Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/01/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
722 PM MST FRI NOV 30 2012
.UPDATE...
ISSUED AT 722 PM MST FRI NOV 30 2012
MOIST SHORT WAVE IS MARCHING ACROSS THE GREAT BASIN WITH THE
LEADING EDGE OF THE DEEPER CLOUD MASS JUST REACHING WRN COLORADO.
THIS SHORT WAVE CONTAINS GOOD MOISTURE BUT MOVES VERY QUICKLY.
HIGHER RESOLUTION MODELS SUCH AS THE HRRR INDICATING SOME PCPN AS
FAR SOUTH AS THE LA SAL AND THE NRN SIDE OF THE SAN JUAN
MOUNTAINS. BUT THE NRN MOUNTAINS STAND THE BEST CHANCE OF SNOW
WITH 3-5 INCH ACCUMULATION POSSIBLE ABOVE 9000 FEET. WARM AIR MASS
RESULTS IN HIGH SNOW LEVELS AND APPEARS WILL RANGE FROM 7500 TO
8000 FEET OVERNIGHT. BOOSTED VALUES IN THE POP GRIDS...PRIMARILY
OVER NW COLORADO. BY DAYBREAK...THIS SHORT WAVE WILL HAVE CROSSED
THE DIVIDE WITH A CLEARING TREND FROM THE WEST.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 317 PM MST FRI NOV 30 2012
MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM INTO THE FORECAST
AREA AS AN UPPER LEVEL LOW PRESSURE SYSTEM OFF THE PACIFIC
NORTHWEST COAST CONTINUES TO SPIN...BRINGING IN A STEADY STREAM OF
MOISTURE. 700MB WINDS ARE IN THE 35 TO 45 KT RANGE WITH AN UPPER
LEVEL JET OF 80 KTS OVERHEAD IN A SOUTHWEST TO WEST FLOW. VISIBLE
SATELLITE AND VISUAL OBSERVATIONS INDICATE MOUNTAIN WAVE CLOUDS
ALREADY FORMING OVER THE UNCOMPAHGRE PLATEAU AND ON THE LEE SIDE
OF SOME RIDGES...WHICH WOULD INDICATE A STABLE ATMOSPHERE. SOME
GUSTS ARE REACHING THE SURFACE AT CRAIG AND MEEKER WHICH HAVE BEEN
GUSTING ANYWHERE FROM 20 TO 30 KTS.
THIS IS ALL OUT AHEAD OF AN EMBEDDED DISTURBANCE THAT WILL MOVE
THROUGH THIS EVENING THROUGH SATURDAY MORNING. THE BEST DYNAMICS
LIE NORTH OF THE FORECAST AREA AS THIS DISTURBANCE TRACKS FROM
NORTHERN NEVADA THROUGH NORTHERN UTAH INTO SOUTHERN IDAHO AND
WYOMING. AREAS NORTH OF I-70 WILL PRIMARILY BE AFFECTED BY THIS
DISTURBANCE AS IT CLIPS THESE ZONES. WHEN ANALYZING TIME HEIGHTS
OVER SEVERAL POINTS ACROSS THESE AFFECTED AREAS...700MB
TEMPERATURES WERE ANYWHERE FROM -1C TO -3C WHICH WOULD PUT SNOW
LEVELS AT ABOUT 7000 TO 8000 FT. WHILE THERE IS MOISTURE AND
INSTABILITY...THE FORCING IS NOT ALL THAT STRONG AND THE SATURATED
MOISTURE LAYER IS FAIRLY SHALLOW. MUCH OF THE FORCING IS CAPPED BY
A FAIRLY STABLE LAYER OVERHEAD. WITH THAT BEING SAID...IT LOOKS
LIKE THE EASTERN UINTAS...PARK AND GORE MOUNTAINS AS WELL AS THE
ELKHEADS AND FLATTOPS WILL BE FAVORED FOR ACCUMULATING SNOWFALL IN
THE 1 TO 2 INCH RANGE WITH SOME SPOTS SEEING AS MUCH AS 3.
PRIMARILY LIGHT RAIN WILL OCCUR IN THE NORTHERN VALLEYS. THE BULK
OF THE PRECIPITATION LOOKS TO OCCUR AFTER MIDNIGHT TO AROUND
SUNRISE. THE REST OF THE FORECAST AREA WILL SEE LITTLE IF ANY
PRECIPITATION...JUST SOME INCREASED CLOUD COVER. LEANED TOWARDS
THE WARMER SIDE OF GUIDANCE TONIGHT FOR LOW TEMPERATURES DUE TO
INCREASED CLOUD COVER.
SHOWERS WILL TAPER OFF AFTER SUNRISE AND WILL BE LIMITED TO THE
HIGHER PEAKS OF THE NORTHWEST COLORADO MOUNTAINS THROUGH ABOUT
NOON AS MOISTURE AND CLOUDS WILL HUG THE TERRAIN. ALTHOUGH PRECIP
WILL COME TO AN END AND CLOUD HEIGHTS WILL RISE SATURDAY
AFTERNOON...SOME HIGH CLOUDS WILL CONTINUE TO MOVE THROUGH AS THE
UPPER LEVEL LOW FEEDS MORE MOISTURE INTO THE AREA. EVEN THOUGH
THERE WILL BE A SLIGHT COOL DOWN ON SATURDAY FROM FRIDAYS HIGHS
PARTICULARLY UP NORTH...AFTERNOON HIGH TEMPERATURES WILL STILL
REMAIN SOME 10 TO 15 DEGREES ABOVE NORMAL FOR EARLY DECEMBER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 317 PM MST FRI NOV 30 2012
HIGH CLOUDS OUT AHEAD OF THE NEXT PACIFIC WAVE WILL BEGIN TO
SPREAD OVER THE FORECAST AREA EARLY SUNDAY...THEN THICKEN AND
LOWER DURING THE AFTERNOON. MODELS CONTINUE TO SHOW A WEAKENED
SYSTEM AS COMPARED TO WHAT WAS PROGGED SEVERAL DAYS AGO. SO IN
LIGHT OF THAT EARLIER PROMISE AND BECAUSE WE REALLY NEED THE
MOISTURE...THIS STORM IS LOOKING LIKE IT WILL BE A DISAPPOINTMENT.
THAT SAID...WINDS WILL STRENGTHEN SUNDAY AFTERNOON...AND
PRECIPITATION WILL INCREASE THROUGH THE EVENING HOURS...BOTH
FAVORING THE NORTH. I HAVE SPLIT THE EVENING GRID INTO 3 HOUR
BLOCKS TO ADDRESS THIS PRECIPITATION TREND. THERE ALSO CONTINUES
TO BE SOME MODEL TIMING DIFFERENCES. THE ASSOCIATED COLD FRONT
WILL REACH THE NORTHWEST CORNER LATE IN THE EVENING INTO THE
OVERNIGHT PERIOD...DEPENDING ON THE MODEL. THE FRONT WILL QUICKLY
WEAKEN AS IT HEADS SOUTH...MOSTLY WASHING OUT BY THE TIME IT
REACHES SAN JUAN MOUNTAINS MON MORNING. THE GFS IS THE FASTER
MODEL WITH THE NAM AND ECMWF LAGGING BY JUST A FEW HOURS. THE LOW
AMPLITUDE UPPER TROUGH AXIS FOLLOWS NOT FAR BEHIND FRONT...SO THE
BEST PRECIPITATION WILL BE FROM LATE IN THE EVENING THROUGH THE
OVERNIGHT HOURS. THE GFS SHOWS SHOWERS QUICKLY DIMINISHING BY MID
MORNING ON MON. THE EC AND NAM KEEP THINGS GOING THROUGH THE
MORNING AT LEAST...WITH MOUNTAIN SHOWERS LINGERING THROUGH THE
AFTERNOON. THINK THE GFS IS TOO FAST IN AGREEMENT WITH HPC...SO
HAVE EXTENDED BETTER POPS INTO MON. THIS STORM DOES NOT PACK MUCH
COLD AIR SO SNOW LEVELS WILL REMAIN RELATIVELY HIGH. EXPECT RAIN
TO CHANGE OVER TO SNOW ACROSS MOST OF THE NORTHERN AND HIGHER
VALLEYS. BUT PRECIPITATION IN THE OTHER VALLEYS COULD REMAIN
LIQUID...OR MIXED PHASE AT BEST. HIGHS ON MON WILL STILL BE IN THE
50S ACROSS THE SOUTHERN AND CENTRAL VALLEYS AT THE MID-LOWER
ELEVATIONS.
ONCE THE STORM HAS EXITED TO THE EAST...STORM TOTAL SNOW AMOUNTS
OVER THE MOUNTAINS SHOULD REACH A FEW INCHES...WITH THE NORTH
SEEING THE BEST ACCUMULATIONS. ADVISORY AMOUNTS MAY BE POSSIBLE
FOR THE NORTH AND CENTRAL MOUNTAINS. BUT THE SHORT DURATION AND
WARM NATURE OF THE STORM...ARE LIMITING FACTORS.
DRIER AND WARMER CONDITIONS FOLLOW TROUGH MIDWEEK. THEN ANOTHER
PACIFIC TROUGH AND COLD FRONT IS PROGGED TO PASS OVER THE REGION
WED NIGHT-THU NIGHT. THE MODELS HAVE AGAIN TRENDED WEAKER WITH
THIS SYSTEM COMPARED TO WHEN IT WAS FIRST ADVERTISED A COUPLE OF
DAYS AGO. ALSO THERE CONTINUES TO BE SOME TIMING DIFFERENCES WITH
THE GFS STILL THE FASTER MODEL. SO FAR THIS SYSTEM PACKS A COLDER
CORE THAN THE ONE ON SUN NIGHT/MON. AND IF MODELS DO NOT WEAKEN IT
TOO MUCH...THIS STORM SHOULD AGAIN BRING A ROUND OF MOUNTAIN
SNOW...WITH A CHANCE OF VALLEY RAIN AND/OR SNOW SHOWERS.
MODEL INCONSISTENCIES GROW BEYOND THIS WAVE...BUT COOLER
TEMPERATURES SHOULD FOLLOW WITH DRIER CONDITIONS ON FRIDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 317 PM MST FRI NOV 30 2012
MID AND HIGH CLOUDS WILL CONTINUE TO STREAM ACROSS THE FORECAST
AREA WITH ALL TAF SITES SEEING VFR CONDITIONS THROUGH THE EVENING
AS CLOUD HEIGHTS LOWER DUE TO THE APPROACHING DISTURBANCE. LOCAL
MVFR CONDITIONS MAY OCCUR AT TAF SITES NORTH AND ALONG I-70 UNDER
PERIODS OF LIGHT RAIN/SNOW FROM 06Z TO 12Z.
MOUNTAINS AROUND KSBS...THE FLATTOPS...AND EASTERN UINTAS WILL
BECOME OBSCURED AT TIMES UNDER CLOUDS AND LIGHT SNOW SHOWERS BY
MIDNIGHT TONIGHT LASTING UNTIL SUNRISE. SHOWERS WILL BE CONFINED
TO THE HIGHER PEAKS OF THE PARK/GORE/ELKHEAD MOUNTAINS AFTER
SUNRISE UNTIL ABOUT 15Z.
SOME MOUNTAIN WAVES ARE POSSIBLE ON THE LEE SIDE OF RIDGES AS THE
SW TO W FLOW ALOFT STRENGTHENS INTO THE EVENING.
CONDITIONS WILL IMPROVE ACROSS THE AREA LATE SATURDAY MORNING
THROUGH THE AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...MDA
LONG TERM...EH
AVIATION...MDA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1021 AM EST THU NOV 29 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS TO OUR SOUTH TODAY, BEFORE A WEAK COLD FRONT
MOVES ACROSS THE AREA FROM THE NORTH FRIDAY MORNING. STRENGTHENING
CANADIAN HIGH PRESSURE WILL FOLLOW ACROSS NEW ENGLAND THEN INTO
THE CANADIAN MARITIMES FROM FRIDAY INTO THE WEEKEND. A WARM FRONT
IS EXPECTED TO LIFT NORTH OF THE AREA SUNDAY, POSSIBLY FOLLOWED
BY ANOTHER COLD FRONT FROM THE NORTH ON MONDAY. A COLD FRONT IS
EXPECTED TO MOVE IN FROM THE WEST LATE TUESDAY INTO EARLY
WEDNESDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SANDY CORRECTION: REVIEWING DATA WE FOUND THE MAX WIND GUST AT SANDY
HOOK NOS TIDE LOCATION WAS 69 MPH...642 PM ON THE 29TH. (DATA STOPPED
FLOWING THERE AT ABOUT 736 PM. THAT CORRECTS DOWN FROM THE PREVIOUS
REPORT OF 77 MPH AT 715PM). THE TEXAS TECH 2.5 METER STICK MEASUREMENT
NEARBY AROUND 830P OF 75 MPH AND THE 87 MPH WXFLOW MESONET OB AT
ABOUT 835PM BOTH CONTINUE AS IS.
DID NOT RESEND THE PNS...ITS A MONTH SINCE THE STORM OCCURRED PLUS
WE HAD ADDED LOWEST PRES AND SURGE DATA THAT IS NOT IN THE ECLAIRS
PROGRAM WHERE-FROM THE RAIN/SNOW/WIND DATA ARE PRODUCED. I COULD
NOT ACCESS THAT PARTICULAR PNSFILE IN AWIPS ATTM...THOUGH IT
CONTINUES TO RESIDE ON THE WEB.
934AM ESTF UPDATE RAN THE FCST WITH THIS AFTN AND ADJUSTED SKYCOVER
EVEN HIGHER WITH A RESULTANT MORE DEFINED WORDING IN SOME OF THE
ZONES NORTH OF PHILADELPHIA.
TODAY...PERIODS OF THICK HIGH CLOUDS ARE STREAMING ESE ACROSS THE
AREA TODAY...MOSTLY FROM ILG LATITUDE NORTH. 12Z NAM AND CURRENT RUC13
RUNS CONTINUE THE THEME FROM SUCCESSIVE PRIOR MULTI MODEL RUNS.
RGEM AND RUC RH AS WELL AS GFS MOS DO NOT ALL CAPTURE THE VISUAL
SEE-THROUGH IMPACT. THICK CLOUD COVER SHOULD THIN LATE THIS AFTERNOON
BUT DUE TO SHORTER DAYLIGHT HOURS...THIS CLOUD DECK MAY MODIFY THE
WARMING RATE AND MAY FORCE A SLIGHTLY COOLER DAY THAN CURRENTLY
FCST...ESPECIALLY THE STILL SNOW COVERED NE PA AND NW NJ.
THE LOW LEVELS ARE DRY...SO NO PRECIPITATION IS EXPECTED FROM THE
MID LEVEL CLOUDINESS. 850 MB TEMPERATURES WOULD SUPPORT HIGHS
RANGING FROM THE UPPER 30S TO MID 40S FROM NORTH TO SOUTH. SINCE
MODEL SOUNDINGS SUGGEST MIXING FROM 850 MB...HIGHS ARE BASED ON
THESE NUMBERS. THE HIGHS ABOVE ACROSS CLOSER TO THE COOLER GFS MOS
VALUES.
THE GRADIENT FLOW SHOULD SUPPORT WINDS BETWEEN 10 AND 15 MPH. MODEL
SOUNDINGS ARE SUGGESTING THAT GUSTS TO 20 MPH ARE POSSIBLE THIS
AFTERNOON WITH THE PASSAGE OF THE SHORT WAVE...AS THE DEPTH OF THE
MIXED LAYER OVER LAND INCREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE MID LEVEL CLOUDINESS SHOULD EXIT THIS EVENING...AND THE GRADIENT
FLOW SHOULD RELAX BY MID EVENING. HOWEVER...IT DOES NOT APPEAR AS
THOUGH THE FLOW BECOMES CALM...SO TEMPERATURES ARE NOT EXPECTED TO
PLUMMET THIS EVENING LIKE THEY DID WEDNESDAY EVENING.
ANOTHER SHORT WAVE IN THE MID LEVEL FLOW WILL TRY TO PUSH A COLD
FRONT SOUTH TOWARD THE REGION AFTER 0600 UTC FRIDAY. RIGHT NOW...IT
APPEARS AS THOUGH THE BEST MID LEVEL FORCING AHEAD OF THE SHORT WAVE
WILL REMAIN NORTH AND WEST OF THE AREA THROUGH DAYBREAK FRIDAY. THIS
SHOULD ALSO KEEP ANY PRECIPITATION NORTH OF THE AREA AS WELL.
MODEL SOUNDINGS SUGGEST THAT STRATOCUMULUS LEVEL CLOUDINESS SHOULD
APPROACH NORTHERN ZONES LATE TONIGHT. ELSEWHERE...SKIES SHOULD
REMAIN MOSTLY CLEAR. FOR THE MOST PART...LOWS WERE BASED ON THE MOS
BLEND.
FRIDAY...BACKDOOR CF SAGS SOUTHWARD INTO THE FORECAST AREA. LIGHT
SOUTHWEST WIND SHIFTING EAST NORTHEAST IN THE AFTERNOON.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A SERIES OF BACKDOOR TYPE COLD FRONTAL PASSAGE AND SHORT WAVES ARE
EXPECTED DURING THE LONG TERM PORTION OF THE FORECAST, FOLLOWED BY A
TYPICAL COLD FRONTAL PASSAGE FROM THE WEST LATE IN THE PERIOD.
POST BACK DOOR COOL FRONT...ANY LIFT/MOISTURE IS EXPECTED TO LAG
BEHIND THE BOUNDARY AND LIKELY BE CONFINED ACROSS THE NORTHERN
HALF OF THE CWA. THEREFORE, WE HAVE ANY PRECIP CHANCES OVERNIGHT
FRIDAY. HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST SATURDAY,
DEVELOPING A RETURN FLOW ACROSS THE AREA. THERE MAY BE ENOUGH
MOISTURE REMAINING ACROSS THE AREA THAT SOME LIGHT PRECIP COULD
CONTINUE TO BE SQUEEZED OUT ACROSS THE AREA AS A SHORT WAVES
CONTINUES TO SLIDE ACROSS THE AREA. IT`S POSSIBLE THAT THIS MAY
END UP BEING MORE DRIZZLE/FLURRIES THAN RAIN/SNOW FRIDAY NIGHT AND
SATURDAY, BUT WE KEEP IT RAIN/SNOW AS THE PRECIP TYPE.
PRECIP CHANCES DIMINISH SATURDAY NIGHT INTO EARLY SUNDAY, BEFORE
INCREASING ONCE AGAIN LATER ON SUNDAY INTO SUNDAY NIGHT. A WARM
FRONT IS FORECAST TO LIFT NORTH OF THE AREA ON SUNDAY, FOLLOWED BY A
SHORT WAVE ALOFT LATER SUNDAY INTO SUNDAY NIGHT. THERE MAY BE ENOUGH
MOISTURE COMBINED WITH THE ENHANCED LIFT TO CREATE SOME
PRECIPITATION ACROSS THE AREA. TEMPERATURES ARE FORECAST TO BE
WARM ENOUGH TO KEEP IT ALL RAIN.
ANOTHER WEAK BACKDOOR TYPE COLD FRONT IS FORECAST TO APPROACH THE
AREA ON MONDAY, HOWEVER, ITS PASSAGE IS EXPECTED TO BE A DRY ONE.
THEREFORE, THE FORECAST IS DRY FOR MONDAY THROUGH MONDAY NIGHT.
FINALLY, A TYPICAL COLD FRONT IS EXPECTED TO APPROACH THE AREA FROM
THE WEST LATER TUESDAY, AND CROSS THE AREA TUESDAY NIGHT INTO
WEDNESDAY MORNING. PRECIPITATION CHANCES INCREASE WITH THE PASSAGE
OF THE FRONTAL BOUNDARY, WHICH IS CURRENTLY EXPECTED TUESDAY
NIGHT. TEMPERATURES ARE EXPECTED TO BE WARM ENOUGH TO KEEP P-TYPE
ALL RAIN.
TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FRIDAY, BEFORE
RISING OVER THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES LATE IN
THE WEEKEND INTO EARLY NEXT WEEK ARE EXPECTED TO BE SEVERAL DEGREES
ABOVE NORMAL, THEN DROP BACK CLOSER TO NORMAL BEHIND THE FRONTAL
BOUNDARY FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR OCNL CIGS AOA 10000 FEET...MOSTLY NORTH OF KILG. WEST
WINDS OF 8 TO 12 KNOTS ARE EXPECTED TODAY...WITH A FEW GUSTS NEAR
18 KNOTS POSSIBLE IN THE AFTERNOON (BETWEEN 1700 AND 2100 UTC) AT
THE KPHL METRO AIRPORTS.
TONIGHT...VFR CONDITIONS ARE EXPECTED WITH SOUTHWEST WINDS OF 5
KNOTS OR LESS. SOME HIGH AND MID LEVEL CLOUDINESS IS POSSIBLE
TOWARD DAYBREAK FRIDAY AHEAD OF A BACKDOOR COLD FRONT.
FRIDAY...VFR. A PERIOD OF CIGS AOA 8000 FT EXPECTED DURING MIDDAY
JUST BEHIND THE SURFACE WIND SHIFT-COLD FRONT. MVFR CIGS MAY DEVELOP
IN THE INCREASING ENE FLOW BEHIND THE FRONT...NEAR AND NORTH OF
KSMQ.
OUTLOOK...
FRIDAY NIGHT-SATURDAY...MOSTLY VFR.
SATURDAY NIGHT-SUNDAY NIGHT...MVFR CONDITIONS POSSIBLE.
MONDAY...MVFR CONDITIONS POSSIBLE EARLY...IMPROVING TO VFR.
&&
.MARINE...
SCA DISCONTINUED WITH THE 10 AM CWF/MWW ISSUANCE.
WEST WINDS MAY BRIEFLY INCREASE LATE THIS AFTERNOON OR EVENING IN
THE NNJ WATERS BUT FOR NOW NOT ANTICIPATING ANY FURTHER SCA THROUGH
FRIDAY.
OUTLOOK...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS FOR
FRIDAY NIGHT THROUGH SATURDAY AS WEAK HIGH PRESSURE BUILDS DOWN ACROSS
THE WATERS FROM THE NORTH. WINDS AND WAVES MAY APPROACH ADVISORY
LEVELS AGAIN LATE SUNDAY THROUGH SUNDAY NIGHT, AS THE SOUTHERLY
FLOW INCREASES BEHIND A WARM FRONT THAT LIFTS TO OUR NORTH.
CONDITIONS ON MONDAY SHOULD REMAIN BELOW ADVISORY LEVELS AS WEAK
COLD FRONT MOVES ACROSS THE WATERS FROM THE NORTH AND WEAK HIGH
PRESSURE REMAINS TO OUR SOUTH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/HAYES
SHORT TERM...DRAG/HAYES
LONG TERM...ROBERTSON
AVIATION...DRAG/HAYES/ROBERTSON
MARINE...DRAG/HAYES/ROBERTSON 1020A
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
949 AM EST THU NOV 29 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS TO OUR SOUTH TODAY, BEFORE A WEAK COLD FRONT
MOVES ACROSS THE AREA FROM THE NORTH FRIDAY MORNING. STRENGTHENING
CANADIAN HIGH PRESSURE WILL FOLLOW ACROSS NEW ENGLAND THEN INTO
THE CANADIAN MARITIMES FROM FRIDAY INTO THE WEEKEND. A WARM FRONT
IS EXPECTED TO LIFT NORTH OF THE AREA SUNDAY, POSSIBLY FOLLOWED
BY ANOTHER COLD FRONT FROM THE NORTH ON MONDAY. A COLD FRONT IS
EXPECTED TO MOVE IN FROM THE WEST LATE TUESDAY INTO EARLY
WEDNESDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SANDY CORRECTION: REVIEWING DATA WE FOUND THE MAX WIND GUST AT SANDY
HOOK NOS TIDE LOCATION WAS 69 MPH...642 PM ON THE 29TH. (DATA STOPPED
FLOWING THERE AT ABOUT 736 PM. THAT CORRECTS DOWN FROM THE PREVIOUS
REPORT OF 77 MPH AT 715PM). THE TEXAS TECH 2.5 METER STICK MEASUREMENT
NEARBY AROUND 830P OF 75 MPH AND THE 87 MPH WXFLOW MESONET OB AT
ABOUT 835PM BOTH CONTINUE AS IS.
DID NOT RESEND THE PNS...ITS A MONTH SINCE THE STORM OCCURRED PLUS
WE HAD ADDED LOWEST PRES AND SURGE DATA THAT IS NOT IN THE ECLAIRS
PROGRAM WHERE-FROM THE RAIN/SNOW/WIND DATA ARE PRODUCED. I COULD
NOT ACCESS THAT PARTICULAR PNSFILE IN AWIPS ATTM...THOUGH IT
CONTINUES TO RESIDE ON THE WEB.
934AM ESTF UPDATE RAN THE FCST WITH THIS AFTN AND ADJUSTED SKYCOVER
EVEN HIGHER WITH A RESULTANT MORE DEFINED WORDING IN SOME OF THE
ZONES NORTH OF PHILADELPHIA.
TODAY...PERIODS OF THICK HIGH CLOUDS ARE STREAMING ESE ACROSS THE
AREA TODAY...MOSTLY FROM ILG LATITUDE NORTH. 12Z NAM AND CURRENT RUC13
RUNS CONTINUE THE THEME FROM SUCCESSIVE PRIOR MULTI MODEL RUNS.
RGEM AND RUC RH AS WELL AS GFS MOS DO NOT ALL CAPTURE THE VISUAL
SEE-THROUGH IMPACT. THICK CLOUD COVER SHOULD THIN LATE THIS AFTERNOON
BUT DUE TO SHORTER DAYLIGHT HOURS...THIS CLOUD DECK MAY MODIFY THE
WARMING RATE AND MAY FORCE A SLIGHTLY COOLER DAY THAN CURRENTLY
FCST...ESPECIALLY THE STILL SNOW COVERED NE PA AND NW NJ.
THE LOW LEVELS ARE DRY...SO NO PRECIPITATION IS EXPECTED FROM THE
MID LEVEL CLOUDINESS. 850 MB TEMPERATURES WOULD SUPPORT HIGHS
RANGING FROM THE UPPER 30S TO MID 40S FROM NORTH TO SOUTH. SINCE
MODEL SOUNDINGS SUGGEST MIXING FROM 850 MB...HIGHS ARE BASED ON
THESE NUMBERS. THE HIGHS ABOVE ACROSS CLOSER TO THE COOLER GFS MOS
VALUES.
THE GRADIENT FLOW SHOULD SUPPORT WINDS BETWEEN 10 AND 15 MPH. MODEL
SOUNDINGS ARE SUGGESTING THAT GUSTS TO 20 MPH ARE POSSIBLE THIS
AFTERNOON WITH THE PASSAGE OF THE SHORT WAVE...AS THE DEPTH OF THE
MIXED LAYER OVER LAND INCREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE MID LEVEL CLOUDINESS SHOULD EXIT THIS EVENING...AND THE GRADIENT
FLOW SHOULD RELAX BY MID EVENING. HOWEVER...IT DOES NOT APPEAR AS
THOUGH THE FLOW BECOMES CALM...SO TEMPERATURES ARE NOT EXPECTED TO
PLUMMET THIS EVENING LIKE THEY DID WEDNESDAY EVENING.
ANOTHER SHORT WAVE IN THE MID LEVEL FLOW WILL TRY TO PUSH A COLD
FRONT SOUTH TOWARD THE REGION AFTER 0600 UTC FRIDAY. RIGHT NOW...IT
APPEARS AS THOUGH THE BEST MID LEVEL FORCING AHEAD OF THE SHORT WAVE
WILL REMAIN NORTH AND WEST OF THE AREA THROUGH DAYBREAK FRIDAY. THIS
SHOULD ALSO KEEP ANY PRECIPITATION NORTH OF THE AREA AS WELL.
MODEL SOUNDINGS SUGGEST THAT STRATOCUMULUS LEVEL CLOUDINESS SHOULD
APPROACH NORTHERN ZONES LATE TONIGHT. ELSEWHERE...SKIES SHOULD
REMAIN MOSTLY CLEAR. FOR THE MOST PART...LOWS WERE BASED ON THE MOS
BLEND.
FRIDAY...BACKDOOR CF SAGS SOUTHWARD INTO THE FORECAST AREA. LIGHT
SOUTHWEST WIND SHIFTING EAST NORTHEAST IN THE AFTERNOON.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A SERIES OF BACKDOOR TYPE COLD FRONTAL PASSAGE AND SHORT WAVES ARE
EXPECTED DURING THE LONG TERM PORTION OF THE FORECAST, FOLLOWED BY A
TYPICAL COLD FRONTAL PASSAGE FROM THE WEST LATE IN THE PERIOD.
POST BACK DOOR COOL FRONT...ANY LIFT/MOISTURE IS EXPECTED TO LAG
BEHIND THE BOUNDARY AND LIKELY BE CONFINED ACROSS THE NORTHERN
HALF OF THE CWA. THEREFORE, WE HAVE ANY PRECIP CHANCES OVERNIGHT
FRIDAY. HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST SATURDAY,
DEVELOPING A RETURN FLOW ACROSS THE AREA. THERE MAY BE ENOUGH
MOISTURE REMAINING ACROSS THE AREA THAT SOME LIGHT PRECIP COULD
CONTINUE TO BE SQUEEZED OUT ACROSS THE AREA AS A SHORT WAVES
CONTINUES TO SLIDE ACROSS THE AREA. IT`S POSSIBLE THAT THIS MAY
END UP BEING MORE DRIZZLE/FLURRIES THAN RAIN/SNOW FRIDAY NIGHT AND
SATURDAY, BUT WE KEEP IT RAIN/SNOW AS THE PRECIP TYPE.
PRECIP CHANCES DIMINISH SATURDAY NIGHT INTO EARLY SUNDAY, BEFORE
INCREASING ONCE AGAIN LATER ON SUNDAY INTO SUNDAY NIGHT. A WARM
FRONT IS FORECAST TO LIFT NORTH OF THE AREA ON SUNDAY, FOLLOWED BY A
SHORT WAVE ALOFT LATER SUNDAY INTO SUNDAY NIGHT. THERE MAY BE ENOUGH
MOISTURE COMBINED WITH THE ENHANCED LIFT TO CREATE SOME
PRECIPITATION ACROSS THE AREA. TEMPERATURES ARE FORECAST TO BE
WARM ENOUGH TO KEEP IT ALL RAIN.
ANOTHER WEAK BACKDOOR TYPE COLD FRONT IS FORECAST TO APPROACH THE
AREA ON MONDAY, HOWEVER, ITS PASSAGE IS EXPECTED TO BE A DRY ONE.
THEREFORE, THE FORECAST IS DRY FOR MONDAY THROUGH MONDAY NIGHT.
FINALLY, A TYPICAL COLD FRONT IS EXPECTED TO APPROACH THE AREA FROM
THE WEST LATER TUESDAY, AND CROSS THE AREA TUESDAY NIGHT INTO
WEDNESDAY MORNING. PRECIPITATION CHANCES INCREASE WITH THE PASSAGE
OF THE FRONTAL BOUNDARY, WHICH IS CURRENTLY EXPECTED TUESDAY
NIGHT. TEMPERATURES ARE EXPECTED TO BE WARM ENOUGH TO KEEP P-TYPE
ALL RAIN.
TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL FRIDAY, BEFORE
RISING OVER THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES LATE IN
THE WEEKEND INTO EARLY NEXT WEEK ARE EXPECTED TO BE SEVERAL DEGREES
ABOVE NORMAL, THEN DROP BACK CLOSER TO NORMAL BEHIND THE FRONTAL
BOUNDARY FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR OCNL CIGS AOA 10000 FEET...MOSTLY NORTH OF KILG. WEST
WINDS OF 8 TO 12 KNOTS ARE EXPECTED TODAY...WITH A FEW GUSTS NEAR
18 KNOTS POSSIBLE IN THE AFTERNOON (BETWEEN 1700 AND 2100 UTC) AT
THE KPHL METRO AIRPORTS.
TONIGHT...VFR CONDITIONS ARE EXPECTED WITH SOUTHWEST WINDS OF 5
KNOTS OR LESS. SOME HIGH AND MID LEVEL CLOUDINESS IS POSSIBLE
TOWARD DAYBREAK FRIDAY AHEAD OF A BACKDOOR COLD FRONT.
FRIDAY...VFR. A PERIOD OF CIGS AOA 8000 FT EXPECTED DURING MIDDAY
JUST BEHIND THE SURFACE WIND SHIFT-COLD FRONT. MVFR CIGS MAY DEVELOP
IN THE INCREASING ENE FLOW BEHIND THE FRONT...NEAR AND NORTH OF
KSMQ.
OUTLOOK...
FRIDAY NIGHT-SATURDAY...MOSTLY VFR.
SATURDAY NIGHT-SUNDAY NIGHT...MVFR CONDITIONS POSSIBLE.
MONDAY...MVFR CONDITIONS POSSIBLE EARLY...IMPROVING TO VFR.
&&
.MARINE...
WILL DISCONTINUE SCA WITH THE 10 AM EXPIRATION AND RUN MWW AND CWF
SHORTLY AFTER 10 AM.
WEST WINDS MAY BRIEFLY INCREASE LATE THIS AFTERNOON OR EVENING IN
THE NNJ WATERS BUT FOR NOW NOT ANTICIPATING ANY FURTHER SCA THROUGH
FRIDAY.
OUTLOOK...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS FOR
FRIDAY NIGHT THROUGH SATURDAY AS WEAK HIGH PRESSURE BUILDS DOWN ACROSS
THE WATERS FROM THE NORTH. WINDS AND WAVES MAY APPROACH ADVISORY
LEVELS AGAIN LATE SUNDAY THROUGH SUNDAY NIGHT, AS THE SOUTHERLY
FLOW INCREASES BEHIND A WARM FRONT THAT LIFTS TO OUR NORTH.
CONDITIONS ON MONDAY SHOULD REMAIN BELOW ADVISORY LEVELS AS WEAK
COLD FRONT MOVES ACROSS THE WATERS FROM THE NORTH AND WEAK HIGH
PRESSURE REMAINS TO OUR SOUTH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ450-
451.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/HAYES 949
SHORT TERM...DRAG/HAYES
LONG TERM...ROBERTSON
AVIATION...DRAG/HAYES/ROBERTSON
MARINE...DRAG/HAYES/ROBERTSON 949
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
903 PM EST FRI NOV 30 2012
.SYNOPSIS...
AN EASTBOUND UPPER DISTURBANCE WILL MAINTAIN MOSTLY CLOUDY SKIES
ACROSS THE UPPER OHIO VALLEY TONIGHT WHILE SOUTHWESTERLY WIND
PROVIDES MILD TEMPERATURES WHICH WILL PERSIST FOR THE WEEKEND.
PERIODIC SHOWER CHANCES CAN BE EXPECTED FOR THE FIRST HALF OF NEXT
WEEK WEEK AS A FRONTAL SYSTEM ADVANCES ON AND CROSS THE REGION.
&&
.NEAR TERM /THROUGH SATURDAY/...
ONLY CHANGES NEEDED FOR THE LATE EVE UPDATE WERE TWEAKS TO HOURLY
TRENDS...INCLUDING THE REMOVAL OF SPRINKLE-MENTION.
PREVIOUS...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA COUPLED
WITH RECENT RAP AND NAM MODEL OUTPUT...THICK ALTOCUMULUS AND
CIRROPSTRATUS CLOUDS WILL CONTINUE TO FLOW OVER THE REGION TONIGHT
AS SHORTWAVE TROUGH PROGRESSES EASTWARD. RECENT RADAR DATA ALSO
INDICATES SOME LIGHT SHOWERS...BUT THE DRY LOW LEVEL OF THE
ATMOSPHERE WILL INHIBIT ANY MEASURABLE PRECIP...HENCE...MENTION OF
SPRINKLES FOR THE EVE SHOULD SUFFICE.
OVERNIGHT LOW WERE FORECAST ABOUT 5 DEGREES ABOVE THE AVERAGES
USING GFS...NAM MOS AND RAP MODEL OUTPUT.
BETTER INSOLATION IN THE WAKE OF TONIGHTS UPPER DISTURBANCE...IN
ADDITION TO WARM ADVCTN REGIME OVR THE AREA...WILL SUPPORT
SATURDAY HIGHS APPROXIMATELY 10 TO 15 ABOVE NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
WARM TO NEUTRAL ADVCTN IN ADVN OF...AND FOLLOWING PASSAGE OF A SHORTWAVE
IN GENLY ZONAL FLOW WILL MAINTAIN CONTINUED WARMTH ACROSS THE UPPER
OHIO VALLEY FOR THE SHORT TERM PERIOD. GFS AND NAM MOS SUGGEST TEMPERATURES
MAY BE 15 TO 20 DEGREES WARMER THAN NORMAL. HOWEVER...THE RELIEF FROM
COLD WILL BE MARRED BY INCREASING SHOWER CHANCES ON SUNDAY AS MOISTURE
AND ASCENT PROFILES ARE ALSO BE IMPROVED BY THE APPROACHING SYSTEM.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
NO RESTRICTIONS ARE EXPECTED DURING THE TAF PERIOD ALTHOUGH MID
AND HIGH CLOUDS WILL STREAM ACRS UPR OH TERMINALS TONIGHT WITH
PASSAGE OF A CROSSING SHORTWAVE. MODELS ALSO HINT AT MVFR STRATOCU
DVLPMNT IN VICINITY OF THE WARM FRONT WHICH WAS ANALYZED NR FKL
AND DUJ...BUT CONFIDENCE IN THAT SCENARIO IS NOT STRONG AND WL
ONLY HIT AT LOWER CLOUDS IN THE TAFS FOR THOSE PORTS.
OTHERWISE...SUSTAINED WIND IS EXPECTED TO RMN LESS THAN 10 KTS FOR
THE PD.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
554 PM CST FRI NOV 30 2012
.UPDATE...
.AVIATION...
SFC OBS FROM SERN KS AND OUTPUT FROM THE RAP MODEL INDICATE
STRATUS AND MVFR CIGS COULD MOVE INTO FRONTIER...CUSTER AND
WHEELER COUNTIES BETWEEN 11Z AND 16Z SATURDAY. OTHERWISE...VFR IS
EXPECTED ALL AREAS.
&&
.PREV DISCUSSION... /ISSUED 519 PM CST FRI NOV 30 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH SATURDAY.
SCT-BKN HIGH LEVEL CLOUDINESS FROM A LARGE PACIFIC STORM SYSTEM WILL
CONTINUE TO MOVE ACROSS THE FCST AREA THROUGH SATURDAY.
PREV DISCUSSION... /ISSUED 310 PM CST FRI NOV 30 2012/
SYNOPSIS...
