOW ON THE GROUND TEMPERATURES WILL ALSO
CONTINUE THE ABOVE NORMAL TREND WITH HIGHS STAYING NEAR 30 OR EVEN
CLIMBING INTO THE 40S THROUGH THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
STRATUS REMAINS ACROSS THE REGION BUT HAS LIFTED TO AOA
2KFT. CIGS WILL BEGIN TO BREAK UP LATE THIS AFTERNOON...AND VISBY
IS EXPECTED TO REMAIN VFR. WINDS OUT OF THE NORTHWEST AT 20G30MPH
WILL CONTINUE THROUGH THIS MORNING BUT GRADUALLY DIMINISH FROM
WEST TO EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
537 AM CST THU DEC 15 2011
.DISCUSSION.../ISSUED AT 407 AM CST/
STRONG NORTHERN STREAM WAVE WILL DELIVER AT LEAST A TEMPORARY RETURN
TOWARD MORE TYPICAL MID DECEMBER WEATHER ACROSS THE AREA TODAY.
MASSIVE STRATUS FIELD IN WAKE OF LEADING WAVE LIFTING TOWARD
NORTHERN WISCONSIN...AS WELL AS GOOD DOSE OF 25 TO 35 MPH NORTHWEST
WINDS. WITH CLOUDS...TEMPERATURES HAVE BEEN MORE SLUGGISH TO FALL
AS HAVE BEEN EQUALIZING WITH MIXING...BUT COLD AIR ADVECTION WILL
SOON BEGIN TO GET THE UPPER HAND...LIKELY KEEPING A DOWNWARD TREND
GOING WELL INTO THE MORNING BEFORE SOME DIURNAL RECOVERY. CLOUDS
WILL HAVE A LOT TO SAY ABOUT THIS...AND HAVE LITTLE OPTION THAN TO
BE EVEN MORE PESSIMISTIC GIVEN TRAJECTORY OF LOW LEVEL FLOW AND
THE CURRENT STRATUS FIELD. FOLLOWED CLOSER TO THE RUC AND FRIENDS
RELATIVE HUMIDITY FIELDS WHICH SEEMED TO HAVE AT LEAST A CLUE WHERE
STRATUS FIELD CURRENTLY RESIDES. OTHER ISSUE THAT HAS BEEN OCCURRING
OVERNIGHT HAS BEEN A FEW FLURRIES. THESE SEEM TO BE MOST CONCENTRATED
IN SMALLER AREAS WITHIN STRATUS FIELD WHERE CLOUD TOPS ARE JUST A
BIT COOLER THAN THE SURROUNDINGS...VERY EVIDENT WITH INITIAL AREA
MOVING THROUGH NORTHWEST IOWA AT 09Z...AND THEN SECONDARY AREA
UP ACROSS NORTHEAST SOUTH DAKOTA. WITH CLOUDS LAYER SNEAKING INTO
THE WARMER END OF THE DENDRITIC LAYER...WOULD NOT BE SURPRISED TO
GET CONTINUATION OF FLURRIES AT TIMES THROUGH AT LEAST MID TO LATE
MORNING WHEN SOME LIFT SUPPORT FROM NORTHERN STREAM UPPER WAVE.
MAY FINALLY GET TO SEE A MORE RAPID EROSION/ADVECTION OF THE CLOUD
BOUNDARY BY THE AFTERNOON AS CONTINUED DRIER LOW LEVEL AIR WORKS ON
CLOUDS FROM BOTTOM UP...AND SUBSIDENCE TO THE SOUTHWEST FLANK OF
UPPER WAVE WORKS FROM THE TOP. WINDS STRONGEST THROUGH THE EARLY
AFTERNOON HOURS...DIMINISHING FROM WEST WITH APPROACH OF RIDGE
AXIS...BUT HANGING ON A BIT STRONGER THROUGH ELEVATED SOUTHWEST
MINNESOTA AREAS WITH DEEPENING SYSTEM TO EAST AND MORE PERSISTENT
COLD AIR ADVECTION.
TONIGHT...CHILLY RIDGE WILL DRIFT EAST ACROSS THE AREA. WILL START
TO GET SOME RETURN FLOW STRENGTHENING A TOUCH FROM THE JAMES VALLEY
WESTWARD...AND THAT ALONG WITH THE THICKENING MID AND HIGH CLOUDS
WILL LIKELY BRING A NON DIURNAL TREND TO LOWS WEST...WITH MORE
TYPICAL FALLS UNDER LINGERING RIDGE THROUGH SOUTHEASTERN AREAS.
NORTHERN PORTION OF TROUGH DIGGING INTO THE SOUTHWEST WILL DETACH
AND MOVE THROUGH THE NORTHERN STREAM...RACING THROUGH THE NORTHERN
PLAINS ON FRIDAY. WEAK SURFACE LOW/TROUGH WILL PUSH QUICKLY ACROSS
SOUTH DAKOTA AND LIKELY TO REACH NORTHWEST IOWA BY EVENING. WHILE
MOISTURE WILL BE LIMITED...AND SPEED OF SYSTEM REDUCING POTENTIAL
EFFICIENCY OF LIFT...TEMPERATURES ARE FAIRLY FAVORABLE FOR ICE
CRYSTAL GROWTH. USED LOWER TO MID LEVEL WARM AIR ADVECTION/QG
FORCING TO TIME OUT A SMALL THREAT FOR SNOWFALL FROM MIDDAY THROUGH
THE AFTERNOON GLANCING THE NORTHEASTERN 1/3 OF THE AREA. LITTLE
WINDOW FOR MIXING BEHIND THE WEAK SURFACE WAVE ACROSS THE SOUTHWEST
CWA BEFORE COLD AIR ADVECTION TAKES TOLL ON TEMPERATURES LATER IN
THE AFTERNOON. /CHAPMAN
FRIDAY NIGHT INTO SATURDAY WILL SEE A RIDGE OF HIGH PRESSURE PASS
THROUGH WITH RETURN FLOW ALOFT DEVELOPING...POSSIBLY SETTING UP A
BIT OF AN INVERSION. BUT...AS IS THE STORY EARLY THIS WINTER...NO
SNOW COVER SHOUD ALLOW A FAVORABLE WIND FOR MIXING TO DEVELOP AND
TEMPERATURES WILL LIKELY CLIMB AT LEAST INTO THE UPPER 30S TO LWOER
40S IN MOST SPOTS. EVEN PLANNING ON SOME MID TO UPER 40S IN SOUTH
CENTRAL SOUTH DAKOTA. A FAIRLY WEAK PRESSURE GRADIENT ON SATURDAY
NIGHT WILL AID IN SOEM DROP OFF IN TEMPERATURES...BUT STILL LOOKING
WELL ABOVE NORMAL.
IN THE LATTER PERIODS(SUN/WED)...A MARGINALLY AGREED UPON JET STREAK
WILL TRAVERSE THE NORTHERN PLAINS EARLY IN THE PERIOD...DROPPING A
COLD FRONT THROUGH ON MONDAY. A SOUTHERN STREAM CUT OFF LOW WILL
MOVE THROUGH KANSAS INTO MISSOURI AND SHOULD NOT REALLY AFFECT THE
AREA. SPLIT FLOW INTENSIFIES DURING THE SECOND HALF OF THE
PERIOD...ALTHOUGH THE MODELS DO INDICATE A DEEPER TROUGH TRYING TO
CARVE OUT OVER THE WESTERN UNITED STATES. HOWEVER...WITH A FAIRLY
STRONG NORTHERN STREAM IT APPEARS THAT IT WILL EJECT POSITIVELY
TILTED THUS NOT CREATING MUCH OF A PROBLEM FOR THE AREA. SO...WILL
GO ABOVE OR AT THE WARMEST GUIDANCE ON SUNDAY WITH A VERY FAVORABLE
FLOW AND ABSOLUTELY NO SNOW COVER ANYWHERE TO SPEAK OF. WILL
INCREASE LOWS A BIT ON SUNDAY NIGHT/MONDAY MORNING CLOSER TO THE RAW
OUTPUT WHICH GENERALLY HANDLES NIGHTS WITH WIND BETTER. COLDER AIR
IN ON MONDAY BUT WILL STILL LEAN TOWARDS MILDER GUIDANCE NUMBERS
WITH NO SNOW ON GROUND. MONDAY NIGHT A LITTLE TRICKY WITH A RIDGE OF
HIGH PRESSURE SLIPPING THROUGH...SO LOWERED LOWS JUST A BIT TO
COMPENSATE FOR THE POTENTIAL FOR A RADIATIONAL DROP OFF...ESPECIALLY
IN THE SOUTHERN CWA. NO BIG CHANGES FOR TUESDAY AND WEDNESDAY THIS
TIME AROUND...JUST A BIT WARMER ON TUESDAY WITH DECENT POTENTIAL LOW
LEVEL WIND FIELD. /08
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
WIDESPREAD MVFR CIGS IN STRATUS FIELD HAVE BEEN GRADUALLY CLIMBING
INTO THE LOWER END VFR WEST OF INTERSTATE 29...AS DRIER LOW LEVEL
AIR PUSHES INTO THE AREA. THESE CEILINGS WILL BE SLOW TO ERODE
EASTWARD THROUGH THE DAY...BUT SHOULD START TO GET SOME CLEARING
OF NOTE WORKING TOWARD THE KHON AREA AROUND 18Z...KSUX 20Z...AND
KFSD AROUND 22Z. OTHER SIGNFICANT CONCERN TODAY TO AVIATION IS THE
STRONG NORTHWEST WINDS...WHICH WILL LIKELY GUST AT OR ABOVE 25 KNOTS
THROUGH MID TO LATE AFTERNOON...WITH GUSTS TO AROUND 35 KNOTS ACROSS
SOUTHWEST MINNESOTA AND NORTHWEST IOWA THROUGH MIDDAY. /CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
527 AM CST THU DEC 15 2011
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
AN ABUNDANCE OF STRATUS CLOUDS CONTINUE TO MOVE SOUTHEAST ACROSS
THE DAKOTAS...WITH THE EXTENT OF IT PUSHING WELL NORTH BACK INTO
SOUTHERN CANADA. WESTERN EDGE OF CLOUDS ACROSS SOUTH DAKOTA LIES
ALONG THE MISSOURI RIVER. ALTHOUGH...WITH A SOUTHEAST MOVEMENT TO
THE CLOUDS AND PLENTY LEFT UPSTREAM...EXPECTING THE EASTERN CWA TO
REMAIN IN CLOUDS MOST OF THE DAY. THE WESTERN CWA WILL LIKELY SEE
A BIT MORE SUNSHINE TODAY. MOST MODELS HAVING A HARD TIME PICKING
UP ON THE CLOUD COVER BUT THE RUC13 850 RH SEEMS TO HAVE A BETTER
HANDLE ON THINGS. IT WOULD SUGGEST CLOUD COVER THROUGH THE
AFTERNOON ACROSS THE EASTERN CWA...WITH THE WESTERN CWA IN MORE
SUNSHINE...AS PREVIOUSLY STATED. HAVE ALSO BEEN SEEING SCT
FLURRIES WITH THE STRATUS CLOUDS. PLENTY OF THAT UPSTREAM AS WELL
WITH KBIS AND KMBX RADARS SHOWING FLURRIES. EVEN OBS IN SOUTHERN
CANADA SHOWING -SN FROM TIME TO TIME. HAVE THEREFORE ADDED SCT
FLURRIES TO FORECAST THROUGH 18Z AND COULD BE A SITUATION WHERE IT
MAY NEED TO BE EXTENDED FURTHER INTO THE AFTERNOON ACROSS THE
EASTERN CWA WHEREVER STRATUS CLOUDS HANG ON THE LONGEST.
AGAIN...PLENTY OF ACTIVITY NOTED WELL UPSTREAM INTO SOUTHERN
CANADA. NORTHWEST WINDS WILL REMAIN BREEZY TODAY AS THE PRESSURE
GRADIENT REMAINS FAIRLY TIGHT WITH HIGH PRESSURE BUILDING IN.
HIGHEST SPEEDS WILL BE ACROSS THE EASTERN CWA WITH A DROP OFF IN
WINDS ACROSS THE WESTERN COUNTIES BY THIS AFTERNOON.
SFC HIGH WILL SETTLE IN OVER THE AREA TONIGHT BRINGING LIGHT
WINDS. NEXT ITEM TO WATCH WILL BE THE WEAK SHORTWAVE CROSSING THE
DAKOTAS LATE TONIGHT AND FRIDAY. MODELS STILL PEGGING MOST OF
THE LIGHT SNOWFALL ACROSS ND BUT THERE HAS BEEN A SLIGHT SHIFT
FURTHER SOUTH INTO NORTHERN SD. COUPLE MODELS BRINGING LIGHT QPF
INTO THE NORTHEASTERN COUNTIES AND SREF PROBS FOR .01 SHOWING
DECENT CHANCES ACROSS THE NORTHEASTERN CWA AS WELL. HAVE THEREFORE
INCREASED POPS SLIGHTLY FOR FRIDAY.
FOCUS WILL THEN SHIFT TO THE DEGREE OF WARMTH ON SATURDAY AS MILD
PACIFIC AIR BEGINS TO STREAM ACROSS THE NORTHERN PLAINS. WARM
FRONT CROSSES THE AREA DURING THE DAY SATURDAY WITH WINDS TURNING
WESTERLY. 850 MB TEMPS RISE TO JUST ABOVE ZERO C. WITH THE WIND
SHIFT AND A DECENT AMOUNT OF SUN...WILL SEE TEMPS RISE INTO THE
30S AND 40S.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
NOT MUCH TO TALK ABOUT IN THE EXTENDED FORECAST. CONSENSUS MODELS
ARE STILL GOING WITH CONTINUED DRY CONDITIONS. INTERESTINGLY THE
GFS IS STARTING TO HINT AT THE POSSIBILITY OF SOME PRECIP AT THE
END OF THE FORECAST PERIOD ASSOCIATED WITH THE NEXT UPPER TROF
THAT DIGS INTO THE PLAINS SO WILL NEED TO KEEP AN EYE ON HOW THAT
SYSTEM DEVELOPS. FOR NOW THOUGH LEFT THE FORECAST PRECIP FREE.
WITH THE LACK OF SNOW ON THE GROUND TEMPERATURES WILL ALSO
CONTINUE THE ABOVE NORMAL TREND WITH HIGHS STAYING NEAR 30 OR EVEN
CLIMBING INTO THE 40S THROUGH THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
STRATUS REMAINS ACROSS THE REGION BUT HAS LIFTED TO AOA
2KFT. CIGS WILL BEGIN TO BREAK UP LATE THIS AFTERNOON...AND VISBY
IS EXPECTED TO REMAIN VFR. WINDS OUT OF THE NORTHWEST AT 20G30MPH
WILL CONTINUE THROUGH THIS MORNING BUT GRADUALLY DIMINISH FROM
WEST TO EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
407 AM CST THU DEC 15 2011
.DISCUSSION.../ISSUED AT 400 AM CST/
STRONG NORTHERN STREAM WAVE WILL DELIVER AT LEAST A TEMPORARY RETURN
TOWARD MORE TYPICAL MID DECEMBER WEATHER ACROSS THE AREA TODAY.
MASSIVE STRATUS FIELD IN WAKE OF LEADING WAVE LIFTING TOWARD
NORTHERN WISCONSIN...AS WELL AS GOOD DOSE OF 25 TO 35 MPH NORTHWEST
WINDS. WITH CLOUDS...TEMPERATURES HAVE BEEN MORE SLUGGISH TO FALL
AS HAVE BEEN EQUALIZING WITH MIXING...BUT COLD AIR ADVECTION WILL
SOON BEGIN TO GET THE UPPER HAND...LIKELY KEEPING A DOWNWARD TREND
GOING WELL INTO THE MORNING BEFORE SOME DIURNAL RECOVERY. CLOUDS
WILL HAVE A LOT TO SAY ABOUT THIS...AND HAVE LITTLE OPTION THAN TO
BE EVEN MORE PESSIMISTIC GIVEN TRAJECTORY OF LOW LEVEL FLOW AND
THE CURRENT STRATUS FIELD. FOLLOWED CLOSER TO THE RUC AND FRIENDS
RELATIVE HUMIDITY FIELDS WHICH SEEMED TO HAVE AT LEAST A CLUE WHERE
STRATUS FIELD CURRENTLY RESIDES. OTHER ISSUE THAT HAS BEEN OCCURRING
OVERNIGHT HAS BEEN A FEW FLURRIES. THESE SEEM TO BE MOST CONCENTRATED
IN SMALLER AREAS WITHIN STRATUS FIELD WHERE CLOUD TOPS ARE JUST A
BIT COOLER THAN THE SURROUNDINGS...VERY EVIDENT WITH INITIAL AREA
MOVING THROUGH NORTHWEST IOWA AT 09Z...AND THEN SECONDARY AREA
UP ACROSS NORTHEAST SOUTH DAKOTA. WITH CLOUDS LAYER SNEAKING INTO
THE WARMER END OF THE DENDRITIC LAYER...WOULD NOT BE SURPRISED TO
GET CONTINUATION OF FLURRIES AT TIMES THROUGH AT LEAST MID TO LATE
MORNING WHEN SOME LIFT SUPPORT FROM NORTHERN STREAM UPPER WAVE.
MAY FINALLY GET TO SEE A MORE RAPID EROSION/ADVECTION OF THE CLOUD
BOUNDARY BY THE AFTERNOON AS CONTINUED DRIER LOW LEVEL AIR WORKS ON
CLOUDS FROM BOTTOM UP...AND SUBSIDENCE TO THE SOUTHWEST FLANK OF
UPPER WAVE WORKS FROM THE TOP. WINDS STRONGEST THROUGH THE EARLY
AFTERNOON HOURS...DIMINISHING FROM WEST WITH APPROACH OF RIDGE
AXIS...BUT HANGING ON A BIT STRONGER THROUGH ELEVATED SOUTHWEST
MINNESOTA AREAS WITH DEEPENING SYSTEM TO EAST AND MORE PERSISTENT
COLD AIR ADVECTION.
TONIGHT...CHILLY RIDGE WILL DRIFT EAST ACROSS THE AREA. WILL START
TO GET SOME RETURN FLOW STRENGTHENING A TOUCH FROM THE JAMES VALLEY
WESTWARD...AND THAT ALONG WITH THE THICKENING MID AND HIGH CLOUDS
WILL LIKELY BRING A NON DIURNAL TREND TO LOWS WEST...WITH MORE
TYPICAL FALLS UNDER LINGERING RIDGE THROUGH SOUTHEASTERN AREAS.
NORTHERN PORTION OF TROUGH DIGGING INTO THE SOUTHWEST WILL DETACH
AND MOVE THROUGH THE NORTHERN STREAM...RACING THROUGH THE NORTHERN
PLAINS ON FRIDAY. WEAK SURFACE LOW/TROUGH WILL PUSH QUICKLY ACROSS
SOUTH DAKOTA AND LIKELY TO REACH NORTHWEST IOWA BY EVENING. WHILE
MOISTURE WILL BE LIMITED...AND SPEED OF SYSTEM REDUCING POTENTIAL
EFFICIENCY OF LIFT...TEMPERATURES ARE FAIRLY FAVORABLE FOR ICE
CRYSTAL GROWTH. USED LOWER TO MID LEVEL WARM AIR ADVECTION/QG
FORCING TO TIME OUT A SMALL THREAT FOR SNOWFALL FROM MIDDAY THROUGH
THE AFTERNOON GLANCING THE NORTHEASTERN 1/3 OF THE AREA. LITTLE
WINDOW FOR MIXING BEHIND THE WEAK SURFACE WAVE ACROSS THE SOUTHWEST
CWA BEFORE COLD AIR ADVECTION TAKES TOLL ON TEMPERATURES LATER IN
THE AFTERNOON. /CHAPMAN
FRIDAY NIGHT INTO SATURDAY WILL SEE A RIDGE OF HIGH PRESSURE PASS
THROUGH WITH RETURN FLOW ALOFT DEVELOPING...POSSIBLY SETTING UP A
BIT OF AN INVERSION. BUT...AS IS THE STORY EARLY THIS WINTER...NO
SNOW COVER SHOUD ALLOW A FAVORABLE WIND FOR MIXING TO DEVELOP AND
TEMPERATURES WILL LIKELY CLIMB AT LEAST INTO THE UPPER 30S TO LWOER
40S IN MOST SPOTS. EVEN PLANNING ON SOME MID TO UPER 40S IN SOUTH
CENTRAL SOUTH DAKOTA. A FAIRLY WEAK PRESSURE GRADIENT ON SATURDAY
NIGHT WILL AID IN SOEM DROP OFF IN TEMPERATURES...BUT STILL LOOKING
WELL ABOVE NORMAL.
IN THE LATTER PERIODS(SUN/WED)...A MARGINALLY AGREED UPON JET STREAK
WILL TRAVERSE THE NORTHERN PLAINS EARLY IN THE PERIOD...DROPPING A
COLD FRONT THROUGH ON MONDAY. A SOUTHERN STREAM CUT OFF LOW WILL
MOVE THROUGH KANSAS INTO MISSOURI AND SHOULD NOT REALLY AFFECT THE
AREA. SPLIT FLOW INTENSIFIES DURING THE SECOND HALF OF THE
PERIOD...ALTHOUGH THE MODELS DO INDICATE A DEEPER TROUGH TRYING TO
CARVE OUT OVER THE WESTERN UNITED STATES. HOWEVER...WITH A FAIRLY
STRONG NORTHERN STREAM IT APPEARS THAT IT WILL EJECT POSITIVELY
TILTED THUS NOT CREATING MUCH OF A PROBLEM FOR THE AREA. SO...WILL
GO ABOVE OR AT THE WARMEST GUIDANCE ON SUNDAY WITH A VERY FAVORABLE
FLOW AND ABSOLUTELY NO SNOW COVER ANYWHERE TO SPEAK OF. WILL
INCREASE LOWS A BIT ON SUNDAY NIGHT/MONDAY MORNING CLOSER TO THE RAW
OUTPUT WHICH GENERALLY HANDLES NIGHTS WITH WIND BETTER. COLDER AIR
IN ON MONDAY BUT WILL STILL LEAN TOWARDS MILDER GUIDANCE NUMBERS
WITH NO SNOW ON GROUND. MONDAY NIGHT A LITTLE TRICKY WITH A RIDGE OF
HIGH PRESSURE SLIPPING THROUGH...SO LOWERED LOWS JUST A BIT TO
COMPENSATE FOR THE POTENTIAL FOR A RADIATIONAL DROP OFF...ESPECIALLY
IN THE SOUTHERN CWA. NO BIG CHANGES FOR TUESDAY AND WEDNESDAY THIS
TIME AROUND...JUST A BIT WARMER ON TUESDAY WITH DECENT POTENTIAL LOW
LEVEL WIND FIELD. /08
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
WIDESPREAD MVFR CEILINGS CAN BE EXPECTED THROUGH 15Z AND THEN
GRADUALLY BECOME VFR FROM THE NORTHWEST. GUSTY NORTHWEST SURFACE
WINDS WILL GUST TO 30 KNOTS THROUGH 00Z FRIDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
344 AM CST THU DEC 15 2011
.SHORT TERM...TODAY THROUGH SATURDAY
AN ABUNDANCE OF STRATUS CLOUDS CONTINUE TO MOVE SOUTHEAST ACROSS
THE DAKOTAS...WITH THE EXTENT OF IT PUSHING WELL NORTH BACK INTO
SOUTHERN CANADA. WESTERN EDGE OF CLOUDS ACROSS SOUTH DAKOTA LIES
ALONG THE MISSOURI RIVER. ALTHOUGH...WITH A SOUTHEAST MOVEMENT TO
THE CLOUDS AND PLENTY LEFT UPSTREAM...EXPECTING THE EASTERN CWA TO
REMAIN IN CLOUDS MOST OF THE DAY. THE WESTERN CWA WILL LIKELY SEE
A BIT MORE SUNSHINE TODAY. MOST MODELS HAVING A HARD TIME PICKING
UP ON THE CLOUD COVER BUT THE RUC13 850 RH SEEMS TO HAVE A BETTER
HANDLE ON THINGS. IT WOULD SUGGEST CLOUD COVER THROUGH THE
AFTERNOON ACROSS THE EASTERN CWA...WITH THE WESTERN CWA IN MORE
SUNSHINE...AS PREVIOUSLY STATED. HAVE ALSO BEEN SEEING SCT
FLURRIES WITH THE STRATUS CLOUDS. PLENTY OF THAT UPSTREAM AS WELL
WITH KBIS AND KMBX RADARS SHOWING FLURRIES. EVEN OBS IN SOUTHERN
CANADA SHOWING -SN FROM TIME TO TIME. HAVE THEREFORE ADDED SCT
FLURRIES TO FORECAST THROUGH 18Z AND COULD BE A SITUATION WHERE IT
MAY NEED TO BE EXTENDED FURTHER INTO THE AFTERNOON ACROSS THE
EASTERN CWA WHEREVER STRATUS CLOUDS HANG ON THE LONGEST.
AGAIN...PLENTY OF ACTIVITY NOTED WELL UPSTREAM INTO SOUTHERN
CANADA. NORTHWEST WINDS WILL REMAIN BREEZY TODAY AS THE PRESSURE
GRADIENT REMAINS FAIRLY TIGHT WITH HIGH PRESSURE BUILDING IN.
HIGHEST SPEEDS WILL BE ACROSS THE EASTERN CWA WITH A DROP OFF IN
WINDS ACROSS THE WESTERN COUNTIES BY THIS AFTERNOON.
SFC HIGH WILL SETTLE IN OVER THE AREA TONIGHT BRINGING LIGHT
WINDS. NEXT ITEM TO WATCH WILL BE THE WEAK SHORTWAVE CROSSING THE
DAKOTAS LATE TONIGHT AND FRIDAY. MODELS STILL PEGGING MOST OF
THE LIGHT SNOWFALL ACROSS ND BUT THERE HAS BEEN A SLIGHT SHIFT
FURTHER SOUTH INTO NORTHERN SD. COUPLE MODELS BRINGING LIGHT QPF
INTO THE NORTHEASTERN COUNTIES AND SREF PROBS FOR .01 SHOWING
DECENT CHANCES ACROSS THE NORTHEASTERN CWA AS WELL. HAVE THEREFORE
INCREASED POPS SLIGHTLY FOR FRIDAY.
FOCUS WILL THEN SHIFT TO THE DEGREE OF WARMTH ON SATURDAY AS MILD
PACIFIC AIR BEGINS TO STREAM ACROSS THE NORTHERN PLAINS. WARM
FRONT CROSSES THE AREA DURING THE DAY SATURDAY WITH WINDS TURNING
WESTERLY. 850 MB TEMPS RISE TO JUST ABOVE ZERO C. WITH THE WIND
SHIFT AND A DECENT AMOUNT OF SUN...WILL SEE TEMPS RISE INTO THE
30S AND 40S.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
NOT MUCH TO TALK ABOUT IN THE EXTENDED FORECAST. CONSENSUS MODELS
ARE STILL GOING WITH CONTINUED DRY CONDITIONS. INTERESTINGLY THE
GFS IS STARTING TO HINT AT THE POSSIBILITY OF SOME PRECIP AT THE
END OF THE FORECAST PERIOD ASSOCIATED WITH THE NEXT UPPER TROF
THAT DIGS INTO THE PLAINS SO WILL NEED TO KEEP AN EYE ON HOW THAT
SYSTEM DEVELOPS. FOR NOW THOUGH LEFT THE FORECAST PRECIP FREE.
WITH THE LACK OF SNOW ON THE GROUND TEMPERATURES WILL ALSO
CONTINUE THE ABOVE NORMAL TREND WITH HIGHS STAYING NEAR 30 OR EVEN
CLIMBING INTO THE 40S THROUGH THE PERIOD.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
STRATUS REMAINS ACROSS THE REGION BUT HAS LIFTED TO AOA
2KFT...WITH THE EXCEPTION OF KATY WHICH HAS BEEN DELAYED A COUPLE
OF HOURS. CIGS WILL BEGIN TO BREAK UP DURING THE DAY
THURSDAY...AND VISBY IS EXPECTED TO REMAIN VFR. WINDS OUT OF THE
NORTHWEST AT 20G35MPH TONIGHT AND INTO THE DAY THURSDAY AS WELL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1132 PM CST WED DEC 14 2011
.AVIATION...
KACT...A LINE OF SHOWERS AND THUNDERSTORMS OVER THE AIRPORT AT THE
BEGINNING OF THE TAF PERIOD IS EXPECTED TO CLEAR THE AIRPORT BY
08Z/2 AM CST. AS THE LINE CLEARS...CIGS WILL IMPROVE AND THE WINDS
WILL SHIFT TO THE NORTHWEST. HOWEVER...ADDITIONAL RAIN ACTIVITY IS
EXPECTED TO DEVELOP LATER TONIGHT AS A COLD FRONT APPROACHES. THIS
NEXT EPISODE OF RAIN ACTIVITY WILL CONTINUE INTO THE DAY ON
THURSDAY AS AN UPPER LEVEL TROUGH APPROACHES THE REGION. SHOWERS
WILL BE LIKELY FOR MUCH OF THE DAY AND INTO THE EVENING HOURS ON
THURSDAY. THERE COULD BE PERIODS OR A FEW HOURS WHERE NO RAIN
OCCURS NEAR THE AIRPORT BUT THIS TIMING IS TOO CHALLENGING TO
PINPOINT AT THIS TIME. BY LATE THURSDAY EVENING...CIGS ARE
EXPECTED TO RETURN TO MVFR CONDITIONS AROUND 015 KFT.
DFW METROPLEX TERMINALS...VFR CONDITIONS WILL PREVAIL THROUGH THE
NIGHT. WEST WINDS WILL SHIFT TO THE NORTH AS A COLD FRONT PASSES
AROUND 12Z/6 AM CST. AS AN UPPER LEVEL TROUGH APPROACHES THE
REGION TOMORROW...ADDITIONAL SHOWERS ARE EXPECTED TO DEVELOP.
THESE SHOWERS COULD DEVELOP AS EARLY AS THE LATE MORNING HOURS BUT
ARE MORE LIKELY IN THE AFTERNOON AND EVENING HOURS. BY LATE
THURSDAY EVENING...CIGS ARE EXPECTED TO RETURN TO MVFR CONDITIONS
AROUND 015 KFT.
82/JLD
&&
.UPDATE...
THE RAIN HAS ENDED FOR TONIGHT ALONG AND WEST OF A SHERMAN...FORT
WORTH...COMANCHE LINE. TO THE WEST OF THIS LINE WINDS HAVE BECOME
SOUTHWEST TO WEST. WINDS WILL COME AROUND TO THE NORTHWEST AND NORTH
OVERNIGHT INTO THURSDAY MORNING AS A COLD FRONT MOVES THROUGH THE
REGION. NO CHANGES WERE MADE TO THE TOMORROW ONWARD FORECAST...AS
AN APPROACHING SHORTWAVE THURSDAY WILL RESULT IN RAIN DEVELOPING
AREAWIDE. HAVE ADJUSTED THE REST OF THE EVENING/OVERNIGHT
POPS/WEATHER/QPF FOR ONGOING TRENDS.
58
&&
.PREV DISCUSSION... /ISSUED 331 PM CST WED DEC 14 2011/
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE ONGOING ACROSS NORTH
TEXAS THIS AFTERNOON AS A PACIFIC COLD FRONT MOVES EAST. THE UPPER
LEVEL SYSTEM RESPONSIBLE FOR DEEP LAYER ASCENT IS SHEARING OUT
ACROSS THE SOUTHERN PLAINS AND WILL MOVE NORTHEAST THIS EVENING
ALLOWING THE FRONTAL BOUNDARY TO SLOW DOWN AS IT MOVES EAST.
LATEST RUC SOUNDINGS AND LOCALLY DERIVED CONVECTIVE PARAMETERS
INDICATE THAT 700MB WARM NOSE HAS MOSTLY ERODED WITH ONLY WEAK
INHIBITION PRESENT IN VICINITY OF THE FRONT. ANYWHERE FROM
500-700J/KG OF INSTABILITY REMAINS PRESENT AND WILL SUPPORT
THUNDERSTORMS THROUGH THE REMAINDER OF THE EVENING INTO TONIGHT.
OVERALL SEVERE WEATHER THREAT IS LOW BUT SOME HAIL WILL REMAIN
POSSIBLE. FRONT WILL DRIFT SOUTH AND EAST LATER TONIGHT WITH
PRECIP TAPERING FROM WEST TO EAST.
ALTHOUGH SURFACE FRONT WILL BE SOUTH OF THE AREA ON THURSDAY AMPLE
MOISTURE WILL RIDE ATOP THE SHALLOW COOLER AIR. REMNANTS OF THE
UPPER LOW OVER THE SOUTHWEST IS EXPECTED TO EJECT NORTHEAST DURING
THE DAY TOMORROW. THIS SYSTEM SHOULD PROVIDE SUFFICIENT FORCING TO
LIFT MOISTURE IN THE 850-700MB LAYER. ELEVATED INSTABILITY WILL BE
WEAK ALTHOUGH IT SHOULD BE SUFFICIENT FOR SHOWERY TYPE PRECIP TO
DEVELOP EVEN THOUGH THE NEAR SURFACE LAYER WILL BE DRY. MODEL
GUIDANCE IS IN GOOD AGREEMENT ON THIS SOLUTION AND HAVE RAISED
POPS FOR THU/THU NIGHT ACROSS NORTH TEXAS.
FRIDAY AND SATURDAY STILL LOOK LIKE THE QUIETEST DAYS THROUGH THE
NEXT SEVERAL WITH MOST AREAS STAYING DRY. THE NEXT STRONG SYSTEM
IS EXPECTED TO MOVE OUT OF THE SOUTHWEST US BY SUNDAY. MOISTURE
WILL SURGE NORTHWARD AHEAD OF THIS UPPER LOW...WHICH IS FORECAST
TO REMAIN CLOSED AS IT MOVES ACROSS NORTH TEXAS. THIS SYSTEM
CONTINUES TO LOOK MORE POTENT AND AGAIN WE MAY SEE SOME
SIGNIFICANT RAINFALL AS IT MOVES THROUGH. WILL HAVE TO MONITOR FOR
SEVERE WEATHER POTENTIAL AS WE GET CLOSER TO THE EVENT.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 54 56 40 54 38 / 30 50 70 10 10
WACO, TX 58 58 42 53 42 / 60 60 70 20 20
PARIS, TX 55 57 39 51 37 / 90 40 70 20 10
DENTON, TX 51 54 38 51 33 / 20 40 70 10 10
MCKINNEY, TX 54 56 41 52 36 / 40 40 70 20 10
DALLAS, TX 55 58 41 54 41 / 40 50 70 20 10
TERRELL, TX 57 59 42 52 40 / 90 50 70 20 10
CORSICANA, TX 59 62 45 54 42 / 70 60 70 30 20
TEMPLE, TX 59 59 42 53 43 / 60 70 70 20 20
MINERAL WELLS, TX 48 52 37 50 35 / 10 40 60 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/58
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 PM CST FRI DEC 16 2011
.SHORT TERM...TONIGHT
645 PM CST FRI DEC 16 2011
LIGHT SNOW HAS BEGUN IN SOUTHEAST MINNESOTA...MUCH FASTER THAN THE
16.12Z TO 16.18Z GUIDANCE WAS SUGGESTING...AS A MID LEVEL SHORT
WAVE TROUGH DIVES SOUTH ACROSS MINNESOTA. EVEN THE 16.23Z RUC WAS
STILL SUGGESTING THAT THE LOW LEVEL DRY LAYER WOULDNT GO AWAY
UNTIL SOMEWHERE AROUND 4Z AT RST...BUT THE SNOW HAS ALREADY BEGUN
TO DROP THERE. AS QG FORCING INCREASES OVERNIGHT...EXPECT THAT THE
SNOW WILL INCREASE IN COVERAGE ACROSS THE REGION.
