Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/30/12
PREVIOUS FORECAST DISCUSSION IS BELOW...
AS OF 4 PM EST...FIRST BATCH OF SNOW MOVING THROUGH THE
ADIRONDACKS WITH THE FIRST BOUNDARY WITH THE MAIN EVENT YET TO
FOLLOW AS THE LEADING EDGE OF SNOW AHEAD OF THE CLIPPER SYSTEM
MOVING INTO WESTERN NEW YORK. THE WINTER WEATHER ADVISORY
CONTINUES FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY
UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS RANGING FROM 3
TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING SNOW AS WEST
TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO 25 MPH WILL BE
COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW SQUALLS LATER
THIS EVENING. THIS CLIPPER TYPE SYSTEM HAS SOME FAIRLY GOOD
DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND LATEST IR SAT
PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO COULD BE SOME
EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN ISOLATED CHC OF
SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE ONTARIO AS THE
SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE HIRESWRF MODEL
COMPOSITE REFLECTIVITY AND THE HRRR COL MAX REFLECTIVITY HAVE
REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS DURING THE LATE
EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE SNOW SQUALLS
BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED. LOWS TONIGHT ARE
EXPECTED TO RANGE FROM THE MID TO UPPER TEENS NORTHWEST TO UPPER
20S SOUTHEAST.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KGFL/KALB/KPOU TAF SITES
THROUGH THE TAF PERIOD ENDING AT 00Z TUESDAY. HOWEVER...AS ANOTHER
FRONTAL BOUNDARY CROSSES THE REGION DURING THE NITE...THERE IS THE
POTENTIAL FOR MVFR/IFR CONDITIONS IN SNOW SHOWERS BEFORE/DURING AND
AFTER FORNTAL PASSAGE. THE CHANCES ARE BEST AT KGFL WHERE A PERIOD
OF MVFR CONDITIONS HAVE BEEN FORECAST BETWEEN 05Z AND 10Z...WITH A
TEMPO GROUP FOR IFR VSBYS IN SNOW SHOWERS BETWEEN 05Z AND 08Z. MUCH
LESS THREAT FOR MVFR/IFR CONDITIONS AT KALB...SO ONLY VCSH HAS BEEN
INCLUDED IN THE FORECAST. AT KPOU NO PCPN IS EXPECTED DURING THE TAF
PERIOD. AFTER ABOUT 10Z...VFR CONDITIONS WILL PREVAIL AT ALL THREE
TAF SITES AS GUSTY WESTERLY WINDS BRING COLDER AIR TO THE REGION AND
GNERALLY SCT/BKN CU/SC.
SURFACE WINDS WILL BE 10 KTS OR LESS FROM THE SOUTH OR SOUTHWEST
THIS EVENING AHEAD OF THE FRONTAL BOUNDARY. WINDS WILL SHOFT BETWEEN
05Z AND 07Z AT THE TAF SITES AND BECOME WESTERLY AT 10 TO 15 KTS
WITH GUSTS OF 15 TO 25 KTS BEHIND THE FRONT AND THROUGH MOST OF
MONDAY. BY LATE IN THE DAY ON MONDAY THE WINDS WILL DECREASE TO LESS
THAN 10 KTS.
CLOUDS WILL ALSO BEGIN TO INCREASE AGAIN LATE IN THE DAY AHEAD OF A
WARM FRONT.
OUTLOOK...
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/11
NEAR TERM...GJM/FRUGIS/11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...GJM
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS NEW YORK NY
710 PM EST SUN JAN 29 2012
.SYNOPSIS...
A COLD FRONT PASSES THROUGH LATE TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF
THE AREA TUESDAY MORNING. A COLD FRONT APPROACHES THE AREA
WEDNESDAY AND THEN MOVES THROUGH WEDNESDAY NIGHT. HIGH PRESSURE
BUILDS IN BRIEFLY ON THURSDAY. UNSETTLED FOR THURSDAY NIGHT
THROUGH SUNDAY WITH POTENTIAL IMPACTS FROM SEVERAL STORM SYSTEMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MOSTLY CLEAR SKIES AROUND THE AREA WITH JUST SOME HIGH CLOUDINESS
IN SPOTS. THIS WILL GIVE WAY TO LOWERING AND THICKENING CLOUDS AS
A COLD FRONT APPROACHES TONIGHT. THE FRONT IS FORECAST TO MOVE
THROUGH AFTER MIDNIGHT.
OTHERWISE...INCREASING PRESSURE GRADIENT BETWEEN HIGH OFFSHORE
AND LOW APPROACHING FROM GREAT LAKES. POTENT SHORTWAVE ALOFT WITH
500 MB VORT MAX AXIS MOVING THROUGH THE REGION LATE THIS EVENING
AND THEN EXITING TO THE EAST LATER OVERNIGHT. LOW LEVEL JET
INCREASES QUITE A BIT WITH 925 MB WINDS OF 40 TO 45 KT MOVING
ACROSS JUST AHEAD OF THE FRONT WITH BEST MIXING OVER THE WATER.
MAX WINDS LOOK TO BE GENERALLY 4Z TO 8Z...WITH WIND GUSTS MOSTLY
NEAR 30 MPH OVER LAND.
CONCERNING POPS...THE FORCING FROM THE SHORTWAVE ALONE KEEPS THE
FORECAST AT CHANCE...BUT NOT ANY HIGHER CONSIDERING THE DRY LOW
LEVELS AND MODEL SOLUTIONS. THE LARGE LIFTED INDEX TENDENCY AND
STEEPER LAPSE RATES IN THE LOWER LEVELS GO INTO THE FORCING
FACTORS. PRECIP TYPE WILL BE MAINLY SNOW SHOWERS NORTH AND WEST
OF NEW YORK CITY AND RAIN SHOWERS MIXING WITH SNOW SHOWERS FOR THE
REMAINDER OF THE AREA. THERE IS A CHANCE SNOW SHOWERS COULD BE
LOCALLY MODERATE TO HEAVY IN THE FORM OF SNOW SQUALLS BUT WILL BE
QUITE BRIEF IN DURATION. THIS IS MAINLY ACROSS THE COLDER
LOCATIONS IN LOWER HUDSON VALLEY...INTERIOR NORTHEAST NEW JERSEY
AND INTERIOR SOUTHWEST CONNECTICUT. JUST HAVE A FEW TENTHS OF AN
INCH OF SNOW IN NORTHERN ORANGE WHERE CONFIDENCE IS A BIT HIGHER
WITH SNOWFALL BUT IN THOSE OTHER LOCATIONS MENTIONED
PREVIOUSLY...COULD ALSO HAVE A QUICK COATING OF SNOW. MESOSCALE
MODELS OF NSSL WRF AND HRRR DEPICT A DETERIORATING LINE OF
REFLECTIVITY REPRESENTING THE SHOWERS APPROACHING LATER THIS
EVENING AND MOVING THROUGH BETWEEN 4 AND 8Z. AGAIN...THIS IS A
QUICK DURATION AND THINKING THAT IF TURNS OUT THIS LINE OF SHOWERS
IS LONGER LIVED AND STRONGER MORE PLACES COULD GET A QUICK COATING
OF SNOW...MAINLY ON THE GRASSY SURFACES WITH SOME QUICK 1 INCH
SNOW AMOUNTS MAINLY ON HIGHER ELEVATIONS. HOWEVER...CONFIDENCE IS
NOT THAT HIGH WITH MODEL POPS BEING SO LOW.
MODEL QPF FIELDS ARE VERY LOW THOUGH ON THE ORDER OF JUST A FEW
HUNDREDTHS OF AN INCH AND AGAIN DRY LOW LEVELS WILL ACT TO
DIMINISH THE PRECIP COMING IN FROM THE WEST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
WINDS WILL BE DECREASING AS THE LOW PUSHES TO THE EAST OFFSHORE AND
SOUTH OF NOVA SCOTIA ON MONDAY. DRIER AIR MOVES INTO PLACE AS HIGH
PRESSURE FROM THE SOUTH WILL BE BUILDING IN WITH SOME RIDGING.
HOWEVER...COLDER 850 TEMPS DOWN TO -9 TO -13 C LEAD TO A GREATER
WEIGHT OF THE COLDER MET GUIDANCE FOR HIGH TEMPS. IN
ADDITION...LESS VERTICAL MIXING IS EXPECTED THAN TODAY WITH MIXING
UP TO A LITTLE ABOVE 850 HPA. FLOW ALOFT BECOMES QUASI-ZONAL.
MONDAY NIGHT...AN APPROACHING WARM FRONT FROM THE WEST WILL MOVE
INTO THE AREA. MOST PRECIP WILL BE IN THE FORM OF SNOW SHOWERS
MOSTLY IN THE NORTHERN ZONES. QPF AGAIN IS ONLY ON THE ORDER OF A
FEW HUNDREDTHS OF AN INCH AND FORCING IS EVEN WEAKER THAN FORCING
TONIGHT. THEREFORE...JUST LEFT SLIGHT CHANCE POPS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WARM FRONT LIFTS NORTH OF THE AREA EARLY TUESDAY WITH UNSEASONABLY
MILD TEMPS EXPECTED FOR TUESDAY AND WEDNESDAY. CHANCE OF SHOWERS
BEGINNING LATE TUESDAY NIGHT AS A COLD FRONT APPROACHES...WITH THE
BEST CHANCE FOR RAIN ARRIVING WEDNESDAY AFTERNOON AHEAD OF THE
FRONT. COLD FRONT PASSAGE EXPECTED OVERNIGHT WEDNESDAY...WITH COOLER
BUT STILL ABOVE AVERAGE TEMPS ON THURSDAY.
AFTER THURSDAY...THE PICTURE BECOMES MUCH LESS CERTAIN WITH WIDE
DIVERGENCE IN MODEL SOLUTIONS CONTINUING. ECMWF HAS COME IN EVEN
QUICKER WITH ITS HANDLING OF A SURFACE LOW MOVING OUT OF THE OHIO
VALLEY...LATEST RUN MOVES THE LOW JUST SOUTH OF THE AREA THURSDAY
NIGHT AND DEEPENS IT EAST OF THE AREA ON FRIDAY. THIS SYSTEM IS
FOLLOWED BY A COLDER SYSTEM WITH SECONDARY COASTAL LOW DEVELOPMENT
STARTING LATE SUNDAY. THE CURRENT CANADIAN RUN MOVES A PRECIP SHIELD
INTO THE AREA ON SATURDAY AHEAD OF A SOUTHERN STREAM LOW OVER THE
MISSISSIPPI VALLEY AND DEVELOPING SECONDARY LOW. THE OPERATIONAL GFS
IS DRY OVER THE SAME PERIOD WITH SURFACE LOWS PASSING TO THE SOUTH
AND EAST OF THE AREA ON FRIDAY AND SUNDAY. KEPT HIGHEST POPS IN FOR
SATURDAY CLOSER TO PREVIOUS ECWMF RUNS AND AS A NOD TO THE CANADIAN
SOLUTION. THIS IS EMPHATICALLY A LOW CONFIDENCE FORECAST FOR THE
THURSDAY NIGHT THROUGH SUNDAY PERIOD.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAINLY VFR. STRONG COLD FRONT APPROACHES THROUGH EARLY THIS
EVENING. THE FRONT CROSSES THE TERMINALS FROM ABOUT 05Z THROUGH
10Z. HIGH PRESSURE BUILDS BEHIND THE FRONT MONDAY.
MAIN CONCERN WILL BE STRONG WINDSHIFT FROM SW TO W BEHIND FRONT
AND 2 TO 4 PERIOD OF 30 TO 35 KT GUSTS. THERE WILL ALSO BE
POTENTIAL FOR SCATTERED SNOW SHOWERS AND ISOLATED SNOW SQUALLS
WITH THE FRONT. BRIEF MVFR CONDS WITH ANY SNOW SHOWERS...AND IFR
OR LOWER IN HEAVIER SNOW SQUALL. BEST CHANCE WILL BE AT KSWF FROM
05Z TO 08Z.
GUSTY WESTERLY WINDS ON MONDAY...PRIMARILY LEFT OF 300 TRUE. SCT-
BKN VFR STRATO-CU FROM MID MORNING THROUGH LATE AFTERNOON.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
MONDAY NIGHT THROUGH TUESDAY...VFR.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
GALES EXPECTED TO DEVELOP BETWEEN 0Z AND 6Z MON ACROSS THE WATERS
AND THEN DIMINISH TOWARDS MONDAY MORNING AS LOW PRESSURE
APPROACHES FROM THE WEST. HIGHEST WINDS AND SEAS EXPECTED NEAR
AND SHORTLY AFTER MIDNIGHT WITH BEST LOW TO MID LEVEL FORCING NEAR
THAT TIME. SCA THEREAFTER LATER ON MONDAY AS LOW PULLS AWAY
OFFSHORE.
SCA LEVEL SEAS FOR THE ATLANTIC ZONES EXPECTED ON TUESDAY WITH
STRONG SOUTHERLY FLOW FOLLOWING WARM FRONTAL PASSAGE. SEAS MAY
BRIEFLY SUBSIDE BELOW SCA CRITERIA TUESDAY NIGHT INTO WEDNESDAY
BEFORE BUILDING BACK LATE WEDNESDAY AHEAD OF A COLD FRONT. ROUGH
SEAS CONTINUING WEDNESDAY NIGHT INTO THURSDAY MORNING FOLLOWING COLD
FRONT PASSAGE...BEFORE DIMINISHING LATE THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE GENERALLY LESS THAN A TENTH OF AN INCH ON AVERAGE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ330-335-338-340-345-
350-353-355.
&&
$$
SYNOPSIS...JM/MAS
NEAR TERM...JM/MAS
SHORT TERM...JM
LONG TERM...MAS
AVIATION...
MARINE...JM/MAS
HYDROLOGY...JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 PM EST SUN JAN 29 2012
.SYNOPSIS...
A FAST MOVING CLIPPER TYPE SYSTEM WILL BRING SOME SNOW TO A GOOD
PORTION OF OUR REGION TONIGHT WITH SOME GUSTY WINDS AND SNOW
SQUALLS ALSO POSSIBLE. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
INTO THE REGION ON MONDAY. THIS WILL BE FOLLOWED BY A WARM FRONT
WHICH WILL APPROACH OUR REGION FROM THE SOUTHWEST MONDAY NIGHT...
BRINGING ANOTHER ROUND OF SNOW TO OUR REGION MONDAY NIGHT INTO
TUESDAY MORNING.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 4 PM EST...FIRST BATCH OF SNOW MOVING THROUGH THE
ADIRONDACKS WITH THE FIRST BOUNDARY WITH THE MAIN EVENT YET TO
FOLLOW AS THE LEADING EDGE OF SNOW AHEAD OF THE CLIPPER SYSTEM
MOVING INTO WESTERN NEW YORK. THE WINTER WEATHER ADVISORY
CONTINUES FOR THE WESTERN ADIRONDACKS AND WESTERN MOHAWK VALLEY
UNTIL 10 AM MONDAY MORNING. EXPECT SNOWFALL AMOUNTS RANGING FROM 3
TO 8 INCHES IN THE ADVISORY AREA ALONG WITH BLOWING SNOW AS WEST
TO NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS UP TO 25 MPH WILL BE
COMMON WITH HIGHER GUSTS POSSIBLE WITH SOME SNOW SQUALLS LATER
THIS EVENING. THIS CLIPPER TYPE SYSTEM HAS SOME FAIRLY GOOD
DYNAMICS WITH IT INCLUDING A STRONG VORT AXIS AND LATEST IR SAT
PICS ARE INDICATING COOLING CLOUD TOPS. THERE ALSO COULD BE SOME
EMBEDDED SNOW SQUALLS THIS EVENING AND EVEN AN ISOLATED CHC OF
SOME THUNDER SNOW ESPECIALLY CLOSER TO LAKE ONTARIO AS THE
SHOWALTER INDICES BRIEFLY GET BELOW ZERO. BOTH THE HIRESWRF MODEL
COMPOSITE REFLECTIVITY AND THE HRRR COL MAX REFLECTIVITY HAVE
REFLECTIVITY VALUES INDICATIVE OF SNOW SQUALLS DURING THE LATE
EVENING TO AROUND MIDNIGHT TIME FRAME. IF THESE SNOW SQUALLS
BECOME MORE CERTAIN SPS WILL LIKELY BE ISSUED. LOWS TONIGHT ARE
EXPECTED TO RANGE FROM THE MID TO UPPER TEENS NORTHWEST TO UPPER
20S SOUTHEAST.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KGFL/KALB/KPOU TAF SITES
THROUGH THE TAF PERIOD ENDING AT 00Z TUESDAY. HOWEVER...AS ANOTHER
FRONTAL BOUNDARY CROSSES THE REGION DURING THE NITE...THERE IS THE
POTENTIAL FOR MVFR/IFR CONDITIONS IN SNOW SHOWERS BEFORE/DURING AND
AFTER FORNTAL PASSAGE. THE CHANCES ARE BEST AT KGFL WHERE A PERIOD
OF MVFR CONDITIONS HAVE BEEN FORECAST BETWEEN 05Z AND 10Z...WITH A
TEMPO GROUP FOR IFR VSBYS IN SNOW SHOWERS BETWEEN 05Z AND 08Z. MUCH
LESS THREAT FOR MVFR/IFR CONDITIONS AT KALB...SO ONLY VCSH HAS BEEN
INCLUDED IN THE FORECAST. AT KPOU NO PCPN IS EXPECTED DURING THE TAF
PERIOD. AFTER ABOUT 10Z...VFR CONDITIONS WILL PREVAIL AT ALL THREE
TAF SITES AS GUSTY WESTERLY WINDS BRING COLDER AIR TO THE REGION AND
GNERALLY SCT/BKN CU/SC.
SURFACE WINDS WILL BE 10 KTS OR LESS FROM THE SOUTH OR SOUTHWEST
THIS EVENING AHEAD OF THE FRONTAL BOUNDARY. WINDS WILL SHOFT BETWEEN
05Z AND 07Z AT THE TAF SITES AND BECOME WESTERLY AT 10 TO 15 KTS
WITH GUSTS OF 15 TO 25 KTS BEHIND THE FRONT AND THROUGH MOST OF
MONDAY. BY LATE IN THE DAY ON MONDAY THE WINDS WILL DECREASE TO LESS
THAN 10 KTS.
CLOUDS WILL ALSO BEGIN TO INCREASE AGAIN LATE IN THE DAY AHEAD OF A
WARM FRONT.
OUTLOOK...
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ032-033-
038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11
NEAR TERM...11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS NEW YORK NY
626 PM EST SUN JAN 29 2012
.SYNOPSIS...
A COLD FRONT PASSES THROUGH LATE TONIGHT. HIGH PRESSURE RETURNS ON
MONDAY. A WARM FRONT APPROACHES MONDAY NIGHT AND LIFTS NORTH OF
THE AREA TUESDAY MORNING. A COLD FRONT APPROACHES THE AREA
WEDNESDAY AND THEN MOVES THROUGH WEDNESDAY NIGHT. HIGH PRESSURE
BUILDS IN BRIEFLY ON THURSDAY. UNSETTLED FOR THURSDAY NIGHT
THROUGH SUNDAY WITH POTENTIAL IMPACTS FROM SEVERAL STORM SYSTEMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MOSTLY CLEAR SKIES AROUND THE AREA WITH JUST SOME HIGH CLOUDINESS
IN SPOTS. THIS WILL GIVE WAY TO LOWERING AND THICKENING CLOUDS AS
A COLD FRONT APPROACHES TONIGHT. THE FRONT IS FORECAST TO MOVE
THROUGH AFTER MIDNIGHT.
OTHERWISE...INCREASING PRESSURE GRADIENT BETWEEN HIGH OFFSHORE
AND LOW APPROACHING FROM GREAT LAKES. POTENT SHORTWAVE ALOFT WITH
500 MB VORT MAX AXIS MOVING THROUGH THE REGION LATE THIS EVENING
AND THEN EXITING TO THE EAST LATER OVERNIGHT. LOW LEVEL JET
INCREASES QUITE A BIT WITH 925 MB WINDS OF 40 TO 45 KT MOVING
ACROSS JUST AHEAD OF THE FRONT WITH BEST MIXING OVER THE WATER.
MAX WINDS LOOK TO BE GENERALLY 4Z TO 8Z...WITH WIND GUSTS MOSTLY
NEAR 30 MPH OVER LAND.
CONCERNING POPS...THE FORCING FROM THE SHORTWAVE ALONE KEEPS THE
FORECAST AT CHANCE...BUT NOT ANY HIGHER CONSIDERING THE DRY LOW
LEVELS AND MODEL SOLUTIONS. THE LARGE LIFTED INDEX TENDENCY AND
STEEPER LAPSE RATES IN THE LOWER LEVELS GO INTO THE FORCING
FACTORS. PRECIP TYPE WILL BE MAINLY SNOW SHOWERS NORTH AND WEST
OF NEW YORK CITY AND RAIN SHOWERS MIXING WITH SNOW SHOWERS FOR THE
REMAINDER OF THE AREA. THERE IS A CHANCE SNOW SHOWERS COULD BE
LOCALLY MODERATE TO HEAVY IN THE FORM OF SNOW SQUALLS BUT WILL BE
QUITE BRIEF IN DURATION. THIS IS MAINLY ACROSS THE COLDER
LOCATIONS IN LOWER HUDSON VALLEY...INTERIOR NORTHEAST NEW JERSEY
AND INTERIOR SOUTHWEST CONNECTICUT. JUST HAVE A FEW TENTHS OF AN
INCH OF SNOW IN NORTHERN ORANGE WHERE CONFIDENCE IS A BIT HIGHER
WITH SNOWFALL BUT IN THOSE OTHER LOCATIONS MENTIONED
PREVIOUSLY...COULD ALSO HAVE A QUICK COATING OF SNOW. MESOSCALE
MODELS OF NSSL WRF AND HRRR DEPICT A DETERIORATING LINE OF
REFLECTIVITY REPRESENTING THE SHOWERS APPROACHING LATER THIS
EVENING AND MOVING THROUGH BETWEEN 4 AND 8Z. AGAIN...THIS IS A
QUICK DURATION AND THINKING THAT IF TURNS OUT THIS LINE OF SHOWERS
IS LONGER LIVED AND STRONGER MORE PLACES COULD GET A QUICK COATING
OF SNOW...MAINLY ON THE GRASSY SURFACES WITH SOME QUICK 1 INCH
SNOW AMOUNTS MAINLY ON HIGHER ELEVATIONS. HOWEVER...CONFIDENCE IS
NOT THAT HIGH WITH MODEL POPS BEING SO LOW.
MODEL QPF FIELDS ARE VERY LOW THOUGH ON THE ORDER OF JUST A FEW
HUNDREDTHS OF AN INCH AND AGAIN DRY LOW LEVELS WILL ACT TO
DIMINISH THE PRECIP COMING IN FROM THE WEST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
WINDS WILL BE DECREASING AS THE LOW PUSHES TO THE EAST OFFSHORE AND
SOUTH OF NOVA SCOTIA ON MONDAY. DRIER AIR MOVES INTO PLACE AS HIGH
PRESSURE FROM THE SOUTH WILL BE BUILDING IN WITH SOME RIDGING.
HOWEVER...COLDER 850 TEMPS DOWN TO -9 TO -13 C LEAD TO A GREATER
WEIGHT OF THE COLDER MET GUIDANCE FOR HIGH TEMPS. IN
ADDITION...LESS VERTICAL MIXING IS EXPECTED THAN TODAY WITH MIXING
UP TO A LITTLE ABOVE 850 HPA. FLOW ALOFT BECOMES QUASI-ZONAL.
MONDAY NIGHT...AN APPROACHING WARM FRONT FROM THE WEST WILL MOVE
INTO THE AREA. MOST PRECIP WILL BE IN THE FORM OF SNOW SHOWERS
MOSTLY IN THE NORTHERN ZONES. QPF AGAIN IS ONLY ON THE ORDER OF A
FEW HUNDREDTHS OF AN INCH AND FORCING IS EVEN WEAKER THAN FORCING
TONIGHT. THEREFORE...JUST LEFT SLIGHT CHANCE POPS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WARM FRONT LIFTS NORTH OF THE AREA EARLY TUESDAY WITH UNSEASONABLY
MILD TEMPS EXPECTED FOR TUESDAY AND WEDNESDAY. CHANCE OF SHOWERS
BEGINNING LATE TUESDAY NIGHT AS A COLD FRONT APPROACHES...WITH THE
BEST CHANCE FOR RAIN ARRIVING WEDNESDAY AFTERNOON AHEAD OF THE
FRONT. COLD FRONT PASSAGE EXPECTED OVERNIGHT WEDNESDAY...WITH COOLER
BUT STILL ABOVE AVERAGE TEMPS ON THURSDAY.
AFTER THURSDAY...THE PICTURE BECOMES MUCH LESS CERTAIN WITH WIDE
DIVERGENCE IN MODEL SOLUTIONS CONTINUING. ECMWF HAS COME IN EVEN
QUICKER WITH ITS HANDLING OF A SURFACE LOW MOVING OUT OF THE OHIO
VALLEY...LATEST RUN MOVES THE LOW JUST SOUTH OF THE AREA THURSDAY
NIGHT AND DEEPENS IT EAST OF THE AREA ON FRIDAY. THIS SYSTEM IS
FOLLOWED BY A COLDER SYSTEM WITH SECONDARY COASTAL LOW DEVELOPMENT
STARTING LATE SUNDAY. THE CURRENT CANADIAN RUN MOVES A PRECIP SHIELD
INTO THE AREA ON SATURDAY AHEAD OF A SOUTHERN STREAM LOW OVER THE
MISSISSIPPI VALLEY AND DEVELOPING SECONDARY LOW. THE OPERATIONAL GFS
IS DRY OVER THE SAME PERIOD WITH SURFACE LOWS PASSING TO THE SOUTH
AND EAST OF THE AREA ON FRIDAY AND SUNDAY. KEPT HIGHEST POPS IN FOR
SATURDAY CLOSER TO PREVIOUS ECWMF RUNS AND AS A NOD TO THE CANADIAN
SOLUTION. THIS IS EMPHATICALLY A LOW CONFIDENCE FORECAST FOR THE
THURSDAY NIGHT THROUGH SUNDAY PERIOD.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE TO THE EAST WEAKENS AS A COLD FRONT
APPROACHES THROUGH EARLY THIS EVENING. THE FRONT CROSSES THE
TERMINALS FROM ABOUT 05Z THROUGH 10Z. HIGH PRESSURE BUILDS BEHIND
THE FRONT MONDAY.
VFR THROUGH THE TAF PERIOD. MAINLY DRY...HOWEVER THERE IS A CHANCE
OF SCATTERED SNOW SHOWERS WITH THE FRONT. BEST CHANCE WILL BE AT
KSWF WHERE LOW END VFR TO HIGH END MVFR CONDITIONS WILL BE POSSIBLE
FROM 05Z TO 08Z.
GUSTY SOUTHWESTERLY WINDS SHIFT BACK TO WEST WITH THE PASSAGE OF THE
FRONT...AND GUSTS INCREASE FOR A TIME...NEARING 30 KTS. SOME
UNCERTAINTY WITH THE TIMING OF THE WIND SHIFT AND MAY BE AN HOUR OR
SO EITHER SIDE OF THE FORECAST TIME.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
MONDAY THROUGH TUESDAY...VFR. GUSTY WESTERLY WINDS MONDAY.
WEDNESDAY...SUB-VFR POSSIBLE IN RAIN.
THURSDAY...VFR.
FRIDAY...LOW CHANCE OF SUB VFR.
&&
.MARINE...
GALES EXPECTED TO DEVELOP BETWEEN 0Z AND 6Z MON ACROSS THE WATERS
AND THEN DIMINISH TOWARDS MONDAY MORNING AS LOW PRESSURE
APPROACHES FROM THE WEST. HIGHEST WINDS AND SEAS EXPECTED NEAR
AND SHORTLY AFTER MIDNIGHT WITH BEST LOW TO MID LEVEL FORCING NEAR
THAT TIME. SCA THEREAFTER LATER ON MONDAY AS LOW PULLS AWAY
OFFSHORE.
SCA LEVEL SEAS FOR THE ATLANTIC ZONES EXPECTED ON TUESDAY WITH
STRONG SOUTHERLY FLOW FOLLOWING WARM FRONTAL PASSAGE. SEAS MAY
BRIEFLY SUBSIDE BELOW SCA CRITERIA TUESDAY NIGHT INTO WEDNESDAY
BEFORE BUILDING BACK LATE WEDNESDAY AHEAD OF A COLD FRONT. ROUGH
SEAS CONTINUING WEDNESDAY NIGHT INTO THURSDAY MORNING FOLLOWING COLD
FRONT PASSAGE...BEFORE DIMINISHING LATE THURSDAY AND FRIDAY.
&&
.HYDROLOGY...
ANY LIQUID EQUIVALENT PRECIPITATION THROUGH WEDNESDAY IS EXPECTED
TO BE GENERALLY LESS THAN A TENTH OF AN INCH ON AVERAGE.
&&
.EQUIPMENT...
THE WEATHER OBSERVATION FROM CENTRAL PARK WILL BE UNAVAILABLE
UNTIL FURTHER NOTICE. THIS IS DUE TO A SIGNIFICANT POWER
INTERRUPTION TO THE CENTRAL PARK AUTOMATED SURFACE OBSERVING
STATION /ASOS/ AND BACKUP STATION. UTILITY WORKERS ARE ADDRESSING
THE PROBLEM...BUT THERE IS CURRENTLY NO ESTIMATED TIME FOR RETURN
TO SERVICE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST MONDAY FOR ANZ330-335-338-340-345-
350-353-355.
&&
$$
SYNOPSIS...JM/MAS
NEAR TERM...JM/MAS
SHORT TERM...JM
LONG TERM...MAS
AVIATION...MET
MARINE...JM/MAS
HYDROLOGY...JM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
434 PM EST SAT JAN 28 2012
.SYNOPSIS...
A COLD FRONT ASSOCIATED WITH LOW PRESSURE MOVING ACROSS
SOUTHERN QUEBEC TONIGHT WILL BRING SOME SCATTERED SNOW SHOWERS AND
FLURRIES TO THE REGION. SOME LAKE EFFECT SNOW WILL IMPACT THE
WESTERN ADIRONDACKS IN THE WAKE OF THE FRONT UNTIL LATE TOMORROW
MORNING. ANOTHER CLIPPER APPROACHING FROM THE GREAT LAKES REGION
TOMORROW WILL BRING ANOTHER CHANCE OF SNOW SHOWERS AND FLURRIES
SUNDAY NIGHT....AS HIGH PRESSURE WILL BRIEFLY BUILD IN FOR PORTIONS
OF THE REGION ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 400 PM EST...THE WATER VAPOR LOOP THIS AFTERNOON CONTINUES
TO SHOW A SHORT-WAVE IN THE W/SW FLOW APPROACHING FROM THE GREAT
LAKES REGION AND LAKE ERIE. A FASTING MOVING SFC LOW OR A CLIPPER
ROTATING AROUND A CLOSED H500 CIRCULATION OVER HUDSONS BAY IS
MOVING ACROSS SE ONTARIO INTO SRN QUEBEC. THE COLD FRONT TO THE
CLIPPER HAS MOVED ACROSS OH AND MI AND IS MOVING INTO WRN NY AND
WRN PA. CLOUDS WILL CONTINUE TO THICKEN AND LOWER AHEAD OF THE
FRONT. THERE IS A BAND OF SNOW SHOWERS MOVING INTO THE TUG HILL
PLATEAU REGION...THAT WILL MOVE INTO THE WRN DACKS OVER THE NEXT
FEW HOURS. THE BEST LOW-LEVEL CONVERGENCE IS ALONG THE FRONTAL
BOUNDARY...AND MAINLY NORTH OF THE MOHAWK RIVER VALLEY. MOISTURE
WILL BE TAPPED FROM THE ERN GREAT LAKES WITH THE BEST MOISTURE
CONVERGENCE NORTHWEST OF THE CAPITAL REGION ALONG THE NOSE OF A
50-60 KT H850 LLJ. THE LATEST HRRR 3KM COLUMNAR MAX REF CONTINUES
TO SHOW A BROKEN BAND OF CELLS WITH SOME 30-40 DBZ ECHOES MOVE
ACROSS THE FCST AREA AHEAD OF THE FRONT BTWN 00Z-02Z. THERE COULD
BE SOME ISOLD SNOW SQUALLS THAT PUT OUT A BRIEF BURST OF SNOW.
WE KEPT THE HIGHEST POPS TO THE NORTH AND WEST OF THE CAPITAL
REGION...AND SLIGHT CHC TO LOW CHC FURTHER SOUTH AND EAST.
THE WINDS INCREASE IN THE WAKE OF THE FRONT FROM THE W/NW AT 15 TO
25 MPH WITH A FEW GUSTS IN THE 30-40 MPH RANGE...AND THE LAKE EFFECT
POTENTIAL INCREASES FOR THE WRN DACKS. THE NAM AND CAN REGIONAL
CONTINUE TO PRODUCE A QUARTER TO FOUR TENTHS OF AN INCH OF QPF
WITH A FAVORABLE 260 DEGREE LAKE TRAJECTORY IN THIS AREA. THE SFC-H850
WINDS ALIGN WELL FROM THE WEST WITH LITTLE DIRECTIONAL SHEAR. THE
INVERSION IS WELL ABOVE 10KFT AGL BASED ON NAM SOUNDING PROFILES
OVER NRN HERKIMER COUNTY...AND THEN SLOWLY LOWER TO ABOUT 7-8 KFT
AGL AROUND 12Z- 15Z. THE INSTABILITY CLASS OFF THE BUFKIT PROFILES
CONTINUES TO BE CONDITIONAL WITH MARGINAL DELTA T/S. WE PUT OUT A
LAKE EFFECT ADVISORY FOR NRN HERKIMER CTY FROM 00Z/SUN TO 15/SUN
FOR NRN HERKIMER CTY. THE LOCATIONS IMPACTED WILL GENERALLY BE
FROM THE RT 28/OLD FORGE CORRIDOR NORTHWARD WITH 3 TO 7 INCHES OF
ACCUMULATION. THERE COULD ALSO BE SOME BLOWING SNOW TONIGHT.
FURTHER EAST INTO HAMILTON COUNTY EXPECT 2 TO 5 INCHES OF SNOWFALL
WITH THE BAND EXTENSION IN QUESTION. ELSEWHERE FROM THE SCT SNOW
SHOWERS AND ISOLD SQUALLS...A COATING TO HALF AN INCH WILL BE
POSSIBLE. COLD ADVECTION OCCURS OVERNIGHT WITH H850 TEMPS FALLING
BACK TO -8C TO -12C. EXPECT LOWS TO BE A LITTLE COLDER TONIGHT
THAN LAST NIGHT WITH LOWS IN THE MID AND U20S IN THE VALLEYS...AND
UPPER TEENS AND LOWER 20S OVER THE MTNS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
TOMORROW...THE LAKE EFFECT BEGINS TO DIMINISH WITH THE LOWERING
INVERSION...AND THE LOW LEVEL FLOW BACKING TO THE SOUTH/SOUTHWEST
AHEAD OF THE NEXT DISTURBANCE APPROACHING FROM THE LOWER GREAT
LAKES REGION. HIGH PRESSURE WILL BRIEFLY RIDGE IN FROM THE SOUTH.
THE SHORT-WAVE IS A BIT STRONGER THAN THE ONE TONIGHT. THE STRONG
CYCLONIC VORTICITY ADVECTION COUPLED WITH STEEP LAPSE RATES MAY
FOCUS A ROBUST BAND OF SNOW SHOWERS APPROACHING FROM W-CNTRL NY
LATE IN THE AFTERNOON. WE INCREASED THE POPS PREDOMINANTLY WEST OF
THE HUDSON VALLEY IN THE MID TO LATE AFTERNOON WITH SLIGHT CHC TO
CHC VALUES...EXCEPT LIKELY AND CATEGORICAL VALUES OVER THE WRN
MOHAWK VALLEY...AND SRN DACKS. WE WENT CLOSE TO GFSMOS MAX TEMPS
WITH HIGHS IN THE U30S TO L40S IN THE VALLEYS /A FEW M40S IN THE
MID HUDSON VALLEY/...AND U20S TO M30S OVER THE MTNS.
TOMORROW NIGHT...THE POTENT VORT MAX AND ITS ASSOCIATED COLD FRONT
TIED TO THE TROUGH OF LOW PRESSURE/CLIPPER MOVING ACROSS SE QUEBEC
WILL MOVE ACROSS THE REGION BTWN 00Z-06Z. THE STRONG CONVERGENCE
ALONG THE BOUNDARY MAY PRODUCE MORE WIDESPREAD ONE INCH AMOUNTS
WITH THIS SYSTEM. THE WRN DACKS COULD GET ANOTHER 1 TO 4
INCHES...AS LAKE EFFECT STARTS AGAIN. LOWS WILL GENERALLY BE IN
THE TEENS OVER THE HILLS AND MTNS...AND L20S IN THE VALLEYS...AS
STRONG COLD ADVECTION SWEEPS OVER THE REGION.
MONDAY...ANOTHER BRIEF LAKE CONNECTION IS EXPECTED MONDAY MORNING.
THIS TIME A 290 DEGREE LOW-LEVEL TRAJECTORY WOULD BE FAVORED WITH
THE SW DACKS...W-CNTRL MOHAWK VALLEY...AND NRN CATSKILLS IMPACTED.
WE COULD SEE A BAND SNEAK DOWN THE MOHAWK RIVER VALLEY EARLY IN
THE DAY...AND WE KEPT SOME SLIGHT-LOW CHC POPS IN FOR THE CAPITAL
REGION...TACONICS...AND BERKSHIRES. RIGHT NOW...SNOW ACCUMULATIONS
WEST OF ALBANY WOULD BE IN THE 1 TO 3 INCH RANGE. THE NAM
CONTINUES TO SHOW THE LAKE EFFECT POTENTIAL WEAKENING DURING THE
DAY WITH THE FLOW BEGINNING TO BACK AGAIN...AND THE INVERSION
LOWERING...AS HIGH PRESSURE BRIEFLY BUILDS IN AGAIN. H850 TEMPS
TUMBLE CLOSER TO SEASONABLE LEVELS AT -13C TO -16C OVER THE REGION
WITH HIGHS IN THE U20S TO M30S IN THE VALLEYS AND LOWER
ELEVATIONS...AND LOWER TO M20S OVER THE MTNS.
MONDAY NIGHT...A WARM FRONT WILL MOVE INTO THE REGION FROM THE
OHIO VALLEY AND THE LOWER GREAT LAKES REGION. THE ISENTROPIC LIFT
INCREASES ON THE 295K SFC. OVERRUNNING LIGHT SNOWFALL WILL
OVERSPREAD THE REGION. THE BETTER QG LIFT IS FROM THE HUDSON
VALLEY WESTWARD. WE KEPT HIGH CHC POPS IN THE FORECAST FOR THIS
TIME FRAME. THE WARM FRONT SLOWLY LIFT NORTHWARD OF THE I-90
CORRIDOR BY TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AT THE START OF THE EXTENDED PERIOD...A WARM FRONT WILL BE MOVING
NORTH THROUGH THE REGION DURING TUESDAY MORNING. THIS WILL CONTINUE
TO BRING SOME LIGHT SNOW FOR AREAS MAINLY TO THE NORTH OF I-90. BY
AFTERNOON...MUCH OF THE PRECIPITATION SHOULD BE DONE ACROSS THE
REGION....WITH THE EXCEPTION ACROSS PARTS OF THE SOUTHERN
ADIRONDACKS/LAKE GEORGE AREA.
BEHIND THIS WARM FRONT...A WARMER SOUTHERLY FLOW WILL TAKE OVER.
THIS WILL ALLOW FOR TUESDAY NIGHT MIN TEMPS NOT TO BE AS COOL AS
RECENT NIGHTS...WITH MUCH OF THE CAPITAL REGION REMAINING ABOVE
FREEZING EVEN DURING THE OVERNIGHT. TEMPS WILL CONTINUE TO BE ABOVE
NORMAL RIGHT INTO WEDNESDAY...WITH 40S ACROSS THE ENTIRE AREA BY WED
AFTN. SOME RAIN SHOWERS WILL BE POSSIBLE...ESP FOR WEDNESDAY...AS A
STORM SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE STORM/S COLD FRONT
PROVIDES SOME LIFT FOR SHOWERS ACROSS OUR AREA.
THE MODELS DISAGREE ON WHAT OCCURS FOR WEDNESDAY NIGHT AND BEYOND.
THE 12 UTC ECMWF ATTEMPTS TO DEVELOP A WAVE ALONG THE FRONTAL
BOUNDARY AS IT MOVES OFF THE EASTERN SEABOARD...WHICH COULD BRING
SOME ADDITIONAL LIGHT PRECIP /RAIN OR SNOW/ TO SOUTHEASTERN PARTS OF
THE AREA FOR WED NIGHT INTO THURSDAY. MEANWHILE...THE GFS IS MUCH
MORE PROGRESSIVE AND KEEPS IT FAIRLY DRY WITH JUST SOME CYCLONIC
FLOW RAIN/SNOW SHOWER FOR NORTHWESTERN PARTS OF THE AREA. THE GFS
HAS BEEN PERSISTENT IN GOING AGAINST THE IDEA OF A BIG STORM DURING
THIS PERIOD...AND THE 12 UTC GEFS ONLY SUPPORTS LIGHT PRECIP FROM
WRAP AROUND OF THE CANADIAN LOW PRESSURE DURING THIS TIME FRAME AS
WELL. EVEN THE ECMWF IS STARTING TO BACK OFF ON THE IDEA OF A
STRONGER SECONDARY WAVE DURING THIS PERIOD...AS IT ONLY HAS A WEAK
LOW ALONG THE FRONT...WITH THE STORM WAITING UNTIL ITS MUCH FURTHER
OFFSHORE BEFORE RAPID DEEPENING. FOR NOW...WITH GO WITH LOW POPS
FOR WED NIGHT/THURS AND CONTINUE TO SHOW TEMPS ABOVE NORMAL.
TEMPS WILL CONTINUE TO BE SOMEWHAT ABOVE NORMAL FOR FRIDAY INTO
SATURDAY ACROSS THE AREA. FOR NOW...WILL GO WITH SLIGHT CHC POPS AS
SOME WEAK UPPER LEVEL DISTURBANCES MAY ALLOW FOR A RAIN OR SNOW
SHOWER...ESP FOR THE HIGHER TERRAIN...BEFORE A STRONG AREA OF HIGH
PRESSURE MOVES TOWARDS THE AREA FOR LATER IN THE WEEKEND.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES FOR MUCH OF THE TAF
PERIOD ENDING AT 18Z SUNDAY. THE EXCEPTION MAY BE SNOW SQUALLS/SNOW
SHOWERS IN THE VICINITY OF KGFL/KALB FROM THIS EVENING UNTIL SEVERAL
HOURS AFTER MIDNIGHT AHEAD OF AND IN THE WAKE OF A COLD FRONT WHICH
MAY BRIEFLY REDUCE VSBYS AND CIGS TO MVFR/IFR. SINCE THE PROBABILITY
OF THESE OCCURRING IS LOW WILL HANDLE WITH A VCSH IN THE TAFS.
WINDS WILL BE LIGHT AND VARIABLE THIS AFTERNOON AND THEN BECOME
SOUTHWEST TO WEST AT 5 TO 10 KTS WITH A FRONTAL PASSAGE THIS EVENING
AND THEN SOUTHWEST TO WEST AT 8-14 KTS WITH GUSTS TO 24 KTS AT KALB
LATE TONIGHT INTO SUNDAY MORNING.
OUTLOOK...
SUN/SUN NIGHT...VFR/MVFR. CHC -SHSN.
MON-TUE...VFR. NO SIG WX.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE FROM THE RAIN AND MIXED
PRECIPITATION YESTERDAY. THE FLOOD WARNING WAS CANCELED FOR
MCKEEVER ON THE MOOSE RIVER...AS THE ICE JAM HAS BROKEN...AND WATER
IS FREELY FLOWING AGAIN.
A COUPLE OF CLIPPER LOW PRESSURE SYSTEMS AND THEIR ASSOCIATED COLD
FRONTS WILL IMPACT THE REGION LATE TODAY AND TONIGHT...AND SUNDAY
NIGHT INTO MONDAY MORNING. SOME SCATTERED SNOW SHOWERS AND
FLURRIES WILL BE COMMON WITH LIGHT SNOW ACCUMULATIONS UP TO A FEW
INCHES IN THE SOUTHERN ADIRONDACKS. SOME MODERATE SNOW
ACCUMULATIONS WILL BE POSSIBLE TONIGHT IN THE WESTERN ADIRONDACKS. A
WARM FRONT WILL ALSO BRING SOME LIGHT SNOW MONDAY NIGHT INTO
TUESDAY MORNING.
OVERALL...RIVER FLOWS WILL CONTINUE TO RECEDE INTO THE MID WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
SUNDAY FOR NYZ032.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...FRUGIS
AVIATION...11
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
305 PM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 21Z...
* GUSTY WEST WINDS AROUND 30 KTS THIS AFTERNOON.
* POTENTIAL FOR A PERIOD OF LIGHT SNOW LATE TONIGHT/EARLY SUNDAY
WITH ATTENDANT POSSIBILITY OF BRIEF IFR VIS/MVFR CIGS.
* MVFR CIGS MAY LINGER SUNDAY MORNING.
RATZER
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS ACROSS THE TERMINALS THIS AFTERNOON IN DRY/COLDER
AIR IN WAKE OF COLD FRONT WHICH MOVED THROUGH OVERNIGHT. MAIN
AVIATION WEATHER ISSUE IN THE SHORT TERM ARE THE GUSTY WEST WINDS
PRODUCED BY COMBINATION OF RELATIVELY TIGHT SURFACE PRESSURE
GRADIENT AND FAIRLY DEEP BOUNDARY LAYER MIXING IN LOW-LEVEL COLD
ADVECTION REGIME BEHIND THE FRONT. OBSERVATIONS INDICATE WINDS
GUSTING AROUND 30 KTS AS SUGGESTED BY FORECAST SOUNDINGS...AND
EXPECT THIS TO CONTINUE FOR THE BALANCE OF THE AFTERNOON HOURS.
WINDS SHOULD DIMINISH...PARTICULARLY THE HIGHER GUSTS...THIS
EVENING WITH SUNSET...THOUGH NEXT QUICK MOVING LOW PRESSURE SYSTEM
IS ALREADY DROPPING SOUTHEAST ACROSS NORTH DAKOTA AT MIDDAY AND
PRESSURE FALLS WITH THIS APPROACHING SYSTEM WILL HELP TO KEEP
WINDS FROM FALLING OFF TOO MUCH TONIGHT. WINDS WILL BACK FROM
CURRENT WESTERLY DIRECTION TO SOUTHWEST THIS EVENING/OVERNIGHT
AHEAD OF THE LOW...BUT GUSTS SHOULD DIMINISH TO 15-20 KTS.
LOW PRESSURE OVER THE DAKOTAS IS ASSOCIATED WITH ANOTHER QUICK
MOVING CLIPPER SYSTEM WHICH IS PROGGED TO REACH THE FORECAST AREA
BY EARLY SUNDAY MORNING. FORECAST SOUNDINGS AND TIME/HEIGHT
DEPICTIONS INDICATE INCREASING ASCENT IN LOW LEVELS THIS EVENING
AS WARM ADVECTION DEVELOPS IN RESPONSE TO MID-LEVEL WAVE...THOUGH
DRY MODIFIED-ARCTIC AIR MASS WILL TAKE CONSIDERABLE LIFTING TO
SATURATE. MODELS ARE IN DECENT AGREEMENT HOWEVER IN DEVELOPING
MID-LEVEL CLOUD DECK AND EVENTUALLY SATURATING LOW LEVELS ENOUGH
FROM THE TOP DOWN FOR A PERIOD OF LIGHT SNOW A FEW HOURS AFTER
MIDNIGHT...WITH AREAS ACROSS FAR NORTHERN IL/SOUTHERN WI FAVORED
FOR SOME MINOR ACCUMULATIONS. VARIOUS MODELS ALL DEVELOP SOME
MEASURABLE PRECIP ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST
TOWARD 08-10Z...LINGERING THROUGH 12-14Z OR SO WITH THAT PERIOD
HAVING THE HIGHEST LIKELIHOOD OF BRIEF IFR VIS/MVFR CIGS IN LIGHT
SNOW. MVFR CIGS 2000-2500 FT MAY LINGER FOR A TIME DURING THE
MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 21Z...
* HIGH CONFIDENCE IN GUSTY WEST WINDS THROUGH THIS AFTERNOON.
MEDIUM CONFIDENCE IN GUST TRENDS THIS EVENING/OVERNIGHT.
* MEDIUM-HIGH CONFIDENCE IN LIGHT SNOW DEVELOPING LATE TONIGHT.
MEDIUM CONFIDENCE IN TIMING...LOW CONFIDENCE IN VIS/CIG TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHANCE OF RAIN/DRIZZLE.
WEDNESDAY...MORNING MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...VFR.
MTF
&&
.MARINE...
244 PM CST
A RATHER PROGRESSIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT
LAKES REGION THROUGH THE FORECAST PERIOD.
IN THE NEAR TERM...WESTERLY GALES WILL DIMINISH THIS EVENING AS AN
AREA OF LOW PRESSURE MOVES EAST OF THE LAKES AND INTO SOUTHERN
QUEBEC TONIGHT. WHILE WINDS WILL DIMINISH BELOW GALE FORCE...THE
GRADIENT WILL REMAIN SOMEWHAT TIGHT AS ANOTHER AREA OF LOW PRESSURE
QUICKLY DROPS SOUTHEAST FROM THE DAKOTAS TO LOWER MICHIGAN BY SUNDAY
MORNING. AFTER A PUSH OF SOMEWHAT COLDER AIR AND A PERIOD OF GUSTY
NORTHWEST WINDS SUNDAY MORNING...THE GRADIENT WILL FINALLY LOOSEN
AND ALLOW WINDS TO DIMINISH LATE SUNDAY AND SUNDAY NIGHT AS A RIDGE
OF HIGH PRESSURE BUILDS EAST ACROSS THE WESTERN LAKES. THE LULL WONT
LAST TOO LONG HOWEVER...AS A WARM FRONT LIFTS NORTHEAST ACROSS THE
REGION MONDAY AND MONDAY NIGHT AHEAD OF AN ELONGATED AREA OF LOW
PRESSURE ALONG THE CANADIAN BORDER. WINDS WILL SHIFT SOUTH BEHIND
THE WARM FRONT BY LATE MONDAY...BUT WILL SHIFT BACK TO THE NORTHWEST
TUESDAY NIGHT AS THE LOW ALONG THE BORDER MOVES EAST ACROSS THE
NORTHERN LAKES AND TRAILS ANOTHER COLD FRONT ACROSS LAKE MICHIGAN.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
244 PM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY WEST WINDS AROUND 30 KTS THIS AFTERNOON.
* POTENTIAL FOR A PERIOD OF LIGHT SNOW LATE TONIGHT/EARLY SUNDAY
WITH ATTENDANT POSSIBILITY OF BRIEF IFR VIS/MVFR CIGS.
* MVFR CIGS MAY LINGER SUNDAY MORNING.
RATZER
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS ACROSS THE TERMINALS THIS AFTERNOON IN DRY/COLDER
AIR IN WAKE OF COLD FRONT WHICH MOVED THROUGH OVERNIGHT. MAIN
AVIATION WEATHER ISSUE IN THE SHORT TERM ARE THE GUSTY WEST WINDS
PRODUCED BY COMBINATION OF RELATIVELY TIGHT SURFACE PRESSURE
GRADIENT AND FAIRLY DEEP BOUNDARY LAYER MIXING IN LOW-LEVEL COLD
ADVECTION REGIME BEHIND THE FRONT. OBSERVATIONS INDICATE WINDS
GUSTING AROUND 30 KTS AS SUGGESTED BY FORECAST SOUNDINGS...AND
EXPECT THIS TO CONTINUE FOR THE BALANCE OF THE AFTERNOON HOURS.
WINDS SHOULD DIMINISH...PARTICULARLY THE HIGHER GUSTS...THIS
EVENING WITH SUNSET...THOUGH NEXT QUICK MOVING LOW PRESSURE SYSTEM
IS ALREADY DROPPING SOUTHEAST ACROSS NORTH DAKOTA AT MIDDAY AND
PRESSURE FALLS WITH THIS APPROACHING SYSTEM WILL HELP TO KEEP
WINDS FROM FALLING OFF TOO MUCH TONIGHT. WINDS WILL BACK FROM
CURRENT WESTERLY DIRECTION TO SOUTHWEST THIS EVENING/OVERNIGHT
AHEAD OF THE LOW...BUT GUSTS SHOULD DIMINISH TO 15-20 KTS.
LOW PRESSURE OVER THE DAKOTAS IS ASSOCIATED WITH ANOTHER QUICK
MOVING CLIPPER SYSTEM WHICH IS PROGGED TO REACH THE FORECAST AREA
BY EARLY SUNDAY MORNING. FORECAST SOUNDINGS AND TIME/HEIGHT
DEPICTIONS INDICATE INCREASING ASCENT IN LOW LEVELS THIS EVENING
AS WARM ADVECTION DEVELOPS IN RESPONSE TO MID-LEVEL WAVE...THOUGH
DRY MODIFIED-ARCTIC AIR MASS WILL TAKE CONSIDERABLE LIFTING TO
SATURATE. MODELS ARE IN DECENT AGREEMENT HOWEVER IN DEVELOPING
MID-LEVEL CLOUD DECK AND EVENTUALLY SATURATING LOW LEVELS ENOUGH
FROM THE TOP DOWN FOR A PERIOD OF LIGHT SNOW A FEW HOURS AFTER
MIDNIGHT...WITH AREAS ACROSS FAR NORTHERN IL/SOUTHERN WI FAVORED
FOR SOME MINOR ACCUMULATIONS. VARIOUS MODELS ALL DEVELOP SOME
MEASURABLE PRECIP ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST
TOWARD 08-10Z...LINGERING THROUGH 12-14Z OR SO WITH THAT PERIOD
HAVING THE HIGHEST LIKELIHOOD OF BRIEF IFR VIS/MVFR CIGS IN LIGHT
SNOW. MVFR CIGS 2000-2500 FT MAY LINGER FOR A TIME DURING THE
MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN GUSTY WEST WINDS THROUGH THIS AFTERNOON.
MEDIUM CONFIDENCE IN GUST TRENDS THIS EVENING/OVERNIGHT.
* MEDIUM-HIGH CONFIDENCE IN LIGHT SNOW DEVELOPING LATE TONIGHT.
MEDIUM CONFIDENCE IN TIMING...LOW CONFIDENCE IN VIS/CIG TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHANCE OF RAIN/DRIZZLE.
WEDNESDAY...MORNING MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...VFR.
MTF
&&
.MARINE...
244 PM CST
A RATHER PROGRESSIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT
LAKES REGION THROUGH THE FORECAST PERIOD.
IN THE NEAR TERM...WESTERLY GALES WILL DIMINISH THIS EVENING AS AN
AREA OF LOW PRESSURE MOVES EAST OF THE LAKES AND INTO SOUTHERN
QUEBEC TONIGHT. WHILE WINDS WILL DIMINISH BELOW GALE FORCE...THE
GRADIENT WILL REMAIN SOMEWHAT TIGHT AS ANOTHER AREA OF LOW PRESSURE
QUICKLY DROPS SOUTHEAST FROM THE DAKOTAS TO LOWER MICHIGAN BY SUNDAY
MORNING. AFTER A PUSH OF SOMEWHAT COLDER AIR AND A PERIOD OF GUSTY
NORTHWEST WINDS SUNDAY MORNING...THE GRADIENT WILL FINALLY LOOSEN
AND ALLOW WINDS TO DIMINISH LATE SUNDAY AND SUNDAY NIGHT AS A RIDGE
OF HIGH PRESSURE BUILDS EAST ACROSS THE WESTERN LAKES. THE LULL WONT
LAST TOO LONG HOWEVER...AS A WARM FRONT LIFTS NORTHEAST ACROSS THE
REGION MONDAY AND MONDAY NIGHT AHEAD OF AN ELONGATED AREA OF LOW
PRESSURE ALONG THE CANADIAN BORDER. WINDS WILL SHIFT SOUTH BEHIND
THE WARM FRONT BY LATE MONDAY...BUT WILL SHIFT BACK TO THE NORTHWEST
TUESDAY NIGHT AS THE LOW ALONG THE BORDER MOVES EAST ACROSS THE
NORTHERN LAKES AND TRAILS ANOTHER COLD FRONT ACROSS LAKE MICHIGAN.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1204 PM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY WEST WINDS AROUND 30 KTS THIS AFTERNOON.
* POTENTIAL FOR A PERIOD OF LIGHT SNOW LATE TONIGHT/EARLY SUNDAY
WITH ATTENDANT POSSIBILITY OF BRIEF IFR VIS/MVFR CIGS.
* MVFR CIGS MAY LINGER SUNDAY MORNING.
RATZER
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS ACROSS THE TERMINALS THIS AFTERNOON IN DRY/COLDER
AIR IN WAKE OF COLD FRONT WHICH MOVED THROUGH OVERNIGHT. MAIN
AVIATION WEATHER ISSUE IN THE SHORT TERM ARE THE GUSTY WEST WINDS
PRODUCED BY COMBINATION OF RELATIVELY TIGHT SURFACE PRESSURE
GRADIENT AND FAIRLY DEEP BOUNDARY LAYER MIXING IN LOW-LEVEL COLD
ADVECTION REGIME BEHIND THE FRONT. OBSERVATIONS INDICATE WINDS
GUSTING AROUND 30 KTS AS SUGGESTED BY FORECAST SOUNDINGS...AND
EXPECT THIS TO CONTINUE FOR THE BALANCE OF THE AFTERNOON HOURS.
WINDS SHOULD DIMINISH...PARTICULARLY THE HIGHER GUSTS...THIS
EVENING WITH SUNSET...THOUGH NEXT QUICK MOVING LOW PRESSURE SYSTEM
IS ALREADY DROPPING SOUTHEAST ACROSS NORTH DAKOTA AT MIDDAY AND
PRESSURE FALLS WITH THIS APPROACHING SYSTEM WILL HELP TO KEEP
WINDS FROM FALLING OFF TOO MUCH TONIGHT. WINDS WILL BACK FROM
CURRENT WESTERLY DIRECTION TO SOUTHWEST THIS EVENING/OVERNIGHT
AHEAD OF THE LOW...BUT GUSTS SHOULD DIMINISH TO 15-20 KTS.
LOW PRESSURE OVER THE DAKOTAS IS ASSOCIATED WITH ANOTHER QUICK
MOVING CLIPPER SYSTEM WHICH IS PROGGED TO REACH THE FORECAST AREA
BY EARLY SUNDAY MORNING. FORECAST SOUNDINGS AND TIME/HEIGHT
DEPICTIONS INDICATE INCREASING ASCENT IN LOW LEVELS THIS EVENING
AS WARM ADVECTION DEVELOPS IN RESPONSE TO MID-LEVEL WAVE...THOUGH
DRY MODIFIED-ARCTIC AIR MASS WILL TAKE CONSIDERABLE LIFTING TO
SATURATE. MODELS ARE IN DECENT AGREEMENT HOWEVER IN DEVELOPING
MID-LEVEL CLOUD DECK AND EVENTUALLY SATURATING LOW LEVELS ENOUGH
FROM THE TOP DOWN FOR A PERIOD OF LIGHT SNOW A FEW HOURS AFTER
MIDNIGHT...WITH AREAS ACROSS FAR NORTHERN IL/SOUTHERN WI FAVORED
FOR SOME MINOR ACCUMULATIONS. VARIOUS MODELS ALL DEVELOP SOME
MEASURABLE PRECIP ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST
TOWARD 08-10Z...LINGERING THROUGH 12-14Z OR SO WITH THAT PERIOD
HAVING THE HIGHEST LIKELIHOOD OF BRIEF IFR VIS/MVFR CIGS IN LIGHT
SNOW. MVFR CIGS 2000-2500 FT MAY LINGER FOR A TIME DURING THE
MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN GUSTY WEST WINDS THROUGH THIS AFTERNOON.
MEDIUM CONFIDENCE IN GUST TRENDS THIS EVENING/OVERNIGHT.
* MEDIUM-HIGH CONFIDENCE IN LIGHT SNOW DEVELOPING LATE TONIGHT.
MEDIUM CONFIDENCE IN TIMING...LOW CONFIDENCE IN VIS/CIG TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHANCE OF RAIN/DRIZZLE.
WEDNESDAY...MORNING MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...VFR.
MTF
&&
.MARINE...
226 AM CST
AN ACTIVE PATTERN WILL REMAIN IN PLACE OVER THE LAKES BASICALLY
THROUGH TUESDAY AND POSSIBLY EVEN FURTHER. AS A COLD FRONT CLEARS
THE LAKE NEAR DAYBREAK...COLDER AIR WILL ADVECT OVER THE REGION
WITHIN A STRONG NORTHWEST PUSH OF WINDS. TOGETHER THIS WILL HELP TO
STEEPEN LAPSE RATES AND PROMOTE GALE FORCE WESTERLY WINDS ACROSS THE
SOUTHERN LAKE...INCLUDING NEARSHORE AREAS OF IL AND IN...AND
SPREADING TO THE NORTH OPEN WATERS BY LATE MORNING. WHILE GALE FORCE
GUSTS WILL SLOWLY DIMINISH THIS EVENING...WINDS WILL GENERALLY STAY
AT LEAST 20 KT THROUGH SUNDAY AND SUNDAY EVENING AS ANOTHER LOW
PRESSURE AREA MOVES EAST ACROSS THE NORTHERN LAKES. WINDS WILL TURN
SOUTHERLY FROM MONDAY INTO MONDAY NIGHT WITH A WARM FRONT MOVING
NORTH ACROSS THE LAKE. LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE
LAKE BY LATE TUESDAY. WITH THIS FEATURE GALE FORCE GUSTS MAY AGAIN
BE POSSIBLE FOR A BRIEF PERIOD. AT THIS TIME...A SLIGHTLY QUIETER
PATTERN UNDER WEAK RIDGING IS FAVORED WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...BUT CONFIDENCE IS LOW IN THE EXTENDED FORECAST
WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
904 AM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 15Z...
* WEST WINDS GUSTING TO 30 KT OR SLIGHTLY HIGHER TODAY.
* WINDS TURNING SOUTHWEST BY EVENING.
* SNOW CHANCES LATE TONIGHT.
//DISCUSSION...UPDATED 12Z...
A STRONG SURFACE COLD FRONT WILL CONTINUE TO MOVE EAST THROUGH
LOWER MICHIGAN AND INDIANA EARLY THIS MORNING WITH WEST TO
NORTHWEST WINDS PUSHING ACROSS THE REGION. THESE WINDS WILL BECOME
SOLIDLY DUE WEST BY LATE MORNING AND INCREASE IN MAGNITUDE...WITH
GUSTS TO AT LEAST 27 KT WITH HIGH CONFIDENCE. EVEN A FEW GUSTS TO
33 KT ARE POSSIBLE. AS ANOTHER COLD FRONT APPROACHES FROM THE
NORTHWEST THIS EVENING...THE WINDS WILL RESPOND BY TURNING
SOUTHWEST IN ADVANCE. OCCASIONAL GUSTS ARE EXPECTED TONIGHT...AS
THE WINDS IMMEDIATELY OFF THE SURFACE WILL BE QUITE STRONG.
BETWEEN 1500 AND 2500 FT...SOUTHWEST WINDS TONIGHT ARE LIKELY TO
BE AROUND 40 KT. AS THE FRONT APPROACHES LATE TONIGHT...AND AN
UPPER LEVEL DISTURBANCE ALOFT INTERACTS WITH THE FRONT...SPOTTY
SNOW SHOWERS/FLURRIES ARE LIKELY TO BE GENERATED. UNDER
THESE...SOME BRIEF REDUCTION IN VISIBILITY CAN BE FAVORED. CIGS
ARE LIKELY TO LOWER TO MVFR BY MORNING. WIND SPEEDS WILL AGAIN BE
GUSTY FROM THE WEST TO NORTHWEST ON SUNDAY...THOUGH NOT AS HIGH IN
SPEED AS TODAY.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH TODAY. WIND DIRECTION
MAY BACK AS MUCH AS 240 TO 250 DURING THE MID TO LATE AFTERNOON.
* SOUTHWEST WINDS THIS EVENING MAY HAVE OCCASIONAL GUSTS TO 20
KT...BUT CONFIDENCE ON GUST MAGNITUDE IS LOW.
* CONFIDENCE IN SNOW OCCURRING TONIGHT IS LOW...BUT IF IT DOES THE
CONFIDENCE IS HIGH THAT IT WILL ONLY BRIEFLY REDUCE VISIBILITY
WITH TOTAL ACCUMULATION OF 0.2 OF AN INCH OR LESS.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHANCE OF RAIN/DRIZZLE.
WEDNESDAY...MORNING MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...VFR.
MTF
&&
.MARINE...
226 AM CST
AN ACTIVE PATTERN WILL REMAIN IN PLACE OVER THE LAKES BASICALLY
THROUGH TUESDAY AND POSSIBLY EVEN FURTHER. AS A COLD FRONT CLEARS
THE LAKE NEAR DAYBREAK...COLDER AIR WILL ADVECT OVER THE REGION
WITHIN A STRONG NORTHWEST PUSH OF WINDS. TOGETHER THIS WILL HELP TO
STEEPEN LAPSE RATES AND PROMOTE GALE FORCE WESTERLY WINDS ACROSS THE
SOUTHERN LAKE...INCLUDING NEARSHORE AREAS OF IL AND IN...AND
SPREADING TO THE NORTH OPEN WATERS BY LATE MORNING. WHILE GALE FORCE
GUSTS WILL SLOWLY DIMINISH THIS EVENING...WINDS WILL GENERALLY STAY
AT LEAST 20 KT THROUGH SUNDAY AND SUNDAY EVENING AS ANOTHER LOW
PRESSURE AREA MOVES EAST ACROSS THE NORTHERN LAKES. WINDS WILL TURN
SOUTHERLY FROM MONDAY INTO MONDAY NIGHT WITH A WARM FRONT MOVING
NORTH ACROSS THE LAKE. LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE
LAKE BY LATE TUESDAY. WITH THIS FEATURE GALE FORCE GUSTS MAY AGAIN
BE POSSIBLE FOR A BRIEF PERIOD. AT THIS TIME...A SLIGHTLY QUIETER
PATTERN UNDER WEAK RIDGING IS FAVORED WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...BUT CONFIDENCE IS LOW IN THE EXTENDED FORECAST
WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SATURDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 9
PM SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
520 AM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* DEPARTING MVFR CIGS.
* WESTERLY WINDS GUSTING TO 30 KT OR SLIGHTLY HIGHER TODAY.
* WINDS TURNING SOUTHWEST BY EVENING.
* SNOW CHANCES LATE TONIGHT.
//DISCUSSION...UPDATED 12Z...
A STRONG SURFACE COLD FRONT WILL CONTINUE TO MOVE EAST THROUGH
LOWER MICHIGAN AND INDIANA EARLY THIS MORNING WITH WEST TO
NORTHWEST WINDS PUSHING ACROSS THE REGION. THESE WINDS WILL BECOME
SOLIDLY DUE WEST BY LATE MORNING AND INCREASE IN MAGNITUDE...WITH
GUSTS TO AT LEAST 27 KT WITH HIGH CONFIDENCE. EVEN A FEW GUSTS TO
33 KT ARE POSSIBLE. AS ANOTHER COLD FRONT APPROACHES FROM THE
NORTHWEST THIS EVENING...THE WINDS WILL RESPOND BY TURNING
SOUTHWEST IN ADVANCE. OCCASIONAL GUSTS ARE EXPECTED TONIGHT...AS
THE WINDS IMMEDIATELY OFF THE SURFACE WILL BE QUITE STRONG.
BETWEEN 1500 AND 2500 FT...SOUTHWEST WINDS TONIGHT ARE LIKELY TO
BE AROUND 40 KT. AS THE FRONT APPROACHES LATE TONIGHT...AND AN
UPPER LEVEL DISTURBANCE ALOFT INTERACTS WITH THE FRONT...SPOTTY
SNOW SHOWERS/FLURRIES ARE LIKELY TO BE GENERATED. UNDER
THESE...SOME BRIEF REDUCTION IN VISIBILITY CAN BE FAVORED. CIGS
ARE LIKELY TO LOWER TO MVFR BY MORNING. WIND SPEEDS WILL AGAIN BE
GUSTY FROM THE WEST TO NORTHWEST ON SUNDAY...THOUGH NOT AS HIGH IN
SPEED AS TODAY.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL ELEMENTS THROUGH TODAY. WIND DIRECTION
MAY BACK AS MUCH AS 240 TO 250 DURING THE MID TO LATE AFTERNOON.
* SOUTHWEST WINDS THIS EVENING MAY HAVE OCCASIONAL GUSTS TO 20
KT...BUT CONFIDENCE ON GUST MAGNITUDE IS LOW.
* CONFIDENCE IN SNOW OCCURRING TONIGHT IS LOW...BUT IF IT DOES THE
CONFIDENCE IS HIGH THAT IT WILL ONLY BRIEFLY REDUCE VISIBILITY
WITH TOTAL ACCUMULATION OF 0.2 OF AN INCH OR LESS.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHANCE OF RAIN/DRIZZLE.
WEDNESDAY...MORNING MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...VFR.
MTF
&&
.MARINE...
226 AM CST
AN ACTIVE PATTERN WILL REMAIN IN PLACE OVER THE LAKES BASICALLY
THROUGH TUESDAY AND POSSIBLY EVEN FURTHER. AS A COLD FRONT CLEARS
THE LAKE NEAR DAYBREAK...COLDER AIR WILL ADVECT OVER THE REGION
WITHIN A STRONG NORTHWEST PUSH OF WINDS. TOGETHER THIS WILL HELP TO
STEEPEN LAPSE RATES AND PROMOTE GALE FORCE WESTERLY WINDS ACROSS THE
SOUTHERN LAKE...INCLUDING NEARSHORE AREAS OF IL AND IN...AND
SPREADING TO THE NORTH OPEN WATERS BY LATE MORNING. WHILE GALE FORCE
GUSTS WILL SLOWLY DIMINISH THIS EVENING...WINDS WILL GENERALLY STAY
AT LEAST 20 KT THROUGH SUNDAY AND SUNDAY EVENING AS ANOTHER LOW
PRESSURE AREA MOVES EAST ACROSS THE NORTHERN LAKES. WINDS WILL TURN
SOUTHERLY FROM MONDAY INTO MONDAY NIGHT WITH A WARM FRONT MOVING
NORTH ACROSS THE LAKE. LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE
LAKE BY LATE TUESDAY. WITH THIS FEATURE GALE FORCE GUSTS MAY AGAIN
BE POSSIBLE FOR A BRIEF PERIOD. AT THIS TIME...A SLIGHTLY QUIETER
PATTERN UNDER WEAK RIDGING IS FAVORED WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...BUT CONFIDENCE IS LOW IN THE EXTENDED FORECAST
WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...10 AM
SATURDAY TO 9 PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 AM CST SAT JAN 28 2012
.DISCUSSION...