H5 ANALYSIS THIS MORNING HAS A BROAD AREA OF LOW PRESSURE OFF THE
COAST OF BRITISH COLUMBIA WITH A SECOND LOW LOCATED OVER NORTH
CENTRAL CANADA. A JET STREAK EXTENDED FROM NORTHERN CALIFORNIA INTO
NWRN MT THIS MORNING WITH A SECOND JET STREAK EXTENDING FROM SRN
QUEBEC INTO THE CANADIAN MARITIMES. WV IMAGERY...AND IR IMAGERY
CONTINUES TO INDICATE ABUNDANT TROPICAL MOISTURE WORKING INTO
CENTRAL AND NRN CALIFORNIA...AS WELL AS OREGON AND WASHINGTON
STATE...AND EXTENDED EAST TO NEVADA...IDAHO AND MONTANA. HIGH LEVEL
CLOUDINESS HAS EXITED CENTRAL AND WESTERN NEBRASKA EARLIER THIS
MORNING LEADING TO MOSTLY SUNNY SKIES THIS AFTERNOON. ANOTHER BATCH
OF BROKEN TO OVERCAST HIGH CLOUDINESS CONTINUES TO PUSH INTO THE
CENTRAL AND NORTHERN ROCKIES THIS AFTERNOON AND WILL ARRIVE ACROSS
THE CENTRAL AND NORTHERN PLAINS LATER THIS EVENING. TEMPERATURES AS
OF 2 PM CST RANGED FROM 47 AT O`NEILL...TO 60 AT OGALLALA AND
THEDFORD.
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH MONDAY...MAIN FORECASTING CHALLENGES
CONTINUE TO REVOLVE AROUND TEMPERATURES AND THE IMPACTS OF HIGH
CLOUDINESS ON THEM. IN ADDITION...WINDS AND WIND SPEEDS IN
ASSOCIATION WITH A COLD FROPA MONDAY CONTINUE TO BE PROBLEMATIC.
FOR TONIGHT AND SATURDAY...SKIES WILL TRANSITION TO MOSTLY CLOUDY
LATER TONIGHT AS ABUNDANT UPPER LEVEL MOISTURE AND HIGH CLOUDINESS
STREAMS INTO THE REGION FROM THE CENTRAL AND NORTHERN ROCKIES. NO
PRECIPITATION IS EXPECTED THOUGH AS VERY DRY CONDITIONS REMAIN BLO
15000 FT AGL. WITH ABUNDANT CLOUD COVER...OVERNIGHT LOWS WILL BE
MILD WITH READINGS MAINLY IN THE LOWER 30S. DID DECIDE TO GO WITH
UPPER 20S IN THE PLATTE RIVER VALLEY THANKS TO DRY AIR AND LIGHT
WESTERLY WINDS...WHICH ALLOW TEMPS TO TANK THIS EVENING AHEAD OF THE
ARRIVAL OF CLOUD COVER. CLOUDS WILL TRANSITION EAST QUICKLY ON
SATURDAY AND ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY LATE
MORNING. LOW PRESSURE AND AN ASSOCIATED SURFACE TROUGH OF LOW
PRESSURE WILL TRACK INTO THE EASTERN DAKOTAS AND EASTERN NEBRASKA ON
SATURDAY...RESULTING IN WESTERLY WINDS ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA SATURDAY AFTERNOON. THE COMBINATION OF FULL
SUN...WESTERLY DOWN SLOPING WINDS...AND DRY AIR...WILL ALLOW TEMPS
TO CLIMB QUICKLY INTO THE UPPER 50S AND LOWER 60S BY MIDDAY
SATURDAY. HIGHS ARE EXPECTED TO REACH THE UPPER 60S TO NEAR 70 IN
THE SOUTHWEST...WITH LOWER TO MID 60S EXPECTED ELSEWHERE.
FYI...RECORD HIGHS TOMORROW FOR VALENTINE...NORTH PLATTE AND
IMPERIAL ARE 74...71 AND 72 RESPECTIVELY WITH 68 BEING THE RECORD AT
BROKEN BOW.
WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NEBRASKA SATURDAY NIGHT.
CLEAR SKIES...LIGHT WINDS AND DRY AIR...WILL ALLOW LOWS TO DROP
QUICKLY INTO THE UPPER 20S TO NEAR 30. INSERTED SOME MID 20S IN THE
PLATTE RIVER VALLEY AND WESTERN SAND HILLS...THANKS TO LIGHT
WESTERLY WINDS AND A GOOD SETUP FOR COLD AIR DRAINAGE. ON
SUNDAY...HIGH PRESSURE WILL DRIFT EAST OF THE AREA...WITH A LEE SIDE
TROUGH OF LOW PRESSURE DEVELOPING ACROSS THE PANHANDLE...EASTERN
WYOMING AND EASTERN COLORADO...ALLOWING SRLY WINDS TO INCREASE. THE
COMBINATION OF DECENT MIXING AND H85 TEMPS OF 12 TO 15C...WILL PUSH
AFTERNOON HIGHS INTO THE MID AND UPPER 60S.
A COLD FRONT WILL APPROACH THE FORECAST AREA SUNDAY NIGHT. SRLY
WINDS WILL CONTINUE EAST OF THE FRONT AND ARE NOT EXPECTED TO
TOTALLY DECOUPLE. THIS WILL LEAD TO LOWS IN THE 30S FOR SUNDAY
NIGHT. ON MONDAY THE BEFORE MENTIONED COLD FRONT WILL TRACK ACROSS
THE REGION. DECENT NWRLY WINDS WILL DEVELOP WITH PASSAGE OF THIS
FEATURE AND MAY BECOME STRONG BY MIDDAY MONDAY. BASED ON GFS AND NAM
BUFKIT SOUNDINGS...THERE IS A SMALL THREAT FOR WIND GUSTS OVER 40
MPH MID DAY MONDAY. ATTM THE GREATEST THREAT FOR WINDS OF THIS
MAGNITUDE IS OVER NORTHERN NEBRASKA...WHERE COLD AIR ADVECTION WILL
BE STRONGEST BEHIND THE FRONT. FURTHER SOUTH AND WEST...COLD AIR
ADVECTION WILL BE MUCH WEAKER...LIMITING GUST POTENTIAL MONDAY
AFTERNOON. HIGHS WILL BE COOLER WITH READINGS IN THE UPPER 40S AND
50S EXPECTED...WHICH IS STILL 10 TO 15 DEGREES ABOVE CLIMO.
LONG RANGE...MONDAY NIGHT THROUGH FRIDAY...MILD AND DRY WEATHER WILL
BEGIN THE EXTENDED PERIOD...WITH HIGHS WELL INTO THE 50S AND
POSSIBLE NEAR 60 DEGREES TUESDAY AND WEDNESDAY. THE WEATHER WILL
BEGIN TO CHANGE THURSDAY AS A STRONG SHORTWAVE TROUGH MOVES ACROSS
SOUTHERN CANADA AND THE NORTHERN PLAINS. THIS WILL DRIVE A COLD
FRONT THROUGH THE AREA...WITH A HYBRID OF PACIFIC AND ARCTIC AIR
INTRUDING THE AREA BEHIND THE FRONT ON FRIDAY. THE COLDEST /MOST OF
THE ARCTIC/ AIR IS EXPECTED TO STAY NORTHEAST OF THE AREA...SO WHILE
IT WILL BE COLDER FRIDAY HIGHS WILL ONLY BE SLIGHTLY BELOW NORMAL.
ALL INDICATIONS ARE THAT CONDITIONS WILL WARM AGAIN DURING THE
WEEKEND JUST BEYOND THE FORECAST PERIOD.
PRECIPITATION CHANCES ARE SMALL BUT POSSIBLE ON THURSDAY AFTER THE
FRONTAL PASSAGE. AREA IS IN THE RIGHT REAR QUADRANT OF A SIGNIFICANT
JET STREAK...AND SOME DECENT FRONTOGENESIS DEVELOPS ACROSS THE AREA.
SO WILL CONTINUE THE SLIGHT CHANCES FOR RAIN AND SNOW.
AVIATION...
NO AVIATION CONCERNS OVER THE NEXT 24 HOURS. ONLY MID TO HIGH
LEVEL CLOUDS ARE EXPECTED. WINDS WILL BE SOUTHERLY AROUND 10 KTS
THROUGH THE EVENING. WINDS AT KVTN WILL REMAIN ELEVATED OUT OF
THROUGH THE NIGHT AS A SFC LOW PRESSURE PASSES THROUGH THE
DAKOTAS. FRONT PASSES THROUGH THE AREA TOMORROW MORNING WITH WINDS
SWITCHING TO WEST NORTHWEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
952 PM EST FRI NOV 30 2012
.SYNOPSIS...
A FRONT WILL CROSS THROUGH THE FINGER LAKES AND MOHAWK VALLEY
TONIGHT. SOME LIGHT SNOW AND FLURRIES WILL OCCUR IN THE VICINITY
OF THE FRONT. COLD AIR WILL HANG UP AGAINST THE CATSKILLS AND
POCONOS OVERNIGHT...WHICH ALONG WITH A MOISTENING LOWER
ATMOSPHERE...WILL LEAD TO PATCHY FREEZING DRIZZLE OR A LIGHT
WINTRY MIX FOR SOME LOCATIONS INTO SATURDAY MORNING...ESPECIALLY
SULLIVAN AND PIKE COUNTIES. THOUGH SOME SHOWERS WILL MOVE IN
SUNDAY...ABOVE NORMAL TEMPERATURES ARE EXPECTED INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
10 PM UPDATE...
NO SIGNS OF FRZG PCPN DVLPNG ACRS THE SE AT THIS TIME. HV ISSUED A
SPECIAL WX STATEMENT FOR BLACK ICE FOR THE SRN TIER AND A ROW OF
CNTYS JUST TO THE NORTH, WHERE SNOW MELTED THIS AFTN AND RE-FROZE
ON ROADWAYS.
NO CHGS NEEDED TO FCST FOR NOW.
PREV DISCUSSIONS BLO...
830 PM UPDATE...
STILL A CONVOLUTED WX PATTERN IN PLACE FOR TONIGHT. LIGHT SNOW IS
OCCURRING ALONG THIS BNDRY INTO THE FINGER LKS AND MOHAWK VLY. H5
S/WV HAS PASSED AND LIFTED THE FRONTAL BNDRY NORTH OF THE SRN
TIER, BRINGING AN END TO THE SNOW FOR TONIGHT. MAIN QUESTION FOR
TONIGHT IS HOW MUCH DRIZZLE AND/OR PCPN WL THE CATSKILLS AND
POCONOS SEE OVRNGT. CHECKING THE FORT DIX VAD WIND PROFILE FM THE
JERSEY COAST DOES NOT GIVE MUCH CONFIDENCE TO SERLY FLOW KICKING
IN, AS IT CONTS TO RMN NRLY FLOW. HWVR, FURTHER NORTH JUST TO THE
SOUTH OF THE WMFNT, I.E KBGM, SERLY FLOW IS WELL-ESTABLISHED.
SO QUESTION IS WL THIS BE ENUF TO GENERATE DRIZZLE AS THE ATLANTIC
IS ESSENTIALLY CLOSED OFF? MODEL SNDGS AT KMSV PER 18Z NAM
INDICATES A SATURATED LOW-LVL ATMOSPHERE UP THRU ABOUT H9 THEN IS
QUESTIONABLE FURTHER ALOFT. RAP INDICATES SATURATED LAYER NEVER
MAKES IT UP TO H9. WL THIS BE ENUF TO GENERATE ANY DRIZZLE OR
STRICTLY A FRZG FOG SCENARIO. QPF FIELDS FM 18Z NAM INDICATE SOME
PCPN MAY FORM FROM SULLIVAN CNTY INTO SRN LUZERNE CNTY, LIKELY DUE
TO OROGRAPHIC AFFECTS. THEREFORE, THE QUESTION BCMS SHUD WE EXPAND
THE ADVISORY WEST EVEN IF WE ARE NOT CONVINCED IT WL BE FZDZ? FOR
NOW WL PASS ON CONCERNS TO THE NEXT SHIFT TO KEEP A CLOSE EYE ON
ANY DVLPMNT BUT PLAN TO KEEP THINGS AS IS FOR THE TIME BEING. WITH
AREAS OF FZDZ IN SULLIVAN/PIKE CNTYS AND PATCHY FZDZ FURTHER WEST
INTO THE POCONOS.
ONLY MINOR TWEAKS TO HRLY T/TD/WIND TRENDS.
4 PM UPDATE...
BAND OF LIGHT SNOW IN IMMEDIATE VICINITY OF FRONT INITIALLY
STALLED OUT AROUND THE TWIN TIERS...IS FINALLY BEGINNING TO EDGE
NORTH AS WAVE FINISHES PASSING ALOFT...AND THE BOUNDARY IS
BECOMING A WARM FRONT. WHERE THINGS LINED UP JUST
RIGHT...GENERALLY ALONG THE SOUTHERN TIER OF NEW YORK...THE FRONT
WAS ABLE TO SQUEEZE OUT AN INCH OR SO OF SNOW...WHEREAS ELSEWHERE
THE COLUMN HAS BEEN TOO DRY. THE THINNING BAND OF SNOW WILL
CONTINUE TO MOVE NORTH WITH THE WARM FRONT THROUGH FINGER
LAKES/MOHAWK VALLEY THIS EVENING.
AFTER THE WAVE ALOFT MOVES THROUGH...WE LOSE THE DEEPER MOISTURE.
MEANWHILE...STRONG SURFACE HIGH WILL MOVE OVER FROM QUEBEC INTO
MAINE...WITH FLOW AROUND IT SETTING UP COLD AIR DAMMING AGAINST
THE MOUNTAINS. NAM MODEL SOUNDING ESPECIALLY MONTICELLO AREA SHOW
THERMAL PROFILE THAT LATE TONIGHT LOSES ABILITY TO INTRODUCE ICE
CRYSTALS FROM ABOVE /BECAUSE TEMPERATURES WARMER THAN MINUS-8
CELSIUS WITHIN THE SHALLOWER SATURATED LAYER/. COLD AIR DAMMING
AT SURFACE LOOKS LIKELY TO KEEP SULLIVAN/PIKE COUNTIES BELOW
FREEZING. THUS WE HAVE A FAVORABLE SET UP FOR AREAS OF FREEZING
DRIZZLE...WITH AT LEAST A CHANCE OF VERY LIGHT WINTRY MIX
/SNOW...SLEET...FREEZING RAIN/. WINTER WEATHER ADVISORY HAS BEEN
HOISTED FOR 1AM-10AM SATURDAY FOR THAT REASON. ACTUAL PRECIPITATION
AMOUNTS WILL BE MINIMAL...BUT EVEN A VERY LIGHT GLAZE OF ICE FROM
FREEZING DRIZZLE IS CAPABLE OF PRODUCING HAZARDOUS TRAVEL
CONDITIONS. WE WILL BE MONITORING CLOSELY TO SEE IF OTHER COUNTIES
MAY NEED TO BE INCLUDED. EASTERN EDGES OF DELAWARE-OTSEGO-WAYNE-
ONEIDA COUNTIES COULD POTENTIALLY HAVE AT LEAST PATCHY FREEZING
DRIZZLE.
ON SATURDAY...CENTRAL TO WESTERN CWA LOOKS DRY WITH WARMING
TEMPERATURES. HOWEVER...CONTINUED SOUTHEAST LOW LEVEL FLOW AGAINST
CATSKILLS/POCONOS WILL HOLD TEMPERATURES BACK IN THE SOUTHEAST.
BIGGEST CONCERN AT THIS TIME IS WHETHER PATCHY FREEZING DRIZZLE
WILL BE ABLE TO PERSIST BEYOND 10 AM...BUT HOPEFULLY DIURNAL
HEATING WILL MITIGATE THAT...BUT THERE IS UNCERTAINTY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
4 PM UPDATE...
WARM AIR ADVECTION CONTINUES SATURDAY NIGHT INTO SUNDAY...TO THE
POINT THAT A GOOD PART OF THE AREA /ESPECIALLY WESTERN/ SHOULD
MANAGE TO GET INTO 50S FOR HIGHS SUNDAY. WEAKENING COLD FRONT
WILL SPREAD SHOWERS WEST TO EAST SUNDAY AFTERNOON AND
EVENING...BUT TEMPERATURES WILL BE WARM ENOUGH FOR ALL RAIN. ONLY
EXPECTING A FEW TENTHS OF AN INCH AT BEST WITH BRISKNESS OF FLOW
ALOFT. VERY BRIEF SLIGHT COLD AIR ADVECTION SUNDAY NIGHT...QUICKLY
NEUTRALIZES ALLOWING TEMPERATURES MONDAY TO BE NEAR OR ABOVE HIGHS
FROM SUNDAY. WEAK SURFACE HIGH PRESSURE TAKES CHARGE
MONDAY...WHICH FOR MOST IF NOT ALL WILL KEEP THE WEATHER DRY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
415 PM UPDATE...
IT WILL BE MILD AND QUIET INTO MONDAY EVENING, BEFORE A STORM
SYSTEM MOVING THROUGH LOWER ONTARIO PULLS A COLD FRONT INTO NY/PA.
THIS WILL CAUSE RAIN SHOWERS TUESDAY AND TUESDAY NIGHT. SOME WET
SNOW SHOWERS WILL BE POSSIBLE EARLY WEDNESDAY MORNING AS -4C 850MB
ISOTHERM CROSSES THE I-81 CORRIDOR.
TEMPERATURES WILL REMAIN COOL INTO EARLY THURSDAY. HOWEVER THE GFS
IS NOW FORECASTING A NEW RIDGE TO BUILD THURSDAY AFTERNOON INTO
FRIDAY, POTENTIALLY RESULTING IN ANOTHER WARMING TREND.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
7 PM UPDATE...
A BOUNDARY NOW ACROSS CENTRAL NY WILL CONTINUE TO LIFT NORTH WITH
THE BIGGEST AVIATION IMPACT THROUGH 04Z AT KSYR AND KRME IN LIGHT
SNOW. MAINLY MVFR CIGS AND VSBYS EXPECTED HERE THROUGH 04Z.
BASED ON OBS BACK TO THE WEST AT KROC INCLUDED A TWO HOUR TEMPO
GROUP FOR BRIEF IFR VSBYS AT BOTH TERMINALS TO ACCOUNT FOR THE
STEADIER PERIODS OF SNOW. ELSEWHERE WITH THE BOUNDARY NORTH OF THE
TERMINALS...VFR CIGS AROUND 5KFT EXPECTED THROUGH 06Z.
AFTER 06Z ACROSS THE SOUTHERN TERMINALS...MODEL SOUNDINGS CONTINUE
TO SUGGEST WE MOISTEN UP ENOUGH IN A SOUTHEAST FLOW FOR IFR CIGS
TO DEVELOP. A BIT CONCERNED THE MODELS MAY BE TOO FAST WITH THE
IFR CIGS BASED ON VFR ALL THE WAY TO THE COAST...SO I PUSHED BACK
THE TIMING A BIT FROM THE PREVIOUS FORECAST.
OUTLOOK...
SAT...MVFR CIGS EARLY ESPECIALLY SOUTHERN TERMINALS THEN MAINLY VFR.
SUN...MVFR IN RAIN SHOWERS MAINLY DURING THE AFTERNOON AND
OVERNIGHT PERIOD.
MONDAY...VFR.
TUESDAY...FROPA WITH MVFR IN RAIN SHOWERS DURING THE AFTERNOON/EVENING.
WEDNESDAY...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SATURDAY FOR
PAZ048.
NY...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SATURDAY FOR
NYZ062.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
831 PM EST FRI NOV 30 2012
.SYNOPSIS...
A FRONT WILL CROSS THROUGH THE FINGER LAKES AND MOHAWK VALLEY
TONIGHT. SOME LIGHT SNOW WILL OCCUR IN THE VICINITY OF THE FRONT.
COLD AIR WILL HANG UP AGAINST THE CATSKILLS AND POCONOS
OVERNIGHT...WHICH ALONG WITH A MOISTENING LOWER ATMOSPHERE...WILL
LEAD TO PATCHY FREEZING DRIZZLE OR A LIGHT WINTRY MIX FOR SOME
LOCATIONS INTO SATURDAY MORNING...ESPECIALLY SULLIVAN AND PIKE
COUNTIES. THOUGH SOME SHOWERS WILL MOVE IN SUNDAY...ABOVE NORMAL
TEMPERATURES ARE EXPECTED INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
830 PM UPDATE...
STILL A CONVOLUTED WX PATTERN IN PLACE FOR TONIGHT. LIGHT SNOW IS
OCCURRING ALONG THIS BNDRY INTO THE FINGER LKS AND MOHAWK VLY. H5
S/WV HAS PASSED AND LIFTED THE FRONTAL BNDRY NORTH OF THE SRN
TIER, BRINGING AN END TO THE SNOW FOR TONIGHT. MAIN QUESTION FOR
TONIGHT IS HOW MUCH DRIZZLE AND/OR PCPN WL THE CATSKILLS AND
POCONOS SEE OVRNGT. CHECKING THE FORT DIX VAD WIND PROFILE FM THE
JERSEY COAST DOES NOT GIVE MUCH CONFIDENCE TO SERLY FLOW KICKING
IN, AS IT CONTS TO RMN NRLY FLOW. HWVR, FURTHER NORTH JUST TO THE
SOUTH OF THE WMFNT, I.E KBGM, SERLY FLOW IS WELL-ESTABLISHED.
SO QUESTION IS WL THIS BE ENUF TO GENERATE DRIZZLE AS THE ATLANTIC
IS ESSENTIALLY CLOSED OFF? MODEL SNDGS AT KMSV PER 18Z NAM
INDICATES A SATURATED LOW-LVL ATMOSPHERE UP THRU ABOUT H9 THEN IS
QUESTIONABLE FURTHER ALOFT. RAP INDICATES SATURATED LAYER NEVER
MAKES IT UP TO H9. WL THIS BE ENUF TO GENERATE ANY DRIZZLE OR
STRICTLY A FRZG FOG SCENARIO. QPF FIELDS FM 18Z NAM INDICATE SOME
PCPN MAY FORM FROM SULLIVAN CNTY INTO SRN LUZERNE CNTY, LIKELY DUE
TO OROGRAPHIC AFFECTS. THEREFORE, THE QUESTION BCMS SHUD WE EXPAND
THE ADVISORY WEST EVEN IF WE ARE NOT CONVINCED IT WL BE FZDZ? FOR
NOW WL PASS ON CONCERNS TO THE NEXT SHIFT TO KEEP A CLOSE EYE ON
ANY DVLPMNT BUT PLAN TO KEEP THINGS AS IS FOR THE TIME BEING. WITH
AREAS OF FZDZ IN SULLIVAN/PIKE CNTYS AND PATCHY FZDZ FURTHER WEST
INTO THE POCONOS.
ONLY MINOR TWEAKS TO HRLY T/TD/WIND TRENDS.
PREV DISCUSSION BLO...
4 PM UPDATE...
BAND OF LIGHT SNOW IN IMMEDIATE VICINITY OF FRONT INITIALLY STALLED
OUT AROUND THE TWIN TIERS...IS FINALLY BEGINNING TO EDGE NORTH AS
WAVE FINISHES PASSING ALOFT...AND THE BOUNDARY IS BECOMING A WARM
FRONT. WHERE THINGS LINED UP JUST RIGHT...GENERALLY ALONG THE
SOUTHERN TIER OF NEW YORK...THE FRONT WAS ABLE TO SQUEEZE OUT AN
INCH OR SO OF SNOW...WHEREAS ELSEWHERE THE COLUMN HAS BEEN TOO
DRY. THE THINNING BAND OF SNOW WILL CONTINUE TO MOVE NORTH WITH
THE WARM FRONT THROUGH FINGER LAKES/MOHAWK VALLEY THIS EVENING.
AFTER THE WAVE ALOFT MOVES THROUGH...WE LOSE THE DEEPER MOISTURE.
MEANWHILE...STRONG SURFACE HIGH WILL MOVE OVER FROM QUEBEC INTO
MAINE...WITH FLOW AROUND IT SETTING UP COLD AIR DAMMING AGAINST
THE MOUNTAINS. NAM MODEL SOUNDING ESPECIALLY MONTICELLO AREA SHOW
THERMAL PROFILE THAT LATE TONIGHT LOSES ABILITY TO INTRODUCE ICE
CRYSTALS FROM ABOVE /BECAUSE TEMPERATURES WARMER THAN MINUS-8
CELSIUS WITHIN THE SHALLOWER SATURATED LAYER/. COLD AIR DAMMING
AT SURFACE LOOKS LIKELY TO KEEP SULLIVAN/PIKE COUNTIES BELOW
FREEZING. THUS WE HAVE A FAVORABLE SET UP FOR AREAS OF FREEZING
DRIZZLE...WITH AT LEAST A CHANCE OF VERY LIGHT WINTRY MIX
/SNOW...SLEET...FREEZING RAIN/. WINTER WEATHER ADVISORY HAS BEEN
HOISTED FOR 1AM-10AM SATURDAY FOR THAT REASON. ACTUAL PRECIPITATION
AMOUNTS WILL BE MINIMAL...BUT EVEN A VERY LIGHT GLAZE OF ICE FROM
FREEZING DRIZZLE IS CAPABLE OF PRODUCING HAZARDOUS TRAVEL
CONDITIONS. WE WILL BE MONITORING CLOSELY TO SEE IF OTHER COUNTIES
MAY NEED TO BE INCLUDED. EASTERN EDGES OF DELAWARE-OTSEGO-WAYNE-
ONEIDA COUNTIES COULD POTENTIALLY HAVE AT LEAST PATCHY FREEZING
DRIZZLE.
ON SATURDAY...CENTRAL TO WESTERN CWA LOOKS DRY WITH WARMING
TEMPERATURES. HOWEVER...CONTINUED SOUTHEAST LOW LEVEL FLOW AGAINST
CATSKILLS/POCONOS WILL HOLD TEMPERATURES BACK IN THE SOUTHEAST.
BIGGEST CONCERN AT THIS TIME IS WHETHER PATCHY FREEZING DRIZZLE
WILL BE ABLE TO PERSIST BEYOND 10 AM...BUT HOPEFULLY DIURNAL
HEATING WILL MITIGATE THAT...BUT THERE IS UNCERTAINTY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
4 PM UPDATE...
WARM AIR ADVECTION CONTINUES SATURDAY NIGHT INTO SUNDAY...TO THE
POINT THAT A GOOD PART OF THE AREA /ESPECIALLY WESTERN/ SHOULD
MANAGE TO GET INTO 50S FOR HIGHS SUNDAY. WEAKENING COLD FRONT
WILL SPREAD SHOWERS WEST TO EAST SUNDAY AFTERNOON AND
EVENING...BUT TEMPERATURES WILL BE WARM ENOUGH FOR ALL RAIN. ONLY
EXPECTING A FEW TENTHS OF AN INCH AT BEST WITH BRISKNESS OF FLOW
ALOFT. VERY BRIEF SLIGHT COLD AIR ADVECTION SUNDAY NIGHT...QUICKLY
NEUTRALIZES ALLOWING TEMPERATURES MONDAY TO BE NEAR OR ABOVE HIGHS
FROM SUNDAY. WEAK SURFACE HIGH PRESSURE TAKES CHARGE
MONDAY...WHICH FOR MOST IF NOT ALL WILL KEEP THE WEATHER DRY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
415 PM UPDATE...
IT WILL BE MILD AND QUIET INTO MONDAY EVENING, BEFORE A STORM
SYSTEM MOVING THROUGH LOWER ONTARIO PULLS A COLD FRONT INTO NY/PA.
THIS WILL CAUSE RAIN SHOWERS TUESDAY AND TUESDAY NIGHT. SOME WET
SNOW SHOWERS WILL BE POSSIBLE EARLY WEDNESDAY MORNING AS -4C 850MB
ISOTHERM CROSSES THE I-81 CORRIDOR.
TEMPERATURES WILL REMAIN COOL INTO EARLY THURSDAY. HOWEVER THE GFS
IS NOW FORECASTING A NEW RIDGE TO BUILD THURSDAY AFTERNOON INTO
FRIDAY, POTENTIALLY RESULTING IN ANOTHER WARMING TREND.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
7 PM UPDATE...
A BOUNDARY NOW ACROSS CENTRAL NY WILL CONTINUE TO LIFT NORTH WITH
THE BIGGEST AVIATION IMPACT THROUGH 04Z AT KSYR AND KRME IN LIGHT
SNOW. MAINLY MVFR CIGS AND VSBYS EXPECTED HERE THROUGH 04Z.
BASED ON OBS BACK TO THE WEST AT KROC INCLUDED A TWO HOUR TEMPO
GROUP FOR BRIEF IFR VSBYS AT BOTH TERMINALS TO ACCOUNT FOR THE
STEADIER PERIODS OF SNOW. ELSEWHERE WITH THE BOUNDARY NORTH OF THE
TERMINALS...VFR CIGS AROUND 5KFT EXPECTED THROUGH 06Z.
AFTER 06Z ACROSS THE SOUTHERN TERMINALS...MODEL SOUNDINGS CONTINUE
TO SUGGEST WE MOISTEN UP ENOUGH IN A SOUTHEAST FLOW FOR IFR CIGS
TO DEVELOP. A BIT CONCERNED THE MODELS MAY BE TOO FAST WITH THE
IFR CIGS BASED ON VFR ALL THE WAY TO THE COAST...SO I PUSHED BACK
THE TIMING A BIT FROM THE PREVIOUS FORECAST.
OUTLOOK...
SAT...MVFR CIGS EARLY ESPECIALLY SOUTHERN TERMINALS THEN MAINLY VFR.
SUN...MVFR IN RAIN SHOWERS MAINLY DURING THE AFTERNOON AND
OVERNIGHT PERIOD.
MONDAY...VFR.
TUESDAY...FROPA WITH MVFR IN RAIN SHOWERS DURING THE AFTERNOON/EVENING.
WEDNESDAY...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SATURDAY FOR
PAZ048.
NY...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SATURDAY FOR
NYZ062.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
959 PM MST FRI NOV 30 2012
.UPDATE...
ISSUED AT 722 PM MST FRI NOV 30 2012
MOIST SHORT WAVE IS MARCHING ACROSS THE GREAT BASIN WITH THE
LEADING EDGE OF THE DEEPER CLOUD MASS JUST REACHING WRN COLORADO.
THIS SHORT WAVE CONTAINS GOOD MOISTURE BUT MOVES VERY QUICKLY.
HIGHER RESOLUTION MODELS SUCH AS THE HRRR INDICATING SOME PCPN AS
FAR SOUTH AS THE LA SAL AND THE NRN SIDE OF THE SAN JUAN
MOUNTAINS. BUT THE NRN MOUNTAINS STAND THE BEST CHANCE OF SNOW
WITH 3-5 INCH ACCUMULATION POSSIBLE ABOVE 9000 FEET. WARM AIR MASS
RESULTS IN HIGH SNOW LEVELS AND APPEARS WILL RANGE FROM 7500 TO
8000 FEET OVERNIGHT. BOOSTED VALUES IN THE POP GRIDS...PRIMARILY
OVER NW COLORADO. BY DAYBREAK...THIS SHORT WAVE WILL HAVE CROSSED
THE DIVIDE WITH A CLEARING TREND FROM THE WEST.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 317 PM MST FRI NOV 30 2012
MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM INTO THE FORECAST
AREA AS AN UPPER LEVEL LOW PRESSURE SYSTEM OFF THE PACIFIC
NORTHWEST COAST CONTINUES TO SPIN...BRINGING IN A STEADY STREAM OF
MOISTURE. 700MB WINDS ARE IN THE 35 TO 45 KT RANGE WITH AN UPPER
LEVEL JET OF 80 KTS OVERHEAD IN A SOUTHWEST TO WEST FLOW. VISIBLE
SATELLITE AND VISUAL OBSERVATIONS INDICATE MOUNTAIN WAVE CLOUDS
ALREADY FORMING OVER THE UNCOMPAHGRE PLATEAU AND ON THE LEE SIDE
OF SOME RIDGES...WHICH WOULD INDICATE A STABLE ATMOSPHERE. SOME
GUSTS ARE REACHING THE SURFACE AT CRAIG AND MEEKER WHICH HAVE BEEN
GUSTING ANYWHERE FROM 20 TO 30 KTS.
THIS IS ALL OUT AHEAD OF AN EMBEDDED DISTURBANCE THAT WILL MOVE
THROUGH THIS EVENING THROUGH SATURDAY MORNING. THE BEST DYNAMICS
LIE NORTH OF THE FORECAST AREA AS THIS DISTURBANCE TRACKS FROM
NORTHERN NEVADA THROUGH NORTHERN UTAH INTO SOUTHERN IDAHO AND
WYOMING. AREAS NORTH OF I-70 WILL PRIMARILY BE AFFECTED BY THIS
DISTURBANCE AS IT CLIPS THESE ZONES. WHEN ANALYZING TIME HEIGHTS
OVER SEVERAL POINTS ACROSS THESE AFFECTED AREAS...700MB
TEMPERATURES WERE ANYWHERE FROM -1C TO -3C WHICH WOULD PUT SNOW
LEVELS AT ABOUT 7000 TO 8000 FT. WHILE THERE IS MOISTURE AND
INSTABILITY...THE FORCING IS NOT ALL THAT STRONG AND THE SATURATED
MOISTURE LAYER IS FAIRLY SHALLOW. MUCH OF THE FORCING IS CAPPED BY
A FAIRLY STABLE LAYER OVERHEAD. WITH THAT BEING SAID...IT LOOKS
LIKE THE EASTERN UINTAS...PARK AND GORE MOUNTAINS AS WELL AS THE
ELKHEADS AND FLATTOPS WILL BE FAVORED FOR ACCUMULATING SNOWFALL IN
THE 1 TO 2 INCH RANGE WITH SOME SPOTS SEEING AS MUCH AS 3.
PRIMARILY LIGHT RAIN WILL OCCUR IN THE NORTHERN VALLEYS. THE BULK
OF THE PRECIPITATION LOOKS TO OCCUR AFTER MIDNIGHT TO AROUND
SUNRISE. THE REST OF THE FORECAST AREA WILL SEE LITTLE IF ANY
PRECIPITATION...JUST SOME INCREASED CLOUD COVER. LEANED TOWARDS
THE WARMER SIDE OF GUIDANCE TONIGHT FOR LOW TEMPERATURES DUE TO
INCREASED CLOUD COVER.
SHOWERS WILL TAPER OFF AFTER SUNRISE AND WILL BE LIMITED TO THE
HIGHER PEAKS OF THE NORTHWEST COLORADO MOUNTAINS THROUGH ABOUT
NOON AS MOISTURE AND CLOUDS WILL HUG THE TERRAIN. ALTHOUGH PRECIP
WILL COME TO AN END AND CLOUD HEIGHTS WILL RISE SATURDAY
AFTERNOON...SOME HIGH CLOUDS WILL CONTINUE TO MOVE THROUGH AS THE
UPPER LEVEL LOW FEEDS MORE MOISTURE INTO THE AREA. EVEN THOUGH
THERE WILL BE A SLIGHT COOL DOWN ON SATURDAY FROM FRIDAYS HIGHS
PARTICULARLY UP NORTH...AFTERNOON HIGH TEMPERATURES WILL STILL
REMAIN SOME 10 TO 15 DEGREES ABOVE NORMAL FOR EARLY DECEMBER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 317 PM MST FRI NOV 30 2012
HIGH CLOUDS OUT AHEAD OF THE NEXT PACIFIC WAVE WILL BEGIN TO
SPREAD OVER THE FORECAST AREA EARLY SUNDAY...THEN THICKEN AND
LOWER DURING THE AFTERNOON. MODELS CONTINUE TO SHOW A WEAKENED
SYSTEM AS COMPARED TO WHAT WAS PROGGED SEVERAL DAYS AGO. SO IN
LIGHT OF THAT EARLIER PROMISE AND BECAUSE WE REALLY NEED THE
MOISTURE...THIS STORM IS LOOKING LIKE IT WILL BE A DISAPPOINTMENT.
THAT SAID...WINDS WILL STRENGTHEN SUNDAY AFTERNOON...AND
PRECIPITATION WILL INCREASE THROUGH THE EVENING HOURS...BOTH
FAVORING THE NORTH. I HAVE SPLIT THE EVENING GRID INTO 3 HOUR
BLOCKS TO ADDRESS THIS PRECIPITATION TREND. THERE ALSO CONTINUES
TO BE SOME MODEL TIMING DIFFERENCES. THE ASSOCIATED COLD FRONT
WILL REACH THE NORTHWEST CORNER LATE IN THE EVENING INTO THE
OVERNIGHT PERIOD...DEPENDING ON THE MODEL. THE FRONT WILL QUICKLY
WEAKEN AS IT HEADS SOUTH...MOSTLY WASHING OUT BY THE TIME IT
REACHES SAN JUAN MOUNTAINS MON MORNING. THE GFS IS THE FASTER
MODEL WITH THE NAM AND ECMWF LAGGING BY JUST A FEW HOURS. THE LOW
AMPLITUDE UPPER TROUGH AXIS FOLLOWS NOT FAR BEHIND FRONT...SO THE
BEST PRECIPITATION WILL BE FROM LATE IN THE EVENING THROUGH THE
OVERNIGHT HOURS. THE GFS SHOWS SHOWERS QUICKLY DIMINISHING BY MID
MORNING ON MON. THE EC AND NAM KEEP THINGS GOING THROUGH THE
MORNING AT LEAST...WITH MOUNTAIN SHOWERS LINGERING THROUGH THE
AFTERNOON. THINK THE GFS IS TOO FAST IN AGREEMENT WITH HPC...SO
HAVE EXTENDED BETTER POPS INTO MON. THIS STORM DOES NOT PACK MUCH
COLD AIR SO SNOW LEVELS WILL REMAIN RELATIVELY HIGH. EXPECT RAIN
TO CHANGE OVER TO SNOW ACROSS MOST OF THE NORTHERN AND HIGHER
VALLEYS. BUT PRECIPITATION IN THE OTHER VALLEYS COULD REMAIN
LIQUID...OR MIXED PHASE AT BEST. HIGHS ON MON WILL STILL BE IN THE
50S ACROSS THE SOUTHERN AND CENTRAL VALLEYS AT THE MID-LOWER
ELEVATIONS.
ONCE THE STORM HAS EXITED TO THE EAST...STORM TOTAL SNOW AMOUNTS
OVER THE MOUNTAINS SHOULD REACH A FEW INCHES...WITH THE NORTH
SEEING THE BEST ACCUMULATIONS. ADVISORY AMOUNTS MAY BE POSSIBLE
FOR THE NORTH AND CENTRAL MOUNTAINS. BUT THE SHORT DURATION AND
WARM NATURE OF THE STORM...ARE LIMITING FACTORS.