HAVE UPDATED THE FORECAST TO HIT THE MAIN SNOW BAND THE
HARDEST...WHICH CURRENTLY APPEARS TO BE SETTING UP FROM MANKATO
EAST TOWARD ROCHESTER AND THEN SOUTHEAST TOWARD SOUTHWEST
WISCONSIN. COBB DATA SUGGEST THAT SNOW ACCUMULATIONS OF UP TO AN
INCH WILL BE POSSIBLE ALONG THIS MAIN SNOW BAND WITH LESSER
AMOUNTS AS YOU GO NORTH AND SOUTH OF THE BAND...WHICH SEEMS
REASONABLE GIVEN THE QUICK RESIDENCE TIME OF THIS SYSTEM.
THE MAIN CONCERN IMPACT WISE IS WITH ANY TRAVEL OCCURRING TONIGHT
FOR THE WEEKEND. WINDS WILL BE VERY LIGHT...WHICH WILL LEAD TO NO
DRIFTING OF THE SNOW. HOWEVER...WITH TEMPERATURES WELL BELOW
FREEZING AND MANY OF THE LEFTOVER ROAD TREATMENT CHEMICALS WASHED
AWAY FROM RECENT RAINS...THERE WILL LIKELY BE ACCUMULATION ON
ROADS THAT CAUSE SOME SLIPPERY CONDITIONS TONIGHT.
.LONG TERM...TUESDAY THROUGH FRIDAY
205 PM CST FRI DEC 16 2011
16.12Z GFS/ECMWF MAINTAIN A RATHER QUIET WEATHER REGIME ACROSS THE
REGION THROUGH THE PERIOD WITH SPLIT NORTHERN/SOUTHERN STREAM FLOW.
THIS KEEPS CYCLONE TRACKS ACROSS CANADA AND ACROSS THE SOUTHERN
PLAINS/SOUTHEAST WITH OUR AREA DRY THROUGH THURSDAY. MAY HAVE TO
WATCH FOR LAST-DITCH CHANCE FOR A WHITE CHRISTMAS CHANCE OF LIGHT
SNOW ON FRIDAY AS A MID-LEVEL TROUGH PASSES ACROSS THE AREA. THE
ECMWF REMAINS DRY WITH THIS FEATURE WHILE THE GFS SHOWS SOME
FRONTOGENESIS/BAND OF LIGHT SNOW POTENTIAL. WENT WITH THE MODEL
CONSENSUS/SLIGHT CHANCE POP FOR NOW.
&&
.AVIATION...TONIGHT AND SATURDAY
546 PM CST FRI DEC 16 2011
LIGHT SNOW HAS DEVELOPED ACROSS MUCH OF SOUTHERN MINNESOTA AND
WILL BE INTO RST AND LSE EARLY THIS EVENING. SNOW WILL EXPAND IN
COVERAGE THROUGH THE NIGHT WITH VISIBILITY EXPECTED TO LINGER
AROUND 1SM ONCE THE SNOW STARTS UP. RST IS ALREADY REPORTING -SN
AS OF TAF ISSUANCE WITH THE SNOW EXPECTED TO REACH LSE AROUND 3Z.
CEILINGS WILL DROP ACCORDINGLY INTO THE 600FT TO 1200FT RANGE AT
BOTH SITES AS THE SNOW FALLS THIS EVENING AND OVERNIGHT. THIS SNOW
IS EXPECTED TO DIMINISH IN COVERAGE TOWARD DAYBREAK AS THE SYSTEM
MOVES TO THE EAST. SOME LOW END MVFR CEILINGS IN THE 1KFT TO 2KFT
RANGE COULD HANG ON THROUGH MUCH OF THE DAY BEFORE DRIER AIR MOVES
IN TOWARD AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
205 PM CST FRI DEC 16 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM.... DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
547 PM CST FRI DEC 16 2011
.SHORT TERM...
326 PM CST FRI DEC 16 2011
HAVE INCREASED SNOW CHANCES TONIGHT ACROSS THE SOUTH INTO LIKELY
CATEGORY. THIS WAS BASED ON 18Z NAM/LATEST RUC TRENDS WHICH NOW
SHOW COLUMN SATURATION SHOULD BE MUCH OF A PROBLEM GIVEN FAIRLY
STRONG PUSH OF ISENTROPIC LIFT AND MODERATE BAND OF 850-700MB
FRONTOGENESIS CENTERED AROUND 06Z. CURRENT THINKING IS THAT AROUND
A HALF INCH OF SNOW WILL BE POSSIBLE WITH THE MAIN AXIS EXTENDING
FROM NEAR ROCHESTER MN TO PLATTEVILLE WI.
REST OF PREVIOUS SHORT TERM DISCUSSION:
NORTHWEST FLOW CONTINUES TO AFFECT THE AREA ON SATURDAY AS YET
ANOTHER SHORTWAVE TROUGH ROTATES OUT OF CANADA TOWARD THE AREA. THIS
TIME IT APPEARS THE BEST FORCING WILL REMAIN NORTHEAST OF I-94...SO
KEPT CHANCE CONFINED ACROSS THAT AREA. THIS BEING SAID...IT APPEARS
LIKE ANOTHER VERY LIGHT SNOW EVENT WITH NOT MUCH MORE THAN A COUPLE
TENTHS OF AN INCH EXPECTED.
WITH MAIN UPPER LEVEL TROUGHINESS PUSHING EAST OF THE REGION ON
SUNDAY...HEIGHTS BUILD NICELY ACROSS THE PLAINS/UPPER MISSISSIPPI
RIVER REGION. THE NAM BRINGS 925MB AIR OF 4-8C INTO THE AREA WITH
AMPLE SUNSHINE. WITH BARE GROUND...THIS HEATING SHOULD WARM HIGHS
INTO THE 35-40 DEGREE RANGE NORTHEAST OF I-94...AND INTO THE 40-45
DEGREE RANGE ACROSS THE SOUTHWEST.
A COLD FRONT IS THEN SLATED TO MOVE ACROSS THE AREA SUNDAY
NIGHT/MONDAY. NAM DOES INDICATE AN INCREASE IN LOWER LEVEL 0.5-1KM
RH/STRATUS ACROSS THE AREA AS THE FRONT APPROACHES PASSES. MAY HAVE
TO KEEP AN EYE ON THIS FOR PERHAPS SOME DRIZZLE POTENTIAL...BUT WILL
KEEP DRY FOR NOW.
CLEARING THEN EXPECTED MONDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM
THE NORTHERN PLAINS.
.LONG TERM...TUESDAY THROUGH FRIDAY
205 PM CST FRI DEC 16 2011
16.12Z GFS/ECMWF MAINTAIN A RATHER QUIET WEATHER REGIME ACROSS THE
REGION THROUGH THE PERIOD WITH SPLIT NORTHERN/SOUTHERN STREAM FLOW.
THIS KEEPS CYCLONE TRACKS ACROSS CANADA AND ACROSS THE SOUTHERN
PLAINS/SOUTHEAST WITH OUR AREA DRY THROUGH THURSDAY. MAY HAVE TO
WATCH FOR LAST-DITCH CHANCE FOR A WHITE CHRISTMAS CHANCE OF LIGHT
SNOW ON FRIDAY AS A MID-LEVEL TROUGH PASSES ACROSS THE AREA. THE
ECMWF REMAINS DRY WITH THIS FEATURE WHILE THE GFS SHOWS SOME
FRONTOGENESIS/BAND OF LIGHT SNOW POTENTIAL. WENT WITH THE MODEL
CONSENSUS/SLIGHT CHANCE POP FOR NOW.
&&
.AVIATION...TONIGHT AND SATURDAY
546 PM CST FRI DEC 16 2011
LIGHT SNOW HAS DEVELOPED ACROSS MUCH OF SOUTHERN MINNESOTA AND
WILL BE INTO RST AND LSE EARLY THIS EVENING. SNOW WILL EXPAND IN
COVERAGE THROUGH THE NIGHT WITH VISIBILITY EXPECTED TO LINGER
AROUND 1SM ONCE THE SNOW STARTS UP. RST IS ALREADY REPORTING -SN
AS OF TAF ISSUANCE WITH THE SNOW EXPECTED TO REACH LSE AROUND 3Z.
CEILINGS WILL DROP ACCORDINGLY INTO THE 600FT TO 1200FT RANGE AT
BOTH SITES AS THE SNOW FALLS THIS EVENING AND OVERNIGHT. THIS SNOW
IS EXPECTED TO DIMINISH IN COVERAGE TOWARD DAYBREAK AS THE SYSTEM
MOVES TO THE EAST. SOME LOW END MVFR CEILINGS IN THE 1KFT TO 2KFT
RANGE COULD HANG ON THROUGH MUCH OF THE DAY BEFORE DRIER AIR MOVES
IN TOWARD AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
205 PM CST FRI DEC 16 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM.... DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 AM CST THU DEC 15 2011
.SHORT TERM...TODAY THROUGH SATURDAY
343 AM CST THU DEC 15 2011
MAIN FORECAST CONCERNS ARE ON BLUSTERY NORTHWEST WINDS TODAY/CHANCES
FOR FREEZING DRIZZLE THIS MORNING...AND CLOUD COVER/FLURRIES
THROUGH THE DAY. FOCUS THEN TURNS TO SNOW CHANCES LATE FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT.
CURRENT SURFACE OBSERVATIONS SHOW A COLD FRONT EXTENDING FROM THE
NORTHERN LOWER MICHIGAN SOUTHWEST INTO NORTH CENTRAL MISSOURI.
SPRINKLES CONTINUE ACROSS THE FORECAST AREA THIS MORNING AS
STRATUS AND LOW LEVEL LIFT REMAIN IN PLACE. COLDER AIR WAS
FILTERING INTO THE REGION WITH TEMPERATURES FALLING INTO THE MID
30S. LOOK FOR TEMPERATURES TO CONTINUE FALLING THIS MORNING...WITH
THE POTENTIAL FOR FREEZING DRIZZLE THROUGH LATE MORNING.
LOW LEVEL SATURATION AND LIFT MAY PRODUCE SOME LIGHT FREEZING
DRIZZLE OR SNOW THIS MORNING...THEN SOME FLURRIES THIS AFTERNOON.
OTHERWISE PLAN ON CLOUDY SKIES TODAY WITH LOW LEVEL MOISTURE
REMAINING IN PLACE. MODELS ARE HAVING A DIFFICULT TIME HANDLING
THE LOW LEVEL MOISTURE TODAY...EXCEPT FOR THE RUC. HAVE TRENDED
CLOUDS AND TEMPERATURES TOWARDS THE RUC TODAY. ANY LINGERING
FREEZING DRIZZLE IS EXPECTED TO SWITCH OVER TO FLURRIES BY THIS
AFTERNOON AS COLDER AIR ALOFT MOVES IN. MESOSCALE MODELS INDICATE
PATCHY PRECIP ACROSS SOUTHEAST MINNESOTA AND MUCH OF WESTERN
WISCONSIN INTO THE AFTERNOON HOURS. THIS SIGNAL IS OFTEN
INDICATIVE OF FLURRIES OR DRIZZLE SO WILL HAVE TO KEEP A CLOSE EYE
ON THIS THROUGH THE MORNING HOURS. FORECAST SOUNDINGS SUGGEST MUCH
OF THE LOW LEVEL LIFT WILL BE LOST BY LATE AFTERNOON ALONG WITH
DRIER LOW LEVEL AIR PUSHING IN. THIS SHOULD END ANY LINGERING
PRECIPITATION. LOOK FOR BLUSTERY NORTHWEST WINDS TODAY...WITH
SPEEDS OF 15 TO 25 MPH AND GUSTS UP TO 40 MPH POSSIBLE. IT APPEARS
THAT WINDS WILL STAY BELOW ADVISORY CRITERIA SO WILL NOT BE
HOISTING A WIND ADVISORY TODAY. LOOK FOR HIGHS TO OCCUR EARLY THIS
MORNING...WITH TEMPERATURES FALLING THROUGH THE MORNING INTO THE
AFTERNOON. PLAN ON TEMPERATURES FALLING INTO THE UPPER 20S TO
LOWER 30S BY EARLY AFTERNOON. THE MAIN CONCERN TONIGHT WILL BE
CLOUD COVER AND LOW TEMPERATURES. LOOKING AT THE STRATUS
UPSTREAM...AND THE TRAJECTORIES...WOULD EXPECT THE CLOUDS TO
LINGER THROUGH TONIGHT. HAVE ADJUSTED LOWS UPWARD SLIGHTLY TO
ACCOUNT FOR THE EXPECTED CLOUD COVER. SHOULD SEE LOWS FALL INTO
THE UPPER TEENS TO LOWER 20S.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OVER THE UPPER MISSISSIPPI
RIVER VALLEY ON FRIDAY WITH CLOUDS DECREASING ACROSS THE AREA EARLY
IN THE DAY...THEN GRADUALLY INCREASING FROM THE NORTHWEST LATE IN
THE AFTERNOON AS ANOTHER SYSTEM MOVES IN. 15.00 MODELS INDICATE A
SHORTWAVE TROUGH MOVING FROM NORTHEAST MONTANA THROUGH THE DAKOTAS
EARLY ON FRIDAY. THE SHORTWAVE WILL MOVE INTO THE FORECAST AREA LATE
FRIDAY AFTERNOON INTO FRIDAY EVENING...WITH POTENTIAL VORTICITY
ADVECTION OF 15 PVU/S IN THE 500-300 MB LAYER...MOVING INTO THE
FORECAST AREA EARLY. ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA ON
THE 275-285 K SURFACES AS THE WAVE MOVES THROUGH. FORECAST SOUNDINGS
ARE SHOWING A 5000 FT DENDRITIC GROWTH ZONE FRIDAY EVENING. SHOULD
SEE A BRIEF SHOT OF SNOW FRIDAY EVENING. GIVEN THE SHORT DURATION OF
FORCING OVER THE AREA...SNOW ACCUMULATION SHOULD BE ON THE LIGHT
SIDE...RANGING FROM A HALF INCH TO PERHAPS A FEW LOCATIONS RECEIVING
AROUND 2 INCHES. HAVE INCREASED PRECIPITATION CHANCES ACROSS MUCH OF
THE FORECAST AREA FRIDAY EVENING INTO LATE FRIDAY NIGHT. CURRENT
THINKING IS THAT THE SNOW BAND WILL SET UP FROM SOUTHEAST MINNESOTA
THROUGH CENTRAL WISCONSIN...WITH THE GREATEST ACCUMULATIONS OCCURRING
ACROSS THESE AREAS. THE SNOW SHOULD TAPER OFF AFTER MIDNIGHT AS THE
SHORTWAVE MOVES INTO EASTERN WISCONSIN. LOOK FOR LOW TEMPERATURES TO
RANGE FROM THE MID TO UPPER TEENS ACROSS SOUTHEAST MINNESOTA THROUGH
NORTH CENTRAL WISCONSIN...TO THE LOWER 20S ACROSS FAR SOUTHWEST
WISCONSIN.
NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST ACROSS THE AREA ON
SATURDAY. A SHORTWAVE TROUGH WILL MOVE ACROSS LAKE SUPERIOR AND FAR
NORTHERN WISCONSIN DURING THE DAYTIME HOURS. MODELS ARE GENERATING
SOME LIGHT SNOW WITH THIS FEATURE AS IT MOVES THROUGH. THE SNOW
SHOULD STAY NORTH OF THE FORECAST AREA BUT WILL HAVE TO KEEP A CLOSE
WATCH ON THE NEXT SET OF MODEL RUNS. A FEW FLURRIES COULD FALL
ACROSS NORTH CENTRAL WISCONSIN AS THIS WAVE MOVES THROUGH. THE MAIN
IMPACT THE WAVE WILL HAVE ON THE FORECAST AREA...IS INCREASING CLOUD
COVER. LOOK FOR HIGH TEMPERATURES ON SATURDAY TO RANGE FROM THE
UPPER 20S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS
NORTHEAST IOWA THROUGH FAR SOUTHWEST WISCONSIN. 250 MB JET STREAK
WILL MOVE ACROSS THE REGION SATURDAY NIGHT. A SURFACE RIDGE IS
EXPECTED TO MOVE DURING THE OVERNIGHT HOURS PROVIDING MOSTLY CLEAR
SKIES. 850 MB TEMPERATURES WILL WARM THROUGH THE NIGHT...STARTING
OUT AROUND -2C AT 00Z AND WARMING TO PLUS 2 C BY 12 SUNDAY. FORECAST
SOUNDINGS ARE SHOWING THE COLD AIR HOLDING STRONG NEAR THE SURFACE
AS WARM AIR MOVES IN ALOFT. THE SOUNDINGS ALSO SATURATE NEAR THE
SURFACE SUGGESTING SOME LOW CLOUD/FOG DEVELOPMENT. LOOK FOR LOWS TO
FALL INTO THE 20S SATURDAY NIGHT.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
343 AM CST THU DEC 15 2011
15.00 MEDIUM RANGE MODELS CONTINUE TO SHOW A SPLIT FLOW PATTERN
PERSISTING ACROSS THE CONUS INTO THE MIDDLE OF NEXT WEEK. A COLD
FRONT IS EXPECTED TO SAG SOUTH ACROSS THE FORECAST AREA ON LATE
SUNDAY INTO MONDAY. THIS SYSTEM MAY BRING SOME LIGHT SNOW TO THE
AREA BUT MOISTURE WILL BE LACKING...SO ANY SNOWFALL AMOUNTS WOULD
LIKELY BE MINIMAL. THE GFS AND NAM TAKE AN UPPER LOW OVER THE
SOUTHWEST CONUS...EAST INTO THE SOUTHERN PLAINS LATE MONDAY INTO
TUESDAY. THE MODELS THEN TAKE THE LOW ACROSS THE MID MISSISSIPPI
RIVER VALLEY LATE TUESDAY INTO WEDNESDAY. MUCH OF THE PRECIPITATION
LOOKS TO STAY WELL SOUTH OF THE AREA. A MAJORITY OF THE GFS ENSEMBLE
MEMBERS ARE ALSO IN FAVOR OF THE SOUTHERN TRACK. THE GEM OFFERS A
DIFFERENT SOLUTION...TAKING THE LOW INTO THE CENTRAL PLAINS LATE
MONDAY AND LIFTING IT ACROSS SOUTHERN IOWA INTO SOUTHEAST WISCONSIN ON
TUESDAY. WILL CONTINUE A MODEL CONSENSUS BLEND DURING THIS
TIMEFRAME...KEEPING PRECIPITATION CHANCES MAINLY ALONG AND SOUTH OF
THE I-90 CORRIDOR LATE MONDAY NIGHT INTO TUESDAY. PLAN ON HIGHS
GENERALLY IN THE 30S MONDAY THROUGH WEDNESDAY...WITH LOWS IN THE 20S.
&&
.AVIATION...THROUGH 18Z FRIDAY
1135 AM CST THU DEC 15 2011
MAIN CONCERN WILL BE GUSTY NORTHWEST SURFACE WINDS THIS AFTERNOON
IN TIGHT PRESSURE BETWEEN LOW PRESSURE OVER SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE PLAINS. LOOK FOR SUSTAINED NORTHWEST
WINDS IN THE 15-25KT RANGE WITH GUSTS IN THE 30-40KT RANGE. EXPECT
THESE WINDS TO SUBSIDE FAIRLY RAPIDLY THIS EVENING. OTHERWISE...
STRATOCUMULUS CEILINGS HAVE BEEN RISING THROUGH THIS MORNING AND
ARE NOW IN VFR CATEGORY AT BOTH KRST/KLSE AS OF 17Z. THERE WERE
ALSO A FEW SNOW SHOWERS MAINLY NORTH OF THE I-90 CORRIDOR IN
WISCONSIN. HAVE THEREFORE OPTED TO CARRY A P6SM -SHSN IN THE KLSE
TAF THROUGH THE AFTERNOON. ALONG WITH DIMINISHING WINDS...LOOK FOR
A GRADUAL DECREASE IN CLOUDS THROUGH THIS EVENING AS WELL. VFR
CONDITIONS EXPECTED TO CONTINUE THROUGH FRIDAY MORNING AS THE RIDGE
OF HIGH PRESSURE DRIFTS ACROSS THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
343 AM CST THU DEC 15 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
535 AM CST THU DEC 15 2011
.SHORT TERM...TODAY THROUGH SATURDAY
343 AM CST THU DEC 15 2011
MAIN FORECAST CONCERNS ARE ON BLUSTERY NORTHWEST WINDS TODAY/CHANCES
FOR FREEZING DRIZZLE THIS MORNING...AND CLOUD COVER/FLURRIES
THROUGH THE DAY. FOCUS THEN TURNS TO SNOW CHANCES LATE FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT.
CURRENT SURFACE OBSERVATIONS SHOW A COLD FRONT EXTENDING FROM THE
NORTHERN LOWER MICHIGAN SOUTHWEST INTO NORTH CENTRAL MISSOURI.
SPRINKLES CONTINUE ACROSS THE FORECAST AREA THIS MORNING AS
STRATUS AND LOW LEVEL LIFT REMAIN IN PLACE. COLDER AIR WAS
FILTERING INTO THE REGION WITH TEMPERATURES FALLING INTO THE MID
30S. LOOK FOR TEMPERATURES TO CONTINUE FALLING THIS MORNING...WITH
THE POTENTIAL FOR FREEZING DRIZZLE THROUGH LATE MORNING.
LOW LEVEL SATURATION AND LIFT MAY PRODUCE SOME LIGHT FREEZING
DRIZZLE OR SNOW THIS MORNING...THEN SOME FLURRIES THIS AFTERNOON.
OTHERWISE PLAN ON CLOUDY SKIES TODAY WITH LOW LEVEL MOISTURE
REMAINING IN PLACE. MODELS ARE HAVING A DIFFICULT TIME HANDLING
THE LOW LEVEL MOISTURE TODAY...EXCEPT FOR THE RUC. HAVE TRENDED
CLOUDS AND TEMPERATURES TOWARDS THE RUC TODAY. ANY LINGERING
FREEZING DRIZZLE IS EXPECTED TO SWITCH OVER TO FLURRIES BY THIS
AFTERNOON AS COLDER AIR ALOFT MOVES IN. MESOSCALE MODELS INDICATE
PATCHY PRECIP ACROSS SOUTHEAST MINNESOTA AND MUCH OF WESTERN
WISCONSIN INTO THE AFTERNOON HOURS. THIS SIGNAL IS OFTEN
INDICATIVE OF FLURRIES OR DRIZZLE SO WILL HAVE TO KEEP A CLOSE EYE
ON THIS THROUGH THE MORNING HOURS. FORECAST SOUNDINGS SUGGEST MUCH
OF THE LOW LEVEL LIFT WILL BE LOST BY LATE AFTERNOON ALONG WITH
DRIER LOW LEVEL AIR PUSHING IN. THIS SHOULD END ANY LINGERING
PRECIPITATION. LOOK FOR BLUSTERY NORTHWEST WINDS TODAY...WITH
SPEEDS OF 15 TO 25 MPH AND GUSTS UP TO 40 MPH POSSIBLE. IT APPEARS
THAT WINDS WILL STAY BELOW ADVISORY CRITERIA SO WILL NOT BE
HOISTING A WIND ADVISORY TODAY. LOOK FOR HIGHS TO OCCUR EARLY THIS
MORNING...WITH TEMPERATURES FALLING THROUGH THE MORNING INTO THE
AFTERNOON. PLAN ON TEMPERATURES FALLING INTO THE UPPER 20S TO
LOWER 30S BY EARLY AFTERNOON. THE MAIN CONCERN TONIGHT WILL BE
CLOUD COVER AND LOW TEMPERATURES. LOOKING AT THE STRATUS
UPSTREAM...AND THE TRAJECTORIES...WOULD EXPECT THE CLOUDS TO
LINGER THROUGH TONIGHT. HAVE ADJUSTED LOWS UPWARD SLIGHTLY TO
ACCOUNT FOR THE EXPECTED CLOUD COVER. SHOULD SEE LOWS FALL INTO
THE UPPER TEENS TO LOWER 20S.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OVER THE UPPER MISSISSIPPI
RIVER VALLEY ON FRIDAY WITH CLOUDS DECREASING ACROSS THE AREA EARLY
IN THE DAY...THEN GRADUALLY INCREASING FROM THE NORTHWEST LATE IN
THE AFTERNOON AS ANOTHER SYSTEM MOVES IN. 15.00 MODELS INDICATE A
SHORTWAVE TROUGH MOVING FROM NORTHEAST MONTANA THROUGH THE DAKOTAS
EARLY ON FRIDAY. THE SHORTWAVE WILL MOVE INTO THE FORECAST AREA LATE
FRIDAY AFTERNOON INTO FRIDAY EVENING...WITH POTENTIAL VORTICITY
ADVECTION OF 15 PVU/S IN THE 500-300 MB LAYER...MOVING INTO THE
FORECAST AREA EARLY. ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA ON
THE 275-285 K SURFACES AS THE WAVE MOVES THROUGH. FORECAST SOUNDINGS
ARE SHOWING A 5000 FT DENDRITIC GROWTH ZONE FRIDAY EVENING. SHOULD
SEE A BRIEF SHOT OF SNOW FRIDAY EVENING. GIVEN THE SHORT DURATION OF
FORCING OVER THE AREA...SNOW ACCUMULATION SHOULD BE ON THE LIGHT
SIDE...RANGING FROM A HALF INCH TO PERHAPS A FEW LOCATIONS RECEIVING
AROUND 2 INCHES. HAVE INCREASED PRECIPITATION CHANCES ACROSS MUCH OF
THE FORECAST AREA FRIDAY EVENING INTO LATE FRIDAY NIGHT. CURRENT
THINKING IS THAT THE SNOW BAND WILL SET UP FROM SOUTHEAST MINNESOTA
THROUGH CENTRAL WISCONSIN...WITH THE GREATEST ACCUMULATIONS OCCURRING
ACROSS THESE AREAS. THE SNOW SHOULD TAPER OFF AFTER MIDNIGHT AS THE
SHORTWAVE MOVES INTO EASTERN WISCONSIN. LOOK FOR LOW TEMPERATURES TO
RANGE FROM THE MID TO UPPER TEENS ACROSS SOUTHEAST MINNESOTA THROUGH
NORTH CENTRAL WISCONSIN...TO THE LOWER 20S ACROSS FAR SOUTHWEST
WISCONSIN.
NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST ACROSS THE AREA ON
SATURDAY. A SHORTWAVE TROUGH WILL MOVE ACROSS LAKE SUPERIOR AND FAR
NORTHERN WISCONSIN DURING THE DAYTIME HOURS. MODELS ARE GENERATING
SOME LIGHT SNOW WITH THIS FEATURE AS IT MOVES THROUGH. THE SNOW
SHOULD STAY NORTH OF THE FORECAST AREA BUT WILL HAVE TO KEEP A CLOSE
WATCH ON THE NEXT SET OF MODEL RUNS. A FEW FLURRIES COULD FALL
ACROSS NORTH CENTRAL WISCONSIN AS THIS WAVE MOVES THROUGH. THE MAIN
IMPACT THE WAVE WILL HAVE ON THE FORECAST AREA...IS INCREASING CLOUD
COVER. LOOK FOR HIGH TEMPERATURES ON SATURDAY TO RANGE FROM THE
UPPER 20S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS
NORTHEAST IOWA THROUGH FAR SOUTHWEST WISCONSIN. 250 MB JET STREAK
WILL MOVE ACROSS THE REGION SATURDAY NIGHT. A SURFACE RIDGE IS
EXPECTED TO MOVE DURING THE OVERNIGHT HOURS PROVIDING MOSTLY CLEAR
SKIES. 850 MB TEMPERATURES WILL WARM THROUGH THE NIGHT...STARTING
OUT AROUND -2C AT 00Z AND WARMING TO PLUS 2 C BY 12 SUNDAY. FORECAST
SOUNDINGS ARE SHOWING THE COLD AIR HOLDING STRONG NEAR THE SURFACE
AS WARM AIR MOVES IN ALOFT. THE SOUNDINGS ALSO SATURATE NEAR THE
SURFACE SUGGESTING SOME LOW CLOUD/FOG DEVELOPMENT. LOOK FOR LOWS TO
FALL INTO THE 20S SATURDAY NIGHT.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
343 AM CST THU DEC 15 2011
15.00 MEDIUM RANGE MODELS CONTINUE TO SHOW A SPLIT FLOW PATTERN
PERSISTING ACROSS THE CONUS INTO THE MIDDLE OF NEXT WEEK. A COLD
FRONT IS EXPECTED TO SAG SOUTH ACROSS THE FORECAST AREA ON LATE
SUNDAY INTO MONDAY. THIS SYSTEM MAY BRING SOME LIGHT SNOW TO THE
AREA BUT MOISTURE WILL BE LACKING...SO ANY SNOWFALL AMOUNTS WOULD
LIKELY BE MINIMAL. THE GFS AND NAM TAKE AN UPPER LOW OVER THE
SOUTHWEST CONUS...EAST INTO THE SOUTHERN PLAINS LATE MONDAY INTO
TUESDAY. THE MODELS THEN TAKE THE LOW ACROSS THE MID MISSISSIPPI
RIVER VALLEY LATE TUESDAY INTO WEDNESDAY. MUCH OF THE PRECIPITATION
LOOKS TO STAY WELL SOUTH OF THE AREA. A MAJORITY OF THE GFS ENSEMBLE
MEMBERS ARE ALSO IN FAVOR OF THE SOUTHERN TRACK. THE GEM OFFERS A
DIFFERENT SOLUTION...TAKING THE LOW INTO THE CENTRAL PLAINS LATE
MONDAY AND LIFTING IT ACROSS SOUTHERN IOWA INTO SOUTHEAST WISCONSIN ON
TUESDAY. WILL CONTINUE A MODEL CONSENSUS BLEND DURING THIS
TIMEFRAME...KEEPING PRECIPITATION CHANCES MAINLY ALONG AND SOUTH OF
THE I-90 CORRIDOR LATE MONDAY NIGHT INTO TUESDAY. PLAN ON HIGHS
GENERALLY IN THE 30S MONDAY THROUGH WEDNESDAY...WITH LOWS IN THE 20S.
&&
.AVIATION...TODAY AND TONIGHT
535 AM CST THU DEC 15 2011
CEILING HEIGHTS AND WINDS ARE THE MAIN CONCERN. STRONG COLD
ADVECTION IN THE WAKE OF THE FRONT WILL CONTINUE THROUGHOUT THE DAY
WITH THE PRESSURE GRADIENT TIGHTENING. MODEL SOUNDING SUGGEST GUST
POTENTIAL TO 35 KNOTS TODAY...ESPECIALLY AT KRST AND THUS HAVE
RAISED WINDS FROM PREVIOUS SET OF TAFS. THESE WINDS WILL RESULT IN
STRONG CROSS WINDS FOR NORTH SOUTH RUNWAYS. THESE WINDS WILL
DIMINISH THIS EVENING...UNDER 10 KNOTS BETWEEN 03Z-06Z.
AS FOR CEILING HEIGHTS...A SLOW INCREASE IN CEILINGS IS EXPECTED
TODAY...BUT REMAINING IN THE MVFR CATEGORY. THE QUESTION IS WILL
THERE BE ANY CLEARING TONIGHT. MODELS WOULD SAY YES...AS THEY ARE
RATHER BULLISH ON PUSHING THE STRATUS OUT OF THE AREA. CONFIDENCE
NOT HIGH ON THIS...BUT DID BRING SCATTERED CONDITIONS IN BETWEEN 04Z-06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
343 AM CST THU DEC 15 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
343 AM CST THU DEC 15 2011
.SHORT TERM...TODAY THROUGH SATURDAY
343 AM CST THU DEC 15 2011
MAIN FORECAST CONCERNS ARE ON BLUSTERY NORTHWEST WINDS TODAY/CHANCES
FOR FREEZING DRIZZLE THIS MORNING...AND CLOUD COVER/FLURRIES
THROUGH THE DAY. FOCUS THEN TURNS TO SNOW CHANCES LATE FRIDAY
AFTERNOON THROUGH FRIDAY NIGHT.
CURRENT SURFACE OBSERVATIONS SHOW A COLD FRONT EXTENDING FROM THE
NORTHERN LOWER MICHIGAN SOUTHWEST INTO NORTH CENTRAL MISSOURI.
SPRINKLES CONTINUE ACROSS THE FORECAST AREA THIS MORNING AS
STRATUS AND LOW LEVEL LIFT REMAIN IN PLACE. COLDER AIR WAS
FILTERING INTO THE REGION WITH TEMPERATURES FALLING INTO THE MID
30S. LOOK FOR TEMPERATURES TO CONTINUE FALLING THIS MORNING...WITH
THE POTENTIAL FOR FREEZING DRIZZLE THROUGH LATE MORNING.
LOW LEVEL SATURATION AND LIFT MAY PRODUCE SOME LIGHT FREEZING
DRIZZLE OR SNOW THIS MORNING...THEN SOME FLURRIES THIS AFTERNOON.
OTHERWISE PLAN ON CLOUDY SKIES TODAY WITH LOW LEVEL MOISTURE
REMAINING IN PLACE. MODELS ARE HAVING A DIFFICULT TIME HANDLING
THE LOW LEVEL MOISTURE TODAY...EXCEPT FOR THE RUC. HAVE TRENDED
CLOUDS AND TEMPERATURES TOWARDS THE RUC TODAY. ANY LINGERING
FREEZING DRIZZLE IS EXPECTED TO SWITCH OVER TO FLURRIES BY THIS
AFTERNOON AS COLDER AIR ALOFT MOVES IN. MESOSCALE MODELS INDICATE
PATCHY PRECIP ACROSS SOUTHEAST MINNESOTA AND MUCH OF WESTERN
WISCONSIN INTO THE AFTERNOON HOURS. THIS SIGNAL IS OFTEN
INDICATIVE OF FLURRIES OR DRIZZLE SO WILL HAVE TO KEEP A CLOSE EYE
ON THIS THROUGH THE MORNING HOURS. FORECAST SOUNDINGS SUGGEST MUCH
OF THE LOW LEVEL LIFT WILL BE LOST BY LATE AFTERNOON ALONG WITH
DRIER LOW LEVEL AIR PUSHING IN. THIS SHOULD END ANY LINGERING
PRECIPITATION. LOOK FOR BLUSTERY NORTHWEST WINDS TODAY...WITH
SPEEDS OF 15 TO 25 MPH AND GUSTS UP TO 40 MPH POSSIBLE. IT APPEARS
THAT WINDS WILL STAY BELOW ADVISORY CRITERIA SO WILL NOT BE
HOISTING A WIND ADVISORY TODAY. LOOK FOR HIGHS TO OCCUR EARLY THIS
MORNING...WITH TEMPERATURES FALLING THROUGH THE MORNING INTO THE
AFTERNOON. PLAN ON TEMPERATURES FALLING INTO THE UPPER 20S TO
LOWER 30S BY EARLY AFTERNOON. THE MAIN CONCERN TONIGHT WILL BE
CLOUD COVER AND LOW TEMPERATURES. LOOKING AT THE STRATUS
UPSTREAM...AND THE TRAJECTORIES...WOULD EXPECT THE CLOUDS TO
LINGER THROUGH TONIGHT. HAVE ADJUSTED LOWS UPWARD SLIGHTLY TO
ACCOUNT FOR THE EXPECTED CLOUD COVER. SHOULD SEE LOWS FALL INTO
THE UPPER TEENS TO LOWER 20S.