337 AM CST
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DENOTE A CLOSED
CIRCULATION ACROSS CENTRAL CANADA...WITH A LARGE TROUGH EXTENDING
TO THE SOUTH AND PUSHING THROUGH OUR REGION. THIS TROUGH WILL
CONTINUE TO ADVANCE EAST THROUGH THE DAY...AND PUSH A SURFACE
FRONT/TROUGH INTO THE OHIO VALLEY. AS OF 3 AM...THE MAIN FRONT HAD
PUSHED THROUGH DKB AND WAS ON ITS WAY TOWARDS LAKE MICHIGAN. BY
SUNRISE MOST IF NOT ALL LOCATIONS ACROSS ILLINOIS AND NORTHWESTERN
INDIANA SHOULD BE FREE FROM SNOWFALL. WINDS WILL BECOME WESTERLY
AND THEN NORTHWESTERLY WITH GUSTS INCREASING THROUGHOUT THE DAY.
FORECAST SOUNDINGS HIGHLIGHT EFFICIENT AND DEEP MIXING BEYOND H9
THIS THIS AFTERNOON. UPSTREAM OBS HIGHLIGHT MID 20 KT GUSTS ACROSS
THE MN/WI BORDER...AND THAT WILL WORK SOUTH ACROSS THE CWA INTO
THE MORNING HOURS. STRONG NORTHWESTERLY FLOW THROUGH THE MID
LEVELS ON THE BACK SIDE OF THE TROUGH WILL LEAD TO MEAN GUSTS
AROUND 30-35 KT THROUGH THE MIXED LAYER WORKING TO THE
SURFACE...ESPECIALLY ONCE CLOUDS CLEAR OUT...THOUGH NO ADVISORY
LEVEL GUSTS ANTICIPATED.
THE NEXT RIPPLE IN THE FLOW ALOFT WILL WORK SOUTHEAST ACROSS THE
DAKOTAS AND MINNESOTA OVERNIGHT...BRINGING ANOTHER CLIPPER ACROSS
THE IL/WI BORDER. AS WITH MANY CLIPPER SYSTEMS...THIS ONE WILL BE
RATHER MOISTURE DEVOID. ISENTROPIC ANALYSIS SHOWCASES THE BEST
UPGLIDE HAPPENING OVERNIGHT...WITH A LOT BEING WASTED ON
SATURATION IN THE 06 TO 12Z TIMEFRAME. GIVEN THE STEEP LAPSE RATES
THROUGH THE MORNING HOURS AND WEAK Q-VECTOR CONVERGENCE...WILL
KEEP THE MENTION OF LIGHT SNOW SHOWERS INTO THE MORNING HOURS OF
SUNDAY...BUT STILL KEEPING TOTALS LOW...AND WOULD BE SURPRISED IF
MORE THAN A QUARTER TO HALF OF AN INCH OF SNOW ARE SQUEEZED OUT
ACROSS THE NORTHERN COUNTIES.
THE PATTERN FOR THE PREVIOUS DAY AND NEXT FEW DAYS IS ACTING LIKE A
BROKEN RECORD. SNOW A LITTLE...CLEAR OUT...SLOWLY COOL...INCREASE
CLOUDS AND START OVER. SUNDAY WILL BE SIMILAR WITH ONE MINOR
EXCEPTION. LIGHT CAA WILL CONTINUE ALLOWING SUNDAY TEMPERATURES TO
SWING A FEW DEGREES COOLER THAN TODAY. THE NEXT RIPPLE IN THE FLOW
WILL AGAIN COME RACING SOUTH THROUGH THE DAKOTAS AND MINNESOTA...BUT
THIS TIME IS PROGGED TO REMAIN NORTH ACROSS CENTRAL WISCONSIN.
CLOUDS WILL INCREASE AGAIN OVERNIGHT SUNDAY AS THE WAVE APPROACHES.
THE START OF THE WEEK WILL BE SIMILAR TO FLIPPING AN OLD LP RECORD
FROM SIDE A TO SIDE B. THE PERSISTENT AND MINUSCULE WAVES THAT
HAVE BEEN DIVING THROUGH HERE...WITH ABOUT A 24 HOUR
PERIODICITY...WILL COME TO AN END AS FLOW ALOFT ATTEMPTS TO
BECOME ZONAL AS THE LARGE WEST COAST RIDGE BEGINS TO FLATTEN.
SURFACE HIGH PRESSURE ACROSS THE PLAINS WILL SQUEEZE OUT AND SOUTH
OF THE REGION AND TAKE RESIDENCE ACROSS THE SOUTHEASTERN CONUS.
THIS WILL ALLOW LOW AND MID LEVEL FLOW TO BECOME
SOUTHWESTERLY...BRINGING IN UNSEASONABLE WARMTH...AGAIN. HIGHS
MONDAY AND INTO TUESDAY ARE LOOKING TO RANGE FROM 10 TO
POTENTIALLY WELL OVER 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SECOND LAW OF THERMODYNAMICS STATES THAT FOR EVERY
ACTION...THERE IS AN EQUAL AND OPPOSITE REACTION. THANKFULLY THE
ATMOSPHERIC REACTION TO THE WARMTH WILL NOT HAPPEN QUICKLY.
DESPITE CONTINUED MODEL VARIANCES THESE LAST FEW NIGHTS...LONG
RANGE MODELS ARE STILL IN AGREEMENT WITH A WAVE DEEPENING ACROSS
THE PLAINS AND LIFTING ACROSS IL/WI BY THE MIDDLE OF THE WEEK. THE
LATEST EC HAS COME INTO AGREEMENT WITH THE GFS...AND EVEN SREF TO
SOME RESPECTS...WITH MOVING A SURFACE FEATURE ACROSS THE AREA. I
SAY FEATURE AT THIS POINT...BEING 96 HOURS OUT...AS THE MODELS
STILL DIFFER WITH RESPECT TO EITHER HAVING A LOW LIFT ACROSS THE
BORDER...OR ELSE KEEP THE LOW TO THE NORTHWEST AND LIFT A WARM
FRONT ACROSS...BEFORE BOTH SHIFT A COLD FRONT THROUGH.
REGARDLESS...DID UP POP CHANCES MID WEEK IN THE TUES AFTERNOON/EVE
WINDOW. WITH STRONG WAA UNDERWAY...PROFILES WILL BE WARM ENOUGH TO
SUPPORT RAIN UNTIL THE EARLY MORNING HOURS OF WEDNESDAY...WHEN THE
NORTHWESTERN COUNTIES MAY SEE A RAIN AND SNOW MIX.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* DEPARTING SNOW AND IFR CONDITIONS PRIOR TO DAYBREAK.
* LINGERING MVFR CLOUDS CHANCES THROUGH JUST AFTER DAYBREAK.
* STRONG/GUSTY WEST NORTHWEST WINDS TODAY.
* CHANCE OF SNOW LATE TONIGHT.
//DISCUSSION...UPDATED 06Z...
LIGHT SNOW WITH GENERALLY IFR CONDITIONS WILL CONTINUE THROUGH A
GOOD CHUNK OF THE OVERNIGHT HOURS ENDING JUST PRIOR TO SUNRISE IN
CHICAGO AREA...A COUPLE HOURS EARLIER WEST TOWARD ROCKFORD. SKIES
SHOULD CLEAR QUICKLY AFTER THE SNOW ENDS WITH WINDS BECOMING MORE
WEST-NORTHWESTERLY AND BECOMING INCREASINGLY GUSTY. BY LATE SAT
MORNING INTO THE AFTERNOON SHOULD SEE WIND GUSTS AROUND 30KT
BEFORE WINDS SUBSIDE NEAR SUNSET. ANOTHER WEAK SYSTEM WILL
APPROACH FROM THE NORTHWEST LATE SAT NIGHT BRINGING ANOTHER CHANCE
OF LIGHT SNOW DURING THE PREDAWN HOURS SUNDAY.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MODERATE CONFIDENCE IN DEPARTING TIME OF SNOW AND IFR/MVFR
CONDITIONS. SOME BRIEF SNOW SHOWERS/FLURRIES MAY BE OBSERVED
THROUGH 12Z.
* HIGH CONFIDENCE IN WIND TRENDS AND TIMING.
* LOW CONFIDENCE IN SNOW OCCURRING LATE TONIGHT.
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHC AM -SN AND MVFR CIGS.
MONDAY...VFR.
TUESDAY...IFR CIGS POSSIBLE. CHC -R OR -DZ.
WEDNESDAY AND THURSDAY...VFR.
IZZI/MTF
&&
.MARINE...
226 AM CST
AN ACTIVE PATTERN WILL REMAIN IN PLACE OVER THE LAKES BASICALLY
THROUGH TUESDAY AND POSSIBLY EVEN FURTHER. AS A COLD FRONT CLEARS
THE LAKE NEAR DAYBREAK...COLDER AIR WILL ADVECT OVER THE REGION
WITHIN A STRONG NORTHWEST PUSH OF WINDS. TOGETHER THIS WILL HELP TO
STEEPEN LAPSE RATES AND PROMOTE GALE FORCE WESTERLY WINDS ACROSS THE
SOUTHERN LAKE...INCLUDING NEARSHORE AREAS OF IL AND IN...AND
SPREADING TO THE NORTH OPEN WATERS BY LATE MORNING. WHILE GALE FORCE
GUSTS WILL SLOWLY DIMINISH THIS EVENING...WINDS WILL GENERALLY STAY
AT LEAST 20 KT THROUGH SUNDAY AND SUNDAY EVENING AS ANOTHER LOW
PRESSURE AREA MOVES EAST ACROSS THE NORTHERN LAKES. WINDS WILL TURN
SOUTHERLY FROM MONDAY INTO MONDAY NIGHT WITH A WARM FRONT MOVING
NORTH ACROSS THE LAKE. LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE
LAKE BY LATE TUESDAY. WITH THIS FEATURE GALE FORCE GUSTS MAY AGAIN
BE POSSIBLE FOR A BRIEF PERIOD. AT THIS TIME...A SLIGHTLY QUIETER
PATTERN UNDER WEAK RIDGING IS FAVORED WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT...BUT CONFIDENCE IS LOW IN THE EXTENDED FORECAST
WINDS.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 6
PM SATURDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...10 AM
SATURDAY TO 9 PM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
339 PM EST SAT JAN 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A SERIES OF FRONTS WILL MOVE ACROSS THE AREA THIS WEEKEND INTO NEXT
WEEK BRINGING CHANCES FOR PRECIPITATION ALONG WITH BREEZY CONDITIONS
AT TIMES. TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE...
ESPECIALLY FOR THE FIRST HALF OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
FRONTAL BOUNDARY HAS SURGED EAST OF THE REGION THIS MORNING TAKING
ALL OF THE SNOW WITH IT. SKIES HAVE RAPIDLY CLEARED IN WAKE OF THE
FRONTAL BOUNDARY AS MUCH DRIER AIR AND DEEPER SUBSIDENCE
OVERSPREAD CENTRAL INDIANA. TEMPS WERE RUNNING BETWEEN 30 AND 35
DEGREES FROM NORTH TO SOUTH AS OF 14Z.
MAIN FEATURE OF THE MORNING UPDATE WAS TO FRESHEN THE FORECAST AND
REMOVE ALL MENTION OF SNOW CHANCES. ALSO UPDATED SKY GRIDS WITH
MAINLY CLEAR SKIES EXPECTED ACROSS THE ENTIRE AREA BY 16Z.
COMBINATION OF COLD ADVECTION AND STRONG LOW LEVEL JET ROTATING
THROUGH THE REGION WILL SERVE TO KEEP WIND GUSTS AT 30-35MPH INTO
THE MID AFTERNOON. MOST RECENT RUC GUIDANCE INDICATING THAT THE
JET SHOULD SHIFT NORTH LATER THIS AFTERNOON AS THE LOW PRESSURE
SYSTEM OVER THE NORTHERN GREAT LAKES PULLS AWAY TO THE NORTHEAST.
MAY SEE GUSTS DROP OFF A BIT AS A RESULT DURING THE SECOND HALF OF
THE AFTERNOON...BUT EXPECT WIND GUSTS TO PERSIST IN SOME FASHION
UNTIL SUNSET. TWEAKED HIGH TEMPS DOWN A DEGREE OR TWO BASED ON
CURRENT READINGS AND THE COUNTERACTING IMPACT OF THE COLD
ADVECTION INTO THE AFTERNOON EVEN WITH FULL SUN ANTICIPATED.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS IS ON CHANCES FOR SNOW AND WINDS SUNDAY. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
TONIGHT WILL BE DRY AS CLOUDS INCREASE AHEAD OF THE NEXT FRONT. AT
THE MOMENT FEEL THAT THE SNOW AHEAD OF THE FRONT WILL REMAIN JUST
WEST OF THE AREA THROUGH 12Z...SO KEPT FORECAST AREA DRY TONIGHT.
WINDS SHOULD STAY UP WITH A TIGHTENING PRESSURE GRADIENT. THIS PLUS
INCREASING CLOUDS LEADS TO LOW TEMPERATURES AT OR ABOVE MAV MOS.
FRONT SWEEPS ACROSS THE AREA EARLY SUNDAY ALONG WITH SOME UPPER
SUPPORT. Q-VECTOR CONVERGENCE FORECASTS ARE ACTUALLY HIGHER FOR
SUNDAY THAN SATURDAY INDICATING BETTER FORCING. HOWEVER MOISTURE
WILL NOT BE AS PLENTIFUL. GIVEN THE FORCING WILL GO ABOVE MOS POPS
BUT STILL KEEP POPS IN CHANCE CATEGORY. BEST FORCING/MOISTURE
COMBINATION WILL BE ACROSS THE NORTHEAST FORECAST AREA SO WILL GO
HIGHEST POPS THERE. THE SOUTHWEST THIRD OF THE FORECAST AREA SHOULD
BE FAR ENOUGH REMOVED FROM FORCING/MOISTURE TO GO WITH A DRY
FORECAST THERE.
DECENT PRESSURE GRADIENT WILL ALLOW BREEZY CONDITIONS TO CONTINUE ON
SUNDAY...WITH SOME MIXING ALLOWING GUSTS AROUND 30 MPH ONCE AGAIN.
MOS TEMPERATURES LOOK OK NORTH ON SUNDAY BUT LOOK A BIT WARM SOUTH
GIVEN EXPECTED COLD ADVECTION.
A WARM FRONT WILL DEVELOP AND MOVE ACROSS THE AREA FOR MONDAY. WITH
THE LIMITED FORCING AND MOISTURE WITH THIS FRONT DECIDED TO CONTINUE
A DRY FORECAST SUNDAY NIGHT THROUGH MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE POPS ESPECIALLY LATE IN THE
PERIOD. THE 00Z ECMWF IS NOW IN BETTER AGREEMENT WITH THE 00Z GFS
AND ENSEMBLES AS IT IS DRY THURSDAY NIGHT AND FRIDAY. HOWEVER...THE
CR INITIALIZATION WAS GIVING US SMALL POPS. WITH THE MODELS BEING
INCONSISTENT OVER THE LAST SEVERAL RUNS AND AFTER COORDINATING WITH
ADJACENT OFFICES...WILL GO AHEAD AND KEEP THEM IN DESPITE DRY 00Z
MODEL CONSENSUS. COULD SEE A MIX THURSDAY NIGHT WITH ALL RAIN FRIDAY
AHEAD OF SEPARATE UPPER TROUGHS. PRIOR TO THURSDAY NIGHT...MODELS IN
A LITTLE BETTER AGREEMENT ON A FRONT MOVING ACROSS CENTRAL INDIANA
MIDWEEK WHICH WILL BRING RAIN CHANCES TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING...AND ADDITIONAL RAIN CHANCES ON WEDNESDAY NIGHT
AND THURSDAY AHEAD OF THE FIRST OF TWO UPPER TROUGHS AND TO THE
NORTH OF A SURFACE SYSTEM MOVING ACROSS KENTUCKY. THESE TWO TROUGHS
WILL HELP BRING SOME COLDER AIR ACROSS CENTRAL INDIANA LATE IN THE
WEEK REPLACING A VERY MILD AIRMASS WITH EARLY AND MID WEEK HIGHS IN
THE 50S.
&&
.AVIATION /DISCUSSION FOR THE 28/21Z TAF DISCUSSION/...
TWEAKED CURRENT OBSERVATIONS. PREVIOUS DISCUSSION FOLLOWS...
MID LEVEL CLOUDS WILL INCREASE LATE THIS AFTERNOON AND EVENING AS
ANOTHER COLD FRONT MOVES THROUGH TAF SITES TONIGHT. HOWEVER...VFR
CONDITIONS ARE STILL EXPECTED TO PREVAIL THROUGH DURATION OF TAF
PERIOD. LIGHT RAIN SHOWERS WILL ACCOMPANY FRONTAL PASSAGE AROUND
MID MORNING TOMORROW AND INTO THE AFTERNOON HOURS...MAINLY AT KLAF
AND KIND. BRIEF FALLS TO MVFR COULD BE POSSIBLE AT TAF SITES WHEN
FRONT MOVES THROUGH...BUT FOR THE MOST PART IT WILL STAY AT VFR
CATEGORY.
WEST/SOUTHWEST WINDS WILL REMAIN STRONG THROUGH TAF PERIOD.
SUSTAINED SPEEDS WILL RANGE FROM 15 TO 20 KTS WITH GUSTS TO 30 KTS
INTO THIS EVENING. GUSTS SHOULD TAPER OFF BY LATE EVENING...AND
SUSTAINED WINDS WILL ALSO DECREASE TO 10 TO 12 KTS. THIS WILL BE
SHORT-LIVED THOUGH AS THEY INCREASE AGAIN TOMORROW MORNING BEHIND
AFOREMENTIONED COLD FRONT. SUSTAINED WINDS WILL INCREASE TO 15 TO
20 KTS ONCE AGAIN WITH GUSTS UP TO 32 KTS. THEY WILL REMAIN
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD/CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1255 PM EST SAT JAN 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A SERIES OF FRONTS WILL MOVE ACROSS THE AREA THIS WEEKEND INTO NEXT
WEEK BRINGING CHANCES FOR PRECIPITATION ALONG WITH BREEZY CONDITIONS
AT TIMES. TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE...
ESPECIALLY FOR THE FIRST HALF OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
FRONTAL BOUNDARY HAS SURGED EAST OF THE REGION THIS MORNING TAKING
ALL OF THE SNOW WITH IT. SKIES HAVE RAPIDLY CLEARED IN WAKE OF THE
FRONTAL BOUNDARY AS MUCH DRIER AIR AND DEEPER SUBSIDENCE
OVERSPREAD CENTRAL INDIANA. TEMPS WERE RUNNING BETWEEN 30 AND 35
DEGREES FROM NORTH TO SOUTH AS OF 14Z.
MAIN FEATURE OF THE MORNING UPDATE WAS TO FRESHEN THE FORECAST AND
REMOVE ALL MENTION OF SNOW CHANCES. ALSO UPDATED SKY GRIDS WITH
MAINLY CLEAR SKIES EXPECTED ACROSS THE ENTIRE AREA BY 16Z.
COMBINATION OF COLD ADVECTION AND STRONG LOW LEVEL JET ROTATING
THROUGH THE REGION WILL SERVE TO KEEP WIND GUSTS AT 30-35MPH INTO
THE MID AFTERNOON. MOST RECENT RUC GUIDANCE INDICATING THAT THE
JET SHOULD SHIFT NORTH LATER THIS AFTERNOON AS THE LOW PRESSURE
SYSTEM OVER THE NORTHERN GREAT LAKES PULLS AWAY TO THE NORTHEAST.
MAY SEE GUSTS DROP OFF A BIT AS A RESULT DURING THE SECOND HALF OF
THE AFTERNOON...BUT EXPECT WIND GUSTS TO PERSIST IN SOME FASHION
UNTIL SUNSET. TWEAKED HIGH TEMPS DOWN A DEGREE OR TWO BASED ON
CURRENT READINGS AND THE COUNTERACTING IMPACT OF THE COLD
ADVECTION INTO THE AFTERNOON EVEN WITH FULL SUN ANTICIPATED.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS IS ON CHANCES FOR SNOW AND WINDS SUNDAY. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
TONIGHT WILL BE DRY AS CLOUDS INCREASE AHEAD OF THE NEXT FRONT. AT
THE MOMENT FEEL THAT THE SNOW AHEAD OF THE FRONT WILL REMAIN JUST
WEST OF THE AREA THROUGH 12Z...SO KEPT FORECAST AREA DRY TONIGHT.
WINDS SHOULD STAY UP WITH A TIGHTENING PRESSURE GRADIENT. THIS PLUS
INCREASING CLOUDS LEADS TO LOW TEMPERATURES AT OR ABOVE MAV MOS.
FRONT SWEEPS ACROSS THE AREA EARLY SUNDAY ALONG WITH SOME UPPER
SUPPORT. Q-VECTOR CONVERGENCE FORECASTS ARE ACTUALLY HIGHER FOR
SUNDAY THAN SATURDAY INDICATING BETTER FORCING. HOWEVER MOISTURE
WILL NOT BE AS PLENTIFUL. GIVEN THE FORCING WILL GO ABOVE MOS POPS
BUT STILL KEEP POPS IN CHANCE CATEGORY. BEST FORCING/MOISTURE
COMBINATION WILL BE ACROSS THE NORTHEAST FORECAST AREA SO WILL GO
HIGHEST POPS THERE. THE SOUTHWEST THIRD OF THE FORECAST AREA SHOULD
BE FAR ENOUGH REMOVED FROM FORCING/MOISTURE TO GO WITH A DRY
FORECAST THERE.
DECENT PRESSURE GRADIENT WILL ALLOW BREEZY CONDITIONS TO CONTINUE ON
SUNDAY...WITH SOME MIXING ALLOWING GUSTS AROUND 30 MPH ONCE AGAIN.
MOS TEMPERATURES LOOK OK NORTH ON SUNDAY BUT LOOK A BIT WARM SOUTH
GIVEN EXPECTED COLD ADVECTION.
A WARM FRONT WILL DEVELOP AND MOVE ACROSS THE AREA FOR MONDAY. WITH
THE LIMITED FORCING AND MOISTURE WITH THIS FRONT DECIDED TO CONTINUE
A DRY FORECAST SUNDAY NIGHT THROUGH MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE POPS ESPECIALLY LATE IN THE
PERIOD. THE 00Z ECMWF IS NOW IN BETTER AGREEMENT WITH THE 00Z GFS
AND ENSEMBLES AS IT IS DRY THURSDAY NIGHT AND FRIDAY. HOWEVER...THE
CR INITIALIZATION WAS GIVING US SMALL POPS. WITH THE MODELS BEING
INCONSISTENT OVER THE LAST SEVERAL RUNS AND AFTER COORDINATING WITH
ADJACENT OFFICES...WILL GO AHEAD AND KEEP THEM IN DESPITE DRY 00Z
MODEL CONSENSUS. COULD SEE A MIX THURSDAY NIGHT WITH ALL RAIN FRIDAY
AHEAD OF SEPARATE UPPER TROUGHS. PRIOR TO THURSDAY NIGHT...MODELS IN
A LITTLE BETTER AGREEMENT ON A FRONT MOVING ACROSS CENTRAL INDIANA
MIDWEEK WHICH WILL BRING RAIN CHANCES TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING...AND ADDITIONAL RAIN CHANCES ON WEDNESDAY NIGHT
AND THURSDAY AHEAD OF THE FIRST OF TWO UPPER TROUGHS AND TO THE
NORTH OF A SURFACE SYSTEM MOVING ACROSS KENTUCKY. THESE TWO TROUGHS
WILL HELP BRING SOME COLDER AIR ACROSS CENTRAL INDIANA LATE IN THE
WEEK REPLACING A VERY MILD AIRMASS WITH EARLY AND MID WEEK HIGHS IN
THE 50S.
&&
.AVIATION /DISCUSSION FOR THE 28/18Z TAF DISCUSSION/...
MID LEVEL CLOUDS WILL INCREASE LATE THIS AFTERNOON AND EVENING AS
ANOTHER COLD FRONT MOVES THROUGH TAF SITES TONIGHT. HOWEVER...VFR
CONDITIONS ARE STILL EXPECTED TO PREVAIL THROUGH DURATION OF TAF
PERIOD. LIGHT RAIN SHOWERS WILL ACCOMPANY FRONTAL PASSAGE AROUND
MID MORNING TOMORROW AND INTO THE AFTERNOON HOURS...MAINLY AT KLAF
AND KIND. BRIEF FALLS TO MVFR COULD BE POSSIBLE AT TAF SITES WHEN
FRONT MOVES THROUGH...BUT FOR THE MOST PART IT WILL STAY AT VFR
CATEGORY.
WEST/SOUTHWEST WINDS WILL REMAIN STRONG THROUGH TAF PERIOD.
SUSTAINED SPEEDS WILL RANGE FROM 15 TO 20 KTS WITH GUSTS TO 30 KTS
INTO THIS EVENING. GUSTS SHOULD TAPER OFF BY LATE EVENING...AND
SUSTAINED WINDS WILL ALSO DECREASE TO 10 TO 12 KTS. THIS WILL BE
SHORT-LIVED THOUGH AS THEY INCRASE AGAIN TOMORROW MORNING BEHIND
AFOREMENTIONED COLD FRONT. SUSTAINED WINDS WILL INCREASE TO 15 TO
20 KTS ONCE AGAIN WITH GUSTS UP TO 32 KTS. THEY WILL REMAIN
WESTERLY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
948 AM EST SAT JAN 28 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A SERIES OF FRONTS WILL MOVE ACROSS THE AREA THIS WEEKEND INTO NEXT
WEEK BRINGING CHANCES FOR PRECIPITATION ALONG WITH BREEZY CONDITIONS
AT TIMES. TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE...
ESPECIALLY FOR THE FIRST HALF OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
FRONTAL BOUNDARY HAS SURGED EAST OF THE REGION THIS MORNING TAKING
ALL OF THE SNOW WITH IT. SKIES HAVE RAPIDLY CLEARED IN WAKE OF THE
FRONTAL BOUNDARY AS MUCH DRIER AIR AND DEEPER SUBSIDENCE
OVERSPREAD CENTRAL INDIANA. TEMPS WERE RUNNING BETWEEN 30 AND 35
DEGREES FROM NORTH TO SOUTH AS OF 14Z.
MAIN FEATURE OF THE MORNING UPDATE WAS TO FRESHEN THE FORECAST AND
REMOVE ALL MENTION OF SNOW CHANCES. ALSO UPDATED SKY GRIDS WITH
MAINLY CLEAR SKIES EXPECTED ACROSS THE ENTIRE AREA BY 16Z.
COMBINATION OF COLD ADVECTION AND STRONG LOW LEVEL JET ROTATING
THROUGH THE REGION WILL SERVE TO KEEP WIND GUSTS AT 30-35MPH INTO
THE MID AFTERNOON. MOST RECENT RUC GUIDANCE INDICATING THAT THE
JET SHOULD SHIFT NORTH LATER THIS AFTERNOON AS THE LOW PRESSURE
SYSTEM OVER THE NORTHERN GREAT LAKES PULLS AWAY TO THE NORTHEAST.
MAY SEE GUSTS DROP OFF A BIT AS A RESULT DURING THE SECOND HALF OF
THE AFTERNOON...BUT EXPECT WIND GUSTS TO PERSIST IN SOME FASHION
UNTIL SUNSET. TWEAKED HIGH TEMPS DOWN A DEGREE OR TWO BASED ON
CURRENT READINGS AND THE COUNTERACTING IMPACT OF THE COLD
ADVECTION INTO THE AFTERNOON EVEN WITH FULL SUN ANTICIPATED.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS IS ON CHANCES FOR SNOW AND WINDS SUNDAY. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
TONIGHT WILL BE DRY AS CLOUDS INCREASE AHEAD OF THE NEXT FRONT. AT
THE MOMENT FEEL THAT THE SNOW AHEAD OF THE FRONT WILL REMAIN JUST
WEST OF THE AREA THROUGH 12Z...SO KEPT FORECAST AREA DRY TONIGHT.
WINDS SHOULD STAY UP WITH A TIGHTENING PRESSURE GRADIENT. THIS PLUS
INCREASING CLOUDS LEADS TO LOW TEMPERATURES AT OR ABOVE MAV MOS.
FRONT SWEEPS ACROSS THE AREA EARLY SUNDAY ALONG WITH SOME UPPER
SUPPORT. Q-VECTOR CONVERGENCE FORECASTS ARE ACTUALLY HIGHER FOR
SUNDAY THAN SATURDAY INDICATING BETTER FORCING. HOWEVER MOISTURE
WILL NOT BE AS PLENTIFUL. GIVEN THE FORCING WILL GO ABOVE MOS POPS
BUT STILL KEEP POPS IN CHANCE CATEGORY. BEST FORCING/MOISTURE
COMBINATION WILL BE ACROSS THE NORTHEAST FORECAST AREA SO WILL GO
HIGHEST POPS THERE. THE SOUTHWEST THIRD OF THE FORECAST AREA SHOULD
BE FAR ENOUGH REMOVED FROM FORCING/MOISTURE TO GO WITH A DRY
FORECAST THERE.
DECENT PRESSURE GRADIENT WILL ALLOW BREEZY CONDITIONS TO CONTINUE ON
SUNDAY...WITH SOME MIXING ALLOWING GUSTS AROUND 30 MPH ONCE AGAIN.
MOS TEMPERATURES LOOK OK NORTH ON SUNDAY BUT LOOK A BIT WARM SOUTH
GIVEN EXPECTED COLD ADVECTION.
A WARM FRONT WILL DEVELOP AND MOVE ACROSS THE AREA FOR MONDAY. WITH
THE LIMITED FORCING AND MOISTURE WITH THIS FRONT DECIDED TO CONTINUE
A DRY FORECAST SUNDAY NIGHT THROUGH MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE POPS ESPECIALLY LATE IN THE
PERIOD. THE 00Z ECMWF IS NOW IN BETTER AGREEMENT WITH THE 00Z GFS
AND ENSEMBLES AS IT IS DRY THURSDAY NIGHT AND FRIDAY. HOWEVER...THE
CR INITIALIZATION WAS GIVING US SMALL POPS. WITH THE MODELS BEING
INCONSISTENT OVER THE LAST SEVERAL RUNS AND AFTER COORDINATING WITH
ADJACENT OFFICES...WILL GO AHEAD AND KEEP THEM IN DESPITE DRY 00Z
MODEL CONSENSUS. COULD SEE A MIX THURSDAY NIGHT WITH ALL RAIN FRIDAY
AHEAD OF SEPARATE UPPER TROUGHS. PRIOR TO THURSDAY NIGHT...MODELS IN
A LITTLE BETTER AGREEMENT ON A FRONT MOVING ACROSS CENTRAL INDIANA
MIDWEEK WHICH WILL BRING RAIN CHANCES TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING...AND ADDITIONAL RAIN CHANCES ON WEDNESDAY NIGHT
AND THURSDAY AHEAD OF THE FIRST OF TWO UPPER TROUGHS AND TO THE
NORTH OF A SURFACE SYSTEM MOVING ACROSS KENTUCKY. THESE TWO TROUGHS
WILL HELP BRING SOME COLDER AIR ACROSS CENTRAL INDIANA LATE IN THE
WEEK REPLACING A VERY MILD AIRMASS WITH EARLY AND MID WEEK HIGHS IN
THE 50S.
&&
.AVIATION /DISCUSSION FOR THE 281500Z TAF UPDATE/...
UPDATE...
BUMPED WINDS UP A FEW KNOTS. OTHER THAN THAT...SKIES ARE CLEARING
OUT AS EXPECTED. KIND AND KBMG HAVE ALREADY RETURNED TO VFR
CATEGORY...AND KLAF AND KHUF SHOULD FOLLOW SHORTLY.
RADAR AND OBSERVATIONAL TRENDS ALONG WITH THE RAPID REFRESH AND
AWIPS DISTANCE SPEED TOOL ALL SUGGEST THE EDGE OF THE SNOW AND COLD
FRONT WILL BE KNOCKING ON THE DOOR AT HUF AND LAF AT 12Z WHERE
CEILINGS SHOULD BE MVFR AND WINDS WILL BECOME WEST AND GUST TO
AROUND 20 KNOTS. SKIES SHOULD THEN CLEAR THERE BY 14Z AND WINDS
SHOULD INCREASE TO NEAR 20 KNOTS WITH NEAR 30 KNOT GUSTS AFTER 16Z.
MEANWHILE...IND SHOULD START OUT WITH IFR CEILINGS AND VISIBILITIES
IN SNOW AND THEN FOLLOW THE TRENDS OF LAF AND HUF AFTER 14Z. BMG
SHOULD DO THE SAME EXCEPT...THE SNOW SHOULD BE MIXED WITH RAIN.
THEN...EXPECT AND INCREASE IN MID CLOUDS AFTER 00Z WITH WINDS
SHIFTING TO THE SOUTHWEST AT 10 KNOTS OR SLIGHTLY MORE AHEAD OF
ANOTHER COLD FRONT THAT WILL PASS THROUGH SUNDAY AFTER 12Z. THIS
FRONT IS EXPECTED TO BRING MVFR CONDITIONS AND MORE GUSTY WINDS FROM
THE WEST TO NEAR 30 KNOTS TO THE IND VICINITY WITH FROPA AROUND 15Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...MK/TDUD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
506 AM EST SAT JAN 28 2012
.SHORT TERM...
TODAY THROUGH SUNDAY NIGHT. FEW CHNGS TO ONGOING FCST NEEDED.
PRIMARY FOCUS ON SHARP BACK EDGE/DRYING IN WAKE OF CLIPPER WITH
VEERED UPSTREAM FLOW TO HAVE DELETERIOUS EFFECT ON AVBL THETA-E
WITHIN SFC-8H LYR. CRNT INDICATION OF SLIGHTLY HIR REFL IN HIGH
RES REFL CURVE W/BANDED RETURNS LIFTING ENEWD THROUGH CWA...NOW
FM DEKALB INTO SRN KOSCIUSKO COUNTY. NOTED AREA COINCIDENT WITH
TRANSLATION OF MIDLVL HGHT FALLS/ASCENT IN THIS RAPID MIDLVL FLOW
REGIME ACRS SRN GRTLKS. WITH SFC TEMPS 0-1C ACRS CWA WL LKLY NEED
THESE BRIEF HIR RETURNS TO REALIZE SOME SPOT HIR AMOUNTS IN 1 TO
2 INCH RANGE BEFORE SETTLING/GRDL MELT REDUCES DEPTH. BY MIDDAY
TRANSITION TO MINOR LAKE EFFECT COMPONENT...HOWEVER SVRL IMPEDING
COMPONENT NOTED...FOREMOST WITH FAR SRN LAKE MICHIGAN MLYR THERMAL
INSTABILITY LAGGING WITH LK/8H DELTA RUNNING 13-14C THIS
AFTERNOON. SHORT RESIDENCE TIME IN 30-40 KT CBL FLOW WITH DRY AIR
ENTRAINMENT PER MID TEENS SFC DPS ADVECTING UPWIND OF LK MI AS
WELL. SLIGHT MOD TO TAKE SRN FRINGE OF SCT -SHSN A BIT FURTHER NWD
GIVEN NAM/HRRR SUPPORT FOR LTL MORE THAN FLURRIES KSBN VCNTY EWD
ALONG TOLL ROAD. RAPID INVERSION CRASH/BACKING FLOW REMOVED ALL
MENTION TONIGHT SAVE FOR FAR NRN BERRIEN CO AS LAKE PROCESSES SHUT
COMPLETELY. GOOD AGREEMENT IN INTER/INTRA MODEL TIMING/STRENGTH OF
SECOND CLIPPER EVEN WEAKER/LESS GROSS MSTR AVAILABILITY AND SHORT
WINDOW FOR ACCUM POTNL SUNDAY MORNING. ANTICIPATE LITTLE MORE THAN
SKIFF AMNTS ALL BUT NRN THIRD CWA WHERE BETTER SATURATION/LIFT IS
COINCIDENT IN THIN DENDRITIC FAVORED LYR.
SLGHT MOD TO CRNT FCST/BIAS CORRECTED MOS BLEND WITH SLIGHT LWRG
TODAY/TONIGHT IN DEFERENCE TO THIN SNOW COVER/M2-M3C COOLING IN
SFC-8H LYR TODAY...AND NONDIURNAL/MORE RAPID COOLING POTNL
TONIGHT PER LESSER CLOUD COVER IN 00-06UTC SUN TIMEFRAME.
&&
.LONG TERM...
LACK OF NORTH ATLANTIC DOWNSTREAM BLOCKING...COMBINED WITH A
PERSISTENT DEEP UPPER TROUGH OVER THE NORTHERN PAC INTO NE
RUSSIA...WILL CONTINUE TO SUPPORT FAST NW FLOW THROUGH THE EXTENDED
PERIOD WITH MILD PAC DOWNSLOPE FLOW. INHERENT DIFFICULTY IN
RESOLVING THIS TYPE OF FLOW PATTERN IN THE LONG TERM PERIOD...WILL
SUPPORT A TREND TOWARD FORECAST CONSISTENCY/PERSISTENCE PER
POPS...WHICH IS ALSO IN LINE WITH FLOW PATTERN CONCERNS. THIS IS
ESPECIALLY TRUE GIVEN POORLY ANALYZED TURBULENT NORTHERN STREAM FLOW
WITH ROCKIES INTERACTION. JET CORES/ASSOCIATED SUBTLE WAVES/AND CAA
PROCESSES ARE FAR FROM BEING RESOLVED...AND ATTM WILL SIDE HEAVY
TOWARD FORECAST PERSISTENCE...WHICH INCLUDES A WX MENTION FOR THE
THE TWO IMPULSES EXPECTED TO ADVECT THROUGH THE FLOW. THE ECMWF
REMAINS THE MODEL OF CHOICE. HOWEVER...IT/S SOLUTIONS ARE EXHIBITING
TRACK/STRENGTH DIFFERENCES PER THE LATE PERIOD THUR IMPULSE...WITH A
STRONG SOUTHERN BIAS NOTED IN THE 00Z RUN.
MONDAY...HEIGHT/THERMAL RISES EXPECTED INTO THE REGION AHEAD OF A
STRONGER DIGGING UPPER TROUGH...SUPPORTING A FRONTOLYTIC RESPONSE
ACROSS THE CENTRAL GREAT LAKES. EMBEDDED FLOW IMPULSES WILL LIKELY
SUPPORT HIGH CENTERED LIFT...WITH ELEVATED SATURATION ABOVE A VERY
DRY SUB CLOUD LAYER. SNOW WILL BE A POSSIBILITY ACROSS THE FAR
NORTHERN ZONES. HOWEVER...BEST FORCING FOR ASCENT AND SATURATION
WILL LIKELY OCCUR NORTH OF THE REGION. WILL LEAVE FORECAST MAINLY
DRY...SAVE FOR A SMALL CHANCE SNOW MENTION CROSS THE FAR NORTH. DO
PREFER THE COOLER NUMBERS SUGGESTED IN THE ECMWF GIVEN EXPECTED
CLOUD COVER WITH SFC PRESSURE FALLS...LIKELY SUPPORTING A BACKED LL
WIND FIELD.
TUE-FRI...WARM/MILD CONDITIONS EXPECTED WITH PASSING IMPULSES
EXPECTED TO SUPPORT PRECIP AT TIMES IN THE PERIOD. BEST CHANCE FOR
PRECIP LOOKS TO BE IN THE TUE-TUE NIGHT PERIOD GIVEN CONTINUED
PROGGED SUFFICIENT LL MOISTURE AHEAD OF THE EXPECTED UPPER IMPULSE.
DRY CONDITIONS STILL FAVORED WED...GIVEN WIDESPREAD MODEL SUPPORT
FOR SFC RIDGING. THUR STILL REMAINS QUESTIONABLE GIVEN AN EJECTING
SW CONUS UPPER TROUGH. IF NORTHERN STREAM PHASING DEVELOPS...A
SLOWER AND MORE NORTHERN BIAS TO THE SFC LOW TRACK WOULD BE
EXPECTED. LEFT PREVIOUS FORECAST NUMBERS WHICH COVER THESE CONCERNS.
AGAIN...MILD CONDITIONS EXPECTED AS TEMPS WILL APPROACH 50 IN THE
PERIOD...ESP SOUTH TUE IF ENOUGH INSOLATION IS ATTAINED. HAVE
CONTINUED ABOVE NORMAL TEMPS.
&&
.AVIATION /06 UTC TAFS/...
LEADING EDGE OF RAPID DETERIORATING FLIGHT CONDS INTO KSBN-KFWA LINE
ATTM WITH PRIMARY FOCUS ONTO BREVITY OF ANTICIPATED LIFR MET CONDS
AT KSBN AS SUBCLOUD LYR RAPIDLY SATURATES NEXT HOUR THEN HONED END
TIME AS FOCUS FOR LIFT MOVES RAPIDLY EWD. SIMILARLY AT KFWA SLIGHTLY
BETTER OVERALL CONDS FORECAST...GIVEN BOTH ANTECEDENT LARGE
900-700MB DEWPOINT DEPRESSIONS AND BEING MORE ON SRN PERIPHERY OF
STRONGER LIFT. LEANED HEAVILY ONTO HRRR TRENDS FOR RAPIDLY IMPROVING
CONDS 12-14 UTC WITH CLIPPER FOLLOWED BY SIG STRONGER SFC FLOW/GUSTS
PER INCRSD DOWNWARD MOMENTUM XFER AS SFC-800MB LAPSE RATES STEEPEN.
&&
.PREV DISCUSSION... /ISSUED 100 AM EST SAT JAN 28 2012/
AVIATION /06 UTC TAFS/...
LEADING EDGE OF RAPID DETERIORATING FLIGHT CONDS INTO KSBN-KFWA LINE
ATTM WITH PRIMARY FOCUS ONTO BREVITY OF ANTICIPATED LIFR MET CONDS
AT KSBN AS SUBCLOUD LYR RAPIDLY SATURATES NEXT HOUR THEN HONED END
TIME AS FOCUS FOR LIFT MOVES RAPIDLY EWD. SIMILARLY AT KFWA SLIGHTLY
BETTER OVERALL CONDS FORECAST...GIVEN BOTH ANTECEDENT LARGE
900-700MB DEWPOINT DEPRESSIONS AND BEING MORE ON SRN PERIPHERY OF
STRONGER LIFT. LEANED HEAVILY ONTO HRRR TRENDS FOR RAPIDLY IMPROVING
CONDS 12-14 UTC WITH CLIPPER FOLLOWED BY SIG STRONGER SFC FLOW/GUSTS
PER INCRSD DOWNWARD MOMENTUM XFER AS SFC-800MB LAPSE RATES STEEPEN.
UPDATE...
CURRENT OBSERVATIONAL TRENDS SEEM TO BE SUPPORTING PREVIOUS
FORECAST TO THIS POINT. INCREASE IN RADAR RETURNS NOTED THE PAST
FEW HOURS ACROSS CENTRAL ILLINOIS DOWNSTREAM OF THE STRONGER UPPER
LEVEL FORCING JUST NOW EXITING THE CENTRAL PLAINS. A WEAKLY
FRONTOGENETIC FLOW APPEARS TO BE SETTING UP AND ENHANCING A FAIRLY
STRONG LOW LEVEL THERMAL RIBBON (-5 DEG CELSIUS PER 00Z KDVN RAOB
AND +1 DEG CELSIUS PER 00Z KILN RAOB). HIGHER RESOLUTION MODEL
OUTPUT AND EVEN NAM40 APPEAR TO HAVE SOME INDICATION OF THIS WEST
TO EAST EXPANSION OVER THE NEXT SEVERAL HOURS ACROSS WEST CENTRAL
AND SOUTHWEST PORTIONS OF THE AREA INITIALLY. ISENTROPIC PROGS OF
285K SFC ALSO SUGGEST SOME INCREASING ISENTROPIC ASCENT LATER THIS
EVENING ACROSS NORTHWEST PORTIONS OF THE AREA EVENTUALLY ALLOWING
SNOW TO OVERSPREAD NWRN HALF OF THE AREA TOWARD 06Z. EVEN SOME
REPORTS OF SOME -RA WITH BOUNDARY LAYER TEMPS IN THE LOWER TO MID
30S ACROSS EAST CENTRAL ILLINOIS. DID ADD A CHANCE RAIN/SNOW
MENTION ACROSS THE SOUTHWEST FOR A FEW HOURS THIS EVENING BUT WILL
STAY WITH PREDOMINATELY SNOW FOR THE OVERNIGHT.
PREVIOUS FCSTED SNOW AMOUNTS STILL APPEAR REASONABLE WITH A
POSSIBILITY OF TWO AREAS OF SLIGHTLY ENHANCED MAXIMUM
SNOWFALL...ONE ACROSS FAR NWRN IND/SWRN LWR MICHIGAN WITH SOME
WEAK LAKE ENHANCEMENT...AND ANOTHER POSSIBLE ACROSS SOUTHWEST
PORTIONS OF THE AREA WHERE A PERIOD OF SOME BETTER WEST TO EAST
BANDING IS POSSIBLE DURING EARLIER STAGES OF THE OVERNIGHT. SOME
OF THE INITIAL LIFT LATER THIS EVENING HOWEVER WILL BE SPENT TOWARD
ERODING A FAIRLY PRONOUNCED DRY LAYER EVIDENT IN THE 900 TO 750
HPA LAYER ON THIS EVENINGS REGIONAL AMDAR SOUNDINGS. ALL IN
ALL...1 TO 2 INCH SNOW AMOUNTS APPEAR TO BE INLINE AS UPPER
FORCING INCREASES WITH BETTER DEEPER SATURATION OVERNIGHT.
SLIGHTLY LESSER AMOUNTS EXPECTED ACROSS FAR EAST/SOUTHEAST WHERE
ISENTROPIC/FRONTOGENESIS PROGS ARE NOT EXPECTED TO BE QUITE AS
IMPRESSIVE.
PREV DISCUSSION... /ISSUED 727 PM EST FRI JAN 27 2012/
AVIATION...
00Z TAFS...SNOW WILL OVERSPREAD THE AREA LATE THIS EVENING INTO
THE OVERNIGHT HOURS IN ASSOCIATION WITH A FAST MOVING UPPER LEVEL
SYSTEM. IN THE MEANTIME...SOME FAIRLY DRY LOW LEVEL AIR NOTED IN
THIS EVENINGS REGIONAL AMDAR SOUNDINGS. MORE IMPRESSIVE BAND OF
SNOW PER REGIONAL RADAR MOSAIC/SFC EXTENDS FROM NORTHERN MISSOURI
INTO CENTRAL ILLINOIS WILL CONTINUE TO EXPAND EASTWARD THIS
EVENING IN ASSOCIATION WITH SOME LOW LEVEL FRONTOGENESIS FORCING.
NUMERICAL GUIDANCE STILL SUGGESTS INCREASING ISENTROPIC LIFT
FURTHER TO THE NORTH ACROSS NORTHERN INDIANA AND SHOULD SEE AN
EXPANSION OF -SN ACROSS FAR NRN INDIANA TOWARD MIDNIGHT ALONG WITH
DETERIORATING CONDITIONS TO IFR AND POSSIBLY SHORTER LIVED LIFR
WITH HEAVIER SNOW BURSTS OVERNIGHT. PREVIOUS TIMING IN TAFS STILL
LOOKS REASONABLE...WITH ONSET OF SNOW AT 05Z AT KSBN AND SHORTLY
AFTER THIS TIME AT KFWA. SNOW SHOULD END FROM WEST TO EAST IN THE
11Z-13Z TIMEFRAME. WEST WINDS EARLY THIS EVENING WILL VEER
SOUTHWEST TONIGHT IN ADVANCE OF A COLD FRONT...AND THEN SHIFT TO
THE WEST WITH FRONTAL PASSAGE EARLY SATURDAY MORNING. STEEP LOW
LEVEL LAPSE RATES AND DEEP WESTERLY FLOW WILL BE CONDUCIVE FOR A
WINDY DAY ON SATURDAY WITH LATE MORNING/AFTERNOON GUSTS INTO THE
30 TO 35 KNOT RANGE.
PREV DISCUSSION... /ISSUED 434 PM EST FRI JAN 27 2012/
SHORT TERM...
TONIGHT THROUGH SATURDAY NIGHT...THE CHALLENGES THIS PERIOD INCLUDE
THE TIMING AND AMOUNTS OF SNOW FROM AN UPPER LEVEL SYSTEM REACHING
THE AREA TONIGHT...AND ANOTHER SYSTEM SATURDAY NIGHT. FOR THIS
PACKAGE...PREFERRED THE HIGHER RESOLUTION NCEP MODELS WHICH APPEAR
TO HAVE THE BEST HANDLE ON THIS SYSTEM. ISENTROPIC LIFT WILL
INCREASE RAPIDLY TONIGHT WITH MOISTURE ON THE 285K SFC BETWEEN 2
AND 3 G/KG. USING THE GARCIA METHOD WITH THIS ENVIRONMENT YIELDS 2
TO 3 INCHES OF SNOW USING A 6 HOUR DURATION INPUT TIME. HOWEVER...
SOME CONCERN FOR SATURATION TIME AND MELTING SUGGESTS 1 TO 2
INCH SNOW AMOUNTS ARE MORE REASONABLE. CROSS SECTIONS INDICATE
THAT THE MOISTURE DEPTH IS SUFFICIENT FOR SNOW AND THE MAXIMUM
OMEGA FIELD INTERSECTS THE DENDRITIC GROWTH ZONE VERY WELL.
CURRENT THINKING IS WIDESPREAD SNOW FROM AFTER MIDNIGHT ENDING
SATURDAY MORNING. DOWNWARD MOTION BEHIND THE FRONT SHOULD HELP
WITH A RAPID END OF SNOW...ALTHOUGH WIND SPEEDS WILL INCREASE
SIGNIFICANTLY. AS FOR THE SYSTEM SATURDAY NIGHT...MUCH WEAKER LIFT
AND LIMITED MOISTURE INDICATE ANY SNOW AMOUNTS LESS THAN AN INCH.
LONG TERM...
NRN STREAM SW TROUGH OVR NWRN BC WILL AMPLIFY SEWD THROUGH THE SHRT
TERM AS MEAN ERN CONUS MID LVL TROUGH DEEPENS. 12Z SOLUTIONS ACRS
THE BOARD ARE MORE ROBUST ALOFT ESP THE GEM AND SUGGEST SOME UPWARD
BUMPING TO POPS IN ORDER ESP IMMEDIATELY DOWNSTREAM OF THE LK ACRS
SW MI IN RESPONSE TO PASSAGE OF SECONDARY CAA BURST DURING THE DAY
SUN.
OTHERWISE PRIMARY THEME THIS PD IS FOR DEAMPLIFICATION THROUGH MID
PD FOLLOWED BY MORE SIG WRN RIDGE/ERN TROUGH DVLPMNT TWD DY8. GIVEN
FAST FLW ALOFT...DETAIL PREDICTABILITY REMAINS LOW AND CAN NOT
ARGUE AGAINST LWR BOUND CHC POPS THROUGHOUT MUCH OF THE DY5-8 PD
GIVEN UNSETTLED/DISTURBANCE RIDDLED STREAM FLW THAT EXTENDS BACK
ACRS THE NPAC. LEAD IMPULSE MARKING THIS CHG RIDES EWD THROUGH THE
NRN PLAINS/SE CANADA MID PD W/SIG WARMING ANTICIPATED LOCALLY ESP
TUE/WED COINCIDENT W/LL THERMAL RIDGE SHIFTING ACRS THE AREA. AND AS
MENTIONED IN PRIOR DISC...SOME AREAS MAY WARM INTO THE 50S AS ELUDED
TO IN LATEST 12Z GFS MOS GUIDANCE ESP IF GREATER THAN ANTICIPATED
INSOLATION IS REALIZED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
SHORT TERM...MURPHY
LONG TERM...JC
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
310 PM EST FRI JAN 27 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A FAST MOVING CLIPPER SYSTEM WILL BRING LIGHT PRECIPITATION TO
CENTRAL INDIANA LATE TONIGHT AND EARLY SATURDAY...WITH THE POTENTIAL
FOR LIGHT SNOW OVER THE NORTHERN HALF OF THE REGION. COLDER AIR WILL
SPREAD INTO THE OHIO VALLEY FOR THE REST OF THE WEEKEND WITH THE
POSSIBILITY FOR ADDITIONAL LIGHT SNOW SHOWERS AND FLURRIES AS A
SYSTEM PASSES THROUGH THE AREAS SUNDAY MORNING. ADDITIONAL PRECIP
CHANCES ARRIVE FOR TUESDAY AND WEDNESDAY AND AGAIN FOR LATE NEXT
WEEK AS A SERIES OF FRONTS PASS THROUGH THE OHIO VALLEY.
&&
.NEAR TERM /REST OF TONIGHT/...
MAIN ADJUSTMENT DURING THE OVERNIGHT HOURS WILL BE TO SLOW DOWN
TIMING OF SNOW A LITTLE. BOTH RUC AND NEW NAM SHOW ALMOST ZERO QPF
ACROSS THE SOUTHEAST HALF OF OUR FORECAST AREA PRIOR TO 09Z. IN
ADDITION 1000-850 MB THICKNESS DO NOT DROP TO 1300 AT KIND UNTIL
AROUND 09Z. BUFKIT SHOWS GREATEST QPF OCCURRING DURING THE 09Z-14Z
PERIOD. WILL NOT MAKE ANY SIGNIFICANT CHANGES TO SNOW TOTALS OTHER
THAN TO DELAY THE TIMING A LITTLE WHERE SOME OF THIS WILL OCCUR
AFTER 12Z ACROSS THE EASTERN HALF OF OUR REGION.
PRIOR TO 09Z WILL GO WITH A MIXTURE OF RAIN AND SNOW OVER ALL BUT
FAR NORTHWEST AREAS. PREVIOUS FORECAST RELIED HEAVILY ON LAV
TEMPERATURES AND THIS SEEMS REASONABLE.
COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL SWEEP INTO THE
FORECAST AREA TOWARDS DAYBREAK WITH PRECIP ENDING SHORTLY
THEREAFTER.
TEMPS...AS MENTIONED ABOVE...EXPECT SURFACE TEMPERATURES WILL HOVER
AT OR ABOVE FREEZING FOR MUCH OF THE NIGHT. HAVE LEANED QUITE A BIT
CLOSER TO THE LAMP AND SREF RAW TEMPS AS OPPOSED TO MOS WHICH LOOKS
TO BE TOO COLD. ANY DROPS TO BELOW FREEZING TEMPS SHOULD NOT TAKE
PLACE UNTIL AROUND OR SHORTLY AFTER THE FRONTAL PASSAGE WITH THE
BOUNDARY LOCATED SOMEWHERE OVER THE EASTERN HALF OF THE FORECAST
AREA AT 12Z.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
RAISED POPS A LITTLE OVER ALL BUT FAR WESTERN SECTIONS EARLY
SATURDAY DUE TO SLOWER MOVEMENT OF SNOW. PREVIOUS SHORT TERM
DISCUSSION FOLLOWS BELOW.
FORECAST CHALLENGES FOCUS ON TEMPS AND WINDS IN WAKE OF THE CLIPPER
SATURDAY...AND POSSIBILITY OF ADDITIONAL FLURRIES/LIGHT SNOW SHOWERS
WITH A SECONDARY CLIPPER SUNDAY MORNING.
SHARP SUBSIDENCE AND DEEP DRYING ASSOCIATED WITH HIGH PRESSURE RIDGE
IN WAKE OF THE FRONT SATURDAY MORNING. PRECIP SET TO END OVER
EASTERN COUNTIES BY MID MORNING AT THE LATEST. IN PRESENCE OF
ABUNDANT DRY AIR...SKIES WILL BECOME MAINLY SUNNY FOR THE REMAINDER
OF THE DAY. STRONG LOW LEVEL JET AND COLD ADVECTION IN WAKE OF THE
CLIPPER WILL HELP FEED LOW LEVEL MIXING SATURDAY WITH GUSTY WINDS OF
30 TO 35 MPH POSSIBLE. GUSTS WILL DROP OFF SATURDAY NIGHT BUT
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SHOULD ENABLE SUSTAINED
OF 10-20MPH ALL NIGHT. MID AND HIGH LEVEL CLOUDS WILL INCREASE LATE
SATURDAY NIGHT AS ANOTHER SHORTWAVE ROTATES THROUGH THE WESTERN
GREAT LAKES.
SHORTWAVE ALOFT AND FRONTAL BOUNDARY AT SURFACE WILL ROTATE THROUGH
THE REGION SUNDAY MORNING. FORCING ALOFT IS WEAKER WITH
THIS SYSTEM AS OPPOSED TO THE ONE PASSING THROUGH THE GREAT LAKES
TONIGHT AND EARLY SATURDAY. HOWEVER...THAT AREA OF FORCING IS
FOCUSED MORE OVER THE NORTHERN HALF OF INDIANA AS OPPOSED TO THE
GREAT LAKES AND MODEL SOUNDINGS INDICATE SOME WEAK INSTABILITY
PRESENT IN THE BOUNDARY LAYER FOR SUNDAY MORNING. DESPITE LIMITED
MOISTURE...THINK THE PRESENCE OF THE FORCING AND INSTABILITY WILL
PROVIDE FOR A BRIEF PERIOD OF MORE THAN JUST FLURRIES SUNDAY
MORNING...ESPECIALLY OVER NORTHERN COUNTIES. HAVE INSERTED ACCUMS
OF A FEW TENTHS FOCUSED FROM LAFAYETTE TO MUNCIE WITH TRACE
AMOUNTS AS FAR SOUTH AS THE I-70 CORRIDOR. WILL BE A MUCH DRIER
SNOW WITH A COLDER AIRMASS PRESENT. ALL SNOW WILL BE EAST OF THE
FORECAST AREA BY MIDDAY. PARTLY CLOUDY SKIES CAN THEN BE EXPECTED
FOR THE REST OF THE PERIOD AS ANOTHER HIGH PRESSURE RIDGE BUILDS
INTO THE OHIO VALLEY.
TEMPS...COULD SEE TEMPS FALL A COUPLE DEGREES FROM 12Z LOWS SATURDAY
MORNING AS INITIAL SURGE OF COLD ADVECTION BEHIND FRONT ARRIVES.
TEMPS SHOULD REBOUND SOME FOR THE AFTERNOON BUT IN COLD ADVECTION
PATTERN AM UNDERCUTTING GUIDANCE. LOWS WILL BE REACHED SATURDAY
NIGHT BY MIDNIGHT AS QUICK SHOT OF WARM ADVECTION DEVELOPS AHEAD OF
THE SECONDARY CLIPPER. LEANED TOWARDS COOLER MAVMOS FOR SUNDAY WITH
THE RENEWAL OF COLD ADVECTION IN WAKE OF THE SECOND CLIPPER. COLDEST
NIGHT WILL BE SUNDAY NIGHT WITH LOWS FALLING INTO THE LOWER 20S FOR
MUCH OF THE FORECAST AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MAIN CHALLENGE TO THE EXTENDED WILL BE POPS ESPECIALLY LATE IN THE
PERIOD. THE 00Z ECMWF IS NOW IN BETTER AGREEMENT WITH THE 00Z GFS
AND ENSEMBLES AS IT IS DRY THURSDAY NIGHT AND FRIDAY. HOWEVER...THE
CR INITITIALIZATION WAS GIVING US SMALL POPS. WITH THE MODELS BEING
INCONSISTANT OVER THE LAST SEVERAL RUNS AND AFTER COORDINATING WITH
ADJACENT OFFICES...WILL GO AHEAD AND KEEP THEM IN DESPITE DRY 00Z
MODEL CONSENSUS. COULD SEE A MIX THURSDAY NIGHT WITH ALL RAIN FRIDAY
AHEAD OF SEPARATE UPPER TROUGHS. PRIOR TO THURSDAY NIGHT...MODELS IN
A LITTLE BETTER AGREEMENT ON A FRONT MOVING ACROSS CENTRAL INDIANA
MIDWEEK WHICH WILL BRING RAIN CHANCES TUESDAY AFTERNOON THROUGH
WEDNESDAY MORNING...AND ADDITIONAL RAIN CHANCES ON WEDNESDAY NIGHT
AND THURSDAY AHEAD OF THE FIRST OF TWO UPPER TROUGHS AND TO THE
NORTH OF A SURFACE SYSTEM MOVING ACROSS KENTUCKY. THESE TWO TROUGHS
WILL HELP BRING SOME COLDER AIR ACROSS CENTRAL INDIANA LATE IN THE
WEEK REPLACING A VERY MILD AIRMASS WITH EARLY AND MID WEEK HIGHS IN
THE 50S.
&&
.AVIATION /DISCUSSION FOR THE 280600Z TAF ISSUANCE/...
MVFR CEILINGS HAVE ARRIVED OR WILL SHORTLY ARRIVE AT ALL THE SITES
AHEAD OF THE CLIPPER SYSTEM THAT IS APPROACHING THE AREA. SNOW
SHOULD ARRIVE SHORTLY AT KLAF AND A MIX OF RAIN AND SNOW WILL MOVE
INTO KHUF OVER THE NEXT COUPLE OF HOURS. TIMING OF SNOW ARRIVAL AT
INDIANAPOLIS SHOULD BE AROUND 9Z WITH SIMILAR TIMING FOR A RAIN SNOW
MIX AT KBMG. WITH THE BEST FORCING AND MOISTURE IN THE NORTH HAVE
INCLUDED A TEMPO GROUP OF IFR VISIBILITIES AT KLAF. PRECIPITATION
SHOULD BE MOVING OUT OF THE AREA STARTING AROUND 12Z IN THE WEST AND
WORKING ITS WAY EAST SO THAT IT IS CLEAR OF ALL SITES BY AROUND 14Z.
SUBSIDENCE IN THE WAKE OF THE CLIPPER SYSTEM SHOULD ALLOW MVFR
CLOUDS TO SCATTER OUT BY LATE MORNING. A TIGHTENING PRESSURE
GRADIENT IN THE WAKE OF THE SYSTEM WILL BRING WIND GUSTS WITH
IT...WITH SUSTAINED WINDS OF 10-20 KTS AND GUSTS OF 25-30 KTS OUT OF
THE NORTHWEST DURING THE DAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN/JH
LONG TERM....MK
AVIATION...CP/MK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
100 AM EST SAT JAN 28 2012
.AVIATION /06 UTC TAFS/...
LEADING EDGE OF RAPID DETERIORATING FLIGHT CONDS INTO KSBN-KFWA LINE
ATTM WITH PRIMARY FOCUS ONTO BREVITY OF ANTICIPATED LIFR MET CONDS
AT KSBN AS SUBCLOUD LYR RAPIDLY SATURATES NEXT HOUR THEN HONED END
TIME AS FOCUS FOR LIFT MOVES RAPIDLY EWD. SIMILARLY AT KFWA SLIGHTLY
BETTER OVERALL CONDS FORECAST...GIVEN BOTH ANTECEDENT LARGE
900-700MB DEWPOINT DEPRESSIONS AND BEING MORE ON SRN PERIPHERY OF
STRONGER LIFT. LEANED HEAVILY ONTO HRRR TRENDS FOR RAPIDLY IMPROVING
CONDS 12-14 UTC WITH CLIPPER FOLLOWED BY SIG STRONGER SFC FLOW/GUSTS
PER INCRSD DOWNWARD MOMENTUM XFER AS SFC-800MB LAPSE RATES STEEPEN.
&&
.UPDATE...
CURRENT OBSERVATIONAL TRENDS SEEM TO BE SUPPORTING PREVIOUS
FORECAST TO THIS POINT. INCREASE IN RADAR RETURNS NOTED THE PAST
FEW HOURS ACROSS CENTRAL ILLINOIS DOWNSTREAM OF THE STRONGER UPPER
LEVEL FORCING JUST NOW EXITING THE CENTRAL PLAINS. A WEAKLY
FRONTOGENETIC FLOW APPEARS TO BE SETTING UP AND ENHANCING A FAIRLY
STRONG LOW LEVEL THERMAL RIBBON (-5 DEG CELSIUS PER 00Z KDVN RAOB
AND +1 DEG CELSIUS PER 00Z KILN RAOB). HIGHER RESOLUTION MODEL
OUTPUT AND EVEN NAM40 APPEAR TO HAVE SOME INDICATION OF THIS WEST
TO EAST EXPANSION OVER THE NEXT SEVERAL HOURS ACROSS WEST CENTRAL
AND SOUTHWEST PORTIONS OF THE AREA INITIALLY. ISENTROPIC PROGS OF
285K SFC ALSO SUGGEST SOME INCREASING ISENTROPIC ASCENT LATER THIS
EVENING ACROSS NORTHWEST PORTIONS OF THE AREA EVENTUALLY ALLOWING
SNOW TO OVERSPREAD NWRN HALF OF THE AREA TOWARD 06Z. EVEN SOME
REPORTS OF SOME -RA WITH BOUNDARY LAYER TEMPS IN THE LOWER TO MID
30S ACROSS EAST CENTRAL ILLINOIS. DID ADD A CHANCE RAIN/SNOW
MENTION ACROSS THE SOUTHWEST FOR A FEW HOURS THIS EVENING BUT WILL
STAY WITH PREDOMINATELY SNOW FOR THE OVERNIGHT.
PREVIOUS FCSTED SNOW AMOUNTS STILL APPEAR REASONABLE WITH A
POSSIBILITY OF TWO AREAS OF SLIGHTLY ENHANCED MAXIMUM
SNOWFALL...ONE ACROSS FAR NWRN IND/SWRN LWR MICHIGAN WITH SOME
WEAK LAKE ENHANCEMENT...AND ANOTHER POSSIBLE ACROSS SOUTHWEST
PORTIONS OF THE AREA WHERE A PERIOD OF SOME BETTER WEST TO EAST
BANDING IS POSSIBLE DURING EARLIER STAGES OF THE OVERNIGHT. SOME
OF THE INITIAL LIFT LATER THIS EVENING HOWEVER WILL BE SPENT TOWARD
ERODING A FAIRLY PRONOUNCED DRY LAYER EVIDENT IN THE 900 TO 750
HPA LAYER ON THIS EVENINGS REGIONAL AMDAR SOUNDINGS. ALL IN
ALL...1 TO 2 INCH SNOW AMOUNTS APPEAR TO BE INLINE AS UPPER
FORCING INCREASES WITH BETTER DEEPER SATURATION OVERNIGHT.
SLIGHTLY LESSER AMOUNTS EXPECTED ACROSS FAR EAST/SOUTHEAST WHERE
ISENTROPIC/FRONTOGENESIS PROGS ARE NOT EXPECTED TO BE QUITE AS
IMPRESSIVE.
&&
.PREV DISCUSSION... /ISSUED 727 PM EST FRI JAN 27 2012/
AVIATION...
00Z TAFS...SNOW WILL OVERSPREAD THE AREA LATE THIS EVENING INTO
THE OVERNIGHT HOURS IN ASSOCIATION WITH A FAST MOVING UPPER LEVEL
SYSTEM. IN THE MEANTIME...SOME FAIRLY DRY LOW LEVEL AIR NOTED IN
THIS EVENINGS REGIONAL AMDAR SOUNDINGS. MORE IMPRESSIVE BAND OF
SNOW PER REGIONAL RADAR MOSAIC/SFC EXTENDS FROM NORTHERN MISSOURI
INTO CENTRAL ILLINOIS WILL CONTINUE TO EXPAND EASTWARD THIS
EVENING IN ASSOCIATION WITH SOME LOW LEVEL FRONTOGENESIS FORCING.
NUMERICAL GUIDANCE STILL SUGGESTS INCREASING ISENTROPIC LIFT
FURTHER TO THE NORTH ACROSS NORTHERN INDIANA AND SHOULD SEE AN
EXPANSION OF -SN ACROSS FAR NRN INDIANA TOWARD MIDNIGHT ALONG WITH
DETERIORATING CONDITIONS TO IFR AND POSSIBLY SHORTER LIVED LIFR
WITH HEAVIER SNOW BURSTS OVERNIGHT. PREVIOUS TIMING IN TAFS STILL
LOOKS REASONABLE...WITH ONSET OF SNOW AT 05Z AT KSBN AND SHORTLY
AFTER THIS TIME AT KFWA. SNOW SHOULD END FROM WEST TO EAST IN THE
11Z-13Z TIMEFRAME. WEST WINDS EARLY THIS EVENING WILL VEER
SOUTHWEST TONIGHT IN ADVANCE OF A COLD FRONT...AND THEN SHIFT TO
THE WEST WITH FRONTAL PASSAGE EARLY SATURDAY MORNING. STEEP LOW
LEVEL LAPSE RATES AND DEEP WESTERLY FLOW WILL BE CONDUCIVE FOR A
WINDY DAY ON SATURDAY WITH LATE MORNING/AFTERNOON GUSTS INTO THE
30 TO 35 KNOT RANGE.
PREV DISCUSSION... /ISSUED 434 PM EST FRI JAN 27 2012/
SHORT TERM...
TONIGHT THROUGH SATURDAY NIGHT...THE CHALLENGES THIS PERIOD INCLUDE
THE TIMING AND AMOUNTS OF SNOW FROM AN UPPER LEVEL SYSTEM REACHING
THE AREA TONIGHT...AND ANOTHER SYSTEM SATURDAY NIGHT. FOR THIS
PACKAGE...PREFERRED THE HIGHER RESOLUTION NCEP MODELS WHICH APPEAR
TO HAVE THE BEST HANDLE ON THIS SYSTEM. ISENTROPIC LIFT WILL
INCREASE RAPIDLY TONIGHT WITH MOISTURE ON THE 285K SFC BETWEEN 2
AND 3 G/KG. USING THE GARCIA METHOD WITH THIS ENVIRONMENT YIELDS 2
TO 3 INCHES OF SNOW USING A 6 HOUR DURATION INPUT TIME. HOWEVER...
SOME CONCERN FOR SATURATION TIME AND MELTING SUGGESTS 1 TO 2
INCH SNOW AMOUNTS ARE MORE REASONABLE. CROSS SECTIONS INDICATE
THAT THE MOISTURE DEPTH IS SUFFICIENT FOR SNOW AND THE MAXIMUM
OMEGA FIELD INTERSECTS THE DENDRITIC GROWTH ZONE VERY WELL.
CURRENT THINKING IS WIDESPREAD SNOW FROM AFTER MIDNIGHT ENDING
SATURDAY MORNING. DOWNWARD MOTION BEHIND THE FRONT SHOULD HELP
WITH A RAPID END OF SNOW...ALTHOUGH WIND SPEEDS WILL INCREASE
SIGNIFICANTLY. AS FOR THE SYSTEM SATURDAY NIGHT...MUCH WEAKER LIFT
AND LIMITED MOISTURE INDICATE ANY SNOW AMOUNTS LESS THAN AN INCH.
LONG TERM...