DRIER AND WARMER CONDITIONS FOLLOW TROUGH MIDWEEK. THEN ANOTHER
PACIFIC TROUGH AND COLD FRONT IS PROGGED TO PASS OVER THE REGION
WED NIGHT-THU NIGHT. THE MODELS HAVE AGAIN TRENDED WEAKER WITH
THIS SYSTEM COMPARED TO WHEN IT WAS FIRST ADVERTISED A COUPLE OF
DAYS AGO. ALSO THERE CONTINUES TO BE SOME TIMING DIFFERENCES WITH
THE GFS STILL THE FASTER MODEL. SO FAR THIS SYSTEM PACKS A COLDER
CORE THAN THE ONE ON SUN NIGHT/MON. AND IF MODELS DO NOT WEAKEN IT
TOO MUCH...THIS STORM SHOULD AGAIN BRING A ROUND OF MOUNTAIN
SNOW...WITH A CHANCE OF VALLEY RAIN AND/OR SNOW SHOWERS.
MODEL INCONSISTENCIES GROW BEYOND THIS WAVE...BUT COOLER
TEMPERATURES SHOULD FOLLOW WITH DRIER CONDITIONS ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 959 PM MST FRI NOV 30 2012
LOWER CIGS THROUGH 15Z BUT MAINTAINING VFR FOR MOST AREAS.
MOUNTAIN AIRPORTS MAY HAVE CIGS LOWERING TO BELOW AIRPORT MINIMUMS
FOR BRIEF PERIDS FROM PASSING -SHRA/-SHSN SNOW LEVEL NEAR 075-080.
MOUNTAIN TOPS WILL BE PARTIALLY OBSCURED IN SNOW AND FOG.
EXPECT MECHANICAL TURBULENCE ACROSS THE REGION.
AFTER 15Z...IMPROVING CONDITIONS WITH LOCAL -SHSN ENDING AND
DISSIPATING CIGS. VFR EXPECTED AT ALL TAF SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...MDA
LONG TERM...EH
AVIATION...PF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 AM CST SAT DEC 1 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
&&
.SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. ..08..
.LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.AVIATION...
RAP MODEL TRENDS INDICATE THE LOW LEVEL STRATUS WITH MVFR/IFR CIGS
SHOULD MOVE INTO EASTERN IOWA SHORTLY BEFORE SUNRISE AND AFFECT ALL
TAF SITES BY 18Z/01. AHEAD OF THE LOW CLOUDS MVFR/IFR CONDITIONS IN
FOG ARE EXPECTED WITH POCKETS OF LIFR/VLIFR CONDITIONS POSSIBLE.
ONCE THE LOW CLOUDS ARRIVE...A PROLONGED PERIOD OF IFR/LIFR
CONDITIONS ARE EXPECTED. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
345 AM CST SAT DEC 1 2012
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
MVFR/IFR STRATUS WILL CONTINUE TO DEVELOP WITH LIFR CIGS/VSBYS IN
FOG BY 09Z AT ALL TERMINALS. GRADUAL VEERING LLVL FLOW WITH
DECREASING WAA/MOISTURE ADVECTION WILL ALLOW CIGS/VSBYS TO SLOWLY
IMPROVE BEYOND 15-17Z TIME FRAME. VFR STRATOCU EXPECTED BY 20Z AS
SUBSIDENCE AND DRYING ADVECT EASTWARD IN THE WAKE OF THE DEPARTING
SHORTWAVE TROUGH.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ008>010-
020-021-034-035.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
209 AM CST SAT DEC 1 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 204 AM CST SAT DEC 1 2012
A SHALLOW LAYER OF LOW LEVEL MOISTURE WAS STREAMING NORTHWARD
ACROSS CENTRAL KANSAS EARLIER THIS MORNING. AS OF 6Z SEVERAL SITES
IN SOUTH CENTRAL KANSAS REPORTED VISIBILITIES OF A 1/4 MILE. PHONE
CALLS TO THESE AREAS REVEALED THERE WERE ALSO SEVERAL OTHER
LOCATIONS WHERE VISIBILITIES WERE LOWER THAN THIS. AS A RESULT A
DENSE FOG ADVISORY WAS ISSUED ALONG AND NEAR A LINE FROM ROUGHLY
WAKEENEY TO LARNED TO PRATT AND MEDICINE LODGE. THIS WAS WHERE
UPSLOPE FLOW AND BETTER MOISTURE WAS LOCATED. VISIBILITIES WILL
BEGIN TO IMPROVE LATER THIS MORNING AS SOUTHEAST WINDS VEER MORE
TO THE SOUTHWEST, HOWEVER SOME MID TO HIGH LEVEL MOISTURE
PRECEDING A WESTERN UNITED STATES UPPER LEVEL TROUGH MAY LIMIT HOW
QUICKLY THE SHALLOW LOW LEVEL STATUS/FOG WILL ERODE. AT THIS TIME
BASED ON THE NAM, NMM, AND ARW THE SURFACE WINDS WILL BECOME MORE
SOUTHWESTERLY AFTER 12Z SO VISIBILITIES ARE EXPECTED TO BEGIN TO
IMPROVE AROUND DAYBREAK. EARLY MORNING CLOUDS WILL EVENTUALLY GIVE
WAY TO SUNNY SKIES AS THE UPPER LEVEL TROUGH CROSSES WESTERN
KANSAS. MORE CLOUDS THAN SUN HOWEVER WILL BE POSSIBLE DURING THE
EARLY AFTERNOON IN NORTH CENTRAL KANSAS WHICH SHOULD AID IN
KEEPING HIGHS TODAY SLIGHTLY COOLER THAN WHAT THE 850MB MIXDOWN
TEMPERATURES WOULD SUGGEST. WILL THEREFORE STAY CLOSE TO THE
COOLER GUIDANCE FORECAST OF MID 60S FOR HIGHS IN NORTH CENTRAL
KANSAS. FURTHER SOUTHWEST WILL TREND MORE TOWARDS THE WARMER
MIXDOWN TEMPERATURES FROM THE 00Z NAM GIVEN BETTER INSOLATION.
TONIGHT SKIES WILL BE CLEAR AS WINDS DECREASE TO 10MPH OR LESS.
WITH DEWPOINT FORECAST TO BE IN THE LOW TO MID 30S THE LATEST
MET/MAV GUIDANCE APPEARS REASONABLE WITH LOWS HOVERING MAINLY IN
THE 32 TO 38 DEGREE RANGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 36 71 41 / 0 0 0 0
GCK 71 33 71 37 / 0 0 0 0
EHA 72 39 72 40 / 0 0 0 0
LBL 72 31 73 36 / 0 0 0 0
HYS 66 31 71 38 / 0 0 0 0
P28 70 36 73 47 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031-
045-046-064>066-079>081-089-090.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1201 AM CST SAT DEC 1 2012
...UPDATED TO INSERT DENSE FOG ADVISORY FOR SOUTH CENTRAL KANSAS...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.UPDATE...
ISSUED AT 1156 PM CST FRI NOV 30 2012
AREAS OF FOG ACROSS SOUTH CENTRAL KASNAS WERE ALREADY REDUCING
VISIBILITIES TO LESS THAN ONE QUARTER MILE AS OF 11:45 PM. WITH A
MOIST UPSLOPE FLOW CONTINUING THROUGH THE PREDAWN HOURS THE DENSE
FOG IS EXPECTED TO BECOME MORE WIDESPREAD THROUGH DAYBREAK.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR KSZ046-065-066-
079>081-089-090.
&&
$$
UPDATE...BURGERT
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
1125 PM CST FRI NOV 30 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT ACROSS SOUTHWEST KANSAS. WINDS ARE FORECAST TO VEER MORE
SOUTHERLY AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW WHICH MAY
LIMIT HOW LOW VISIBILITIES WILL GET OVERNIGHT. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT HYS AND DDC. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE BUT WILL STILL INSERT A BRIEF PERIOD OF IFR VSBYS
BETWEEN 8Z AND 11Z. IF WINDS REMAIN SOUTHEAST THROUGH 12Z THEN
LIFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK AT DDC AND HYS,
ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1122 PM CST FRI NOV 30 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1109 PM CST FRI NOV 30 2012
AT 00Z SATURDAY AN UPPER LEVEL LOW WAS LOCATED OFF THE WEST COAST
OF BRITISH COLUMBIA. ONE UPPER LEVEL DISTURBANCE WAS LOCATED NEAR
THE BASED OF THE UPPER LOW, JUST OFF THE COAST OF THE PACIFIC
NORTHWEST. ANOTHER UPPER LEVEL TROUGH APPEARS TO EXTEND FROM
EXTREME NORTHWEST NEVADA INTO EAST CENTRAL CALIFORNIA. WEAK 500MB
RIDGING WAS PRESENT ACROSS THE ROCKIES. AT THE 700MB LEVEL A +4C
TO +8C RIDGE OF WARM AIR EXTENDED FROM WEST TEXAS NORTHWARD ALONG
THE LEE OF THE ROCKIES INTO EASTERN WYOMING/SOUTHWEST SOUTH
DAKOTA. AT THE 850MB LEVEL A WARM LEE TROUGH STRETCHED FROM
WESTERN NORTH DAKOTA INTO EASTERN ARIZONA. THE 850MB TEMPERATURE
AT AMARILLO AT 00Z SATURDAY WAS 18C, DODGE CITY AND RAPID CITY
HAD A 850MB TEMPERATURE OF +12. 850MB MOISTURE APPEARED TO BE
PRIMARILY CONFINED TO NORTH CENTRAL OKLAHOMA. AT THE SURFACE
EARLIER THIS EVENING A MOIST SOUTHEAST UPSLOPE FLOW HAD DEVELOPED
ACROSS WESTERN KANSAS. DEWPOINTS ACROSS NORTH CENTRAL OKLAHOMA
WERE IN THE LOWER 50S AND AS OF 04Z FOG HAD ALREADY DEVELOPED
ACROSS SOUTH CENTRAL AND PORTIONS OF WESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 245 PM CST FRI NOV 30 2012
THE UPPER LEVEL FLOW PATTERN OVER NORTH AMERICA CONTINUES TO BE
ZONAL WITH PERIODIC FAST MOVING SHORTWAVE TROUGHS EMBEDDED IN THE
FLOW OVER THE UNITED STATES. THIS MORNINGS ANALYSIS SHOWED ONE
SHORTWAVE MOVING OVER THE MISSISSIPPI VALLEY WHILE ANOTHER WAVE WAS
MOVING ONSHORE OVER THE WEST COAST. IN THE LOWER LEVELS, A LOW
PRESSURE TROUGH WAS LOCATED FROM EASTERN COLORADO INTO THE TEXAS
PANHANDLE. WEAK SOUTHERLY FLOW EAST OF THE TROUGH WAS BRINGING
40S/50S DEWPOINTS UP THROUGH OKLAHOMA INTO SOUTH CENTRAL AND
SOUTHEAST KANSAS.
THE MAIN FORECAST CONCERN TONIGHT WILL BE THE POTENTIAL FOR FOG
DEVELOPMENT OVER CENTRAL AND SOUTH CENTRAL PARTS OF KANSAS AND
POSSIBLY INTO PORTIONS OF SOUTHWEST KANSAS. THE 12Z NAM HAD A GOOD
HANDLE ON THE LOW LEVEL MOISTURE FIELDS ACROSS OKLAHOMA THIS MORNING
AND SHOWS THE 40 DEG ISODROSOTHERM MOVING UP TO AN ASHLAND-STAFFORD
LINE THIS EVENING. NAM BUFR SOUNDINGS SHOW THAT THE MOISTURE LAYER
WILL BE VERY SHALLOW, ONLY A FEW HUNDRED FEET THICK DEEP. THIS
SHOULD STILL BE DEEP ENOUGH FOR FOG DEVELOPMENT AND I HAVE ADDED
PATCHY FOG ALONG WITH AREAS OF FOG QUALIFIED WITH PATCHY DENSE TO
THE FORECAST FOR SOUTH CENTRAL KANSAS LATER TONIGHT. WIDESPREAD
DENSE FOG MAY BE KEPT IN CHECK BY SUFFICIENT MIXING IN THE BOUNDARY
LAYER ESPECIALLY ALONG HIGHWAY 281. MIXING LOOKS WEAKER FARTHER WEST
SO THERE COULD BE MORE POTENTIAL. THE NEXT APPROACHING SHORTWAVE
WILL BEGIN TO PUSH DRIER AIR EASTWARD INTO THE ASHLAND/DODGE CITY
/GREENSBURG AREAS EARLIER IN THE NIGHT WHICH WOULD DIMINISH THE
THREAT FOR DENSE FOG THERE. FOR NOW WILL HOLD OFF ON A FOG HEADLINE
AND LET THE NEXT SHIFT MAKE THAT DETERMINATION.
ANY FOG THAT DEVELOPS SHOULD BURN OFF A FEW HOURS AFTER SUNRISE ON
SATURDAY. AS THE SHORTWAVE TROUGH CONTINUES TO MOVE THROUGH, SURFACE
WINDS WILL BECOME NORTHWESTERLY AND INCREASE TO THE 10 TO 20 MPH
DURING THE MORNING HOURS BEFORE DIMINISHING IN THE AFTERNOON. HIGHS
SHOULD TOP OUT IN THE UPPER 60S TO LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 245 PM CST FRI NOV 30 2012
BEYOND THE WEEKEND, THE LARGE SCALE SYNOPTIC PATTERN BECOMES
CONSIDERABLY MORE ACTIVE ACROSS THE WESTERN TWO THURSDAY OF THE
COUNTRY. THIS WILL NOT HOWEVER BRING A HIGH PROBABILITY OF
PRECIPITATION, HOWEVER, THE ODDS WILL INCREASE BY FRIDAY.
A ZONAL PATTERN WILL STILL BE FOUND ACROSS THE CENTRAL PLAINS
SATURDAY AND INTO SUNDAY, WITH THE POLAR JET DISPLACED FARTHER NORTH
ACROSS THE NORTHERN PLAINS. THIS PATTERN WILL AID IN MAINTAINING
LIGHT SOUTHERLY SURFACE WINDS, AS WELL AS WARMER THAN NORMAL HIGHS
IN THE 60`S, TO NEAR 70 DEGREES ON SUNDAY. A FAST MOVING STRONG
SHORTWAVE TROUGH ASSOCIATED WITH A STRONG EASTERN PACIFIC JET WILL
MOVE RAPIDLY EAST ACROSS THE COLORADO PLATEAU INTO THE HIGH PLAINS
REGION BY SUNDAY NIGHT. IMPRESSIVE SURFACE PRESSURE FALLS WILL TAKE
PLACE ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS REGIONS SUNDAY
NIGHT, DEVELOPING LEE TROUGHING FROM NEW MEXICO INTO MONTANA. THE
MODELS THEN SHOVE A PACIFIC COLD FRONT ACROSS WESTERN KANSAS MONDAY
MORNING. THE COLD FRONT IS NOT EXPECTED TO BE PARTICULARLY STRONG,
BUT GFS AND IT`S MOS SUGGEST WIND SPEEDS BETWEEN 20 AND 25 KNOTS
DURING THE LATE MORNING AND AFTERNOON. WINDS SHOULD RAPIDLY
DECOUPLE, AND THE GRADIENT SHOULD SLACKEN CONSIDERABLY IN THE
EVENING TO ALLOW WINDS SPEED TO DECREASE TO AROUND 12 KNOTS OR LESS.
TEMPERATURES FOR MONDAY NIGHT WERE ADJUSTED TO COINCIDE CLOSER TO A
MOS CONSENSUS RATHER THAN THE WARM BIASED RAW MODELS. SURFACE HIGH
PRESSURE SHOULD HAVE AN IMPACT ON TUESDAY HIGHS. TEMPERATURES WILL
STRUGGLE THROUGH THE 50`S TUESDAY AFTERNOON AS COOL HIGH PRESSURE
CONTINUES TO PROMOTE LIGHT WINDS WITH NO SIGNIFICANT DOWNSLOPE
EFFECT. A REBOUND IN TEMPERATURES (ALBEIT SLIGHT) IS EXPECTED ONCE
AGAIN ON WEDNESDAY AS 500 MB HEIGHTS INCREASE AND THE BOUNDARY LAYER
SEES A RETURN TO SOUTHERLY WINDS. THE MODELS SUPPORT A BROAD TROUGH
MOVING ACROSS THE WESTERN UNITED STATES DURING THIS PERIOD. THE GFS
AND ECMWF HAVE DISTINCTLY DIFFERENT SOLUTIONS IN THE THERMODYNAMIC
FIELDS BY AROUND 180 HOURS. THE GFS ALLOWS THE SLUG OF VERY COLD
-20 TO -30 DEGREE C AIR AT 500 MB AIR TO SWING FARTHER SOUTH ACROSS
THE SOUTHERN CENTRAL HIGH PLAINS. THIS MORE AMPLIFIED PATTERN BETTER
SUPPORTS A DEEP UNSTABLE LAYER IN THIS TIME FRAME, AS WELL AS A
DEEPER DENDRITIC GROWTH POTENTIAL FOR SNOW ACROSS EASTERN COLORADO
AND WESTERN KANSAS AS EARLY AS FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI NOV 30 2012
A MOIST SOUTHEAST UPSLOPE FLOW WILL PERSIST THROUGH MUCH OF THE
NIGHT AT DDC AND HYS. WINDS ARE FORECAST TO VEER MORE SOUTHERLY
AFTER 10Z WHICH GIVEN LOSS IN UPSLOPE FLOW MAY LIMIT HOW LOW
VISIBILITIES WILL GET OVER NIGHT AT DDC AND HYS. EVEN WITH THIS IN
MIND THE LATEST HRRR STILL SUGGESTED A BRIEF PERIOD OF IFR
VSBY/CIGS BETWEEN 9Z AND 12Z AT DDC AND HYS. BASED ON A QUICK 5Z
VERIFICATION ON SURFACE INFORMATION THE HRRR MAY BE A LITTLE
AGGRESSIVE, STILL IN INSERT A PERIOD OF MVFR VSBYS AT DDC AND HYS
BETWEEN 9Z AND 12Z. LOWEST VSBYS ARE EXPECTED TO BE IN THE HAYS
AREA MAY MAY LINGER THROUGH 15Z. IF WINDS REMAIN SOUTHEAST THROUGH
THE PREDAWN HOURS THEN IFR VSBYS WILL BE LIKELY TOWARDS DAYBREAK
AT DDC AND HYS, ESPECIALLY HYS.
&&
.FIRE WEATHER...
ISSUED AT 245 PM CST FRI NOV 30 2012
RELATIVELY WARM AND DRY CONDITIONS ARE FORECAST SATURDAY SUNDAY AND
MONDAY. RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 20
PERCENT OR LOWER EACH AFTERNOON FOR A FEW HOURS. WINDS WILL BE LIGHT
SATURDAY AND SUNDAY, BUT INCREASE SUBSTANTIALLY ON MONDAY AS A COLD
FRONTAL BOUNDARY SWEEPS THROUGH WESTERN KANSAS. NORTH WINDS OF
AROUND 25 MPH WITH RELATIVE HUMIDITY FALLING TO AROUND 20 PERCENT
ARE EXPECTED MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 70 41 70 / 0 0 0 0
GCK 32 72 35 70 / 0 0 0 0
EHA 38 73 35 71 / 0 0 0 0
LBL 32 73 37 71 / 0 0 0 0
HYS 34 68 34 69 / 0 0 0 0
P28 42 72 40 72 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...GERARD
LONG TERM...RUSSELL
AVIATION...BURGERT
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1115 PM CST FRI NOV 30 2012
.UPDATE...
.AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH SATURDAY EVENING.
THE RAP MODEL SUGGESTS SOME PATCHY FOG OR
STRATUS...MVFR...CREEPING INTO FRONTIER...CUSTER AND
WHEELER COUNTIES BETWEEN 09Z AND 14Z. IF THIS CONDITION
DEVELOPS...WEST WINDS DEVELOPING SATURDAY MORNING WILL PUSH IT
QUICKLY EAST OF THE AREA. OTHERWISE...SCT-BKN HIGH LEVEL CLOUDINESS
FROM A LARGE PACIFIC STORM SYSTEM WILL CONTINUE TO MOVE ACROSS THE
FCST AREA THROUGH SATURDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 554 PM CST FRI NOV 30 2012/
UPDATE...
AVIATION...
SFC OBS FROM SERN KS AND OUTPUT FROM THE RAP MODEL INDICATE
STRATUS AND MVFR CIGS COULD MOVE INTO FRONTIER...CUSTER AND
WHEELER COUNTIES BETWEEN 11Z AND 16Z SATURDAY. OTHERWISE...VFR IS
EXPECTED ALL AREAS.
PREV DISCUSSION... /ISSUED 519 PM CST FRI NOV 30 2012/
UPDATE...
AVIATION...
VFR IS EXPECTED ALL AREAS OVERNIGHT THROUGH SATURDAY.
SCT-BKN HIGH LEVEL CLOUDINESS FROM A LARGE PACIFIC STORM SYSTEM WILL
CONTINUE TO MOVE ACROSS THE FCST AREA THROUGH SATURDAY.
PREV DISCUSSION... /ISSUED 310 PM CST FRI NOV 30 2012/
SYNOPSIS...
H5 ANALYSIS THIS MORNING HAS A BROAD AREA OF LOW PRESSURE OFF THE
COAST OF BRITISH COLUMBIA WITH A SECOND LOW LOCATED OVER NORTH
CENTRAL CANADA. A JET STREAK EXTENDED FROM NORTHERN CALIFORNIA INTO
NWRN MT THIS MORNING WITH A SECOND JET STREAK EXTENDING FROM SRN
QUEBEC INTO THE CANADIAN MARITIMES. WV IMAGERY...AND IR IMAGERY
CONTINUES TO INDICATE ABUNDANT TROPICAL MOISTURE WORKING INTO
CENTRAL AND NRN CALIFORNIA...AS WELL AS OREGON AND WASHINGTON
STATE...AND EXTENDED EAST TO NEVADA...IDAHO AND MONTANA. HIGH LEVEL
CLOUDINESS HAS EXITED CENTRAL AND WESTERN NEBRASKA EARLIER THIS
MORNING LEADING TO MOSTLY SUNNY SKIES THIS AFTERNOON. ANOTHER BATCH
OF BROKEN TO OVERCAST HIGH CLOUDINESS CONTINUES TO PUSH INTO THE
CENTRAL AND NORTHERN ROCKIES THIS AFTERNOON AND WILL ARRIVE ACROSS
THE CENTRAL AND NORTHERN PLAINS LATER THIS EVENING. TEMPERATURES AS
OF 2 PM CST RANGED FROM 47 AT O`NEILL...TO 60 AT OGALLALA AND
THEDFORD.
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH MONDAY...MAIN FORECASTING CHALLENGES
CONTINUE TO REVOLVE AROUND TEMPERATURES AND THE IMPACTS OF HIGH
CLOUDINESS ON THEM. IN ADDITION...WINDS AND WIND SPEEDS IN
ASSOCIATION WITH A COLD FROPA MONDAY CONTINUE TO BE PROBLEMATIC.
FOR TONIGHT AND SATURDAY...SKIES WILL TRANSITION TO MOSTLY CLOUDY
LATER TONIGHT AS ABUNDANT UPPER LEVEL MOISTURE AND HIGH CLOUDINESS
STREAMS INTO THE REGION FROM THE CENTRAL AND NORTHERN ROCKIES. NO
PRECIPITATION IS EXPECTED THOUGH AS VERY DRY CONDITIONS REMAIN BLO
15000 FT AGL. WITH ABUNDANT CLOUD COVER...OVERNIGHT LOWS WILL BE
MILD WITH READINGS MAINLY IN THE LOWER 30S. DID DECIDE TO GO WITH
UPPER 20S IN THE PLATTE RIVER VALLEY THANKS TO DRY AIR AND LIGHT
WESTERLY WINDS...WHICH ALLOW TEMPS TO TANK THIS EVENING AHEAD OF THE
ARRIVAL OF CLOUD COVER. CLOUDS WILL TRANSITION EAST QUICKLY ON
SATURDAY AND ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY LATE
MORNING. LOW PRESSURE AND AN ASSOCIATED SURFACE TROUGH OF LOW
PRESSURE WILL TRACK INTO THE EASTERN DAKOTAS AND EASTERN NEBRASKA ON
SATURDAY...RESULTING IN WESTERLY WINDS ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA SATURDAY AFTERNOON. THE COMBINATION OF FULL
SUN...WESTERLY DOWN SLOPING WINDS...AND DRY AIR...WILL ALLOW TEMPS
TO CLIMB QUICKLY INTO THE UPPER 50S AND LOWER 60S BY MIDDAY
SATURDAY. HIGHS ARE EXPECTED TO REACH THE UPPER 60S TO NEAR 70 IN
THE SOUTHWEST...WITH LOWER TO MID 60S EXPECTED ELSEWHERE.
FYI...RECORD HIGHS TOMORROW FOR VALENTINE...NORTH PLATTE AND
IMPERIAL ARE 74...71 AND 72 RESPECTIVELY WITH 68 BEING THE RECORD AT
BROKEN BOW.
WEAK HIGH PRESSURE WILL BUILD INTO CENTRAL NEBRASKA SATURDAY NIGHT.
CLEAR SKIES...LIGHT WINDS AND DRY AIR...WILL ALLOW LOWS TO DROP
QUICKLY INTO THE UPPER 20S TO NEAR 30. INSERTED SOME MID 20S IN THE
PLATTE RIVER VALLEY AND WESTERN SAND HILLS...THANKS TO LIGHT
WESTERLY WINDS AND A GOOD SETUP FOR COLD AIR DRAINAGE. ON
SUNDAY...HIGH PRESSURE WILL DRIFT EAST OF THE AREA...WITH A LEE SIDE
TROUGH OF LOW PRESSURE DEVELOPING ACROSS THE PANHANDLE...EASTERN
WYOMING AND EASTERN COLORADO...ALLOWING SRLY WINDS TO INCREASE. THE
COMBINATION OF DECENT MIXING AND H85 TEMPS OF 12 TO 15C...WILL PUSH
AFTERNOON HIGHS INTO THE MID AND UPPER 60S.
A COLD FRONT WILL APPROACH THE FORECAST AREA SUNDAY NIGHT. SRLY
WINDS WILL CONTINUE EAST OF THE FRONT AND ARE NOT EXPECTED TO
TOTALLY DECOUPLE. THIS WILL LEAD TO LOWS IN THE 30S FOR SUNDAY
NIGHT. ON MONDAY THE BEFORE MENTIONED COLD FRONT WILL TRACK ACROSS
THE REGION. DECENT NWRLY WINDS WILL DEVELOP WITH PASSAGE OF THIS
FEATURE AND MAY BECOME STRONG BY MIDDAY MONDAY. BASED ON GFS AND NAM
BUFKIT SOUNDINGS...THERE IS A SMALL THREAT FOR WIND GUSTS OVER 40
MPH MID DAY MONDAY. ATTM THE GREATEST THREAT FOR WINDS OF THIS
MAGNITUDE IS OVER NORTHERN NEBRASKA...WHERE COLD AIR ADVECTION WILL
BE STRONGEST BEHIND THE FRONT. FURTHER SOUTH AND WEST...COLD AIR
ADVECTION WILL BE MUCH WEAKER...LIMITING GUST POTENTIAL MONDAY
AFTERNOON. HIGHS WILL BE COOLER WITH READINGS IN THE UPPER 40S AND
50S EXPECTED...WHICH IS STILL 10 TO 15 DEGREES ABOVE CLIMO.
LONG RANGE...MONDAY NIGHT THROUGH FRIDAY...MILD AND DRY WEATHER WILL
BEGIN THE EXTENDED PERIOD...WITH HIGHS WELL INTO THE 50S AND
POSSIBLE NEAR 60 DEGREES TUESDAY AND WEDNESDAY. THE WEATHER WILL
BEGIN TO CHANGE THURSDAY AS A STRONG SHORTWAVE TROUGH MOVES ACROSS
SOUTHERN CANADA AND THE NORTHERN PLAINS. THIS WILL DRIVE A COLD
FRONT THROUGH THE AREA...WITH A HYBRID OF PACIFIC AND ARCTIC AIR
INTRUDING THE AREA BEHIND THE FRONT ON FRIDAY. THE COLDEST /MOST OF
THE ARCTIC/ AIR IS EXPECTED TO STAY NORTHEAST OF THE AREA...SO WHILE
IT WILL BE COLDER FRIDAY HIGHS WILL ONLY BE SLIGHTLY BELOW NORMAL.
ALL INDICATIONS ARE THAT CONDITIONS WILL WARM AGAIN DURING THE
WEEKEND JUST BEYOND THE FORECAST PERIOD.
PRECIPITATION CHANCES ARE SMALL BUT POSSIBLE ON THURSDAY AFTER THE
FRONTAL PASSAGE. AREA IS IN THE RIGHT REAR QUADRANT OF A SIGNIFICANT
JET STREAK...AND SOME DECENT FRONTOGENESIS DEVELOPS ACROSS THE AREA.
SO WILL CONTINUE THE SLIGHT CHANCES FOR RAIN AND SNOW.
AVIATION...
NO AVIATION CONCERNS OVER THE NEXT 24 HOURS. ONLY MID TO HIGH
LEVEL CLOUDS ARE EXPECTED. WINDS WILL BE SOUTHERLY AROUND 10 KTS
THROUGH THE EVENING. WINDS AT KVTN WILL REMAIN ELEVATED OUT OF
THROUGH THE NIGHT AS A SFC LOW PRESSURE PASSES THROUGH THE
DAKOTAS. FRONT PASSES THROUGH THE AREA TOMORROW MORNING WITH WINDS
SWITCHING TO WEST NORTHWEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1243 AM EST SAT DEC 1 2012
.SYNOPSIS...
A FRONT WILL CROSS THROUGH THE FINGER LAKES AND MOHAWK VALLEY
TONIGHT. SOME LIGHT SNOW AND FLURRIES WILL OCCUR IN THE VICINITY
OF THE FRONT. COLD AIR WILL HANG UP AGAINST THE CATSKILLS AND
POCONOS OVERNIGHT...WHICH ALONG WITH A MOISTENING LOWER
ATMOSPHERE...WILL LEAD TO PATCHY FREEZING DRIZZLE OR A LIGHT
WINTRY MIX FOR SOME LOCATIONS INTO SATURDAY MORNING...ESPECIALLY
SULLIVAN AND PIKE COUNTIES. THOUGH SOME SHOWERS WILL MOVE IN
SUNDAY...ABOVE NORMAL TEMPERATURES ARE EXPECTED INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
10 PM UPDATE...
NO SIGNS OF FRZG PCPN DVLPNG ACRS THE SE AT THIS TIME. HV ISSUED A
SPECIAL WX STATEMENT FOR BLACK ICE FOR THE SRN TIER AND A ROW OF
CNTYS JUST TO THE NORTH, WHERE SNOW MELTED THIS AFTN AND RE-FROZE
ON ROADWAYS.
NO CHGS NEEDED TO FCST FOR NOW.
PREV DISCUSSIONS BLO...
830 PM UPDATE...
STILL A CONVOLUTED WX PATTERN IN PLACE FOR TONIGHT. LIGHT SNOW IS
OCCURRING ALONG THIS BNDRY INTO THE FINGER LKS AND MOHAWK VLY. H5
S/WV HAS PASSED AND LIFTED THE FRONTAL BNDRY NORTH OF THE SRN
TIER, BRINGING AN END TO THE SNOW FOR TONIGHT. MAIN QUESTION FOR
TONIGHT IS HOW MUCH DRIZZLE AND/OR PCPN WL THE CATSKILLS AND
POCONOS SEE OVRNGT. CHECKING THE FORT DIX VAD WIND PROFILE FM THE
JERSEY COAST DOES NOT GIVE MUCH CONFIDENCE TO SERLY FLOW KICKING
IN, AS IT CONTS TO RMN NRLY FLOW. HWVR, FURTHER NORTH JUST TO THE
SOUTH OF THE WMFNT, I.E KBGM, SERLY FLOW IS WELL-ESTABLISHED.
SO QUESTION IS WL THIS BE ENUF TO GENERATE DRIZZLE AS THE ATLANTIC
IS ESSENTIALLY CLOSED OFF? MODEL SNDGS AT KMSV PER 18Z NAM
INDICATES A SATURATED LOW-LVL ATMOSPHERE UP THRU ABOUT H9 THEN IS
QUESTIONABLE FURTHER ALOFT. RAP INDICATES SATURATED LAYER NEVER
MAKES IT UP TO H9. WL THIS BE ENUF TO GENERATE ANY DRIZZLE OR
STRICTLY A FRZG FOG SCENARIO. QPF FIELDS FM 18Z NAM INDICATE SOME
PCPN MAY FORM FROM SULLIVAN CNTY INTO SRN LUZERNE CNTY, LIKELY DUE
TO OROGRAPHIC AFFECTS. THEREFORE, THE QUESTION BCMS SHUD WE EXPAND
THE ADVISORY WEST EVEN IF WE ARE NOT CONVINCED IT WL BE FZDZ? FOR
NOW WL PASS ON CONCERNS TO THE NEXT SHIFT TO KEEP A CLOSE EYE ON
ANY DVLPMNT BUT PLAN TO KEEP THINGS AS IS FOR THE TIME BEING. WITH
AREAS OF FZDZ IN SULLIVAN/PIKE CNTYS AND PATCHY FZDZ FURTHER WEST
INTO THE POCONOS.
ONLY MINOR TWEAKS TO HRLY T/TD/WIND TRENDS.
4 PM UPDATE...
BAND OF LIGHT SNOW IN IMMEDIATE VICINITY OF FRONT INITIALLY
STALLED OUT AROUND THE TWIN TIERS...IS FINALLY BEGINNING TO EDGE
NORTH AS WAVE FINISHES PASSING ALOFT...AND THE BOUNDARY IS
BECOMING A WARM FRONT. WHERE THINGS LINED UP JUST
RIGHT...GENERALLY ALONG THE SOUTHERN TIER OF NEW YORK...THE FRONT
WAS ABLE TO SQUEEZE OUT AN INCH OR SO OF SNOW...WHEREAS ELSEWHERE
THE COLUMN HAS BEEN TOO DRY. THE THINNING BAND OF SNOW WILL
CONTINUE TO MOVE NORTH WITH THE WARM FRONT THROUGH FINGER
LAKES/MOHAWK VALLEY THIS EVENING.
AFTER THE WAVE ALOFT MOVES THROUGH...WE LOSE THE DEEPER MOISTURE.
MEANWHILE...STRONG SURFACE HIGH WILL MOVE OVER FROM QUEBEC INTO
MAINE...WITH FLOW AROUND IT SETTING UP COLD AIR DAMMING AGAINST
THE MOUNTAINS. NAM MODEL SOUNDING ESPECIALLY MONTICELLO AREA SHOW
THERMAL PROFILE THAT LATE TONIGHT LOSES ABILITY TO INTRODUCE ICE
CRYSTALS FROM ABOVE /BECAUSE TEMPERATURES WARMER THAN MINUS-8
CELSIUS WITHIN THE SHALLOWER SATURATED LAYER/. COLD AIR DAMMING
AT SURFACE LOOKS LIKELY TO KEEP SULLIVAN/PIKE COUNTIES BELOW
FREEZING. THUS WE HAVE A FAVORABLE SET UP FOR AREAS OF FREEZING
DRIZZLE...WITH AT LEAST A CHANCE OF VERY LIGHT WINTRY MIX
/SNOW...SLEET...FREEZING RAIN/. WINTER WEATHER ADVISORY HAS BEEN
HOISTED FOR 1AM-10AM SATURDAY FOR THAT REASON. ACTUAL PRECIPITATION
AMOUNTS WILL BE MINIMAL...BUT EVEN A VERY LIGHT GLAZE OF ICE FROM
FREEZING DRIZZLE IS CAPABLE OF PRODUCING HAZARDOUS TRAVEL
CONDITIONS. WE WILL BE MONITORING CLOSELY TO SEE IF OTHER COUNTIES
MAY NEED TO BE INCLUDED. EASTERN EDGES OF DELAWARE-OTSEGO-WAYNE-
ONEIDA COUNTIES COULD POTENTIALLY HAVE AT LEAST PATCHY FREEZING
DRIZZLE.
ON SATURDAY...CENTRAL TO WESTERN CWA LOOKS DRY WITH WARMING
TEMPERATURES. HOWEVER...CONTINUED SOUTHEAST LOW LEVEL FLOW AGAINST
CATSKILLS/POCONOS WILL HOLD TEMPERATURES BACK IN THE SOUTHEAST.
BIGGEST CONCERN AT THIS TIME IS WHETHER PATCHY FREEZING DRIZZLE
WILL BE ABLE TO PERSIST BEYOND 10 AM...BUT HOPEFULLY DIURNAL
HEATING WILL MITIGATE THAT...BUT THERE IS UNCERTAINTY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
4 PM UPDATE...
WARM AIR ADVECTION CONTINUES SATURDAY NIGHT INTO SUNDAY...TO THE
POINT THAT A GOOD PART OF THE AREA /ESPECIALLY WESTERN/ SHOULD
MANAGE TO GET INTO 50S FOR HIGHS SUNDAY. WEAKENING COLD FRONT
WILL SPREAD SHOWERS WEST TO EAST SUNDAY AFTERNOON AND
EVENING...BUT TEMPERATURES WILL BE WARM ENOUGH FOR ALL RAIN. ONLY
EXPECTING A FEW TENTHS OF AN INCH AT BEST WITH BRISKNESS OF FLOW
ALOFT. VERY BRIEF SLIGHT COLD AIR ADVECTION SUNDAY NIGHT...QUICKLY
NEUTRALIZES ALLOWING TEMPERATURES MONDAY TO BE NEAR OR ABOVE HIGHS
FROM SUNDAY. WEAK SURFACE HIGH PRESSURE TAKES CHARGE
MONDAY...WHICH FOR MOST IF NOT ALL WILL KEEP THE WEATHER DRY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
415 PM UPDATE...
IT WILL BE MILD AND QUIET INTO MONDAY EVENING, BEFORE A STORM
SYSTEM MOVING THROUGH LOWER ONTARIO PULLS A COLD FRONT INTO NY/PA.
THIS WILL CAUSE RAIN SHOWERS TUESDAY AND TUESDAY NIGHT. SOME WET
SNOW SHOWERS WILL BE POSSIBLE EARLY WEDNESDAY MORNING AS -4C 850MB
ISOTHERM CROSSES THE I-81 CORRIDOR.
TEMPERATURES WILL REMAIN COOL INTO EARLY THURSDAY. HOWEVER THE GFS
IS NOW FORECASTING A NEW RIDGE TO BUILD THURSDAY AFTERNOON INTO
FRIDAY, POTENTIALLY RESULTING IN ANOTHER WARMING TREND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WRM FNT OVER THE NRN ZONES BRINGING MVFR CIGS AND VSBY TO RME WILL
LFT NWRD ENDING THE SNOW THERE. OTRW...PLENTLY OF LEFTOVER LL
MOISTURE ASISISTED BY A SELY FLOW BRINGING A MARINE LYR INTO THE
AREA. THIS WILL LWR CIGS INTO THE IFR RANGE SOME STATIONS...WITH
MVFR VSBYS. XPCT SOME IMPRVMT AFT 12Z BUT WITH CLDS AND LOW SUN
ANGLE...WILL BE DFCLT TO MIX OUT MUCH WITH CIGS RISIONG SLOWLY.