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OVER THE UPPER MISSISSIPPI
RIVER VALLEY ON FRIDAY WITH CLOUDS DECREASING ACROSS THE AREA EARLY
IN THE DAY...THEN GRADUALLY INCREASING FROM THE NORTHWEST LATE IN
THE AFTERNOON AS ANOTHER SYSTEM MOVES IN. 15.00 MODELS INDICATE A
SHORTWAVE TROUGH MOVING FROM NORTHEAST MONTANA THROUGH THE DAKOTAS
EARLY ON FRIDAY. THE SHORTWAVE WILL MOVE INTO THE FORECAST AREA LATE
FRIDAY AFTERNOON INTO FRIDAY EVENING...WITH POTENTIAL VORTICITY
ADVECTION OF 15 PVU/S IN THE 500-300 MB LAYER...MOVING INTO THE
FORECAST AREA EARLY. ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA ON
THE 275-285 K SURFACES AS THE WAVE MOVES THROUGH. FORECAST SOUNDINGS
ARE SHOWING A 5000 FT DENDRITIC GROWTH ZONE FRIDAY EVENING. SHOULD
SEE A BRIEF SHOT OF SNOW FRIDAY EVENING. GIVEN THE SHORT DURATION OF
FORCING OVER THE AREA...SNOW ACCUMULATION SHOULD BE ON THE LIGHT
SIDE...RANGING FROM A HALF INCH TO PERHAPS A FEW LOCATIONS RECEIVING
AROUND 2 INCHES. HAVE INCREASED PRECIPITATION CHANCES ACROSS MUCH OF
THE FORECAST AREA FRIDAY EVENING INTO LATE FRIDAY NIGHT. CURRENT
THINKING IS THAT THE SNOW BAND WILL SET UP FROM SOUTHEAST MINNESOTA
THROUGH CENTRAL WISCONSIN...WITH THE GREATEST ACCUMULATIONS OCCURRING
ACROSS THESE AREAS. THE SNOW SHOULD TAPER OFF AFTER MIDNIGHT AS THE
SHORTWAVE MOVES INTO EASTERN WISCONSIN. LOOK FOR LOW TEMPERATURES TO
RANGE FROM THE MID TO UPPER TEENS ACROSS SOUTHEAST MINNESOTA THROUGH
NORTH CENTRAL WISCONSIN...TO THE LOWER 20S ACROSS FAR SOUTHWEST
WISCONSIN.
NORTHWEST FLOW ALOFT IS EXPECTED TO PERSIST ACROSS THE AREA ON
SATURDAY. A SHORTWAVE TROUGH WILL MOVE ACROSS LAKE SUPERIOR AND FAR
NORTHERN WISCONSIN DURING THE DAYTIME HOURS. MODELS ARE GENERATING
SOME LIGHT SNOW WITH THIS FEATURE AS IT MOVES THROUGH. THE SNOW
SHOULD STAY NORTH OF THE FORECAST AREA BUT WILL HAVE TO KEEP A CLOSE
WATCH ON THE NEXT SET OF MODEL RUNS. A FEW FLURRIES COULD FALL
ACROSS NORTH CENTRAL WISCONSIN AS THIS WAVE MOVES THROUGH. THE MAIN
IMPACT THE WAVE WILL HAVE ON THE FORECAST AREA...IS INCREASING CLOUD
COVER. LOOK FOR HIGH TEMPERATURES ON SATURDAY TO RANGE FROM THE
UPPER 20S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 30S ACROSS
NORTHEAST IOWA THROUGH FAR SOUTHWEST WISCONSIN. 250 MB JET STREAK
WILL MOVE ACROSS THE REGION SATURDAY NIGHT. A SURFACE RIDGE IS
EXPECTED TO MOVE DURING THE OVERNIGHT HOURS PROVIDING MOSTLY CLEAR
SKIES. 850 MB TEMPERATURES WILL WARM THROUGH THE NIGHT...STARTING
OUT AROUND -2C AT 00Z AND WARMING TO PLUS 2 C BY 12 SUNDAY. FORECAST
SOUNDINGS ARE SHOWING THE COLD AIR HOLDING STRONG NEAR THE SURFACE
AS WARM AIR MOVES IN ALOFT. THE SOUNDINGS ALSO SATURATE NEAR THE
SURFACE SUGGESTING SOME LOW CLOUD/FOG DEVELOPMENT. LOOK FOR LOWS TO
FALL INTO THE 20S SATURDAY NIGHT.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
343 AM CST THU DEC 15 2011
15.00 MEDIUM RANGE MODELS CONTINUE TO SHOW A SPLIT FLOW PATTERN
PERSISTING ACROSS THE CONUS INTO THE MIDDLE OF NEXT WEEK. A COLD
FRONT IS EXPECTED TO SAG SOUTH ACROSS THE FORECAST AREA ON LATE
SUNDAY INTO MONDAY. THIS SYSTEM MAY BRING SOME LIGHT SNOW TO THE
AREA BUT MOISTURE WILL BE LACKING...SO ANY SNOWFALL AMOUNTS WOULD
LIKELY BE MINIMAL. THE GFS AND NAM TAKE AN UPPER LOW OVER THE
SOUTHWEST CONUS...EAST INTO THE SOUTHERN PLAINS LATE MONDAY INTO
TUESDAY. THE MODELS THEN TAKE THE LOW ACROSS THE MID MISSISSIPPI
RIVER VALLEY LATE TUESDAY INTO WEDNESDAY. MUCH OF THE PRECIPITATION
LOOKS TO STAY WELL SOUTH OF THE AREA. A MAJORITY OF THE GFS ENSEMBLE
MEMBERS ARE ALSO IN FAVOR OF THE SOUTHERN TRACK. THE GEM OFFERS A
DIFFERENT SOLUTION...TAKING THE LOW INTO THE CENTRAL PLAINS LATE
MONDAY AND LIFTING IT ACROSS SOUTHERN IOWA INTO SOUTHEAST WISCONSIN ON
TUESDAY. WILL CONTINUE A MODEL CONSENSUS BLEND DURING THIS
TIMEFRAME...KEEPING PRECIPITATION CHANCES MAINLY ALONG AND SOUTH OF
THE I-90 CORRIDOR LATE MONDAY NIGHT INTO TUESDAY. PLAN ON HIGHS
GENERALLY IN THE 30S MONDAY THROUGH WEDNESDAY...WITH LOWS IN THE 20S.
&&
.AVIATION...THROUGH 06Z FRIDAY
1130 PM CST WED DEC 14 2011
CEILINGS AND WINDS ARE THE MAIN AVIATION CONCERNS THROUGH THURSDAY
EVENING. NORTHWEST WINDS ARE BEGINNING TO INCREASE IN THE WAKE OF
LOW PRESSURE LIFTING THROUGH THE GREEN BAY AREA. THESE WINDS ARE
HELPING TO DISSIPATE THE FOG...WITH VISIBILITIES NOW VFR AT KRST
AND IFR AT KLSE. ANTICIPATING THE IFR VISIBILITIES AT KLSE TO BE
SHORT LIVED...CLIMBING TO VFR BY 09Z. CEILINGS...ON THE OTHER
HAND...ARE NEARLY REVERSED AT THE TAF SITES WITH LIFR CONDITIONS
AT KRST AND MVFR CONDITIONS AT KLSE. WITH PLENTY OF LOW LEVEL
MOISTURE AROUND AND TEMPERATURES GRADUALLY FALLING DUE TO THE
NORTHWEST WINDS BRINGING IN COOLER AIR...THE RISE IN CEILINGS
SHOULD BE SLOW TO OCCUR. THEREFORE...AT KLSE HAVE MAINTAINED AN
MVFR CEILINGS THROUGH THURSDAY EVENING. AT KRST...ANTICIPATING
IFR/LIFR CEILINGS TO PERSIST THROUGH THURSDAY MORNING...THEN CLIMB
TO MVFR THANKS TO DAYTIME HEATING AROUND NOON. A STEADY NORTHWEST
WIND SHOULD PREVENT THE CEILINGS FROM FALLING BACK DOWN THURSDAY
NIGHT...DESPITE NIGHTTIME COOLING.
REGARDING WINDS...A TIGHTENING PRESSURE GRADIENT BEHIND THE
DEPARTING SURFACE LOW SHOULD GET KRST GUSTING OUT OF THE NORTHWEST
TO 25 KT BY 09Z AND AT KLSE BY 13Z. FURTHER INCREASES IN THE
GUSTS ARE POSSIBLE AT KRST TO 30KT AND POSSIBLY SLIGHTLY HIGHER
DURING THE DAYTIME HOURS...DUE TO DAYTIME MIXING. GUSTS AND WIND
SPEEDS SHOULD DIMINISH SOME DURING THE EVENING AS THE PRESSURE
GRADIENT BEGINS TO RELAX AND TEMPERATURES COOL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
343 AM CST THU DEC 15 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CST WED DEC 14 2011
.SHORT TERM...TONIGHT THROUGH FRIDAY
1130 PM CST WED DEC 14 2011
QUICK 1130 PM UPDATE...HAVE CANCELLED THE DENSE FOG ADVISORY WITH
VISIBILITIES ACROSS MUCH OF THE AREA NOW ABOVE 1/4SM. NOTE THAT
RIDGE TOPS COULD STILL SEE SOME DENSE FOG UNTIL 1 AM OR
SO...BEFORE INCREASING WEST TO NORTHWEST WINDS HELP DISSIPATE
THAT FOG TOO.
01Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED AN UPPER
TORUGH OVER MINNESOTA WITH A SHORTWAVE EVIDENT CROSSING SOUTHEAST
MINNESOTA. DPVA AHEAD OF THIS SHORTWAVE HELPING TO PRODUCE SHOWERS
MOSTLY ALONG AND NORTH OF I-90. ELSEWHERE...AREAS OF DRIZZLE
EXISTS DUE TO A PERSISTENT WEAK WARM ADVECTION AHEAD OF LOW
PRESSURE LIFTING NORTHEAST...LOCATED NEAR WATERLOO IOWA AS OF 01Z.
REGARDING THE FOG...DENSE FOG THAT DEVELOPED DURING THE AFTERNOON
DOES SEEM TO BE DISSIPATING...DUE TO EITHER RAIN MOVING ACROSS OR
WINDS TURNING NORTHWEST IN THE WAKE OF THE LOW.
SHOWERS SHOULD CONTINUE TO LIFT TO THE NORTHEAST DURING THE REST
OF THE EVENING...WITH DRIZZLE SLOWLY ENDING THROUGH THE NIGHT AS
THE LOW PULLS AWAY AND LIFT DIMINISHES. HAVE REDUCED PRECIPITATION
CHANCES FOR PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN
THIS EVENING...DUE TO MAINLY AREAS OF DRIZZLE THAT ARE NOT
PRODUCING A WIDESPREAD 0.01 OF AN INCH OF RAINFALL. ALSO...
DECREASED PRECIPITATION CHANCES AFTER MIDNIGHT WITH THE
DIMINISHING LIFT. STILL MAINTAINED SOME CHANCE...THOUGH...GIVEN
HRRR RUNS PERSISTENT SHOWING OF SOME DRIZZLE COMING IN AFTER
MIDNIGHT. THINKING IS THE HRRR MIGHT BE USING TURBULENCE BETWEEN
THE MOIST LOW LEVELS AND DRYING COMING IN ALOFT SEEN ON WATER
VAPOR AND ON THE 00Z OAX/ABR SOUNDINGS. AS FAR AS THE FOG
SITUATION GOES...WITH RECENT TRENDS OF VISIBILITIES CLIMBING...
MIGHT BE ABLE TO START CANCELLING SOME OF THE DENSE FOG ADVISORIES
EARLY. CERTAINLY MORE CONFIDENT OF THE DENSE FOG DISSIPATING ONCE
WINDS TURN WESTERLY...AS NOTED BY VISIBILITIES AT OR ABOVE 1 MILE
ALONG/WEST OF I-35 IN SOUTHERN MINNESOTA/NORTHERN IOWA.
REGARDING PRECIPITATION TYPE TONIGHT...DID REMOVE ANY MENTION OF
SNOW SINCE MODEL SOUNDINGS AS WELL AS RAOBS SUGGEST NO ICE
PRODUCTION. ALSO...LIMITED SOME OF THE FREEZING DRIZZLE
DEVELOPMENT...SHOULD IT OCCUR AT ALL...TO LATE IN THE NIGHT AS IT
MAY TAKE AWHILE FOR TEMPERATURES TO FALL GIVEN THE WIDESPREAD
ABOVE FREEZING TEMPERATURES OFF TO THE NORTHWEST.
FOR THURSDAY AND THURSDAY NIGHT...CONCERN IS GROWING THAT WE MAY
BE DEALING WITH MORE STRATUS THAN IS CURRENTLY IN THE FORECAST.
CURRENT SATELLITE IMAGERY SHOWERS STRATUS COVERING ALL OF NORTH
DAKOTA INTO NORTHEAST SOUTH DAKOTA AND EASTWARD INTO OUR FORECAST
AREA. THE 18Z NAM/GFS POORLY FORECAST THE 00Z BIS SOUNDING...WITH
900MB TEMPERATURES 4C TOO WARM...SO THE MODELS MAY NOT BE HANDLING
THE STRATUS WELL. THINKING THAT THE STRATUS MAY END UP LINGERING
RIGHT THROUGH THURSDAY NIGHT...WAITING FOR THE SURFACE RIDGE AXIS
TO PASS ON FRIDAY BEFORE IT CAN CLEAR. THIS WOULD MAKE SENSE GIVEN
HOW MUCH MOISTURE WE HAVE RECEIVED...TRYING TO PUSH COLDER AIR
INTO THE MORE MOIST AIRMASS...AND SUBSIDENCE ALOFT TRAPPING THE
LOW LEVEL MOISTURE. WITH MORE CLOUDS...TEMPERATURES THURSDAY
NIGHT COULD END UP TOO COLD. WILL PASS ON THE STRATUS ISSUE FOR THE
NEXT FULL FORECAST. FOR NOW...HAVE ONLY INCREASED CLOUD COVER SOME
ON THURSDAY INTO THURSDAY EVENING.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
305 PM CST WED DEC 14 2011
YET ANOTHER SHORT WAVE TROUGH ZIPS THROUGH THE REGION IN NORTHWEST
FLOW ON SATURDAY. ONCE AGAIN...THERE IS A CHANCE FOR A BRIEF PERIOD
OF LIGHT SNOW ALONG THE BAROCLINIC ZONE RUNNING FROM NORTHWEST
THROUGH SOUTHEAST ACROSS THE REGION.
BEYOND THIS...THE ATTENTION TURNS TO A POTENT STORM SYSTEM WHICH
WILL TAKE SHAPE OVER THE DESERT SOUTHWEST OVER THE WEEKEND...AND
WILL MOVE INTO OUR AREA BY MONDAY. THE COMPUTER MODEL SIMULATIONS
CONTINUE TO STRUGGLE AND ARE AT ODDS WITH EACH OTHER AS TO HOW THIS
WILL EVOLVE. ONE SET OF SOLUTIONS SHOW A SLOW-MOVING SOUTHERN STREAM
CLOSED SYSTEM...KEEPING THE BULK OF ANY PRECIPITATION SOUTH OF OUR
AREA. BUT OTHER SOLUTIONS SUGGEST SOME PHASING WITH THE NORTHERN
STREAM...WITH A FASTER MOVEMENT AND STRONGER SYSTEM MOVING RIGHT
THROUGH THE HEART OF THE NATION. WHILE CONFIDENCE REMAINS SOMEWHAT
LOW ON WHAT WILL EVENTUALLY HAPPEN...THERE IS ENOUGH OF A HINT IN THE
VARIOUS SOLUTIONS THAT POINT TO THE LATTER OPTION. POPS ARE STILL
SOMEWHAT LOW...BUT WE SHOULD BEGIN TO HAVE A BETTER IDEA ON THIS
SYSTEM IN THE COMING DAYS.
&&
.AVIATION...THROUGH 06Z FRIDAY
1130 PM CST WED DEC 14 2011
CEILINGS AND WINDS ARE THE MAIN AVIATION CONCERNS THROUGH THURSDAY
EVENING. NORTHWEST WINDS ARE BEGINNING TO INCREASE IN THE WAKE OF
LOW PRESSURE LIFTING THROUGH THE GREEN BAY AREA. THESE WINDS ARE
HELPING TO DISSIPATE THE FOG...WITH VISIBILITIES NOW VFR AT KRST
AND IFR AT KLSE. ANTICIPATING THE IFR VISIBILITIES AT KLSE TO BE
SHORT LIVED...CLIMBING TO VFR BY 09Z. CEILINGS...ON THE OTHER
HAND...ARE NEARLY REVERSED AT THE TAF SITES WITH LIFR CONDITIONS
AT KRST AND MVFR CONDITIONS AT KLSE. WITH PLENTY OF LOW LEVEL
MOISTURE AROUND AND TEMPERATURES GRADUALLY FALLING DUE TO THE
NORTHWEST WINDS BRINGING IN COOLER AIR...THE RISE IN CEILINGS
SHOULD BE SLOW TO OCCUR. THEREFORE...AT KLSE HAVE MAINTAINED AN
MVFR CEILINGS THROUGH THURSDAY EVENING. AT KRST...ANTICIPATING
IFR/LIFR CEILINGS TO PERSIST THROUGH THURSDAY MORNING...THEN CLIMB
TO MVFR THANKS TO DAYTIME HEATING AROUND NOON. A STEADY NORTHWEST
WIND SHOULD PREVENT THE CEILINGS FROM FALLING BACK DOWN THURSDAY
NIGHT...DESPITE NIGHTTIME COOLING.
REGARDING WINDS...A TIGHTENING PRESSURE GRADIENT BEHIND THE
DEPARTING SURFACE LOW SHOULD GET KRST GUSTING OUT OF THE NORTHWEST
TO 25 KT BY 09Z AND AT KLSE BY 13Z. FURTHER INCREASES IN THE
GUSTS ARE POSSIBLE AT KRST TO 30KT AND POSSIBLY SLIGHTLY HIGHER
DURING THE DAYTIME HOURS...DUE TO DAYTIME MIXING. GUSTS AND WIND
SPEEDS SHOULD DIMINISH SOME DURING THE EVENING AS THE PRESSURE
GRADIENT BEGINS TO RELAX AND TEMPERATURES COOL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1130 PM CST WED DEC 14 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....MW
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
403 AM EST SAT DEC 17 2011
.SYNOPSIS...
WEAK FRONTAL BOUNDARY HAS MOVED JUST EAST OF THE FORECAST AREA AND
WILL CONTINUE TO TRACK AWAY FROM THE AREA TODAY. THIS WILL ALLOW
HIGH PRESSURE ALONG WITH COOLER AND DRIER AIR TO ENTER THE REGION
THROUGH MONDAY. ANOTHER FRONTAL SYSTEM AND CHANCES OF RAIN WILL
MOVE INTO THE REGION ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK FRONTAL BOUNDARY WHICH BROUGHT SOME LIGHT SHOWERS TO THE FAR
NORTHERN MIDLANDS HAS MOVED EAST OF THE FORECAST AREA AND WILL BE
OFFSHORE BY LATE THIS MORNING. THIS WILL BRING HIGH PRESSURE BACK
TO THE REGION ALONG WITH SLIGHTLY COOLER AIR AND SKIES BECOMING
MOSTLY SUNNY. WEAK COLD AIR ADVECTION WILL OFFSET THE INCREASING
SUNSHINE AND PREVENT TEMPERATURES FROM CLIMBING MUCH TODAY...WITH
AFTERNOON HIGHS IN THE MIDDLE 50S NORTH TO THE LOWER 60S IN THE
SOUTHERN MIDLANDS AND CSRA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL CONTINUE MOVING OVER THE REGION THROUGH THE
WEEKEND AND BE CENTERED OVER THE FORECAST AREA ON SUNDAY
AFTERNOON. THIS WILL RESULT IN THE WEEKEND BEING DOMINATED BY
MOSTLY CLEAR SKIES AND LIGHT WINDS. HIGH TEMPERATURES WILL BE IN
THE UPPER 50S TO LOWER 60S WITH OVERNIGHT LOWS IN THE LOWER 30S
AND SLIGHTLY COOLER IN OUTLYING AREAS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT THROUGH THE LONG
TERM...HOWEVER CONTINUE TO DIFFER ON MAJOR FEATURES FROM WEDNESDAY
ONWARD. OVERALL THE MODELS AGREE THE PATTERN FOR THE LONG TERM
WILL BE MORE ACTIVE WITH LOW PRESSURE SYSTEMS QUICKLY CROSSING THE
REGION. IN GENERAL HAVE INCREASED POPS TUESDAY AND TUESDAY NIGHT
AS MODELS AGREE ON SYNOPTIC PATTERN BUT CONTINUE TO HAVE TIMING
ISSUES WITH THE GFS BEING FASTER AND MORE AMPLIFIED THAN THE
ECMWF. THIS SYSTEM WILL MOVE EAST OF THE AREA LATE WEDNESDAY
AFTERNOON/WEDNESDAY NIGHT WITH THE FRONT STALLING ACROSS THE FL
PENINSULA. THE FRONT WILL MOVE BACK NORTHWARD ACROSS THE REGION
THURSDAY NIGHT/FRIDAY AS THE NEXT SYSTEM MOVES THROUGH. WITH THE
CONTINUED CHANGES IN THE MODELS FROM RUN TO RUN CONFIDENCE REMAINS
LOW FOR WEDNESDAY THROUGH FRIDAY. TEMPERATURES THROUGH THE LONG
TERM WILL GENERALLY BE A COUPLE TO SEVERAL DEGREES ABOVE NORMAL
FOR DAYTIME HIGHS AND OVERNIGHT LOWS.
&&
.AVIATION /09Z SATURDAY THROUGH THURSDAY/...
COLD FRONTAL BOUNDARY APPROACHING KOGB AT 09Z...WILL BE SOUTH OF ALL
TAF SITES BY 10Z. MVFR CIGS AT KCAE/KCUB...SPREADING SOUTHWARD.
LATEST RUC MODEL STILL HAS MVFR CIGS REACHING KAGS/KDNL BY 11Z. CIGS
MAY TEMPORARILY GO BELOW 1000 FEET THROUGH 13Z. WILL NOT MENTION
TAFS SINCE CONFIDENCE IS LOW.
AFTER 15Z EXPECT VFR ALL TAF SITES AS THE BULK OF THE LOW LEVEL
MOISTURE MOVES ON EAST. MAY SEE A PERIOD OF SCT/BKN CLOUDS AROUND
4000 FEET FROM LATE AFTERNOON INTO THE EVENING AS MID LEVEL
DISTURBANCE CROSSES THE REGION.
EXTENDED AVIATION OUTLOOK...MVFR CONDITIONS POSSIBLE TUESDAY NIGHT
INTO WEDNESDAY AS ANOTHER FRONT CROSSES THE AREA.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1118 PM CST FRI DEC 16 2011
.DISCUSSION...
ISSUED 852 PM CST FRI DEC 16 2011
WEAK WEATHER SYSTEM ACRS MINNESOTA AND NORTHERN IOWA TRACKING SE
WITH SOME LIGHT SNOW AND FLURRIES BEING REPORTED OVER PARTS OF
NORTH CENTRAL THRU NE IOWA THIS EVENING. LOOKS AS IF THE BULK OF
THE LIGHT SNOW SHOULD SKIRT JUST NORTH OF THE AREA LATE TONIGHT
THRU SATURDAY MORNING...BUT WILL INCLUDE SOME FLURRIES ROUGHLY
FROM WYOMING SE TO NEAR CHAMPAIGN AND DANVILLE. HI-RES MODELS AND
LATEST RUC SUGGESTS A LITTLE FURTHER SOUTHWARD SHIFT IN THE VORT
TRACK AND MID LEVEL LIFT...RESULTING IN THE ADJUSTMENT TO THE
PRECIP CHANCES LATE TONIGHT THRU SAT MORNING...MAINLY FROM 2 AM
THRU 10 AM ACROSS THE FAR NORTH. ELSEWHERE...FORECAST SEEMS TO
BE IN GOOD SHAPE AS THE INCREASE IN CLOUD COVER SHOULD KEEP TEMPS
FROM FALLING OFF MUCH FURTHER THIS EVENING. SHOULD HAVE THE UPDATED
ZONE FORECAST OUT BY 915 PM.
&&
.AVIATION...
ISSUED 1110 PM CST FRI DEC 16 2011
WEATHER SYSTEM PUSHING ACRS THE NORTHERN PLAINS WILL PUSH JUST
NORTH OF THE TAF SITES LATE TONIGHT INTO SATURDAY MORNING. MAY
SEE A FEW FLURRIES AT BMI AND CMI SATURDAY MORNING BUT IT
APPEARS THE BULK OF ANY ACCUMULATING SNOW WILL REMAIN NORTH
OF OUR AREA. MAY SEE A BRIEF PERIOD OF CIGS BETWEEN 3500-4500
FEET A PIA...BMI AND CMI TOMORROW MORNING...BUT THE REMAINDER
OF THE AREA SHOULD SEE CIGS AOA 5000 FEET. SFC WINDS WILL
GRADUALLY BACK INTO THE SOUTHWEST TONIGHT AND SOUTH TO SOUTHWEST
WINDS SATURDAY MORNING WILL VEER INTO MORE OF A WESTERLY DIRECTION
DURING THE LATE MORNING AND EARLY AFTN HOURS. WINDS TONIGHT WILL
BE LIGHT...AROUND 5 KTS...AND THEN INCREASE TO BETWEEN 10 AND 15
KTS ON SATURDAY.
SMITH
&&
.PREV DISCUSSION...
ISSUED 300 PM CST FRI DEC 16 2011
SHORT TERM...TONIGHT THROUGH MONDAY...
WEAK UPPER SHORTWAVE MOVING INTO MN AND NORTHWESTERN IA IS PRODUCING
A LITTLE LIGHT SNOW/FLURRIES THIS AFTERNOON. THE MAIN ENERGY WITH
THE WAVE...ALONG WITH THE SNOW...WILL BE STAYING NORTH OF THE
FORECAST AREA AS IT PASSES BY TONIGHT. 18Z NAM REFLECTIVITY
SIMULATIONS ALSO KEEP PRECIPITATION TO THE NORTH...BUT NOT BY MUCH.
A FEW FLURRIES CAN BE ADDED IN THE NORTH LATER IF THE CURRENT RADAR
ECHOES TAKE AN UNEXPECTED SOUTHEAST TURN.
OTHERWISE...DRY WEATHER WITH A SLOW WARMING TREND IS EXPECTED
THROUGH THE WEEKEND AS AN AREA OF HIGH PRESSURE MOVES TO THE SOUTH
OF IL AND RESULTS IN WARM ADVECTION WITH INCREASING WEST TO
SOUTHWEST WINDS. INITIAL 850 MB TEMPERATURES AROUND -4C SHOULD RISE
TO 5 ABOVE BY THE END OF THE DAY SUNDAY.
SPLIT UPPER FLOW WILL CONTINUE OVER THE CONUS FOR MUCH OF THIS
PERIOD. A SHORTWAVE IN THE NORTHERN BRANCH WILL MOVE ACROSS SOUTHERN
CANADA WITH AN ATTENDING COLD FRONT COMING SOUTHWARD INTO IL ON
MONDAY. BY THEN...THE SOUTHERN SURFACE HIGH WILL HAVE MOVED EAST
WHICH WILL ALLOW MOISTURE FROM THE GULF TO COME NORTHWARD INTO THE
MIDWEST. BY MONDAY AFTERNOON...THIS MOISTURE WILL BE LIFTED BY THE
APPROACHING COLD FRONT AND RESULT IN AN INCREASED CHANCE OF RAIN.
WILL START OUT WITH CHANCE POPS IN THE MORNING...THEN LIKELY IN THE
AFTERNOON AS THE MOISTURE DEEPENS OVER THE AREA. AT THIS TIME IT
LOOKS LIKE THERE WILL BE SUFFICIENT WARM ADVECTION AHEAD OF THE COLD
FRONT TO PRECLUDE SNOW INTO AT LEAST MONDAY EVENING.
LONG TERM...TUESDAY THROUGH FRIDAY...
AS THE COLD FRONT STALLS OUT OVER THE MIDWEST...PRECIPITATION
CHANCES WILL INCREASE AS AN UPPER LOW NOW OVER BAHA CA COMES
NORTHEASTWARD AND INTERACTS WITH THE FRONT. WILL CONTINUE LIKELY
POPS OVER THE SOUTHERN HALF OF THE AREA CLOSER TO THE FRONT...WHICH
WILL PROVIDE A LOW LEVEL FOCUS. AT THE SAME TIME...COLD AIR WILL
BEGIN COMING INTO NORTH-CENTRAL IL NORTH OF THE FRONT AND GRADUALLY
CHANGE THE RAIN TO SNOW. IT IS STILL UNCLEAR HOW FAR SOUTH THE COLD
AIR WILL COME OR HOW DEEP IT WILL BE AS THE APPROACH OF THE
SOUTHWESTERN LOW WILL CAUSE WARM ADVECTION AT LEAST ALOFT. IF THE
COMBINATION OF CLOUDS/PRECIP KEEPS SURFACE TEMPERATURES COOL
ENOUGH...THEN AN ELEVATED WARM LAYER COULD CAUSE SOME MIXED
PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY. ALTHOUGH THE OVERALL
LONG-RANGE MODEL SOLUTIONS ARE BEGINNING TO COME INTO BETTER
AGREEMENT IN THE OVERALL SYNOPTIC FEATURES... SIGNIFICANT
DIFFERENCES IN THE LOW LEVEL THERMAL STRUCTURE STILL EXIST WHICH
WILL PLAY A SIGNIFICANT ROLE IN PRECIPITATION TYPES. FOR NOW WILL
INDICATE A RATHER SMOOTH TRANSITION FROM RAIN TO SNOW NORTHWEST TO
SOUTHEAST TUESDAY INTO TUESDAY NIGHT AS THE COLD AIR DEEPENS. BY
TUESDAY NIGHT MOST OF THE PRECIPITATION WILL BE MOVING EAST...AND
WEDNESDAY THROUGH THURSDAY LOOK PRETTY MUCH DRY SO FAR. ANOTHER RAIN
OR RAIN/SNOW CHANCE WILL RETURN ON THURSDAY NIGHT/FRIDAY AS SOME OF
THE MODELS INDICATE A SOUTHERN STORM SYSTEM PASSING JUST TO OUR
SOUTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1236 AM EST SAT DEC 17 2011
.AVIATION...
PREVIOUS TAFS STILL IN TRACK AS COMBINATION OF CLIPPER SYSTEM
MOVING THROUGH MINNESOTA ATTM AND SOME ENHANCEMENT FROM LAKE MI
SET THE STAGE FOR PERIOD OF RENEWED MVFR CONDITIONS AT KSBN AND TO
A LESSER EXTENT KFWA. LAKE EFFECT CLOUD COVER HAS HELD STRONG WITH
LEADING EDGE SITTING JUST TO THE WEST OF BOTH SITES. CIGS HAVE
SLOWLY EDGE UPWARD NOW SITTING RIGHT AROUND 3000 FT. HIGH
CONFIDENCE IN CIGS DROPPING BACK INTO MVFR RANGE SATURDAY MORNING
WITH VSBYS IMPACTED AS WELL AT KSBN. UPSTREAM OBSERVATIONS HAVE
GENERALLY BEEN FROM 3 TO 5 SM IN AREAS OF LIGHT SNOW WITH A FEW
POCKETS OF 1SM OR LESS AT TIMES. GIVEN LAKE CONTRIBUTION IN THE 12
TO 18Z SAT TIME FRAME...VSBYS LOWER THAN 2 MILES WILL BE POSSIBLE.
WILL ADJUST FURTHER WITH 12Z TAFS AFTER LOOK AT NEWEST HIGH RES
MODELS. AT KFWA...MAIN SNOWFALL AND LOWEST CONDITIONS MAY REMAIN
JUST TO THE NORTH. CONTINUED MVFR CIG FOR A PERIOD DURING THE DAY.
AS SYSTEM QUICKLY DEPARTS BY LATE AFTERNOON AND FLOW BECOMES MORE
SW WITH TIME...CLOUDS SHOULD PUSH OUT OVERNIGHT WITH IMPROVING
FLGT CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 655 PM EST FRI DEC 16 2011/
UPDATE...
18Z MODEL DATA ALONG WITH LATEST RUC ANALYSIS SUGGEST SOME CHANGES
IN ORDER FOR FORECAST. MODELS CONTINUE TO TREND TOWARD A STRONGER
SHORT WAVE WITH POTENT 120 KNOT JET MAX DIGGING INTO THE REGION
SATURDAY MORNING. ISENTROPIC LIFT AND SYNOPTIC MOISTURE LACKING SO
ONLY EXPECTING FLURRIES OR VERY LIGHT SNOW SHOWERS AWAY FROM LAKE
MICHIGAN. HOWEVER...PER LATEST MODEL DATA...A WINDOW EXISTS SATURDAY
MORNING FOR SOME LAKE ENHANCEMENT ACROSS NORTHERN INDIANA AND
SOUTHERN LOWER MICHIGAN AND MODELS SEEM TO BE PICKING UP ON THIS.
NAM12 SHOWING LAKE PLUME DEVELOPING TOWARD 12Z WITH 925-850MB OMEGA
INCREASING FROM 12-18Z WITH DELTA T VALUES IN MID TEENS COINCIDENT
WITH SYNOPTIC SHORT WAVE AND DEEPENING MOISTURE COLUMN. DGZ LOOKS TO
BE SATURATED WITH STRONGEST LIFT JUST REACHING THIS LEVEL BRIEFLY.
COULD PRODUCE A QUICK PERIOD OF LAKE ENHANCED SNOW. WILL BE
INCREASING POPS TO AT LEAST HIGH CHANCE IN THE NORTH WITH THIS
UPDATE. 18Z MODEL DATA SOMETIMES BECOMES OVERLY AGGRESSIVE SO
WOULD LIKE TO ALLOW LOOK AT 00Z DATA BEFORE INCREASING ANY FURTHER
ESPECIALLY GIVEN LACK OF GOOD SYNOPTIC SCALE LIFT AND MOISTURE WITH
DRY LOWER LEVELS TO OVERCOME INITIALLY. ACCUMS WOULD LIKELY BE AN
INCH
TO POSSIBLY TWO IN LAKE EFFECT AREAS WHERE ENHANCEMENT POTENTIAL
WOULD OBVIOUSLY BE GREATEST. OUTSIDE OF THIS AREA LIKELY JUST A
DUSTING OR LESS. UPDATE OUT SHORTLY.
PREV FORECAST...