NRN STREAM SW TROUGH OVR NWRN BC WILL AMPLIFY SEWD THROUGH THE SHRT
TERM AS MEAN ERN CONUS MID LVL TROUGH DEEPENS. 12Z SOLUTIONS ACRS
THE BOARD ARE MORE ROBUST ALOFT ESP THE GEM AND SUGGEST SOME UPWARD
BUMPING TO POPS IN ORDER ESP IMMEDIATELY DOWNSTREAM OF THE LK ACRS
SW MI IN RESPONSE TO PASSAGE OF SECONDARY CAA BURST DURING THE DAY
SUN.
OTHERWISE PRIMARY THEME THIS PD IS FOR DEAMPLIFICATION THROUGH MID
PD FOLLOWED BY MORE SIG WRN RIDGE/ERN TROUGH DVLPMNT TWD DY8. GIVEN
FAST FLW ALOFT...DETAIL PREDICTABILITY REMAINS LOW AND CAN NOT
ARGUE AGAINST LWR BOUND CHC POPS THROUGHOUT MUCH OF THE DY5-8 PD
GIVEN UNSETTLED/DISTURBANCE RIDDLED STREAM FLW THAT EXTENDS BACK
ACRS THE NPAC. LEAD IMPULSE MARKING THIS CHG RIDES EWD THROUGH THE
NRN PLAINS/SE CANADA MID PD W/SIG WARMING ANTICIPATED LOCALLY ESP
TUE/WED COINCIDENT W/LL THERMAL RIDGE SHIFTING ACRS THE AREA. AND AS
MENTIONED IN PRIOR DISC...SOME AREAS MAY WARM INTO THE 50S AS ELUDED
TO IN LATEST 12Z GFS MOS GUIDANCE ESP IF GREATER THAN ANTICIPATED
INSOLATION IS REALIZED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...GALE WARNING FROM 4 AM TO 7 PM EST SATURDAY FOR LMZ043-046.
&&
$$
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...MURPHY
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1136 PM EST FRI JAN 27 2012
.UPDATE...
THE AVIATION SECTION HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A FAST MOVING CLIPPER SYSTEM WILL BRING LIGHT PRECIPITATION TO
CENTRAL INDIANA LATE TONIGHT AND EARLY SATURDAY...WITH THE POTENTIAL
FOR LIGHT SNOW OVER THE NORTHERN HALF OF THE REGION. COLDER AIR WILL
SPREAD INTO THE OHIO VALLEY FOR THE REST OF THE WEEKEND WITH THE
POSSIBILITY FOR ADDITIONAL LIGHT SNOW SHOWERS AND FLURRIES AS A
SYSTEM PASSES THROUGH THE AREAS SUNDAY MORNING. ADDITIONAL PRECIP
CHANCES ARRIVE FOR TUESDAY AND WEDNESDAY AND AGAIN FOR LATE NEXT
WEEK AS A SERIES OF FRONTS PASS THROUGH THE OHIO VALLEY.
&&
.NEAR TERM /REST OF TONIGHT/...
MAIN ADJUSTMENT DURING THE OVERNIGHT HOURS WILL BE TO SLOW DOWN
TIMING OF SNOW A LITTLE. BOTH RUC AND NEW NAM SHOW ALMOST ZERO QPF
ACROSS THE SOUTHEAST HALF OF OUR FORECAST AREA PRIOR TO 09Z. IN
ADDITION 1000-850 MB THICKNESS DO NOT DROP TO 1300 AT KIND UNTIL
AROUND 09Z. BUFKIT SHOWS GREATEST QPF OCCURRING DURING THE 09Z-14Z
PERIOD. WILL NOT MAKE ANY SIGNIFICANT CHANGES TO SNOW TOTALS OTHER
THAN TO DELAY THE TIMING A LITTLE WHERE SOME OF THIS WILL OCCUR
AFTER 12Z ACROSS THE EASTERN HALF OF OUR REGION.
PRIOR TO 09Z WILL GO WITH A MIXTURE OF RAIN AND SNOW OVER ALL BUT
FAR NORTHWEST AREAS. PREVIOUS FORECAST RELIED HEAVILY ON LAV
TEMPERATURES AND THIS SEEMS REASONABLE.
COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL SWEEP INTO THE
FORECAST AREA TOWARDS DAYBREAK WITH PRECIP ENDING SHORTLY
THEREAFTER.
TEMPS...AS MENTIONED ABOVE...EXPECT SURFACE TEMPERATURES WILL HOVER
AT OR ABOVE FREEZING FOR MUCH OF THE NIGHT. HAVE LEANED QUITE A BIT
CLOSER TO THE LAMP AND SREF RAW TEMPS AS OPPOSED TO MOS WHICH LOOKS
TO BE TOO COLD. ANY DROPS TO BELOW FREEZING TEMPS SHOULD NOT TAKE
PLACE UNTIL AROUND OR SHORTLY AFTER THE FRONTAL PASSAGE WITH THE
BOUNDARY LOCATED SOMEWHERE OVER THE EASTERN HALF OF THE FORECAST
AREA AT 12Z.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
RAISED POPS A LITTLE OVER ALL BUT FAR WESTERN SECTIONS EARLY
SATURDAY DUE TO SLOWER MOVEMENT OF SNOW. PREVIOUS SHORT TERM
DISCUSSION FOLLOWS BELOW.
FORECAST CHALLENGES FOCUS ON TEMPS AND WINDS IN WAKE OF THE CLIPPER
SATURDAY...AND POSSIBILITY OF ADDITIONAL FLURRIES/LIGHT SNOW SHOWERS
WITH A SECONDARY CLIPPER SUNDAY MORNING.
SHARP SUBSIDENCE AND DEEP DRYING ASSOCIATED WITH HIGH PRESSURE RIDGE
IN WAKE OF THE FRONT SATURDAY MORNING. PRECIP SET TO END OVER
EASTERN COUNTIES BY MID MORNING AT THE LATEST. IN PRESENCE OF
ABUNDANT DRY AIR...SKIES WILL BECOME MAINLY SUNNY FOR THE REMAINDER
OF THE DAY. STRONG LOW LEVEL JET AND COLD ADVECTION IN WAKE OF THE
CLIPPER WILL HELP FEED LOW LEVEL MIXING SATURDAY WITH GUSTY WINDS OF
30 TO 35 MPH POSSIBLE. GUSTS WILL DROP OFF SATURDAY NIGHT BUT
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SHOULD ENABLE SUSTAINED
OF 10-20MPH ALL NIGHT. MID AND HIGH LEVEL CLOUDS WILL INCREASE LATE
SATURDAY NIGHT AS ANOTHER SHORTWAVE ROTATES THROUGH THE WESTERN
GREAT LAKES.
SHORTWAVE ALOFT AND FRONTAL BOUNDARY AT SURFACE WILL ROTATE THROUGH
THE REGION SUNDAY MORNING. FORCING ALOFT IS WEAKER WITH
THIS SYSTEM AS OPPOSED TO THE ONE PASSING THROUGH THE GREAT LAKES
TONIGHT AND EARLY SATURDAY. HOWEVER...THAT AREA OF FORCING IS
FOCUSED MORE OVER THE NORTHERN HALF OF INDIANA AS OPPOSED TO THE
GREAT LAKES AND MODEL SOUNDINGS INDICATE SOME WEAK INSTABILITY
PRESENT IN THE BOUNDARY LAYER FOR SUNDAY MORNING. DESPITE LIMITED
MOISTURE...THINK THE PRESENCE OF THE FORCING AND INSTABILITY WILL
PROVIDE FOR A BRIEF PERIOD OF MORE THAN JUST FLURRIES SUNDAY
MORNING...ESPECIALLY OVER NORTHERN COUNTIES. HAVE INSERTED ACCUMS
OF A FEW TENTHS FOCUSED FROM LAFAYETTE TO MUNCIE WITH TRACE
AMOUNTS AS FAR SOUTH AS THE I-70 CORRIDOR. WILL BE A MUCH DRIER
SNOW WITH A COLDER AIRMASS PRESENT. ALL SNOW WILL BE EAST OF THE
FORECAST AREA BY MIDDAY. PARTLY CLOUDY SKIES CAN THEN BE EXPECTED
FOR THE REST OF THE PERIOD AS ANOTHER HIGH PRESSURE RIDGE BUILDS
INTO THE OHIO VALLEY.
TEMPS...COULD SEE TEMPS FALL A COUPLE DEGREES FROM 12Z LOWS SATURDAY
MORNING AS INITIAL SURGE OF COLD ADVECTION BEHIND FRONT ARRIVES.
TEMPS SHOULD REBOUND SOME FOR THE AFTERNOON BUT IN COLD ADVECTION
PATTERN AM UNDERCUTTING GUIDANCE. LOWS WILL BE REACHED SATURDAY
NIGHT BY MIDNIGHT AS QUICK SHOT OF WARM ADVECTION DEVELOPS AHEAD OF
THE SECONDARY CLIPPER. LEANED TOWARDS COOLER MAVMOS FOR SUNDAY WITH
THE RENEWAL OF COLD ADVECTION IN WAKE OF THE SECOND CLIPPER. COLDEST
NIGHT WILL BE SUNDAY NIGHT WITH LOWS FALLING INTO THE LOWER 20S FOR
MUCH OF THE FORECAST AREA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MODELS CONCUR WITH ACTIVE PATTERN. BIG DIFFERENCES MORE IN TIMING
THAN CONCEPTS. THIS IS A SITUATION THAT CALLS FOR ENSEMBLE
TACTICS. ALL BLEND PROVIDED BY CENTRAL REGION SHOULD BE JUST THE
TICKET.
MOST IMPORTANT QUESTION WILL BE WHETHER WE CAN PRODUCE ANY SNOW IN
SYSTEMS PASSING FRIDAY. RIGHT NOW...ITS JUST TOO EARLY SAY MORE
THAN A CHANCE OF RAIN OR SNOW.
&&
.AVIATION /DISCUSSION FOR THE 280600Z TAF ISSUANCE/...
MVFR CEILINGS HAVE ARRIVED OR WILL SHORTLY ARRIVE AT ALL THE SITES
AHEAD OF THE CLIPPER SYSTEM THAT IS APPROACHING THE AREA. SNOW
SHOULD ARRIVE SHORTLY AT KLAF AND A MIX OF RAIN AND SNOW WILL MOVE
INTO KHUF OVER THE NEXT COUPLE OF HOURS. TIMING OF SNOW ARRIVAL AT
INDIANAPOLIS SHOULD BE AROUND 9Z WITH SIMILAR TIMING FOR A RAIN SNOW
MIX AT KBMG. WITH THE BEST FORCING AND MOISTURE IN THE NORTH HAVE
INCLUDED A TEMPO GROUP OF IFR VISIBILITIES AT KLAF. PRECIPITATION
SHOULD BE MOVING OUT OF THE AREA STARTING AROUND 12Z IN THE WEST AND
WORKING ITS WAY EAST SO THAT IT IS CLEAR OF ALL SITES BY AROUND 14Z.
SUBSIDENCE IN THE WAKE OF THE CLIPPER SYSTEM SHOULD ALLOW MVFR
CLOUDS TO SCATTER OUT BY LATE MORNING. A TIGHTENING PRESSURE
GRADIENT IN THE WAKE OF THE SYSTEM WILL BRING WIND GUSTS WITH
IT...WITH SUSTAINED WINDS OF 10-20 KTS AND GUSTS OF 25-30 KTS OUT OF
THE NORTHWEST DURING THE DAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN/JH
LONG TERM....JK
AVIATION...CP
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
259 PM CST SAT JAN 28 2012
.DISCUSSION...
DAYS 1-2...
.SHORT TERM /TODAY THROUGH MONDAY/
SURFACE HIGH PRESSURE RESIDES TO THE IMMEDIATE SOUTH OF THE AREA
THIS AFTERNOON PROVIDING LIGHT NORTHWEST WINDS ACROSS THE BULK OF
THE FORECAST AREA. THE AIRMASS IS QUITE DRY AND AFTERNOON MIXING
HAS CREATED VERY LOW DEW POINTS ACROSS THE AREA THAT HAVE PUSHED
RELATIVE HUMIDITIES INTO THE 15 TO 20 PERCENT RANGE ACROSS A LARGE
PORTION OF THE EAST. WITH WIND GUSTS BETWEEN 20 AND 30 MPH, THIS
HAS BROUGHT CONDITIONS CLOSE TO RED FLAG THIS AFTERNOON. IT IS
LIKELY SOME LOCATIONS OF THE EAST CENTRAL INCLUDING PRATT AND
STAFFORD COUNTIES MIGHT REACH THE RED FLAG RH AND WIND ELEMENTS
LOCALLY, BUT IT DOES NOT APPEAR A TIME THRESHOLD FOR TRUE RED FLAG
WARNING WILL BE MET SINCE TEMPERATURES WILL BEGIN TO RADIATIONAL
COOL RAPIDLY BY 5 PM.
THE MODELS SHOW FAIRLY SIMILAR FIELDS OVER THE NEXT COUPLE OF DAYS
ON THE SYNOPTIC AND MESOSCALE. THE WARM UP THAT WAS FORECAST IS STILL
EXPECTED. DEW POINTS SHOULD INCREASE FROM THE VERY LOW VALUES WE
OBSERVED THIS AFTERNOON, AS THE SURFACE ANTICYCLONE DRIFTS INTO THE
LOWER MISSISSIPPI VALLEY. MAINLY SUNNY SKIES ARE ANTICIPATED AS
WELL, ALTHOUGH SOME CIRRUS MY BE OFF TO THE NORTHEAST ASSOCIATED THE
NORTHWESTERLY ORIENTED JET. AS THE UPPER FLOW SLOWLY BECOMES ZONAL
OVER WESTERN KANSAS, A WEAK SURFACE TROUGH WILL REMAIN ANCHORED
ACROSS EASTERN COLORADO ALLOWING SOUTHWEST TO SOUTH WINDS OVER
ACROSS OUR COUNTIES. BOUNDARY LAYER THETA-E WILL INCREASE THROUGH
THE OVERNIGHT INTO MONDAY PERIOD ALLOWING AFTERNOON HIGHS TO RISE
THROUGH THE LOW 50S ON SUNDAY AND THE UPPER 50S AND LOW 60S ON
MONDAY. LOWS WILL PROBABLY NOT GET QUITE AS COLD WITH SOME LIGHT
WINDS EXPECTED OVERNIGHT AND LESS DRY AIR. STILL - TEMPERATURES
TONIGHT MAY REACH THE UPPER TEENS WITH VERY STRONG RADIATIONAL
COOLING, BUT THETA-E INCREASE ON SUNDAY SHOULD LIMIT COOLING TO THE
UPPER 20S ON SUNDAY NIGHT.
DAYS 3-7...
WESTERLY FLOW WILL IMPROVE EARLY NEXT AS A SERIES OF UPPER LEVEL
DISTURBANCES MOVE OUT OF THE PACIFIC AND ACROSS THE WESTERN/CENTRAL
UNITED STATES. THE FIRST UPPER LEVEL TROUGH REMAINS ON TRACK TO
CROSS OUT OF THE ROCKIES AND INTO THE CENTRAL PLAINS ON TUESDAY WITH
THE NEXT, STRONGER UPPER LEVEL TROUGH FORECAST TO DIG FURTHER SOUTH
INTO THE SOUTHERN PLAINS BY EARLY THURSDAY. FOR WESTERN KANSAS THE
MOISTURE WITH EACH OF THESE SYSTEMS APPEAR TO BE CONFINED MAINLY IN
THE MID TO UPPER LEVELS. ON TUESDAY THERE WILL BE SOME UPPER LEVEL
JET DYNAMICS IN THE NORTH WHILE ON THURSDAY THERE WILL BE BETTER MID
LEVEL LAPSE RATES, 700MB IMPROVING FRONTOGENESIS, AND 850MB WARM AIR
ADVECTION DEVELOPING ACROSS PORTIONS OF SOUTH CENTRAL KANSAS AHEAD
OF THIS WAVE. MAIN CONCERN THIS SECOND UPPER LEVEL TROUGH IS THE
EVOLUTION AND TRACK GIVEN THAT THE NEW GFS AND ECMWF ARE NOW
DIFFERING FROM PREVIOUS RUNS. AS A RESULT CONFIDENCE AFTER DAY 5 IS
LOW SO GIVEN THIS WILL STAY CLOSE TO THE PREVIOUS FORECAST AND LEAVE
THE LATER PERIODS FREE FROM ANY TYPE OF PRECIPITATION.
AS FOR TEMPERATURES...A WEAK COLD FRONT WILL BRIEFLY RETURN ON
TUESDAY BEHIND OUR FIRST UPPER LEVEL TROUGH. TEMPERATURES THEN
BRIEFLY WARM MID TO LATE WEEK UNTIL OUR ANOTHER COLD FRONT RETURNS
ON FRIDAY AS THE SECOND, STRONGER, UPPER LEVEL TROUGH CROSSES THE
CENTRAL/SOUTHERN PLAINS.
$$
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
WEST WINDS WILL INCREASE INTO THE 15 TO NEAR 20 KT RANGE THIS
AFTERNOON BASED ON MIXED LAYER WINDS FROM THE RUC AND NAM MODEL
SOUNDINGS. THESE GUSTY AFTERNOON WINDS WILL THEN SUBSIDE AFTER
SUNSET AS THE ATMOSPHERE DECOUPLES. MODELS SOUNDINGS TODAY ALSO
INDICATING VFR CONDITIONS THROUGHOUT THE PERIOD.
$$
18
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 59 27 64 / 0 0 0 0
GCK 19 59 25 64 / 0 0 0 0
EHA 23 59 27 65 / 0 0 0 0
LBL 22 58 27 65 / 0 0 0 0
HYS 20 58 26 65 / 0 0 0 0
P28 21 58 27 63 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1106 AM CST SAT JAN 28 2012
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 312 AM CST SAT JAN 28 2012
PERSISTENT DOWNSLOPE FLOW IN THE MID LEVELS WILL ALLOW FOR A FAIRLY
DECENT WARM-UP IN TEMPERATURES TODAY AND SUNDAY. THE SURFACE HIGH
WHICH WAS CENTERED OVER COLORADO DURING THE OVERNIGHT HOURS...WILL
SHIFT SOUTHEAST TO THE RED RIVER VALLEY...RESULTING IN A GENERAL
WEST WIND ACROSS WESTERN KANSAS. HIGHS SHOULD REACH UPPER 40S WITH
EASE AND A FEW 50 DEGREE READINGS WILL LIKELY DOT SOUTHWEST KANSAS
AS WELL.
ANOTHER NORTHWEST FLOW JET STREAK WILL PASS BY TO THE NORTHEAST AND
HAVE NO IMPACT ON SENSIBLE WEATHER ACROSS WESTERN KANSAS TONIGHT
THROUGH SUNDAY NIGHT...IN FACT AFTER THIS JET PASSES BY WE WILL
START TO SEE A MARKED INCREASE IN THE LOW LEVEL
THICKNESSES/TEMPERATURE. 850MB TEMPERATURES WILL BE +6 TO +8C AND
DESPITE THE FAIRLY SHALLOW WINTER MIXING DEPTHS, HIGHS WELL INTO THE
50S TO NEAR 60 WILL LIKELY OCCUR GIVEN THIS WARM OF A LOWER
TROPOSPHERE FROM DOWNSLOPE. WINDS WILL RESPOND MARGINALLY TO A LEE
TROUGH OVER THE NORTHERN PLAINS...MORE OUT OF THE SOUTHWEST ON
SUNDAY VERSUS DUE WEST LIKE WE WILL SEE TODAY. THE SOUTHWEST WINDS
SHOULD CONTINUE THROUGH THE NIGHT SUNDAY NIGHT RESULTING IN MINIMUM
TEMPERATURES ABOVE AVERAGE IN THE UPPER 20S ACROSS MOST OF THE DDC
FORECAST AREA. -UMSCHEID
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 312 AM CST SAT JAN 28 2012
THE EXTENDED PERIOD BEGINS 12Z MONDAY AND GENERALLY IS MARKED BY DRY
CONDITIONS AND ABOVE NORMAL TEMPERATURES.
MONDAY:
THE BEGINNING OF THE NEXT WORK WEEK LOOKS TO BE A RELATIVELY WARM
ONE. A RATHER BROAD SHORTWAVE TROUGH IS EXPECTED TO BE LOCATED OVER
THE NORTHERN ROCKIES. THE 28.00Z ECMWF IS SLIGHTLY MORE PROGRESSIVE
COMPARED TO THE 28.00Z GFS WITH THE UPPER LEVEL WAVE. RELIED MORE
HEAVILY ON THE ECMWF FOR GRID MODIFICATIONS GIVEN THE POOR
PERFORMANCE OF THE GFS RECENTLY. DOWNSTREAM OF THE SHORTWAVE, A WARM
AIR ADVECTION PATTERN WILL BE IN PLACE ACROSS WESTERN KANSAS. LEE
TROUGHING AND 850 HPA TEMPERATURES WARMING INTO THE 11 TO 15 DEG C
RANGE PLUS A BIT OF DOWNSLOPE SOUTHWESTERLY SURFACE WINDS WILL
PROMOTE HIGH TEMPERATURES PEAKING WELL INTO THE 60S DEG F.
TUESDAY:
THE UPPER LEVEL WAVE WILL MOVE ACROSS THE CENTRAL PLAINS BY TUESDAY
AND WILL DRIVE A WEAK COLD FRONT ALONG WITH IT. NEGATIVE TEMPERATURE
ADVECTION IN ASSOCIATION WITH THE FRONT IS NOT VERY STRONG ALTHOUGH
ENOUGH TO DRIVE TEMPERATURES BACK DOWN INTO THE 50S DEG F. EVEN IF
THE 50S DEG F OCCUR, THESE VALUES ARE STILL WELL ABOVE NORMAL (NORM
IS IN THE 40S DEG F). THIS FRONT WILL BE MAINLY DRY SO HAVE CONTINUE
WITH THE ALLBLEND POP GRIDS THAT ARE LESS THAN 15 PERCENT.
WEDNESDAY:
ANOTHER SHORTWAVE TROUGH WILL CONTINUE TO DEEPEN ACROSS THE ROCKIES
AND WILL EVENTUALLY MOVE OUT ACROSS THE PLAINS BY MIDWEEK. EVEN
THOUGH KANSAS WILL BECOME IN A MORE FAVORABLE JET STREAK QUADRANT
(RIGHT ENTRANCE REGION), MOISTURE ASSOCIATED WITH THIS WAVE LOOKS
MAINLY TO BE LIMITED TO THE MID LEVELS OF THE ATMOSPHERE (600 TO 400
HPA). AS A RESULT AND AFTER COORDINATION WITH OTHER WFOS, HAVE
CAPPED OFF THE POP VALUES TO 14 PERCENT (FROM 15 TO 16 PERCENT).
THURSDAY:
HIGH PRESSURE WILL BUILD ACROSS THE PLAINS THURSDAY WITH
TEMPERATURES STARTING OUT COOL IN THE MORNING. COORDINATED WITH
OTHER WFO OFFICES IN USING THE BCALLBLEND AS THE COOL HIGH PRESSURE
CENTER SLIDES ACROSS KANSAS. EXPECT TEMPERATURES IN THE LOW TO MID
50S DEG F FOR HIGHS AND 20S DEG F FOR LOWS.
FRIDAY/SATURDAY:
DID NOT STRAY MUCH FROM THE ALLBLEND APPROACH AS CONFIDENCE
DECREASES THIS FAR OUT IN THE EXTENDED PERIOD. THE OVERALL SYNOPTIC
PATTERN IN BOTH THE GFS/ECMWF IS NOT FAVORABLE FOR PRECIPITATION FOR
SW KANSAS. A LARGE AMPLIFIED 500 HPA RIDGE IS FORECAST OVER THE
ROCKIES AND WILL PUT KANSAS IN A DRY NW/N FLOW ALOFT CONFIGURATION.
THIS COULD FAVOR PASSAGES OF WEAK/DRY FRONTS. TEMPERATURES WILL
STILL CONTINUE TO TREND ABOVE NORMAL IN THIS LA NINA WINTER. -SUGDEN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1105 AM CST SAT JAN 28 2012
WEST WINDS WILL INCREASE INTO THE 15 TO NEAR 20 KT RANGE THIS
AFTERNOON BASED ON MIXED LAYER WINDS FROM THE RUC AND NAM MODEL
SOUNDINGS. THESE GUSTY AFTERNOON WINDS WILL THEN SUBSIDE AFTER
SUNSET AS THE ATMOSPHERE DECOUPLES. MODELS SOUNDINGS TODAY ALSO INDICATING
VFR CONDITIONS THROUGHOUT THE PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 312 AM CST SAT JAN 28 2012
WE WILL BE WATCHING FOR NEAR-CRITICAL FIRE WEATHER CONDITIONS
DEVELOPING ACROSS WEST-CENTRAL KANSAS TODAY AS THE PRESSURE GRADIENT
WILL BE STRONGEST ACROSS THE INTERSTATE-70 CORRIDOR. SURFACE WINDS
SHOULD INCREASE TO 18 TO 24 KNOTS IN THIS AREA. THE DEWPOINT AND
RESULTING RELATIVE HUMIDITY FORECAST IS TRICKY...BUT AT THIS TIME WE
BELIEVE THE MINIMUM AFTERNOON RELATIVE HUMIDITY WILL STAY ABOVE THE
15 PERCENT THRESHOLD FOR CRITICAL FIRE. WILL MENTION "NEAR
CRITICAL" FIRE WEATHER IN THE HAZARDOUS WEATHER OUTLOOK. ANOTHER
WARM, DRY, AND BREEZY DAY IS EXPECTED SUNDAY WHICH WILL MOST LIKELY
YIELD NEAR-CRITICAL CONDITIONS AGAIN. -UMSCHEID
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 20 59 28 / 0 0 0 0
GCK 47 19 59 26 / 0 0 0 0
EHA 48 22 59 29 / 0 0 0 0
LBL 48 20 58 27 / 0 0 0 0
HYS 49 18 58 27 / 0 0 0 0
P28 48 23 58 29 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...25
SHORT TERM...25
LONG TERM....36
AVIATION...99
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
350 PM EST SAT JAN 28 2012
.SYNOPSIS...
A SERIES OF WEAK COLD FRONTS WILL ZIP THROUGH THE UPPER OHIO
VALLEY THIS WEEKEND AND BRING A MIX OF LIGHT RAIN AND SNOW
SHOWERS, ALONG WITH GUSTY WINDS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MAIN ADDITION WAS TO ADD MENTION OF MIX WITH SLEET LATE AFTERNOON. ALSO
UPPED WIND GUSTS TO 40 TO 45 MPH PER RECENT UPWIND SURFACE DATA
AND NAM MODEL PROFILES. RECENT RADAR DATA AND HRRR MODEL OUTPUT
SHOW POST FRONTAL SNOW SHOWERS ENDING EARLY TONIGHT, WITH MINIMAL
SNOW ACCUMULATION NORTH AND MOUNTAINS.
FORECASTED LOW TEMPERATURES TO BE NEAR NORMAL, USING BLEND OF NAM
AND GFS MOS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
PER RECENT NAM MODEL OUTPUT, EXPECT CLIPPER-TYPE LOW PRESSURE
MOVING QUICKLY THROUGH THE GREAT LAKES TO PUSH A COLD FRONT
THROUGH THE UPPER OHIO VALLEY SUNDAY MIDDAY AND AFTERNOON.
EXPECT TEMPERATURES TO BE A TAD COLDER THAN SATURDAY, HENCE MORE
AREAS CAN SEE LIGHT SNOW SHOWERS. ITS POSSIBLE THERE CAN BE SHORT
BURSTS OF SLEET, BUT HAVE HELD OFF MENTION. SNOW ACCUMULATIONS
WILL AGAIN BE MINIMAL.
WITH UPPER JETSTREAM FLOW BACKING SLIGHTLY INTO THE WEST
SOUTHWEST, THE NEXT CLIPPER-TYPE SYSTEM TO PASS EASTWARD THROUGH
THE GREAT LAKES MAY HAVE LESS IMPACT ON THE UPPER OHIO VALLEY.
STILL INCLUDED A CHANCE OF SHOWERS OF RAIN AND SNOW, BUT MAINLY
NORTH.
FORECASTED HIGHS MONDAY TO BE 2-3 DEGREES WARMER THAN SUNDAY.
RECENT ECMWF MODEL OUTPUT SHOWS A DRY BREAK MONDAY NIGHT AND
TUESDAY WITH SOUTHWEST WINDS PROVIDING A WARM UP TO 10 DEGREES
ABOVE NORMAL, PER GFS AND NAEFS VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN FAIRLY GOOD AGREEMENT ON A COLD FRONT PASSAGE
WEDNESDAY AS THE ASSOCIATED LOW PRESSURE SYSTEM CROSSES NORTH OF THE
GREAT LAKES. BEYOND WEDNESDAY...THERE ARE INCONSISTENCIES FROM
RUN TO RUN WITH THE DETERMINISTIC MODELS KEEPING CONFIDENCE
RELATIVELY LOW ESPECIALLY INTO FRIDAY AND SATURDAY.
ALL MODELS SUGGEST A GRADUAL DEEPENING LONG WAVE TROUGH OVER THE
CENTRAL U.S WITH THE GFS THE STRONGEST AND THE ECMWF AND GEFS
ENSEMBLES REMAINING LESS AMPLIFIED. THIS IN TURN MAKES LOW
PLACEMENT SIGNIFICANTLY DIFFERENT BETWEEN THE MODELS. WITH SUCH A
WIDE SPREAD...OPTED TO REMAIN CLOSE TO HPC GUIDANCE FOR THE PERIOD
FROM THURSDAY THROUGH SATURDAY...WHICH IS CLOSEST TO THE 00/12Z
ECMWF AND GEFS. THIS WOULD BRING A SURFACE LOW SOUTH ALONG THE
APPALACHIANS AND OFF THE COAST BY FRIDAY.
KEPT TEMPERATURES CLOSE TO AN HPC MEX BLEND WHICH SEEMED TO MATCH UP
WELL WITH NAEFS TRENDS.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
A FAST MOVING COLD FRONT WILL KEEP TERMINALS MVFR WITH POSSIBLE IFR
VSBY IN SNOW THROUGH EARLY THIS AFTERNOON. TRIED BEST TO TIME THE
COLD FRONT PASSAGE THROUGH ALL TERMINAL SITES BY 22Z BASED OFF OF
CURRENT SATELLITE AND RADAR TRENDS AS WELL AS LAMP GUIDANCE.
CONDITIONS SHOULD QUICKLY IMPROVE TO VFR BEHIND THE COLD FRONT...WITH
THE EXCEPTION BEING KFKL AND KDUJ WHICH MAY TAKE LONGER TO IMPROVE.
WINDS WILL VEER MORE WESTERLY BEHIND THE FRONT AND GUSTS TO 35-40MPH
WILL BE POSSIBLE THROUGH THE REST OF THE AFTERNOON. WIND GUSTS
SHOULD BEGIN TO DIMINISH BY SUNSET TO 10KTS OR LESS AS HIGH PRESSURE
BUILDS IN BRIEFLY BEFORE THE NEXT QUICK MOVING SYSTEM APPROACHES
SUNDAY.
OUTLOOK...SUNDAY THROUGH THURSDAY...
THE POTENTIAL FOR RESTRICTIONS WILL EXIST AGAIN SUNDAY AFTN AS
ANOTHER UPPER TROUGH GENERATES SNOW SHOWERS FOR MOST TERMINALS. VFR
CONDITIONS ARE THEN ANTICIPATED MONDAY AND TUESDAY UNDER HIGH
PRESSURE. A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND
POSSIBLE RESTRICTIONS ON WEDNESDAY AND THURSDAY
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1125 AM EST SAT JAN 28 2012
.SYNOPSIS...
A SERIES OF WEAK COLD FRONTS WILL ZIP THROUGH THE UPPER OHIO
VALLEY THIS WEEKEND AND BRING A MIX OF LIGHT RAIN AND SNOW
SHOWERS, ALONG WITH GUSTY WINDS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TWEAKED HOURLY TEMPERATURES AND WEATHER FORECASTS THROUGH EVENING,
BASED ON RECENT SURFACE AND RADAR DATA AND HRRR MODEL OUTPUT.
SLIGHTLY RAISED POSTFRONTAL WIND GUSTS LATE THIS AFTERNOON TO
30-35 MPH PER NAM MODEL OUTPUT.
WITH TEMPERATURES MAINLY WARMER THAN 32 BEFORE SHOWERS WANE THIS
EVENING, EXPECT NO MORE THAN TRIVIAL SNOW ACCUMULATIONS ACROSS
HIGHER ELEVATIONS AND NORTH.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
THE NEXT UPPER LEVEL SHORT WAVE, AND ITS WEAK SURFACE COLD FRONT,
WILL PROGRESS ACROSS THE UPPER OHIO REGION ON SUNDAY. WITH
TEMPERATURES A TAD COLDER THAN SATURDAY, EXPECT THE MAIN
PRECIPITATION TYPE TO BE SNOW, WITH A BETTER CHANCE FOR SOME LIGHT
ACCUMULATION FOR AREAS NORTH OF I 70.
BUILDING HIGH IN THE WAKE OF THAT TROUGH IS FORECAST TO DRY THE
WEATHER AGAIN FOR SUNDAY NIGHT AND MONDAY.
SHORT-TERM TEMPERATURES WERE PROGGED NEAR THE SEASONAL
NORMALS...AGAIN USING A GUIDANCE BLEND.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE IS PROJECTED TO MOVE OFF THE SOUTHEASTERN UNITED
STATES COAST TUESDAY...WITH CONDITIONS REMAINING DRY. MODELS ARE
IN GOOD AGREEMENT SHOWING LOW PRESSURE MOVING ACROSS CANADA AND
BRINGING A COLD FRONT ACROSS THE REGION...ALTHOUGH THERE IS SOME
DISAGREEMENT WITH TIMING. AVERAGE TIMING PUTS FRONTAL PASSAGE
AROUND WEDNESDAY...AND HAVE PUT HIGHEST POPS IN THE FORECAST AT
THAT TIME. 12Z GFS/ECMWF ARE MORE AGGRESSIVE THAN THEIR 00Z
COUNTERPARTS IN DEVELOPING A LOW ACROSS THE SOUTHEASTERN UNITED
STATES...AND MOVING IT OFFSHORE OF NEW YORK CITY BY FRIDAY
MORNING. THIS BRINGS IN POPS FOR THE EASTERN HALF OF THE REGION
THURSDAY INTO FRIDAY...WITH SLIGHT CHANCE POPS TO THE WEST.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL DURING THIS TIME
PERIOD.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCUMULUS WILL REMAIN OVER THE REGION THIS MORNING AHEAD
OF AN APPROACHING UPPER TROUGH AND ASSOCIATED WEAK SURFACE COLD
FRONT. SOUTHWEST SURFACE WINDS WILL INCREASE THIS AFTERNOON WITH GUSTS
TO 25 KTS.
LIGHT MIX OF RAIN AND SNOW SHOWERS CAN MAINTAIN MVFR RESTRICTIONS. SPOTTY
IFR CONDITIONS ARE POSSIBLE...ESPECIALLY IN THE NORTH, WHERE SNOW
SHOWERS CAN BE MORE THE PREVALENT WEATHER TYPE.
BEHIND THE COLD FRONT...WINDS WILL BECOME WESTERLY WITH GUSTS TO
25-30 KTS INTO EARLY EVENING, THEN DIMINISH TO SOUTHWEST AT 10 KTS
OR LESS. AS PRECIPITATION ENDS THIS EVENING, STRATOCUMULUS
CEILINGS WILL LIFT TO VFR TONIGHT.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
POTENTIAL FOR RESTRICTIONS WILL EXIST AGAIN SUNDAY AS ANOTHER UPPER
TROUGH GENERATES SNOW SHOWERS FOR MOST TERMINALS. VFR CONDITIONS
ARE THEN ANTICIPATED MONDAY AND TUESDAY UNDER HIGH PRESSURE. A
COLD FRONT IS EXPECTED TO BRING ANOTHER ROUND OF SHOWERS AND
RESTRICTIONS ON WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATE
NWS MARQUETTE MI
805 PM EST SUN JAN 29 2012
.UPDATE...
TEMPS HAVE FALLEN QUITE SHARPLY NEAR THE WI BORDER WHERE SKIES HAVE
CLEARED IN THE PRESENCE OF LGT WINDS AND DRY AIRMASS...PROBABLY WELL
REPRESENTED BY 12Z PWAT OF 0.09 INCH AT INL. SO LOWERED GOING FCST
MIN TEMPS IN AREAS WHERE SKIES ARE NOW CLR NEAR THE WI BORDER OR WL
BECOME MOCLR OVERNGT INLAND FM LK SUP. WITH THE ARRIVAL OF WAD CLD
LATER TNGT...EXPECT TEMPS TO RISE THEN...SO ADJUSTED HOURLY TEMPS IN
THE GRIDS TO REFLECT THESE EXPECTATIONS.
EARLIER UPDATE ISSUED AT 7 PM...
OPTED TO ISSUE AN LES ADVY FOR ERN ALGER/NRN LUCE COUNTY UNTIL EARLY
MON MRNG AS 18Z NAM/LOCAL WRF-ARW RUNS SHOW AREA OF FOCUSED LLVL
CNVGC IN THIS AREA THRU ABOUT 06Z WITH MORE WSW LAND BREEZE FLOW
OVER THE INTERIOR AND PERSISTENT WNW FLOW OVER THE WATER. WFR-ARW
RUN ALSO INDICATES FAVORABLE OMEGA WITHIN THE DGZ IN THIS AREA WITH
INVRN BASE ARND 5K FT...SO HEADLINE SEEMS WARRANTED. ONCE THE H925
WINDS BACK SUFFICIENTLY TO WSW BY ARND 09Z...LINGERING LES SHOULD
SHIFT OFFSHORE.
COORDINATED WITH APX.
&&
.SHORT TERM /TONIGHT AND MONDAY/ ISSUED AT 449 PM...
WV IMAGERY AND RUC ANALYSIS SHOWS THE UPPER TROUGH THAT HAS BEEN
OVER THE UPPER GREAT LAKES OVER THE LAST DAY STARTING TO SHIFT TO
THE EAST. UPSTREAM...BROAD MOISTURE PLUME RUNNING OVER THE RIDGE
OVER THE US/CANADIAN ROCKIES AND MOVING INTO THE NRN PLAINS. CLOSER
TO HOME...VIS SATELLITE SHOWING LAKE EFFECT CLOUDS HANGING ON OVER
MUCH OF UPPER MICHIGAN...BUT DRIER AIR FROM THE APPROACHING SFC
RIDGE IN MN HAS QUICKLY ATE AWAY AT THE CLOUDS/SHOWERS OVER WRN LK
SUPERIOR. OVER THE ERN LK...LES CONTINUES...ALTHOUGH THE DRIER AIR
HAS STARTED TO DIMINISH THE INTENSITY OF THE SHOWERS...WHICH KMQT
RADAR IS SHOWING MAINLY 1HR SNOWFALL RATES OF 0.5 IN/HR. THE
STRONGEST SWRN BAND NEAR MUNISING HAS PICKED UP SLIGHTLY OVER THE
LAST HOUR...AS LLVL WINDS OFF MARQUETTE COUNTY HAVE SHIFTED SLIGHTLY
TO THE WNW AND INCREASED CONVERGENCE.
TONIGHT...WITH THE UPPER TROUGH CONTINUING TO PUSH E...SFC RIDGE
CURRENTLY OVER THE MN WILL PUSH INTO THE AREA. H850-700 SUBSIDENCE
AND DRY AIR ALREADY TAKEN HOLD OVER WRN LK SUPERIOR AND DIMINISHED
THE -SHSN OVER THE WRN CWA. AS SFC HIGH BUILDS INTO UPPER MI THIS
EVENING...WINDS WILL BE BACKING THROUGH THE EVENING HOURS AND END UP
FOCUSING ANY LINGERING LES OVER THE KEWEENAW PENINSULA BY MIDNIGHT.
SINCE INVERSION HEIGHTS ON BUFKIT SOUNDINGS OVER THE KEWEENAW ARE
ONLY AROUND 3KFT...DON/T EXPECT MUCH FOR ACCUMULATIONS...ESPECIALLY
WITH THE TRANSIENT NATURE OF THE LES.
OVER ERN ALGER AND LUCE COUNTIES...EXPECT LES TO BE ONGOING AT THE
START OF THE TONIGHT PERIOD WITH THE NW FLOW AND -18C H850 TEMPS.
DEEPER MOISTURE WILL DEPART LATE THIS AFTN AS SUBSIDENCE FROM
H850-700 WITH THE UPPER RIDGING WILL CAUSE INVERSION HEIGHTS TO FALL
TO 4-5KFT. STILL SHOULD SEE LES CONTINUING IN THE NW WIND SNOW BELTS
FROM MUNISING E THIS EVENING...BUT INTENSITY WILL BE LOWER THAN
TODAY. IN ADDITION...WITH WINDS BACKING TO THE W BY MIDNIGHT AND
THEN SW BY DAYBREAK...THE BANDS SHOULD BE SHIFTING TO THE ENE FROM
LATE EVENING ON. THUS...EXPECT LIMITED ACCUMULATION DUE TO THE
TRANSIENT NATURE OF THE BANDS AND WILL LET THE WARNING CONTINUE
UNTIL 00Z.
LOWS TONIGHT ARE VERY TRICKY...SINCE CLEARING SKIES...WEAKENING
WINDS WITH THE SFC RIDGE...AND PWATS AROUND 35 PERCENT OF NORMAL
LEAD TO A FAVORABLE RADIATION COOLING NIGHT. FORECAST IS DIFFICULT
DUE TO THE APPROACHING HIGH CLOUDS CURRENTLY MOVING INTO WRN MN.
THESE SHOULD START TO ARRIVE AFTER MIDNIGHT AND CAUSE FOR STEADY OR
RISING TEMPS LATE. WENT WITH A NON-DIURNAL TREND AND HAVE LOWS ALONG
THE WI BORDER IN THE MID SINGLE DIGITS BELOW ZERO AND WOULD NOT BE
SURPRISED IF THEY GET EVEN COLDER IF CLOUDS ARE DELAYED.
LATE TONIGHT INTO MONDAY...CLIPPER SYSTEM CURRENTLY TAKING SHAPE IN
ALBERTA WILL SLIDE A WARM FRONT ACROSS MN AND WI ON MON. H700-500
WAA AND MOISTURE...ALONG WITH ISENTROPIC ASCENT ON THE 275-300K SFCS
PUSHES ACROSS THE AREA FROM SW TO NE BETWEEN 09Z AND 18Z MON. BEST
MID LVL WAA LOOKS TO FOCUS OVER THE S HALF OF UPPER MI...MAINLY OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE. WILL FOLLOW THAT SOLN FOR
QPF AMNTS FOR LATE TONIGHT INTO MON MORNING. WITH A GOOD CONSENSUS
ON FORCING/QPF/TIMING...HAVE BUMPED POPS UP TO LIKELY FOR MOST OF
THE LAND AREAS.
12Z NAM/GFS/GEM-REG CONSISTENT ON 0.12-0.2IN OF QPF OVER THE SRN
HALF OF UPPER MI BY MON EVENING AND MADE SOME MINOR ADJUSTMENTS UP
FROM PREVIOUS SHIFT. COBB OUTPUT FOR KESC/KIMT SHOWING HIGH RATIOS
AROUND 15/18-1 INITIALLY...THEN FALLING BELOW 10-1 HEADING INTO THE
AFTN AS THE DEEPER MOISTURE IS CUT OUT REMAINING FORCING/MOISTURE IS
BELOW THE DGZ. THINK MUCH OF THE SNOW WILL FALL IN THE HIGHER SNOW
RATIO PERIOD AND USED THAT AS THE STARTING POINT FOR SNOWFALL.
EXPECT A PERIOD OF LK ENHANCEMENT AFTER 15Z ON MON...WHEN LLVL
MOISTURE PROFILES FINALLY MOISTEN UP AND SRLY WINDS TAKE HOLD. WITH
H850 TEMPS AROUND -11C DURING THE PCPN PERIOD...SHOULD BE ENOUGH
LLVL INSTABILITY TO PROVIDE ENHANCEMENT OVER DELTA/SCHOOLCRAFT/LUCE
COUNTIES AND HAVE BUMPED UP QPF AMNTS SLIGHTLY IN THOSE
AREAS...ESPECIALLY SCHOOLCRAFT/LUCE. OVERALL...HAVE A GENERAL 1-2IN
OVER MUCH OF THE CWA. COULD BE SOME ISOLATED ADVY AMNTS OF 3IN OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE...BUT THE OVERALL AVG WILL
BE BELOW ADVY AND WILL NOT ISSUE ANYTHING AT THIS TIME.
FINALLY...WITH THE MAIN FORCING AND DEEPER MOISTURE PULLING NE IN
THE AFTN...COULD SEE A PERIOD OF FZDZ. THIS IS DUE TO THE LINGERING
FORCING/MOISTURE BELOW THE ICE CRYSTAL AREA /ISENTROPIC ASCENT ON
275-280K SFCS AND H925-800 MOISTURE/. ADDED THIS TO THE GRIDS IN THE
AFTN FROM SW TO NE AS THE DEEP MOISTURE PULLS OUT...AND MAY BE MOST
PRONOUNCED OVER THE HIGHER TERRAIN NCNTRL...WHERE THE SSE UPSLOPE
FLOW WOULD FAVOR IT.
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG FCST QUESTION FOR MONDAY NIGHT INTO TUESDAY TIME FRAME WILL BE
THE POTENTIAL FOR FZDZ IN THE WAKE OF MONDAYS TROUGH/WARM FRONT.
FCST SNDGS...ESPECIALLY THE NAM BUFR SNDGS...SHOW LINGERING SHALLOW
MOIST LAYER NEAR THE SFC AS DRYING/SUBSIDENCE OCCURS IN MID-LVLS IN
THE WAKE OF THE WARM FRONT. EXPECT LOCATIONS AFFECTED BY AN UPSLOPE
SRLY FLOW WILL BE MOST SUSCEPTIBLE TO PATCHY FZDZ MON NIGHT INTO
TUESDAY MORNING BUT WILL INCLUDE A MENTION FOR MOST OF THE CWA. ANY
LINGERING FZDZ SHOULD TURN TO DZ TUE AFTERNOON AS MOIST LOW-LVLS
WARM ABV FREEZING.
ANOTHER SHORTWAVE AND ASSOC COLD FRONT WILL MOVE THROUGH TUE
AFTERNOON AND TUE NIGHT. TRACK OF THE SHORTWAVE AND THE ASSOC SFC
LOW WOULD FAVOR MAINLY THE NRN TIER FOR SOME LIGHT RAIN OR SNOW AS
THIS IS WHERE MODELS INDICATE DEEPER MOISTURE AND CLOSER PROXIMITY
TO MODERATE Q-VECT CONV AND LIFT ASSOC WITH SHORTWAVE. RAIN/SNOW MIX
ALONG THE NRN TIER SHOULD TURN OVER TO ALL SNOW LATE TUE NIGHT WITH
CAA BEHIND FRONT AND WOULD EXPECT A DIMINISH TREND AS SHORTWAVE/SFC
LOW DEPART QUICKLY EAST.
WEAK RDGG BUILDING IN FROM THE WEST SHOULD RESULT IN MAINLY DRY
CONDITIONS ON WEDNESDAY.
FOR THE EXTENDED /THURSDAY THROUGH SUNDAY/...
MODEL DISAGREEMENTS WILL CONTINUE THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD PERTAINING TO THE LOCATION AND TIMING OF SHORTWAVES
AFFECTING THE AREA...SO HAVE NOT DIVERGED MUCH FROM CONSENSUS THIS
FAR OUT. MODELS ARE IN FAIRLY GOOD AGREEMENT...HOWEVER...THAT STRONG
RIDGING OFF THE PACIFIC NORTHWEST WEDNESDAY NIGHT/THURSDAY MORNING
WILL ALLOW THE JET STREAM TO TRANSITION TO A MERIDIONAL FLOW ON THE
DESCENDING BRANCH...CREATING AN ENHANCED TROUGHING PATTERN OVER THE
CENTRAL CONUS. GFS IS THE MOST PROGRESSIVE OF THE MODELS...KEEPING
THE TROUGH PLACEMENT FARTHER NORTH AND HAVING IT MOVE EAST MORE
QUICKLY THAN ECMWF/GEM. AS HIGH PRESSURE CONTINUES TO BUILD IN WEST
THROUGH SUNDAY...DESCENDING BRANCH OF TROUGH WILL BEGIN TO
RETROGRADE AND BECOME POSITIVELY TILTED.
TRANSLATING THIS TO THE UPPER GREAT LAKES REGION...OVERALL...THIS
WILL CREATE A FAIRLY BENIGN SYNOPTIC WEATHER PATTERN AS MUCH OF THE
SHORTWAVES WILL PASS TO OUR SOUTH TRAVERSING THE DESCENDING EDGE OF
THE TROUGH. HOWEVER...IF THE MORE NORTHERN PLACEMENT OF THE GFS PANS
OUT...AS THE TROUGH BECOMES POSITIVELY TILTED OVER THE UPPER GREAT
LAKES ON FRIDAY...EXPECT SHORTWAVE TO DEVELOP AND TRAVERSE THE AREA.
THIS WILL BRING THE BEST CHANCE FOR PRECIP DURING THE PERIOD
WITH STRONG QVECTOR CONVERGENCE AND FAIRLY MOIST PROFILE/STEEP LAPSE
RATES DURING ITS PASSAGE. THE ECMWF AND THE GEM ON THE OTHER HAND
HAVE THIS SYSTEM DEVELOPING MUCH FARTHER SOUTH AND THEREBY NOT
IMPACTING THE FORECAST PERIOD AT ALL...SO DIDN`T GO ANY HIGHER THAN
SLIGHT CHANCES. OTHERWISE...PREDOMINATE W AND SW WINDS ALOFT AHEAD
OF DESCENDING JET WILL KEEP TEMPERATURES WELL ABOVE NORMAL THURSDAY.
WITH LOW CONFIDENCE ON PLACEMENT AND STRENGTH OF JET AS IT NEARS THE
AREA...WILL KEEP WITH THE LOWERING TREND OF TEMPS AS WINDS TURN MORE
NORTHERLY BY THE END OF THE PERIOD...BUT MAGNITUDE OF THIS COLD AIR
INTRUSION IS YET TO BE DETERMINED. IF THE MORE AMPLIFIED TROF AND
COLDER SOLN OF THE ECMWF SOLUTION VERIFIES...THEN TEMPS WILL
PROBABLY NEED TO BE LOWERED AND POPS MAY NEED TO BE INCREASED FOR
NEXT WEEKEND FOR AREAS DOWNWIND OF LAKE SUPERIOR IN N-NW FLOW.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
AS A HI PRES RDG MOVES E ACROSS THE UPR MIDWEST TNGT...EXPECT VFR
CONDITIONS TO PREDOMINATE AT IWD/SAW WITH DRY WLY FLOW. SINCE THIS
WLY FLOW WL UPSLOPE AT CMX...MVFR CONDITIONS WL BE MORE RESILIENT
THERE AND NOT RISE TO VFR UNTIL LATE TNGT WHEN THE FLOW BACKS
FURTHER TO SW. SN IN ADVANCE OF AN APRCHG WARM FNT WL DVLP ON MON
MRNG...LOWERING CONDITIONS TO IFR AT ALL 3 SITES BY NOON. SINCE THE
S WIND WL DOWNSLOPE AT IWD...CONDITIONS THERE WL PROBABLY BE MVFR
MOST OF THE TIME.
&&
.MARINE /FOR THE 4PM LAKE SUPERIOR FORECAST ISSUANCE/...
HIGH PRESSURE RIDGE SHIFTING OVER LAKE SUPERIOR TONIGHT WILL BRING
DECREASING WINDS TONIGHT...BELOW 20KTS. A CLIPPER SYSTEM DEVELOPING
IN ALBERTA WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS ON MONDAY
AFTERNOON AND EVENING BEFORE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY NIGHT. SOUTHERLY WINDS AHEAD OF THIS SYSTEM COULD PRODUCE
GUSTS TO 30KTS OVER THE ERN LK ON MONDAY AFTN AND EVENING. THE LOW
WILL SHIFT E ON WED...ALLOWING WEAK HIGH PRESSURE TO BUILD OVER THE
UPPER GREAT LAKES THROUGH THURS. A LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE OHIO RIVER VALLEY ON FRI...BUT SHOULD HAVE LIMITED
EFFECTS ON LK SUPERIOR. EXPECT WINDS TO BE BELOW 25KTS FROM TUESDAY
MORNING THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST MONDAY FOR MIZ006-007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...VOSS
EXTENDED...JMW
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATE
NWS MARQUETTE MI
700 PM EST SUN JAN 29 2012
.UPDATE...
OPTED TO ISSUE AN LES ADVY FOR ERN ALGER/NRN LUCE COUNTY UNTIL EARLY
MON MRNG AS 18Z NAM/LOCAL WRF-ARW RUNS SHOW AREA OF FOCUSED LLVL
CNVGC IN THIS AREA THRU ABOUT 06Z WITH MORE WSW LAND BREEZE FLOW
OVER THE INTERIOR AND PERSISTENT WNW FLOW OVER THE WATER. WFR-ARW
RUN ALSO INDICATES FAVORABLE OMEGA WITHIN THE DGZ IN THIS AREA WITH
INVRN BASE ARND 5K FT...SO HEADLINE SEEMS WARRANTED. ONCE THE H925
WINDS BACK SUFFICIENTLY TO WSW BY ARND 09Z...LINGERING LES SHOULD
SHIFT OFFSHORE.
COORDINATED WITH APX.
&&
.SHORT TERM /TONIGHT AND MONDAY/ ISSUED AT 449 PM...
WV IMAGERY AND RUC ANALYSIS SHOWS THE UPPER TROUGH THAT HAS BEEN
OVER THE UPPER GREAT LAKES OVER THE LAST DAY STARTING TO SHIFT TO
THE EAST. UPSTREAM...BROAD MOISTURE PLUME RUNNING OVER THE RIDGE
OVER THE US/CANADIAN ROCKIES AND MOVING INTO THE NRN PLAINS. CLOSER
TO HOME...VIS SATELLITE SHOWING LAKE EFFECT CLOUDS HANGING ON OVER
MUCH OF UPPER MICHIGAN...BUT DRIER AIR FROM THE APPROACHING SFC
RIDGE IN MN HAS QUICKLY ATE AWAY AT THE CLOUDS/SHOWERS OVER WRN LK
SUPERIOR. OVER THE ERN LK...LES CONTINUES...ALTHOUGH THE DRIER AIR
HAS STARTED TO DIMINISH THE INTENSITY OF THE SHOWERS...WHICH KMQT
RADAR IS SHOWING MAINLY 1HR SNOWFALL RATES OF 0.5 IN/HR. THE
STRONGEST SWRN BAND NEAR MUNISING HAS PICKED UP SLIGHTLY OVER THE
LAST HOUR...AS LLVL WINDS OFF MARQUETTE COUNTY HAVE SHIFTED SLIGHTLY
TO THE WNW AND INCREASED CONVERGENCE.
TONIGHT...WITH THE UPPER TROUGH CONTINUING TO PUSH E...SFC RIDGE
CURRENTLY OVER THE MN WILL PUSH INTO THE AREA. H850-700 SUBSIDENCE
AND DRY AIR ALREADY TAKEN HOLD OVER WRN LK SUPERIOR AND DIMINISHED
THE -SHSN OVER THE WRN CWA. AS SFC HIGH BUILDS INTO UPPER MI THIS
EVENING...WINDS WILL BE BACKING THROUGH THE EVENING HOURS AND END UP
FOCUSING ANY LINGERING LES OVER THE KEWEENAW PENINSULA BY MIDNIGHT.
SINCE INVERSION HEIGHTS ON BUFKIT SOUNDINGS OVER THE KEWEENAW ARE
ONLY AROUND 3KFT...DON/T EXPECT MUCH FOR ACCUMULATIONS...ESPECIALLY
WITH THE TRANSIENT NATURE OF THE LES.
OVER ERN ALGER AND LUCE COUNTIES...EXPECT LES TO BE ONGOING AT THE
START OF THE TONIGHT PERIOD WITH THE NW FLOW AND -18C H850 TEMPS.
DEEPER MOISTURE WILL DEPART LATE THIS AFTN AS SUBSIDENCE FROM
H850-700 WITH THE UPPER RIDGING WILL CAUSE INVERSION HEIGHTS TO FALL
TO 4-5KFT. STILL SHOULD SEE LES CONTINUING IN THE NW WIND SNOW BELTS
FROM MUNISING E THIS EVENING...BUT INTENSITY WILL BE LOWER THAN
TODAY. IN ADDITION...WITH WINDS BACKING TO THE W BY MIDNIGHT AND
THEN SW BY DAYBREAK...THE BANDS SHOULD BE SHIFTING TO THE ENE FROM
LATE EVENING ON. THUS...EXPECT LIMITED ACCUMULATION DUE TO THE
TRANSIENT NATURE OF THE BANDS AND WILL LET THE WARNING CONTINUE
UNTIL 00Z.
LOWS TONIGHT ARE VERY TRICKY...SINCE CLEARING SKIES...WEAKENING
WINDS WITH THE SFC RIDGE...AND PWATS AROUND 35 PERCENT OF NORMAL
LEAD TO A FAVORABLE RADIATION COOLING NIGHT. FORECAST IS DIFFICULT
DUE TO THE APPROACHING HIGH CLOUDS CURRENTLY MOVING INTO WRN MN.
THESE SHOULD START TO ARRIVE AFTER MIDNIGHT AND CAUSE FOR STEADY OR
RISING TEMPS LATE. WENT WITH A NON-DIURNAL TREND AND HAVE LOWS ALONG
THE WI BORDER IN THE MID SINGLE DIGITS BELOW ZERO AND WOULD NOT BE
SURPRISED IF THEY GET EVEN COLDER IF CLOUDS ARE DELAYED.
LATE TONIGHT INTO MONDAY...CLIPPER SYSTEM CURRENTLY TAKING SHAPE IN
ALBERTA WILL SLIDE A WARM FRONT ACROSS MN AND WI ON MON. H700-500
WAA AND MOISTURE...ALONG WITH ISENTROPIC ASCENT ON THE 275-300K SFCS
PUSHES ACROSS THE AREA FROM SW TO NE BETWEEN 09Z AND 18Z MON. BEST
MID LVL WAA LOOKS TO FOCUS OVER THE S HALF OF UPPER MI...MAINLY OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE. WILL FOLLOW THAT SOLN FOR
QPF AMNTS FOR LATE TONIGHT INTO MON MORNING. WITH A GOOD CONSENSUS
ON FORCING/QPF/TIMING...HAVE BUMPED POPS UP TO LIKELY FOR MOST OF
THE LAND AREAS.
12Z NAM/GFS/GEM-REG CONSISTENT ON 0.12-0.2IN OF QPF OVER THE SRN
HALF OF UPPER MI BY MON EVENING AND MADE SOME MINOR ADJUSTMENTS UP
FROM PREVIOUS SHIFT. COBB OUTPUT FOR KESC/KIMT SHOWING HIGH RATIOS
AROUND 15/18-1 INITIALLY...THEN FALLING BELOW 10-1 HEADING INTO THE
AFTN AS THE DEEPER MOISTURE IS CUT OUT REMAINING FORCING/MOISTURE IS
BELOW THE DGZ. THINK MUCH OF THE SNOW WILL FALL IN THE HIGHER SNOW
RATIO PERIOD AND USED THAT AS THE STARTING POINT FOR SNOWFALL.
EXPECT A PERIOD OF LK ENHANCEMENT AFTER 15Z ON MON...WHEN LLVL
MOISTURE PROFILES FINALLY MOISTEN UP AND SRLY WINDS TAKE HOLD. WITH
H850 TEMPS AROUND -11C DURING THE PCPN PERIOD...SHOULD BE ENOUGH
LLVL INSTABILITY TO PROVIDE ENHANCEMENT OVER DELTA/SCHOOLCRAFT/LUCE
COUNTIES AND HAVE BUMPED UP QPF AMNTS SLIGHTLY IN THOSE
AREAS...ESPECIALLY SCHOOLCRAFT/LUCE. OVERALL...HAVE A GENERAL 1-2IN
OVER MUCH OF THE CWA. COULD BE SOME ISOLATED ADVY AMNTS OF 3IN OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE...BUT THE OVERALL AVG WILL
BE BELOW ADVY AND WILL NOT ISSUE ANYTHING AT THIS TIME.
FINALLY...WITH THE MAIN FORCING AND DEEPER MOISTURE PULLING NE IN
THE AFTN...COULD SEE A PERIOD OF FZDZ. THIS IS DUE TO THE LINGERING
FORCING/MOISTURE BELOW THE ICE CRYSTAL AREA /ISENTROPIC ASCENT ON
275-280K SFCS AND H925-800 MOISTURE/. ADDED THIS TO THE GRIDS IN THE
AFTN FROM SW TO NE AS THE DEEP MOISTURE PULLS OUT...AND MAY BE MOST
PRONOUNCED OVER THE HIGHER TERRAIN NCNTRL...WHERE THE SSE UPSLOPE
FLOW WOULD FAVOR IT.
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG FCST QUESTION FOR MONDAY NIGHT INTO TUESDAY TIME FRAME WILL BE
THE POTENTIAL FOR FZDZ IN THE WAKE OF MONDAYS TROUGH/WARM FRONT.
FCST SNDGS...ESPECIALLY THE NAM BUFR SNDGS...SHOW LINGERING SHALLOW
MOIST LAYER NEAR THE SFC AS DRYING/SUBSIDENCE OCCURS IN MID-LVLS IN
THE WAKE OF THE WARM FRONT. EXPECT LOCATIONS AFFECTED BY AN UPSLOPE
SRLY FLOW WILL BE MOST SUSCEPTIBLE TO PATCHY FZDZ MON NIGHT INTO
TUESDAY MORNING BUT WILL INCLUDE A MENTION FOR MOST OF THE CWA. ANY
LINGERING FZDZ SHOULD TURN TO DZ TUE AFTERNOON AS MOIST LOW-LVLS
WARM ABV FREEZING.
ANOTHER SHORTWAVE AND ASSOC COLD FRONT WILL MOVE THROUGH TUE
AFTERNOON AND TUE NIGHT. TRACK OF THE SHORTWAVE AND THE ASSOC SFC
LOW WOULD FAVOR MAINLY THE NRN TIER FOR SOME LIGHT RAIN OR SNOW AS
THIS IS WHERE MODELS INDICATE DEEPER MOISTURE AND CLOSER PROXIMITY
TO MODERATE Q-VECT CONV AND LIFT ASSOC WITH SHORTWAVE. RAIN/SNOW MIX
ALONG THE NRN TIER SHOULD TURN OVER TO ALL SNOW LATE TUE NIGHT WITH
CAA BEHIND FRONT AND WOULD EXPECT A DIMINISH TREND AS SHORTWAVE/SFC
LOW DEPART QUICKLY EAST.
WEAK RDGG BUILDING IN FROM THE WEST SHOULD RESULT IN MAINLY DRY
CONDITIONS ON WEDNESDAY.
FOR THE EXTENDED /THURSDAY THROUGH SUNDAY/...
MODEL DISAGREEMENTS WILL CONTINUE THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD PERTAINING TO THE LOCATION AND TIMING OF SHORTWAVES
AFFECTING THE AREA...SO HAVE NOT DIVERGED MUCH FROM CONSENSUS THIS
FAR OUT. MODELS ARE IN FAIRLY GOOD AGREEMENT...HOWEVER...THAT STRONG
RIDGING OFF THE PACIFIC NORTHWEST WEDNESDAY NIGHT/THURSDAY MORNING
WILL ALLOW THE JET STREAM TO TRANSITION TO A MERIDIONAL FLOW ON THE
DESCENDING BRANCH...CREATING AN ENHANCED TROUGHING PATTERN OVER THE
CENTRAL CONUS. GFS IS THE MOST PROGRESSIVE OF THE MODELS...KEEPING
THE TROUGH PLACEMENT FARTHER NORTH AND HAVING IT MOVE EAST MORE
QUICKLY THAN ECMWF/GEM. AS HIGH PRESSURE CONTINUES TO BUILD IN WEST
THROUGH SUNDAY...DESCENDING BRANCH OF TROUGH WILL BEGIN TO
RETROGRADE AND BECOME POSITIVELY TILTED.
TRANSLATING THIS TO THE UPPER GREAT LAKES REGION...OVERALL...THIS
WILL CREATE A FAIRLY BENIGN SYNOPTIC WEATHER PATTERN AS MUCH OF THE
SHORTWAVES WILL PASS TO OUR SOUTH TRAVERSING THE DESCENDING EDGE OF
THE TROUGH. HOWEVER...IF THE MORE NORTHERN PLACEMENT OF THE GFS PANS
OUT...AS THE TROUGH BECOMES POSITIVELY TILTED OVER THE UPPER GREAT
LAKES ON FRIDAY...EXPECT SHORTWAVE TO DEVELOP AND TRAVERSE THE AREA.
THIS WILL BRING THE BEST CHANCE FOR PRECIP DURING THE PERIOD
WITH STRONG QVECTOR CONVERGENCE AND FAIRLY MOIST PROFILE/STEEP LAPSE
RATES DURING ITS PASSAGE. THE ECMWF AND THE GEM ON THE OTHER HAND
HAVE THIS SYSTEM DEVELOPING MUCH FARTHER SOUTH AND THEREBY NOT
IMPACTING THE FORECAST PERIOD AT ALL...SO DIDN`T GO ANY HIGHER THAN
SLIGHT CHANCES. OTHERWISE...PREDOMINATE W AND SW WINDS ALOFT AHEAD
OF DESCENDING JET WILL KEEP TEMPERATURES WELL ABOVE NORMAL THURSDAY.
WITH LOW CONFIDENCE ON PLACEMENT AND STRENGTH OF JET AS IT NEARS THE
AREA...WILL KEEP WITH THE LOWERING TREND OF TEMPS AS WINDS TURN MORE
NORTHERLY BY THE END OF THE PERIOD...BUT MAGNITUDE OF THIS COLD AIR
INTRUSION IS YET TO BE DETERMINED. IF THE MORE AMPLIFIED TROF AND
COLDER SOLN OF THE ECMWF SOLUTION VERIFIES...THEN TEMPS WILL
PROBABLY NEED TO BE LOWERED AND POPS MAY NEED TO BE INCREASED FOR
NEXT WEEKEND FOR AREAS DOWNWIND OF LAKE SUPERIOR IN N-NW FLOW.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
AS A HI PRES RDG MOVES E ACROSS THE UPR MIDWEST TNGT...EXPECT VFR
CONDITIONS TO PREDOMINATE AT IWD/SAW WITH DRY WLY FLOW. SINCE THIS
WLY FLOW WL UPSLOPE AT CMX...MVFR CONDITIONS WL BE MORE RESILIENT
THERE AND NOT RISE TO VFR UNTIL LATE TNGT WHEN THE FLOW BACKS
FURTHER TO SW. SN IN ADVANCE OF AN APRCHG WARM FNT WL DVLP ON MON
MRNG...LOWERING CONDITIONS TO IFR AT ALL 3 SITES BY NOON. SINCE THE
S WIND WL DOWNSLOPE AT IWD...CONDITIONS THERE WL PROBABLY BE MVFR
MOST OF THE TIME.
&&
.MARINE /FOR THE 4PM LAKE SUPERIOR FORECAST ISSUANCE/...
HIGH PRESSURE RIDGE SHIFTING OVER LAKE SUPERIOR TONIGHT WILL BRING
DECREASING WINDS TONIGHT...BELOW 20KTS. A CLIPPER SYSTEM DEVELOPING
IN ALBERTA WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS ON MONDAY
AFTERNOON AND EVENING BEFORE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY NIGHT. SOUTHERLY WINDS AHEAD OF THIS SYSTEM COULD PRODUCE
GUSTS TO 30KTS OVER THE ERN LK ON MONDAY AFTN AND EVENING. THE LOW
WILL SHIFT E ON WED...ALLOWING WEAK HIGH PRESSURE TO BUILD OVER THE
UPPER GREAT LAKES THROUGH THURS. A LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE OHIO RIVER VALLEY ON FRI...BUT SHOULD HAVE LIMITED
EFFECTS ON LK SUPERIOR. EXPECT WINDS TO BE BELOW 25KTS FROM TUESDAY
MORNING THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST MONDAY FOR MIZ006-007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...VOSS
EXTENDED...JMW
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
700 PM CST SUN JAN 29 2012
.UPDATE...
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
ANOTHER MILD WEEK IS AHEAD OF US...WITH HIGHS IN THE MID 30S TO
LOWER 40S COMING FOR MONDAY THROUGH THURSDAY. IMPRESSIVE WARM
FRONT COMING THROUGH TONIGHT WILL BRING ABOUT THE CHANCE FOR
ANOTHER DUSTING OF SNOW...WHILE A LOW PASSING ACROSS NRN MN
TUESDAY MAY BRING SOME LIGHT PRECIP TO NRN SECTIONS OF THE CWA.
AFTER THAT...THE REST OF THE FORECAST IS DRY...WITH ONLY A MODEST
COOL DOWN EXPECTED FOR THE WEEKEND.
STRONG WARM FRONT THIS AFTERNOON STRETCHES FROM KC TO NE MONTANA.
TO GO ALONG WITH THIS...UPPER RIDGE IS WORKING INTO THE
PLAINS...WITH THE RUC SWINGING 160M 12 HR H5 HEIGHT RISES ACROSS
THE AREA THIS AFTERNOON. COMBINATION OF A SHORTWAVE MOVING INTO
MT...ALONG WITH STRONG ISENTROPIC/FGEN FORCING TO THE NORTH OF THE
FRONT HAS RESULTED IN THE GENERATION OF A NICE BAND OF SNOW ACROSS
NODAK. SHORT TERM HI RES GUIDANCE ALL SIMILAR WITH THIS BAND OF
SNOW REACHING THE NW CWA BETWEEN 2Z AND 4Z AND QUICKLY WORKING
EAST THROUGH THE NIGHT...EXITING THE WI CWA AROUND 15Z MON
MORNING. ONE ISSUE TO WATCH FOR TONIGHT IS A DRY LAYER OF AIR THAT
IS DEVELOPING THIS AFTERNOON BETWEEN H9 AND H7. INDICATIONS FROM
BUFKIT SOUNDINGS IS THAT WE WILL BE MOISTENING THIS LAYER FROM
TOP-DOWN...SO MUCH OF THE SNOW MAY BE LOST TO SUBLIMATION. ARW
1 KM AGL REFLECTIVITY FORECASTS ARE SPOTTY/NON-EXISTENT ACROSS
MUCH OF THE MPX CWA...AND THIS DRY LAYER LIKELY HAS A LOT TO DO
WITH IT. STILL...SREF PROBS ARE UP OVER 80 PERCENT FROM CENTRAL MN
INTO WRN WI...WHICH MATCHES UP WELL WITH BEST THALER QG FORCING.