XPCT CIGS TO LWR ONCE AGAIN AFT 00Z AS WE STABILIZE.
OUTLOOK...
SUN...MVFR IN RAIN SHOWERS MAINLY DURING THE AFTERNOON AND
OVERNIGHT PERIOD.
MONDAY...VFR.
TUESDAY...FROPA WITH MVFR IN RAIN
SHOWERS DURING THE AFTERNOON/EVENING.
WEDNESDAY...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ048.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ062.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...DGM
AREA FORECAST DISCUSSION...CORRECTED
NWS PORTLAND OR
924 PM PST FRI NOV 30 2012
.SYNOPSIS...A BROAD UPPER LOW OVER THE NE PACIFIC WILL CONTINUE
UNSETTLED WEATHER INTO NEXT WEEK. THE NEXT FRONT WILL MOVE THROUGH
THE AREA TONIGHT AND SATURDAY MORNING. SNOW LEVELS WILL LOWER TO PASS
LEVEL WITH THIS SYSTEM. ANOTHER FRONT WILL BRING MORE SUBSTANTIAL
CASCADE SNOW SATURDAY NIGHT AND SUNDAY.A STRONG UPPER JET WILL
CONTINUE SHOWERS THROUGH SUNDAY NIGHT. THERE WILL BE A BRIEF BREAK IN
PRECIPITATION MONDAY MORNING BEFORE ANOTHER MOIST FRONT WILL MOVE
THROUGH MONDAY NIGHT AND TUESDAY.
&&
.SHORT TERM...A VIGOROUS VORT MAX AND SHORTWAVE TROUGH MOVING INTO
WEST COAST ARE RESPONSIBLE FOR RAIN SHOWERS LIFTING NORTHEASTWARD
ACROSS THE REGION THIS EVENING. SO FAR RAIN IS PRIMARILY CONFINED
ACROSS THE NORTHWESTERN HALF OF THE CWA...BUT EXPECT THIS BROAD BAND
OF PRECIPITATION TO SHIFT SOUTHEASTWARD AS THE NIGHT PROGRESSES. SNOW
LEVELS NEAR 5000-5500 FT THIS EVENING SHOULD DROP TO NEAR 4000 FT BY
MORNING WITH 5 TO 8 INCHES OF NEW SNOW EXPECTED
ISOLATED THUNDERSTORMS HAVE BEEN DEVELOPING ACROSS OUR WATERS WITH A
FEW BEGINNING TO PUSH ASHORE NEAR BAY CITY AND TILLAMOOK. AN EVEN
MORE NOTEWORTHY CLUSTER OF THUNDERSTORMS HAS ERUPTED WEST OF COOS
BAY. IT APPEARS THIS CLUSTER WILL LIFT EAST-NORTHEASTWARD INTO THE
SOUTH CENTRAL OREGON COAST. AS A RESULT OF ALL THIS
ACTIVITY...THUNDER WAS ADDED TO THE OVERNIGHT FORECAST FOR THE COAST
RANGE AND THE SOUTH WILLAMETTE VALLEY.
NUMEROUS SITES HOVERED IN THE 45 TO 55 MPH RANGE FOR WIND GUSTS THIS
EVENING. THE RUC SEEMED TO INDICATE THE HIGH WINDS WERE ABOUT TO
SUBSIDE AND THAT WE WERE GOING TO ESCAPE UNSCATHED...JUST BEFORE
SEVERAL SITES REACHED HIGH WIND CRITERIA ALONG THE COAST. THESE
INCLUDED LINCOLN CITY...THE YAQUINA BRIDGE AND GARIBALDI. THIS
COINCIDED NICELY WITH AN INFLUX OF 65 TO 75KT INBOUND RETURNS AT
APPROXIMATELY 7500 FT VIA THE KRTX RADAR. WINDS APPEAR TO HAVE
TEMPORARILY BACKED OFF ALOFT VIA RADAR...BUT AN ADDITIONAL SPIKE IN
WINDS IN ANOTHER HOUR OR TWO ASSOCIATED WITH THE NEXT BAND OF
CONVECTION SEEMS PLAUSIBLE.
NO FLOODING IS ANTICIPATED DUE TO THE RAINFALL EXPECTED OVERNIGHT.
WITH THAT SAID...THE GRAYS RIVER AT ROSBURG IS BEGINNING TO GO UP
SOMEWHAT SHARPLY SO THIS WILL BE MONITORED CLOSELY OVERNIGHT.
/NEUMAN
PREVIOUS DISCUSSION BELOW...A LARGE COMPLEX UPPER LOW OVER THE NE
PACIFIC WILL CONTINUE TO SEND SYSTEMS ACROSS THE REGION INTO NEXT
WEEK. CONVECTIVE SHOWERS WILL CONTINUE GUSTY AND SHOWERY WEATHER LATE
THIS AFTERNOON...ESPECIALLY FOR THE COAST AND COAST RANGE. THE
SHOWERS WILL RAMP UP THIS EVENING AS THE NEXT SYSTEM...CURRENTLY NEAR
43N 134W APPROACHES. THIS SYSTEM WILL BRING ANOTHER ROUND OF GUSTY
WINDS AND HEAVY RAIN TONIGHT.
COOLER AIR WILL MOVE IN BEHIND THE FRONT WITH 700 MB MODELED
TEMPERATURES COOLING TO -9C BETWEEN 4 AND 10 PST SATURDAY MORNING.
SNOW LEVELS WILL LOWER TO NEAR OR JUST BELOW PASS LEVEL EARLY
SATURDAY MORNING. ALTHOUGH THE MAIN RAIN BAND WILL HAVE PUSHED
THROUGH BY THEN...A 120KT PLUS JET WILL CONTINUE SHOWERS THROUGH
SATURDAY AND EXPECT SOME DECENT SNOW ACCUMULATIONS AT THE PASSES
SATURDAY MORNING. THE SOUTH WASHINGTON CASCADES WILL HAVE THE HIGHEST
SNOW AMOUNTS AND HAVE ISSUED A LOW-END WINTER WEATHER ADVISORY FOR
TONIGHT THROUGH SATURDAY.
SHOWERS WILL LIGHTEN UP BRIEFLY SATURDAY AFTERNOON BEFORE THE NEXT.
SYSTEM...CURRENTLY NEAR 43N 148W CONTINUES THE UNSETTLED WEATHER.
THERE IS MORE MOISTURE WITH THIS SYSTEM THEN THE FEW PREVIOUS ONES
WITH MODELED TROPICAL PRECIPITABLE WATER VALUES NEAR AN INCH...AND
EXPECT SLIGHTLY MORE PRECIPITATION WITH THE FRONT EARLY SUNDAY
MORNING.THERE IS ALSO A STRONGER JET (150 +KT) BACKING UP THIS
SYSTEM THAT WILL RESULT IN MORE SUBSTANTIAL POST-FRONTAL SHOWERS
SUNDAY AFTERNOON AND NIGHT.
THE LOW HAS A FAVORABLE STORM TRACK FOR PRODUCING STRONG INLAND
WINDS...BUT THE MODELS HAVE BEEN BACKING OFF ON THE STRENGTH OF THE
LOW AND CURRENTLY THINK THE WINDS WILL REMAIN BELOW WARNING...BUT
GUSTY FOR SURE.
SNOW LEVELS WILL NOT RECOVER MUCH BETWEEN THE SATURDAY AND SUNDAY
SYSTEMS AND EXPECT MORE ABUNDANT SNOW IN THE CASCADES. THERE WILL BE
AT LEAST SOLID ADVISORY SNOW FROM SATURDAY NIGHT THROUGH SUNDAY
AFTERNOON...BUT WARNING AMOUNTS ARE NOT OUT OF THE QUESTION AND HAVE
ISSUED A WINTER STORM WATCH FOR ALL OF THE CASCADES.
SHOWERS WILL LIGHTEN UP SOME MONDAY MORNING...BUT WILL NOT END ALL
TOGETHER AS ANOTHER LOW WILL DROP DOWN INTO THE NE PACIFIC AND
BRING ANOTHER POTENTIALLY MOIST STORM MONDAY AFTERNOON AND EVENING.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...MODEL GUIDANCE IS SHOWING
REASONABLY GOOD AGREEMENT THROUGH THE FIRST HALF OF NEXT WEEK. THE
LATEST MEDIUM RANGE MODEL RUNS HAVE SPED UP THE PROGRESSION OF THE
NEXT FRONTAL SYSTEM. NOW EXPECT PRECIPITATION TO BEGIN SPREADING INTO
THE COAST MONDAY NIGHT...THEN PROGRESS INLAND DURING THE DAY TUE. IT
APPEARS THAT THIS FRONT WILL MAINTAIN A CONNECTION TO TROPICAL
MOISTURE. MODEL PWAT VALUES OF 1 TO 1.25 INCHES COMBINED WITH A
STRONG LOW LEVEL JET ARE EXPECTED TO BRING FAIRLY IMPRESSIVE MOISTURE
TRANSPORT INTO THE REGION. A MODERATE-TO-HEAVY RAINFALL EVENT IS
LOOKING LIKELY AT THIS POINT...WITH THE POTENTIAL FOR SOME GUSTY
COASTAL WINDS. HOWEVER...AT THIS POINT THE FOCUS OF THE HEAVIEST RAIN
APPEARS TO REMAIN TO OUR SOUTH...ALONG THE CA/OR BORDER...SO WE MAY
AVOID SIGNIFICANT HYDROLOGIC ISSUES. THE HEAVY RAINFALL SHOULD TAPER
OFF LATER TUE AS THE FRONT PUSHES EAST...BUT EXPECT SHOWER ACTIVITY
TO CONTINUE OVERNIGHT TUE AND WED AS THE PARENT UPPER TROUGH PUSHES
THROUGH THE PAC NW. WE SHOULD TREND DRIER OVER THE SECOND HALF OF THE
WEEK AS WEAK UPPER LEVEL RIDGING BUILDS IN BEHIND THE DEPARTING
TROUGH. PYLE
&&
.AVIATION...COOL MOIST AND UNSTABLE AIR MASS REMAINS OVER THE
REGION. W TO SW FLOW ALOFT CONTINUES WITH EMBEDDED DISTURBANCES
THESE DISTURBANCES WILL ENHANCE THE SHOWER BANDS THIS AFTERNOON
FOR THE COAST...AND FOR MOST AREAS AGAIN LATER THIS EVENING.
EXPECT MVFR CHANCES WILL BE MOST PERSISTENT ALONG THE COAST
THROUGH THE PERIOD...WITH THE BEST MVFR CHANCES INLAND OVERNIGHT.
BEST THREAT FOR TSTORMS REMAINS FROM COAST RANGE WESTWARD...WITH A
SMALL CHANCE OF IMPACTING THE COASTAL TERMINALS MAINLY DURING THE
LATE EVENING AND OVERNIGHT HOURS AS THE NEXT STRONGER FRONT MOVES
IN. TSTORM THREAT SHIFTS NORTH OF THE COLUMBIA RIVER SUNDAY
MORNING.
KPDX AND APPROACHES...VFR CONDITIONS WITH INTERMITTENT SHOWERS
THROUGH THIS EVENING...WITH BRIEF MVFR UNDER THE SHOWERS. BETTER
CHANCE FOR MVFR IN RAIN OVERNIGHT. GUSTY S TO SE WINDS WILL
CONTINUE THROUGH THE PERIOD...THOUGH MAINLY GUSTS TO 25 KT OR
LESS...POSSIBLY HIGHER AT TIMES OVERNIGHT. VFR RETURNS SATURDAY AS
FRONT CLEARS THE TERMINAL BY DAYBREAK. KMD/BROWN
&&
.MARINE...STRONG LOW PRESSURE OFFSHORE OF THE TIP OF VANCOUVER
ISLAND WILL SLOWLY WEAKEN THROUGH THE WEEKEND...BUT A FAIRLY
STRONG PRESSURE GRADIENT WILL REMAIN DRAPED OVER THE WATERS. THIS
COMBINED WITH SHOWER ACTIVITY FROM A SERIES OF FRONTS MOVING
THROUGH THE WATERS TONIGHT AND AGAIN SATURDAY WILL CREATE GALE
FORCE GUSTS THROUGH THE DAY ON SATURDAY. GALES MAY WEAKEN AT
TIMES.
SEAS WILL REMAIN IN THE 16 TO 18 FT RANGE THROUGH SAT...THOUGH
MAY GET UP TO 19-20 FT TONIGHT WITH A FRONTAL PASSAGE AND
ESPECIALLY ACROSS THE CENTRAL OREGON WATERS. SEAS GRADUALLY
SUBSIDING ON SUN INTO MON BACK INTO THE LOWER TEENS...BUT
CONFIDENCE IS LOW ON SEAS DROPPING BACK BELOW 10 FT FOR ANY
EXTENDED PERIOD UNTIL THE LATTER HALF OF NEXT WEEK WHEN HIGH
PRESSURE ATTEMPTS TO BUILD IN. KMD/BROWN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES.
HIGH WIND WARNING UNTIL 1 AM PST SATURDAY FOR CENTRAL OREGON
COAST-NORTH OREGON COAST.
WA...WINTER WEATHER ADVISORY FROM 1 AM TO 4 PM PST SATURDAY FOR SOUTH
WASHINGTON CASCADES.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY
NIGHT FOR SOUTH WASHINGTON CASCADES.
PZ...GALE WARNING UNTIL 10 PM PST SATURDAY FOR COASTAL WATERS FROM
CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
335 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MVFR FOG AND A FEW AREAS OF IFR WITH CEILINGS BELOW 1K FEET AND
VISIBILITIES 1-3SM LIKELY TO REMAIN STEADY THROUGH 14Z OR ABATE
SLOWLY FROM THE WEST. STRONG LOW LEVEL FLOW ABOVE THE SURFACE WILL
LIKELY KEEP CONDITIONS FROM GENERALLY WORSENING DURING THE REST OF
THE NIGHT. THE SAME STRENGTHENING LOW LEVEL FLOW SHOULD KEEP
GENERALLY VFR CONDITIONS OVER SOUTHEAST SD. KFSD AND KSUX TAF SITES
WILL BE ON THE EDGE AND COULD POSSIBLY DROP TO 5SM BUT WILL PROBABLY
KEEP OUT OF TAFS GIVEN INDICATIONS OF HOW STRONG THOSE WINDS JUST
ABOVE THE SURFACE ARE GETTING. AFTER 15Z CONDITIONS IN SOUTHWEST MN
AND NORTHWEST IA WILL IMPROVE TO VFR FROM THE WEST...THOUGH THE
SOUTHEAST CORNER OF THE AREA FROM SOUTH OF SPW TO SLB COULD SEE SOME
DEEPER AND LONGER LASTING STRATUS IN THE MORNING. WHATEVER LINGERS
INTO THE AFTERNOON IF ANYTHING SHOULD RAPIDLY IMPROVE AFTER 18Z WITH
APPROACH AND ARRIVAL OF SURFACE TROUGH.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
540 AM CST SAT DEC 1 2012
.AVIATION...
VFR TO IFR CONDITIONS WILL SLOWLY DETERIORATE TO IFR/LIFR
CONDITIONS THROUGH 18Z/01 AS LOW CLOUDS MOVE NORTHEAST FROM
MISSOURI AND KANSAS. IFR/LIFR CONDITIONS WITH DZ OR SHRA ARE THEN
EXPECTED THROUGH 06Z/02 BEFORE A SLOW IMPROVEMENT BEGINS. THERE IS
A POSSIBILITY OF MORE FOG AFT 06Z/02 WHICH MAY ALLOW THE IFR/LIFR
CONDITIONS TO PERSIST. ..08..
&&
.PREV DISCUSSION... /ISSUED 311 AM CST SAT DEC 1 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. ..08..
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
542 AM CST SAT DEC 1 2012
...UPDATE TO AVIATION...
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
IFR TO MVFR CIGS WILL CONTINUE INTO THE LATE MORNING HOURS. MVFR
CIGS ARE EXPECTED BY 18Z. LOW LEVEL MOISTURE WILL BE SLOW TO MOVE
OUT SO KEPT MVFR CIGS IN UNTIL 23Z-24Z. WINDS WILL BE SOUTH NEAR
10 KTS VEERING TO THE SOUTHWEST AND DECREASING BY 00Z SUNDAY.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR
KSZ008>010-020-021-034-035.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1041 AM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE RIDGING SOUTHWARD TOWARD THE MID-ATLANTIC REGION
TODAY WILL SHIFT OFF THE COAST TONIGHT WHILE A STALLED FRONT
DRAPED SOUTH OF THE AREA RETREATS NORTHEASTWARD AS A WARM FRONT
TONIGHT INTO SUNDAY. A WEAK COLD FRONT WILL MOVE EAST THROUGH THE
REGION SUNDAY NIGHT. A SLIGHTLY STRONGER COLD FRONT WILL MOVE
THROUGH THE MID ATLANTIC LATE TUESDAY AND EARLY WEDNESDAY FOLLOWED
BY HIGH PRESSURE BUILDING IN FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST SFC ANALYSIS SHOWS A 1041 MB HIGH CENTERED OVER NRN NEW
ENGLAND. HIPRES HAS RIDGED SWD TOWARD THE MID-ATLANTIC REGION...
PRODUCING A CAD SETUP. A VERY DIFFUSE FRONTAL BOUNDARY LIES NEARLY
STATIONARY SOUTH AND WEST OF THE CWA. 12Z IAD RAOB SHOWS THIS
WEDGE OF COLD AIR NEAR THE SFC IS TRAPPED WITHIN A SIGNIFICANT
INVERSION LAYER IN THE LOWEST 3 KFT. SHALLOW E-NE FLOW NEAR THE
SFC HAS ADVECTED LOW STRATUS AND FOG INLAND TOWARD NORTH- CENTRAL
AND SRN MD...AND NRN VA. FCST FOR EROSION OF MRNG STRATUS IS MORE
PESSIMISTIC THAN ALL MODEL GUIDANCE AS THE LOW DEC SUN ANGLE WILL
LIMIT ABILITY OF DAYTIME MIXING TO ERODE THE INVERSION. EXPECT TO
SEE SOME IMPROVEMENT MIDDAY ALONG THE PERIPHERY OF THE STRATUS
DECK...BUT OVER NERN MD...WHERE CAD IS SOCKED IN...CLEARING MAY
NOT OCCUR UNTIL MID AFTN.
HIPRES BEGINS TO SHIFT OFF MAINE COAST LATE THIS AFTN. WITH
DEVELOPING SLY RETURN FLOW...THE AFOREMENTIONED FRONTAL BOUNDARY
WILL ATTEMPT TO LIFT BACK NWD AS A WARM FRONT. NOT SURE HOW MUCH
NWD PROGRESSION IT WILL MAKE...ESPECIALLY EAST OF THE BLUE
RIDGE...WITH SHALLOW WEDGE OF COLD AIR STUBBORN TO ERODE. CLOUD
COVER AND CAD WILL YIELD A HIGHER THAN NORMAL N-S TEMPERATURE
GRADIENT. MAX TEMPS WILL RANGE FROM THE UPPER 40S ACROSS THE NRN
SUBURBS OF BALTIMORE TO NEAR 60F SOUTH OF CHO.
RDGG WL TAKE HOLD AT THE SFC AND ALOFT TNGT. NRN CNTYS WL BE
NEARER TO FASTER MID-LVL FLOW...SO WL PAINT SCT TO ALMOST BKN CLDS
THERE. LOW STRATUS AND FOG MAY REDEVELOP AGAIN TNGT. DEWPTS SHUD
BE HIER /A RSLT OF RESIDUAL MSTR FM THE PRESENT ENE FLOW/...SO HV
FCST MIN-T LIKEWISE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
SOME DEJA VU MOMENTS OVER THE COMING WEEK...AS A COUPLE OF FRONTAL
PASSAGES SHAPING UP FOR THE REGION - BRIDGED BY SIMILAR BOUTS OF
HIGH PRESSURE. THE FIRST FRONT WILL LARGELY WASH OUT AS IT CROSSES
THE AREA OVERNIGHT SUN INTO EARLY MON. THE PARENT LOW WILL SPEED OFF
TO THE NE FROM THE GREAT LAKES REGION ON SUN...LEAVING THE FRONT TO
DISSIPATE AS IT CROSSES THE APLCNS SUN NIGHT. UNLIKE MOST FRONTAL
PASSAGES...ESPECIALLY THIS TIME OF YEAR...IT WON`T EXACTLY BE MARKED
BY A SIGNIFICANT TEMP CHANGE. IN FACT...SUN NIGHT WILL BE ONE OF THE
WARMER NIGHTS IN RECENT MEMORY - ONLY DROPPING INTO THE U40S FOR
OVERNIGHT LOWS. A FEW LIGHT SHOWERS MAY REAPPEAR ALONG THE I-95
CORRIDOR BEFORE THE FRONT MOVES OFF THE COAST...BUT VERY LIGHT AND
SHORT LIVED.
THE WARM OVERNIGHT PERIOD SUN NIGHT WILL OCCUR IN LARGE PART BECAUSE
THE DAYTIME HRS ON SUN WILL HAVE HAD A GOOD SLY BREEZE IN
PLACE...INCREASING THE LOW LEVEL MOISTURE. DESPITE THE WIND SHIFT W/
THE FRONT EARLY MON TOWARD THE NW...DRIER AIR WILL NOT MIX INTO THE
AREA - HELPING TO KEEP TEMPS MODERATED OVERNIGHT. SAME STORY ON
MON...AS THE SFC HIGH REESTABLISHES ITSELF OVER THE EAST COAST AND
SENDS ANOTHER SEVERAL HRS OF WARM/MOIST SLY WINDS UP THE ERN
SEABOARD. TEMPS WILL MAKE THEIR WAY WELL INTO THE 60S ACROSS THE
REGION ON MON AFTN...WHICH WILL SET US UP FOR YET ANOTHER RELATIVELY
WARM OVERNIGHT PERIOD...W/ LOWS BARELY DROPPING INTO THE 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AN ENCORE OF MON WILL BE ON TUE...AHEAD OF A SIMILAR FRONTAL PASSAGE
ON WED. THE FRONT ON WED MAY BRING A BIT MORE SHOWER ACTIVITY TO THE
AREA...AND MOVE THRU ON WED MRNG. THIS FRONT HOWEVER...WILL BRING A
NOTICEABLE TEMP CHANGE - DROPPING HIGHS AND LOWS DOWN ABOUT 10-15
DEGREES FOR THE NEXT COUPLE OF DAYS. THIS PASSAGE WILL BE AIDED BY A
STRONGER PARENT LOW PRESSURE SYSTEM OVER THE GREAT LAKES THAT WILL
TAP INTO A BETTER COLD CANADIAN AIR FETCH. OVER THE LONGER TERM...IT
APPEARS THAT A SLIGHTLY STRONGER SYSTEM THAN THIS ONE WILL THEN
MAKES AN DIVE TOWARD THE AREA BY THE END OF THE COMING WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
STRATUS EXPECTED TO HOLD ON LONGER THAN PREV FCST. IFR CIGS/VSBYS AT
IAD/DCA/BWI/MTN WILL IMPROVE GRADUALLY FROM SW TO NE BETWEEN
MIDDAY AND MID AFTN. STRATUS DID NOT REACH MRB/CHO...AND DO NOT
EXPECT IT TO REACH THESE TERMINALS.
VFR SHUD PREVAIL LATE THIS AFTN/EVE. REDEVELOPMENT OF FOG/STRATUS
POSSIBLE AGAIN LATE TNGT AND SUN MRNG...ESPECIALLY OVER THE SAME
LOCATIONS THAT SAW IT THIS MRNG. FCST WILL MORE PESSIMISTIC THAN
CURRENT MODEL GUIDANCE AS GUIDANCE DID NOT CAPTURE THE CURRENT
FOG/STRATUS EVENT WELL /EXCEPT FOR THE HRRR TO SOME EXTENT/.
A WEAK FRONTAL BOUNDARY WILL SLIDE THRU THE AREA DURING THE PREDAWN
HRS MON...SHIFTING WINDS FROM SLY TO NWLY BY THE MID MRNG HRS...
THOUGH THE MAGNITUDES WILL DECREASE. HIGH PRESSURE WILL BUILD FOR
MON AND TUE...THEN A COLD FRONT WILL MOVE THRU ON WED W/ STRONGER
NWLY WINDS GUSTS IN THE 15-25KT RANGE. CONDITIONS WILL SUBSIDE AGAIN
OVERNIGHT AS HIGH PRESSURE BUILDS IN FOR THU AND INTO FRI.
&&
.MARINE...
FOG ACRS WATERS THIS MRNG...SPCLY MID BAY AND LWR PTMC. XPCT
IMPVMNT BY ERY AFTN. OTRW NO SGFNT WX TDA-TNGT. NE WNDS AOB 10
KT TDA BCMG SELY TNGT.
HIGH PRESSURE WILL BE IN PLACE FOR MUCH OF THE WEEK...THOUGH A
COUPLE OF FRONTAL PASSAGES WILL IMPACT THE AREA. THE FIRST FRONT
WILL MAKE LITTLE IMPACT OTHER THAN TO CHANGE THE WIND DIRECTION ON
MON MRNG...FROM SLY TO NWLY. THE FRONT ON WED MRNG WILL BRING THE
SAME CHANGE...THOUGH WINDS WILL BE BREEZY ACROSS THE WATERS FOR MUCH
OF THE DAY. WINDS WILL TAPER OFF HEADING INTO NEXT WEEKEND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KLEIN
PREV DISC...HTS/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
801 AM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING THE RISK FOR SHOWERS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK UPPER LEVEL RIDGE WILL MOVE THROUGH THE OHIO VALLEY THROUGH
THIS AFTERNOON WITH DRY CONDITIONS EXPECTED.
SATELLITE SHOWS SOME STRATOCU DRIFTING NE ACROSS THE REGION.
MORNING RAOB AND RUC DATA INDICATE SOME OF THIS WILL MOVE EWD
ACROSS THE AREA THROUGH THE AFTERNOON WITH PARTLY SUNNY SKIES.
MORNING RAOB DATA SUPPORTS ABOVE NORMAL HIGHS IN THE 50S TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON. WITH VERY LITTLE UPPER
LEVEL SUPPORT ACCOMPANYING THE BOUNDARY...IT WILL HAVE A DIFFICULT
TIME MAKING MUCH SOUTHWARD PROGRESS. BY LATE SUNDAY AFTERNOON...IT
BECOMES DIFFICULT TO FIND THE SFC BOUNDARY AS IT LOSES MUCH OF IT
DEFINITION. MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING
THROUGH SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER
WEAK SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA
MOST LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO
THE POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED. THERE WILL
BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD WEATHER WILL
CONTINUE ON SUNDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AN AREA OF MID AND HIGH CLOUDS IN ASSOCIATION WITH A PASSING MID-
LEVEL SYSTEM WILL MOVE THROUGH THE AREA. OTHERWISE...RAGGED HIGH
CLOUDS WILL BE COMMON ACROSS THE REGION...AND WINDS GIVE A WEAK
SURFACE PATTERN WILL BE RATHER LIGHT. AS SUCH...GENERALLY VFR
CONDITIONS SHOULD PREVAIL AT ALL SITES THROUGH SATURDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BILLINGS MT
350 AM MST SAT DEC 1 2012
.SHORT TERM...VALID FOR TDY AND SUN...
THE PASSAGE OF AN ENERGETIC SHORT WAVE TROUGH SUN AND SUN NIGHT IS
THE MAIN FOCUS OF THE SHORT TERM...AS IT WILL PROVIDE A THREAT FOR
HIGH WINDS FROM LIVINGSTON AND NYE UP TO HARLOWTON...AND HAZARDOUS
WINTER WEATHER IN THE BEARTOOTH/ABSAROKA MOUNTAINS. THE STRONG JET
ASSOCIATED WITH THIS WAVE CAN ALREADY BE SEEN AS AN AREA OF DRYING
APPROACHING THE CA AND OR COASTLINE ON MOISTURE CHANNEL IMAGERY AT
10 UTC.
TODAY...WE DECIDED TO CARRY A DRY FORECAST OVER THE PLAINS...WHICH
COUNTS ON THE SHOWERS NOTED EAST OF BILLINGS DIMINISHING BY 12 UTC
LIKE THE LAST SEVERAL RAP AND HRRR SOLUTIONS SUGGEST. WE FEEL THAT
IDEA IS A GOOD ONE SINCE SATELLITE IMAGERY SHOWS SOME DRYING ALOFT
IN SOUTH CENTRAL MT ALREADY...SIGNALING THE EXIT OF THE WEAK SHORT
WAVE RESPONSIBLE FOR THE SHOWERS. THE 00 UTC MODELS...AND EVEN THE
03 UTC SREF...ALL SUGGEST THE NEXT BATCH OF MOUNTAIN PRECIPITATION
WILL MOVE IN AFTER 18 UTC...SO WE HAVE LIKELY POPS FOR PLACES LIKE
COOKE CITY THIS AFTERNOON AFTER A RELATIVE LULL THIS MORNING. MILD
CONDITIONS WILL CONTINUE IN THE LOWER ELEVATIONS...THOUGH WITH THE
MILES CITY AREA NOT MIXING OUT TOO WELL THE LAST FEW DAYS...WE ARE
NOT ENTIRELY CONFIDENT IN THE DEGREE OF WARMING. WE USED THE BIAS-
CORRECTED 00 UTC MOS CONSENSUS FOR FORECAST HIGHS SINCE THERE WILL
NOT BE A DOWNSLOPE LOW-LEVEL TRAJECTORY TO PUSH HIGHS TOO FAR AWAY
FROM MOS-BASED EXPECTATIONS. FINALLY...WINDS AROUND LIVINGSTON AND
BIG TIMBER WILL PICK UP AGAIN TODAY WITH MIXING...BUT THE FORECAST
SOUNDINGS FOR THOSE LOCATIONS ONLY HAVE ABOUT 45 KT OF WIND WITHIN
THE MIXED LAYER.
TONIGHT...SOME SNOW SHOWERS WILL LIKELY CONTINUE IN THE MOUNTAINS.
SURFACE PRESSURE FALLS WILL RAMP UP IN THE NORTHERN ROCKIES...WITH
GAP-AIDED WINDS LIKELY INCREASING OVERNIGHT AT LIVINGSTON AND NYE.
SUN...SUBSTANTIAL SURFACE PRESSURE FALLS OF 10-15 HPA/6 HOURS WILL
SHIFT EAST ACROSS NORTHERN MT AS A 988-HPA SURFACE LOW DEVELOPS IN
THE LEE OF THE ROCKIES. THIS REFLECTS THE TIGHT LOW- AND MID-LEVEL
HEIGHT GRADIENT THAT WILL GENERATE 700-HPA WINDS OF 70 TO 80 KT IN
PARTS OF SOUTH CENTRAL MT. FORECAST SOUNDINGS SUGGEST AN INVERSION
NEAR THE MOUNTAIN-TOP LEVEL AT LIVINGSTON TO HELP WITH GAP FLOW...
AND THE MET MOS THERE EVEN SHOWS A 49 KT SUSTAINED SPEED AT 18 UTC
SUN. THOSE SOUNDINGS ALSO SUGGEST MIXING SHOULD HAVE ACCESS TO THE
STRONG WINDS OFF THE SURFACE EVEN AFTER 18 UTC...AND IN FACT 500 M
AGL WINDS FROM THE 00 UTC GFS RUN 50+ KT DURING THE AFTERNOON FROM
LIVINGSTON TO BIG TIMBER AND UP TO HARLOWTON...WHICH WAS ENOUGH TO
MAKE US HOIST A HIGH WIND WATCH FOR THAT WHOLE CORRIDOR. THERE MAY
BE SOME SUBSIDENCE TO HELP DRIVE THE WINDS TOO PER OMEGA FIELDS IN
FORECAST SOUNDINGS...AND A 100 KT SOUTHWESTERLY 300-HPA JET SHOULD
ALSO PROVIDE A PERIOD OF SUBSIDENCE AND DEEP LINKAGE AS IT CROSSES
THE REGION IN THE AFTERNOON AND EVENING. STRONG MOUNTAIN-TOP WINDS
ON THE ORDER OF 80+ KT ARE ALSO SUGGESTED IN ALL 00 UTC MODELS. WE
THUS ARE CONCERNED WITH MOUNTAIN WAVE ACTIVITY FOR PLACES LIKE RED
LODGE...BUT MODEL-DERIVED CROSS SECTIONS SHOW ONLY A WEAK CRITICAL
LAYER OF SPEED SHEAR ABOVE THE MOUNTAIN-TOP LEVEL...AND THERE JUST
IS NOT A STRONG DOWNWARD MOMENTUM SIGNATURE SHOWN IN THETA FIELDS.
THUS...WE DECIDED AGAINST A HIGH WIND WATCH FOR RED LODGE...THOUGH
WE NEED TO STRESS THAT RED LODGE MOUNTAIN WILL PROBABLY EXPERIENCE
STRONG WINDS EITHER WAY.
WHERE THE BEARTOOTH AND ABSAROKA MOUNTAINS ARE CONCERNED...WE LEFT
THE WINTER STORM WATCH IN PLAY...WITH SNOW-TO-LIQUID RATIOS ONE OF
THE MAIN UNCERTAINTIES IN THIS EVENT DUE TO THE MILD NATURE OF THE
SOUTHWEST FLOW ALOFT. THE STRONG WINDS MAY STILL CAUSE SOME PRETTY
HIGH IMPACTS IN THE HIGH COUNTRY THOUGH...EVEN IF SNOW AMOUNTS ARE
HELD BELOW THE 12 INCHES USUALLY NEEDED IN 24 HOURS FOR A WARNING.
SUN NIGHT...A SURFACE COLD FRONT WILL CROSS THE AREA...AND WE HAVE
SOME 20 TO 30 POPS IN PLACE EVEN OVER THE PLAINS WITH ITS PASSAGE.
THE 00 UTC GFS REVEALS POTENTIAL FOR A MOUNTAIN WAVE-INDUCED WIND
EVENT AT SHERIDAN...BUT AGAIN THETA FIELDS WOULD SUGGEST THE WINDS
MAY NOT ACTUALLY MAKE IT DOWN TOO FAR OFF THE BIG HORN RANGE. MOST
PAST MOUNTAIN WAVE EPISODES AT SHERIDAN ALSO HAD A JET ORIENTATION
THAT WAS MORE EAST TO WEST THAN THE UPCOMING EVENT...WHICH REDUCES
CONFIDENCE A BIT AS WELL. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
TRANQUIL WEATHER PATTERN IS EXPECTED MONDAY THROUGH SATURDAY WITH
VERY GOOD AGREEMENT AMONG THE MEDIUM RANGE GUIDANCE.
POST-FRONTAL CONDITIONS WILL PREVAIL ON MONDAY IN WAKE OF WEAK
PACIFIC COLD FRONT WHICH MOVED THROUGH THE AREA SUNDAY NIGHT.
TEMPERATURES WILL BE SOMEWHAT COOLER ON MONDAY...BUT STILL WELL
ABOVE SEASONAL NORMALS. LEE TROUGHINESS WILL REDEVELOP ON TUESDAY
IN ADVANCE OF NEXT APPROACHING UPPER LEVEL TROUGH FROM THE PACIFIC
NORTHWEST. UPPER LEVEL SHORTWAVE TROUGH TRANSITS THE STATE
WEDNESDAY NIGHT BRINGING A THREAT FOR SCATTERED SHOWERS ACROSS THE
PLAINS OF SOUTHERN MONTANA AND NORTHERN WYOMING. HOWEVER THIS
LOOKS TO BE A QUICK SHOT OF MOISTURE AND RELATIVELY INSIGNIFICANT
AT THIS POINT. THURSDAY WILL BE SLIGHTLY COOLER IN THE WAKE OF
THIS SHORTWAVE TROUGH...WHICH AMPLIFIES UPPER LEVEL TROUGHINESS
OVER THE NORTHERN PLAINS THURSDAY AND INTO FRIDAY. THIS WILL KEEP
FRIDAY SLIGHTLY COOLER AS WELL...BUT AGAIN STILL WELL ABOVE
SEASONAL NORMALS. UPPER FLOW WILL REMAIN ZONAL WITH EMBEDDED WEAK
SHORTWAVE TROUGH SLATED TO MOVE ACROSS THE REGION AGAIN ON
SATURDAY...WHICH WILL KEEP TEMPERATURES CONSISTENT WITH THOSE OF
PRECEDING DAYS. OVERALL PERIOD LOOKS DRY...OTHER THAN
PRECIPITATION THREAT FOR WEDNESDAY NIGHT. MEIER
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS THE AREA THROUGH THE
NEXT 24 HOURS. AN AREA OF VERY LIGHT SHOWERS WILL EXIT SOUTHEAST
MONTANA BY MID-MORNING. WINDS WILL BE GENERALLY LIGHT ACROSS THE
AREA...WITH THE EXCEPTION OF THE UPPER YELLOWSTONE VALLEY IN THE
VICINITY OF LIVINGSTON...WHERE SOUTHWEST WINDS INCREASE BY MID
MORNING TO SUSTAINED AROUND 30 KNOTS WITH GUSTS TO 45 KNOTS. MEIER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 055 039/059 038/050 031/049 035/053 032/041 025/041
1/B 00/N 20/N 00/B 01/B 31/E 11/B
LVM 054 043/057 037/046 033/047 033/053 030/038 019/038
1/N 13/W 33/W 11/N 12/W 31/B 11/B
HDN 056 033/058 032/052 026/048 030/054 029/042 025/040
1/B 00/B 20/N 00/U 01/B 31/E 11/B
MLS 052 031/056 036/049 026/047 029/052 029/039 019/036
1/B 00/B 30/N 00/U 01/B 21/B 11/B
4BQ 056 031/061 036/050 027/049 030/055 030/039 021/037
1/B 00/B 30/N 00/U 01/B 32/W 10/B
BHK 053 029/057 035/048 023/045 028/049 025/035 016/032
1/B 00/B 30/N 00/U 01/B 21/B 10/B
SHR 053 029/056 030/044 020/045 028/050 025/033 020/032
1/B 00/N 22/W 00/U 02/W 44/J 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WATCH IN EFFECT FROM LATE TONIGHT THROUGH SUNDAY
EVENING FOR ZONES 28-41-42-63-65-66.
WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH LATE
SUNDAY NIGHT FOR ZONE 67.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
723 AM CST SAT DEC 1 2012
.UPDATE...BASED ON LATEST AUTOMATED OBS AT SITES SUCH AS
KEARNEY/HOLDREGE AND VISIBILITY TRENDS FROM LATEST HIGHER-RES
MODELS SUCH AS HRRR AND RAP13...TACKED ON YET ANOTHER ROW OF
COUNTIES TO THE NORTHWEST EDGE OF THE DENSE FOG ADVISORY...WHICH
NOW INCLUDES ALL BUT 5 COUNTIES IN THE FAR WESTERN/NORTHERN CWA.
LATEST THINKING IS THAT FOG MAY BE SLOWER TO VACATE THAN
PREVIOUSLY THOUGHT...AND DAY SHIFT WILL BE MONITORING CLOSELY FOR
A POSSIBLE EXTENSION IN TIME OF THE FOG HEADLINE PAST 10 AM.
OTHERWISE...ONLY UPDATED TEMP/DEWPOINT GRIDS THROUGH THE NEXT
SEVERAL HOURS TO BETTER MATCH OBSERVATIONAL TRENDS. NO OTHER
CHANGES MADE AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 600 AM CST SAT DEC 1 2012/
AVIATION...12Z KGRI TAF. AS IT TURNED OUT...CONDITIONS DID IN
FACT DETERIORATE CONSIDERABLY OVER THE PAST FEW HOURS AS A SURGE
OF LOW LEVEL MOISTURE WORKED NORTH INTO THE AREA...WITH LIFR CEILING
NOW IN PLACE...AND VISIBILITY STEADILY DECREASING TOWARD IFR/LIFR
THRESHOLDS AS WELL. AS A RESULT...HAVE TRENDED THE TAF IN A VERY
PESSIMISTIC DIRECTION FOR THE FIRST FEW HOURS THIS MORNING...WITH
VISIBILITY POSSIBLY DROPPING UNDER 1/2SM. ALTHOUGH CONFIDENCE
REMAINS A BIT SHAKY ON WHEN FOG AND LINGERING LOW CLOUDS WILL
BREAK...ESPECIALLY CONSIDERING THAT KGRI WILL RESIDE VERY NEAR THE
INTERFACE BETWEEN LIGHTER FOG TO THE WEST AND MORE WIDESPREAD
DENSE FOG TO THE EAST/SOUTHEAST...HAVE AIMED FOR A RETURN TO VFR
VISIBILITY BY 17Z AS AN APPROACHING SURFACE TROUGH AXIS STARTS
SCOURING OUT FOG...AND A RETURN TO VFR CEILING BY 20Z AS STRATUS
FINALLY SCATTERS OUT. CERTAINLY PREPARE FOR POSSIBLE ADJUSTMENTS
WITHIN A FEW HOURS EITHER SIDE OF THIS THINKING. ONCE VFR
CONDITIONS RETURN TODAY...THEY ARE EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE PERIOD...AS WESTERLY LOW LEVEL BREEZES SHUNT LOW
CLOUDS OFF TO THE EAST. THESE SURFACE WINDS WILL NOT BE MUCH OF AN
ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS EXPECTED TO
AVERAGE UNDER 8KT AS DIRECTION GRADUALLY SHIFTS FROM SOUTHERLY TO
WESTERLY.
PREV DISCUSSION... /ISSUED 439 AM CST SAT DEC 1 2012/
UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ041-
047>049-061>064-073>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
LATEST UPDATE/AVIATION/LONG TERM...PFANNKUCH
PREVIOUS UPDATE/SHORT TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
600 AM CST SAT DEC 1 2012
.AVIATION...12Z KGRI TAF. AS IT TURNED OUT...CONDITIONS DID IN
FACT DETERIORATE CONSIDERABLY OVER THE PAST FEW HOURS AS A SURGE
OF LOW LEVEL MOISTURE WORKED NORTH INTO THE AREA...WITH LIFR CEILING
NOW IN PLACE...AND VISIBILITY STEADILY DECREASING TOWARD IFR/LIFR
THRESHOLDS AS WELL. AS A RESULT...HAVE TRENDED THE TAF IN A VERY
PESSIMISTIC DIRECTION FOR THE FIRST FEW HOURS THIS MORNING...WITH
VISIBILITY POSSIBLY DROPPING UNDER 1/2SM. ALTHOUGH CONFIDENCE
REMAINS A BIT SHAKY ON WHEN FOG AND LINGERING LOW CLOUDS WILL
BREAK...ESPECIALLY CONSIDERING THAT KGRI WILL RESIDE VERY NEAR THE
INTERFACE BETWEEN LIGHTER FOG TO THE WEST AND MORE WIDESPREAD
DENSE FOG TO THE EAST/SOUTHEAST...HAVE AIMED FOR A RETURN TO VFR
VISIBILITY BY 17Z AS AN APPROACHING SURFACE TROUGH AXIS STARTS
SCOURING OUT FOG...AND A RETURN TO VFR CEILING BY 20Z AS STRATUS
FINALLY SCATTERS OUT. CERTAINLY PREPARE FOR POSSIBLE ADJUSTMENTS
WITHIN A FEW HOURS EITHER SIDE OF THIS THINKING. ONCE VFR
CONDITIONS RETURN TODAY...THEY ARE EXPECTED TO PERSIST THROUGH THE
REMAINDER OF THE PERIOD...AS WESTERLY LOW LEVEL BREEZES SHUNT LOW
CLOUDS OFF TO THE EAST. THESE SURFACE WINDS WILL NOT BE MUCH OF AN
ISSUE THROUGH THE PERIOD...WITH SUSTAINED SPEEDS EXPECTED TO
AVERAGE UNDER 8KT AS DIRECTION GRADUALLY SHIFTS FROM SOUTHERLY TO
WESTERLY.
&&
.PREV DISCUSSION... /ISSUED 439 AM CST SAT DEC 1 2012/
UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ048-049-
062>064-074>077-083>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM/UPDATE...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
439 AM CST SAT DEC 1 2012
.UPDATE...HAVE EXPANDED THE DENSE FOG ADVISORY FARTHER NORTH INTO
SOUTH CENTRAL NEB AS LLVL MOISTURE CONTINUES TO SURGE NORTH AND
VSBYS RAPIDLY DROP. CURRENT HEADLINE FOLLOWS CLOSE TO RAP VSBY
PROGS THIS MORNING...BUT WILL CONTINUE TO MONITOR AS TO WHETHER
FURTHER HEADLINE EXPANSION IS NEEDED. 06Z MODELS CONTINUE TO SLOW
PROGRESSION OF TROUGH THIS MORNING AND SUBSEQUENTLY HAVE LOWERED
TEMPS IN OUR EASTERN ZONES FOR THIS AFTN.
&&
.PREV DISCUSSION... /ISSUED 312 AM CST SAT DEC 1 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MAIN FOCUS IS ON FOG
THIS MORNING...AND TEMPERATURES THE NEXT SEVERAL DAYS. THE
PATTERN ALOFT FEATURED MAINLY ZONAL...PROGRESSIVE FLOW ACROSS THE
CONUS WITH EMBEDDED SHORTWAVE TROUGHS. UPSTREAM...A CLOSED LOW
PRESSURE SYSTEM REMAINED ORIENTED OFF THE COAST IN THE PACIFIC
NORTHWEST. AT THE SURFACE...LOW PRESSURE CENTERS WERE LOCATED IN
THE WESTERN DAKOTAS...AND IN SOUTHEAST COLORADO. IN THE SOUTHERLY
LLVL FLOW...MOISTURE IS BEING DRAWN NORTH FM THE SOUTHERN PLAINS
STATES. SFC DPS HAVE RISEN INTO THE LOWER 50S ALREADY IN SOUTHERN
KANSAS. THESE HIGH DPS ARE GREATER THAN NORMAL HIGHS FOR THIS TIME
OF YEAR AND ANOMALY PAGE INDICATES THAT THE 925MB SPECIFIC
HUMIDITIES ARE ROUGHLY 4 STANDARD DEVIATIONS ABOVE NORMAL ACROSS
SOUTHEAST NEBRASKA AND NORTHEAST KANSAS. THE LLVL MOISTURE WILL
CONTINUE TO ADVECT NORTH THRU KS INTO PORTIONS OF CENTRAL/EASTERN
NEBRASKA AHEAD OF SFC TROUGH AXIS EDGING EAST FM THE HIGH PLAINS.
LOW CLOUDS/STRATUS WILL EXPAND NORTHWARD THRU THE OVERNIGHT AND
EARLY MORNING HOURS AND WILL BE KEEPING A CLOSE EYE ON VSBY
RESTRICTIONS IN FOG AS WE ARE ALREADY STARTING TO SEE VSBYS DROP
TO A QUARTER MILE AT TIMES IN NORTH CENTRAL KS AND FAR SOUTHERN
NEB. WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR
SOUTHEAST ZONES AND MONITOR FOR POSSIBLE HEADLINE EXPANSION.
THE DEEPER LLVL MOISTURE IN OUR SOUTHEAST ZONES AND INCREASING
BOUNDARY LAYER MIXING COULD REALISTICALLY LEAD TO SOME DRIZZLE
DEVELOPMENT AND WILL MENTION FOR A FEW HOURS THIS MORNING. AS WE
HEAD THROUGH THE DAY...THE SURFACE TROUGH AXIS SLOWLY ADVANCES
EASTWARD...REACHING OUR CENTRAL CWA AROUND MIDDAY AND OUR EASTERN
ZONES IN THE LATE AFTN. AS THE TROUGH WORKS EAST...IT WILL SCOUR
THE LLVL MOISTURE EASTWARD. STILL SOME QUESTION ON HOW DENSE/THIN THE
HIGH LEVEL CLOUD COVER WILL BE THIS AFTN WITH MODELS FAIRLY
CONSISTENT THAT THE HIGH CLOUDS WILL THIN/DECREASE AFTER 18Z
TODAY. IN INCREASING INSOLATION THIS AFTN BEHIND SFC TROUGH AND
WESTERLY DOWNSLOPE CONDITIONS...THE WESTERN HALF TO TWO THIRDS OF
OUR CWA SHLD SEE A RATHER NICE DAY WITH HIGHS IN THE 60S.
TEMPERATURES IN OUR EASTERN ZONES WILL BE DEPENDENT UPON THE
TIMING OF THE TROUGH PASSAGE AS LLVL MOISTURE LINGERS LONGER. WILL
PLAY THINGS MORE CONSERVATIVELY HERE WITH COOLER TEMPS...BUT
POTENTIAL DOES EXIST FOR LATE DAY RECOVERY IF TROUGH MOVES THRU
FAST ENOUGH. IF TROUGH DOES NOT MOVE THRU AS QUICK AS
EXPECTED...TEMPERATURES WILL RISE VERY LITTLE.
SUNDAY IS STILL SHAPING UP TO BE A REMARKABLY NICE DAY FOR EARLY
DECEMBER. IN THE DRY...WARM AIRMASS...FORECAST SOUNDINGS INDICATE
DEEP MIXING IN THE AFTN WITH NEGLIGIBLE CLOUD COVER. WESTERLY
DOWNSLOPE WINDS INITIALLY DURING THE DAY WILL TRANSITION SOUTHERLY
WITH DEEPENING SFC LOW IN THE NORTHERN HIGH PLAINS. SOUTHERLY WINDS
INCREASE DURING THE AFTN...NOT OVERLY STRONG PER SE...BUT STEADY
BY LATE AFTN. RIGHT NOW IT LOOKS LIKE WE WILL BE HARD PRESSED NOT
TO SEE TEMPS AT OR ABOVE RECORD HIGHS. CURRENT RECORDS STAND AT
67F FOR GRAND ISLAND AND 68F FOR HASTINGS...BOTH SET IN 1956.
SOMEWHAT SIMILAR TO WHAT IS HAPPENING THIS MORNING WITH THE
INCREASING LLVL MOISTURE...SUNDAY NIGHT WILL ALSO SEE LLVL MOISTURE
WORKING NORTH IN INCREASING LLVL SOUTHERLY FLOW/STRENGTHENING LLVL
JET AHEAD OF APPROACHING SFC TROUGH/COOL FRONTAL BOUNDARY. MODELS
PROG SFC DPS WELL INTO THE 40S FOR SE NEB AND 50S FOR EASTERN KS
AGAIN...WITH OUR EASTERN/SOUTHEAST ZONES ON THE PERIPHERY OF THIS
MAIN MOISTURE AXIS. ANOMALY PAGE AGAIN INDICATES 925MB SPECIFIC
HUMIDITIES 4 STANDARD DEVIATIONS ABOVE NORMAL IN FAR SOUTHEAST
NEBRASKA...NORTHEAST KANSAS...INTO IA/MO. THE ANOMALIES OF 3
STANDARD DEVIATIONS REACH OUR EASTERN ZONES. AGAIN IT LOOKS LIKE
STRATUS DEVELOPMENT IS POSSIBLE FOR OUR EASTERN ZONES...AND SREF
VSBY PROBS INDICATE 50 PCNT CHC FOR VSBYS BELOW ONE MILE ACROSS
OUR EASTERN TIER COUNTIES. WILL NEED TO MONITOR FOR POTENTIAL FOG
DEVELOPMENT...BUT IT DOES APPEAR THAT WINDS WILL BE STEADY ENOUGH
TO PRECLUDE SIGNIFICANT VSBY RESTRICTIONS AND MAY BE MORE OF A
STRATUS/DRIZZLE POTENTIAL ALONG/NEAR OUR FAR EASTERN ZONES.
FRONT CURRENTLY LOOKS TO CROSS OUR CWA MONDAY MORNING...AND BOUNDARY
WILL AGAIN SCOUR THE LLVL MOISTURE. 3HR PRESSURE RISES BEHIND THE
FRONT AVERAGE 3 TO 5MB AND IN TIGHT PRESSURE GRADIENT/DEEP
MIXING...BREEZY/WINDY CONDITIONS DEVELOP. FORECAST SOUNDINGS
SUGGEST MIXING TO AROUND H825 WITH WINDS AT THE TOP OF THE LAYER
BETWEEN 30 AND 35KTS. ATTM EXPECTING SUSTAINED WINDS IN THE 20 TO
25 MPH RANGE WITH GUSTS OVER 30MPH. H85 TEMPS DROP 7C MONDAY
COMPARED TO SUNDAY BEHIND THE FRONT AND IN THE CAA...TEMPS MONDAY
SHLD ONLY REACH THE LOW/MID 50S IN OUR NORTH...WITH UPPER 50S/NEAR
60F IN OUR SOUTH. SFC DPS DROP TO THE TEENS/LOW 20S MONDAY NIGHT
IN THE POST FRONTAL DRIER AIRMASS...AND A 1025MB SFC HIGH BUILDS
IN BEHIND THE FRONT. NIGHT TIME TEMPS WILL BE COOLER THAN EARLIER
IN THE WEEKEND WITH MAINLY 20S EXPECTED.
LONG TERM...TUESDAY DAYTIME THROUGH FRIDAY. ALL IN ALL...VERY
LITTLE NOTICEABLE CHANGE MADE TO THE FORECAST...WITH BY FAR THE MAIN
PERIOD OF CONCERN FOR POSSIBLE RAIN OR SNOW CENTERED FROM THURS
NIGHT INTO FRIDAY MORNING...BUT THIS IS FAR FROM A DONE DEAL.
OTHERWISE...WELL ABOVE NORMAL HIGHS CONTINUE INTO THURSDAY...BEFORE
A COOL DOWN TO NEAR SEASONAL NORMS BY FRIDAY.
TUESDAY INTO TUES NIGHT...HIGH CONFIDENCE IN A DRY 24 HOURS...AS
THE 00Z ECMWF/GFS RUNS ARE IN EXCELLENT AGREEMENT REGARDING THE
BIG PICTURE...AS THE CENTRAL PLAINS LIES UNDER DRY WEST-NORTHWEST
FLOW IN THE WAKE OF A STOUT SHORTWAVE TROUGH TRACKING INTO AND
THROUGH THE GREAT LAKES REGION. AT THE SURFACE...A LIGHT WIND
REGIME WILL BE IN PLACE DURING THE DAY...WHILE TUES NIGHT WILL
BRING MORE OF A STEADY SOUTH BREEZE IN RESPONSE TO A DEVELOPING
HIGH PLAINS LEE TROUGH. NUDGED UP BOTH HIGHS AND LOWS 1-2 DEGREES
IN MOST AREAS...WITH HIGHS GENERALLY MID-UPPER 50S AND LOWS 30-34.
WEDNESDAY/WEDNESDAY NIGHT...THE FLOW ALOFT TURNS VERY ZONAL...AS
THE CENTRAL PLAINS IS BRUSHED BY LOW AMPLITUDE SHORTWAVE
DISTURBANCES WELL TO THE SOUTH OF A MORE ORGANIZED TROUGH TRACKING
ACROSS SOUTHERN CANADA. SOUTHERLY BREEZES WILL PICK UP ANOTHER
NOTCH DURING THE DAY AS THE HIGH PLAINS LEE TROUGH STRENGTHENS
MORE...WITH THIS DAY POSSIBLY TRENDING TOWARD LEGITIMATELY BREEZY.
THE DAY SHOULD REMAIN DRY...ALTHOUGH BOTH MODELS SPIT OUT SOME
LIGHT QPF A FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA.
TEMP-WISE...THIS STILL LOOKS TO BE THE WARMEST OF THESE 4
DAYS...AND MADE VERY LITTLE CHANGE RANGING FROM UPPER 50S
NORTHEAST TO LOW 60S SOUTHWEST. WED NIGHT...MODELS SUCH AS THE
ECMWF ACTUALLY START SPITTING OUT SOME RAIN SHOWER ACTIVITY ACROSS
PARTS OF THE CWA ALONG AN ADVANCING COLD FRONT...BUT THE GFS/GFS
ENSEMBLE KEEPS THE MAIN SUPPORT FOR PRECIP NORTH OF THE AREA SO
WILL LEAVE THIS PERIOD DRY FOR NOW.
THURSDAY/THURSDAY NIGHT...POSSIBLE PRECIP ENTERS THE
PICTURE...AS MID LEVEL FRONTOGENESIS RAMPS UP OVER THE CENTRAL
PLAINS IN RESPONSE TO SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE
SOUTHWEST PERIPHERY OF A PARENT LOW PRESSURE SYSTEM TRACKING
THROUGH SOUTHEAST CANADA. MEANWHILE AT THE SURFACE...A MODEST COLD
FRONT SHOULD CLEAR THE ENTIRE CWA DURING THE DAY...RESULTING IN
HIGH TEMPS 5-10 DEGREES COOLER THAN WEDNESDAY...AND ROUGHLY CLOSE
TO 50 MOST AREAS. PRECIP WISE...FOLLOWED ALLBLEND MODEL CONSENSUS
PROCEDURE WHICH KEPT SLIGHT RAIN CHANCES DURING THE DAY ONLY IN
THE FAR NORTHERN CWA...BUT BLANKETED ALL AREAS WITH 20-30 POPS
DURING THE NIGHT. THIS IS STILL HIGHLY UNCERTAIN HOWEVER...AS EVEN
THE ECMWF ITSELF CONTINUES TO SHOW PLENTY OF RUN-TO-RUN
INCONSISTENCY REGARDING WHETHER THIS IS MORE OF AN ORGANIZED
BANDED-TYPE OF PRECIP EVENT/OR MORE OF A HIT/MISS THING. AS FOR
PRECIP TYPE THURS NIGHT...WENT WITH RAIN OR SNOW WORDING TO IMPLY
THE CONSIDERABLE UNCERTAINTY REGARDING THE LOW LEVEL TEMP
PROFILES...BUT BOTTOM LINE IS THIS CONTINUES TO LOOK LIKE A
RELATIVELY LOW IMPACT EVENT AT THIS POINT.
FRIDAY DAYTIME...THIS FINALLY LOOKS TO BE THE COOLEST DAY ACROSS
THE CWA IN 11 DAYS SINCE NOV. 26TH...AS COLDER AIR CONTINUES TO
FILTER SOUTHWARD ALONG THE SOUTHERN PERIPHERY OF THE LARGER SCALE
TROUGH CENTERED SOMEWHERE FROM THE NORTHERN PLAINS TO SOUTHEAST
CANADA. THAT BEING SAID...THIS IS STILL BY NO MEANS A
BONE-CHILLING DAY FOR EARLY DECEMBER...AND HAVE CONTINUED TO
ADVERTISE HIGHS AT LEAST INTO THE LOW 40S. PRECIP-WISE...WHATEVER
HAPPENS THURS NIGHT COULD LINGER INTO FRIDAY ACROSS KS ZONES PER
ECMWF SOLUTION...AND WILL KEEP A SLIGHT CHANCE OF RAIN OR SNOW
GOING FOR MOST AREAS SOUTH OF THE STATE LINE.
AVIATION...ALTHOUGH THE MAJORITY OF THE PERIOD FEATURES A HIGH
CONFIDENCE IN VFR CEILING/VISIBILITY WITH ONLY VARYING DEGREES OF
PASSING HIGH CLOUDS...A ROUGHLY 4-7 HOUR PERIOD CENTERED BETWEEN
10Z-17Z THIS MORNING IS STILL VERY UNCLEAR REGARDING THE
LIKELIHOOD OF POSSIBLE MVFR/IFR CEILING AND OR/VISIBILITY...AND
CONFIDENCE IS ADMITTEDLY QUITE LOW. IN SHORT...MODELS AND
NUMERICAL GUIDANCE CONTINUE TO OFFER A WIDE RANGE OF SOLUTIONS
RANGING FROM NO WORSE THAN A LIGHT FOG WITH NO LOW CEILING...TO
POTENTIALLY DENSE FOG AND AT LEAST AN IFR CEILING IF NOT WORSE.
FOR NOW WILL CONTINUE TO PLAY A MIDDLE GROUND BETWEEN THESE TWO
EXTREMES...AS KGRI WILL LIKELY END UP ALONG THE WESTERN EDGE OF
THE AREA MOST FAVORED FOR POOR AVIATION CONDITIONS...WHICH ARE
MORE FAVORED FARTHER EAST. STAY TUNED FOR PLENTY OF FINE-TUNING
OVER THE NEXT 12 HOURS. OTHERWISE...ONCE ANY POSSIBLE LOW CLOUDS
VACATE BY MID-DAY OR SO...SHOULD BE A SOLID RETURN TO LEGITIMATE
VFR CONDITIONS AS AN INVADING SURFACE TROUGH SCOURS OUT THIS LOW
LEVEL MOISTURE. SURFACE WINDS SHOULD NOT BE A MAJOR ISSUE...WITH
SUSTAINED SPEEDS EXPECTED TO AVERAGE UNDER 12KT THROUGH THE ENTIRE
PERIOD...ALTHOUGH DIRECTION WILL SHIFT FROM SOUTHERLY THIS MORNING
TO WEST-NORTHWEST THIS AFTERNOON AS THE TROUGH AXIS MOVES IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ048-049-
062>064-074>077-083>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1030 AM EST SAT DEC 1 2012
.SYNOPSIS...
ARCTIC HIGH PRESSURE OVER MAINE WILL RETREAT NORTHEAST THROUGH THE
CANADIAN MARITIMES INTO THE NORTHERN ATLANTIC BY SUNDAY. MEANWHILE A
WARM FRONT NEAR THE PENNSYLVANIA NEW YORK BORDER WILL LIFT SLOWLY
NORTH INTO NEW ENGLAND...AS A MILD SOUTHWEST FLOW OVERSPREADS THE
AREA AHEAD OF A COLD FRONT MOVING INTO THE GREAT LAKES. THIS
FRONTAL SYSTEM WILL BRING A FEW SHOWERS TO THE AREA LATER
SUNDAY...WITH A BETTER CHANCE FOR RAIN COMING ON TUESDAY WITH A
STRONGER COLD FRONT. TEMPERATURES WILL BE WELL ABOVE NORMAL EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM MORNING UPDATE...
LOW CLOUDS COVER ABOUT THE EASTERN 1/2 OF MY FCST AREA...WITH THE
WESTWARD MOVEMENT SEEMING TO HAVE SLOWED OR HALTED AS OF MID
MORNING. THE LATEST RAP FCST SOUNDINGS AND NAM MOS GUIDANCE INDICATE
THE STRATUS WILL BE VERY DIFFICULT TO DISLODGE OVR THE MID-LWR
SUSQ...WITH THE LLVL MSTR REMAINING TRAPPED UNDER STRONG INVERSION.
MADE ONLY SLIGHT TWEAKS TO THE SHORT TERM UPDATE.
PREVIOUS DISCUSSION...
THE EASTERLY MARITIME/UPSLOPE FLOW WILL BE TOPPED BY MODERATELY
STRONG MID-LVL WARM ADVECTION FROM THE SOUTHWEST...WHICH WILL
MAINTAIN LOW CLOUDS ACROSS CENTRAL AND ERN PENN. THE LOW CLOUDS
WILL EFFECTIVELY HOLD TEMPS IN THE UPPER 30S/LOW 40S OVR THE ERN
1/3 OF THE CWA. MEANWHILE...PARTLY TO MOSTLY SUNNY CONDS OVR THE
SWRN 1/2 OF THE AREA WILL ALLOW TEMPS TO CLIMB INTO THE UPPER 40S.
LOW LEVEL WINDS WILL TURN MORE SOUTHERLY TNT...WITH LOW CLOUDS
REMAINING OVR THE NRN AND ERN PARTS OF THE CWA. CLOUDS AND
INCREASING SLY FLOW AHEAD OF WEAK PAC FNTL SYS CROSSING THE GRT
LKS WILL BRING RELATIVELY MILD OVERNIGHT TEMPS IN 35-40F
RANGE...OR 5-10 DEGREES ABV NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SFC WARM FRONT WILL LIFT WELL TO THE NORTHEAST OF THE REGION EARLY
SUNDAY. A WEAK COLD FRONT WILL RACE EAST FROM THE OHIO VALLEY AND
SPREAD LOWERING AND THICKENING CLOUDS ACROSS THE NORTHWEST HALF F
THE CWA DURING THE MORNING FOLLOWED BY A SEVERAL TO 10 HOUR PERIOD
OF MAINLY LIGHT SHOWERS SUNDAY AFTERNOON AND NIGHT.
ACROSS THE APPROXIMATE SE HALF OF THE STATE....BKN-OVC CLOUD WILL BE
MAINLY IN THE FORM OF ALTO CU/ALTO STRATUS WITH SOME LIGHTER SHOWERS
LATE SUNDAY INTO EARLY MONDAY.
00Z OPERATIONAL MODEL/ENSEMBLE BLEND INDICATES THAT TOTAL RAINFALL
WITH THIS FRONT AND ASSOCIATED...FLAT UPPER SHORT WAVE WILL RANGE
FROM 3-4 TENTHS ACROSS THE NW MTNS...TO ONLY AROUND 0.10 OVER THE
LOWER SUSQ VALLEY.
SHOWERS WILL DIMINISH VERY EARLY MONDAY AS A RIDGE OF HIGH PRESSURE
AT THE SFC AND ALOFT BUILDS IN FROM THE WEST.
HIGH TEMPS SUNDAY WILL BE 10 TO 20 DEGREES ABOVE NORMAL SUNDAY
AFTERNOON...WITH THE GREATEST DEPARTURES OCCURRING ACROSS THE LAUREL
HIGHLANDS. HIGHS SUNDAY WILL RANGE FROM NEAR 50 ACROSS THE MTNS
NORTHEAST OF KIPT...TO THE LOWER 60S IN THE SOUTHWEST PART OF THE
CWA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
BEHIND THE QUICK MOVING UPPER WAVE AND SFC FRONT...500 MB HEIGHTS
WILL RISE BY 30-40M...TO NEARLY PLUS 2 SIGMA MONDAY. THIS /COMBINED
WITH A NORTH/SOUTH SFC RIDGE BECOMING LOCATED RIGHT OVER THE REGION
MONDAY AFTERNOON/ WILL BRING PARTIAL CLEARING AT LEAST ACROSS THE
CENTRAL AND ERN VALLEYS...ALONG WITH CONTINUED UNSEASONABLY MILD
TEMPS IN THE MID 50S NORTH...TO AROUND 60F ACROSS THE SOUTH.
TUESDAY WILL CONTINUE THIS STRING OF WELL ABOVE NORMAL TEMPS WITH
SOME PERIODS OF PARTIAL SUNSHINE...FOLLOWED BY AN INCREASE IN LATE
DAY CLOUDS FROM THE WEST AHEAD OF THE NEXT COLD FRONT. A
GUSTY...DOWNSLOPING SOUTHWESTERLY WIND IN THE AFTERNOON WILL BLOW AT
15-20 KTS.
HIGHS TUESDAY SHOULD BE SIMILAR TO...IF NOT A FEW DEG F WARMER THAN
MONDAY/S QUITE BALMY TEMPS FOR EARLY DECEMBER.
A RATHER VIGOROUS MID/UPPER LEVEL TROUGH AND SFC COLD FRONT WILL
APPROACH FROM THE MIDWEST DURING THE DAY TUESDAY...AND COMBINE WITH
THE RIGHT ENTRANCE REGION OF A SWRLY 110 KT JET MAX TO BRING A
PERIOD OF SHOWERS...FOCUSED PRIMARILY IN THE LATE TUESDAY/TUESDAY
NIGHT TIMEFRAME.
OPERATIONAL MODEL/ENSEMBLE CONSENSUS QPF FORECAST IS BETWEEN 1-3
TENTHS OF AN INCH ACROSS THE SE HALF OF THE CWA THROUGH EARLY
WED...WITH AS MUCH AS 0.50 INCH OF RAINFALL ACROSS THE NW MTNS.
A QUICK SURGE OF COLDER/ALBEIT GREATLY MODIFIED CP AIR WILL FOLLOW
FOR WEDNESDAY AND WEDNESDAY NIGHT WITH SCATTERED SNOW SHOWERS AND
PERHAPS SOME LIGHT ACCUMS ACROSS THE NW MTNS AS A SHARP MID/UPPER
LEVEL THERMAL TROUGH CROSSES THE REGION WITH THE SUBSIDENCE
INVERSION BASE RISING TO AROUND 5 KFT AGL WITH A DEEP AND
WELL-ALIGNED NWRLY FLOW TRANSPORTING LIMITED MOISTURE INLAND FROM
THE GLAKES.
FOR THE CENTRAL RIDGE AND VALLEY REGION...SPRINKLES AND FLURRIES OR
PERHAPS A FEW BRIEF RAIN/SNOW SHOWERS WILL SPILL SE OFF THE
ALLEGHENY PLATEAU.
THE COLD AIR PUSH DOESN/T LAST LONG AS ANOTHER RIDGE BUILDS OVER THE
REGION STARTING THURSDAY...BRINGING A RETURN TO SLIGHTLY WARMER THAN
NORMAL TEMPS THE END OF NEXT WEEK. A CLIPPER-TYPE SYSTEM SLIDES
THROUGH OVER THE WEEKEND...WITH LIMITED MOISTURE AND LOW POPS.
ANOTHER MORE SIG TROUGH COULD BE IN STORE FOR VERY LATE NEXT WEEKEND
INTO MONDAY - 10 DEC IF THE ECMWF...AND SEVERAL HIGHER END GEFS
MEMBERS ARE FOLLOWED. A DIFFERING AND FLATTER...MORE PROGRESSIVE
00/06Z GFS SOLUTION THAT FAR OUT CAUTIONS THAT THIS FORECAST PERIOD
CONTAINS LARGE AMOUNTS OF UNCERTAINTY.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
10 AM UPDATE...
LOW CLOUDS ARE HANGING TOUGH OVER ABOUT THE EASTERN HALF OF THE
FCST AREA...AFFECTING TERMINALS FROM UNV EASTWARD WITH MVFR/IFR
CEILINGS AND VIZ IN THE 4-6MI RANGE.
OF THE TERMINALS CURRENTLY SUB-VFR...UNV...BEING ON THE WESTERN
EDGE OF THE STRATUS AND MOST PRONE TO MIXING AND SOME
HEATING...WILL HAVE THE BEST CHANCE FOR SOME IMPROVEMENT FOR A
TIME THIS AFTERNOON. ELSEWHERE OVER THE SUSQ VALLEY THE CLOUDS
WILL BE TOUGH TO DISLODGE SO EXPECT CEILINGS TO REMAIN RATHER LOW
INTO SUNDAY.
WESTERN TERMINALS WILL REMAIN VFR INTO TONIGHT BEFORE THE LOW
CLOUDS BEGIN TO ENCROACH WESTWARD ONCE AGAIN.
OUTLOOK...
SUN...MVFR/IFR EAST. PM MVFR NW MTNS. SCT -SHRA.
MON...MVFR/IFR CIGS LKLY WEST.
TUE...VFR TO MVFR. PM SHRA LKLY.
WED...NO SIG WX EXPECTED.
&&
.CLIMATE...
NOVEMBER 2012 WAS A COLD AND DRY MONTH AT BOTH OFFICIAL CLIMATE
SITES. IT WAS AN EXCEPTIONALLY DRY MONTH AT WILLIAMSPORT.
AT WILLIAMSPORT...THE AVERAGE MONTHLY TEMPERATURE OF 39.6 DEGREES
TIED 1971 AS THE 25TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 0.65 INCHES RANKED AS THE 5TH DRIEST NOVEMBER ON
RECORD. THE TOP 5 DRIEST NOVEMBER`S AT WILLIAMSPORT ARE:
1. 1904 - 0.51 INCHES
2. 1917 - 0.53 INCHES
3. 1908 - 0.56 INCHES
4. 1909 - 0.59 INCHES
5. 2012 - 0.65 INCHES
AT HARRISBURG...THE AVERAGE MONTHLY TEMPERATURE OF 40.7 DEGREES
RANKED AS THE 16TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 1.05 INCHES RANKED AS THE 19TH DRIEST NOVEMBER ON
RECORD.
NO DAILY RECORDS WERE SET AT EITHER SITE DURING NOVEMBER 2012. A
CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT HARRISBURG SINCE
1888...AND SINCE 1895 AT WILLIAMSPORT.
TODAY IS THE FIRST DAY OF DECEMBER...THE START OF METEOROLOGICAL
WINTER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE/STEINBUGL
CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
941 AM EST SAT DEC 1 2012
.SYNOPSIS...
ARCTIC HIGH PRESSURE OVER MAINE WILL RETREAT NORTHEAST THROUGH THE
CANADIAN MARITIMES INTO THE NORTHERN ATLANTIC BY SUNDAY. MEANWHILE A
WARM FRONT NEAR THE PENNSYLVANIA NEW YORK BORDER WILL LIFT SLOWLY
NORTH INTO NEW ENGLAND...AS A MILD SOUTHWEST FLOW OVERSPREADS THE
AREA AHEAD OF A COLD FRONT MOVING INTO THE GREAT LAKES. THIS
FRONTAL SYSTEM WILL BRING A FEW SHOWERS TO THE AREA LATER
SUNDAY...WITH A BETTER CHANCE FOR RAIN COMING ON TUESDAY WITH A
STRONGER COLD FRONT. TEMPERATURES WILL BE WELL ABOVE NORMAL EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM MORNING UPDATE...
LOW CLOUDS COVER ABOUT THE EASTERN 1/2 OF MY FCST AREA...WITH THE
WESTWARD MOVEMENT SEEMING TO HAVE SLOWED OR HALTED AS OF MID
MORNING. THE LATEST RAP FCST SOUNDINGS AND NAM MOS GUIDANCE INDICATE
THE STRATUS WILL BE VERY DIFFICULT TO DISLODGE OVR THE MID-LWR
SUSQ...WITH THE LLVL MSTR REMAINING TRAPPED UNDER STRONG INVERSION.
MADE ONLY SLIGHT TWEAKS TO THE SHORT TERM UPDATE.
PREVIOUS DISCUSSION...
THE EASTERLY MARITIME/UPSLOPE FLOW WILL BE TOPPED BY MODERATELY
STRONG MID-LVL WARM ADVECTION FROM THE SOUTHWEST...WHICH WILL
MAINTAIN LOW CLOUDS ACROSS CENTRAL AND ERN PENN. THE LOW CLOUDS
WILL EFFECTIVELY HOLD TEMPS IN THE UPPER 30S/LOW 40S OVR THE ERN
1/3 OF THE CWA. MEANWHILE...PARTLY TO MOSTLY SUNNY CONDS OVR THE
SWRN 1/2 OF THE AREA WILL ALLOW TEMPS TO CLIMB INTO THE UPPER 40S.
LOW LEVEL WINDS WILL TURN MORE SOUTHERLY TNT...WITH LOW CLOUDS
REMAINING OVR THE NRN AND ERN PARTS OF THE CWA. CLOUDS AND
INCREASING SLY FLOW AHEAD OF WEAK PAC FNTL SYS CROSSING THE GRT
LKS WILL BRING RELATIVELY MILD OVERNIGHT TEMPS IN 35-40F
RANGE...OR 5-10 DEGREES ABV NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SFC WARM FRONT WILL LIFT WELL TO THE NORTHEAST OF THE REGION EARLY
SUNDAY. A WEAK COLD FRONT WILL RACE EAST FROM THE OHIO VALLEY AND
SPREAD LOWERING AND THICKENING CLOUDS ACROSS THE NORTHWEST HALF F
THE CWA DURING THE MORNING FOLLOWED BY A SEVERAL TO 10 HOUR PERIOD
OF MAINLY LIGHT SHOWERS SUNDAY AFTERNOON AND NIGHT.
ACROSS THE APPROXIMATE SE HALF OF THE STATE....BKN-OVC CLOUD WILL BE
MAINLY IN THE FORM OF ALTO CU/ALTO STRATUS WITH SOME LIGHTER SHOWERS
LATE SUNDAY INTO EARLY MONDAY.
00Z OPERATIONAL MODEL/ENSEMBLE BLEND INDICATES THAT TOTAL RAINFALL
WITH THIS FRONT AND ASSOCIATED...FLAT UPPER SHORT WAVE WILL RANGE
FROM 3-4 TENTHS ACROSS THE NW MTNS...TO ONLY AROUND 0.10 OVER THE
LOWER SUSQ VALLEY.
SHOWERS WILL DIMINISH VERY EARLY MONDAY AS A RIDGE OF HIGH PRESSURE
AT THE SFC AND ALOFT BUILDS IN FROM THE WEST.
HIGH TEMPS SUNDAY WILL BE 10 TO 20 DEGREES ABOVE NORMAL SUNDAY
AFTERNOON...WITH THE GREATEST DEPARTURES OCCURRING ACROSS THE LAUREL
HIGHLANDS. HIGHS SUNDAY WILL RANGE FROM NEAR 50 ACROSS THE MTNS
NORTHEAST OF KIPT...TO THE LOWER 60S IN THE SOUTHWEST PART OF THE
CWA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
BEHIND THE QUICK MOVING UPPER WAVE AND SFC FRONT...500 MB HEIGHTS
WILL RISE BY 30-40M...TO NEARLY PLUS 2 SIGMA MONDAY. THIS /COMBINED
WITH A NORTH/SOUTH SFC RIDGE BECOMING LOCATED RIGHT OVER THE REGION
MONDAY AFTERNOON/ WILL BRING PARTIAL CLEARING AT LEAST ACROSS THE
CENTRAL AND ERN VALLEYS...ALONG WITH CONTINUED UNSEASONABLY MILD
TEMPS IN THE MID 50S NORTH...TO AROUND 60F ACROSS THE SOUTH.