SHORT TERM... / TONIGHT THROUGH SATURDAY NIGHT /
LATEST VIS SAT SHOWING LAKE INDUCED CLOUD DECK HANGING TOUGH OVER
THE NORTHERN HALF OF THE CWA THIS AFTERNOON. SOUTHERN EDGE
GRADUALLY ERODING AND EXPECT THIS TREND TO CONTINUE. SFC HIGH
PRESSURE RIDGE EXTENDING DOWN THE NORTHERN PLAINS AND INTO THE MID
MISSISSIPPI VALLEY WILL MAKE A LITTLE EASTWARD PROGRESS THIS
EVENING...BUT MID LEVEL NW FLOW PATTERN WILL BE MAIN FOCUS IN THE
SHORT TERM. MODELS ARE NOW TRENDING TO A BIT MORE POTENT SHORT
WAVE DROPPING DOWN INTO THE REGION...WITH ADDITIONAL UPPER LEVEL
SUPPORT FROM FAVORABLE JET DYNAMICS. AS USUAL IN NW FLOW...MODELS
SHOWING DIFFERENCES IN TIMING/PLACEMENT/INTENSITY...SO FOR NOW
WILL NOT STRAY TOO FAR FROM GOING FORECAST. WILL KEEP HIGH CHANCE
POPS WITH LIGHT ACCUMS GOING IN THE NORTH AND EXPAND TO 12 HOUR
TIME PERIOD FROM 18Z SAT TO 06Z SUN TO ACCOUNT FOR TIMING
DISCREPANCIES. TEMPS EXPECTED TO BE NEAR CLIMO WITH M30S
HIGHS/M20S LOWS.
LONG TERM... / SUNDAY THROUGH FRIDAY /
PROGRESSIVE/ACTIVE PATTERN WILL CONTINUE IN ABSENCE OF ANY TRUE HIGH
LATITUDE BLOCKING AS POS AO/NAO REGIME CONTINUES THIS PERIOD. THIS
SHOULD RESULT IN A CONTINUATION OF ABOVE NORMAL TEMPS AND
PRECIPITATION NEXT SEVERAL WEEKS.
SUNDAY STILL LOOKS LIKE A DRY DAY WITH TEMPS A LITTLE ABOVE NORMAL
PER HEIGHT RISES AND DEVELOPING LOW LVL ANTICYCLONIC FLOW. 12Z
MODELS CONTINUED TO SHOW A RATHER POTENT NORTHERN STREAM SHORTWAVE
TRAVERSING SOUTH-CENTRAL AND SOUTHEAST CANADA SUNDAY INTO
MONDAY...FORCING A FRONTAL BOUNDARY SEWD INTO THE SRN GREAT LAKES OR
OH VALLEY BY LATE MONDAY/TUESDAY. THIS WILL BE COINCIDENT WITH A SRN
STREAM CLOSED LOW (NOW OVER NRN BAJA PER AFTN WATER VAPOR) FINALLY
GETTING KICKED OUT TOWARDS THE CENTRAL PLAINS AND MID MS VALLEY BY
EARLY NEXT WEEK. THIS APPROACHING POSITIVE PV ANOMALY WILL SUPPORT
BACKING WINDS AND INCREASING ISENTROPIC LIFT...WHICH WHEN COMBINED
WITH INCREASING DIFFLUENCE ALOFT WILL ALLOW THE BAROCLINIC ZONE TO
STALL AND DEEPEN EITHER OVER OR JUST SOUTH OF THE FA DURING THIS
TIME. THE RESULT SHOULD BE AN EXPANDING AREA OF LGT/MOD PRECIP INVOF
THIS FRONTAL CIRCULATION. AS EXPECTED MODELS DO DIFFER WITH TIMING
AND PLACEMENT THIS FAR IN ADVANCE WITH SOME GUIDANCE SETTING UP THIS
BAROCLINIC ZONE AND RESULTING PRECIP WELL SOUTH OF THE FA MONDAY
NIGHT INTO TUESDAY MORNING. GIVEN THIS UNCERTAINTY AND SPREAD WITHIN
GUIDANCE WILL RETAIN CHC POPS...HIGHEST SOUTH. PRECIP SHOULD MAINLY
BE IN THE FORM OF RAIN...WITH SOME WET SNOW POSSIBLE ON THE FAR NRN
FRINGE OF THE PRECIP SHIELD LATE MONDAY NIGHT INTO TUESDAY.
A MODEL CONSENSUS FINALLY EDGES THE FILLING/WEAKENING SRN STREAM
WAVE THROUGH THE AREA LATE TUESDAY AFTN INTO TUESDAY NIGHT...WHEN
LIGHT PRECIPITATION MAY LINGER ACROSS THE AREA AS MID LVL
DEFORMATION FORCING SWINGS THROUGH. THERE COULD BE A NARROW BAND OF
SNOW ON THE NW FRINGE OF THIS SYSTEM...BEST CHANCES ACROSS OUR
NORTHWEST ZONES. ATTM NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATION. THE FA WILL DRY OUT BEHIND THIS SHORTWAVE WEDNESDAY
INTO THURSDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LOGSDON
LONG TERM...STEINWEDEL
AVIATION...FISHER
UPDATE...LASHLEY
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1155 PM EST FRI DEC 16 2011
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE LOWER
GREAT LAKES ON SATURDAY...AND MAY BRING A FEW FLURRIES TO NORTHERN
PORTIONS OF THE FORECAST AREA. OTHERWISE...EXPECT DRY WEATHER AS HIGH
PRESSURE ACROSS THE PLAINS SETTLES INTO THE SOUTHERN STATES AND OHIO
VALLEY BY LATE WEEKEND. THEN...A COLD FRONT IS EXPECTED TO DROP
SOUTHEAST ACROSS CENTRAL INDIANA ON MONDAY BEFORE STALLING NEAR
THE OHIO RIVER AS A WAVE DEVELOPS ALONG THE SOUTHERN EDGE OF THE
FRONT ACROSS THE SOUTHERN PLAINS. THIS WAVE WILL THEN LIFT
NORTHEAST ALONG THE FRONT AND ACROSS THE OHIO VALLEY TUESDAY
NIGHT. THIS WILL RESULT IN A RAINY PERIOD STARTING MONDAY AND
ENDING EARLY WEDNESDAY. THEN...HIGH PRESSURE WILL ALLOW FOR A DRY
WEDNESDAY NIGHT AND THURSDAY BEFORE A SOUTHERN PLAINS SYSTEM
BRINGS A CHANCE OF RAIN OR SNOW ON THURSDAY NIGHT AND FRIDAY.
TEMPERATURES SHOULD REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL
THROUGH NEXT WEEK.
&&
.NEAR TERM /OVERNIGHT/...
STRATOCU CONTINUES TO BE RATHER STUBBORN IN DEPARTING EASTERN
PORTIONS OF THE FORECAST AREA. WITH LOW LEVEL FLOW LARGELY OUT OF
THE N/NW...AM BECOMING LESS OPTIMISTIC THAT THESE CLOUDS WILL
COMPLETELY SCOUR OUT OF THE FORECAST AREA BEFORE RAPIDLY
APPROACHING MID AND HIGH LEVEL CLOUDS EXPAND INTO THE REGION FROM
THE WEST AFTER MIDNIGHT. HAVE THEREFORE BEEFED UP CLOUD COVERAGE
QUITE A BIT FOR MUCH OF THE REST OF THE NIGHT...WITH MANY
LOCATIONS NORTH AND EAST OF THE INDY METRO REMAINING MOSTLY
CLOUDY. MADE MINOR TWEAKS TO TEMPS OVERNIGHT BUT WITH CURRENT
TEMPS ALREADY IN THE UPPER 20S AND LOWER 30S...FORECAST LOWS IN
THE MID 20S LOOK TO BE ON TRACK EVEN WITH THE INCREASE IN CLOUD
COVER.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUD COVER...TEMPERATURES
AND TIMING OF RAIN BACK INTO CENTRAL INDIANA.
MODELS HAVE SOME DIFFERENCES BUT NOTHING REAL DRAMATIC REGARDING
MAJOR SYNOPTIC FEATURES IN THE SHORT TERM. SATURDAY WILL START OFF
WITH SOME MID AND HIGH CLOUDS AROUND ESPECIALLY NORTHEAST SECTIONS
AS A SHORT WAVE AND ASSOCIATED MOISTURE DROP SOUTHEAST ACROSS THE
LOWER GREAT LAKES IN THE FAST NORTHWEST FLOW ALOFT. MODEL RUNS
THIS EVENING SHOWING A BIT MORE IN THE WAY OF ISENTROPIC LIFT
PASSING THROUGH NORTHERN FORECAST AREA AND MOST RECENT HRRR DATA
INDICATING MAY SEE A PERIOD WITH FLURRIES OR VERY LIGHT SNOW
SHOWERS GRAZE FAR NORTHERN FORECAST AREA THROUGH 18Z SATURDAY.
IN THE WAKE OF THE SHORT WAVE...SKIES SHOULD BECOME MOSTLY CLEAR
SATURDAY NIGHT AND SUNDAY IN SUBSIDENCE IN PERSISTENT FAST
NORTHWEST FLOW ALOFT AND WITH SURFACE HIGH PRESSURE SLIDING EAST
ACROSS THE SOUTHERN STATES AND OHIO VALLEY. FINALLY...A COLD FRONT
WILL SLIDE SOUTHEAST ACROSS NORTHERN INDIANA ON MONDAY WHICH
SHOULD BRING A CHANCE FOR RAIN ESPECIALLY ACROSS OUR NORTHERN
COUNTIES CLOSER TO THE FRONT.
BASED ON LOW LEVEL THERMAL PROGS WITH 850 MILLIBAR TEMPERATURES
CLIMBING TO 2 TO 4 DEGREES CELSIUS BY LATE SUNDAY AND CLOUD
COVER...GOING WITH THE WARMER NAM MOS FOR TEMPERATURES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT WITH EJECTION OF SYSTEM FROM
THE SOUTHWEST USA EARLY IN THE EXTENDED...BUT CONTINUE TO DIFFER
SOME LATER IN THE EXTENDED LIKE THEY HAVE BEEN DOING. GIVEN THIS THE
ALL-BLEND INITIALIZATION LOOKS GOOD ENOUGH FOR THE MOST PART
THROUGHOUT THE EXTENDED.
TEMPERATURES WILL RUN NEAR OR ABOVE AVERAGE FOR THE MOST PART. 00Z
ECMWF AND 12Z GFS BOTH AGREE THAT TUESDAY NIGHT SHOULD REMAIN AT
LEAST JUST WARM ENOUGH FOR ALL RAIN. WILL REMOVE SNOW MENTION
TUESDAY NIGHT AND WEDNESDAY.
WITH THE UNCERTAINTY WITH POPS FOR THURSDAY NIGHT INTO FRIDAY KEPT
POPS LOW AND MENTIONED CHANCE OF RAIN OR SNOW WITH MARGINAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 17/06Z TAF ISSUANCE/...
LOW LEVEL CLOUDS CONTINUE TO BE PERSISTENT AT KIND AND KBMG...AND
REMAIN JUST BELOW VFR CATEGORY AT THIS TIME. HOWEVER...LOW CLOUDS
SHOULD SCATTER OUT BY SAT 09Z AND CEILINGS WILL BECOME VFR
CATEGORY AT ALL TAF SITES. THEY WILL THEN STAY AT VFR CATEGORY FOR
ENTIRE TAF PERIOD DESPITE INCREASED CLOUD COVERAGE IN THE MID AND
HIGH LEVELS DUE TO A DISTURBANCE PASSING OVER THE GREAT LAKES
REGION ON SAT MORN AND AFTERNOON. WINDS WILL INITIALLY BE
WEST/NORTHWESTERLY AND THEN BACK TO THE SOUTHWEST LATE IN TAF
PERIOD. THEY WILL NOT HAVE AN IMPACT ON OPERATIONS THOUGH WITH
SUSTAINED SPEEDS OF ONLY 4 TO 8 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK/RYAN
NEAR TERM...RYAN
SHORT TERM...MK/RYAN
LONG TERM....CS
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
309 AM CST SAT DEC 17 2011
.SYNOPSIS...
ALOFT...THE LONG WAVE PATTERN IS MARKED BY SPLIT FLOW...WITH A
CUT-OFF LOW OVER LOS ANGELES WHILE THE MIDWEST AND NORTHEAST U.S.
ARE UNDER THE INFLUENCE OF THE ACTIVE NORTHERN STREAM. CLIPPER
CURRENTLY CROSSING THE UPPER MIDWEST HAS WRUNG OUT 1 TO 3 INCHES OF
SNOW FOR NORTHERN SECTIONS OF THE FORECAST AREA. SURFACE LOW OVER
IOWA NEAR FORT DODGE /KFOD/ THIS MORNING WITH THE STRONGEST PRESSURE
FALLS SPANNING EASTERN IOWA. ..DMD..
&&
.SHORT TERM...TODAY AND TONIGHT...
MAIN FOCUS THIS MORNING IS WALKING OUT THE SNOWFALL...THEN CLOUDS
FOR THE REMAINDER OF TODAY. RUC FORECASTS SHOW LOW LEVEL
FRONTOGENETIC FORCING ASSOCIATED WITH THE CLIPPER TRACKING RAPIDLY
NORTHEAST ACROSS SOUTHERN WISCONSIN BY 11Z AND RADAR AND SATELLITE
TRENDS SHOW A FAIRLY SHARP BACK EDGE TO THE ACCUMULATING SNOW. THUS
WILL END SNOW ACROSS CWFA BY 12Z. AS FOR THE STRATUS...RUC 800MB RH
FIELD HAS A DECENT HANDLE ON THE CURRENT PROGRESS OF THE CLEARING
LINE AND WILL USE FOR NOWCASTING THE BACK EDGE. THIS TIMING WOULD
SUGGEST CLEARING REACHING THE MISSISSIPPI RIVER BY ABOUT 15Z. ..DMD..
.LONG TERM...SUNDAY THROUGH FRIDAY...
A SPLIT FLOW PATTERN WILL REMAIN OVER THE U.S. FOR THE UPCOMING
WEEK. EASTERN PACIFIC S/W ENERGY WILL CONTINUE TO BE SHUNTED NORTH
INTO BRITISH COLUMBIA OR THE PAC NW BY A STUBBORN EASTERN PACIFIC
RIDGE. SOME OF THIS ENERGY GETS PICKED UP IN THE SOUTHERN STREAM FLOW
EAST OF THE RIDGE AXIS...HELPING TO MAINTAIN SOME MID LEVEL
TROFFING OVER THE WESTERN U.S.
THE MAIN CONCERNS FOR THIS PERIOD CONTINUE TO BE IN THE EARLY PART
OF THE WEEK WITH THE SOUTHWESTERN U.S. CUTOFF LOW EJECTING INTO
THE MID MISSISSIPPI VALLEY BY TUESDAY/TUESDAY NIGHT. THE LONG
RANGE MODELS WERE IN REASONABLY GOOD AGREEMENT WITH THIS SYSTEM
WHICH IMPROVES CONFIDENCE THAT THE BULK OF THE PRECIPITATION WILL
STAY TO OUR SOUTH. HOWEVER...A NORTHERN STREAM S/W THAT WILL
INFLUENCE THE TRACK OF THE CUTOFF LOW IS STILL OVER THE PACIFIC
AND IS NOT YET BEING SAMPLED BY THE UPPER AIR NETWORK. THIS COULD
LEAD TO MORE MODEL VARIATIONS WITH THIS SYSTEM ON TODAY/S MODEL
RUNS. ONCE THE S/W REACHES THE WESTERN CONUS THIS EVENING THE
MODELS WILL HAVE MORE DATA TO WORK WITH.
FOR SUNDAY AND SUNDAY NIGHT MILD WEATHER WILL BE OVER THE AREA
WITH SOUTHWESTERLY FLOW INPLACE AHEAD OF A NORTHERN PLAINS COLD FRONT.
THE NAM/GFS SHOW A LOW LEVEL THERMAL RIDGE OVER THE AREA SUNDAY
AFTERNOON. WITH DRY AIR OVER THE AREA WE SHOULD HAVE MOSTLY SUNNY
SKIES WHICH ALLOW DEEP ENOUGH MIXING TO TAP SOME OF THE WARMER
AIR. THE TEMPERATURE FORECAST FOR SUNDAY AND SUNDAY NIGHT WERE
SKEWED TOWARD THE WARM MET MOS GUIDANCE WHICH SUGGEST MAXT TEMPS
IN THE LOW 50S OVER THE SOUTHWEST AND LOW TO MID 40S NORTHEAST.
INCREASING LOW LEVEL MOISTURE/CLOUDS SUNDAY NIGHT WILL KEEP
TEMPERATURE SOUTH IN THE UPPER 40S. IN THE NORTHWEST THE COLD
FRONT SHOULD BE MOVING IN AFTER MIDNIGHT...DROPPING TEMPERATURES IN
THE MID/UPPER 20S BY MONDAY MORNING.
FOR MONDAY THROUGH TUESDAY NIGHT THE 00Z RUNS ARE IN REASONABLE
AGREEMENT BRINGING THE UPPER LOW OUT ON A MORE SOUTHERLY COURSE.
AS A RESULT HAVE STARTED TO TREND PRECIPITATION CHANCES DOWN ACROSS
THE NORTH AND KEPT POPS IN THE SOUTHERN FOURTH OF THE AREA
LIMITED TO CHANCE CATEGORY. THE EXCEPTION TO THIS WILL BE SOME
LIKELY POPS SOUTH TUESDAY WHEN THE UPPER LOW MOVES INTO MO
SPREADING STRONGLY DIFFLUENT MID LEVEL FLOW SPREADS NORTHEAST
INTO SOUTHERN IA AND CENTRAL IL. THERMAL PROFILES SUGGEST ANY
PRECIPITATION MONDAY WILL BE RAIN. AS THE COLD AIR PUSHES SOUTH
AND DEEPENS MONDAY NIGHT AND TUESDAY THE RAIN SHOULD CHANGE TO
SNOW. WITH MODELS SHOWING THE INITIALLY SHALLOW COLD AIR
UNDERCUTTING WARMER 850MB TEMPS THERE COULD BE SOME SORT OF A MIX
MONDAY AFTERNOON/EVENING ALONG THE NORTHERN EDGE OF THE
PRECIPITATION SHIELD WHICH COULD INCLUDE SLEET AND POSSIBLY SOME
FREEZING RAIN. BY LATE MONDAY NIGHT AND TUESDAY TEMPERATURES
SHOULD BE COLD ENOUGH FOR MAINLY SNOW. THE SYSTEM WILL BE MOVING
EAST OF THE AREA BY LATE TUESDAY NIGHT. BY THIS TIME THERE IS
POTENTIAL FOR SOME MINOR SNOW ACCUMULATIONS ESPECIALLY SOUTH OF
HIGHWAY 34 BETWEEN OTTUMWA AND MACOMB.
FOR THE REST OF THE WEEK HAVE GONE WITH A MAINLY DRY FORECAST
EXPECTING NEAR NORMAL TEMPERATURES. MODELS SHOW THE WESTERN U.S.
TROF REDEVELOPING WITH A S/W EJECTING OUT OF THE TROF BY LATE
WEEK. THE GFS/ECMWF SHOW THE S/W DIGGING WELL INTO MEXICO THEN
EJECTING ON A TRACK THAT WOULD TAKE IT SOUTH OF THE AREA. THE GEM
IS LESS AMPLIFIED AND MOVES THE SYSTEM THROUGH THE MID MISSISSIPPI
VALLEY BY LATE WEEK SUPPORTING SOME PRECIPITATION OVER THE AREA. THE
ONLY POPS THEN WILL BE SOME SLIGHT CHANCE POPS FROM THURSDAY NIGHT
THROUGH FRIDAY TO COVER THE THREAT OF SNOW WITH THE EJECTING WAVE.
..DLF..
&&
.AVIATION...
LINGERING SNOW NORTH OF HIGHWAY 30 WILL MOVE INTO NORTHEASTERN
ILLINOIS AND SOUTHEASTERN WISCONSIN BY 12Z. OTHERWISE...A WEAK
SURFACE LOW PRESSURE AVE WILL TRACK ACROSS THE DUBUQUE TRI-STATE
REGION...RESULTING IN VARYING BUT GENERALLY LIGHT SURFACE WINDS. A
LARGE AREA OF MVFR STRATUS CLOUDS WILL ALSO MOVE EAST ACROSS THE
AREA WITH THIS SYSTEM. LOCAL TAF SITES WILL SEE CLEARING OF THIS
DECK BETWEEN 14 AND 17Z. ..DMD..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
DMD/DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
925 PM MST FRI DEC 16 2011
.DISCUSSION...
227 PM MST FRI DEC 16 2011
MAIN FORECAST PROBLEM WILL BE STORM FOR THE BEGINNING OF NEXT WEEK
WITH SECONDARY PROBLEMS OF HOW MUCH TO WARM IT UP BEFORE THIS NEXT
UPPER LOW FOLLOWED BY WHAT KIND OF WEATHER THE NEXT COMPLICATED UPPER
TROUGH/S WILL BRING TO THE AREA THE END OF NEXT WEEK. SATELLITE
SHOWING AN AMPLIFIED/AMPLIFYING PATTERN FROM THE PACIFIC INTO NORTH
AMERICA. DUE TO DEEPENING TROUGH OVER THE WESTERN PACIFIC...SOUTHERN
END OF EASTERN PACIFIC TROUGH IS DEEPENING AND CAUSING THE WESTERN
RIDGE TO BUILD. THIS AND HEIGHT FALL ANALYSIS SHOWS UPPER LOW OVER
BAJA SINKING SOUTH AND WEST. THIS IS PART OF SPLIT FLOW/MEAN TROUGH
THAT EXISTS OVER MOST OF THE REST OF THE COUNTRY.
IN REGARDS TO THE JET OVER THE NORTHEAST PACIFIC AND ROUNDING OVER
THE TOP OF THE RIDGE...THE MODELS LOOK UNDERDONE ON SPEEDS. ON THE
SEGMENT THAT EXTENDS FROM MONTANA TO THE NORTHWEST OF THE UPPER LOW
THE MODELS TENDED TO BE SLIGHTLY UNDERDONE AND TOO FAR EAST AND
SOUTH WITH THE SEGMENT. THE NAM WAS DOING THE BEST FOLLOWED BY THE
UKMET AND THE CANADIAN. SAME THING AT MID LEVELS WITH THE NAM DOING
SLIGHTLY BETTER THAN THE CANADIAN AND UKMET. AT THE SURFACE...THE
ECMWF WAS DOING SLIGHTLY BETTER THAN THE NAM. ON THE LOW LEVEL
THERMAL FIELD THE NAM AND GFS WERE DOING SLIGHTLY BETTER THAN THE
REMAINING OUTPUT.
TONIGHT...CURRENT SURFACE OBSERVATIONS SHOW A SURFACE TROUGH MOVING
EAST ACROSS THE TRI-STATE AREA. WINDS HAVE REMAINED LIGHT TO
BREEZY...BUT A FEW GUSTS HAVE APPROACHED 25 MPH AHEAD AND BEHIND THE
TROUGH. RUC UPPER AIR ANALYSIS SHOWS AN UPPER LEVEL TROUGH
FOLLOWING THE SURFACE FEATURE...AND SATELLITE IMAGERY CONTINUES TO
SHOW A FEW MID AND HIGH CLOUDS ON EITHER SIDE OF THE UPPER LEVEL
TROUGH. FURTHER WEST THE CLOSED LOW REMAINS POSITIONED OVER THE
BAJA PENINSULA AND HAS BEEN SLOWLY RETROGRADING TO THE WEST THROUGH
THE DAY.
NORTHWEST WINDS WILL GRADUALLY TURN TO THE WEST DURING THE EVENING...
AS A SURFACE RIDGE OF HIGH PRESSURE MOVES ACROSS THE TRI-STATE AREA
BEHIND THE SURFACE TROUGH. RELATIVE HUMIDITY VALUES WILL BE NEAR 100
PERCENT OVER THE SNOW FIELD FOR THE MCCOOK AND OBERLIN AREA. HOWEVER
THE LIGHT WEST WINDS AND DRY AIR ABOVE THE SURFACE WOULD SUPPORT NO
FOG FORMING. OTHERWISE LOWS WILL BE SIMILAR TO LAST NIGHT.
SATURDAY/SATURDAY NIGHT...AREA REMAINS UNDER SUBSIDENCE AND
INFLUENCE FROM THE MID/UPPER RIDGE. WILL BE DOWNSLOPE WINDS BUT
MOSTLY LIGHT. DID WARM UP TEMPERATURES BUT POTENTIAL IS THERE TO BE
WARMER THAN WHAT I HAVE. DURING THE NIGHT DOWNSLOPE WINDS ARE IN
PLACE AND CLOUDS DO INCREASE A LITTLE.
SUNDAY...MAIN JET IS STILL FAR AWAY FROM THE AREA. DUE TO THE UPPER
LOW STILL BEING VERY FAR AWAY...MID LEVEL RIDGING AND DRYING WILL
BE IN PLACE. BY THIS TIME...WHATEVER SNOW IS HERE NOW SHOULD NOT BE
A FACTOR IN MAXES. MODELS DIFFER ON THE AMOUNT OF WARMUP WITH THE
ECMWF SHOWING THE MOST. THERE IS WEAK DOWNSLOPING OF THE WINDS WITH
THE MODELS SHOWING LITTLE IF ANY MIXING. ALSO BECAUSE OF THE
MID/UPPER LEVEL RIDGING IN PLACE...IT LOOKS LIKE THERE WILL BE A LOT
OF SUNSHINE. SO IT LOOKS LIKE MODELS ARE UNDERDOING THE WARMING AT
THIS TIME. RAISED MAXES BUT TEMPERED IT SOMEWHAT BASED ON
COLLABORATION AND THRESHOLDS. HOWEVER...THE POTENTIAL FOR BEING
MUCH WARMER THAN WHAT IS CURRENTLY IN THERE IS PRETTY HIGH. IF THE
MIXING GETS CLOSER TO 700 MB...TEMPERATURES COULD SORE INTO THE 60S
BUT I DEFINITELY DID NOT GO THAT FAR.
SUNDAY NIGHT/MONDAY...WEAKER LEFT FRONT QUADRANT OF THE SOUTHERN JET
LOOKS TO START AFFECT THE SOUTHEAST PORTION OF THE AREA LATE IN THE
NIGHT. OF NOTE HIGHER JET SPEEDS ARE STILL BEHIND INCOMING SYSTEM
AS OF 12Z MONDAY. MOST OF THE DETERMINISTIC AND ENSEMBLE DATA SHOW
THE NEXT SYSTEM COMING FURTHER SOUTH AND SLOWER WITH STILL SOMEWHAT
OF A SPREAD. THE NAM AND GEFS MEAN ARE THE FASTEST AND FURTHEST
NORTH WITH THE CANADIAN AND ECMWF FURTHEST SOUTH. IT IS STARTING TO
LOOK LIKE FURTHER SOUTH IS APPEARING MORE LIKELY. THAT SAID WITH
LITTLE IF ANY LIFT AND SOUNDINGS SHOWING AIR MASS STILL DRY...THE
DRY FORECAST FOR SUNDAY NIGHT STILL LOOKS GOOD.
LEFT FRONT QUADRANT OF THE JET AFFECTS MAINLY SOUTHEAST HALF OF THE
AREA EARLY IN THE DAY. MOST OF THE FORCING STILL LOOKS TO BE OVER
TH SOUTHERN PORTION OF THE AREA. IF NAM/GEFS RIGHT...PRECIPITATION
CHANCE WILL BE GREATER. IF ECMWF AND ESPECIALLY THE CANADIAN IS
RIGHT...PRECIPITATION WILL BE LOWER. SINCE THERE IS STILL A LOT OF
MODEL SPREAD AND CURRENT MODEL DATA SUPPORTS THE ONGOING FORECAST...
DID NOT CHANGE MONDAYS PRECIPITATION FORECAST. IT WILL DEFINITELY
WILL BE WINDY AND COLDER ON MONDAY. IF CURRENT TRENDS CONTINUE IT IS
POSSIBLE THAT MAXES WILL NEED TO BE LOWERED MORE.
MONDAY NIGHT THROUGH FRIDAY...SPREAD ON THE DETERMINISTIC AND
ENSEMBLE OUTPUT EARLY ON THROUGH TUESDAY IS PRETTY LARGE. THINKING
THAT THE SYSTEM IS LOOKING TO BE FURTHER SOUTH...PRECIPITATION
SHOULD BE DONE OR MOSTLY DONE BY 12Z TUESDAY. MODERATION OF
TEMPERATURES THEN OCCUR AS THE WESTERN TROUGH RELOADS AND MODELS TRY
TO DECIDE WHAT TO DO WITH THE NEXT SYSTEM. SPREAD IN DETERMINISTIC
AND ENSEMBLE OUTPUT CONTINUES WITH THIS NEXT SET OF STORM SYSTEMS AS
WELL.
ON THURSDAY ALL THE MODELS DO BRING A MID LEVEL TROUGH THROUGH
BUT DIFFER ON THE STRENGTH AND SPEED. IF ECMWF WERE TO VERIFY THEN
PRECIPITATION MAY NEED TO BE EXPANDED FROM WHERE IT IS AT NOW. MODELS
SHOW A FRONT MOVE THROUGH LATE WEDNESDAY NIGHT INTO THURSDAY BUT
DIFFER ON TIME. DUE TO ITS HANDLING OF THE SYSTEM AT MID LEVELS...
THE ECMWF IS MORE AGGRESSIVE WITH THE COOLING...AND LOOKS LIKE IT
IS THE BEST SOLUTION...TEMPERATURES WILL BE COOLED MORE FROM THEY
ARE AT NOW. FRIDAY LOOKS DRY AT THIS TIME BUT WITH MODEL SPREAD
THAT COULD CHANGE. COLDER WORKS ITS WAY INTO THE AREA...COLD MAXES
IN GRIDS LOOK GOOD.
THANKS TO ALL THAT COLLABORATED.
BULLER
&&
.AVIATION...
925 PM MST FRI DEC 16 2011
FOR THE 06Z TAFS...VFR CONDITIONS WITH A GENERAL LIGHT WESTERLY WIND
WILL PREVAIL THROUGH THE VALID PERIOD AS UPPER LEVEL HIGH PRESSURE
CONTINUES TO BUILD INTO THE REGION WITH SURFACE HIGH PRESSURE CENTERED
OVER THE TX/OK PANHANDLE REGION.
050
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS GLASGOW MT
1133 PM MST FRI DEC 16 2011
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
UPDATE MADE EARLIER TO EXPAND DENSE FOG ADVISORY. CLEAR SKIES
WITH LIGHT WINDS AND AN INVERSION ALREADY IN PLACE LED TO DENSE
FOG FORMATION THIS AFTERNOON AND EVENING. FAIRLY STRONG SURFACE-
BASED INVERSION WITH SNOWCOVER SEEN ON 00Z KGGW SOUNDING...BUT
WITH ONLY A SHALLOW MOIST LAYER...AND 20KT WIND JUST OFF SURFACE.
WHILE SURFACE PRESSURE GRADIENTS ARE GENERALLY WEAK...NOT THE MOST
IDEAL FOR WIDESPREAD FOG...AS WIND IN SOME PLACES ENOUGH TO
PREVENT FOG FORMATION...MAINLY IN OUR SW. FOG LOOKING RATHER
PATCHY ON SATELLITE FOG LOOP ELSEWHERE.
MODELS INDICATE NOT MUCH CHANGE OVERNIGHT. RUC KEEPS A LARGE AREA
OF RELATIVE HUMIDITY ABOVE 95 PCT...CENTERED OVER VALLEY
COUNTY...WHICH LOOKS GOOD. WITH SOME WIND AND SHALLOWNESS OF THE
INVERSION THOUGH...EXPECT THE FOG TO BE QUITE CHANGEABLE...IN AND
OUT...AND PATCHY AT TIMES...BUT DENSE. THEREFORE DENSE FOG
ADVISORY MAINTAINED. MADE UPDATE FOR TEMPS AS SOME FORECAST LOWS
ALREADY SURPASSED. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST
MONTANA...TONIGHT THROUGH SUNDAY...UPPER RIDGING WILL HOLD THROUGH
SUNDAY AFTERNOON...MAKING FOR WARMING TEMPERATURES AND DRY
CONDITIONS.
LOW CLOUDS AND STRATUS CONTINUE TO BE THE CHALLENGE OF THE
IMMEDIATE SHORT TERM. THE CLEARING LINE ON THE SOUTHERN EDGE OF
THE STRATUS DECK HAS CLEARED GLASGOW AND GLENDIVE AND IS
CONTINUING TO MOVE NORTHWARD. THIS BRINGS UP THE ISSUE OF THE
DENSE FOG ADVISORY...WHICH HAS BEEN EXTENDED THROUGH 9 PM. WITH
THAT SAID THERE IS SOME POTENTIAL FOR THE CLEARING TO HALT OR FOR
THE STRATUS/FOG TO REDEVELOP...CAUSING THE FOG TO LINGER
OVERNIGHT. WILL NEED TO BE MONITORED FOR SURE.
OTHERWISE TONIGHT EXPECT WARMER OVERNIGHT LOWS ACROSS THE
SOUTHWEST THANKS TO A CHINOOK IN CENTRAL MONTANA AND WESTERLY LOW
LEVEL FLOW. SOME POTENTIAL WILL REMAIN FOR RADIATIONAL FOG TO FORM
SO WILL KEEP IN MENTION OF FOG OVERNIGHT FOR MUCH OF THE AREA TONIGHT
INTO EARLY SATURDAY.
WITH THE CHINOOK IN FULL FORCE ACROSS CENTRAL MONTANA ON SATURDAY
EXPECT AN UNSEASONABLY WARM DAY ON SATURDAY AS SOUTHWEST WINDS
USHERING IN WARMER AIR. SATURDAY NIGHT THE WARM CONDITIONS WILL
PERSIST...WITH MIN TEMPS CLOSE TO CLIMATOLOGICAL MAX READINGS.
SUNDAY A COLD FRONT WILL SWEEP THROUGH NORTHEAST
MONTANA...BRINGING COOLER TEMPERATURES AND NORTHWEST WINDS. MODELS
CONTINUE TO SLIGHTLY DIFFER REGARDING THE ASSOCIATED UPPER
TROUGH...BUT ALL AGREE WITH THE BETTER POTENTIAL FOR PRECIP
FALLING ON SUNDAY NIGHT. WITH THAT SAID FELT THERE WAS ENOUGH POTENTIAL
FOR LIGHT SNOWFALL ACROSS THE NORTHWEST ZONES DURING THE
AFTERNOON TO WARRANT SLIGHT CHANCE POPS IN THE FORECAST. GILCHRIST
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
12Z GFS SLOWER WITH THE MID WEEK SYSTEM NOW AND OTHER MODELS ARE
DRIER THAN THE GFS. DID RAISE POPS A BIT FOR WEDNESDAY NIGHT FOR
THE SW ZONES AS OTHER MODELS ARE NARROWING ON A BETTER SOLUTION
WITH THIS SYSTEM. IT LOOKS LIKE MUCH OF THE MOISTURE WILL BE
AIMING MORE TOWARD THE WESTERN OR CENTRAL PORTION OF THE STATE.
LOW TEMPS WERE ADJUSTED SUNDAY AND MONDAY NIGHT. JAMBA
PREVIOUS DISCUSSION...
UPPER RIDGE REMAINS ALONG THE WEST COAST...WITH NO MAJOR WEATHER
SYSTEMS HEADING OUR WAY AFTER SUNDAY NIGHT. WE ARE ON THE E SIDE
OF THE RIDGE THOUGH...WHICH IS THE COLDER SIDE AS WE GET FRESH
INTRUSIONS OF POLAR AIR EVERY COUPLE OF DAYS OR SO. THIS IS
KEEPING TEMPS NEAR NORMAL.
THE MAIN SHORTWAVE HEADING OUR WAY FROM THE NW ARRIVES WED. ALL
MODELS HAVE A FAMILIAR (OF LATE) STRONG SPLITTING MOTION WITH IT.