THEREFORE...HAVE CATEGORICAL POPS ALONG AND NORTH OF AN
AXN/STC/EAU LINE FOR TONIGHT...WHERE FORCING AND MOISTURE LOOK
MOST LIKELY TO COINCIDE. CERTAINLY LOOKING GRIM FOR ANYONE ALONG
AND SOUTH OF THE MN RIVER TO SEE MUCH PRECIP. AS FOR
P-TYPE...STILL SEEING A SIGNIFICANT WARM NOSE COMING IN WITH THE
WARM FRONT...BUT MODELS CONTINUE TO SHOW THE PRECIP REMAINING OUT
AHEAD OF THE WARM NOSE...WITH ONLY AN HOUR OR TWO OF A WINTRY MIX
POSSIBLE AS THE PRECIP PULLS OUT. LOOKS TO BE YET ANOTHER SYSTEM
THIS YEAR THAT LAYS DOWN A QUICK HALF INCH TO AN INCH WHERE
CATEGORICAL POPS ARE LOCATED.
BESIDE THE PRECIP COMING IN...ALL GUIDANCE SIMILAR WITH A NON-
DIURNAL TREND FOR TONIGHT...WITH HIGHS STEADILY RISING THROUGH THE
NIGHT. IN FACT...GFSLAMP HAS ABOUT 10 DEGREES OF WARMING FOR ALL
MN LOCATIONS THROUGH THE NIGHT. EVEN IN WI...TEMPS SHOULD ONLY
FALL THROUGH ABOUT 3Z BEFORE GOING STEADY AND THEN RISING.
BIG QUESTION FOR MONDAY IS WHERE DOES THE WARM FRONT SET UP. 12Z
GUIDANCE HAS THE FRONT SOMEWHERE BETWEEN I-94 AND A HINCKLEY TO
FARGO LINE AT 6PM MONDAY. THIS WILL LEAD TO SOME UNCERTAINTY FOR
HIGHS ON MONDAY...AS AREAS SOUTH OF THE WARM FRONT WILL LIKELY
MAKE A RUN INTO THE 40S...WHILE AREAS ALONG AND NORTH REMAIN
CLOUDY WITH HIGHS LIKELY ONLY TOPPING OUT AROUND FREEZING. IN
ADDITION...THERE IS SOME CONCERN FOR DRIZZLE NORTH OF THE FRONT
GIVEN THE AMOUNT OF LOW LEVEL MOISTURE EXPECTED. HOWEVER...NAM/GFS
BUFKIT SOUNDINGS OVER CENTRAL MN SHOW A SHALLOW MIXED BOUNDARY
LAYER DEVELOPING DURING THE AFTERNOON...WITH A BIT OF A TEMP/DEWP
SPREAD NOTED ON THE SOUNDINGS. BECAUSE OF THIS...NOT TOO CONFIDENT
THAT WE WILL SEE THAT MUCH DZ GENERATION ACROSS CENTRAL
MN...DESPITE PERSISTENT LIFT ALONG THE FRONT. OTHER VARIABLE TO
CONTEND WITH FOR TEMPS ON MONDAY WILL BE SNOW COVER. SATELLITE
IMAGES THIS MORNING SHOWED MOST OF YELLOW MEDICINE AND LAC QUI
PARLE COUNTIES ARE SNOW FREE...AND GIVEN FAVORABLE WSW FLOW ON
MONDAY...PLACES SUCH AS MADISON AND MONTEVIDEO COULD SEE HIGHS TOP
OUT IN THE LOW 50S. SOUTH CENTRAL MN HAS THE OPPOSITE PROBLEM...AS
COOP OBSERVES THIS MORNING REPORTED 3 TO 5 INCHES OF SNOW ON THE
GROUND DOWN THERE...THIS MAY RESULT IN HIGHS BEING A BIT OVER DONE
DOWN THERE. AT ANY RATE...A BLEND OF THE MET/MAV BIAS CORRECTED
DATA WAS USED FOR HIGHS TOMORROW.
THE MILD CONDITIONS WILL REMAIN IN PLACE MONDAY NIGHT THROUGH
THURSDAY. MODELS SWING A COLD FRONT ACROSS THE AREA TUESDAY
MORNING...WITH LOWS IN THE WARM SECTOR OUT AHEAD OF IT MONDAY
NIGHT LIKELY STRUGGLING TO FALL BELOW FREEZING. H85 TEMPS LOOKS TO
ONLY GET KNOCKED DOWN TO AROUND 0C BEHIND THE FRONT...WITH HIGHS
TUESDAY THROUGH THURSDAY LOOKING TO BE A DEGREE OR TWO COLDER THAN
THE PREVIOUS DAY. IN FACT...OVERNIGHT LOWS LOOK TO ONLY FALL BACK
TO AROUND THE AVERAGE HIGHS FOR THIS TIME OF YEAR. BY THE TIME
JANUARY IS ALL SAID AND DONE...SHOULD HAVE AN AVERAGE TEMPERATURE
DEPARTURE AT MSP SOMEWHERE IN THE NEIGHBORHOOD OF 8 DEGREES...WITH
JANUARY OF 2012 POSSIBLY REPLACING JANUARY OF 1933 AS 8TH WARMEST
ALL TIME /23.1 WAS THE AVE TEMP FOR JAN OF 1933/.
ONLY OTHER CHANCE FOR PRECIP LOOKS TO COME LATE MONDAY NIGHT INTO
TUESDAY AS A SFC LOW TRACKS ACROSS NRN MN. UNFORTUNATELY...THIS
LOW AND ITS ASSOCIATED COLD FRONT WILL BE ENCOUNTERING QUITE A BIT
OF DRY AIR OVER THE MPX CWA...WITH BEST PRECIP SIGNAL BEING UP
ACROSS NRN MN. STILL...SLIGHT SOUTHWARD SHIFT IN MODELS THIS
MORNING PROMPTED AN INTRODUCTION FOR SOME SLIGHT CHANCE POPS
ACROSS FAR NRN CWA LATE MONDAY NIGHT THAT LAST THROUGH THE DAY ON
TUESDAY. AN PRECIP AMOUNTS LOOK LIGHT...WITH P-TYPE BEING A RA/SN
MIX INTO TUESDAY MORNING THAT TRANSITIONS TO MAINLY RA DURING THE
DAY.
AS WE END THE WEEK...THE BIG STORY HERE WILL BE THE SIGNIFICANT
PATTERN SHIFT THE MEDIUM RANGE MODELS ARE SHOWING GOING INTO THE
WEEKEND. OUR CURRENT FAST WNW FLOW LOOKS TO BECOME MORE AMPLIFIED
BY THE WEEKEND...WITH A STRONG UPPER RIDGE DEVELOPING OVER WRN
NOAM AND THE PATTERN RESEMBLING MORE A LA NINA SITUATION FOR
ONCE. THOUGH THIS DOES OPEN US UP TO N/NW FLOW THIS WEEKEND...THE
ASSOCIATED COOL DOWN LOOKS TO ONLY TAKE ABOUT 10 DEGREES OFF OF
HIGHS...WITH READINGS GOING FROM 15 TO 20 DEGREES ABOVE NORMAL BACK
DOWN TO 5 TO 10 DEGREES ABOVE NORMAL. THERE ARE NO INDICATIONS OF
SIGNIFICANT COLD AIR SHOWING UP UNTIL THE SECOND WEEK OF
FEB...WHEN BOTH THE GFS/ECMWF SHOW A POLAR VORTEX SHOWING UP OVER
SRN HUDSON BAY. EVEN THEN THOUGH...MN LOOKS TO BE ON THE BOUNDARY
BETWEEN THE ARCTIC AIR TO THE EAST AND THE MILD PACIFIC AIR TO THE
WEST.
&&
.AVIATION.../00Z TAF ISSUANCE/
WARM FRONT GRADUALLY APPROACHING FROM THE WSW THIS EVENING WILL
SLOWLY PROGRESS EWD OVER THE REGION THROUGH THE OVERNIGHT HOURS.
ALREADY SEEING WEAK -SN ECHOES SHOWING UP ON KMPX RADAR AND
RUC/SREF/HRRR ALL SHOW INTENSITIES INCRG AS THE WMFNT APPROACHES.
A BIT PROBLEMATIC BASED ON INITIAL CLOUD CIG/COVERAGE TRENDS TO
DETERMINE WHICH AIRPORTS WILL SEE THE GREATEST FLIGHT COND
REDUCTION BUT AM THINKING ALL AIRPORTS /EXCEPT KRWF/ WILL SEE NOT
ONLY A DROP TO MVFR CIGS BUT ALSO BRIEF PERIODS OF IFR VSBY DUE TO
-SN. KRWF LOOKS TO BE FAR ENOUGH DISPLACED SW TO AVOID ANY OF THE
MORE PRONOUNCED SNOW BANDS...RELATIVELY SPEAKING. EVEN IF
INTENSITIES ARE SUCH THAT VSBYS DROP TO 1SM...SNOW IS NOT EXPECTED
TO HAVE LONG DURATION AND ACCUMULATIONS WILL GENERALLY BE AN INCH
OR LESS. SNOW SHOULD END BY DAYBREAK FROM ALL SITES...THOUGH SOME
LINGERING MVFR CIGS CAN BE EXPECTED. ALSO OF CONCERN...ESP IF
WINDS DROP BELOW 5 KT IN THE PRE-DAWN HOURS...IS THAT SOME GROUND
FOG COULD DEVELOP WITH INCREASING DEWPOINTS ASSOCIATED WITH THE
WARM FROPA. LARGE DEWPOINT DEPRESSIONS WOULD NEED TO BE OVERCOME
BUT IT IS POSSIBLE. AFTER DAYBREAK...SKIES WILL SCATTER OUT
LEADING TO PREVAILING VFR CONDS THROUGH MON AFTN AND EVE. WINDS
WILL EVENTUALLY GO TO SE AT ALL SITES AHEAD OF THE WMFNT THEN
SHIFT TO S AND SW POST-FRONT TMRW. SPEEDS LOOK TO INCRS TO THE
10-15 KT RANGE WITH SOME GUSTS NEAR 20 KT WITH THE FROPA BUT THIS
WILL BE SHORT-LIVED.
MSP...LOWERING CLOUDS ALREADY SEEN AT KMSP AND UPSTREAM OBS AS
WMFNT APPROACHES. ELEVATED -SN ECHOES ARE INCRG IN COVERAGE SO
WILL LOOK FOR CLOUDS TO CONTINUE LOWERING AND PRECIP TO REACH THE
KMSP AREA ARND 03Z. A FEW BANDS OF HEAVIER INTENSITY BANDS CAN BE
EXPECTED CLOSER TO MIDNIGHT AND THIS IS REFLECTED IN THE IFR VSBY
TEMPO GROUP. NOT EXPECTING CIGS TO DROP BELOW 2 KFT...BUT IT
CANNOT BE RULED OUT SO WILL MONITOR UPSTREAM OBS AND AMEND IF
NEEDED BY 03Z. ANY HEAVIER BANDS OF -SN WILL BE SHORT-LIVED AND
WILL LOOK FOR PRECIP TO BE WINDING DOWN IN THE EARLY MRNG HOURS.
PRECIP MAY MIX WITH OR CHANGE OVER TO -IP BEFORE ENDING AS WARMER
AIR MIXES INTO THE BOUNDARY LAYER...BUT NO SIGNIFICANT IMPACTS ARE
EXPECTED. AFTER THE PRECIP ENDS...SOME GROUND FOG MAY FORM DUE TO
THE INCREASE IN DEWPOINTS OVER THE COOLER SFC AIR...BUT THIS MAY
BE MITIGATED BY WINDS OVER 5 KT. CONDITIONS RETURN TO VFR BY
DAYBREAK AND WILL REMAIN AS SUCH THROUGH TMRW AFTN AND EVE.
OUTLOOK...
/TUE/...VFR.
/WED/...MVFR WITH PRECIPITATION POSSIBLE.
/THU/...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1121 PM CST FRI JAN 27 2012
.AVIATION...06Z TAF. QUIET PERIOD FOR THE TAF. VFR CONDITIONS ARE
EXPECTED THROUGH THE TAF PERIOD WITH ONLY HIGH CIRRUS EXPECTED TO
MOVE THROUGH THE AREA. A SURFACE HIGH PRESSURE SYSTEM TO THE WEST
WILL KEEP WINDS FROM THE WEST WITH STRONGER WINDS DURING THE
DAYTIME HOURS SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 911 PM CST FRI JAN 27 2012/
UPDATE...SENT AN ADDITIONAL UPDATE TO THE FORECAST TO ACCOUNT
FOR A FEW STUBBORN LIGHT SNOW SHOWERS CONTINUING TO TRACK RAPIDLY
SOUTHEASTWARD ACROSS PORTIONS OF HARLAN AND PHILLIPS COUNTY THIS
HOUR. DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATION WITH THESE
SHOWERS...MAYBE A FEW TENTHS OF AN INCH OF TOTAL SNOWFALL
ACCUMULATION IN SPOTS AS EVIDENT IN A COUPLE OF NE ROAD CAMERAS
UPSTREAM OF THIS AREA. HOWEVER...BY MIDNIGHT...ALL ACTIVITY SHOULD
HAVE DIMINISHED OR TRACKED OUT OF THE LOCAL AREA AND CLEARING
SKIES AND LIGHT WINDS WILL LIKELY LEAD TO SEASONABLY COOL MORNING
ACROSS THE REGION ON SATURDAY. NO OTHER CHANGES MADE TO FORECAST
AT THIS TIME.
PREV DISCUSSION... /ISSUED 601 PM CST FRI JAN 27 2012/
UPDATE...WILL GO AHEAD AND UPDATE THE FORECAST PACKAGE TO
REFLECT THE EXPIRATION OF THE WIND ADVISORY AS WINDS CONTINUE TO
RELAX AND HAVE NOW FALLEN BELOW ADVISORY CRITERIA. NO OTHER
CHANGES NECESSARY AT THIS TIME.
PREV DISCUSSION... /ISSUED 421 PM CST FRI JAN 27 2012/
SHORT TERM...THROUGH SATURDAY AFTERNOON. PRIMARY CONCERNS ARE
TWO-FOLD...FIRST THE ONGOING WIND ADVISORY THIS AFTERNOON...AND
THEN POTENTIAL/LIKELY FIRE WEATHER ISSUES ON SATURDAY AFTERNOON.
AT 21Z...OBJECTIVE SURFACE ANALYSIS REVEALS A HEALTHY PRESSURE
GRADIENT ACROSS THE AREA...AS A 1022+MB HIGH SETTLES INTO THE
NORTHERN ROCKIES. WITH FORECAST SOUNDINGS INDICATING DEEP MIXING
TO AROUND 800MB...THE WIND ADVISORY FOR ALL BUT THE FAR EASTERN
CWA HAS WORKED OUT FAIRLY WELL...WITH SEVERAL AUTOMATED AIRPORT
SITES RECORDING SUSTAINED SPEEDS NEAR/JUST OVER 30 MPH...ALTHOUGH
PEAK GUSTS HAVE LARGELY TOPPED OUT AROUND 40 MPH...MAKING THIS A
LOW-END WIND ADVISORY OVERALL. ALOFT...AFTERNOON WATER VAPOR AND
SHORT TERM MODEL DATA CONFIRMS A BROAD SHORTWAVE TROUGH SWINGING
ACROSS THE CENTRAL CONUS. WITH PRIMARY ZONE OF SYNOPTIC SCALE LIFT
AND MID LEVEL SATURATION HAS BEEN OFF TO THE EAST FOR SEVERAL
HOURS NOW...WITH NO PRECIPITATION NOTED SO FAR THIS AFTERNOON
WITHIN THE CWA. TEMP WISE...HIGHS THIS AFTERNOON MET OR ONLY SLIGHTLY
EXCEEDED ORIGINAL FORECAST FROM THIS MORNING...RANGING FROM AROUND
40 IN THE NORTH TO UPPER 40S SOUTH.
LATE THIS AFTERNOON/TONIGHT...THE MAIN ISSUE IS THE ONGOING WIND
ADVISORY. WITH NAM FORECAST SOUNDINGS INDICATING A RAPID DIURNAL
DIMINISHMENT IN MIXING AROUND SUNSET...THE 00Z EXPIRATION TIME
LOOKS LIKE ON TARGET. THAT BEING SAID...IT WILL REMAIN RATHER
BREEZY WELL INTO THE EVENING HOURS...WITH SUSTAINED SPEEDS HOLDING
UP IN THE 15-20 MPH RANGE WITH HIGHER GUSTS. BY MIDNIGHT AND
THEREAFTER...SPEEDS SHOULD EASE DOWN INTO THE 5-15 MPH RANGE AND
TRANSITION MORE WESTERLY AS THE CENTER OF THE EXPANSIVE SURFACE
HIGH TO THE WEST SLIDES SOUTH. TURNING TO PRECIPITATION TRENDS
LATE THIS AFTERNOON/TONIGHT...INTRODUCED A MENTION OF
SCATTERED/ISOLATED FLURRIES THROUGH 03Z ACROSS MOST NEB ZONES...TO
ACCOUNT FOR UPSTREAM SNOW SHOWERS NOW EVIDENT OVER WESTERN/NORTH
CENTRAL NEBRASKA. THESE SNOW SHOWERS ARE A CLASSIC CASE OF PARTIAL
SUNSHINE ACTING UPON STEEP LOW LEVEL LAPSE RATES UNDER THE COLD
POCKET ALOFT...WITH THE LATEST SPC RUC MESOANALYSIS INDICATING 0-3KM
LAPSE RATES NOW IN THE 7.5-8.5 C/KM RANGE. SHORT TERM HIGH
RESOLUTION MODELS SUCH AS THE HRRR AND 4KM WRF-NMM HAVE HAD A GOOD
HANDLE ON THIS SNOW SHOWER/FLURRY ACTIVITY ALL DAY NOW...WITH THE
HRRR AND RADAR TRENDS CONFIRMING THAT THE WESTERN 1/2 OF THE CWA
IS MOST AT RISK FOR CATCHING SOME OF THIS FAST-MOVING ACTIVITY.
STRONGLY CONSIDERED ADDING A LOW MEASURABLE POP TO ACCOUNT FOR
POSSIBILITY THAT A FEW SPOTS MAINLY TOWARD DAWSON/VALLEY/SHERMAN
COUNTY AREA COULD MEASURE A QUICK FEW TENTHS OF SNOWFALL...BUT
WITH THE BETTER FOCUS REMAINING JUST NORTHWEST OF THE AREA...FELT
A SCATTERED FLURRY MENTION MIGHT BETTER CAPTURE THE BRIEF NATURE
OF ANY FALLING SNOW. AS LAPSE RATES LESSEN AFTER DARK AND THE
PRIMARY SHORTWAVE AXIS SLIDES EAST...ANY SNOW SHOWERS SHOULD
QUICKLY FADE AWAY...WITH LITTLE IF ANY RISK FOR THIS ACTIVITY
EXPECTED TO REMAIN BEYOND 03Z. TEMPERATURE WISE TONIGHT...THE
HEALTHY EVENING BREEZES SHOULD KEEP THINGS FROM DROPPING OFF VERY
QUICKLY...BUT EVENTUALLY EXPECT LOWS TO DROP INTO THE 17-21 RANGE
ACROSS MOST AREAS AS SKIES CLEAR...EXCEPT FOR SLIGHTLY COLDER READINGS
IN THE FAVORED SPOTS FROM VALLEY TOWARD DAWSON COUNTIES IN THE
WEST.
ON SATURDAY...THE MAIN CONCERN TURNS TO FIRE WEATHER...WHICH IS
COVERED IN THE FIRE WEATHER SECTION BELOW. ON THE LARGER SCALE
ALOFT...SLIGHT MID LEVEL HEIGHT RISES OCCUR AS BROAD RATHER HIGH
AMPLIFIED RIDGING DOMINATES THE WESTERN CONUS...WHILE OFF TO THE
EAST...THE PRIMARY SHORTWAVE PASSING THROUGH THE AREA TODAY WILL
SWING ACROSS THE SOUTHERN GREAT LAKES...WHILE AN UPSTREAM
SHORTWAVE/AREA OF CHANNELED VORTICITY SLIDES OUT OF CANADA INTO
THE EASTERN DAKOTAS. ANY PRECIPITATION ASSOCIATED WITH THIS WAVE
SHOULD REMAIN AT LEAST A FEW HUNDRED MILES OFF TO THE
NORTH/NORTHEAST OF THE CWA DURING THE AFTERNOON. IN THE LOW
LEVELS...IT WILL BE ANOTHER RATHER BREEZY LATE MORNING THROUGH
LATE AFTERNOON...BUT THIS TIME FROM THE WEST. NAM FORECAST
SOUNDINGS INDICATE IMPRESSIVE MIXING TO 800-750MB DURING THE
AFTERNOON. ALTHOUGH NOT ANTICIPATING ADVISORY LEVEL
WINDS...SUSTAINED SPEEDS OF 15-25 MPH WITH GUSTS 30-35 MPH WILL BE
COMMON. ALTHOUGH IT WILL REMAIN RATHER COOL ALOFT WITH 850MB TEMPS
ONLY RISING INTO THE -1 TO -3C RANGE DURING THE AFTERNOON...THE
DOWNSLOPE FLOW ALONG WITH NO WORSE THAN PARTLY CLOUDY SKIES SHOULD
MILK EVERY BIT OF WARMTH OUT OF THE AIRMASS AS POSSIBLE...AND
NUDGED HIGH TEMPERATURES UP SLIGHTLY FROM PREVIOUS FORECAST MOST
AREAS...WITH MOST NEB ZONES ADVERTISED BETWEEN 45-48...AND KS
ZONES 47-49. AS COVERED FURTHER IN THE FIRE WEATHER SECTION
BELOW...DEWPOINTS WERE LOWERED SEVERAL DEGREES FROM PREVIOUS
FORECAST.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. THE MAJORITY OF THE
LONG TERM PERIOD WILL FEATURE WEST/NORTHWESTERLY FLOW ALOFT WITH
SEVERAL FAST MOVING WAVES RIPPLING THROUGH THE UPPER FLOW. THE
MEDIUM RANGE MODELS GENERALLY AGREE THAT THE BULK OF THE ENERGY
ASSOCIATED WITH THE WAVES NEVER REALLY TAKES DIRECT AIM AT THE
FORECAST AREA...AND WITH DRY AIR IN THE LOW LEVELS...PRECIPITATION
WILL BE HARD TO GENERATE. NOT TO SAY THERE MAY NOT BE A SMALL
CHANCE OF RAIN OR SNOW AT SOME POINT...BUT WITHOUT ANY DECENT
CHANCES OF PRECIPITATION SHOWN BY THE DETERMINISTIC RUNS...AND WITH
GEFS POPS SO LOW...WILL KEEP IT DRY THROUGH THE PERIOD.
TEMPERATURES THROUGH THE PERIOD SHOULD STAY ON THE WARM SIDE OF
NORMAL. IN FACT...MUCH OF NEXT WEEK SHOULD SEE HIGHS NEARLY 10 TO
15 DEGREES ABOVE SEASONAL AVERAGES. THE WARMEST DAY APPEARS TO BE
MONDAY WITH H85 TEMPERATURES NEAR 10 CELSIUS AND SOME MODEL
SOLUTIONS SUGGESTING HIGHS IN THE LOWER 60S. HAVE NOT GONE QUITE
THAT WARM IN THE GRIDS YET...BUT DO HAVE TEMPERATURES SOLIDLY IN THE
MID 50S TO NEAR 60. THERE SHOULD BE A COOL DOWN TOWARDS THE END OF
NEXT WEEK AS A COLD FRONT MOVES THROUGH THE REGION.
FIRE WEATHER...A FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE
ENTIRE CWA FROM 18Z-00Z SATURDAY AFTERNOON...AND AN UPGRADE TO A
RED FLAG WARNING IS VERY POSSIBLE FOR AT LEAST WESTERN PORTIONS OF
THE WATCH AREA LATER TONIGHT. WITH DEEP MIXING NEAR/IN EXCESS OF
800MB EXPECTED...AND NEARLY DUE WESTERLY LOW LEVEL WINDS...THIS IS
A CLASSIC SET UP FOR A PRONOUNCED MIX-OUT OF DAYTIME DEW POINTS.
DESPITE SURFACE TEMPERATURES ONLY TOPPING OUT IN THE 40S...THE
ANTICIPATION OF DEWPOINTS FALLING INTO THE SINGLE DIGITS MOST
AREAS YIELDS A LARGE AREA OF AFTERNOON RELATIVE HUMIDITY VALUES
FALLING BETWEEN 15-23 PERCENT...ESPECIALLY FOR LOCATIONS SOUTHWEST
OF A LINE FROM ORD TO SUPERIOR...INCLUDING NORTH CENTRAL KANSAS.
THE LATEST ECMWF/GFS DETERMINISTIC SOLUTIONS EVEN SUGGEST THAT
DEWPOINTS COULD DROP BELOW ZERO ACROSS PARTS OF THE DISTRICT...AND
ALTHOUGH DIDN/T BUY THIS FULLY YET...ITS NOT OUT OF THE QUESTION
IN THIS WESTERLY WIND REGIME. AT ANY RATE...EASTERN PORTIONS OF
THE WATCH ARE OF LOWEST CONFIDENCE TO REACH RED FLAG
WARNING...WITH HIGHEST CONFIDENCE IN THE SOUTHWEST. THE WIND
CRITERIA OF 20 MPH SUSTAINED/GUSTS TO 25 MPH ARE NOT EXPECTED TO
BE A PROBLEM...SO EVERYTHING WILL HINGE ON THE COMBINATION OF
RISING TEMPERATURES/FALLING DEWPOINTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR NEZ039>041-046>049-
060>064-072>077-082>087.
KS...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR KSZ005>007-017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
500 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL LIFT JUST NORTH OF THE REGION TODAY...BRINGING A
SHARP COLD FRONT ACROSS THE REGION THROUGH THIS EVENING. THIS WILL
BRING WINDY CONDITIONS THIS EVENING AND SOME LAKE EFFECT SNOW EAST OF
THE LAKES TONIGHT. ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL
CROSS THE REGION SUNDAY...WHICH WILL BRING A A GENERAL LIGHT
SNOWFALL TO WESTERN NEW YORK FOLLOWED BY MORE LAKE EFFECT SNOW
EAST OF THE LAKES SUNDAY NIGHT. A THIRD FAST MOVING SYSTEM WILL
BRING ANOTHER CHANCE OF SNOW LATE MONDAY BEFORE ANOTHER SIGNIFICANT
WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
MADE A QUICK UPDATE TO INCLUDE MONROE COUNTY IN THE WIND ADVISORY
THIS EVENING. WILL ALSO ISSUE A LAKE SHORE FLOOD ADVISORY FOR
CHAUTAUQUA AND SOUTHERN ERIE COUNTIES DUE TO THE POTENTIAL FOR MINOR
FLOODING WITH THE STRONG SOUTHWEST WINDS.
THE LATEST MOMENTUM TRANSFER SCHEMES SUGGEST THAT WINDS EAST OF LAKE
ONTARIO WILL ALSO GUST UP TO ADVISORY CRITERIA LATER THIS EVENING
THROUGH THE FIRST HALF OF TONIGHT. BASED ON THIS TREND...WILL
ISSUE A WIND ADVISORY FOR AREAS EAST OF LAKE ONTARIO.
LOW PRESSURE PASSING TO THE NORTH WILL DRAG A COLD FRONT ACROSS THE
REGION THROUGH THIS EVENING. AS OF 300 PM...ENTERING FAR WESTERN NEW
YORK NEAR BUFFALO.
THIS FRONT WILL BRING A PERIOD OF STRONG GUSTY WINDS...ESPECIALLY
ALONG LAKE ERIE AND THE NIAGARA FRONTIER. THE 12Z RUNS OF THE NAM/GFS
SHOWS WINDS AT 2000 FEET OF 50 TO 55 KTS...WITH SEVERAL RUC RUNS
SHOWING UP TO 60 KTS. WHILE THIS MAY NOT MIX DOWN ACROSS THE
INTERIOR VALLEYS...POST FRONTAL SW FLOW DO TYPICALLY MIX QUITE WELL
ACROSS FAR WESTERN NEW YORK...WHERE HIGHER TERRAIN HELPS FUNNEL
WINDS ALONG LAKE ERIE...AND ACROSS THE NIAGARA FRONTIER. EXPECT
SEVERAL HOURS OF WIND GUSTS TO 50 MPH IN THIS REGION...WITH THE
STRONGEST WINDS LIKELY BETWEEN 500 PM AND 900 PM.
THE OTHER ISSUE WITH THIS SYSTEM WILL BE SNOW FALL...MAINLY OF THE
LAKE EFFECT VARIETY. AHEAD OF THE FRONT...A BAND OF LIGHT SNOW WILL
WEAKEN AS IT MOVES EAST. WITH TEMPERATURES WARMER THERE...SNOW WILL
MIX WITH RAIN AT TIMES...WHICH WILL LIMIT PREFRONTAL ACCUMULATION.
WINDS WILL BOTH INCREASE AND SHIFT TO THE SW BEHIND THE FRONT. 850
MB TEMPERATURES WILL DROP TO AROUND -12C BEHIND THE FRONT...WHICH
WILL ONLY RESULT IN MODEST INSTABILITY OFF LAKE ERIE. WITH THE
STRONG FLOW LIMITING FETCH...EXPECT ONLY LIGHT LAKE EFFECT SNOWS OFF
LAKE ERIE...WITH VERY LIMITED ACCUMULATIONS.
OFF LAKE ONTARIO IS A DIFFERENT STORY...SINCE LAKE ONTARIO IS A BIT
WARMER...THE FLOW SHOULD BE FAIRLY WELL ALIENED FROM THE WSW ACROSS
THE LAKE. THIS WOULD PROBABLY STILL NOT BE ENOUGH FOR SIGNIFICANT
ACCUMULATIONS...EXCEPT THAT TERRAIN...ESPECIALLY THE TUG HILL...WILL
FURTHER ENHANCE QPF. THE ENTIRE REGION EAST OF LAKE ONTARIO SHOULD
GET AN INCH OR SO OF SNOW AHEAD OF THE FRONT LATE AFTERNOON. AFTER
THIS...LAKE EFFECT BANDS WILL SET UP...WITH WINDS LIKELY TO SUPPORT
A BAND SOMEWHERE NEAR OR JUST NORTH OF THE JEFFERSON/OSWEGO COUNTY
LINE. INITIALLY...EXPECT STRONG WINDS TO PREVENT AN ORGANIZED
CONVERGENCE BAND ON THE LAKE...WITH UPSLOPING THE BEST LIFTING
MECHANISM...FOCUSING STEADIEST SNOWS ON THE TUG HILL. THE RGEM KEYS
ON THIS...AS IT TYPICALLY WILL FORECAST LAKE BANDS WELL...BUT
INSTEAD IT KEYS ON THE UPSLOPING ON THE TUG HILL...AND ACROSS HIGHER
TERRAIN IN INTERIOR LEWIS COUNTY. WINDS WILL DIMINISH A BIT LATER IN
THE NIGHT...POTENTIALLY ALLOWING SOME ORGANIZATION OF A TIGHTER BUT
MORE INTENSE BAND...BEFORE MOISTURE DIMINISHES ON THE BACK OF THE
EXITING UPPER TROF. WILL KEEP THE ADVISORY AND SNOWFALL AMOUNTS IN
PLACE. CONFIDENCE IS NOT TERRIBLY HIGH...WITH STRONG WINDS
POTENTIALLY A LIMITING FACTOR...BUT GIVEN GOOD MOISTURE EARLY IN THE
EVENT...AND THE UPSLOPE COMPONENT...4 TO 7 INCHES STILL LOOKS
REASONABLE IN PORTIONS OF THE ADVISORY AREA.
FOR SUNDAY...A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD TO THE
SOUTH...AS ANOTHER CLIPPER LOW DEVELOPS TO THE WEST. THE MORNING
HOURS WOULD BE UNEVENTFUL...EXCEPT FOR THE POTENTIAL FOR A LAKE
EFFECT BAND TO LIFT NORTHWARD ACROSS THE NIAGARA FRONTIER DURING THE
MORNING HOURS. WINDS WILL SHIFT FROM WSW TO SSW...SUPPORTING THE
LIFTING OF WHATEVER LAKE SNOWS REMAIN. INSTABILITY AND MOISTURE WILL
BE QUITE LIMITED BY THEN...BUT STILL MAY SEE A PERIOD OF LAKE SNOWS
DURING THE SUNDAY MORNING HOURS...WITH MINIMAL ACCUMULATION. A
SIMILAR STORY WILL PLAY OUT EAST OF LAKE ONTARIO...WITH THE BAND
THERE ALSO LIKELY TO LIFT NORTH TOWARD WATERTOWN TOWARD DAYBREAK.
AS LOW PRESSURE TRACKS ACROSS THE REGION LATE SUNDAY...EXPECT A
FAIRLY WIDESPREAD BUT GENERALLY LIGHT SNOWFALL FOR MOST OF THE
REGION. WHILE THE LAKES WILL PLAY SOME ROLE ENHANCING MOISTURE...THE
MAIN SOURCE OF LIFT WILL BE THE UPPER LEVEL TROF WITH THE LOW. THIS
SHOULD START IN MOST LOCATIONS DURING THE AFTERNOON HOURS. USING A
BLEND OF THE RGEM/NAM12 QPF...EXPECT AN INCH OR SO ACROSS INTERIOR
SECTIONS...WITH 1 TO 2 INCHES EAST OF THE LAKES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE WAKE OF THE DEPARTING SURFACE LOW...COLDER AIR ARRIVES WITH
850 MB TEMPS FALLING FROM -8C TO -11C AT THE START OF THE NIGHT TO
ABOUT -14C/-15C BY MIDNIGHT. THIS WILL TRIGGER THE REDEVELOPMENT OF
SOME ACCUMULATING LAKE EFFECT SNOWS TO THE EAST AND EAST-SOUTHEAST
OF BOTH LAKES...WITH THE ACTIVITY PEAKING BETWEEN THE EARLY TO MID
EVENING AND EARLY OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS
STRONG LOW LEVEL RIDGING AND INCREASING AMOUNTS OF DRIER
AIR/SUBSIDENCE BUILD EAST FROM THE CENTRAL LAKES AND OHIO VALLEY.
THE SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD TEND
TO RESULT IN BORDERLINE ADVISORY CRITERIA ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS TO THE EAST-SOUTHEAST OF LAKE ONTARIO WHERE LONGER FETCH
AND MODEL-IMPLIED UPSTREAM CONNECTION TO GEORGIAN BAY WILL BE MORE
FAVORABLE.
DURING MONDAY...THE LOW LEVEL RIDGE AXIS WILL SHIFT EAST TO EASTERN
NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT WAVE OF LOW
PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN BETWEEN THESE
TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP ACROSS THE
AREA...WEAKENING AND SUPPRESSING ANY REMAINING LAKE EFFECT SNOWS.
LATE MONDAY/MONDAY NIGHT WILL FEATURE SWATH OF LIGHT WARM ADVECTIVE
SNOW SHOWERS LIFTING NORTHEASTWARD ACROSS THE AREA...AS THE RIDGE OF
HIGH PRESSURE CONTINUES EASTWARD OF THE REGION AND THE WESTERN GREAT
LAKES LOW PUSHES ITS WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL
BROADBRUSH MID-RANGE CHANCE POPS DURING THIS PERIOD...WHEN SOME
LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE AREAWIDE.
TEMPS WILL BE MUCH CLOSER TO SEASONAL NORMALS ON SUNDAY NIGHT AND
MONDAY WITH LOWS IN THE MIDDLE TEENS TO LOWER 20S AND HIGHS IN THE
20S TO NEAR 30 DEGREES. EXPECT WARMER TEMPS AGAIN ON TUESDAY WITH
HIGHS IN THE MID TO UPPER 30S ACROSS THE NORTH COUNTRY AND THE LOWER
TO MID 40S ELSEWHERE. SOUTHERLY WINDS WILL KEEP TUESDAY NIGHT LOWS
QUITE MILD FOR THIS TIME OF YEAR WITH MID 20S TO LOW 30S EAST OF
LAKE ONTARIO AND THE LOWER TO MID 30S FOR THE REST OF THE FORECAST
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END. EXPECT A COLDER BUT DRY NORTHERLY FLOW
ON SATURDAY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION LATE AFTERNOON INTO
THIS EVENING. AHEAD OF THIS...WITH BE PERIODS OF SNOW...MIXED WITH RAIN AT
TIMES. EXPECT LOWEST CONDITIONS TO BE WEST AT BUF/IAG/JHW...WHERE
PERIODS OF LIFR CONDITIONS ARE LIKELY AHEAD OF THE FRONT.
OTHERWISE...EXPECT MAINLY MVFR CONDITIONS OUTSIDE OF THE AREAS OF
SNOW.
THE FRONT WILL PUSH ACROSS THE REGION BETWEEN 21Z AND
00Z...WHICH WILL CAUSE WINDS TO INCREASE SIGNIFICANTLY. EXPECT
BUF/IAG TO BOTH EXPERIENCE GUSTS TO 40 KTS FROM THE POST-FRONTAL
SW FLOW...BEFORE WINDS DIMINISH LATER TONIGHT. MEANWHILE...CIGS
AND VSBY SHOULD IMPROVE BEHIND THE FRONT...AS SNOW SHOWERS TAPER
OFF...AND DRIER AIR WORKS IN.
SUNDAY SHOULD START OFF VFR/MVFR BEHIND THE FRONT...HOWEVER A LAKE
EFFECT SNOW BAND MAY CROSS ART AT SOME POINT DURING THE MORNING
HOURS.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR CONDITIONS IN SNOW SHOWERS EARLY...IMPROVING
OVERNIGHT.
MONDAY...MVFR/IFR WITH AREAS OF SNOW.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO THIS EVENING...WITH A SIGNIFICANT COLD FRONT CROSSING THE
LAKES LATE AFTERNOON AND EARLY EVENING. THE STRONGEST WINDS WILL BE
THROUGH THIS EVENING...AS A 50 TO 55 KT FLOW ALOFT PARTIALLY MIXES
DOWN IN THE SW FLOW BEHIND THE FRONT. EXPECT WINDS TO 40 KTS ACROSS
MUCH OF THE WATERS THIS EVENING...WITHOUT HIS GRADUALLY DIMINISHING
LATER TONIGHT.
WHILE WINDS WILL DIMINISH BELOW GALES LATE TONIGHT...MODERATE TO
STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH SOLID
SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS INTO THE
LOWER LAKES MONDAY WITH DIMINISHING WINDS.
OTHERWISE...A SERIES OF WEAK SYSTEMS WILL PASS THROUGH LATE NEXT
WILL...WITH WINDS GENERALLY ON THE LIGHT SIDE OUTSIDE OF A FEW
PERIODS WHERE SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ007-
008.
WIND ADVISORY UNTIL 1 AM EST SUNDAY FOR NYZ006>008.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ001>003-010-
011-019-085.
LAKESHORE FLOOD ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING UNTIL 4 AM EST SUNDAY FOR LOZ030.
GALE WARNING UNTIL 7 AM EST SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/TJP
SHORT TERM...WCH
LONG TERM...JJR/WCH
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
324 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL LIFT JUST NORTH OF THE REGION TODAY...BRINGING A
SHARP COLD FRONT ACROSS THE REGION THROUGH THIS EVENING. THIS WILL
BRING WINDY CONDITIONS THIS EVENING AND SOME LAKE EFFECT SNOW EAST OF
THE LAKES TONIGHT. ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL
CROSS THE REGION SUNDAY...WHICH WILL BRING A A GENERAL LIGHT
SNOWFALL TO WESTERN NEW YORK FOLLOWED BY MORE LAKE EFFECT SNOW
EAST OF THE LAKES SUNDAY NIGHT. A THIRD FAST MOVING SYSTEM WILL
BRING ANOTHER CHANCE OF SNOW LATE MONDAY BEFORE ANOTHER SIGNIFICANT
WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
LOW PRESSURE PASSING TO THE NORTH WILL DRAG A COLD FRONT ACROSS THE
REGION THROUGH THIS EVENING. AS OF 300 PM...ENTERING FAR WESTERN NEW
YORK NEAR BUFFALO.
THIS FRONT WILL BRING A PERIOD OF STRONG GUSTY WINDS...ESPECIALLY
ALONG LAKE ERIE AND THE NIAGARA FRONTIER. THE 12Z RUNS OF THE NAM/GFS
SHOWS WINDS AT 2000 FEET OF 50 TO 55 KTS...WITH SEVERAL RUC RUNS
SHOWING UP TO 60 KTS. WHILE THIS MAY NOT MIX DOWN ACROSS THE
INTERIOR VALLEYS...POST FRONTAL SW FLOW DO TYPICALLY MIX QUITE WELL
ACROSS FAR WESTERN NEW YORK...WHERE HIGHER TERRAIN HELPS FUNNEL
WINDS ALONG LAKE ERIE...AND ACROSS THE NIAGARA FRONTIER. EXPECT
SEVERAL HOURS OF WIND GUSTS TO 50 MPH IN THIS REGION...WITH THE
STRONGEST WINDS LIKELY BETWEEN 500 PM AND 900 PM.
THE OTHER ISSUE WITH THIS SYSTEM WILL BE SNOW FALL...MAINLY OF THE
LAKE EFFECT VARIETY. AHEAD OF THE FRONT...A BAND OF LIGHT SNOW WILL
WEAKEN AS IT MOVES EAST. WITH TEMPERATURES WARMER THERE...SNOW WILL
MIX WITH RAIN AT TIMES...WHICH WILL LIMIT PREFRONTAL ACCUMULATION.
WINDS WILL BOTH INCREASE AND SHIFT TO THE SW BEHIND THE FRONT. 850
MB TEMPERATURES WILL DROP TO AROUND -12C BEHIND THE FRONT...WHICH
WILL ONLY RESULT IN MODEST INSTABILITY OFF LAKE ERIE. WITH THE
STRONG FLOW LIMITING FETCH...EXPECT ONLY LIGHT LAKE EFFECT SNOWS OFF
LAKE ERIE...WITH VERY LIMITED ACCUMULATIONS.
OFF LAKE ONTARIO IS A DIFFERENT STORY...SINCE LAKE ONTARIO IS A BIT
WARMER...THE FLOW SHOULD BE FAIRLY WELL ALIENED FROM THE WSW ACROSS
THE LAKE. THIS WOULD PROBABLY STILL NOT BE ENOUGH FOR SIGNIFICANT
ACCUMULATIONS...EXCEPT THAT TERRAIN...ESPECIALLY THE TUG HILL...WILL
FURTHER ENHANCE QPF. THE ENTIRE REGION EAST OF LAKE ONTARIO SHOULD
GET AN INCH OR SO OF SNOW AHEAD OF THE FRONT LATE AFTERNOON. AFTER
THIS...LAKE EFFECT BANDS WILL SET UP...WITH WINDS LIKELY TO SUPPORT
A BAND SOMEWHERE NEAR OR JUST NORTH OF THE JEFFERSON/OSWEGO COUNTY
LINE. INITIALLY...EXPECT STRONG WINDS TO PREVENT AN ORGANIZED
CONVERGENCE BAND ON THE LAKE...WITH UPSLOPING THE BEST LIFTING
MECHANISM...FOCUSING STEADIEST SNOWS ON THE TUG HILL. THE RGEM KEYS
ON THIS...AS IT TYPICALLY WILL FORECAST LAKE BANDS WELL...BUT
INSTEAD IT KEYS ON THE UPSLOPING ON THE TUG HILL...AND ACROSS HIGHER
TERRAIN IN INTERIOR LEWIS COUNTY. WINDS WILL DIMINISH A BIT LATER IN
THE NIGHT...POTENTIALLY ALLOWING SOME ORGANIZATION OF A TIGHTER BUT
MORE INTENSE BAND...BEFORE MOISTURE DIMINISHES ON THE BACK OF THE
EXITING UPPER TROF. WILL KEEP THE ADVISORY AND SNOWFALL AMOUNTS IN
PLACE. CONFIDENCE IS NOT TERRIBLY HIGH...WITH STRONG WINDS
POTENTIALLY A LIMITING FACTOR...BUT GIVEN GOOD MOISTURE EARLY IN THE
EVENT...AND THE UPSLOPE COMPONENT...4 TO 7 INCHES STILL LOOKS
REASONABLE IN PORTIONS OF THE ADVISORY AREA.
FOR SUNDAY...A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD TO THE
SOUTH...AS ANOTHER CLIPPER LOW DEVELOPS TO THE WEST. THE MORNING
HOURS WOULD BE UNEVENTFUL...EXCEPT FOR THE POTENTIAL FOR A LAKE
EFFECT BAND TO LIFT NORTHWARD ACROSS THE NIAGARA FRONTIER DURING THE
MORNING HOURS. WINDS WILL SHIFT FROM WSW TO SSW...SUPPORTING THE
LIFTING OF WHATEVER LAKE SNOWS REMAIN. INSTABILITY AND MOISTURE WILL
BE QUITE LIMITED BY THEN...BUT STILL MAY SEE A PERIOD OF LAKE SNOWS
DURING THE SUNDAY MORNING HOURS...WITH MINIMAL ACCUMULATION. A
SIMILAR STORY WILL PLAY OUT EAST OF LAKE ONTARIO...WITH THE BAND
THERE ALSO LIKELY TO LIFT NORTH TOWARD WATERTOWN TOWARD DAYBREAK.
AS LOW PRESSURE TRACKS ACROSS THE REGION LATE SUNDAY...EXPECT A
FAIRLY WIDESPREAD BUT GENERALLY LIGHT SNOWFALL FOR MOST OF THE
REGION. WHILE THE LAKES WILL PLAY SOME ROLE ENHANCING MOISTURE...THE
MAIN SOURCE OF LIFT WILL BE THE UPPER LEVEL TROF WITH THE LOW. THIS
SHOULD START IN MOST LOCATIONS DURING THE AFTERNOON HOURS. USING A
BLEND OF THE RGEM/NAM12 QPF...EXPECT AN INCH OR SO ACROSS INTERIOR
SECTIONS...WITH 1 TO 2 INCHES EAST OF THE LAKES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE WAKE OF THE DEPARTING SURFACE LOW...COLDER AIR ARRIVES WITH
850 MB TEMPS FALLING FROM -8C TO -11C AT THE START OF THE NIGHT TO
ABOUT -14C/-15C BY MIDNIGHT. THIS WILL TRIGGER THE REDEVELOPMENT OF
SOME ACCUMULATING LAKE EFFECT SNOWS TO THE EAST AND EAST-SOUTHEAST
OF BOTH LAKES...WITH THE ACTIVITY PEAKING BETWEEN THE EARLY TO MID
EVENING AND EARLY OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS
STRONG LOW LEVEL RIDGING AND INCREASING AMOUNTS OF DRIER
AIR/SUBSIDENCE BUILD EAST FROM THE CENTRAL LAKES AND OHIO VALLEY.
THE SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD TEND
TO RESULT IN BORDERLINE ADVISORY CRITERIA ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS TO THE EAST-SOUTHEAST OF LAKE ONTARIO WHERE LONGER FETCH
AND MODEL-IMPLIED UPSTREAM CONNECTION TO GEORGIAN BAY WILL BE MORE
FAVORABLE.
DURING MONDAY...THE LOW LEVEL RIDGE AXIS WILL SHIFT EAST TO EASTERN
NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT WAVE OF LOW
PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN BETWEEN THESE
TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP ACROSS THE
AREA...WEAKENING AND SUPPRESSING ANY REMAINING LAKE EFFECT SNOWS.
LATE MONDAY/MONDAY NIGHT WILL FEATURE SWATH OF LIGHT WARM ADVECTIVE
SNOW SHOWERS LIFTING NORTHEASTWARD ACROSS THE AREA...AS THE RIDGE OF
HIGH PRESSURE CONTINUES EASTWARD OF THE REGION AND THE WESTERN GREAT
LAKES LOW PUSHES ITS WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL
BROADBRUSH MID-RANGE CHANCE POPS DURING THIS PERIOD...WHEN SOME
LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE AREAWIDE.
TEMPS WILL BE MUCH CLOSER TO SEASONAL NORMALS ON SUNDAY NIGHT AND
MONDAY WITH LOWS IN THE MIDDLE TEENS TO LOWER 20S AND HIGHS IN THE
20S TO NEAR 30 DEGREES. EXPECT WARMER TEMPS AGAIN ON TUESDAY WITH
HIGHS IN THE MID TO UPPER 30S ACROSS THE NORTH COUNTRY AND THE LOWER
TO MID 40S ELSEWHERE. SOUTHERLY WINDS WILL KEEP TUESDAY NIGHT LOWS
QUITE MILD FOR THIS TIME OF YEAR WITH MID 20S TO LOW 30S EAST OF
LAKE ONTARIO AND THE LOWER TO MID 30S FOR THE REST OF THE FORECAST
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END. EXPECT A COLDER BUT DRY NORTHERLY FLOW
ON SATURDAY.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION LATE AFTERNOON INTO
THIS EVENING. AHEAD OF THIS...WITH BE PERIODS OF SNOW...MIXED WITH RAIN AT
TIMES. EXPECT LOWEST CONDITIONS TO BE WEST AT BUF/IAG/JHW...WHERE
PERIODS OF LIFR CONDITIONS ARE LIKELY AHEAD OF THE FRONT.
OTHERWISE...EXPECT MAINLY MVFR CONDITIONS OUTSIDE OF THE AREAS OF
SNOW.
THE FRONT WILL PUSH ACROSS THE REGION BETWEEN 21Z AND
00Z...WHICH WILL CAUSE WINDS TO INCREASE SIGNIFICANTLY. EXPECT
BUF/IAG TO BOTH EXPERIENCE GUSTS TO 40 KTS FROM THE POST-FRONTAL
SW FLOW...BEFORE WINDS DIMINISH LATER TONIGHT. MEANWHILE...CIGS
AND VSBY SHOULD IMPROVE BEHIND THE FRONT...AS SNOW SHOWERS TAPER
OFF...AND DRIER AIR WORKS IN.
SUNDAY SHOULD START OFF VFR/MVFR BEHIND THE FRONT...HOWEVER A LAKE
EFFECT SNOW BAND MAY CROSS ART AT SOME POINT DURING THE MORNING
HOURS.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR CONDITIONS IN SNOW SHOWERS EARLY...IMPROVING
OVERNIGHT.
MONDAY...MVFR/IFR WITH AREAS OF SNOW.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO THIS EVENING...WITH A SIGNIFICANT COLD FRONT CROSSING THE
LAKES LATE AFTERNOON AND EARLY EVENING. THE STRONGEST WINDS WILL BE
THROUGH THIS EVENING...AS A 50 TO 55 KT FLOW ALOFT PARTIALLY MIXES
DOWN IN THE SW FLOW BEHIND THE FRONT. EXPECT WINDS TO 40 KTS ACROSS
MUCH OF THE WATERS THIS EVENING...WITHOUT HIS GRADUALLY DIMINISHING
LATER TONIGHT.
WHILE WINDS WILL DIMINISH BELOW GALES LATE TONIGHT...MODERATE TO
STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH SOLID
SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS INTO THE
LOWER LAKES MONDAY WITH DIMINISHING WINDS.
OTHERWISE...A SERIES OF WEAK SYSTEMS WILL PASS THROUGH LATE NEXT
WILL...WITH WINDS GENERALLY ON THE LIGHT SIDE OUTSIDE OF A FEW
PERIODS WHERE SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ007-
008.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ001-002-010-
011-019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING UNTIL 4 AM EST SUNDAY FOR LOZ030.
GALE WARNING UNTIL 7 AM EST SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...JJR/WCH
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
316 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL LIFT JUST NORTH OF THE REGION TODAY...BRINGING A
SHARP COLD FRONT ACROSS THE REGION THROUGH THIS EVENING. THIS WILL
BRING WINDY CONDITIONS THIS EVENING AND SOME LAKE EFFECT SNOW EAST OF
THE LAKES TONIGHT. ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL
CROSS THE REGION SUNDAY...WHICH WILL BRING A A GENERAL LIGHT
SNOWFALL TO WESTERN NEW YORK FOLLOWED BY MORE LAKE EFFECT SNOW
EAST OF THE LAKES SUNDAY NIGHT. A THIRD FAST MOVING SYSTEM WILL
BRING ANOTHER CHANCE OF SNOW LATE MONDAY BEFORE ANOTHER SIGNIFICANT
WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
LOW PRESSURE PASSING TO THE NORTH WILL DRAG A COLD FRONT ACROSS THE
REGION THROUGH THIS EVENING. AS OF 300 PM...ENTERING FAR WESTERN NEW
YORK NEAR BUFFALO.
THIS FRONT WILL BRING A PERIOD OF STRONG GUSTY WINDS...ESPECIALLY
ALONG LAKE ERIE AND THE NIAGARA FRONTIER. THE 12Z RUNS OF THE NAM/GFS
SHOWS WINDS AT 2000 FEET OF 50 TO 55 KTS...WITH SEVERAL RUC RUNS
SHOWING UP TO 60 KTS. WHILE THIS MAY NOT MIX DOWN ACROSS THE
INTERIOR VALLEYS...POST FRONTAL SW FLOW DO TYPICALLY MIX QUITE WELL
ACROSS FAR WESTERN NEW YORK...WHERE HIGHER TERRAIN HELPS FUNNEL
WINDS ALONG LAKE ERIE...AND ACROSS THE NIAGARA FRONTIER. EXPECT
SEVERAL HOURS OF WIND GUSTS TO 50 MPH IN THIS REGION...WITH THE
STRONGEST WINDS LIKELY BETWEEN 500 PM AND 900 PM.
THE OTHER ISSUE WITH THIS SYSTEM WILL BE SNOW FALL...MAINLY OF THE
LAKE EFFECT VARIETY. AHEAD OF THE FRONT...A BAND OF LIGHT SNOW WILL
WEAKEN AS IT MOVES EAST. WITH TEMPERATURES WARMER THERE...SNOW WILL
MIX WITH RAIN AT TIMES...WHICH WILL LIMIT PREFRONTAL ACCUMULATION.
WINDS WILL BOTH INCREASE AND SHIFT TO THE SW BEHIND THE FRONT. 850
MB TEMPERATURES WILL DROP TO AROUND -12C BEHIND THE FRONT...WHICH
WILL ONLY RESULT IN MODEST INSTABILITY OFF LAKE ERIE. WITH THE
STRONG FLOW LIMITING FETCH...EXPECT ONLY LIGHT LAKE EFFECT SNOWS OFF
LAKE ERIE...WITH VERY LIMITED ACCUMULATIONS.
OFF LAKE ONTARIO IS A DIFFERENT STORY...SINCE LAKE ONTARIO IS A BIT
WARMER...THE FLOW SHOULD BE FAIRLY WELL ALIENED FROM THE WSW ACROSS
THE LAKE. THIS WOULD PROBABLY STILL NOT BE ENOUGH FOR SIGNIFICANT
ACCUMULATIONS...EXCEPT THAT TERRAIN...ESPECIALLY THE TUG HILL...WILL
FURTHER ENHANCE QPF. THE ENTIRE REGION EAST OF LAKE ONTARIO SHOULD
GET AN INCH OR SO OF SNOW AHEAD OF THE FRONT LATE AFTERNOON. AFTER
THIS...LAKE EFFECT BANDS WILL SET UP...WITH WINDS LIKELY TO SUPPORT
A BAND SOMEWHERE NEAR OR JUST NORTH OF THE JEFFERSON/OSWEGO COUNTY
LINE. INITIALLY...EXPECT STRONG WINDS TO PREVENT AN ORGANIZED
CONVERGENCE BAND ON THE LAKE...WITH UPSLOPING THE BEST LIFTING
MECHANISM...FOCUSING STEADIEST SNOWS ON THE TUG HILL. THE RGEM KEYS
ON THIS...AS IT TYPICALLY WILL FORECAST LAKE BANDS WELL...BUT
INSTEAD IT KEYS ON THE UPSLOPING ON THE TUG HILL...AND ACROSS HIGHER
TERRAIN IN INTERIOR LEWIS COUNTY. WINDS WILL DIMINISH A BIT LATER IN
THE NIGHT...POTENTIALLY ALLOWING SOME ORGANIZATION OF A TIGHTER BUT
MORE INTENSE BAND...BEFORE MOISTURE DIMINISHES ON THE BACK OF THE
EXITING UPPER TROF. WILL KEEP THE ADVISORY AND SNOWFALL AMOUNTS IN
PLACE. CONFIDENCE IS NOT TERRIBLY HIGH...WITH STRONG WINDS
POTENTIALLY A LIMITING FACTOR...BUT GIVEN GOOD MOISTURE EARLY IN THE
EVENT...AND THE UPSLOPE COMPONENT...4 TO 7 INCHES STILL LOOKS
REASONABLE IN PORTIONS OF THE ADVISORY AREA.
FOR SUNDAY...A HIGH PRESSURE RIDGE WILL BRIEFLY BUILD TO THE
SOUTH...AS ANOTHER CLIPPER LOW DEVELOPS TO THE WEST. THE MORNING
HOURS WOULD BE UNEVENTFUL...EXCEPT FOR THE POTENTIAL FOR A LAKE
EFFECT BAND TO LIFT NORTHWARD ACROSS THE NIAGARA FRONTIER DURING THE
MORNING HOURS. WINDS WILL SHIFT FROM WSW TO SSW...SUPPORTING THE
LIFTING OF WHATEVER LAKE SNOWS REMAIN. INSTABILITY AND MOISTURE WILL
BE QUITE LIMITED BY THEN...BUT STILL MAY SEE A PERIOD OF LAKE SNOWS
DURING THE SUNDAY MORNING HOURS...WITH MINIMAL ACCUMULATION. A
SIMILAR STORY WILL PLAY OUT EAST OF LAKE ONTARIO...WITH THE BAND
THERE ALSO LIKELY TO LIFT NORTH TOWARD WATERTOWN TOWARD DAYBREAK.
AS LOW PRESSURE TRACKS ACROSS THE REGION LATE SUNDAY...EXPECT A
FAIRLY WIDESPREAD BUT GENERALLY LIGHT SNOWFALL FOR MOST OF THE
REGION. WHILE THE LAKES WILL PLAY SOME ROLE ENHANCING MOISTURE...THE
MAIN SOURCE OF LIFT WILL BE THE UPPER LEVEL TROF WITH THE LOW. THIS
SHOULD START IN MOST LOCATIONS DURING THE AFTERNOON HOURS. USING A
BLEND OF THE RGEM/NAM12 QPF...EXPECT AN INCH OR SO ACROSS INTERIOR
SECTIONS...WITH 1 TO 2 INCHES EAST OF THE LAKES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE WAKE OF THE DEPARTING SURFACE LOW...COLDER AIR ARRIVES WITH
850 MB TEMPS FALLING FROM -8C TO -11C AT THE START OF THE NIGHT TO
ABOUT -14C/-15C BY MIDNIGHT. THIS WILL TRIGGER THE REDEVELOPMENT OF
SOME ACCUMULATING LAKE EFFECT SNOWS TO THE EAST AND EAST-SOUTHEAST
OF BOTH LAKES...WITH THE ACTIVITY PEAKING BETWEEN THE EARLY TO MID
EVENING AND EARLY OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS
STRONG LOW LEVEL RIDGING AND INCREASING AMOUNTS OF DRIER
AIR/SUBSIDENCE BUILD EAST FROM THE CENTRAL LAKES AND OHIO VALLEY.
THE SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD TEND
TO RESULT IN BORDERLINE ADVISORY CRITERIA ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS TO THE EAST-SOUTHEAST OF LAKE ONTARIO WHERE LONGER FETCH
AND MODEL-IMPLIED UPSTREAM CONNECTION TO GEORGIAN BAY WILL BE MORE
FAVORABLE.
DURING MONDAY...THE LOW LEVEL RIDGE AXIS WILL SHIFT EAST TO EASTERN
NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT WAVE OF LOW
PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN BETWEEN THESE
TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP ACROSS THE
AREA...WEAKENING AND SUPPRESSING ANY REMAINING LAKE EFFECT SNOWS.
LATE MONDAY/MONDAY NIGHT WILL FEATURE SWATH OF LIGHT WARM ADVECTIVE
SNOW SHOWERS LIFTING NORTHEASTWARD ACROSS THE AREA...AS THE RIDGE OF
HIGH PRESSURE CONTINUES EASTWARD OF THE REGION AND THE WESTERN GREAT
LAKES LOW PUSHES ITS WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL
BROADBRUSH MID-RANGE CHANCE POPS DURING THIS PERIOD...WHEN SOME
LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE AREAWIDE.
TEMPS WILL BE MUCH CLOSER TO SEASONAL NORMALS ON SUNDAY NIGHT AND
MONDAY WITH LOWS IN THE MIDDLE TEENS TO LOWER 20S AND HIGHS IN THE
20S TO NEAR 30 DEGREES. EXPECT WARMER TEMPS AGAIN ON TUESDAY WITH
HIGHS IN THE MID TO UPPER 30S ACROSS THE NORTH COUNTRY AND THE LOWER
TO MID 40S ELSEWHERE. SOUTHERLY WINDS WILL KEEP TUESDAY NIGHT LOWS
QUITE MILD FOR THIS TIME OF YEAR WITH MID 20S TO LOW 30S EAST OF
LAKE ONTARIO AND THE LOWER TO MID 30S FOR THE REST OF THE FORECAST
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END. EXPECT A COLDER BUT DRY NORTHERLY FLOW
ON SATURDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION LATE AFTERNOON INTO
THIS EVENING. AHEAD OF THIS...WITH BE PERIODS OF SNOW...MIXED WITH RAIN AT
TIMES. EXPECT LOWEST CONDITIONS TO BE WEST AT BUF/IAG/JHW...WHERE
PERIODS OF LIFR CONDITIONS ARE LIKELY AHEAD OF THE FRONT.
OTHERWISE...EXPECT MAINLY MVFR CONDITIONS OUTSIDE OF THE AREAS OF
SNOW.
THE FRONT WILL PUSH ACROSS THE REGION BETWEEN 21Z AND
00Z...WHICH WILL CAUSE WINDS TO INCREASE SIGNIFICANTLY. EXPECT
BUF/IAG TO BOTH EXPERIENCE GUSTS TO 40 KTS FROM THE POST-FRONTAL
SW FLOW...BEFORE WINDS DIMINISH LATER TONIGHT. MEANWHILE...CIGS
AND VSBY SHOULD IMPROVE BEHIND THE FRONT...AS SNOW SHOWERS TAPER
OFF...AND DRIER AIR WORKS IN.
SUNDAY SHOULD START OFF VFR/MVFR BEHIND THE FRONT...HOWEVER A LAKE
EFFECT SNOW BAND MAY CROSS ART AT SOME POINT DURING THE MORNING
HOURS.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR CONDITIONS IN SNOW SHOWERS EARLY...IMPROVING
OVERNIGHT.
MONDAY...MVFR/IFR WITH AREAS OF SNOW.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO THIS EVENING...WITH A SIGNIFICANT COLD FRONT CROSSING THE
LAKES LATE AFTERNOON AND EARLY EVENING. THE STRONGEST WINDS WILL BE
THROUGH THIS EVENING...AS A 50 TO 55 KT FLOW ALOFT PARTIALLY MIXES
DOWN IN THE SW FLOW BEHIND THE FRONT. EXPECT WINDS TO 40 KTS ACROSS
MUCH OF THE WATERS THIS EVENING...WITHOUT HIS GRADUALLY DIMINISHING
LATER TONIGHT.
WHILE WINDS WILL DIMINISH BELOW GALES LATE TONIGHT...MODERATE TO
STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH SOLID
SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS INTO THE
LOWER LAKES MONDAY WITH DIMINISHING WINDS.
OTHERWISE...A SERIES OF WEAK SYSTEMS WILL PASS THROUGH LATE NEXT
WILL...WITH WINDS GENERALLY ON THE LIGHT SIDE OUTSIDE OF A FEW
PERIODS WHERE SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST SUNDAY FOR NYZ007-
008.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ001-002-010-
011-019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING UNTIL 7 AM EST SUNDAY FOR LOZ042>045-
062>065.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...JJR/WCH
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1234 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE BY JUST NORTH OF THE REGION TODAY AND BRING
A ROUND OF WET SNOW WHICH WILL STRUGGLE TO ACCUMULATE AS TEMPERATURES
WILL BE NEAR OR ABOVE FREEZING. IT WILL ALSO BECOME WINDY TODAY
AND TONIGHT AS THE LOW MOVES BY. SOME LAKE EFFECT SNOW WILL
DEVELOP EAST OF THE LAKES TONIGHT WITH ANOTHER FAST MOVING LOW
PRESSURE SYSTEM BRINGING A GENERAL LIGHT SNOWFALL TO THE AREA
SUNDAY FOLLOWED BY MORE LAKE EFFECT SNOW EAST OF THE LAKES SUNDAY
NIGHT. A THIRD FAST MOVING SYSTEM WILL BRING ANOTHER GENERAL LIGHT
SNOW TO THE REGION LATE MONDAY AND MONDAY NIGHT BEFORE ANOTHER
SIGNIFICANT WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH NOON...RADAR SNOWS LIGHT SNOW ACROSS FAR WESTERN NEW YORK.
THIS IS THE LEADING EDGE OF A SECOND BAND WHICH SHOULD MOVE ACROSS
THE REGION EARLY AFTERNOON...WITH ROUGHLY .10 OF QPF WITH THIS.
WHILE THE 12Z BUF SOUNDING SHOWED A WARM AND DRY LAYER BETWEEN 850
MB AND 600 MB...THIS HAS CERTAINLY SATURATED AND COOLED. WHILE
DOWNSLOPING SHOULD HELP WARM TEMPERATURES A BIT...NOW EXPECT MOST
HEAVIER PRECIPITATION TO FALL AS SNOW EARLY AFTERNOON AS
WELL...THOUGH THE WARM SURFACE TEMPERATURES SHOULD LIMIT
ACCUMULATION. WITH TEMPERATURES A TAD WARMER...SNOW SHOULD
STRUGGLE TO ACCUMULATE ACROSS THE NIAGARA FRONTIER....HOWEVER A
SLUSHY INCH IS POSSIBLE ACROSS HIGHER TERRAIN OF THE SOUTHERN TIER
WHERE IT IS STILL BELOW FREEZING.
AS THE LOW PASSES TO THE NORTH...IT WILL BRING A COLD FRONT ACROSS
THE REGION LATE AFTERNOON INTO THIS EVENING. IT WILL BECOME
QUITE WINDY THIS AFTERNOON AND TONIGHT AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN THE SURFACE LOW PASSING ACROSS SOUTHERN
QUEBEC...AND HIGH PRESSURE PARKED OVER THE OHIO VALLEY. BOTH THE
12Z NAM AND RUC SHOW A 50 TO 55 KT FLOW AT 2000 FEET BEHIND THIS
FRONT...AND GIVEN THE WELL ALIGNED SW POST-FRONTAL FLOW...EXPECT A
GOOD PART OF THIS WILL TRANSLATE TO THE SURFACE ACROSS THE NIAGARA FRONTIER.
THE RESULT WILL BE GUSTY WINDS...WITH GUSTS TO 50 MPH LIKELY
IMMEDIATELY BEHIND THE FRONT. BECAUSE OF THIS POTENTIAL...WILL
ISSUE A BRIEF WIND ADVISORY FOR THE NIAGARA FRONTIER...AND WESTERN
PORTIONS OF THE SOUTHERN TIER FOR LATE THIS AFTERNOON INTO THIS
EVENING. WHILE THESE STRONG GUSTS SHOULD ONLY BE FOR ABOUT A 3
HOUR PERIOD...EXPECT BUF-IAG TO BOTH REPORT PEAK GUSTS IN THE 50
TO 55 MPH RANGE.
SO THE UPDATES...ISSUED A WIND ADVISORY FOR FAR WESTERN NEW YORK.
ALSO NUDGED UP THE TIMING OF THE LAKE EFFECT SNOW ADVISORY EAST OF
LAKE ONTARIO...BASED ON THE SLIGHTLY EARLIER TIMING OF THE FRONT.
FOLLOWING THE SYSTEM TONIGHT OUR ATTENTION TURNS TO LAKE EFFECT
POTENTIAL.
OFF LAKE ERIE...THE SETUP IS QUITE MARGINAL AS SURFACE HIGH PRESSURE
OVER THE OHIO VALLEY QUICKLY NOSES NORTH WITH A RAPID LOSS OF LOW
LEVEL MOISTURE OVERNIGHT. THERE STILL SHOULD BE A BRIEF 2-4 HOUR
WINDOW DURING THE LATE AFTERNOON AND EVENING WHERE LAKE INDUCED
CAPES IMPROVE TO AROUND 8-10K FEET IN WSW FLOW. GUSTY WINDS AND A
LACK OF UPSTREAM CONNECTION SHOULD KEEP THIS RATHER DISORGANIZED...
WITH SNOW SHOWERS FOCUSING ON THE HIGHER TERRAIN OF SKI COUNTRY.
EXPECT ACCUMULATIONS OF 1-2 INCHES ON THE HILLS THIS EVENING WITH A
DIMINISHING TREND OVERNIGHT AS THE COLUMN QUICKLY DRYS OUT. WHATEVER
REMAINS WILL DRIFT NORTH TOWARDS THE BUFFALO SOUTHTOWNS LATE
TONIGHT...BUT DONT EXPECT MUCH MORE THAN SCATTERED FLURRIES OR LIGHT
SNOW SHOWERS TO BE LEFT.
OFF LAKE ONTARIO...CONDITIONS ARE MORE FAVORABLE WITH A WARMER
LAKE...A LITTLE DEEPER COLD AIR...AND PROSPECTS OF AN UPSTREAM
CONNECTION TO LAKE HURON. LAKE INDUCED EQUILIBRIUM LEVELS ARE
FORECAST TO PEAK AROUND 15K FEET TONIGHT...AND MOST OF THE MESOSCALE
MODEL GUIDANCE SUCH AS THE CANADIAN REGIONAL GEM...WORKSTATION WRF
AND THE HIGH RES WRF-ARW DEVELOP AND UPSTREAM CONNECTION TO LAKE
HURON BANDING OVERNIGHT...WHICH ACTS TO ENHANCE BOTH MOISTURE AND
CONVERGENCE. ALL THREE OF THESE MODELS DEVELOP A PLUME OF MODERATE
QPF OVERNIGHT. THE MEAN BOUNDARY LAYER FLOW SETTLES TO ABOUT 260
OVERNIGHT...WHICH SHOULD FAVOR A BAND ACROSS SOUTHERN JEFFERSON AND
NORTH CENTRAL LEWIS COUNTY...ROUGHLY FROM ADAMS TO BARNES CORNERS
AND CROGHAN.