TUESDAY WILL CONTINUE THIS STRING OF WELL ABOVE NORMAL TEMPS WITH
SOME PERIODS OF PARTIAL SUNSHINE...FOLLOWED BY AN INCREASE IN LATE
DAY CLOUDS FROM THE WEST AHEAD OF THE NEXT COLD FRONT. A
GUSTY...DOWNSLOPING SOUTHWESTERLY WIND IN THE AFTERNOON WILL BLOW AT
15-20 KTS.
HIGHS TUESDAY SHOULD BE SIMILAR TO...IF NOT A FEW DEG F WARMER THAN
MONDAY/S QUITE BALMY TEMPS FOR EARLY DECEMBER.
A RATHER VIGOROUS MID/UPPER LEVEL TROUGH AND SFC COLD FRONT WILL
APPROACH FROM THE MIDWEST DURING THE DAY TUESDAY...AND COMBINE WITH
THE RIGHT ENTRANCE REGION OF A SWRLY 110 KT JET MAX TO BRING A
PERIOD OF SHOWERS...FOCUSED PRIMARILY IN THE LATE TUESDAY/TUESDAY
NIGHT TIMEFRAME.
OPERATIONAL MODEL/ENSEMBLE CONSENSUS QPF FORECAST IS BETWEEN 1-3
TENTHS OF AN INCH ACROSS THE SE HALF OF THE CWA THROUGH EARLY
WED...WITH AS MUCH AS 0.50 INCH OF RAINFL ACROSS THE NW MTNS.
A QUICK SURGE OF COLDER/ALBEIT GREATLY MODIFIED CP AIR WILL FOLLOW
FOR WEDNESDAY AND WEDNESDAY NIGHT WITH SCATTERED SNOW SHOWERS AND
PERHAPS SOME LIGHT ACCUMS ACROSS THE NW MTNS AS A SHARP MID/UPPER
LEVEL THERMAL TROUGH CROSSES THE REGION WITH THE SUBSIDENCE
INVERSION BASE RISING TO AROUND 5 KFT AGL WITH A DEEP AND
WELL-ALIGNED NWRLY FLOW TRANSPORTING LIMITED MOISTURE INLAND FROM
THE GLAKES.
FOR THE CENTRAL RIDGE AND VALLEY REGION...SPRINKLES AND FLURRIES OR
PERHAPS A FEW BRIEF RAIN/SNOW SHOWERS WILL SPILL SE OFF THE
ALLEGHENY PLATEAU.
THE COLD AIR PUSH DOESN/T LAST LONG AS ANOTHER RIDGE BUILDS OVER THE
REGION STARTING THURSDAY...BRINGING A RETURN TO SLIGHTLY WARMER THAN
NORMAL TEMPS THE END OF NEXT WEEK. A CLIPPER-TYPE SYSTEM SLIDES
THROUGH OVER THE WEEKEND...WITH LIMITED MOISTURE AND LOW POPS.
ANOTHER MORE SIG TROUGH COULD BE IN STORE FOR VERY LATE NEXT WEEKEND
INTO MONDAY - 10 DEC IF THE ECMWF...AND SEVERAL HIGHER END GEFS
MEMBERS ARE FOLLOWED. A DIFFERING AND FLATTER...MORE PROGRESSIVE
00/06Z GFS SOLUTION THAT FAR OUT CAUTIONS THAT THIS FORECAST PERIOD
CONTAINS LARGE AMOUNTS OF UNCERTAINTY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
01/12 - 02/12
LOW MVFR CIGS AROUND 1KFT AGL WILL CONTINUE TO IMPACT THE ERN
TERMINALS MDT-IPT-LNS THIS MORNING. CIGS MAY GRADUALLY LIFT SOME
BY THE AFTN BUT SHOULD REMAIN MVFR. UNV REMAINS A TOUGH CALL WITH
LOW CLOUDS JUST EAST OF THE AIRFIELD PER IR SATL. WRN SITES IN ZOB
SECTOR EXPECTED TO REMAIN VFR. AS THE LLVL FLOW TURNS MORE THE
SOUTH...LOW CLOUDS SHOULD BE MORE WDSPRD TNT WITH MVFR CONDS LKLY
AT MOST AIRFIELDS.
OUTLOOK...
SUN...MVFR/IFR EAST. PM MVFR NW MTNS. SCT -SHRA.
MON...MVFR/IFR CIGS LKLY WEST.
TUE...VFR TO MVFR. PM SHRA LKLY.
WED...NO SIG WX EXPECTED.
&&
.CLIMATE...
NOVEMBER 2012 WAS A COLD AND DRY MONTH AT BOTH OFFICIAL CLIMATE
SITES. IT WAS AN EXCEPTIONALLY DRY MONTH AT WILLIAMSPORT.
AT WILLIAMSPORT...THE AVERAGE MONTHLY TEMPERATURE OF 39.6 DEGREES
TIED 1971 AS THE 25TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 0.65 INCHES RANKED AS THE 5TH DRIEST NOVEMBER ON
RECORD. THE TOP 5 DRIEST NOVEMBER`S AT WILLIAMSPORT ARE:
1. 1904 - 0.51 INCHES
2. 1917 - 0.53 INCHES
3. 1908 - 0.56 INCHES
4. 1909 - 0.59 INCHES
5. 2012 - 0.65 INCHES
AT HARRISBURG...THE AVERAGE MONTHLY TEMPERATURE OF 40.7 DEGREES
RANKED AS THE 16TH COLDEST NOVEMBER ON RECORD. THE TOTAL MONTHLY
PRECIPITATION OF 1.05 INCHES RANKED AS THE 19TH DRIEST NOVEMBER ON
RECORD.
NO DAILY RECORDS WERE SET AT EITHER SITE DURING NOVEMBER 2012. A
CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT HARRISBURG SINCE
1888...AND SINCE 1895 AT WILLIAMSPORT.
TODAY IS THE FIRST DAY OF DECEMBER...THE START OF METEOROLOGICAL WINTER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...LA CORTE/STEINBUGL
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...STEINBUGL
CLIMATE...
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
532 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
OCCASIONAL IFR CEILINGS EAST OF I29 THROUGH 16Z THIS MORNING ALONG
WITH VISIBILITIES BELOW 3 MILES IN FOG. CONDITIONS SHOULD BECOME VFR
BY 16Z. ALSO LLWS NEAR 1000 FT WITH WIND DIRECTION AND SPEED 18035KT
ALONG AND EAST OF I29 THROUGH 16Z. WEST OF I29...VFR CONDITIONS
EXPECTED THROUGH THE FORECAST PERIOD WITH SOUTH WINDS GRADUALLY
SHIFTING TO THE WEST TODAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
905 AM CST SAT DEC 1 2012
.UPDATE...
UPDATED TO ADD SLIGHT CHANCE OF SPRINKLES ACROSS THE WEST
&&
.DISCUSSION...
A FEW MINOR CHANGES TO THE FORECAST THIS MORNING. FIRST A FEW
LIGHT RAIN SHOWERS ARE BEGINNING TO POP UP ON LZK RADAR. THIS
ACTIVITY IS BEING PICKED UP FROM THE RUC MODEL...AND FORECASTED TO
MOVE INTO THE WESTERN MIDSOUTH COUNTIES IN THE NEXT HOUR OR TWO.
SO HAVE PLACED A SLIGHT CHANCE OF SPRINKLES IN THIS REGION THROUGH
LATE AFTERNOON. ALSO ADJUSTED CLOUD COVER OVER THE EAST AND
SOUTHEAST COUNTIES FOR THE DAY WHERE IT APPEARS MOSTLY SUNNY
SKIES WILL PREVAIL. LAST...MADE SLIGHT INCREASES IN WIND SPEEDS
AND POTENTIAL GUSTS DURING THE MIDDAY HOURS TO AREAS WEST OF A
DYERSBURG TENNESSEE TO CHARLESTON MISSISSIPPI LINE.
JAB
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SAT DEC 1 2012/
DISCUSSION...
UPDATED AVIATION DISCUSSION FOR 12Z TAFS.
PREV DISCUSSION... /ISSUED 349 AM CST SAT DEC 1 2012/
DISCUSSION...
MILD WEATHER FOR EARLY DECEMBER TO PREVAIL THROUGH MONDAY...
COURTESY OF DEEP SOUTHERLY LOW LEVEL FLOW AND LOW AMPLITUDE
RIDGING ALOFT.
AN OPEN UPPER LEVEL TROF WILL APPROACH THE MIDSOUTH FROM THE
SOUTHERN PLAINS MONDAY NIGHT. AN ASSOCIATED SURFACE COLD FRONT
WILL MOVE INTO THE MIDSOUTH DURING THE DAY TUESDAY... TRACKING
EASTWARD WITH THE MID LEVEL TROF PASSAGE. SURFACE HIGH PRESSURE OF
PACIFIC ORIGIN WILL ENTER THE MIDSOUTH LATE TUESDAY...WHILE AN
ARCTIC SURFACE HIGH TRACKS EASTWARD THROUGH THE NORTHERN GREAT
LAKES.
RAINFALL SHOULD END OVER THE MIDSOUTH LATE TUESDAY INTO TUESDAY
EVENING. FAIR WEATHER IS FORECAST FOR THE MIDWEEK PERIODS...WITH
AFTERNOON MAX TEMPS LOWER...BUT STILL WELL ABOVE NORMAL. LOW DEWPOINTS
WILL RESULT IN WIDE DIURNAL TEMPERATURE RANGES WEDNESDAY AND THURSDAY.
GFS AND ECMWF MODELS BRING A ANOTHER OPEN MID LATITUDE TROF AND
ASSOCIATED PACIFIC SURFACE COLD FRONT ACROSS THE PLAINS AND LOWER
MS RIVER VALLEY LATE NEXT WEEK. HOWEVER... SIGNIFICANT TIMING
DIFFERENCES WERE SHOWN ON THE 00Z/01 RUNS. THE ECMWF HAS SHOWN
GREATER RUN TO RUN CONSISTENCY AND ITS SLOWER TIMING WAS FAVORED
FOR THE MORNING FORECAST PACKAGE. AS SUCH...LOW LEVEL MOISTURE
SHOULD INCREASE FRIDAY...ACCOMPANIED BY MILD TEMPERATURES. A
PACIFIC COLD FRONTAL PASSAGE SHOULD FOLLOW FRIDAY NIGHT INTO EARLY
SATURDAY.
PWB
&&
.AVIATION...
12Z TAF CYCLE
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD. ONLY
THING CLOSE IS THE CEILINGS TODAY...EXPECT MOST CLOUDS TO BE ABOVE
FOUR THOUSAND FEET. WINDS WILL PICK UP THIS AFTERNOON WITH WESTERN
SITES SEEING SOME GUSTY WINDS AS ATMOSPHERE MIXES DOWN TO THE
SURFACE. TLSJR
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 57 71 60 / 0 10 10 0
MKL 69 54 70 57 / 0 10 10 0
JBR 67 57 71 57 / 20 10 10 10
TUP 69 51 71 55 / 0 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
356 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH MONDAY...PROVIDING
FAIR WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES. A COLD FRONT
WILL MOVE THROUGH THE REGION AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HIGH PRESSURE OVER SOUTH CAROLINA WILL KEEP PARTLY TO MOSTLY SUNNY
SKIES AND LIGHT WINDS INTO THIS EVENING. TEMPERATURES WILL BE IN
THE LOWER 60S BY THIS EVENING. UPDATED HIGH TEMPERATURES USING THE
MODIFIED RUC13 GRIDDED DATA.
TONIGHT...USED A BLEND OF MAV/MET GUIDANCE FOR THE LOW TEMPERATURES.
MOISTURE WILL BE TRAPPED NEAR THE SURFACE UNDER A SUBSIDENCE
INVERSION AS AN UPPER RIDGE BUILDS IN ACROSS THE REGION FROM THE
WEST.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL GIVE THE AREA PATCHY FOG
TOWARD SUNDAY MORNING. THE INTENSITY OF THE FOG WILL DEPEND ON SKY
COVER...WITH INCREASED CLOUDINESS EXPECTED ACROSS THE AREA AHEAD OF
ANOTHER SHORT WAVE MOVING TOWARD OUR AREA FROM KANSAS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
FLAT MID/UPPER LEVEL RIDGE OVER THE GULF OF MEXICO SUNDAY AMPLIFIES
OVER THE EASTERN STATES MONDAY THEN MOVES OFF THE EAST COAST TUESDAY
AS A TROUGH CROSSES THE CENTRAL U.S. SURFACE HIGH PRESSURE
EXTENDING FROM THE WESTERN ATLANTIC INTO THE SOUTHEASTERN STATES
FINALLY WEAKENS TUESDAY NIGHT AS A COLD FRONT APPROACHES FROM THE
WEST.
PRECIPITABLE WATER REMAINS BELOW ONE INCH. WARM AIR ADVECTION WILL
MAKE FOR ABOVE NORMAL TEMPS. ENSEMBLE MOS HOLD TEMPS ABOVE NORMAL
WITH CHANCE OF RAIN BELOW NORMAL. WILL CONTINUE TO FORECAST DRY
WEATHER WITH HIGHS IN THE LOW/MID 70S AND LOWS MOSTLY IN THE 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL TROUGH MOVES OFF THE EAST COAST WITH LESS AMPLIFIED
FLOW ACROSS THE CENTRAL AND EASTERN CONUS. SURFACE COLD FRONT TO
CROSS THE REGION WEDNESDAY. A LOW CHANCE OF SHOWERS STILL LOOK
REASONABLE...BUT AMOUNTS MAY BE LIMITED GIVEN WEST TO NORTHWEST H850
FLOW. MEDIUM RANGE MODELS INDICATE DRY HIGH PRESSURE OVER THE REGION
THURSDAY AND FRIDAY. ANOTHER COLD FRONT AFFECTING THE AREA SATURDAY
WITH A CHANCE OF SHOWERS. TEMPS AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AN ONSHORE FLOW HAS RESULTED IN AN INCREASE IN LOW-LEVEL MOISTURE.
THIS MOISTURE PLUS DIURNAL COOLING SHOULD CAUSE THE DEVELOPMENT OF
STRATUS AND FOG LATE TONIGHT ESPECIALLY AT AGS AND DNL WHERE
HIGHER DEW POINT TEMPERATURES HAVE ADVECTED INTO THE AREA. HEATING
AND MIXING SHOULD BRING AN IMPROVEMENT LATE SUNDAY MORNING. USED
THE GFS LAMP FOR THE TIMING.
EXTENDED AVIATION OUTLOOK...CONTINUED LOW-LEVEL MOISTURE AND
DIURNAL COOLING MAY LEAD TO AREAS OF LATE NIGHT AND EARLY MORNING
MVFR OR IFR STRATUS AND FOG THROUGH TUESDAY. RESTRICTIONS MAY
OCCUR IN SHOWERS ASSOCIATED WITH A COLD FRONT WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
315 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH EARLY NEXT WEEK...WHILE A
WEAK COASTAL TROUGH PERSISTS ALONG THE SOUTHEAST COAST. A COLD
FRONT WILL THEN PASS OVER THE REGION DURING THE MIDDLE OF NEXT
WEEK FOLLOWED BY COOLER HIGH PRESSURE FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MARINE OBSERVATIONS STILL SHOW INDICATIONS OF A WEAK COASTAL
TROUGH JUST OFF THE COAST...BUT IT DOES NOT LOOK AS WELL DEFINED
AS IT DID EARLIER IN THE DAY. SHOULD SEE THE COASTAL TROUGH
CONTINUE TO DAMPEN OUT SOME OVERNIGHT AS HIGH PRESSURE SHIFTS
FARTHER OFF THE NORTH CAROLINA COAST. ISOLATED SHOWER ACTIVITY HAS
BEEN PERSISTENT OFFSHORE ALONG THE WESTERN WALL OF THE GULF STREAM
FOR MUCH OF THE DAY. THE 01/12Z MODELS ARE SIMILAR TO THEIR
PREVIOUS RUNS IN BEING TOO AGGRESSIVE WITH THE COVERAGE AND
INTENSITY OF THIS ACTIVITY SO WILL ONCE AGAIN FORECAST DRY
CONDITIONS FOR THE OVERNIGHT PERIOD...ALTHOUGH THE PRIMARY SHOWER
AREA MAY DRIFT WEST INTO THE NEARSHORE WATERS LATER THIS EVENING.
THE BIG FORECAST CHALLENGE FOR TONIGHT IS TRYING TO PIN DOWN SKY
COVER AND ITS POTENTIAL IMPACTS ON THE FOG AND LOW TEMPERATURE
FORECAST. THE VARIOUS 12Z GUIDANCE IS OFFERING A NUMBER OF
POSSIBLE OUTCOMES RANGING FROM CLEAR TO CLOUDY. SUSPECT MUCH OF
THE STRATOCUMULUS SHOULD DISSIPATE AS SUNSET APPROACHES AND
INSOLATION WANES. THIS SHOULD RESULT IN MOSTLY CLEAR TO PARTLY
CLOUDY SKIES...EXCEPT POSSIBLY ALONG THE ALTAMAHA RIVER WHERE
SUBTLE ISENTROPIC LIFT SHOULD KEEP MOSTLY CLOUDY SKIES GOING
THROUGH THE EVENING HOURS. THINGS BEGIN TO CHANGE LATER THIS
EVENING AND OVERNIGHT AS ANOTHER ROUND OF WEAK ISENTROPIC LIFT
REDEVELOPS ALONG THE 295K SURFACE. WRF SIMULATED CLOUD PRODUCTS
MATCH THE LATEST RAP ISENTROPIC PROGNOSTICATIONS QUITE WELL AND
SHOW LOW/MID-LEVEL CLOUDS REFORMING ACROSS MUCH OF SOUTHEAST
GEORGIA SHORT AFTER MIDNIGHT...ARCHING BACK THROUGH THE CSRA AND
SOUTHERN MIDLANDS BY SUNRISE SUNDAY. MODIFIED THE SKY FORECAST TO
MATCH THIS IDEA...WITH MOST AREAS BECOMING PARTLY TO MOSTLY CLOUDY
LATE. LOWS WILL RANGE FROM THE MID-UPPER 40S INLAND WITH LOWER-MID
50S AT THE COAST. HOURLY TEMPERATURES WILL BE NEARLY IMPOSSIBLE TO
PIN DOWN AS FLUCTUATIONS WILL OCCUR WHERE CLOUD LAYERS FORM. IF
THIS FORECAST HOLDS...WOULD EXPECT MOST AREAS SOUTH OF THE
SAVANNAH RIVER TO SEE TEMPERATURES HOLD STEADY OR EVEN SLOWLY RISE
BETWEEN 3 AM AND SUNRISE IN RESPONSE TO THICKENING CLOUD COVER.
FOG WILL BE ANOTHER CONCERN AS DEWPOINT DEPRESSIONS DROP TO ZERO
WITHIN A DECOUPLED BOUNDARY LAYER. THERE IS A POTENTIAL FOR MORE
SIGNIFICANT FOG FORMATION EARLY SUNDAY IF CLOUDS DO NOT THICKEN UP
AS EXPECTED. WILL STICK WITH A PATCHY AREAL QUALIFIER FOR
NOW...BUT IT SHOULD BE NOTED THERE ARE SOME INDICATIONS THAT THE
FOG FORECAST MAY BE MORE SIGNIFICANT. THE EVENING SHIFT WILL
CERTAINLY MONITOR THIS AND MAKE ADJUSTMENTS AS NEEDED.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
DEEP HIGH PRESSURE WILL PERSIST OVER THE SOUTHEASTERN UNITED STATES
INTO EARLY NEXT WEEK....WHILE A COASTAL TROUGH LINGERS OFF THE SOUTH
CAROLINA AND GEORGIA COAST. A SLIGHT CHANCE OF PRECIP WILL REMAIN IN
THE FORECAST SUNDAY AFTERNOON INTO MONDAY AS THE COASTAL TROUGH
GRADUALLY SHIFTS ONSHORE. ISENTROPIC ASCENT ALONG WITH INCREASING
MOISTURE WILL ALSO PRODUCE A FAIR AMOUNT OF CLOUD COVER AS THIS
PROCESS UNFOLDS. A DRY MID/UPPER LVL ATMOSPHERE HOWEVER...WILL
LIKELY CONFINE PRECIP ACTIVITY TO COASTAL COUNTIES.
OVERALL...TEMPS WILL MODIFY EACH DAY AS MID LVL RIDGING INCREASES
AHEAD OF A TROUGH AND ASSOCIATED COLD FRONT TO OUR WEST. TEMPS WILL
LIKELY REACH 5-10 DEGREES ABOVE CLIMATOLOGY DURING THE PERIOD.
PARTLY SUNNY SKIES...SOUTH/SOUTHEAST RETURN FLOW AND 1000-850 MB
THICKNESSES FAVOR AFTERNOON HIGHS LOW/MID 70S EACH DAY. TEMPS WILL
BE WARMEST AWAY FROM THE IMMEDIATE COAST.
A DECENT AMOUNT OF RADIATIONAL COOLING IS ANTICIPATED EACH NIGHT AS
BREAKS IN CLOUD COVER OCCUR AND WINDS DECOUPLE....ESPECIALLY OVER
INLAND LOCATIONS. GIVEN A RETURN FLOW FROM THE SOUTH/SOUTHEAST...SFC
DEWPTS WILL APPROACH THE MID 50S...SETTING UP FAVORABLE CONDITIONS
FOR AT LEAST PATCHY FOG BEGINNING SUNDAY NIGHT. CHANCES OF FOG
APPEAR GREATEST MONDAY NIGHT INTO TUESDAY MORNING WHEN LOW LEVEL
MOISTURE IS ENHANCED. SHOULD TRENDS PERSIST...A DENSE FOG ADVISORY
MAY BE NEEDED OVER PORTIONS OF THE AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AN UPPER TROUGH OF LOW PRESSURE ALONG WITH A SURFACE COLD FRONT LOOK
TO AFFECT THE AREA BY THE MIDDLE OF THE WEEK BUT DEEP MOISTURE AND
STRONG FORCING IS GOING TO BE LACKING AND THUS THE PROSPECTS FOR
MUCH RAINFALL APPEAR SMALL. TEMPERATURES WILL BE ABOVE NORMAL UNTIL
THURSDAY WHEN COOLER HIGH PRESSURE WEDGES IN FROM THE NORTH. SOME
MODEL DISAGREEMENT LEADS TO LOWER CONFIDENCE FOR FRIDAY BUT
PREFERRED THE SLOWER 00Z ECMWF WHICH AGREES WITH THE 12Z GFS
ENSEMBLE WHICH INDICATES THE WEDGE HOLDING IN PLACE WITH A TROUGH OF
LOW PRESSURE DEVELOPING ACROSS THE NEARBY COASTAL WATERS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE 18Z TAF
PERIOD FOR KCHS AND KSAV. A PERSISTENT ONSHORE FLOW WILL ALLOW
SCATTERED TO BROKEN VFR STRATOCUMULUS TO PREVAIL THROUGH MUCH OF THE
AFTERNOON. OVERNIGHT...EXPECT LINGERING SCATTERED CLOUDS TO HINDER
ANY SIGNIFICANT FOG POTENTIAL. STILL...SOME PATCHY FOG COULD DEVELOP
LATE TONIGHT BUT DUE TO LIMITED COVERAGE WILL MAINTAIN VFR
VISIBILITIES AT BOTH TERMINALS. WILL HAVE TO CONTINUE TO MONITOR
CLOUD COVERAGE OVERNIGHT AS ANY POCKETS OF CLEARING COULD EASILY RESULT
IN AN INCREASE IN FOG POTENTIAL.
EXTENDED AVIATION OUTLOOK...MVFR CEILINGS AND VISIBILITIES ARE
EXPECTED DURING LATE NIGHT/EARLY MORNING HOURS INTO EARLY NEXT WEEK.
CHANCES OF IFR VSBYS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY MORNING
WITH FOG.
&&
.MARINE...
TONIGHT...A SWELL TRAIN THAT WAS GENERATED BY DEEP EASTERLY WINDS
AROUND HIGH PRESSURE OVER THE NORTH ATLANTIC IS FORECAST TO BEGIN
TO IMPACT THE WATERS TONIGHT. ALTHOUGH WINDS WILL GENERALLY REMAIN
10 KT OR LESS THROUGH SUNRISE...SEAS WILL BUILD SLIGHTLY AS
EASTERLY SWELLS INCREASE. SEAS WILL INCREASE TO 3-4 FT NEARSHORE
WATERS AND 4-5 FT OFFSHORE WATERS LATER TONIGHT. WHILE A FEW 6 FT
SEAS COULD BRUSH THE FAR EASTERN FRINGES OF THE GEORGIA OFFSHORE
WATERS...WILL HOLD OFF ON HOISTING A SMALL CRAFT ADVISORY FOR THIS
AREA GIVEN THE RELATIVELY SMALL AREA THAT WOULD BE IMPACTED.
SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL DOMINANT SC WATERS OVER
THE PERIOD...KEEPING WINDS/SEAS WELL BELOW SMALL CRAFT ADVISORY
THRESHOLDS. A COASTAL TROUGH WILL LINGER ALONG THE SOUTHERN
PERIPHERY OF HIGH PRESSURE IN GEORGIA WATERS SUNDAY/MONDAY...LEADING
TO A SLIGHT CHANCE OF SHOWERS. IN GENERAL...E/NE WINDS WILL PEAK
AROUND 10 KTS WITH SEAS OF 3-5 FT...HIGHEST OVER OUTER GEORGIA
WATERS. WINDS WILL BEGIN TO VEER TO SOUTH/SOUTHEAST AS THE COASTAL
TROUGH DRIFTS ONSHORE MONDAY. A COLD FRONT WILL THEN PUSH THROUGH
THE WATERS WEDNESDAY FOLLOWED BY HIGH PRESSURE WEDGING DOWN THE
COAST FROM THE NORTH THURSDAY. A NORTHEAST WIND SURGE WILL CAUSE
DETERIORATING CONDITIONS BEHIND THE COLD FRONT THURSDAY BUT NO
HEADLINES ARE EXPECTED AT THIS TIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/DPB/JHP
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 PM EST SAT DEC 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH MONDAY...PROVIDING
FAIR WEATHER ALONG WITH ABOVE NORMAL TEMPERATURES. A COLD FRONT
WILL MOVE THROUGH THE REGION AROUND THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE OVER SOUTH CAROLINA WILL KEEP PARTLY TO MOSTLY SUNNY
SKIES AND LIGHT WINDS INTO THIS EVENING. TEMPERATURES WILL BE IN
THE LOWER 60S BY THIS EVENING. UPDATED HIGH TEMPERATURES USING THE
MODIFIED RUC13 GRIDDED DATA.
TONIGHT...USED A BLEND OF MAV/MET GUIDANCE FOR THE LOW TEMPERATURES.
MOISTURE WILL BE TRAPPED NEAR THE SURFACE UNDER A SUBSIDENCE
INVERSION AS AN UPPER RIDGE BUILDS IN ACROSS THE REGION FROM THE
WEST.
MOSTLY CLEAR SKIES EARLY THIS EVENING WILL GIVE THE AREA PATCHY FOG
TOWARD SUNDAY MORNING. THE INTENSITY OF THE FOG WILL DEPEND ON SKY
COVER...WITH INCREASED CLOUDINESS EXPECTED ACROSS THE AREA AHEAD OF
ANOTHER SHORT WAVE MOVING TOWARD OUR AREA FROM KANSAS.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
FLAT MID/UPPER LEVEL RIDGE OVER THE GULF OF MEXICO SUNDAY AMPLIFIES
OVER THE EASTERN STATES MONDAY THEN MOVES OFF THE EAST COAST TUESDAY
AS A TROUGH CROSSES THE CENTRAL U.S. SURFACE HIGH PRESSURE
EXTENDING FROM THE WESTERN ATLANTIC INTO THE SOUTHEASTERN STATES
FINALLY WEAKENS TUESDAY NIGHT AS A COLD FRONT APPROACHES FROM THE
WEST.
PRECIPITABLE WATER REMAINS BELOW ONE INCH. WARM AIR ADVECTION WILL
MAKE FOR ABOVE NORMAL TEMPS. ENSEMBLE MOS HOLD TEMPS ABOVE NORMAL
WITH CHANCE OF RAIN BELOW NORMAL. WILL CONTINUE TO FORECAST DRY
WEATHER WITH HIGHS IN THE LOW/MID 70S AND LOWS MOSTLY IN THE 40S.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
UPPER LEVEL TROUGH MOVES OFF THE EAST COAST WITH LESS AMPLIFIED
FLOW ACROSS THE CENTRAL AND EASTERN CONUS. SURFACE COLD FRONT TO
CROSS THE REGION WEDNESDAY. A LOW CHANCE OF SHOWERS STILL LOOK
REASONABLE...BUT AMOUNTS MAY BE LIMITED GIVEN WEST TO NORTHWEST H850
FLOW. MEDIUM RANGE MODELS INDICATE DRY HIGH PRESSURE OVER THE REGION
THURSDAY AND FRIDAY. ANOTHER COLD FRONT AFFECTING THE AREA SATURDAY
WITH A CHANCE OF SHOWERS. TEMPS AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
LOWER LEVEL CLOUD DECK HAS BROKEN UP THIS AFTERNOON. WINDS
CONTINUE TO RANGE FROM LIGHT EASTERLY TO CALM. HIGH PRESSURE RIDGE
OVER THE MID ATLANTIC STATES EXTENDING SOUTHWEST ACROSS THE
SOUTHEAST UNITED STATES ARE KEEPING THAT WEAK EASTERLY TO
NORTHEASTERLY FLOW IN THE LOW LEVELS. MEANWHILE A RIDGE OF HIGH
PRESSURE IS BUILDING IN FROM THE WEST BEHIND A SHORT WAVE WHICH
BROUGHT THE CLOUDINESS THIS MORNING. HIGH LEVEL CLOUDINESS
CONTINUES TO STREAM IN ACROSS THE REGION THIS AFTERNOON.
EXPECT SCATTERED MID LEVEL CLOUDINESS FOR THE REMAINDER OF THE DAY
AS WELL AS HIGH CLOUDS. LOW LEVEL FLOW WILL KEEP MOISTURE IN THE
LOW LEVELS FOR THE NEXT 24 HOURS. UPPER LEVEL RIDGE WILL HELP
KEEP THE MOISTURE TRAPPED NEAR THE SURFACE. LIGHT WINDS AND
MOISTURE IS SETTING UP A CHANCE OF FOG TOWARD SUNDAY MORNING AT
ALL TERMINALS. QUESTION IS...WILL THE UPPER CLOUDINESS BECOME THIN
ENOUGH TO ALLOW RADIATIONAL COOLING NECESSARY FOR FOG DEVELOPMENT.
GFS MOS IS INDICATING A GOOD CHANCE OF MVFR TO IFR FOG DEVELOPMENT
WHILE THE NAM IS LESS FAVORABLE FOR FOG DEVELOPMENT. LEANED THE
FORECAST TOWARD THE GFS...PLACING MVFR CONDITIONS AT ALL TERMINALS
TOWARD SUNDAY MORNING WITH VFR CONDITIONS RETURNING LATER SUNDAY MORNING.
HOWEVER...CONFIDENCE IS TOO LOW TO PLACE IFR CONDITIONS IN THE
FOR CAST. WILL WAIT FOR LATER MODEL RUNS TO BETTER DETERMINE THAT
CHANCE.
EXTENDED AVIATION OUTLOOK...LOW LEVEL MOISTURE COULD PROVIDE MVFR
CONDITIONS EACH MORNING THROUGH TUESDAY. MVFR CONDITIONS ARE
POSSIBLE INTO WEDNESDAY MORNING AHEAD OF AN APPROACHING FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1213 PM CST SAT DEC 1 2012
.AVIATION...
LOW LEVEL MOISTURE WILL CONTINUE TO INCREASE INTO TNGT WITH
CONDITIONS DETERIORATING TO IFR AND LIFR IN LOW CLOUDS... FOG
AND DRIZZLE. IN ADDITION... WILL SEE AT LEAST SCT SHRA OVER
THE AREA INTO THIS EVE AHEAD OF AN UPPER LEVEL DISTURBANCE.
CANT RULE OUT EVEN AN ELEVATED ISOLD TSRA WITH LOW LEVEL JET
BUT ANY DEVELOPMENT MAINLY FAVORED EAST OF THE MISSISSIPPI
RIVER... BUT PROBS TOO LOW FOR INCLUSION AT KMLI. ANTICIPATE
AREAS OF DENSE FOG AND VLIFR CONDITIONS TO DEVELOP THIS EVE
INTO THE OVRNGT WITH DECREASING WINDS AND WEAK LOW LEVEL
CONVERGENCE AHEAD OF SFC TROUGH/WIND SHIFT. THIS TROUGH WILL
SAG THROUGH THE REGION LATE TNGT THROUGH SUN AM... AND THE
COMBINATION OF WESTERLY WINDS AND LOW LEVEL DRYING LIKELY TO
BRING IMPROVEMENT IN BOTH VSBYS AND CIGS FROM NW TO SE AT THE
TERMINALS.
&&
.PREV DISCUSSION... /ISSUED 311 AM CST SAT DEC 1 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONTAL BOUNDARY FROM THE SOUTH SHORE OF
LAKE ERIE WEST SOUTHWEST INTO NORTHERN KANSAS. DEW POINTS SOUTH OF
THE FRONT WERE IN THE 40S AND 50S WHILE 20S AND 30S WERE NORTH OF
THE FRONT. SATELLITE TRENDS SHOW A LARGE EXPANSE OF LOW CLOUDS
ACROSS WI/MN WITH ADDITIONAL LOW CLOUDS MOVING NORTH THROUGH
MISSOURI AND KANSAS WITH A SLOWLY THICKENING CI/CS SHIELD IN
BETWEEN.
SHORT TERM...TODAY AND TONIGHT...
BASED ON REAL DATA...THE RAP APPEARS TO HAVE A REASONABLY GOOD
HANDLE ON THE LOW CLOUDS APPROACHING FROM THE SOUTH IN THE 900-950MB
LAYER RH. USING THIS AND SATELLITE INDICATES THE LOW CLOUDS SHOULD
ENTER THE FAR SOUTHWESTERN PART OF THE CWFA PRIOR TO SUNRISE AND
OVERSPREAD THE CWFA DURING THE MORNING HOURS. AHEAD OF THESE LOW
CLOUDS SHOULD BE PATCHY TO AREAS OF FOG. ONCE THE LOW CLOUDS
ARRIVE THE FOG SHOULD BECOME MORE PATCHY.
USING THE OVERALL FORCING AND CONDENSATION PRESSURE DEFICITS FROM
TRENDS IN THE RAP MODEL...DRIZZLE SHOULD DEVELOP BY MID TO LATE
MORNING UNDER THE LOW CLOUDS WITH SOME PATCHY LIGHT RAIN POSSIBLE.
FCST SOUNDINGS INDICATE PLENTY OF DRIZZLE SHOULD BE SEEN ACROSS THE
AREA DURING THE AFTERNOON HOURS WITH SOME LIGHT RAIN BASED ON THE
INCREASED FORCING AND LOWERING CONDENSATION PRESSURE DEFICITS.
MAX TEMPERATURES TODAY WILL BE INTERESTING. IN SPITE OF THE CI/CS
SHIELD...AREAS AHEAD OF THE LOW CLOUDS SHOULD WARM UP DURING THE
MORNING. THE CONTINUED PUSH OF LOW LEVEL MOISTURE INTO THE AREA WILL
ALSO BODILY FORCE TEMPERATURES UP IN SPITE OF THE LOW CLOUDS ACROSS
THE AREA DURING THE AFTERNOON. THE CURRENT MAX TEMPS OF LOW 50S TO
LOW 60S MAY STILL BE A BIT TOO WARM.
TONIGHT...DRIZZLE WILL CONTINUE ACROSS THE AREA DURING THE EVENING
HOURS ALONG WITH SOME LIGHT RAIN. AFTER MIDNIGHT THE RAIN AND
DRIZZLE WILL SLOWLY END FROM WEST TO EAST. THERE MAY OR MAY NOT BE
SOME PATCHY FOG THAT OCCURS AFTER MIDNIGHT AS THE PRECIPITATION ENDS
AND THE ATMOSPHERE COOLS. 08
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW A SERIES OF SHORT WAVES MOVING THROUGH THE
REGION IN A PERSISTENT ZONAL FLOW PATTERN. SYSTEMS ARE PROGGED TO
MOVE THROUGH THE REGION MONDAY AND THURSDAY NIGHT. EACH SYSTEM WILL
BE LACKING SIGNIFICANT...DEEP...MOISTURE AS THEY APPROACH THE REGION
AND START TO PICKUP SOME GULF MOISTURE AS THEY MOVE THROUGH. THE
GENERAL TREND THEN WILL BE BETTER CHANCES OF RAIN EAST OF THE
MISSISSIPPI RIVER. THE ZONAL PATTERN WILL ALSO KEEP MOST OF THE
COLD AIR OVER CANADA THROUGH MID WEEK. A BRIEF INTRUSION OF
CANADIAN AIR WILL OCCUR BEHIND THE EARLY WEEK SYSTEM BUT WILL STAY
WELL NORTH AND NORTHEAST OF THE FORECAST AREA. THERE IS GOOD
AGREEMENT BETWEEN THE 00Z GFS/ECMWF THAT THE END OF THE WEEK SYSTEM
WILL HAVE ENOUGH AMPLIFICATION TO PULL THE COLDER AIR FURTHER SOUTH
AND SHOULD RETURN NEAR NORMAL TEMPERATURES TO THE AREA FOR THE END
OF THE WEEK.