EVEN SO... PAST 2 GFS RUNS GENERATE A SURPRISING AMOUNT OF
MOISTURE/QPF WHICH LOOKS OVERDONE. ALL OTHER MODELS ARE MUCH DRIER
AND PREFERRED. GFS ALSO APPEARS TOO FAST WITH THIS SYSTEM. SIMONSEN
&&
.AVIATION...
DENSE FOG CONTINUES NORTH OF THE MISSOURI RIVER THIS EVENING AND
SHOULD BEGIN TO SPREAD DOWN THE YELLOWSTONE RIVER VALLEY
OVERNIGHT. LOOK FOR IFR CONDITIONS BASED MAINLY ON VISIBILITY
TONIGHT FOR THE AREA. LOCALLY AT KGGW SKY IS PARTIALLY OBSCURED
WHERE STARS ARE VISIBLE ABOVE...HOWEVER HORIZONTAL VISIBILITY
LOWERS BELOW AN 1/8TH OF A MILE AT TIMES. CONDITIONS SHOULD
IMPROVE TO VFR AFTER 15Z AT ALL LOCATIONS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM MST SATURDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
SHERIDAN...WESTERN ROOSEVELT...MCCONE...RICHLAND...DAWSON...
NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY...
EASTERN ROOSEVELT.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1001 PM MST FRI DEC 16 2011
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT...
UPDATE MADE EARLIER TO EXPAND DENSE FOG ADVISORY. CLEAR SKIES
WITH LIGHT WINDS AND AN INVERSION ALREADY IN PLACE LED TO DENSE
FOG FORMATION THIS AFTERNOON AND EVENING. FAIRLY STRONG SURFACE-
BASED INVERSION WITH SNOWCOVER SEEN ON 00Z KGGW SOUNDING...BUT
WITH ONLY A SHALLOW MOIST LAYER...AND 20KT WIND JUST OFF SURFACE.
WHILE SURFACE PRESSURE GRADIENTS ARE GENERALLY WEAK...NOT THE MOST
IDEAL FOR WIDESPREAD FOG...AS WIND IN SOME PLACES ENOUGH TO
PREVENT FOG FORMATION...MAINLY IN OUR SW. FOG LOOKING RATHER
PATCHY ON SATELLITE FOG LOOP ELSEWHERE.
MODELS INDICATE NOT MUCH CHANGE OVERNIGHT. RUC KEEPS A LARGE AREA
OF RELATIVE HUMIDITY ABOVE 95 PCT...CENTERED OVER VALLEY
COUNTY...WHICH LOOKS GOOD. WITH SOME WIND AND SHALLOWNESS OF THE
INVERSION THOUGH...EXPECT THE FOG TO BE QUITE CHANGEABLE...IN AND
OUT...AND PATCHY AT TIMES...BUT DENSE. THEREFORE DENSE FOG
ADVISORY MAINTAINED. MAN UPDATE FOR TEMPS AS SOME FORECAST LOWS
ALREADY SURPASSED. SIMONSEN
PREVIOUS SHORT TERM...FOR NORTHEAST
MONTANA...TONIGHT THROUGH SUNDAY...UPPER RIDGING WILL HOLD THROUGH
SUNDAY AFTERNOON...MAKING FOR WARMING TEMPERATURES AND DRY
CONDITIONS.
LOW CLOUDS AND STRATUS CONTINUE TO BE THE CHALLENGE OF THE
IMMEDIATE SHORT TERM. THE CLEARING LINE ON THE SOUTHERN EDGE OF
THE STRATUS DECK HAS CLEARED GLASGOW AND GLENDIVE AND IS
CONTINUING TO MOVE NORTHWARD. THIS BRINGS UP THE ISSUE OF THE
DENSE FOG ADVISORY...WHICH HAS BEEN EXTENDED THROUGH 9 PM. WITH
THAT SAID THERE IS SOME POTENTIAL FOR THE CLEARING TO HALT OR FOR
THE STRATUS/FOG TO REDEVELOP...CAUSING THE FOG TO LINGER
OVERNIGHT. WILL NEED TO BE MONITORED FOR SURE.
OTHERWISE TONIGHT EXPECT WARMER OVERNIGHT LOWS ACROSS THE
SOUTHWEST THANKS TO A CHINOOK IN CENTRAL MONTANA AND WESTERLY LOW
LEVEL FLOW. SOME POTENTIAL WILL REMAIN FOR RADIATIONAL FOG TO FORM
SO WILL KEEP IN MENTION OF FOG OVERNIGHT FOR MUCH OF THE AREA TONIGHT
INTO EARLY SATURDAY.
WITH THE CHINOOK IN FULL FORCE ACROSS CENTRAL MONTANA ON SATURDAY
EXPECT AN UNSEASONABLY WARM DAY ON SATURDAY AS SOUTHWEST WINDS
USHERING IN WARMER AIR. SATURDAY NIGHT THE WARM CONDITIONS WILL
PERSIST...WITH MIN TEMPS CLOSE TO CLIMATOLOGICAL MAX READINGS.
SUNDAY A COLD FRONT WILL SWEEP THROUGH NORTHEAST
MONTANA...BRINGING COOLER TEMPERATURES AND NORTHWEST WINDS. MODELS
CONTINUE TO SLIGHTLY DIFFER REGARDING THE ASSOCIATED UPPER
TROUGH...BUT ALL AGREE WITH THE BETTER POTENTIAL FOR PRECIP
FALLING ON SUNDAY NIGHT. WITH THAT SAID FELT THERE WAS ENOUGH POTENTIAL
FOR LIGHT SNOWFALL ACROSS THE NORTHWEST ZONES DURING THE
AFTERNOON TO WARRANT SLIGHT CHANCE POPS IN THE FORECAST. GILCHRIST
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
12Z GFS SLOWER WITH THE MID WEEK SYSTEM NOW AND OTHER MODELS ARE
DRIER THAN THE GFS. DID RAISE POPS A BIT FOR WEDNESDAY NIGHT FOR
THE SW ZONES AS OTHER MODELS ARE NARROWING ON A BETTER SOLUTION
WITH THIS SYSTEM. IT LOOKS LIKE MUCH OF THE MOISTURE WILL BE
AIMING MORE TOWARD THE WESTERN OR CENTRAL PORTION OF THE STATE.
LOW TEMPS WERE ADJUSTED SUNDAY AND MONDAY NIGHT. JAMBA
PREVIOUS DISCUSSION...
UPPER RIDGE REMAINS ALONG THE WEST COAST...WITH NO MAJOR WEATHER
SYSTEMS HEADING OUR WAY AFTER SUNDAY NIGHT. WE ARE ON THE E SIDE
OF THE RIDGE THOUGH...WHICH IS THE COLDER SIDE AS WE GET FRESH
INTRUSIONS OF POLAR AIR EVERY COUPLE OF DAYS OR SO. THIS IS
KEEPING TEMPS NEAR NORMAL.
THE MAIN SHORTWAVE HEADING OUR WAY FROM THE NW ARRIVES WED. ALL
MODELS HAVE A FAMILIAR (OF LATE) STRONG SPLITTING MOTION WITH IT.
EVEN SO... PAST 2 GFS RUNS GENERATE A SURPRISING AMOUNT OF
MOISTURE/QPF WHICH LOOKS OVERDONE. ALL OTHER MODELS ARE MUCH DRIER
AND PREFERRED. GFS ALSO APPEARS TOO FAST WITH THIS SYSTEM. SIMONSEN
&&
.AVIATION...
DENSE FOG CONTINUES NORTH OF THE MISSOURI RIVER THIS EVENING AND
SHOULD BEGIN TO SPREAD DOWN THE YELLOWSTONE RIVER VALLEY
OVERNIGHT. LOOK FOR IFR CONDITIONS BASED MAINLY ON VISIBILITY
TONIGHT FOR THE AREA. LOCALLY AT KGGW SKY IS PARTIALLY OBSCURED
WHERE STARS ARE VISIBLE ABOVE...HOWEVER HORIZONTAL VISIBILITY
LOWERS BELOW AN 1/8TH OF A MILE AT TIMES. CONDITIONS SHOULD
IMPROVE TO VFR AFTER 15Z AT ALL LOCATIONS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM MST SATURDAY FOR CENTRAL AND
SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...
SHERIDAN...WESTERN ROOSEVELT...MCCONE...RICHLAND...DAWSON...
NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY...
EASTERN ROOSEVELT.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
412 AM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
LE SNOWS WILL CAUSE SOME IFR CIGS AND VSBYS AT TIMES AT RME AND
SYR OVRNGT...AND PSBL MVFR AT ITH AND BGM. IN GNRL...LE WILL
WEAKEN AS THE FLOW CONTS TO BECOME MORE NWLY BHD THE SFC TROF.
SOME LEFTOVER LGT LE SNOW SHWRS AFT DAYBRK SAT...OTRW VFR CONDS
UNDER HIPRES WILL HOLD THUR THE REST OF THE TAF PD.
.OUTLOOK...
SAT NGT THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...DGM/MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 AM EST SAT DEC 17 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA OVERNIGHT...BRINGING ONLY A
SMALL CHANCE OF LIGHT RAIN. MUCH COLDER AIR WILL MOVE IN FOR THE
WEEKEND AS ARCTIC HIGH PRESSURE APPROACHES FROM THE WEST.
TEMPERATURES WILL RETURN TO ABOVE NORMAL LEVELS NEXT WEEK AS THE
HIGH MOVES OFFSHORE LATE MONDAY AND TUESDAY. ANOTHER COLD FRONT
WILL MOVE INTO THE AREA ON WEDNESDAY AND MAY STALL. RAIN CHANCES
WILL INCREASE DURING THE LATTER PORTION OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM SATURDAY...COLD FRONT HAS MOVED THROUGH OUR NC
COUNTIES AND SHOULD CLEAR THE CWA BY DAWN. SHIELD OF LIGHT PRECIP
PASSING TO OUR NORTH AND LOOKS UNLIKELY WE WILL SEE ANY
ACCUMULATIONS FROM THIS. UPDATE FORECAST ACCORDINGLY. RELEVANT
PORTIONS OF PREVIOUS DISCUSSION FOLLOWS:
RAIN CHANCES ARE THE BIGGEST FORECAST CONCERN OVERNIGHT. CURRENT
RADAR COMPOSITES SHOW A RATHER EXPANSIVE AREA OF LIGHT RAIN
EXTENDING FROM THE CHARLOTTE METRO AREA INTO NORTHEASTERN NORTH
CAROLINA. VERY LITTLE RAIN EXTENDS SOUTH OF THIS BATCH TO IMPACT
OUR FORECAST AREA OVERNIGHT. SHALLOW LIFT OVER THE FRONTAL SURFACE
WITHIN A ZONE OF MOISTURE EXTENDING UP TO 775 MB COULD CAUSE SOME
PATCHES OF LIGHT RAIN TO DEVELOP AS FAR SOUTH AS FLORENCE...
MARION...CONWAY...AND SOUTHPORT...ALTHOUGH THE CHANCES OF
RECEIVING A MEASURABLE 0.01" IS PRETTY SLIM. WE WILL MAINTAIN A 20
(SLIGHT CHANCE) POP FOR THE AFOREMENTIONED AREAS...WITH SOME OF
THE LATEST HRRR RUNS STILL SHOWING VERY LIGHT PRECIPITATION
DEVELOPING AFTER 06Z ACROSS SOUTHEASTERN NORTH CAROLINA AND
ADJACENT PORTIONS OF SOUTH CAROLINA.
AS THE FRONT PASSES BY OVERNIGHT TEMPERATURES WILL FALL INTO THE MID
TO UPPER 40S ACROSS INTERIOR SECTIONS OF THE CAROLINAS...WITH TEMPS
~5 DEGREES WARMER AT THE IMMEDIATE COAST DUE TO SOME WEAK MARINE
INFLUENCE ON THE NORTH-NORTHEAST POST-FRONTAL WIND. AHEAD OF THE
FRONT CURRENT (9 PM) TEMPERATURES RANGE FROM THE MID TO UPPER 50S
WHERE SKIES ARE CLEAR...TO THE LOWER 60S WHERE SKIES ARE CURRENTLY
CLOUDY.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A SURFACE COLD FRONT WILL BE SOUTH OF THE
SOUTH SANTEE RIVER SAT MORNING AND WILL CONTINUE TO MOVE TO THE
SOUTH. AN UPPER TROUGH WILL BOTTOM OUT ACROSS THE EAST COAST SAT
AND SAT NIGHT. THIS TROUGH WILL BE VERY PROGRESSIVE...MOVING
OFFSHORE DURING SUN. UPPER RIDGE WILL THEN BUILD ACROSS THE AREA
SUN NIGHT AND MON. FORECAST PERIOD WILL START WITH BKN TO OVC LOW
CLOUDS AND PERHAPS SOME SPRINKLES AS LOW LEVEL MOISTURE REMAINS
LOCKED BENEATH A FRONTAL INVERSION. A SHORTWAVE TROUGH WILL MOVE
ACROSS THE AREA SAT AFTERNOON AND EVE AND THIS WILL SCOUR OUT
REMAINING LOW LEVEL MOISTURE.
CLOUDINESS WILL EVENTUALLY ERODE DURING SAT WITH SKIES CLEAR OR
CLEARING BY EVE. H8 TEMPS WILL DROP FROM AROUND 7 DEG C TO 3 DEG C
SAT. H8 TEMPS WILL BOTTOM OUT AROUND ZERO DEG C ON SUN. THIS INFLUX
OF COLD AIR WILL DELAY ANY SIGNIFICANT UPWARD TREND IN TEMPS SAT.
TEMPS SHOULD STILL BE DROPPING SAT MORNING...BUT AFTERNOON TEMPS
SHOULD BE ABLE TO RECOVER TO THE MID 50S MOST PLACES AND CLOSER TO
60 DEG AS YOU NEAR THE SOUTH SANTEE RIVER. AS SURFACE HIGH
PRESSURE...CENTERED ACROSS THE MID SOUTH AND GULF COAST GROWS
CLOSER...WINDS SHOULD FULLY DECOUPLE DURING SAT NIGHT. CLEAR SKIES
AND LIGHT N WINDS SHOULD ALLOW RADIATIONAL COOLING TO GAIN A STRONG
FOOT HOLD OVERNIGHT. READINGS SUN MORNING WILL BE IN THE LOWER TO
MID 30S WITH SOME OF OUR NORMALLY COLD SPOTS DROPPING INTO THE UPPER
20S. BRIGHT SUNSHINE ON SUN WILL ONLY BE ABLE TO PROPEL TEMPS INTO
THE MID AND UPPER 50S. SUN NIGHT SHOULD BE COLDER THAN THE PREVIOUS
NIGHT. HIGH PRESSURE WILL BE CENTERED VIRTUALLY OVERHEAD SUN NIGHT
WITH SOME THIN CIRRUS INCREASING LATE. TEMPS MON MORNING WILL BE IN
THE UPPER 20S TO LOWER 30S WITH SOME MID 20S IN THE COLDEST
LOCATIONS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...THE EXTENDED FORECAST WARRANTS FEW CHANGES
THIS AFTERNOON AS MOST OF THE ACTION WILL BE CONCENTRATED ON THE
MIDDLE AND LATTER PART OF THE PERIOD. A WEAKENING SHORTWAVE WILL
MOVE ACROSS THE MISSISSIPPI VALLEY LATE TUESDAY AND WEDNESDAY WITH
A WEAK FRONT MOVING ACROSS THE SOUTH. AS HAS BEEN THE CASE THE
PAST FEW WEEKS...THE BEST FORCING WITH THIS SYSTEM MOVES OFF TO
THE NORTHEAST. TWEAKED THE TIMING WITH THE LATEST FORECAST TO
DELAY THE TIMING OTHERWISE I MAINTAINED THE CHANCE POPS FOR LATE
TUESDAY INTO WEDNESDAY FOR OUR AREA. ANOTHER SYSTEM IN THE
SOUTHERN BRANCH QUICKLY FOLLOWS FOR LATE THURSDAY INTO FRIDAY WITH
A BRIEF REPRIEVE EARLY THURSDAY. TEMPERATURES LOOK TO REMAIN ABOVE
NORMAL WITH THE EXCEPTION OF MONDAY WHEN HIGH PRESSURE WILL BE
ESSENTIALLY OVERHEAD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...MODERATE CONFIDENCE OVERNIGHT AS COLD FRONT BRINGS A
CHANCE OF SOME VERY LIGHT RAIN AND MVFR. VFR WILL DEVELOP SATURDAY
AFTN.
COLD FRONT HAS PASSED THROUGH ALL TERMINALS EXCEPT THE MYRTLES...AND
THIS WILL OCCUR SHORTLY THERE AS WELL. RAIN HAS HAD A VERY DIFFICULT
TIME MAKING ANY SE PROGRESS BEHIND THE FRONT. AM CONFIDENT IN
MVFR CIGS. UPSTREAM OBS SHOW WIDESPREAD POST-FRONTAL MVFR
STRATUS...AND EXPECT THIS SO SLOWLY ADVECT SE WITH THE FRONT.
QUESTION AS TO WHETHER CIGS WILL LOWER TO IFR STILL EXISTS...BUT
MOST GUIDANCE HAS BACKED OFF ON THIS POTENTIAL. STILL SEEING IFR
ONLY OCCURRING WHERE SIGNIFICANT RAIN HAS FALLEN...WHICH WILL NOT
OCCUR EVEN AT LBT...SO HAVE CONTINUED WITH MVFR AS THE WORST
RESTRICTION AND WILL MONITOR AS NECESSARY. CANNOT RULE SOME OUT
IFR AT LBT OVERNIGHT.
S/W WILL PUSH OFF TO THE EAST EARLY SATURDAY BRINGING DRIER AIR TO
THE REGION. THIS WILL HELP ERODE CLOUD COVER AND VFR WILL DEVELOP BY
LATE MORNING OR EARLY AFTN. WINDS WILL PERSIST FROM THE NORTH
THROUGH SATURDAY AROUND 10 KTS. SKY CONDITIONS WILL IMPROVE TO SKC
WHILE WINDS DROP TO NEAR CALM AFTER NIGHTFALL.
EXTENDED OUTLOOK...VFR SUNDAY AND MONDAY. MORNING FOG POSSIBLE
TUESDAY. SHOWERS ASSOCIATED WITH A COLD FRONT MAY IMPACT THE AREA
WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM SATURDAY...COLD FRONT PASSING FROM NORTH TO SOUTH
ACROSS OUR NC WATERS WITH WINDS SHIFTING TO W AND THEN NW. EXPECT
FRONT TO CLEAR OUR SOUTHERN WATERS BY DAWN. CURRENT BUOY OBS SHOW
2 TO 4 FT SEAS OVER THE COASTAL WATERS...WHICH IS AS FORECAST.
PREVIOUS DISCUSSION FOLLOWS:
A COLD FRONT ACROSS EASTERN NORTH CAROLINA HAS MOVED THROUGH
MOREHEAD CITY AND JACKSONVILLE...AND WILL BE IN SURF CITY WITHIN
THE NEXT HOUR. THIS FRONT SHOULD CONTINUE MOVING SOUTH
TONIGHT...MOVING ACROSS CAPE FEAR BETWEEN MIDNIGHT AND 2
AM...MYRTLE BEACH BETWEEN 1-3 AM...AND THROUGH GEORGETOWN AN HOUR
OR TWO BEFORE DAYBREAK SATURDAY. SOUTHWEST WINDS WILL TURN
WESTERLY AHEAD OF THE FRONT LATER THIS EVENING...THEN WILL
ABRUPTLY SHIFT TO THE NORTH BEHIND THE FRONT. WITH QUICKLY FALLING
TEMPERATURES BEHIND THE FRONT WINDS WILL BECOME GUSTY WITH GUSTS
OVER 20 KNOTS POSSIBLE FOR A FEW HOURS. ANY LIGHT RAIN ASSOCIATED
WITH THE FRONT SHOULD REMAIN MAINLY NORTH OF CAPE FEAR...BUT THE
LATEST MODEL PROJECTIONS ARE THAT VERY LITTLE RAIN WILL FALL EVEN
HERE.
SEAS RANGE FROM 2.5 TO 4 FT AT THE BUOYS THIS EVENING...AND THE
SPECTRAL WAVE PLOT FROM FRYING PAN SHOALS SHOWS THE WAVES ARE ALMOST
EXCLUSIVELY AN 11-14 SECOND SOUTHEAST SWELL. VERY LITTLE WIND CHOP
EXISTS ACROSS THE WATERS CURRENTLY...BUT THIS SHOULD CHANGE LATE
TONIGHT BEHIND THE FRONT WITH THE INCREASING COLD NORTHERLY WINDS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...A MODEST NORTHERLY SURGE WILL BE UNDERWAY
AT THE START OF THE PERIOD. INITIAL SURGE WILL WANE SAT AFTERNOON
WITH ANOTHER SURGE EXPECTED SAT NIGHT AND THEN AGAIN DURING SUN. N
WINDS WILL VEER TO NE SUN NIGHT AS WINDS DIMINISH. WINDS WILL
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. SEAS
SHOULD PEAK IN 3 TO 5 FT RANGE ACROSS THE WATERS OFF OF CAPE FEAR
DURING SAT AND 3 TO 4 FT ACROSS THE OUTER FRINGES OF THE SOUTHERN
WATERS. SIX FT SEAS ARE POSSIBLE AROUND FRYING PAN SHOALS BUOY ON
SAT. SUBSEQUENT SURGES ARE NOT EXPECTED TO PRODUCE WAVE HEIGHTS
ECLIPSING THESE VALUES.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 230 PM FRIDAY...LIGHT WINDS WILL GREET MARINERS MONDAY AS
HIGH PRESSURE RESIDES OVERHEAD. A SOUTHERLY FLOW WILL DEVELOP
LATER MONDAY AND PREVAIL TUESDAY AS THE HIGH MOVES OFFSHORE. WINDS
WILL TURN MORE TO THE SOUTHWEST WEDNESDAY AS LOW PRESSURE MOVES
THROUGH THE OHIO VALLEY. THIS STRONGEST WINDS WILL PREVAIL
WEDNESDAY AS WELL WITH 20-25 KNOTS. WAVEWATCH SEAS LOOK REASONABLE
WITH 2-4 FEET EARLY INCREASING TO 4-6 FEET WEDNESDAY. FINALLY
THERE IS THE POSSIBILITY FOR SEA FOG TUESDAY BEFORE WINDS TURN
MORE SOUTHWEST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
AVIATION...JDW/REK
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
326 AM CST SAT DEC 17 2011
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
SHORTWAVE AND ISENTROPIC LIFT GENERATING A BAND OF LIGHT SNOW THAT
WILL MOVE ACROSS MUCH OF THE FORECAST AREA. HIGHEST AMOUNTS WILL
BE ACROSS THE SOUTHWEST HALF WITH LIGHTER AMOUNTS TOWARD FOND DU
LAC AND SHEBOYGAN. LATEST NAM AND HRRR HAVE A GOOD HANDLE ON IT
AND EXPECT A BAND OF 1 TO 2 INCHES OVER THE SOUTHWEST HALF OF THE
FORECAST AREA. A FEW 3 INCH TOTALS ARE POSSIBLE MAINLY WEST AND
SOUTHWEST OF MADISON.
SNOW WILL PULL OUT OF THE EAST IN THE MORNING. ANOTHER SHORTWAVE
WILL DROP ACROSS MAINLY NORTHERN WISCONSIN DURING THE AFTERNOON
AND EARLY EVENING...MAYBE BRINGING SOME LIGHT SNOW TOWARD FOND DU
LAC AND SHEBOYGAN. OVERALL SETUP NOT AS GOOD AS FIRST WAVE THOUGH
WITH BEST LIFT TO THE NORTH.
ANOTHER WEAKER SHORTWAVE AND MID LEVEL WARM ADVECTION LATE TONIGHT
IN A FAST NORTHWEST FLOW. HOWEVER MAINLY MID LEVEL CLOUDS WITH
THIS FEATURE AND NO PRECIPITATION EXPECTED.
.SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE
MEDIUM.
WARM AIR ADVECTION CONTINUES ACROSS THE AREA ON SUNDAY. PUSH OF
DRIER AIR INTO THE AREA WILL GRADUALLY PUSH OUT CLOUDS AS THE DAY
GOES ON. A MILD DAY IS EXPECTED...WITH LOWER TO MID 40S FOR HIGHS.
SOUTHWEST WINDS CONTINUE TO HOLD THE MILD AIRMASS ACROSS THE AREA
SUNDAY NIGHT...AS A COLD FRONT MOVES SOUTHEAST INTO THE AREA. NAM
INDICATING SOME POTENTIAL FOR LOW STRATUS DEVELOPMENT DURING THIS
TIME...WITH THE GFS SOMEWHAT LESS AGGRESSIVE WITH THE LOW LEVEL
SATURATION. WILL TREND TOWARDS MOSTLY CLOUDY SKIES LATE SUNDAY
NIGHT. NAM INDICATING LIGHT QPF WITH THE FRONT...WITH THE
GFS/ECMWF DRY. NAM FORECAST SOUNDINGS NOT IMPRESSIVE WITH MOISTURE
PROFILE ABOVE INVERSION...SO LEFT THIS PERIOD DRY.
COLD FRONT SLIDES SOUTHEAST ACROSS THE AREA DURING THE MORNING ON
MONDAY...THEN SOUTHEAST IN THE AFTERNOON. NAM/GFS FORECAST
SOUNDINGS STILL NOT SHOWING MUCH WITH MOISTURE ABOVE INVERSION IN
THE MORNING...WITH A DRYING TREND WITH COLD AIR ADVECTION IN THE
AFTERNOON. KEPT SLIGHT CHANCES FOR LIGHT RAIN AND LIGHT SNOW IN
THE FAR SOUTHEAST COUNTIES MONDAY...CLOSEST TO THE FRONT. HIGHS
WILL BE MILD UNTIL FRONTAL PASSAGE...WITH A FALL DURING THE
AFTERNOON.
HIGH PRESSURE MOVING INTO THE REGION MONDAY NIGHT WILL BRING A
REINFORCING SHOT OF DRY AIR ACROSS THE AREA. STRONG VORTICITY
MAXIMUM SHIFTING SOUTHEAST THROUGH THE AREA MAY BE ENOUGH FOR
LIGHT SNOW. CONTINUED TO KEEP LOW END POPS MONDAY NIGHT IN THE FAR
SOUTHEAST COUNTIES. LOW TEMPERATURES SHOULD BE MORE SEASONABLE
WITH THE COLDER AIR MOVING INTO THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE LOW TO
MEDIUM.
GFS/ECMWF IN SOMEWHAT BETTER AGREEMENT WITH SYSTEM FOR
TUESDAY...THEN CONTINUE TO DIFFER TUESDAY NIGHT AND WEDNESDAY.
THEY BOTH ARE KEEPING THE SURFACE LOW WELL SOUTH OF THE AREA. THEY
TAKE IT EAST NORTHEAST FROM THE SOUTHERN PLAINS TO THE MIDDLE
MISSISSIPPI RIVER VALLEY TUESDAY ON THE GFS...THEN INTO
OHIO/EASTERN PENNSYLVANIA TUESDAY NIGHT. THE STRONG UPPER LOW
LINGERS TO THE NORTHWEST OF THE SURFACE LOW...TAKING A SIMILAR
EAST NORTHEAST PATH.
THE ECMWF CONTINUES TO BE SLOWER WITH THIS SYSTEM...AND DOES NOT
HAVE THE SURFACE LOW IN THE MIDDLE MISSISSIPPI RIVER VALLEY UNTIL
LATE TUESDAY NIGHT/EARLY WEDNESDAY. IT THEN MOVES THE LOW EAST
NORTHEAST FROM THERE WEDNESDAY INTO WEDNESDAY NIGHT. ITS
PRECIPITATION SHIELD MISSES SOUTHERN WISCONSIN. HAVE SEEN SYSTEMS
LIKE THESE TREND SOUTHWARD...ONLY TO TREND BACK NORTH AND BRING
THE AREA PRECIPITATION. FOR NOW...WILL MAINTAIN SMALL CHANCES FOR
PRECIPITATION ACROSS THE SOUTHEAST COUNTIES.
MODELS SHOW HIGH PRESSURE PASSING SOUTH OF THE AREA WEDNESDAY.
THIS SHOULD BRING QUIET WEATHER...WITH MILD TEMPERATURES.
MODELS THEN BRING A COLD FRONT THROUGH THE AREA THURSDAY...WITH NO
QPF ASSOCIATED WITH IT. MORE DIFFERENCES THEN OCCUR BETWEEN THESE
MODELS INTO FRIDAY. THE GFS BRINGS AN AMPLIFIED SHORTWAVE TROUGH
SOUTHEAST THROUGH THE REGION THURSDAY NIGHT AND FRIDAY...WITH THE
ECMWF CLIPPING THIS AREA FRIDAY. QPF IS LIGHT WITH THE GFS...EVEN
WITH THE STRONG SHORTWAVE TROUGH. FOR NOW...WILL LEAN TOWARD
CONSENSUS POPS AND TEMPERATURES THIS FAR OUT IN THE FORECAST.
&&
.AVIATION/12Z TAFS/...
MAINLY MVFR CIGS AND IFR VSBY EARLY THIS MORNING OVER MUCH OF THE
FORECAST AREA EXCEPT NORTHEAST TOWARD SHEBOYGAN.
ANOTHER ROUND OF LIGHT SNOW MAY SLIDE THROUGH THE NORTHEAST THIRD
OF THE FORECAST AREA LATE THIS AFTERNOON AND INTO THE
EVENING...BUT BEST MOISTURE AND LIFT EXPECTED TO PASS BY TO THE
NORTH AND NORTHEAST.
MAINLY MID LEVEL VFR CLOUDS TONIGHT.
&&
.MARINE...
SOUTH WINDS WILL INCREASE ON SUNDAY AHEAD OF LOW PRESSURE MOVING
NORTH OF LAKE SUPERIOR...WITH WINDS AND WAVES LIKELY REACHING
SMALL CRAFT CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
303 AM CST SAT DEC 17 2011
.SYNOPSIS...A RELATIVELY QUIET PERIOD FOR MID-DECEMBER WITH
TEMPERATURES ABV SEASONAL NORMALS.
CLASSIC SPLIT FLOW REGIME WL CONT ACRS NOAM THROUGH THE PERIOD AND
BEYOND. THE FCST AREA WL BE UNDER THE INFLUENCE OF THE NRN STREAM
THROUGH AT LEAST THE MIDDLE OF NEXT WK. THE PATTERN COMBINED WITH
LACK OF SIG SNOW COVER ACRS THE RGN SUPPORTS ABV NORMAL TEMPS. NRN
STREAM SYSTEMS WL BRING SOME LGT PCPN AT TIMES...BUT AMNTS WL END
UP BLO NORMAL.
&&
.SHORT TERM...TDA/TNGT/SUN. WV PASSING S OF THE AREA WL BRUSH THE
FAR S WITH SOME S-/S-- EARLY TDA. ALSO NEED TO KEEP AN EYE ON THE
LAKE-EFFECT POTENTIAL AS HRRR WAS DEVELOPING CYCLONIC CIRCULATION
OVER CENTRAL LAKE MICHIGAN...AND SFC OBS SEEM TO BE BEARING THAT
OUT.
BETTER CHC OF PCPN WL COME TO THE NE 1/2 OF THE FCST AREA THIS
AFTN AS THE NEXT NRN STREAM SHRTWV PUSHES INTO THE RGN. THE
COMBINATION OF QG FORCING WITH THE MID-LVL SHRTWV...ISENT LIFT...
AND DIV IN LFQ OF UPR JET SUPPORTED KEEPING LIKELY POPS OVER THE
NE. CONT TO HAVE POPS TAPER BACK TO CHC TO THE SW...WHICH WL ONLY
BE BRUSHED BY THE BETTER FORCING. EXPECT A FAIRLY FAST MOVG BAND
OF SN TO PUSH ACRS DURING THE AFTN. WL STICK WITH MENTION OF UP TO
AN INCH OVER THE NE.
SUBSIDENCE BEHIND THE WV AND DEEP WLY FLOW SHOULD HELP STRIP OUT
LOW AND MIDDLE CLDS TNGT. COULD BE SOME HIGH CLDS WORKING BACK IN
LATE. SOME SFC PRESSURE GRADIENT REMAINS...BUT PROBABLY NOT ENOUGH
TO RELY ON TO KEEP TEMPS UP. TENDED DOWN WITH TEMPS OVER THE NRN
PART OF THE AREA.
WARMER AIR WL BEGIN FLOWING BACK INTO THE AREA SUN. BUT THE BULK
OF THE WARMING WL BE ALOFT. STAYED RATHER CONSERVATIVE WITH MAX
TEMP FCST AS IT WL TAKE A WHILE FOR WARMER AIR TO WORK IN AT THE
SFC. ALSO STAYED RATHER MODEST WITH WINDS AS STRONGEST FLOW WL BE
ABV THE SFC AND POTENTIAL FOR MIXING WL BE VERY LTD.
.LONG TERM...SUNDAY NGT THRU NXT FRI. LITTLE CHG IN THE OVERALL
SYNOPTIC PATN ACROSS THE CONUS DURING THE EXTENDED PERIOD WITH
SPLIT FLOW PERSISTING UNTIL FURTHER NOTICE. EARLY WEEK SYSTEM NOW
DOES APR TO STAY TO OUR SOUTH...THUS NO SNOW WITH THIS FEATURE.
MAIN FCST FOCUS TO BE ON TEMPS INITIALLY AND THEN WL HAVE TO WATCH
LATE NXT WEEK FOR THE NXT SNOW CHC.
MDLS CONT TO SHOW A CDFNT RACING THRU ALL BUT SE WI SUNDAY NGT...
BRINGING SOME CLOUDS AND A WIND SHIFT BUT NO PCPN AS TIME SECTIONS/
FCST SNDNGS SHOW LITTLE MSTR IN THE MID-LVLS OF THE ATM. SINCE
BETTER FORCING REMAINS WELL TO OUR NORTH IN THE VCNTY OF THE
PRIMARY SHRTWV AND MSTR TO BE LIMITED...HAVE GONE WITH A DRY FROPA.
WINDS WL REMAIN RATHER MODEST THRU MOST OF THE NGT WHICH WOULD
HELP PREVENT TEMPS FROM FALLING MUCH. IN FACT...MIN TEMPS ARE
EXPECTED TO BE NEAR NORMAL MAX TEMPS FOR THIS TIME OF YEAR (LWR 20S
NORTH TO UPR 20S E-CNTRL).
WINDS TO VEER MORE NW BY MON MORNING WITH MODEST LEVELS OF CAA
TAKING OVER WI THRU THE DAY. 8H TEMPS OVER LK SUPERIOR DROP TO
AROUND -10C WHICH WOULD RAISE DELTA-T VALUES INTO THE MID TEENS
AND LEAD TO THE POSSIBILITY OF LK EFFECT SNOW SHWRS PRIMARILY
ACROSS VILAS CNTY. THESE SNOW SHWRS HOWEVER DO NOT LOOK SIGNIFICANT
AS HI PRES ALREADY BUILDING INTO THE WRN GREAT LKS AND ADVECTING
DRY AIR INTO THE RGN. HAVE ONLY KEPT A TOKEN POP FOR VILAS CNTY
WITH ONLY A COUPLE TENTHS OF AN INCH EXPECTED. THE REST OF THE FCST
AREA SHOULD SEE A MIX OF SUN AND CLOUDS WITH MAX TEMPS RANGING FROM
AROUND 30 NORTH TO THE MID 30S E-CNTRL WI.