WITH THE ABOVE IN MIND...WE WILL HOIST A LAKE EFFECT SNOW ADVISORY
FOR JEFFERSON AND LEWIS COUNTIES STARTING EARLY THIS EVENING AND
RUNNING THROUGH SUNDAY MORNING. EXPECT TOTAL ACCUMS OF 4-7 INCHES
WITHIN THE BAND MENTIONED ABOVE. IT WILL BE A CLOSE CALL IN FAR
NORTHERN OSWEGO COUNTY WITH SOME UPSLOPE SUPPORTING A FEW INCHES
NEAR REDFIELD...BUT THE MEAN 260 WIND DIRECTION SHOULD KEEP THE
ADVISORY AMOUNTS JUST NORTH OF THE COUNTY LINE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ON SUNDAY...YET ANOTHER POTENT SHORTWAVE TROUGH WILL PRESS EAST
ACROSS THE LOWER GREAT LAKES REGION...WITH AN ASSOCIATED SURFACE
WAVE ALSO SLIDING EAST FROM LOWER MICHIGAN INTO CENTRAL NEW YORK BY
THE END OF THE DAY. IN ADVANCE OF THIS WAVE...THE COMBINATION OF
MODEST WARMING ALOFT AND AN INCREASINGLY SHEARED SOUTHWESTERLY FLOW
WILL ACT TO DISRUPT ANY LINGERING LAKE EFFECT SNOW SHOWERS NORTHEAST
OF THE LAKES DURING THE COURSE OF SUNDAY MORNING...WITH THIS PROCESS
TAKING PLACE FAIRLY EARLY IN THE DAY OFF LAKE ERIE...AND BY THE MID
TO LATE MORNING HOURS OFF LAKE ONTARIO. THEREAFTER...A SWATH OF MORE
GENERAL SYNOPTICALLY-DRIVEN SNOW SHOWERS SHOULD SPREAD ACROSS THE
AREA FROM WEST TO EAST DURING THE AFTERNOON WITH THE ARRIVAL OF THE
SURFACE WAVE. WITH BOTH THE NAM/GFS NOW BOTH INDICATING A FAVORABLE
SWATH OF LIFT AND MOISTURE ACCOMPANYING THE WAVE...HAVE BUMPED POPS
FOR THIS TIME FRAME UP TO THE HIGH LIKELY RANGE. AT THIS
POINT...MODEL QPF CONSENSUS SUPPORTS FAIRLY WIDESPREAD LIGHT
SNOWFALL ACCUMULATIONS RANGING FROM AN INCH OR LESS IN MOST PLACES
DURING SUNDAY...TO AS MUCH AS 1-2 INCHES IN THE TYPICAL AREAS OF
TERRAIN ENHANCEMENT EAST OF THE LAKES.
SUNDAY EVENING...THE AFOREMENTIONED SHORTWAVE AND SURFACE LOW WILL
QUICKLY EXIT TO THE EAST WITH ANY SYNOPTICALLY-DRIVEN SNOW SHOWERS
ALSO QUICKLY DIMINISHING FROM WEST TO EAST DURING THE EVENING...WITH
ANOTHER GENERAL INCH OR LESS OF ACCUMULATION POSSIBLE FOR SITES EAST
OF THE GENESEE VALLEY. AT THE SAME TIME HOWEVER...MESOSCALE
PROCESSES WILL AGAIN BECOME MORE DOMINANT AS A WESTERLY TO
WEST-NORTHWESTERLY FLOW OF COLDER AIR OVERSPREADS THE LOWER LAKES
BEHIND THE DEPARTING WAVE...WITH 850 MB TEMPS FALLING FROM -8C TO
-11C AT THE START OF THE NIGHT TO ABOUT -14C/-15C BY MIDNIGHT. THIS
WILL TRIGGER THE REDEVELOPMENT OF SOME ACCUMULATING LAKE EFFECT
SNOWS TO THE EAST AND EAST-SOUTHEAST OF BOTH LAKES...WITH THE
ACTIVITY PEAKING BETWEEN THE EARLY TO MID EVENING AND EARLY
OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS STRONG LOW LEVEL
RIDGING AND INCREASING AMOUNTS OF DRIER AIR/SUBSIDENCE BUILD EAST
FROM THE CENTRAL LAKES AND OHIO VALLEY. AT THIS JUNCTURE...FEEL THE
RELATIVELY SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD
TEND TO RESULT IN POTENTIAL ADVISORY-TYPE ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS COMING EAST-SOUTHEAST OF LAKE ONTARIO WHERE ENVIRONMENTAL
CONDITIONS WILL BE SOMEWHAT MORE FAVORABLE OVERALL.
DURING MONDAY...THE AFOREMENTIONED LOW LEVEL RIDGE AXIS WILL SHIFT
EAST TO EASTERN NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT
WAVE OF LOW PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN
BETWEEN THESE TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP
ACROSS THE AREA...WHILE THE LOW LEVEL FLOW WILL BACK TO
SOUTHWESTERLY OR EVEN SOUTHERLY AND BECOME RATHER SHEARED. THIS WILL
RESULT IN THE LAKE SNOWS CONTINUING TO WEAKEN WHILE LIFTING BACK
NORTH TO THE BUFFALO AND WATERTOWN AREAS...WITH THIS WEAKENING MOST
PRONOUNCED EAST OF LAKE ERIE WHERE STRONGER WARM AIR ADVECTION AND
SUBSIDENCE WILL TAKE HOLD.
FINALLY...THE VERY LATE MONDAY/MONDAY NIGHT PERIOD SHOULD FEATURE A
BROAD SWATH OF LIGHT WARM ADVECTIVE SNOW SHOWERS LIFTING NORTHEAST
ACROSS THE AREA...AS THE WESTERN GREAT LAKES LOW PUSHES ITS
ASSOCIATED WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL THEREFORE
ADVERTISE SOME BROADBRUSH MID-RANGE CHANCE POPS DURING THIS
PERIOD...WHEN SOME LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE
AREAWIDE.
AS FOR TEMPS...DESPITE THE ARRIVAL OF A COLDER CANADIAN AIRMASS LATE
SUNDAY AND SUNDAY NIGHT AND ITS SLOW DEPARTURE ON MONDAY...TEMPS
THROUGH THIS PERIOD WILL STILL ONLY AVERAGE CLOSE TO NORMAL. IN
GENERAL...EXPECT HIGH TEMPS TO RANGE IN THE 30S ON SUNDAY AND IN THE
MID 20S TO AROUND 30 ON MONDAY...WITH OVERNIGHT LOWS GENERALLY
BETWEEN FALLING BETWEEN THE MID TEENS AND MID 20S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END...ALONG WITH A GENERAL LOW CHANCE OF
SNOW SHOWERS. AGAIN THOUGH...THE LACK OF ANY TRULY ARCTIC AIR WITHIN
THIS TROUGH WILL LIKELY RESULT IN TEMPS ONLY FALLING BACK TO NEAR
NORMAL LEVELS...AND LIKELY REMAINING WARM ENOUGH TO PRECLUDE THE
DEVELOPMENT OF LAKE EFFECT SNOWS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION. AHEAD OF
THIS...WITH BE PERIODS OF SNOW...MIXED WITH RAIN AT TIMES. EXPECT
LOWEST CONDITIONS TO BE WEST AT BUF/IAG/JHW...WHERE PERIODS OF
LIFR CONDITIONS ARE LIKELY AHEAD OF THE FRONT. OTHERWISE...EXPECT
MAINLY MVFR CONDITIONS OUTSIDE OF THE AREAS OF SNOW.
THE FRONT WILL PUSH ACROSS THE REGION BETWEEN 21Z AND
00Z...WHICH WILL CAUSE WINDS TO INCREASE SIGNIFICANTLY. EXPECT
BUF/IAG TO BOTH EXPERIENCE GUSTS TO 40 KTS FROM THE POST-FRONTAL
SW FLOW...BEFORE WINDS DIMINISH LATER TONIGHT. MEANWHILE...CIGS
AND VSBY SHOULD IMPROVE BEHIND THE FRONT...AS SNOW SHOWERS TAPER
OFF...AND DRIER AIR WORKS IN.
SUNDAY SHOULD START OFF VFR/MVFR BEHIND THE FRONT...HOWEVER A LAKE
EFFECT SNOW BAND MAY CROSS ART AT SOME POINT DURING THE MORNING
HOURS.
OUTLOOK...
SUNDAY...AREAS OF IFR WITH SNOW SHOWERS LIKELY.
MONDAY...MVFR/IFR WITH LAKE EFFECT EAST OF THE LAKES ENDING
EARLY...THEN A GENERAL LIGHT SNOW LATE.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE LOW
AND HIGH PRESSURE OVER THE OHIO VALLEY. THE STRONGEST WINDS WILL
ARRIVE LATE THIS AFTERNOON AND TONIGHT AS 40-45 KNOT FLOW JUST OFF
THE DECK BEGINS TO MIX DOWN AS LOW LEVEL COLD ADVECTION STEEPENS
LAPSE RATES AND DESTABILIZES THE BOUNDARY LAYER...ESPECIALLY OVER
THE RELATIVELY WARMER LAKES. THIS WILL PRODUCE A LOW END GALE ON
BOTH LAKES ERIE AND ONTARIO...WITH WINDS PEAKING THIS EVENING.
WINDS WILL DIMINISH BELOW GALES LATE SATURDAY NIGHT...BUT MODERATE
TO STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH
SOLID SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS
INTO THE LOWER LAKES MONDAY WITH DIMINISHING WINDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST SUNDAY FOR NYZ007-008.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ001-002-010-
011-019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST
SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL/JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1203 PM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE BY JUST NORTH OF THE REGION TODAY AND BRING
A ROUND OF WET SNOW WHICH WILL STRUGGLE TO ACCUMULATE AS TEMPERATURES
WILL BE NEAR OR ABOVE FREEZING. IT WILL ALSO BECOME WINDY TODAY
AND TONIGHT AS THE LOW MOVES BY. SOME LAKE EFFECT SNOW WILL
DEVELOP EAST OF THE LAKES TONIGHT WITH ANOTHER FAST MOVING LOW
PRESSURE SYSTEM BRINGING A GENERAL LIGHT SNOWFALL TO THE AREA
SUNDAY FOLLOWED BY MORE LAKE EFFECT SNOW EAST OF THE LAKES SUNDAY
NIGHT. A THIRD FAST MOVING SYSTEM WILL BRING ANOTHER GENERAL LIGHT
SNOW TO THE REGION LATE MONDAY AND MONDAY NIGHT BEFORE ANOTHER
SIGNIFICANT WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH NOON...RADAR SNOWS LIGHT SNOW ACROSS FAR WESTERN NEW YORK.
THIS IS THE LEADING EDGE OF A SECOND BAND WHICH SHOULD MOVE ACROSS
THE REGION EARLY AFTERNOON...WITH ROUGHLY .10 OF QPF WITH THIS.
WHILE THE 12Z BUF SOUNDING SHOWED A WARM AND DRY LAYER BETWEEN 850
MB AND 600 MB...THIS HAS CERTAINLY SATURATED AND COOLED. WHILE
DOWNSLOPING SHOULD HELP WARM TEMPERATURES A BIT...NOW EXPECT MOST
HEAVIER PRECIPITATION TO FALL AS SNOW EARLY AFTERNOON AS
WELL...THOUGH THE WARM SURFACE TEMPERATURES SHOULD LIMIT
ACCUMULATION. WITH TEMPERATURES A TAD WARMER...SNOW SHOULD
STRUGGLE TO ACCUMULATE ACROSS THE NIAGARA FRONTIER....HOWEVER A
SLUSHY INCH IS POSSIBLE ACROSS HIGHER TERRAIN OF THE SOUTHERN TIER
WHERE IT IS STILL BELOW FREEZING.
AS THE LOW PASSES TO THE NORTH...IT WILL BRING A COLD FRONT ACROSS
THE REGION LATE AFTERNOON INTO THIS EVENING. IT WILL BECOME
QUITE WINDY THIS AFTERNOON AND TONIGHT AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN THE SURFACE LOW PASSING ACROSS SOUTHERN
QUEBEC...AND HIGH PRESSURE PARKED OVER THE OHIO VALLEY. BOTH THE
12Z NAM AND RUC SHOW A 50 TO 55 KT FLOW AT 2000 FEET BEHIND THIS
FRONT...AND GIVEN THE WELL ALIGNED SW POST-FRONTAL FLOW...EXPECT A
GOOD PART OF THIS WILL TRANSLATE TO THE SURFACE ACROSS THE NIAGARA FRONTIER.
THE RESULT WILL BE GUSTY WINDS...WITH GUSTS TO 50 MPH LIKELY
IMMEDIATELY BEHIND THE FRONT. BECAUSE OF THIS POTENTIAL...WILL
ISSUE A BRIEF WIND ADVISORY FOR THE NIAGARA FRONTIER...AND WESTERN
PORTIONS OF THE SOUTHERN TIER FOR LATE THIS AFTERNOON INTO THIS
EVENING. WHILE THESE STRONG GUSTS SHOULD ONLY BE FOR ABOUT A 3
HOUR PERIOD...EXPECT BUF-IAG TO BOTH REPORT PEAK GUSTS IN THE 50
TO 55 MPH RANGE.
SO THE UPDATES...ISSUED A WIND ADVISORY FOR FAR WESTERN NEW YORK.
ALSO NUDGED UP THE TIMING OF THE LAKE EFFECT SNOW ADVISORY EAST OF
LAKE ONTARIO...BASED ON THE SLIGHTLY EARLIER TIMING OF THE FRONT.
FOLLOWING THE SYSTEM TONIGHT OUR ATTENTION TURNS TO LAKE EFFECT
POTENTIAL.
OFF LAKE ERIE...THE SETUP IS QUITE MARGINAL AS SURFACE HIGH PRESSURE
OVER THE OHIO VALLEY QUICKLY NOSES NORTH WITH A RAPID LOSS OF LOW
LEVEL MOISTURE OVERNIGHT. THERE STILL SHOULD BE A BRIEF 2-4 HOUR
WINDOW DURING THE LATE AFTERNOON AND EVENING WHERE LAKE INDUCED
CAPES IMPROVE TO AROUND 8-10K FEET IN WSW FLOW. GUSTY WINDS AND A
LACK OF UPSTREAM CONNECTION SHOULD KEEP THIS RATHER DISORGANIZED...
WITH SNOW SHOWERS FOCUSING ON THE HIGHER TERRAIN OF SKI COUNTRY.
EXPECT ACCUMULATIONS OF 1-2 INCHES ON THE HILLS THIS EVENING WITH A
DIMINISHING TREND OVERNIGHT AS THE COLUMN QUICKLY DRYS OUT. WHATEVER
REMAINS WILL DRIFT NORTH TOWARDS THE BUFFALO SOUTHTOWNS LATE
TONIGHT...BUT DONT EXPECT MUCH MORE THAN SCATTERED FLURRIES OR LIGHT
SNOW SHOWERS TO BE LEFT.
OFF LAKE ONTARIO...CONDITIONS ARE MORE FAVORABLE WITH A WARMER
LAKE...A LITTLE DEEPER COLD AIR...AND PROSPECTS OF AN UPSTREAM
CONNECTION TO LAKE HURON. LAKE INDUCED EQUILIBRIUM LEVELS ARE
FORECAST TO PEAK AROUND 15K FEET TONIGHT...AND MOST OF THE MESOSCALE
MODEL GUIDANCE SUCH AS THE CANADIAN REGIONAL GEM...WORKSTATION WRF
AND THE HIGH RES WRF-ARW DEVELOP AND UPSTREAM CONNECTION TO LAKE
HURON BANDING OVERNIGHT...WHICH ACTS TO ENHANCE BOTH MOISTURE AND
CONVERGENCE. ALL THREE OF THESE MODELS DEVELOP A PLUME OF MODERATE
QPF OVERNIGHT. THE MEAN BOUNDARY LAYER FLOW SETTLES TO ABOUT 260
OVERNIGHT...WHICH SHOULD FAVOR A BAND ACROSS SOUTHERN JEFFERSON AND
NORTH CENTRAL LEWIS COUNTY...ROUGHLY FROM ADAMS TO BARNES CORNERS
AND CROGHAN.
WITH THE ABOVE IN MIND...WE WILL HOIST A LAKE EFFECT SNOW ADVISORY
FOR JEFFERSON AND LEWIS COUNTIES STARTING EARLY THIS EVENING AND
RUNNING THROUGH SUNDAY MORNING. EXPECT TOTAL ACCUMS OF 4-7 INCHES
WITHIN THE BAND MENTIONED ABOVE. IT WILL BE A CLOSE CALL IN FAR
NORTHERN OSWEGO COUNTY WITH SOME UPSLOPE SUPPORTING A FEW INCHES
NEAR REDFIELD...BUT THE MEAN 260 WIND DIRECTION SHOULD KEEP THE
ADVISORY AMOUNTS JUST NORTH OF THE COUNTY LINE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ON SUNDAY...YET ANOTHER POTENT SHORTWAVE TROUGH WILL PRESS EAST
ACROSS THE LOWER GREAT LAKES REGION...WITH AN ASSOCIATED SURFACE
WAVE ALSO SLIDING EAST FROM LOWER MICHIGAN INTO CENTRAL NEW YORK BY
THE END OF THE DAY. IN ADVANCE OF THIS WAVE...THE COMBINATION OF
MODEST WARMING ALOFT AND AN INCREASINGLY SHEARED SOUTHWESTERLY FLOW
WILL ACT TO DISRUPT ANY LINGERING LAKE EFFECT SNOW SHOWERS NORTHEAST
OF THE LAKES DURING THE COURSE OF SUNDAY MORNING...WITH THIS PROCESS
TAKING PLACE FAIRLY EARLY IN THE DAY OFF LAKE ERIE...AND BY THE MID
TO LATE MORNING HOURS OFF LAKE ONTARIO. THEREAFTER...A SWATH OF MORE
GENERAL SYNOPTICALLY-DRIVEN SNOW SHOWERS SHOULD SPREAD ACROSS THE
AREA FROM WEST TO EAST DURING THE AFTERNOON WITH THE ARRIVAL OF THE
SURFACE WAVE. WITH BOTH THE NAM/GFS NOW BOTH INDICATING A FAVORABLE
SWATH OF LIFT AND MOISTURE ACCOMPANYING THE WAVE...HAVE BUMPED POPS
FOR THIS TIME FRAME UP TO THE HIGH LIKELY RANGE. AT THIS
POINT...MODEL QPF CONSENSUS SUPPORTS FAIRLY WIDESPREAD LIGHT
SNOWFALL ACCUMULATIONS RANGING FROM AN INCH OR LESS IN MOST PLACES
DURING SUNDAY...TO AS MUCH AS 1-2 INCHES IN THE TYPICAL AREAS OF
TERRAIN ENHANCEMENT EAST OF THE LAKES.
SUNDAY EVENING...THE AFOREMENTIONED SHORTWAVE AND SURFACE LOW WILL
QUICKLY EXIT TO THE EAST WITH ANY SYNOPTICALLY-DRIVEN SNOW SHOWERS
ALSO QUICKLY DIMINISHING FROM WEST TO EAST DURING THE EVENING...WITH
ANOTHER GENERAL INCH OR LESS OF ACCUMULATION POSSIBLE FOR SITES EAST
OF THE GENESEE VALLEY. AT THE SAME TIME HOWEVER...MESOSCALE
PROCESSES WILL AGAIN BECOME MORE DOMINANT AS A WESTERLY TO
WEST-NORTHWESTERLY FLOW OF COLDER AIR OVERSPREADS THE LOWER LAKES
BEHIND THE DEPARTING WAVE...WITH 850 MB TEMPS FALLING FROM -8C TO
-11C AT THE START OF THE NIGHT TO ABOUT -14C/-15C BY MIDNIGHT. THIS
WILL TRIGGER THE REDEVELOPMENT OF SOME ACCUMULATING LAKE EFFECT
SNOWS TO THE EAST AND EAST-SOUTHEAST OF BOTH LAKES...WITH THE
ACTIVITY PEAKING BETWEEN THE EARLY TO MID EVENING AND EARLY
OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS STRONG LOW LEVEL
RIDGING AND INCREASING AMOUNTS OF DRIER AIR/SUBSIDENCE BUILD EAST
FROM THE CENTRAL LAKES AND OHIO VALLEY. AT THIS JUNCTURE...FEEL THE
RELATIVELY SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD
TEND TO RESULT IN POTENTIAL ADVISORY-TYPE ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS COMING EAST-SOUTHEAST OF LAKE ONTARIO WHERE ENVIRONMENTAL
CONDITIONS WILL BE SOMEWHAT MORE FAVORABLE OVERALL.
DURING MONDAY...THE AFOREMENTIONED LOW LEVEL RIDGE AXIS WILL SHIFT
EAST TO EASTERN NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT
WAVE OF LOW PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN
BETWEEN THESE TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP
ACROSS THE AREA...WHILE THE LOW LEVEL FLOW WILL BACK TO
SOUTHWESTERLY OR EVEN SOUTHERLY AND BECOME RATHER SHEARED. THIS WILL
RESULT IN THE LAKE SNOWS CONTINUING TO WEAKEN WHILE LIFTING BACK
NORTH TO THE BUFFALO AND WATERTOWN AREAS...WITH THIS WEAKENING MOST
PRONOUNCED EAST OF LAKE ERIE WHERE STRONGER WARM AIR ADVECTION AND
SUBSIDENCE WILL TAKE HOLD.
FINALLY...THE VERY LATE MONDAY/MONDAY NIGHT PERIOD SHOULD FEATURE A
BROAD SWATH OF LIGHT WARM ADVECTIVE SNOW SHOWERS LIFTING NORTHEAST
ACROSS THE AREA...AS THE WESTERN GREAT LAKES LOW PUSHES ITS
ASSOCIATED WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL THEREFORE
ADVERTISE SOME BROADBRUSH MID-RANGE CHANCE POPS DURING THIS
PERIOD...WHEN SOME LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE
AREAWIDE.
AS FOR TEMPS...DESPITE THE ARRIVAL OF A COLDER CANADIAN AIRMASS LATE
SUNDAY AND SUNDAY NIGHT AND ITS SLOW DEPARTURE ON MONDAY...TEMPS
THROUGH THIS PERIOD WILL STILL ONLY AVERAGE CLOSE TO NORMAL. IN
GENERAL...EXPECT HIGH TEMPS TO RANGE IN THE 30S ON SUNDAY AND IN THE
MID 20S TO AROUND 30 ON MONDAY...WITH OVERNIGHT LOWS GENERALLY
BETWEEN FALLING BETWEEN THE MID TEENS AND MID 20S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END...ALONG WITH A GENERAL LOW CHANCE OF
SNOW SHOWERS. AGAIN THOUGH...THE LACK OF ANY TRULY ARCTIC AIR WITHIN
THIS TROUGH WILL LIKELY RESULT IN TEMPS ONLY FALLING BACK TO NEAR
NORMAL LEVELS...AND LIKELY REMAINING WARM ENOUGH TO PRECLUDE THE
DEVELOPMENT OF LAKE EFFECT SNOWS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
EXPECT PRECIPITATION TO INITIALLY START OFF MAINLY AS SNOW...AS
EVAPORATIONAL COOLING FROM DECENT SNOWFALL RATES WINS OUT OVER
DOWNSLOPING. AS THE INTITIAL BAND LIFTS NORTH...VSBY SHOULD COME UP
EARLY AFTERNOON...WITH SOME MIXING WITH RAIN POSSIBLE. VSBY/CIGS
WILL VARY WIDELY DURING THIS TIME...ANYWHERES FROM LIFR TO VFR IN
AND OUT OF AREAS OF SNOW.
A FRONT WILL CROSS FROM WEST TO EAST LATE AFTERNOON...SHIFTING
WINDS TO THE SW...AND CAUSING THEM TO INCREASE AS WELL. PRECIPITATION
WILL RAPIDLY END IN MOST AREAS FROM WEST TO EAST DURING THE LATE
AFTERNOON AND EARLY EVENING WITH MVFR IMPROVING TO VFR. LAKE
EFFECT SNOW SHOWERS WILL LINGER EAST OF LAKE ERIE WITH AREAS OF
MVFR AND SPOTTY IFR THROUGH MID TO LATE EVENING. EXPECT THE SNOW
TO DIMINISH OVERNIGHT...ALTHOUGH A PLUME OF MVFR CIGS WILL LIKELY
PERSIST THROUGH THE NIGHT. EAST OF LAKE ONTARIO A MORE SIGNIFICANT
BAND OF LAKE EFFECT SNOW WILL DEVELOP JUST SOUTH OF KART WITH
LOCAL IFR CONDITIONS. THIS MAY DRIFT UP TOWARDS KART LATE TONIGHT
AND SUNDAY MORNING.
IT WILL BECOME QUITE WINDY TODAY...ESPECIALLY DOWNWIND OF LAKES ERIE
AND ONTARIO WHERE GUSTS IN THE 30-40 KNOT RANGE WILL BE COMMON THIS
AFTERNOON AND EVENING.
OUTLOOK...
SUNDAY...AREAS OF IFR WITH SNOW SHOWERS LIKELY.
MONDAY...MVFR/IFR WITH LAKE EFFECT EAST OF THE LAKES ENDING
EARLY...THEN A GENERAL LIGHT SNOW LATE.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE LOW
AND HIGH PRESSURE OVER THE OHIO VALLEY. THE STRONGEST WINDS WILL
ARRIVE LATE THIS AFTERNOON AND TONIGHT AS 40-45 KNOT FLOW JUST OFF
THE DECK BEGINS TO MIX DOWN AS LOW LEVEL COLD ADVECTION STEEPENS
LAPSE RATES AND DESTABILIZES THE BOUNDARY LAYER...ESPECIALLY OVER
THE RELATIVELY WARMER LAKES. THIS WILL PRODUCE A LOW END GALE ON
BOTH LAKES ERIE AND ONTARIO...WITH WINDS PEAKING THIS EVENING.
WINDS WILL DIMINISH BELOW GALES LATE SATURDAY NIGHT...BUT MODERATE
TO STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH
SOLID SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS
INTO THE LOWER LAKES MONDAY WITH DIMINISHING WINDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST SUNDAY FOR NYZ007-008.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 10 PM EST THIS
EVENING FOR NYZ001-002-010-011-019-085.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ020-040-041.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST
SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL/JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1020 AM EST SAT JAN 28 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE BY JUST NORTH OF THE REGION TODAY AND BRING
A ROUND OF WET SNOW WHICH WILL STRUGGLE TO ACCUMULATE AS TEMPERATURES
WILL BE NEAR OR ABOVE FREEZING. IT WILL ALSO BECOME WINDY TODAY
AND TONIGHT AS THE LOW MOVES BY. SOME LAKE EFFECT SNOW WILL
DEVELOP EAST OF THE LAKES TONIGHT WITH ANOTHER FAST MOVING LOW
PRESSURE SYSTEM BRINGING A GENERAL LIGHT SNOWFALL TO THE AREA
SUNDAY FOLLOWED BY MORE LAKE EFFECT SNOW EAST OF THE LAKES SUNDAY
NIGHT. A THIRD FAST MOVING SYSTEM WILL BRING ANOTHER GENERAL LIGHT
SNOW TO THE REGION LATE MONDAY AND MONDAY NIGHT BEFORE ANOTHER
SIGNIFICANT WARM UP BY MIDWEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH 1000 AM...SNOW HAS MOVED IN JUST A TAD FASTER THAN MOST
PREVIOUS MODEL RUNS INDICATED. WITH TEMPERATURES STILL COOLER FROM
LAST NIGHT...THIS HAS ALLOWED PRECIPITATION TO START OFF AS ALL
SNOW IN MOST LOCATIONS. FOUND MOST MODELS CONTINUE TO BE
SLOW...BUT ONLY BY AN HOUR OR TWO...WITH THE HRRR PROVIDING THE
MOST USEFUL GUIDANCE.
BOTH THE HRRR AND RADAR TRENDS SHOW THIS INITIAL BAND LIFTING
ACROSS NW NY FROM DUNKIRK TO ROCHESTER NORTHWARD THROUGH EARLY
AFTERNOON. THIS WILL BRING A DECENT BUT BRIEF PERIOD OF
SNOW...GENERALLY AMOUNTING TO LESS THAN AN INCH AS IT SHOULD
STRUGGLE TO ACCUMULATE WITH ABOVE FREEZING TEMPERATURES. ANOTHER
ROUND WHICH IS ACROSS NE OHIO LATE THIS MORNING SHOULD LIFT ACROSS
AS WELL...WITH THIS THE AREA THE NAM/RGEM/GFS HAVE BEEN KEYING ON.
THIS SHOULD BRING ANOTHER ROUND OF PRECIPITATION...WITH ROUGHLY
.10 OF QPF WITH THIS. WHILE THE 12Z BUF SOUNDING SHOWED A WARM AND
DRY LAYER BETWEEN 850 MB AND 600 MB...THIS HAS CERTAINLY SATURATED
AND COOLED. WHILE DOWNSLOPING SHOULD HELP WARM TEMPERATURES A
BIT...NOW EXPECT MOST HEAVIER PRECIPITATION TO FALL AS SNOW EARLY
AFTERNOON AS WELL...THOUGH THE WARM SURFACE TEMPERATURES SHOULD
LIMIT ACCUMULATION. EXPECT THE SECOND BAND (EARLY AFTERNOON BAND)
TO ACCUMULATE LITTLE ACROSS THE NIAGARA FRONTIER. HOWEVER...IT MAY
BRING A SLUSHY INCH TO HIGHER TERRAIN IN WESTERN PORTIONS OF THE
SOUTHERN TIER...AND PERHAPS HIGHER TERRAIN IN SOUTHERN
ERIE/WYOMING COUNTIES.
SUMMARY OF CHANGES IN THE UPDATE...NUDGE UP TIMING OF PRECIPITATION
BY AN HOUR OR TWO. NUDGE DOWN FORECAST HIGHS. SPEED UP THE FRONT
BY AN HOUR OR SO.
IT WILL BECOME QUITE WINDY THIS AFTERNOON AND TONIGHT AS THE
PRESSURE GRADIENT TIGHTENS BETWEEN THE SURFACE LOW PASSING ACROSS
SOUTHERN QUEBEC...AND HIGH PRESSURE PARKED OVER THE OHIO VALLEY. LOW
LEVEL COLD ADVECTION BY LATE AFTERNOON WILL ALLOW LAPSE RATES TO
STEEPEN AND ENHANCE MIXING OF STRONGER 40-45 KNOT WINDS ALOFT DOWN
TO THE SURFACE. MODEL GUIDANCE HAS BACKED OFF A LITTLE FROM PREVIOUS
RUNS ON THE STRENGTH OF WINDS ALOFT AND MIXING POTENTIAL...SO IT
APPEARS WINDS WILL REMAIN JUST BARELY BELOW ADVISORY CRITERIA. THE
STRONGEST WINDS ARE LIKELY IN A 4-6 HOUR PERIOD FROM THE LAKE ERIE
SHORE NORTHEAST ACROSS THE NIAGARA FRONTIER TO ROCHESTER...AND ALSO
ALONG THE EASTERN SHORES OF LAKE ONTARIO WITH GUSTS IN THE 40-45 MPH
RANGE IN BOTH THESE LOCATIONS. FARTHER INLAND GUSTS WILL RANGE FROM
30-40 MPH.
FOLLOWING THE SYSTEM TONIGHT OUR ATTENTION TURNS TO LAKE EFFECT
POTENTIAL.
OFF LAKE ERIE...THE SETUP IS QUITE MARGINAL AS SURFACE HIGH PRESSURE
OVER THE OHIO VALLEY QUICKLY NOSES NORTH WITH A RAPID LOSS OF LOW
LEVEL MOISTURE OVERNIGHT. THERE STILL SHOULD BE A BRIEF 2-4 HOUR
WINDOW DURING THE LATE AFTERNOON AND EVENING WHERE LAKE INDUCED
CAPES IMPROVE TO AROUND 8-10K FEET IN WSW FLOW. GUSTY WINDS AND A
LACK OF UPSTREAM CONNECTION SHOULD KEEP THIS RATHER DISORGANIZED...
WITH SNOW SHOWERS FOCUSING ON THE HIGHER TERRAIN OF SKI COUNTRY.
EXPECT ACCUMULATIONS OF 1-2 INCHES ON THE HILLS THIS EVENING WITH A
DIMINISHING TREND OVERNIGHT AS THE COLUMN QUICKLY DRYS OUT. WHATEVER
REMAINS WILL DRIFT NORTH TOWARDS THE BUFFALO SOUTHTOWNS LATE
TONIGHT...BUT DONT EXPECT MUCH MORE THAN SCATTERED FLURRIES OR LIGHT
SNOW SHOWERS TO BE LEFT.
OFF LAKE ONTARIO...CONDITIONS ARE MORE FAVORABLE WITH A WARMER
LAKE...A LITTLE DEEPER COLD AIR...AND PROSPECTS OF AN UPSTREAM
CONNECTION TO LAKE HURON. LAKE INDUCED EQUILIBRIUM LEVELS ARE
FORECAST TO PEAK AROUND 15K FEET TONIGHT...AND MOST OF THE MESOSCALE
MODEL GUIDANCE SUCH AS THE CANADIAN REGIONAL GEM...WORKSTATION WRF
AND THE HIGH RES WRF-ARW DEVELOP AND UPSTREAM CONNECTION TO LAKE
HURON BANDING OVERNIGHT...WHICH ACTS TO ENHANCE BOTH MOISTURE AND
CONVERGENCE. ALL THREE OF THESE MODELS DEVELOP A PLUME OF MODERATE
QPF OVERNIGHT. THE MEAN BOUNDARY LAYER FLOW SETTLES TO ABOUT 260
OVERNIGHT...WHICH SHOULD FAVOR A BAND ACROSS SOUTHERN JEFFERSON AND
NORTH CENTRAL LEWIS COUNTY...ROUGHLY FROM ADAMS TO BARNES CORNERS
AND CROGHAN.
WITH THE ABOVE IN MIND...WE WILL HOIST A LAKE EFFECT SNOW ADVISORY
FOR JEFFERSON AND LEWIS COUNTIES STARTING EARLY THIS EVENING AND
RUNNING THROUGH SUNDAY MORNING. EXPECT TOTAL ACCUMS OF 4-7 INCHES
WITHIN THE BAND MENTIONED ABOVE. IT WILL BE A CLOSE CALL IN FAR
NORTHERN OSWEGO COUNTY WITH SOME UPSLOPE SUPPORTING A FEW INCHES
NEAR REDFIELD...BUT THE MEAN 260 WIND DIRECTION SHOULD KEEP THE
ADVISORY AMOUNTS JUST NORTH OF THE COUNTY LINE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ON SUNDAY...YET ANOTHER POTENT SHORTWAVE TROUGH WILL PRESS EAST
ACROSS THE LOWER GREAT LAKES REGION...WITH AN ASSOCIATED SURFACE
WAVE ALSO SLIDING EAST FROM LOWER MICHIGAN INTO CENTRAL NEW YORK BY
THE END OF THE DAY. IN ADVANCE OF THIS WAVE...THE COMBINATION OF
MODEST WARMING ALOFT AND AN INCREASINGLY SHEARED SOUTHWESTERLY FLOW
WILL ACT TO DISRUPT ANY LINGERING LAKE EFFECT SNOW SHOWERS NORTHEAST
OF THE LAKES DURING THE COURSE OF SUNDAY MORNING...WITH THIS PROCESS
TAKING PLACE FAIRLY EARLY IN THE DAY OFF LAKE ERIE...AND BY THE MID
TO LATE MORNING HOURS OFF LAKE ONTARIO. THEREAFTER...A SWATH OF MORE
GENERAL SYNOPTICALLY-DRIVEN SNOW SHOWERS SHOULD SPREAD ACROSS THE
AREA FROM WEST TO EAST DURING THE AFTERNOON WITH THE ARRIVAL OF THE
SURFACE WAVE. WITH BOTH THE NAM/GFS NOW BOTH INDICATING A FAVORABLE
SWATH OF LIFT AND MOISTURE ACCOMPANYING THE WAVE...HAVE BUMPED POPS
FOR THIS TIME FRAME UP TO THE HIGH LIKELY RANGE. AT THIS
POINT...MODEL QPF CONSENSUS SUPPORTS FAIRLY WIDESPREAD LIGHT
SNOWFALL ACCUMULATIONS RANGING FROM AN INCH OR LESS IN MOST PLACES
DURING SUNDAY...TO AS MUCH AS 1-2 INCHES IN THE TYPICAL AREAS OF
TERRAIN ENHANCEMENT EAST OF THE LAKES.
SUNDAY EVENING...THE AFOREMENTIONED SHORTWAVE AND SURFACE LOW WILL
QUICKLY EXIT TO THE EAST WITH ANY SYNOPTICALLY-DRIVEN SNOW SHOWERS
ALSO QUICKLY DIMINISHING FROM WEST TO EAST DURING THE EVENING...WITH
ANOTHER GENERAL INCH OR LESS OF ACCUMULATION POSSIBLE FOR SITES EAST
OF THE GENESEE VALLEY. AT THE SAME TIME HOWEVER...MESOSCALE
PROCESSES WILL AGAIN BECOME MORE DOMINANT AS A WESTERLY TO
WEST-NORTHWESTERLY FLOW OF COLDER AIR OVERSPREADS THE LOWER LAKES
BEHIND THE DEPARTING WAVE...WITH 850 MB TEMPS FALLING FROM -8C TO
-11C AT THE START OF THE NIGHT TO ABOUT -14C/-15C BY MIDNIGHT. THIS
WILL TRIGGER THE REDEVELOPMENT OF SOME ACCUMULATING LAKE EFFECT
SNOWS TO THE EAST AND EAST-SOUTHEAST OF BOTH LAKES...WITH THE
ACTIVITY PEAKING BETWEEN THE EARLY TO MID EVENING AND EARLY
OVERNIGHT HOURS...THEN WEAKENING THEREAFTER AS STRONG LOW LEVEL
RIDGING AND INCREASING AMOUNTS OF DRIER AIR/SUBSIDENCE BUILD EAST
FROM THE CENTRAL LAKES AND OHIO VALLEY. AT THIS JUNCTURE...FEEL THE
RELATIVELY SHORT-LIVED NATURE OF THE MOST FAVORABLE CONDITIONS WOULD
TEND TO RESULT IN POTENTIAL ADVISORY-TYPE ACCUMULATIONS EAST AND
EAST-SOUTHEAST OF BOTH LAKES SUNDAY NIGHT...WITH THE BEST CHANCES
FOR THIS COMING EAST-SOUTHEAST OF LAKE ONTARIO WHERE ENVIRONMENTAL
CONDITIONS WILL BE SOMEWHAT MORE FAVORABLE OVERALL.
DURING MONDAY...THE AFOREMENTIONED LOW LEVEL RIDGE AXIS WILL SHIFT
EAST TO EASTERN NEW YORK AND WESTERN NEW ENGLAND...WHILE THE NEXT
WAVE OF LOW PRESSURE PUSHES EAST INTO THE UPPER GREAT LAKES. IN
BETWEEN THESE TWO FEATURES...A WARM ADVECTION PATTERN WILL SET UP
ACROSS THE AREA...WHILE THE LOW LEVEL FLOW WILL BACK TO
SOUTHWESTERLY OR EVEN SOUTHERLY AND BECOME RATHER SHEARED. THIS WILL
RESULT IN THE LAKE SNOWS CONTINUING TO WEAKEN WHILE LIFTING BACK
NORTH TO THE BUFFALO AND WATERTOWN AREAS...WITH THIS WEAKENING MOST
PRONOUNCED EAST OF LAKE ERIE WHERE STRONGER WARM AIR ADVECTION AND
SUBSIDENCE WILL TAKE HOLD.
FINALLY...THE VERY LATE MONDAY/MONDAY NIGHT PERIOD SHOULD FEATURE A
BROAD SWATH OF LIGHT WARM ADVECTIVE SNOW SHOWERS LIFTING NORTHEAST
ACROSS THE AREA...AS THE WESTERN GREAT LAKES LOW PUSHES ITS
ASSOCIATED WARM FRONT NORTHEAST INTO NEW YORK STATE. WILL THEREFORE
ADVERTISE SOME BROADBRUSH MID-RANGE CHANCE POPS DURING THIS
PERIOD...WHEN SOME LIGHT SNOWFALL ACCUMULATIONS WILL BE POSSIBLE
AREAWIDE.
AS FOR TEMPS...DESPITE THE ARRIVAL OF A COLDER CANADIAN AIRMASS LATE
SUNDAY AND SUNDAY NIGHT AND ITS SLOW DEPARTURE ON MONDAY...TEMPS
THROUGH THIS PERIOD WILL STILL ONLY AVERAGE CLOSE TO NORMAL. IN
GENERAL...EXPECT HIGH TEMPS TO RANGE IN THE 30S ON SUNDAY AND IN THE
MID 20S TO AROUND 30 ON MONDAY...WITH OVERNIGHT LOWS GENERALLY
BETWEEN FALLING BETWEEN THE MID TEENS AND MID 20S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THIS PERIOD WILL FEATURE A RETURN TO A MORE PROGRESSIVE ZONAL
FLOW...WITH A SERIES OF LOW AMPLITUDE WAVES MOVING ALONG THE
CANADIAN BORDER AND KEEPING A GENERAL CHANCE OF PRECIP IN PLACE
RIGHT THROUGH THURSDAY. WITH MILDER PACIFIC AIR DOMINATING OUR
REGION UNDER THIS PATTERN...TEMPS WILL ONCE AGAIN REBOUND TO ABOVE
NORMAL LEVELS...AND WILL BE SUPPORTIVE OF A RAIN/SNOW MIX AT
NIGHT...WITH RAIN THE MORE DOMINANT PRECIP TYPE DURING THE DAYTIME
PERIODS. AT THIS POINT...THE WARMEST TIME FRAME APPEARS TO BE
WEDNESDAY...WHEN TEMPS SHOULD AT LEAST SURGE WELL INTO THE 40S IN
THE WARM SECTOR OF THE SECOND AND STRONGEST WAVE IN THE SERIES OF
SURFACE LOWS.
LATE IN THE PERIOD...THE GFS/ECMWF BOTH SUGGEST A RETURN OF
LARGER-SCALE TROUGHING ACROSS THE EASTERN THIRD OF THE COUNTRY AS
ANOTHER LARGE BUT ALSO PROGRESSIVE UPPER RIDGE BUILDS ACROSS THE
INTERMOUNTAIN WEST...WHICH WOULD RESULT IN A RETURN TO SEASONABLY
COLDER TEMPS FOR WEEK`S END...ALONG WITH A GENERAL LOW CHANCE OF
SNOW SHOWERS. AGAIN THOUGH...THE LACK OF ANY TRULY ARCTIC AIR WITHIN
THIS TROUGH WILL LIKELY RESULT IN TEMPS ONLY FALLING BACK TO NEAR
NORMAL LEVELS...AND LIKELY REMAINING WARM ENOUGH TO PRECLUDE THE
DEVELOPMENT OF LAKE EFFECT SNOWS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
EXPECT PRECIPITATION TO INITIALLY START OFF MAINLY AS SNOW...AS
EVAPORATIONAL COOLING FROM DECENT SNOWFALL RATES WINS OUT OVER
DOWNSLOPING. AS THE INTIAL BAND LIFTS NORTH...VSBY SHOULD COME UP
EARLY AFTERNOON...WITH SOME MIXING WITH RAIN POSSIBLE. VSBY/CIGS
WILL VARY WIDELY DURING THIS TIME...ANYWHERES FROM LIFR TO VFR IN
AND OUT OF AREAS OF SNOW.
A FRONT WILL CROSS FROM WEST TO EAST LATE AFTERNOON...SHIFTING
WINDS TO THE SW...AND CAUSING THEM TO INCREASE AS WELL. PRECIPITATION
WILL RAPIDLY END IN MOST AREAS FROM WEST TO EAST DURING THE LATE
AFTERNOON AND EARLY EVENING WITH MVFR IMPROVING TO VFR. LAKE
EFFECT SNOW SHOWERS WILL LINGER EAST OF LAKE ERIE WITH AREAS OF
MVFR AND SPOTTY IFR THROUGH MID TO LATE EVENING. EXPECT THE SNOW
TO DIMINISH OVERNIGHT...ALTHOUGH A PLUME OF MVFR CIGS WILL LIKELY
PERSIST THROUGH THE NIGHT. EAST OF LAKE ONTARIO A MORE SIGNIFICANT
BAND OF LAKE EFFECT SNOW WILL DEVELOP JUST SOUTH OF KART WITH
LOCAL IFR CONDITIONS. THIS MAY DRIFT UP TOWARDS KART LATE TONIGHT
AND SUNDAY MORNING.
IT WILL BECOME QUITE WINDY TODAY...ESPECIALLY DOWNWIND OF LAKES ERIE
AND ONTARIO WHERE GUSTS IN THE 30-40 KNOT RANGE WILL BE COMMON THIS
AFTERNOON AND EVENING.
OUTLOOK...
SUNDAY...AREAS OF IFR WITH SNOW SHOWERS LIKELY.
MONDAY...MVFR/IFR WITH LAKE EFFECT EAST OF THE LAKES ENDING
EARLY...THEN A GENERAL LIGHT SNOW LATE.
TUESDAY...MAINLY VFR WITH SLIGHT CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY...VFR/MVFR WITH A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL SWING BY JUST NORTH OF LAKES ERIE AND
ONTARIO TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE LOW
AND HIGH PRESSURE OVER THE OHIO VALLEY. THE STRONGEST WINDS WILL
ARRIVE LATE THIS AFTERNOON AND TONIGHT AS 40-45 KNOT FLOW JUST OFF
THE DECK BEGINS TO MIX DOWN AS LOW LEVEL COLD ADVECTION STEEPENS
LAPSE RATES AND DESTABILIZES THE BOUNDARY LAYER...ESPECIALLY OVER
THE RELATIVELY WARMER LAKES. THIS WILL PRODUCE A LOW END GALE ON
BOTH LAKES ERIE AND ONTARIO...WITH WINDS PEAKING THIS EVENING.
WINDS WILL DIMINISH BELOW GALES LATE SATURDAY NIGHT...BUT MODERATE
TO STRONG WESTERLIES WILL CONTINUE SUNDAY AND SUNDAY NIGHT WITH
SOLID SMALL CRAFT ADVISORY CONDITIONS BEFORE HIGH PRESSURE BUILDS
INTO THE LOWER LAKES MONDAY WITH DIMINISHING WINDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM
EST SUNDAY FOR NYZ007-008.
MARINE...GALE WARNING FROM 2 PM THIS AFTERNOON TO 4 AM EST SUNDAY FOR
LEZ020-040-041.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST
SUNDAY FOR LOZ042>045-062>065.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL/JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1211 AM EST SAT JAN 28 2012
.SYNOPSIS...
A WEAK CLIPPER SYSTEM WILL MOVE THROUGH THE GREAT LAKES REGION
SATURDAY FOLLOWED BY ANOTHER DISTURBANCE ON SUNDAY. WEAK HIGH
PRESSURE WILL BUILD IN FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RUC HAS LIGHT SNOW REACHING NW OH AROUND 09Z AND THE I-71
CORRIDOR AROUND 12Z. THE CURRENT FORECAST HAS A PRETTY GOOD HANDLE
ON THIS AND HAVE MADE ONLY A FEW CHANGES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
EXPECT SNOW WILL BE MOVING INTO THE AREA FROM THE WEST IN THE
MORNING. MODELS HAVE DEEP MOISTURE SWINGING ACROSS THE AREA WITH
THE SHORT WAVE SO WOULD EXPECT A PERIOD OF SNOW WITH BEST CHANCES
WEST IN THE MORNING AND EAST AFTERNOON. EXPECT ACCUMS TO BE
ROUGHLY AN INCH OR LESS ALTHOUGH NWRN PA COULD SEE A COUPLE.
SHOULD SEE A QUICK BREAK SATURDAY NIGHT BUT BY 12Z SUNDAY MODELS
HAVE THE NEXT WAVE ALREADY MOVING INTO NWRN OHIO. WEST WITH HIGH
CHANCE OR LIKELY POPS. SUNDAY NIGHT WILL KEEP A CHANCE ACROSS NERN
OHIO AND NWRN PA DUE TO THE LAKE. WEAK HIGH PRESSURE WILL MOVE IN
FOR MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
BY LATE MONDAY INTO TUESDAY A HIGH PRESSURE RIDGE SHIFTS EASTWARD
AND ALLOWS A WARM FRONT TO LIFT ACROSS THE GREAT LAKES REGION. WITH
THE WARM FRONT NORTH OF THE FORECAST AREA TUESDAY AFTERNOON THIS
WILL PUSH TEMPERATURES TO CLIMB TO ABOVE NORMAL TUESDAY AND
WEDNESDAY...AND JUST SLIGHTLY COOLER ON THE BACKSIDE OF THE SYSTEM
THURSDAY. THE PRECIPITATION SHOULD BE MOSTLY RAIN SHOWERS TUESDAY
AND WEDNESDAY...THEN POSSIBLY MIXED ON THURSDAY. FOR THURSDAY NIGHT
AND FRIDAY ANOTHER LOW PRESSURE SYSTEM COMES OUT OF THE TENNESSEE
VALLEY REGION BRINGS SOME ADDITIONAL PRECIPITATION TO THE REGION.
THIS TIME THE AIR MASS JUST MIGHT BE COLD ENOUGH TO GET SOME
MEASURABLE SNOW FROM THIS EVENT. MODELS STILL SHOWING SOME
DIFFERENCES AS WE GET INTO THURSDAY AND FRIDAY.
HIGH TEMPERATURES IN THE LOWER TO MID 40S TUESDAY AND WEDNESDAY...
AND HIGHS 35 TO 40 ON THURSDAY.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
STRATOCU PUSHED INLAND FROM THE LAKE THIS EVENING BUT ONLY MADE IT
SOUTH TO A MFD/CAK LINE BEFORE LOW LEVEL FLOW SHIFTED AROUND TO THE
SOUTH. STRATOCU IS STARTING TO SPREAD NORTH AGAIN AND WILL FILL
BACK INTO THE TAF SITES THROUGH 08Z. UPSTREAM RADARS ACROSS
INDIANA SHOW A LEADING BAND OF SNOW SPREADING TOWARDS NW OHIO.
THIS INITIAL ROUND OF SNOW WILL HAVE TO OVERCOME A VERY DRY
AIRMASS SO ONLY INCLUDED IN A TEMPO AT TOL/FDY BETWEEN 07-10Z. A
WIDESPREAD BUT BRIEF PERIOD OF SNOW IS THEN EXPECTED TO SPREAD
FROM WEST TO EAST ACROSS THE FORECAST AREA THROUGH MID-AFTERNOON.
EACH SITE WILL ONLY SEE SNOW FOR ROUGHLY A 3-4 FOUR HOUR WINDOW
WITH IFR CONDITIONS. SOUTHWESTERLY WINDS WILL INCREASE AHEAD OF
THE FRONT WITH GUSTS TO AROUND 20 KNOTS. WHICH WILL BE MUCH
STRONGER BEHIND THE FRONT AS THEY VEER TO THE WEST WITH GUSTS TO
AROUND 35 KNOTS DURING THE AFTERNOON. MUCH DRIER AIR WILL USHER IN
BEHIND THE FRONT AND HAVE SCATTERED THE CLOUDS OUT QUICKLY TO
3000-4000 FEET.
.OUTLOOK...NON VFR CONDITIONS WILL RETURN ON SUNDAY WITH ANOTHER
ROUND OF SNOW. A BRIEF PERIOD OF NON-VFR CONDITIONS ARE POSSIBLE ON
TUESDAY NIGHT FOLLOWED BY ANOTHER ROUND ON THURSDAY.
&&
.MARINE...
STILL LOOKS LIKE SCA CONDITIONS WILL SUBSIDE FOR A WHILE TONIGHT
INTO EARLY SAT THEN RAMP UP SAT MORNING THEN TO GALES WITH THE
PASSAGE OF THE FIRST OF TWO COLD FRONTS THAT WILL MOVE THROUGH SAT
AND AGAIN SUN. THE WINDS WITH THE FRONT SUN DON`T LOOK AS STRONG AS
ON SAT SO PROBABLY JUST A SCA SITUATION WHICH IS TYPICAL FOR THIS
TIME OF YEAR. TO KEEP THINGS LESS CONFUSING WILL JUST GO WITH THE
GALE WARNING WITH THE 330 PM FORECAST PACKAGE SINCE THIS IS BY FAR
THE MOST SIGNIFICANT ISSUE OVER THE NEXT 24 TO 36 HOURS.
WINDS SHOULD BACK TO SSW MON BUT WINDS SHOULD INCREASE TO 15 TO 25
MON NIGHT SO DOUBT IF SCA WILL BE TAKEN DOWN THROUGH WED AS WINDS
LIKELY TO REMAIN 15 TO 25 KNOTS OR BETTER WHILE FINALLY VEERING TO
WEST ON WED WITH THE PASSAGE OF ANOTHER COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST SUNDAY FOR
LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...TK
NEAR TERM...KUBINA
SHORT TERM...TK
LONG TERM...BC
AVIATION...KEC
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
540 PM CST SUN JAN 29 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SYNOPSIS...MORE MILD WEATHER.
MODEST LARGE SCALE TROF OVER THE ERN CONUS WL SHIFT NEWD THE NEXT
COUPLE DAYS...PUTTING US BACK INTO WHAT HAS BECOME THE PATTERN OF
THE WINTER...A BROAD SOMEWHAT SPLIT ZONAL REGIME. HEIGHTS OVER WRN
CANADA WL GRADUALLY RISE LATER THIS WK. THAT WL EVENTUALLY FAVOR A
RETURN TO AN ERN TROF. MODELS OFFERED VARYING IDEAS ON HOW
SHARP/STG THE WRN RIDGE WL BECOME...AND THAT WILL MODULATE THE
STRENGTH OF THE DOWNSTREAM TROF. PERSISTENCE WOULD FAVOR THE
LESS AMPLIFIED OF THE GUIDANCE SOLUTIONS.
AFTER A RELATIVELY COLD NGT TNGT...TEMPS WL WARM TO SIGNIFICANTLY
ABV NORMAL LEVELS AGAIN FOR THE EARLY PART OF THE FCST PERIOD.
THEY WL DROP BACK CLOSER TO NORMAL BY NEXT WEEKEND...BUT UNLESS
ERN TROF GETS A LOT DEEPER THAN NOW EXPECTED...IT/S HARD TO SEE
THEM GOING BLO NORMAL. THE FCST AREA WL PROBABLY HAVE A COUPLE LGT
PCPN EVENTS...WITH AMNTS PROBABLY ENDING UP BLO NORMAL FOR THE
PERIOD AS A WHOLE.
&&
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE WORKING EASTWARD ACROSS THE NORTHERN MISSISSIPPI VALLEY
EARLY THIS AFTERNOON. LOW STRATO-CU CLOUD DECK IS SLOWLY LIFTING
OFF TO THE NORTHEAST OVER NORTHEAST WISCONSIN...WHILE THE REST OF
THE REGION REMAINS SUNNY. LOOKING UPSTREAM...PRETTY EXPANSIVE CLOUD
SHIELD IS PRESSING EAST ACROSS THE DAKOTAS...JUST AHEAD OF A
DEVELOPING SURFACE WARM FRONT. AS THE WARM FRONT MOVES EAST ACROSS
THE REGION LATE TONIGHT INTO MONDAY...PRECIP TIMING AND AMOUNTS ARE
THE MAIN FORECAST CONCERNS.
TONIGHT...THE HIGH PRESSURE RIDGE AXIS WILL SLIDE ACROSS THE STATE
DURING THE EVENING HOURS. SHOULD SEE A PERIOD OF CLEAR SKIES AND
LIGHT WINDS THAT WOULD ALLOW TEMPS TO TAKE A TUMBLE. WENT ON THE
COLD SIDE OF GUIDANCE FOR THIS REASON...AS IT USUALLY DOESNT TAKE
MUCH TIME FOR TEMPS TO FALL 20 DEGREES...ESPECIALLY OVER
NORTH-CENTRAL WISCONSIN. THEREAFTER...A 850MB WARM FRONT OVER THE
NORTHERN PLAINS WILL SHIFT EAST INTO SOUTHWEST WISCONSIN AFTER
MIDNIGHT. MODELS HAVE A VARIETY OF ARRIVAL TIMINGS OF THE LIGHT
SNOW AS IT SPREADS SE ALONG THE FRONT INTO CENTRAL WISCONSIN LATE.
DONT REALLY HAVE A GOOD FEEL IF THE FASTER PACE OF THE GFS COMPARED
TO THE NAM IS LIKELY TO BE CORRECT. SO WENT MIDDLE OF THE ROAD FOR
POPS/QPF WHICH PLACES LIKELY POPS OVER NORTH-CENTRAL AND CENTRAL
WISCONSIN. PERHAPS CENTRAL WISCONSIN COULD SEE A QUICK HALF INCH OF
FLUFF BY 12Z. TEMPS SHOULD REBOUND ONCE THE CLOUDS ROLL IN...SO
MIDNIGHT LOWS WILL CREEP BACK UP THROUGH THE OVERNIGHT.
MONDAY...THE WARM FRONT WILL CONTINUE TO MOVE EAST ACROSS THE REGION
ON MONDAY. WILL SEE THE MOST WIDESPREAD SNOW DURING THE MORNING
HOURS WHEN A DECENT BAND OF MID-LEVEL FGEN MOVES OVERHEAD. MOST
PLACES WILL SEE 1-2 INCHES OF SNOW. THE PRIMARY UNCERTAINTY OF THE
EVENT WILL BE THE PTYPE ON THE BACK EDGE OF THE PRECIPITATION SHIELD
WHEN MOISTURE FALLS BELOW -10C...WHICH INCREASES THE PROBABILITY OF
THE ABSENCE OF ICE CRYSTALS IN THE CLOUD. WITH CLOUD COVER AND
PRECIP HOLDING BACK SURFACE TEMPS...THINK THERE COULD BE A RIBBON OF
FREEZING DRIZZLE...MAINLY OVER CENTRAL AND EAST-CENTRAL WISCONSIN ON
THE BACK EDGE. BUT DONT THINK IT WILL POSE A HAZARD AS THE FRONT IS
RELATIVELY FAST MOVING AND SHARP...AS OPPOSED TO A LONG DURATION
OVER-RUNNING EVENT. TEMPS MAY REACH ABOVE FREEZING OVER CENTRAL AND
E-C WISCONSIN AS THE PRECIP ENDS AND CLOUDS ERODE HERE FIRST LATE IN
THE AFTERNOON.
.LONG TERM...MON NGT THROUGH NEXT SUN. THE MESO WRF RUNS FM NCEP
SUGGESTED SOME LGT PCPN COULD STILL LINGER IN THE THE NE EARLY MON
NGT...BUT WITH LITTLE SUPPORT FM ANY OF THE OTHER MODELS STUCK
WITH A DRY FCST. MILD SLY FLOW WL PREVENT MUCH DROP IN TEMPS...SO
BUILT 3 HOURLY TEMP GRIDS FROM A ROBUST BLEND OF GUID PRODUCTS AND
THEN GENERATED MIN GRID FROM THAT.
TUE WAS THE MOST CHALLENGING DAY OF THE FCST PERIOD. WK CYCLONE WL
BE TRACKING EWD ALONG THE U.S. CANADIAN BORDER TOWARD LAKE
SUPERIOR...WITH FCST AREA BASICALLY IN THE WARM SECTOR. OVERALL...
FORCING FOR PCPN WEAK. BUT SOME QG FORCING FM UPR SHRTWV COULD
GENERATE SOME LGT PCPN ACRS THE NW PART OF THE FCST AREA DURING
THE AFTN. CONTD SLGT CHC OF RA/SN TO ACCOUNT FOR THAT. MAIN
QUESTION HOWEVER IS THE CLDS AND THEIR IMPACT ON TEMPS. IT COULD
BE A VERY MILD DAY IF WE CAN ESCAPE HAVING ST FORM ACRS THE AREA.
IF THE ST DOES FORM...IT WL LIMIT TEMPS AND DAMP SLY FLOW WL
PROBABLY MAKE IT SEEM COLDER THAN IT IS. STUCK WITH MAX TEMPS FM
PREV FCST WHICH WERE GENERALLY BLO WHAT BEST PERFORMING GUID WOULD
SUGGEST FOR HIGH TEMPS. INCOMING DWPTS IN THE LOWER TO MIDDLE 30S
MARGINAL FOR ST FORMATION...AND DIDN/T WANT TO TAKE TEMPS BEYOND
WHAT WE HAD GOING WITHOUT HAVING MORE CONFIDENCE THAT WE WOULDN/T
GET STUCK WITH LOW CLDS.
QUIET WX THEN EXPECTED TUE NGT AND WED AS THE CYCLONE PASSES OFF
TO THE E OF THE RGN.
&&
.AVIATION...VFR THROUGH 09Z TONIGHT AS HIGH CLOUDS INCREASE FROM
THE WEST. CIGS AND VSBYS WILL FALL QUICKLY BETWEEN 09Z AND 12Z
MONDAY AS AN AREA OF SNOW FORMS NORTH OF A WARM FRONT. THE SNOW
WILL TAPER OFF BY EARLY AFTERNOON. THERE IS A SMALL CHANCE OF
FREEZING DRIZZLE MONDAY AFTERNOON BUT DID NOT INCLUDE IN TAFS
RIGHT NOW AS CHANCE IS SMALL. THE SNOW SHOULD BE LIGHT ENOUGH TO
SWEEP OFF RUNWAYS AT MOST AIRPORTS AS ACCUMULATIONS SHOULD BE 1
TO 2 INCHES AT MOST.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
150 PM CST SAT JAN 28 2012
.SYNOPSIS...MORE OF WHAT HAS COME TO BE THE NORM FOR THIS
WINTER...ABOVE NORMAL TEMPERATURES WITH ONLY A COUPLE MODEST PCPN
EVENTS.
UPR PATTERN CURRENTLY FEATURES MODEST TROF OVER THE N-C CONUS...
BUT FLOW WL FLATTEN BACK TO ZONAL REGIME DURING THE NEXT COUPLE
DAYS. MED RANGE MODELS AGREEDED IN GRADUALLY BUILDING SOME RIDGING
OVER WRN CANADA DURING THE LATTER PART OF THE FCST PERIOD. BUT RIDGE
NEVER SEEMS TO GET STG/SHARP ENOUGH TO FORCE A DISTINCT DOWNSTREAM
TROF OVER ERN CONUS. SO WL PROBABLY CONT WITH GENERAL WLY FLOW AND
FAIRLY HIGH UPR HGTS.
OTHER THAN A COUPLE GLANCING SHOTS OF COLDER AIR BEHIND INDIVIDUAL
WX SYSTEMS...THE FCST AREA WL PRIMARILY BE DOMINATED BY PACIFIC
AIR. THAT WL RESULT IN ABV NORMAL TEMPS. PATTERN WL SUPPORT A FEW
PCPN PRODUCING SYSTEMS...BUT NO STG STORMS IN THE OFFING.
&&
.SHORT TERM...TONIGHT AND SUNDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE STATE
OF WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE ONTARIO/QUEBEC
BORDER AND HIGH PRESSURE SITUATED OVER THE SOUTHERN PLAINS.
CYCLONIC FLOW AND THERMAL TROUGHING BETWEEN THESE FEATURES ARE
CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD STRETCHING FROM
NORTHERN MINNESOTA TO LOWER MICHIGAN. PLENTY OF SNOW SHOWER ACTIVITY
WITHIN THE COLDER CLOUD TOPS OVER NORTH-CENTRAL WISCONSIN AND THE
WESTERN UPPER PENINSULA EARLY THIS AFTERNOON. THE NEXT SHORTWAVE IS
OBSERVED PUSHING INTO NORTH DAKOTA WHICH WILL HEAD FOR THE REGION
TONIGHT. PRECIP CHANCES WITH THIS FEATURE AND CLOUD COVER ARE THE
MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...SHORTWAVE TROUGH OVER THE DAKOTAS IS NOW EXPECTED TO TAKE
A SLIGHTLY MORE SOUTHERLY TRACK THAN PROJECTED YESTERDAY...FROM
ABOUT EASTERN SOUTH DAKOTA TO NORTHERN ILLINOIS. THOUGH THE WAVE
WILL STILL HAVE GOOD QG FORCING WITH IT...THE MORE SOUTHERLY TRACK
WILL SHIFT THE COMMA HEAD OF THE COMPACT WAVE OVER SOUTHERN
WISCONSIN RATHER THAN CENTRAL WISCONSIN. AS A RESULT...HAVE REMOVED
POPS FROM CENTRAL AND EAST-CENTRAL WISCONSIN TONIGHT.
OTHERWISE...CYCLONIC FLOW SUBTLY BROADENS OUT TONIGHT...WHICH SHOULD
ALLOW THE LOW STRATO-CU TO RETREAT TO THE NORTH. PLENTY OF FLURRY
ACTIVITY UPSTREAM WILL FORCE ME TO KEEP A MENTION OVER N-C
WISCONSIN. LOW LEVEL WINDS ARE TOO WESTERLY HOWEVER TO HAVE MUCH OF
A LAKE INFLUENCE. LOWS WILL RANGE FROM THE MIDDLE SINGLE DIGITS
ABOVE ZERO NORTH TO THE MID TEENS SOUTHEAST.
SUNDAY...MID-LEVEL CLOUDS FROM THE SHORTWAVE WILL DEPART TO THE
SOUTHEAST EARLY SUNDAY MORNING WHICH MAY LEAVE A PERIOD OF MOSTLY
SUNNY CONDITIONS OVER CENTRAL AND EAST-CENTRAL WISCONSIN TO START
THE DAY. LOW LEVEL WINDS WILL TURN BACK TO THE NORTHWEST BEHIND THE
DEPARTING WAVE. AS THIS OCCURS...COLD ADVECTION WILL RESUME WHICH
SHOULD LEAD TO ANOTHER SURGE SOUTHEAST OF THE LOW STRATO-CU LATE
MORNING INTO EARLY AFTERNOON. WINDS THEN BACK AROUND TO THE WEST MID
TO LATE AFTERNOON AS THE SURFACE RIDGE APPROACHES. SHOULD SEE THE
STRATO-CU BREAK UP SOME AS DRIER AIR PUSHES IN FROM THE WEST. HIGH
TEMPS RANGING FROM THE MID TEENS NORTH TO THE LOWER 20S SOUTHEAST.
.LONG TERM...SUN NGT THROUGH NEXT SAT. TEMPS WL PROBABLY FALL OFF
FAIRLY QUICKLY EARLY SUN NGT WITH SFC RIDGE COMING ACRS THE
AREA...BUT THEN START TO RISE AS CLDS INCR. ISENT LIFT WL SWEEP
EWD ACRS THE AREA LATE AT NGT AND MON MORNING. MODELS SEEMED A BIT
SLOWER WITH THE PCPN...SO TWEAKED TIMING BACK A BIT. TOOK THE N UP
TO LIKELIES MON MORNING. WL PROBABLY GET A COUPLE INCHES OF SNOW
ACRS THE N...AND MAYBE AN INCH OR SO IN THE S. PCPN WL PROBABLY
TAPER OFF TO FZDZ/DZ AS MIDDLE LEVEL MOISTURE GETS STRIPPED OFF TO
THE NE.
12Z RUN OF THE ECMWF BACKED OFF WITH PCPN CHCS TUE. THE OTHER
MODELS ALREADY WERE TAMER. MAY VERY WELL GET BY WITHOUT ANY PCPN
AS FCST AREA WL JUST BE IN THE WARM SECTOR OF WK CYCLONE TRACKING
ALONG THE U.S/CANADIAN BORDER. BUT DIDN/T WANT TO COMPLETELY PULL
PCPN WITH SYSTEM CROSSING THE RGN...SO SETTLED FOR TRENDING POPS
DOWN.
&&
.AVIATION...MVFR CIGS AND FLURRY ACTIVITY STRETCHING ALL THE WAY
BACK TO NORTHERN MINNESOTA AT MIDDAY. THESE MVFR CIGS WILL REACH
INTO THE FOX VALLEY THIS AFTERNOON BUT DOWNSLOPING WINDS SHOULD KEEP
FEW TO SCT CONDITIONS OVER FAR NE WISCONSIN. CIGS LOOK TO LIFT THIS
EVENING OVER CENTRAL AND EAST-CENTRAL WISCONSIN AS AN UPPER LEVEL
DISTURBANCE NOW LOOKS TO PASS TO THE SOUTH OF THE AREA. NOT MUCH
EXPECTED OTHER THAN AN INCREASE OF MID CLOUDS. ANOTHER SURGE OF
MVFR CLOUDS LOOKS TO OCCUR BEHIND THE DISTURBANCE SUNDAY MORNING.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/SKOWRONSKI
AREA FORECAST DISCUSSION
NWS ALBANY NY
102 AM EST MON JAN 30 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SNOW SHOWERS AND
SQUALLS TONIGHT...MAINLY FOR WESTERN AND NORTHERN PARTS OF THE
REGION. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION ON
MONDAY BEFORE BEING FOLLOWED BY A WARM FRONT...WHICH WILL BRING
ANOTHER ROUND OF SNOW TO THE AREA FOR MONDAY NIGHT INTO TUESDAY
MORNING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...POTENT BUT COMPACT UPPER LEVEL DISTURBANCE
CLEARLY EVIDENT OF WATER VAPOR IMAGERY WITH A DISTINCT SWIRL SEEN
WITH COMMA-HEAD MOVING INTO EAST CENTRAL NY. SNOW SQUALL ACTIVITY
NOT AS WIDESPREAD AS EARLY ACROSS WESTERN/CENTRAL NY. BROKEN LINES
OF SNOW SHOWERS WITH A FEW BRIEF INTENSE SQUALLS WILL CONTINUE TO
BE POSSIBLE THROUGH THE REST OF THE NIGHT...MAINLY ACROSS THE
HIGHER TERRAIN WEST OF THE CAPITAL REGION. WILL NOT MAKE ANY
CHANGES TO SNOWFALL FORECAST OR HEADLINES AT THIS TIME AS REPORTS
ARE SCARCE THIS TIME OF DAY. ALSO UPDATED HOURLY GRIDS TO REFLECT
CURRENT OBS AND TRENDS.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 1000 PM...INTENSE NORTH-SOUTH SNOW SQUALL THAT WAS MOVING
ACROSS WESTERN AND CENTRAL PA/NY HAD WEAKENED AND BROKEN UP
CONSIDERABLY. RADAR STILL SHOWS SOME SNOW SQUALLS PRODUCING HEAVY
SNOW...BUT MOST OF THESE WILL MOVE ACROSS HERKIMER AND HAMILTON
COUNTIES WHERE WINTER WEATHER ADVISORIES ARE ALREADY UP. ELSEWHERE
THE SNOW SHOWERS WILL CONTINUE TO DECREASE IN COVERAGE AS THEY MOVE
EAST. IN GENERAL HAVE RAISED POPS TO LIKELY ACROSS THE EASTERN
CATSKILLS AND NORTHERN BERKSHIRE COUNTY...WITH LIKELY POPS OR HIGHER
ALREADY IN THE GRIDS IN AREAS FURTHER NORTH. FROM THE CAPITAL
DISTRICT TO THE MID HUDSON VALLEY AND SOUTHERN BERKSHIRE COUNTY AND
LITCHFIELD COUNTY...HAVE ALSO RAISED POPS IN THESE AREAS...BUT THE
FORECAST REMAINS IN THE CHANCE CATEGORY. REST OF THE PREVIOUS
FORECAST GENERALLY UNCHANGED.