SUNDAY RETURN FLOW WILL BE DEVELOPING DURING THE DAY AS WEAK SURFACE
HIGH PRESSURE MOVES EAST OF THE CWFA. THE LIGHT SOUTH FLOW WITH
MOSTLY SUNNY SKIES SHOULD PUSH TEMPERATURES INTO THE LOW 60S SOUTH
AND MID TO UPPER 50S NORTH. THE SOUTHERN AREAS WILL BE CLOSE TO
RECORD HIGHS FOR SUNDAY. SUNDAY NIGHT INTO MONDAY MORNING THE
MODELS ARE SHOWING A GOOD SURGE OF LOW LEVEL MOISTURE INTO THE
REGION SUGGESTING SOME STRATUS AND POSSIBLY DRIZZLE DEVELOPING AFTER
MIDNIGHT AND CONTINUING INTO MONDAY MORNING. THE NAM WAS ALSO
SUGGESTING SOME CONVECTIVE POTENTIAL LATE SUNDAY NIGHT AS IT MOVED
AN AREA OF ELEVATED CAPES AROUND 700J/KG AND STEEP MID LEVEL LAPSE
RATES NORTHEAST THROUGH THE FORECAST AREA. THE GFS THOUGH WAS
BARELY SHOWING ANY CAPE FOR THE SAME TIME PERIOD SO WILL HOLD OFF ON
MENTIONING ANY TSRA FOR NOW. THE COLD FRONT IS EXPECTED TO MOVE
THROUGH DURING THE LATE AFTERNOON AND EARLY EVENING WITH RAIN
CHANCES INCREASING WITH THE FROPA. DUE TO THE SHALLOW
MOISTURE...POPS WILL BE KEPT IN THE CHANCE CATEGORY. RAIN CHANCES
WERE CONTINUED THROUGH TUESDAY MORNING PER THE 00Z ECMWF. IF THE
MORE PROGRESSIVE GFS VERIFIES THEN THE RAIN SHOULD BE EAST OF THE
FORECAST AREA BY MIDNIGHT.
WITH THE INFLUX OF MOISTURE SUNDAY NIGHT MINS WILL PROBABLY BE
REACHED DURING THE EVENING THEN HOLD STEADY OR RISE SOME AFTER
MIDNIGHT. BY MONDAY MORNING INCREASING SURFACE DEWPOINTS WILL DRIVE
TEMPERATURES INTO THE 50S. DESPITE LOW CLOUDS AND DRIZZLE MONDAY
MORNING...THE CONTINUING WARM ADVECTION SHOULD PUSH TEMPS INTO THE
60S OVER THE ENTIRE AREA...JUST UNDER RECORD HIGHS FOR THE 3RD.
FOR TUESDAY THROUGH WEDNESDAY DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES COOLING OFF SOME BUT STILL STAYING ABOVE NORMAL. THE
NEXT SYSTEM IS PROGGED TO MOVE THROUGH THE REGION THURSDAY SO CHANCE
POPS FOR RAIN LOOK REASONABLE THURSDAY INTO FRIDAY. THE MORE
AMPLIFIED WAVE IS EXPECTED TO BRING THE COLDER AIR FURTHER SOUTH
RETURNING LATE WEEK TEMPERATURES TO NEAR NORMAL.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
243 PM CST SAT DEC 1 2012
.SYNOPSIS...
ISSUED AT 933 AM CST SAT DEC 1 2012
THE 01.12Z 250 HPA MAP SHOWED MOSTLY A ZONAL FLOW ACROSS THE NATION
WITH A FEW SUBTLE WAVES. A 120 KT JET WAS OBSERVED ACROSS SOUTHWESTERN
OREGON. ANOTHER 100 KT JET WAS OBSERVED ACROSS NORTH DAKOTA. AT 500
HPA, A DEEP CYCLONE WAS LOCATED WEST OF BRITISH COLUMBIA WITH AN ASSOCIATED
TROF MOVING ACROSS THE PACIFIC NORTHWEST. ANOTHER TROF WAS MOVING OUT
ACROSS THE PLAINS. MID LEVEL TEMPERATURES WERE MAINLY IN THE NEGATIVE
TEENS/20S WITH -30 DEG C AND BELOW CONFINED TO SE CANADA. AT 700 HPA,
TEMPERATURES INCREASED A FEW DEGREES CENTIGRADE AT KDDC AHEAD OF A WAVE.
AT 850 HPA, A WARM PLUME OF AROUND 18 DEG C PREVAILED ACROSS THE SOUTHERN
AND CENTRAL PLAINS. THE ATMOSPHERE WAS FAIRLY DRY AT THIS CONSTANT PRESSURE
LEVEL AS WELL. THE COLDER AIR OF -15 DEG C AND BELOW WAS CONFINED TO
SE CANADA. AT THE SFC, A STATIONARY BOUNDARY WAS DRAPED ACROSS KANSAS.
RESPECTABLE DEWPOINTS...FOR THE BEGINNING OF DECEMBER...WITH VALUES
RUNNING IN THE 50S DEG F WERE SOUTH OF SAID BOUNDARY ACROSS THE SC/SE
PORTION OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 136 PM CST SAT DEC 1 2012
TONIGHT:
FAIRLY TRANQUIL CONDITIONS ARE EXPECTED TONIGHT. HIGH LEVEL CLOUDS WILL
MOVE OFF TO THE EAST THIS EVENING AND SKIES SHOULD BE CLEAR THROUGH
THE OVERNIGHT HOURS. BUFKIT FORECAST SOUNDINGS, MOS GUIDANCE, THE VERY
END OF THE HRRR RUN, AND THE NSSL WRF MODEL HIGHLIGHTS A CONCERN FOR PATCHY
FOG TOMORROW MORNING. DEWPOINTS WILL BE LOWER THAN COMPARED TO THIS
MORNING. DRIER AIR WILL ADVECT IN FROM THE NW. STILL, CONSIDERING EVERYTHING
ABOVE, I HAVE INSERTED PATCHY FOG ALONG AND EAST OF HIGHWAY 283. THIS
MIGHT BE ON THE LIBERAL SIDE AND MAY HAVE TO BE TRIMMED FARTHER EAST.
OTHERWISE, LOWS WILL BE MAINLY IN THE 30S DEG F.
TOMORROW:
OTHER THAN THE AFOREMENTIONED FOG AND SOME AFTERNOON CIRRUS, TOMORROW
WILL BE CLEAR WITH FULL INSOLATION. DID NOT CHANGE MAXIMUM TEMPERATURES
FOR TOMORROW AS THE GRID LOOKS STILL ON TRACK WITH 12Z DATA. IT WILL
BE VERY WARM TOMORROW WITH HIGHS AROUND 70 DEG F. THE AVERAGE HIGH FOR
THIS TIME OF YEAR IS AROUND 48 DEG F. THESE WARM TEMPERATURES ARE A
RESULT OF THE DEEPENING OF THE LEE SURFACE TROUGH ACROSS EASTERN COLORADO
AND RESULTANT CONTINUED WARM AIR ADVECTION. 850 HPA TEMPERATURES AROUND
15 DEG C AND ADIABATIC MIXING STILL SUPPORT THE WARM TEMPS AT THE SURFACE.
LASTLY, RH`S LOOK MARGINAL FOR TOMORROW SO NOT EXPECTING ANY FIRE WX
CONCERNS ATTM. IT WILL BE BREEZY TOMORROW, BUT NOTHING OUT OF THE ORDINARY
IN TERMS OF WESTERN KANSAS WIND STANDARDS (GENERALLY 12-21 KT).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 239 PM CST SAT DEC 1 2012
FOR MONDAY, A DRY AND PROGRESSIVE UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE ACROSS THE PLAINS HELPING TO PUSH A COLD FRONT ACROSS WESTERN
KANSAS IN THE MORNING. WINDS WILL BE GUSTY TO 15 TO 25 MPH WITH THE
COLD FRONT. HIGHS WILL STILL BE MILD IN THE 60S. FOR TUESDAY INTO
THURSDAY, DRY WEST TO NORTHWESTERLY UPPER LEVEL FLOW CONTINUES
ACROSS THE CENTRAL CONUS, WITH THE NEXT UPPER LEVEL SHORTWAVE TROUGH
DIGGING INTO THE INTERMOUNTAIN WEST ON THURSDAY FROM THE PACIFIC
NORTHWEST. HIGHS LOOK MILD AND AROUND 60 WITH SOUTHERLY FLOW AHEAD
OF A LEE SURFACE TROUGH. THIS NEXT SHORTWAVE WILL MOVE ACROSS THE
PLAINS ON FRIDAY WITH INCREASING MID AND UPPER LEVEL MOISTURE AND A
CANADIAN COLD FRONT. A FEW LIGHT RAIN OR LIGHT SNOW SHOWERS ARE
POSSIBLE, HOWEVER THE LOWER LEVELS LOOK FAIRLY DRY AND MAY BE MOSTLY
VIRGA. WILL LEAVE A SMALL POP GOING IN CASE. BOTH THE GFS AND ECMWF
SHOW VERY MINOR AMOUNTS IF ANY WITH HIGHS IN THE 40S. BY SATURDAY
THE MODELS DIVERGE WITH THE GFS SHOWING A WARM SOUTHWESTERLY UPPER
LEVEL FLOW, WHILE THE ECMWF IS SHOWING A COOLER NORTHWESTERLY FLOW
ALOFT. CONSENSUS HAS HIGHS IN THE 40S WHICH LOOKS REASONABLE.
OVERNIGHT LOWS THROUGH THE PERIOD LOOK TO BE IN 30S COOLING INTO THE
20S BY SATURDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT DEC 1 2012
CIGS ARE IMPROVING TO VFR THIS MORNING AS FOG DISSIPATES. MOS GUIDANCE
AND BUFKIT PROFILES SUGGEST FOG IS POSSIBLE AGAIN TOMORROW MORNING.
THIS FOG SHOULD NOT BE AS DENSE AS DRIER AIR ADVECTS IN FROM THE NORTHWEST.
WILL GO AHEAD AND HEDGE TO MVFR FOR KDDC/KHYS AND LET FUTURE SHIFTS ADJUST
AS NEEDED FOR TOMORROW AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 71 38 65 / 0 0 0 0
GCK 33 71 36 64 / 0 0 0 0
EHA 39 72 38 64 / 0 0 0 0
LBL 36 73 35 65 / 0 0 0 0
HYS 34 71 36 62 / 0 0 0 0
P28 36 73 47 68 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
233 PM CST SAT DEC 1 2012
.DISCUSSION...
TONIGHT-SUNDAY NGT:
THE PRIMARY PROBLEM IS FOG POTENTIAL IN SE KS WHERE A WEAK SFC TROF WILL
DRIFT SE OVER THE REGION LATE TONIGHT. THE DIMINISHING SLY WINDS COUPLED
WITH RICH MOISTURE AXIS SITUATED ALONG & SE OF THE TROF SHOULD PROMOTE
FOG REDEVELOPMENT OVER THESE AREAS FROM ~3-10AM. BOTH NAM & HRRR DEPICT
SATURATED LAYER ~300FT DEEP TRAPPED BENEATH SHARP INVERSION DURING THIS
PERIOD. SUNDAY WILL BE VERY WARM AS A GRADUALLY STRENGTHENING WRN PLAINS
SFC TROF INDUCES LWR-DECK FLOW TO RESUME SLY COMPONENT BY MID-DAY. STILL
ANTICIPATE RECORD HIGHS TO BE SET/TIED ACROSS THE REGION...ESPECIALLY IN
CNTRL & SC KS. A VERY BALMY SUNDAY NGT AWAITS NEARLY ALL AREAS AS THE
EWD-DRIFTING SFC TROF INDUCES A PERSISTENT WARM/MOIST SLY FLOW OVER ALL
BUT RUSSELL & BARTON COUNTIES. RECORD WARMEST LOWS ARE POSSIBLE IN SOME
AREAS.
MON & MON NGT:
STILL ANTICIPATE A FEW -SHRA/-TSRA OCCURRING OVER SE KS MON AFTERNOON &
EVENING AS A WEAK MID-LVL SHORTWAVE SCOOTS E FROM THE CNTRL/SRN ROCKIES
ACROSS THE SRN PLAINS. THE WAVE WILL SWEEP A COLD FRONT SE ACROSS KS IN
THE AFTERNOON & EARLY EVENING BUT THE BOUNDARY WILL NOT ENCOUNTER ANY
NOTEWORTHY MOISTURE UNTIL IT VENTURES INTO SE KS.
TUE-FRI NGT:
QUIET WEATHER SLATED FOR ALL AREAS UNTIL THU NGT WHEN THE NEXT WEAK MID
LVL SHORTWAVE VENTURES E/SE ACROSS KS. AS THE ATTENDANT COLD FRONT MOVES
SE ACROSS KS AREAS OF -RA WILL DEVELOP OVER KICT COUNTRY & MAY BE MIXED
WITH -SN IN CNTRL KS LATE THU NGT/EARLY FRI MORNING. AS THE MID-LVL WAVE
VENTURES FURTHER E/SE IT MAY STRENGTHEN. AS SUCH A FEW -TSRA REMAIN
POSSIBLE OVER SE KS ON FRI.
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
TIMING THE ENDING OF IFR STRATUS/FOG THIS AFTERNOON WILL BE THE MAIN
CONCERN...AS SOUTHERLY FLOW HAS ALLOWED SHALLOW GULF MOISTURE TO
MOVE NORTHWARD INTO THE AREA...RESULTING IN ANTICIPATED LOW
STRATUS...WITH SOME PESKY DENSE FOG IN CENTRAL KS. EXPECT THE
DENSE FOG TO SLOWLY BURN OFF ACROSS CEN KS...STRATUS WILL BE SLOW TO
ERODE NORTHEASTWARD THIS AFTERNOON...AS A SURFACE WAVE TRACKS ACROSS
CENTRAL KS AND SLOWLY DRIFTS SOUTHEAST WITH LIGHT/VARIABLE WINDS.
SOUTH CENTRAL KS LOOKS TO BREAK OUT OF LOW CLOUDS BY MIDDAY...WITH
CENTRAL AND SOUTHEAST KS TAKING MUCH OF THE DAY. SO WILL SEE A
GENERAL IMPROVEMENT FROM IFR TO MVFR TO VFR AS THE AFTERNOON
CONTINUES.
WILL CARRY VFR FORECAST AREA WIDE TONIGHT WITH LIGHT WEST
SOUTHWESTERLY WIND COMPONENT.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 36 72 55 69 / 0 0 0 10
HUTCHINSON 34 72 53 66 / 0 0 0 10
NEWTON 35 72 55 67 / 0 0 0 10
ELDORADO 36 71 55 69 / 0 0 0 10
WINFIELD-KWLD 38 72 57 71 / 0 0 0 10
RUSSELL 34 72 42 64 / 0 0 0 0
GREAT BEND 33 71 44 65 / 0 0 0 0
SALINA 34 73 50 66 / 0 0 0 0
MCPHERSON 34 72 53 66 / 0 0 0 10
COFFEYVILLE 49 71 59 71 / 0 0 0 20
CHANUTE 43 70 56 70 / 0 0 0 20
IOLA 40 70 56 70 / 0 0 0 20
PARSONS-KPPF 47 71 59 71 / 0 0 0 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
136 PM CST SAT DEC 1 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 933 AM CST SAT DEC 1 2012
THE 01.12Z 250 HPA MAP SHOWED MOSTLY A ZONAL FLOW ACROSS THE NATION
WITH A FEW SUBTLE WAVES. A 120 KT JET WAS OBSERVED ACROSS SOUTHWESTERN
OREGON. ANOTHER 100 KT JET WAS OBSERVED ACROSS NORTH DAKOTA. AT 500
HPA, A DEEP CYCLONE WAS LOCATED WEST OF BRITISH COLUMBIA WITH AN ASSOCIATED
TROF MOVING ACROSS THE PACIFIC NORTHWEST. ANOTHER TROF WAS MOVING OUT
ACROSS THE PLAINS. MID LEVEL TEMPERATURES WERE MAINLY IN THE NEGATIVE
TEENS/20S WITH -30 DEG C AND BELOW CONFINED TO SE CANADA. AT 700 HPA,
TEMPERATURES INCREASED A FEW DEGREES CENTIGRADE AT KDDC AHEAD OF A WAVE.
AT 850 HPA, A WARM PLUME OF AROUND 18 DEG C PREVAILED ACROSS THE SOUTHERN
AND CENTRAL PLAINS. THE ATMOSPHERE WAS FAIRLY DRY AT THIS CONSTANT PRESSURE
LEVEL AS WELL. THE COLDER AIR OF -15 DEG C AND BELOW WAS CONFINED TO
SE CANADA. AT THE SFC, A STATIONARY BOUNDARY WAS DRAPED ACROSS KANSAS.
RESPECTABLE DEWPOINTS...FOR THE BEGINNING OF DECEMBER...WITH VALUES
RUNNING IN THE 50S DEG F WERE SOUTH OF SAID BOUNDARY ACROSS THE SC/SE
PORTION OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 136 PM CST SAT DEC 1 2012
TONIGHT:
FAIRLY TRANQUIL CONDITIONS ARE EXPECTED TONIGHT. HIGH LEVEL CLOUDS WILL
MOVE OFF TO THE EAST THIS EVENING AND SKIES SHOULD BE CLEAR THROUGH
THE OVERNIGHT HOURS. BUFKIT FORECAST SOUNDINGS, MOS GUIDANCE, THE VERY
END OF THE HRRR RUN, AND THE NSSL WRF MODEL HIGHLIGHTS A CONCERN FOR PATCHY
FOG TOMORROW MORNING. DEWPOINTS WILL BE LOWER THAN COMPARED TO THIS
MORNING. DRIER AIR WILL ADVECT IN FROM THE NW. STILL, CONSIDERING EVERYTHING
ABOVE, I HAVE INSERTED PATCHY FOG ALONG AND EAST OF HIGHWAY 283. THIS
MIGHT BE ON THE LIBERAL SIDE AND MAY HAVE TO BE TRIMMED FARTHER EAST.
OTHERWISE, LOWS WILL BE MAINLY IN THE 30S DEG F.
TOMORROW:
OTHER THAN THE AFOREMENTIONED FOG AND SOME AFTERNOON CIRRUS, TOMORROW
WILL BE CLEAR WITH FULL INSOLATION. DID NOT CHANGE MAXIMUM TEMPERATURES
FOR TOMORROW AS THE GRID LOOKS STILL ON TRACK WITH 12Z DATA. IT WILL
BE VERY WARM TOMORROW WITH HIGHS AROUND 70 DEG F. THE AVERAGE HIGH FOR
THIS TIME OF YEAR IS AROUND 48 DEG F. THESE WARM TEMPERATURES ARE A
RESULT OF THE DEEPENING OF THE LEE SURFACE TROUGH ACROSS EASTERN COLORADO
AND RESULTANT CONTINUED WARM AIR ADVECTION. 850 HPA TEMPERATURES AROUND
15 DEG C AND ADIABATIC MIXING STILL SUPPORT THE WARM TEMPS AT THE SURFACE.
LASTLY, RH`S LOOK MARGINAL FOR TOMORROW SO NOT EXPECTING ANY FIRE WX
CONCERNS ATTM. IT WILL BE BREEZY TOMORROW, BUT NOTHING OUT OF THE ORDINARY
IN TERMS OF WESTERN KANSAS WIND STANDARDS (GENERALLY 12-21 KT).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CST SAT DEC 1 2012
A PROGRESSIVE ZONAL FLOW REGIME WILL CONTINUE TO DOMINATE THE
CENTRAL PLAINS ON SUNDAY. FURTHER, THIS WILL OCCUR WHILE A POTENT
120 KT EAST PACIFIC JET, BEGINS TO CARVE OUT A TROUGH OVER THE
PACIFIC NORTHWEST SUNDAY AFTERNOON TO EVENING. MODEST WEST TO
EAST MID/UPPER FLOW OVER THE ROCKIES, WILL AID IN SLOWLY DEEPENING
THE LEE TROUGH IN THE WESTERN HIGH PLAINS OF COLORADO ON SUNDAY.
THIS WILL RESULT IN WARM SOUTH TO SOUTHEAST WINDS PREVAILING AHEAD
OF THE TROUGH ON SUNDAY AS 850 HPA TEMPERATURES OF +12C TO +15C
EXIST OVER SOUTHWEST INTO CENTRAL KANSAS. HOWEVER, SOME CIRRUS
STREAMING OFF THE ROCKIES MAY SLIGHTLY LIMIT SOLAR INSOLATION/MIXING
ON SUNDAY BUT HIGHS IN THE UPPER 60S TO MID 70S STILL LOOK LIKELY.
THE PATTERN THEN BEGINS TO CHANGE SUNDAY NIGHT INTO MONDAY AS THE
AFOREMENTIONED UPPER JET AND ASSOCIATED TROUGH, SLIDE VERY QUICKLY
EAST INTO THE PLAINS. IN RESPONSE TO THIS WAVE, A FAST MOVING
PACIFIC FRONT WILL PUSH THROUGH SOUTHWEST INTO CENTRAL KANSAS MONDAY
MORNING TO EARLY AFTERNOON. ALTHOUGH THIS FRONTAL PASSAGE WILL
RESULT IN LITTLE IF ANY THREAT FOR PRECIPITATION, WIND SPEEDS ARE A
DIFFERENT MATTER. A MODEST 3 HOUR PRESSURE RISE BEHIND THE BOUNDARY
WILL PRODUCE AN ISALLOBARIC RESPONSE IN THE WIND FIELD WITH NORTH
WINDS OF 25 TO 30 MPH POSSIBLE THROUGH MID AFTERNOON ON MONDAY.
TEMPERATURES WILL BE TRICKY ON MONDAY GIVEN THE FRONTAL PASSAGE
AFTER SUNRISE BUT BEFORE PEAK HEATING. WILL AIM FOR HIGHS IN THE
LOWER 60S NEAR WAKEENEY...TO THE UPPER 60S NEAR THE OKLAHOMA BORDER.
TUESDAY WILL REMAIN DRY YET MILD FOR EARLY DECEMBER AS THE UPPER
TROUGH SWINGS EAST OF THE PLAINS WHILE ARCTIC AIR DIGS INTO THE
GREAT LAKES REGION. INCREASING ZONAL MID LEVEL FLOW OVER THE CENTRAL
ROCKIES WILL BEGIN TO DEEPEN THE LEE TROUGH BY TUESDAY AFTERNOON
WITH WINDS TURNING MORE SOUTHERLY AS THERMAL MIXING UP TO 850 HPA
SUPPORTS HIGHS IN THE UPPER 50S TO LOWER 60S.
WEDNESDAY INTO EARLY THURSDAY WILL BE A TRANSITIONAL PERIOD BETWEEN
THE EXITING WAVE FROM MONDAY AND THE NEXT TROUGH MOVING INTO THE
PLAINS BY LATE THURSDAY. THE LEE TROUGH WILL CONTINUE TO DEEPEN
DURING THIS TIME PERIOD WITH WARM SOUTHERLY WINDS PUSHING 850 HPA
TEMPERATURES INTO THE +10 TO +15C RANGE. THIS WILL SUPPORT A
COUPLE MORE DAYS OF MILD HIGH TEMPERATURES IN THE UPPER 50S TO
60S.
ATTENTION THEN TURNS TOWARD THE LATTER HALF OF THURSDAY INTO FRIDAY
AS AN OPEN BUT STRONG UPPER WAVE SLIDES THROUGH PLAINS. THIS SYSTEM
WILL PUSH A POTENT COLD FRONT WITH SOME ARCTIC AIR BEHIND IT,
THROUGH KANSAS BY THURSDAY EVENING. FURTHER, ALTHOUGH THE WAVE WILL
REMAIN OPEN, FAVORABLE JET DYNAMICS MAY BRING A LOWER END CHANCE
FOR SOME LIGHT PRECIPITATION LATE THURSDAY INTO EARLY FRIDAY
BEFORE SUBSIDENCE TAKES HOLD OF THE AREA FRIDAY AFTERNOON.
OTHERWISE, TEMPERATURES WILL COOL SUBSTANTIALLY BEHIND THE FRONT WITH
HIGH TEMPERATURES IN THE 40S TO NEAR 50 EXPECTED FRIDAY AND
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT DEC 1 2012
CIGS ARE IMPROVING TO VFR THIS MORNING AS FOG DISSIPATES. MOS GUIDANCE
AND BUFKIT PROFILES SUGGEST FOG IS POSSIBLE AGAIN TOMORROW MORNING.
THIS FOG SHOULD NOT BE AS DENSE AS DRIER AIR ADVECTS IN FROM THE NORTHWEST.
WILL GO AHEAD AND HEDGE TO MVFR FOR KDDC/KHYS AND LET FUTURE SHIFTS ADJUST
AS NEEDED FOR TOMORROW AM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 71 41 66 / 0 0 0 0
GCK 33 71 37 64 / 0 0 0 0
EHA 39 72 40 65 / 0 0 0 0
LBL 36 73 36 66 / 0 0 0 0
HYS 34 71 38 63 / 0 0 0 0
P28 36 73 47 69 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...AJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1122 AM CST SAT DEC 1 2012
...UPDATE TO AVIATION...
.UPDATE...
AFTER CALLING NUMEROUS SPOTTERS ACROSS THE OBSERVATION- SPARSE
REGIONS OF NORTH CENTRAL AND NORTHEAST KANSAS...HAVE CONCLUDED
THAT DENSE FOG CONTINUES IN FULL EFFECT NEAR AND NORTHWEST OF A
LINE FROM MINNEAPOLIS TO CLAY CENTER TO WASHINGTON. VISIBILITY IN
THESE AREAS RANGED FROM AROUND 100 FEET TO AROUND ONE QUARTER
MILE. VISIBILITY HAD GRADUALLY IMPROVED SOUTHEAST OF THIS LINE AND
SHOULD CONTINUE TO DO SO...WITH VISIBILITY RANGING FROM ONE
QUARTER TO 2 MILES SOUTHEAST OF THE LINE...AND IMPROVING
FURTHERMORE NEAR AND SOUTH OF I-70 AND WEST OF ABILENE. WITH THIS
IN MIND...HAVE ALLOWED THE ADVISORY TO EXPIRE FOR MARSHALL AND
DICKINSON COUNTIES...WHILE EXTENDING IT UNTIL NOON FOR POINTS
FURTHER NORTHWEST. THERE IS SOME POTENTIAL FOR THE DENSE FOG TO
CONTINUE PAST NOON IN THE CONCORDIA AND BELLEVILLE AREAS AND WILL
CONTINUE TO EVALUATE THIS AS THE MORNING GOES ON.
BARJENBRUCH
&&
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
WHILE CONDITIONS SINCE 15Z HAVE BOUNCED BETWEEN VFR AND MVFR
CIGS...EXPECT PREDOMINANT MVFR CIGS AT ALL TAF SITES WITH TEMPO
VFR THROUGH 20Z. DRY AIR MOVES IN BETWEEN 23Z AND 01Z AND SHOULD
SCATTER STRATUS OUT. TIMING OF SCATTERING MAY VARY BY A FEW HOURS
WITH TAFS INDICATING MOST LIKELY SCENARIO. CLEARING SKIES OVER
THE MOIST AIRMASS SHOULD LEAD TO FOG REDEVELOPMENT BY LATE EVENING
OR EARLY MORNING HOURS. HAVE GONE WITH SEVERAL HOURS OF MVFR AND
IFR VIS FOR SUNDAY MORNING...BUT CONFIDENCE IS NOT PARTICULARLY
HIGH REGARDING EXTENT OF FOG...AND COULD SEE CONDITIONS RANGING
FROM VFR TO VLIFR AT TAF SITES BY SUNRISE.
BARJENBRUCH
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ008-009-020-021-
034.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1007 AM CST SAT DEC 1 2012
.UPDATE...
...UPDATE FOR DENSE FOG FORECAST...
AFTER CALLING NUMEROUS SPOTTERS ACROSS THE OBSERVATION- SPARSE
REGIONS OF NORTH CENTRAL AND NORTHEAST KANSAS...HAVE CONCLUDED
THAT DENSE FOG CONTINUES IN FULL EFFECT NEAR AND NORTHWEST OF A
LINE FROM MINNEAPOLIS TO CLAY CENTER TO WASHINGTON. VISIBILITY IN
THESE AREAS RANGED FROM AROUND 100 FEET TO AROUND ONE QUARTER
MILE. VISIBILITY HAD GRADUALLY IMPROVED SOUTHEAST OF THIS LINE AND
SHOULD CONTINUE TO DO SO...WITH VISIBILITY RANGING FROM ONE
QUARTER TO 2 MILES SOUTHEAST OF THE LINE...AND IMPROVING
FURTHERMORE NEAR AND SOUTH OF I-70 AND WEST OF ABILENE. WITH THIS
IN MIND...HAVE ALLOWED THE ADVISORY TO EXPIRE FOR MARSHALL AND
DICKINSON COUNTIES...WHILE EXTENDING IT UNTIL NOON FOR POINTS
FURTHER NORTHWEST. THERE IS SOME POTENTIAL FOR THE DENSE FOG TO
CONTINUE PAST NOON IN THE CONCORDIA AND BELLEVILLE AREAS AND WILL
CONTINUE TO EVALUATE THIS AS THE MORNING GOES ON.
BARJENBRUCH
&&
.DISCUSSION...
QUICK LOW LEVEL SOUTHERLY FLOW WITH 925MB WINDS AROUND 30KT
BRINGING MOISTURE UNDER INVERSION NOTED ON KTOP 0Z SOUNDING. WITH
LIGHT SURFACE WINDS NEAR THE OLD BOUNDARY IN NORTHERN KANSAS AND
SOME BREAKS IN THE CIRRUS...TEMPS COOLED SUFFICIENTLY FOR THE
MOISTURE TO RESULT IN WIDESPREAD LOW CLOUDS. RECENT HOURS HAVE
SEEN DEWPOINTS RISE RATHER SHARPLY AND RESULTING IN DENSE FOG FOR
MUCH OF THE WESTERN HALF OF THE CWA. LAST FEW OBSERVATIONS IN
SOUTH CENTRAL AND SOUTHEAST KANSAS INDICATE RISING VISIBILITIES
AND CLOUD DECKS AND CONFIDENCE IN HOW LONG THE DENSE FOG WILL LAST
IS NOT HIGH....BUT AT LEAST THROUGH POST-SUNRISE SEEMS IN ORDER.
08Z 3-HOUR PRESSURE TRENDS HAVE BEST FALLS IN SOUTHWEST KANSAS
EAST OF A SURFACE LOW. THIS LOW IS PROGGED TO PUSH EAST IN THE
ZONAL FLOW ALOFT...WITH MODERATE CONVERGENCE RESULTING TODAY FOR
NORTHERN KANSAS. UNDER SOMEWHAT VEERED WINDS JUST ABOVE IT...THERE
MAY BE ENOUGH MOISTURE CONVERGENCE FOR SOME DRIZZLE TO BE SQUEEZED
OUT OF THE MOIST LOWER FEW THOUSAND FEET. MOST RECENT
SREF...NAM...AND RAP SUGGEST LOW CLOUDS WILL BE SLOWER TO CLEAR ON
THE NORTHWEST SIDE OF THE LOW AND HAVE COOLED HIGHS SEVERAL
DEGREES AS A RESULT. INCREASING WESTERLY FLOW BEHIND THE LOW
SHOULD ALLOW FOR CLEARING AND DRYING CONDITIONS BY EARLY EVENING.
SUNDAY LOOKING RATHER WARM WITH 850MB TEMPS IN THE 12-14C RANGE.
AFTER WEAK SURFACE RIDGING BUILDS IN TONIGHT...WINDS WILL BE RATHER
LIGHT FOR MUCH OF THE DAY...THOUGH SOUTH WINDS AND CIRRUS WILL BE
INCREASING IN THE AFTERNOON AS AN UPPER WAVE MAKES EASTWARD PROGRESS
OVER THE NORTHERN ROCKIES. BELIEVE MIXING WILL STILL NOT BE HARD TO
MANAGE IN THE RATHER DRY LOWER TROPOSPHERE AND NEAR RECORD TEMPS
STILL ON TRACK.
SUNDAY NIGHT INTO MONDAY ARE SHOWING SIMILARITIES TO CURRENT AND
NEAR FUTURE EXPECTATIONS WITH THE LOW LEVELS MOISTENING AGAIN.
RISING TEMPS AND FOG CHANCES PRESENT THEMSELVES BUT MUCH TO EARLY
TO GET TOO CONCERNED. FRONTAL PASSAGE WITH THE NORTHERN WAVE STILL
ON TRACK FOR MONDAY...BUT STOUTNESS OF THE INVERSION IS STARTING
TO LOOK TOO STRONG FOR PRECIP AGAIN...AND DRIZZLE COULD AGAIN BE
THE PRIMARY WEATHER. WILL BEGIN TO TAPER PRECIP COVERAGE ON THE
NORTHERN AND WESTERN ENDS AT THIS POINT. FRONT STILL NOT TAPPING
INTO A SIGNIFICANTLY COOLER AIRMASS AND TEMPS ONLY DROP SOME 10
DEGREES FROM EARLIER DAYS.
NEXT FRONT STILL ON TRACK FOR THE THURSDAY/THURSDAY NIGHT PERIODS
WITH BROAD UPPER TROFFING MOVING THROUGH INTO FRIDAY. DEEP LAYER
SATURATION IS BETTER BUT STILL NOT IDEAL FOR WIDESPREAD
PRECIPITATION. COOLER AIR DOES MAKE ITS WAY SOUTH FOR EVEN SOME
FROZEN PRECIP POTENTIAL. SMALL CHANCES WILL BE MAINTAINED AT THIS
POINT.
65
&&
.AVIATION...
IFR TO MVFR CIGS WILL CONTINUE INTO THE LATE MORNING HOURS. MVFR
CIGS ARE EXPECTED BY 18Z. LOW LEVEL MOISTURE WILL BE SLOW TO MOVE
OUT SO KEPT MVFR CIGS IN UNTIL 23Z-24Z. WINDS WILL BE SOUTH NEAR
10 KTS VEERING TO THE SOUTHWEST AND DECREASING BY 00Z SUNDAY.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ008-009-020-021-
034.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1057 AM CST SAT DEC 1 2012
.UPDATE...
ISSUED AT 1057 AM CST SAT DEC 1 2012
,MESOSCALE UPDATE...MINOR ADJUSTMENT TO SHORT TERM GRIDS FOR LATE
THIS MORNING AND INTO THIS AFTERNOON. KPAH WSR-88D HAS BEEN
INDICATING SOME 15-25 DBZ LINEAR ORIENTED RADAR RETURNS BETWEEN
2.5-5KFT MSL SINCE ABOUT 14Z..JUST EAST OF THE MISSISSIPPI
RIVER...JUST SOUTH OF CAIRO IL. THE VISIBLE SATELLITE IMAGERY WAS
ALSO SHOWING SOME CONVECTIVE ELEMENTS IN A SOUTHWEST TO NORTHEAST
ORIENTED BAND FROM THE CONFLUENCE OF THE OH/MS RIVER TO THE
CONFLUENCE OF THE WABASH/OHIO RIVER. THESE ELEMENTS WERE EMBEDDED
IN A BROADER...ISENTROPICALLY LIFTED CLOUD SHIELD COVERING MOST OF
THE WFO PAH FORECAST AREA...WITH THE EXCEPTION OF PARTS OF THE
PENNYRILE REGION OF WEST KENTUCKY...AS WELL AS SWRN IL/FOOTHILLS
OF SOUTHEAST MO.
GIVEN THE LIMITED LIFT AND INSTABILITY...DO NOT EXPECT MUCH MORE
THAN SPRINKLES /TRACE PRECIPITATION POTENTIAL/ ORIENTED IN THE
AFOREMENTIONED CONVECTIVE BAND SHIFTS NORTHEASTWARD INTO SOUTHWEST
INDIANA THIS AFTERNOON. GIVEN THE SMALL AREA IN BOTH TIME AND
SPACE...THIS PRECIPITATION WILL NOT LIKELY SHOW UP IN THE BROADER
WORDED TEXT PRODUCTS OR PERIODIC TABULAR PRODUCTS...BUT SHOULD BE
NOTICEABLE IN THE GRIDDED FORECAST PRODUCTS THAT WILL BE
EFFECTIVELY DEPICTED IN THE WEB-BASED POINT AND CLICK PRODUCTS.
LEANED CLOSER TO THE 3KM HRRR AND 12KM NAM-WRF GUIDANCE FOR THE
REFLECTIVITY/PRECIPITATION/POP POTENTIAL FOR THE REST OF TODAY.
GIVEN THE GREATER MOISTURE PLUME IN THE WESTERN 1/3 OF THE WFO PAH
FORECAST AREA THIS MORNING /0.80+ INCHES PER THE GOES PRECIPITABLE
WATER SOUNDER DATA/...LEANED TOWARD THE RUC/RAP/NAM SOLUTION WITH
RESPECT THE INFLUX OF WARM/MOIST ADVECTION INTO THE WFO PAH CWA.
WITH THAT IN MIND...ADJUSTED MAX TEMPERATURES UP SLIGHTLY /
FORECAST TEMPERATURES THE LAST COUPLE OF HOURS WERE RUNNING 1-3
DEGREES SLIGHTLY COOLER DEPENDING ON LOCATION/.
OTHER ADJUSTMENTS WERE MADE TO SHORT TERM DEWPOINTS...SKY COVER
AND WINDS THROUGH THE EVENING AND OVERNIGHT HOURS...AS THE
AGEOSTROPHIC RESPONSE TO THE APPROACHING COLD FRONT COMES INTO
PLAY WITH TIME.
MAY NEED TO TAKE A CLOSER LOOK AT INSTABILITY TONIGHT...WFO IND
AND SPC HINT THAT MIXED LAYER CAPE MAY BE A LITTLE GREATER THAN
FORECAST AT THIS TIME...WILL TAKE A LOOK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 337 AM CST SAT DEC 1 2012
MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT TERM. SLIGHT
DIFFERENCES IN THE TIMING OF PRECIP CHANCES. HAVE HELD OFF
INTRODUCING CHANCES OF SHOWERS ACROSS THE OZARKS INTO SW ILLINOIS
UNTIL AFTER SUNSET TODAY. NAM SHOWS A COUPLE OF VERY DISTINCT
IMPULSES THAT WILL BRING THE THREAT...ALBEIT SMALL...OF RAINFALL TO
THE REGION. MAIN THREATS APPEAR TO BE SATURDAY NIGHT INTO SUNDAY
MORNING LINGERING INTO MONDAY MAINLY IN THE EASTERN SECTIONS. ALL OF
THIS IS IN ADVANCE OF A LARGER STORM SYSTEM APPROACHING.
SOUTH WINDS HAVE ALREADY KICKED TEMPS AND DEWPOINTS UP. GOING TO
STRUGGLE TO DROP TO THE FORECAST LOWS THIS MORNING. EXPECT STEADILY
INCREASING HIGH TEMPS THROUGH MONDAY. MONDAY SHOULD SEE 70 DEGREES
IN MOST LOCATIONS. LOWS THE NEXT COUPLE OF NIGHTS WILL STAY IN THE
50S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT DEC 1 2012
THE EXTENDED PORTION OF THE FORECAST WILL BE DOMINATED BY A FAST
WEST TO EAST ZONAL FLOW PATTERN ACROSS MUCH OF THE CONUS. THE
PASSAGE OF A COUPLE OF FRONTAL SYSTEMS WILL PROVIDE THE POTENTIAL
FOR LIQUID PRECIPITATION. THE FIRST SYSTEM IS SLATED FOR MONDAY
NIGHT AND TUESDAY...WITH THE SECOND LATE IN THE WEEK.
FORECAST CONFIDENCE WITH THE FIRST SYSTEM IS RELATIVELY HIGH AS
MODELS REMAIN IN GOOD AGREEMENT ON THE TIMING AND PLACEMENT OF
SURFACE AND UPPER LEVEL FEATURES. A STRONG COLD FRONT WILL BE
SITUATED ALONG THE WESTERN PERIPHERY OF THE FORECAST AREA AT
DAYBREAK TUESDAY. THE FRONT WILL PROGRESS EAST ACROSS THE REGION
THROUGH THE COURSE OF THE DAY. STRONG FORCING FOR ASCENT AND
RELATIVELY HIGH ATMOSPHERIC MOISTURE WILL RESULT IN A WIDESPREAD
RAIN EVENT. MARGINAL ELEVATED INSTABILITY MAY ALSO YIELD A FEW
RUMBLES OF THUNDER AS WELL. BEST CHANCES FOR RAIN SHOWERS WILL
ENTER WESTERN PORTIONS OF SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS
LATE MONDAY NIGHT...AND SPREAD ACROSS THE REMAINDER OF THE REGION
ON TUESDAY. CLOUDS AND MIXING WILL KEEP TEMPERATURES UNSEASONABLY
WARM MONDAY NIGHT. TEMPERATURES TUESDAY WILL NOT RISE MUCH...AND
MAY ACTUALLY FALL INTO THE AFTERNOON IN THE WAKE OF THE FRONT.
ANY LINGERING SHOWERS WILL COME TO AN END TUESDAY EVENING ACROSS
WESTERN KENTUCKY. THE CORE OF HIGH PRESSURE WILL SLIDE ACROSS
THE GREAT LAKES REGION ON WEDNESDAY...AND INTO THE NORTHEAST ON
THURSDAY. THIS WILL RESULT IN A PERIOD OF DRY AND SEASONABLY COOL
WEATHER BOTH DAYS. MORNINGS WILL START OFF COLD...BUT MILD WEATHER
WILL TAKE HOLD BY AFTERNOON.
AS OPPOSED TO THE FIRST SYSTEM...FORECAST CONFIDENCE WITH THE LATE
WEEK SYSTEM IS SOMEWHAT LOWER. WHILE BOTH THE GFS AND ECMWF AGREE
ON AN INCREASED CHANCE FOR RAIN LATE IN THE WEEK...THE GFS
CONTINUES TO SIGNAL FRONTAL PASSAGE ABOUT 12 TO 18 HOURS SOONER
THAN THE ECMWF...ADMITTEDLY NOT TOO SHABBY...CONSIDERING THIS IS
DAY 7. FOR NOW...WILL USE A BLEND OF BOTH MODELS UNTIL SUCH TIME A
FRONTRUNNER EMERGES. LATE WEEK TEMPERATURES WILL WARM TO WELL
ABOVE NORMAL AHEAD OF THE APPROACHING FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1057 AM CST SAT DEC 1 2012
LIFT BECOMES A LITTLE GREATER FROM WEST TO EAST FROM SUNSET
ONWARD. LOOK FOR CEILINGS TO TRANSITION FROM VFR TO MVFR BETWEEN
06Z TO 09Z SUNDAY AT KCGI WITH THE THE POTENTIAL FOR 3SM TO 5SM
SHOWERS AND IFR CEILINGS /THUNDER POTENTIAL STILL BE ASSESSED AT
THIS TIME/ BETWEEN THE 09Z-15Z TIME AT KCGI. THIS SIMILAR CEILING
AND VISIBILITY SCENARIO WILL LIKELY BE OFFSET AT LEAST TWO HOURS
FORWARD IN TIME AT KPAH...KEVV...KOWB PERSISTING FOR THE REMAINDER
OF THE FORECAST PERIOD AT THESE SITE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...ML
LONG TERM....RJP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
323 PM EST SAT DEC 1 2012
.SYNOPSIS...
LOW PRESSURE MOVING EASTWARD THROUGH THE GREAT LAKES SUNDAY WILL
BRING SHOWERS TO THE UPPER OHIO VALLEY SUNDAY AFTERNOON AND NIGHT.
CONDITIONS WILL REMAIN SEASONABLY WARM UNTIL A STRONG COLD FRONT
MOVES THROUGH TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
BASED ON RECENT SURFACE AND SATELLITE DATA EXPECT NO MORE THAN
PARTLY CLOUDY SKIES EARLY TONIGHT. RECENT SREF MODEL OUTPUT WITH
DETAILS FROM RECENT NAM AND GFS...SHOW CLOUDS INCREASING LATE
TONIGHT AND SUNDAY ACROSS THE UPPER OHIO VALLEY.
BANDS OF SHOWERS...ASSOCIATED WITH EASTBOUND LOW PRESSURE THROUGH
THE GREAT LAKES...WILL MOVE EASTWARD THROUGH THE UPPER OHIO VALLEY
MAINLY SUNDAY AFTERNOON AND EVENING.
BASED ON BLEND OF RECENT RAP MODEL OUTPUT...AND NAM AND GFS
MOS...FORECASTED TEMPERATURES TO BE MUCH AS 15 DEGREES WARMER
THAN NORMAL TONIGHT AND UP TO 20 DEGREES WARMER THAN NORMAL
SUNDAY. PRE-SHOWER VERTICAL MIXING MAY PROMOTE WINDS TO GUST TO 30
MPH.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
BLEND OF SREF AND ECMWF MODEL OUTPUT SHOW HIGH PRESSURE WILL
FOLLOW TO PROVIDE A DRY BREAK MONDAY INTO EARLY TUESDAY.
A STRONG EASTBOUND COLD FRONT WILL BRING BANDS OF SHOWERS MAINLY
TUESDAY AFTERNOON AND EVENING.
BASED ON RECENT NAM GFS AND ECMWF MOS...FORECASTED TEMPERATURES TO
AS MUCH AS 20 DEGREES WARMER THAN NORMAL MONDAY AND TUESDAY.
POSTFRONTAL LOWS TUESDAY NIGHT WILL BE NO MORE THAN 5 DEGREES
ABOVE NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN THROUGH THE
LONG TERM PERIOD.
CAA IN NW FLOW ACROSS LAKE ERIE...COMBINED WITH AN UPPER LEVEL
TROUGH MOVING ACROSS THE EASTERN GREAT LAKES...COULD BRING A FEW
SNOW SHOWERS MAINLY TO AREAS NORTH OF PITTSBURGH WEDNESDAY. HIGH
PRESSURE BUILDING IN BY LATE WEDNESDAY INTO THURSDAY SHOULD BRING AN
END TO ANY SNOW SHOWER ACTIVITY.
ANOTHER COLD FRONT IS EXPECTED TO MOVE SLOWLY EAST ACROSS THE AREA
FRIDAY INTO FRIDAY NIGHT...BRINGING ANOTHER CHANCE OF RAIN SHOWERS.
TEMPERATURES SHOULD AVERAGE NEAR OR A LITTLE ABOVE NORMAL THROUGH
THE PERIOD.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WITH PATCHY STRATOCU AND HIGH CLOUDS ARE EXPECTED
THROUGH TONIGHT. LOW LEVEL WINDS INCREASE OVERNIGHT INTO SUNDAY
MORNING...WITH THE BEST CHANCE OF SEEING LLWS ACROSS FKL AND DUJ
IN THE NORTH. LLWS CHANCES APPEAR MORE MARGINAL FOR OTHER SITES
AND KEPT OUT OF THE TAFS FOR NOW. EXPECT SFC WND GUSTS OF AROUND
20KT FROM THE SW AS MIXING BEGINS AFTER SUNRISE SUNDAY MORNING.
MVFR FLIGHT CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON AND NIGHT WITH
BANDS OF SHOWERS ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD
THROUGH THE GREAT LAKES.
.OUTLOOK.../MONDAY THROUGH THURSDAY/...
VFR WILL BE PREVALENT MONDAY INTO MIDDAY TUESDAY DUE TO PASSING
HIGH PRESSURE. RESTRICTIONS WILL BE POSSIBLE LATE TUESDAY INTO
WEDNESDAY DUE TO A STRONG COLD FRONT AND ENSUING LAKE-EFFECT AND
COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS NORTH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING SHOWERS SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT SURFACE AND SATELLITE DATA SHOW SCATTERED CUMULUS AND BANDS
OF NUMEROUS CIRRUS CLOUDS WILL CONTINUE TO MOVE SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY THIS AFTERNOON. CLOUDS APPEAR RATHER
THIN...SO EXPECT PARTLY TO MOSTLY SUNNY CONDITIONS THIS AFTERNOON.
SOUTHWEST SURFACE WINDS...IN THE WAKE OF OFFSHORE HIGH PRESSURE...CONTINUE
TO BRING WARMER AIR...SO HAVE RAISED TEMPERATURES THIS AFTERNOON
BY A COUPLE DEGREES WITH HIGHS AS MUCH AS 15 DEGREES WARMER THAN
NORMAL PER RECENT RAP MODEL OUTPUT AND GFS LAMP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON.
WITH VERY LITTLE UPPER LEVEL SUPPORT ACCOMPANYING THE
BOUNDARY...IT WILL HAVE A DIFFICULT TIME MAKING MUCH SOUTHWARD
PROGRESS. BY LATE SUNDAY AFTERNOON...IT BECOMES DIFFICULT TO FIND
THE SFC BOUNDARY AS IT LOSES MUCH OF IT DEFINITION.
MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING THROUGH
SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER WEAK
SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA MOST
LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO THE
POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED.
THERE WILL BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD
WEATHER WILL CONTINUE INTO MONDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WITH PATCHY STRATOCU AND HIGH CLOUDS ARE EXPECTED
THROUGH TONIGHT. LOW LEVEL WINDS INCREASE OVERNIGHT INTO SUNDAY
MORNING...WITH THE BEST CHANCE OF SEEING LLWS ACROSS FKL AND DUJ
IN THE NORTH. LLWS CHANCES APPEAR MORE MARGINAL FOR OTHER SITES
AND KEPT OUT OF THE TAFS FOR NOW. EXPECT SFC WND GUSTS OF AROUND
20KT FROM THE SW AS MIXING BEGINS AFTER SUNRISE SUNDAY MORNING.
.OUTLOOK.../SUNDAY THROUGH WEDNESDAY/...
MVFR CONDITIONS ARE POSSIBLE SUNDAY AFTERNOON AND EVENING AS A
WEAK DISTURBANCE MOVES ACROSS THE AREA. RESTRICTIONS ARE POSSIBLE
AGAIN LATE TUESDAY INTO WEDNESDAY AS A COLD FRONT MOVES ACROSS THE
AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1153 AM EST SAT DEC 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE INTO EARLY SUNDAY. A WEAK COLD FRONT
WILL BRING SHOWERS SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT SURFACE AND SATELLITE DATA SHOW SCATTERED CUMULUS AND BANDS
OF NUMEROUS CIRRUS CLOUDS WILL CONTINUE TO MOVE SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY THIS AFTERNOON. CLOUDS APPEAR RATHER
THIN...SO EXPECT PARTLY TO MOSTLY SUNNY CONDITIONS THIS AFTERNOON.
SOUTHWEST SURFACE WINDS...IN THE WAKE OF OFFSHORE HIGH PRESSURE...CONTINUE
TO BRING WARMER AIR...SO HAVE RAISED TEMPERATURES THIS AFTERNOON
BY A COUPLE DEGREES WITH HIGHS AS MUCH AS 15 DEGREES WARMER THAN
NORMAL PER RECENT RAP MODEL OUTPUT AND GFS LAMP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL FLOW BECOMES ZONAL TONIGHT...AHEAD OF A SHORTWAVE
TROUGH THAT WILL MOVE THROUGH THE UPPER MIDWEST. THIS WAVE WILL
BRING AN INCREASE IN CLOUD COVER LATE TONIGHT. FOLLOWING ON THE
HEELS OF THE SHORTWAVE IS A WEAK COLD FRONT WHICH WILL SLOWLY MOVE
THROUGH THE GREAT LAKES SUNDAY AFTERNOON.
WITH VERY LITTLE UPPER LEVEL SUPPORT ACCOMPANYING THE
BOUNDARY...IT WILL HAVE A DIFFICULT TIME MAKING MUCH SOUTHWARD
PROGRESS. BY LATE SUNDAY AFTERNOON...IT BECOMES DIFFICULT TO FIND
THE SFC BOUNDARY AS IT LOSES MUCH OF IT DEFINITION.
MODELS CONTINUE TO SHOW AN AREA OF SHOWERS MOVING THROUGH
SUNDAY...BUT THIS APPEARS TO BE MORE RELATED TO ANOTHER WEAK
SHORTWAVE SWINGING THROUGH LATE SUNDAY. WOULD THINK THE AREA MOST
LIKELY TO SEE RAIN SUNDAY WOULD BE ACROSS THE NORTH...DUE TO THE
POSITIONING OF THE VORT MAX. THERE WILL BE PLENTY OF CLOUD ON
SUNDAY...BUT MOST OF THE SHOWERS WOULD BE SCATTERED.
THERE WILL BE LITTLE IF ANY CHANGE IN AIR MASS...SO THE MILD
WEATHER WILL CONTINUE INTO MONDAY.
UPPER LEVEL RIDGE BUILDS BACK IN ON MONDAY...MEANING ANOTHER DRY
AND MILD DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS WERE IN GENERAL AGREEMENT ON THE OVERALL PATTERN DURING THE
LONG TERM PERIOD...BUT VARY ON TIMING. PREFERRED THE NAEFS SOLUTION
WHICH WAS SLOWER THAN THE GFS BUT SLIGHTLY FASTER THAN THE ECMWF.
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TUESDAY INTO TUESDAY
NIGHT BRINGING A FEW SHOWERS. COLDER AIR MOVING IN BEHIND THE FRONT
ON WEDNESDAY...COMBINED WITH AN UPPER LEVEL TROF MOVING ACROSS THE
GREAT LAKES...COULD BRING A FEW SNOW SHOWERS TO THE FAR NORTHERN
COUNTIES DURING THE DAY...HOWEVER HIGH PRESSURE SHOULD QUICKLY BUILD
IN ENDING ANY PRECIP.
EXPECT TEMPS WEDNESDAY TO SLOWLY FALL OFF DURING THE LATE MORNING
AND AFTERNOON AS WELL WITH THE CAA. TEMPS SHOULD INCREASE TO ABOVE
NORMAL LEVELS AGAIN BY LATE IN THE WEEK.
ANOTHER COLD FRONT APPROACHES FROM THE WEST FRIDAY AFTERNOON.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AN AREA OF MID AND HIGH CLOUDS IN ASSOCIATION WITH A PASSING MID-
LEVEL SYSTEM WILL MOVE THROUGH THE AREA. OTHERWISE...RAGGED HIGH
CLOUDS WILL BE COMMON ACROSS THE REGION...AND WINDS GIVE A WEAK
SURFACE PATTERN WILL BE RATHER LIGHT. AS SUCH...GENERALLY VFR
CONDITIONS SHOULD PREVAIL AT ALL SITES THROUGH SATURDAY.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RESTRICTIONS WILL BE POSSIBLE SUNDAY AFTERNOON AND NIGHT...DUE TO
SHOWER FORMATION ALONG A WEAK EASTBOUND FRONT. A BETTER RESTRICTION
CHANCE WILL ACCOMPANY A STRONG COLD FRONT PASSAGE ON TUESDAY NIGHT...AND
WILL LIKELY PERSIST WITH COLD POOL CLOUDS AND SCATTERED SNOW SHOWERS
WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1100 AM CST SAT DEC 01 2012
.DISCUSSION.../ISSUED AT 1100 AM CST/
STRATUS AND PATCHY FOG UNDER A LAYER OF HIGHER CLOUDS IS RAPIDLY
CLEARING BEHIND THE FRONT ACROSS SOUTH CENTRAL SD AND THE JAMES
VALLEY AREA THIS MORNING. WITH THE FRONT ADVANCING QUICKLY EASTWARD
AND DECENT POST FRONTAL MIXING...IT SHOULD BE A VERY MILD DAY FOR
THE FIRST DAY OF METEOROLOGICAL WINTER. TEMPERATURES IN
CHAMBERLAIN...WINNER AND AINSWORTH ARE WELL INTO THE 50S
ALREADY...SO BOOSTED TEMPERATURES A FEW DEGREES IN SOUTH CENTRAL SD.
CLOUDS LINGERING A BIT LONGER IN OUR FAR EASTERN COUNTIES WILL HOLD
BACK TEMPERATURES CLOSER TO 50...OTHERWISE HIGHS ARE ON TRACK FOR
THE LOW 50S TO LOW 60S. UPDATED CLOUD COVERAGE TO MATCH THE FASTER
CLEARING IN THE WESTERN HALF.
&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
STRATUS AND PATCHY IFR FOG ACROSS NORTHWEST IOWA AND SOUTHWEST
MINNESOTA WILL CONTINUE TO LIFT FROM WEST TO EAST THROUGH THE NEXT
FEW HOURS AS FRONT SWEEPS THROUGH THE AREA AND DRIER CONDITIONS
FILTER IN BEHIND IT. SOUTH TO SOUTHWEST WINDS GENERALLY 10 KT OR
LESS WILL SWITCH TO THE WEST TO NORTHWEST BEHIND THE FRONT.
&&
.PREV DISCUSSION.../ISSUED AT 335 AM CST/
SEEING SOME PATCHY FOG THIS MORNING ACROSS PORTIONS THE CWA. ALSO
HAVE AN EXPANDING STRATUS DECK STREAMING NORTH OUT OF KANSAS. NAM
AND RAP SEEM TO HAVE BEST HANDLE ON THE SITUATION...AND BOTH SUGGEST
THIS STRATUS MOVES INTO OUR IOWA COUNTIES NEAR 12Z. THINKING OUR
SOUTH DAKOTA COUNTIES AND MOST OF OUR MINNESOTA AREA SHOULD STAY
STRATUS FREE...ALTHOUGH WILL HAVE TO MONITOR TRENDS THIS MORNING.
HIGH TEMPERATURES A BIT TRICKY GIVEN THE STRATUS AND MID CLOUD DECK.
THINK MID CLOUD DECK CLEARS THIS AFTERNOON GIVING WAY TO MOSTLY
SUNNY SKIES. IF THE STRATUS MOVES IN...IT WILL LIKELY BE SLOW TO
ERODE AS THE COLD FRONT WASHES OUT ACROSS NORTHWEST IOWA AND THE
FLOW BECOMES WEAK. GENERALLY WENT ON THE WARMER SIDE OF GUIDANCE
WITH HIGHS IN THE 50S MOST PLACES...HOWEVER LOW CONFIDENCE ACROSS
NORTHWEST IOWA...WHERE HIGHS COULD BE SEVERAL DEGREES COOLER IF
STRATUS MOVES IN AND HANGS AROUND. WENT BELOW GUIDANCE FOR LOWS
TONIGHT WITH CLEAR SKIES AND GENERALLY LIGHT WINDS EXPECTED...TEMPS
SHOULD GET DOWN INTO THE MID AND UPPER 20S.
SUNDAY STILL LOOKS TO FEATURE WELL ABOVE NORMAL TEMPERATURES. COULD
BE SOME PATCHY MORNING FOG...HOWEVER THAT SHOULD QUICKLY GIVE WAY TO
MOSTLY SUNNY SKIES...WITH EVEN THE CIRRUS POTENTIAL LOOKING LOW.
WILL HAVE TO MIX OUT A STRONG MORNING INVERSION...AND ALTHOUGH WOULD
PREFER TO HAVE A BIT MORE WESTERLY COMPONENT TO THE WIND...A DECENT
SOUTHERLY BREEZE SHOULD HELP SOME WITH MIXING. THE NAM AND GEM
REGIONAL TEMPERATURE GUIDANCE SEEMS TO PERFORM BEST ON THESE WARM
DAYS...THUS WENT CLOSE TO THEM...GIVING MID AND UPPER 50S SOUTHWEST
MINNESOTA...TO THE MID 60S ALONG THE MISSOURI RIVER. SUNDAY NIGHT
WILL BE A MILD ONE...WITH A 40 TO 50 KT JET AT 900 MB KEEPING US
MIXED AND BREEZY THROUGH THE NIGHT. LOWS MOST PLACES WILL PROBABLY
REMAIN IN THE LOWER 40S.
A STRONGER COLD FRONT WILL PUSH ACROSS ON MONDAY. ANOTHER BATCH OF
LOW STRATUS AND FOG SHOULD ADVECT IN AHEAD OF THIS BOUNDARY MONDAY
MORNING EAST OF INTERSTATE 29. HOWEVER THE STRONG NORTHWEST PUSH
BEHIND THE FRONT SHOULD BRING MOSTLY SUNNY SKIES BY AFTERNOON. LOOKS
LIKE A DRY FRONTAL PASSAGE...WITH THE BEST DYNAMICS REMAINING TO OUR
NORTH. NOT THAT MUCH OF A COLD PUSH BEHIND THE FRONT...AND WITH GOOD
MIXING EXPECTED...HIGHS SHOULD NOT HAVE A PROBLEM RISING INTO THE
MID 50S MOST SPOTS. MODELS HAVE TRENDED WEAKER AND FURTHER NORTH
WITH THIS SYSTEM...AND THUS THE WINDS HAVE ALSO TRENDED DOWN A BIT.
ALTHOUGH STILL SHOULD BE A WINDY AFTERNOON...WITH NORTHWEST GUSTS UP
TO 40 MPH.
A MAINLY ZONAL FLOW CONTINUES INTO THE EXTENDED. COLD SHOT ON
TUESDAY CONTINUES TO LOOK WEAKER...WITH JUST ABOUT ALL THE COLD AIR
STAYING TO OUR NORTH. THUS HIGHS SHOULD REMAIN ABOVE NORMAL...40S
NORTH TO MID 50S SOUTH. RETURN SOUTHERLY FLOW ON WEDNESDAY BRINGS
THE WARMER LOW LEVEL TEMPERATURE PROFILES BACK INTO THE AREA.
HOWEVER THERE ARE SOME CLOUD COVER CONCERNS...AND IN FACT THE ECMWF
IS SHOWING A WAVE AND MAYBE EVEN A FEW SHOWERS. WILL LEAVE THE
FORECAST DRY WITH LIMITED MOISTURE IN THE LOW LEVELS...BUT CLOUDS
WILL PROBABLY KEEP TEMPERATURES FROM REACHING THEIR FULL
POTENTIAL...THUS WILL LEAVE CONSENSUS VALUES IN FOR NOW. NEXT COLD
FRONT WILL PUSH ACROSS WEDNESDAY NIGHT INTO THURSDAY. HOWEVER THIS
FRONT IS ALSO TRENDING WEAKER AND FURTHER NORTH. KEPT SOME POPS IN
THURSDAY AND THURSDAY NIGHT FOR CONTINUITY. HOWEVER THE ECMWF AND
GEM ARE NOW DRY AND THE GFS ENSEMBLE PROBABILITIES ARE VERY LOW.
THUS WOULD NOT BE SURPRISED IF FUTURE SHIFTS END UP TRIMMING BACK
POPS EVEN MORE. SHOULD TURN COOLER ON FRIDAY BEHIND THE FRONT...BUT
AGAIN NOT AS COLD AS IT ONCE LOOKED...WITH THE BRUNT OF THE COLD
AIRMASS PROBABLY STAYING TO OUR NORTH. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1216 PM CST SAT DEC 1 2012
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 905 AM CST SAT DEC 1 2012/
.UPDATE...
UPDATED TO ADD SLIGHT CHANCE OF SPRINKLES ACROSS THE WEST
DISCUSSION...
A FEW MINOR CHANGES TO THE FORECAST THIS MORNING. FIRST A FEW
LIGHT RAIN SHOWERS ARE BEGINNING TO POP UP ON LZK RADAR. THIS
ACTIVITY IS BEING PICKED UP FROM THE RUC MODEL...AND FORECASTED TO
MOVE INTO THE WESTERN MIDSOUTH COUNTIES IN THE NEXT HOUR OR TWO.
SO HAVE PLACED A SLIGHT CHANCE OF SPRINKLES IN THIS REGION THROUGH
LATE AFTERNOON. ALSO ADJUSTED CLOUD COVER OVER THE EAST AND
SOUTHEAST COUNTIES FOR THE DAY WHERE IT APPEARS MOSTLY SUNNY
SKIES WILL PREVAIL. LAST...MADE SLIGHT INCREASES IN WIND SPEEDS
AND POTENTIAL GUSTS DURING THE MIDDAY HOURS TO AREAS WEST OF A
DYERSBURG TENNESSEE TO CHARLESTON MISSISSIPPI LINE.
JAB
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SAT DEC 1 2012/
DISCUSSION...
UPDATED AVIATION DISCUSSION FOR 12Z TAFS.
PREV DISCUSSION... /ISSUED 349 AM CST SAT DEC 1 2012/
DISCUSSION...
MILD WEATHER FOR EARLY DECEMBER TO PREVAIL THROUGH MONDAY...
COURTESY OF DEEP SOUTHERLY LOW LEVEL FLOW AND LOW AMPLITUDE
RIDGING ALOFT.
AN OPEN UPPER LEVEL TROF WILL APPROACH THE MIDSOUTH FROM THE
SOUTHERN PLAINS MONDAY NIGHT. AN ASSOCIATED SURFACE COLD FRONT
WILL MOVE INTO THE MIDSOUTH DURING THE DAY TUESDAY... TRACKING
EASTWARD WITH THE MID LEVEL TROF PASSAGE. SURFACE HIGH PRESSURE OF
PACIFIC ORIGIN WILL ENTER THE MIDSOUTH LATE TUESDAY...WHILE AN
ARCTIC SURFACE HIGH TRACKS EASTWARD THROUGH THE NORTHERN GREAT
LAKES.
RAINFALL SHOULD END OVER THE MIDSOUTH LATE TUESDAY INTO TUESDAY
EVENING. FAIR WEATHER IS FORECAST FOR THE MIDWEEK PERIODS...WITH
AFTERNOON MAX TEMPS LOWER...BUT STILL WELL ABOVE NORMAL. LOW
DEWPOINTS WILL RESULT IN WIDE DIURNAL TEMPERATURE RANGES WEDNESDAY
AND THURSDAY.
GFS AND ECMWF MODELS BRING A ANOTHER OPEN MID LATITUDE TROF AND
ASSOCIATED PACIFIC SURFACE COLD FRONT ACROSS THE PLAINS AND LOWER
MS RIVER VALLEY LATE NEXT WEEK. HOWEVER... SIGNIFICANT TIMING
DIFFERENCES WERE SHOWN ON THE 00Z/01 RUNS. THE ECMWF HAS SHOWN
GREATER RUN TO RUN CONSISTENCY AND ITS SLOWER TIMING WAS FAVORED
FOR THE MORNING FORECAST PACKAGE. AS SUCH...LOW LEVEL MOISTURE
SHOULD INCREASE FRIDAY...ACCOMPANIED BY MILD TEMPERATURES. A
PACIFIC COLD FRONTAL PASSAGE SHOULD FOLLOW FRIDAY NIGHT INTO EARLY
SATURDAY.
PWB
&&
.AVIATION...
18Z TAF CYCLE
BIGGEST CONSIDERATION THIS AFTERNOON ARE WIND GUSTS IN THE
NORTHWEST PART OF THE CWA. EXPECT LOW CEILINGS TMR MORNING.
WER
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 58 72 60 / 0 10 10 0
MKL 69 54 70 57 / 0 10 10 0
JBR 67 55 70 57 / 20 10 10 10
TUP 69 51 71 55 / 0 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
350 PM CDT SAT DEC 1 2012
.VERY SHORT TERM...TONIGHT AND SUNDAY.
AREA OF STRONG ISENTROPIC LIFT IN SOUTHWEST WI AT 18Z IS SHIFTING
ENE THIS AFTERNOON. THE NAM 290K PRESSURE ADVECTION PLOT SHOWS THIS
AREA WELL...AND BRINGS IT TO MILWAUKEE AROUND 22Z. THIS AREA IS ALSO
DEPICTED ON RADAR BY AN AREA OF SHOWERS OVER CENTRAL PORTIONS OF THE
FORECAST AREA EARLY THIS AFTERNOON. THEY ARE SPREADING EAST QUICKLY.
IT IS POSSIBLE THAT THE FEW HIGHER RETURNS ON THE RADAR HAVE SOME
THUNDER...AS RAP AND NAM SOUNDINGS SHOW WEAK ELEVATED CAPE ABOVE
5000 FEET.
THE ISENTROPIC LIFT COINCIDES WITH WEAK VORTICITY ADVECTION
ASSOCIATED WITH A MID LEVEL SHORTWAVE...850/700MB MOISTURE
CONVERGENCE...AND WEAK UPPER DIVERGENCE TO SUPPORT LIGHT RAIN LATE
THIS AFTERNOON THROUGH THE FIRST HALF OF THE EVENING...ESPECIALLY IN
SOUTHEAST WI. THEN THE MOISTURE AND PRESSURE ADVECTION WILL LINGER
ACROSS THE SOUTHEAST HALF OF WI THROUGH AROUND MIDNIGHT...UNTIL THE
NEXT WEAK 500MB SHORTWAVE SWEEPS THROUGH AND KICKS OUT THE SURFACE
TROUGH.
RAIN SHOWERS SHOULD KEEP REGENERATING THROUGH THE EVENING IN THE
SOUTHEAST...BUT THERE IS A GOOD CHANCE THAT THE RAIN WEST OF MADISON
IS DONE AND ONLY DRIZZLE AND FOG WILL BE THE CONCERN THE REST OF THE
EVENING.
THERE IS SOME CONCERN FOR DENSE FOG TO DEVELOP THIS EVENING IN SOUTH
CENTRAL WI WHILE WAITING FOR THAT NEXT SHORTWAVE...AND ALSO LATE
TONIGHT JUST BEHIND THE SURFACE TROUGH...ESPECIALLY AROUND SUNRISE
TIME. FAR SOUTHEAST WI WILL HAVE THE LIMITING FACTOR OF BRISK WEST
WINDS JUST ABOVE THE SURFACE. THE WESTERN FORECAST AREA INCLUDING
MADISON LOOKS LIKE IT HAS THE BEST CHANCE OF DENSE FOG OVERNIGHT.
NOT QUITE CONFIDENT ENOUGH AT THIS TIME TO ISSUE ANY HEADLINES
THOUGH.
DEWPOINT TEMPS SHOULD ONLY DROP A COUPLE OF DEGREES BEHIND THIS COLD
FRONT BY SUNDAY MORNING. DRIER AIR WILL MOVE IN ALOFT WITH MID LEVEL
RIDGING. EXPECTING SUNSHINE TO BEGIN SPREADING INTO SOUTHERN WI BY
MID SUNDAY MORNING AND ACROSS THE WHOLE AREA BY SUNDAY AFTERNOON.
THIS SHOULD ALLOW HIGHS TO CREEP INTO THE UPPER 50S FAR SOUTH.
.SHORT TERM...SUNDAY NIGHT THROUGH TUESDAY.
WEAK FRONTAL BOUNDARY EXPECTED TO SLOG THROUGH SOUTHERN WI LATER
TONIGHT AND SUNDAY AND WILL BECOME NEARLY STATIONARY ACROSS
NORTHERN/CENTRAL IL BY SUNDAY EVENING. INCREASING SOUTHERLY LOW
LEVEL WINDS LATER SUNDAY NIGHT AND MONDAY WILL CARRY WARM FRONT
RAPIDLY NORTHWARD. INITIALLY CLEAR SKIES...LIGHT WINDS AND DEWPTS IN
THE LOW TO MID 40S WILL ALLOW PATCHY FOG TO DEVELOP SUNDAY EVENING.
NOT EXPECTING VISIBILITIES TO GET TO LOW HOWEVER AS BOUNDARY LAYER
MIXING INCREASES AFTER MIDNIGHT.
QUITE A BIT OF CLOUDINESS EXPECTED ON MONDAY...EVEN AFTER WARM FRONT
PASSES TO THE NORTH. CLOUDS AND BREEZY SOUTH WINDS SHOULD KEEP
DAYTIME TEMPERATURES FROM GETTING TOO WARM...HOWEVER WITH 925H TEMPS
RISING TO AROUND 13C...WILL BE FLIRTING WITH RECORD HIGHS FOR 3 DEC.
RECORDS MOSTLY IN THE 60 TO 65 DEGREE RANGE.
PREFER SLOWER MOVEMENT OF SURFACE FRONT FROM MORE CONSISTENT ECMWF
AND NAM SOLUTIONS. HENCE MORE TIME FOR RETURN OF DEEPER COLUMN
MOISTURE AS PWAT VALUES RETURN TO AROUND THREE QUARTERS INCH. SHORT
TERM GUIDANCE IN AGREEMENT ON CARRYING LOW LEVEL FRONTOGENETICAL
FORCING ACROSS SRN WI DURING THE AFTN AND EARLY EVENING. HENCE WL
KEEP LIKELY POPS GOING AND ADD LIKELY WORDING TO EAST IN THE
EVENING. SOUNDINGS SHOWING SOME ELEVATED INSTABILITY...HOWEVER
ELEVATED CIN REMAINS AROUND OR HIGHER THAN 50 J/KG. WL HOLD OFF ON
INTRODUCING ISOLD T FOR NOW.
DRIER...COOLER AIR SWEEPS IN MONDAY NIGHT BUT COLDEST AIR REMAINS TO
THE NORTH. COLDEST AIR REMAINS TO THE NORTH...AND ONLY GLANCES
ACROSS SOUTHERN WI TUESDAY AFTERNOON AND EVE. LOW LEVELS REMAIN DRY
SO NO PRECIP EXPECTED WITH THIS SECONDARY CDFNT.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
SOUTHERN WI RECEIVES GLANCING BLOW FROM SURGE OF COLDER AIR
ASSOCIATED WITH SECONDARY FRONT TUESDAY NIGHT. LIGHT WINDS AND
COLDER AIR SHOULD RESULT IN TEMPS DROPPING TO AROUND SEASONAL
NORMALS TUESDAY NIGHT. THERMAL TROUGH QUICKLY PUSHES OFF TO THE EAST
ON WEDNESDAY AS LOW TO MID LEVEL RIDGING MOVES ACROSS THE REGION.
WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE ENERGY DEVELOPS ON
WEDNESDAY WITH STRONG LOW LEVEL WINDS AND INCREASING MOISTURE WED
NGT INTO THURSDAY. ENOUGH INCREASING COLUMN MOISTURE WITH PWAT
VALUES CLIMBING TO AROUND THREE QUARTERS INCH TO WARRANT SMALL POPS
FOR LIGHT PRECIP IN PARTS OF THE AREA WEDNESDAY NIGHT INTO THURSDAY
MORNING. LATEST DETERMINISTIC RUNS OF ECMWF AND GFS INCREASES
FORWARD SPEED OF PIECE OF SHORT WAVE ENERGY MOVING THROUGH THE
WESTERLIES. MAIN SYNOPTIC FORCING WITH THIS FEATURE NOW EXPECTED TO
AFFECT SRN WI ON THU/THU EVE...SO WL CONTINUE TO BUMP UP POPS ACROSS
THE CWA DURING THIS PERIOD.
PROGRESSIVE FLOW WILL CARRY THIS FEATURE TO THE EAST LATER THU NIGHT
AS COLDER...DRIER AIR SETTLES INTO THE REGION FOR FRIDAY. GEM...
ECMWF AND UKMT HINTING AT UPSTREAM RIDGING TAKING ON HIGHER
AMPLITUDE LATE IN THE WEEK WITH MORE W-NW FLOW CARRYING COLDER AIR
INTO THE REGION AND LINGERING THRU THE WEEKEND. ALTHOUGH LATEST
DETERMINISTIC GFS NOT AS COLD...GFS 5 DAY 500H ANOMOLIES CONTINUE TO
SHOW BROADSCALE TROFING SETTLING OVER THE UPPER MIDWEST BY THE
WEEKEND WITH NEGATIVE ANOMOLIES OF 75-100M OVER WI BY AROUND 00Z/12.
MAJORITY OF GFS ENSEMBLE MEMBERS AT MID-UPPER LEVELS ALSO FAVOR
COLDER SCENARIO. THIS WOULD RESULT IN MORE PERSISTENT SEASONAL TEMPS
FOR THE SECOND FULL WEEK OF DEC.
&&
.AVIATION /00Z TAFS/...
A WARM FRONT IS PUSHING THROUGH SOUTHERN WISCONSIN THIS AFTERNOON AS
LOW PRESSURE TRACKS ACROSS NORTHERN MINNESOTA TO JUST NORTH OF LAKE
SUPERIOR. LIGHT RAIN IS SPREADING ACROSS SOUTHERN WI WITH A SURGE OF
MOISTURE PUSHING INTO THE AREA. LIGHT RAIN SHOWERS SHOULD KEEP
REGENERATING IN SOUTHEAST WI...BUT ONLY EXPECTING DRIZZLE WEST OF
MADISON THE REST OF THE EVENING.
EXPECT LINGERING IFR/LIFR LOW CLOUDS...FOG AND DRIZZLE THROUGH MID
SUNDAY MORNING BEFORE THE DRIER AIR AND HIGH PRESSURE CAN TAKE OVER.
THERE IS A CHANCE FOR DENSE FOG FOR A PERIOD OF TIME LATE
TONIGHT/EARLY SUN MORNING JUST AFTER THE LOW PRESSURE TROUGH PASSES
THROUGH...ESPECIALLY NEAR MADISON AND WEST.
&&
.MARINE...
SOUTH WINDS SHOULD GUST TO AROUND 25 KNOTS THROUGH AROUND
MIDNIGHT...THEN DIMINISH AS THEY VEER TO THE WEST BEHIND A PASSING
COLD FRONT/SURFACE LOW PRESSURE TROUGH.
PERSISTENT SOUTH WINDS ARE BUILDING HIGH WAVES. SMALL CRAFT ADVISORY
IN EFFECT THROUGH 10Z TONIGHT. WAVES WILL SUBSIDE AFTER MIDNIGHT
WITH THE OFFSHORE DIMINISHING WINDS.
SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY BE MET ONCE AGAIN MONDAY
WITH SOUTH WINDS AHEAD OF A STRONGER LOW PRESSURE SYSTEM.
&&
.CONFIDENCE...
TONIGHT AND SUNDAY...LOW TO MEDIUM.
SUNDAY NIGHT...MEDIUM.
MONDAY AND MONDAY NIGHT...MEDIUM.
TUESDAY AND TUESDAY NIGHT...MEDIUM TO HIGH.
WEDNESDAY THROUGH THURSDAY...LOW TO MEDIUM.
FRIDAY AND SATURDAY...MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY LMZ643>646 TIL 10Z/02.
&&
$$
VERY SHORT TERM/AVIATION/MARINE...MRC
SHORT TERM/LONG TERM...MBK