THIS HI PRES TO THEN SPRAWL ACROSS THE GREAT LKS MON NGT WITH SKIES
BECMG MOSTLY CLEAR AND WINDS BECMG LGT/VRBL. THIS SHOULD ALLOW
TEMPS TO CRASH AND WL NEED TO CHOP A GOOD 3 TO 5 DEGS FROM THE PREV
FCST. COULD EASILY SEE THE COLD SPOTS OF NRN WI DROP INTO THE
SINGLE DIGITS WHILE ONLY AREAS NEAR LK MI HOLD IN THE 20S. AFTER
DAYS OF MDL INCONSISTENCY WITH THE HANDLING OF A PSBL NRN/SRN
STREAM PHASING/STORM TRACK ISSUES ON TUE...THE MEDIUM RANGE MDLS
HAVE COME INTO AGREEMENT THAT ANY PHASING WOULD NOT OCCUR UNTIL
FARTHER TO OUR EAST. THIS TRANSLATES TO THE SRN STREAM UPR LOW
STAYING FAR ENUF SOUTH SUCH THAT ANY ACCUMULATING SNOW WOULD ONLY
REACH FAR SRN WI AT BEST. STILL EXPECT TO SEE SOME CLOUDS TO
INCREASE OVER THE SE HALF OF THE FCST AREA ON TUE...BUT NON POPS
WL BE NEEDED.
WHILE THE SRN STREAM SYSTEM CONTS TO LIFT NE INTO THE OHIO RIVER
VALLEY TUE NGT...THE TRAILING NRN STREAM SHRTWV TROF MOVES THRU
THE WRN GREAT LKS AND SENDS A CDFNT THRU WI. ONCE AGAIN...BETTER
FORCING GOES EITHER NORTH OR SOUTH OF WI...THUS A CONTINUATION OF
A DRY FCST. A WEAK SFC RDG IS THEN FCST TO MOVE ACROSS MAINLY THE
SRN SECTIONS OF THE GREAT LKS LATER TUE NGT INTO WED. UNDER MOSTLY
CLEAR TO PARTLY CLDY SKIES...LOOK FOR TEMPS TO REMAIN WELL ABV
NORMAL.
FCST BECOME MORE MUDDLED FOR THE LATTER PART OF THE WORK WEEK AS
THE NXT SIGNIFICANT NRN STREAM SHRTWV ENERGY DROPS SE INTO THE
GREAT BASIN. ISSUES AMONG THE MDLS CENTER ON WHETHER THIS ENERGY
WL CLOSE OFF TO ANOTHER CLOSED UPR LOW OR PROGRESS EAST WITH TIME
AND INCREASE SNOW CHCS ACROSS WI. A PROGRESSIVE SOLN WOULD BRING A
LGT SNOW POTENTIAL TO NE WI BY THU NGT INTO FRI...BUT WITH ALL THE
UNCERTAINTY INVOLVED AT THIS TIME...HAVE GONE WITH THE MDL
CONSENSUS SOLN OF ONLY SLGT CHC POPS FOR NOW.
&&
.AVIATION...FOR 12Z TAF ISSUANCE. MVFR CIGS HAVE WORKED INTO GRB
OFF THE BAY. THAT WL PERSIST AS FLOW STAYS NE FOR A TIME...BUT LOW
CLDS SHOULD MOVE BACK OUT LATER. THEN EXPECT A BAND OF IFR
CONDITIONS...PRIMARILY DUE TO VSBYS...TO SWEEP ACRS THE NE 1/2 OF
THE FCST AREA THIS AFTN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SKOWRONSKI/KALLAS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
530 AM CST SAT DEC 17 2011
.AVIATION... /ISSUED 309 AM CST SAT DEC 17 2011/
LINGERING SNOW NORTH AND EAST OF DUBUQUE /KDBQ/ WILL MOVE OUT OF
THE LOCAL AREA BY MID MORNING. OTHERWISE...A WEAK SURFACE LOW
PRESSURE WAVE WILL TRACK ACROSS THE DUBUQUE TRI- STATE REGION...
RESULTING IN VARYING BUT GENERALLY LIGHT SURFACE WINDS. A LARGE
AREA OF MVFR STRATUS CLOUDS WILL ALSO MOVE EAST ACROSS THE AREA
WITH THIS SYSTEM. LOCAL TAF SITES WILL SEE CLEARING OF THIS DECK
BETWEEN 17 AND 21Z TODAY. ..DMD..
&&
.PREV DISCUSSION... /ISSUED 309 AM CST SAT DEC 17 2011/
SYNOPSIS...
ALOFT...THE LONG WAVE PATTERN IS MARKED BY SPLIT FLOW...WITH A
CUT-OFF LOW OVER LOS ANGELES WHILE THE MIDWEST AND NORTHEAST U.S.
ARE UNDER THE INFLUENCE OF THE ACTIVE NORTHERN STREAM. CLIPPER
CURRENTLY CROSSING THE UPPER MIDWEST HAS WRUNG OUT 1 TO 3 INCHES OF
SNOW FOR NORTHERN SECTIONS OF THE FORECAST AREA. SURFACE LOW OVER
IOWA NEAR FORT DODGE /KFOD/ THIS MORNING WITH THE STRONGEST PRESSURE
FALLS SPANNING EASTERN IOWA. ..DMD..
SHORT TERM...TODAY AND TONIGHT...
MAIN FOCUS THIS MORNING IS WALKING OUT THE SNOWFALL...THEN CLOUDS
FOR THE REMAINDER OF TODAY. RUC FORECASTS SHOW LOW LEVEL
FRONTOGENETIC FORCING ASSOCIATED WITH THE CLIPPER TRACKING RAPIDLY
NORTHEAST ACROSS SOUTHERN WISCONSIN BY 11Z AND RADAR AND SATELLITE
TRENDS SHOW A FAIRLY SHARP BACK EDGE TO THE ACCUMULATING SNOW. THUS
WILL END SNOW ACROSS CWFA BY 12Z. AS FOR THE STRATUS...RUC 800MB RH
FIELD HAS A DECENT HANDLE ON THE CURRENT PROGRESS OF THE CLEARING
LINE AND WILL USE FOR NOWCASTING THE BACK EDGE. THIS TIMING WOULD
SUGGEST CLEARING REACHING THE MISSISSIPPI RIVER BY ABOUT 15Z. ..DMD..
LONG TERM...SUNDAY THROUGH FRIDAY...
A SPLIT FLOW PATTERN WILL REMAIN OVER THE U.S. FOR THE UPCOMING
WEEK. EASTERN PACIFIC S/W ENERGY WILL CONTINUE TO BE SHUNTED NORTH
INTO BRITISH COLUMBIA OR THE PAC NW BY A STUBBORN EASTERN PACIFIC
RIDGE. SOME OF THIS ENERGY GETS PICKED UP IN THE SOUTHERN STREAM FLOW
EAST OF THE RIDGE AXIS...HELPING TO MAINTAIN SOME MID LEVEL
TROFFING OVER THE WESTERN U.S.
THE MAIN CONCERNS FOR THIS PERIOD CONTINUE TO BE IN THE EARLY PART
OF THE WEEK WITH THE SOUTHWESTERN U.S. CUTOFF LOW EJECTING INTO
THE MID MISSISSIPPI VALLEY BY TUESDAY/TUESDAY NIGHT. THE LONG
RANGE MODELS WERE IN REASONABLY GOOD AGREEMENT WITH THIS SYSTEM
WHICH IMPROVES CONFIDENCE THAT THE BULK OF THE PRECIPITATION WILL
STAY TO OUR SOUTH. HOWEVER...A NORTHERN STREAM S/W THAT WILL
INFLUENCE THE TRACK OF THE CUTOFF LOW IS STILL OVER THE PACIFIC
AND IS NOT YET BEING SAMPLED BY THE UPPER AIR NETWORK. THIS COULD
LEAD TO MORE MODEL VARIATIONS WITH THIS SYSTEM ON TODAY/S MODEL
RUNS. ONCE THE S/W REACHES THE WESTERN CONUS THIS EVENING THE
MODELS WILL HAVE MORE DATA TO WORK WITH.
FOR SUNDAY AND SUNDAY NIGHT MILD WEATHER WILL BE OVER THE AREA
WITH SOUTHWESTERLY FLOW IN PLACE AHEAD OF A NORTHERN PLAINS COLD FRONT.
THE NAM/GFS SHOW A LOW LEVEL THERMAL RIDGE OVER THE AREA SUNDAY
AFTERNOON. WITH DRY AIR OVER THE AREA WE SHOULD HAVE MOSTLY SUNNY
SKIES WHICH ALLOW DEEP ENOUGH MIXING TO TAP SOME OF THE WARMER
AIR. THE TEMPERATURE FORECAST FOR SUNDAY AND SUNDAY NIGHT WERE
SKEWED TOWARD THE WARM MET MOS GUIDANCE WHICH SUGGEST MAXT TEMPS
IN THE LOW 50S OVER THE SOUTHWEST AND LOW TO MID 40S NORTHEAST.
INCREASING LOW LEVEL MOISTURE/CLOUDS SUNDAY NIGHT WILL KEEP
TEMPERATURE SOUTH IN THE UPPER 40S. IN THE NORTHWEST THE COLD
FRONT SHOULD BE MOVING IN AFTER MIDNIGHT...DROPPING TEMPERATURES IN
THE MID/UPPER 20S BY MONDAY MORNING.
FOR MONDAY THROUGH TUESDAY NIGHT THE 00Z RUNS ARE IN REASONABLE
AGREEMENT BRINGING THE UPPER LOW OUT ON A MORE SOUTHERLY COURSE.
AS A RESULT HAVE STARTED TO TREND PRECIPITATION CHANCES DOWN ACROSS
THE NORTH AND KEPT POPS IN THE SOUTHERN FOURTH OF THE AREA
LIMITED TO CHANCE CATEGORY. THE EXCEPTION TO THIS WILL BE SOME
LIKELY POPS SOUTH TUESDAY WHEN THE UPPER LOW MOVES INTO MO
SPREADING STRONGLY DIFFLUENT MID LEVEL FLOW SPREADS NORTHEAST
INTO SOUTHERN IA AND CENTRAL IL. THERMAL PROFILES SUGGEST ANY
PRECIPITATION MONDAY WILL BE RAIN. AS THE COLD AIR PUSHES SOUTH
AND DEEPENS MONDAY NIGHT AND TUESDAY THE RAIN SHOULD CHANGE TO
SNOW. WITH MODELS SHOWING THE INITIALLY SHALLOW COLD AIR
UNDERCUTTING WARMER 850MB TEMPS THERE COULD BE SOME SORT OF A MIX
MONDAY AFTERNOON/EVENING ALONG THE NORTHERN EDGE OF THE
PRECIPITATION SHIELD WHICH COULD INCLUDE SLEET AND POSSIBLY SOME
FREEZING RAIN. BY LATE MONDAY NIGHT AND TUESDAY TEMPERATURES
SHOULD BE COLD ENOUGH FOR MAINLY SNOW. THE SYSTEM WILL BE MOVING
EAST OF THE AREA BY LATE TUESDAY NIGHT. BY THIS TIME THERE IS
POTENTIAL FOR SOME MINOR SNOW ACCUMULATIONS ESPECIALLY SOUTH OF
HIGHWAY 34 BETWEEN OTTUMWA AND MACOMB.
FOR THE REST OF THE WEEK HAVE GONE WITH A MAINLY DRY FORECAST
EXPECTING NEAR NORMAL TEMPERATURES. MODELS SHOW THE WESTERN U.S.
TROF REDEVELOPING WITH A S/W EJECTING OUT OF THE TROF BY LATE
WEEK. THE GFS/ECMWF SHOW THE S/W DIGGING WELL INTO MEXICO THEN
EJECTING ON A TRACK THAT WOULD TAKE IT SOUTH OF THE AREA. THE GEM
IS LESS AMPLIFIED AND MOVES THE SYSTEM THROUGH THE MID MISSISSIPPI
VALLEY BY LATE WEEK SUPPORTING SOME PRECIPITATION OVER THE AREA. THE
ONLY POPS THEN WILL BE SOME SLIGHT CHANCE POPS FROM THURSDAY NIGHT
THROUGH FRIDAY TO COVER THE THREAT OF SNOW WITH THE EJECTING WAVE.
.DLF..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
630 AM EST SAT DEC 17 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW RIDGING INTO
WRN CANADA. DOWNSTREAM...A TROF EXTENDS S INTO THE ERN CONUS FROM A
POLAR VORTEX CENTERED JUST N OF HUDSON BAY. IN THE NW FLOW DIRECTED
INTO THE GREAT LAKES...A VIGOROUS LOOKING SHORTWAVE IS DIVING SE
THRU SRN MANITOBA. CANADIAN RADARS SHOW A SMALL AREA OF -SN
DEVELOPING SE TOWARD NRN MN IN ASSOCIATION WITH THE WAVE. CLOSER TO
HOME...DESPITE 850MB TEMPS AROUND -15C OVER LAKE SUPERIOR...LES TO
THE E OF KMQT HAS DIMINISHED TO JUST SOME FLURRIES. OVER THE W...
THERE`S VERY LITTLE OR NO CLOUDS OFF THE LAKE...SURPRISING GIVEN THE
OVERWATER INSTABILITY. PERIOD OF MOSTLY CLEAR SKIES HAS ALLOWED
TEMPS TO FALL TO NEAR OR JUST BLO 0F AT MANY LOCATIONS OVER WRN
UPPER MI...INCLUDING THE KEWEENAW.
&&
.DISCUSSION...
WEATHER THRU THIS FCST PERIOD WILL BE DOMINATED BY A MEAN RIDGE OF
VARYING AMPLITUDE EXTENDING INTO WRN CANADA AND A DOWNSTREAM POLAR
VORTEX IN THE VCNTY OF NRN HUDSON BAY/BAFFIN ISLAND. IN GENERAL...
BLO NORMAL HEIGHTS WILL EXIST ACROSS NRN CANADA. END RESULT WILL BE
A SERIES OF MOISTURE STARVED NRN STREAM SHORTWAVES PRODUCING LITTLE
PCPN OUTSIDE OF AREAS THAT MIGHT SEE SOME LIGHT LAKE EFFECT/LAKE
ENHANCED SNOW WITH EACH PASSING WAVE. FLOW ALSO LOOKS TO REMAIN
SPLIT WITH SRN STREAM WAVES AND ASSOCIATED PCPN PASSING S OF UPPER
MI. OVERALL...IT WILL NOT BE VERY WINTRY ACROSS THE UPPER LAKES
HEADING TOWARD LATE DEC AS NORTHERLY POSITION OF POLAR VORTEX AND
BLO NORMAL HEIGHTS ACROSS NRN CANADA HOLD ARCTIC AIR N OF THE AREA.
ONLY BRIEF INTRUSIONS OF COLDER AIR WILL OCCUR OVER THE NEXT 7
DAYS...AND TEMPS OVERALL WILL END UP ABOVE NORMAL. LATEST CPC
8-14DAY OUTLOOK CARRIES ENHANCED ODDS OF ABOVE NORMAL TEMPS OVER
UPPER MI THRU THE END OF DEC.
FOR TODAY...VIGOROUS SHORTWAVE WILL DROP THRU THE UPPER GREAT
LAKES...BUT IT WILL BE WEAKENING AS IT DOES SO. THIS IS VERY EVIDENT
IN DEEP LAYER QVECTORS WHICH SUGGEST HEALTHY DYNAMICS NW OF THE AREA
EARLY THIS MORNING RAPIDLY WEAKENING AS SHORTWAVE MOVES ACROSS THE
UPPER LAKES DURING THE DAY. ALTHOUGH FORCING WILL BE WEAKENING...
STEEP MIDLEVEL LAPSE RATES UPWARDS OF 7.5C/KM MAY HELP TO MAINTAIN
SOME AREAS OF -SN SPREADING INTO THE AREA. ANY SYNOPTIC SNOW
ACCUMULATION WILL BE UNDER AN INCH. 850MB TEMPS AROUND -10C SHOULD
SUPPORT SOME LAKE ENHANCEMENT OVER WRN LAKE SUPERIOR INTO WRN UPPER
MI AS WINDS SHIFT FROM SW TO NW. SHOULDN`T BE A BIG DEAL GIVEN SHORT
WINDOW OF ENHANCEMENT (PROBABLY NOTHING MORE THAN AN INCH OR TWO OF
ACCUMULATION OVER THE NW THIS AFTN INTO EARLY EVENING). BRIEF
ENHANCEMENT WILL SHIFT TO AREAS E OF KMQT THIS EVENING AS WINDS
SHIFT NW (LIMITED ACCUMULATION THERE AS WELL). THERE IS ALSO THE
POTENTIAL FOR SOME LAKE ENHANCEMENT OFF NRN LAKE MICHIGAN INTO THE
FAR ERN FCST AREA THIS AFTN/EARLY EVENING IN THE SW FLOW AHEAD OF
THE SHORTWAVE. SOME GUIDANCE SUGGESTS WINDS WILL BACK ENOUGH FOR
LAKE ENHANCEMENT TO CLIP SCHOOLCRAFT/LUCE COUNTIES. UTILIZED HIGHER
POPS IN THAT AREA...BUT KEPT ACCUMULATIONS ONLY AROUND 1 INCH GIVEN
UNCERTAINTY IN HOW MUCH LOW-LEVEL WINDS WILL BACK.
A LITTLE LIGHT -SN MAY LINGER THIS EVENING OVER THE E IN ASSOCIATION
WITH DEPARTING SHORTWAVE. OTHERWISE...IF THERE IS ANY SCT LIGHT NW
FLOW LES (850MB TEMPS AROUND -12C) BEHIND SYSTEM...IT WILL RAPIDLY
END TONIGHT FROM W TO E UNDER SUBSTANTIAL HEIGHT RISES (500MB
HEIGHTS RISE MORE THAN 120M). ALSO...AIR MASS QUICKLY DRIES...
INVERSION CRASHES TO 3KFT...WINDS BACK AND WAA GETS UNDERWAY.
ON SUN...NEXT SHORTWAVE WILL BE DROPPING SE TOWARD NRN ONTARIO. ALL
GUIDANCE SHOW ASSOCIATED SFC LOW PASSING WELL N OF HERE ACROSS NRN
ONTARIO SUN NIGHT. AHEAD OF WAVE...IMPRESSIVE WAA WILL SEND 850MB
TEMPS ABOVE 0C ACROSS THE FCST AREA SUN. GFS IS MOST AGGRESSIVE WITH
THE WARMING AS IT HAS 850MB TEMPS RANGING FROM 2C E TO 7C W BY SUN
EVENING. ISENTROPIC ASCENT IS STRONG SUN WITH 40KT WINDS ORIENTED
PERPENDICULAR TO TIGHTLY SPACED ISOBARS PER 290K SFC. HOWEVER...
WITH DRY AIR HOLDING AT THE LOW-LEVELS PER FCST SOUNDINGS...PCPN
DEVELOPING ALOFT WILL PROBABLY NOT REACH THE SFC. FOR NOW...WILL
CONTINUE TO CARRY A DRY FCST SUN/SUN NIGHT WITH ANY PCPN PASSING N
OF UPPER MI. IF ANYTHING...WILL NEED TO WATCH FOR SOME LIGHT PCPN
CLIPPING THE KEWEENAW AND THE NE FCST AREA. SHALLOW MOISTURE
DROPPING INTO THE AREA BEHIND COLD FRONT ALONG WITH 850MB TEMPS
FALLING PERHAPS TO AROUND -12C MAY SUPPORT SOME LIGHT LES/FLURRIES
OFF LAKE SUPERIOR LATE SUN NIGHT INTO MON EVENING.
AS PREVIOUSLY MENTIONED...PATTERN NEXT WEEK WILL FEATURE LIMITED
PCPN CHANCES WITH TEMPS AVERAGING ABOVE NORMAL. AT THIS TIME...IT
APPEARS SHORTWAVES WILL PASS ACROSS THE AREA AT SOME POINT LATER
TUE/EARLY WED AND THEN THU. OF THE 2 SHORTWAVES...THE SECOND SHOULD
PROVIDE A BETTER CHC OF PCPN.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A DISTURBANCE DROPPING SE OUT OF CANADA TODAY WILL LEAD TO LOWERING
CIGS LATE THIS MORNING AND -SHSN THIS AFTN. EXPECT FUEL ALTERNATE
CIGS FOR MUCH OF THE LATE MORNING INTO THE EVENING WITH THE PASSAGE
OF THE DISTURBANCE AND ASSOCIATED -SHSN. HAD HIGHEST CONF OF IFR
VSBYS AT KCMX...BUT WOULDN/T BE SURPRISED TO SEE A SHORT PERIOD OF
IFR VSBYS AT KIWD/KSAW. OTHER THAN SOME LINGERING LK ENHANCED CLOUDS
AT KCMX...EXPECT A TRANSITION TO VFR COND DURING THE EVENING.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH SOUTHERN CANADA WILL
PUSH SEVERAL SFC TROUGHS ACROSS LAKE SUPERIOR THROUGH THE FORECAST
PERIOD. FIRST TROUGH APPROACHES TODAY...WHICH WILL INCREASE WINDS TO
30KTS OUT OF THE SW TODAY...ALTHOUGH THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS OVER THE WRN LK. WINDS WILL DIMINISH OVERNIGHT
BEFORE INCREASING AGAIN SUNDAY AFTERNOON AHEAD OF THE NEXT TROUGH.
STRONG INVERSION JUST ABOVE THE SFC WILL LIKELY KEEP SUSTAINED WINDS
IN THE 20-30KT RANGE SUN AFTN AND NIGHT. DEPENDING ON THE STRENGTH
OF THE INVERSION...THERE MAY BE SOME GALE FORCE GUSTS TO 35KTS...DUE
TO WSW WINDS OF 40-50KTS 2-3KFT ABOVE THE LAKE. CONSIDERED ISSUING A
GALE WATCH...BUT WASN/T CONFIDENT ENOUGH ON GALES OCCURRING WITH THE
SW WINDS. THINK THE BEST CHANCE WILL BE AS WINDS TURN TO THE W IN
THE EVENING AND HAVE MENTIONED GALES IN THE TEXT. LIGHTER WINDS ARE
EXPECTED MON AFTN INTO MON NIGHT...BEFORE THE NEXT TROUGH APPROACHES
ON TUESDAY AND PRODUCES GUSTS TO 30KTS. THERE MAY BE A FEW GALE
FORCE GUSTS TO 35KTS OVER CENTRAL LAKE SUPERIOR TUESDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EST SAT DEC 17 2011
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW RIDGING INTO
WRN CANADA. DOWNSTREAM...A TROF EXTENDS S INTO THE ERN CONUS FROM A
POLAR VORTEX CENTERED JUST N OF HUDSON BAY. IN THE NW FLOW DIRECTED
INTO THE GREAT LAKES...A VIGOROUS LOOKING SHORTWAVE IS DIVING SE
THRU SRN MANITOBA. CANADIAN RADARS SHOW A SMALL AREA OF -SN
DEVELOPING SE TOWARD NRN MN IN ASSOCIATION WITH THE WAVE. CLOSER TO
HOME...DESPITE 850MB TEMPS AROUND -15C OVER LAKE SUPERIOR...LES TO
THE E OF KMQT HAS DIMINISHED TO JUST SOME FLURRIES. OVER THE W...
THERE`S VERY LITTLE OR NO CLOUDS OFF THE LAKE...SURPRISING GIVEN THE
OVERWATER INSTABILITY. PERIOD OF MOSTLY CLEAR SKIES HAS ALLOWED
TEMPS TO FALL TO NEAR OR JUST BLO 0F AT MANY LOCATIONS OVER WRN
UPPER MI...INCLUDING THE KEWEENAW.
&&
.DISCUSSION...
WEATHER THRU THIS FCST PERIOD WILL BE DOMINATED BY A MEAN RIDGE OF
VARYING AMPLITUDE EXTENDING INTO WRN CANADA AND A DOWNSTREAM POLAR
VORTEX IN THE VCNTY OF NRN HUDSON BAY/BAFFIN ISLAND. IN GENERAL...
BLO NORMAL HEIGHTS WILL EXIST ACROSS NRN CANADA. END RESULT WILL BE
A SERIES OF MOISTURE STARVED NRN STREAM SHORTWAVES PRODUCING LITTLE
PCPN OUTSIDE OF AREAS THAT MIGHT SEE SOME LIGHT LAKE EFFECT/LAKE
ENHANCED SNOW WITH EACH PASSING WAVE. FLOW ALSO LOOKS TO REMAIN
SPLIT WITH SRN STREAM WAVES AND ASSOCIATED PCPN PASSING S OF UPPER
MI. OVERALL...IT WILL NOT BE VERY WINTRY ACROSS THE UPPER LAKES
HEADING TOWARD LATE DEC AS NORTHERLY POSITION OF POLAR VORTEX AND
BLO NORMAL HEIGHTS ACROSS NRN CANADA HOLD ARCTIC AIR N OF THE AREA.
ONLY BRIEF INTRUSIONS OF COLDER AIR WILL OCCUR OVER THE NEXT 7
DAYS...AND TEMPS OVERALL WILL END UP ABOVE NORMAL. LATEST CPC
8-14DAY OUTLOOK CARRIES ENHANCED ODDS OF ABOVE NORMAL TEMPS OVER
UPPER MI THRU THE END OF DEC.
FOR TODAY...VIGOROUS SHORTWAVE WILL DROP THRU THE UPPER GREAT
LAKES...BUT IT WILL BE WEAKENING AS IT DOES SO. THIS IS VERY EVIDENT
IN DEEP LAYER QVECTORS WHICH SUGGEST HEALTHY DYNAMICS NW OF THE AREA
EARLY THIS MORNING RAPIDLY WEAKENING AS SHORTWAVE MOVES ACROSS THE
UPPER LAKES DURING THE DAY. ALTHOUGH FORCING WILL BE WEAKENING...
STEEP MIDLEVEL LAPSE RATES UPWARDS OF 7.5C/KM MAY HELP TO MAINTAIN
SOME AREAS OF -SN SPREADING INTO THE AREA. ANY SYNOPTIC SNOW
ACCUMULATION WILL BE UNDER AN INCH. 850MB TEMPS AROUND -10C SHOULD
SUPPORT SOME LAKE ENHANCEMENT OVER WRN LAKE SUPERIOR INTO WRN UPPER
MI AS WINDS SHIFT FROM SW TO NW. SHOULDN`T BE A BIG DEAL GIVEN SHORT
WINDOW OF ENHANCEMENT (PROBABLY NOTHING MORE THAN AN INCH OR TWO OF
ACCUMULATION OVER THE NW THIS AFTN INTO EARLY EVENING). BRIEF
ENHANCEMENT WILL SHIFT TO AREAS E OF KMQT THIS EVENING AS WINDS
SHIFT NW (LIMITED ACCUMULATION THERE AS WELL). THERE IS ALSO THE
POTENTIAL FOR SOME LAKE ENHANCEMENT OFF NRN LAKE MICHIGAN INTO THE
FAR ERN FCST AREA THIS AFTN/EARLY EVENING IN THE SW FLOW AHEAD OF
THE SHORTWAVE. SOME GUIDANCE SUGGESTS WINDS WILL BACK ENOUGH FOR
LAKE ENHANCEMENT TO CLIP SCHOOLCRAFT/LUCE COUNTIES. UTILIZED HIGHER
POPS IN THAT AREA...BUT KEPT ACCUMULATIONS ONLY AROUND 1 INCH GIVEN
UNCERTAINTY IN HOW MUCH LOW-LEVEL WINDS WILL BACK.
A LITTLE LIGHT -SN MAY LINGER THIS EVENING OVER THE E IN ASSOCIATION
WITH DEPARTING SHORTWAVE. OTHERWISE...IF THERE IS ANY SCT LIGHT NW
FLOW LES (850MB TEMPS AROUND -12C) BEHIND SYSTEM...IT WILL RAPIDLY
END TONIGHT FROM W TO E UNDER SUBSTANTIAL HEIGHT RISES (500MB
HEIGHTS RISE MORE THAN 120M). ALSO...AIR MASS QUICKLY DRIES...
INVERSION CRASHES TO 3KFT...WINDS BACK AND WAA GETS UNDERWAY.
ON SUN...NEXT SHORTWAVE WILL BE DROPPING SE TOWARD NRN ONTARIO. ALL
GUIDANCE SHOW ASSOCIATED SFC LOW PASSING WELL N OF HERE ACROSS NRN
ONTARIO SUN NIGHT. AHEAD OF WAVE...IMPRESSIVE WAA WILL SEND 850MB
TEMPS ABOVE 0C ACROSS THE FCST AREA SUN. GFS IS MOST AGGRESSIVE WITH
THE WARMING AS IT HAS 850MB TEMPS RANGING FROM 2C E TO 7C W BY SUN
EVENING. ISENTROPIC ASCENT IS STRONG SUN WITH 40KT WINDS ORIENTED
PERPENDICULAR TO TIGHTLY SPACED ISOBARS PER 290K SFC. HOWEVER...
WITH DRY AIR HOLDING AT THE LOW-LEVELS PER FCST SOUNDINGS...PCPN
DEVELOPING ALOFT WILL PROBABLY NOT REACH THE SFC. FOR NOW...WILL
CONTINUE TO CARRY A DRY FCST SUN/SUN NIGHT WITH ANY PCPN PASSING N
OF UPPER MI. IF ANYTHING...WILL NEED TO WATCH FOR SOME LIGHT PCPN
CLIPPING THE KEWEENAW AND THE NE FCST AREA. SHALLOW MOISTURE
DROPPING INTO THE AREA BEHIND COLD FRONT ALONG WITH 850MB TEMPS
FALLING PERHAPS TO AROUND -12C MAY SUPPORT SOME LIGHT LES/FLURRIES
OFF LAKE SUPERIOR LATE SUN NIGHT INTO MON EVENING.
AS PREVIOUSLY MENTIONED...PATTERN NEXT WEEK WILL FEATURE LIMITED
PCPN CHANCES WITH TEMPS AVERAGING ABOVE NORMAL. AT THIS TIME...IT
APPEARS SHORTWAVES WILL PASS ACROSS THE AREA AT SOME POINT LATER
TUE/EARLY WED AND THEN THU. OF THE 2 SHORTWAVES...THE SECOND SHOULD
PROVIDE A BETTER CHC OF PCPN.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
A FEW LEFTOVER LAKE EFFECT CLOUDS INTO KIWD WITH OCNL MVFR CIGS
SHOULD GIVE WAY TO CLEARING AS DRIER AIR AND LOW LEVEL RIDGING MOVES
IN. OTHERWISE...SOME MID CLOUDS WILL BE PUSHING ACROSS THE UPPER
LAKES WITH VFR CONDITIONS AT ALL THE TAF SITES. CEILINGS
WILL BEGIN TO LOWER FROM WEST TO EAST STARTING SAT MORNING AHEAD OF
AN UPPER LEVEL DISTURBANCE...BUT SHOULD NOT FALL INTO MVFR RANGE
UNTIL LATE MORNING OF AFTERNOON. AREAS OF LIGHT SNOW WILL ALSO
DEVELOP BUT VSBY SHOULD ALSO NOT FALL BELOW MVFR.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH SOUTHERN CANADA WILL
PUSH SEVERAL SFC TROUGHS ACROSS LAKE SUPERIOR THROUGH THE FORECAST
PERIOD. FIRST TROUGH APPROACHES TODAY...WHICH WILL INCREASE WINDS TO
30KTS OUT OF THE SW TODAY...ALTHOUGH THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS OVER THE WRN LK. WINDS WILL DIMINISH OVERNIGHT
BEFORE INCREASING AGAIN SUNDAY AFTERNOON AHEAD OF THE NEXT TROUGH.
STRONG INVERSION JUST ABOVE THE SFC WILL LIKELY KEEP SUSTAINED WINDS
IN THE 20-30KT RANGE SUN AFTN AND NIGHT. DEPENDING ON THE STRENGTH
OF THE INVERSION...THERE MAY BE SOME GALE FORCE GUSTS TO 35KTS...DUE
TO WSW WINDS OF 40-50KTS 2-3KFT ABOVE THE LAKE. CONSIDERED ISSUING A
GALE WATCH...BUT WASN/T CONFIDENT ENOUGH ON GALES OCCURRING WITH THE
SW WINDS. THINK THE BEST CHANCE WILL BE AS WINDS TURN TO THE W IN
THE EVENING AND HAVE MENTIONED GALES IN THE TEXT. LIGHTER WINDS ARE
EXPECTED MON AFTN INTO MON NIGHT...BEFORE THE NEXT TROUGH APPROACHES
ON TUESDAY AND PRODUCES GUSTS TO 30KTS. THERE MAY BE A FEW GALE
FORCE GUSTS TO 35KTS OVER CENTRAL LAKE SUPERIOR TUESDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1031 AM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1030 AM...WEAK BACKDOOR-TYPE MESO FRONT EVIDENT OVER
LAKE ONTARIO INTO CNTRL CAYUGA AND SRN ONONDAGA/SRN MADISON...BEHIND
WHICH TD`S DROP OFF RAPIDLY. THIS LOW LVL DRYING IN COMBINATION
WITH DIURNAL EFFECTS WILL CONTINUE TO ERODE THE -SHSN ACTIVITY
CRNTLY OVER THE FCST AREA...ABD RDR TRENDS SUPPORT THIS WEAKENING.
FCST ON TRACK AND NO SIG CHGS ANTICIPATED. PREV BLO...
UPDATED AT 830 AM...FLURRIES AND SCT -SHSN ACRS THE RGN ATTM.
GRADUAL IMPRVMNT THIS AFTN BUT UNTIL THEN WE`LL SEE THE ACTIVITY
CONTINUE. TWEEKED 1ST PD POPS AND WX GRIDS OTRW NO CHGS. PREV BLO...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
A NW FLOW OFF LAKE ONTARIO WILL KEEP LE SNOW SHWRS IN THE AREA
THRU ABT 15Z WITH MVFR AND OCNL IFR CIGS DOWNWIND OF THE LAKE AT
ITH AND BGM. ELSEWHERE GNRL VFR CONDS THIS MRNG WITH SCT LGT SNOW
SHWRS. DRIER AIR MVG IN LTR THIS MRNG AND THRU THE END OF THE PD
WILL END MUCH OF THE LAKE EFFECT AND BRING VFR CONDS THRU 12Z SUN.
.OUTLOOK...
SAT NGT THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
832 AM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 830 AM...FLURRIES AND SCT -SHSN ACRS THE RGN ATTM.
GRADUAL IMPRVMNT THIS AFTN BUT UNTIL THEN WE`LL SEE THE ACTIVITY
CONTINUE. TWEEKED 1ST PD POPS AND WX GRIDS OTRW NO CHGS. PREV BLO...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
A NW FLOW OFF LAKE ONTARIO WILL KEEP LE SNOW SHWRS IN THE AREA
THRU ABT 15Z WITH MVFR AND OCNL IFR CIGS DOWNWIND OF THE LAKE AT
ITH AND BGM. ELSEWHERE GNRL VFR CONDS THIS MRNG WITH SCT LGT SNOW
SHWRS. DRIER AIR MVG IN LTR THIS MRNG AND THRU THE END OF THE PD
WILL END MUCH OF THE LAKE EFFECT AND BRING VFR CONDS THRU 12Z SUN.
.OUTLOOK...