AS OF 648 PM EST...HAVE UPDATED T/TD TO ACCOUNT FOR LATEST
OBSERVATIONS AND TRENDS. CURRENT FORECAST MIN TEMPS APPEAR ON
TRACK WITH 20S FOR MOST AREAS /SOME TEENS ACROSS THE SRN ADKS/.
LATEST RADAR RETURNS SHOW SOME MODERATE SNOWFALL DUE TO SOME LAKE
MOISTURE UPSLOPING THE HIGH TERRAIN AFFECTING THE WESTERN
ADKS...MAINLY TO THE NORTH OF OLD FORGE AND INLET. THIS LOOKS TO
CONTINUE OVER THE NEXT SEVERAL HOURS...WITH A FEW INCHES POSSIBLE.
THIS ACTIVITY WILL WANE SOMEWHAT AS THE FLOW SHIFTS AHEAD OF AN
APPROACHING SHORTWAVE AND ASSOCIATED SURFACE BOUNDARY.
THE 20Z 3KM HRRR GUIDANCE STILL DEPICTS A FAST MOVING LINE OF SNOW
SHOWERS/SQUALLS ASSOCIATED WITH THE AFOREMENTIONED COLD FRONTAL
BOUNDARY HEADING TOWARDS OUR AREA AROUND MIDNIGHT. MODEL GUIDANCE
SUGGESTS THAT THIS ACTIVITY WON/T BE QUITE AS STRONG AS IT WILL BE
EARLIER IN THE EVENING ACROSS WESTERN NY/WESTERN AND CENTRAL
PA...BUT IT SHOULD STILL BE ENOUGH TO BRING ADDITIONAL ACCUMULATION
AND PROVIDE LOW VISIBILITY WITHIN GUSTY WINDS. THE 18Z NAM STILL
DEPICTS SHOWALTER VALUES NEAR OR JUST BELOW ZERO FOR WESTERN PARTS
OF THE AREA. LTG DETECTION HAS ALREADY NOTED SOME LTG ACROSS
WESTERN PA AND WESTERN NY...SO CANNOT TOTALLY RULE OUT SOME LTG
WITHIN THE HEAVIEST SQUALLS. HOWEVER...DO NOT FEEL CONFIDENT THIS
WILL BE WIDESPREAD ENOUGH TO INCLUDE IN THE GRIDS...BUT IT
CERTAINLY COULD OCCUR IN A FEW ISOLD SPOTS. THE BEST CHANCE OF
SEEING THE SNOW SQUALLS WILL BE ACROSS THE MOHAWK VALLEY/SRN
ADIRONDACKS AND EVENTUALLY THE LAKE GEORGE SARATOGA REGION...WHERE
WE CURRENTLY HAVE THE HIGHEST POPS /LIKELY TO CATEGORICAL/. THE
ACTIVITY LOOKS TO WEAKEN ENOUGH FOR SNOW SHOWERS TO BE RATHER SCT
ONCE ACTIVITY GETS TOWARDS THE CAPITAL REGION BY AROUND 06Z TO
07Z. WHILE A COATING OF SNOWFALL IS POSSIBLE...THE LINE LOOKS TO
BREAK ENOUGH FOR IT TO BE HIT OR MISS ACROSS FOR THE CAPITAL REGION.
FURTHER SOUTH...DOWNSLOPING OFF THE CATSKILLS SHOULD KEEP ANY
ACTIVITY FAIRLY ISOLD FOR THE MID HUDSON VALLEY AND NW
CT...ALTHOUGH UPSLOPE FLOW COULD ALLOW FOR A LITTLE BETTER
COVERAGE ACROSS THE TACONICS/BERKSHIRES/SOUTHERN GREENS...WHERE A
LIGHT ACCUMULATION IS POSSIBLE.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AN UPPER LEVEL DISTURBANCE AND FRONTAL BOUNDARY WILL CROSS THE REGION
OVERNIGHT ACCOMPANIED BY SNOW SHOWERS AND SOME SNOW SQUALLS. MVFR
CONDITIONS ARE EXPECTED AS THE SHOWERS MOVE THROUGH AT KGFL AND
KALB. IF A SNOW SQUALL OCCURS THEN A BRIEF PERIOD OF IFR WILL OCCUR
AS IT MOVES THROUGH...HOWEVER DO NOT HAVE ENOUGH CONFIDENCE TO PUT
THAT IN THE TAFS. AT KPOU...HAVE ADDRESSED SNOW SHOWERS WILL
VICINITY SHOWERS AS IT APPEARS THE ACTIVITY SHOULD PASS TO THE
NORTH.
CLOUD COVER IS EXPECTED TO DECREASE FOR A PERIOD LATE TONIGHT INTO
THE DAY MONDAY...THEN CLOUDS AHEAD OF AN APPROACHING WARM FRONT WILL
STREAM IN BY EVENING TIME. PRECIPITATION...SNOW...ASSOCIATED WITH
WARM AIR ADVECTION SHOULD DEVELOP/ARRIVE AROUND 06Z/TUESDAY.
SURFACE WINDS ARE LIGHT AND SOUTHERLY TO CALM AT THIS TIME AND WILL
SWING AROUND TO THE WEST WITH THE PASSAGE OF THE FRONTAL BOUNDARY.
THE WESTERLY WINDS ARE EXPECTED TO BECOME GUSTY MONDAY MORNING AS
THE ATMOSPHERE MIXES...THEN BY LATE IN THE DAY DECREASE TO LESS THAN
10 KNOTS.
OUTLOOK...
MON NIGHT...VFR/MVFR WITH BECOMING -SN LIKELY LATE.
TUE...VFR/MVFR AT KGFL AND KALB WITH CHC -SHRA/-SHSN. KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN
THU...VFR. SLIGHT CHC -SHRA/-SHSN AT NIGHT.
FRI...VFR. CHC -SNSH.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ032-033-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/11
NEAR TERM...FRUGIS/GJM/JPV
SHORT TERM...11
LONG TERM...WASULA
AVIATION...IAA
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST MON JAN 30 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SNOW SHOWERS AND
SQUALLS TONIGHT...MAINLY FOR WESTERN AND NORTHERN PARTS OF THE
REGION. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION ON
MONDAY BEFORE BEING FOLLOWED BY A WARM FRONT...WHICH WILL BRING
ANOTHER ROUND OF SNOW TO THE AREA FOR MONDAY NIGHT INTO TUESDAY
MORNING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...POTENT BUT COMPACT UPPER LEVEL DISTURBANCE
CLEARLY EVIDENT OF WATER VAPOR IMAGERY WITH A DISTINCT SWIRL SEEN
WITH COMMA-HEAD MOVING INTO EAST CENTRAL NY. SNOW SQUALL ACTIVITY
NOT AS WIDESPREAD AS EARLY ACROSS WESTERN/CENTRAL NY. BROKEN LINES
OF SNOW SHOWERS WITH A FEW BRIEF INTENSE SQUALLS WILL CONTINUE TO
BE POSSIBLE THROUGH THE REST OF THE NIGHT...MAINLY ACROSS THE
HIGHER TERRAIN WEST OF THE CAPITAL REGION. WILL NOT MAKE ANY
CHANGES TO SNOWFALL FORECAST OR HEADLINES AT THIS TIME AS REPORTS
ARE SCARCE THIS TIME OF DAY. ALSO UPDATED HOURLY GRIDS TO REFLECT
CURRENT OBS AND TRENDS.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 1000 PM...INTENSE NORTH-SOUTH SNOW SQUALL THAT WAS MOVING
ACROSS WESTERN AND CENTRAL PA/NY HAD WEAKENED AND BROKEN UP
CONSIDERABLY. RADAR STILL SHOWS SOME SNOW SQUALLS PRODUCING HEAVY
SNOW...BUT MOST OF THESE WILL MOVE ACROSS HERKIMER AND HAMILTON
COUNTIES WHERE WINTER WEATHER ADVISORIES ARE ALREADY UP. ELSEWHERE
THE SNOW SHOWERS WILL CONTINUE TO DECREASE IN COVERAGE AS THEY MOVE
EAST. IN GENERAL HAVE RAISED POPS TO LIKELY ACROSS THE EASTERN
CATSKILLS AND NORTHERN BERKSHIRE COUNTY...WITH LIKELY POPS OR HIGHER
ALREADY IN THE GRIDS IN AREAS FURTHER NORTH. FROM THE CAPITAL
DISTRICT TO THE MID HUDSON VALLEY AND SOUTHERN BERKSHIRE COUNTY AND
LITCHFIELD COUNTY...HAVE ALSO RAISED POPS IN THESE AREAS...BUT THE
FORECAST REMAINS IN THE CHANCE CATEGORY. REST OF THE PREVIOUS
FORECAST GENERALLY UNCHANGED.
AS OF 648 PM EST...HAVE UPDATED T/TD TO ACCOUNT FOR LATEST
OBSERVATIONS AND TRENDS. CURRENT FORECAST MIN TEMPS APPEAR ON
TRACK WITH 20S FOR MOST AREAS /SOME TEENS ACROSS THE SRN ADKS/.
LATEST RADAR RETURNS SHOW SOME MODERATE SNOWFALL DUE TO SOME LAKE
MOISTURE UPSLOPING THE HIGH TERRAIN AFFECTING THE WESTERN
ADKS...MAINLY TO THE NORTH OF OLD FORGE AND INLET. THIS LOOKS TO
CONTINUE OVER THE NEXT SEVERAL HOURS...WITH A FEW INCHES POSSIBLE.
THIS ACTIVITY WILL WANE SOMEWHAT AS THE FLOW SHIFTS AHEAD OF AN
APPROACHING SHORTWAVE AND ASSOCIATED SURFACE BOUNDARY.
THE 20Z 3KM HRRR GUIDANCE STILL DEPICTS A FAST MOVING LINE OF SNOW
SHOWERS/SQUALLS ASSOCIATED WITH THE AFOREMENTIONED COLD FRONTAL
BOUNDARY HEADING TOWARDS OUR AREA AROUND MIDNIGHT. MODEL GUIDANCE
SUGGESTS THAT THIS ACTIVITY WON/T BE QUITE AS STRONG AS IT WILL BE
EARLIER IN THE EVENING ACROSS WESTERN NY/WESTERN AND CENTRAL
PA...BUT IT SHOULD STILL BE ENOUGH TO BRING ADDITIONAL ACCUMULATION
AND PROVIDE LOW VISIBILITY WITHIN GUSTY WINDS. THE 18Z NAM STILL
DEPICTS SHOWALTER VALUES NEAR OR JUST BELOW ZERO FOR WESTERN PARTS
OF THE AREA. LTG DETECTION HAS ALREADY NOTED SOME LTG ACROSS
WESTERN PA AND WESTERN NY...SO CANNOT TOTALLY RULE OUT SOME LTG
WITHIN THE HEAVIEST SQUALLS. HOWEVER...DO NOT FEEL CONFIDENT THIS
WILL BE WIDESPREAD ENOUGH TO INCLUDE IN THE GRIDS...BUT IT
CERTAINLY COULD OCCUR IN A FEW ISOLD SPOTS. THE BEST CHANCE OF
SEEING THE SNOW SQUALLS WILL BE ACROSS THE MOHAWK VALLEY/SRN
ADIRONDACKS AND EVENTUALLY THE LAKE GEORGE SARATOGA REGION...WHERE
WE CURRENTLY HAVE THE HIGHEST POPS /LIKELY TO CATEGORICAL/. THE
ACTIVITY LOOKS TO WEAKEN ENOUGH FOR SNOW SHOWERS TO BE RATHER SCT
ONCE ACTIVITY GETS TOWARDS THE CAPITAL REGION BY AROUND 06Z TO
07Z. WHILE A COATING OF SNOWFALL IS POSSIBLE...THE LINE LOOKS TO
BREAK ENOUGH FOR IT TO BE HIT OR MISS ACROSS FOR THE CAPITAL REGION.
FURTHER SOUTH...DOWNLOPING OFF THE CATSKILLS SHOULD KEEP ANY
ACTIVITY FAIRLY ISOLD FOR THE MID HUDSON VALLEY AND NW
CT...ALTHOUGH UPSLOPE FLOW COULD ALLOW FOR A LITTLE BETTER
COVERAGE ACROSS THE TACONICS/BERKSHIRES/SOUTHERN GREENS...WHERE A
LIGHT ACCUMULATION IS POSSIBLE.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KGFL/KALB/KPOU TAF SITES
THROUGH THE TAF PERIOD ENDING AT 00Z TUESDAY. HOWEVER...AS ANOTHER
FRONTAL BOUNDARY CROSSES THE REGION DURING THE NITE...THERE IS THE
POTENTIAL FOR MVFR/IFR CONDITIONS IN SNOW SHOWERS BEFORE/DURING AND
AFTER FORNTAL PASSAGE. THE CHANCES ARE BEST AT KGFL WHERE A PERIOD
OF MVFR CONDITIONS HAVE BEEN FORECAST BETWEEN 05Z AND 10Z...WITH A
TEMPO GROUP FOR IFR VSBYS IN SNOW SHOWERS BETWEEN 05Z AND 08Z. MUCH
LESS THREAT FOR MVFR/IFR CONDITIONS AT KALB...SO ONLY VCSH HAS BEEN
INCLUDED IN THE FORECAST. AT KPOU NO PCPN IS EXPECTED DURING THE TAF
PERIOD. AFTER ABOUT 10Z...VFR CONDITIONS WILL PREVAIL AT ALL THREE
TAF SITES AS GUSTY WESTERLY WINDS BRING COLDER AIR TO THE REGION AND
GNERALLY SCT/BKN CU/SC.
SURFACE WINDS WILL BE 10 KTS OR LESS FROM THE SOUTH OR SOUTHWEST
THIS EVENING AHEAD OF THE FRONTAL BOUNDARY. WINDS WILL SHOFT BETWEEN
05Z AND 07Z AT THE TAF SITES AND BECOME WESTERLY AT 10 TO 15 KTS
WITH GUSTS OF 15 TO 25 KTS BEHIND THE FRONT AND THROUGH MOST OF
MONDAY. BY LATE IN THE DAY ON MONDAY THE WINDS WILL DECREASE TO LESS
THAN 10 KTS.
CLOUDS WILL ALSO BEGIN TO INCREASE AGAIN LATE IN THE DAY AHEAD OF A
WARM FRONT.
OUTLOOK...
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ032-033-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/11
NEAR TERM...FRUGIS/GJM/JPV
SHORT TERM...11
LONG TERM...WASUIAGJM
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1248 AM EST MON JAN 30 2012
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SNOW SHOWERS AND
SQUALLS TONIGHT...MAINLY FOR WESTERN AND NORTHERN PARTS OF THE
REGION. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION ON
MONDAY BEFORE BEING FOLLOWED BY A WARM FRONT...WHICH WILL BRING
ANOTHER ROUND OF SNOW TO THE AREA FOR MONDAY NIGHT INTO TUESDAY
MORNING.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...POTENT BUT COMPACT UPPER LEVEL DISTURBANCE
CLEARLY EVIDENT OF WATER VAPOR IMAGERY WITH A DISTINCT SWIRL SEEN
WITH COMMA-HEAD MOVING INTO EAST CENTRAL NY. SNOW SQUALL ACTIVITY
NOT AS WIDESPREAD AS EARLY ACROSS WESTERN/CENTRAL NY. BROKEN LINES
OF SNOW SHOWERS WITH A FEW BRIEF INTENSE SQUALLS WILL CONTINUE TO
BE POSSIBLE THROUGH THE REST OF THE NIGHT...MAINLY ACROSS THE
HIGHER TERRAIN WEST OF THE CAPITAL REGION. WILL NOT MAKE ANY
CHANGES TO SNOWFALL FORECAST OR HEADLINES AT THIS TIME AS REPORTS
ARE SCARCE THIS TIME OF DAY. ALSO UPDATED HOURLY GRIDS TO REFLECT
CURRENT OBS AND TRENDS.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 1000 PM...INTENSE NORTH-SOUTH SNOW SQUALL THAT WAS MOVING
ACROSS WESTERN AND CENTRAL PA/NY HAD WEAKENED AND BROKEN UP
CONSIDERABLY. RADAR STILL SHOWS SOME SNOW SQUALLS PRODUCING HEAVY
SNOW...BUT MOST OF THESE WILL MOVE ACROSS HERKIMER AND HAMILTON
COUNTIES WHERE WINTER WEATHER ADVISORIES ARE ALREADY UP. ELSEWHERE
THE SNOW SHOWERS WILL CONTINUE TO DECREASE IN COVERAGE AS THEY MOVE
EAST. IN GENERAL HAVE RAISED POPS TO LIKELY ACROSS THE EASTERN
CATSKILLS AND NORTHERN BERKSHIRE COUNTY...WITH LIKELY POPS OR HIGHER
ALREADY IN THE GRIDS IN AREAS FURTHER NORTH. FROM THE CAPITAL
DISTRICT TO THE MID HUDSON VALLEY AND SOUTHERN BERKSHIRE COUNTY AND
LITCHFIELD COUNTY...HAVE ALSO RAISED POPS IN THESE AREAS...BUT THE
FORECAST REMAINS IN THE CHANCE CATEGORY. REST OF THE PREVIOUS
FORECAST GENERALLY UNCHANGED.
AS OF 648 PM EST...HAVE UPDATED T/TD TO ACCOUNT FOR LATEST
OBSERVATIONS AND TRENDS. CURRENT FORECAST MIN TEMPS APPEAR ON
TRACK WITH 20S FOR MOST AREAS /SOME TEENS ACROSS THE SRN ADKS/.
LATEST RADAR RETURNS SHOW SOME MODERATE SNOWFALL DUE TO SOME LAKE
MOISTURE UPSLOPING THE HIGH TERRAIN AFFECTING THE WESTERN
ADKS...MAINLY TO THE NORTH OF OLD FORGE AND INLET. THIS LOOKS TO
CONTINUE OVER THE NEXT SEVERAL HOURS...WITH A FEW INCHES POSSIBLE.
THIS ACTIVITY WILL WANE SOMEWHAT AS THE FLOW SHIFTS AHEAD OF AN
APPROACHING SHORTWAVE AND ASSOCIATED SURFACE BOUNDARY.
THE 20Z 3KM HRRR GUIDANCE STILL DEPICTS A FAST MOVING LINE OF SNOW
SHOWERS/SQUALLS ASSOCIATED WITH THE AFOREMENTIONED COLD FRONTAL
BOUNDARY HEADING TOWARDS OUR AREA AROUND MIDNIGHT. MODEL GUIDANCE
SUGGESTS THAT THIS ACTIVITY WON/T BE QUITE AS STRONG AS IT WILL BE
EARLIER IN THE EVENING ACROSS WESTERN NY/WESTERN AND CENTRAL
PA...BUT IT SHOULD STILL BE ENOUGH TO BRING ADDITIONAL ACCUMULATION
AND PROVIDE LOW VISIBILITY WITHIN GUSTY WINDS. THE 18Z NAM STILL
DEPICTS SHOWALTER VALUES NEAR OR JUST BELOW ZERO FOR WESTERN PARTS
OF THE AREA. LTG DETECTION HAS ALREADY NOTED SOME LTG ACROSS
WESTERN PA AND WESTERN NY...SO CANNOT TOTALLY RULE OUT SOME LTG
WITHIN THE HEAVIEST SQUALLS. HOWEVER...DO NOT FEEL CONFIDENT THIS
WILL BE WIDESPREAD ENOUGH TO INCLUDE IN THE GRIDS...BUT IT
CERTAINLY COULD OCCUR IN A FEW ISOLD SPOTS. THE BEST CHANCE OF
SEEING THE SNOW SQUALLS WILL BE ACROSS THE MOHAWK VALLEY/SRN
ADIRONDACKS AND EVENTUALLY THE LAKE GEORGE SARATOGA REGION...WHERE
WE CURRENTLY HAVE THE HIGHEST POPS /LIKELY TO CATEGORICAL/. THE
ACTIVITY LOOKS TO WEAKEN ENOUGH FOR SNOW SHOWERS TO BE RATHER SCT
ONCE ACTIVITY GETS TOWARDS THE CAPITAL REGION BY AROUND 06Z TO
07Z. WHILE A COATING OF SNOWFALL IS POSSIBLE...THE LINE LOOKS TO
BREAK ENOUGH FOR IT TO BE HIT OR MISS ACROSS FOR THE CAPITAL REGION.
FURTHER SOUTH...DOWNLOPING OFF THE CATSKILLS SHOULD KEEP ANY
ACTIVITY FAIRLY ISOLD FOR THE MID HUDSON VALLEY AND NW
CT...ALTHOUGH UPSLOPE FLOW COULD ALLOW FOR A LITTLE BETTER
COVERAGE ACROSS THE TACONICS/BERKSHIRES/SOUTHERN GREENS...WHERE A
LIGHT ACCUMULATION IS POSSIBLE.
LATE TONIGHT AND MONDAY...IN THE WAKE OF THE CLIPPER TYPE SYSTEM
A LAKE EFFECT BAND WILL SET UP WHICH WILL INITIALLY BE ORIENTED
TOWARD THE WESTERN ADIRONDACKS AND THEN SLIDE SOUTHEASTWARD INTO
THE MOHAWK VALLEY. AS THIS BAND WILL BE SHORT LIVED WITH A RIDGE
OF HIGH PRESSURE BUILDING QUICKLY INTO THE REGION BY
LATE MORNING...EXPECT THE GREATEST ACCUMULATIONS WILL BE ACROSS
SOUTHERN PORTIONS WESTERN ADIRONDACKS AND THE WESTERN MOHAWK
VALLEY. THIS ADDITIONAL SNOW IN THE WESTERN MOHAWK VALLEY SHOULD
BE ENOUGH TO RESULT IN THE AREA AVERAGING OVER 4 INCHES OF SNOW
WHEN COUPLED WITH THE SNOW FROM THE CLIPPER TYPE SYSTEM. BY MONDAY
AFTERNOON THE RIDGE OF HIGH PRESSURE IS ALREADY CRESTING ACROSS
THE FA AND THEN SLIDING EAST OF THE FA BY EVENING. EXPECT HIGHS ON
MONDAY TO RANGE FROM THE LOW TO MID 20S NORTHWEST TO MID TO UPPER
30S SOUTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
MONDAY NIGHT INTO TUESDAY MORNING THE FA IS EXPECTED TO BE
IMPACTED BY A WARM FRONT LIFTING NE FROM THE OHIO VALLEY. LIGHT
SNOW IS EXPECTED TO OVERSPREAD MUCH OF THE FA FROM SOUTHWEST TO
NORTHEAST MONDAY EVENING WITH THE HIGHEST QPF FROM THE MOHAWK
VALLEY NORTH IN NEW YORK AND ACROSS SOUTHERN VERMONT. THIS EVENT
GENERALLY LOOKS LIKE 2 TO 4 INCHES TOTAL ACROSS NORTHWEST PORTIONS
OF THE FA WITH MOST OTHER AREAS HAVING AROUND AN INCH OF
SNOW...ALTHOUGH THE MOUNTAINS EITHER SIDE OF THE GREATER CAPITAL
DISTRICT MAY PICK UP A COUPLE OF INCHES. EXPECT LOWS MONDAY NIGHT
TO BE IN THE MID TEENS TO MID 20S.
TUESDAY AFTERNOON INTO TUESDAY NIGHT EXPECT THE WARM FRONT TO BE
NORTH OF THE BULK OF THE FA BY TUESDAY EVENING WITH THE FA LEFT IN
THE WARM SECTOR. THERE WILL STILL BE A CHANCE OF PCPN TUESDAY
AFTERNOON INTO TUESDAY NIGHT MAINLY ACROSS THE NORTHERN HALF OF
THE FA UNTIL THE COLD FRONT ARRIVES ON WEDNESDAY. EXPECT HIGHS ON
TUESDAY TO RANGE FROM THE MID 30S NORTHWEST TO UPPER 40S TO AROUND
50 SOUTHEAST WITH LOWS TUESDAY NIGHT RANGING FROM THE UPPER 20S TO
LOWER 30S NORTH TO MID 30S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST STARTS OUT VERY MILD MID WEEK...AND THEN
BECOMES VERY UNSETTLED WITH CONTINUED MEDIUM RANGE DETERMINISTIC AND
ENSEMBLE MODEL UNCERTAINTY...WITH A LOW CONFIDENCE FORECAST FROM
THURSDAY INTO WEEKEND. WE WENT CLOSE TO THE HPC GUIDANCE...HOWEVER
THE LATEST 12Z ECMWF WOULD INDICATE THAT TWO SEPARATE SYSTEMS IN THE
W/SW FLOW COULD IMPACT THE NORTHEAST THU NIGHT THROUGH FRIDAY...AND
ANOTHER SYSTEM LATER ON THE WEEKEND WITH SOME SNOW. THE CANADIAN
GGEM IS ALSO HINTING AT ANOTHER SYSTEM DEVELOPING SATURDAY NEXT
WEEKEND OVER THE CNTRL MS RIVER VALLEY THAT COULD IMPACT THE
NORTHEAST FOR SUNDAY TOO. MEANWHILE...THE GFS IS COLD AND DRY LATE
IN THE WEEK WITH A SHORT-WAVE TROUGH IN THE NW FLOW THAT COULD
PRODUCE SOME SOME SNOW SHOWERS LATER NEXT WEEKEND.
WED-WED NIGHT...HIGH PRESSURE RETREATS OFF THE MID ATLANTIC
COAST...AS A WAVE OF LOW PRESSURE MOVES ACROSS SRN QUEBEC. MOST OF
THE FCST AREA GETS INTO A WARM SECTOR WITH H850 TEMPS JUMPING UP TO
+1 TO +5C. MAX TEMPS COULD BE 10 TO 20 DEGREES ABOVE NORMAL WITH
HIGHS IN THE M40S TO L50S IN THE VALLEYS...AND LOWER TO M40S OVER
THE HILLS AND MTNS. THE COLD FRONT QUICKLY APPROACHES LATE IN THE
DAY INTO THE EVENING WITH A GOOD CHANCE OF SHOWERS...TRANSITIONING
TO SNOW SHOWERS WITH THE COLD AIR ADVECTION. WE KEPT THE TREND OF
LIKELY POPS NORTH OF THE CAPITAL REGION CLOSER TO THE BETTER
CONVERGENCE AND LIFT WITH THE WAVE AND FRONT. LOWS WILL RANGE FROM
THE LOWER TO M20S OVER THE MTNS...AND U20S TO L30S IN THE VALLEYS.
THU-THU NIGHT...THE GFS HAS HIGH PRESSURE BUILDING IN FROM SRN
QUEBEC WITH A BROAD LONGWAVE TROUGH OVER THE NRN TIER. THE ECMWF
HAS A SHORT-WAVE IN THE SRN STREAM PHASING INTO THE NRN STREAM NEAR
THE CNTRL MS RIVER VALLEY...AND MOVES IT INTO THE OHIO VALLEY BY
THURSDAY MORNING. THIS SYSTEM MOVES ALONG THE BAROCLINIC ZONE FROM
THE FRONTAL PASSAGE ON WED NIGHT. THE SFC WAVE MOVES NORTHEAST INTO
PA AND UPSTATE NY BY LATE IN THE DAY ON THU VIA THE ECMWF. THE HPC
GUIDANCE...AND GFS HAVE A SECONDARY COLD FRONT SLIP SOUTH OF THE
REGION DURING THE DAY...AND THE WAVE IS MUCH FLATTER PASSING SOUTH
OF THE REGION. WE KEPT MUCH OF THE DAY DRY ON THU WITH HIGH
PRESSURE IN CONTROL. WE DID ADD A SLIGHT CHC OF SNOW THU NIGHT
OVER MOST OF THE REGION IN THE GRIDDED FCST JUST IN CASE THE ECMWF
IS CORRECT HERE. LATER RUNS OF THE GFS COULD TREND FURTHER NORTHWARD
WITH THE ACTIVE W/SW FLOW ALOFT.
FRI-FRI NIGHT...THIS IS WHERE THE MEDIUM RANGE GUIDANCE CONTINUES TO
DIVERGE. THE HPC GUIDANCE AND GFS HAVE A COLD FRONT MOVING SOUTH
WITH HIGH PRESSURE RIDGING BACK IN WITH A NRN STREAM DISTURBANCE
DIGGING S/SE FROM THE UPPER MIDWEST. THE SUBTROPICAL JET/SRN STREAM
DISTURBANCE IS EJECTING OUT OF TX. WE KEPT SOME SLIGHT OR LOW CHC
POPS IN FOR SNOW SHOWERS OR LIGHT SNOW DURING THIS TIME FRAME WITH
THE FIRST WAVE MOVING INTO GULF OF MAINE AND THE CANADIAN
MARITIMES. THE ECMWF/CANADIAN GGEM/SOME GLOBAL ENSEMBLES MEMBERS
HAVE A AN IMPRESSIVE SYSTEM FORMING OVER THE SRN PLAINS/LOWER MS
RIVER VALLEY FRI NIGHT WITH A POSITIVELY TILTED LONGWAVE TROUGH
BEING CARVED OUT OVER THE CNTRL PLAINS.
SAT-SUN...VERY LOW CONFIDENCE FORECAST CONTINUES. CAN GGEM AND
ECMWF CONTINUES TO HAVE COASTAL WAVE MOVING NORTHEAST INTO MID
ATLANTIC REGION...AND SOUTH OF LONG ISLAND BY SUNDAY. THE 18Z HPC
GUIDANCE IS TRENDING FURTHER NORTH LATE SAT INTO SUNDAY WITH THE
WAVE. WE KEPT SLIGHT TO LOW CHC POPS IN FOR THE WEEKEND WITH SNOW
AS THE MAIN PTYPE /AS SUFFICIENTLY COLD ENOUGH AIR IS IMPLIED/. THE
TIMING AND EVOLUTION OF THE LATE WEEK INTO THE WEEKEND SYSTEMS IS
VERY UNCERTAIN. IT COULD BE VERY ACTIVE. TEMPS LOOK TO AVERAGE
NEAR NORMAL FOR FEBRUARY DURING THIS STRETCH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KGFL/KALB/KPOU TAF SITES
THROUGH THE TAF PERIOD ENDING AT 00Z TUESDAY. HOWEVER...AS ANOTHER
FRONTAL BOUNDARY CROSSES THE REGION DURING THE NITE...THERE IS THE
POTENTIAL FOR MVFR/IFR CONDITIONS IN SNOW SHOWERS BEFORE/DURING AND
AFTER FORNTAL PASSAGE. THE CHANCES ARE BEST AT KGFL WHERE A PERIOD
OF MVFR CONDITIONS HAVE BEEN FORECAST BETWEEN 05Z AND 10Z...WITH A
TEMPO GROUP FOR IFR VSBYS IN SNOW SHOWERS BETWEEN 05Z AND 08Z. MUCH
LESS THREAT FOR MVFR/IFR CONDITIONS AT KALB...SO ONLY VCSH HAS BEEN
INCLUDED IN THE FORECAST. AT KPOU NO PCPN IS EXPECTED DURING THE TAF
PERIOD. AFTER ABOUT 10Z...VFR CONDITIONS WILL PREVAIL AT ALL THREE
TAF SITES AS GUSTY WESTERLY WINDS BRING COLDER AIR TO THE REGION AND
GNERALLY SCT/BKN CU/SC.
SURFACE WINDS WILL BE 10 KTS OR LESS FROM THE SOUTH OR SOUTHWEST
THIS EVENING AHEAD OF THE FRONTAL BOUNDARY. WINDS WILL SHOFT BETWEEN
05Z AND 07Z AT THE TAF SITES AND BECOME WESTERLY AT 10 TO 15 KTS
WITH GUSTS OF 15 TO 25 KTS BEHIND THE FRONT AND THROUGH MOST OF
MONDAY. BY LATE IN THE DAY ON MONDAY THE WINDS WILL DECREASE TO LESS
THAN 10 KTS.
CLOUDS WILL ALSO BEGIN TO INCREASE AGAIN LATE IN THE DAY AHEAD OF A
WARM FRONT.
OUTLOOK...
MON NIGHT...VFR/MVFR WITH -SN LIKELY.
TUE...VFR/MVFR AT KGFL WITH -SN LIKELY ESP IN THE MORNING. KALB
SOUTH TO KPOU VFR.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA/-SHSN.
THU...VFR...SLIGHT CHC -SHRA AT KPOU.
FRI...VFR...SLIGHT CHC -SHRA/-SNSHS.
&&
.HYDROLOGY...
RIVER FLOWS CONTINUE TO RECEDE...ALTHOUGH SOME GAGE SITES REMAIN
IMPACTED BY ICE INCLUDING MCKN6. NO MAJOR PROBLEMS ARE EXPECTED ON
THE RIVERS THROUGH THE MID WEEK PERIOD...OTHER THAN THOSE AREAS
SUCH AS MCKN6 WHERE ICE JAMS ARE STILL A POSSIBILITY. THE
PRECIPITATION THROUGH THE MID WEEK PERIOD IS EXPECTED TO BE MAINLY
IN THE FORM OF SNOW WITH QPF AMOUNTS RANGING FROM A FEW HUNDREDTHS
OF AN INCH TO A QUARTER TO A THIRD OF AN INCH ACROSS NORTHWEST
PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ032-033-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/11
NEAR TERM...FRUGIS/GJM/JPV
SHORT TERM...11
LONG TERM...WASULA
AVIATION...GJM
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1202 AM EST MON JAN 30 2012
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.UPDATE /ISSUED AT 805 PM/...
TEMPS HAVE FALLEN QUITE SHARPLY NEAR THE WI BORDER WHERE SKIES HAVE
CLEARED IN THE PRESENCE OF LGT WINDS AND DRY AIRMASS...PROBABLY WELL
REPRESENTED BY 12Z PWAT OF 0.09 INCH AT INL. SO LOWERED GOING FCST
MIN TEMPS IN AREAS WHERE SKIES ARE NOW CLR NEAR THE WI BORDER OR WL
BECOME MOCLR OVERNGT INLAND FM LK SUP. WITH THE ARRIVAL OF WAD CLD
LATER TNGT...EXPECT TEMPS TO RISE THEN...SO ADJUSTED HOURLY TEMPS IN
THE GRIDS TO REFLECT THESE EXPECTATIONS.
EARLIER UPDATE ISSUED AT 7 PM...
OPTED TO ISSUE AN LES ADVY FOR ERN ALGER/NRN LUCE COUNTY UNTIL EARLY
MON MRNG AS 18Z NAM/LOCAL WRF-ARW RUNS SHOW AREA OF FOCUSED LLVL
CNVGC IN THIS AREA THRU ABOUT 06Z WITH MORE WSW LAND BREEZE FLOW
OVER THE INTERIOR AND PERSISTENT WNW FLOW OVER THE WATER. WFR-ARW
RUN ALSO INDICATES FAVORABLE OMEGA WITHIN THE DGZ IN THIS AREA WITH
INVRN BASE ARND 5K FT...SO HEADLINE SEEMS WARRANTED. ONCE THE H925
WINDS BACK SUFFICIENTLY TO WSW BY ARND 09Z...LINGERING LES SHOULD
SHIFT OFFSHORE.
COORDINATED WITH APX.
&&
.SHORT TERM /TONIGHT AND MONDAY/ ISSUED AT 449 PM...
WV IMAGERY AND RUC ANALYSIS SHOWS THE UPPER TROUGH THAT HAS BEEN
OVER THE UPPER GREAT LAKES OVER THE LAST DAY STARTING TO SHIFT TO
THE EAST. UPSTREAM...BROAD MOISTURE PLUME RUNNING OVER THE RIDGE
OVER THE US/CANADIAN ROCKIES AND MOVING INTO THE NRN PLAINS. CLOSER
TO HOME...VIS SATELLITE SHOWING LAKE EFFECT CLOUDS HANGING ON OVER
MUCH OF UPPER MICHIGAN...BUT DRIER AIR FROM THE APPROACHING SFC
RIDGE IN MN HAS QUICKLY ATE AWAY AT THE CLOUDS/SHOWERS OVER WRN LK
SUPERIOR. OVER THE ERN LK...LES CONTINUES...ALTHOUGH THE DRIER AIR
HAS STARTED TO DIMINISH THE INTENSITY OF THE SHOWERS...WHICH KMQT
RADAR IS SHOWING MAINLY 1HR SNOWFALL RATES OF 0.5 IN/HR. THE
STRONGEST SWRN BAND NEAR MUNISING HAS PICKED UP SLIGHTLY OVER THE
LAST HOUR...AS LLVL WINDS OFF MARQUETTE COUNTY HAVE SHIFTED SLIGHTLY
TO THE WNW AND INCREASED CONVERGENCE.
TONIGHT...WITH THE UPPER TROUGH CONTINUING TO PUSH E...SFC RIDGE
CURRENTLY OVER THE MN WILL PUSH INTO THE AREA. H850-700 SUBSIDENCE
AND DRY AIR ALREADY TAKEN HOLD OVER WRN LK SUPERIOR AND DIMINISHED
THE -SHSN OVER THE WRN CWA. AS SFC HIGH BUILDS INTO UPPER MI THIS
EVENING...WINDS WILL BE BACKING THROUGH THE EVENING HOURS AND END UP
FOCUSING ANY LINGERING LES OVER THE KEWEENAW PENINSULA BY MIDNIGHT.
SINCE INVERSION HEIGHTS ON BUFKIT SOUNDINGS OVER THE KEWEENAW ARE
ONLY AROUND 3KFT...DON/T EXPECT MUCH FOR ACCUMULATIONS...ESPECIALLY
WITH THE TRANSIENT NATURE OF THE LES.
OVER ERN ALGER AND LUCE COUNTIES...EXPECT LES TO BE ONGOING AT THE
START OF THE TONIGHT PERIOD WITH THE NW FLOW AND -18C H850 TEMPS.
DEEPER MOISTURE WILL DEPART LATE THIS AFTN AS SUBSIDENCE FROM
H850-700 WITH THE UPPER RIDGING WILL CAUSE INVERSION HEIGHTS TO FALL
TO 4-5KFT. STILL SHOULD SEE LES CONTINUING IN THE NW WIND SNOW BELTS
FROM MUNISING E THIS EVENING...BUT INTENSITY WILL BE LOWER THAN
TODAY. IN ADDITION...WITH WINDS BACKING TO THE W BY MIDNIGHT AND
THEN SW BY DAYBREAK...THE BANDS SHOULD BE SHIFTING TO THE ENE FROM
LATE EVENING ON. THUS...EXPECT LIMITED ACCUMULATION DUE TO THE
TRANSIENT NATURE OF THE BANDS AND WILL LET THE WARNING CONTINUE
UNTIL 00Z.
LOWS TONIGHT ARE VERY TRICKY...SINCE CLEARING SKIES...WEAKENING
WINDS WITH THE SFC RIDGE...AND PWATS AROUND 35 PERCENT OF NORMAL
LEAD TO A FAVORABLE RADIATION COOLING NIGHT. FORECAST IS DIFFICULT
DUE TO THE APPROACHING HIGH CLOUDS CURRENTLY MOVING INTO WRN MN.
THESE SHOULD START TO ARRIVE AFTER MIDNIGHT AND CAUSE FOR STEADY OR
RISING TEMPS LATE. WENT WITH A NON-DIURNAL TREND AND HAVE LOWS ALONG
THE WI BORDER IN THE MID SINGLE DIGITS BELOW ZERO AND WOULD NOT BE
SURPRISED IF THEY GET EVEN COLDER IF CLOUDS ARE DELAYED.
LATE TONIGHT INTO MONDAY...CLIPPER SYSTEM CURRENTLY TAKING SHAPE IN
ALBERTA WILL SLIDE A WARM FRONT ACROSS MN AND WI ON MON. H700-500
WAA AND MOISTURE...ALONG WITH ISENTROPIC ASCENT ON THE 275-300K SFCS
PUSHES ACROSS THE AREA FROM SW TO NE BETWEEN 09Z AND 18Z MON. BEST
MID LVL WAA LOOKS TO FOCUS OVER THE S HALF OF UPPER MI...MAINLY OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE. WILL FOLLOW THAT SOLN FOR
QPF AMNTS FOR LATE TONIGHT INTO MON MORNING. WITH A GOOD CONSENSUS
ON FORCING/QPF/TIMING...HAVE BUMPED POPS UP TO LIKELY FOR MOST OF
THE LAND AREAS.
12Z NAM/GFS/GEM-REG CONSISTENT ON 0.12-0.2IN OF QPF OVER THE SRN
HALF OF UPPER MI BY MON EVENING AND MADE SOME MINOR ADJUSTMENTS UP
FROM PREVIOUS SHIFT. COBB OUTPUT FOR KESC/KIMT SHOWING HIGH RATIOS
AROUND 15/18-1 INITIALLY...THEN FALLING BELOW 10-1 HEADING INTO THE
AFTN AS THE DEEPER MOISTURE IS CUT OUT REMAINING FORCING/MOISTURE IS
BELOW THE DGZ. THINK MUCH OF THE SNOW WILL FALL IN THE HIGHER SNOW
RATIO PERIOD AND USED THAT AS THE STARTING POINT FOR SNOWFALL.
EXPECT A PERIOD OF LK ENHANCEMENT AFTER 15Z ON MON...WHEN LLVL
MOISTURE PROFILES FINALLY MOISTEN UP AND SRLY WINDS TAKE HOLD. WITH
H850 TEMPS AROUND -11C DURING THE PCPN PERIOD...SHOULD BE ENOUGH
LLVL INSTABILITY TO PROVIDE ENHANCEMENT OVER DELTA/SCHOOLCRAFT/LUCE
COUNTIES AND HAVE BUMPED UP QPF AMNTS SLIGHTLY IN THOSE
AREAS...ESPECIALLY SCHOOLCRAFT/LUCE. OVERALL...HAVE A GENERAL 1-2IN
OVER MUCH OF THE CWA. COULD BE SOME ISOLATED ADVY AMNTS OF 3IN OVER
THE SCNTRL AND ALONG THE LK MI SHORELINE...BUT THE OVERALL AVG WILL
BE BELOW ADVY AND WILL NOT ISSUE ANYTHING AT THIS TIME.
FINALLY...WITH THE MAIN FORCING AND DEEPER MOISTURE PULLING NE IN
THE AFTN...COULD SEE A PERIOD OF FZDZ. THIS IS DUE TO THE LINGERING
FORCING/MOISTURE BELOW THE ICE CRYSTAL AREA /ISENTROPIC ASCENT ON
275-280K SFCS AND H925-800 MOISTURE/. ADDED THIS TO THE GRIDS IN THE
AFTN FROM SW TO NE AS THE DEEP MOISTURE PULLS OUT...AND MAY BE MOST
PRONOUNCED OVER THE HIGHER TERRAIN NCNTRL...WHERE THE SSE UPSLOPE
FLOW WOULD FAVOR IT.
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG FCST QUESTION FOR MONDAY NIGHT INTO TUESDAY TIME FRAME WILL BE
THE POTENTIAL FOR FZDZ IN THE WAKE OF MONDAYS TROUGH/WARM FRONT.
FCST SNDGS...ESPECIALLY THE NAM BUFR SNDGS...SHOW LINGERING SHALLOW
MOIST LAYER NEAR THE SFC AS DRYING/SUBSIDENCE OCCURS IN MID-LVLS IN
THE WAKE OF THE WARM FRONT. EXPECT LOCATIONS AFFECTED BY AN UPSLOPE
SRLY FLOW WILL BE MOST SUSCEPTIBLE TO PATCHY FZDZ MON NIGHT INTO
TUESDAY MORNING BUT WILL INCLUDE A MENTION FOR MOST OF THE CWA. ANY
LINGERING FZDZ SHOULD TURN TO DZ TUE AFTERNOON AS MOIST LOW-LVLS
WARM ABV FREEZING.
ANOTHER SHORTWAVE AND ASSOC COLD FRONT WILL MOVE THROUGH TUE
AFTERNOON AND TUE NIGHT. TRACK OF THE SHORTWAVE AND THE ASSOC SFC
LOW WOULD FAVOR MAINLY THE NRN TIER FOR SOME LIGHT RAIN OR SNOW AS
THIS IS WHERE MODELS INDICATE DEEPER MOISTURE AND CLOSER PROXIMITY
TO MODERATE Q-VECT CONV AND LIFT ASSOC WITH SHORTWAVE. RAIN/SNOW MIX
ALONG THE NRN TIER SHOULD TURN OVER TO ALL SNOW LATE TUE NIGHT WITH
CAA BEHIND FRONT AND WOULD EXPECT A DIMINISH TREND AS SHORTWAVE/SFC
LOW DEPART QUICKLY EAST.
WEAK RDGG BUILDING IN FROM THE WEST SHOULD RESULT IN MAINLY DRY
CONDITIONS ON WEDNESDAY.
FOR THE EXTENDED /THURSDAY THROUGH SUNDAY/...
MODEL DISAGREEMENTS WILL CONTINUE THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD PERTAINING TO THE LOCATION AND TIMING OF SHORTWAVES
AFFECTING THE AREA...SO HAVE NOT DIVERGED MUCH FROM CONSENSUS THIS
FAR OUT. MODELS ARE IN FAIRLY GOOD AGREEMENT...HOWEVER...THAT STRONG
RIDGING OFF THE PACIFIC NORTHWEST WEDNESDAY NIGHT/THURSDAY MORNING
WILL ALLOW THE JET STREAM TO TRANSITION TO A MERIDIONAL FLOW ON THE
DESCENDING BRANCH...CREATING AN ENHANCED TROUGHING PATTERN OVER THE
CENTRAL CONUS. GFS IS THE MOST PROGRESSIVE OF THE MODELS...KEEPING
THE TROUGH PLACEMENT FARTHER NORTH AND HAVING IT MOVE EAST MORE
QUICKLY THAN ECMWF/GEM. AS HIGH PRESSURE CONTINUES TO BUILD IN WEST
THROUGH SUNDAY...DESCENDING BRANCH OF TROUGH WILL BEGIN TO
RETROGRADE AND BECOME POSITIVELY TILTED.
TRANSLATING THIS TO THE UPPER GREAT LAKES REGION...OVERALL...THIS
WILL CREATE A FAIRLY BENIGN SYNOPTIC WEATHER PATTERN AS MUCH OF THE
SHORTWAVES WILL PASS TO OUR SOUTH TRAVERSING THE DESCENDING EDGE OF
THE TROUGH. HOWEVER...IF THE MORE NORTHERN PLACEMENT OF THE GFS PANS
OUT...AS THE TROUGH BECOMES POSITIVELY TILTED OVER THE UPPER GREAT
LAKES ON FRIDAY...EXPECT SHORTWAVE TO DEVELOP AND TRAVERSE THE AREA.
THIS WILL BRING THE BEST CHANCE FOR PRECIP DURING THE PERIOD
WITH STRONG QVECTOR CONVERGENCE AND FAIRLY MOIST PROFILE/STEEP LAPSE
RATES DURING ITS PASSAGE. THE ECMWF AND THE GEM ON THE OTHER HAND
HAVE THIS SYSTEM DEVELOPING MUCH FARTHER SOUTH AND THEREBY NOT
IMPACTING THE FORECAST PERIOD AT ALL...SO DIDN`T GO ANY HIGHER THAN
SLIGHT CHANCES. OTHERWISE...PREDOMINATE W AND SW WINDS ALOFT AHEAD
OF DESCENDING JET WILL KEEP TEMPERATURES WELL ABOVE NORMAL THURSDAY.
WITH LOW CONFIDENCE ON PLACEMENT AND STRENGTH OF JET AS IT NEARS THE
AREA...WILL KEEP WITH THE LOWERING TREND OF TEMPS AS WINDS TURN MORE
NORTHERLY BY THE END OF THE PERIOD...BUT MAGNITUDE OF THIS COLD AIR
INTRUSION IS YET TO BE DETERMINED. IF THE MORE AMPLIFIED TROF AND
COLDER SOLN OF THE ECMWF SOLUTION VERIFIES...THEN TEMPS WILL
PROBABLY NEED TO BE LOWERED AND POPS MAY NEED TO BE INCREASED FOR
NEXT WEEKEND FOR AREAS DOWNWIND OF LAKE SUPERIOR IN N-NW FLOW.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
AS A HI PRES RDG MOVES E ACROSS THE UPR MIDWEST EARLY THIS MRNG AND
THE FLOW BACKS MORE TO THE SW...EXPECT LINGERING LO CLDS/MVFR CIGS
AT CMX/SAW TO GIVE WAY TO CLRG AND VFR CONDITIONS. ALTHOUGH MID/HI
CLDS WL THICKEN TOWARD SUNRISE...EXPECT VFR CONDITIONS WITH LLVL DRY
AIR AT IWD. AS A WARM FNT TO THE W MOVES CLOSER THIS MRNG...EXPECT
PERIODS OF -SN TO DVLP WITH CONDITIONS DETERIORATING TO MVFR...
FIRST AT IWD AND THEN AT SAW/CMX BY LATE MRNG. SINCE THE S WIND WL
DOWNSLOPE AT IWD AND CMX...CONDITIONS AT THOSE SITES WL PROBABLY
HAVE A HARDER TIME FALLING TO IFR THAN AT SAW. EVEN AFT THE SN
ENDS...LO CLDS AND MVFR/IFR CIGS WL LINGER WITH FORECAST SOUNDINGS
SHOWING CONSIDERABLE LLVL MSTR.
&&
.MARINE /FOR THE 4PM LAKE SUPERIOR FORECAST ISSUANCE/...
HIGH PRESSURE RIDGE SHIFTING OVER LAKE SUPERIOR TONIGHT WILL BRING
DECREASING WINDS TONIGHT...BELOW 20KTS. A CLIPPER SYSTEM DEVELOPING
IN ALBERTA WILL BEGIN TO MOVE INTO THE NORTHERN PLAINS ON MONDAY
AFTERNOON AND EVENING BEFORE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY NIGHT. SOUTHERLY WINDS AHEAD OF THIS SYSTEM COULD PRODUCE
GUSTS TO 30KTS OVER THE ERN LK ON MONDAY AFTN AND EVENING. THE LOW
WILL SHIFT E ON WED...ALLOWING WEAK HIGH PRESSURE TO BUILD OVER THE
UPPER GREAT LAKES THROUGH THURS. A LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE OHIO RIVER VALLEY ON FRI...BUT SHOULD HAVE LIMITED
EFFECTS ON LK SUPERIOR. EXPECT WINDS TO BE BELOW 25KTS FROM TUESDAY
MORNING THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST MONDAY FOR MIZ006-007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...VOSS
EXTENDED...JMW
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1100 PM CST SUN JAN 29 2012
.UPDATE...
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
ANOTHER MILD WEEK IS AHEAD OF US...WITH HIGHS IN THE MID 30S TO
LOWER 40S COMING FOR MONDAY THROUGH THURSDAY. IMPRESSIVE WARM
FRONT COMING THROUGH TONIGHT WILL BRING ABOUT THE CHANCE FOR
ANOTHER DUSTING OF SNOW...WHILE A LOW PASSING ACROSS NRN MN
TUESDAY MAY BRING SOME LIGHT PRECIP TO NRN SECTIONS OF THE CWA.
AFTER THAT...THE REST OF THE FORECAST IS DRY...WITH ONLY A MODEST
COOL DOWN EXPECTED FOR THE WEEKEND.
STRONG WARM FRONT THIS AFTERNOON STRETCHES FROM KC TO NE MONTANA.
TO GO ALONG WITH THIS...UPPER RIDGE IS WORKING INTO THE
PLAINS...WITH THE RUC SWINGING 160M 12 HR H5 HEIGHT RISES ACROSS
THE AREA THIS AFTERNOON. COMBINATION OF A SHORTWAVE MOVING INTO
MT...ALONG WITH STRONG ISENTROPIC/FGEN FORCING TO THE NORTH OF THE
FRONT HAS RESULTED IN THE GENERATION OF A NICE BAND OF SNOW ACROSS
NODAK. SHORT TERM HI RES GUIDANCE ALL SIMILAR WITH THIS BAND OF
SNOW REACHING THE NW CWA BETWEEN 2Z AND 4Z AND QUICKLY WORKING
EAST THROUGH THE NIGHT...EXITING THE WI CWA AROUND 15Z MON
MORNING. ONE ISSUE TO WATCH FOR TONIGHT IS A DRY LAYER OF AIR THAT
IS DEVELOPING THIS AFTERNOON BETWEEN H9 AND H7. INDICATIONS FROM
BUFKIT SOUNDINGS IS THAT WE WILL BE MOISTENING THIS LAYER FROM
TOP-DOWN...SO MUCH OF THE SNOW MAY BE LOST TO SUBLIMATION. ARW
1 KM AGL REFLECTIVITY FORECASTS ARE SPOTTY/NON-EXISTENT ACROSS
MUCH OF THE MPX CWA...AND THIS DRY LAYER LIKELY HAS A LOT TO DO
WITH IT. STILL...SREF PROBS ARE UP OVER 80 PERCENT FROM CENTRAL MN
INTO WRN WI...WHICH MATCHES UP WELL WITH BEST THALER QG FORCING.
THEREFORE...HAVE CATEGORICAL POPS ALONG AND NORTH OF AN
AXN/STC/EAU LINE FOR TONIGHT...WHERE FORCING AND MOISTURE LOOK
MOST LIKELY TO COINCIDE. CERTAINLY LOOKING GRIM FOR ANYONE ALONG
AND SOUTH OF THE MN RIVER TO SEE MUCH PRECIP. AS FOR
P-TYPE...STILL SEEING A SIGNIFICANT WARM NOSE COMING IN WITH THE
WARM FRONT...BUT MODELS CONTINUE TO SHOW THE PRECIP REMAINING OUT
AHEAD OF THE WARM NOSE...WITH ONLY AN HOUR OR TWO OF A WINTRY MIX
POSSIBLE AS THE PRECIP PULLS OUT. LOOKS TO BE YET ANOTHER SYSTEM
THIS YEAR THAT LAYS DOWN A QUICK HALF INCH TO AN INCH WHERE
CATEGORICAL POPS ARE LOCATED.
BESIDE THE PRECIP COMING IN...ALL GUIDANCE SIMILAR WITH A NON-
DIURNAL TREND FOR TONIGHT...WITH HIGHS STEADILY RISING THROUGH THE
NIGHT. IN FACT...GFSLAMP HAS ABOUT 10 DEGREES OF WARMING FOR ALL
MN LOCATIONS THROUGH THE NIGHT. EVEN IN WI...TEMPS SHOULD ONLY
FALL THROUGH ABOUT 3Z BEFORE GOING STEADY AND THEN RISING.
BIG QUESTION FOR MONDAY IS WHERE DOES THE WARM FRONT SET UP. 12Z
GUIDANCE HAS THE FRONT SOMEWHERE BETWEEN I-94 AND A HINCKLEY TO
FARGO LINE AT 6PM MONDAY. THIS WILL LEAD TO SOME UNCERTAINTY FOR
HIGHS ON MONDAY...AS AREAS SOUTH OF THE WARM FRONT WILL LIKELY
MAKE A RUN INTO THE 40S...WHILE AREAS ALONG AND NORTH REMAIN
CLOUDY WITH HIGHS LIKELY ONLY TOPPING OUT AROUND FREEZING. IN
ADDITION...THERE IS SOME CONCERN FOR DRIZZLE NORTH OF THE FRONT
GIVEN THE AMOUNT OF LOW LEVEL MOISTURE EXPECTED. HOWEVER...NAM/GFS
BUFKIT SOUNDINGS OVER CENTRAL MN SHOW A SHALLOW MIXED BOUNDARY
LAYER DEVELOPING DURING THE AFTERNOON...WITH A BIT OF A TEMP/DEWP
SPREAD NOTED ON THE SOUNDINGS. BECAUSE OF THIS...NOT TOO CONFIDENT
THAT WE WILL SEE THAT MUCH DZ GENERATION ACROSS CENTRAL
MN...DESPITE PERSISTENT LIFT ALONG THE FRONT. OTHER VARIABLE TO
CONTEND WITH FOR TEMPS ON MONDAY WILL BE SNOW COVER. SATELLITE
IMAGES THIS MORNING SHOWED MOST OF YELLOW MEDICINE AND LAC QUI
PARLE COUNTIES ARE SNOW FREE...AND GIVEN FAVORABLE WSW FLOW ON
MONDAY...PLACES SUCH AS MADISON AND MONTEVIDEO COULD SEE HIGHS TOP
OUT IN THE LOW 50S. SOUTH CENTRAL MN HAS THE OPPOSITE PROBLEM...AS
COOP OBSERVES THIS MORNING REPORTED 3 TO 5 INCHES OF SNOW ON THE
GROUND DOWN THERE...THIS MAY RESULT IN HIGHS BEING A BIT OVER DONE
DOWN THERE. AT ANY RATE...A BLEND OF THE MET/MAV BIAS CORRECTED
DATA WAS USED FOR HIGHS TOMORROW.
THE MILD CONDITIONS WILL REMAIN IN PLACE MONDAY NIGHT THROUGH
THURSDAY. MODELS SWING A COLD FRONT ACROSS THE AREA TUESDAY
MORNING...WITH LOWS IN THE WARM SECTOR OUT AHEAD OF IT MONDAY
NIGHT LIKELY STRUGGLING TO FALL BELOW FREEZING. H85 TEMPS LOOKS TO
ONLY GET KNOCKED DOWN TO AROUND 0C BEHIND THE FRONT...WITH HIGHS
TUESDAY THROUGH THURSDAY LOOKING TO BE A DEGREE OR TWO COLDER THAN
THE PREVIOUS DAY. IN FACT...OVERNIGHT LOWS LOOK TO ONLY FALL BACK
TO AROUND THE AVERAGE HIGHS FOR THIS TIME OF YEAR. BY THE TIME
JANUARY IS ALL SAID AND DONE...SHOULD HAVE AN AVERAGE TEMPERATURE
DEPARTURE AT MSP SOMEWHERE IN THE NEIGHBORHOOD OF 8 DEGREES...WITH
JANUARY OF 2012 POSSIBLY REPLACING JANUARY OF 1933 AS 8TH WARMEST
ALL TIME /23.1 WAS THE AVE TEMP FOR JAN OF 1933/.
ONLY OTHER CHANCE FOR PRECIP LOOKS TO COME LATE MONDAY NIGHT INTO
TUESDAY AS A SFC LOW TRACKS ACROSS NRN MN. UNFORTUNATELY...THIS
LOW AND ITS ASSOCIATED COLD FRONT WILL BE ENCOUNTERING QUITE A BIT
OF DRY AIR OVER THE MPX CWA...WITH BEST PRECIP SIGNAL BEING UP
ACROSS NRN MN. STILL...SLIGHT SOUTHWARD SHIFT IN MODELS THIS
MORNING PROMPTED AN INTRODUCTION FOR SOME SLIGHT CHANCE POPS
ACROSS FAR NRN CWA LATE MONDAY NIGHT THAT LAST THROUGH THE DAY ON
TUESDAY. AN PRECIP AMOUNTS LOOK LIGHT...WITH P-TYPE BEING A RA/SN
MIX INTO TUESDAY MORNING THAT TRANSITIONS TO MAINLY RA DURING THE
DAY.
AS WE END THE WEEK...THE BIG STORY HERE WILL BE THE SIGNIFICANT
PATTERN SHIFT THE MEDIUM RANGE MODELS ARE SHOWING GOING INTO THE
WEEKEND. OUR CURRENT FAST WNW FLOW LOOKS TO BECOME MORE AMPLIFIED
BY THE WEEKEND...WITH A STRONG UPPER RIDGE DEVELOPING OVER WRN
NOAM AND THE PATTERN RESEMBLING MORE A LA NINA SITUATION FOR
ONCE. THOUGH THIS DOES OPEN US UP TO N/NW FLOW THIS WEEKEND...THE
ASSOCIATED COOL DOWN LOOKS TO ONLY TAKE ABOUT 10 DEGREES OFF OF
HIGHS...WITH READINGS GOING FROM 15 TO 20 DEGREES ABOVE NORMAL BACK
DOWN TO 5 TO 10 DEGREES ABOVE NORMAL. THERE ARE NO INDICATIONS OF
SIGNIFICANT COLD AIR SHOWING UP UNTIL THE SECOND WEEK OF
FEB...WHEN BOTH THE GFS/ECMWF SHOW A POLAR VORTEX SHOWING UP OVER
SRN HUDSON BAY. EVEN THEN THOUGH...MN LOOKS TO BE ON THE BOUNDARY
BETWEEN THE ARCTIC AIR TO THE EAST AND THE MILD PACIFIC AIR TO THE
WEST.
&&
.AVIATION.../06Z TAF ISSUANCE/
WARM FRONT BUILDING INTO SOUTHWEST MN THIS EVENING AND GRADUALLY
SATURATING ATMOSPHERIC COLUMN ACROSS EASTERN AREAS. RADAR TRENDS
INDICATE INCREASING REFLECTIVITY PATTERN TO THE WEST OF KSTC/KMSP.
SHOULD SEE SOME LIGHT SNOW MOVE EAST INTO WEST CENTRAL WISCONSIN THE
REMAINDER OF THE NIGHT. AS PRECIPITATION ENDS AND WARM FRONT SURGES
TO THE NORTHEAST...SHOULD SEE LOWERING CEILINGS TO IFR FROM EAST OF
KMSP INTO WISCONSIN AFTER THROUGH MONDAY MORNING. EXPECT THIS TO
LIFT NORTHEAST DURING THE REMAINDER OF THE DAY WITH STRATUS LIFTING
TO THE NORTH OF THE TAF SITES BY 18Z. THEN VFR CONDITIONS INTO
MONDAY NIGHT. SOUTHEAST SURFACE WIND FLOW AHEAD OF FRONT...MAY BE A
BIT GUSTY AT KAXN INTO THE EARLY MORNING BEFORE FROPA. THEN WINDS
BECOMING MORE SOUTH TO SOUTHWEST DURING TH DAY MONDAY AS WARM AIR
LIFTS TO THE NORTHEAST.
KMSP...LOWERING CEILINGS TO MVFR WITH SOME LIGHT SNOW FROM 07Z-09Z.
QUESTION REMAINS IF WE SATURATE AHEAD OF INCOMING WARM FRONT. WILL
HOLD ONTO MVFR CEILINGS THROUGH 14Z THEN BECOMING VFR WITH FROPA.
SOME THREAT OF IFR STRATUS CEILINGS BEFORE FROPA IN THE MORNING AND
WILL HAVE TO MONITOR. SOUTHEAST WINDS BECOMING MORE SOUTH TO
SOUTHWEST DURING THE DAY MONDAY AS WARMER AIR MOVES INTO THE
REGION.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
323 AM CST MON JAN 30 2012
.DISCUSSION...
/323 AM CST MON JAN 30 2012/
MAIN CONCERNS ARE WELL ABOVE NORMAL TEMPERATURES THE NEXT TWO DAYS AND
THEN CHANCES FOR SNOW LATE THIS WEEK INTO NEXT WEEKEND.
STILL BELIEVE WE WILL BE IN RECORD TEMPERATURE TERRITORY TODAY GIVEN
THE MOSTLY SUNNY SKIES AND SOUTHWEST WINDS WHICH ARE TYPICALLY A
WARM UP WIND. RUC SOUNDINGS DO SHOW AN INVERSION AROUND 900MB
WHICH WILL LIMIT MIXING HEIGHTS TODAY...HOWEVER THE TEMPERATURES
AT THIS LEVEL WILL BE AROUND +10C WHICH STILL FAVORS HIGHS
REACHING THE LOWER TO MIDDLE 60S OVER MUCH OF THE AREA. THESE
VALUES MATCH THE MOS TEMPS REASONABLY WELL. SURFACE PRESSURE
GRADIENT WILL REMAIN TIGHT ENOUGH TONIGHT TO PREVENT MUCH OF A DROP
OFF IN WIND SPEED...AND HENCE SHOULD KEEP LOWS FROM FALLING MUCH
BELOW NORMAL DAYTIME HIGHS FOR THE END OF JANUARY. THE WARM START
TOMORROW WILL FAVOR TEMPERATURES CLIMBING CLOSE THE AGREEABLE MOS
NUMBERS.
MODELS STILL SHOW THAT LOW LEVEL MOISTURE WILL STREAM NORTHWARD
INTO OUR AREA TOMORROW...SO SHOULD SEE AN INCREASE IN MOISTURE AND
CLOUDS. DID GO WITH SPOTTY DRIZZLE OVER CENTRAL MO INTO WEST
CENTRAL IL WHERE MODEL CROSS SECTIONS ARE SHOWING DEEP LOW LEVEL
MOISTURE WILL SOME WEAK ASCENT. BETTER CHANCE OF MEASUREABLE RAIN
WILL OCCUR TUESDAY NIGHT FROM SOUTHEASTERN MO INTO SOUTHERN IL
WHEN THERE WILL BE SOME MODEST LARGE SCALE ASCENT ON THE TAIL END
OF A GREAT LAKES TROUGH.
THERE IS SLIGHTLY BETTER CONTINUITY AND AGREEMENT BETWEEN THE GFS/
ECMWF/CANADIAN GEM THAN 24 HOURS AGO...THOUGH THERE ARE STILL
ENOUGH DIFFERENCES TO MAKE FOR A LOW CONFIDENCE FORECAST FOR LATE
WEEK INTO NEXT WEEKEND. WITH THIS SAID...IT DOES LOOK LIKE THERE
WILL BE A STORM SYSTEM MOVE ACROSS MO/IL EARLY NEXT WEEKEND THAT
WILL HAVE ENOUGH COLD AIR TO PROVIDE AT LEAST A MIX OF RAIN/SNOW
ON FRIDAY NIGHT AND SATURDAY. 00Z OPERATIONAL GFS DEPICTS A
DEFORMATION ZONE THAT WOULD PRODUCE A BAND OF SNOW OVER THE
CENTRAL PART OF THE CWA DURING THIS PERIOD...BUT IT IS FASTER AND
MORE NORTH WITH THIS SYSTEM THAN THE OTHER MODELS...INCLUDING
MOST OF THE GFS ENSEMBLE MEMBERS. FOR NOW WILL JUST MENTION A
CHANCE OF RAIN AND SNOW AND SEE WHAT FUTURE MODELS RUNS DEPICT.
BRITT/KANOFKSY
&&
.AVIATION...
/1012 PM CST SUN JAN 29 2012/
MID-HIGH LEVEL CLOUDINESS WILL CONTINUE TO ADVECT SEWD THROUGH
THE TAF SITES LATE TGT. THE MODELS WERE SHOWING MID LEVEL
CLOUDINESS...MOISTURE CENTERED AROUND 700 MB...DROPPING SEWD
THROUGH THE AREA LATE TGT...ESPECIALLY UIN AREA DUE TO STRONG
LOW-MID LEVEL WAA. SELY SFC WINDS WILL GRADUALLY INCREASE IN SPEED
LATE TGT...THEN VEER AROUND TO A SLY DIRECTION BY EARLY MRNG...AND
SWLY AND GUSTY ON MON AFTER THE PASSAGE OF A WARM FRONT LATE TGT.
THERE WILL BE SOME LLWS IN UIN EARLY MON MRNG DUE TO A WLY LOW
LEVEL JET OVER IA AND NRN IL BUT IT DOES NOT APPEAR TO BE STRONG
ENOUGH TO INCLUDE IN THE UIN TAF. JUST HIGH LEVEL CLOUDINESS ON
MON.
SPECIFICS FOR KSTL...HIGH LEVEL CLOUDINESS THIS FORECAST PERIOD
WITH MID LEVEL CLOUDS AROUND 10000 FT MAINLY LATE TGT. SELY
SFC WIND WILL VEER AROUND TO A SLY DIRECTION BY EARLY MRNG...THEN
STRONGER AND GUSTY FROM A SWLY DIRECTION ON MON. S-SWLY SFC WNDS
WILL CONTINUE MON NGT. LOW LEVEL MOISTURE WILL BE INCREASING LATE
MON NGT BUT IT DOES NOT LOOK LIKE LOW LEVEL CLOUD COVER WILL
DEVELOP OR ADVECT INTO STL UNTIL AFTER THE TAF FORECAST PERIOD.
GKS
&&
.FIRE WEATHER...
WILL MENTION AN INCREASED FIRE DANGER TODAY OVER PARTS OF CENTRAL
AND SOUTHEAST MISSOURI. NOT MUCH CHANGE TO PREVIOUS FORECAST
THINKING. SOUTHWEST WINDS WILL BRING IN SLIGHTLY MORE MOISTURE
THROUGH THE DAY...BUT TEMPERATURES NEARING RECORDS WILL STILL
FORCE MINIMUM RELATIVELY HUMIDITY VALUES INTO THE 25-30 PERCENT
RANGE. THIS SAME AREA WILL ALSO HAVE SUSTAINED 20FT WINDS IN THE
10-15 MPH RANGE WITH HIGHER GUSTS. TEN HOUR FUELS WILL LIKELY FALL
BELOW 10 PERCENT IN THIS SAME AREA. HOWEVER AS MENTIONED IN THE
PREVIOUS DISCUSSION...RECENT COLLABORATION WITH THE USFS SUGGESTS
THAT DEAD FUELS MAY BE DRY ON TOP...BUT BE DAMP JUST BELOW THE
SURFACE WHICH WOULD GREATLY REDUCE THE RISK OF UNCONTROLLED FIRES
INSPITE OF OTHER FACTORS. THE DRIEST PART OF THE AREA...CENTRAL
AND SOUTHEAST MISSOURI...RECEIVED MEASURABLE PRECIPITATION AS
RECENTLY AS 3 DAYS AGO...AND THOSE AREAS HAVE HAD AS MUCH AS AN
INCH OR MORE WITHIN THE PAST COUPLE OF WEEKS. BY TOMORROW...LOW
LEVEL MOISTURE WILL INCREASE ENOUGH TO END RISK OF WILDFIRES.
BRITT/CARNEY
&&
.CLIMATE...
RECORD HIGHS FOR MONDAY JANUARY 30TH
KSTL 67 IN 1884
KCOU 68 IN 1890
RECORD HIGH LOW TEMPERATURES FOR JANUARY 31ST
KSTL 53 IN 1877
KCOU 46 IN 1923
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
321 AM EST MON JAN 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ITS EASTWARD PROGRESSION THROUGH THE
SOUTHEAST...MOVING OVERHEAD ON LATER TODAY. THIS HIGH PRESSURE
SYSTEM WILL SHIFT OFF THE COAST BY TUESDAY...MOVING FARTHER OFF
SHORE THROUGH MID WEEK. A COLD FRONT WILL MOVE THROUGH THURSDAY
NIGHT INTO FRIDAY WITH UNSETTLED WEATHER POSSIBLY CONTINUING
THROUGH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM MONDAY...THE UPPER TROF ACROSS THE FA WILL DE-AMPLIFY
AS IT PUSHES EAST. THIS WILL LEAVE RATHER ZONAL FLOW ALOFT...
BASICALLY FROM THE W TO WNW DIRECTION THRU THE ATM COLUMN...WITH
THE EXCEPTION IN THE BOUNDARY LAYER. MODELS PROG THE MOVEMENT OF
THE HIGHS RATHER TIGHT CENTER ACROSS THE CAROLINAS TODAY...AND
JUST OFFSHORE FROM THE CAROLINAS TONIGHT. WITH THE SUBSIDENCE
SHOULD SEE WIDESPREAD DEWPOINTS IN THE 20S WITH A FEW UPPER TEENS
POSSIBLE. MEAN RHS THRU 5H REMAIN QUITE LOW AND WILL THEREFORE
CONTINUE THE CLEAR FORECAST THRUOUT THE NEAR TERM. BASICALLY
NEUTRAL ADVECTION TODAY WITH MODEL MOS GUIDANCE IN GOOD AGREEMENT
WITH HIGHS IN THE UPPER 50S TO LOW 60S. FOR TONIGHT...WAA ALOFT TO
DEVELOP AND CAN BE WITNESSED WITH MODEL 8H TEMPS AND 1K-8H
THICKNESSES BOTH INCREASING. HOWEVER...THE SFC BASED INVERSION
FOLLOWED BY WINDS DECOUPLING WILL OCCUR AFTER SUNSET. THIS WILL
PREVENT THE WAA JUST OFF THE DECK FROM MIXING DOWN TO THE SFC. AS
A RESULT...HAVE GONE BELOW MODEL MOS GUIDANCE WITH TONIGHTS
LOWS...WITH LOWS STRADDLING THE 32 DEGREE MARK.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...DRY PROGRESSIVE FLOW ALOFT AND SURFACE RIDGING
WILL WORK TO KEEP THE AREA DRY THROUGH THE PERIOD. INITIALLY LOW
LEVEL FLOW IS LIGHT AND VARIABLE BUT BY TUE AFTERNOON THE SURFACE
RIDGE AXIS SHIFTS OFFSHORE AND RETURN FLOW SETS UP. WARM ADVECTION
WILL LEAD TO INCREASING TEMPERATURES AND DEW POINTS...BUT DEEP DRY
AIR KEEPS SKIES NEARLY CLOUD FREE. HIGHS WILL CLIMB INTO THE MID TO
UPPER 60S WITH SOUTHERLY FLOW TUE NIGHT KEEPING LOWS IN THE LOW TO
MID 40S.
WEAK 5H RIDGE BUILDS NORTH WED AS SURFACE RIDGE SHIFTS FARTHER
OFFSHORE. THE 00Z NAM/GFS MOVE AN AREA OF POSITIVE VORTICITY...BORN
OF CONVECTION...NORTH INTO THE SOUTHEAST US AND INTERACT IT WITH
WEAK SHORTWAVE TROUGH EJECTING OUT OF THE WEST. THE ECMWF/CANADIAN
MINIMIZE THE INTERACTION OF THE FEATURE WITH THE WEAK 5H TROUGH AND
MOVE IT EAST ACROSS NORTHERN FL. GIVEN THE KNOWN TENDENCY FOR
CONVECTIVE FEEDBACK WITHIN THE GFS/NAM HAVE CHOSEN TO FAVOR THE
ECMWF/CANADIAN SOLUTIONS. THE RESULT IS A DRY WARM FORECAST WITH
SOME CLOUD COVER SPREADING NORTH LATE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...EXTENDED FORECAST REMAINS CLOUDED IN MYSTERY.
THE 00Z GFS IS NOT SHOWING MUCH CONTINUITY FROM ITS 12Z 1/29 RUN AND
ITS BASICALLY THE SAME STORY FOR THE ECMWF AND THE CANADIAN. AT THIS
POINT CANNOT SEE HOW CONFIDENCE COULD BE ANY LOWER. THE MAIN ISSUE
IS THE EVOLUTION OF THE UPPER PATTERN AND THE IMPACT THIS HAS ON
SHORTWAVE EJECTING FROM THE SOUTHWEST LATE IN THE WEEK. THE 00Z GFS
REMAINS MORE PROGRESSIVE THAN THE 00Z ECMWF/CANADIAN BUT IS SLOWER
AND MORE AMPLIFIED THAN ITS PREVIOUS 12Z RUN. THE 00Z ECMWF NOW
KEEPS THE 5H LOW CUTOFF OVER THE SOUTHWEST WITH 5H RIDGE BUILDING IN
THE EAST...A SOLUTION THE CANADIAN DOES APPEAR TO BE TRENDING TOWARD
AND A PATTERN THAT HAS BEEN SEEN BEFORE THIS WINTER.
NOW LOOKS LIKE FRI WILL END UP DRIER...SO WENT AHEAD AND CUT BACK
POP FRI/FRI NIGHT. COLD FRONT MOVES ACROSS THE AREA THU NIGHT INTO
FRI BUT LACKS ANY SIGNIFICANT COLD ADVECTION. IT ALSO APPEARS A
PORTION OF THE WEEKEND WILL BE WET...FOR NOW THAT LOOKS TO BE SAT
INTO SUN BUT AGAIN WITH SUCH LOW CONFIDENCE CANNOT SEE GOING ABOVE
30 PERCENT AT THIS TIME. TEMPERATURES ABOVE TO WELL ABOVE CLIMO
EARLY IN THE PERIOD...BUT COULD SEE A 10 DEGREE OR MORE SWING IN
TEMPERATURES DEPENDING ON HOW THE PATTERN EVOLVES. FOR NOW FAVORED
THE PROGRESSIVE SOLUTION WHICH WOULD PRODUCE COOLER...NEAR
CLIMO...TEMPERATURES LATE IN THE PERIOD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF
ISSUANCE PERIOD. CALM TO LIGHT W TO SW WINDS TONIGHT WILL BECOME NW
TO N AT 5 TO 10 KT AFTER SUNRISE BEFORE BACKING TO THE SW AND A
DURING THE AFTERNOON. WINDS ARE EXPECTED TO BECOME CALM OR VARIABLE
BY 2 KT AFTER SUNSET.
EXTENDED OUTLOOK...POTENTIAL MORNING FOG TUESDAY AND WEDNESDAY. LOW
CONFIDENCE FOR PRECIP ON THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...NO ADVISORIES OR CAUTION FLAGS FOR THE NEAR
TERM.
WINDS ACROSS THE ILM WATERS WILL BE GOVERNED BY SFC HIGH PRESSURE.
THE CENTER OF THIS HIGH TO MIGRATE EAST TO THE COASTAL CAROLINAS
TODAY. IT WILL CONTINUE TO RIDGE BACK ACROSS THE LOCAL WATERS AS IT
MOVES JUST OFFSHORE TONIGHT. WHAT THIS ALL SPELLS IS FOR WINDS TO
DIMINISH TO 10 KT OR LESS WHILE VEERING FROM THE NW TO N BY
EARLY TO MID AFTERNOON VIA THE LATEST HRRR RUN. FOR TONIGHT...HAVE
INDICATED A DOMINATE SOUTHERLY WIND 10 KT OR LESS. WOULD NOT BE
SURPRISED TO OBSERVE A VARIABLE WIND DIRECTION AT TIMES TONIGHT DUE
TO THE HIGHS CENTER IN CLOSE PROXIMITY. WAVEWATCH3 INDICATES A
LESS THAN 1 FT 9+ SECOND ESE GROUND SWELL TO COMBINE WITH A 2 TO 4
SECOND PERIOD WIND WAVES...AND PRODUCE SIGNIFICANT SEAS OF 2 FT OR
LESS THROUGH THE PERIOD.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ELONGATED SURFACE RIDGE AXIS OVER THE WATERS
EARLY TUE WILL SHIFT OFFSHORE DURING TUE. WILL SEE A SLIGHT INCREASE
IS SOUTHWEST FLOW BY AFTERNOON...BUT SPEEDS SHOULD STILL BE NO MORE
THAN 10 KT WITH THE EXCEPTION BEING RIGHT ALONG THE COAST WHERE SEA
BREEZE WILL INCREASE SPEEDS AND LEAD TO ONSHORE FLOW. MUCH THE SAME
STORY EXPECTED FOR WED ALTHOUGH LATE WED/WED NIGHT A COLD FRONT
DROPPING INTO THE CAROLINAS/TN VALLEY WILL PINCH THE GRADIENT A
BIT...BUMPING SOUTHWEST TO 10 TO 15 KT. SEAS AROUND 2 FT TUE WILL
BUILD TO 2 TO 3 FT WED AND A SOLID 3 FT WED NIGHT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...BENIGN CONDITIONS EXPECTED THU AND FRI. LATE THU
SOUTHWEST FLOW MAY TOUCH 15 KT WITH GRADIENT TIGHTENING UP AS WEAK
FRONT INCHES CLOSER. WEAK COLD FRONT MOVES ACROSS THE WATERS EARLY
FRI WITH LIGHT NORTHERLY FLOW DEVELOPING. SEAS BRIEFLY BUILD TO 3 TO
4 FT LATE THU WITH INCREASING SOUTHWEST FLOW BUT DROP BACK TO 2 TO 3
FT ONCE NORTHERLY FLOW SETS UP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...III
AVIATION...DCH/RAN
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
248 AM CST MON JAN 30 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
IMPRESSIVE WARM AIR ADVECTION OCCURRING THIS MORNING...BUT THE
ATMOSPHERE IS REALLY STRUGGLING TO SATURATE INTO THE LOWER LEVELS.
THE BULK OF ANY MEASURABLE SNOW SHOULD REMAIN ACROSS THE NORTHERN
1/3 OF THE CWA THIS MORNING. THE HRRR DOES SHOW THE POTENTIAL FOR A
VERY NARROW BAND OF SNOW DEVELOPING BETWEEN 10-13Z THAT STRETCHES
SOUTHEAST INTO JEFFERSON/WAUKESHA COUNTIES. THIS IS WITHIN A NARROW
REGION OF DECENT ISENTROPIC LIFT. CERTAINLY CAN/T RULE IT OUT. AT
WORST WE ARE LOOKING AT PROBABLY 1/2 INCH OR LESS OF SNOW ACCUM.
I/M NOT SEEING A GOOD REASON TO HANG ONTO ANY FREEZING TYPE PRECIP
LATER THIS MORNING ACROSS THE NORTHEAST. IT APPEARS THE PRECIP WILL
BE GONE BEFORE WE GET AN ELEVATED WARM LAYER COMPLICATING THINGS. AS
THE WARM FRONT PUSHES THROUGH AROUND MID DAY...SHOULD SEE SOME
CLEARING/SUNSHINE IN ITS WAKE. SOUNDINGS SUGGEST THE BULK OF THE
WARMING WILL STAY ABOVE THE BOUNDARY LAYER...ESPECIALLY WITH FAIRLY
LOW SFC DWPNTS INITIALLY...SO DON/T WANT TO GO TOO CRAZY WITH HIGHS
TODAY. SUSPECT ANY 40S WILL BE LIMITED TO THE FAR SOUTHERN CWA.
TEMPS WON/T MOVE VERY MUCH TONIGHT...BUT DEW POINTS WILL BE ON THE
RISE. TEMP/DWPNT DEPRESSION REALLY NARROWS ACROSS THE SOUTHEAST HALF
OF THE CWA AS DWPNTS CLIMB TO AT OR ABOVE FREEZING. THIS COULD ALSO
LEAD TO SOME STRATUS DEVELOPMENT. THINK ANY DRIZZLE/LGT RAIN WILL
HAVE TO WAIT UNTIL DEEPER SATURATION OCCURS ON TUESDAY.
TUESDAY - CONFIDENCE...MEDIUM
INFLUENCE OF APPROACHING NORTHERN PLAINS STAYS LARGELY NORTH OF CWA
THROUGH THE DAY...WITH SOME PVA WORKING IN DURING THE EVENING. 850
JET SHOVES BRUNT OF MOISTURE NORTHEAST INTO THE OHIO VALLEY. BOTH
GFS AND NAM BUFKIT SHOW A STRONG INVERSION...WITH NO MOISTURE ABOVE
900 MILLIBARS. POTENTIAL CERTAINLY THERE FOR A MOIST AND MILD DAY
WITH LOW STRATUS AND LIGHT FOG. SHOULD BE ENOUGH WIND IN THE LOWEST
LEVELS TO KEEP THE SOUTHWEST WIND GOING. HOPEFULLY KEEPING THINGS
STIRRED UP ENOUGH TO PREVENT WIDESPREAD DENSE FOG FORMATION. NAM AND
GFS BOTH SHOW VERY LIGHT QPF WITH THE 850 FRONT SO WILL SIDE WITH
THE SLIGHTISH ALLBLEND POPS TO ACCOUNT FOR THIS. 00Z ECMWF IMPLIES
THAT BETTER PRECIP CHANCE COMES IN THE AFTERNOON HOURS. WILL GO
WITH SMALL POPS IN THE EAST FOR LIGHT RAIN AND HAVE PATCHY DRIZZLE
IN THE WEST AS LOW LEVEL MOISTURE TO AVOID MIXING MEASURABLE AND
NONMEASURABLE PTYPES. MID LEVEL DRY AIR BECOMES VERY PRONOUNCED
ABOVE INVERSION.
WEDNESDAY AND THURSDAY - CONFIDENCE...MEDIUM
LOOKS QUIET WITH WEAK COOL AIR ADVECTION. NO FORCING OF NOTE AND
COLUMN LOOKS PARCHED. TEMPS REMAIN UNSEASONABLY MILD. NOT MUCH FLOW.
WITH CONTINUED SNOWMELT AND SUBSEQUENT MOISTENING OF THE BOUNDARY
LAYER...WILL HAVE TO WATCH FOR STRATUS/FOG POTENTIAL.
FRIDAY THROUGH SUNDAY - CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING DIFFERENT SOLUTIONS WITH RESPECT TO THE UPPER LOW
PLODDING THROUGH MID MISSISSIPPI VALLEY INTO THE OHIO VALLEY.
SUGGESTION IS THAT WI WILL BE MORE UNDER THE INFLUENCE OF THE UPPER
FLOW OUT OF CANADA...WHICH SETS UP A CONFLUENT ZONE ACROSS WI. AT
THIS POINT GEMNH AND GFS MOST CLOSELY RESEMBLE EACH OTHER WHILE THE
ECMWF HAS A MUCH SLOWER...FURTHER WEST AND NORTH POSITIONING OF
UPPER LOW. NO INVASION OF ANYTHING RESEMBLING AN ARCTIC AIRMASS.
ONSHORE FLOW FRIDAY AND SATURDAY HOWEVER AT THIS POINT THE DELTA-T
VALUES DO NOT LOOK SUPPORTIVE OF PRECIPITATION DEVELOPMENT. MILD
EARLY FEBRUARY TEMPS CONTINUE.
&&
.AVIATION/12Z TAFS/...LOOKS LIKE VFR CONDITIONS WILL RULE THROUGH MOST
OF THE TAF FCST PERIOD. THE WARM AIR ADVECTION PRECIP SHOULD
MOSTLY STAY NORTH OF A MILWAUKEE TO MADISON LINE...BUT CAN/T RULE
OUT A BRIEF PERIOD OF LIGHT SNOW OR FLURRIES BEFORE ABOUT 12Z AT
MADISON AND 15Z AT MILWAUKEE. LITTLE OR NO ACCUMULATION IS
EXPECTED. WARMER AND MORE MOIST AIR ARRIVING TONIGHT COULD LEAD TO
STATUS DEVELOPMENT... ESPECIALLY FOR MILWAUKEE/WAUKESHA AND
KENOSHA. CONFIDENCE ON THIS OCCURRING BEFORE 12Z TUE IS RATHER
LOW...SO MAY LEAVE THIS OUT OF THE TAFS FOR NOW.
&&
.MARINE...BRISK SOUTHEAST WINDS AHEAD OF THE APPROACHING WARM FRONT WILL
LIKELY LEAD TO SMALL CRAFT ADVISORY CONDITIONS TODAY. WINDS ARE A
BIT MARGINAL...BUT THE TRAJECTORY IS FAVORABLE FOR RAPID WAVE
DEVELOPMENT EXCEEDING 4 FEET. WINDS AND WAVES DIMINISH BY EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1137 PM CST SUN JAN 29 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SYNOPSIS...MORE MILD WEATHER.
MODEST LARGE SCALE TROF OVER THE ERN CONUS WL SHIFT NEWD THE NEXT
COUPLE DAYS...PUTTING US BACK INTO WHAT HAS BECOME THE PATTERN OF
THE WINTER...A BROAD SOMEWHAT SPLIT ZONAL REGIME. HEIGHTS OVER WRN
CANADA WL GRADUALLY RISE LATER THIS WK. THAT WL EVENTUALLY FAVOR A
RETURN TO AN ERN TROF. MODELS OFFERED VARYING IDEAS ON HOW
SHARP/STG THE WRN RIDGE WL BECOME...AND THAT WILL MODULATE THE
STRENGTH OF THE DOWNSTREAM TROF. PERSISTENCE WOULD FAVOR THE
LESS AMPLIFIED OF THE GUIDANCE SOLUTIONS.
AFTER A RELATIVELY COLD NGT TNGT...TEMPS WL WARM TO SIGNIFICANTLY
ABV NORMAL LEVELS AGAIN FOR THE EARLY PART OF THE FCST PERIOD.
THEY WL DROP BACK CLOSER TO NORMAL BY NEXT WEEKEND...BUT UNLESS
ERN TROF GETS A LOT DEEPER THAN NOW EXPECTED...IT/S HARD TO SEE
THEM GOING BLO NORMAL. THE FCST AREA WL PROBABLY HAVE A COUPLE LGT
PCPN EVENTS...WITH AMNTS PROBABLY ENDING UP BLO NORMAL FOR THE
PERIOD AS A WHOLE.
&&
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE WORKING EASTWARD ACROSS THE NORTHERN MISSISSIPPI VALLEY
EARLY THIS AFTERNOON. LOW STRATO-CU CLOUD DECK IS SLOWLY LIFTING
OFF TO THE NORTHEAST OVER NORTHEAST WISCONSIN...WHILE THE REST OF
THE REGION REMAINS SUNNY. LOOKING UPSTREAM...PRETTY EXPANSIVE CLOUD
SHIELD IS PRESSING EAST ACROSS THE DAKOTAS...JUST AHEAD OF A
DEVELOPING SURFACE WARM FRONT. AS THE WARM FRONT MOVES EAST ACROSS
THE REGION LATE TONIGHT INTO MONDAY...PRECIP TIMING AND AMOUNTS ARE
THE MAIN FORECAST CONCERNS.
TONIGHT...THE HIGH PRESSURE RIDGE AXIS WILL SLIDE ACROSS THE STATE
DURING THE EVENING HOURS. SHOULD SEE A PERIOD OF CLEAR SKIES AND
LIGHT WINDS THAT WOULD ALLOW TEMPS TO TAKE A TUMBLE. WENT ON THE
COLD SIDE OF GUIDANCE FOR THIS REASON...AS IT USUALLY DOESNT TAKE
MUCH TIME FOR TEMPS TO FALL 20 DEGREES...ESPECIALLY OVER
NORTH-CENTRAL WISCONSIN. THEREAFTER...A 850MB WARM FRONT OVER THE
NORTHERN PLAINS WILL SHIFT EAST INTO SOUTHWEST WISCONSIN AFTER
MIDNIGHT. MODELS HAVE A VARIETY OF ARRIVAL TIMINGS OF THE LIGHT
SNOW AS IT SPREADS SE ALONG THE FRONT INTO CENTRAL WISCONSIN LATE.
DONT REALLY HAVE A GOOD FEEL IF THE FASTER PACE OF THE GFS COMPARED
TO THE NAM IS LIKELY TO BE CORRECT. SO WENT MIDDLE OF THE ROAD FOR
POPS/QPF WHICH PLACES LIKELY POPS OVER NORTH-CENTRAL AND CENTRAL
WISCONSIN. PERHAPS CENTRAL WISCONSIN COULD SEE A QUICK HALF INCH OF
FLUFF BY 12Z. TEMPS SHOULD REBOUND ONCE THE CLOUDS ROLL IN...SO
MIDNIGHT LOWS WILL CREEP BACK UP THROUGH THE OVERNIGHT.
MONDAY...THE WARM FRONT WILL CONTINUE TO MOVE EAST ACROSS THE REGION
ON MONDAY. WILL SEE THE MOST WIDESPREAD SNOW DURING THE MORNING
HOURS WHEN A DECENT BAND OF MID-LEVEL FGEN MOVES OVERHEAD. MOST
PLACES WILL SEE 1-2 INCHES OF SNOW. THE PRIMARY UNCERTAINTY OF THE
EVENT WILL BE THE PTYPE ON THE BACK EDGE OF THE PRECIPITATION SHIELD
WHEN MOISTURE FALLS BELOW -10C...WHICH INCREASES THE PROBABILITY OF
THE ABSENCE OF ICE CRYSTALS IN THE CLOUD. WITH CLOUD COVER AND
PRECIP HOLDING BACK SURFACE TEMPS...THINK THERE COULD BE A RIBBON OF
FREEZING DRIZZLE...MAINLY OVER CENTRAL AND EAST-CENTRAL WISCONSIN ON
THE BACK EDGE. BUT DONT THINK IT WILL POSE A HAZARD AS THE FRONT IS
RELATIVELY FAST MOVING AND SHARP...AS OPPOSED TO A LONG DURATION
OVER-RUNNING EVENT. TEMPS MAY REACH ABOVE FREEZING OVER CENTRAL AND
E-C WISCONSIN AS THE PRECIP ENDS AND CLOUDS ERODE HERE FIRST LATE IN
THE AFTERNOON.
.LONG TERM...MON NGT THROUGH NEXT SUN. THE MESO WRF RUNS FM NCEP
SUGGESTED SOME LGT PCPN COULD STILL LINGER IN THE THE NE EARLY MON
NGT...BUT WITH LITTLE SUPPORT FM ANY OF THE OTHER MODELS STUCK
WITH A DRY FCST. MILD SLY FLOW WL PREVENT MUCH DROP IN TEMPS...SO
BUILT 3 HOURLY TEMP GRIDS FROM A ROBUST BLEND OF GUID PRODUCTS AND
THEN GENERATED MIN GRID FROM THAT.
TUE WAS THE MOST CHALLENGING DAY OF THE FCST PERIOD. WK CYCLONE WL
BE TRACKING EWD ALONG THE U.S. CANADIAN BORDER TOWARD LAKE
SUPERIOR...WITH FCST AREA BASICALLY IN THE WARM SECTOR. OVERALL...
FORCING FOR PCPN WEAK. BUT SOME QG FORCING FM UPR SHRTWV COULD
GENERATE SOME LGT PCPN ACRS THE NW PART OF THE FCST AREA DURING
THE AFTN. CONTD SLGT CHC OF RA/SN TO ACCOUNT FOR THAT. MAIN
QUESTION HOWEVER IS THE CLDS AND THEIR IMPACT ON TEMPS. IT COULD
BE A VERY MILD DAY IF WE CAN ESCAPE HAVING ST FORM ACRS THE AREA.
IF THE ST DOES FORM...IT WL LIMIT TEMPS AND DAMP SLY FLOW WL
PROBABLY MAKE IT SEEM COLDER THAN IT IS. STUCK WITH MAX TEMPS FM
PREV FCST WHICH WERE GENERALLY BLO WHAT BEST PERFORMING GUID WOULD
SUGGEST FOR HIGH TEMPS. INCOMING DWPTS IN THE LOWER TO MIDDLE 30S
MARGINAL FOR ST FORMATION...AND DIDN/T WANT TO TAKE TEMPS BEYOND
WHAT WE HAD GOING WITHOUT HAVING MORE CONFIDENCE THAT WE WOULDN/T
GET STUCK WITH LOW CLDS.
QUIET WX THEN EXPECTED TUE NGT AND WED AS THE CYCLONE PASSES OFF
TO THE E OF THE RGN.
&&
.AVIATION...VFR THROUGH 09Z TONIGHT AS HIGH CLOUDS INCREASE FROM
THE WEST. CIGS AND VSBYS WILL FALL QUICKLY BETWEEN 09Z AND 12Z
MONDAY AS AN AREA OF SNOW FORMS NORTH OF A WARM FRONT. THE SNOW
WILL TAPER OFF BY EARLY AFTERNOON. THERE IS A SMALL CHANCE OF
FREEZING DRIZZLE MONDAY AFTERNOON BUT DID NOT INCLUDE IN TAFS
RIGHT NOW AS CHANCE IS SMALL. THE SNOW SHOULD BE LIGHT ENOUGH TO
SWEEP OFF RUNWAYS AT MOST AIRPORTS AS ACCUMULATIONS SHOULD BE 1
TO 2 INCHES AT MOST.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1000 AM CST MON JAN 30 2012
.DISCUSSION...
ISSUED 1000 AM CST MON JAN 30 2012
AREA OF MID-LEVEL CLOUDINESS IS NOW GENERALLY NORTH OF A MACOMB TO
EFFINGHAM LINE. LATEST RUC GUIDANCE SHOWING THESE TO RECEDE
ACROSS THE NORTHERN CWA THROUGH EARLY AFTERNOON AS A WARM FRONT
LIFTS NORTHWARD ACROSS THE AREA. HOWEVER...WILL CONTINUE TO SEE
SOME PERIODIC HIGH CLOUDS OVER THE CWA THROUGH THE AFTERNOON.
CURRENT TRENDS SHOWING THAT FORECAST HIGH TEMPERATURES ARE ON
TARGET...WITH THE ONLY AREA OF CONCERN AROUND PEORIA AND
BLOOMINGTON WHERE ABOUT AN INCH OF SNOW STILL REMAINS ON THE
GROUND. WIND GUSTS WILL BE INCREASING THROUGH THE DAY...AS A
STRONG SOUTHWEST LOW-LEVEL JET AROUND 45 KNOTS STARTS MIXING DOWN
WHEN THE SUNSHINE BECOMES MORE DOMINANT.
UPDATED GRIDS HAVE BEEN SENT TO INCORPORATE THE RECENT HOURLY
TRENDS. WILL SEND OUT A ZONE UPDATE CLOSER TO NOON...PRIMARILY TO
UPDATE THE SKY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 515 AM CST MON JAN 30 2012
WIND WILL BE THE MAIN ISSUE THIS TAF PERIOD. INITIAL WINDS SOUTH TO
SOUTHEAST 10-15 KT WILL INCREASE FROM THE SOUTH-SOUTHWEST WITH
SUSTAINED 16-21 KT AND GUSTS 25-30 KT. MODEL SOUNDINGS INDICATE 2K
FT WINDS 25045 KT AS WARM FRONT PASSES THROUGH THIS MORNING AND
MAINTAINS THESE SPEEDS...SO WILL INDICATE LLWS THROUGH THE PERIOD
ALTHOUGH IT MIGHT BE MARGINAL DURING PEAK MIXING TIME IN THE EARLY
AFTERNOON. ONLY CLOUDS WILL BE SCT-BKN ALTOCU AND SCT-BKN HIGH
CLOUDS.
04
&&
.PREV DISCUSSION...
ISSUED 251 AM CST MON JAN 30 2012
MAIN CONCERNS WITH THIS FORECAST PACKAGE WILL BE RAIN CHANCES LATE
TUESDAY...THEN POTENTIAL FOR WINTRY PRECIP BY NEXT WEEKEND.
08Z SURFACE ANALYSIS SHOWS WARM FRONT EXTENDING FROM THE NORTHERN
PLAINS INTO THE OHIO RIVER VALLEY. TEMPERATURES AHEAD OF THE
BOUNDARY ACROSS THE UPPER MIDWEST/GREAT LAKES ARE CURRENTLY IN THE
TEENS AND 20S...WHILE READINGS BEHIND THE FRONT ACROSS THE CENTRAL
PLAINS ARE IN THE 40S. ALOFT...ZONAL FLOW PATTERN CONTINUES TO
DOMINATE ACROSS THE CONUS...KEEPING THE BITTERLY COLD POLAR AIRMASS
BOTTLED UP WELL TO THE NORTH ACROSS ALASKA AND NORTHERN CANADA.
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT WILL LIFT NORTHWARD TODAY...ALLOWING WINDS TO VEER TO THE
SOUTHWEST AND MUCH WARMER AIR TO FLOW INTO CENTRAL ILLINOIS. BAND OF
MID-LEVEL CLOUDINESS ASSOCIATED WITH THE FRONT WILL ENSURE A MOSTLY
CLOUDY MORNING...HOWEVER SKIES WILL BECOME MOSTLY SUNNY BY
AFTERNOON. THANKS TO AMPLE LATE DAY SUNSHINE AND SOUTHWESTERLY WINDS
GUSTING TO BETWEEN 25 AND 30 MPH...HIGH TEMPS WILL SOAR WELL INTO
THE 50S.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER THE
PACIFIC NORTHWEST WILL TRACK EASTWARD ALONG THE US/CANADIAN
BORDER...ARRIVING IN THE NORTHERN GREAT LAKES BY TUESDAY EVENING.
TRAILING COLD FRONT WILL REMAIN WEST OF THE MISSISSIPPI RIVER
THROUGH THE DAY TUESDAY...ALLOWING SOUTHWESTERLY FLOW TO CONTINUE
ACROSS CENTRAL ILLINOIS. INCREASING FETCH OF LOW-LEVEL MOISTURE OFF
THE WESTERN GULF OF MEXICO WILL RESULT IN CLOUDY SKIES...HOWEVER
CONTINUED WAA WILL ALLOW TEMPS TO RISE A FEW DEGREES HIGHER THAN
TODAY...WITH AFTERNOON HIGHS TOPPING THE 60 DEGREE MARK ACROSS MOST
LOCATIONS SOUTH OF THE I-72 CORRIDOR. MODELS TRY TO SQUEEZE OUT SOME
LIGHT QPF DURING THE AFTERNOON...HOWEVER FORECAST SOUNDINGS DO NOT
FULLY MOISTEN THROUGHOUT THE PROFILE...SO DO NOT THINK WIDESPREAD
PRECIP IS LIKELY. HAVE INCLUDED JUST A SLIGHT CHANCE POP ACROSS THE
WESTERN KILX CWA TUESDAY AFTERNOON AS THE FRONT APPROACHES FROM THE
WEST. DEEPER MOISTURE GRADUALLY ARRIVES FROM THE SOUTH TUESDAY
EVENING...RESULTING IN SHOWERS INCREASING IN AREAL COVERAGE AHEAD OF
THE COLD FRONT...MAINLY ACROSS EAST-CENTRAL AND SOUTHEAST ILLINOIS.
HAVE THEREFORE HIT RAIN CHANCES HARDEST ALONG AND EAST OF
I-57...WHERE LIKELY POPS ARE IN ORDER. FURTHER WEST...RAIN CHANCES
STEADILY DECREASE...WITH ONLY SLIGHT CHANCES ACROSS THE ILLINOIS
RIVER VALLEY.
COLD FRONT WILL SETTLE FURTHER SOUTHWARD ON WEDNESDAY...AS SURFACE
RIDGE BUILDS IN FROM THE NORTHWEST. SHORT-WAVE TROUGH TRACKING
EASTWARD OUT OF THE PLAINS WILL LIKELY ENHANCE PRECIP ALONG/NORTH OF
THE BOUNDARY...HOWEVER IT APPEARS ANY RAIN WILL STAY SOUTH OF
ILLINOIS ACROSS THE OHIO RIVER VALLEY. AS A RESULT...HAVE GONE WITH
A DRY FORECAST ON WEDNESDAY...WITH SLIGHTLY COOLER TEMPS IN THE
UPPER 40S/LOWER 50S.
LONG TERM...THURSDAY THROUGH SUNDAY
AFTER SOME RECENT MODEL DISCREPANCIES...00Z 30 JAN SUITE HAS COME
INTO GOOD AGREEMENT FOR THURSDAY/FRIDAY TIME FRAME. WITH BAROCLINIC
ZONE EXPECTED TO BE WELL SOUTH OF THE REGION...DRY WEATHER WILL
PREVAIL THROUGH THE END OF THE WORK WEEK. AFTER THAT...MODEL
SOLUTIONS DIVERGE SOMEWHAT FOR THE WEEKEND AS STRONG RIDGE BUILDS
OVER THE WESTERN CONUS AND CORRESPONDING TROUGH DEVELOPS ACROSS THE
EAST. STILL LOOKS LIKE A MARKED COOLING TREND ARRIVING BY SATURDAY
AND SUNDAY...WITH TEMPS RETURNING TO NEAR NORMAL IN THE 30S. MAIN
QUESTION WILL BE HOW FAR NORTH A DEVELOPING SURFACE LOW WILL
TRACK...AND WILL IT BRING SNOW TO PARTS OF CENTRAL ILLINOIS. GFS IS
THE FURTHEST NORTH WITH THE LOW...SPREADING SNOW ACROSS THE SOUTHERN
TWO-THIRDS OF THE KILX CWA FRIDAY NIGHT AND SATURDAY. CANADIAN/ECMWF
ARE A BIT FURTHER SOUTH...BUT STILL BRING PRECIP INTO AT LEAST THE
FAR SE. STILL QUITE A BIT OF TIME TO WORK OUT THE DETAILS...BUT FOR
NOW...IT APPEARS COLDER WEATHER AND SOME SNOW ARE ON THE WAY FOR NEXT
WEEKEND.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
532 AM CST MON JAN 30 2012
.DISCUSSION...
/323 AM CST MON JAN 30 2012/
MAIN CONCERNS ARE WELL ABOVE NORMAL TEMPERATURES THE NEXT TWO DAYS AND
THEN CHANCES FOR SNOW LATE THIS WEEK INTO NEXT WEEKEND.
STILL BELIEVE WE WILL BE IN RECORD TEMPERATURE TERRITORY TODAY GIVEN
THE MOSTLY SUNNY SKIES AND SOUTHWEST WINDS WHICH ARE TYPICALLY A
WARM UP WIND. RUC SOUNDINGS DO SHOW AN INVERSION AROUND 900MB
WHICH WILL LIMIT MIXING HEIGHTS TODAY...HOWEVER THE TEMPERATURES
AT THIS LEVEL WILL BE AROUND +10C WHICH STILL FAVORS HIGHS
REACHING THE LOWER TO MIDDLE 60S OVER MUCH OF THE AREA. THESE
VALUES MATCH THE MOS TEMPS REASONABLY WELL. SURFACE PRESSURE
GRADIENT WILL REMAIN TIGHT ENOUGH TONIGHT TO PREVENT MUCH OF A DROP
OFF IN WIND SPEED...AND HENCE SHOULD KEEP LOWS FROM FALLING MUCH
BELOW NORMAL DAYTIME HIGHS FOR THE END OF JANUARY. THE WARM START
TOMORROW WILL FAVOR TEMPERATURES CLIMBING CLOSE THE AGREEABLE MOS
NUMBERS.
MODELS STILL SHOW THAT LOW LEVEL MOISTURE WILL STREAM NORTHWARD
INTO OUR AREA TOMORROW...SO SHOULD SEE AN INCREASE IN MOISTURE AND
CLOUDS. DID GO WITH SPOTTY DRIZZLE OVER CENTRAL MO INTO WEST
CENTRAL IL WHERE MODEL CROSS SECTIONS ARE SHOWING DEEP LOW LEVEL
MOISTURE WITH SOME WEAK ASCENT. BETTER CHANCE OF MEASURABLE RAIN
WILL OCCUR TUESDAY NIGHT FROM SOUTHEASTERN MO INTO SOUTHERN IL
WHEN THERE WILL BE SOME MODEST LARGE SCALE ASCENT ON THE TAIL END
OF A GREAT LAKES TROUGH.
THERE IS SLIGHTLY BETTER CONTINUITY AND AGREEMENT BETWEEN THE GFS/
ECMWF/CANADIAN GEM THAN 24 HOURS AGO...THOUGH THERE ARE STILL
ENOUGH DIFFERENCES TO MAKE FOR A LOW CONFIDENCE FORECAST FOR LATE
WEEK INTO NEXT WEEKEND. WITH THIS SAID...IT DOES LOOK LIKE THERE
WILL BE A STORM SYSTEM MOVING ACROSS MO/IL EARLY NEXT WEEKEND THAT
WILL HAVE ENOUGH COLD AIR TO PROVIDE AT LEAST A MIX OF RAIN/SNOW
ON FRIDAY NIGHT AND SATURDAY. 00Z OPERATIONAL GFS DEPICTS A
DEFORMATION ZONE THAT WOULD PRODUCE A BAND OF SNOW OVER THE
CENTRAL PART OF THE CWA DURING THIS PERIOD...BUT IT IS FASTER AND
MORE NORTH WITH THIS SYSTEM THAN THE OTHER MODELS...INCLUDING MOST
OF THE GFS ENSEMBLE MEMBERS. FOR NOW WILL JUST MENTION A CHANCE OF
RAIN AND SNOW AND SEE WHAT FUTURE MODELS RUNS DEPICT.
BRITT/KANOFSKY
&&
.AVIATION...
/520 AM CST MON JAN 30 2012/
VFR CONDITIONS EXPECTED TODAY WITH SWLY WINDS GUSTING TO AROUND
25 KTS BY LATE MORNING DUE TO DIURNAL MIXING. THE PRESSURE
GRADIENT SHOULD REMAIN TIGHT ENOUGH OVERNIGHT TO KEEP WINDS FROM
FALLING BELOW 8-12KTS. MODELS SHOW INCREASING MOISTURE LATE
TONIGHT AHEAD OF A SHORTWAVE WHICH WILL PROBABLY CAUSE A STRATUS
OR STRATOCU DECK TO SPREAD NWD HOWEVER CONFIDENCE IN MVFR CIGS
REMAINS TOO LOW TO MENTION IN THE TAFS ATTM.
SPECIFICS FOR KSTL...VFR CONDITIONS EXPECTED TODAY WITH SWLY WINDS
GUSTING TO AROUND 25 KTS BY LATE MORNING DUE TO DIURNAL MIXING.
THE PRESSURE GRADIENT SHOULD REMAIN TIGHT ENOUGH OVERNIGHT TO KEEP
WINDS FROM FALLING BELOW 8-12KTS. MODELS SHOW INCREASING MOISTURE
LATE TONIGHT AHEAD OF A SHORTWAVE WHICH WILL PROBABLY CAUSE A
STRATUS OR STRATOCU DECK TO SPREAD NWD HOWEVER CONFIDENCE IN MVFR
CIGS REMAINS TOO LOW TO MENTION IN THE KSTL TAF ATTM.
KANOFSKY
&&
.FIRE WEATHER...
WILL MENTION AN INCREASED FIRE DANGER TODAY OVER PARTS OF CENTRAL
AND SOUTHEAST MISSOURI. NOT MUCH CHANGE TO PREVIOUS FORECAST
THINKING. SOUTHWEST WINDS WILL BRING IN SLIGHTLY MORE MOISTURE
THROUGH THE DAY...BUT TEMPERATURES NEARING RECORDS WILL STILL
FORCE MINIMUM RELATIVELY HUMIDITY VALUES INTO THE 25-30 PERCENT
RANGE. THIS SAME AREA WILL ALSO HAVE SUSTAINED 20FT WINDS IN THE
10-15 MPH RANGE WITH HIGHER GUSTS. TEN HOUR FUELS WILL LIKELY FALL
BELOW 10 PERCENT IN THIS SAME AREA. HOWEVER AS MENTIONED IN THE
PREVIOUS DISCUSSION...RECENT COLLABORATION WITH THE USFS SUGGESTS
THAT DEAD FUELS MAY BE DRY ON TOP...BUT BE DAMP JUST BELOW THE
SURFACE WHICH WOULD GREATLY REDUCE THE RISK OF UNCONTROLLED FIRES
IN SPITE OF OTHER FACTORS. THE DRIEST PART OF THE AREA...CENTRAL
AND SOUTHEAST MISSOURI...RECEIVED MEASURABLE PRECIPITATION AS
RECENTLY AS 3 DAYS AGO...AND THOSE AREAS HAVE HAD AS MUCH AS AN
INCH OR MORE WITHIN THE PAST COUPLE OF WEEKS. BY TOMORROW...LOW
LEVEL MOISTURE WILL INCREASE ENOUGH TO END RISK OF WILDFIRES.
BRITT/CARNEY
&&
.CLIMATE...
RECORD HIGHS FOR MONDAY JANUARY 30TH
KSTL 67 IN 1884
KCOU 68 IN 1890
RECORD HIGH LOW TEMPERATURES FOR JANUARY 31ST
KSTL 53 IN 1877
KCOU 46 IN 1923
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
842 AM MST MON JAN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
UPPER DISTURBANCE ON THE WATER VAPOR UP OVER EAST CENTRAL BRITISH
COLUMBIA IS DROPPING SOUTHEAST INTO ALBERTA. MODELS ARE HINTING AT
SOME INSTABILITY TO GENERATE SHOWERS AS THE DISTURBANCE DROPS IN
THIS AFTERNOON. TEMPS GENERALLY LOOK TOO WARM FOR SNOW. GENERALLY
FOLLOWED THE 06Z GFS FOR POPS AND QPF AS THE 12Z NAM LOOKS TOO WET
(WHICH HAS BEEN THE CASE LATELY). REST OF FORECAST LOOKED GOOD.
ALSO ADDED MENTION OF RECORD HIGH TEMP FOR THE GLASGOW AREA TODAY.
RECORD MAX LOW TEMPERATURE LOOKS TO BE IN JEOPARDY TODAY. JAMBA
PREVIOUS DISCUSSION...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A LITTLE MORE
PROGRESSIVE AND OVERALL ACTIVE CONUS WEATHER PATTERN TODAY. THE
HUDSON BAY UPPER LOW IS PINWHEELING THE LAST REMNANTS OF ITS
EMBEDDED UPPER LEVEL SHORT WAVE TROUGH THROUGH THE NEW ENGLAND
STATES WHILE BEING WEAKENED BY ENCROACHING LARGE SCALE RIDGING
FROM THE WEST. EMBEDDED WITHIN THIS BROAD AND WEAK UPPER RIDGING
OVER THE CENTRAL AND WESTERN PORTIONS OF CANADA AND OUR CONUS...IS
A SHORT WAVE TROUGH HAVING ALREADY MOVED ONSHORE OVER THE PACIFIC
NORTHWEST.
THIS APPROACHING STORM SYSTEM FROM THE WEST TODAY IS PUSHING AMPLE
MOISTURE OVER THE CONTINENTAL DIVIDE AND ACROSS THE STATE OF MONTANA.
FORECAST CHALLENGES WILL INCLUDE THE TIMING AND TYPE OF
PRECIPITATION WITH THE STORM SYSTEM LASTING FROM LATE THIS MORNING
THROUGH EARLY TUESDAY MORNING.
SHORT TERM OPERATIONAL MODEL SOLUTIONS SHOW MODERATE AGREEMENT
WITH A BAND OF RAIN SHOWERS DESCENDING SOUTHEASTWARD FROM THE
CANADIAN ROCKIES AND THROUGH NORTHEAST MONTANA THROUGH THE LATTER
PART OF THE DAY TODAY AND INTO EARLY TUESDAY MORNING. CURRENT AND
EXPECTED WARM TEMPERATURES WILL KEEP MOST OF THE INITIAL
PRECIPITATION AS RAIN. BEGINNING THIS EVENING...A RAIN AND SNOW
MIX WILL BE POSSIBLE...FOLLOWED BY A CHANGE OVER TO ALL SNOW AFTER
MIDNIGHT AS THE SYSTEM MAKES A QUICK EXIT TO THE EAST.
RECENT MODEL PERFORMANCE WOULD SUGGEST FAVORING THE GFS OVER THE
NAM WITH SOME INFLUENCE FROM THE HRRR MODEL. THE NAM MAY DO WELL
WITH TIMING AND PLACEMENT...BUT HAS BEEN OVERLY WET. AS THE GFS
HAS COME INTO PLACEMENT AGREEMENT...THE LESSER QPF AMOUNTS
ADVERTISED BY IT MAY BE THE MORE ACCURATE SOLUTION. AS THE LAST
STORM SYSTEM RESULTED IN VERY LITTLE PRECIPITATION AT THE
SURFACE...IF ANY AT ALL...I KEPT THE STORM SYSTEM FOR TODAY
RELATIVELY DRY...ALBEIT 0.01 TO 0.04 INCHES OF PRECIP FOR ANY
GIVEN 6 HOUR PERIOD OF TIME. THIS SEEMS TO BE GENEROUS ENOUGH
UNTIL WE ACTUALLY SEE OBSERVATIONAL DATA TO THE CONTRARY.
TUESDAY WILL DAWN BRIGHT WITH CLEARING FROM THE WEST. THIS WILL
SIGNAL THE BEGINNING OF A SERIES OF QUICKLY PASSING SHORT WAVE
TROUGHS AND RIDGES SET TO MOVE THROUGH MONTANA THROUGH THE MIDDLE
OF THE WEEK. NONE OF THE TROUGHS APPEAR TO HAVE ENOUGH MOISTURE
AND LIFT TO GENERATE ANY PRECIP AT THIS TIME. KEPT THIS PART OF
THE FORECAST DRY. BMICKELSON
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MODELS CONTINUE TO INDICATE TRANSITION FROM ZONAL PATTERN TO A
HIGH AMPLITUDE BLOCKING PATTERN EARLY IN THE EXTENDED PERIOD. NEW
WRINKLE IS TAKING THE SHORTWAVE DROPPING THROUGH THE GREAT BASIN
WEDNESDAY/WEDNESDAY NIGHT AND DEVELOPING A CLOSED LOW OVER THE
SOUTHWEST STATES. RIDGE STILL EXPECTED OVER THE NORTHERN ROCKIES
BUT WILL GET CLOSED OR PINCHED OFF BY LOW TO THE SOUTH AND TROF
IN THE EAST PACIFIC.
INITIAL PUSH OF WARM AIR INTO THE REGION WITH RIDGE WILL GRADUALLY
MODERATE AS SHORTWAVES PUSH THROUGH THE TOP OF THE RIDGE. OVERALL
STILL EXPECTING WELL ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. EBERT
&&
.AVIATION...
VFR WITH MID TO HIGH CLOUDS THROUGH TODAY. A PACIFIC DISTURBANCE
WILL MOVE THROUGH THE REGION TODAY WHICH COULD BRING SOME LOWER
CLOUDS AND POSSIBLY SHOWERS LATE IN THE DAY. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
350 AM MST MON JAN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A LITTLE MORE
PROGRESSIVE AND OVERALL ACTIVE CONUS WEATHER PATTERN TODAY. THE
HUDSON BAY UPPER LOW IS PINWHEELING THE LAST REMNANTS OF ITS
EMBEDDED UPPER LEVEL SHORT WAVE TROUGH THROUGH THE NEW ENGLAND
STATES WHILE BEING WEAKENED BY ENCROACHING LARGE SCALE RIDGING
FROM THE WEST. EMBEDDED WITHIN THIS BROAD AND WEAK UPPER RIDGING
OVER THE CENTRAL AND WESTERN PORTIONS OF CANADA AND OUR CONUS...IS
A SHORT WAVE TROUGH HAVING ALREADY MOVED ONSHORE OVER THE PACIFIC NORTHWEST.
THIS APPROACHING STORM SYSTEM FROM THE WEST TODAY IS PUSHING AMPLE
MOISTURE OVER THE CONTINENTAL DIVIDE AND ACROSS THE STATE OF MONTANA.
FORECAST CHALLENGES WILL INCLUDE THE TIMING AND TYPE OF
PRECIPITATION WITH THE STORM SYSTEM LASTING FROM LATE THIS MORNING
THROUGH EARLY TUESDAY MORNING.
SHORT TERM OPERATIONAL MODEL SOLUTIONS SHOW MODERATE AGREEMENT
WITH A BAND OF RAIN SHOWERS DESCENDING SOUTHEASTWARD FROM THE
CANADIAN ROCKIES AND THROUGH NORTHEAST MONTANA THROUGH THE LATTER
PART OF THE DAY TODAY AND INTO EARLY TUESDAY MORNING. CURRENT AND
EXPECTED WARM TEMPERATURES WILL KEEP MOST OF THE INITIAL
PRECIPITATION AS RAIN. BEGINNING THIS EVENING...A RAIN AND SNOW
MIX WILL BE POSSIBLE...FOLLOWED BY A CHANGE OVER TO ALL SNOW AFTER
MIDNIGHT AS THE SYSTEM MAKES A QUICK EXIT TO THE EAST.
RECENT MODEL PERFORMANCE WOULD SUGGEST FAVORING THE GFS OVER THE
NAM WITH SOME INFLUENCE FROM THE HRRR MODEL. THE NAM MAY DO WELL
WITH TIMING AND PLACEMENT...BUT HAS BEEN OVERLY WET. AS THE GFS
HAS COME INTO PLACEMENT AGREEMENT...THE LESSER QPF AMOUNTS
ADVERTISED BY IT MAY BE THE MORE ACCURATE SOLUTION. AS THE LAST
STORM SYSTEM RESULTED IN VERY LITTLE PRECIPITATION AT THE
SURFACE...IF ANY AT ALL...I KEPT THE STORM SYSTEM FOR TODAY
RELATIVELY DRY...ALBEIT 0.01 TO 0.04 INCHES OF PRECIP FOR ANY
GIVEN 6 HOUR PERIOD OF TIME. THIS SEEMS TO BE GENEROUS ENOUGH
UNTIL WE ACTUALLY SEE OBSERVATIONAL DATA TO THE CONTRARY.
TUESDAY WILL DAWN BRIGHT WITH CLEARING FROM THE WEST. THIS WILL
SIGNAL THE BEGINNING OF A SERIES OF QUICKLY PASSING SHORT WAVE
TROUGHS AND RIDGES SET TO MOVE THROUGH MONTANA THROUGH THE MIDDLE
OF THE WEEK. NONE OF THE TROUGHS APPEAR TO HAVE ENOUGH MOISTURE
AND LIFT TO GENERATE ANY PRECIP AT THIS TIME. KEPT THIS PART OF
THE FORECAST DRY. BMICKELSON
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MODELS CONTINUE TO INDICATE TRANSITION FROM ZONAL PATTERN TO A
HIGH AMPLITUDE BLOCKING PATTERN EARLY IN THE EXTENDED PERIOD. NEW
WRINKLE IS TAKING THE SHORTWAVE DROPPING THROUGH THE GREAT BASIN
WEDNESDAY/WEDNESDAY NIGHT AND DEVELOPING A CLOSED LOW OVER THE
SOUTHWEST STATES. RIDGE STILL EXPECTED OVER THE NORTHERN ROCKIES
BUT WILL GET CLOSED OR PINCHED OFF BY LOW TO THE SOUTH AND TROF
IN THE EAST PACIFIC.
INITIAL PUSH OF WARM AIR INTO THE REGION WITH RIDGE WILL GRADUALLY
MODERATE AS SHORTWAVES PUSH THROUGH THE TOP OF THE RIDGE. OVERALL
STILL EXPECTING WELL ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. EBERT
&&
.AVIATION...
VFR WITH MID TO HIGH CLOUDS THROUGH TODAY. A PACIFIC DISTURBANCE
WILL MOVE THROUGH THE REGION TODAY WHICH COULD BRING SOME LOWER
CLOUDS AND POSSIBLY SHOWERS LATE IN THE DAY. RAE
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...COR SYNOPSIS
NWS WILMINGTON NC
822 AM EST MON JAN 30 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE OFFSHORE OF THE CAROLINAS
TUESDAY. A WARMING TREND WILL FOLLOW THROUGH MID WEEK. A COLD FRONT
WILL PASS ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY WITH UNSETTLED
WEATHER POSSIBLY PREVAILING INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 620 AM MONDAY...THE UPPER TROF ACROSS THE FA WILL DE-AMPLIFY
AS IT PUSHES EAST. THIS WILL LEAVE RATHER ZONAL FLOW ALOFT...WITH
FLOW FROM THE W TO WNW DIRECTION...THRU THE ATM COLUMN WITH THE
EXCEPTION IN THE BOUNDARY LAYER. MODELS PROG THE MOVEMENT OF THE SFC
HIGHS RATHER TIGHT CENTER ACROSS THE CAROLINAS TODAY...AND JUST
OFFSHORE FROM THE CAROLINAS TONIGHT. WITH THE SUBSIDENCE...SHOULD
SEE WIDESPREAD DEWPOINTS IN THE 20S WITH A FEW UPPER TEENS POSSIBLE.
PROGGED MEAN RHS THRU THE ATM COLUMN REMAIN QUITE LOW AND WILL
CONTINUE THE CLEAR FORECAST THRUOUT THE NEAR TERM. BASICALLY NEUTRAL
ADVECTION TODAY WITH MODEL MOS GUIDANCE IN GOOD AGREEMENT WITH HIGHS
IN THE UPPER 50S TO LOW 60S. FOR TONIGHT...WAA ALOFT TO DEVELOP AND
CAN BE WITNESSED WITH MODEL 8H TEMPS AND 1K-8H THICKNESSES BOTH
INCREASING. HOWEVER...THE SFC BASED INVERSION DEVELOPING AFTER
SUNSET...WILL RESULT IN WINDS DECOUPLING. THIS WILL PREVENT THE WAA
JUST OFF THE DECK FROM MIXING DOWN TO THE SFC. AS A RESULT...HAVE
GONE BELOW MODEL MOS GUIDANCE WITH TONIGHTS LOWS...WITH LOWS
STRADDLING THE 32 DEGREE MARK AWAY FROM THE COAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...DRY PROGRESSIVE FLOW ALOFT AND SURFACE RIDGING
WILL WORK TO KEEP THE AREA DRY THROUGH THE PERIOD. INITIALLY LOW
LEVEL FLOW IS LIGHT AND VARIABLE BUT BY TUE AFTERNOON THE SURFACE
RIDGE AXIS SHIFTS OFFSHORE AND RETURN FLOW SETS UP. WARM ADVECTION
WILL LEAD TO INCREASING TEMPERATURES AND DEW POINTS...BUT DEEP DRY
AIR KEEPS SKIES NEARLY CLOUD FREE. HIGHS WILL CLIMB INTO THE MID TO
UPPER 60S WITH SOUTHERLY FLOW TUE NIGHT KEEPING LOWS IN THE LOW TO
MID 40S.
WEAK 5H RIDGE BUILDS NORTH WED AS SURFACE RIDGE SHIFTS FARTHER
OFFSHORE. THE 00Z NAM/GFS MOVE AN AREA OF POSITIVE VORTICITY...BORN
OF CONVECTION...NORTH INTO THE SOUTHEAST US AND INTERACT IT WITH
WEAK SHORTWAVE TROUGH EJECTING OUT OF THE WEST. THE ECMWF/CANADIAN
MINIMIZE THE INTERACTION OF THE FEATURE WITH THE WEAK 5H TROUGH AND
MOVE IT EAST ACROSS NORTHERN FL. GIVEN THE KNOWN TENDENCY FOR
CONVECTIVE FEEDBACK WITHIN THE GFS/NAM HAVE CHOSEN TO FAVOR THE
ECMWF/CANADIAN SOLUTIONS. THE RESULT IS A DRY WARM FORECAST WITH
SOME CLOUD COVER SPREADING NORTH LATE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...EXTENDED FORECAST REMAINS CLOUDED IN MYSTERY.
THE 00Z GFS IS NOT SHOWING MUCH CONTINUITY FROM ITS 12Z 1/29 RUN AND
ITS BASICALLY THE SAME STORY FOR THE ECMWF AND THE CANADIAN. AT THIS
POINT CANNOT SEE HOW CONFIDENCE COULD BE ANY LOWER. THE MAIN ISSUE
IS THE EVOLUTION OF THE UPPER PATTERN AND THE IMPACT THIS HAS ON
SHORTWAVE EJECTING FROM THE SOUTHWEST LATE IN THE WEEK. THE 00Z GFS
REMAINS MORE PROGRESSIVE THAN THE 00Z ECMWF/CANADIAN BUT IS SLOWER
AND MORE AMPLIFIED THAN ITS PREVIOUS 12Z RUN. THE 00Z ECMWF NOW
KEEPS THE 5H LOW CUTOFF OVER THE SOUTHWEST WITH 5H RIDGE BUILDING IN
THE EAST...A SOLUTION THE CANADIAN DOES APPEAR TO BE TRENDING TOWARD
AND A PATTERN THAT HAS BEEN SEEN BEFORE THIS WINTER.
NOW LOOKS LIKE FRI WILL END UP DRIER...SO WENT AHEAD AND CUT BACK
POP FRI/FRI NIGHT. COLD FRONT MOVES ACROSS THE AREA THU NIGHT INTO
FRI BUT LACKS ANY SIGNIFICANT COLD ADVECTION. IT ALSO APPEARS A
PORTION OF THE WEEKEND WILL BE WET...FOR NOW THAT LOOKS TO BE SAT
INTO SUN BUT AGAIN WITH SUCH LOW CONFIDENCE CANNOT SEE GOING ABOVE
30 PERCENT AT THIS TIME. TEMPERATURES ABOVE TO WELL ABOVE CLIMO
EARLY IN THE PERIOD...BUT COULD SEE A 10 DEGREE OR MORE SWING IN
TEMPERATURES DEPENDING ON HOW THE PATTERN EVOLVES. FOR NOW FAVORED
THE PROGRESSIVE SOLUTION WHICH WOULD PRODUCE COOLER...NEAR
CLIMO...TEMPERATURES LATE IN THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...VFR EXPECTED THROUGH THE TAF VALID PERIOD WITH ONLY
SCATTERED CIRRUS EXPECTED.
AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BE MOVING ACROSS THE
TERMINALS TODAY. EXPECT WEST TO NORTHWEST WINDS THIS MORNING TO
BECOME SOUTHWEST AT FLO/LBT BY EARLY AFTERNOON...AND SOUTHEAST AT
THE ILM/CRE/MYR TERMINALS MID-LATE AFTERNOON.
THIS EVENING WITH GOOD RADIATIONAL COOLING A LOW-LEVEL INVERSION
WILL QUICKLY SET UP WHICH SHOULD ALLOW FOR WINDS TO BECOME CALM OR
LIGHT AND VARIABLE BY EARLY EVENING. RADIATIONAL COOLING WILL BE
MAXIMIZED AND WILL NEED TO MONITOR THE CRE TERMINAL DURING THE
EARLY EVENING FOR VISIBILITY REDUCTIONS IN BR AS SOME LOW-LEVEL
MOISTURE INCREASE IS LIKELY DUE TO ONSHORE FLOW THIS AFTERNOON.
EXTENDED OUTLOOK...LOW CONFIDENCE FOR FOG WEDNESDAY MORNING. LOW
CONFIDENCE FOR IFR ASSOCIATED WITH PRECIPITATION THURSDAY. VFR
FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 620 AM MONDAY...NO ADVISORIES OR CAUTION FLAGS FOR THE NEAR
TERM.
WINDS ACROSS THE ILM WATERS WILL BE GOVERNED BY SFC HIGH PRESSURE.
THE CENTER OF THIS HIGH TO MIGRATE EAST TO THE COASTAL CAROLINAS
TODAY. IT WILL CONTINUE TO RIDGE BACK ACROSS THE LOCAL WATERS AS IT
MOVES JUST OFFSHORE TONIGHT. WHAT THIS ALL SPELLS IS FOR WINDS TO
DIMINISH TO 10 KT OR LESS WHILE VEERING FROM THE NW TO N BY MID
AFTERNOON VIA THE LATEST HRRR RUNS. FOR TONIGHT...HAVE INDICATED A
DOMINATE SOUTHERLY WIND LESS THAN 10 KT. WOULD NOT BE SURPRISED TO
OBSERVE A VARIABLE WIND DIRECTION AT TIMES TONIGHT DUE TO THE HIGHS
CENTER IN CLOSE PROXIMITY. WAVEWATCH3 INDICATES A LESS THAN 1 FT 9+
SECOND ESE GROUND SWELL TO COMBINE WITH A 2 TO 4 SECOND PERIOD WIND
WAVES...AND PRODUCE SIGNIFICANT SEAS OF 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ELONGATED SURFACE RIDGE AXIS OVER THE WATERS
EARLY TUE WILL SHIFT OFFSHORE DURING TUE. WILL SEE A SLIGHT INCREASE
IS SOUTHWEST FLOW BY AFTERNOON...BUT SPEEDS SHOULD STILL BE NO MORE
THAN 10 KT WITH THE EXCEPTION BEING RIGHT ALONG THE COAST WHERE SEA
BREEZE WILL INCREASE SPEEDS AND LEAD TO ONSHORE FLOW. MUCH THE SAME
STORY EXPECTED FOR WED ALTHOUGH LATE WED/WED NIGHT A COLD FRONT
DROPPING INTO THE CAROLINAS/TN VALLEY WILL PINCH THE GRADIENT A
BIT...BUMPING SOUTHWEST TO 10 TO 15 KT. SEAS AROUND 2 FT TUE WILL
BUILD TO 2 TO 3 FT WED AND A SOLID 3 FT WED NIGHT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...BENIGN CONDITIONS EXPECTED THU AND FRI. LATE THU
SOUTHWEST FLOW MAY TOUCH 15 KT WITH GRADIENT TIGHTENING UP AS WEAK
FRONT INCHES CLOSER. WEAK COLD FRONT MOVES ACROSS THE WATERS EARLY
FRI WITH LIGHT NORTHERLY FLOW DEVELOPING. SEAS BRIEFLY BUILD TO 3 TO
4 FT LATE THU WITH INCREASING SOUTHWEST FLOW BUT DROP BACK TO 2 TO 3
FT ONCE NORTHERLY FLOW SETS UP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/8
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
620 AM EST MON JAN 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ITS EASTWARD PROGRESSION THROUGH THE
SOUTHEAST...MOVING OVERHEAD ON LATER TODAY. THIS HIGH PRESSURE
SYSTEM WILL SHIFT OFF THE COAST BY TUESDAY...MOVING FARTHER OFF
SHORE THROUGH MID WEEK. A COLD FRONT WILL MOVE THROUGH THURSDAY
NIGHT INTO FRIDAY WITH UNSETTLED WEATHER POSSIBLY CONTINUING
THROUGH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 620 AM MONDAY...THE UPPER TROF ACROSS THE FA WILL DE-AMPLIFY
AS IT PUSHES EAST. THIS WILL LEAVE RATHER ZONAL FLOW ALOFT...WITH
FLOW FROM THE W TO WNW DIRECTION...THRU THE ATM COLUMN WITH THE
EXCEPTION IN THE BOUNDARY LAYER. MODELS PROG THE MOVEMENT OF THE SFC
HIGHS RATHER TIGHT CENTER ACROSS THE CAROLINAS TODAY...AND JUST
OFFSHORE FROM THE CAROLINAS TONIGHT. WITH THE SUBSIDENCE...SHOULD
SEE WIDESPREAD DEWPOINTS IN THE 20S WITH A FEW UPPER TEENS POSSIBLE.
PROGGED MEAN RHS THRU THE ATM COLUMN REMAIN QUITE LOW AND WILL
CONTINUE THE CLEAR FORECAST THRUOUT THE NEAR TERM. BASICALLY NEUTRAL
ADVECTION TODAY WITH MODEL MOS GUIDANCE IN GOOD AGREEMENT WITH HIGHS
IN THE UPPER 50S TO LOW 60S. FOR TONIGHT...WAA ALOFT TO DEVELOP AND
CAN BE WITNESSED WITH MODEL 8H TEMPS AND 1K-8H THICKNESSES BOTH
INCREASING. HOWEVER...THE SFC BASED INVERSION DEVELOPING AFTER
SUNSET...WILL RESULT IN WINDS DECOUPLING. THIS WILL PREVENT THE WAA
JUST OFF THE DECK FROM MIXING DOWN TO THE SFC. AS A RESULT...HAVE
GONE BELOW MODEL MOS GUIDANCE WITH TONIGHTS LOWS...WITH LOWS
STRADDLING THE 32 DEGREE MARK AWAY FROM THE COAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...DRY PROGRESSIVE FLOW ALOFT AND SURFACE RIDGING
WILL WORK TO KEEP THE AREA DRY THROUGH THE PERIOD. INITIALLY LOW
LEVEL FLOW IS LIGHT AND VARIABLE BUT BY TUE AFTERNOON THE SURFACE
RIDGE AXIS SHIFTS OFFSHORE AND RETURN FLOW SETS UP. WARM ADVECTION
WILL LEAD TO INCREASING TEMPERATURES AND DEW POINTS...BUT DEEP DRY
AIR KEEPS SKIES NEARLY CLOUD FREE. HIGHS WILL CLIMB INTO THE MID TO
UPPER 60S WITH SOUTHERLY FLOW TUE NIGHT KEEPING LOWS IN THE LOW TO
MID 40S.
WEAK 5H RIDGE BUILDS NORTH WED AS SURFACE RIDGE SHIFTS FARTHER
OFFSHORE. THE 00Z NAM/GFS MOVE AN AREA OF POSITIVE VORTICITY...BORN
OF CONVECTION...NORTH INTO THE SOUTHEAST US AND INTERACT IT WITH
WEAK SHORTWAVE TROUGH EJECTING OUT OF THE WEST. THE ECMWF/CANADIAN
MINIMIZE THE INTERACTION OF THE FEATURE WITH THE WEAK 5H TROUGH AND
MOVE IT EAST ACROSS NORTHERN FL. GIVEN THE KNOWN TENDENCY FOR
CONVECTIVE FEEDBACK WITHIN THE GFS/NAM HAVE CHOSEN TO FAVOR THE
ECMWF/CANADIAN SOLUTIONS. THE RESULT IS A DRY WARM FORECAST WITH
SOME CLOUD COVER SPREADING NORTH LATE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...EXTENDED FORECAST REMAINS CLOUDED IN MYSTERY.
THE 00Z GFS IS NOT SHOWING MUCH CONTINUITY FROM ITS 12Z 1/29 RUN AND
ITS BASICALLY THE SAME STORY FOR THE ECMWF AND THE CANADIAN. AT THIS
POINT CANNOT SEE HOW CONFIDENCE COULD BE ANY LOWER. THE MAIN ISSUE
IS THE EVOLUTION OF THE UPPER PATTERN AND THE IMPACT THIS HAS ON
SHORTWAVE EJECTING FROM THE SOUTHWEST LATE IN THE WEEK. THE 00Z GFS
REMAINS MORE PROGRESSIVE THAN THE 00Z ECMWF/CANADIAN BUT IS SLOWER
AND MORE AMPLIFIED THAN ITS PREVIOUS 12Z RUN. THE 00Z ECMWF NOW
KEEPS THE 5H LOW CUTOFF OVER THE SOUTHWEST WITH 5H RIDGE BUILDING IN
THE EAST...A SOLUTION THE CANADIAN DOES APPEAR TO BE TRENDING TOWARD
AND A PATTERN THAT HAS BEEN SEEN BEFORE THIS WINTER.
NOW LOOKS LIKE FRI WILL END UP DRIER...SO WENT AHEAD AND CUT BACK
POP FRI/FRI NIGHT. COLD FRONT MOVES ACROSS THE AREA THU NIGHT INTO
FRI BUT LACKS ANY SIGNIFICANT COLD ADVECTION. IT ALSO APPEARS A
PORTION OF THE WEEKEND WILL BE WET...FOR NOW THAT LOOKS TO BE SAT
INTO SUN BUT AGAIN WITH SUCH LOW CONFIDENCE CANNOT SEE GOING ABOVE
30 PERCENT AT THIS TIME. TEMPERATURES ABOVE TO WELL ABOVE CLIMO
EARLY IN THE PERIOD...BUT COULD SEE A 10 DEGREE OR MORE SWING IN
TEMPERATURES DEPENDING ON HOW THE PATTERN EVOLVES. FOR NOW FAVORED
THE PROGRESSIVE SOLUTION WHICH WOULD PRODUCE COOLER...NEAR
CLIMO...TEMPERATURES LATE IN THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...VFR EXPECTED THROUGH THE TAF VALID PERIOD WITH ONLY
SCATTERED CIRRUS EXPECTED.
AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BE MOVING ACROSS THE
TERMINALS TODAY. EXPECT WEST TO NORTHWEST WINDS THIS MORNING TO
BECOME SOUTHWEST AT FLO/LBT BY EARLY AFTERNOON...AND SOUTHEAST AT
THE ILM/CRE/MYR TERMINALS MID-LATE AFTERNOON.
THIS EVENING WITH GOOD RADIATIONAL COOLING A LOW-LEVEL INVERSION
WILL QUICKLY SET UP WHICH SHOULD ALLOW FOR WINDS TO BECOME CALM OR
LIGHT AND VARIABLE BY EARLY EVENING. RADIATIONAL COOLING WILL BE
MAXIMIZED AND WILL NEED TO MONITOR THE CRE TERMINAL DURING THE
EARLY EVENING FOR VISIBILITY REDUCTIONS IN BR AS SOME LOW-LEVEL
MOISTURE INCREASE IS LIKELY DUE TO ONSHORE FLOW THIS AFTERNOON.
EXTENDED OUTLOOK...LOW CONFIDENCE FOR FOG WEDNESDAY MORNING. LOW
CONFIDENCE FOR IFR ASSOCIATED WITH PRECIPITATION THURSDAY. VFR
FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 620 AM MONDAY...NO ADVISORIES OR CAUTION FLAGS FOR THE NEAR
TERM.
WINDS ACROSS THE ILM WATERS WILL BE GOVERNED BY SFC HIGH PRESSURE.
THE CENTER OF THIS HIGH TO MIGRATE EAST TO THE COASTAL CAROLINAS
TODAY. IT WILL CONTINUE TO RIDGE BACK ACROSS THE LOCAL WATERS AS IT
MOVES JUST OFFSHORE TONIGHT. WHAT THIS ALL SPELLS IS FOR WINDS TO
DIMINISH TO 10 KT OR LESS WHILE VEERING FROM THE NW TO N BY MID
AFTERNOON VIA THE LATEST HRRR RUNS. FOR TONIGHT...HAVE INDICATED A
DOMINATE SOUTHERLY WIND LESS THAN 10 KT. WOULD NOT BE SURPRISED TO
OBSERVE A VARIABLE WIND DIRECTION AT TIMES TONIGHT DUE TO THE HIGHS
CENTER IN CLOSE PROXIMITY. WAVEWATCH3 INDICATES A LESS THAN 1 FT 9+
SECOND ESE GROUND SWELL TO COMBINE WITH A 2 TO 4 SECOND PERIOD WIND
WAVES...AND PRODUCE SIGNIFICANT SEAS OF 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ELONGATED SURFACE RIDGE AXIS OVER THE WATERS
EARLY TUE WILL SHIFT OFFSHORE DURING TUE. WILL SEE A SLIGHT INCREASE
IS SOUTHWEST FLOW BY AFTERNOON...BUT SPEEDS SHOULD STILL BE NO MORE
THAN 10 KT WITH THE EXCEPTION BEING RIGHT ALONG THE COAST WHERE SEA
BREEZE WILL INCREASE SPEEDS AND LEAD TO ONSHORE FLOW. MUCH THE SAME
STORY EXPECTED FOR WED ALTHOUGH LATE WED/WED NIGHT A COLD FRONT
DROPPING INTO THE CAROLINAS/TN VALLEY WILL PINCH THE GRADIENT A
BIT...BUMPING SOUTHWEST TO 10 TO 15 KT. SEAS AROUND 2 FT TUE WILL
BUILD TO 2 TO 3 FT WED AND A SOLID 3 FT WED NIGHT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...BENIGN CONDITIONS EXPECTED THU AND FRI. LATE THU
SOUTHWEST FLOW MAY TOUCH 15 KT WITH GRADIENT TIGHTENING UP AS WEAK
FRONT INCHES CLOSER. WEAK COLD FRONT MOVES ACROSS THE WATERS EARLY
FRI WITH LIGHT NORTHERLY FLOW DEVELOPING. SEAS BRIEFLY BUILD TO 3 TO
4 FT LATE THU WITH INCREASING SOUTHWEST FLOW BUT DROP BACK TO 2 TO 3
FT ONCE NORTHERLY FLOW SETS UP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1122 AM CST MON JAN 30 2012
.DISCUSSION...