SAT NGT THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
752 AM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
A NW FLOW OFF LAKE ONTARIO WILL KEEP LE SNOW SHWRS IN THE AREA
THRU ABT 15Z WITH MVFR AND OCNL IFR CIGS DOWNWIND OF THE LAKE AT
ITH AND BGM. ELSEWHERE GNRL VFR CONDS THIS MRNG WITH SCT LGT SNOW
SHWRS. DRIER AIR MVG IN LTR THIS MRNG AND THRU THE END OF THE PD
WILL END MUCH OF THE LAKE EFFECT AND BRING VFR CONDS THRU 12Z SUN.
.OUTLOOK...
SAT NGT THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
643 AM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A NW FLOW OFF LAKE ONTARIO WILL KEEP LE SNOW SHWRS IN THE AREA
THRU ABT 15Z WITH MVFR AND OCNL IFR CIGS DOWNWIND OF THE LAKE AT
ITH AND BGM. ELSEWHERE GNRL VFR CONDS THIS MRNG WITH SCT LGT SNOW
SHWRS. DRIER AIR MVG IN LTR THIS MRNG AND THRU THE END OF THE PD
WILL END MUCH OF THE LAKE EFFECT AND BRING VFR CONDS THRU 12Z SUN.
.OUTLOOK...
SAT NGT THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
425 PM EST SAT DEC 17 2011
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL MOVE ACROSS THE REGION
TONIGHT THROUGH SUNDAY AND GIVE US MAINLY DRY AND COLD WEATHER.
SUNDAY WILL FEEL LIKE WINTER...WITH FORECAST HIGH TEMPERATURES
GENERALLY BELOW FREEZING. ON MONDAY...AN APPROACHING COLD FRONT WILL
BRING INCREASING CLOUDS AND BREEZY CONDITIONS WITH MODERATING
TEMPERATURES.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPPER LEVEL TROUGH IS OVER THE REGION. SHORT WAVE MOVING THROUGH
TROUGH CURRENTLY OVER WEST VIRGINIA. THIS SHORTWAVE PRODUCING
SOLID MID LEVEL CLOUD DECK OVER AREA. COLD NORTHWEST FLOW
PRODUCING SNOW SHOWER/FLURRY ACTIVITY OVER GOOD PART OF FORECAST
AREA. SOME CHAMPLAIN EFFECT NOTED OVER WASHINGTON COUNTY WITH
UPSLOPE ACTIVITY OVER TACONICS. HUDSON MOHAWK CONVERGENCE HAS SET
UP WITH NE WINDS AT KGFL AND NW AT KRME. HRRR INDICATES SNOW
SHOWER ACTIVITY CURRENTLY EAST OF HUDSON SHOULD MIGRATE WESTWARD
ACROSS CAPITAL DISTRICT THIS EVENING SO 30 POP IN GRIDS THROUGH 8 PM.
COLD...BLUSTERY CONDITIONS WILL CONTINUE THIS EVENING.
PREVIOUS...
AS OF 1 PM...COLD AIR CONTINUES TO FILTER INTO THE FORECAST AREA
FROM THE NORTH. TEMPERATURES HAVE STARTED TO DROP AT KALB SO WE
HAVE LIKELY REACHED OUR MAXIMUM TEMPERATURES FOR THE DAY FROM
ALBANY NORTH. TO THE SOUTH ANOTHER DEGREE OR TWO UP IS POSSIBLE
BEFORE TEMPS START DROPPING UNTIL AFTER SUNRISE TOMORROW.
LATEST RUC ANALYSIS SHOWS A SHORTWAVE EMBEDDED IN 500MB FLOW OVER
OHIO VALLEY. WAVE SEEMS TO BE DIGGING SOME AS MIDLEVEL CLOUDS ARE
INCREASING AND NOT MOVING EASTWARD. VAD SCATTERERS SHOW LOW CLOUDS
FROM 2000 TO ABOUT 7000FT WITH MID DECK FROM 14000-22000 FEET.
MOHAWK-HUDSON VALLEY CONVERGENCE SCENARIO IN PLACE...BUT AIR IS SO
DRY JUST SOME SCATTERED FLURRIES SHOWING UP ON RADAR. HIGHER RES
MODELS SHOW SOME FLURRIES OR LIGHT SNOW MOVE ACROSS CAPITAL
DISTRICT THIS EVENING. NO ACCUMULATION EXPECTED.
LATEST UPDATE INCLUDES A PRELIMINARY REFRESH OF GRIDS THROUGH 72 HOURS
BASED ON 12Z/NAM AND CURRENT TRENDS. TEMPS A BLEND OF MET/MAV MOS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE RIDGE WILL BUILD IN FROM THE NORTHWEST. WITH A
MAINLY CLEAR SKY AND DIMINISHING WIND...THE STAGE WILL BE SET FOR
GOOD RADIATIONAL COOLING. THE ONLY INGREDIENT MISSING IN MOST
PLACES WILL BE AN EXTENSIVE SNOWPACK. EVEN WITHOUT ONE...MANY
AREAS LOOK TO HAVE THEIR COLDEST NIGHT OF THE WINTER SEASON THUS
FALL. OVERNIGHT LOWS LOOK TO DIP WELL DOWN INTO THE TEENS FROM THE
CAPITAL DISTRICT AND POINTS SOUTHWARD. WELL TO THE NORTH OF THE
MOHAWK RIVER...SINGLE DIGITS WILL BE THE RULE. SOME OF THE COLDEST
AND SNOW COVERED AREAS OF THE ADIRONDACKS ARE FORECAST TO DROP
BELOW ZERO.
ANOTHER SUNNY SUNDAY IS ON TAP (THIS IS AT LEAST THE 4TH IN A ROW).
HIGH PRESSURE WILL REMAIN IN COMMAND. DESPITE ABUNDANT
SUNSHINE...TEMPERATURES WILL STRUGGLE TO REACH FREEZING AT MOST
LOCATIONS.
HIGH PRESSURE WILL SLIP OFFSHORE LATE SUNDAY NIGHT. WARM AIR
ADVECTION COMBINED WITH A SOUTHWEST FLOW OFF LAKE ONTARIO AND EVEN
LAKE ERIE MIGHT PRODUCE SOME LIGHT ENHANCED SNOW SHOWERS ACROSS
OUR ADIRONDACKS OVERNIGHT SUNDAY INTO EARLY MONDAY. WILL CONTINUE
WITH SLIGHT CHANCES IN THOSE AREAS WHILE EVERYONE ELSE REMAINS
COMPLETELY DRY.
BY MONDAY...A SOUTHWESTERLY FLOW TAKES SHAPE AS H850
TEMPERATURES NUDGE ZERO DEG C AHEAD OF ANOTHER FAST MOVING COLD
FRONT. EVEN WITH MORE CLOUDS AROUND...TEMPERATURES LOOK TO
MODERATE FROM THE MID 30S TO LOWER 40S REGION WIDE. THERE STILL
WILL BE A CHANCE OF RAIN OR SNOW SHOWERS...MAINLY TO THE NORTH AND
WEST OF ALBANY AHEAD OF THE COLD FRONT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
TWO WORDS COME TO MIND WITH RESPECT TO OUR LONG TERM PORTION OF THE
FORECAST...UNCERTAINTY AND TIMING.
THE MAIN CULPRIT TO THIS FORECAST DILEMMA IS CURRENTLY OVER NORTHERN
BAJA CALIFORNIA. ALL GLOBAL MODELS DO AGREE...THIS SYSTEM WILL
EJECT OUT OVER THE SOUTHERN AND CENTRAL PLAINS DURING THE MID WEEK
PERIOD WITH A POTENTIAL PHASING WITH THE NORTHERN STREAM. THIS DOES
SEEM TO SUGGEST WE WILL EXPERIENCE AN OVERRUNNING EVENT THAT COULD
LEAD TO A WINTRY MIXTURE. HOWEVER...TRENDS ARE FOR THE WARM AIR
ADVECTION TO EVENTUALLY ERODE THE COLDER BOUNDARY LAYER FOR MAINLY A
RAIN EVENT FOR THE MID WEEK PERIOD. THEREAFTER...COLDER WEATHER
WITH A CHANCE FOR A SMALLER WAVE TO BRING PERHAPS SOME SNOW TO THE
REGION FOR THE END OF THE WORK WEEK.
DETAILS...
TUESDAY...A RIDGE OF HIGH PRESSURE IS EXPECTED TO CREST OVER THE
REGION WITH DRY YET SEASONABLE CONDITIONS. UPSTREAM UPPER LOW
BEGINS ITS APPROACH TOWARD THE MID-MISSISSIPPI RIVER VALLEY WITH
OVERRUNNING PATTERN UNFOLDING ACROSS THE OHIO VALLEY.
TUESDAY NIGHT INTO WEDNESDAY...OVERRUNNING PATTERN UNFOLDS WITH
CLOUDS ON THE INCREASE ALONG WITH THE CHANCE FOR A WINTRY MIXTURE.
THE ECMWF KEEPS THE BULK OF THE MOISTURE SOUTH OF THE REGION. THE
GFS/DGEX/CMC ARE CONSIDERABLY MORE MOIST AND PROLIFIC WITH THE
DEGREE OF MOISTURE TRANSPORT INTO THE NORTHEAST. THERMAL PROFILES
CONTINUE TO WARM THAT WOULD SUGGEST ANY PRECIP TRANSITIONING TOWARD
MAINLY RAIN.
WEDNESDAY NIGHT...WITH THE EXCEPTION OF THE DGEX...REMAINDER OF THE
GLOBAL MODELS FAVOR THE CONTINUATION OF THE WARM ADVECTION REGIME.
THIS SHOULD KEEP TEMPERATURES TO REMAIN EITHER STEADY OR SLOWLY
CLIMBING TO REDUCE THE THREAT FOR WINTRY TYPE PRECIPITATION. 850MB
TEMPS AVERAGE AOA +4C.
THURSDAY INTO THURSDAY NIGHT...THE UPPER LOW AND SURFACE WAVE ARE
EXPECTED TO BE OFF THE NEW ENGLAND COAST WITH MINIMAL COLD ADVECTION
DUE TO THE PARALLEL FLOW TO THE THERMAL GRADIENT OVER THE REGION.
WE WILL BE WATCHING FOR THE NEXT SOUTHERN WAVE TO ROUND OUT THE BASE
OF THE ELONGATED TROUGH AND BEGIN TO INTERACT WITH AN OPEN GULF OF
MEXICO. HERE...THE ENSEMBLES OFFER A WIDE DEGREE OF SOLUTIONS FOR
THURSDAY NIGHT WHERE A PERIOD OF LIGHT SNOW COULD EVOLVE ACROSS THE
REGION.
FRIDAY...WHATEVER OCCURS THURSDAY NIGHT IS EXPECTED TO BE WELL
OFFSHORE WITH COLD FROPA DURING THE DAY. THE COMBINATION OF
CYCLONIC FLOW ALOFT AND INCREASING LAKE ONTARIO CONTRIBUTION FOR THE
CHANCE OF EITHER RAIN OR SNOW...DEPENDING ON THOSE BOUNDARY LAYER
TEMPS.
OVERALL...WHEN COMPARED TO CLIMATOLOGY...PRECIPITATION AND
TEMPERATURES EITHER AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THE NEXT 24 HOURS. A
COLD FRONT MOVING SOUTH AND ALMOST THROUGH THE NORTHERN TWO-
THIRDS OF THE FA...WILL SHIFT NORTHWEST WINDS TO NORTH BEHIND IT
WITH SPEEDS AROUND 10 KTS AND GUSTS 15-25 KTS.
WINDS WILL DECREASE TO 5-10 KTS IN THE MID TO LATE
AFTERNOON...FURTHER DIMINISHING TO LIGHT CONDITIONS AT ALL THREE
TERMINALS OVERNIGHT. WINDS WON/T RECOVER TIL LATE SUNDAY
MORNING...ONLY INCREASING TO 4-8 KTS DURING THE DAY.
OVERCAST VFR CIGS WILL CONTINUE THROUGH THE REST OF TODAY. CLOUD
COVER EXPECTED TO BREAK UP OVER NIGHT...WITH SCT TO FEW HIGH
CLOUDS LEFT BY SUNDAY MORNING. OVERALL FAIR WEATHER CONDITIONS
EXPECTED ON SUNDAY.
OUTLOOK...
MON...VFR...NO SIG WX.
MON NIGHT-TUE...VFR...CHC -SHSN/-SHRA.
TUE NIGHT...VFR/MVFR...CHC SNOW.
WED...MVFR/IFR...CHC MIXED PCPN CHANGING TO RAIN.
THU...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDROLOGIC PROBLEMS EXPECTED THROUGH AT LEAST TUESDAY.
THE ONLY PRECIPITATION FORECAST THROUGH TUESDAY ARE SOME SCATTERED
LIGHT SNOW OR RAIN SHOWERS. THERE IS THE POSSIBILITY OF SOME WET
WEATHER WEDNESDAY OR THURSDAY. ENSEMBLE PRECIPITATION FORECASTS
ARE MOSTLY LESS THAN AN INCH OF LIQUID TOTAL THROUGH THE
WEEK...AND THE MULTI-MODEL HYDROLOGIC ENSEMBLE FORECAST SYSTEM
SHOWS NO FLOODING THROUGH THE UPCOMING WEEK. TEMPERATURES ARE NOT
FORECAST TO BE PERSISTENTLY COLD ENOUGH THIS WEEK TO FORM
SIGNIFICANT RIVER ICE.
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...SND
NEAR TERM...SND
SHORT TERM...SND
LONG TERM...BGM
AVIATION...KGM
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
119 PM EST SAT DEC 17 2011
.SYNOPSIS...
A SECONDARY COLD FRONT WILL CONTINUE TO MOVE ACROSS THE
REGION TODAY. THIS WILL BRING A REINFORCING SHOT OF COLD AIR, .WITH
HIGH PRESSURE BUILDING IN OVER FOR THE LATTER PORTION OF THE
WEEKEND. THIS HIGH PRESSURE WILL BRING DRY AND COLD CONDITIONS
TONIGHT AND SUNDAY. AS HIGH PRESSURE MOVES OFFSHORE, A SOUTHERLY FLOW
WILL BRING A MODERATION IN TEMPERATURE FOR MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM...COLD AIR CONTINUES TO FILTER INTO THE FORECAST AREA
FROM THE NORTH. TEMPERATURES HAVE STARTED TO DROP AT KALB SO WE
HAVE LIKELY REACHED OUR MAXIMUM TEMPERATURES FOR THE DAY FROM
ALBANY NORTH. TO THE SOUTH ANOTHER DEGREE OR TWO UP IS POSSIBLE
BEFORE TEMPS START DROPPING UNTIL AFTER SUNRISE TOMORROW.
LATEST RUC ANALYSIS SHOWS A SHORTWAVE EMBEDDED IN 500MB FLOW OVER
OHIO VALLEY. WAVE SEEMS TO BE DIGGING SOME AS MIDLEVEL CLOUDS ARE
INCREASING AND NOT MOVING EASTWARD. VAD SCATTERERS SHOW LOW CLOUDS
FROM 2000 TO ABOUT 7000FT WITH MID DECK FROM 14000-22000 FEET.
MOHAWK-HUDSON VALLEY CONVERGENCE SCENARIO IN PLACE...BUT AIR IS SO
DRY JUST SOME SCATTERED FLURRIES SHOWING UP ON RADAR. HIGHER RES
MODELS SHOW SOME FLURRIES OR LIGHT SNOW MOVE ACROSS CAPITAL
DISTRICT THIS EVENING. NO ACCUMULATION EXPECTED.
LATEST UPDATE INCLUDES A PRELIMINARY REFRESH OF GRIDS THROUGH 72 HOURS
BASED ON 12Z/NAM AND CURRENT TRENDS. TEMPS A BLEND OF MET/MAV MOS.
PREVIOUS...
AS OF 930 AM...COLD FRONT HAS PASSED SOUTH OF I90 AND ITS
APPROACHING THE CATSKILLS...MID HUDSON VALLEY AND NW CT. DEWPOINT
DROPS OF 3-5 DEGREES PER HOUR HAVE BEEN OBSERVED AND TEMPERATURES
HAVE EITHER REMAINED STEADY OR SLOWLY FALLING. SOME FLURRIES/LIGHT
SNOW SHOWERS ARE MOVING ACROSS THE CWFA WITH MINIMAL CONTRIBUTION
FROM LAKE ONTARIO. 12Z SOUNDINGS REVEAL THE CAPPING INVERSION WAS
SITUATED AOA 800MB AND FORECAST PROFILES LOWER THROUGH THE DAY.
MAIN UPDATE TO THIS PACKAGE WAS TO REFRESH HOURLY
TEMPS/DEWPOINTS AND HOLD THESE VALUES NEARLY STEADY OR SLOWLY
FALLING FOR THE REMAINDER OF THE DAY... POPS/WX FOR THE SNOW
SHOWERS/FLURRIES WITH A DECREASING TREND THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD IN FROM EASTERN CANADA. WITH A MAINLY CLEAR
SKY AND LITTLE OR NO WIND...THE STAGE WILL BE SET FOR GOOD
RADIATIONAL COOLING. THE ONLY INGREDIENT MISSING IN MOST PLACES WILL
BE AN EXTENSIVE SNOWPACK. EVEN WITHOUT ONE...MANY AREAS LOOK TO HAVE
THEIR COLDEST NIGHT OF THE WINTER SEASON THUS FALL. OVERNIGHT LOWS
LOOK TO DIP WELL DOWN INTO THE TEENS FROM THE CAPITAL DISTRICT AND
POINTS SOUTHWARD. WELL TO THE NORTH OF THE MOHAWK RIVER...SINGLE
DIGITS WILL BE THE RULE. SOME OF THE COLDEST AND SNOW COVERED
SHELTERED VALLEY COULD APPROACH ZERO DEGREES!
ANOTHER SUNNY SUNDAY IS ON TAP. HIGH PRESSURE WILL REMAIN IN
COMMAND. DESPITE ABUNDANT SUNSHINE...TEMPERATURES WILL STRUGGLE TO
REACH BACK TO 30...AND TO THE NORTH OF ALBANY WILL ONLY MAKE IT INTO
THE 20S. IF OUR FORECAST PANS OUT...THIS WILL BE THE FIRST
SUBFREEZING DAY IN ALBANY SINCE MARCH 7TH.
HIGH PRESSURE WILL BEGRUDGINGLY SLIP OFFSHORE LATE SUNDAY NIGHT.
DURING THE EARLY PART OF THE EVENING...THE SKY LOOKS TO BE MAINLY
CLEAR AND THE WIND STILL LIGHT. TEMPERATURES WILL DIP DOWN MAINLY
BACK INTO THE TEENS. THEN...AS WARM ADVECTION CLOUDS TEND TO THICKEN
AND A SOUTHERLY BREEZE ENSUES...TEMPERATURES MIGHT STALL OVERNIGHT.
FOR NOW...SINCE THIS IS STILL SEVERAL NIGHTS...WILL FOLLOW THE MORE
TYPICAL DIURNAL CURVE. BOTTOM LINE...ANOTHER COLD NIGHT...BUT NOT AS
MUCH AS SATURDAY OVERNIGHT.
WARM AIR ADVECTION COMBINED WITH A SOUTHWEST FLOW OFF LAKE ONTARIO
AND EVEN LAKE ERIE MIGHT PRODUCE SOME LIGHT ENHANCED SNOW SHOWERS
ACROSS OUR ADIRONDACKS OVERNIGHT SUNDAY INTO EARLY MONDAY. WILL
CONTINUE WITH SLIGHT CHANCES IN THOSE AREAS WHILE EVERYONE ELSE
REMAINS COMPLETELY DRY.
BY MONDAY...A SOUTHERLY FLOW TAKES SHAPE AS H850
TEMPERATURES...WHICH START AROUND -2C...LOOK TO BRIEFLY WARM UP TO
ABOUT +3C...AHEAD OF ANOTHER FAST MOVING COLD FRONT. EVEN WITH MORE
CLOUDS AROUND THAN SUNDAY...TEMPERATURES LOOK TO MODERATE FROM THE
MID 30S TO LOWER 40S REGION WIDE. THERE STILL WILL BE A CHANCE OF
RAIN OR SNOW SHOWERS...MAINLY ACROSS TO THE NORTH AND WEST OF ALBANY
AHEAD OF THE COLD FRONT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UNCERTAINTY IS PLENTIFUL IN THE LONG TERM FORECAST. MODELS AGREE
THAT A COUPLE OF LOW PRESSURE SYSTEMS WILL AFFECT THE REGION BETWEEN
MONDAY NIGHT AND FRIDAY. HOWEVER...THE AGREEMENT ENDS THERE WITH
SIGNIFICANT TIMING AND TRACK DIFFERENCES BETWEEN MODELS...AND EVEN
BETWEEN DIFFERENT RUNS OF THE SAME MODEL. THUS...IT IS HIGHLY LIKELY
THAT THIS FORECAST WILL CHANGE CONSIDERABLY OVER THE NEXT 24 HOURS
AND THERE IS NO NEED TO GET TOO SPECIFIC AT THIS TIME. HAVE CHOSEN
TO BASE THE FORECAST ON THE 00Z GFS FOR NOW WHICH RESULTS IN HIGH
CHANCE POPS TUESDAY NIGHT INTO WEDNESDAY. TEMP PROFILES SUGGEST THAT
A SIGNIFICANT PORTION OF THE PCPN WITH THIS EVENT WILL BE RAIN.
THE NEXT SYSTEM IS FORECAST TO BEGIN TO AFFECT THE REGION ON FRIDAY
AND CONTINUE INTO EARLY NEXT WEEKEND. TEMP PROFILES ARE COLDER WITH
THIS SYSTEM...SO MORE OF THE PCPN WITH THIS SYSTEM IS FORECAST TO BE
SNOW.
ONCE AGAIN THIS LONG TERM PERIOD FEATURES ABOVE NORMAL TEMPS. LOWS
MONDAY THROUGH THURSDAY NIGHTS WILL GENERALLY BE BETWEEN 20 AND 30.
HIGHS TUESDAY WILL BE IN THE UPPER 20S TO LOWER 40S. HIGHS WEDNESDAY
IN THE UPPER 30S AND 40S. MID 30S TO MID 40S THURSDAY...AND MID 30S
TO LOWER 40S FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST THE NEXT 24 HOURS. A
COLD FRONT MOVING SOUTH AND ALMOST THROUGH THE NORTHERN TWO-
THIRDS OF THE FA...WILL SHIFT NORTHWEST WINDS TO NORTH BEHIND IT
WITH SPEEDS AROUND 10 KTS AND GUSTS 15-25 KTS.
WINDS WILL DECREASE TO 5-10 KTS IN THE MID TO LATE
AFTERNOON...FURTHER DIMINISHING TO LIGHT CONDITIONS AT ALL THREE
TERMINALS OVERNIGHT. WINDS WON/T RECOVER TIL LATE SUNDAY
MORNING...ONLY INCREASING TO 4-8 KTS DURING THE DAY.
OVERCAST VFR CIGS WILL CONTINUE THROUGH THE REST OF TODAY. CLOUD
COVER EXPECTED TO BREAK UP OVER NIGHT...WITH SCT TO FEW HIGH
CLOUDS LEFT BY SUNDAY MORNING. OVERALL FAIR WEATHER CONDITIONS
EXPECTED ON SUNDAY.
OUTLOOK...
MON...VFR...NO SIG WX.
MON NIGHT-TUE...VFR...CHC -SHSN/-SHRA.
TUE NIGHT...VFR/MVFR...CHC SNOW.
WED...MVFR/IFR...CHC MIXED PCPN CHANGING TO RAIN.
THU...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGY PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
MAINLY DRY WEATHER EXPECTED THROUGH THE WEEKEND AND MOST OF MONDAY.
A FRONTAL SYSTEM MOVING THROUGH THE REGION MONDAY WILL BRING THE
NEXT CHANCE FOR SOME PRECIP BUT THIS SYSTEM LOOKS TO BE LIGHT WITH
SOME OF FALLING AS SNOW NORTH AND WEST OF ALBANY. THEREFORE RIVERS
WILL CONTINUE TO RECEDE BEFORE ANOTHER STORM MAY AFFECT THE REGION
LATER IN THE WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.CLIMATE...
2011 SITS IN THIRD PLACE FOR WETTEST YEARS ON RECORD FOR ALBANY
NY. PRECIPITATION RECORDS DATE BACK TO 1826.
1) 56.78 INCHES 1871
2) 55.81 INCHES 1870
3) 51.87 INCHES THROUGH 4 PM DECEMBER 16TH
4) 51.83 INCHES 1850
5) 49.80 INCHES 1827
6) 49.37 INCHES 1878
7) 48.35 INCHES 1843
8) 48.22 INCHES 1848
9) 47.79 INCHES 2008
10) 47.72 INCHES 2005
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/SND
NEAR TERM...SND/BGM
SHORT TERM...SND/HWJIV
LONG TERM...GJM
AVIATION...KGM
HYDROLOGY...HWJIV/RCK
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1212 PM CST SAT DEC 17 2011
.AVIATION...
STORM SYSTEM WHICH BROUGHT EARLY AM SNOW TO NORTHEAST IA AND NORTHERN
IL HAS MOSTLY EXITED REGION. WEAK SFC LOW PASSING NEAR KDBQ
EARLY THIS AFTN AND MOVING EWD... WITH BAND OF LOW CLOUDS WITH
LOW VFR TO HIGH MVFR CIGS IN WAKE TO EXIT KDBQ AND KMLI TERMINALS
PRIOR TO SUNSET LEAVING BEHIND MAINLY CLEAR SKIES. WEAK SFC RIDGE
WILL THEN PASS OVRNGT WITH SOME RADIATION FOG LOOKING MORE LIKELY AS
CROSSOVER TEMPS BREACHED. IN GENERAL MVFR VSBYS WITH ANY FOG WITH SOME
IFR VSBYS POSSIBLE ESPECIALLY SNOW COVERED AREAS NORTHEAST IA INTO
NORTHERN IL. WINDS WLY 5-10 KTS BECOMING LIGHT SW TNGT THEN INCREASING
FROM SW AT 10-20 KTS DURING DAY SUN AS SFC RIDGE MOVES EAST AND PRESSURE
GRADIENT INCREASES.
&&
.PREV DISCUSSION... /ISSUED 309 AM CST SAT DEC 17 2011/
SYNOPSIS...
ALOFT...THE LONG WAVE PATTERN IS MARKED BY SPLIT FLOW...WITH A
CUT-OFF LOW OVER LOS ANGELES WHILE THE MIDWEST AND NORTHEAST U.S.
ARE UNDER THE INFLUENCE OF THE ACTIVE NORTHERN STREAM. CLIPPER
CURRENTLY CROSSING THE UPPER MIDWEST HAS WRUNG OUT 1 TO 3 INCHES OF
SNOW FOR NORTHERN SECTIONS OF THE FORECAST AREA. SURFACE LOW OVER
IOWA NEAR FORT DODGE /KFOD/ THIS MORNING WITH THE STRONGEST PRESSURE
FALLS SPANNING EASTERN IOWA. ..DMD..
SHORT TERM...TODAY AND TONIGHT...
MAIN FOCUS THIS MORNING IS WALKING OUT THE SNOWFALL...THEN CLOUDS
FOR THE REMAINDER OF TODAY. RUC FORECASTS SHOW LOW LEVEL
FRONTOGENETIC FORCING ASSOCIATED WITH THE CLIPPER TRACKING RAPIDLY
NORTHEAST ACROSS SOUTHERN WISCONSIN BY 11Z AND RADAR AND SATELLITE
TRENDS SHOW A FAIRLY SHARP BACK EDGE TO THE ACCUMULATING SNOW. THUS
WILL END SNOW ACROSS CWFA BY 12Z. AS FOR THE STRATUS...RUC 800MB RH
FIELD HAS A DECENT HANDLE ON THE CURRENT PROGRESS OF THE CLEARING
LINE AND WILL USE FOR NOWCASTING THE BACK EDGE. THIS TIMING WOULD
SUGGEST CLEARING REACHING THE MISSISSIPPI RIVER BY ABOUT 15Z. ..DMD..
LONG TERM...SUNDAY THROUGH FRIDAY...
A SPLIT FLOW PATTERN WILL REMAIN OVER THE U.S. FOR THE UPCOMING
WEEK. EASTERN PACIFIC S/W ENERGY WILL CONTINUE TO BE SHUNTED NORTH
INTO BRITISH COLUMBIA OR THE PAC NW BY A STUBBORN EASTERN PACIFIC
RIDGE. SOME OF THIS ENERGY GETS PICKED UP IN THE SOUTHERN STREAM FLOW
EAST OF THE RIDGE AXIS...HELPING TO MAINTAIN SOME MID LEVEL
TROFFING OVER THE WESTERN U.S.
THE MAIN CONCERNS FOR THIS PERIOD CONTINUE TO BE IN THE EARLY PART
OF THE WEEK WITH THE SOUTHWESTERN U.S. CUTOFF LOW EJECTING INTO
THE MID MISSISSIPPI VALLEY BY TUESDAY/TUESDAY NIGHT. THE LONG
RANGE MODELS WERE IN REASONABLY GOOD AGREEMENT WITH THIS SYSTEM
WHICH IMPROVES CONFIDENCE THAT THE BULK OF THE PRECIPITATION WILL
STAY TO OUR SOUTH. HOWEVER...A NORTHERN STREAM S/W THAT WILL
INFLUENCE THE TRACK OF THE CUTOFF LOW IS STILL OVER THE PACIFIC
AND IS NOT YET BEING SAMPLED BY THE UPPER AIR NETWORK. THIS COULD
LEAD TO MORE MODEL VARIATIONS WITH THIS SYSTEM ON TODAY/S MODEL
RUNS. ONCE THE S/W REACHES THE WESTERN CONUS THIS EVENING THE
MODELS WILL HAVE MORE DATA TO WORK WITH.
FOR SUNDAY AND SUNDAY NIGHT MILD WEATHER WILL BE OVER THE AREA
WITH SOUTHWESTERLY FLOW IN PLACE AHEAD OF A NORTHERN PLAINS COLD FRONT.
THE NAM/GFS SHOW A LOW LEVEL THERMAL RIDGE OVER THE AREA SUNDAY
AFTERNOON. WITH DRY AIR OVER THE AREA WE SHOULD HAVE MOSTLY SUNNY
SKIES WHICH ALLOW DEEP ENOUGH MIXING TO TAP SOME OF THE WARMER
AIR. THE TEMPERATURE FORECAST FOR SUNDAY AND SUNDAY NIGHT WERE
SKEWED TOWARD THE WARM MET MOS GUIDANCE WHICH SUGGEST MAXT TEMPS
IN THE LOW 50S OVER THE SOUTHWEST AND LOW TO MID 40S NORTHEAST.
INCREASING LOW LEVEL MOISTURE/CLOUDS SUNDAY NIGHT WILL KEEP
TEMPERATURE SOUTH IN THE UPPER 40S. IN THE NORTHWEST THE COLD
FRONT SHOULD BE MOVING IN AFTER MIDNIGHT...DROPPING TEMPERATURES IN
THE MID/UPPER 20S BY MONDAY MORNING.
FOR MONDAY THROUGH TUESDAY NIGHT THE 00Z RUNS ARE IN REASONABLE
AGREEMENT BRINGING THE UPPER LOW OUT ON A MORE SOUTHERLY COURSE.
AS A RESULT HAVE STARTED TO TREND PRECIPITATION CHANCES DOWN ACROSS
THE NORTH AND KEPT POPS IN THE SOUTHERN FOURTH OF THE AREA
LIMITED TO CHANCE CATEGORY. THE EXCEPTION TO THIS WILL BE SOME
LIKELY POPS SOUTH TUESDAY WHEN THE UPPER LOW MOVES INTO MO
SPREADING STRONGLY DIFFLUENT MID LEVEL FLOW SPREADS NORTHEAST
INTO SOUTHERN IA AND CENTRAL IL. THERMAL PROFILES SUGGEST ANY
PRECIPITATION MONDAY WILL BE RAIN. AS THE COLD AIR PUSHES SOUTH
AND DEEPENS MONDAY NIGHT AND TUESDAY THE RAIN SHOULD CHANGE TO
SNOW. WITH MODELS SHOWING THE INITIALLY SHALLOW COLD AIR
UNDERCUTTING WARMER 850MB TEMPS THERE COULD BE SOME SORT OF A MIX
MONDAY AFTERNOON/EVENING ALONG THE NORTHERN EDGE OF THE
PRECIPITATION SHIELD WHICH COULD INCLUDE SLEET AND POSSIBLY SOME
FREEZING RAIN. BY LATE MONDAY NIGHT AND TUESDAY TEMPERATURES
SHOULD BE COLD ENOUGH FOR MAINLY SNOW. THE SYSTEM WILL BE MOVING
EAST OF THE AREA BY LATE TUESDAY NIGHT. BY THIS TIME THERE IS
POTENTIAL FOR SOME MINOR SNOW ACCUMULATIONS ESPECIALLY SOUTH OF
HIGHWAY 34 BETWEEN OTTUMWA AND MACOMB.
FOR THE REST OF THE WEEK HAVE GONE WITH A MAINLY DRY FORECAST
EXPECTING NEAR NORMAL TEMPERATURES. MODELS SHOW THE WESTERN U.S.
TROF REDEVELOPING WITH A S/W EJECTING OUT OF THE TROF BY LATE
WEEK. THE GFS/ECMWF SHOW THE S/W DIGGING WELL INTO MEXICO THEN
EJECTING ON A TRACK THAT WOULD TAKE IT SOUTH OF THE AREA. THE GEM
IS LESS AMPLIFIED AND MOVES THE SYSTEM THROUGH THE MID MISSISSIPPI
VALLEY BY LATE WEEK SUPPORTING SOME PRECIPITATION OVER THE AREA. THE
ONLY POPS THEN WILL BE SOME SLIGHT CHANCE POPS FROM THURSDAY NIGHT
THROUGH FRIDAY TO COVER THE THREAT OF SNOW WITH THE EJECTING WAVE.
DLF..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
101 PM EST SAT DEC 17 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW RIDGING INTO
WRN CANADA. DOWNSTREAM...A TROF EXTENDS S INTO THE ERN CONUS FROM A
POLAR VORTEX CENTERED JUST N OF HUDSON BAY. IN THE NW FLOW DIRECTED
INTO THE GREAT LAKES...A VIGOROUS LOOKING SHORTWAVE IS DIVING SE
THRU SRN MANITOBA. CANADIAN RADARS SHOW A SMALL AREA OF -SN
DEVELOPING SE TOWARD NRN MN IN ASSOCIATION WITH THE WAVE. CLOSER TO
HOME...DESPITE 850MB TEMPS AROUND -15C OVER LAKE SUPERIOR...LES TO
THE E OF KMQT HAS DIMINISHED TO JUST SOME FLURRIES. OVER THE W...
THERE`S VERY LITTLE OR NO CLOUDS OFF THE LAKE...SURPRISING GIVEN THE
OVERWATER INSTABILITY. PERIOD OF MOSTLY CLEAR SKIES HAS ALLOWED
TEMPS TO FALL TO NEAR OR JUST BLO 0F AT MANY LOCATIONS OVER WRN
UPPER MI...INCLUDING THE KEWEENAW.
&&
.DISCUSSION...
WEATHER THRU THIS FCST PERIOD WILL BE DOMINATED BY A MEAN RIDGE OF
VARYING AMPLITUDE EXTENDING INTO WRN CANADA AND A DOWNSTREAM POLAR
VORTEX IN THE VCNTY OF NRN HUDSON BAY/BAFFIN ISLAND. IN GENERAL...
BLO NORMAL HEIGHTS WILL EXIST ACROSS NRN CANADA. END RESULT WILL BE
A SERIES OF MOISTURE STARVED NRN STREAM SHORTWAVES PRODUCING LITTLE
PCPN OUTSIDE OF AREAS THAT MIGHT SEE SOME LIGHT LAKE EFFECT/LAKE
ENHANCED SNOW WITH EACH PASSING WAVE. FLOW ALSO LOOKS TO REMAIN
SPLIT WITH SRN STREAM WAVES AND ASSOCIATED PCPN PASSING S OF UPPER
MI. OVERALL...IT WILL NOT BE VERY WINTRY ACROSS THE UPPER LAKES
HEADING TOWARD LATE DEC AS NORTHERLY POSITION OF POLAR VORTEX AND
BLO NORMAL HEIGHTS ACROSS NRN CANADA HOLD ARCTIC AIR N OF THE AREA.
ONLY BRIEF INTRUSIONS OF COLDER AIR WILL OCCUR OVER THE NEXT 7
DAYS...AND TEMPS OVERALL WILL END UP ABOVE NORMAL. LATEST CPC
8-14DAY OUTLOOK CARRIES ENHANCED ODDS OF ABOVE NORMAL TEMPS OVER
UPPER MI THRU THE END OF DEC.
FOR TODAY...VIGOROUS SHORTWAVE WILL DROP THRU THE UPPER GREAT
LAKES...BUT IT WILL BE WEAKENING AS IT DOES SO. THIS IS VERY EVIDENT
IN DEEP LAYER QVECTORS WHICH SUGGEST HEALTHY DYNAMICS NW OF THE AREA
EARLY THIS MORNING RAPIDLY WEAKENING AS SHORTWAVE MOVES ACROSS THE
UPPER LAKES DURING THE DAY. ALTHOUGH FORCING WILL BE WEAKENING...
STEEP MIDLEVEL LAPSE RATES UPWARDS OF 7.5C/KM MAY HELP TO MAINTAIN
SOME AREAS OF -SN SPREADING INTO THE AREA. ANY SYNOPTIC SNOW
ACCUMULATION WILL BE UNDER AN INCH. 850MB TEMPS AROUND -10C SHOULD
SUPPORT SOME LAKE ENHANCEMENT OVER WRN LAKE SUPERIOR INTO WRN UPPER
MI AS WINDS SHIFT FROM SW TO NW. SHOULDN`T BE A BIG DEAL GIVEN SHORT
WINDOW OF ENHANCEMENT (PROBABLY NOTHING MORE THAN AN INCH OR TWO OF
ACCUMULATION OVER THE NW THIS AFTN INTO EARLY EVENING). BRIEF
ENHANCEMENT WILL SHIFT TO AREAS E OF KMQT THIS EVENING AS WINDS
SHIFT NW (LIMITED ACCUMULATION THERE AS WELL). THERE IS ALSO THE
POTENTIAL FOR SOME LAKE ENHANCEMENT OFF NRN LAKE MICHIGAN INTO THE
FAR ERN FCST AREA THIS AFTN/EARLY EVENING IN THE SW FLOW AHEAD OF
THE SHORTWAVE. SOME GUIDANCE SUGGESTS WINDS WILL BACK ENOUGH FOR
LAKE ENHANCEMENT TO CLIP SCHOOLCRAFT/LUCE COUNTIES. UTILIZED HIGHER
POPS IN THAT AREA...BUT KEPT ACCUMULATIONS ONLY AROUND 1 INCH GIVEN
UNCERTAINTY IN HOW MUCH LOW-LEVEL WINDS WILL BACK.
A LITTLE LIGHT -SN MAY LINGER THIS EVENING OVER THE E IN ASSOCIATION
WITH DEPARTING SHORTWAVE. OTHERWISE...IF THERE IS ANY SCT LIGHT NW
FLOW LES (850MB TEMPS AROUND -12C) BEHIND SYSTEM...IT WILL RAPIDLY
END TONIGHT FROM W TO E UNDER SUBSTANTIAL HEIGHT RISES (500MB
HEIGHTS RISE MORE THAN 120M). ALSO...AIR MASS QUICKLY DRIES...
INVERSION CRASHES TO 3KFT...WINDS BACK AND WAA GETS UNDERWAY.
ON SUN...NEXT SHORTWAVE WILL BE DROPPING SE TOWARD NRN ONTARIO. ALL
GUIDANCE SHOW ASSOCIATED SFC LOW PASSING WELL N OF HERE ACROSS NRN
ONTARIO SUN NIGHT. AHEAD OF WAVE...IMPRESSIVE WAA WILL SEND 850MB
TEMPS ABOVE 0C ACROSS THE FCST AREA SUN. GFS IS MOST AGGRESSIVE WITH
THE WARMING AS IT HAS 850MB TEMPS RANGING FROM 2C E TO 7C W BY SUN
EVENING. ISENTROPIC ASCENT IS STRONG SUN WITH 40KT WINDS ORIENTED
PERPENDICULAR TO TIGHTLY SPACED ISOBARS PER 290K SFC. HOWEVER...
WITH DRY AIR HOLDING AT THE LOW-LEVELS PER FCST SOUNDINGS...PCPN
DEVELOPING ALOFT WILL PROBABLY NOT REACH THE SFC. FOR NOW...WILL
CONTINUE TO CARRY A DRY FCST SUN/SUN NIGHT WITH ANY PCPN PASSING N
OF UPPER MI. IF ANYTHING...WILL NEED TO WATCH FOR SOME LIGHT PCPN
CLIPPING THE KEWEENAW AND THE NE FCST AREA. SHALLOW MOISTURE
DROPPING INTO THE AREA BEHIND COLD FRONT ALONG WITH 850MB TEMPS
FALLING PERHAPS TO AROUND -12C MAY SUPPORT SOME LIGHT LES/FLURRIES
OFF LAKE SUPERIOR LATE SUN NIGHT INTO MON EVENING.
AS PREVIOUSLY MENTIONED...PATTERN NEXT WEEK WILL FEATURE LIMITED
PCPN CHANCES WITH TEMPS AVERAGING ABOVE NORMAL. AT THIS TIME...IT
APPEARS SHORTWAVES WILL PASS ACROSS THE AREA AT SOME POINT LATER
TUE/EARLY WED AND THEN THU. OF THE 2 SHORTWAVES...THE SECOND SHOULD
PROVIDE A BETTER CHC OF PCPN.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
THERE WILL BE A COUPLE DIFFERENT PERIODS OF INTEREST FOR THIS TAF
ISSUANCE...INITIALLY WITH A DISTURBANCE SWEEPING IN FROM THE
NW...AND TOWARDS THE END OF THE PERIOD WITH INCREASING SOUTHERLY
WINDS AHEAD OF THE NEXT SFC LOW NEARING FROM SOUTHERN MANITOBA. VIS
WAS TEMPORARILY REDUCED TO LESS THAN 2SM AT IWD...ASSOCIATED WITH A
BAND OF LOWER CLOUDS AND -SHSN MEASURING 80 MILES ACROSS NEAR IWD.
AS A RESULT...EXPECT RESTRICTIONS /FUEL ALT CEIGS/ AT ALL 3 SITES
FROM TIME TO TIME THROUGH 02 TO 04Z...AND POSSIBLY A BIT LONGER AT
CMX WHICH WILL BE CLOSER TO THE EXITING DISTURBANCE AND HAVE
FAVORABLE WIND COMPONENT OFF THE LAKE. VFR CEIGS AND VIS WILL THEN
BE THE RULE...THROUGH SUNDAY AFTERNOON...WITH INCREASING SOUTHERLY
WINDS GUSTING 22 TO 30KTS /STRONGEST AT SAW AND TO A LESSER EXTENT
IWD/.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH SOUTHERN CANADA WILL
PUSH SEVERAL SFC TROUGHS ACROSS LAKE SUPERIOR THROUGH THE FORECAST
PERIOD. FIRST TROUGH APPROACHES TODAY...WHICH WILL INCREASE WINDS TO
30KTS OUT OF THE SW TODAY...ALTHOUGH THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS OVER THE WRN LK. WINDS WILL DIMINISH OVERNIGHT
BEFORE INCREASING AGAIN SUNDAY AFTERNOON AHEAD OF THE NEXT TROUGH.
STRONG INVERSION JUST ABOVE THE SFC WILL LIKELY KEEP SUSTAINED WINDS
IN THE 20-30KT RANGE SUN AFTN AND NIGHT. DEPENDING ON THE STRENGTH
OF THE INVERSION...THERE MAY BE SOME GALE FORCE GUSTS TO 35KTS...DUE
TO WSW WINDS OF 40-50KTS 2-3KFT ABOVE THE LAKE. CONSIDERED ISSUING A
GALE WATCH...BUT WASN/T CONFIDENT ENOUGH ON GALES OCCURRING WITH THE
SW WINDS. THINK THE BEST CHANCE WILL BE AS WINDS TURN TO THE W IN
THE EVENING AND HAVE MENTIONED GALES IN THE TEXT. LIGHTER WINDS ARE
EXPECTED MON AFTN INTO MON NIGHT...BEFORE THE NEXT TROUGH APPROACHES
ON TUESDAY AND PRODUCES GUSTS TO 30KTS. THERE MAY BE A FEW GALE
FORCE GUSTS TO 35KTS OVER CENTRAL LAKE SUPERIOR TUESDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1219 PM EST SAT DEC 17 2011
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL COME TO AN END LATER TODAY AS HIGH
PRESSURE BUILDS IN OVER THE EAST COAST FOR THE REMAINDER OF THE
WEEKEND. A LOW PRESSURE SYSTEM WILL APPROACH THE AREA LATE
MONDAY...WHICH WILL BRING THE NEXT CHANCE OF PRECIPITATION WHICH
WILL BE THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1030 AM...WEAK BACKDOOR-TYPE MESO FRONT EVIDENT OVER
LAKE ONTARIO INTO CNTRL CAYUGA AND SRN ONONDAGA/SRN MADISON...BEHIND
WHICH TD`S DROP OFF RAPIDLY. THIS LOW LVL DRYING IN COMBINATION
WITH DIURNAL EFFECTS WILL CONTINUE TO ERODE THE -SHSN ACTIVITY
CRNTLY OVER THE FCST AREA...ABD RDR TRENDS SUPPORT THIS WEAKENING.
FCST ON TRACK AND NO SIG CHGS ANTICIPATED. PREV BLO...
UPDATED AT 830 AM...FLURRIES AND SCT -SHSN ACRS THE RGN ATTM.
GRADUAL IMPRVMNT THIS AFTN BUT UNTIL THEN WE`LL SEE THE ACTIVITY
CONTINUE. TWEEKED 1ST PD POPS AND WX GRIDS OTRW NO CHGS. PREV BLO...
RADAR IMAGERY FROM BGM AND TYX, SHOWING LES IS COMING FROM A WNW
FLOW AND HAS SPREAD OUT MAINLY OVER ONEIDA, MADISON, AND ONONDAGA
COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW OVER OTSEGO COUNTY.
THESE SHOWERS SHOULD REMAIN LIGHT IN NATURE AND WILL GET LIGHTER
AS THE FLOW TURNS MORE NORTHERLY AND HIGH PRESSURE BUILDS IN.
LOOKING AT THE RADAR AND THE OBS, ANY HEAVIER SHOWERS, AND USING
THAT TERM LOOSELY, HAVE MOVED AWAY FROM THE LAKE SHORE. HOWEVER,
SOME ISOLATED SHOWERS MAY STILL DEVELOP NEAR THE LAKE SHORE AND
MOVE INTO THE CWA THROUGH THE MORNING HOURS. THE HRRR SHOWS MOST
OF THE ACTIVITY WELL TO THE SW OF THE CWA BY 20Z. OTHER MODELS
SHOW THEM DISSIPATING EVEN EARLIER. SO, TO SUM IT UP, FLURRIES TO
LIGHT SNOW SHOWERS POSSIBLE, MAINLY IN NEW YORK AND THE NORTHERN
TIER OF PA THROUGH MID AFTERNOON TO VERY EARLY EVENING. OTHERWISE,
CLOUDY BUT QUIET WEATHER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD IN FOR THE REMAINDER OF THE WEEKEND AND
MONDAY. SUNDAYS TEMPS WILL BE NEAR NORMAL FOR THIS TIME OF YEAR.
THERE WILL BE A WARM UP ON MONDAY, WITH HIGHS REACHING INTO THE
LOW TO MID 40S. THIS IS AHEAD OF THE NEXT SYSTEM.
BY MONDAY AFTERNOON, A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE
SYSTEM NEAR THE HUDSON BAY, WILL APPROACH THE AREA. MODELS ARE IN
PRETTY GOOD AGREEMENT, WITH THIS FRONT SLOWING AND STALLING MONDAY
NIGHT SOMEWHERE OVER THE CWA. THIS FRONT WILL BRING THE NEXT
CHANCE FOR RAIN AND SNOW SHOWERS TO THE AREA. MODELS ALSO
INDICATE, THAT THE PRECIPITATION SHOULD BE LIGHT AND THEN FIZZLE
OUT BY LATE MONDAY NIGHT/EARLY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LONG TERM IS DOMINATED OVERALL BY SOUTHWEST FLOW...WITH UNSETTLED
INTERRUPTION BY A COUPLE OF WAVES. NO MAJOR CONCERNS DISCERNIBLE
AT THIS TIME.
WEAKENING FRONT WILL SETTLE THROUGH THE AREA MONDAY NIGHT. GFS/ECWMF
BOTH SETTLE IT JUST SOUTH OF THE CWA TUESDAY...BEFORE RETURNING
NORTHWARD. HOWEVER...I ACCEPTED THE LOW CHANCE POPS OFFERED BY HPC
BECAUSE WITH FRONT BECOMING NEARLY FLOW-PARALLEL...IT MAY STRUGGLE
TO PUSH ALL THE WAY THROUGH AND COULD GET HUNG UP. ANY RESULTING
PRECIPITATION THOUGH WOULD BE VERY LIGHT.
ECMWF AND GFS ARE IN BETTER AGREEMENT ON AN UPPER LOW EJECTING OUT
OF THE SOUTHWEST U.S. AND OPENING UP WHILE GETTING ABSORBED INTO
THE WESTERLIES. WARM AIR ADVECTION AHEAD OF THE SYSTEM GETS
TEMPERATURES TO POINT WHERE PRECIPITATION SHOULD BE MAINLY RAIN...DURING
THE DAY WEDNESDAY...BUT UNCERTAINTY ON FRONT AND BACK ENDS FOR
PRECIPITATION TYPE. THOUGH NOT LIKELY...WINTRY MIX DURING THE
ONSET TUESDAY NIGHT IS NOT OUT OF THE QUESTION WITH ONLY SLIGHT
SHIFTS IN THE CURRENTLY PROJECTED TEMPERATURE PROFILES. THIS WILL
HAVE TO BE MONITORED. BECAUSE TIMING OF UPPER LOW EJECTION OUT OF
THE SOUTHWEST IS TYPICALLY SOMETHING THE MODELS STRUGGLE WITH...I
WENT AHEAD AND KEPT POPS IN CHANCE RANGE /40S-LOW 50S PCT/ TUESDAY
NIGHT AND WEDNESDAY UNTIL MORE MODEL RUNS CAN CONFIRM DETAILS
BETTER.
GFS/ECMWF DIVERGE AS WE HEAD LATE INTO THE WORKWEEK. BOTH REVERT TO
SOME SORT OF SOUTHWEST FLOW BUT ARE AT LEAST DAY OFF OF EACH
OTHER FOR WHEN TO SEND THE NEXT WAVE THROUGH THE FLOW. ECWMF HAS
WEAK AND DRY WAVE THURSDAY...GFS HAS A SLIGHTLY MORE AMPLIFIED
WAVE WAITING UNTIL FRIDAY...COMPLETE WITH GRADUALLY DEEPENING
SURFACE LOW OFF OF THE COAST. THE STRUGGLE APPEARS TO BE WHETHER
OR NOT THE SOUTHERN STREAM WAVE...CAN PHASE UP WITH A DIGGING
NORTHERN STREAM TROUGH. WITH SUCH UNCERTAINTY...KEEPING POPS IN
LINE WITH HPC...ONLY IN SLIGHT TO LOW CHANCE RANGE...PEAKING
FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
NORTHWEST WINDS ARE VEERING TO NORTH AS COLD AND DRY HIGH PRESSURE
BUILDS INTO THE AREA THIS AFTERNOON. WHAT IS LEFT OF THE LAKE
EFFECT FLURRIES...CURRENTLY AROUND KITH-KELM-KBGM...IS QUICKLY
COMING TO AN END WITH THE PUSH OF LOWER DEWPOINTS COMING IN FROM
THE NORTH. THIS AFTERNOON AND INTO TONIGHT...SOME
MOISTURE...ALBEIT LIMITED...REMAINS TRAPPED UNDER THE SUBSIDENCE
INVERSION. SO WHILE CLOUDS WILL SCATTER OUT AND IT WILL BE MAINLY
VFR THROUGH 18Z SUNDAY...THERE MAY BE SPOTS THIS AFTERNOON THROUGH
TONIGHT THAT WILL SOMETIMES CROSS THAT FINE SCT-BKN LINE FOR BRIEF
MVFR CIGS.
.OUTLOOK...
SUN AFTN THRU MON NGT...MAINLY VFR.
TUE/WED...POSSIBLE MVFR/IFR...ESPECIALLY TUE NGT AND WED AS SYSTEM
COMES THROUGH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...
SHORT TERM...SLI
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1146 AM CST SAT DEC 17 2011
.UPDATE...LOW CLOUD COVER OVER MOST OF CWA KEEPING TEMPS COOLER THAN
PREVIOUSLY FORECAST. LIKEWISE...DEEPER THAN EXPECTED SNOW COVER OVER
THE SOUTHWEST COULD HELP HOLD TEMPS DOWN. WILL LOWER HIGHS EXCEPT IN
THE NORTHEAST WHERE THERE IS LESS SNOW AND SKIES WERE CLEARER THIS
MORNING. PERSISTENT FLURRIES OVER THE SOUTHEAST ASSOCIATED WITH LOW
LEVEL CONVERGENCE IN NEAR SATURATED LAYER. CONVERGENCE EXPECTED TO
WEAKEN AND LAYER TO DRY SO DO NOT EXPECT MORE SIGNIFICANT PRECIP TO
RESULT.
&&
.AVIATION/18Z TAFS/...LOWER CIGS CONTINUE TO SPREAD NORTHEAST
THROUGH SOUTHERN WISCONSIN. LOOKS LIKE MOST PLACES WILL HAVE MVFR
CIGS THROUGH THE AFTERNOON...AND POSSIBLY INTO THE EVENING GIVEN
LATEST MODEL 925 MB RH. MAY SEE IFR CIGS FOR A TIME. CLOUDS
EXPECTED TO THEN DECREASE WEST TO EAST THIS EVENING...WITH JUST
SCATTERED MID OR HIGH LEVEL CLOUDS REMAINING BY MIDNIGHT. VFR
CONDITIONS THEN EXPECTED THROUGH SUNDAY AS HIGH PRESSURE SLIDES BY
TO THE SOUTHEAST.
&&
.PREV DISCUSSION... /ISSUED 326 AM CST SAT DEC 17 2011/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
SHORTWAVE AND ISENTROPIC LIFT GENERATING A BAND OF LIGHT SNOW THAT
WILL MOVE ACROSS MUCH OF THE FORECAST AREA. HIGHEST AMOUNTS WILL
BE ACROSS THE SOUTHWEST HALF WITH LIGHTER AMOUNTS TOWARD FOND DU
LAC AND SHEBOYGAN. LATEST NAM AND HRRR HAVE A GOOD HANDLE ON IT
AND EXPECT A BAND OF 1 TO 2 INCHES OVER THE SOUTHWEST HALF OF THE
FORECAST AREA. A FEW 3 INCH TOTALS ARE POSSIBLE MAINLY WEST AND
SOUTHWEST OF MADISON.
SNOW WILL PULL OUT OF THE EAST IN THE MORNING. ANOTHER SHORTWAVE
WILL DROP ACROSS MAINLY NORTHERN WISCONSIN DURING THE AFTERNOON
AND EARLY EVENING...MAYBE BRINGING SOME LIGHT SNOW TOWARD FOND DU
LAC AND SHEBOYGAN. OVERALL SETUP NOT AS GOOD AS FIRST WAVE THOUGH
WITH BEST LIFT TO THE NORTH.
ANOTHER WEAKER SHORTWAVE AND MID LEVEL WARM ADVECTION LATE TONIGHT
IN A FAST NORTHWEST FLOW. HOWEVER MAINLY MID LEVEL CLOUDS WITH
THIS FEATURE AND NO PRECIPITATION EXPECTED.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE
MEDIUM.
WARM AIR ADVECTION CONTINUES ACROSS THE AREA ON SUNDAY. PUSH OF
DRIER AIR INTO THE AREA WILL GRADUALLY PUSH OUT CLOUDS AS THE DAY
GOES ON. A MILD DAY IS EXPECTED...WITH LOWER TO MID 40S FOR HIGHS.
SOUTHWEST WINDS CONTINUE TO HOLD THE MILD AIRMASS ACROSS THE AREA
SUNDAY NIGHT...AS A COLD FRONT MOVES SOUTHEAST INTO THE AREA. NAM
INDICATING SOME POTENTIAL FOR LOW STRATUS DEVELOPMENT DURING THIS
TIME...WITH THE GFS SOMEWHAT LESS AGGRESSIVE WITH THE LOW LEVEL
SATURATION. WILL TREND TOWARDS MOSTLY CLOUDY SKIES LATE SUNDAY
NIGHT. NAM INDICATING LIGHT QPF WITH THE FRONT...WITH THE
GFS/ECMWF DRY. NAM FORECAST SOUNDINGS NOT IMPRESSIVE WITH MOISTURE
PROFILE ABOVE INVERSION...SO LEFT THIS PERIOD DRY.
COLD FRONT SLIDES SOUTHEAST ACROSS THE AREA DURING THE MORNING ON
MONDAY...THEN SOUTHEAST IN THE AFTERNOON. NAM/GFS FORECAST
SOUNDINGS STILL NOT SHOWING MUCH WITH MOISTURE ABOVE INVERSION IN
THE MORNING...WITH A DRYING TREND WITH COLD AIR ADVECTION IN THE
AFTERNOON. KEPT SLIGHT CHANCES FOR LIGHT RAIN AND LIGHT SNOW IN
THE FAR SOUTHEAST COUNTIES MONDAY...CLOSEST TO THE FRONT. HIGHS
WILL BE MILD UNTIL FRONTAL PASSAGE...WITH A FALL DURING THE
AFTERNOON.
HIGH PRESSURE MOVING INTO THE REGION MONDAY NIGHT WILL BRING A
REINFORCING SHOT OF DRY AIR ACROSS THE AREA. STRONG VORTICITY
MAXIMUM SHIFTING SOUTHEAST THROUGH THE AREA MAY BE ENOUGH FOR
LIGHT SNOW. CONTINUED TO KEEP LOW END POPS MONDAY NIGHT IN THE FAR
SOUTHEAST COUNTIES. LOW TEMPERATURES SHOULD BE MORE SEASONABLE
WITH THE COLDER AIR MOVING INTO THE AREA.
LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE LOW TO
MEDIUM.
GFS/ECMWF IN SOMEWHAT BETTER AGREEMENT WITH SYSTEM FOR
TUESDAY...THEN CONTINUE TO DIFFER TUESDAY NIGHT AND WEDNESDAY.
THEY BOTH ARE KEEPING THE SURFACE LOW WELL SOUTH OF THE AREA. THEY
TAKE IT EAST NORTHEAST FROM THE SOUTHERN PLAINS TO THE MIDDLE
MISSISSIPPI RIVER VALLEY TUESDAY ON THE GFS...THEN INTO
OHIO/EASTERN PENNSYLVANIA TUESDAY NIGHT. THE STRONG UPPER LOW
LINGERS TO THE NORTHWEST OF THE SURFACE LOW...TAKING A SIMILAR
EAST NORTHEAST PATH.
THE ECMWF CONTINUES TO BE SLOWER WITH THIS SYSTEM...AND DOES NOT
HAVE THE SURFACE LOW IN THE MIDDLE MISSISSIPPI RIVER VALLEY UNTIL
LATE TUESDAY NIGHT/EARLY WEDNESDAY. IT THEN MOVES THE LOW EAST
NORTHEAST FROM THERE WEDNESDAY INTO WEDNESDAY NIGHT. ITS
PRECIPITATION SHIELD MISSES SOUTHERN WISCONSIN. HAVE SEEN SYSTEMS
LIKE THESE TREND SOUTHWARD...ONLY TO TREND BACK NORTH AND BRING
THE AREA PRECIPITATION. FOR NOW...WILL MAINTAIN SMALL CHANCES FOR
PRECIPITATION ACROSS THE SOUTHEAST COUNTIES.
MODELS SHOW HIGH PRESSURE PASSING SOUTH OF THE AREA WEDNESDAY.
THIS SHOULD BRING QUIET WEATHER...WITH MILD TEMPERATURES.
MODELS THEN BRING A COLD FRONT THROUGH THE AREA THURSDAY...WITH NO
QPF ASSOCIATED WITH IT. MORE DIFFERENCES THEN OCCUR BETWEEN THESE
MODELS INTO FRIDAY. THE GFS BRINGS AN AMPLIFIED SHORTWAVE TROUGH
SOUTHEAST THROUGH THE REGION THURSDAY NIGHT AND FRIDAY...WITH THE
ECMWF CLIPPING THIS AREA FRIDAY. QPF IS LIGHT WITH THE GFS...EVEN
WITH THE STRONG SHORTWAVE TROUGH. FOR NOW...WILL LEAN TOWARD
CONSENSUS POPS AND TEMPERATURES THIS FAR OUT IN THE FORECAST.
AVIATION/12Z TAFS/...
MAINLY MVFR CIGS AND IFR VSBY EARLY THIS MORNING OVER MUCH OF THE
FORECAST AREA EXCEPT NORTHEAST TOWARD SHEBOYGAN.
ANOTHER ROUND OF LIGHT SNOW MAY SLIDE THROUGH THE NORTHEAST THIRD
OF THE FORECAST AREA LATE THIS AFTERNOON AND INTO THE
EVENING...BUT BEST MOISTURE AND LIFT EXPECTED TO PASS BY TO THE
NORTH AND NORTHEAST.
MAINLY MID LEVEL VFR CLOUDS TONIGHT.
MARINE...
SOUTH WINDS WILL INCREASE ON SUNDAY AHEAD OF LOW PRESSURE MOVING
NORTH OF LAKE SUPERIOR...WITH WINDS AND WAVES LIKELY REACHING
SMALL CRAFT CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1139 AM CST SAT DEC 17 2011
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SYNOPSIS...A RELATIVELY QUIET PERIOD FOR MID-DECEMBER WITH
TEMPERATURES ABV SEASONAL NORMALS.
CLASSIC SPLIT FLOW REGIME WL CONT ACRS NOAM THROUGH THE PERIOD AND
BEYOND. THE FCST AREA WL BE UNDER THE INFLUENCE OF THE NRN STREAM
THROUGH AT LEAST THE MIDDLE OF NEXT WK. THE PATTERN COMBINED WITH
LACK OF SIG SNOW COVER ACRS THE RGN SUPPORTS ABV NORMAL TEMPS. NRN
STREAM SYSTEMS WL BRING SOME LGT PCPN AT TIMES...BUT AMNTS WL END
UP BLO NORMAL.
&&
.SHORT TERM...TDA/TNGT/SUN. WV PASSING S OF THE AREA WL BRUSH THE
FAR S WITH SOME S-/S-- EARLY TDA. ALSO NEED TO KEEP AN EYE ON THE
LAKE-EFFECT POTENTIAL AS HRRR WAS DEVELOPING CYCLONIC CIRCULATION
OVER CENTRAL LAKE MICHIGAN...AND SFC OBS SEEM TO BE BEARING THAT
OUT.
BETTER CHC OF PCPN WL COME TO THE NE 1/2 OF THE FCST AREA THIS
AFTN AS THE NEXT NRN STREAM SHRTWV PUSHES INTO THE RGN. THE
COMBINATION OF QG FORCING WITH THE MID-LVL SHRTWV...ISENT LIFT...
AND DIV IN LFQ OF UPR JET SUPPORTED KEEPING LIKELY POPS OVER THE
NE. CONT TO HAVE POPS TAPER BACK TO CHC TO THE SW...WHICH WL ONLY
BE BRUSHED BY THE BETTER FORCING. EXPECT A FAIRLY FAST MOVG BAND
OF SN TO PUSH ACRS DURING THE AFTN. WL STICK WITH MENTION OF UP TO
AN INCH OVER THE NE.
SUBSIDENCE BEHIND THE WV AND DEEP WLY FLOW SHOULD HELP STRIP OUT
LOW AND MIDDLE CLDS TNGT. COULD BE SOME HIGH CLDS WORKING BACK IN
LATE. SOME SFC PRESSURE GRADIENT REMAINS...BUT PROBABLY NOT ENOUGH
TO RELY ON TO KEEP TEMPS UP. TENDED DOWN WITH TEMPS OVER THE NRN
PART OF THE AREA.
WARMER AIR WL BEGIN FLOWING BACK INTO THE AREA SUN. BUT THE BULK
OF THE WARMING WL BE ALOFT. STAYED RATHER CONSERVATIVE WITH MAX
TEMP FCST AS IT WL TAKE A WHILE FOR WARMER AIR TO WORK IN AT THE
SFC. ALSO STAYED RATHER MODEST WITH WINDS AS STRONGEST FLOW WL BE
ABV THE SFC AND POTENTIAL FOR MIXING WL BE VERY LTD.
.LONG TERM...SUNDAY NGT THRU NXT FRI. LITTLE CHG IN THE OVERALL
SYNOPTIC PATN ACROSS THE CONUS DURING THE EXTENDED PERIOD WITH
SPLIT FLOW PERSISTING UNTIL FURTHER NOTICE. EARLY WEEK SYSTEM NOW
DOES APR TO STAY TO OUR SOUTH...THUS NO SNOW WITH THIS FEATURE.
MAIN FCST FOCUS TO BE ON TEMPS INITIALLY AND THEN WL HAVE TO WATCH
LATE NXT WEEK FOR THE NXT SNOW CHC.
MDLS CONT TO SHOW A CDFNT RACING THRU ALL BUT SE WI SUNDAY NGT...
BRINGING SOME CLOUDS AND A WIND SHIFT BUT NO PCPN AS TIME SECTIONS/
FCST SNDNGS SHOW LITTLE MSTR IN THE MID-LVLS OF THE ATM. SINCE
BETTER FORCING REMAINS WELL TO OUR NORTH IN THE VCNTY OF THE
PRIMARY SHRTWV AND MSTR TO BE LIMITED...HAVE GONE WITH A DRY FROPA.
WINDS WL REMAIN RATHER MODEST THRU MOST OF THE NGT WHICH WOULD
HELP PREVENT TEMPS FROM FALLING MUCH. IN FACT...MIN TEMPS ARE
EXPECTED TO BE NEAR NORMAL MAX TEMPS FOR THIS TIME OF YEAR (LWR 20S
NORTH TO UPR 20S E-CNTRL).
WINDS TO VEER MORE NW BY MON MORNING WITH MODEST LEVELS OF CAA
TAKING OVER WI THRU THE DAY. 8H TEMPS OVER LK SUPERIOR DROP TO
AROUND -10C WHICH WOULD RAISE DELTA-T VALUES INTO THE MID TEENS
AND LEAD TO THE POSSIBILITY OF LK EFFECT SNOW SHWRS PRIMARILY
ACROSS VILAS CNTY. THESE SNOW SHWRS HOWEVER DO NOT LOOK SIGNIFICANT
AS HI PRES ALREADY BUILDING INTO THE WRN GREAT LKS AND ADVECTING
DRY AIR INTO THE RGN. HAVE ONLY KEPT A TOKEN POP FOR VILAS CNTY
WITH ONLY A COUPLE TENTHS OF AN INCH EXPECTED. THE REST OF THE FCST
AREA SHOULD SEE A MIX OF SUN AND CLOUDS WITH MAX TEMPS RANGING FROM
AROUND 30 NORTH TO THE MID 30S E-CNTRL WI.
THIS HI PRES TO THEN SPRAWL ACROSS THE GREAT LKS MON NGT WITH SKIES
BECMG MOSTLY CLEAR AND WINDS BECMG LGT/VRBL. THIS SHOULD ALLOW
TEMPS TO CRASH AND WL NEED TO CHOP A GOOD 3 TO 5 DEGS FROM THE PREV
FCST. COULD EASILY SEE THE COLD SPOTS OF NRN WI DROP INTO THE
SINGLE DIGITS WHILE ONLY AREAS NEAR LK MI HOLD IN THE 20S. AFTER
DAYS OF MDL INCONSISTENCY WITH THE HANDLING OF A PSBL NRN/SRN
STREAM PHASING/STORM TRACK ISSUES ON TUE...THE MEDIUM RANGE MDLS
HAVE COME INTO AGREEMENT THAT ANY PHASING WOULD NOT OCCUR UNTIL
FARTHER TO OUR EAST. THIS TRANSLATES TO THE SRN STREAM UPR LOW
STAYING FAR ENUF SOUTH SUCH THAT ANY ACCUMULATING SNOW WOULD ONLY
REACH FAR SRN WI AT BEST. STILL EXPECT TO SEE SOME CLOUDS TO
INCREASE OVER THE SE HALF OF THE FCST AREA ON TUE...BUT NON POPS
WL BE NEEDED.
WHILE THE SRN STREAM SYSTEM CONTS TO LIFT NE INTO THE OHIO RIVER
VALLEY TUE NGT...THE TRAILING NRN STREAM SHRTWV TROF MOVES THRU
THE WRN GREAT LKS AND SENDS A CDFNT THRU WI. ONCE AGAIN...BETTER
FORCING GOES EITHER NORTH OR SOUTH OF WI...THUS A CONTINUATION OF
A DRY FCST. A WEAK SFC RDG IS THEN FCST TO MOVE ACROSS MAINLY THE
SRN SECTIONS OF THE GREAT LKS LATER TUE NGT INTO WED. UNDER MOSTLY
CLEAR TO PARTLY CLDY SKIES...LOOK FOR TEMPS TO REMAIN WELL ABV
NORMAL.
FCST BECOME MORE MUDDLED FOR THE LATTER PART OF THE WORK WEEK AS
THE NXT SIGNIFICANT NRN STREAM SHRTWV ENERGY DROPS SE INTO THE
GREAT BASIN. ISSUES AMONG THE MDLS CENTER ON WHETHER THIS ENERGY
WL CLOSE OFF TO ANOTHER CLOSED UPR LOW OR PROGRESS EAST WITH TIME
AND INCREASE SNOW CHCS ACROSS WI. A PROGRESSIVE SOLN WOULD BRING A
LGT SNOW POTENTIAL TO NE WI BY THU NGT INTO FRI...BUT WITH ALL THE
UNCERTAINTY INVOLVED AT THIS TIME...HAVE GONE WITH THE MDL
CONSENSUS SOLN OF ONLY SLGT CHC POPS FOR NOW.
&&
.AVIATION...CIGS GENERALLY BETWEEN 1000` AND 2000` AGL THROUGH
EARLY EVENING. AN UPPER LEVEL DISTURBANCE WILL PRODUCE SOME
SCATTERED SNOW SHOWERS WITH BRIEF IFR CIGS AND VSBYS. SHOULD
BECOME GENERALLY VFR LATE TONIGHT. VFR CIGS BETWEEN 5000` AND
10000` AGL SUNDAY.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$