ISSUED 1000 AM CST MON JAN 30 2012
AREA OF MID-LEVEL CLOUDINESS IS NOW GENERALLY NORTH OF A MACOMB TO
EFFINGHAM LINE. LATEST RUC GUIDANCE SHOWING THESE TO RECEDE
ACROSS THE NORTHERN CWA THROUGH EARLY AFTERNOON AS A WARM FRONT
LIFTS NORTHWARD ACROSS THE AREA. HOWEVER...WILL CONTINUE TO SEE
SOME PERIODIC HIGH CLOUDS OVER THE CWA THROUGH THE AFTERNOON.
CURRENT TRENDS SHOWING THAT FORECAST HIGH TEMPERATURES ARE ON
TARGET...WITH THE ONLY AREA OF CONCERN AROUND PEORIA AND
BLOOMINGTON WHERE ABOUT AN INCH OF SNOW STILL REMAINS ON THE
GROUND. WIND GUSTS WILL BE INCREASING THROUGH THE DAY...AS A
STRONG SOUTHWEST LOW-LEVEL JET AROUND 45 KNOTS STARTS MIXING DOWN
WHEN THE SUNSHINE BECOMES MORE DOMINANT.
UPDATED GRIDS HAVE BEEN SENT TO INCORPORATE THE RECENT HOURLY
TRENDS. WILL SEND OUT A ZONE UPDATE CLOSER TO NOON...PRIMARILY TO
UPDATE THE SKY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1122 AM CST MON JAN 30 2012
BULK OF THE MID-LEVEL CLOUDINESS HAS MOVED NORTHEAST OF THE TAF
SITES LATE THIS MORNING. THE LOW-LEVEL JET HAS BEGUN MIXING TOWARD
THE SURFACE...AS EVIDENCED BY DECREASING SPEEDS ON THE LOWEST
GATES OF THE 88D/WIND PROFILER NETWORK AND AREA AMDAR SOUNDINGS...
WITH SURFACE GUSTS OF 20-25 KNOTS BECOMING MORE COMMON OVER THE
LAST HOUR OR TWO. THINK THIS TREND WILL CONTINUE THROUGH THE
AFTERNOON...SO HAVE REMOVED LLWS MENTION FOR THE AFTERNOON.
HOWEVER...SOUNDINGS ARE PROMINENTLY WITH LLWS RETURNING SHORTLY
AFTER SUNSET...AND LASTING MOST OF THE NIGHT...SO WILL KEEP THE
LLWS ALREADY IN THE TAFS FOR THAT PERIOD.
LOW-LEVEL MOISTURE WILL BE SURGING NORTHEASTWARD LATE IN THE
NIGHT...AHEAD OF AN APPROACHING COLD FRONT FROM THE WEST. WILL
MENTION CEILINGS IN THE 3500 FOOT RANGE FOR THE LATTER PORTIONS OF
THE PERIOD. HOWEVER...HAVE SOME CONCERNS FOR POTENTIAL MVFR
CONDITIONS AROUND KPIA/KBMI...WHERE THERE WILL BE SOME MELTING
SNOW TODAY TO ADD MOISTURE TO THE LOWER LEVELS. SOUNDINGS OFF THE
NAM MODEL HINT AT SOME CEILINGS AS LOW AS 1000 FEET FOR A FEW
HOURS TUESDAY MORNING. CONFIDENCE IS NOT PARTICULARLY HIGH AT THIS
TIME...SO WILL ONLY MENTION A SCATTERED LAYER AROUND THAT LEVEL
FOR NOW AND CONTINUE TO MONITOR.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 251 AM CST MON JAN 30 2012
MAIN CONCERNS WITH THIS FORECAST PACKAGE WILL BE RAIN CHANCES LATE
TUESDAY...THEN POTENTIAL FOR WINTRY PRECIP BY NEXT WEEKEND.
08Z SURFACE ANALYSIS SHOWS WARM FRONT EXTENDING FROM THE NORTHERN
PLAINS INTO THE OHIO RIVER VALLEY. TEMPERATURES AHEAD OF THE
BOUNDARY ACROSS THE UPPER MIDWEST/GREAT LAKES ARE CURRENTLY IN THE
TEENS AND 20S...WHILE READINGS BEHIND THE FRONT ACROSS THE CENTRAL
PLAINS ARE IN THE 40S. ALOFT...ZONAL FLOW PATTERN CONTINUES TO
DOMINATE ACROSS THE CONUS...KEEPING THE BITTERLY COLD POLAR AIRMASS
BOTTLED UP WELL TO THE NORTH ACROSS ALASKA AND NORTHERN CANADA.
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT WILL LIFT NORTHWARD TODAY...ALLOWING WINDS TO VEER TO THE
SOUTHWEST AND MUCH WARMER AIR TO FLOW INTO CENTRAL ILLINOIS. BAND OF
MID-LEVEL CLOUDINESS ASSOCIATED WITH THE FRONT WILL ENSURE A MOSTLY
CLOUDY MORNING...HOWEVER SKIES WILL BECOME MOSTLY SUNNY BY
AFTERNOON. THANKS TO AMPLE LATE DAY SUNSHINE AND SOUTHWESTERLY WINDS
GUSTING TO BETWEEN 25 AND 30 MPH...HIGH TEMPS WILL SOAR WELL INTO
THE 50S.
SHORT-WAVE TROUGH CURRENTLY EVIDENT ON WATER VAPOR IMAGERY OVER THE
PACIFIC NORTHWEST WILL TRACK EASTWARD ALONG THE US/CANADIAN
BORDER...ARRIVING IN THE NORTHERN GREAT LAKES BY TUESDAY EVENING.
TRAILING COLD FRONT WILL REMAIN WEST OF THE MISSISSIPPI RIVER
THROUGH THE DAY TUESDAY...ALLOWING SOUTHWESTERLY FLOW TO CONTINUE
ACROSS CENTRAL ILLINOIS. INCREASING FETCH OF LOW-LEVEL MOISTURE OFF
THE WESTERN GULF OF MEXICO WILL RESULT IN CLOUDY SKIES...HOWEVER
CONTINUED WAA WILL ALLOW TEMPS TO RISE A FEW DEGREES HIGHER THAN
TODAY...WITH AFTERNOON HIGHS TOPPING THE 60 DEGREE MARK ACROSS MOST
LOCATIONS SOUTH OF THE I-72 CORRIDOR. MODELS TRY TO SQUEEZE OUT SOME
LIGHT QPF DURING THE AFTERNOON...HOWEVER FORECAST SOUNDINGS DO NOT
FULLY MOISTEN THROUGHOUT THE PROFILE...SO DO NOT THINK WIDESPREAD
PRECIP IS LIKELY. HAVE INCLUDED JUST A SLIGHT CHANCE POP ACROSS THE
WESTERN KILX CWA TUESDAY AFTERNOON AS THE FRONT APPROACHES FROM THE
WEST. DEEPER MOISTURE GRADUALLY ARRIVES FROM THE SOUTH TUESDAY
EVENING...RESULTING IN SHOWERS INCREASING IN AREAL COVERAGE AHEAD OF
THE COLD FRONT...MAINLY ACROSS EAST-CENTRAL AND SOUTHEAST ILLINOIS.
HAVE THEREFORE HIT RAIN CHANCES HARDEST ALONG AND EAST OF
I-57...WHERE LIKELY POPS ARE IN ORDER. FURTHER WEST...RAIN CHANCES
STEADILY DECREASE...WITH ONLY SLIGHT CHANCES ACROSS THE ILLINOIS
RIVER VALLEY.
COLD FRONT WILL SETTLE FURTHER SOUTHWARD ON WEDNESDAY...AS SURFACE
RIDGE BUILDS IN FROM THE NORTHWEST. SHORT-WAVE TROUGH TRACKING
EASTWARD OUT OF THE PLAINS WILL LIKELY ENHANCE PRECIP ALONG/NORTH OF
THE BOUNDARY...HOWEVER IT APPEARS ANY RAIN WILL STAY SOUTH OF
ILLINOIS ACROSS THE OHIO RIVER VALLEY. AS A RESULT...HAVE GONE WITH
A DRY FORECAST ON WEDNESDAY...WITH SLIGHTLY COOLER TEMPS IN THE
UPPER 40S/LOWER 50S.
LONG TERM...THURSDAY THROUGH SUNDAY
AFTER SOME RECENT MODEL DISCREPANCIES...00Z 30 JAN SUITE HAS COME
INTO GOOD AGREEMENT FOR THURSDAY/FRIDAY TIME FRAME. WITH BAROCLINIC
ZONE EXPECTED TO BE WELL SOUTH OF THE REGION...DRY WEATHER WILL
PREVAIL THROUGH THE END OF THE WORK WEEK. AFTER THAT...MODEL
SOLUTIONS DIVERGE SOMEWHAT FOR THE WEEKEND AS STRONG RIDGE BUILDS
OVER THE WESTERN CONUS AND CORRESPONDING TROUGH DEVELOPS ACROSS THE
EAST. STILL LOOKS LIKE A MARKED COOLING TREND ARRIVING BY SATURDAY
AND SUNDAY...WITH TEMPS RETURNING TO NEAR NORMAL IN THE 30S. MAIN
QUESTION WILL BE HOW FAR NORTH A DEVELOPING SURFACE LOW WILL
TRACK...AND WILL IT BRING SNOW TO PARTS OF CENTRAL ILLINOIS. GFS IS
THE FURTHEST NORTH WITH THE LOW...SPREADING SNOW ACROSS THE SOUTHERN
TWO-THIRDS OF THE KILX CWA FRIDAY NIGHT AND SATURDAY. CANADIAN/ECMWF
ARE A BIT FURTHER SOUTH...BUT STILL BRING PRECIP INTO AT LEAST THE
FAR SE. STILL QUITE A BIT OF TIME TO WORK OUT THE DETAILS...BUT FOR
NOW...IT APPEARS COLDER WEATHER AND SOME SNOW ARE ON THE WAY FOR NEXT
WEEKEND.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
306 PM CST MON JAN 30 2012
.DISCUSSION...
21Z WATER VAPOR IMAGERY SHOWS A SHORTWAVE MOVING ACROSS MT AND ID
AND INTO THE NORTHERN PLAINS. MEANWHILE SURFACE OBS SHOW A BROAD
TROUGH OF LOW PRESSURE FROM THE SOUTHERN HIGH PLAINS INTO THE
NORTHERN PLAINS. THIS HAS ALLOWED FOR HIGHS TO WARM INTO THE MID
AND UPPER 60S WHILE DEWPOINTS INCREASED INTO THE 30S ACROSS THE
FORECAST AREA.
FOR TONIGHT AND TUESDAY...THE MAIN CONCERN IS WHAT THE STRONG
MOISTURE ADVECTION WILL DO OVERNIGHT AND EARLY TUESDAY MORNING.
MODELS ARE KEEPING THE FORCING FROM THE NORTHERN PLAINS SHORTWAVE TO
THE NORTH OF THE FORECAST AREA...AND A DECENT ELEVATED MIXED LAYER
IS PROGGED TO KEEP THE BOUNDARY LAYER CAPPED. THEREFORE CHANCES FOR
MEASURABLE PRECIP LOOK PRETTY SLIM AS A COLD FRONT ASSOCIATED WITH
THE NORTHERN PLAINS WAVE PUSHES THROUGH THE AREA DURING THE DAY
TUESDAY. HOWEVER LOW LEVEL MOISTURE IS EXPECTED TO CONTINUE TO
ADVECT NORTH INTO EASTERN KS THROUGH THE NIGHT WITH READINGS
POSSIBLY IN THE MID 40S BY SUNRISE. THE LATEST RUC AND NAM FORECAST
SOUNDINGS CONTINUE TO SHOW THE BOUNDARY LAYER SATURATING BY 12Z
AHEAD OF THE SFC COLD FRONT. THERE ALSO APPEARS TO BE SOME WEAK LIFT
ON THE 285K ISENTROPIC SFC AHEAD OF THE FRONT. THEREFORE DID NOT SEE
ANY REASON TO CHANGE THE MENTION OF FOG AND DRIZZLE FROM THE
PREVIOUS FORECAST. WINDS SHOULD STAY UP FAVORING MORE STRATUS THAN
FOG SO DO NOT ANTICIPATE THERE BEING A SEVERE RESTRICTION TO
VISIBILITIES AT THIS TIME. OVERNIGHT LOWS WILL BE MILD DUE TO THE
WARM AIR AND MOISTURE MOVING NORTH. FOR HIGHS TUESDAY...THE MODELS
ARE MIXING THE BOUNDARY LAYER TO AT LEAST 900 MB WITH NOT A WHOLE
LOT OF COLD AIR BEHIND THE FRONT. BECAUSE OF THIS...HAVE BUMPED HIGHS
UP INTO THE UPPER 50S AND AROUND 60 THINKING THERE SHOULD BE ENOUGH
INSOLATION IN THE AFTERNOON TO HELP TEMPS WARM.
WOLTERS
FOR TUESDAY NIGHT THROUGH THURSDAY...MID AND HIGH LEVEL CLOUDS COULD
BE RATHER PERSISTENT...WITH A BRIEF BREAK LATE WEDNESDAY...WITH MID
AND LOW LEVELS STILL ON THE DRY SIDE BEHIND THE COLD FRONT. AS
MENTIONED ABOVE...AIRMASS COMING IN BEHIND IS ONLY SLIGHTLY COOLER
THAN TUESDAY...BUT MIXING WILL BE MORE LIMITED FOR WEDNESDAY SO
EXPECT SOMEWHAT COOLER TEMPS. FAVORING THE MORE-AGREED-UPON SLOWER
MODELS OVER THE NAM FOR THURSDAY...WITH WEAK MID LEVEL WARM AIR
ADVECTION BRINGING IN DEEPENING HIGH CLOUDS THURSDAY AFTERNOON AS
THE WESTERN UPPER TROF DIGS INTO THE ROCKIES. TEMPS IN THE LOW TO
MID 50S STILL EXPECTED UNDER EASTERLY WINDS.
MEDIUM RANGE MODELS CONTINUE TO COME TOGETHER WITH THE UPPER TROF AT
LEAST PARTIALLY CUTTING OFF FROM THE FLOW FOR THE LATE WEEK AND
WEEKEND PERIODS. OF COURSE ANY SPECIFICS ARE FAR FROM CERTAIN...BUT
PRECIPITATION FALLING ON MOST LOCATIONS AT LEAST ONCE IN THIS PERIOD
IS BECOMING A GOOD BET. STILL APPEARS TEMPS MAY BE COLD ENOUGH TO
SUPPORT SOME SNOW...BUT AGAIN MUCH TO BE DETERMINED HERE. OVERALL
TEMPS NOT EXPECTED TO STRAY FAR FROM EARLY FEBRUARY NORMALS.
65
&&
.AVIATION...
DRY MID LEVELS AND NO REAL FORCING WILL LEAD TO VFR CONDITIONS
TODAY. SFC OBS ACROSS THE SOUTHERN PLAINS SHOWS THE MOISTURE
ADVECTION IS UNDERWAY. DUE TO GOOD CONSISTENCY IN THE MODELS SHOWING
THE BOUNDARY LAYER SATURATING EARLY TUESDAY MORNING...HAVE GONE
AHEAD AND INTRODUCED SOME MVFR CIGS IN THE TAFS FOR TOP AND FOE. MHK
LOOKS TO BE ON THE WESTERN EDGE OF THE LOW LEVEL TONGUE OF
MOISTURE. LATER SHIFTS WILL NEED TO LOOK AND SEE IF THE STRATUS
COMES IN BELOW 1 KFT.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
313 PM EST MON JAN 30 2012
.SYNOPSIS...
WITH A WARM FRONT HAVING GONE NORTH TO THE GREAT LAKES, EXPECT DRY
AND MILD CONDITIONS TONIGHT AND TUESDAY. A WEAK COLD FRONT, COMING
SOUTHEAST FROM THE CANADIAN ROCKIES, WILL BRING RAIN SHOWERS LATE
TUESDAY NIGHT AND WEDNESDAY, WITH TEMPERATURES RETURNING TO
SEASONABLE LEVELS.
&&
.NEAR TERM /THROUGH TUESDAY/...
RECENT SATELLITE DATA SHOWS THICK CLOUDS, ASSOCIATED WITH A
NORTHWARD-MOVING WARM FRONT, PASSING EASTWARD ACROSS THE I-80
CORRIDOR THIS EVENING, SO HAVE MAINTAINED MENTION OF ISOLATED
FLURRIES FOR THAT AREA.
THE REST OF THE UPPER OHIO VALLEY CAN EXPECT CLOUDS TO DECREASE
OVERNIGHT. WITH THE UPPER OHIO VALLEY IN THE SO-CALLED WARM SECTOR
DAYTIME TUESDAY, EXPECT THERE TO MORE FREQUENT PERIODS OF
SUNSHINE.
FORECASTED TEMPERATURES FOR TONIGHT, USING BLEND OF HRRR AND GFS
LAMP MODEL OUTPUT. THIS SHOWED TEMPERATURES WILL ONLY DROP A
COUPLE DEGREES OVERNIGHT, MAKING LOWS AT LEAST 10 DEGREES WARMER
THAN NORMAL.
FOR TEMPERATURES TUESDAY, RELIED MORE ON NAM AND GFS MOS OUTPUT
WHICH SHOWED AFTERNOON HIGHS CAN BE UP TO 15-20 DEGREES WARMER
THAN NORMAL.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A LOW PRESSURE SYSTEM,
COMING SOUTHEAST FROM ALBERTA, PUSHING A COLD FRONTAL BAND OF SHOWERS
THROUGH THE UPPER OHIO VALLEY LATE TUESDAY NIGHT AND WEDNESDAY
MORNING. IN THE PREFRONTAL SOUTHWEST FLOW, BLEND OF GFS AND NAM
MOS SHOWED LOW TEMPERATURES TUESDAY NIGHT CAN BE WARMER THAN
NORMAL JANUARY HIGHS.
WITH THE UPPER LEVEL JETSTREAM BECOMING MORE WESTERLY MID-WEEK,
EXPECT A WEAK POST FRONTAL COOL DOWN WEDNESDAY AFTERNOON. HENCE FORECASTED
TEMPERATURES WEDNESDAY, AGAIN USING BLEND OF GFS AND NAM MOS, TO
YIELD EARLY AFTERNOON HIGHS UP TO 15 DEGREES WARMER THAN NORMAL.
THERE CAN BE LINGERING COLD POOL STRATOCUMULUS WEDNESDAY NIGHT AND THURSDAY,
WITH PERHAPS A MIX OF LIGHT RAIN AND SNOW SHOWERS ACROSS ON THE
WINDWARD SLOPES OF THE MOUNTAINS.
GFS AND NAM MOS SHOWED TEMPERATURES THURSDAY NOT AS WARM AS
WEDNESDAY, BUT STILL 5-8 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THIS PERIOD REMAINS DIFFICULT DESPITE COMMON
LONG WAVE PATTERN SIMILARITIES BETWEEN THE DETERMINISTIC MODELS.
AS HAS BEEN THE CASE OVER THE LAST FEW DAYS...A DEEP POSITIVELY
TILTED TROUGH WILL DEVELOP OVER THE EASTERN EDGE OF THE
ROCKIES...WITH A STRONG FOLD-OVER RIDGE OVER THE WESTERN U.S.
WHERE THE MODELS DIFFER IS IN TIMING. SOME OF THE MODELS SUGGEST
THAT THE LOW WILL REMAIN ESSENTIALLY CUTOFF FROM THE REST OF THE
FLOW WHILE OTHERS EJECT THE LOW EASTWARD FAIRLY QUICKLY. THE SPLIT
FLOW PATTERN IS WHAT IS MAKING THE SMALLER SHORTWAVE TIMING AND
PLACEMENT DIFFICULT.
HAVE OPTED TO REMAIN CLOSEST TO HPC AND IN TURN ACCOUNT FOR GENERAL
SHORTWAVE PATTERN SIMILARITIES BETWEEN THE 00Z ECMWF AND 06/12Z GFS
THROUGH THE PERIOD. MAINTAINED ONLY LOW CHANCE POPS THROUGH MOST OF
THE PERIOD WITH SUCH MODEL UNCERTAINTY AND TEMPERATURES CLOSE TO AN
HPC/MEX BLEND.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE SOUTH TODAY. SOME MID-LEVEL CLOUDS
ASSOCIATED WITH A WARM FRONT WILL CROSS THE AREA THIS AFTERNOON AND
TONIGHT.
WINDS MAY GUSTS OUT OF THE S-SW TO 20KTS THIS AFTERNOON BUT
GENERALLY JUST MAINTAINED HIGHER WIND SPEEDS AT ALL SITES. WINDS
WILL DIMINISH TONIGHT. HOWEVER...MENTIONED LOW LEVEL WIND SHEAR AS
NAM MODEL PROFILES SHOW A STABLE SURFACE LAYER WITH WINDS INCREASING
TO OVER 45 KTS ABOVE 2 KFT AGL.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL CONTINUE TUESDAY EVENING. A COLD FRONTAL BAND
OF SHOWERS WILL PROVIDE RESTRICTIONS LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. POST FRONTAL STRATOCUMULUS MAY CAUSE CEILING
RESTRICTIONS TO LINGER INTO THURSDAY. VFR CONDITIONS WILL RETURN TO
THE TERMINALS ON FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1200 PM EST MON JAN 30 2012
.SYNOPSIS...
EASTBOUND HIGH PRESSURE, WILL PROVIDE DRY CONDITIONS AND
SEASONABLE TEMPERATURES TODAY, BUT A PLEASANT WARM UP ON TUESDAY. A
COLD FRONT WILL BRING SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY
WITH TEMPERATURES RETURNING TO SEASONABLE LEVELS.
&&
.NEAR TERM /THROUGH TUESDAY/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA, COUPLED WITH HRRR
AND NAM MODEL OUTPUT, HAVE DECREASED POTENTIAL FOR WARM FRONTAL
PRECIPITATION ACROSS THE I-80 CORRIDOR TO NO MORE THAN ISOLATED
FLURRIES LATE THIS AFTERNOON AND EARLY TONIGHT.
THE REST OF THE UPPER OHIO VALLEY CAN ENTERTAIN AN INCREASE IN
HIGH CLOUDS, BUT STILL EXPECT PARTLY SUNNY CONDITIONS THIS
AFTERNOON. WITH THE UPPER OHIO VALLEY IN THE SO-CALLED WARM SECTOR
DAYTIME TUESDAY, EXPECT THERE TO MORE FREQUENT PERIODS OF
SUNSHINE.
FORECASTED TEMPERATURES USING BLEND OF HRRR AND GFS LAMP MODEL
OUTPUT FOR THIS AFTERNOON, WHICH YIELDED NEAR NORMAL VALUES.
RELIED MORE ON NAM AND GFS MOS OUTPUT FOR TONIGHT AND DAYTIME
TUESDAY, WHICH SHOWED VALUES UP TO 15-20 DEGREES WARMER THAN
NORMAL.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A LOW PRESSURE SYSTEM,
COMING SOUTHEAST FROM ALBERTA, PUSHING A COLD FRONTAL BAND OF SHOWERS
THROUGH THE UPPER OHIO VALLEY LATE TUESDAY NIGHT AND WEDNESDAY
MORNING. IN THE PREFRONTAL SOUTHWEST FLOW, BLEND OF GFS AND NAM
MOS SHOW LOWS TEMPERATURES TUESDAY NIGHT CAN BE WARMER THAN NORMAL
JANUARY HIGHS.
WITH THE UPPER LEVEL JETSTREAM BECOMING MORE WESTERLY MID-WEEK,
EXPECT A WEAK POST FRONTAL COOL DOWN WEDNESDAY AFTERNOON. HENCE FORECASTED
TEMPERATURES WEDNESDAY, AGAIN USING BLEND OF GFS AND NAM MOS, TO
YIELD EARLY AFTERNOON HIGHS UP TO 15 DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS WAS THE CASE YESTERDAY...MODELS CONTINUE TO HAVE TROUBLE
RESOLVING THE PLACEMENT AND TIMING OF SYSTEMS DURING THIS PERIOD.
WHILE ALL THE MODELS CONTINUE TO SUGGEST A DEEPENING LONG WAVE
PATTERN...WITH A STRONG RIDGE OVER THE WESTERN U.S AND A DEEP TROUGH
OVER THE EASTERN U.S...THE SHORTWAVE PATTERN AND IN TURN LOW
PLACEMENT REMAINS INCONSISTENT FROM RUN TO RUN.
IN GENERAL...MODELS SUGGEST THAT THE COLD FRONT...PROGGED TO CROSS
THE OHIO VALLEY DURING THE DAY WEDNESDAY...WILL HANG UP AROUND THE
MASON-DIXON LINE AND EVENTUALLY MOVE NORTHWARD AS A WARM FRONT. THE
QUESTION IS WHEN AND HOW FAR NORTH WILL THE SYSTEM MAKE IT AT THIS
POINT.
CONTINUED TO REMAIN CLOSE TO HPC GUIDANCE WITH ONLY LOW CHANCE POPS
THROUGH MOST OF THE PERIOD WITH SUCH MODEL UNCERTAINTY AND
TEMPERATURES CLOSE TO AN HPC MEX BLEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE SOUTH TODAY. MID-LEVEL CLOUDS WILL
CROSS THE AREA THIS AFTERNOON.
SOUTHWESTERLY WINDS CAN GUST TO 20KTS AT KFKL/KDUJ. WINDS WILL
DIMINISH TONIGHT AS MID-LEVEL CLOUDS CONTINUE TO FILTER ACROSS THE
TERMINALS. AM CONSIDERING MENTION OF LOW LEVEL WIND SHEAR TONIGHT,
AS NAM MODEL PROFILES SHOW A STABLE SURFACE LAYER TONIGHT WITH
WINDS INCREASING TO OVER 40 KTS ABOVE 2 KFT AGL.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
VFR CONDITIONS WILL CONTINUE TUESDAY EVENING. A COLD FRONTAL BAND
OF SHOWERS WILL PROVIDE RESTRICTIONS LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. POST FRONTAL STRATOCUMULUS MAY CAUSE CEILING
RESTRICTIONS TO LINGER INTO THURSDAY. VFR CONDITIONS WILL RETURN
TO THE TERMINALS ON FRIDAY AS HIGH PRESSURE BUILDS INTO THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1209 PM CST MON JAN 30 2012
.DISCUSSION...
/323 AM CST MON JAN 30 2012/
MAIN CONCERNS ARE WELL ABOVE NORMAL TEMPERATURES THE NEXT TWO DAYS AND
THEN CHANCES FOR SNOW LATE THIS WEEK INTO NEXT WEEKEND.
STILL BELIEVE WE WILL BE IN RECORD TEMPERATURE TERRITORY TODAY GIVEN
THE MOSTLY SUNNY SKIES AND SOUTHWEST WINDS WHICH ARE TYPICALLY A
WARM UP WIND. RUC SOUNDINGS DO SHOW AN INVERSION AROUND 900MB
WHICH WILL LIMIT MIXING HEIGHTS TODAY...HOWEVER THE TEMPERATURES
AT THIS LEVEL WILL BE AROUND +10C WHICH STILL FAVORS HIGHS
REACHING THE LOWER TO MIDDLE 60S OVER MUCH OF THE AREA. THESE
VALUES MATCH THE MOS TEMPS REASONABLY WELL. SURFACE PRESSURE
GRADIENT WILL REMAIN TIGHT ENOUGH TONIGHT TO PREVENT MUCH OF A DROP
OFF IN WIND SPEED...AND HENCE SHOULD KEEP LOWS FROM FALLING MUCH
BELOW NORMAL DAYTIME HIGHS FOR THE END OF JANUARY. THE WARM START
TOMORROW WILL FAVOR TEMPERATURES CLIMBING CLOSE THE AGREEABLE MOS
NUMBERS.
MODELS STILL SHOW THAT LOW LEVEL MOISTURE WILL STREAM NORTHWARD
INTO OUR AREA TOMORROW...SO SHOULD SEE AN INCREASE IN MOISTURE AND
CLOUDS. DID GO WITH SPOTTY DRIZZLE OVER CENTRAL MO INTO WEST
CENTRAL IL WHERE MODEL CROSS SECTIONS ARE SHOWING DEEP LOW LEVEL
MOISTURE WITH SOME WEAK ASCENT. BETTER CHANCE OF MEASURABLE RAIN
WILL OCCUR TUESDAY NIGHT FROM SOUTHEASTERN MO INTO SOUTHERN IL
WHEN THERE WILL BE SOME MODEST LARGE SCALE ASCENT ON THE TAIL END
OF A GREAT LAKES TROUGH.
THERE IS SLIGHTLY BETTER CONTINUITY AND AGREEMENT BETWEEN THE GFS/
ECMWF/CANADIAN GEM THAN 24 HOURS AGO...THOUGH THERE ARE STILL
ENOUGH DIFFERENCES TO MAKE FOR A LOW CONFIDENCE FORECAST FOR LATE
WEEK INTO NEXT WEEKEND. WITH THIS SAID...IT DOES LOOK LIKE THERE
WILL BE A STORM SYSTEM MOVING ACROSS MO/IL EARLY NEXT WEEKEND THAT
WILL HAVE ENOUGH COLD AIR TO PROVIDE AT LEAST A MIX OF RAIN/SNOW
ON FRIDAY NIGHT AND SATURDAY. 00Z OPERATIONAL GFS DEPICTS A
DEFORMATION ZONE THAT WOULD PRODUCE A BAND OF SNOW OVER THE
CENTRAL PART OF THE CWA DURING THIS PERIOD...BUT IT IS FASTER AND
MORE NORTH WITH THIS SYSTEM THAN THE OTHER MODELS...INCLUDING MOST
OF THE GFS ENSEMBLE MEMBERS. FOR NOW WILL JUST MENTION A CHANCE OF
RAIN AND SNOW AND SEE WHAT FUTURE MODELS RUNS DEPICT.
BRITT/KANOFSKY
&&
.AVIATION...
/1154 AM CST MON JAN 30 2012/
PRIMARY CONCERN TODAY WILL BE CROSSWINDS WITH PERSISTENT SOUTHWEST
FLOW GUSTING TO 25KTS. GUSTS WILL SUBSIDE THIS EVENING BUT WIND
WILL STAY BETWEEN 12-15KTS. WIND WILL INCREASE WITH HEIGHT TO
AROUND 40-45KTS FROM THE WEST-SOUTHWEST AT AROUND 2000FT...BUT
INCREASE SHOULD BE GRADUAL ENOUGH THAT LLWS SHOULD BE MARGINAL AT
WORST. MOISTURE FROM THE GULF WILL EVENTUALLY MAKE IT UP INTO THE
REGION TUESDAY MORNING AND AM EXPECTING A STRATUS DECK TO MOVE IN
BETWEEN 10Z-14Z AND OVERSPREAD THE AREA. UNSURE WHAT THE HEIGHT OF
THE DECK WILL BE AT THIS TIME BUT MOST LIKELY HEIGHT LOOKS TO BE
BETWEEN 2500-3500FT.
SPECIFICS FOR KSTL...
VFR FLIGHT CONDITIONS WILL PREVAIL AT LAMBERT THIS
AFTERNOON...HOWEVER SOUTHWEST FLOW RIGHT AROUND 210 DEGREES WILL
PRODUCE A DIRECT CROSSWIND ACROSS THE MAIN RUNWAYS. GUSTS WILL
SUBSIDE THIS EVENING BUT WIND WILL STAY BETWEEN 12-15KTS. WIND
WILL INCREASE WITH HEIGHT TO AROUND 40-45KTS FROM THE WEST-
SOUTHWEST AT AROUND 2000FT...BUT INCREASE SHOULD BE GRADUAL ENOUGH
THAT LLWS SHOULD BE MARGINAL AT WORST. EXPECTING A STRATUS DECK
TO MOVE IN BETWEEN AFTER 12Z AND OVERSPREAD THE AREA. TIMING AND
HEIGHT OF THE DECK IS STILL UNCERTAIN BUT MOST LIKELY HEIGHT
LOOKS TO BE BETWEEN 3500-4000FT WITH TIMING AROUND 15Z. COULD SEE
SOME LIGHT RAIN DEVELOP LATE TUESDAY AFTERNOON OR EARLY
EVENING...BUT THE BEST CHANCE OF PRECIP WILL BE EAST OF THE TERMINAL.
CARNEY
&&
.FIRE WEATHER...
WILL MENTION AN INCREASED FIRE DANGER TODAY OVER PARTS OF CENTRAL
AND SOUTHEAST MISSOURI. NOT MUCH CHANGE TO PREVIOUS FORECAST
THINKING. SOUTHWEST WINDS WILL BRING IN SLIGHTLY MORE MOISTURE
THROUGH THE DAY...BUT TEMPERATURES NEARING RECORDS WILL STILL
FORCE MINIMUM RELATIVELY HUMIDITY VALUES INTO THE 25-30 PERCENT
RANGE. THIS SAME AREA WILL ALSO HAVE SUSTAINED 20FT WINDS IN THE
10-15 MPH RANGE WITH HIGHER GUSTS. TEN HOUR FUELS WILL LIKELY FALL
BELOW 10 PERCENT IN THIS SAME AREA. HOWEVER AS MENTIONED IN THE
PREVIOUS DISCUSSION...RECENT COLLABORATION WITH THE USFS SUGGESTS
THAT DEAD FUELS MAY BE DRY ON TOP...BUT BE DAMP JUST BELOW THE
SURFACE WHICH WOULD GREATLY REDUCE THE RISK OF UNCONTROLLED FIRES
IN SPITE OF OTHER FACTORS. THE DRIEST PART OF THE AREA...CENTRAL
AND SOUTHEAST MISSOURI...RECEIVED MEASURABLE PRECIPITATION AS
RECENTLY AS 3 DAYS AGO...AND THOSE AREAS HAVE HAD AS MUCH AS AN
INCH OR MORE WITHIN THE PAST COUPLE OF WEEKS. BY TOMORROW...LOW
LEVEL MOISTURE WILL INCREASE ENOUGH TO END RISK OF WILDFIRES.
BRITT/CARNEY
&&
.CLIMATE...
RECORD HIGHS FOR MONDAY JANUARY 30TH
KSTL 67 IN 1884
KCOU 68 IN 1890
RECORD HIGH LOW TEMPERATURES FOR JANUARY 31ST
KSTL 53 IN 1877
KCOU 46 IN 1923
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
301 PM MST MON JAN 30 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
A WEST TO NORTHWEST FLOW RESIDES OVER THE AREA WITH A WEAK
DISTURBANCE MOVING EAST THROUGH MONTANA TODAY. RADAR ECHOES OVER
THE STATE HAVE BEEN SPOTTY IN THE PAST 12 TO 18 HOURS BUT SOME
INCREASES ARE SHOWING UP IN NORTH-CENTRAL MONTANA AND A BIT INTO
THE WESTERN AND CENTRAL ZONES EARLY THIS AFTERNOON.
THESE ECHOES ARE EXPECTED TO INCREASE IN INTENSITY INTO THE LATE
AFTERNOON THEN BEGIN TO DIMINISH THIS EVENING. THE NAM AND GFS
SHOW IT TO HIT MAINLY THE CENTRAL ZONES...AND HAVE INCREASED POPS
ACCORDINGLY. THE HRRR SHOWED IT PRODUCE THE GREATEST QPF OVER THE
SE ZONES THAN THE GFS. HAVE LEANED MORE WITH THE GFS THOUGH BASED
ON RECENT PERFORMANCE. THE NAM HAS BEEN MUCH TOO WET WITH RECENT
SYSTEMS. ALBEIT BRIEF...THE SYSTEM LOOKS INTENSE WITH MOST OF THE
LIFT OCCURRING JUST ABOVE 700 MB AND WHERE TEMPS ARE AROUND -15C
(AND GOOD DENDREDIC GROWTH). PRECIP TYPE LOOKS TRICKY WITH MODEL
NAM SOUNDINGS SHOWING A POSSIBLE MIX WITH SNOW WHILE THE GFS IS
WARMER AND KEEPS THE PRECIP ALL LIQUID.
SYSTEM PASSES OFF TO OUR SOUTHEAST TONIGHT. WITH POSSIBLE WET
ROADWAYS...CLEARING SKIES AND TEMPS DROPPING BELOW FREEZING...ICY
ROADS ARE A GOOD POSSIBILITY. HAVE HIGHLIGHTED THIS IN AN HWO.
AFTERWARDS...IT LOOKS TO REMAIN PARTLY CLOUDY WITH CONTINUED ABOVE
NORMAL TEMPS. WENT ABOVE MAV AND MET GUIDANCE ON TEMPS...CLOSER
TO BIAS CORRECTED NUMBERS. CLOUDS LOOK TO BEGIN INCREASING
WEDNESDAY AFTERNOON WITH THE NEXT SYSTEM COMING IN. JAMBA
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
MORE SPRING-LIKE WEATHER IN THE OFFING. IN THE MIDST OF AN
AMPLIFYING PATTERN...THE LAST IN A SERIES OF SHORTWAVES MOVES SE
ACROSS THE AREA WED NIGHT...WITH SOME SPLITTING MOTION THOUGH. WILL
RAISE POPS TO A SLIGHT CHANCE OF SNOW SHOWERS.
THEN...AN UNUSUALLY STRONG UPPER RIDGE TAKES HOLD OVER THE WESTERN
STATES...THEN CLOSING OFF A CENTER OVER THE NORTHERN ROCKIES TO
THE PACIFIC NW. THIS GIVES SEVERAL DAYS OF DRY AND MAINLY SUNNY
WEATHER...WITH WINDS ON THE LIGHT SIDE. TEMPS LIKELY TO REMAIN
WELL ABOVE NORMAL WITH THICKNESSES OFTEN IN THE 540S DM...BUT 850
MB FORECAST TEMPS AND MODEL SPECTRUM DO SHOW SIGNIFICANT
DIFFERENCES...SEEMING TO INDICATE POSSIBLE STRONG INVERSIONS.
WITHOUT SNOWCOVER THOUGH...PREFER TO STAY ON THE WARM SIDE OF
GUIDANCE.
LATE IN THE PERIOD...SIGNS OF THE RIDGE SHARPENING...AND A LITTLE
FARTHER W. THIS MAY ALLOW AN ARCITC COLD FRONT FROM THE N TO
BRUSH OUR AREA. MUCH MODEL DIFFERENCE ON TIMING...BEING ANYWHERE
FROM SUNDAY TO TUESDAY...AND ON INTENSITY OF THE FRONT AND UPPER
SUPPORT AS WELL. THEREFORE AM STAYING CONSERVATIVE AS IT IS STILL
OUT THERE ON DAYS 6 TO 8. SIMONSEN
PREVIOUS LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... MODELS
CONTINUE TO INDICATE TRANSITION FROM ZONAL PATTERN TO A HIGH
AMPLITUDE BLOCKING PATTERN EARLY IN THE EXTENDED PERIOD. NEW
WRINKLE IS TAKING THE SHORTWAVE DROPPING THROUGH THE GREAT BASIN
WEDNESDAY/WEDNESDAY NIGHT AND DEVELOPING A CLOSED LOW OVER THE
SOUTHWEST STATES. RIDGE STILL EXPECTED OVER THE NORTHERN ROCKIES
BUT WILL GET CLOSED OR PINCHED OFF BY LOW TO THE SOUTH AND TROF IN
THE EAST PACIFIC.
INITIAL PUSH OF WARM AIR INTO THE REGION WITH RIDGE WILL GRADUALLY
MODERATE AS SHORTWAVES PUSH THROUGH THE TOP OF THE RIDGE. OVERALL
STILL EXPECTING WELL ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. EBERT
&&
.AVIATION...
CEILINGS LOWERING TO AROUND 4K FT AGL OVERCAST LATE THIS AFTERNOON AND
EVENING WITH RAIN SHOWERS DEVELOPING AND MOVING E. THESE WILL
LIKELY TURN TO SNOW SHOWERS THIS EVENING BEFORE ENDING...WHICH
COULD REDUCE VISIBILITY TO 2 TO 4 MILES AND CEILINGS TO 2-3K FT AGL
FOR A SHORT TIME. VFR WITH SCATTERED TO BROKEN LAYERS ABOVE 8K FT
AGL FOR TUE. SIMONSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
924 AM MST MON JAN 30 2012
.SHORT TERM...VALID FOR TDY AND TUE...
UPDATE TO ZFP AND NO UPDATE TO WRKAFP. SITES AROUND KLVM WERE
OCCASIONALLY HITTING WIND ADVISORY CRITERIA THIS MORNING DUE TO
TIGHT N-S ORIENTED PRESSURE GRADIENT OVER KLVM AND THE BEARTOOTH
FOOTHILLS. STILLWATER MINE JUST UNDER ADVISORY CRITERIA PER RECENT
REPORT. WILL CONTINUE THE ADVISORY AND RE-EVALUATE WITH THE
AFTERNOON PACKAGE. WILL NEED TO WATCH BIG TIMBER AS GRADIENT WAS
FORECAST ON 12Z WRF TO BECOME REORIENTED W TO E WHICH FAVORS THIS
SITE FOR STRONG WINDS.
250 MB JET COUPLET SEEN IN RUC DATE WAS BRINGING UPPER DIVERGENCE TO
WESTERN AREAS THIS MORNING. IN ADDITION...STRONG VORTICITY MAXIMUM
SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA THROUGH EARLY
THIS EVENING. MOIST WESTERLY FLOW WILL ACCOMPANY THE SYSTEM. COOKE
CITY WEB CAMS SHOWED ACCUMULATING SNOW THIS MORNING AND SNOW OVER
THE CRAZY MOUNTAINS COULD BE INFERRED FROM THE BIG TIMBER WEBCAM.
SNOTELS WERE NOT SHOWING MUCH IN THE WAY OF ACCUMULATION THROUGH 8
AM MST...BUT BASED ON WEBCAMS AND THE ABOVE FACTORS...HAVE INCREASED
POPS OVER W-FACING SLOPES OF THE BEARTOOTHS/ABSAROKAS AND OVER THE
CRAZYS AS WELL. ECHOES ON RADAR OVER THE PLAINS WERE LIKELY JUST
ALTOCUMULUS AT THIS POINT GIVEN HIGH TEMPERATURE/DEWPOINT SPREADS.
BULK OF THE MOISTURE WILL BE OVER NE MT THIS AFTERNOON...SO WILL
LEAVE THE DRY FORECAST FOR THE PLAINS. MOISTURE WILL MOVE SE THIS
EVENING...SUPPORTING THE GOING POPS. WINDS AND TEMPERATURES WERE IN
GOOD SHAPE BASED ON EXPECTED MIXING. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
A SHORTWAVE WILL MOVE ACROSS THE REGION WEDNESDAY NIGHT THROUGH
THURSDAY. THE STRONGEST FORCING WILL TRACK SOUTH OF THE CWA SO
KEPT POPS LOW. AN UPPER-LEVEL RIDGE WILL BUILD OVER THE REGION
THROUGH THE REST OF THE EXTENDED PERIOD. ABOVE AVERAGE
TEMPERATURES AND DRY CONDITIONS WILL PREVAIL. BLENDED INHERITED
MAX/MIN TEMPS WITH THE BEST-PERFORMING 00Z GUIDANCE...BCCONSMOS
AND CONSRAW RESPECTIVELY. BRS
&&
.AVIATION...
VFR AND WINDY CONDITIONS WILL PREVAIL TODAY. A FEW SHOWERS WILL
BE POSSIBLE OVER THE MOUNTAINS AND MAY BRIEFLY IMPACT KLVM.
MOUNTAIN OBSCURATIONS ARE EXPECTED TODAY. SCATTERED SHOWERS WILL
BE POSSIBLE GENERALLY AROUND KMLS TO KBHK LATE TONIGHT INTO EARLY
TUESDAY MORNING. BRIEF MVFR/IFR CONDITIONS WILL BE POSSIBLE.
CHURCH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 054 031/047 027/047 029/044 025/047 023/053 029/051
1/N 20/B 01/B 20/B 00/U 00/U 00/U
LVM 050 029/044 033/046 024/042 018/049 021/052 028/054
3/W 21/N 12/W 21/B 00/B 00/U 00/U
HDN 052 026/047 021/048 028/049 021/048 020/053 024/055
1/N 30/B 01/B 20/B 01/U 00/U 00/U
MLS 052 026/044 020/044 027/043 023/044 021/048 024/050
1/B 30/B 01/B 10/B 01/B 00/U 00/U
4BQ 052 027/043 023/045 026/044 022/046 020/050 024/051
1/E 30/B 01/B 21/B 11/B 00/U 00/U
BHK 051 025/043 019/044 025/040 021/042 021/048 022/048
1/B 30/B 00/B 11/B 10/B 00/U 00/U
SHR 053 023/042 018/045 023/040 020/045 020/048 026/050
1/E 20/B 01/B 21/B 01/B 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT UNTIL 6 PM MST THIS EVENING FOR ZONES
65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
543 PM EST MON JAN 30 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE STATE TONIGHT...USHERING IN VERY
MILD TEMPERATURES FOR MUCH OF THE WEEK. THE WEATHER WILL REMAIN
MAINLY DRY...EXCEPT FOR A CHANCE OF LIGHT SNOW SHOWERS TONIGHT IN
THE NORTHERN MOUNTAINS...AND SCATTERED RAIN SHOWERS WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
HIGH PRESSURE OVER PENNSYLVANIA CEDES TO APPROACHING WARM FRONT
OVERNIGHT. WAA OVER GLAKES GENERATING JUST ENOUGH LIFT FOR A
NARROW AREA OF LIGHT SNOW. THIS WILL SLIDE EASTWARD THIS
EVENING...BRUSHING NORTHERN PA WITH JUST LIGHT ACCUMS AT MOST.
SW-W 850MB JET OF 50KTS NOSES IN FROM THE WEST WITH THE WARM FRONT
TONIGHT...LEADING THE PUSH OF MILDER AIR BACK INTO CENTRAL PA.
LOWS TONIGHT WILL ONLY DIP INTO THE MID AND UPPER 20S...AND WILL
LIKELY BEGIN TO SLOWLY RISE AFTER 06Z ACROSS THE WEST BEHIND
FROPA.
WARM FRONT BY TUE WILL BE ACROSS NY STATE...AND BROAD WSW FLOW
WILL KEEP PENNSYLVANIA DRY THRU TUESDAY. VERY MILD TEMPS WILL BE
SEEN AS 500MB HEIGHTS REACH 560 AND 850MB TEMPS RISE TO 5C+. THIS
SHOULD TRANSLATE INTO HIGHS TUESDAY APPROACHING 60F OVER SOME
SOUTHERN LOCATIONS...WITH UPPER 40S TO MID 50S FURTHER NORTH. THIS
WILL BE AS MUCH AS 15 TO 20 DEG ABOVE SEASONAL NORMS. WESTERLY
WINDS WILL BE BREEZY...ESP IN THE WESTERN HIGHER TERRAIN...BUT
NOTHING APPROACHING WHAT WE/VE SEEN OVER THE PAST COUPLE OF DAYS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A NRN STREAM SHORTWAVE TROUGH WILL PROGRESS EWD FROM THE NRN PLAINS
TO THE NORTHEAST TUE-WED. THE LOW-AMPLITUDE FAST-MOVG MID/UPPER
SYSTEM WILL BE ACCOMPANIED BY A WEAK SFC LOW TRACKING EWD ALONG THE
U.S./CANADIAN BORDER FROM MINNESOTA TO MAINE BY 0000 UTC 2 FEB 2012.
A BREEZY AND UNSEASONABLY MILD SWLY FLOW IN THE WARM SECTOR
PRECEDING THE TRAILING COLD FRONT WILL HELP BOOST TEMPERATURES
WELL-ABOVE CLIMATOLOGY /15-25 DEGREES/ PRIOR TO FROPA WHICH SHOULD
SLIDE NW-SE ACROSS THE COMMONWEALTH BY WED EVE. DESPITE FAIRLY
STRONG NEWD MOISTURE TRANSPORT INTO THE AREA VIA 40-50KT SWLY LLJ
THROUGH THE OH VALLEY...PCPN COVERAGE AND AMTS LOOK TO BE ON THE
LIGHTER SIDE GIVEN PROGRESSIVE NATURE OF THE SYSTEM...NWD
DISPLACEMENT OF BEST FORCING AND WEAK LOW-LEVEL CONVERGENCE. THE
SURFACE BOUNDARY WILL STALL-OUT NEAR OR SOUTH OF THE MASON DIXON
LINE AS THE FOCUS SHIFTS TO SPLIT FLOW TROUGH CROSSING THE PLAINS/MS
VLY AND ENTERING THE TN VLY/MID-ATLC REGION ON THURS. THIS FEATURE
SHOULD INDUCE A WEAK SFC WAVE TO TRACK EWD ALONG THE QUASI-STNRY
BAROCLINIC FRONTAL ZONE TO THE SOUTH OF PA.
CONCERNING THE FRONTAL WAVE FORECAST TO TRACK SOUTH OF PA WED
NGT-THURS...THE 12Z NAM IS THE MOST PROGRESSIVE SOLUTION THROUGHOUT
AND APPEARS TO BE AN OUTLIER COMPARED TO THE REST OF THE GUIDANCE.
THERE IS SLIGHT SPREAD WITH THE 12Z GFS/UKMET/ECMWF AND 00Z ECMWF ON
THE PROGRESSION BUT NOT AMPLIFICATION OF THE TROUGH AXIS HEADING
DOWNSTREAM. THE 12Z ECMWF DOES TREND A BIT WEAKER ALOFT WITH THIS
FEATURE THROUGH THE ERN PORTION OF THE COUNTRY BUT OVERALL NO LARGE
SCALE DIFFERENCES. HPC MODEL DIAGS PREFERRED A BLEND/COMPROMISE OF
THE OPERATIONAL GFS/UKMET AND ECMWF. THESE MODELS QPF FIELDS ARE IN
REASONABLY GOOD AGREEMENT SHOWING A RELATIVELY TIGHT GRADIENT OF
POSSIBLY ENHANCED PCPN ALONG/NORTH OF THE LOW TRACK FROM ERN KY ACRS
THE VIRGINIAS TO THE DELMARVA...AS UPPER LEVEL JET STREAK BECOMES
WELL-DEFINED. THIS SYSTEM SHOULD EXIT OFFSHORE THURS NGT AS HIGH
PRES OVERSPREADS THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODEL AND ENSEMBLE GUID STARTS THE PERIOD IN MUCH
BETTER AGREEMENT COMPARED TO YESTERDAY...SHOWING A HIGHLY AMPLIFIED
WEST COAST RIDGE/ROCKIES-PLAINS TROUGH CONFIGURATION WITH CONFLUENT
ZONAL FLOW DOWNSTREAM IN THE EAST. INDIVIDUAL SOLUTION SPREAD GROWS
QUICKLY IN TIME AND THE GUIDANCE BECOMES RATHER CHAOTIC WITH
VIRTUALLY NO RUN-TO-RUN CONSISTENCY. THE GFS/GEFS ARE QUICKER TO
EJECT THE PLAINS ENERGY EWD INTO THE OH VLY BY THE END OF THE PD
WHILE THE ECMWF LEAVES BEHIND SIGNIFICANT ENERGY IN THE SWRN CONUS.
GIVEN THE HIGH UNCERTAINTY IN THE EVOLUTION OF THE LARGE SCALE FLOW
FORECASTER CONFIDENCE REMAINS LOW. THEREFORE...THE LONG TERM GRIDS
WERE DERIVED USING A NEAR EQUAL BLEND OF HPC/GMOS AND GFS/ECMWF
GUIDANCE WHICH FAVORS NEAR TO ABOVE AVG TEMPERATURES AND A GRADUAL
INCREASE IN POPS FROM LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
A WARM FRONT OVR THE OHIO VALLEY WILL LIFT NORTHEAST THRU CENTRAL
PA LATE TONIGHT. JUST ENOUGH LIFT AHEAD OF THIS BOUNDARY TO
PRODUCE A BIT OF VERY LIGHT SNOW AT BFD EARLY THIS EVENING.
OTHERWISE...MDL DATA AND UPSTREAM OBS BOTH STRONGLY INDICATING
VFR CONDS OVERNIGHT WITH CLOUD BASES6666 ARND 10KFT. BIGGEST AVIATION
CONCERN TONIGHT WILL BE DEVELOPING LLWS...THE RESULT OF STRONG
WSWRLY LOW LVL JET OVERSPREADING THE AREA...IN CONJUNCTION WITH
MUCH LIGHTER SOUTHERLY WINDS AT GROUND LEVEL. LATEST RUC 0-0.5KM
BULK SHEAR SUGGESTS LLWS CRITERIA WILL BE MET BY ARND 02Z OVR THE
W MTNS...THEN REACHING THE SUSQ VALLEY LATER TONIGHT. SFC WARM
FRONT MAY WORK INTO JST BY ARND MIDNIGHT...RESULTING IN GUSTY SW
WINDS AND DIMINISHED LLWS THERE LATE TONIGHT.
FOR THE BULK OF CENTRAL PA...WARM FRONT WILL LIFT NORTH OF THE
AREA BY LATE AM...RESULTING IN A DECREASING THREAT OF LLWS BUT
INCREASING SW WINDS AT THE SFC GUSTING TO NR 25KTS. ALL MDL DATA
POINTING TOWARD A HIGH DEGREE OF CONFIDENCE IN VFR CONDS TUESDAY
WITH THE POSSIBLE EXCEPTION OF LATE DAY MVFR CIGS AT BFD.
OUTLOOK...
WED...SCT SHRA. LOW CIGS/SHRA POSSIBLE W MTNS. VFR ELSEWHERE.
THU...SCT SHRA. MVFR CIGS POSSIBLE.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...RXR
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST MON JAN 30 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
321 PM CST MON JAN 30 2012
MAIN FORECAST CONCERNS ARE ON PATCHY FOG/LOW STRATUS POTENTIAL
TONIGHT INTO TUESDAY MORNING. FOCUS THEN TURNS TO CLOUD COVER AND
TEMPERATURES TUESDAY AFTERNOON THROUGH THURSDAY
CURRENT SURFACE OBSERVATIONS PLACE A WARM FRONT EXTENDING FROM NORTH
CENTRAL NORTH DAKOTA....SOUTHEAST TO JUST NORTH OF MINNEAPOLIS...TO
ALONG THE INTERSTATE 94 CORRIDOR ACROSS CENTRAL WISCONSIN. A PLUME
OF GULF MOISTURE WAS NOTED OVER NORTHERN MISSOURI/SOUTHEAST
IOWA...MOVING NORTHEAST. DEW POINTS WITHIN THIS PLUME RANGED FROM
THE MID TO UPPER 30S.
THE WARM FRONT WILL LIFT SLIGHTLY NORTH TONIGHT AS SOUTHERLY FLOW
CONTINUES ACROSS THE FORECAST AREA. WITH TEMPERATURES WARMING ABOVE
FREEZING THIS AFTERNOON ALLOWING SOME MELTING OF THE SNOW PACK...AND
INTRODUCING MORE MOISTURE INTO THE BOUNDARY LAYER...SHOULD SEE SOME
PATCHY FOG DEVELOPMENT TONIGHT. THERE IS UNCERTAINTY REGARDING THE
DEVELOPMENT OF A STRATUS DECK OVER THE SNOW PACK TONIGHT. THE SOUTH
TO SOUTHWEST WINDS WOULD FAVOR TAKING THE HIGHER DEW POINT AIR JUST
EAST OF THE FORECAST AREA. HOWEVER...MODELS ARE INDICATING THE
GRADIENT WILL SLACKEN AND ALLOW WINDS TO BACK TO THE
SOUTH...ADVECTING IN THE HIGHER DEW POINT AIR. THERE ARE CONCERNS
ON WHETHER OR NOT THE STRATUS OR FOG WILL DEVELOP WITH WINDS JUST
ABOVE THE SURFACE OUT OF THE SOUTHWEST...WITH VERY DRY AIR IN
PLACE ALOFT. THE NAM/RUC ARE SHOWING THE DEVELOPMENT OF LOW
STRATUS AND FOG ACROSS MUCH OF THE FORECAST AREA TONIGHT. FEEL
THESE SOLUTIONS ARE A BIT OVERDONE WITH THE DRY AIR ACROSS WESTERN
NEBRASKA INTO WESTERN IOWA...ADVECTING NORTHEAST. THINKING IF
STRATUS/FOG DOES DEVELOP...IT WOULD OCCUR MAINLY ACROSS NORTHEAST
IOWA...AND ALONG/EAST OF THE MISSISSIPPI RIVER. HAVE DECIDED TO
INCLUDE PATCHY FOG IN THE FORECAST LATE TONIGHT THROUGH EARLY
TUESDAY MORNING MAINLY SOUTH OF INTERSTATE 90. GIVEN THE MIXING
AND DRY AIR ALOFT...FOG LOOKS TO BE MUCH MORE FAVORABLE THAN
STRATUS. ALSO HAVE INCREASE CLOUD COVER SLIGHTLY MAINLY ALONG AND
SOUTHEAST OF A LINE FROM CHARLES CITY IA TO MARSHFIELD WI. LOOK
FOR LOW TEMPERATURES TO RANGE FROM THE UPPER 20S ACROSS NORTH
CENTRAL WISCONSIN TO THE LOWER 30S ACROSS NORTHEAST IOWA.
A COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE TUESDAY
AFTERNOON BRINGING A BRIEF SHOT OF SLIGHTLY COOLER AIR TO THE
AREA. BEFORE THE FRONT MOVES IN...LOOK FOR HIGH TEMPERATURES TO
CLIMB INTO THE UPPER 30S TO LOWER 40S. STRATUS IS EXPECTED TO MOVE
INTO THE AREA BEHIND THE FRONT DURING THE LATE AFTERNOON INTO THE
EARLY EVENING HOURS...LEADING TO MOSTLY CLOUDY SKIES. WEAK HIGH
PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
PROVIDING DRY AND QUIET WEATHER. PLAN ON HIGHS ON WEDNESDAY
RANGING FROM THE MID 30S ACROSS NORTH CENTRAL WISCONSIN TO AROUND
40 ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.
30.12 MODELS IN AGREEMENT ON THURSDAY...SHOWING A TROUGH DIGGING
INTO THE CENTRAL ROCKIES WITH RIDGING ALOFT MOVING ACROSS THE
FORECAST AREA. MODEL SOLUTIONS START TO DIVERGE GREATLY THURSDAY
NIGHT. THE OPERATIONAL GFS/GEM DEVELOP A POTENT LOW PRESSURE SYSTEM
ACROSS THE CENTRAL PLAINS...AND SUGGEST IT WILL MOVE NORTHEAST
TOWARDS THE FORECAST AREA INTO FRIDAY. ON THE OTHER HAND...THE GFS
ENSEMBLE MEMBERS AND ECMWF TAKE THIS FEATURE WELL SOUTH OF THE
REGION. WILL HAVE TO KEEP A CLOSE WATCH ON THE NEXT FEW MODELS RUNS.
PLAN ON HIGHS ON THURSDAY RANGING FROM THE MID 30S ACROSS NORTH
CENTRAL WISCONSIN TO THE LOWER 40S ACROSS NORTHEAST IOWA. LOOK FOR
LOWS TO FALL INTO THE 20S.
.LONG TERM...FRIDAY THROUGH MONDAY
321 PM CST MON JAN 30 2012
MAIN FORECAST CHALLENGE THIS PERIOD IS EVOLUTION OF THE 500MB TROUGH
ACROSS THE ROCKIES...AND POTENTIAL DEVELOPMENT OF SURFACE LOW LIFTING
ACROSS THE CENTRAL PLAINS FRIDAY THROUGH SUNDAY...WITH IMPACT ON
TEMPERATURES AND PRECIPITATION CHANCES.
LONG RANGE GUIDANCE COMING INTO SLIGHTLY BETTER AGREEMENT THAT A 500MB
TROUGH SWINGS ACROSS ROCKIES LATE THURSDAY NIGHT...BECOMING CUT OFF
FRIDAY 12Z ACROSS SOUTHERN COLORADO / NORTHERN NEW MEXICO. AS THIS
ENERGY EJECTS INTO THE CENTRAL PLAINS...THE 30.12Z GFS / GEM-NH
DEPICTS A SURFACE LOW DEVELOPING...LIFTING NORTHEAST TOWARDS THE
AREA. MEANWHILE...30.12Z ECMWF IS VERY SIMILAR TO ITS PREVIOUS
RUN...AND DIGS THE 500MB TROUGH A BIT FURTHER SOUTH. THIS WOULD
ALLOW THE SURFACE LOW TO BE PICKED UP IN THE SOUTHERN
STREAM...SHUNTING THE LOW ACROSS THE OHIO RIVER VALLEY. THE GFS /
GEM-NH SCENARIO IS CONSIDERED THE DEEPER...SLOWER SOLUTION AND WOULD
HAVE A LARGE PRECIPITATION SHIELD ACROSS MUCH OF THE NORTHERN PLAINS
INTO PARTS OF THE UPPER MIDWEST. THE FORECAST AREA WOULD PRIMARILY
BE ON THE WARM SIDE...WITH A SNOW QUICKLY CHANGING TO
RAIN/SNOW...EVEN ALL RAIN...STARTING FRIDAY NIGHT THROUGH SUNDAY
MORNING. THE 30.12 ECMWF SOLUTION WOULD KEEP THE FORECAST AREA DRY
THROUGH THE WEEKEND. THE SOMEWHAT MORE CONSISTENT ECMWF HAS ITS
MERIT...BUT THE LATEST GFS / GEM-NH SOLUTIONS NEED TO BE KEPT IN
MIND.
AT THIS TIME GIVEN THE SPREAD BETWEEN THE OPERATIONAL MODELS AND LOW
RUN-TO-RUN CONSISTENCY...WILL SIDE WITH MODEL CONSENSUS BLEND AND
INCLUDE SLIGHT CHANCES OF PRECIPITATION THIS WEEKEND.
&&
.AVIATION...THROUGH 18Z TUESDAY
321 PM CST MON JAN 30 2012
CURRENT SURFACE MAP HAS LOW PRESSURE OVER ND WITH A WARM FRONT
EXTENDING SOUTHEAST ACROSS CENTRAL MN INTO CENTRAL WI. SOUTHWEST
FLOW SOUTH OF THE WARM FRONT HAS WARMED TEMPERATURES UP TODAY
SIGNIFICANTLY...AND WAS PRODUCING SNOW MELT ACROSS SOUTHERN
MN/NORTHEAST IA/SOUTHWEST WI. HOWEVER...DEW POINT ANALYSIS SHOWS
THAT DRIER SOUTHWEST FLOW FROM THE CENTRAL PLAINS WAS OFF-SETTING
LOWER BOUNDARY LAYER MOISTURE LOADING FROM THE SNOW MELT. 18Z NAM
AND 20Z RUC MODELS/BUFKIT SOUNDINGS SHOW VERY SHALLOW LOW LAYER OF
MOISTURE TONIGHT INTO TUESDAY MORNING. 18Z TAF ISSUANCE ORIGINALLY
HAD IFR CIG IN STRATUS IN THE KLSE/KRST TAFS AFTER TUE 12Z...BUT
THINKING NOW THAT DEEPER BOUNDARY LAYER MOISTURE FOR STRATUS WILL
REMAIN SOUTHEAST OF THE SITES. AMENDED 18Z TAFS TO GO WITH THIS
TREND AND CARRIED 5-6SM BR AFTER 03Z TONIGHT...LASTING INTO TUESDAY
MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CST MON JAN 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....ZT
AVIATION.....DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
245 PM CST MON JAN 30 2012
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LIGHT SNOW
ASSOCIATED WITH A MID-LEVEL FGEN BAND ALONG AN ELEVATED WARM FRONT
HAS RAPIDLY PUSHED TO THE EAST EARLY THIS AFTERNOON LEAVING
WIDESPREAD MID AND HIGH CLOUDS OVERHEAD. THE SURFACE WARM FRONT IS
STILL LAGGING BEHIND FROM MINNEAPOLIS TO CHICAGO...BUT SE WINDS
NORTH OF THE BOUNDARY HAS BROUGHT WARMER MARINE AIR INTO
NORTHEAST WISCONSIN WHERE TEMPS HAVE REACHED INTO THE MIDDLE 30S.
DESPITE THE WARM ADVECTION...NO SIGN OF ANY STRATUS/DRIZZLE/FOG
DEVELOPMENT UPSTREAM SO FAR...BUT THE ABOVE 30F DEWPOINTS ARE NOW
REACHING INTO EASTERN IOWA AND NORTHERN ILLINOIS. AS WARM ADVECTION
CONTINUES UNABATED AHEAD OF LOW PRESSURE DEVELOPING OVER THE
NORTHERN ROCKIES...LOW STRATUS AND FOG POTENTIAL ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...A SHORTWAVE TROUGH WILL MOVE ACROSS THE DAKOTAS AND PUSH
SURFACE LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY. AHEAD OF
THE LOW...H850 WARM FRONT WILL LIFT ACROSS THE U.P. INTO
LAKE SUPERIOR. THE THREAT OF PRECIP WILL BE LOCATED ALONG THIS
BOUNDARY AND NORTH OF THE FORECAST AREA...SO HAVE REMOVED POPS FOR
TONIGHT. WILL STILL HAVE PLENTY OF MID AND UPPER MOISTURE AROUND
CARRIED IN BY THE JET STREAM TO MAKE FOR A PARTLY TO MOSTLY CLOUDY
NIGHT. THE BIGGEST FORECAST CHALLENGE TONIGHT WILL BE THE
POSSIBILITY OF FOG OR LOW STRATUS DEVELOPMENT LATE. SSW WILL CARRY
DEWPOINTS IN THE UPPER 20S TO LOWER 30S OVER THE MID-MISSISSIPPI
VALLEY INTO THE REGION TONIGHT. THE NAM IN PARTICULAR IS BULLISH ON
CREATING LOW STRATUS OR FOG BUT COULD BE ONE OF THOSE SCENARIOS
WHERE TEMPS JUST ABOVE THE SURFACE RISE COINCIDENT WITH DEW POINTS
WHICH WOULD CREATE SOME LOWER VSBYS AND FROST DEPOSITS BUT WITHOUT
ANY FOG OR STRATUS. NOT SEEING MUCH POTENTIAL FOR DRIZZLE AS THE
MOISTURE DOESNT APPEAR DEEP ENOUGH. SO WILL PUNT IT OFF TO THE
EVENING CREW UNTIL CAN SEE THE WHITES OF ITS EYES. WITH THE WARM
ADVECTION...LOW TEMPS WILL NOT FALL MUCH...FROM THE MID 20S NORTH TO
LOW 30S SE.
TUESDAY...LOW PRESSURE WILL CONTINUE TO TRACK EAST ALONG THE WARM
FRONT OVER THE U.P. SOUTH OF THE LOW TRACK...GULF MOISTURE WILL
SURGE NORTHEAST BUT LOOKS TO BYPASS THE REGION INTO LOWER MICHIGAN.
AS A RESULT...OUR AIR WILL ARRIVE FROM THE DRIER SOUTHERN GREAT
PLAINS WHICH WILL KEEP THE MID-LEVELS DRY DESPITE A WEAK PACIFIC
COOL FRONT PASSING ACROSS THE AREA IN THE AFTERNOON. AFTER SOME
MORNING MIST OR LOW STRATUS...SHOULD SEE PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE AREA IN THE AFTERNOON. HIGHS WILL BE WARM AFTER A
MILD START TO THE DAY...WITH HIGHS RANGING FROM THE UPPER 30S NORTH
TO MIDDLE 40S SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MILD WEATHER WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEK AND INTO EARLY NEXT
WEEK. CLOUD COVER AND TEMPERATURES ARE THE PRIMARY CHALLENGE
THROUGH SATURDAY AS THERE IS LITTLE CHANCE OF ANY PRECIPITATION.
THE VERY MILD TEMPERATURES AND MELTING SNOW WILL LIKELY PRODUCE
LOW CLOUDS AND FOG AT SOME POINT...ESPECIALLY IN NORTHERN
WISCONSIN WHERE SNOW COVER IS A FOOT OR SO. BUT NOT CERTAIN ENOUGH
ABOUT WHEN THIS MIGHT OCCUR SO DID NOT MENTION ANY FOG IN THE
FORECAST. WE DO EXPECT SOME BY LATER IN THE WEEK.
THE MODELS DO BRING SOME SOUTHERN STREAM JET ENERGY FROM FOUR
CORNERS AREA FRIDAY INTO THE CENTRAL PLAINS SATURDAY AND SUNDAY.
THE EVOLUTION OF THE SYSTEM IS DIFFERENT FROM MODEL TO MODEL AND
RUN TO RUN SO DO NOT HAVE A LOT OF CONFIDENCE AT THIS POINT. THE
GFS SOLUTIONS COULD PRODUCE CONSIDERABLE SNOW OVER WESTERN
WISCONSIN IF IT WOULD VERIFY. THERE IS SOME DECENT AGREEMENT NOW
THAT AN UPPER RIDGE WILL FORM OVER THE WESTERN PART OF NORTH
AMERICA WITH A TROUGH EAST OF ROCKIES. THE MODELS HAVE ADVERTISED
THIS A COUPLE OF TIMES THIS WINTER BUT IT HAS NOT MATERIALIZED.
&&
.AVIATION...WITH THE SNOW DEPARTING FAR NE WISCONSIN BY EARLY THIS
AFTERNOON...SOUTHWEST FLOW WILL DEVELOP LATER TODAY AND CONTINUE THROUGH
THE REST OF THE TAF PERIOD. THOUGH THERE WILL BE PLENTY OF MID AND
HIGH CLOUDS OVERHEAD...MODELS INSIST ON TRANSPORTING LOW LEVEL
MOISTURE FROM THE MID-MISSISSIPPI VALLEY INTO THE REGION LATE
TONIGHT INTO TOMORROW MORNING. DEWPOINTS IN THE UPPER 20S TO LOWER
30S EXIST THERE CURRENTLY AND NOT INCONCEIVABLE THAT LOW STRATUS MAY
DEVELOP LATE. UNCERTAINTY IS FAIRLY HIGH HERE...AS THERE IS NO
STRATUS UPSTREAM. HAVE SIDED OPTIMISTICALLY...AND ADDED MVFR VSBYS
IN MIST IN THE TAFS LATE TONIGHT INTO TOMORROW MORNING. LATER
SHIFTS WILL HAVE TO REFINE PENDING THE DEVELOPMENT OF STRATUS.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM